JPH10100876A - Brake equipment - Google Patents

Abstract

(57) [Summary] To provide a brake assist control by operating a pump at the time of a brake operation, and to improve the operation responsiveness of the pump. A master cylinder is connected to a suction side of a pump by a passage, and high-pressure hydraulic fluid is introduced from the master cylinder to a suction side of the pump.
To reduce the amount of pressurization, thereby improving the operation responsiveness of the pump 62.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake device for a vehicle, and more particularly to a brake device having a pump as a hydraulic pressure source.

[0002]

2. Description of the Related Art A brake device of the above-mentioned type generally comprises (a)
A brake cylinder that operates a wheel brake based on hydraulic pressure; and (b) a hydraulic pressure generator that generates hydraulic pressure in response to a brake operation by a driver, such as a master cylinder, that is a hydraulic pressure source for the brake cylinder. And (c) a hydraulic pump that selects one of the hydraulic pressure generating device and the pump as a hydraulic pressure source of the brake cylinder. And a pressure source selection device.

[0003]

The brake assist control is already known as one of the brake controls. Even during an emergency brake operation, the braking performance of the vehicle may not be able to be fully exerted due to the lack of the braking operation force by the driver. The supplementary control is the brake assist control. In order to execute the brake assist control, a mechanism for generating a hydraulic pressure higher than a normal value in the brake cylinder is required. The present applicant has previously developed the following brake device in a brake device having a pump as a hydraulic pressure source in order to execute brake assist control by effectively using the pump. that is,
In addition to including the brake cylinder, a hydraulic pressure generating device, and a pump, the hydraulic pressure source selection includes a pump selecting device that operates a pump at least at one time during a brake operation and selects the pump as a hydraulic pressure source of the brake cylinder. It is a braking device. However, in the developed brake device, a reservoir is connected to the suction side of the pump. The reservoir stores the hydraulic fluid discharged from the brake cylinder substantially at atmospheric pressure. Therefore, in this brake device, the pump must pressurize the hydraulic fluid at substantially atmospheric pressure, and after the brake assist control is started, the discharge pressure of the pump, that is, the brake cylinder fluid pressure reaches the target pressure. There was a problem that it took a long time before being raised. In view of such circumstances, an object of the present invention is to provide a brake device capable of rapidly increasing the brake cylinder fluid pressure by a pump during a brake operation.

[0004]

Means for Solving the Problems, Functions and Effects of the Invention
According to the first aspect of the present invention, the brake cylinder, the hydraulic pressure generating device, the pump and the pump selecting device, and the suction pressure, which is the hydraulic pressure on the suction side of the pump, are made higher than the atmospheric pressure. And a suction pressure control device that changes the height in accordance with the level of the hydraulic pressure generated in the hydraulic pressure generating device.

According to the first aspect of the present invention, the suction pressure of the pump is made higher than the atmospheric pressure and is changed in accordance with the hydraulic pressure generated in the hydraulic pressure generating device. In comparison with the case where the pressures are equal to each other, the difference between the target pressurized amount of the pump, that is, the target value of the discharge pressure, which is the hydraulic pressure on the discharge side of the pump, and the actual value of the suction pressure is reduced, and the discharge pressure of the pump quickly reaches the target value. As a result, the effect of improving the operation responsiveness of the pump is obtained.

In a preferred embodiment of the present invention, a brake control for generating a hydraulic pressure higher than the master cylinder hydraulic pressure in the brake cylinder during the brake operation is performed. Here, the "brake control for generating a hydraulic pressure higher than the master cylinder hydraulic pressure in the brake cylinder at the time of the brake operation" is, for example, the above-described brake assist control or provided between the brake operating member and the hydraulic pressure generating device. Despite the booster, which boosts the operating force of the brake operating member and transmits it to the hydraulic pressure generator, has an assisting limit,
A brake effect that controls the relationship between the brake operating force and the brake cylinder fluid pressure based on the brake operating force-related value related to the brake operating force so that the brake cylinder fluid pressure increases at almost the same gradient according to the brake operating force Characteristic control can be performed. Further, in the first aspect of the present invention, the suction pressure control device may be configured to change the suction pressure of the pump in accordance with and equal to the hydraulic pressure of the hydraulic pressure generating device. A configuration in which the pressure is changed in accordance with the hydraulic pressure and in a lower pressure state, or a configuration in which the pressure is changed in accordance with the hydraulic pressure of the hydraulic pressure generator and in a higher pressure state than that.

According to a second aspect of the present invention, in the brake device according to the first aspect, the suction pressure control device connects the hydraulic pressure generating device and the suction side of the pump to each other to supply hydraulic fluid to the hydraulic pressure generating device. A brake device is provided that includes a hydraulic fluid introduction passage that is introduced from a pressure generating device to a suction side of a pump.

[0008] In the first aspect of the present invention, for example, the suction pressure control device may control the hydraulic pressure other than the hydraulic pressure generated in the hydraulic pressure generating device, for example, the discharge pressure of a pump for a power steering device provided in a vehicle. By using the above, the height of the suction pressure of the pump for the brake device can be changed in accordance with the height of the hydraulic pressure generated in the hydraulic pressure generating device. On the other hand, in the second aspect of the present invention, by utilizing the hydraulic pressure generated in the hydraulic pressure generating device, the height of the suction pressure of the pump for the brake device is increased by the hydraulic pressure generated in the hydraulic pressure generating device. Can be changed according to the height of the object. Further, in the second aspect of the invention, the suction pressure of the pump is controlled by a relatively simple technique of introducing the hydraulic fluid from the hydraulic pressure generating device to the suction side of the pump through the passage. Therefore, according to the second aspect of the present invention, there is obtained an effect that the suction pressure control device is provided relatively easily and inexpensively.

In practicing the second aspect of the present invention, it is not essential to connect the reservoir containing the hydraulic fluid discharged from the brake cylinder to the suction side of the pump. The invention according to claim 2 can be implemented in a form in which the suction side of the pump is connected only to the hydraulic pressure generating device by the hydraulic fluid introducing passage. That is, in a preferred embodiment of the second aspect of the present invention, as shown in FIG. 12, the hydraulic pressure generator 300 and the brake cylinder 302 are connected to each other by a main passage 304, and a pump 306 is connected to a discharge side thereof. While connected to the main passage 304 by the pump discharge passage 308, the suction side thereof is connected to the portion of the main passage 302 between the connection point with the pump discharge passage 308 and the hydraulic pressure generating device 300 by the pump suction passage 310. The hydraulic pressure generating device 300, the brake cylinder 302, and the pump 306 are provided in a portion of the main passage 304 between a connection point with the pump suction passage 310 and a connection point with the pump discharge passage 308. A flow control device 312 is provided for controlling the flow state of the hydraulic fluid between the flow control device and the flow control device.

