JP3508458B2 - Hydraulic brake control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention 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 hydraulic pressure sources.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent 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 hydraulic pressure sources. The above-mentioned 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 hydraulic pressure to the wheel cylinder. Further, the above-mentioned conventional device is provided with a mechanical switching valve between the master cylinder and the wheel cylinder that brings them into a conducting state or a blocking state.

The mechanical switching valve provided in the above-mentioned conventional device operates by using the hydraulic pressure supplied from the linear control valve to the wheel cylinder as the pilot pressure. Specifically, the switching valve brings the master cylinder and the wheel cylinder into a conductive state when the hydraulic pressure supplied from the linear control valve toward 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 conventional device, when the linear control valve is functioning normally, the brake operation is performed to increase the hydraulic pressure supplied from the linear control valve toward the wheel cylinder. At the same time, the master cylinder and the wheel cylinder are cut off. Therefore, in this case, the wheel cylinder pressure P is set using the linear control valve as the hydraulic pressure source.
_{W / C} pressure can be increased.

Further, according to the above-mentioned conventional apparatus, in the case where an abnormality occurs in the high pressure source or the linear control valve and 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 the conductive state. Therefore, according to the conventional device described above, the wheel cylinder pressure P _{W / C} can be reliably increased even when an abnormality occurs in the linear control valve or the like.

By the way, in the above-mentioned conventional apparatus, the mechanical switching valve for controlling the conduction state between the master cylinder and the wheel cylinder is required until the hydraulic pressure supplied from the linear control valve to the wheel cylinder becomes low to some extent. The master cylinder and the wheel cylinder are kept in the disconnected state. Therefore, for example, from the linear control valve to the wheel cylinder,
If an abnormality occurs in the linear control valve under the condition that a high hydraulic pressure is supplied, the master cylinder and the wheel cylinder cannot be brought into conduction until the wheel cylinder pressure is appropriately reduced. Absent.

Therefore, according to the above-mentioned conventional apparatus, even when 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 then removed. The high-pressure liquid pressure does not flow back from the master cylinder toward the master cylinder. For this reason,
According to the conventional device described above, a reliable fail-safe can be realized without impairing the durability of the master cylinder and without causing pedal kickback during brake operation.

[0008]

SUMMARY OF THE INVENTION In a vehicle, for example, to realize a control (hereinafter referred to as TRC control) for canceling an excessive driving force generated in driving wheels to suppress idling of the wheels. Alternatively, in order to realize the control for stabilizing the vehicle posture by generating a braking force on an appropriate wheel (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 conventional device described above, 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 conventional device, TRC control and V
SC control can be realized.

However, in the above-mentioned conventional apparatus, the mechanical switching valve maintains the master cylinder and the wheel cylinder in a conductive state while the hydraulic pressure supplied from the linear control valve to the wheel cylinder is low. On the other hand, the wheel cylinder pressure P required for TRC control and VSC control
_{W / C} is relatively low pressure. Therefore, according to the above-mentioned conventional device, for a certain period of time after the TRC control or the VSC control is started, those controls are executed in a state where the master cylinder and the wheel cylinder are electrically connected.

The master cylinder is normally communicated with the reservoir tank when the brake pedal is not depressed. Therefore, during the execution of the TRC control and the VSC control, the master cylinder and the reservoir tank are maintained in the conductive state. Therefore, according to the above 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, those controls are executed in a state where the wheel cylinder and the reservoir tank are in conduction. become. Therefore, in the above-mentioned conventional device, it is difficult to secure excellent initial responsiveness when 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.

