JPH11153105A - Hydraulic pressure control device and hydraulic fluid viscosity acquisition device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To acquire the viscosity of a hydraulic fluid based on physical quantities other than temperature. SOLUTION: In a steady state (S1), no hydraulic fluid flows through the linear valve device, and the hydraulic pressure difference on both sides is kept constant. From this state, the linear valve device is opened with an opening area of a predetermined size to allow the hydraulic fluid to flow (S3). A hydraulic pressure ratio with respect to the master cylinder hydraulic pressure in the steady state of the wheel cylinder hydraulic pressure after the lapse of the set time is obtained (S4). When the viscosity is large, the hydraulic pressure ratio is smaller than when the viscosity is small. Therefore, based on these relationships, the viscosity can be obtained (S5).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to reducing the influence of the viscosity of hydraulic fluid in hydraulic pressure control.

[0002]

2. Description of the Related Art One embodiment of a hydraulic pressure control apparatus in which the influence of the viscosity of a hydraulic fluid is reduced is described in Japanese Patent Application No. 61-157217, a microfilm. In this fluid pressure control device, the fluid pressure control valve provided between the master cylinder and the wheel cylinder has a larger opening area (flow path area) when the temperature of the hydraulic fluid is low than when it is high. Is controlled. When the temperature is low, the viscosity of the hydraulic fluid is higher than that when the temperature is high, and it is difficult to flow. Therefore, when the temperature is low, the opening area is increased to reduce the hydraulic pressure control response delay,
The effect of viscosity on hydraulic control is reduced. In this hydraulic pressure control device, the viscosity of the hydraulic fluid is substantially acquired based on the temperature.

[0003]

