JP2003019952A - Brake fluid pressure control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely control an electric current to a control valve, and to easily detect abnormality of sensor without requiring an M/C pressure sensor and a W/C pressure sensor when controlling the electric current to control valves. SOLUTION: After starting pressure reduction of brake fluid of W/C 4 and 6 by ABS control, when performing a pressure increase of first time, a current- carrying quantity to the pressure increase control valves 8 and 9 at that time is detected. When performing pressure reduction thereafter, an electric current quantity corresponding to differential pressure on the upstream-downstream side of the pressure increase control valves 8 and 9 generated by the pressure reduction is added to the current-carrying quantity to the pressure increase control valves 8 and 9 at pressure increase time of first time. Such constitution can set the current-carrying quantity to the pressure increase control valves 8 and 9 corresponding to a balance point, and can precisely control the electric current to the pressure increase control valves 8 and 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake fluid pressure control device for adjusting wheel slip that occurs during vehicle braking by controlling brake fluid pressure.

[0002]

2. Description of the Related Art Conventionally, in ABS control, a master cylinder (hereinafter,
There is a demand for linearly controlling the control valve by controlling the amount of electricity supplied to the control valve or the like arranged between the M / C) and the wheel cylinder (hereinafter referred to as W / C). By controlling the control valve linearly in this way, it is possible to reduce the operating noise of the control valve, maintain an appropriate brake pressure, and improve braking efficiency.

When current control of the control valve is performed in this way, the point at which the valve opens, that is, the balance point of the valve, changes due to the differential pressure of the brake fluid in the upstream and downstream of the control valve. There may be pressure delay, pressure reduction delay, excessive pressure increase, and excessive pressure decrease. Such a balance point can be known by detecting the M / C pressure or the W / C pressure with a pressure sensor.
There is a problem that a sensor for detecting each C pressure is required.

In addition, M / C for detecting M / C pressure and W / C pressure
In a system having a C pressure sensor, it is difficult to detect a sensor failure especially during control, so that there is a problem that reliability is lowered.

In view of the above points, the present invention provides an M / C pressure sensor and a W / C when controlling a current of a control valve.
An object of the present invention is to enable accurate current control to the control valve without the need for a pressure sensor. Another object is to improve the reliability of the system with a hydraulic sensor.

[0006]

In order to achieve the above object, the invention according to claim 1 provides a master cylinder (2).
(A) connecting the wheel cylinders (4, 6) with
A brake fluid pressure control device for performing brake fluid pressure control for increasing / decreasing the brake fluid pressure generated in a wheel cylinder by controlling the current of control valves (8, 9) provided in the vehicle. When the brake fluid pressure control starts to reduce the brake fluid pressure in the wheel cylinders and then the pressure is increased, the amount of electricity supplied to the control valve during the pressure increase is detected. It is characterized in that the energization amount to the control valve is set based on the subsequent pressure increase.

As described above, the energization amount at the balance point can be obtained based on the energization amount of the control valve when the pressure is increased after the pressure reduction is started, and the M / C pressure sensor or the W / C pressure sensor is not required. It is possible to precisely control the current to the control valve.

For example, as described in claim 2, after the depressurization is started, the energization amount to the control valve at the time of the subsequent pressure increase is determined based on the energization amount to the control valve at the time of the pressure increase before the depressurization. Set. Further, as described in claim 4, when the pressure is reduced after the pressure is increased, a current amount corresponding to the differential pressure in the upstream and downstream of the control valve, which is generated by the pressure reduction, is calculated at the time of the pressure increase before the pressure reduction. By adding to the energization amount to the control valve, it is possible to set the energization amount to the control valve during the subsequent pressure increase.

According to the third aspect of the present invention, during braking, when the brake fluid pressure control is started to reduce the brake fluid pressure of the wheel cylinders, and when the first pressure increase is performed, the pressure increase is performed. It is characterized in that the amount of electricity supplied to the control valve at the time of execution is set to a value estimated according to the type of traveling road surface and the master cylinder pressure.