The present invention has been made in view of the above points, and when the hydraulic pressure source for increasing the wheel cylinder pressure P _{W / C} is changed from the high pressure source to the master cylinder, Brake fluid does not flow backward from the cylinder to the master cylinder, and a large wheel cylinder pressure P
_An object of the present invention is to provide a hydraulic brake control device that can realize excellent initial response when executing control that does not require generation of _{W / C.}

[0012]

The above-mentioned object is defined in claim 1.
As described in, a hydraulic brake that selectively uses, as a hydraulic pressure source, a master cylinder that generates a hydraulic pressure according to the brake operating amount and a high pressure source that generates a predetermined hydraulic pressure regardless of the brake operating amount. in the control unit, a front SL and the solenoid valve for controlling the conduction state between the master cylinder and the wheel cylinder, linear control valve that obtained by supplying the hydraulic pressure generated by the said high pressure source to the reduced pressure to the wheel cylinder to the target hydraulic pressure, the First fail-safe means for stopping the control of the linear control valve and disconnecting the high-pressure source and the wheel cylinder when the hydraulic pressure supplied from the linear control valve to the wheel cylinder is not controlled in the vicinity of the target hydraulic pressure. And after the high pressure source and the wheel cylinder are cut off by the first fail-safe means,
This is achieved by a hydraulic brake control device that includes a second fail-safe means that opens the electromagnetic valve and brings the master cylinder and the wheel cylinder into conduction.

[0013]

In the present invention, when 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. As a result, the wheel cylinder 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, high pressure brake fluid cannot flow backward from the wheel cylinder to the master cylinder after the solenoid valve is opened. Absent.

The above-mentioned object is, as described in claim 2, that the master cylinder generates a hydraulic pressure corresponding to a brake operation amount.
Generates a predetermined hydraulic pressure regardless of the amount of brake operation
And a high-pressure source that selectively use as a hydraulic pressure source.
In the control device, the master cylinder and the wheel cylinder
Solenoid valve that controls the electrical connection with the
To the target hydraulic pressure and supply it to the wheel cylinder.
A linear control valve to obtain, when the request for supplying hydraulic pressure wheel cylinder from the high pressure source has disappeared, and stops the control of the linear control valve, a first ending means for blocking said high pressure source and the wheel cylinder And by the first ending means,
Also achieved by a hydraulic brake control device, comprising: a second ending means for opening the solenoid valve and bringing the master cylinder and the wheel cylinder into conduction after the high pressure source and the wheel cylinder are disconnected. To be done.

In the present invention, when it becomes unnecessary 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 wheel cylinder and the master cylinder are electrically connected. To be in a 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 back from the wheel cylinder to the master cylinder.

Further, according to the above process, when it is not necessary to supply the hydraulic pressure to the wheel cylinder, the wheel cylinder and the master cylinder can always be brought into a conductive state. The master cylinder communicates with the reservoir tank when the brake operation is not performed. Therefore, in the present invention, the wheel cylinder is brought into conduction with the reservoir tank when it is not necessary to supply hydraulic pressure to the wheel cylinder. If this situation occurs when hydraulic pressure does not need to be supplied to the wheel cylinders, the wheel cylinder pressure will be maintained at atmospheric pressure, even if, for example, the linear control valve is leaking hydraulic pressure. can do. Furthermore,
For the above-mentioned purpose, as described in claim 3, the brake operation is performed.
A master cylinder that generates hydraulic pressure according to the amount, and a brake
Select a high pressure source that generates a predetermined hydraulic pressure regardless of the manipulated variable
The hydraulic brake control device used as a hydraulic pressure source
By increasing the master cylinder pressure,
Solenoid valve that shuts off the cylinder and wheel cylinder
And reduce the hydraulic pressure generated by the high pressure source to the target hydraulic pressure.
The linear control valve that can be supplied to the cylinder and the high pressure source.
When the demand to supply hydraulic pressure to the wheel cylinder disappears
To stop the control of the linear control valve,
First ending means for shutting off the wheel cylinder;
The high pressure source and the foil cylinder are shielded by the termination means.
After being cut off, the solenoid valve is opened and the mass
The second end that brings the cylinder and the wheel cylinder into conduction.
Hydraulic brake control characterized by comprising:
It is also achieved by the device. In the present invention, the master
The Linda pressure is increased and hydraulic pressure is supplied to the wheel cylinder.
When the need arises, the master cylinder and wheel cylinder
The solenoid valve is driven to shut off and the foil shield
Control the Linda pressure to the target hydraulic pressure according to the master cylinder pressure.
The linear control valve is driven to control. Suitable for linear control valve
If positive hydraulic pressure is generated, the master cylinder pressure must be increased.
Immediately after the operation, the solenoid valve is closed and the master
The Linda and the wheel cylinder are cut off. others
Because, Ho yl cylinder pressure is issued from the linear control valve
It exhibits excellent responsiveness in the region where the liquid pressure is low. Well
Eliminates the need to supply hydraulic pressure to the wheel cylinder
Then, the control of the linear control valve is stopped first, and then the electromagnetic
By opening the valve, the wheel cylinder and master
The Linda is brought into conduction. According to this process,
When the il cylinder and master cylinder are electrically connected
The high pressure break from the wheel cylinder to the master cylinder.
Kiflude will never flow backwards.