Problems to be Solved by the Invention, Means of Solution, Functions and
The object of the present invention is to control the viscosity of the hydraulic fluid by the hydraulic pressure control device.
Device obtained by other means than
That is, the viscosity of the hydraulic fluid is changed to a physical quantity other than temperature.
Hydraulic fluid viscosity acquisition device and viscosity
To obtain a hydraulic pressure control device that utilizes the performance for hydraulic pressure control.
You. Hydraulic pressure control device and operation of the following embodiments according to the present invention
A liquid viscosity acquisition device is obtained. Each aspect is divided into sections.
Number, and, if necessary, cite other section numbers.
In the same format as the claim. Combining the features described in each section
In order to demonstrate the possibility of adoption in combination.
You. (1) Provided between a high-pressure section and a low-pressure section;
Control valve device for controlling the flow of hydraulic fluid between the air and the low pressure section
Position and its hydraulic pressure control valve device to control the height.
Hydraulic pressure control for controlling either one of the pressure section and the low pressure section
A hydraulic control device comprising a control valve control means,
The control valve control means detects a hydraulic pressure difference on both sides of the hydraulic pressure control valve device.
And the flow related to the flow rate of the hydraulic fluid.
A viscosity for obtaining the viscosity of the working fluid based on the volume-related amount.
Property acquisition means and the work acquired by the viscosity acquisition means.
Viscosity-based control for controlling the hydraulic pressure based on the viscosity of the hydraulic fluid
Means for controlling the hydraulic pressure (claim)
1). In the hydraulic pressure control device described in this section,
Viscosity is related to differential pressure related quantity and flow rate in hydraulic control valve device
Obtained based on quantity. And the obtained work
The hydraulic pressure control valve device is controlled based on the viscosity of the fluid. An example
For example, whether the viscosity is high or low,
The fluid is controlled to flow, regardless of the viscosity.
Is controlled so that the desired amount of hydraulic fluid flows exactly.
It is. As a result, the effect of viscosity on hydraulic control response is reduced.
Can be reduced or eliminated, improving hydraulic pressure control accuracy.
Can be up. As mentioned above, the viscosity of the hydraulic fluid
Is the differential pressure related quantity and the flow related quantity in the hydraulic pressure control valve device.
Based on the temperature, and based on the temperature.
It is not. Therefore, to obtain the viscosity of the hydraulic fluid,
The need for a working fluid temperature sensor is eliminated. Hydraulic control described in this section
In the control device, the differential pressure related amount and the
It is necessary to obtain the flow-related quantity, but it is described below.
As such, there is no need for a dedicated sensor or the like to acquire these
In many cases, in which case the hydraulic control system as a whole
Cost can be reduced. About differential pressure related quantity
Is a hydraulic pressure sensor provided for controlling the hydraulic pressure control device
And the like. Differential pressure related quantities include
The hydraulic pressure on the high pressure side of the hydraulic pressure control valve device
Abbreviated) and the hydraulic pressure on the low pressure side (hereinafter abbreviated as the low pressure hydraulic pressure)
Change) in addition to the hydraulic pressure difference itself.
(Corresponding to the hydraulic pressure difference). For example,
Low-pressure hydraulic pressure, which is the ratio of low-pressure hydraulic pressure to high-pressure hydraulic pressure
Ratio, fluid on the side where fluid pressure is controlled between high pressure section and low pressure section
Non-control side fluid which is the hydraulic pressure on the other side of the control side hydraulic pressure
The control side hydraulic pressure ratio, which is the ratio to the pressure,
Ratio to either high-pressure hydraulic pressure or low-pressure hydraulic pressure
Differential pressure ratio, either high-pressure hydraulic pressure or low-pressure hydraulic pressure
On the other hand, the flow condition (transient
Flow state, which is the ratio of the hydraulic pressure in
included. Hydraulic pressure control valve device
If controlled, it is set up to control the hydraulic pressure control valve device.
Can be used when obtaining viscosity.
it can. The hydraulic pressure control valve device
High pressure when controlled based on at least one of
High pressure side pressure sensor that detects the side pressure and low pressure side pressure
And at least one of the low pressure side hydraulic pressure sensors
Will be. High pressure side pressure sensor and low pressure side pressure sensor
If both are installed, use both hydraulic pressure sensors
To obtain the differential pressure related amount including the hydraulic pressure difference, etc.
Either the high pressure side pressure sensor or the low pressure side pressure sensor
Even when only the high pressure side hydraulic pressure and the low pressure side
When the other of the hydraulic pressure is constant (the other of the high pressure section and the low pressure section is
One example is the case of a constant fluid pressure source).
The differential pressure related amount can be obtained based on the pressure. Ma
In addition, the flow-related quantity includes the hydraulic fluid flowing through the hydraulic pressure control valve device.
Not only the flow rate but also the condition of the hydraulic pressure control valve device that can obtain the flow rate
The state quantity, the control quantity for the hydraulic pressure control valve device, etc. correspond. Condition
The parameters include the opening area and opening (opening) of the hydraulic pressure control valve device.
Opening ratio to the maximum value of the mouth area), opening time in the open state
Open time ratio, which is the ratio of closed time to closed time
(The open time ratio is the ratio of open time to control time.
The control amount includes the value supplied to the hydraulic pressure control valve device.
The supplied power and the OFF time of the ON time of the supplied power
ON time ratio, which is the ratio to the ON time ratio (ON time ratio is ON
May be the ratio of time to control time), etc.
You. Of these, the control amount is detected by a sensor, etc.
Can be obtained even if the
It can also be obtained by calculation based on the control amount and the like. Book
In the hydraulic pressure control device described in the section, the viscosity of the working fluid
Because it is not obtained based on degree,
There is also an advantage that the degree can be improved. viscosity
Changes depending on the temperature of the hydraulic fluid,
So it changes. Therefore, the viscosity is limited only to the temperature of the hydraulic fluid.
If the viscosity is obtained based on the
Even if it is small, if the viscosity is large at low temperatures
It is obtained by mistake. On the other hand,
If it is obtained based on the flow related quantity,
When viscosity is low, viscosity is high even at low temperature
It is not obtained by mistake. Hydraulic pressure control valve
The device is provided between the high pressure part and the low pressure part.
However, if the low pressure part is a wheel cylinder,
To control the flow of hydraulic fluid from the pressure section into the wheel cylinder.
It includes a pressure valve, and the high pressure part is
In this case, the hydraulic fluid in the wheel cylinders
It includes a pressure reducing valve to be controlled. Hydraulic pressure control valve device
Shall include both the pressure increasing valve and the pressure reducing valve.
Can also be. In any case, the hydraulic control valve device is
Controlled by the response control means. For example, hydraulic control valve equipment
Allows flow of hydraulic fluid with an opening area corresponding to the supplied power
If an electromagnetic flow control valve that includes
It is controlled based on. Where the viscosity is high and the hydraulic fluid is difficult to flow
When the opening area is large, the viscosity is small and it is easy to flow
Therefore, the opening area is reduced. As a result, the viscous
Make sure that hydraulic fluid flows at almost the same
To reduce the effect of viscosity on hydraulic pressure control response.
it can. Hydraulic pressure control valve device turns supply power ON / OFF
If the system includes an electromagnetic on-off valve that opens and closes more,
The ON time ratio of the force is controlled. Small if viscosity is high
ON time ratio is larger than
So that hydraulic fluid flows at approximately the same flow rate,
It is done. The magnitude of these power supply and ON time ratio
The rate etc. is controlled stepwise even if it is controlled continuously based on viscosity.
You may control. In this way, when the power supply
By controlling the flow ratio, the flow rate of the hydraulic fluid is controlled.
Control of the flow rate, one of the high pressure section and the low pressure section
The change gradient of the hydraulic pressure is controlled. Therefore, the viscosity vs.
Flow control means for viscosity, hydraulic pressure for viscosity
The change gradient control means and the like correspond. Also, hydraulic
Control valve device is exactly what you want, regardless of viscosity
If controlled to flow a volume of hydraulic fluid,
The control means corresponding to the viscosity is referred to as the viscous influence elimination control means.
Can also be. (2) The hydraulic control valve device is connected to a high-pressure unit connected to a high-pressure unit.
Side port and the low pressure side port connected to the low pressure section are formed.
The control valve body and the high pressure
And the communication position for communicating the low side port and the low pressure side port
Movable member that can be moved to a blocking position for blocking
Electromagnetic that applies an electromagnetic driving force to the movable member according to the supplied power
The driving force imparting device and the movable member
Gives elastic force that changes according to the amount of movement from the blocking position
Between the high pressure side port and the low pressure side port.
A pressure actuation force based on at least one pressure is an electromagnetic drive force.
At least one of the pressure actuating force applying devices to be applied in the opposite direction
And the viscous response control means includes the electromagnetic driving force.
Controlling the power supplied to the application device based on the viscosity
Viscous electromagnetic drive force controller that controls electromagnetic drive force by
The hydraulic pressure control apparatus according to item (1), including a step. The movable member is
It is moved by the magnetic driving force. Move to the communication position
If possible, hydraulic fluid from the high pressure port to the low pressure port
The flow is allowed and the hydraulic control valve device is opened. Interception
If it is moved to the disconnection position, the flow of hydraulic fluid is blocked,
It is closed. The elastic force of the elastic member is applied to the movable member.
And at least one of the high pressure side port and the low pressure side port
At least one of pressure-based pressure actuation force is also provided.
Therefore, at least one of these and the electromagnetic driving force applying device
Flow of hydraulic fluid at the opening area determined by the electromagnetic driving force
This is acceptable. Then, the electric power is applied by the electromagnetic driving force applying device.
Magnetic driving force is controlled by viscous electromagnetic driving force control means
Of the hydraulic pressure control valve device
The opening area is controlled according to the viscosity.
The impact is reduced or eliminated. Where the pressure
Set the power supply device to the pressure between the high pressure side port and the low pressure side port.
Pressure-applying force-applying device that applies an operating force according to the pressure difference.
Can be Also, the pressure actuating force applying device is
The material controls the pressure between the high pressure side port and the low pressure side port
Depending on the control pressure of the control pressure port
Control pressure actuating force applying device
In this case, at least the movable member
Moved and controlled by the relationship between the control pressure and the electromagnetic drive
The pressure will be controlled. The electromagnetic driving force is
Even if the force biases the
The force may be a biasing direction. The control valve device is
Even if it includes a seal valve,
Although it may include a seating valve, a seating valve
It is desirable to include it. For spool valve
Slight liquid leakage easily occurs even in the shut-off state.
This is because it does not occur in the swing valve. Spool valve
The hydraulic pressure control valve device includes a master cylinder as the high pressure section
And the low pressure part between the wheel cylinder
In some cases, the mass
Pressurized piston reaches forward end position
Bottoming may occur and the hydraulic pressure may decrease. It
On the other hand, substantial liquid leakage in the seating valve
Because it does not occur, the master cylinder and the wheel cylinder
Even if provided between them, there is no danger of bottoming occurring.
However, the valve clearance of the spool valve is very small
If liquid leakage is unlikely to occur, for example,
Even if it is provided between the star cylinder and the wheel cylinder,
I don't support it. In addition, the high pressure section includes a pump for pumping hydraulic fluid.
If it is a power hydraulic pressure source,
If this occurs, the hydraulic pressure of the high pressure source will not decrease.
A spool valve between the high pressure source and the wheel cylinder.
Can be removed. Viscous electromagnetic drive force control means
The supply power (hydraulic pressure control valve
Power supply large enough to switch the device to the open state)
When the ON / OFF of is controlled, the electromagnetic driving force is applied.
In the device, when ON, electromagnetic drive of a certain size
Force is generated and extinguished when OFF. Yes
In a hydraulic control valve device with a large response speed, the movable member is
It is moved alternately between the communication position and the blocking position,
Can be alternately switched to the closed state, but the response speed is low
In the hydraulic pressure control valve device, the ON / OFF time ratio
The movable member is kept near the determined position, and the hydraulic pressure control valve device
The opening is controlled. This open time ratio (supply power
(ON time ratio of force) is controlled based on viscosity,
The working fluid is caused to flow at a flow rate according to the ratio. Hydraulic pressure control
The valve device can be constituted by, for example, an electromagnetic on-off valve.
You. (3) The valve wherein the movable member is a peripheral portion of a high pressure side port.
A valve that can be moved toward and away from the seat.
The power supply device is electrically operated so that the valve element is separated from the valve seat.
A magnetic driving force is applied, and the control valve device is provided
Gives the elastic force in the direction in which the valve element approaches the valve seat
A vibrating response device including a breaking urging device including a spring;
Magnetic driving force control means for controlling the magnitude of the supplied power
The hydraulic pressure control apparatus according to the above mode (2). In this section
In the seating valve included in the hydraulic pressure control device, the valve
In addition to the elastic force of the coupling and the electromagnetic driving force,
Differential pressure action according to hydraulic pressure difference between pressure side port and low pressure side port
Force is applied, and the valve
It will be moved based on the relationship of the electromagnetic driving force.
You. If the differential pressure acting force is the same,
The trooke is determined based on the power supply and the hydraulic fluid
It is caused to flow with an opening area corresponding to the stroke. Viscosity
If it is large, the power supply will be greater than if it is small.
If the stroking becomes large,
Hydraulic fluid at almost the same flow rate
You. In addition, the electromagnetic driving force applying device causes the valve to approach the valve seat.
Device that applies electromagnetic driving force in any direction.
In the case of, the relationship between the differential pressure acting force and the electromagnetic driving force
The stroke of the valve, that is, the opening area is determined.
You. (4) the liquid pressure in a steady state is obtained by the viscosity obtaining means;
The steady state hydraulic pressure difference, which is the hydraulic pressure difference on both sides of the control valve device,
Hydraulic fluid under predetermined control conditions in pressure control valve device
The high pressure after a set time has passed since the flow of
The amount of change in hydraulic pressure on either one of the
Includes steady-state viscosity acquisition means for acquiring viscosity based on
The hydraulic control device according to any one of paragraphs (1) to (3).
Place. For example, if the hydraulic pressure control valve device is
Hydraulic fluid flows between the
And the hydraulic pressure difference on both sides is kept almost constant.
In the steady state, the hydraulic pressure control valve device is
Wheelchair when opened for a set time with a small opening area
The amount of increase in the hydraulic pressure on the cylinder side is smaller as the viscosity of the hydraulic fluid is larger.
It becomes. Therefore, these steady hydraulic pressure differences, opening area and
And calculate the viscosity from the increase in wheel cylinder side hydraulic pressure.
Can be obtained. In addition, a constant steady hydraulic pressure difference and
The amount of hydraulic pressure increase on the wheel cylinder side under the opening area
If the relationship between viscosity and viscosity is checked beforehand,
Viscosity can also be obtained from the cylinder side hydraulic pressure increase
You. The hydraulic pressure control valve device is
Is located between the damper and the reservoir as a low-pressure part.
In this case, the reservoir side pressure is always constant (for example, atmospheric pressure).
Therefore, if the fluid pressure on the wheel cylinder side is detected,
The normal state hydraulic pressure difference is also determined by the hydraulic pressure control valve device under predetermined conditions.
Fluid pressure change after set time when
Amount), and the viscosity can be easily obtained.
Wear. In the steady state, the brake operating member is almost constant.
It is obtained when operating with the operating force, the vehicle
Can be obtained during running, but during running
Increase or decrease in wheel cylinder side hydraulic pressure causes vehicle deceleration
The degree is increased or decreased, giving the driver an uncomfortable feeling.
Therefore, the steady-state viscosity obtaining means is activated while the vehicle is running.
In the case of
desirable. On the other hand, the brake operation member
Select the state of operation with constant operating force as the steady state.
In other words, the deceleration increases as the wheel cylinder side hydraulic pressure increases.
Since the situation does not increase, set time sufficiently
Can be set longer to improve viscosity detection accuracy
be able to. As described above, the operation in the hydraulic pressure control valve device is performed.
The fluid is allowed to flow, and either the high pressure side or the low pressure side
Even if the hydraulic pressure on one side is changed, the hydraulic pressure on the other side
If there is little change, change the hydraulic pressure on one side
If the amount is detected, the viscosity can be obtained.
You. In addition, the steady state hydraulic pressure difference is
Detect steady state hydraulic pressure difference if more specific
No need. In this case, the hydraulic pressure change on one side
If the amount is detected, the viscosity can be obtained.
The number of pressure sensors can be reduced, and
Can be suppressed. Note that the steady state hydraulic pressure difference is large.
The hydraulic pressure on the wheel cylinder side
The change gradient increases. Therefore, the master cylinder side
Or even if the fluid pressure on the reservoir side is almost constant,
The amount of change in the hydraulic pressure difference on both sides of the control valve increases. And liquid
The pressure control valve device includes the seating valve described in paragraph (3).
The differential pressure acting on the movable member.
If the power supply is kept constant,
The opening area changes due to the change in the pressure acting force. Accordingly
The steady-state viscosity obtaining means is capable of controlling the steady-state