According to a third aspect of the present invention, there is provided the brake device according to the first aspect, further comprising: a reservoir for containing the hydraulic fluid discharged from the brake cylinder; and a reservoir and a suction side of the pump. A pump suction passage connected to the pump, and wherein the suction pressure control device (a) connects the hydraulic pressure generating device and the pump suction passage to each other, and supplies hydraulic fluid from the hydraulic pressure generating device to the suction side of the pump. And (b) the hydraulic pressure generating device is stepped up despite the fact that the hydraulic pressure generating device is connected to the reservoir via the hydraulic fluid introducing passage and the pump suction passage. And a pressurization enabling device that enables the following.

Therefore, according to the third aspect of the present invention, it is possible to increase the pressure of the hydraulic pressure generating device even though the reservoir and the hydraulic pressure generating device are connected to each other on the suction side of the pump. Can be

In a preferred embodiment of the third aspect of the present invention, the "pressurization enabling device" is provided between the connection point of the pump suction passage with the hydraulic fluid introduction passage and the reservoir, and the pump is connected from the reservoir to the pump. It is intended to include a check valve that allows the flow of the working fluid to flow and blocks the flow in the opposite direction.

According to a fourth aspect of the present invention, in the brake device according to the second or third aspect, the suction pressure control device further causes the pump to pump hydraulic fluid when a predetermined condition is satisfied. A brake device is provided that includes a suction control device that prevents suction from the hydraulic pressure generating device.

The invention according to claim 2 or 3 can be implemented in a form in which the pump sucks the hydraulic fluid from the hydraulic pressure generating device as long as the pump operates. However, in this case, the amount of hydraulic fluid consumed by the hydraulic pressure generating device by the pump during brake operation increases, and the hydraulic pressure generating device is
In the case of a type in which the hydraulic pressure at a height corresponding to the operation force of the brake operation member is mechanically generated, the operation position of the brake operation member changes due to the operation of the pump, and the brake operation feeling deteriorates. There is a risk. On the other hand, in the invention according to claim 4, after the predetermined condition is satisfied, the pump is prevented from sucking the hydraulic fluid from the hydraulic pressure generating device despite the pump being operated. . Therefore, according to the invention of claim 4, despite the use of the hydraulic fluid of the hydraulic pressure generator,
The effect is obtained that the operation responsiveness of the pump can be improved without deteriorating the brake operation feeling.

Here, the "predetermined condition" includes, for example, a condition that the volume of the hydraulic fluid sucked from the hydraulic pressure generating device by the pump reaches a set value, or a condition that the pump generates the hydraulic fluid by the hydraulic pressure generating device. In some cases, the elapsed time from the start of inhalation from the device reaches a set time. In a preferred embodiment of the present invention, a first reservoir for containing the hydraulic fluid discharged from the brake cylinder and a pump suction passage connecting the first reservoir and a suction side of the pump to each other. The hydraulic fluid introduction passage is a second hydraulic fluid introduction passage connecting the pump suction passage and the hydraulic pressure generating device to each other, and the suction control device is provided in the middle of the first hydraulic fluid introduction passage. Is provided. According to this aspect, after the predetermined condition is satisfied, the pump draws the hydraulic fluid from the first reservoir instead of the hydraulic pressure generating device, so that the first reservoir overflows with the hydraulic fluid. Does not need to be continued for a long time, and the effect that the pressure of the brake cylinder is normally reduced by the first reservoir can be obtained.

According to a fifth aspect of the present invention, in the brake device according to the fourth aspect, the suction control device is provided in the middle of the hydraulic fluid introduction passage, and the first suction control device is provided on the side of the hydraulic pressure generation device.
The pump operates mechanically based on the difference between the hydraulic pressure and the second hydraulic pressure on the pump side, and the volume of the hydraulic fluid sucked from the hydraulic pressure generating device by the pump does not reach a set value. A brake device is provided that includes a mechanical control mechanism that allows a hydraulic fluid to be drawn in from the hydraulic pressure generator and blocks it after a set value is reached.

The invention according to claim 4 is implemented, for example, in a form in which the "suction control device" is electromagnetically switched between a state in which the pump is prevented from sucking the hydraulic fluid from the hydraulic pressure generating device and a state in which the pump is allowed to suck. It is possible. However, in this case, the size of the suction control device may be increased, and the power consumption by the suction control device may increase. On the other hand, according to the fifth aspect of the present invention, since the “suction prevention device” is of a mechanical type, the size of the suction control device can be easily reduced, and
The effect is obtained that the power consumption does not need to be increased.

In a preferred embodiment of the present invention, the "mechanical control mechanism" comprises: (a) a housing having a cylinder bore formed therein; and (b) a substantially airtight and slidable cylinder bore. A fitted piston, (c) a first fluid chamber in front of the piston, the space in the housing being partitioned by the piston, the first fluid chamber being connected to the hydraulic pressure generating device side; A rear second liquid chamber connected to the pump side, (d) urging means for urging the piston in a direction in which the volume of the second liquid chamber increases, (e) When the piston moves in the direction to decrease the volume of the second liquid chamber and the volume reaches a set value, the piston engages with the piston, and the piston moves in the direction to further reduce the volume of the second liquid chamber. By blocking, the lower limit of the volume of the second liquid chamber is reduced. The are intended to include a piston moving the control mechanism for restricting. Here, the “piston movement control mechanism” is, for example, a stopper that moves integrally with the piston, and the piston does not engage with the housing until the volume of the second liquid chamber reaches the reduction limit, and is reached. Sometimes it may include one that engages the housing, thereby preventing the piston from moving in a direction that further reduces the volume of the second chamber. Further, the "piston movement control mechanism" has an elongated hole formed in an axially intermediate portion of the piston in an axially extending state, and is fixed to the housing, and can be moved in the elongated hole in the axial direction within a certain range. A pin fitted into the second liquid chamber, and when the volume of the second liquid chamber reaches a reduction limit, the pin abuts on an end wall near the first liquid chamber among both end walls of the elongated hole. You can also.

According to a sixth aspect of the present invention, there is provided the brake device according to the fourth or fifth aspect, further comprising: (a) a second reservoir for containing the hydraulic fluid and supplying the hydraulic fluid to the hydraulic pressure generator. (B) replenishing the working fluid from the second reservoir to the suction side of the pump after the suction control device prevents the pump from sucking the working fluid from the hydraulic pressure generating device. And a brake device including the device.

Therefore, according to the present invention, after the pump is prevented from sucking the hydraulic fluid from the hydraulic pressure generating device by the suction control device, the hydraulic fluid flows from the second reservoir to the suction side of the pump. And the effect of increasing the pressure of the brake cylinder by the pump is obtained.

In a preferred embodiment of the present invention, the hydraulic fluid replenishing device includes: (a) connecting the second reservoir and a suction side of the pump to each other, and
(B) a second hydraulic fluid introduction passage introduced from the reservoir to the suction side of the pump; (b) a second hydraulic fluid introduction passage provided in the middle of the second hydraulic fluid introduction passage, wherein the flow of the hydraulic fluid from the second reservoir toward the suction side of the pump is A non-return valve that permits and reverses the flow. According to this aspect, a portion of the first hydraulic fluid introduction passage that connects the hydraulic pressure generation device and the suction side of the pump with respect to the pump with respect to the mechanical control mechanism is connected via the second hydraulic fluid introduction passage. There is an effect that the voltage can be boosted despite being connected to the second reservoir. In another mode, a first reservoir for containing the hydraulic fluid discharged from the brake cylinder and a pump suction passage connecting the first reservoir and a suction side of a pump are provided. A liquid replenishing device is provided in the middle of the (a) the second working fluid introduction passage, (b) the check valve, and (c) the second working fluid introduction passage. It includes an inflow control valve that switches between a state in which the flow of the hydraulic fluid into the suction side is allowed and a state in which the flow is blocked. According to this aspect, despite the fact that the suction side of the pump is connected to the second reservoir,
When the pump needs to preferentially suck the working fluid from the first reservoir, the pump is prevented from being sucked from the second reservoir.