[0018]

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 according to 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 has a stroke simulator 14
The master cylinder 16 is connected via.

The stroke simulator 14 is designed so that when the brake pedal 12 is depressed, the brake pedal 12
In addition, it is a mechanism that gives a stroke according to the brake pedal force. The master cylinder 16 has two hydraulic chambers inside. A master cylinder pressure P _{M / C} corresponding to the brake pedal force is generated in these hydraulic chambers. A reservoir tank 18 is arranged above the master cylinder 16. 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 master cylinder 16 includes a first hydraulic passage 2
0 and the second hydraulic passage 22 communicate with each other. First hydraulic communication
The passage 20 has a hydraulic pressure, that is, a mass, introduced therein.
Ta cylinder pressure P_{M / C}P that outputs a signal according to_{M / C}Sen
A support 24 is provided. P _{M / C}Output signal of sensor 24
Are supplied to the ECU 10. ECU10 is P
_{M / C}Based on the output signal of the sensor 24, the master cylinder pressure
P_{M / C}To detect.

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. As will be described later, the mechanical pressure increasing valve 26 generates a hydraulic pressure having a predetermined boosting ratio with respect to the master cylinder pressure P _{M / C} introduced to the first hydraulic pressure passage 20, and the hydraulic pressure is generated by the front hydraulic pressure. The pressure increasing valve discharges to the pressure passage 28.

An M / C cut valve Fr main 30 is arranged in the front hydraulic passage 28. M / C cut valve F
The r-main 30 normally maintains the valve open state, and the ECU 10
The valve is closed when the drive signal is supplied from 2
Position solenoid valve. The front hydraulic pressure passage 28 branches into an Fr first passage 34 and an Fr second passage 36. F
A wheel cylinder 37 arranged on one of the left and right front wheels communicates with the first passage 34. Also, the Fr first passage 3
The P _{W / C} sensor 38, which outputs a signal corresponding to the hydraulic pressure generated inside thereof, that is, the wheel cylinder pressure P _{W / C} generated in the wheel cylinder 37, communicates with 4. P
The output signal of the _{W / C} sensor 38 is supplied to the ECU 10. The ECU 10 determines 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 is provided in the second Fr passage 36.
An r sub 40 is provided. The M / C cut valve Fr sub 40 is a two-position solenoid valve that normally maintains the valve open state and is closed when a drive signal is supplied from the ECU 10. A wheel cylinder 42 arranged on the other of the left and right front wheels communicates with the Fr second passage 36. Furthermore,
Fr in the second passage 36, P _{W / C} for outputting a signal corresponding to the wheel cylinder pressure P _{W / C} generated in the wheel cylinder 42
The sensor 44 is in communication. The ECU 10 detects the wheel cylinder pressure P _{W / C} generated in the wheel cylinder 42 based on the output signal of the P _{W / C} sensor 44.