Opening area is constant when operating with
Is calculated based on the steady-state hydraulic pressure difference.
It is desirable to make corrections. However, compare the set time
Short, small change in opening area due to change in differential pressure acting force
If no, no correction is necessary. (5) The viscosity obtaining means is configured to control the high pressure of the hydraulic pressure control valve device.
Low-pressure side, which is the ratio of the low-pressure part-side hydraulic pressure to the part-side hydraulic pressure
A low-pressure-side hydraulic pressure ratio obtaining means for obtaining a hydraulic pressure ratio;
Low pressure side hydraulic pressure ratio acquired by the pressure side hydraulic pressure ratio acquisition means
Rate is the differential pressure related quantity, the low pressure side to obtain the viscosity
Item (1) to Item (3) including a liquid pressure ratio corresponding viscosity acquisition means
The hydraulic pressure control device according to any one of the above. Where the low pressure side
The hydraulic pressure ratio γ (= PL / PH) is determined on both sides of the hydraulic pressure control valve device.
Can be obtained by the equation γ = 1−ΔP / PH based on the hydraulic pressure difference ΔP (= PH−PL). This low pressure side hydraulic pressure ratio γ is
This value changes with the change in hydraulic pressure difference.
Can be used. Hydraulic fluid operates the hydraulic pressure control valve device
In the transient state where the flow rate is large, the hydraulic fluid
When viscosity is low and flow is difficult, when viscosity is low and flow is easy
As a result, the hydraulic pressure difference ΔP (= PH−PL) increases,
The side hydraulic pressure ratio γ (= PL / PH) decreases. And
As the high-pressure hydraulic pressure and the low-pressure hydraulic pressure approach,
As the hydraulic pressure difference ΔP (= PH-PL) becomes smaller,
The side hydraulic pressure ratio γ approaches 1. High-pressure side hydraulic pressure and low-pressure side hydraulic pressure
One of the control hydraulic pressures close to the hydraulic pressure on the other side.
(To make the hydraulic pressure difference on both sides close to 0) is the hydraulic pressure
If it is the control target, the low pressure side hydraulic pressure ratio γ is close to 1.
It is almost close to the target, and the low pressure side hydraulic pressure ratio is
It can be referred to as a pressure target arrival rate. In addition, the other
The hydraulic pressure can be referred to as a target hydraulic pressure. For example, hydraulic
The valve device is composed of a master cylinder as a high pressure part and a low pressure part.
If it is provided between the wheel cylinder as
The low pressure side hydraulic pressure ratio γ is the mass of the wheel cylinder side hydraulic pressure PW.
And the ratio (PW / PM) to the hydraulic pressure PM on the cylinder side.
You. Hydraulic fluid is harder to flow when the viscosity is high than when it is low
Therefore, the hydraulic pressure on the wheel cylinder side in the transient state
The increase gradient becomes smaller. Hydraulic fluid in hydraulic control valve device
After the set time has passed since the
The hydraulic pressure of the cylinder is reduced and the hydraulic pressure ratio on the low pressure side is reduced.
You. The wheel cylinder side hydraulic pressure and the master cylinder side
If the hydraulic pressure becomes the same size, the low pressure side hydraulic pressure ratio γ becomes 1.
Become. Hydraulic pressure control valve device is a wheel cylinder
When installed between the damper and the reservoir as a low-pressure part
Means that the low-pressure side hydraulic pressure ratio γ is constant and the reservoir-side hydraulic pressure P
R to the wheel cylinder side hydraulic pressure PW (PR /
PW), and the fluid pressure on the wheel cylinder side is
When the pressure becomes PR, the low pressure side hydraulic pressure ratio γ becomes 1. Viscosity
Larger wheel cylinder fluid pressure than smaller
The pressure reduction gradient in the transient state becomes smaller. Hydraulic pressure control valve
Time has passed since the hydraulic fluid started to flow
The wheel cylinder fluid pressure after passing increases, and the low pressure side fluid pressure
The ratio becomes smaller. Here, the low pressure side hydraulic pressure and the high pressure side hydraulic pressure
The pressure is the state in which the hydraulic fluid is flowing through the hydraulic pressure control valve device.
Pressure in the state, but both are necessarily changing
It is not necessary to be in a state, and one of the hydraulic pressures is, for example,
As in the steady-state hydraulic pressure described in (4),
It may be fixed. For example, if the hydraulic pressure control valve device is
The brake is provided between the cylinder and the wheel cylinder.
The operating member is being operated with a certain operating force.
Hydraulic fluid is allowed to flow slightly through the hydraulic pressure control valve device.
The hydraulic pressure PW on the wheel cylinder side is increased
However, the hydraulic pressure PM on the master cylinder side is kept almost constant.
You. Therefore, the hydraulic fluid starts flowing in the hydraulic pressure control valve device.
Wheel cylinder fluid after a set time has passed
If the pressure PW * is obtained, the low pressure side hydraulic pressure ratio after the set time elapses
γ can be obtained as (PW * / PM). What
Note that the hydraulic pressure control valve device is connected between the wheel cylinder and the reservoir.
In the case where the pressure difference is set between
After the hydraulic fluid is started to flow in the valve
Wheel Cylinder in Steady State of Wheel Cylinder Hydraulic Pressure
Wheel cylinder pressure change
It can also be a ratio (PW * / PW). High viscosity
If the pressure is lower than the
The change ratio increases. (6) the viscosity obtaining means is configured to determine that the hydraulic fluid is a reference hydraulic fluid;
, The relationship between the differential pressure related amount and the flow rate related amount.
Reference relation information storage means for storing reference relation information representing a person in charge
And the reference relation stored in the reference relation information storage means.
Information and the hydraulic fluid actually flowing through the hydraulic pressure control valve device.
Relationship representing the relationship between the differential pressure related amount and the flow related amount
Information to obtain the actual viscosity of the hydraulic fluid based on the information.
Including (1) to (5)
A hydraulic pressure control device according to any one of the preceding claims. As mentioned earlier, the difference
There is a certain relationship between pressure-related quantity, flow-related quantity and viscosity.
is there. Standard hydraulic fluid, that is, viscosity based
Use a hydraulic fluid with a viscosity (viscosity coefficient is the reference value) to
Pressure related quantity and flow rate related to the target hydraulic pressure control valve device
The reference relation information that is the relation with the quantity is obtained in advance, and the reference relation
If stored in the information storage means, the reference relation information
And the differential pressure-related quantity and flow rate detected using actual hydraulic fluid
Based on the detection relationship information indicating the relationship with the related amount,
Obtain the deviation of the hydraulic fluid viscosity from the reference viscosity
And the viscosity of the working fluid can be obtained. (7) The viscosity acquisition means is provided with the ignition switch.
Within a set time after the switch is turned ON
Takes the acquired value as the viscosity of the hydraulic fluid and exceeds the set time.
The viscosity of the hydraulic fluid to a certain value.
Any one of paragraphs (1) to (6), including exchange means
Hydraulic control device. In the hydraulic control device described in this section
Is the ignition switch turned on?
Within the set time, the actual viscosity
Properties are acquired, but if the set time is exceeded, the actual viscosity
Is not obtained and a constant value is used as the actual viscosity.
You. If the vehicle is held stationary for a long time,
Key does not operate, and the temperature of the hydraulic fluid drops to almost ambient temperature.
Let me down. In this state, the viscosity of the hydraulic fluid increases.
But the ignition switch is turned on.
The brakes are often activated when the vehicle is run
The ignition switch is normally
As time elapses since the switch was turned on,
The temperature of the fluid increases and the viscosity decreases. And eventually
The viscosity settles down to a nearly constant value. Therefore, at the time of the above setting
The ignition switch is turned on
Set a very short time (called the room temperature maintenance time)
It is possible to obtain the viscosity of the hydraulic fluid near the ambient temperature.
Can be. Also, if the viscosity near the ambient temperature is obtained,
Can estimate the viscosity of hydraulic fluid at higher temperatures.
You. On the other hand, when the set time is
Time long enough to settle to a constant value (when steady state is reached
If the viscosity changes, the actual
At the same time, the viscosity drops to a nearly constant value.
After flickering, the actual viscosity is not obtained and a constant
Used as fluid viscosity. The constant value is
Use a value at which the viscosity of the hydraulic fluid has almost settled down
Can also be a predetermined reference value. Setting
Even if the fixed time is set to the room temperature holding time, a steady state
Omission of unnecessary viscosity acquisition even when setting the delivery time
Can be In that sense, viscosity switching means is necessary.
It can also be referred to as necessary viscosity acquisition means. In this section,
In the hydraulic control device described, the ignition switch
Based on the elapsed time since the switch was turned on.
Gender switching occurs, but separately from elapsed time, or
Combined with elapsed time, brake pad temperature, engine
Gin cooling water temperature, brake operation time, number of times, etc.
In this case, the switching can be performed. Further
Then, after the viscosity, which is obtained sequentially, has settled to a nearly constant value,
The acquisition of the viscosity may be omitted. (8) The viscous response control means is provided in the hydraulic pressure control valve device.
Viscosity Control that Changes Control Rule Based on Viscosity
Any one of paragraphs (1) to (7), including rules change means
3. The hydraulic pressure control device according to claim 1. For example, if the viscosity of the hydraulic fluid
If the viscosity is greater than the viscosity
Control) and control for the hydraulic control valve device
The rules are changed. This viscosity control system
When the viscosity is smaller than the set viscosity,
Does not perform viscosity-based control.
Viscosity-dependent control execution means and low-viscosity control solution
The removal means is also included. Also, the hydraulic pressure control device described in the item (7)
When the set time is regarded as the steady state arrival time in
Is the normal control (not based on viscosity)
Control). Therefore, the viscosity switching means
Can be considered as a kind of viscous control rule changing means.
You. (9) The viscous response control means is connected to the hydraulic pressure control valve device.
Control variable correction that corrects the control variable of oil based on viscosity
The means described in any one of paragraphs (1) to (8)
Hydraulic pressure control device. The hydraulic fluid flowing through the hydraulic pressure control valve
In the case of fluid, that is, the viscosity coefficient is the reference viscosity coefficient (viscosity
(Reference viscosity) is the supplied power (reference supply power)
And ON time ratio (reference ON time ratio)
The reference supply power and the reference ON time ratio
Depending on the viscosity difference between the viscosity of the hydraulic fluid and the viscosity of the reference hydraulic fluid
Can be corrected. (10) Hydraulic pressure control valve provided between high pressure section and low pressure section
By controlling the device, the high-pressure section and low-pressure section
Control the flow of hydraulic fluid between the high pressure section and the low pressure section.
A hydraulic pressure control method for controlling one of the hydraulic pressures,
The viscosity of the hydraulic fluid is related to the hydraulic pressure difference on both sides of the hydraulic pressure control valve device.
Flow rate related to the differential pressure related quantity and the flow rate of the hydraulic fluid.
A viscosity acquisition step for acquiring the viscosity based on the
Based on the viscosity of the working fluid obtained in the obtaining step,
Viscosity-responsive hydraulic pressure control valve device control that controls the hydraulic pressure control valve device
And a hydraulic pressure control method. (11) provided between the high-pressure section and the low-pressure section;
Control valve for controlling the flow of hydraulic fluid between the pressure section and the low pressure section
Viscosity obtaining device for obtaining the viscosity of the working fluid flowing through the device
Between the high pressure section and the low pressure section of the hydraulic pressure control valve device.
Differential pressure related quantity to obtain the differential pressure related quantity related to the hydraulic pressure difference
Acquisition device and its differential pressure related amount acquisition device
A differential pressure related quantity and a flow related quantity related to the flow rate of the hydraulic fluid
Viscosity acquisition means for acquiring the viscosity based on
A viscosity obtaining device (claim 2). Hagen
・ According to Poisouille's law, hydraulic fluid flowing through a capillary
The viscosity μ and the hydraulic pressure gradient at two places of the capillary which are separated from each other by length L
Distribution dP (= ΔP / L), the flow rate Q of the working fluid,
Between the radius a, the following equation Q = π · dP · a ^Four / 8μ holds. This equation is one of the differential pressure related quantities.
The hydraulic gradient dP as a seed and the flow rate Q as a kind of flow-related quantity
And the viscosity of the hydraulic fluid flowing through the capillary based on the radius a.
It shows that it can be obtained. And the hydraulic pressure control valve device
If the opening of the valve is regarded as a kind of small tube, the differential pressure related amount and the flow rate
The viscosity of the hydraulic fluid flowing through the hydraulic pressure control valve device
Sex can be acquired. Viscosity acquisition device described in this section
, The viscosity, the differential pressure related quantity and the flow related quantity
Utilizing the relationship, the viscosity of the hydraulic fluid flowing through the hydraulic pressure control valve device
Is obtained, and based on the temperature,
There is no. Viscosity is not based on temperature
Therefore, as described above, the viscosity decreases due to the deterioration of the hydraulic fluid.
Can be detected, and the accuracy of viscosity acquisition can be improved.
You. Also obtains the viscosity of the working fluid flowing through a simple capillary
It is possible to control the flow-related quantity
The accuracy of viscosity acquisition can be improved
There are also advantages. Hydraulic fluid flowing through the normal fluid passage (small tube)
When obtaining viscosity, the flow-related quantity is the inner diameter of the liquid passage.
Although it is determined in advance depending on the structure, the hydraulic pressure control valve
The flow-related quantity is controlled by controlling the power supply.
It can be controlled to a desired size. Therefore, the flow rate
The related quantity is controlled to a plurality of different sizes,
Flow-related quantities and the differences corresponding to each of these multiple flow-related quantities
Statistical methods such as obtaining the average value of viscosity based on the pressure-related amount
It can be obtained with high accuracy using the method. (12) The differential pressure related amount acquisition device is in a steady state.
Steady state hydraulic pressure, which is the hydraulic pressure difference on both sides of the hydraulic control valve device
The difference and the control condition predetermined in the hydraulic pressure control valve device
After the set time has passed since the flow of hydraulic fluid was started at
The hydraulic pressure of either one of the high-pressure part side and the low-pressure part side
Steady-state viscosity acquisition means for acquiring viscosity based on the amount of change
The viscosity acquisition device according to (11), including: (13) The differential pressure related amount acquiring device is in a steady state.
The low pressure part side after the lapse of the set time with respect to the liquid pressure on the high pressure part side
Including a low pressure side hydraulic pressure ratio obtaining means for obtaining a hydraulic pressure ratio of
The viscosity acquisition device according to item (12). (14) the viscosity obtaining means is configured to determine that the hydraulic fluid is a reference hydraulic fluid;
The relationship between the differential pressure related amount and the flow related amount
Reference relation information storage means for storing reference relation information representing a person in charge
And the reference stored by the reference relation information storage means.
Relationship information and acquired by the differential pressure related amount acquisition device.
Detection relationship representing the relationship between the differential pressure related amount and the flow related amount
Memory that obtains the actual viscosity of the hydraulic fluid based on the information
Item (11) to (13) including information-dependent viscosity acquisition means
The viscosity acquisition device according to any one of the preceding claims. (15) As described in any one of the above items (11) to (14).
The viscosity acquisition device and the viscosity acquisition device
The state of deterioration of the hydraulic fluid based on the viscosity of the hydraulic fluid
And a deterioration state estimating means. Actuation
Since the viscosity decreases as the liquid deteriorates, the viscosity
Thus, the degree of deterioration can be obtained. Viscosity
If the temperature is obtained based on the temperature,
Contact with the hydraulic fluid.
No decrease in gender can be detected. In contrast,
In the hydraulic fluid state acquisition device, the viscosity is
It is obtained based on the volume-related quantity,
The degree of deterioration can be estimated. For example, Ignit
The temperature of the hydraulic fluid is substantially
Viscous within the room temperature maintenance time
Is obtained and the obtained viscosity is smaller than the set viscosity
Can be presumed that the deterioration is progressing. Ma
In addition, the viscosity was acquired multiple times, and the
If all of them are smaller than the set viscosity,
It can also be estimated. Inferior to the hydraulic fluid state acquisition device
The deterioration of the working fluid estimated by the
When it is necessary to change the hydraulic fluid,
A warning device can also be provided. (16) A hydraulic pressure control valve provided between the high pressure section and the low pressure section
This is a viscosity acquisition method for acquiring the viscosity of the hydraulic fluid flowing through the device.
Thus, the fluid between the high pressure section and the low pressure section of the hydraulic pressure control valve device
Differential pressure related quantity acquisition process to acquire the differential pressure related quantity related to pressure difference
And the differential pressure obtained in the differential pressure related amount obtaining process
A related quantity and a flow related quantity related to the flow rate of the hydraulic fluid.
And obtaining a viscosity based on the viscosity.
A viscosity obtaining method characterized by the following. (17) provided between the high-pressure section and the low-pressure section;
Control valve for controlling the flow of hydraulic fluid between the pressure section and the low pressure section
Viscosity acquisition method for acquiring the viscosity of the working fluid flowing through a device
The high pressure of the hydraulic pressure control valve device in a steady state.
A high-pressure side hydraulic pressure detecting step of detecting the hydraulic pressure of the section,
The flow of the hydraulic fluid is controlled by the control valve device under predetermined control conditions.
The high-pressure section and the low-pressure section after a set time has elapsed since the start
One-side hydraulic pressure detection to detect the hydraulic pressure on either side
And the hydraulic pressure of the one side with respect to the high-pressure side hydraulic pressure
And the detection relationship, which is the relationship between the ratio of
When the hydraulic fluid is the reference hydraulic fluid,
Viscosity to obtain the actual viscosity of the hydraulic fluid based on the
And a viscosity obtaining step.

