JPH09123892A - Hydraulic control device for brake of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce accumulated fluid pressure and an accumulated fluid quantity of an accumulator by connecting a hydraulic pump control means to a wheel brake hydraulic control means, and actuating a hydraulic pump regardless of detecting output of an accumulator fluid pressure detecting means when brake fluid pressure is automatically adjusted. SOLUTION: On a hydraulic pump control of a brake, at antilock control time of a low μ road surface, intermittent actuation of an electric motor is set, and of high μ road surface and medium μroad surface time, the electric motor is set on. When antilock control is not performed, and when accumulator fluid pressure by an accumulator fluid pressure detecting means is not more than a preset value PH, the electric motor is turned on, and when it is not less than the preset value, and when the electric motor is tuened on, the electric motor is turned off after a prescribed time. In this way, accumulator fluid pressure increases by a specific quantity more than the preset value PH. That is, a hydraulic pump is actuated regardless of detecting output of the accumulator fluid pressure detecting means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake fluid pressure control device, and more particularly to an accumulator for accumulating high-pressure hydraulic fluid and an accumulator fluid pressure input from this accumulator into a fluid pressure corresponding to a brake operating force. The present invention relates to a vehicle brake fluid pressure control device that includes a regulator that adjusts and outputs the pressure, and a hydraulic pressure adjustment device that reduces the wheel brake fluid pressure and reincreases the wheel brake fluid pressure by the output fluid pressure of the regulator.

[0002]

2. Description of the Related Art The anti-lock brake system described on pages 3-97 to 3-122 of the Toyota Crown Majesta new model manual (published by Toyota Motor Corporation Service Department on October 11, 1991) is a brake. The brake operating force applied to the pedal is doubled by a hydraulically actuated booster and input to the master cylinder, and the brake hydraulic pressure is supplied from the master cylinder to the wheel brakes.

The booster includes an accumulator for accumulating high-pressure hydraulic fluid, a hydraulic pump for pumping hydraulic fluid from a reservoir to an accumulator, accumulator hydraulic pressure detecting means for detecting hydraulic pressure in the accumulator, and the accumulator hydraulic pressure. From the accumulator, a hydraulic pump control device that starts the operation of the hydraulic pump when the hydraulic pressure detected by the detection means falls below a predetermined lower limit value, and then stops the hydraulic pump when the hydraulic pressure exceeds a predetermined upper limit value. A regulator that adjusts the input accumulator hydraulic pressure to a hydraulic pressure that corresponds to the brake operating force and outputs it, and an output piston that operates by the output hydraulic pressure of this regulator are provided.

In order to perform antilock control, the hydraulic pressure supplied to the wheel brakes is switched from the master cylinder output hydraulic pressure to the regulator output hydraulic pressure in the circuit for supplying the brake hydraulic pressure from the master cylinder to the wheel brakes. Is installed in the circuit from the switch valve to the wheel brake, and a control valve (hydraulic pressure control device) for controlling the opening and closing of the communication state between the switch valve and the wheel brake and the communication state between the wheel brake and the reservoir. ) Is installed.

In the normal state, the control valve is hydraulically connected to the master cylinder by the switching valve, but during antilock control, the control valve is hydraulically connected to the regulator by the switching valve. As a result, in anti-lock control, the fluid in the accumulator is consumed and the fluid in the master cylinder is not consumed when the wheel brake fluid pressure is increased again after the wheel brake fluid pressure is reduced. Change is prevented.

[0006]

In the above antilock brake device in which the hydraulic pump is controlled only in response to the accumulator hydraulic pressure, the coefficient of friction of the road surface (hereinafter referred to as μ To address proper anti-lock control on high roads,
It is necessary to set a high hydraulic pressure to be accumulated in the accumulator and a large amount of accumulated liquid, which is an obstacle to downsizing of the device and cost reduction.