An M / C cut valve Rr main 46 is provided in the second hydraulic pressure passage 22 communicating with the master cylinder 16. The M / C cut valve Rr main 46 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. 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.
Further, in the Rr first passage 48, a P _{W / C} sensor 5 that outputs a signal corresponding to the hydraulic pressure generated inside the Rr first passage 48, that is, the 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
Supplied to U10. The ECU 10 detects the wheel cylinder pressure P _{W / C} generated in the wheel cylinder 52 based on the output signal of the P _{W / C} sensor 54.

In the Rr second passage 50, 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 a valve 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
The sensor 60 is in communication. The ECU 10 detects the wheel cylinder pressure P _{W / C} generated in the wheel cylinder 58 based on the output signal of the P _{W / C} sensor 60.

The hydraulic brake control device includes a reservoir passage 62 communicating with the reservoir tank 18. The reservoir passage 62 communicates with the mechanical pressure increasing valve 26 described above, and also communicates with the suction side of the pump mechanism 66 via the check valve 64. A high pressure passage 70 communicates with the 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
At 0, the UL switch 74 that generates an ON signal when the hydraulic pressure in the high-pressure passage 70 (hereinafter, referred to as accumulator pressure P _ACC ) exceeds the upper limit value, and the accumulator pressure P
An LL switch 76 that outputs an ON signal when _ACC exceeds the lower limit 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 its upper limit value and its lower limit value.

A constant pressure release valve 78 is arranged between the high pressure passage 70 and the reservoir passage 62. Constant pressure release valve 78
Is when the hydraulic pressure on the high pressure passage 70 side becomes higher than the hydraulic pressure on the reservoir passage 62 side by exceeding a predetermined valve opening pressure,
This is a one-way valve that allows only the flow of fluid from the high-pressure passage 70 side toward the reservoir passage 62 side. The high pressure passage 70 communicates with the mechanical pressure increasing valve 26 described above. The mechanical pressure increasing valve 26 uses the accumulator pressure P _ACC introduced from the high pressure passage 70 and the atmospheric pressure introduced from the reservoir passage 62 to generate a liquid having a predetermined boosting ratio with respect to the master cylinder pressure P _{M / C.} Generate pressure.

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

Fr first passage 34, Fr second passage 36, R
Linear pressure reducing valves 90, 92, 94, 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 valves 90, 92, 9
Reference numerals 4 and 96 denote brake fluid flowing from the Fr first passage 34, the Fr second passage 36, the Rr first passage 48, and the Rr second passage 50 side to the reservoir passage 62 in accordance with the drive signal supplied from the ECU 10. It is a control valve that controls the amount linearly.

In the hydraulic brake control apparatus according to the present embodiment, the ECU 10 controls when the brake pedal 12 is depressed and when the brake pedal 12 is released, but the vehicle behavior control is required. 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 will be referred to as normal brake control, and the control executed in the latter case will be 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 increase 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
A state communicating with 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 brought into communication with each other. Therefore, in the above state, the wheel cylinders 37, 42, 52 and 58 are in communication with the reservoir tank 18. When the wheel cylinders 37, 42, 52, 58 and the reservoir tank 18 communicate with each other in this manner, for example, the linear control valves 80, 82, 8
Even if there is an abnormality that causes brake fluid to leak to 6, 88, wheel cylinder pressure P of all wheels
_{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, 88, the brake drag phenomenon does not occur.

In the hydraulic brake control device, when normal brake control or automatic brake control is required,
All the M / C cut valves 30, 40, 46, 56 are closed, the Rr pressure increase cut valve 84 is opened, and the linear control valves 80, 82, 86, 88, 90, 9 are used.
2,94,96 are suitable wheel cylinder pressure P _{W /} for each wheel
_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} corresponding to the states of the linear control valves 88 and 96 is generated.

According to the control described above, the brake pedal 1
When 2 is stepped on, for example, the function as a normal brake device or the well-known antilock brake
The function of the system (ABS) and the like 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 controller, 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 properly controlled. According to the hydraulic brake control device of the present embodiment, when such an abnormality is detected, all the M / C cut valves 30, 4 will be subsequently processed.
0, 46, 56 are always kept open, and all linear control valves 80, 82, 86, 88, 90, 92,
94 and 96 are kept closed.

