JPH10287227A - Fluid pressure brake control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a reverse flow of brake fluid to a master cylinder when a fluid pressure source is changed, in a fluid pressure brake control device using the master cylinder and a high pressure source selectively as the fluid pressure source. SOLUTION: In the case of a system normal, M/C cut valves 30, 40, 46, 56 are placed in a closed condition, linear control valves 80, 82, 86, 88, 90, 92, 94, 96 are controlled, so as to control a wheel cylinder pressure. In the case of detecting abnormality of the system, first the linear control valves 80, 82, 86, 88 are placed in a closed condition, next the M/C cut valves 30, 40, 46, 56 are opened, so as to make wheel cylinders 37, 42, 52, 58 communicate with a master cylinder 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hydraulic brake control device, and more particularly to a hydraulic brake control device that selectively uses a master cylinder and a high pressure source as a hydraulic pressure source.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 5-3902
As disclosed in No. 5, there is known a hydraulic brake device that selectively uses a master cylinder and a high pressure source as a hydraulic pressure source. The above-described conventional apparatus includes a linear control valve between the high-pressure source and the wheel cylinder, which reduces the hydraulic pressure generated by the high-pressure source to an appropriate hydraulic pressure according to the brake operation amount and supplies the reduced pressure to the wheel cylinder. Further, the above-mentioned conventional apparatus is provided with a mechanical switching valve between the master cylinder and the wheel cylinder for turning both of them on or off.

[0003] The mechanical switching valve provided in the above-mentioned conventional device operates using the hydraulic pressure supplied from the linear control valve to the wheel cylinder as pilot pressure. Specifically, the switching valve brings the master cylinder and the wheel cylinder into conduction when the hydraulic pressure supplied from the linear control valve to the wheel cylinder is low. When the hydraulic pressure supplied from the linear control valve to the wheel cylinder is high, the master cylinder and the wheel cylinder are shut off.

According to the above-mentioned conventional apparatus, when the linear control valve is functioning normally, the hydraulic pressure supplied from the linear control valve to the wheel cylinder is increased by performing the brake operation. At the same time, the master cylinder and the wheel cylinder are shut off. Therefore, in this case, the wheel cylinder pressure P
_{W / C} pressure can be increased.

Further, according to the above-mentioned conventional apparatus, when an abnormality occurs in the high-pressure source or the linear control valve, and a situation occurs in which the hydraulic pressure cannot be properly supplied from the linear control valve to the wheel cylinder, After the brake operation is started, the master cylinder and the wheel cylinder can be maintained in a conductive state. Therefore, according to the above-described conventional apparatus, even when an abnormality occurs in the linear control valve or the like, it is possible to surely increase the wheel cylinder pressure P _{W / C.}

In the above-mentioned conventional apparatus, the mechanical switching valve for controlling the conduction state between the master cylinder and the wheel cylinder is used until the hydraulic pressure supplied from the linear control valve to the wheel cylinder becomes low to some extent. Maintain the master cylinder and the wheel cylinder in a disconnected state. For this reason, for example, from a linear control valve to a wheel cylinder,
If an abnormality occurs in the linear control valve in a situation where high hydraulic pressure is supplied, the master cylinder and the wheel cylinder may not be brought into conduction until the wheel cylinder pressure is appropriately reduced. Absent.

Therefore, according to the above-mentioned conventional apparatus, even if an abnormality occurs in the linear control valve or the like under the condition that the high wheel cylinder pressure P _{W / C} is generated in the wheel cylinder, the wheel cylinder is thereafter operated. The high-pressure hydraulic pressure does not flow backward from the pressure toward the master cylinder. For this reason,
According to the above-mentioned conventional device, reliable fail-safe can be realized without impairing the durability of the master cylinder and without causing pedal kickback during the brake operation.

[0008]

SUMMARY OF THE INVENTION In a vehicle, for example, a control (hereinafter, referred to as TRC control) for canceling excessive driving force generated in driving wheels to suppress idling of wheels. Alternatively, in order to realize control for stabilizing the vehicle posture by generating a braking force on appropriate wheels (hereinafter referred to as VSC control), an appropriate wheel is provided under the condition that the brake pedal is not depressed. Cylinder pressure P
It is required to generate _{W / C.} According to the above-described conventional device, even when the brake pedal is not depressed, it is possible to generate an appropriate wheel cylinder pressure P _{W / C} in the wheel cylinder by controlling the linear control valve. Therefore, according to the above-mentioned conventional device, TRC control and V
SC control can be realized.