As described above, since the amount of electricity supplied to the control valve and the pressure difference between the upstream and downstream sides of the control valve are associated with each other depending on the type of road surface on which the vehicle is traveling, the amount of electricity supplied to the control valve on the basis of the type of road surface is It is possible to set.

According to the fifth aspect of the present invention, the brake fluid pressure in the master cylinder is estimated based on the amount of current supplied to the pressure increase control valve and the wheel cylinder pressure, and the estimated value and the detected value of the master cylinder pressure sensor are estimated. It is characterized that the master cylinder pressure sensor is detected to be abnormal by comparing and. Thus, W / C pressure and M /
It is also possible to detect the abnormality of the master cylinder pressure sensor based on the relationship of 1: 1 with the C pressure.

According to the sixth aspect of the invention, when the brake fluid pressure control starts to reduce the brake fluid pressure in the wheel cylinder during braking, the amount of electricity to the pressure reducing control valve during the pressure reduction is detected, It is characterized in that the amount of electricity supplied to the pressure reducing control valve during the subsequent pressure reduction is set based on the amount of electricity supplied at this time. in this way,
It is also possible to perform the same current control as in claim 1 on the pressure reducing control valve. With this configuration, the same effect as that of the first aspect can be obtained.

In this case, for example, as described in claim 7, when the pressure is increased and then the pressure is increased, a current component corresponding to the differential pressure upstream and downstream of the pressure reducing control valve caused by the pressure increase is generated. Is added to the energization amount to the decompression control valve at the time of decompression before the pressure increase, thereby setting the energization amount to the decompression control valve at the time of decompression thereafter. Also in this case, it is possible to detect an abnormality in the master cylinder pressure sensor as described in claim 8.

The reference numerals in parentheses of the above means indicate the correspondence with the specific means described in the embodiments described later.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) The present invention will be described below with reference to the embodiments shown in the drawings. FIG. 1 is a schematic diagram showing the configuration of a brake fluid pressure control device to which an embodiment of the present invention is applied. Although the actual brake fluid pressure control device has a second piping system in addition to the first piping system shown in this figure, it has the same configuration as the first piping system. Will be omitted.

As shown in FIG. 1, an M / C 2 for generating a brake fluid pressure by depressing the brake pedal 1 is provided, and the M / C 2 is connected with first and second piping systems. The conduit A connected to M / C2 is branched into two, one of which is W / C4 for the right front wheel 3 and the other is W / C6 for the left rear wheel 5.
It is connected to the. Wheel speed sensors 7a and 7b of electromagnetic pickup type or electric resistance element (MRE) type are arranged on the right front wheel 3 and the left rear wheel 5, respectively, and these are pulse signals depending on the rotation of the wheels 3 and 5. Generate.

Further, pressure increasing control valves (control valves) 8 and 9 are arranged between the M / C 2 and the W / Cs 4 and 6, respectively. Each of the pressure increase control valves 8 and 9 is composed of an electromagnetic two-position valve having a communication position and a cut-off position, and the communication position and the cut-off position can be changed by energization and at the same time, depending on the energization amount. The pressure difference between the upstream and downstream of the pressure increase control valves 8 and 9 can be adjusted. The amount of electricity supplied to these pressure increase control valves 8 and 9 is controlled by a linear current drive circuit. The linear current drive referred to here is the voltage DU.
It includes PWM control that changes the TY ratio and changes the effective current.

Further, a line A and a reservoir 12 are connected by a line B between each W / C 4, 6 and each pressure increase control valve 8, 9 and the pressure reducing control valve is connected to this line B. 1
3, 14 are arranged. In addition, the reservoir 12 and M /
The pipe C is connected to C2, and a pump 16 driven by a motor 15 and a check valve 17 are arranged in the pipe C. With such a configuration, the brake fluid stored in the reservoir 12 is sucked by the pump 16 and discharged to the M / C2 side, and the check valve 17 prevents the pressure of the M / C2 from flowing to the reservoir 12 side. ing.