[0004]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a hydraulic brake device provided with a hydraulic control device according to an embodiment of the present invention will be described with reference to the drawings. The hydraulic brake device shown in FIG. 1 is used for a hybrid vehicle including both an internal combustion engine and an electric motor as drive sources. Braking of the hybrid vehicle of the present embodiment is performed by braking by the present hydraulic brake device and regenerative braking by a regenerative braking system (not shown). The regenerative braking system is a system that causes the electric motor to function as a generator and stores electric energy generated by the electric motor in a power storage device to brake the vehicle. When the power storage device is charged by the electromotive force generated in the electric motor when the rotating shaft of the electric motor is forcibly rotated by an external force, the electric motor becomes a load with respect to the external force, and the braking force is increased. Occurs.
A part of the kinetic energy of the vehicle during braking is converted to electric energy and stored in the power storage device, which not only can brake the vehicle but also reduces the consumption of electric energy in the power storage device. It can extend the distance that can travel without charging.

[0005] Braking force by regeneration (referred to as regenerative braking force)
Is not always constant. For example, when the running speed of the vehicle is extremely low, the regenerative braking force is almost zero. In addition, when the capacity of the power storage device is completely filled, control is often performed to prohibit energy regeneration in order to prevent deterioration of the power storage device due to overcharging, and during the period when the regeneration is prohibited. Is the regenerative braking force is 0
become. On the other hand, the magnitude of the braking force of the vehicle needs to be controlled to a magnitude according to the intention of the driver, which is not directly related to the magnitude of the regenerative braking force. Therefore, the magnitude of the hydraulic braking force to be generated by the hydraulic braking device is a magnitude obtained by subtracting the regenerative braking force from the required braking force according to the driver's intention. Such control of the hydraulic brake device is referred to as regenerative braking cooperative control. The magnitude of the required braking force can be easily known from the brake operation status such as the operation force, operation stroke, and operation time of the brake operation member.
Information on the magnitude of the regenerative braking force can be obtained from the regenerative braking system.

FIG. 3 conceptually shows an example of the relationship between the required braking force according to the driver's intention, the regenerative braking force by the regenerative braking system, and the hydraulic braking force by the hydraulic brake device. As is clear from the figure, as the required braking force obtained from the braking operation situation increases, the hydraulic braking force and the regenerative braking force are increased. In the figure, the regenerative braking force starts increasing slightly later than the hydraulic braking force, but this is not essential. The hydraulic braking force may start increasing with a delay. After the regenerative braking force reaches the maximum value determined according to the vehicle speed, etc.,
The required braking force is increased by increasing the hydraulic braking force. In the present embodiment, the regenerative braking system is configured to use the regenerative braking force as effectively as possible. When braking is performed, the vehicle speed gradually decreases, so that the regenerative braking force also gradually decreases. However, for simplicity, the drawing illustrates that the regenerative braking force is constant. When the vehicle speed decreases and the required braking force decreases, the regenerative braking force is reduced. When the vehicle speed decreases and the number of revolutions of the electric motor decreases, a large amount of electric power is required to obtain a large regenerative braking force, and the control hunting of the regenerative braking force increases. The power is reduced to zero. After the regenerative braking force is reduced to zero, the hydraulic braking force decreases while maintaining a magnitude substantially equal to the required braking force. The reason why the regenerative braking force is set to 0 is described later. However, when the hydraulic pressure of the wheel cylinder cannot be controlled (the amount of the hydraulic fluid contained in the decompression reservoir increases and the hydraulic fluid is discharged from the wheel cylinder). (The case where the used working fluid cannot be stored).

As shown in FIG. 1, the hydraulic brake device comprises:
A master cylinder 12, a pump 14, and an accumulator 16 for storing high-pressure hydraulic fluid supplied from the pump 14.
Etc. are included. Master cylinder 12 and pump 14
Is supplied with hydraulic fluid from the master reservoir 18. The master cylinder 12 includes two pressurizing chambers F and R. In the two pressurizing chambers, hydraulic pressures having substantially the same magnitude are generated in accordance with the depression of the brake pedal 19. The constant pressure source 20 including the pump 14, the accumulator 16, the master reservoir 18 and the like is connected to the pressurizing chamber R, and the constant pressure source 2 is
Hydraulic fluid is supplied from 0. Thereby, the stroke of the brake pedal 19 can be reduced. The accumulator 16 has a set pressure range (17 MPa to 18 MPa in the present embodiment) by the operation of the pump 14.
(MPa in the range of 174 to 184 kgf / cm ² ). The accumulator 16 is provided with pressure switches 21a and 21b, and the pump 14 is started and stopped in accordance with ON and OFF with hysteresis of the pressure switches 21a and 21b. The accumulator 16 can supply a substantially constant hydraulic pressure.

The pressurizing chamber F of the master cylinder 12 is connected to a wheel cylinder 24 of a left front wheel 23 via a liquid passage 22.
The wheel cylinder 26 of the right front wheel 25 is connected. The liquid passage 22 is provided with normally open electromagnetic on-off valves 30 and 32, and in the liquid passage 40 connecting the wheel cylinders 24 and 26 and the master reservoir 18, electromagnetic solenoid valves as anti-lock control pressure reducing valves are provided. On-off valves 42 and 44 are provided.

On the other hand, a wheel cylinder 50 of a left rear wheel 49 and a right rear wheel 51
Wheel cylinder 52 is connected. Liquid passage 4
8, in order from the pressurizing chamber R side, a linear valve device 56 and an electromagnetic on-off valve 5 as an anti-lock control pressure increasing valve.
8 and a proportioning valve 60 are provided. A fluid pressure sensor 62 is provided at a portion of the fluid passage 48 between the master cylinder 12 and the linear valve device 56, and a fluid pressure sensor 64 is provided at a portion between the linear valve device 56 and the electromagnetic valve 58. Have been. The hydraulic pressure obtained by the hydraulic pressure sensor 62 is called an input hydraulic pressure Pin, and the hydraulic pressure obtained by the hydraulic pressure sensor 64 is called an output hydraulic pressure Pout1. The linear valve device 5 is controlled by the hydraulic pressure sensors 62 and 64.
The fluid pressure before and after 6 can be detected. When the antilock control or the like is not performed, the output hydraulic pressure Pout1 obtained by the hydraulic pressure sensor 64 is also the hydraulic pressure Pr of the wheel cylinders 50 and 52 of the rear wheels. The hydraulic sensors 62 and 64 are connected to a controller 66. As described later, the controller 66 controls the linear valve device 56 based on the output hydraulic pressure Pout1 detected by the hydraulic pressure sensor 64.
Control. An electromagnetic on-off valve 72 as an anti-lock control pressure reducing valve is provided in the middle of the liquid passage 70 connecting the wheel cylinders 50 and 52 and the master reservoir 18.