That is, in vehicle braking on a high μ road surface, the wheel brake hydraulic pressure at which the wheels are locked, that is, the wheel lock pressure is high, and therefore a large amount of liquid is consumed by the antilock control. In order to increase the wheel brake hydraulic pressure to a high hydraulic pressure and at an appropriate rate of change when re-pressurizing in the antilock control process, the accumulator hydraulic pressure is much higher than the wheel lock pressure on a high μ road surface. Therefore, the hydraulic pressure accumulated in the accumulator must be set high and the amount of accumulated liquid must be set high.

As described above, it is necessary to set the hydraulic pressure accumulated in the accumulator to be high and to set the accumulated liquid amount to be large, because the control valve is switched from the master cylinder to the regulator by the switching valve during the antilock control. Not limited to this, the regulator output hydraulic pressure is used to re-increase the wheel brake hydraulic pressure in antilock control, such as the configuration that supplies regulator output hydraulic pressure to the wheel brake during both normal braking and antilock control. It exists in an anti-lock braking device configured to do so.

Further, it is necessary to set the hydraulic pressure accumulated in the accumulator to be high and the accumulated liquid amount to be large.
It is not limited to the case of performing antilock control,
When the vehicle falls into an unstable state while the vehicle is not being operated for braking, one wheel brake or a plurality of wheel brakes may be operated to perform stability control for maintaining vehicle stability.

Further, in the structure in which the control valve is switched from the master cylinder to the regulator by the switching valve during the antilock control, the accumulator hydraulic pressure is lowered by the antilock control on the high μ road surface, and the master cylinder hydraulic pressure ( When the wheel lock pressure is considerably lower than (the wheel lock pressure), a hunting phenomenon occurs in which the start and end of the antilock control are repeated, which causes an inconvenience to the occupant. In other words, generally, when the re-increase duration of the wheel brake hydraulic pressure exceeds the predetermined time, the antilock control is terminated, so the accumulator hydraulic pressure decreases and the wheel brake hydraulic pressure reaches the wheel lock pressure at an appropriate rate of change. When the pressure cannot be increased with, the anti-lock control ends, the wheel brake hydraulic pressure is returned to the master cylinder hydraulic pressure (wheel lock pressure), and the wheels lock again to start the anti-lock control. A hunting phenomenon occurs, which causes a problem such as an occupant feeling discomfort.

According to the invention of this application, an accumulator for accumulating high-pressure hydraulic fluid, a regulator for adjusting the accumulator hydraulic pressure input from the accumulator to a hydraulic pressure corresponding to the brake operating force, and outputting the wheel brake hydraulic pressure. In a vehicle brake hydraulic pressure control device equipped with a hydraulic pressure adjusting device that reduces pressure and re-increases using the output hydraulic pressure of a regulator, the hydraulic pressure to be accumulated in an accumulator is set lower than before and the accumulated liquid amount An object of the present invention is to make it possible to perform satisfactory wheel brake hydraulic pressure control even if the amount is set to a smaller value.

[0012]

An anti-lock brake device according to the invention of this application is described in claim 1 and as shown in FIG. 1, an accumulator for accumulating high-pressure hydraulic fluid and a hydraulic fluid A hydraulic pump for sending pressure from a reservoir to the accumulator, an accumulator hydraulic pressure detecting means for detecting the hydraulic pressure in the accumulator, and a hydraulic pressure for operating and stopping the hydraulic pump based on the detection output of the accumulator hydraulic pressure detecting means. The pump control means, including a regulator that adjusts and outputs the accumulator hydraulic pressure input from the accumulator to a hydraulic pressure corresponding to the brake operating force applied to the brake operating member, to the brake operating force applied to the brake operating member. A hydraulic pressure generator that supplies the corresponding hydraulic pressure to the wheel brakes, and this hydraulic pressure generator and the wheel brakes. A hydraulic pressure adjusting device which is interposed between the hydraulic pressure adjusting device and the hydraulic pressure adjusting device for reducing the wheel brake hydraulic pressure and for increasing the wheel brake hydraulic pressure again by using the output hydraulic pressure of the regulator, and the hydraulic pressure adjusting device based on the input information. In a vehicle brake fluid pressure control device comprising a control means for operating and automatically adjusting wheel brake fluid pressure, the hydraulic pump control means is linked with the control means to automatically adjust the wheel brake fluid pressure. The hydraulic pump is operated regardless of the detection output of the accumulator hydraulic pressure detection means.