[0022]

According to the present invention, the following brake device is also provided. (1) A hydraulic pressure generating device that generates a hydraulic pressure at a height corresponding to the operating force of the brake operating member by the driver of the vehicle, and is connected to the hydraulic pressure generating device by a main passage to brake the wheels of the vehicle. A brake cylinder to be activated, a pump connected to the main passage by an auxiliary passage, and a brake cylinder which is required to generate a hydraulic pressure higher than the hydraulic pressure of the hydraulic pressure generating device during a brake operation. In case,
A pump operating device for operating the pump, and a second hydraulic pressure on the brake cylinder side in the main passage is provided at a portion of the main passage between a connection point with the auxiliary passage and the hydraulic pressure generating device. A pressure control device for controlling relative to a first hydraulic pressure on a hydraulic pressure generating device side, wherein the second hydraulic pressure is higher than the first hydraulic pressure when the hydraulic fluid is being discharged from the pump. If the difference is equal to or less than a set value, the flow of the hydraulic fluid from the pump to the hydraulic pressure generator is prevented,
If the second hydraulic pressure is higher than the first hydraulic pressure and the difference is going to be larger than the set value, the flow of the hydraulic fluid from the pump to the hydraulic pressure generating device is allowed to reduce the second hydraulic pressure to the first hydraulic pressure. A brake device comprising: a control device that controls the suction pressure, which is higher than a hydraulic pressure, so that the difference is equal to the set value; (2) a brake cylinder that operates a wheel brake based on hydraulic pressure, a reservoir that stores hydraulic fluid discharged from the brake cylinder, and a hydraulic pressure source of the brake cylinder, which is used for a driver's brake operation. A hydraulic pressure generating device for generating hydraulic pressure in response to the hydraulic pressure, and a pump having a suction side connected to the reservoir through a pump suction passage, for sucking hydraulic fluid from the reservoir and discharging the hydraulic fluid toward the brake cylinder. A pump selection device that operates the pump at least at one time during a brake operation and selects the pump as a hydraulic pressure source of the brake cylinder; and a pump selection device provided in the middle of the pump suction passage, from the reservoir. A check valve for permitting the flow of the hydraulic fluid toward the suction side of the pump and preventing the flow in the opposite direction; A suction pressure increasing device for increasing a suction pressure, which is a fluid pressure in a portion of the suction passage between the pump and the check valve, higher than a fluid pressure of the working fluid stored in the reservoir. . (3) a brake cylinder that operates a wheel brake based on hydraulic pressure, a hydraulic pressure generator that is a hydraulic pressure source for the brake cylinder, and that generates hydraulic pressure in response to a brake operation by a driver; And a pump selecting device for operating the pump at least one time during a brake operation and selecting the pump as a hydraulic pressure source of the brake cylinder A hydraulic fluid introduction passage connecting the hydraulic pressure generation device and the suction side of the pump to each other, and introducing hydraulic fluid from the hydraulic pressure generation device to the suction side of the pump; and a hydraulic fluid introduction passage provided in the middle of the hydraulic fluid introduction passage. (A) a housing having a cylinder bore formed therein, (b) a piston substantially airtightly and slidably fitted to the cylinder bore, (c) A first fluid chamber in front of the piston, which is connected to the side of the hydraulic pressure generator, and a second fluid chamber behind the piston, in which a space in the housing is partitioned by the piston; (D) biasing means for biasing the piston in a direction in which the volume of the second liquid chamber increases, and (e) the piston reducing the volume of the second liquid chamber. By moving in the decreasing direction and engaging the piston when the volume reaches the set value, the piston prevents the movement in the direction of further decreasing the volume of the second liquid chamber, so that the second liquid chamber is prevented from moving. And a suction control device including a piston movement control mechanism for restricting a reduction limit of the volume.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some specific embodiments of the present invention will be described below in detail with reference to the drawings. First, a brake device according to an embodiment of the present invention will be schematically described. This brake device has a pump as a hydraulic pressure source for the brake cylinder in addition to the master cylinder, and has an electromagnetic hydraulic pressure control device for electrically controlling the brake cylinder hydraulic pressure. The device executes the antilock control and the brake assist control, respectively. Here, "anti-lock control"
If the slip of the wheel becomes excessive during the brake operation, the brake cylinder fluid pressure of the wheel is reduced by the reservoir, and if the slip of the wheel recovers, the brake cylinder fluid pressure is increased by the pump to reduce the wheel slip. This is a control for bringing the state into an appropriate state. The “brake assist control” is a control that activates a pump during an emergency brake operation to compensate for a driver's lack of brake operation force and to prevent a necessary braking deceleration from being obtained. Note that the excess amount of the brake cylinder hydraulic pressure due to the brake assist control is eliminated by the antilock control, and thus the braking performance of the vehicle is improved by the joint use of the brake assist control and the antilock control. That is, in the present embodiment, the pump is shared between the antilock control and the brake assist control.

Next, the brake device will be specifically described. This brake device includes a master cylinder 10 as a hydraulic pressure generator, as shown in FIG. The master cylinder 10 is of a tandem type having two independent pressurizing chambers in series, and applies two hydraulic pressures of a height corresponding to the operating force of a brake pedal 12 as a brake operating member. Each is generated mechanically in the chamber. The brake pedal 12 is linked to the master cylinder 10 via a booster 14. The operating force of the brake pedal 12 is boosted by the booster 14 and input to the master cylinder 10. This brake device is a two-way diagonal system. A brake cylinder 20 for operating a brake of a left front wheel FL and a brake cylinder for operating a brake of a right rear wheel RR are provided in one pressurizing chamber of a master cylinder 10. The other pressurizing chamber is connected to a brake cylinder 20 for operating the brake of the right front wheel FR and a brake cylinder 22 for operating the brake of the left rear wheel RL. The figure shows only one of the two brake systems, to which the brake cylinder 20 of the left front wheel FL and the brake cylinder 22 of the right rear wheel RR belong. Since the two brake systems have a common mechanical configuration and electrical configuration, only the illustrated brake system will be representatively described below, and description of the other brake systems will be omitted.