A liquid passage 76 is connected to a portion of the liquid passage 48 between the linear valve device 56 and the electromagnetic on-off valve 58. The liquid passage 76 is a passage that connects the linear valve device 56 and the wheel cylinders 24 and 26, and the liquid passage 7
In the middle of 6, a normally closed solenoid on-off valve 80 is provided. Further, the wheel cylinders 24, 2 of the solenoid on-off valve 80
Electromagnetic switching valves 84 and 86 as anti-lock control pressure increasing valves are provided on the 6th side, respectively. Liquid passage 76
A fluid pressure sensor 88 is connected to a portion between the electromagnetic on-off valve 80 and the electromagnetic on-off valves 84 and 86. The measurement result by the hydraulic pressure sensor 88 is defined as an output hydraulic pressure Pout2. The output hydraulic pressure Pout2 is used for monitoring whether the output of the hydraulic pressure sensor 64 is normal. When the solenoid on-off valve 80 is in the open state,
When the value of the output hydraulic pressure Pout1 detected by the hydraulic pressure sensor 64 is apart from the value of the output hydraulic pressure Pout2, the hydraulic pressure sensor 6
It is determined that the output of No. 4 may be abnormal. That is, when the electromagnetic on-off valve 80 is in the open state, the hydraulic pressure sensor 64 and the hydraulic pressure sensor 88 are in communication with each other, and when the hydraulic pressure sensors 64 and 88 are both normal, the output hydraulic pressure Pout1 and the output This is because the hydraulic pressure Pout2 should be substantially the same. In the present embodiment, the operator is notified of the fluid pressure sensor abnormality based on the determination result.
May be prohibited. Each of these plural solenoid on-off valves 30, 32, 42,
The solenoids 44, 58, 72, 80, 84 and 86 are controlled based on a command from the controller 66.

A check valve 90 is provided in the bypass passage that bypasses the normally open electromagnetic on-off valve 58, and a check valve is provided in the bypass passage that bypasses the electromagnetic on-off valves 84 and 86, respectively. Valves 92 and 94 are provided. These check valves 90, 92, and 94 are mounted so as to allow the flow of the hydraulic fluid from the corresponding wheel cylinder toward the master cylinder 12, but prevent the flow in the opposite direction. These check valves 90, 92,
94 allows the hydraulic fluid in the wheel cylinders to be quickly returned to the master cylinder 12 when the brake pedal 19 is loosened while the electromagnetic on-off valves 58, 84, 86 are closed. In addition, each wheel 2
3, 25, 49, and 51 are provided with wheel speed sensors 110 to 116 for detecting rotation speeds of these wheels.
A braking slip state or the like can be detected based on the wheel speeds and the like detected by the wheel speed sensors 110 to 116.

FIG. 2 shows the linear valve device 5 shown in FIG.
6 is a system diagram schematically showing a configuration of FIG. The linear valve device 56 includes a pressure increasing linear valve 150, a pressure reducing linear valve 152, a pressure reducing reservoir 154, and a check valve 156, 1.
58. The pressure-increasing linear valve 150 is provided in the middle of the liquid passage 48, and the pressure-reducing linear valve 152 is connected to the liquid passage 1 that connects the liquid passage 48 and the pressure-reducing reservoir 154.
It is provided in the middle of 60. Booster linear valve 150
In the middle of the bypass passage for bypassing the check valve 156
However, the hydraulic fluid is allowed to flow from the wheel cylinder to the master cylinder 12, but is prevented from flowing in the opposite direction. A check valve 158 is provided in the bypass passage that bypasses the pressure-reducing linear valve 152 in a direction in which the flow of the hydraulic fluid from the pressure-reducing reservoir 154 toward the master cylinder 12 is allowed, but the reverse flow is prevented. I have.

The pressure reducing reservoir 154 stores the hydraulic fluid discharged from the wheel cylinder. The volume of the liquid storage chamber for storing the hydraulic fluid is the reservoir capacity, and the reservoir capacity is equal to the maximum amount of the hydraulic fluid that the pressure reducing reservoir 154 can store during one braking operation. In the present embodiment, the reservoir capacity is smaller than the sum of the capacities of the wheel cylinders 24, 26, 50, 52. Therefore, as described above, the decompression reservoir 15
If the amount of hydraulic fluid stored in the cylinder 4 becomes large, it becomes impossible to reduce the wheel cylinder hydraulic pressure, that is, it becomes impossible to control the wheel cylinder hydraulic pressure, and the regenerative braking force becomes zero. Here, the capacity of the wheel cylinders 24, 26, 50, 52 means the maximum amount of hydraulic fluid that the wheel cylinders can accommodate from a non-operating state to an operating state.

The pressure-increasing linear valve 150 includes a seating valve 190 and an electromagnetic biasing device 194.
The seating valve 190 includes a valve 200 and a valve seat 202.
And the electromagnetically biased body 204 that moves integrally with the valve 200
And a spring 206 as an elastic member as an urging means for urging the electromagnetically energized member 204 in a direction in which the valve 200 is seated on the valve seat 202 (hereinafter, the valve 200 of the spring 206 is attached to the valve seat 202). (The biasing force in the seating direction is referred to as a spring biasing force). The electromagnetic urging device 194 includes a solenoid 210, a resin holding member 212 that holds the solenoid 210, a first magnetic path forming body 214, and a second magnetic path forming body 216. When a voltage is applied to both ends of the winding of the solenoid 210, a current flows through the winding of the solenoid 210 and a magnetic field is formed. Most of the magnetic flux is generated by the first magnetic path forming body 214,
It passes through the electromagnetically energized body 204, the air gap between the second magnetic path forming body 216 and the electromagnetically energized body 204 and the second magnetic path forming body 216. If the voltage applied to the winding of the solenoid 210 is changed, the magnetic force acting between the electromagnetically energized member 204 and the second magnetic path forming member 216 also changes. The magnitude of the magnetic force increases with the magnitude of the voltage applied to the winding of the solenoid 210, and the relationship between the applied voltage and the magnetic force can be known in advance. Therefore, by continuously changing the applied voltage according to the relationship,
The force for urging the electromagnetically energized body 204 (the force in the direction in which the electromagnetically energized body 204 is brought closer to the second magnetic path forming body 216 among the magnetic forces described above. (The electromagnetic driving force is a force in the direction opposite to the biasing force of the spring.). An engaging projection 220 is formed on a surface of the electromagnetically energized body 204 facing the first magnetic path forming body 216, and the engaging projection 220 is opposed to the engagement protruding part 204 of the first magnetic path forming body 216. An engagement recess 222 is formed in the portion where the engagement protrusion 220 and the engagement recess 222 are formed in accordance with a change in the relative position between the electromagnetically biased body 204 and the first magnetic path formation body 216. The area of the facing portion therebetween is changed.

Electromagnetic biasing member 204 and second magnetic path forming member 21
The magnetic resistance of the magnetic path formed by 6 changes depending on the relative position of the electromagnetically-urged member 204 and the second magnetic-path forming member 216 in the axial direction. More specifically, the electromagnetically biased member 2
If the relative position of the second magnetic path forming body 216 with respect to the axial direction changes, the minute gap between the fitting projection 220 of the electromagnetic biased member 204 and the fitting concave part 222 of the second magnetic path forming body 216 changes. The area of the cylindrical surfaces facing each other (parts of the outer peripheral surface of the fitting protrusion 220 and the inner peripheral surface of the fitting recess 222 that face each other) changes. If the electromagnetically energized body 204 and the second magnetic path forming body 216 simply face each other with a small gap between the end faces, the electromagnetically energized body 204 and the second magnetic path forming body 216 are opposed to each other. As the distance in the axial direction decreases, that is, approaching, the magnetic resistance decreases at an accelerating rate, and the magnetic force acting between them increases at an accelerating rate. On the other hand, in the pressure-intensifying linear valve 150 of the present embodiment, as the electromagnetically biased member 204 and the second magnetic path forming member 216 approach, the cylindrical shape of the fitting protrusion 220 and the fitting recess 222 is increased. While the surface area increases and the magnetic flux passing through the cylindrical surface increases, the magnetic flux passing through the air gap between the end face of the electromagnetically energized member 204 and the end face of the second magnetic path forming member 216 decreases. As a result, if the voltage applied to the solenoid 210 is constant within a range that is not so large, the magnetic force (electromagnetic driving force) that urges the electromagnetic biased body 204 in the direction of the second magnetic path forming body 216 becomes:
It is substantially constant irrespective of the relative position in the axial direction between the electromagnetically energized member 204 and the second magnetic path forming member 216. On the other hand, the urging force (urging force of the spring) for urging the electromagnetically energized body 204 by the spring 206 in a direction away from the second magnetic path forming body 216 is a combination of the electromagnetically energized body 204 and the second magnetic path forming body. It increases with approach to the H.216. Therefore, in the state where the urging force based on the hydraulic pressure difference between the inlet-side hydraulic pressure and the outlet-side hydraulic pressure (the acting force acting according to this hydraulic pressure difference is referred to as a differential pressure acting force) is not applied, The movement of the electromagnetic urging member 204 in the direction of the second magnetic path forming member 216 is stopped when the urging force of the spring 206 becomes equal to the electromagnetic driving force.

As shown in FIG.
The spring 200 has a biasing force Fp,
The differential pressure acting force Fd and the electromagnetic driving force Fs act, and the sum of the differential pressure acting force Fd and the electromagnetic driving force Fs becomes the urging force Fp of the spring.
When it becomes larger, the valve 200 is separated from the valve seat 202. When the electromagnetic driving force Fs is zero, the pressure is increased when the differential pressure acting force Fd becomes larger than the biasing force Fp of the spring. In the embodiment, the pressure is about 3 MPa (about 30.6 kgf / cm ² ).

FIG. 5A shows a pressure-increasing linear valve 150.
3 shows the relationship between the applied voltage Va corresponding to the electromagnetic driving force Fs and the hydraulic pressure difference ΔPin corresponding to the differential pressure acting force Fd. The applied voltage Va is the minimum valve opening voltage when a hydraulic pressure difference ΔPin (ΔPin = Pin−Pout1) occurs before and after the pressure increasing linear valve 150, and the hydraulic pressure difference ΔPin
When the (differential pressure acting force) is large, the valve can be opened even if the applied voltage Va (electromagnetic driving force) is small. Here, the hydraulic pressure difference ΔPin is the difference between the input hydraulic pressure and the output hydraulic pressure detected by the hydraulic pressure sensors 62 and 64, respectively. The wheel cylinder hydraulic pressure is smaller. In other words, when increasing the pressure when the wheel cylinder fluid pressure is small, the applied voltage may be small,
When the pressure is increased when the wheel cylinder hydraulic pressure is large, a large applied voltage is required.

When the valve 200 is separated from the valve seat 202, the hydraulic fluid flows through a gap between them. FIG. 6 shows the relationship between the opening degree (the ratio of the opening area at that time to the maximum value of the opening area) Ava and the applied voltage Va. When the hydraulic pressure difference is the same, the applied voltage Va is large. The opening degree Ava becomes larger than the case where is small, and the hydraulic fluid flows from the master cylinder side to the wheel cylinder side at a large flow rate. However, even if the opening degree Ava is the same, the flow rate is different if the viscosity of the working fluid is different, and as shown in FIG. 7, the input hydraulic pressure Pin after a set time after switching the pressure-increasing linear valve 150 to the open state. Output hydraulic pressure Pout1
Will be different. When the viscosity is large, the flow is more difficult than when the viscosity is small. Therefore, the ratio γ is small. Even when the opening degree Ava is the same, the increasing gradient of the wheel cylinder hydraulic pressure becomes small, and the output hydraulic pressure Pout1 after the set time becomes small. Become smaller. In other words, when the viscosity is large, the degree of increase in the wheel cylinder hydraulic pressure can be made substantially the same by increasing the opening degree compared to when the viscosity is small.