On the other hand, the detection signals of the wheel speed sensors 6 and 7 are input to an electronic control circuit (hereinafter referred to as ECU) 18. ECU18 is CPU, RO
A well-known microcomputer having M, RAM, and I / O generates control signals for controlling the pressure increasing control valves 8 and 9, the pressure reducing control valves 13 and 14, and the motor 15 based on the detection signals. This control signal determines the boosting output, the holding output and the depressurizing output to be generated for each wheel 3, 5, and the control valves 8, 9, 13 corresponding to the respective outputs will be described below.
The operation of 14 will be described using the right front wheel 3 as an example.

To generate a pressure boosting output to the right front wheel 3 is to generate a control signal so that the pressure boosting control valve 8 is set to the communication position and the pressure reduction control valve 13 is set to the cutoff position. As a result, the brake fluid pressure generated by M / C2 becomes W / C.
4, a differential pressure is formed between the brake fluid pressure on the M / C2 side and the brake fluid pressure on the W / C4 side in accordance with the amount of electricity supplied to the pressure increase control valve 8.

To generate the holding output at the right front wheel 3 is to generate a control signal so that both the pressure increasing control valve 8 and the pressure reducing control valve 13 are in the shut-off position. This gives W
/ C4 brake fluid pressure is maintained. If the brake pedal 1 is loosened while the holding output is continued, the pressure oil flows through the bypass conduit 8a, and the brake fluid pressure of W / C4 is reduced.

To generate a pressure reducing output to the right front wheel 3 means to set the pressure increasing control valve 8 to the shut-off position and the pressure reducing control valve 13 to the communicating position, and to send a control signal to energize the motor 5. Is to occur. As a result, W / C4
Side brake fluid flows into the reservoir 12, and the brake fluid pressure on the W / C 4 side decreases. The ECU 18 also outputs the same to other wheels (the left rear wheel 5) and the like.

Next, the details of the processing executed by the ECU 18 will be described with reference to the flowcharts of FIGS. 2 and 3. ECU
When the ignition switch is turned on, 18 executes the main routine shown in FIG. 2, and this main routine is executed for each wheel 3, 5, etc. by time division.

First, in step S101, initialization processing is performed. By this processing, memory clear, flag reset, etc. are performed. Next, in step S102, in order to perform the transition calculation process every predetermined time Ta (for example, 6 ms), it is determined whether or not the predetermined time Ta has elapsed, thereby waiting for the predetermined time Ta to elapse. .

If YES in step S102, the flow proceeds to step S103 to calculate the wheel speed VW ** of each wheel 3, 5 based on the rotation speed signals from the wheel speed sensors 7a, 7b. Here, "**" is a general term for the symbols FR, RL, RR, FL indicating the wheels 3, 5, etc., that is, "VW **" is VWFR, VWRL, V.
Represents WRR and VWFL, and right front wheel 3 and left rear wheel 5 respectively
And the wheel speeds for the right rear wheel and the left front wheel in the second piping system.

In the following step S104, step S1
The wheel acceleration dVW ** of each of the wheels 3, 5, etc. is calculated by differentiating the wheel speed VW ** obtained in 01. Then, in step S105, step S103
The vehicle body speed (estimated vehicle body speed) is calculated based on the maximum speed VWmax or the like of the wheel speeds VW ** of the wheels 3, 5 etc. This process is performed by, for example, the maximum speed VWma of the wheel speeds VWFR to VWRL of the wheels 3, 5, etc.
Is x within the range from the acceleration limit value Vα obtained by adding a predetermined value to the vehicle body speed VB (n-1) obtained last time to the deceleration limit value Vβ obtained by subtracting the predetermined value from the vehicle body speed VB (n-1)? It is determined whether or not the maximum speed VWmax is from the acceleration limit value Vα to V
If it is within the range up to β, the maximum speed VWmax is set as it is as the vehicle body speed VB, and if the maximum speed VWmax exceeds the acceleration limit value Vα, the acceleration limit value Vα is set as the vehicle body speed VB.
B is set, and if the maximum speed VWmax is below the deceleration limit value Vβ, the deceleration limit speed Vβ is set as the vehicle body speed VB.