In the brake fluid pressure control device constructed as described above, the hydraulic pump is operated in the automatic adjustment process of the wheel brake fluid pressure such as antilock control, and the hydraulic fluid is pumped from the hydraulic pump to the accumulator, so that the wheel The accumulator hydraulic pressure consumed is compensated by automatically adjusting the brake hydraulic pressure. Therefore, the amount of hydraulic pressure and the amount of hydraulic fluid accumulated in the accumulator should be adjusted to the extent that normal braking action is guaranteed.
In other words, when a brake operation is performed on a high μ road surface, the wheel brake hydraulic pressure can be increased to the wheel lock pressure and can be set so that it can be maintained until the brake operation is released. Further, during antilock control, hunting of antilock control in the antilock control device configured to switch and connect the hydraulic pressure control device from the master cylinder to the regulator can be eliminated.

Incidentally, in order to prevent the hydraulic pressure of the accumulator from rising to the relief pressure by operating the hydraulic pump in the process of automatically adjusting the hydraulic pressure of the wheel brakes, as described in claim 2, the road surface A road surface friction coefficient estimating means for estimating μ is provided, and the fluid pressure pump control means is linked to the road surface friction coefficient estimating means to operate the fluid pressure pump in the antilock control process. Whether the operation mode switching means for continuously operating the hydraulic pump when the determination result of is high μ or intermittently operating the hydraulic pump when the determination result of the road surface friction coefficient estimating means is low μ is provided. Alternatively, as described in claim 3, a road surface friction coefficient estimating means for estimating μ of the traveling road surface is provided, and the hydraulic pump control means includes the road surface friction coefficient estimating means. When the judgment result of the road surface friction coefficient estimating means is high when the hydraulic pump is operated in the antilock control process, the hydraulic pump is continuously operated, and the judgment of the road surface friction coefficient estimating means is made. It is preferable to provide an operation mode switching means for deactivating the hydraulic pump when the result is low μ.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the invention according to this application will be described below with reference to FIGS.

FIG. 2 shows a schematic structure of an antilock brake device for an FR vehicle (vehicle with front engine / rear drive). In FIG. 2, the hydraulic pump PM is driven by the electric motor MT to pump the hydraulic fluid in the reservoir REV to the accumulator ACC. PSW is a pressure-responsive electric switch for detecting the hydraulic pressure in the accumulator ACC, and sends its output signal to the electric control unit ECU.
The electric control unit ECU operates and stops the electric motor MT,
That is, the operation and stop of the hydraulic pump PM are controlled. The regulator RG adjusts the accumulator hydraulic pressure input from the accumulator ACC to a hydraulic pressure corresponding to the brake operating force applied to the brake pedal BP, and outputs it to the rear wheel brake hydraulic pressure conduit PR. The master cylinder MC is
The hydraulic pressure corresponding to the brake operating force applied to the brake pedal BP is output to the front wheel brake hydraulic pressure line PF. The relief valve RV is opened when the hydraulic pressure of the accumulator ACC becomes an abnormally high pressure value, and prevents the pressure from further increasing.

The brake pedal BP is a master cylinder MC.
Is located on one end side of the master cylinder MC and the regulator RG is located on the other end side of the master cylinder MC, and the brake operating force is transmitted from the brake pedal BP to the regulator RG via the master cylinder MC. In the master cylinder MC, the piston inside thereof is connected to the rear wheel brake line P.
It is designed to be assisted by the regulator output hydraulic pressure supplied by the R branch line PR1. The detailed structure of the master cylinder MC and the regulator RG has no relation to the features of the invention of this application and is already known (for example, it is shown in GB2285292A, which is the publication of the British patent application), and therefore its description is omitted. To do.