The pressure-reducing linear valve 152 is basically the same as the pressure-increasing linear valve 150. However, as will be described later, the urging force of a spring 224 as an elastic member is different from that of the spring 206 of the pressure-increasing linear valve 150. ing. Among the configurations of the pressure reducing linear valve 152, components similar to those of the pressure increasing linear valve 150 are denoted by the same reference numerals, and description thereof is omitted. Also, the pressure reducing linear valve 152
Is determined based on the applied voltage if the hydraulic pressure difference ΔPout (ΔPout = Pout1−Pres) before and after the pressure reducing linear valve is the same. Here, since the hydraulic pressure Pres of the pressure reducing linear valve 152 on the side of the pressure reducing reservoir 154 is maintained substantially at the atmospheric pressure, the hydraulic pressure difference ΔPout becomes Pout1
It is the same size as. The ratio of the opening area of the gap between the valve element 200 and the valve seat 202 in the pressure reducing linear valve 152 to the maximum opening area is represented by an opening degree Avr.

Similarly, for the pressure-reducing linear valve 152, the valve 200 has the urging force Fp of the spring 224,
The differential pressure acting force Fd and the electromagnetic driving force Fs act. The opening pressure of the pressure reducing linear valve 152 is 18 MPa (# 18
4 kgf / cm ² . (The maximum hydraulic pressure of the hydraulic fluid supplied by the constant hydraulic pressure source 20). Spring 2
The biasing force of the spring 24 is larger (about six times) than that of the spring 206. The maximum value of the hydraulic pressure of the hydraulic fluid acting on the valve 200 in the pressure reducing linear valve 152 is the maximum hydraulic pressure supplied by the pump 14 and stored in the accumulator 16. Therefore, the hydraulic pressure due to the operator's pedaling force exceeds this maximum hydraulic pressure, and the hydraulic pressure of the working fluid acting on the input side port of the pressure reducing linear valve 152 exceeds the valve opening pressure of the pressure reducing linear valve 152. You can think that it is not up.

As shown in FIG. 5B, when the hydraulic pressure difference ΔPout before and after the pressure reducing linear valve 152 is large, the valve can be opened even when the applied voltage Vr is smaller than when it is small. Here, since the hydraulic pressure difference is the difference between the wheel cylinder side hydraulic pressure and the pressure reducing reservoir side hydraulic pressure, the wheel cylinder hydraulic pressure is larger when the hydraulic pressure difference is large than when it is small. Therefore, when the wheel cylinder pressure is reduced, the applied voltage may be small when the wheel cylinder pressure is large, but a large voltage needs to be applied when the wheel cylinder pressure is small. Further, even when the opening degree is the same, when the viscosity of the hydraulic fluid is large, the hydraulic fluid is less likely to flow than when the viscosity is small, so that the decreasing gradient of the wheel cylinder hydraulic pressure is small. Therefore, when the hydraulic pressure drop gradient (outflow flow rate) is the same, it is necessary to increase the opening degree when the viscosity of the hydraulic fluid is high than when it is low.

On the other hand, a liquid pressure sensor 228
(See FIG. 1) is connected, and the fluid pressure in the pressurizing chamber F is detected. The hydraulic pressure of the pressurizing chamber F can be a hydraulic pressure corresponding to the target braking force intended by the driver. In addition, the liquid passage 2
A stroke simulator 230 is connected to 2 to prevent the stroke of the brake pedal 19 from becoming almost zero in a state where both the electromagnetic on-off valves 30 and 32 are closed. This hydraulic braking system is provided with a brake switch 250 for detecting that the brake pedal 19 is depressed and a pad temperature detecting device 252 for detecting the temperature of a brake pad surface (not shown). The hydraulic fluid temperature is estimated according to the temperature of the brake pad.

The controller 66 includes the above-mentioned hydraulic sensors 62, 64, 88, 228 and the wheels 23, 25, 4
Wheel speed sensors 110 for respectively detecting the wheel speeds 9 and 51
To 116 and the switches 250 and 252 are connected, and the output unit is connected to a solenoid or the like of the linear valve device 56 via a drive circuit (not shown). Also,
The ROM stores a viscosity acquisition program represented by the flowchart of FIG. 9, a linear valve device control program represented by the flowchart of FIG. 10, a table represented by graphs of FIGS.

When the brake pedal 19 is depressed, hydraulic pressures of substantially the same magnitude are generated in the pressurizing chambers F and R, respectively, and are supplied to the wheel cylinders 24 and 26 and the wheel cylinders 50 and 52. When the regenerative braking cooperative control is performed in a state where the hydraulic brake device is operating normally, the electromagnetic on-off valves 30 and 32 are closed, the electromagnetic on-off valve 80 is open, and the other electromagnetic The on-off valve is in the state shown in FIG. Wheel cylinder 24, 26
The hydraulic fluid is supplied from the pressurizing chamber R of the master cylinder 12 not through the liquid passage 22 but through the liquid passage 48 from the pressurizing chamber R. Similarly, the hydraulic fluid controlled by the linear valve device 56 is supplied. The hydraulic pressures of all the wheel cylinders are controlled by controlling the pressure increasing linear valve 150 and the pressure reducing linear valve 152 of the linear valve device 56. At the time of decompression, the hydraulic fluid flows out of the wheel cylinder, and the decompression reservoir 15
4 When the regenerative braking cooperative control and the antilock control are performed in parallel, the linear valve device 56
Solenoid valve 5 based on the hydraulic fluid controlled by
By switching between 8, 72, 84, 86, 42, and 44 between the open state and the closed state, the hydraulic pressure of the wheel cylinders maintains the brake slip state of each of the wheels 23, 25, 49, and 51 in an approximately proper state. It is controlled to drip.

In the regenerative braking cooperative control, the linear valve device 56 is controlled so that the output hydraulic pressure Pout1 detected by the hydraulic pressure sensor 64 approaches the target hydraulic pressure Pref. Pressure increasing linear valve 150, pressure reducing linear valve 152
Is applied to each of the solenoids 210. The target hydraulic pressure Pref is obtained as a value obtained by subtracting the hydraulic pressure corresponding to the braking force by regenerative braking from the master cylinder hydraulic pressure Pmc (corresponding to the driver's will), which is the output value of the hydraulic pressure sensor 228. As shown in FIG. 8, the voltage Va applied to the solenoid of the pressure-increasing linear valve 150 and the voltage Vr applied to the solenoid of the pressure-reducing linear valve 152 respectively change the voltages Vga and Vgr into constant voltages Vca and Vcr. The size is added. The change voltages Vga and Vgr are obtained by multiplying the change in the target hydraulic pressure Pref by constants GAINa and GAINr. In the pressure increase control, the hydraulic pressure difference ΔPin decreases as the wheel cylinder hydraulic pressure increases,
Further, when it is necessary to increase the wheel cylinder fluid pressure, the pressure increasing linear valve 150 must be kept open, and as described above, a large voltage needs to be applied. Similarly, in the pressure reducing linear valve 152, the hydraulic pressure difference ΔP
Although out becomes small, when it is necessary to further reduce the pressure, the applied voltage necessary to keep the pressure reducing linear valve 152 open increases.

The constant voltage Vca applied to the pressure-increasing linear valve 150 is determined based on the table shown in the graph of FIG. When the pressure increasing control is started (immediately before), the voltage applied to the solenoid 210 of the pressure increasing linear valve 150 is set to 0, and the valve is in a closed state. However, in order to switch the pressure-increasing linear valve 150 to the open state, it is necessary to apply a voltage higher than the minimum valve opening voltage to the solenoid 210. The magnitude of the minimum valve opening voltage is determined based on the hydraulic pressure difference ΔPin at the start of the pressure increase control, that is, the hydraulic pressure difference ΔPin at the end of the pressure reduction control (or the holding control). Here, when the voltage applied to the solenoid 210 of the pressure-increasing linear valve 150 is increased from 0, the voltage is maintained in the closed state until the voltage reaches the minimum valve-opening voltage, and accordingly, the pressure-increasing delay occurs. In order to reduce this pressure increase delay, the minimum valve opening voltage according to the hydraulic pressure difference before and after the pressure increase linear valve 150 at the end of the pressure reduction control is set as the constant voltage, and the applied voltage is set based on the constant voltage. It is decided. Pressure reducing linear valve 15
Similarly, the constant voltage Vcr corresponding to the hydraulic pressure difference before and after the pressure reducing linear valve 152 at the time when the pressure increase control is finished is determined based on the table shown in the graph of FIG. At the start of the pressure reduction control, the pressure reduction linear valve 152 is immediately switched to the open state, and the pressure reduction delay is reduced.

As described above, the magnitudes of the constant voltages Vca and Vcr are determined based on the graphs of FIGS. 5A and 5B. In the present embodiment, when the viscosity of the hydraulic fluid is large, The magnitude of the constant voltage is determined based on the viscosity of the working fluid flowing through the linear valve device 56, as described later. Since the magnitude of the applied voltage is determined based on the viscosity, the pressure-increasing linear valve 150 and the pressure-reducing linear valve 1
The opening of the valve 52 is controlled based on the viscosity, thereby reducing the influence of the viscosity on the hydraulic pressure change gradient and improving the accuracy of the hydraulic pressure control.

First, the acquisition of the viscosity of the working fluid will be described. In the present embodiment, the hydraulic pressure difference between the high-pressure part and the low-pressure part is determined by the input hydraulic pressure Pin and the output hydraulic pressure detected by the two hydraulic pressure sensors 62 and 64 that detect the hydraulic pressures before and after the pressure-increasing linear valve 150, respectively. It is obtained based on the pressure Pout1 and the opening degree Ava of the pressure-increasing linear valve 150. Further, since the flow rate of the hydraulic fluid is determined according to the opening degree Ava, the opening degree Ava is set as the flow rate-related amount. When the driver depresses the brake pedal 19 to reach a steady state, the hydraulic pressure difference between the master cylinder side and the wheel cylinder side of the pressure-intensifying linear valve 150 becomes about 2 MPa. The hydraulic pressure difference in the steady state can be obtained based on the output signals of the hydraulic pressure sensors 62 and 64. As described above, the booster linear valve 1
When no voltage is applied to the 50 solenoids 210, the valve is opened when the differential pressure acting force reaches 3 MPa, so that the hydraulic pressure difference in a steady state becomes about 2 MPa. As described above, when the hydraulic pressure difference in the steady state is substantially determined by the structure of the linear valve device 56, it is not always necessary to detect the hydraulic pressure difference.

