JPH10332011A - Hydraulic pressure control device - Google Patents

Abstract

(57) [Summary] The present invention relates to a hydraulic control device, and an object thereof is to provide a hydraulic control device capable of controlling a fluid flow rate so that zero is a lower limit. SOLUTION: A spool 124 is accommodated in a cylinder part 122 formed in a housing 120. The fluid supplied to the hydraulic pressure inlet port 32a is supplied to the pressure chamber 128 via the annular chamber 130 and the communication passage 132. Pressure chamber 12
When the hydraulic pressure at 8 rises, the spool is displaced until the annular chamber 130 is disconnected from the hydraulic pressure inflow port 32a, whereby the supply of fluid to the pressure chamber 128 is interrupted. Therefore,
The liquid pressure in the pressure chamber 128 is kept constant. Pressure chamber 128
Is supplied to the valve passage 146. Therefore,
The flow rate of fluid flowing out of the control pressure suction port 32b is controlled according to the open area of the poppet valve 157.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pressure control device, and more particularly to a fluid pressure control device for controlling a fluid pressure of a fluid pressure device which is required to control a flow rate of fluid so that zero is a lower limit. And a hydraulic control device.

[0002]

2. Description of the Related Art As a hydraulic pressure control device capable of controlling the flow rate of fluid, a conventional hydraulic pressure control device, for example, as disclosed in Japanese Utility Model Laid-Open Publication No.
No. 573 is known. The above-mentioned conventional hydraulic pressure control device causes the fluid supplied to the suction port to flow out of the discharge port at a controlled flow rate.

[0003] The above-described conventional hydraulic pressure control device includes a cylinder formed inside a housing, and a spool disposed in the cylinder and driven by an actuator. The internal space of the cylinder is partitioned by a spool into a first liquid chamber and a second liquid chamber. A discharge port communicates with the second liquid chamber. The first liquid chamber communicates with a suction port and a drain port, and also communicates with a discharge port via an orifice.

When the pressure difference between the first liquid chamber and the second liquid chamber changes, the spool is displaced in accordance with the change in the pressure difference. The spool is configured to increase the degree of communication between the first liquid chamber and the drain port as the spool is displaced toward the second liquid chamber. Therefore, the change in the differential pressure is compensated by increasing or decreasing the flow rate of the fluid flowing from the first liquid chamber to the drain port. As a result, the differential pressure between the first liquid chamber and the second liquid chamber, that is, the differential pressure between the first liquid chamber and the discharge port is kept constant. As described above, by maintaining the differential pressure between the first liquid chamber and the discharge port constant, the flow rate of fluid flowing out of the discharge port through the orifice is:
It is kept constant irrespective of the fluid pressure at the suction port.

[0005] When the spool is driven by the actuator, the flow rate of fluid flowing out of the first liquid chamber to the drain port changes according to the position of the spool. Therefore, by changing the position of the spool by the actuator, the flow rate of the fluid flowing out from the discharge port can be controlled.

[0006]

Incidentally, for example, in a vehicle brake system, the wheel cylinder pressure must be controlled so that the atmospheric pressure becomes the lower limit. To control the wheel cylinder pressure so that atmospheric pressure is at the lower limit,
It is necessary to be able to change the flow rate of the fluid flowing into the wheel cylinder so that zero is the lower limit.

However, as described above, in the above-mentioned conventional hydraulic pressure control device, the suction port and the discharge port are always in communication via the first liquid chamber and the orifice. If the suction port and the discharge port are always in communication, the fluid will always flow out of the discharge port. That is,
According to the above-described conventional hydraulic pressure control device, the flow rate of the fluid flowing out from the discharge port cannot be reduced to zero. For this reason, the above-mentioned conventional hydraulic pressure control device cannot be applied to a hydraulic system which needs to control the flow rate of fluid so that zero becomes a lower limit like the above-mentioned hydraulic brake device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is possible to control the flow rate of fluid over a range having a lower limit of zero, whereby the present invention can be applied to a wide range of hydraulic systems. It is an object of the present invention to provide a hydraulic control device capable of performing the following.

[0009]

The above object is achieved by the present invention.
As described in the above, a fluid pressure control device that discharges fluid supplied to the suction port from the discharge port, the supply pressure constant means for regulating the fluid supplied to the suction port to a constant hydraulic pressure, This is achieved by a hydraulic pressure control device comprising: a flow area changing means for changing a flow area of a flow path from the constant hydraulic pressure generating means to the discharge port.

[0010] In the present invention, the supply pressure stabilizing means adjusts the fluid supplied to the suction port to a constant hydraulic pressure. The flow area changing means changes the flow area of the flow path from the constant hydraulic pressure generating means to the discharge port. Therefore, a constant hydraulic pressure is supplied to the upstream side of the flow path area changing means, and a fluid having a flow rate corresponding to the flow path area flows out from the discharge port. In this case, when the flow path area is set to zero, the flow rate of the fluid also becomes zero. Therefore, according to the present invention, the flow rate of the fluid flowing out of the discharge port is changed over a range whose lower limit is zero.

[0011]

FIG. 1 is a system configuration diagram of a hydraulic brake device according to one embodiment of the present invention. The hydraulic brake device of this embodiment is an electronic control unit (not shown)
ECU). As shown in FIG.
The hydraulic brake device according to the present embodiment includes a pump 20. The pump 20 is driven by a motor 22. A reservoir tank 24 communicates with a suction port of the pump 20.
Further, a discharge port of the pump 20 communicates with a high-pressure passage 28 leading to a regulator 26. An accumulator 30 communicates with the high-pressure passage 28. Accumulator 30
Stores the brake fluid discharged from the pump 20.

The regulator 26 includes a hydraulic pressure control device 32
To the main hydraulic pressure passage 33. Regulator 2
6 is the accumulator 3 supplied from the high pressure passage 28.
0 of hydraulic outputs to the main fluid pressure passage 33 and vacuum to a predetermined regulator pressure P _RE. The main fluid pressure passage 33, a fluid pressure sensor 34 that detects the regulator pressure P _RE is disposed. The output signal of the hydraulic pressure sensor 34 is supplied to the ECU. The ECU detects the regulator pressure _PRE based on the output signal of the hydraulic pressure sensor.