However, in the above-mentioned conventional apparatus, the mechanical switching valve keeps the master cylinder and the wheel cylinder conductive while the hydraulic pressure supplied from the linear control valve to the wheel cylinder is low. On the other hand, wheel cylinder pressure P required in TRC control or VSC control
_{W / C} is relatively low pressure. For this reason, according to the above-described conventional apparatus, for a certain period after the TRC control or the VSC control is started, the control is performed in a state where the master cylinder and the wheel cylinder are electrically connected.

[0010] The master cylinder is normally connected to the reservoir tank when the brake pedal is not depressed. Therefore, during execution of the TRC control or the VSC control, the conduction between the master cylinder and the reservoir tank is maintained. For this reason, according to the conventional device, the TRC
After the control or VSC control is started, until the hydraulic pressure supplied from the linear control valve to the wheel cylinder is increased to some extent, the control is performed in a state where the wheel cylinder and the reservoir tank are in conduction. become. For this reason, in the above-described conventional apparatus, it is difficult to ensure excellent initial response when a control such as TRC control or VSC control that does not require generation of a large wheel cylinder pressure P _{W / C} is executed. there were.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has been described in connection with a case where a hydraulic pressure source for increasing the wheel cylinder pressure P _{W / C} is changed from a high pressure source to a master cylinder. The brake fluid does not flow backward from the cylinder to the master cylinder, and a large wheel cylinder pressure P
It is an object of the present invention to provide a hydraulic brake control device capable of achieving excellent initial responsiveness when performing control that does not require generation of _{W / C.}

[0012]

The above object is achieved by the present invention.
As described in, a hydraulic brake that selectively uses a master cylinder that generates a hydraulic pressure according to a brake operation amount and a high-pressure source that generates a predetermined hydraulic pressure regardless of the brake operation amount as a hydraulic pressure source In the control device, a solenoid valve that shuts off the master cylinder and the wheel cylinder by increasing the master cylinder pressure, and a linear valve that reduces the hydraulic pressure generated by the high-pressure source to a target hydraulic pressure and supplies the target hydraulic pressure to the wheel cylinder When the hydraulic pressure supplied to the wheel cylinder from the control valve and the linear control valve is not controlled near the target hydraulic pressure,
The first fail-safe means for stopping the control of the linear control valve and shutting off the high-pressure source and the wheel cylinder, and after the high-pressure source and the wheel cylinder are shut off by the first fail-safe means, This is achieved by a hydraulic brake control device comprising: a second fail-safe means for setting the solenoid valve to an open state and making the master cylinder and the wheel cylinder conductive.

In the present invention, when the master cylinder pressure is increased, the linear control valve is driven to control the wheel cylinder pressure P _{W / C} to a target hydraulic pressure corresponding to the master cylinder pressure. When the linear control valve appropriately generates the hydraulic pressure, the solenoid valve is immediately closed after the master cylinder pressure is increased, and the master cylinder and the wheel cylinder are shut off. For this reason, the wheel cylinder pressure P
_{The W / C} shows excellent responsiveness in a region where the hydraulic pressure emitted from the linear hydraulic valve is low.

If the hydraulic pressure cannot be properly supplied from the linear control valve to the wheel cylinder, the control of the linear control valve is first stopped, and then the solenoid valve is opened, whereby the wheel cylinder is opened. And the master cylinder are brought into conduction. At this time, since the high-pressure source and the wheel cylinder are shut off before the solenoid valve is opened, after the solenoid valve is opened, the high-pressure brake fluid flows back from the wheel cylinder to the master cylinder. Absent.

According to a second aspect of the present invention, in the hydraulic brake control device according to the first aspect, after the request to supply the hydraulic pressure to the wheel cylinder is extinguished, First ending means for stopping control and shutting off the high-pressure source and the wheel cylinder;
After the high-pressure source and the wheel cylinder are shut off by the ending means, the solenoid valve is opened, and the second ending means for making the master cylinder and the wheel cylinder conductive is provided. This is also achieved by the device.