The pressure-responsive electric switch PSW is turned off when the accumulator fluid pressure exceeds a set value PH, and is turned on when the accumulator fluid pressure drops below the set value PH, and its on / off output signal is output to the electrical control device. E
Send to CU. The set value PH is a little higher than the wheel lock pressure on the high μ road surface.

The master cylinder output hydraulic pressure output to the front wheel brake hydraulic pressure line PF is the front wheel brake hydraulic pressure line P.
Front left wheel brake WBF by F and its branch line PF1
L is transmitted to the front wheel brake hydraulic line PF.
And the front right wheel brake WBFR by the branch line PF2
Is transmitted to The normally open opening / closing solenoid valves SFLH and SFRH at the 2-port-2 position are respectively arranged in the branch pipelines PF1 and PF2, and branch from the discharge pipeline PD communicating with the reservoir RV and solenoid valves SFLH and SF.
A branch conduit PD that communicates with conduits PF1 and PF2 between the RH and the wheel brakes WBFL and WBFR, respectively.
The normally closed solenoid valves SFLR and SFRR at 2 ports and 2 positions are arranged at 1 and PD2, respectively. In the pipe line PF, the pipe lines PF1 and PF2 are normally communicated with the master cylinder MC, but when operating, the pipe lines PF1 and PF2 are connected.
The communication between F2 and the master cylinder MC is cut off, and the pipeline PF
1, PF2 to the branch line P of the rear wheel brake hydraulic pressure line PR
A 3-port / 2-position switching solenoid valve SA communicating with R2 is arranged. The regulator output hydraulic pressure output to the rear wheel brake hydraulic pressure conduit PR is the conduit PR and its branch conduit PR.
3 is transmitted to the rear left wheel brake WBRL, and is also transmitted to the rear right wheel brake WBRR by the conduit PR and its branch conduit PR3.

On the branch lines PR3 and PR4, normally open and closed solenoid valves SRLH and SRRH at two ports and two positions are respectively arranged, which branch from the discharge line PD and solenoid valves SRLH and SRRH, and wheel brakes WBRL and 2 ports 2 are provided in the branch conduits PD3 and PD4 communicating with the conduits PR3 and PR4 between the WBRR and the WBRR, respectively.
Positionally closed normally open / close solenoid valves SRLR and SRRR are respectively arranged.

Wheel speed sensors SNFL, SNFR, SN
RL and SNRR are the front left WFL, the front right wheel WFR,
Output signals representing the wheel speeds of the rear left wheel WRL and the rear right wheel WRR are sent to the electric control unit ECU.

To the electric control unit ECU, an ON / OFF output signal of the ignition switch IGSW is input, and further, a signal representing the acceleration detected by detecting the acceleration applied to the vehicle is input from the acceleration sensor GSN.

Solenoid valves SA, SFLH, SFLR, SFR
H, SFRR, SRLH, SRLR, SRRH and S
The RRR is controlled by the electric control unit ECU. The electric control unit ECU uses solenoid valves SA, SFLH, SFLR, SF
When RH, SFRR, SRLH, SRLR, SRRH and SRRR are turned off, that is, when the position shown in FIG. 2 is occupied, the brake operating force is applied to the brake pedal BP, and the master corresponding to the brake operating force is applied. When the cylinder output hydraulic pressure and the regulator output hydraulic pressure are output to the conduits PF and PR, respectively, the master cylinder output hydraulic pressure is the wheel brakes WBFL and WBFR.
Is transmitted to the wheel brakes WBRL and WBRR, and the regulator output hydraulic pressure is transmitted to the wheels WFL and WFL.
The braking force corresponding to the braking operation force is applied to FR, WRL, and WRR.