In this brake device, the master cylinder 10 is divided into two brake cylinders 2 by the main passage 30.
0 and 22 respectively. The main passage 30 is branched in a forked shape after extending from the master cylinder 10, and one main passage 34 and two branch passages 36 are connected to each other. The brake cylinders 20, 22 are connected to the ends of the branch passages 36, respectively. In the middle of each of the branch passages 36, a pressure control valve 40, which is a normally-open electromagnetic on-off valve, is provided. Realize the state. Each pressure control valve 4
0, a bypass passage 42 is connected to each bypass passage 4.
A check valve 44 for returning the hydraulic fluid is provided in the middle of 2. Each of the reservoir passages 46 extends from a portion of each of the branch passages 36 between each of the pressure control valves 40 and each of the brake cylinders 20 and 22 to reach a first reservoir 48. A pressure control valve 50, which is a normally closed solenoid on-off valve, is provided in the middle of each reservoir passage 46, and each of the brake cylinders 20,
A reduced pressure state that allows the flow of the working fluid from 22 to the first reservoir 48 is realized. That is, in the present embodiment, the pressure control valves 40 and 50 constitute an electromagnetic hydraulic pressure control device.

The first reservoir 48 is formed by fitting a reservoir piston 54 to the housing 52 so as to be substantially airtight and slidable, and urges hydraulic fluid in a reservoir chamber 56 formed by the fitting. It is housed under pressure by a spring 58 as a means. However, since the elastic force of the spring 58 is not so large, the first
Reservoir 48 contains the working fluid substantially at atmospheric pressure. The first reservoir 48 is connected to the suction side of a pump 62 by a pump suction passage 60, and the discharge side of the pump 62 is connected to a portion of the main passage 30 between its branch point and the master cylinder 10 by a pump discharge passage 64. It is connected. A suction valve 66 as a check valve is provided in the middle of the pump suction passage 60, and a discharge valve 67 as a check valve is provided in the middle of the pump discharge passage 64.

The flow state of the hydraulic fluid between the master cylinder 10, the brake cylinders 20, 22 and the pump 62 is controlled in a portion of the main passage 30 between the connection point with the pump discharge passage 64 and the master cylinder 10. A flow control valve 68 is provided. The flow control valve 68 allows a bidirectional flow of hydraulic fluid between the master cylinder 10 and the brake cylinders 20, 22 and the pump 62 in the first state shown in FIG. The second hydraulic pressure on the brake cylinder side is controlled relative to the first hydraulic pressure on the master cylinder side. In the second state, when the second hydraulic pressure is higher than the first hydraulic pressure but the difference is equal to or less than the set value, the flow control valve 68 controls the brake cylinder 2
If the second hydraulic pressure is higher than the first hydraulic pressure and the difference is to be larger than the set value, the flow of the hydraulic fluid from 0, 22 and the pump 62 to the master cylinder 10 is blocked.
By allowing the flow of the hydraulic fluid from the brake cylinders 20 and 22 and the pump 62 to the master cylinder 10, the second hydraulic pressure is controlled to be higher than the first hydraulic pressure and the difference between the first hydraulic pressure and the second hydraulic pressure becomes the set value. The flow control valve 68 is switched to the second state at the time of brake control, that is, at least when the brake assist control of the antilock control and the brake assist control is executed, and is switched to the first state at other times. Can be Specifically, as shown in FIG. 2, the flow control valve 68 is a valve 70 that controls the flow state of the hydraulic fluid between the housing (not shown) and the master cylinder side and the brake cylinder side in the main passage 30. And a valve seat 72 to be seated thereon, and a solenoid 74 as a magnetic force generating means for generating a magnetic force for controlling the relative movement of the valve 70 and the valve seat 72. In the flow control valve 68, in the first state (OFF state) in which the solenoid 74 is not excited, the valve 70 is separated from the valve seat 72 by the elastic force of the spring 76, so that the master cylinder side in the main passage 30 A bidirectional flow of the hydraulic fluid between the brake cylinder and the brake cylinder is allowed. As a result, when a brake operation is performed, the brake cylinder hydraulic pressure is changed to be equal to the master cylinder hydraulic pressure. During this braking operation, the valve 70
, A force acts in a direction away from the valve seat 72,
As long as the solenoid 74 is not excited, the valve 70 does not sit on the valve seat 72 even if the master cylinder hydraulic pressure, that is, the brake cylinder hydraulic pressure is increased. That is, the flow control valve 68 is a normally open valve. In contrast,
In the second state (ON state) in which the solenoid 74 is excited, the armature 78 is attracted by the magnetic force of the solenoid 74, and the valve 70 as a movable member that moves integrally with the armature 78 becomes a valve seat as a fixed member. 72. At this time, the valve body 70, a suction force F ₁ based on the magnetic force of the solenoid 74, and the sum of the elastic force F ₃ of the force F ₂ and the spring 76 based on the difference between the brake cylinder pressure and the master cylinder pressure Act in opposite directions to each other. Magnitude of the force F ₂ is the difference between the brake cylinder pressure and the master cylinder pressure, the valve member 70 is expressed by the product of the effective pressure receiving area which receives the brake cylinder pressure. A second state (ON state) in which the solenoid 74 is excited,
In a region where the discharge pressure of the pump 62, that is, the brake cylinder fluid pressure does not increase so much and the relationship represented by the formula of F ₂ ≦ F ₁ −F ₃ holds, the valve element 70 is seated on the valve seat 72 and the pump 62 Is prevented from escaping into the master cylinder 10, so that if the discharge pressure of the pump 62 increases, the brake cylinders 20, 2
2, a hydraulic pressure higher than the master cylinder hydraulic pressure is generated. On the other hand, in a region where the discharge pressure of the pump 62, that is, the brake cylinder fluid pressure further increases, and the relationship represented by the formula of F ₂ > F ₁ −F _{3 is to} be established, the valve 70 is moved from the valve seat 72 to the valve seat 72. As a result, the hydraulic fluid from the pump 62 is released to the master cylinder 10, and as a result, the pump 6
The discharge pressure of 2, ie the brake cylinder pressure, is prevented from further increasing. The brake cylinder 20, 22 in this way, ignoring the elastic force F ₃ of the spring 76, to the difference pressure higher hydraulic pressure based on the solenoid attractive force F ₂ is generated for the master cylinder pressure Become.

In FIG. 1, the first state of the flow control valve 68 is as follows.
A pressure symbol representing a state in which bidirectional flow of the hydraulic fluid between the master cylinder 10 and the brake cylinders 20, 22 and the pump 62 is permitted, while a second state is indicated by the master cylinder 10 and the brake cylinder 20 , 2
2 and the flow of the hydraulic fluid to the pump 62 is always blocked,
The flow in the opposite direction is indicated by a pressure symbol indicating a state allowed when the second hydraulic pressure on the brake cylinder side becomes higher than the first hydraulic pressure on the master cylinder side by a set value or more. In the present embodiment, such a function is provided by the valve 70.
It is realized by electromagnetically controlling the relative movement between the valve seat 72 and the valve seat 72, but can also be realized in other forms. For example, two passages are provided in parallel with each other, and one passage is provided with the master cylinder 10 and the brake cylinders 20 and 22.
And the other passage is provided with a check valve with a spring, so that the other passage is separated from the master cylinder 10 by the brake cylinders 20, 22, and The flow of the hydraulic fluid to the pump 62 is always blocked, and the flow in the opposite direction is allowed when the second hydraulic pressure on the brake cylinder side is equal to or higher than the first hydraulic pressure on the master cylinder side, and further,
The functions described above can be realized by connecting these passages to the middle of the main passage 30 via an electromagnetic directional control valve, and selecting any of these passages as a part of the main passage 30 by the electromagnetic directional control valve. That's it.