In the present invention, when it is no longer necessary to supply the hydraulic pressure to the wheel cylinder, the control of the linear control valve is stopped first, and then the solenoid valve is opened, so that the connection between the wheel cylinder and the master cylinder is established. State.
According to this process, when the wheel cylinder and the master cylinder are brought into conduction, the high-pressure brake fluid does not flow backward from the wheel cylinder to the master cylinder.

Further, according to the above-described processing, when it is not necessary to supply the hydraulic pressure to the wheel cylinder, the wheel cylinder and the master cylinder can be always in a conductive state. The master cylinder is communicated with the reservoir tank when the brake operation is not performed. Therefore, in the present invention, when it is not necessary to supply the hydraulic pressure to the wheel cylinder, the wheel cylinder is brought into conduction with the reservoir tank. If there is no need to supply the hydraulic pressure to the wheel cylinder, and this situation is formed, for example, the wheel cylinder pressure is maintained at atmospheric pressure even when the linear control valve is leaking hydraulic pressure. can do.

[0018]

FIG. 1 is a system configuration diagram of a hydraulic brake control device according to an embodiment of the present invention. The hydraulic brake control device of the present embodiment includes an electronic control unit 10
(Hereinafter, referred to as ECU 10). The hydraulic brake control device includes a brake pedal 12.
The brake pedal 12 includes a stroke simulator 14
, The master cylinder 16 is connected.

When the brake pedal 12 is depressed, the stroke simulator 14
And a mechanism for applying a stroke in accordance with the brake depression force. The master cylinder 16 has two hydraulic chambers inside. In these hydraulic chambers, a master cylinder pressure P _{M / C} corresponding to the brake depression force is generated. Above the master cylinder 16, a reservoir tank 18 is provided. Brake fluid is stored in the reservoir tank 18. The hydraulic chamber of the master cylinder 16 and the reservoir tank 18 are in a conductive state when the depression of the brake pedal 12 is released.

The first hydraulic passage 2 is provided in the master cylinder 16.
The 0 and the second hydraulic passages 22 communicate with each other. 1st hydraulic pressure
The hydraulic pressure introduced into the passage 20, that is, the mass
Ta cylinder pressure P_{M / C}P that outputs a signal according to_{M / C}Sen
A power supply 24 is provided. P _{M / C}Output signal of sensor 24
Are supplied to the ECU 10. The ECU 10 calculates P
_{M / C}Master cylinder pressure based on the output signal of sensor 24
P_{M / C}Is detected.

The first hydraulic passage 20 communicates with a mechanical pressure increasing valve 26. A front hydraulic passage 28 communicates with the mechanical pressure increasing valve 26. The mechanical pressure increasing valve 26 generates a hydraulic pressure having a predetermined boosting ratio with respect to the master cylinder pressure PM _{/ C} guided to the first hydraulic pressure passage 20 as described later, and changes the hydraulic pressure to the front hydraulic pressure. The pressure increasing valve discharges to the pressure passage 28.

The front hydraulic passage 28 is provided with an M / C cut valve Fr main 30. M / C cut valve F
The r main 30 maintains the valve open state in a normal state, and the ECU 10
Is closed by supplying a drive signal from
Position solenoid valve. The front hydraulic passage 28 branches into a first Fr passage 34 and a second Fr passage 36. F
The first cylinder 34 communicates with a wheel cylinder 37 disposed on one of the left and right front wheels. Also, Fr first passage 3
4 is connected to a P _{W / C} sensor 38 that outputs a signal corresponding to the hydraulic pressure generated in the inside, that is, the wheel cylinder pressure P _{W / C} generated in the wheel cylinder 37. P
The output signal of the _{W / C} sensor 38 is supplied to the ECU 10. The ECU 10 controls the wheel cylinder pressure P generated in the wheel cylinder 37 based on the output signal of the P _{W / C} sensor 38.
Detect _{W / C.}

The M / C cut valve F
An r sub 40 is provided. The M / C cut valve Fr sub 40 is a two-position solenoid valve that maintains a valve open state in a normal state and is closed when a drive signal is supplied from the ECU 10. A wheel cylinder 42 disposed on the other of the left and right front wheels communicates with the Fr second passage 36. Furthermore,
In the Fr second passage 36, a P _{W / C} that outputs a signal corresponding to the wheel cylinder pressure P _{W / C} generated in the wheel cylinder 42 is provided.
Sensor 44 is in communication. The ECU 10 detects a wheel cylinder pressure P _{W / C} generated in the wheel cylinder 42 based on an output signal of the P _{W / C} sensor 44.