In the steady state, no voltage is applied to the pressure increasing linear valve 150. In this state, when a voltage of a predetermined magnitude is applied to the solenoid 210, the hydraulic fluid is caused to flow from the master cylinder side toward the wheel cylinder side at the opening Ava according to the applied voltage, and the output hydraulic pressure Pout1 Is increased over time. Since the hydraulic pressure difference in the steady state is substantially constant, the opening is also substantially the same if the applied voltage is the same. On the other hand, the input hydraulic pressure Pin is substantially constant because the driver's depression force of the brake pedal 19 is kept substantially constant.
It is constant. Therefore, the hydraulic pressure difference after the set time from the start of the flow of the hydraulic fluid can be obtained based on the steady-state hydraulic pressure difference in the steady state and the change amount (increase amount) of the output hydraulic pressure Pout1 after the lapse of the set time.

According to Hagen-Poitouille's law,
The viscosity of the hydraulic fluid can be obtained based on the hydraulic pressure difference and the opening area. When the opening area is the same, when the viscosity of the hydraulic fluid is large, the flow is more difficult than when the viscosity is small. Therefore, the change gradient of the output hydraulic pressure Pout1 becomes small, and the hydraulic pressure difference ΔPin after the lapse of the set time becomes large. When the hydraulic fluid is the reference hydraulic fluid and the viscosity is the reference viscosity, the reference relationship between the hydraulic pressure difference and the opening area is stored in advance, and the reference relationship and the hydraulic pressure difference and the opening area of the actual hydraulic fluid are compared. The actual viscosity of the working fluid can be obtained based on the detection relationship. In the present embodiment, the hydraulic pressure difference is not used as it is, but the hydraulic pressure difference is changed to the input hydraulic pressure P in the steady state.
The viscosity is obtained based on the relationship between the value obtained by subtracting the value divided by in from 1 (hydraulic ratio) and the opening area. The hydraulic pressure ratio is the same as the ratio of the output hydraulic pressure Pout1 * after the lapse of the set time to the input hydraulic pressure Pin in the steady state without being calculated based on the hydraulic pressure difference (γ = Pout1).
* / Pin). When the viscosity is large, the hydraulic pressure difference is large as compared with the case where the viscosity is small, but the hydraulic pressure ratio γ is small.
The output hydraulic pressure Pout1 * after the lapse of the set time does not increase so much when the viscosity is large because the increasing gradient of the wheel cylinder hydraulic pressure is smaller than when the viscosity is low.

As described above, in the steady state, the hydraulic pressure difference is substantially constant, so that the differential pressure acting force Fd shown in FIG. 4 is substantially constant, and as shown in FIG. Will be decided. In addition, the linear valve device 5
When the hydraulic fluid flowing through 6 is the reference hydraulic fluid (when the viscosity coefficient is the standard value μ *), the hydraulic pressure ratio γ of the output hydraulic pressure Pout1 * to the input hydraulic pressure Pin after the lapse of the set time and the opening degree Ava Is stored in advance (see FIG. 7). Therefore, based on the reference relation and the detection relation between the actually detected hydraulic pressure ratio γ and the opening degree, the actual viscosity of the working fluid can be obtained. The steady-state hydraulic pressure difference is almost constant, but may change due to settling of the spring 206 or the like. Therefore, the viscosity can be corrected based on the steady-state hydraulic pressure difference. When the steady state hydraulic pressure difference is large, the differential pressure acting force Fd is larger than when it is small, so that the hydraulic pressure ratio γ after the set time becomes large,
The viscosity is detected to a value smaller than the actual value. Therefore, when the steady state hydraulic pressure is large, the viscosity is corrected to a value larger than the obtained value. Even if the applied voltage is the same, the opening is different if the hydraulic pressure difference is different. Therefore, the opening is corrected based on the hydraulic pressure difference, and the viscosity is determined based on the corrected opening and the hydraulic pressure ratio γ. It may be acquired. If the hydraulic pressure difference is large, the opening degree becomes large and the viscosity is detected to be a small value, so the value is corrected to a large value. In addition,
In the present embodiment, the opening is a flow-related amount,
In addition, the magnitude of the applied voltage can be used as the flow rate-related amount. This is because the opening is uniquely determined based on the applied voltage as shown in FIG. Further, the flow rate-related quantity may be the flow rate itself. The flow rate can be determined according to a well-known formula based on the opening area, liquid density, and the like.

The acquisition of the viscosity is performed in a steady state. For example, when the ignition switch is turned OFF to O
When N is set and the brake pedal 19 is in the operating state, when the ignition switch is first turned on after the ignition switch is turned from OFF to ON, it is estimated that the brake pedal 19 is in the steady state. In the steady state, the hydraulic fluid hardly flows through the linear valve device 56, and the hydraulic pressure difference is maintained at a constant level. In these cases, the brake pedal 19 is not depressed while the vehicle is running, so that the depressing force is constant and the depressed state is continued. Many drivers turn on the ignition switch while the brake pedal 19 is depressed, but even if not, the brake pedal 19 is not depressed when switching the shift position from the parking position to the drive position. Many vehicles cannot operate the shift lever, and when operating the shift lever, the brake pedal 1
9 will be stepped on. The stationary state is established not only when the ignition switch is turned on, but also when the brake pedal 19 is depressed when the vehicle is stopped due to a stop signal or the like. In any case, when braking is performed during running (during braking)
However, even if the opening degree of the pressure-intensifying linear valve 150 is changed to obtain the viscosity, the driver's uncomfortable feeling can be reduced. But,
Since the temperature of the working fluid is relatively stable and the viscosity is stable during a period that has not been so long since the ignition switch was turned on, the viscosity can be accurately obtained.

Immediately after the ignition switch is turned on, the voltage applied to the linear valve device 56 is zero. Therefore, if the steady state is reached after the brake pedal 19 is depressed, the hydraulic pressure difference ΔP between the input hydraulic pressure Pin and the output hydraulic pressure Pout1 detected by the hydraulic pressure sensors 62, 64
in is approximately 2 MPa. When a voltage of a predetermined magnitude is applied to the solenoid 210 of the pressure-increasing linear valve 150, the hydraulic fluid is caused to flow at the opening Ava corresponding to the voltage. When the hydraulic pressure difference is substantially the same, the opening is also substantially constant if the applied voltage is substantially constant. The output hydraulic pressure Pout1 increases with the flow of the hydraulic fluid, and the hydraulic pressure ratio γ decreases. The pressure-increasing linear valve 150 also functions as an orifice. A hydraulic pressure ratio γ of the output hydraulic pressure Pout1 to the input hydraulic pressure Pin after a set time has elapsed after the voltage is applied to the solenoid 210 of the pressure increasing linear valve 150,
Based on the detection relationship between the fluid pressure ratio γ and the opening degree Ava, and the reference relationship in the table shown in the graph of FIG. 7, the viscosity of the working fluid can be obtained.

The acquisition of the viscosity is performed according to the execution of the viscosity estimation program shown in the flowchart of FIG. In step 1 (hereinafter, abbreviated as S1; the same applies to other steps), it is determined whether or not the vehicle is in a steady state. That is, whether or not the brake pedal 19 is depressed is determined by turning the ignition switch from OFF to O.
N or not, or the brake pedal 19
The ignition switch is turned off.
It is determined whether or not it is the first time since it was turned ON. If either one of the conditions is satisfied, at S2, the input hydraulic pressure Pi detected by the hydraulic pressure sensors 62 and 64, respectively.
n, the output hydraulic pressure Pout1 is read, and the steady state hydraulic pressure difference in the steady state is obtained. In S3, a voltage of a predetermined magnitude is applied to the solenoid 210 of the pressure-increasing linear valve 150. In S4, the output hydraulic pressure Pout1 after the set time is read. The hydraulic pressure ratio γ after the lapse of the set time is acquired, and in S5, the viscosity of the hydraulic fluid is acquired based on the table shown in the graph of FIG. By comparing the detection relationship between the opening degree and the hydraulic pressure ratio γ with the reference relationship, and determining how far the detection relationship is on the side where the viscosity is greater than the reference relationship, if the detection relationship is determined from the reference value of the viscosity of the hydraulic fluid, The size of the gap can be detected. As shown in FIG. 7, it can be seen that the greater the distance between the detection relation γA and the reference relation γN, the greater the distance from the reference value of the viscosity of the hydraulic fluid. Here, the steady state hydraulic pressure difference is 2 MPa
When the distance is greatly different from the viscosity, the viscosity can be corrected. When the hydraulic pressure difference is larger than 2 MPa, the differential pressure acting force is large and the opening degree is large, so that the hydraulic pressure difference is obtained as a value smaller than the actual viscosity of the hydraulic fluid. Therefore, the viscosity is increased, and conversely, when the hydraulic pressure difference is small, the viscosity is reduced.

As described above, in the present embodiment, the viscosity of the working fluid is obtained based on the hydraulic pressure difference before and after the linear valve device 56, and is not obtained based on the temperature of the working fluid. . Therefore, a dedicated hydraulic fluid temperature sensor or the like for detecting the temperature of the hydraulic fluid is not required, and a cost increase can be avoided accordingly. In the present embodiment, a dedicated sensor or the like for acquiring the differential pressure-related amount and the flow rate-related amount is unnecessary. Further, the viscosity of the working fluid can be obtained with high accuracy. The viscosity of the hydraulic fluid changes depending on the temperature, but may change depending on the degree of deterioration. When the temperature is obtained based on the temperature, even if the working fluid is deteriorated and the viscosity is reduced, if the temperature is low, it is erroneously obtained that the viscosity is large. On the other hand, when the viscosity is acquired based on the differential pressure-related amount and the flow rate-related amount, the decrease in viscosity due to the deterioration can be acquired, so that the decrease in the accuracy of viscosity acquisition can be suppressed. In the conventional viscosity acquisition device, it is difficult to directly detect the temperature of the hydraulic fluid. However, compared to the case where the viscosity is obtained based on such an estimated temperature, the accuracy of obtaining the viscosity can be improved.

In the above-described embodiment, the viscosity is obtained based on the hydraulic ratio γ of the output hydraulic pressure Pout1 * after the set time with respect to the input hydraulic pressure Pin. However, the input hydraulic pressure Pin after the set time is obtained. * And the output hydraulic pressure Pout1 in a steady state.
And a hydraulic pressure difference (Pout1−Pout1 *) which is a hydraulic pressure difference between the output hydraulic pressure Pout1 * and the output hydraulic pressure Pout1 * after a lapse of a set time, or an information based on a ratio of the hydraulic pressure difference to the input hydraulic pressure in a steady state. Or you can. When the viscosity is small, the change gradient of the output hydraulic pressure Pout1 is larger than when the viscosity is large, so that the output hydraulic pressure after the set time increases and the change amount of the output hydraulic pressure ΔPout1 also increases.
In the above embodiment, the viscosity can be corrected based on the steady-state hydraulic pressure difference. However, the correction is not necessarily required. This is because the variation in the steady state hydraulic pressure difference is not so large.