The flow control valve 68 is provided with a bypass passage 82 as shown in FIG.
A check valve 84 is provided in the middle of 2. The check valve 84 allows the flow of the hydraulic fluid from the master cylinder 10 to the brake cylinders 20 and 22 and prevents the flow in the opposite direction. The reason for providing the passage 82 with the check valve 84 that bypasses the flow control valve 68 is that even if the flow control valve 68 is closed,
This is to ensure the flow of the working fluid toward 2.

The pump 62 is operated during antilock control and brake assist control, respectively.
In the anti-lock control, the hydraulic fluid to be sucked by the pump 62 usually exists in the first reservoir 48, whereas in the brake assist control, it does not normally exist. Therefore, during the brake assist control, the first
It is necessary to suck the hydraulic fluid from other than the reservoir 48. Therefore, in the present embodiment, the master cylinder 1
The reservoir 86 for zero, that is, the second reservoir 86 that stores the working fluid under atmospheric pressure and supplies the working fluid to the master cylinder 10, and the pump suction passage 60 are connected to the first reservoir 86.
An auxiliary passage 88 (an example of a second working fluid introduction passage) is connected to each other so that the pump 62 can suck the working fluid from the second reservoir 86. However, if the first auxiliary passage 88 is always open, the pump 62 sucks the hydraulic fluid not only from the first reservoir 48 (antilock control reservoir) but also from the second reservoir 86 during the antilock control. As a result, the amount of hydraulic fluid in the brake system becomes excessive, and the brake cylinder 2
There is a possibility that the decompression of 0.22 will be hindered. Therefore, in the present embodiment, an inflow control valve 90 that is closed during antilock control is provided in the middle of the first auxiliary passage 88. The inflow control valve 90 is a normally closed electromagnetic on-off valve. It is necessary to operate the pump 62 also at the time of the brake assist control. Here, it is conceivable that the hydraulic fluid is sucked from the second reservoir 86. That is, the inflow control valve 90 is opened during the brake assist control. However, the brake assist control is always executed while the brake operation is being performed and the hydraulic pressure is generated in the master cylinder 10. Also, the brake assist control applies a hydraulic pressure higher than the master cylinder hydraulic pressure to the brake cylinders 20,2.
Therefore, if the hydraulic fluid from the master cylinder 10 is introduced into the suction side of the pump 62 without lowering its hydraulic pressure, the pump 62 can increase the hydraulic pressure by the differential pressure. The operation response of the pump 62 is improved. Therefore, in the present embodiment, the main passage 30
Between the master cylinder 10 and the flow control valve 68, and the portion of the pump suction passage 60 between the connection point of the suction valve 66 and the reservoir passage 46.
1 (an example of a first hydraulic fluid introduction passage), and a high-pressure hydraulic fluid is supplied from the master cylinder 10 to the pump 62.
To be introduced into the suction side of the device. However, in this state, the master cylinder 10 is connected not only to the suction side of the pump 62 but also to the first reservoir 48, and it is difficult to raise the pressure of the master cylinder 10. Therefore, in the present embodiment, a portion of the pump suction passage 60 between the connection point with the second auxiliary passage 91 and the connection point with the reservoir passage 46 is directed from the second auxiliary passage 91 to the first reservoir 48. A check valve 92 that prevents the flow of the hydraulic fluid and allows the flow in the opposite direction is provided as a device capable of increasing the pressure. However, simply connecting the suction side of the pump 62 to the master cylinder 10 via the second auxiliary passage 91 increases the consumption of the hydraulic fluid of the master cylinder 10 by the pump 62 during the brake assist control, and deteriorates the brake operation feeling. There is a risk. This is because, when the hydraulic fluid consumption of the master cylinder 10 increases, the depression operation position of the brake pedal 12 becomes deeper, and the sense of rigidity of the brake pedal 12 decreases. Further, during the anti-lock control, the pump 62 preferentially sucks the hydraulic fluid from the master cylinder 10 even though the hydraulic fluid to be sucked is present in the first reservoir 48, and the first reservoir 48 is activated. The overflow time of the liquid becomes longer, and the inconvenience that the brake cylinders 20 and 22 cannot be normally depressurized also occurs. Therefore, in the present embodiment, a mechanical control mechanism 93 is provided in the second auxiliary passage 91 as a suction control device. The mechanical control mechanism 93 has a housing 96 in which a cylinder bore 94 is formed, and a piston 98 is fitted in the cylinder bore 94 in a substantially airtight and slidable manner.
This fitting causes the piston 9 to move in the housing 96.
8, a first liquid chamber 100 in the front, and a second liquid chamber 102 in the rear.
Are formed respectively. The first liquid chamber 100 is connected to a portion of the second auxiliary passage 91 on the master cylinder side,
On the other hand, the second liquid chamber 102 is connected to a portion of the second auxiliary passage 91 on the suction side of the pump 62. In the mechanical control mechanism 93, the forward limit position of the piston 98 is defined by the piston 98 abutting on the housing 96, while the retreat limit position is defined by the stopper 103 moving integrally with the piston 98 against the housing 96. It is defined by contact. The piston 98 is urged toward a forward limit position by a spring 104 as urging means. As described above, in the mechanical control mechanism 93, the retreat limit of the piston 98 is regulated, whereby the increase in the volume of the first liquid chamber 100 and the second liquid chamber 102 are restricted.
The limit of the reduction of the volume of each is limited. During the braking operation and when the pump 62 is not operating, the piston 98 retreats from the illustrated forward end position by the deformation of the passage downstream of the mechanical control mechanism 93 (for example, the pump suction passage 60). Its amount is small. On the other hand, during the brake operation and when the pump 62 is operating, the suction pressure of the pump 62, that is, the mechanical control mechanism 9
3, the liquid pressure of the second liquid chamber 102 becomes lower than the liquid pressure of the first liquid chamber 100, and the first liquid chamber 100 and the second liquid chamber 102
When the pressure difference overcomes the elastic force of the spring 104, the piston 98 starts to retreat, and accordingly, high-pressure hydraulic fluid is discharged from the second fluid chamber 102 toward the suction side of the pump 62, Pumps the high-pressure hydraulic fluid into the second fluid chamber 10.
Inhale from 2. When the piston 98 reaches the retreat end position by this suction, the volume of the second liquid chamber 102 cannot be reduced thereafter, and the pump 62 cannot suction the working fluid from the second liquid chamber 102. On the other hand, the suction side of the pump 62 is connected not only to the master cylinder 10 but also to the first reservoir 48 and the second reservoir 86.
Opened during brake assist control, closed during antilock control. Therefore, after the volume of the second fluid chamber 102 of the mechanical control mechanism 93 reaches the reduction limit, the pump 62 draws the hydraulic fluid from the second reservoir 86 during the brake assist control, and the second fluid during the anti-lock control. The working fluid is sucked from one reservoir 48. Therefore, in the present embodiment, during the brake assist control,
In the first half, the pump 62 sucks high-pressure hydraulic fluid from the master cylinder 10, and in the second half, the second reservoir 86
, The discharge pressure of the pump 62 is quickly increased to a target value, and the hydraulic fluid consumption of the master cylinder 10 is reduced so that the sense of rigidity of the brake pedal 12 is not reduced. Both are achieved. In this mechanical control mechanism 93, the piston 9
8 is a stepped piston, and the pressure receiving area where the piston 98 receives the liquid pressure in the first liquid chamber 100 and the pressure receiving area where the piston 98 receives the liquid pressure in the second liquid chamber 102 can be different from each other.