The hydraulic pressure control device 32 includes a hydraulic pressure inflow port 32.
a, control pressure suction port 32b, and drain port 32
c. The hydraulic passage 33 is connected to the hydraulic inflow port 3.
2a. The hydraulic pressure control device 32 changes the conduction state between the hydraulic pressure inflow port 32a and the control pressure suction port 32b in accordance with a control signal supplied from the ECU, and thereby the brake flowing out of the control pressure suction port 32b. It is configured to control the flow rate of fluid.
The details of the hydraulic pressure control device 32 will be described later.

The drain port 32c of the hydraulic pressure control device 32
Communicates with the reservoir tank 24 via the drain passage 35. A control pressure passage 36 communicates with the control pressure suction port 32b. A check valve 38 is provided between the main hydraulic pressure passage 33 and the control pressure passage 36 in parallel with the hydraulic pressure control device 32 to allow only a fluid flow from the control pressure passage 36 to the main hydraulic pressure passage 33. Are arranged.

[0015] Control pressure passage 36, the internal fluid pressure, i.e., a fluid pressure sensor 39 for detecting the control pressure P _C to be described later
Are arranged. The output signal of the hydraulic pressure sensor 39 is ECU
Is supplied to ECU detects the control pressure P _C on the basis of the output signal of the hydraulic pressure sensor 39. In addition, the control pressure passage 36 has a pressure reducing passage 42 leading to the auxiliary reservoir tank 40.
Are in communication. A pressure reduction control valve 44 is provided in the pressure reduction passage 42.
Are arranged. The pressure reduction control valve 44 is connected to the pressure reduction passage 4.
2 is a linear control valve that controls the conduction state of the second control valve. The pressure reduction control valve 44 changes its opening in accordance with a drive signal supplied from the ECU. A check valve 46 that allows only the flow of the fluid from the auxiliary reservoir tank 40 toward the control pressure passage 36 is provided in the pressure reduction passage 42 in parallel with the pressure reduction control valve 44.

Further, the control pressure passage 36 has rear wheels RL, R
A rear-wheel-side hydraulic pressure passage 52 that leads to the R-side wheel cylinders 48 and 50 communicates with each other. A rear wheel side holding valve 56 and a proportioning valve 58 are arranged in the rear wheel side hydraulic passage 52 in order from the upstream side. Rear wheel holding valve 56
Is a normally open electromagnetic opening / closing valve, which is closed by receiving an ON signal from the ECU. When the hydraulic pressure supplied from the rear-wheel hydraulic passage 52 is equal to or less than a predetermined value, the proportioning valve 58 supplies the hydraulic pressure to the wheel cylinders 48 and 50 as it is, while the rear-wheel hydraulic passage If the hydraulic pressure supplied from the cylinder 52 exceeds a predetermined value, the hydraulic pressure is reduced at a predetermined ratio and the wheel cylinder 4
8, 50.

The rear-wheel holding valve 5 for the rear-wheel hydraulic passage 52
6 and the proportioning valve 58,
A rear wheel side pressure reducing passage 60 leading to the reservoir tank 24 is in communication. A rear wheel side pressure reducing valve 62 is provided in the rear wheel side pressure reducing passage 60.
Are arranged. The rear wheel side pressure reducing valve 62 is a normally closed electromagnetic opening / closing valve, and is opened by receiving an ON signal from the ECU.

A front-wheel-side hydraulic pressure passage 64 communicates with the rear-wheel-side hydraulic pressure passage 52 on the upstream side of the rear-wheel-side holding valve 56. A switching valve 66 is provided in the front wheel side hydraulic pressure passage 64. The switching valve 66 is a normally closed electromagnetic opening / closing valve, and is opened when an ON signal is given from the ECU. The front-wheel liquid pressure passage 64 on the downstream side of the switching valve 66, the internal fluid pressure of the front wheel fluid pressure passage 64, i.e., hydraulic pressure sensor 67 for detecting the front-wheel brake hydraulic pressure P _F
Are arranged. The output signal of the hydraulic pressure sensor 67 is ECU
Is supplied to ECU detects a front-wheel brake hydraulic pressure P _F based on the output signal of the hydraulic pressure sensor 67.

On the downstream side of the switching valve 66, a front-wheel-side hydraulic pressure passage 64 leads to a left-front-wheel hydraulic pressure passage 70 leading to the wheel cylinder 68 of the left-front wheel FL, and a right-front-wheel hydraulic pressure leading to the wheel cylinder 72 of the right-front wheel FR. It communicates with the passage 74. A left front wheel holding valve 76 and a right front wheel holding valve 78 are disposed in the left front wheel hydraulic passage 70 and the right front wheel hydraulic passage 74, respectively. The left front wheel holding valve 76 and the right front wheel holding valve 78 are both normally open electromagnetic open / close valves.
The valve is closed by receiving an ON signal from the CU.

Left front wheel holding valve 7 of left front wheel hydraulic passage 70
6 and the wheel cylinder 68, and the right front wheel holding valve 78 of the right front wheel hydraulic pressure passage 74 and the wheel cylinder 7
2, a left front wheel decompression passage 80 and a right front wheel decompression passage 82 communicate with each other. The left front wheel depressurizing passage 80 and the right front wheel depressurizing passage 82 both communicate with the reservoir tank 24. A left front wheel pressure reduction valve 84 and a right front wheel pressure reduction valve 86 are disposed in the left front wheel pressure reduction passage 80 and the right front wheel pressure reduction passage 82, respectively. The left front wheel pressure reducing valve 84 and the right front wheel pressure reducing valve 86 are both normally closed electromagnetic open / close valves, and are opened when an ON signal is given from the ECU.