Further, in the above embodiment, the viscosity is obtained based on the hydraulic pressure ratio γ when a voltage of a predetermined magnitude is applied to the solenoid 210, but a plurality of voltages of different magnitudes are obtained. The information may be obtained based on the respective hydraulic pressure ratios γ when they are applied. In this case, S1 to S5 are executed a plurality of times, and the average value of the viscosities is regarded as the viscosity of the working fluid. It is not essential that the viscosity is obtained before a long time elapses after the ignition switch is turned ON, and the viscosity may be obtained when the vehicle is stopped. In that case, in S1, it is determined whether or not the vehicle is kept in a stopped state (vehicle speed 0) for a set time or more with the brake pedal 19 depressed, thereby determining whether or not the vehicle is in a steady state. Is done.

Similarly, it is possible to obtain the viscosity of the working fluid flowing through the pressure reducing linear valve 152. In this case, the pressure reducing linear valve 152 is kept open for the set time, and the output hydraulic pressure Pout1 * after the lapse of the set time is detected.
The hydraulic pressure ratio γ (= Prev / Pout1 *) is obtained. The reservoir-side hydraulic pressure Prev is 1 because it is always kept at the atmospheric pressure. And, when the hydraulic fluid is the reference hydraulic fluid, the hydraulic pressure ratio γ
If the reference relationship between the pressure and the opening area is stored in the same manner as in the case of the pressure-increasing linear valve 150, the viscosity of the hydraulic fluid can be obtained based on the reference relationship and the detection relationship.
The viscosity of the pressure-reducing linear valve 152 can be obtained based on the ratio γ ′ of the output hydraulic pressure to the output hydraulic pressure in the steady state after a lapse of a set time.
When the viscosity is large, the change gradient of the output hydraulic pressure Pout1 is smaller than when the viscosity is small, so that the hydraulic pressure ratio γ ′ becomes large.

Next, control based on the magnitude of the viscosity of the working fluid will be described. As described above, the applied voltage is the constant voltage V determined according to the table shown in the graph of FIG.
In the present embodiment, when it is estimated that the viscosity is large, the constant voltage Vca is determined based on the viscosity of the working fluid. That is, when the viscosity is estimated according to the equation Vcaμ = Vca + k · (μ−μ *) (1), and the viscosity is estimated to be substantially the reference value μ *, the voltage Vca represented by the graph of FIG. Will be left as is. Here, k is a constant. When the viscosity is high, the constant voltage Vcaμ is increased and the opening is increased as compared with the case where the viscosity is low. This is because when the viscosity is large, the hydraulic fluid is difficult to flow, the gradient of the hydraulic pressure change becomes small, and there is a possibility that a pressure increase delay occurs. If the opening is increased, the pressure increase delay can be suppressed.

In the flowchart of FIG.
In the above, the target hydraulic pressure Pref is obtained as a hydraulic pressure corresponding to a value obtained by subtracting an actual regenerative braking force actually obtained from a target braking force corresponding to the output hydraulic pressure of the hydraulic pressure sensor 228. S
In steps 21 and 22, it is determined whether the temperature of the brake pad is equal to or higher than the set temperature and whether or not a set time has elapsed since the ignition switch was turned on. If the temperature of the brake pad is equal to or higher than the set temperature or the elapsed time is equal to or longer than the set time, in S23, the viscosity of the working fluid is determined to be the reference value μ *. On the other hand, when the temperature is lower than the set temperature and the elapsed time has not reached the set time, the viscosity is set to an obtained value in S24.

If it is determined that the viscosity is the reference value μ *, the constant voltage Vcaμ is determined in S25 according to the table shown in the graph of FIG. Is determined according to the above equation. Thereafter, in S27, the change voltage is determined, and the applied voltage is determined. As described above, in the present embodiment, when the viscosity is high, the constant voltage is higher than when the viscosity is low, so that the applied voltage increases, and the opening degree increases accordingly. As a result, whether the viscosity is large or small, the hydraulic pressure change gradient can be made substantially the same, and the hydraulic pressure control can be performed well.

In the above embodiment, the viscosity of the working fluid is obtained within the normal temperature maintenance time after the ignition switch is turned ON. Therefore, the viscosity is obtained as a larger value than when the brake is actually operated. The temperature of the hydraulic fluid increases with the lapse of time since the ignition switch was turned ON, and the viscosity decreases. For this reason, while the duration time after turning on the ignition switch is not so long (within the normal temperature maintenance time), the viscosity of the hydraulic fluid is large, and there is a possibility that a pressure increase delay may occur. If the duration time from is longer, it can be estimated that the viscosity of the working fluid has also decreased, and there is no danger that pressure increase delay will occur. Therefore, if the temperature is within the normal temperature maintenance time after the ignition switch is turned on, the viscosity is maintained at the obtained value, and control based on the obtained value is performed. Instead, the reference value μ * is used. In this case, it is not necessary to increase the opening. As described above, in the present embodiment, since the control based on the viscosity is performed only when the viscosity is large and the pressure increase delay may occur, the control based on the viscosity is performed regardless of the magnitude of the viscosity. The control can be simplified as compared with the case where it is performed.

As described above, in the above embodiment, it is considered that the control based on the viscosity is performed only when the viscosity is estimated to be large, and is not performed when the viscosity is estimated to be small. be able to. In other words, the rules for determining the applied voltage are changed depending on whether the viscosity is high or low. It can also be considered that the constant voltage is corrected based on the difference between the viscosity of the working fluid and the reference value of the viscosity.

As described above, in the present embodiment, the hydraulic pressure control valve device is constituted by the linear valve device 56, and the fluid pressure control means is constituted by the controller 66, the fluid pressure sensors 62 and 74, and the like. A portion of the controller 66 that executes the viscosity acquisition program, a portion that executes the linear valve control program, and the like constitute a viscosity response control unit. The viscous response control means is also a viscous influence eliminating control means. Further, the viscosity acquisition means is constituted by a portion of the viscosity correspondence control means for executing the viscosity acquisition program. Then, a viscosity acquiring device is constituted by the viscosity acquiring means and the differential pressure related amount acquiring device constituted by the liquid pressure sensors 62 and 64 and the like.

In the above embodiment, the control rule is changed based on the elapsed time from when the ignition switch is turned ON, but may be changed based on the magnitude of the acquired value. . For example, the control rule can be changed between a case where the acquired value is larger than the reference value by a set value or more and a case where the obtained value is within the set range. Further, it is not essential to detect the temperature of the brake pad, and the viscosity may be obtained based on only the elapsed time. Furthermore, when the acquired value is smaller than the reference value by a set value or more, it can be estimated that the sensor has deteriorated. In this case, control for reducing the opening can be additionally performed. . Further, in the above embodiment, the constant voltage is determined based on the viscosity, but the applied voltage may be directly determined based on the viscosity. For example, the tables represented by the graphs of FIGS. 6 and 7 are stored, and the opening and the applied voltage are determined based on the tables. As shown in FIG. 11, when the desired hydraulic pressure change gradient is determined, the opening is determined based on the hydraulic pressure change gradient and the viscosity, and the opening of the seating valve 190 corresponds to the above opening. The applied voltage is determined based on FIG. 6 so as to obtain the magnitude. Further, it is not essential to change the control rule based on the viscosity, and the applied voltage may be always determined based on the viscosity. For example, the constant voltage can always be determined according to the equation (1). Further, in the above embodiment, the viscosity is set to the reference value after the set time elapses after the ignition switch is turned on, but may be set to a fixed value different from the reference value.

Further, the hydraulic pressure control valve device is not limited to the linear valve device 56 in the above embodiment, but may include a plurality of electromagnetic on-off valves. For example, the flow rate of the working fluid may be determined based on the open time ratio of the open state to the closed state, and the open time ratio may be controlled by controlling the ON time ratio of the applied voltage to control the flow rate. Further, in the above embodiment, the hydraulic brake device is applied to the hydraulic brake device in a hybrid vehicle, but may be applied to various hydraulic brake devices such as the hydraulic brake device in an electric vehicle. it can. Although not specifically exemplified, the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an entire hydraulic brake device including a hydraulic control device according to an embodiment of the present invention. The fluid pressure control device also includes a viscosity acquisition device according to one embodiment of the present invention.

FIG. 2 is a partial sectional view of a linear valve device included in the hydraulic brake device.

FIG. 3 is a control conceptual diagram when regenerative braking cooperative control is performed in the hydraulic brake device.

FIG. 4 is a view conceptually showing a force acting on a pressure-intensifying linear valve included in the linear valve device.

FIG. 5A is a diagram showing a relationship between a hydraulic pressure difference and a minimum valve opening voltage in the pressure increasing linear valve. (B) is a diagram illustrating a relationship between a hydraulic pressure difference and a minimum valve opening voltage in a pressure reducing linear valve included in the linear valve device.

FIG. 6 is a diagram showing a relationship between an opening degree and an applied voltage in the pressure increasing linear valve.

FIG. 7 is a diagram showing a relationship between an opening degree of the pressure increasing linear valve and a hydraulic pressure ratio after a set time.

FIG. 8 is a diagram illustrating an example of a change in target hydraulic pressure and a change in applied voltage when regenerative braking cooperative control is performed in the hydraulic brake device.

FIG. 9 is a flowchart illustrating a viscosity acquisition program stored in a ROM of the hydraulic control device.

FIG. 10 is a flowchart showing a linear valve device control program stored in a ROM of the hydraulic control device.

FIG. 11 is a diagram illustrating a table indicating a relationship between an opening degree of a linear valve device and a target hydraulic pressure change gradient stored in a ROM of a hydraulic control device according to another embodiment of the present invention.

[Explanation of symbols]

 56 Linear valve device 62, 64 Hydraulic pressure sensor 66 Controller

Claims (2)

[Claims] 1. A hydraulic pressure control valve device that is provided between a high pressure portion and a low pressure portion and controls the flow of hydraulic fluid between the high pressure portion and the low pressure portion, and controls the hydraulic pressure control valve device. A hydraulic pressure control valve control means for controlling the hydraulic pressure of either the high pressure part or the low pressure part, whereby the hydraulic pressure control valve control means comprises: Viscosity acquisition means for acquiring the viscosity of the working fluid based on a differential pressure related quantity related to the fluid pressure difference on both sides of the device and a flow related quantity related to the flow rate of the working fluid, and a viscosity acquisition means for acquiring the viscosity of the working fluid. A fluid pressure control device for controlling the fluid pressure based on the viscosity of the working fluid. 2. Viscosity for obtaining the viscosity of the hydraulic fluid flowing between a high-pressure part and a low-pressure part and flowing through a hydraulic pressure control valve device for controlling the flow of the hydraulic fluid between the high-pressure part and the low-pressure part. An acquisition device, comprising: a differential pressure related amount obtaining device that obtains a differential pressure related amount related to a hydraulic pressure difference between a high pressure part and a low pressure part of the hydraulic pressure control valve device; A hydraulic fluid viscosity obtaining device, comprising: a viscosity obtaining unit configured to obtain the viscosity based on the obtained differential pressure-related amount and a flow-related amount related to the flow rate of the hydraulic fluid.