When the above state is realized in the hydraulic brake controller, the wheel cylinders 37, 42,
A state in which 52 and 58 communicate with the master cylinder 16 is formed. In this case, at least all wheel cylinders 37, 42, 52, 58 can generate a wheel cylinder pressure P _{W / C} equal to the master cylinder pressure P _{M / C.} Further, when the mechanical pressure increasing valve 26 functions normally, the wheel cylinder pressures P _{W /} having a predetermined boosting ratio with respect to the master cylinder pressure P _{M / C} are applied to the wheel cylinders 37, 42 of the left and right front wheels. _C can be generated. As described above, the hydraulic brake control device according to the present embodiment has an excellent fail-safe ability against abnormalities in 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 in the open state are opened.
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 valve 56 changing from the valve open state to the valve closed state is poor, the wheel cylinders 37, 42, 52, and 58 are operated by the wheel cylinders 37, 42, 52, and 58 via the master cylinder 16 for a certain period after the request for the automatic brake control is generated. The state of communicating with the tank 18 is maintained.

Under the condition that the wheel cylinders 37, 42, 52, 58 communicate with the reservoir tank 18, it is difficult to properly match the wheel cylinder pressure P _{W / C} of each wheel to the target hydraulic pressure. In this respect, automatic brake control (TRC, V
In order to improve the controllability of (SC, control for realizing automatic braking, etc.), the M / C cut valves 30, 40, 46,
It is important to give 56 good responsiveness.

In the hydraulic brake control system of this embodiment, as described above, the M / C cut valves 30, 40, 46 and 56 are electromagnetic valves. In addition, M / C cut valves 30, 4
0, 46, and 56 are the E that issues 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.
The valves 0, 46 and 56 can be closed. Therefore, according to the system of the present embodiment, it is possible to secure excellent controllability in automatic brake control.

In the hydraulic brake control device of this embodiment, when the request for normal brake control disappears, 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 which is in the closed state is closed.
The cut valves 30, 40, 46, 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 cylinder 37,
A large amount of high pressure brake fluid flows back from the 42, 52, 58 side to the master cylinder 16 side.

Further, in the hydraulic brake control system 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
When 4,96 abnormalities are detected, the linear control valves 80, 82, 86, 88, 90, 92, 94, 9 are then detected.
The control of 6 was stopped and the valve was closed.
/ C cut valves 30, 40, 46 and 56 are opened. Even 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 wheel cylinders 37, 42, 52, 58 will be moved to the master cylinder 16 side.
A large amount of high pressure brake fluid flows back to the side.

In order to ensure the durability of the master cylinder 16 or to suppress the generation of unnecessary pedal kickback during brake operation, it is desirable to suppress such a reverse flow of brake fluid. In order to satisfy the above requirements, the hydraulic brake device of the present embodiment eliminates an abnormality in the linear control valves 80, 82, 86, 88, 90, 92, 94, 96 when the brake control requirement disappears. When detected, the linear control valves 8 in proper sequence
Control stop of 0, 82, 86, 88, 90, 92, 94, 96 and M / C cut valve 30, 40, 46, 56
It is characterized in that the valve opening process is performed. Hereinafter, the characteristic part of the hydraulic brake control device will be described with reference to FIG.

FIG. 2 shows a flow chart of an example of a control routine executed in the hydraulic brake control system of this embodiment. The routine shown in FIG. 2 is a timed interrupt routine that is activated every predetermined time. When the routine shown in FIG. 2 is started, the process of step 100 is first executed. At step 100, it is judged if execution of automatic brake control is requested. As a result, if it is determined that the execution of the automatic brake control is not requested, then the process of step 102 is executed. On the other hand, when it is determined that the execution of the automatic brake control is requested, the step 102 is skipped, and then the step 1
The processing of 04 is executed.