The hydraulic brake device also includes a master cylinder 87. A brake pedal 88 is connected to the master cylinder 87. Master cylinder 87 generates master cylinder pressure P _{M / C} in accordance with the pedaling force applied to brake pedal 88. A master pressure passage 89 communicates with the master cylinder 87. In the master pressure passage 89,
A hydraulic pressure sensor 90 for detecting the master cylinder pressure PM _{/ C} is provided. The output signal of the hydraulic pressure sensor 90 is supplied to the ECU. The ECU detects the master cylinder pressure PM _{/ C} based on the output signal of the hydraulic pressure sensor 90. In the master pressure passage 89, a stroke simulator 92 is provided.

In the master pressure passage 89, a left front wheel master pressure passage 94 leading to the wheel cylinder 68 of the left front wheel FL, and
A right front wheel master pressure passage 96 leading to the wheel cylinder 72 of the right front wheel FR communicates. The switching valve 9 is provided in the left front wheel master pressure passage 94 and the right front wheel master pressure passage 96, respectively.
8 and 100 are provided. Switching valves 98 and 1
Reference numeral 00 denotes a normally open electromagnetic open / close valve, which is closed when an ON signal is given from the ECU.

In this embodiment, when no abnormality occurs in the system, the switching valves 98 and 100 are both closed at the same time as the brake pedal 88 is depressed. For this reason, the brake fluid flowing out of the master cylinder 87 is normally discharged from the wheel cylinders 68, 72.
Does not flow into In this case, the brake pedal 88
When the master cylinder pressure P _{M / C} rises due to depression of the brake pedal, the brake fluid in the master cylinder 87 flows into the stroke simulator 92. When the depression of the brake pedal 88 is released and the master cylinder pressure P _{M / C} decreases, the brake fluid in the stroke simulator 92 flows into the master cylinder 87.
Therefore, according to the stroke simulator 92, it is possible to cause the brake pedal 88 to generate a stroke corresponding to the pedal depression force under the condition that the switching valves 98 and 100 are closed.

When it is detected that an abnormality has occurred in the system, the switching valves 98 and 100 are both opened. In this case, the wheel cylinders 68, 72 on the front wheel side
By communicating with the master cylinder 87, it is assured that the hydraulic pressure of the wheel cylinders 68 and 72 is increased up to the master cylinder pressure PM _{/ C.} Next, the operation of the hydraulic brake device according to the present embodiment will be described. In the hydraulic brake device, during normal braking in which the brake pedal 88 is depressed and none of the wheels has a locking tendency, the rear wheel side holding valve 56, the rear wheel side pressure reducing valve 62, the left front wheel holding valve 76, Right front wheel holding valve 78,
The left front wheel pressure reducing valve 84 and the right front wheel pressure reducing valve 86 are turned off and the switching valves 66, 98, 100
Is turned on. Hereinafter, this state is referred to as a normal brake state.

In the normal braking state, the rear wheel hydraulic passage 52, the front wheel hydraulic passage 64, the left front wheel hydraulic passage 70,
The right front wheel hydraulic pressure passage 74 is in a conductive state. For this reason, the brake fluid flowing out from the control pressure supply port 32b of the hydraulic pressure control device 32 is
0, 68, 72. Wheel cylinder 48,5
0, 68, 72 (hereinafter, wheel cylinder pressure P _{W / C}
) Are wheel cylinders 48, 50, 68, 72
It changes according to the flow rate of the brake fluid flowing into the motor.
Accordingly, by controlling the flow rate of the brake fluid flowing out from the control pressure suction port 32b of the hydraulic pressure control device 32, the wheel cylinder pressure P _{W / C} is increased to a desired value. Further, by controlling the flow rate of the brake fluid flowing out of the wheel cylinders 48, 50, 68, 72 in accordance with the opening degree of the pressure reducing control valve 44, the wheel cylinder pressure P _{W / C} is reduced toward a desired value. Is done.

When it is detected that any one of the wheels has a tendency to lock, ABS control is started for that wheel. For example, when it is detected that the left front wheel FL has a tendency to lock, the ABS control is started for the left front wheel FL. The ABS control for the left front wheel FL is realized by opening and closing the left front wheel holding valve 76 and the left front wheel pressure reducing valve 84 in the normal braking state.

In the normal braking state, when the left front wheel holding valve 76 is closed and the left rear wheel pressure reducing valve 84 is opened, the wheel cylinder 68 is placed in the reservoir tank 2.
Communicate with 4. In this case, the brake fluid flows out of the wheel cylinder 68 to the reservoir tank 24,
The hydraulic pressure of wheel cylinder 68 is immediately reduced. This state is hereinafter referred to as a decompression mode.

Depending on the pressure reduction mode, the wheel cylinder 68
When the left front wheel holding valve 76 is opened and the left front wheel pressure reducing valve 84 is closed in a state where the hydraulic pressure is reduced, the wheel cylinder 68 communicates with the control pressure passage 36.
Thus, fluid pressure in the wheel cylinder 68 is raised toward the control pressure P _C. Hereinafter, this state is referred to as a pressure increase mode.

When both the left front wheel holding valve 76 and the left front wheel pressure reducing valve 84 are closed, the wheel cylinder 68
Is disconnected from the hydraulic brake device. Therefore, the hydraulic pressure of the wheel cylinder 68 is maintained. This state is described below.
This is called a holding mode. The ABS control of the left front wheel FL is executed by switching between the pressure-reducing mode, the pressure-increasing mode, and the holding mode so that the slip ratio of the wheel is kept below a predetermined threshold value. Similarly, in the ABS control of the right front wheel FR, depending on the open / close state of the right front wheel holding valve 78 and the right front wheel pressure reducing valve 86,
This is realized by appropriately switching and forming the pressure reduction mode, the pressure increase mode, and the holding mode. ABS on rear wheel side
The control is performed by the rear wheel side holding valve 56 and the rear wheel side pressure reducing valve 6.
2 is switched, the processing is executed in common for the left and right rear wheels RL and RR.