In the present embodiment, the second control of the mechanical control mechanism 93 is performed even when the inflow control valve 90 is open.
In order to normally perform the brake assist control by increasing the pressure of the liquid chamber 102, the flow of the hydraulic fluid from the second reservoir 86 to the pump 62 is allowed in the middle of the first auxiliary passage 88,
A check valve 106 for blocking the reverse flow is provided.

FIG. 3 shows an electrical configuration of the brake device. This brake device is connected to the controller 1
10 is provided. The controller 110 is a CPU 11
2. A computer 120 including a ROM 114 and a RAM 116 is mainly configured.
The anti-lock control and the brake assist control are executed by reading various routines stored in advance in the CPU 4 and using the RAM 116 while executing them. Controller 11
Various sensors are connected to the 0 input side. The various sensors include a brake operation switch 130 that detects a driver's brake operation, a wheel speed sensor 132 that detects a wheel speed that is the peripheral speed of each of the four wheels of the vehicle, and a state of the driver's brake operation. And a brake operation state sensor 134 to be operated. In the present embodiment, the brake operation switch 130 includes a stop lamp switch,
Further, the brake operation state sensor 134 includes an operation speed sensor that detects an operation speed from a temporal change in the operation position of the brake pedal 12. On the other hand, various actuators are connected to the output side of the controller 110. Various actuators include the flow control valve 68,
An inflow control valve 90, two pressure control valves 40 (pressure increasing valves) and two pressure control valves 50 (pressure reducing valves),
And a pump motor 150 for driving the motor.

The various routines stored in the ROM 114 in advance include an antilock control routine, a brake assist control routine, a flow control valve control routine, an inflow control valve control routine, a pump motor control routine, and a pressure control valve initialization routine. . The anti-lock control routine determines whether or not anti-lock control is necessary, and determines whether the pressure control valve 40,
This is a routine for performing the control of F.50. The brake assist control routine is a routine for determining whether the brake assist control is necessary. The flow control valve control routine is the flow control valve 68, the inflow control valve control routine is the inflow control valve 90, and the pump motor control routine is the pump motor 1
50 is a routine for controlling each of them. The pressure control valve initialization routine is a routine for restoring the pressure control valves 40 and 50 to the initial state when the antilock control is not being performed. Hereinafter, the contents of each of these routines will be described.

FIG. 4 is a flowchart showing the antilock control routine. This routine is repeatedly executed, and in each execution, first, in step S101 (hereinafter simply referred to as “S101”; the same applies to other steps), the brake operation switch 130 is set.
A brake operation signal indicating the presence / absence of a brake operation is taken in from step S102.
, A wheel speed signal representing the wheel speed of each wheel is fetched. Thereafter, in S103, it is determined whether or not the brake operation is currently being performed based on the brake operation signal. If it is assumed that the brake operation is not being performed this time, the determination is NO. In S104, it is determined that the antilock control is not required this time, and
N indicates that antilock control is required,
An antilock control flag F _ABS (hereinafter simply referred to as “flag F” indicating that antilock control is not necessary in the FF state
_ABS ”. ) Is turned off. This completes one execution of this routine. On the other hand, if it is assumed that the brake operation is being performed this time, the determination in S103 is YES, and in S105, it is determined whether or not the slip of each wheel is larger than the set state based on the wheel speed signal. The necessity of anti-lock control is determined, and assuming that the slip of each wheel is not larger than the set state this time,
If the determination is NO, the process proceeds to S104. If it is assumed that the slip of each wheel is greater than the set state this time, the determination is YES, and in S106, it is determined that the antilock control is required this time, and the flag F _ABS is turned on. Thereafter, in S107, the solenoids of the pressure control valves 40, 50 are controlled based on the slip condition of each wheel, and the hydraulic pressure of each brake cylinder 20, 22 is increased or decreased so that the slip of each wheel is in an appropriate state. This completes one execution of this routine.

FIG. 5 is a flowchart showing a brake assist control routine. This routine is also repeatedly executed, and in each execution, first, in S201, a brake operation state signal indicating a brake operation state is fetched from the brake operation state sensor 134.
In S202, it is determined based on the brake operation state signal whether or not an emergency brake operation is currently performed. For example, it is determined whether or not the depressing operation speed of the brake pedal 12 is higher than a set speed, and if it is higher, it is determined that an emergency braking operation is being performed. If it is assumed that it is not an emergency brake operation this time, the determination is NO. In S203, it is determined that the brake assist control is unnecessary this time, provided in the RAM 116, and the brake assist control is required in the ON state. The brake assist control flag F _BA (hereinafter, simply referred to as “flag F _BA ”) indicating that the brake assist control is not necessary in the OFF state is turned off.
This completes one execution of this routine. On the other hand, assuming that this time is the time of emergency braking operation, S
The determination in 202 is YES, and in S204, it is determined that the brake assist control is required this time, and the flag _FBA is turned ON. This completes one execution of this routine.

FIG. 6 is a flowchart showing a flow control valve control routine. This routine is also repeatedly executed. In each execution, first, in S401, RA
The flag _FBA is read from M116. Next, S40
In 2, it is determined from the state of the flag _FBA whether or not the brake assist control is currently required. If it is assumed that the brake assist control is not required this time, the determination is NO, and in S403, a signal for turning off the solenoid of the flow control valve 68 (flow control valve 6
8 is output. This completes one execution of this routine. On the other hand, if the determination in S402 is YES because the anti-lock control is required, in S404, a signal to turn on the solenoid of the flow control valve 68 (flow control valve 68).
) Is output. Thereby,
The state in which the discharge pressure of the pump 62 can be made lower or higher than the master cylinder liquid pressure is established. However,
The upper limit of the discharge pressure of the pump 62 is determined based on the relationship between the magnetic force of the solenoid 74 and the master cylinder hydraulic pressure. This completes one execution of this routine.

FIG. 7 shows a flow chart of the inflow control valve control routine. This routine is also repeatedly executed. In each execution, first, in S501, RA
The flag F _BA is read from M116, and then S502
In, it is determined from the state of the flag _FBA whether or not the brake assist control is necessary. This time, if it is assumed that the brake assist control is not necessary, the determination is NO.
In step S503, a signal for turning off the solenoid of the inflow control valve 90 (a signal for closing the inflow control valve 90) is output. As a result, the pump 62 is in a state where the hydraulic fluid cannot be sucked from the second reservoir 86. This completes one execution of this routine. On the other hand, since the brake assist control is necessary, S
If the determination in 502 is YES, in S504, a signal for turning on the solenoid of the inflow control valve 90 (a signal for opening the inflow control valve 90) is output. As a result, the pump 62 is in a state where the hydraulic fluid can be sucked from the second reservoir 86. This completes one execution of this routine.