Further, in step S106, step S
The vehicle body acceleration dVB is calculated by differentiating the vehicle body speed VB obtained at 105. And step S1
In 07, the calculated vehicle speed VB and wheel speed VB **
The slip ratio SW ** of each wheel 3, 5, etc. is calculated according to.

Next, in step S108, each wheel 3,
5 Slip rate SW ** and wheel acceleration dVW **
Control valves 8, 9, 13, 14 for each wheel 3, 5 based on
Also, the control mode of the motor 15 is calculated. Thus, the control mode, that is, the pressure increasing mode, the holding mode, or the pressure reducing mode is set. These modes include the pressure increasing output, the holding output, and the output to the various control valves 8, 9, 13, 14 and the motor 15 described above.
The pressure reduction output is set. For example, when the pressure increase mode is set, the pressure increase output is continuously output, and when the hold mode is set, the pressure output is continuously output. When is set, the holding output and the pressure reducing output are alternately repeated.

In the following step S109, control current calculation is performed. The details of this control current calculation will be described with reference to the control current calculation flowchart shown in FIG.

First, in step S201, it is determined whether or not the pressure reducing mode is in progress. Whether or not this depressurization mode is in progress is determined by whether or not the above-described depressurization mode has been set, and for example, processing such as setting flags corresponding to various control modes when setting the above-described control mode. By doing so, the discrimination can be performed. The control mode setting flag is reset when, for example, the depression of the brake pedal 1 is stopped.

Then, in step S202, it is determined whether or not the pressure reduction is the first time. Then, if YES, the process proceeds to step S203, and the current instruction value Idw flowing in the pressure increase control valves 3 and 5 at that time is stored in the memory in the ECU 18. On the other hand, if NO, the process proceeds to step S204, and the depressurization time Trel is counted up. By counting up the subtraction time in this way, it is possible to obtain the pressure reduction amount by integrating the pressure reduction time and the pressure reduction gradient.

If it is not in the depressurization mode, step S20.
The process proceeds to step 5 to set whether or not the pressure increasing mode is in progress. The determination in this case is also made based on whether or not the flag corresponding to the pressure increasing mode is set. Then, if YES, the process proceeds to step S206. If NO, the process returns to the main routine.

In step S206, it is determined whether or not it is the first pressure increase after the pressure reduction is started. If YES, the process proceeds to step S207, and if NO, the step S207.
Proceed to 208. Then, in step S207, a control current value serving as a balance point of the pressure increase control valves 8 and 9 is obtained.
Regarding the method of obtaining the control current value, the relationship between the energization amount to the pressure increase control valves 8 and 9 and the differential pressure in the upstream and downstream of the pressure increase control valves 8 and 9 (hereinafter, simply referred to as differential pressure), Also, description will be made with reference to a timing chart during actual braking shown in FIG.

As shown in FIG. 4, the amount of electricity supplied to the pressure increase control valves 8 and 9 and the differential pressure have a predetermined relationship. Assuming that the actual differential pressure is the value shown in the figure, the actual differential pressure will not exceed the actual differential pressure even if the amount of current to the boost control valves 8 and 9 is increased more than the amount of current corresponding to the actual differential pressure. However, when the energization amount is lowered below the value corresponding to the actual differential pressure, the pressure increase control valves 8 and 9 are opened, and the brake fluid pressure from the M / C2 side is transmitted to the W / C4 and 5 sides. At this time, the energization amount corresponding to the actual differential pressure becomes a balance point, and if the energization amount can be set directly at this balance point during pressure increase, the current control to the pressure increase control valves 8 and 9 can be accurately performed. Further, after the balance point is reached, if the energization amount is gradually reduced, smooth pressure increase becomes possible.