An M / C cut valve Rr main 46 is disposed in the second hydraulic passage 22 communicating with the master cylinder 16. The M / C cut valve Rr main 46 is a two-position solenoid valve that keeps the valve open in a normal state and closes when a drive signal is supplied from the ECU 10. The second hydraulic pressure passage 22 includes the Rr first passage 48 and the Rr second passage 5.
It branches to 0. A wheel cylinder 52 arranged on one of the left and right rear wheels communicates with the Rr first passage 48.
The R _W first passage 48 has a P _{W / C} sensor 5 that outputs a signal corresponding to the hydraulic pressure generated therein, that is, a wheel cylinder pressure P _{W / C} generated in the wheel cylinder 52.
4 are in communication. The output signal of the P _{W / C} sensor 54 is EC
It is supplied to U10. The ECU 10 detects a wheel cylinder pressure P _{W / C} generated in the wheel cylinder 52 based on an output signal of the P _{W / C} sensor 54.

The M / C cut valve R
An r sub 56 is provided. The M / C cut valve Rr sub 56 is a two-position solenoid valve that maintains an open state in a normal state and is closed when a drive signal is supplied from the ECU 10. A wheel cylinder 58 disposed on the other of the left and right rear wheels communicates with the Rr second passage 50. Furthermore,
Rr in the second passage 50, P _{W / C} for outputting a signal corresponding to the wheel cylinder pressure P _{W / C} generated in the wheel cylinder 58
Sensor 60 is in communication. The ECU 10 detects a wheel cylinder pressure P _{W / C} generated in the wheel cylinder 58 based on an output signal of the P _{W / C} sensor 60.

The hydraulic brake control device has a reservoir passage 62 communicating with the reservoir tank 18. The reservoir passage 62 communicates with the above-described mechanical booster valve 26 and communicates with the suction side of the pump mechanism 66 via a check valve 64. A high-pressure passage 70 communicates with a discharge side of the pump mechanism 66 via a check valve 68. An accumulator 72 that stores the hydraulic pressure discharged from the pump mechanism 66 communicates with the high-pressure passage 70. Further, the high pressure passage 7
When the hydraulic pressure in the high-pressure passage 70 (hereinafter, referred to as accumulator pressure P _ACC ) exceeds an upper limit value, the UL switch 74 that generates an ON signal and the accumulator pressure P
An LL switch 76 that outputs an ON signal when _ACC exceeds the lower limit value is in communication. The pump mechanism 66 is driven based on the state of the UL switch 74 and the state of the LL switch 76 so that the accumulator pressure P _ACC always falls between the upper limit value and the lower limit value.

A constant pressure release valve 78 is provided between the high pressure passage 70 and the reservoir passage 62. Constant pressure release valve 78
When the hydraulic pressure on the high pressure passage 70 side exceeds the predetermined valve opening pressure and becomes higher than the hydraulic pressure on the reservoir passage 62 side,
This is a one-way valve that allows only the flow of the fluid from the high-pressure passage 70 toward the reservoir passage 62. The high pressure passage 70 communicates with the above-described mechanical pressure increasing valve 26. The mechanical booster valve 26 uses the accumulator pressure P _ACC guided from the high-pressure passage 70 and the atmospheric pressure guided from the reservoir passage 62 to provide a liquid having a predetermined boost ratio with respect to the master cylinder pressure PM _{/ C.} Generate pressure.

The high-pressure passage 70 communicates with linear pressure-intensifying valves 80 and 82 provided for the left and right front wheels, respectively. The high pressure passage 70 has an Rr pressure increasing cut valve 84.
, And linear pressure increasing valves 86 and 88 provided corresponding to the left and right rear wheels, respectively, communicate with each other. Linear booster valve 8
0, 82, 86, and 88 are Fr first passages 34, respectively.
Fr second passage 36, Rr first passage 48, Rr second passage 5
It communicates with 0. Linear booster valves 80, 82, 86, 8
Reference numeral 8 denotes the first Fr passage 34 and the second Fr passage 3 from the high pressure passage 70 side in accordance with a drive signal supplied from the ECU 10.
6, a control valve for linearly controlling the amount of brake fluid flowing into the first Rr passage 48 and the second Rr passage 50.