FIG. 8 shows the pump motor control routine.
It is represented by a row chart. This routine is also executed repeatedly.
In each execution, first, in S601, R
Flag F from AM116_ABSIs read, and then S6
02, the flag F _ABSFrom the current state
It is determined whether or not lock control is necessary. This time
Assuming that antilock control is not required, the decision is N
O, and the flag is read from the RAM 116 in S603.
F_BAIs read. Then, in S604, the
Flag F_BABrake assist control is necessary
It is determined whether it is necessary. This time brake assist
If it is assumed that no control is necessary, the determination is NO and S
At 605, the pump motor 150 is
FF signal (for stopping pump motor 150)
Signal) is output. This completes one execution of this routine.
finish. On the other hand, antilock control and brake
S is required because at least one of the assist controls is required.
If at least one of the determinations of 602 and S604 is YES
If there is, in S606, the pump motor 150
Signal to turn it on (make pump motor 150
(A signal for moving). As a result,
Pressure cylinders 20 and 22 can be increased in pressure by pump 62
State. This completes one execution of this routine.
You. In the case of brake assist control, the inflow control
Since the valve 90 is opened and the pump 62 is operated, the
The rake cylinders 20, 22 are increased in pressure.

FIG. 9 shows a flowchart of the pressure control valve initialization routine.
It is represented by a row chart. This routine is also executed repeatedly.
In each execution, first, in S701, R
Flag F from AM116_ABSIs read, and then S7
02, the flag F _ABSFrom the current state
It is determined whether or not lock control is necessary. This time
Assuming that antilock control is required, the determination is YE
At S, one cycle of this routine is completed.
On the other hand, this time, antilock control is not necessary
Assuming that the determination in S702 is NO, the process proceeds to S703.
In the initial state, the pressure control valves 40 and 50 are
Is output. This routine is completed
Is completed.

As is clear from the above description, in the present embodiment, the master cylinder 10 is a "hydraulic pressure generator".
The part of the flow control valve 68 and the controller 110 that executes the flow control valve control routine of FIG. 6, the brake assist control routine of FIG. 5, and the part that executes S604 and S608 of FIG. The second auxiliary passage 91 (first hydraulic fluid introduction passage), the check valve 92, and the mechanical control mechanism 93 constitute a "suction pressure control device".
It constitutes. Further, in the present embodiment, the check valve 92 constitutes a “pressurization enabling device”, the mechanical control mechanism 93 constitutes a “suction control device” and a “mechanical control mechanism”, respectively. Constitutes a “reservoir”, the second reservoir 86 constitutes a “second reservoir”, and the first auxiliary passage 88, the inflow control valve 90 and the check valve 106 constitute a “hydraulic fluid replenishing device”. is there.

Therefore, according to the present embodiment, at the beginning of the brake assist control, the suction pressure of the pump 62 is made equal to the master cylinder hydraulic pressure. The effect of reducing the target pressurization amount by the pump 62 and improving the operation responsiveness of the pump 62 is obtained. Further, according to the present embodiment, since the suction pressure control device is constituted mainly by the second auxiliary passage 91, the effect that the suction pressure control device is provided relatively easily and inexpensively can be obtained. Furthermore, according to the present embodiment, an effect is obtained that the pressure of the master cylinder 10 can be increased even though the second reservoir 48 and the master cylinder 10 are connected to each other on the suction side of the pump 62. Furthermore, according to the present embodiment, the operation of the pump 62 is started, and after the volume of the working fluid sucked from the second fluid chamber 102 of the mechanical control mechanism 93 by the pump 62 reaches the set value, the pump 62 is stopped. Is prevented from sucking hydraulic fluid from the master cylinder 10, so that the brake pedal 12 does not need to be deepened during the brake assist control, and the pump responsiveness does not deteriorate without deteriorating the brake operation feeling. Can be improved, and furthermore, the first reservoir 4
The state in which the hydraulic fluid 8 overflows with the hydraulic fluid does not need to be continued for a long time, and the effect that the pressure of the brake cylinders 20 and 22 by the first reservoir 48 is reduced normally can be obtained. Furthermore, according to the present embodiment, since the “suction control device” is constituted by the mechanical control mechanism 93, the size of the “suction control device” can be increased and the power consumption by the “suction control device” can be increased. The effect that it can be avoided is also obtained. Furthermore, according to the present embodiment, after the pump 62 is prevented from sucking the working fluid from the master cylinder 10 by the “suction control device”, the working fluid flows from the second reservoir 86 to the suction side of the pump 62. It is possible to obtain an effect that the pressure is increased and the pressure of the brake cylinders 20 and 22 by the pump 62 is increased.
Furthermore, according to the present embodiment, during the brake assist control, during the first half, the pump 62 is
High-pressure hydraulic fluid is sucked through the second reservoir 86, and in the latter half, a low-pressure hydraulic fluid is sucked from the second reservoir 86, thereby improving the operation response of the pump 62 and preventing the depression position of the brake pedal 12 from being deepened. The effect that the pressure increase of the brake cylinders 20 and 22 by the pump 62 is secured is also realized. Furthermore, according to the present embodiment, there is an effect that the pressure can be increased even though the second liquid chamber 102 of the mechanical control mechanism 93 is connected to the second reservoir 86 by the first auxiliary passage 88. . Furthermore, according to the present embodiment, the suction side of the pump 62 is the first side.
When anti-lock control is being performed and the pump 62 needs to preferentially draw the hydraulic fluid from the first reservoir 48 despite being connected to the second reservoir 86 as well as the reservoir 48 , The effect of being prevented from being sucked from the second reservoir 86 is also obtained.

It should be noted that, in this embodiment,
Although the anti-lock control and the brake assist control are respectively executed by the brake device, the present invention can be implemented in a form in which the vehicle stabilization control is further executed. Here, the "vehicle stabilization control" means that when the vehicle behavior is unstable, the pump is operated to generate a pressure difference between the brake cylinders of the left and right wheels, thereby generating a braking force difference between the left and right wheels, and Control that stabilizes behavior.