On the other hand, as shown in FIG. 5, the brake pedal 1 is stepped on and the vehicle body speed VB is decelerated at a time point t.
As shown in 1, when the wheel speed VW ** falls below the vehicle body speed VB, the ABS control is started. At this time, first
The holding mode is set, the energization amount to the pressure increase control valves 8 and 9 is set to the maximum value, and the pressure increase control valves 8 and 9 are set to the cutoff position. Further, when the wheel speed VW ** drops, the pressure reducing control valves 13 and 14 are set to the communicating position, and the pressure reducing mode is set. Then, when the wheel speed VW ** returns, as shown at time t2, the first pressure increase mode after the pressure reduction is started is set, and the amount of electricity to the pressure increase control valves 8 and 9 is reduced. And
When the energization amount is reduced to the above-mentioned balance point as shown at the time point t3, the pressure increase control valves 8 and 9 are in the communicating positions, and the brake fluid pressures of W / C3 and 5 increase. At this time, after the energization amount has decreased to the equilibrium point, the relationship between the energization amount and the differential pressure is obtained as the relationship shown in FIG. 4 as described above.

Then, as shown at time t4, W / C3,
When the wheel speed VW ** falls from the vehicle body speed VB again with the increase of the brake fluid pressure of 5, the pressure reduction mode is set from the second holding mode, and the pressure increase control valves 8 and 9 are set again.
Is set to the shutoff position, and the pressure reducing control valves 13 and 14 are set to the communication positions, so that the brake fluid pressures of the W / Cs 3 and 5 are reduced. At this time, by looking at the energization amount before switching to the depressurization mode, it is possible to obtain the energization amount corresponding to the equilibrium point when the depressurization starts.

Then, when the brake fluid pressures of W / C3 and 5 decrease and the wheel speed VW ** returns as shown at time t5, the second pressure increasing mode is set and W / C
It acts to increase the brake fluid pressure of 3, 5.

At this time, after the depressurization is started, how the differential pressure at the moment of switching from the increased pressure to the reduced pressure changes during depressurization, that is, the differential pressure after depressurization is determined from the depressurization gradient and depressurization time during depressurization. You can And
When converted into an energization amount and obtained, it is shown as the following equation.

[0039]

Iup = Idw + Trel × K1 where Iup is the maximum current value (holding current output in the holding mode) shown in FIG. The difference in the energization amount with the balance point after the end, Idw is the energization amount corresponding to the differential pressure at the moment when the pressure increase is switched to the pressure reduction after the pressure reduction is started, Trel is the pressure reduction time, and the pressure reduction gradient at which K1 is assumed Shows.

After the setting of Iup, it is determined that the pressure is not increased for the first time after depressurization, and as shown in step S208, the previous instruction current is changed by the gradient coefficient (K2) to obtain a new instruction current. Find the value. The gradient coefficient can be changed by the road surface μ, the M / C pressure, or the like.

As described above, for the first pressure increase after the depressurization is started, the energization amount corresponding to the balance point is obtained by the method shown in step S207, and for the second and subsequent pressure increases, step S208 is performed. It is possible to obtain the energization amount corresponding to the equilibrium point by the method shown in.

As described above, the energization amount at the balance point can be obtained based on the energization amount of the pressure increase control valves 8 and 9 at the time of pressure increase after the start of depressurization, and the M / C pressure sensor or W / C can be obtained. It is possible to accurately control the current to the pressure increase control valves 8 and 9 without requiring a pressure sensor.

(Second Embodiment) FIG. 6 is a schematic diagram showing the configuration of a brake fluid pressure control device according to a second embodiment of the present invention. In the present embodiment, unlike the first embodiment, the pressure increase control valves 8 and 9 are not driven by linear current, and the pressure reduction control valves 13 and 1 are
4 is driven by a linear current. In the first embodiment, the above effect is obtained by performing linear current drive on the pressure increase control valves 8 and 9, but the pressure reduction control valves 13 and 14 are driven by linear current drive as in the present embodiment. Thus, it is possible to obtain the same effect as that of the first embodiment.