In this embodiment, the wheel cylinder pressure P
_{W / C} is maintained at atmospheric pressure when no pedaling force is applied to the brake pedal 88,
The pressure must be increased in accordance with the increase in the pedaling force applied to the vehicle. That is, in the present hydraulic brake device, the wheel cylinder pressure P _{W / C} must be controlled such that the lower limit is equal to the atmospheric pressure.

In this case, as in the conventional apparatus described above, the hydraulic pressure
Hydraulic inlet port 32a and control pressure suction port of control device 32
Assuming that 32b is always in communication, the regulator
26 is supplied to the hydraulic pressure inlet port 32a from the brake valve 26.
From the control pressure suction port 32b to the wheel cylinder
48, 50, 68 and 72 always flow. E
Brake flow to IL cylinder 48, 50, 68, 72
The wheel cylinder pressure P_{W / C}Is above atmospheric pressure
Also at high pressure. For this reason, the wheel cylinder pressure P _{W / C}Is large
The pressure can no longer be controlled to the lower limit
I will. Therefore, the wheel cylinder pressure P_{W / C}The atmospheric pressure is below
In order to perform control so as to limit the pressure, the control pressure suction port 3
Lower limit of the flow rate of brake fluid flowing out of 2b to zero
And control over the range.

As described above, the hydraulic brake of this embodiment
In the normal braking state, the hydraulic pressure control device 3
Brake full flowing out of the second control pressure suction port 32b
The flow rate of the fluid (hereinafter referred to as the outflow flow rate Q)
The wheel cylinder pressure P _{W / C}Control the
is there. Therefore, the hydraulic pressure control device 32 is connected to the hydraulic pressure inflow port 3
Regulator P supplied to 2a_REWhen fluctuates
Must be able to control the outflow flow rate Q with high accuracy.
No.

In the hydraulic brake device of this embodiment, the hydraulic pressure control device 32 can control the outflow flow rate Q of the brake fluid flowing out from the control pressure suction port 32b over a range having a lower limit of zero, and can also control the hydraulic pressure inflow. It is characterized in that the outflow flow rate Q can be controlled with high accuracy even when the hydraulic pressure supplied to the port 32a changes. Hereinafter, the configuration of the hydraulic pressure control device 32, which is a characteristic part of the present embodiment, will be described with reference to FIG. FIG. 2 is a sectional view of the hydraulic control device 32. As shown in FIG. 2, the hydraulic control device 32 according to the present embodiment includes a housing 120. A cylinder part 122 is formed inside the housing 120. A spool 124 is provided inside the cylinder section 122.

The spool 124 has a small-diameter portion 124a provided at the center in the axial direction, and large-diameter portions 124b and 124 provided on the left and right sides of the small-diameter portion 124a in FIG.
c. A large diameter portion 124b of the spool 124,
The outer peripheral surface of 124c and the inner peripheral surface of the cylinder portion 122 are substantially slidably engaged with each other. Accordingly, the spool 124 fills the internal space of the cylinder portion 122 with the drain chamber 126 formed on the left side of the large diameter portion 124b in FIG.
And a pressure chamber 1 formed on the right side in FIG. 2 of the large diameter portion 124c.
28 and the annular chamber 13 formed around the small diameter portion 124a.
It is divided into 0. Inside the spool 124, a communication path 132 that connects the annular chamber 130 and the hydraulic chamber 128 is formed.

A spring 134 is provided in the drain chamber 126.
Are arranged. Spring 134 is spool 124
Is urged toward the pressure chamber 128 side. Spool 12
4 is restricted by the engagement step 136 provided on the inner peripheral surface of the cylinder portion 122. Therefore, in a normal state, the spool 124 is held at a position where the end face on the pressure chamber 128 side is engaged with the engagement step 136 (hereinafter, referred to as a pressure chamber side displacement end).

The housing 120 is provided in the drain chamber 126.
The drain port 32c which opens to the outer peripheral surface of this is connected. The brake fluid is applied to the large diameter portion 12 of the spool 124.
When the brake fluid enters the drain chamber 126 via the sliding surface between the cylinder 4b and the cylinder portion 122, the brake fluid is collected in the reservoir tank 24 via the drain port 32c.

The inner circumferential surface of the cylinder portion 122 has an annular groove 1
40 are formed. The annular groove 140 is provided on the spool 12
4 is located at the pressure chamber side displacement end, the annular chamber 13
It is arranged to communicate with zero. The annular groove 140 communicates with a hydraulic pressure inlet port 32 a that opens on the outer peripheral surface of the housing 120. Inside the housing 120,
The right side of the cylinder part 122 in FIG.
44 are provided. The valve chamber 144 is the valve passage 1
It communicates with the pressure chamber 128 via 46. A seat 148 is formed around the opening of the valve passage 146 to the valve chamber 140. In addition, the valve chamber 144 includes
A control pressure suction port 32b opening to the outer peripheral surface of the housing 120 communicates with the housing 120.

Inside the valve chamber 144, a poppet 15 is provided.
2 are arranged so as to face the sheet 148. The poppet 152 is moved by the spring 154 to the seat 14.
It is urged toward 8. Therefore, under normal conditions,
When the poppet 152 is pressed against the seat 148 with a set load corresponding to the urging force of the spring 154, the communication between the valve passage 146 and the control pressure suction port 32b is shut off.

Inside the housing 120, an electromagnetic coil 156 is provided so as to surround the right end of the poppet 152 in FIG. When the electromagnetic coil 156 is energized, the poppet 152 is urged rightward in FIG. 2 by the electromagnetic attraction. When the electromagnetic attraction force acting on the poppet 152 exceeds the combined force of the set load by the spring 154 and the force generated by the thickness difference between the valve passage 148 and the valve chamber 144, the poppet 152 resists the urging force of the spring 154. 2 is displaced rightward in FIG. In this case, when the poppet 152 is separated from the seat 148, the valve passage 146 and the control pressure supply port 32b
Communicates with Thus, sheet 148, poppet 1
The spring 52, the spring 154, and the electromagnetic coil 156 constitute a poppet valve 157 that controls a conduction state between the valve passage 146 and the control pressure suction port 150. The current supplied to the electromagnetic coil 156 is generated by a current driver (not shown) according to a control signal provided from the ECU.