Fr first passage 34, Fr second passage 36, R
Linear pressure reducing valves 90, 92, 94, and 96 communicate with the r first passage 48 and the Rr second passage 50, respectively. The linear pressure reducing valves 90, 92, 94, 96 communicate with the reservoir passage 62. Linear pressure reducing valve 90, 92, 9
The brake fluids 4 and 96 flow from the first Fr passage 34, the second Fr passage 36, the first Rr passage 48, and the second Rr passage 50 to the reservoir passage 62 in response to the drive signal supplied from the ECU 10. This is a control valve that controls the amount linearly.

In the hydraulic brake control device according to the present embodiment, the ECU 10 controls the brake pedal 12 when the brake pedal 12 is depressed and when the brake pedal 12 is depressed, based on a request for vehicle behavior control or the like. When it is required to generate power, the wheel cylinder pressure P _{W / C} of each wheel is increased. Hereinafter, the control executed in the former case is referred to as normal brake control, and the control executed in the latter case is referred to as automatic brake control.

In the hydraulic brake control device, when neither the normal brake control nor the automatic brake control is executed, all the M / C cut valves 30, 40, 46,
56 is opened, the Rr pressure increasing cut valve 84 is closed, and all the linear control valves 80, 82, 8
6, 88, 90, 92, 94, and 96 are closed. In this case, the wheel cylinders 37, 42, 52, 58
Is separated from the high-pressure passage 70 and the master cylinder 1
6 is formed.

When the normal brake control is not required, that is, when the depression of the brake pedal 12 is released, the master cylinder 16 and the reservoir tank 18 are in a communication state. Therefore, in the above state, the wheel cylinders 37, 42, 52, 58 are in communication with the reservoir tank 18. When the wheel cylinders 37, 42, 52, 58 communicate with the reservoir tank 18 in this manner, for example, the linear control valves 80, 82, 8
6 and 88, the wheel cylinder pressures P of all the wheels may be
_{W / C} can be maintained at atmospheric pressure. Therefore, according to the hydraulic brake control device of the present embodiment, the linear control valve 8
Even if an abnormality occurs in 0, 82, 86, or 88, the brake drag phenomenon does not occur.

When normal brake control or automatic brake control is required in the hydraulic brake control device,
All the M / C cut valves 30, 40, 46, 56 are closed, the Rr pressure increasing cut valve 84 is opened, and the linear control valves 80, 82, 86, 88, 90, 9 are set.
2, 94, 96 are wheel wheel pressures P _{W /
C} is controlled to occur. In this case, the wheel cylinders 37, 42, 52, 58 are separated from the master cylinder 16 and the wheel cylinders 37, 42, 52,
58, linear control valves 80 and 90, linear control valves 82 and 92, and linear control valves 86 and 9 respectively.
4. Wheel cylinder pressure P _{W / C} is generated according to the state of linear control valves 88 and 96.

According to the above control, the brake pedal 1
2 is depressed, for example, a function as a normal brake device or a known anti-lock brake
The function of the system (ABS) can be realized.
When the brake pedal 12 is not depressed, for example, a known traction control (TR)
C) function, known vehicle attitude control (VSC) function,
Alternatively, a known automatic braking function or the like can be realized.

In the hydraulic brake control device, the pump mechanism 66 and the linear control valves 80, 82, 86, 88, 90,
When an abnormality occurs in 92, 94, 96, the linear control valve 8
By controlling 0, 82, 86, 88, 90, 92, 94, 96, the wheel cylinder pressure P _{W / C} of each wheel may not be able to be properly controlled. According to the hydraulic brake control device of the present embodiment, when such an abnormality is detected, all of the M / C cut valves 30, 4
0, 46, 56 are always kept open, and all the linear control valves 80, 82, 86, 88, 90, 92,
94 and 96 are maintained in the valve closed state.