At step 102, it is judged if the P _{M / C} sensor 24 is producing an output. As a result, P
_When it is determined that the _{M / C} sensor 24 is producing an output, 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 the P _{M / C} sensor 24 is not outputting, steps 104 to 10 are performed thereafter.
8 is jumped, and the processing of step 110 is executed.

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

In step 106, the linear control valves 80, 82, 86, 88, 90, 92, 9 are used to match the wheel cylinder pressure P _{W / C} of each wheel to the respective target hydraulic pressure.
4, 96 are driven. When the process of step 106 is completed, the process of step 108 is executed next. In step 108, the P _{W / C} sensors 38, 44, 5 of each wheel are
It is determined whether or not 4 and 60 detect an abnormal wheel cylinder pressure P _{W / C.} Specifically, it is determined whether or not the P _{W / C} sensor 38, 44, 54, 60 of each wheel detects a hydraulic pressure that is significantly different from the target hydraulic pressure of each wheel. As a result, if the detected values of the P _{W / C} sensors 38, 44, 54, 60 are abnormal, 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 then executed. On the other hand, the P _{W / C} sensor 38,
When it is determined that the detected values of 44, 54 and 60 are not abnormal, steps 110 and 112 are jumped thereafter, and the routine of this time is promptly ended.

In step 110, the linear control valve 80,
The process of stopping the control of 82, 86, 88, 90, 92, 94, 96 is executed. When the processing of this step 110 is executed, the linear control valves 80, 82, 86, 88 are closed and the wheel cylinders 37, 42, 52, 58 are closed.
The high pressure passage 70 is cut off. This step 110
When the processing of (1) is completed, the processing of step 112 is executed next.

In step 112, all the M / C cut valves 30, 40, 46, 56 are opened and Rr
Processing of the pressure-increasing cut valve 84 in the closed valve state is executed.
When the processing of step 112 is executed, a state in which the wheel cylinders 37, 42, 52, 58 communicate with the master cylinder 16 is formed. When the process of step 112 is completed, the routine of this time is ended.

According to the processing of this routine, when the execution request of the automatic brake control disappears and when the execution request of the normal brake control disappears, step 100 is executed.
After the processing of steps 102 and 102 is performed, first, the wheel cylinders 37, 42, 52, 58 and the high-pressure passage 70 are cut off (step 110), and then the wheel cylinders 37, 42, 52, 58 and the master cylinder. By establishing communication with 16 (step 112), a state for maintaining the wheel cylinder pressure P _{W / C} at atmospheric pressure is formed. In this case, M / C cut valves 30, 40, 46, 5
A large amount of high-pressure brake fluid does not flow back to the master cylinder 16 when the valve 6 is opened.

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

As described above, according to the hydraulic brake control apparatus of this embodiment, the wheel cylinders 37, 42, 52, 58 are provided.
Side, the master cylinder 16 side is prevented from flowing back a large amount of high pressure brake fluid, and excellent controllability is ensured for automatic brake control, and the linear control valves 80, 8 are provided.
It is possible to realize a fail-safe function for abnormalities such as 2,86,88,90,92,94,96.

In the above embodiment, the pump mechanism 66 is the "high pressure source" described in claim 1, and the M / C cut valves 30, 40, 46, 56 are the "solenoid valve" described in claim 1. , And the ECU 10
The "first fail-safe means" according to claim 1, by executing the processes of steps 108 and 110.
However, the "second fail-safe means" according to claim 1 is realized by executing the process of step 112.

Further, in the above embodiment, the ECU 1
0, "the first ending means" of the claims 2 and 3 wherein by executing the process of step 1 0 0,102 and 110, claim 2 and by executing the processing in step 112 The “second terminating means” described in 3 are respectively realized.