FIG. 7 shows a time chart in the case of linearly driving the pressure reducing control valves 13 and 14 in this manner. As shown in this figure, the wheel speed V
When W ** falls, ABS control is started at time t1. Then, the pressure reduction mode is set after the holding mode is set, and the pressure difference is reduced by gradually increasing the amount of electricity supplied to the pressure reduction control valves 13 and 14. Then, when a constant pressure difference occurs and the wheel speed VW ** returns, the pressure increasing mode is set at time t2, and the pressure increasing control valves 8 and 9 increase the W / C pressure.

At this time, since the increase amount of the W / C pressure corresponds to the pressure increasing time, the instruction current to the pressure reducing control valves 13 and 14 corresponding to the W / C pressure at the time t3 after the pressure increasing. The value is calculated by the following equation.

[0046]

## EQU00002 ## Idw = Iup + Tup.times.K1 where Iup is the amount of electricity that corresponds to the differential pressure at the moment when pressure reduction is switched to pressure increase, Tup is the pressure increase time, and K1 is the assumed pressure increase gradient.

Then, when the wheel speed VW ** falls again with respect to the vehicle body speed VB, I calculated based on the equation 2 is obtained.
A current corresponding to dw is passed through the pressure reducing control valves 13 and 14. By doing so, it is possible to flow a current corresponding to the balance point to the pressure reducing control valves 13 and 14. Thus, even if the pressure reducing control valves 13 and 14 are driven by the linear current, the same effect as that of the first embodiment can be obtained.

(Other Embodiments) The pressure increasing control valves 8 and 9 in the first embodiment and the pressure reducing control valves 13 and 1 in the second embodiment.
Although 4 is driven by linear current, both of them may be driven by linear current as shown in FIG. Even in this case, the effects shown in each of the above embodiments can be obtained.

In contrast to the above embodiment, the amount of electricity supplied to the pressure increase control valves 8 and 9 may be changed according to the type of road surface. Further, the energization amount may be corrected by estimating the M / C pressure. As a correction method, the estimation can be performed based on the change in the vehicle body acceleration before the control, the operation time after the start of the control, and the like. For example, by estimating the M / C pressure by the above method,
If the road surface is estimated by the vehicle body deceleration, etc., the differential pressure between the brake fluid pressure at M / C2 and the brake fluid pressure at W / C4, 6 is obtained, and this differential pressure and the energization amount have a relationship of approximately 1: 1. Therefore, the relationship shown in FIG. 4 may be used as a map to estimate the energization amount serving as a balance point from this map.

In this case, for example, a timing chart at the time of actual braking is shown in FIG. 9, and as shown at a time point t1 in the figure, a balance point has been set since the first pressure increasing mode after the start of pressure reduction is set. It is possible to set a corresponding energization amount.

Further, in this patent, the differential pressure between M / C2 and W / C4, 6 corresponds to 1: 1 as shown in FIG. 4 depending on the energization amount of the control valve. In the case where the sensor is provided, it is possible to detect the abnormality of the M / C oil pressure sensor by the energization amount and the W / C oil pressure estimation which is a conventional technique.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a brake fluid pressure control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart of a main routine executed by the ECU shown in FIG.

FIG. 3 is a flowchart of a control current calculation executed by the ECU shown in FIG.

FIG. 4 is an amount of electricity supplied to the pressure increase control valves 8 and 9 and the pressure increase control valves 8 and 9;
FIG. 9 is a diagram showing a relationship with upstream and downstream differential pressures in FIG.

FIG. 5 is a timing chart during actual braking.

FIG. 6 is a diagram showing an overall configuration of a brake fluid pressure control device according to a second embodiment of the present invention.

FIG. 7 is a timing chart during actual manufacturing.

FIG. 8 is a diagram showing an overall configuration of a brake fluid pressure control device according to another embodiment of the present invention.

FIG. 9 is a timing chart at the time of braking according to another embodiment.

[Explanation of symbols]

1 ... Brake pedal, 2 ... M / C, 4, 6 ... W / C, 7
a, 7b ... Wheel speed sensor, 8, 9 ... Pressure increasing control valve, 1
3, 14 ... Pressure reducing control valve, 16 ... Pump, 18 ... ECU.