In the hydraulic brake control device, when the above state is realized, the wheel cylinders 37, 42,
A state is formed in which 52 and 58 communicate with the master cylinder 16. In this case, a wheel cylinder pressure P _{W / C} equal to the master cylinder pressure P _{M / C} can be generated in at least all the wheel cylinders 37, 42, 52, 58. When the mechanical pressure intensifying valve 26 functions normally, the wheel cylinders 37 and 42 of the left and right front wheels are provided with a wheel cylinder pressure P _{W /} having a predetermined boosting ratio with respect to the master cylinder pressure P _{M / C. C} can be generated. As described above, the hydraulic brake control device according to the present embodiment has excellent fail-safe capability against abnormalities of the linear control valves 80, 82, 86, 88, 90, 92, 94, 96 and the like.

By the way, in the hydraulic brake control device, when a request for automatic brake control is generated, the M / C cut valves 30, 40, 46, 56 which have been opened are set.
Are closed, and the linear control valves 80, 82, 8
It is necessary to start the control of 6,88,90,92,94,96. At this time, the M / C cut valves 30, 40, 46,
If the responsiveness of the change of the valve 56 from the open state to the closed state is poor, the wheel cylinders 37, 42, 52, 58 are connected to the reservoir cylinders via the master cylinder 16 for a certain period after the request for the automatic brake control occurs. The state of communication with the tank 18 is maintained.

In a situation where the wheel cylinders 37, 42, 52, 58 communicate with the reservoir tank 18, it is difficult to make the wheel cylinder pressure P _{W / C} of each wheel properly coincide with the target hydraulic pressure. In this regard, automatic brake control (TRC, V
In order to enhance the controllability of the control for realizing the SC, the automatic brake, etc., the M / C cut valves 30, 40, 46,
It is important to give 56 good responsiveness.

As described above, in the hydraulic brake control device of the present embodiment, the M / C cut valves 30, 40, 46, and 56 are constituted by solenoid valves. Also, M / C cut valves 30, 4
0, 46, and 56 indicate a request for automatic brake control.
It is controlled by the CU 10. Therefore, according to the hydraulic brake control device, after the request for the automatic brake control is generated, the M / C cut valves 30, 4 have excellent responsiveness.
0, 46, and 56 can be closed. Therefore, according to the system of the present embodiment, excellent controllability can be ensured with respect to the automatic brake control.

In the hydraulic brake control device according to the present embodiment, when the request for the normal brake control has disappeared, or
When the request for the automatic brake control disappears, the control of the linear control valves 80, 82, 86, 88, 90, 92, 94, 96 is stopped, and the M / C that has been closed is closed.
The cut valves 30, 40, 46, and 56 are opened.
At this time, when the M / C cut valves 30, 40, 46, 56 are opened before the control of the linear control valves 80, 82, 86, 88 is stopped, the wheel cylinders 37,
A situation in which a large amount of high-pressure brake fluid flows backward from the side 42, 52, 58 toward the master cylinder 16 may occur.

In the hydraulic brake control device of this embodiment, the linear control valves 80, 82 are operated under the condition that the high wheel cylinder pressure P _{W / C} is generated in the wheel cylinders 37, 42, 52, 58. , 86,88,90,92,9
If the abnormality of 4,96 is detected, then the linear control valves 80, 82, 86, 88, 90, 92, 94, 9
6 is stopped and the valve M is closed.
The / C cut valves 30, 40, 46, 56 are opened. Also in this case, the M / C cut valves 30, 40,
If the valves 46, 56 are opened before the control of the linear control valves 80, 82, 86, 88 is stopped, the master cylinder 16 is controlled from the wheel cylinders 37, 42, 52, 58 side.
A large amount of high-pressure brake fluid flows backward to the side.

In order to secure the durability of the master cylinder 16 or to suppress the occurrence of unnecessary pedal kickback during the brake operation, it is desirable that such backflow of the brake fluid be suppressed. In order to satisfy the above demands, the hydraulic brake system according to the present embodiment, when the demand for the brake control disappears, and when the abnormality of the linear control valves 80, 82, 86, 88, 90, 92, 94, 96, etc. When detected, the linear control valve 8
0, 82, 86, 88, 90, 92, 94, 96 control stop, and M / C cut valves 30, 40, 46, 56
The feature is that the valve opening process is performed. Hereinafter, the characteristic portion of the hydraulic brake control device will be described with reference to FIG.