[0040] When the brake fluid in the regulator pressure P _RE is supplied to the hydraulic fluid inlet port 32a, the brake fluid annular groove 140, annular chamber 130 and the communication passage 13,
It is led to the pressure chamber 128 via 2. When the brake fluid is guided to the pressure chamber 128, the spool 124 is displaced toward the drain chamber 126 against the urging force of the spring 134 in accordance with the increase in the hydraulic pressure in the pressure chamber 128. When the displacement amount of the spool 124 reaches a predetermined amount S, the spool 1
The 24 large-diameter portions 124 c close the annular groove 140.

When the annular groove 140 is closed, the hydraulic pressure
The communication between the port 142 and the pressure chamber 128 is cut off. this
Therefore, the supply of brake fluid to the pressure chamber 128 is shut off.
And the displacement of the spool 124 is
The hydraulic pressure P at the time when the predetermined amount S is reached₀Is held. Pressure chamber
128 hydraulic pressure is P₀When it is lowered from
The balance of the acting force is lost, and the spool 124
It is displaced to the chamber 128 side. Therefore, the annular groove 140 and the annular
The space 130 is again in communication with the pressure chamber 128.
Fluid supplied to the hydraulic pressure inlet port 142
Is supplied. Brake fluid is supplied to pressure chamber 128
As a result, when the hydraulic pressure rises, the spool 124
Until the large diameter portion 124c closes the annular groove 140 again.
That is, the hydraulic pressure of the pressure chamber 128 is P₀Until you reach
Displace. Therefore, hereinafter, the hydraulic pressure of the pressure chamber 128 becomes P ₀To
Will be retained.

[0042] Thus, the cylinder portion 122, the spool 124, and the spring 134 constitute a spool valve 158 of the hydraulic pressure constant hydraulic P ₀ two tone pressure chamber 128. Therefore, the brake fluid having a constant hydraulic pressure P ₀ is always supplied to the valve passage 146. Here, when the annular groove 140 is closed, that is, when the amount of displacement of the spool 124 reaches the predetermined value S, the urging force generated by the spring 134 is F _k , and the large-diameter portion 124c of the spool 124
Is S, the relationship of equation (1) is established from the balance of the forces acting on the spool 124.

P ₀ · S = F _k (1) Accordingly, the hydraulic pressure P ₀ can be adjusted by changing the urging force F _K generated by the spring 134. When the electromagnetic coil 156 is energized, the poppet 152 is displaced in a direction away from the seat 148 (hereinafter, referred to as a valve opening direction), so that the poppet valve 157 is displaced.
Opens. When the poppet valve 157 is opened, the valve passage 146 communicates with the control pressure suction port 32b, so that the brake fluid in the hydraulic chamber 128 flows out of the control pressure suction port 32b via the valve passage 146.

[0044] In this case, outflow rate Q, the gap between the seat 148 and the poppet 152, i.e., open area of the poppet valve 157 is increased, also the fluid pressure in the valve passage 146 (hereinafter, the valve supply pressure P _V Is called)
And the hydraulic pressure of the control pressure suction port 32b (hereinafter, the control pressure P _C
(Hereinafter referred to as a valve differential pressure ΔP).
The larger the value, the larger the value.

The open area of the poppet valve 157 increases as the poppet 152 is greatly displaced in the valve opening direction. As described above, the poppet 152 is displaced in the valve opening direction by the electromagnetic force generated by the electromagnetic coil 156. When the poppet valve 157 is opened, a biasing force in the valve opening direction acts on the poppet 152 by the valve differential pressure ΔP, so that the poppet 152 further opens by an amount corresponding to the valve differential pressure ΔP. Displace in the direction. That is, the poppet valve 1
The open circuit area of 57 changes depending on both the current supplied to the electromagnetic coil 156 (hereinafter, referred to as the exciting current I) and the valve differential pressure ΔP. Therefore, the outflow flow rate Q changes depending on both the exciting current I and the valve differential pressure ΔP.

[0046] In this embodiment, if the spool valve 158 is not provided, i.e., if the brake fluid is directly supplied from the regulator 26 to the valve passage 146, the valve supply pressure P _V regulator pressure _Equals PRE. In this case, the regulator pressure _PRE
There When fluctuates, even if the control pressure P _C is held at a constant,
The outflow flow rate Q changes as the valve differential pressure ΔP changes.

FIG. 3 shows that the brake fluid is a regulator.
26 when supplied directly to valve passage 146 from
And regulator pressure P_REConstant control when changes
Pressure P _CThe relationship between the exciting current I and the outflow flow rate Q
You. As shown in FIG. 3, as the exciting current I increases,
Regulator pressure P_REAs the pressure becomes higher, the outflow flow rate Q
Is increasing.

As described above, when the brake fluid is supplied directly from the regulator 26 to the valve passage 146, the outflow flow rate Q is changed according to the fluctuation of the regulator pressure _PRE.
Changes. Therefore, in order to accurately control the outflow rate Q becomes necessary to control the excitation current I based on both the control pressure P _C and the regulator pressure P _RE, the control of outflow rate Q is decreased. As a result, it becomes difficult to control the wheel cylinder pressure P _{W / C} with high accuracy.

On the other hand, the hydraulic pressure control device 3 of this embodiment
In 2, that the spool valve 158 is provided, the fluid pressure in the valve passage 146 is always maintained to P _0.
Figure 4 is the hydraulic control device 32 of the present embodiment, when the control pressure P _C is kept constant, the excitation current I and the outflow rate Q
The relationship is shown below. As shown in FIG. 4, according to the hydraulic control device 32 of the present embodiment, the control case pressure P _C is constant, regardless of the change in hydraulic pressure of the brake fluid supplied to the hydraulic fluid inlet port 32a, the constant A constant outflow flow rate Q is obtained with respect to the exciting current I. Therefore, the hydraulic pressure control device 3 of the present embodiment
According to 2, the control pressure P _C by controlling the excitation current I based only on, it becomes easy to control the outflow rate Q to a desired value, thereby controlling the control pressure P _C in high precision be able to.