The brake fluid pressure of the wheel brake WBFL when the brake operation is being performed turns on the solenoid valve SA to connect the pipelines PF1 and PF2 to the pipeline PR2, and the solenoid valves SFLH and SFLR respectively. By controlling the on / off control, the pressure can be reduced and increased again. For example, if the solenoid valve SFLH is turned on and the solenoid valve SFLR is turned off, the brake fluid pressure of the wheel brake WBFL is maintained.

When the solenoid valve SFLH is turned on and the solenoid valve SFLR is also turned on, the brake fluid of the wheel brake WBFL is discharged to the reservoir RV via the discharge conduit PD, and the brake fluid pressure of the wheel brake WBFL is reduced. . If the solenoid valves SFLH and SFLR are turned off after reducing the brake fluid pressure of the wheel brake WBFL, the pressure brake of the conduit PR2 is supplied to the wheel brake WBFL and the brake fluid pressure of the wheel brake WBFL is increased again. . When the brake fluid pressure of the wheel brake WBFL is increased again, when the solenoid valve SFLH is repeatedly turned on and off, the brake fluid pressure of the wheel brake WBFL is increased stepwise,
A so-called pulse pressure increase is performed, and a so-called dither pressure increase is achieved by setting a short ON / OFF cycle of the solenoid valve SFLH at that time. Similarly, when the brake fluid pressure of the wheel brake WBFL is reduced, if the solenoid valve SFLR is repeatedly turned on and off, the brake fluid pressure of the wheel brake WBFL is reduced stepwise, which is so-called pulse pressure reduction.

The brake fluid pressure of the wheel brake WBFR when the brake operation is performed turns on the solenoid valve SA to connect the pipelines PF1 and PF2 to the pipeline PR2, and causes the solenoid valves SFRH and SFRR to operate. By controlling ON / OFF, pressure reduction, pulse pressure reduction, re-pressure increase, pulse pressure increase, and dither pressure increase can be performed. The brake fluid pressure of the wheel brake WBRL when the brake operation is performed turns on each of the solenoid valves SRLH and SRLR,
By performing off control, pressure reduction, pulse pressure reduction, re-pressure increase, pulse pressure increase, and dither pressure increase can be performed. Similarly, the wheel brake WB when a brake operation is performed.
The brake fluid pressure of the RL can be reduced, pulse reduced, re-incremented, pulse increased, or dither increased by controlling each of the solenoid valves SRLH and SRLR to be turned on and off. Details thereof are apparent from the description of the brake fluid pressure of the wheel brake WBFL, and thus the description thereof will be omitted.

As shown in FIG. 3, the electric control unit ECU includes a CPU, a ROM, and an R that are mutually connected via a bus.
It has a microcomputer including an AM, a timer, an input port and an output port. The microcomputer has an output signal of the ignition switch IGSW,
The output signal of the pressure-responsive electric switch PSW, the output signals of the wheel speed sensors SNFL, SNFR, SNRL and SNRR and the output signal of the acceleration sensor GSN are input from the input port. Further, a control signal is output from the output port of the microcomputer to the electric motor MT via the drive circuit DRV1, and the drive circuits DRV2 and DRV are also provided.
V3, DRV4, DRV5, DRV6, DRV7, DR
Solenoid valve SA via V8, DRV9 and DRV10
SFLH, SFLR, SFRH, SFRR, SRLH,
Control signals are output to SRLR, SRRH and SRRR, respectively. The ROM stores a program corresponding to each of the flowcharts shown in FIGS. 4 to 7, the CPU executes the program while the ignition switch is closed, and the RAM temporarily stores variable data necessary for executing the program. Remember.