FIG. 2 is a flowchart showing an example of a control routine executed in the hydraulic brake control device according to the present embodiment. The routine shown in FIG. 2 is a periodic interrupt routine that is started every predetermined time. When the routine shown in FIG. 2 is started, first, the process of step 100 is executed. In step 100, it is determined whether execution of the automatic brake control is requested. As a result, if it is determined that execution of the automatic brake control has not been requested, the process of step 102 is executed next. On the other hand, if it is determined that execution of the automatic brake control is requested, step 102 is jumped, and then step 1 is executed.
04 is executed.

In step 102, it is determined whether or not an output is generated at the _{PM / C} sensor 24. As a result, P
_When it is determined that the output is generated in the _{M / C} sensor 24, it can be determined that the brake pedal 12 is depressed. In this case, the process of step 104 is executed next. On the other hand, when it is determined that no output is generated in the PM _{/ C} sensor 24, the steps 104 to 104 are thereafter performed.
8 is jumped, and the process of step 110 is executed.

In step 104, all the M / C cut valves 30, 40, 46, and 56 are closed, and Rr
The process of opening the pressure increasing cut valve 84 is executed.
When the process of step 104 is executed, the wheel cylinders 37, 42, 52, 58 are disconnected from the master cylinder 16, and the linear control valves 80, 82, 86,
An accumulator pressure P _ACC is led upstream of 88. When the processing of step 104 is completed, next step 106
Is performed.

In step 106, the linear control valves 80, 82, 86, 88, 90, 92, and 9 are adjusted so that the wheel cylinder pressure P _{W / C} of each wheel matches the respective target hydraulic pressure.
4, 96 are driven. When the process of step 106 is completed, the process of step 108 is performed next. In step 108, the P _{W / C} sensors 38, 44, 5 of each wheel
It is determined whether the wheel cylinders 4, 60 have not detected abnormal wheel cylinder pressure P _{W / C.} Specifically, it is determined whether the _{PW / C} sensors 38, 44, 54, and 60 for each wheel detect a hydraulic pressure that is significantly different from the target hydraulic pressure for each wheel. As a result, when abnormality is detected in the detection values of the PW _{/ C} sensors 38, 44, 54, 60, the linear control valves 80, 82, 8
It can be determined that an abnormality has occurred in 6, 88, 90, 92, 94, 96, and the like. In this case, the process of step 110 is executed next. On the other hand, the P _{W / C} sensor 38,
If it is determined that no abnormality is detected in the detected values of 44, 54, and 60, then steps 110 and 112 are jumped, and the current routine is immediately terminated.

In step 110, the linear control valve 80,
Processing for stopping the control of 82, 86, 88, 90, 92, 94, 96 is executed. When the process of step 110 is executed, the linear control valves 80, 82, 86, 88 are closed, and the wheel cylinders 37, 42, 52, 58
And the high-pressure passage 70 are cut off. This step 110
Is completed, the process of step 112 is executed.

In step 112, all the M / C cut valves 30, 40, 46, 56 are opened, and Rr
The process of opening the pressure increasing cut valve 84 is executed.
When the process of step 112 is executed, a state is established in which the wheel cylinders 37, 42, 52, 58 communicate with the master cylinder 16. When the process of step 112 is completed, the current routine is completed.

According to the processing of this routine, when the execution request of the automatic brake control has disappeared and when the execution request of the normal brake control has disappeared, step 100 is executed.
After the processes of steps 102 and 102 are executed, first, the wheel cylinders 37, 42, 52, 58 and the high-pressure passage 70 are closed (step 110), and then the wheel cylinders 37, 42, 52, 58 and the master cylinder 16 is brought into a communicating state (step 112), thereby forming a state for maintaining the wheel cylinder pressure P _{W / C} at atmospheric pressure. In this case, the M / C cut valves 30, 40, 46, 5
With the opening of the valve 6, a large amount of high-pressure brake fluid does not flow backward to the master cylinder 16.