Further, in this embodiment, the electromagnetic coil 15
When no current is supplied to 6, the poppet valve 157 is closed. In this case, the communication between the valve passage 146 and the control pressure suction port 32b is interrupted, so that the outflow flow rate Q
Becomes zero. On the other hand, when the exciting current I supplied to the electromagnetic coil 156 is increased until the electromagnetic attractive force generated by the electromagnetic coil 156 becomes a magnitude corresponding to the urging force of the spring 154, the exciting current I is thereafter increased according to the increase of the exciting current I. Thus, the outflow flow rate Q gradually increases. That is, the hydraulic pressure control device 3
According to 2, the outflow flow rate Q can be continuously changed with the flow rate being zero as the lower limit. Therefore, the hydraulic pressure control device 3
According to No. 2, it is possible to control the wheel cylinder pressure P _{W / C so} that the atmospheric pressure becomes the lower limit.

Further, according to the hydraulic pressure control device 32, since the outflow flow rate Q can be changed so that zero is the lower limit, the required amount of brake fluid can be supplied to the wheel cylinders 224 to 230 without excess or shortage. Can be. Therefore, it is not necessary to circulate excessive brake fluid. In this regard, the hydraulic control device 32 has excellent performance also in terms of energy efficiency.

[0052] Further, if the brake fluid in the regulator pressure P _RE is supplied directly to the valve passage 146, the variation of the regulator pressure P _RE, temporarily an excessive fluid pressure of the brake fluid is supplied to the valve passage 146 May cause the poppet 152 to vibrate. When the poppet 152 is vibrated, inconveniences such as generation of abnormal noise due to the vibration and wear of a seating surface between the poppet 152 and the seat 148 are caused.

On the other hand, the hydraulic pressure control device 3 of this embodiment
2, the spool valve 158 controls the valve passage 14
By maintaining the hydraulic pressure at 6 at a constant hydraulic pressure P ₀ , the supply of brake fluid with excessive hydraulic pressure to the valve passage 146 is prevented. Therefore, according to the present embodiment,
The inconvenience caused by the vibration of the poppet 152 can be avoided.

When the electromagnetic coil 156 is not energized, the poppet 152 is pressed against the seat 148 with a predetermined set load by the urging force of the spring 154. When the valve supply pressure P _V is increased, the poppet 1
A biasing force acts on the valve 52 in the valve opening direction according to the differential pressure ΔP. Therefore, in order to maintain the closed state of the poppet valve 157, the set load by the spring 154 must be set larger than the urging force according to the valve differential pressure ΔP. In this case, assuming that the regulator pressure _PRE is directly supplied to the valve passage 146, the regulator pressure P _RE
As _RE is the closed state of the poppet valve 157 even when the fluctuation is ensured, the set load must value larger set with a margin to corresponding to the upper limit value of the regulator pressure P _RE. To increase the set load, use spring 1
Since it is necessary to increase the wire diameter or the number of turns of 54,
The size of the spring 154 is increased.

On the other hand, in order to open the poppet valve 157, the electromagnetic coil 156 must generate an electromagnetic attraction force that can overcome the set load. Therefore, when the set load increases, the electromagnetic attraction force that the electromagnetic coil 156 should generate to open the poppet valve 157 also increases. To increase the electromagnetic attraction generated by the electromagnetic coil 156, it is necessary to increase the number of turns of the electromagnetic coil 156 or increase the current supplied to the electromagnetic coil 156. As a result, the size of the electromagnetic coil 156 or the size of a current driver that supplies a current to the electromagnetic coil 156 is increased.

On the other hand, in this embodiment,
The hydraulic pressure in the valve passage 146 is a constant hydraulic pressure P ₀Maintained in
The set load of the poppet 152 by the spring 154
Weight and the electromagnetic force generated by the electromagnetic coil 156 are applied to the hydraulic pressure P₀
Can be suppressed to the necessary minimum size according to the above.
That is, the setting of the spring 154 and the electromagnetic coil 156 is performed.
In the measurement, the fluctuation of the hydraulic pressure in the valve passage 146 is taken into consideration.
Is unnecessary. For this reason, according to the present embodiment,
Pulling 154, electromagnetic coil 156, and electromagnetic coil 1
Miniaturization of the current driver that supplies current to the 56
And thereby reduce the cost of the entire device.
It has become possible.

In the above embodiment, the hydraulic pressure of the valve 146 is kept constant by the spool valve 158. However, the present invention is not limited to this. Any type of control valve that can output the control valve can be used. Further, in the above embodiment, the outflow flow rate Q is changed according to the open area of the poppet valve 157. However, the present invention is not limited to this, and the open area can be continuously changed from zero. Any possible type of on-off valve can be used.

In the above embodiment, the regulation
Regulator output P _REThe hydraulic pressure control device 3
2 was supplied to the hydraulic pressure inlet port 32a.
Accumulator pressure P accumulated in accumulator 30_ACC
May be directly supplied to the hydraulic pressure inlet port 32a.
No. That is, according to the hydraulic pressure control device 32, the hydraulic pressure inflow port
Control pressure regardless of changes in the hydraulic pressure supplied to the
P_CCan be controlled with high accuracy.
Ta pressure P_REAccumulator pressure P, which fluctuates more than
_ACCIs supplied to the hydraulic pressure inlet port 32a,
Pressure P_{W / C}Does not affect the controllability of the vehicle.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a configuration diagram of the hydraulic brake device of the present embodiment. The hydraulic brake device according to the present embodiment is controlled by an ECU (not shown). In the present embodiment, the hydraulic control device 32 is applied as a hydraulic control device that controls the wheel cylinder pressure of each wheel. As shown in FIG. 5, the hydraulic brake device of the present embodiment
0 is provided. Master cylinder 200 has two
Two hydraulic chambers 200a and 200b are provided. A brake pedal 204 is connected to the master cylinder 200 via a stroke simulator 202. In the hydraulic chambers 200a and 200b of the master cylinder 200, a master cylinder pressure PM _{/ C} is generated in accordance with the depression force applied to the brake pedal 204.