When the ignition switch is closed, execution of the program corresponding to the flowcharts of FIGS. 4 to 7 starts. When the program starts running
Initial setting is performed in step 101 of 1., various calculated values, estimated vehicle body speed VS0 representing vehicle speed, and wheel speeds VWF.
L, VWFR, VWRL, VWRR and each wheel acceleration DVWFL, DVWFR, DVWRL, DVWRR, etc. are cleared. Then, in step 102, the output signal of the pressure-responsive electric switch PSW, the wheel speed sensor S
The NFL, SNFR, SNRL and SNRR output signals and the acceleration sensor GSN output signal are read,
Next, at step 103, the wheel speeds VWFL, V
WFR, VWRL and VWRR are calculated and then at step 104 each wheel acceleration DVWFL, DVW
FR, DVWRL, and DVWRR are calculated, then the estimated vehicle body speed VS0 is calculated in step 105, and the routine proceeds to step 106. In step 106, road surface μ calculation is performed, then in step 107, front left wheel WFL control calculation is performed, and then step 108.
In step 109, the front right wheel WFR control calculation is performed, and in step 109, the rear left wheel WRL control calculation is performed.
Next, in step 110, the rear right wheel WRR control calculation is performed, and then in step 111, the hydraulic pump P
M control calculation is performed, and then in step 112, the electric motor MT based on the calculation results of steps 107 to 111,
Solenoid valve SA, SFLH, SFLR, SFRH, SFR
After the control outputs of R, SRLH, SRLR, SRRH and SRRR are output, the process returns to step 102.

The road surface μ is set according to the flowchart of FIG. In FIG. 5, first, at step 201, the average wheel speed of the front left and right wheels that are non-driving wheels = (VWFL + VW
FR) / 2 is below a control (antilock control) start determination threshold value = K · VS0−ΔV1 (K is a constant), and it is determined whether the determination result is N (No). In step 202, the low μ flag and the medium μ flag are turned off, the high μ flag is turned on, and the process returns to the main routine of FIG. When the determination result in step 201 is Y (yes), the routine proceeds to step 203, where it is determined whether the output of the acceleration sensor GSN is less than 0.2 G, and if so, the routine proceeds to step 204 and the low μ flag is turned on. At the same time, the medium μ flag and the high μ flag are turned off, and the process returns to the main routine of FIG. When the determination result in step 203 is N, the routine proceeds to step 205, where it is determined whether or not the output of the acceleration sensor GSN is 0.2 G or more and less than 0.4 G, and when the determination result is Y, the routine proceeds to step 206. Low μ with μ flag turned on
The flag and the high μ flag are turned off, and the process returns to the main routine of FIG. When the determination result in step 205 is N, the process proceeds to step 202.

The front left wheel WFL control is set according to the flowchart of FIG. In FIG. 6, first step 3
In 01, it is determined whether or not control (antilock control) is being performed. If the determination result is N, step 30
The routine proceeds to 2 and it is determined whether or not a predetermined control start condition (when the wheel speed VWFL falls below the control start threshold value) is satisfied. When the determination result of step 302 is N, FIG.
When the determination result is Y, the process proceeds to step 303 and the pressure reducing mode is set, and then the process returns to the main routine of FIG. The determination result in step 301 is Y
When is, it is determined whether or not a predetermined control ending condition (when the pulse pressure increase is continuously executed for a predetermined time and then the dither pressure increase is continuously executed for a predetermined time) is satisfied, and the determination result is obtained. Is N, the routine proceeds to step 303, where a pressure reducing mode (a mode in which solenoid valves SA, SFLH and SFLR are turned on), a pulse pressure reducing mode, according to the deviation of the front left wheel speed VWFL from the control reference wheel speed, the front left wheel acceleration DVWFL and the like. (Solenoid valves SA and SFLH
Is turned on and the solenoid valve SFLR is repeatedly turned on and off), pressure increasing mode (a mode mode in which the solenoid valve SA is turned on and the solenoid valves SFLH and SFLR are turned off), and a pulse pressure increasing mode (the solenoid valve SA is turned on). ON, solenoid valve SFLR is turned OFF, solenoid valve SFLH is repeatedly turned ON and OFF), dither pressure increasing mode (solenoid valve S
A is turned on, solenoid valve SFLR is turned off, solenoid valve SF
LH is repeatedly turned on and off in a short cycle)
After any one of the holding modes (a mode in which the solenoid valves SA and SFLH are turned on and the solenoid valve SFLR is turned off) is set, the process returns to the main routine of FIG. Further, when the determination result in step 304 is Y, the routine proceeds to step 305, where it is determined whether or not the front right wheel WFR is under control. When the determination result is N, the routine proceeds to step 306, during control Normal brake mode Turn on the solenoid valve SFLH
And the mode for turning off the SFLR) are set, and then the process returns to the main routine of FIG. When the determination result in step 305 is Y, the normal brake mode (solenoid valves SA, S
After the FLH and SFLR turning off mode is set, the process returns to the main routine of FIG.