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Claims (8)

[Claims] 1. The wheel is controlled by controlling the current of a pressure increasing control valve (8, 9) provided in a conduit (A) connecting the master cylinder (2) and the wheel cylinder (4, 6). A brake fluid pressure control device for executing brake fluid pressure control for increasing / decreasing brake fluid pressure generated in a cylinder, wherein the brake fluid pressure control of the wheel cylinder is started to be reduced during braking. After that, when the pressure is increased, the energization amount to the pressure increase control valve at the time of the pressure increase is detected, and the electricity is applied to the pressure increase control valve at the time of the subsequent pressure increase based on the amount of current supply at this time. A brake fluid pressure control device, characterized in that the amount is set. 2. The amount of electricity supplied to the pressure increasing control valve during the subsequent pressure increase is set based on the amount of electricity supplied to the pressure increasing control valve during the pressure increase before the pressure decrease after the pressure reduction is started. The brake fluid pressure control device according to claim 1, wherein 3. The wheel is controlled by current control of a pressure increasing control valve (8, 9) provided in a pipe line (A) connecting a master cylinder (2) and a wheel cylinder (4, 6). A brake fluid pressure control device that executes brake fluid pressure control to increase and decrease the brake fluid pressure generated in the cylinder.When braking, brake fluid pressure control starts to reduce the brake fluid pressure in the wheel cylinders. When the pressure is increased for the first time, the amount of electricity supplied to the pressure increase control valve at the time of increasing the pressure is estimated according to the type of road surface or the brake fluid pressure in the master cylinder. Brake fluid pressure control device characterized by setting to. 4. When the pressure is reduced after the pressure is increased, the current amount corresponding to the pressure difference between the upstream and downstream of the pressure increase control valve generated by the pressure reduction is increased when the pressure is increased before the pressure reduction. By adding to the energization amount to the pressure increase control valve in
The brake fluid pressure control device according to claim 2 or 3, wherein an energization amount to the pressure increase control valve at the time of subsequent pressure increase is set. 5. A master cylinder pressure sensor for detecting a brake fluid pressure in the master cylinder is provided, and the brake fluid pressure in the master cylinder is estimated based on an amount of electricity supplied to the pressure increase control valve and a wheel cylinder pressure. Then, by comparing the estimated value with the detection value of the master cylinder pressure sensor, the abnormality detection of the master cylinder pressure sensor is performed.
The brake fluid pressure control device according to claim 1. 6. A pipeline (A) connecting a master cylinder (2) and a wheel cylinder (4, 6), a reservoir (12) for releasing brake fluid from the pipeline, the pipeline and the reservoir. And a pressure reducing control valve (13, 14) provided in a pipe line connecting to and a brake for increasing / decreasing the brake fluid pressure generated in the wheel cylinder by controlling the current of the pressure reducing control valve. A brake fluid pressure control device for performing fluid pressure control, wherein when the brake fluid pressure control starts to reduce the brake fluid pressure of the wheel cylinder during braking, the decompression control valve is energized during the pressure reduction. The brake fluid pressure control device is characterized in that the amount of electricity is detected, and the amount of electricity to be supplied to the pressure reducing control valve at the time of subsequent pressure reduction is set based on the amount of electricity to be supplied at this time. 7. When the pressure increase is performed after the pressure reduction is performed, the current amount corresponding to the differential pressure in the upstream and downstream of the pressure reduction control valve, which is generated by the pressure increase, is changed when the pressure is reduced before the pressure increase. By adding to the amount of electricity to the pressure reducing control valve in
The brake fluid pressure control device according to claim 6, wherein an amount of electricity to be supplied to the pressure reducing control valve at the time of subsequent pressure reduction is set. 8. A master cylinder pressure sensor for detecting a brake fluid pressure in the master cylinder is provided, and the brake fluid pressure in the master cylinder is estimated based on an amount of electricity supplied to the pressure reducing control valve and a wheel cylinder pressure. 5. The abnormality detection of the master cylinder pressure sensor is performed by comparing the estimated value with the detection value of the master cylinder pressure sensor.
The brake fluid pressure control device according to claim 1.