Further, according to the processing of this routine, the linear control valves 80, 82, 86, 8
When an abnormality such as 8, 90, 92, 94, 96, etc. is detected, after the processing of steps 100 to 108 is executed, first, the wheel cylinders 37, 42, 52, 58 and the high pressure passage 70 are disconnected. (Step 110), and then
When the wheel cylinders 37, 42, 52, 58 and the master cylinder 16 are in communication (step 112), a state for realizing the fail-safe function is established. In this case, the M / C cut valves 30, 40, 46, 5
With the opening of the valve 6, a large amount of high-pressure brake fluid does not flow backward to the master cylinder 16.

As described above, according to the hydraulic brake control device of the present embodiment, the wheel cylinders 37, 42, 52, 58
A large amount of high-pressure brake fluid does not flow backward from the master cylinder 16 side to the master cylinder 16 side, ensuring excellent controllability with respect to automatic brake control, and the linear control valves 80, 8
A fail-safe function for abnormalities such as 2,86,88,90,92,94,96 can be realized.

In the above embodiment, the pump mechanism 66 corresponds to the "high pressure source" according to the first aspect, and the M / C cut valves 30, 40, 46 and 56 correspond to the "electromagnetic valve" according to the first aspect. , Respectively, and the ECU 10
2. The "first fail-safe means" according to claim 1, by executing the processing of steps 108 and 110.
However, the “second fail-safe means” according to claim 1 is realized by executing the processing of step 112.

In the above embodiment, the ECU 1
0 executes the processing of steps 110, 102 and 110, whereby the “first ending means” according to claim 2 executes the processing of step 112, thereby causing the “first ending means” to execute “processing of step 112”. End means ”are each realized.

[0054]

As described above, according to the first aspect of the present invention, an excellent initial value is obtained in the case where the hydraulic pressure supplied from the linear control valve to the wheel cylinder is not so high. Responsiveness can be realized and high-pressure brake fluid flows back from the wheel cylinder side to the master cylinder side when a situation arises in which the hydraulic pressure cannot be supplied properly from the linear control valve to the wheel cylinder. A state in which the master cylinder pressure PM _{/ C} can be guided to the wheel cylinder can be realized without the need.

According to the second aspect of the present invention, when the need to supply the hydraulic pressure to the wheel cylinder disappears, the wheel cylinder and the master cylinder do not flow back the high-pressure brake fluid from the wheel cylinder to the master cylinder. The connection with the cylinder can be made conductive.

[Brief description of the drawings]

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

FIG. 2 is a flowchart of an example of a control routine executed in the hydraulic brake control device shown in FIG.

[Explanation of symbols]

Reference Signs List 10 Electronic control unit (ECU) 16 Master cylinder 24 P _{M / C} sensor 26 Mechanical booster valve 30, 40, 46, 56 M / C cut valve 37, 42, 52, 58 Wheel cylinder 38, 44, 54, 60P _{W / C} sensor 66 Pump mechanism 80, 82, 86, 88, 90, 92, 94, 96 Linear control valve

Claims (2)

[Claims] 1. A hydraulic brake that selectively uses a master cylinder that generates a hydraulic pressure according to a brake operation amount and a high-pressure source that generates a predetermined hydraulic pressure regardless of a brake operation amount as a hydraulic pressure source. In the control device, a solenoid valve that shuts off the master cylinder and the wheel cylinder by increasing the master cylinder pressure, and a linear valve that reduces the hydraulic pressure generated by the high-pressure source to a target hydraulic pressure and supplies the target hydraulic pressure to the wheel cylinder When the hydraulic pressure supplied to the wheel cylinder from the linear control valve is not controlled near the target hydraulic pressure, the control of the linear control valve is stopped to shut off the high-pressure source and the wheel cylinder. After the high-pressure source and the wheel cylinder are shut off by the first fail-safe means, the solenoid valve is opened and the mass Hydraulic brake control apparatus, characterized in that it comprises a second fail-safe means for the cylinder and the wheel cylinder conductive, the. 2. The hydraulic brake control device according to claim 1, wherein the request for supplying hydraulic pressure to the wheel cylinder disappears.
A first ending means for stopping the control of the linear control valve to shut off the high-pressure source and the wheel cylinder; and after the high-pressure source and the wheel cylinder are shut off by the first ending means, the electromagnetic valve With the valve open
And a second ending means for making the master cylinder and the wheel cylinder conductive.