Another embodiment will be described. However, since this embodiment has many elements in common with the previous embodiment, only different elements will be described in detail, and common elements will be denoted by the same reference numerals and detailed description thereof will be omitted. In this embodiment, the hardware configuration is the same as that of the previous embodiment, and as shown in FIG. 10, the first auxiliary passage 88 is omitted, and the mechanical control mechanism 93 is an electromagnetic suction valve as a suction control valve device. The difference is that the control valve 200 is replaced. In order to simplify the structure of the brake device, all the hydraulic fluid to be sucked by the pump 62 is introduced from the master cylinder 10 during the brake assist control. The suction control valve 200 is switched to the open state when it is necessary to introduce the hydraulic fluid from the master cylinder 10, and is switched to the closed state otherwise. Specifically, when it is necessary to execute the brake assist control, the state is switched to the open state regardless of whether the antilock control is executed. During execution of the anti-lock control, the pump is switched to the open state only when there is no hydraulic fluid to be pumped by the pump 62 in the reservoir 48.
This prevents the occurrence of a situation where the hydraulic fluid is pumped from the master cylinder 10 unexpectedly. Further, in the present embodiment, the determination whether there is no hydraulic fluid to be pumped by the pump 62 in the reservoir 48 is made by the pressure increasing valve 40.
The remaining amount of the hydraulic fluid in the reservoir 48 is estimated based on the relationship between the pressure increase time, which is the integrated value of the time during which the pressure is increased, and the pressure reduction time, which is the integrated value of the time during which the pressure reducing valve 50 is in the reduced pressure state. It is done by doing. FIG. 11 shows a flow chart of the inflow control valve control routine. In this routine, first, in S801, it is determined whether or not the brake assist control is currently being executed.
If it is assumed that the process is being executed this time, the determination becomes YES, and in S802, a signal for turning on the solenoid of the inflow control valve 200, that is, a signal for opening the inflow control valve 200 is output. As a result, the hydraulic fluid is not depressurized from the master cylinder 10 and the pump 6
2 is introduced. On the other hand, if it is assumed that the brake assist control is not being performed this time, the determination in S801 is NO, and in S803, it is determined whether the antilock control is currently being performed. If it is assumed that it is not being executed this time, the determination is NO, and a signal to turn it on is output to the solenoid of the inflow control valve 200 in S802. This completes one execution of this routine. On the other hand, if it is assumed that the antilock control is currently being executed, the determination in S803 becomes YES, and the
In 4, an estimation calculation of the amount of the working fluid existing as the working fluid to be pumped by the pump 62 in the reservoir 48, that is, an estimation calculation of the remaining amount of the reservoir is performed. Subsequently, in S805, the estimated reservoir remaining amount becomes zero.
That is, it is determined whether there is no hydraulic fluid to be pumped by the pump 62 in the reservoir 48. Assuming that the remaining amount of the reservoir is not 0 this time, the determination is NO, and in S806, a signal for turning off the solenoid of the inflow control valve 200, that is, a signal for closing the inflow control valve 200 is output. You. On the other hand, assuming that the remaining amount of the reservoir is 0 this time, the determination in S805 becomes YES, and in S802, a signal to turn on the solenoid of the inflow control valve 200 is output. This completes one execution of this routine. As is clear from the above description, in the present embodiment, the inflow control valve 200 and the part of the controller 110 that executes the inflow control valve control routine of FIG. It constitutes.

While some embodiments of the present invention have been described in detail with reference to the drawings, various modifications may be made based on the knowledge of those skilled in the art without departing from the scope of the claims. Of course, the present invention can be implemented in an improved form.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing the structure and operation of a flow control valve 68 in FIG. 1, respectively.

FIG. 3 is a block diagram showing an electrical configuration of the brake device.

FIG. 4 is a flowchart showing an antilock control routine stored in a ROM 114 of FIG. 3 in advance.

FIG. 5 is a flowchart illustrating a brake assist control routine stored in advance in a ROM 114 of FIG. 3;

FIG. 6 is a flowchart showing a flow control valve control routine stored in advance in a ROM 114 of FIG. 3;

FIG. 7 is a flowchart showing an inflow control valve control routine stored in advance in a ROM 114 of FIG. 3;

FIG. 8 is a flowchart showing a pump motor control routine stored in advance in a ROM 114 of FIG. 3;

FIG. 9 is a flowchart showing a pressure control valve initialization routine stored in advance in a ROM 114 of FIG. 3;

FIG. 10 is a system diagram showing a mechanical configuration of a brake device according to another embodiment of the present invention.

FIG. 11 is a flowchart showing an inflow control valve control routine stored in advance in a ROM 114 in the embodiment.

FIG. 12 is a system diagram schematically illustrating an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 master cylinder 20, 22 brake cylinder 48 first reservoir 60 pump suction passage 62 pump 88 first auxiliary passage 90 inflow control valve 91 second auxiliary passage 92 check valve 93 mechanical control mechanism 106 check valve 110 controller 120 computer 200 Inflow control valve

Claims (6)

[Claims] 1. A brake cylinder for operating a wheel brake based on a hydraulic pressure, a hydraulic pressure source which is a hydraulic pressure source for the brake cylinder and generates a hydraulic pressure in response to a brake operation by a driver, A pump having a pump for sucking hydraulic fluid from a suction side and discharging the hydraulic fluid toward a brake cylinder; and a pump for operating the pump at least at one time during a brake operation and selecting the pump as a hydraulic pressure source for the brake cylinder. A selecting device, and a suction pressure control for increasing a suction pressure, which is a hydraulic pressure on the suction side of the pump, above the atmospheric pressure and changing the height in accordance with a hydraulic pressure generated in the hydraulic pressure generating device. And a brake device including the device. 2. The brake device according to claim 1, wherein the suction pressure control device connects the hydraulic pressure generating device and a suction side of the pump to each other, and sucks hydraulic fluid from the hydraulic pressure generating device to the pump. A brake device that includes a hydraulic fluid introduction passage that is introduced to the side. 3. The brake device according to claim 1, further comprising: a reservoir for containing the hydraulic fluid discharged from the brake cylinder; and a pump suction passage connecting the reservoir and a suction side of the pump to each other. And the suction pressure control device includes: (a) a hydraulic fluid introduction passage connecting the hydraulic pressure generation device and the pump suction passage to each other, and introducing hydraulic fluid from the hydraulic pressure generation device to a suction side of the pump; (B) enabling pressure increase of the hydraulic pressure generating device even though the hydraulic pressure generating device is connected to the reservoir via the working fluid introduction passage and the pump suction passage. And a brake device including the device. 4. The brake device according to claim 2, wherein said suction pressure control device further causes said pump to draw hydraulic fluid from said hydraulic pressure generation device when a predetermined condition is satisfied. A brake device including a suction control device for preventing the operation of the vehicle. 5. The brake device according to claim 4, wherein the suction control device is provided in the middle of the working fluid introduction passage.
The pump operates mechanically based on the difference between the first hydraulic pressure on the side of the hydraulic pressure generator and the second hydraulic pressure on the side of the pump, and the volume of hydraulic fluid sucked from the hydraulic pressure generator by the pump is reduced. A brake device that includes a mechanical control mechanism that allows the pump to draw in hydraulic fluid from the hydraulic pressure generating device until the set value is reached, and blocks it after reaching the set value. 6. The brake device according to claim 4, further comprising: a second reservoir for containing a hydraulic fluid and supplying the hydraulic fluid to the hydraulic pressure generator, and wherein the pump is controlled by the suction control device. A hydraulic fluid replenishing device for replenishing the hydraulic fluid from the second reservoir to the suction side of the pump after the hydraulic fluid is prevented from being sucked from the hydraulic pressure generating device.