As will be described later, in the hydraulic brake system of this embodiment, when the brake pedal is depressed, the hydraulic pressure chambers 200a and 200b of the master cylinder 200 are normally operated.
No brake fluid flows out of the wheel cylinder to the wheel cylinder. Therefore, in the present embodiment, the stroke amount corresponding to the depression force is generated on the brake pedal 204 by the stroke simulator 202.

The hydraulic chambers 200a of the master cylinder 200,
A reservoir tank 206 communicates with 200b. The reservoir tank 206 communicates with a reservoir passage 210 leading to a suction port of a pump 208. The pump 208 is driven by a pump motor 212. A relief valve 214 is provided between the suction port and the discharge port of the pump 208. The relief valve 214 is configured to open when the hydraulic pressure on the discharge port side of the pump 208 becomes higher than the hydraulic pressure on the suction port side by a predetermined value or more. Therefore, the relief valve 214 prevents the discharge pressure of the pump 208 from becoming excessive.

An accumulator 216 and pressure switches 218 and 219 communicate with the discharge port of the pump 208. The pressure switch 218 is a pressure switch that issues an ON signal when the discharge pressure of the pump 208 exceeds a predetermined upper limit pressure. The pressure switch 219 is a pressure switch that issues an ON signal when the discharge pressure of the pump 208 falls below a predetermined lower limit pressure. The ON signals generated by the pressure switches 218 and 219 are supplied to the ECU. When the ECU receives the ON signal from the pressure switch 219, the ECU
2 is transmitted, and when an ON signal from the pressure switch 218 is received, a signal for stopping the pump motor 212 is transmitted. Accordingly, accumulator pressure P _ACC within a predetermined range is accumulated in accumulator 216.

The discharge port of the pump 208 has a high pressure passage 22
0 communicates. The high-pressure passage 220 communicates with the hydraulic pressure inlet port 32a of the hydraulic pressure control device 32 corresponding to the left front wheel FL and the right front wheel FR, respectively, and via the rear wheel pressure increasing cut valve 222, the right rear wheel RR and the right rear wheel RR. Hydraulic pressure inflow ports 3 of hydraulic pressure control device 32 respectively corresponding to left rear wheel RL
2a. The rear wheel pressure increasing cut valve 222 is a normally closed electromagnetic opening / closing valve, and is opened when an ON signal is given from the ECU.

The control pressure suction port 32 of the hydraulic pressure control device 32
b, wheel cylinders 224, 2 of each wheel
Wheel cylinder passage 23 leading to 26, 228, 230
2,234,236,238 are in communication. Further, a drain passage 240 leading to the reservoir tank 206 communicates with the drain port 32 c of the hydraulic pressure control device 32.

The wheel cylinders 224 to 230 are provided with hydraulic pressure sensors 248, 250, 25 for detecting the respective hydraulic pressures.
2,254 are in communication. Hydraulic pressure sensor 248-254
Are supplied to the ECU. The ECU detects the hydraulic pressure of wheel cylinders 224 to 230 based on the output signals of hydraulic pressure sensors 248 to 254. Each of the wheel cylinders 224 to 230 also has a pressure reducing passage 256, 258, 260, 26 to the reservoir tank 206.
Two are communicating. In the pressure reduction passages 256 to 262, a front right wheel pressure reduction control valve 264, a front left wheel pressure reduction control valve 266, a rear right wheel pressure reduction control valve 268, and a rear left wheel pressure reduction control valve 270 are provided, respectively. Right front wheel pressure reduction control valve 264, left front wheel pressure reduction control valve 266, right rear wheel pressure reduction control valve 268, and left rear wheel pressure reduction control valve 27
0 changes the opening degree according to the drive signal given from the ECU.

The discharge port of the pump 208 has a hydraulic passage 272 extending to the hydraulic chamber 200 a of the master cylinder 200.
Are in communication. The hydraulic pressure passage 272 is provided with a mechanical pressure increasing valve 274. A hydraulic passage 276 leading to the reservoir tank 206 and a hydraulic passage 278 leading to the wheel cylinder 226 communicate with the mechanical pressure increasing valve 274. Using the accumulator 216 as a hydraulic pressure source, the mechanical pressure increasing valve 274 increases the master cylinder pressure PM _{/ C} and outputs the master cylinder pressure PM _{/ C} to the hydraulic pressure passage 278.

The mechanical pressure increasing valve 274 of the hydraulic passage 272
A hydraulic pressure sensor 280 for detecting a master cylinder pressure P _{M / C} is provided in a portion between the master cylinder 200 and the master cylinder 200. The output signal of the hydraulic pressure sensor 280 is supplied to the ECU. The ECU detects the master cylinder pressure P _{M / C} based on the output signal of the hydraulic pressure sensor 280. Hydraulic passage 2
At 78, master cylinder cut valves 282 and 284 are provided in order from the mechanical pressure increasing valve 274 side. The master cylinder cut valves 282 and 284 are normally open electromagnetic open / close valves, and are closed when an ON signal is given from the ECU. A portion of the hydraulic passage 278 between the master cylinder cut valves 282 and 284 communicates with the wheel cylinder 224 via a hydraulic passage 286.

A hydraulic passage 288 communicates with the hydraulic chamber 200b of the master cylinder 200. A master cylinder cut valve 290 is provided in the hydraulic passage 288. The master cylinder cut valve 290 is a normally open electromagnetic open / close valve, and is closed when an ON signal is given from the ECU. Hydraulic passages 292 and 294 leading to wheel cylinders 228 and 230 communicate with the hydraulic passage 288 on the downstream side of the master cylinder cut valve 290, respectively. A master cylinder cut valve 296 is provided in the hydraulic passage 294. The master cylinder cut valve 296 is a normally open electromagnetic opening / closing valve, and is closed when an ON signal is given from the ECU.