The contents of the front right wheel WFR control, the rear left wheel WRL control, and the rear right wheel WRR control are substantially the same as the contents of the front left wheel WFR control, and it is obvious from the description of the front left wheel WFR control. As it seems, the detailed description is omitted.

The hydraulic pump PM control is set according to the flowchart of FIG. In FIG. 7, first, step 4
In 01, it is determined whether or not all four wheels are in non-control (non-antilock control). If the result of the determination is N, that is, if even one wheel is in antilock control, step 4
02, it is determined whether the low μ flag is on,
When the result of the determination is Y, that is, when antilock control is to be executed on a low μ road surface, the routine proceeds to step 403, where MT intermittent operation is set (the motor MT is turned on for a predetermined time and then turned off for a predetermined time, and the control is set to repeat it. After that, the process returns to the main routine of FIG. When the determination result in step 402 is N, that is, when antilock control is executed on a high μ road surface or a medium μ road surface, the routine proceeds to step 405.
After setting T ON (setting to continuously operate the electric motor MT), the process returns to the main routine of FIG. When the determination result in step 401 is Y, that is, when the antilock control is not executed, the process proceeds to step 404, and it is determined whether or not the pressure-responsive electric switch PSW output is on, that is, the accumulator hydraulic pressure is equal to or less than the set value PH. Whether the result is Y or not, the process proceeds to step 405 when the result is Y, and the process proceeds to step 406 when the result is N. In step 406, it is determined whether or not MT is on. When the determination result is Y, the process proceeds to step 407, and after a predetermined time, the electric motor MT is set to be turned off, and then the process returns to the main routine of FIG. The judgment result in 406 is N
In case of, it returns to the main routine of FIG. When the hydraulic pump is driven by turning on the electric motor MT and the hydraulic pump PM continues to be driven for a predetermined time after the hydraulic pressure of the accumulator exceeds the set value PH, the driving of the hydraulic pump PM is stopped. The accumulator hydraulic pressure becomes higher than the set value PH by a substantially constant amount.

As shown by the broken line in FIG. 7, when the determination result in step 402 is Y, the process proceeds to step 404 and step 403 is abolished so that the hydraulic pump PM is not driven on the non-μ road surface. Can be changed to the implementation.

[0034]

As described above, the vehicle brake fluid pressure control device according to the invention of this application is an accumulator that accumulates high-pressure hydraulic fluid, and the accumulator fluid pressure input from this accumulator is used as the brake operating force. A vehicle brake fluid pressure control device comprising: a regulator that adjusts and outputs a corresponding fluid pressure; and a fluid pressure adjusting device that reduces the wheel brake fluid pressure and re-increases the pressure using the output fluid pressure of the regulator. In the automatic brake adjustment process, the hydraulic pump is operated regardless of the detection output of the accumulator hydraulic pressure detection means, so the hydraulic pressure to be accumulated in the accumulator is set lower than before and the amount of accumulated liquid is smaller than before. Even if it is set, it is possible to perform satisfactory wheel brake fluid pressure control, and it is possible to reduce the size and cost. It is possible to achieve the reduction.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an outline of a vehicle brake fluid pressure control device according to the invention of this application.

FIG. 2 is a system configuration diagram of an anti-lock brake device that is an embodiment of a vehicle brake fluid pressure control device according to the invention of this application.