[0054]

As described above, according to the first aspect of the present invention, when the control in which the hydraulic pressure supplied from the linear control valve to the wheel cylinder does not become so high is executed, an excellent initial value is obtained. In addition to being able to realize responsiveness, when the hydraulic pressure cannot be properly supplied from the linear control valve to the wheel cylinder, the high pressure brake fluid flows back from the wheel cylinder side to the master cylinder side. Without this, it is possible to realize a state in which the master cylinder pressure P _{M / C} can be guided to the wheel cylinder.

According to the second and third aspects of the present invention, when the need to supply hydraulic pressure to the wheel cylinder disappears, the wheel cylinder does not flow back high pressure brake fluid from the wheel cylinder to the master cylinder. And the master cylinder can be brought into conduction.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a hydraulic brake control device corresponding 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]

10 electronic control unit (ECU) 16 master cylinder 24 P _{M / C} sensor 26 mechanical pressure increasing valve 30, 40, 46, 56 M / C cut valve 37, 42, 52, 58 wheel cylinder 38, 44, 54, 60 P _{W / C} sensor 66 Pump mechanism 80, 82, 86, 88, 90, 92, 94, 96 Linear control valve

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60T 17/18 B60T 13/12 B60T 13/66

Claims (3)

(57) [Claims] 1. A hydraulic brake that selectively uses, as a hydraulic pressure source, a master cylinder that generates a hydraulic pressure according to a brake operating amount and a high pressure source that generates a predetermined hydraulic pressure regardless of the brake operating amount. In the control device, an electromagnetic valve that controls the conduction state between the master cylinder and the wheel cylinder, a linear control valve that can reduce the hydraulic pressure generated by the high-pressure source to a target hydraulic pressure and supply the hydraulic pressure to the wheel cylinder, and the linear control First fail-safe means for stopping the control of the linear control valve to shut off the high pressure source and the wheel cylinder when the hydraulic pressure supplied from the valve to the wheel cylinder is not controlled in the vicinity of the target hydraulic pressure; After the high pressure source and the wheel cylinder are shut off by the first fail-safe means, the solenoid valve is opened to guide the master cylinder and the wheel cylinder. Hydraulic brake control apparatus, characterized in that it comprises a second fail-safe means for the state, the. 2. A hydraulic brake that selectively uses, as a hydraulic pressure source, a master cylinder that generates a hydraulic pressure according to the amount of brake operation and a high pressure source that generates a predetermined hydraulic pressure regardless of the amount of brake operation. In the control device, an electromagnetic valve that controls the conduction state between the master cylinder and the wheel cylinder, a linear control valve that can reduce the hydraulic pressure generated by the high pressure source to a target hydraulic pressure and supply the hydraulic pressure to the wheel cylinder, and the high pressure source When the request to supply hydraulic pressure from the wheel cylinder disappears, the control of the linear control valve is stopped,
A first terminating means for disconnecting the high pressure source and the wheel cylinder; and, after the high pressure source and the wheel cylinder are disconnected by the first terminating means, the solenoid valve is opened.
Hydraulic brake control device, comprising: a second end means for bringing the master cylinder and the wheel cylinder into a conductive state. 3. A hydraulic pressure is generated according to a brake operation amount.
Master cylinder and specified hydraulic pressure regardless of brake operation amount
Liquid used selectively as a fluid pressure source and a pressure source for generating
In the pressure brake control device, the master cylinder pressure is increased to increase the master cylinder pressure.
A solenoid valve that disconnects the binder and the wheel cylinder, and a wheel seal that reduces the hydraulic pressure generated by the high pressure source to a target hydraulic pressure.
The linear control valve that can be supplied to the Linda and the request to supply hydraulic pressure to the wheel cylinder from the high pressure source are required.
When it disappears, stop the control of the linear control valve,
First termination means for disconnecting the high pressure source and the wheel cylinder
And the high-pressure source and the foil cillin by the first terminating means.
After the da and are cut off, the solenoid valve is opened,
The master cylinder and the wheel cylinder are electrically connected.
And a second terminating means which is a hydraulic brake control device.