Next, the operation of the hydraulic brake system according to the present embodiment will be described. When the brake pedal 204 is depressed,
An ON signal is applied to all of the rear wheel pressure increasing cut valve 222 and the master cylinder cut valves 282, 284, 290, and 296. Therefore, when the brake pedal 204 is depressed, the wheel cylinders 224, 226, 22
The communication between the hydraulic cylinders 8 and 230 and the master cylinder 200 is cut off, and the high-pressure passage 220 communicates with the hydraulic pressure inlet ports 32 a of all the hydraulic pressure control devices 32. Therefore, when the brake pedal 204 is depressed, the accumulator pressure P
The brake fluid of the _ACC is supplied to the hydraulic pressure inlet port 32a of each hydraulic pressure control device 32, and the brake fluid flowing out of the control pressure suction port 32b is supplied to the wheel cylinders 224 to 224.
Flow into 230. Therefore, by controlling the outflow flow rate Q, the wheel cylinder pressure P _{W / C} of each wheel is increased toward a desired value. Also, the right front wheel pressure reduction control valve 264, the left front wheel pressure reduction control valve 266, the right rear wheel pressure reduction control valve 26
8, and the amount of brake fluid flowing out of the wheel cylinders 224 to 230 is controlled in accordance with the opening of the left rear wheel pressure reduction control valve 270, so that the wheel cylinder pressure P _{W / C} of each wheel reaches a desired value. The pressure is reduced toward.

In the hydraulic brake system of this embodiment, the hydraulic pressure of the wheel cylinders 224 to 230 is
8 is controlled using the hydraulic pressure source. Therefore, by any chance pump 2
If a failure occurs in a system from 08 to each of the wheel cylinders 224 to 230 (hereinafter, referred to as a main hydraulic system), the hydraulic pressure of each of the wheel cylinders cannot be increased.

Therefore, in this embodiment, when it is detected that a failure has occurred in the main hydraulic system, the ECU sets the rear wheel pressure increasing cut valve 222 and the master cylinder cut valves 282, 284, 290 , 296 are shut off. In this case, the wheel cylinders 224 and 226 on the front wheel side communicate with the mechanical pressure increasing valve 274, and the wheel cylinders 228 and 230 on the rear wheel side communicate with the hydraulic chamber 200 b of the master cylinder 200. Therefore,
The master cylinder pressure PM _{/ C} is applied to the wheel cylinders 224 and 226 by increasing the master cylinder pressure PM _{/ C} by the mechanical pressure increasing valve 274, and the master cylinder pressure PM _{/ C} is applied directly to the wheel cylinders 228 and 230.

If the pump 208 itself fails, the pressure increasing function of the mechanical pressure increasing valve 274 is not exhibited. However, also in this case, the mechanical pressure increasing valve 2
Numeral 74 supplies a hydraulic pressure equal to the master cylinder pressure P _{M / C} to the wheel cylinders 224 and 226. Therefore, according to the present embodiment, even when a failure occurs in the main hydraulic system, the hydraulic pressure of each wheel cylinder can be reliably increased to at least a value equal to the master cylinder pressure.

In this embodiment, the accumulator pressure P _ACC having a relatively large fluctuation is applied to the hydraulic pressure inlet port 32 a of the hydraulic pressure controller 32. However, as described above, according to the hydraulic pressure control device 32, the hydraulic pressure inflow port 32a
The outflow flow rate Q can be controlled with high accuracy even when the hydraulic pressure applied to the fluid fluctuates. Therefore, according to the present embodiment, the wheel cylinder pressure P _{W / C} can be controlled with high accuracy despite the relatively large fluctuation of the accumulator pressure P _ACC .

As described above, according to the hydraulic pressure control device 32, the flow rate Q of the brake fluid flowing out from the control pressure suction port 32b can be changed over a range where the lower limit is zero. Therefore, according to the hydraulic brake device of the present embodiment, the wheel cylinder pressure P _{W / C} of each wheel can be controlled so that the atmospheric pressure becomes the lower limit. In the first and second embodiments, the case where the hydraulic pressure control device 32 is applied as a control valve for controlling the wheel cylinder pressure P _{W / C} in the hydraulic brake device has been described.
The present invention is not limited to this, and can be applied to any hydraulic system that requires the flow rate to be controlled so that the lower limit is zero.

In the above embodiment, the hydraulic pressure inlet port 32a corresponds to the suction port described in claim 1, and the control pressure suction port 32b corresponds to the discharge port described in claim 1.
The spool valve 158 corresponds to the supply pressure stabilizing means described in claim 1, and the poppet valve 157 corresponds to the flow path area changing means described in claim 1.

[0076]

As described above, according to the present invention, the flow rate of fluid can be controlled over a range where the lower limit is zero. Therefore, the hydraulic control device according to the present invention can be applied to a wider range of hydraulic systems such as a hydraulic brake device.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a hydraulic brake device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a hydraulic control device which is a feature of the present embodiment.

FIG. 3 is a diagram showing a relationship between an exciting current I and an outflow flow rate Q when the regulator pressure _PRE changes when the regulator pressure _PRE is directly supplied to a valve passage.

FIG. 4 is a diagram showing a relationship between an exciting current and an outflow flow rate Q of the hydraulic pressure control device of the present embodiment.

FIG. 5 is a system configuration diagram of a hydraulic brake device according to a second embodiment of the present invention.

[Explanation of symbols]

 32 Hydraulic pressure control device 32a Hydraulic pressure inflow port 32b Control pressure suction port 122 Cylinder part 124 Spool 134, 154 Spring 148 Seat 152 Poppet 157 Poppet valve 158 Spool valve

Claims (1)

[Claims] 1. A fluid pressure control device for discharging fluid supplied to a suction port from a discharge port, comprising: a supply pressure stabilizing means for regulating the fluid supplied to the suction port to a constant fluid pressure; A fluid pressure control device comprising: a passage area changing unit that changes a passage area of a passage from the supply pressure stabilizing unit to the discharge port.