3 is a block diagram showing a configuration of an electric control unit ECU in FIG.

FIG. 4 is a flowchart showing the processing contents of antilock control in the electric control unit ECU.

5 is a flowchart showing the processing contents of road surface μ calculation in FIG. 4. FIG.

FIG. 6 is a flowchart showing the processing contents of WFL control calculation in FIG.

FIG. 7 is a flowchart showing the processing contents of PM control calculation in FIG.

[Explanation of symbols]

BP ... Brake pedal REV ... Reservoir PM ... Hydraulic pump MT ... Electric motor ACC ... Accumulator RV ... Relief valve PSW ... Pressure-responsive electric switch RG ... Regulator MC ...・ Master cylinder WFL, WFR, WRL, WRR ... Wheels WBFL, WBFR, WBRL, WBRR ... Wheel brakes SA, SFLH, SFLR, SFRH, SFRR, SR
LH, SRLR, SRRH, SRRR ... Solenoid valve SNFL, SNFR, SNRL, SNRR ... Wheel speed sensor ECU ... Electric control device IGSW ... Ignition switch GSN ... Acceleration sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Nakajima 2-1-1 Asahi-cho, Kariya city, Aichi Prefecture Aisin Seiki Co., Ltd.

Claims (3)

[Claims] 1. An accumulator for accumulating high-pressure hydraulic fluid, a hydraulic pump for pumping hydraulic fluid from a reservoir to the accumulator, an accumulator hydraulic pressure detecting means for detecting hydraulic pressure in the accumulator, and the accumulator hydraulic pressure. A hydraulic pump control means for operating and stopping the hydraulic pump based on the detection output of the detection means, and a regulator for adjusting and outputting the accumulator hydraulic pressure input from the accumulator to a hydraulic pressure corresponding to the brake operating force. Including a hydraulic pressure generator that supplies hydraulic pressure corresponding to the brake operating force applied to the brake operating member to the wheel brake, and the wheel brake hydraulic pressure is interposed between the hydraulic pressure generator and the wheel brake. Based on the input information, a hydraulic pressure regulator that reduces the pressure and increases the wheel brake hydraulic pressure by the output hydraulic pressure of the regulator. In a vehicle brake fluid pressure control device comprising a control means for automatically adjusting the wheel brake fluid pressure by operating the fluid pressure control device, a wheel brake fluid control means is provided in which the fluid pressure pump control means is linked to the control means. The brake hydraulic pressure control device for a vehicle, wherein the hydraulic pump is operated regardless of the detection output of the accumulator hydraulic pressure detection means in the automatic pressure adjustment process. 2. The vehicle brake fluid pressure control device according to claim 1, further comprising: road surface friction coefficient estimating means for estimating a friction coefficient of a traveling road surface, wherein the hydraulic pump control means estimates the road surface friction coefficient. When the determination result of the road surface friction coefficient estimating means is a high friction coefficient when the hydraulic pump is operated in the automatic adjustment process of the wheel brake hydraulic pressure in cooperation with the means, the hydraulic pump is continuously operated, and A brake fluid pressure control device for a vehicle, comprising: an operation mode switching means for intermittently operating the hydraulic pump when a determination result of the road surface friction coefficient estimating means is a low friction coefficient. 3. The vehicle brake fluid pressure control device according to claim 1, further comprising: road surface friction coefficient estimating means for estimating a friction coefficient of a traveling road surface, wherein the hydraulic pump control means estimates the road surface friction coefficient. When the determination result of the road surface friction coefficient estimating means is a high friction coefficient when the hydraulic pump is operated in the automatic adjustment process of the wheel brake hydraulic pressure in cooperation with the means, the hydraulic pump is continuously operated, and A brake fluid pressure control device for a vehicle, comprising: an operation mode switching means that deactivates the hydraulic pump when the determination result of the road surface friction coefficient estimating means is a low friction coefficient.