JP5409761B2 - Brake hydraulic pressure control device for vehicles - Google Patents

Description

  The present invention relates to a vehicle brake hydraulic pressure control device that controls a normally open proportional solenoid valve.

  Conventionally, as a brake fluid pressure control device for a vehicle that performs pressure increase control using a normally open proportional solenoid valve, after performing rapid pressure increase control that increases pressure with a steep gradient, the pressure increase with a gentle gradient is performed. What performs the slow pressure increase control to perform is known (refer patent document 1). Specifically, in this technology, the breakpoint current value is set, and the sudden pressure increase control is executed by decreasing the current value with a steep slope until the breakpoint current value is reached. Slow pressure increase control is executed by lowering the value.

  In other words, in this technique, the control is executed by dividing the indicated hydraulic pressure, which is the target hydraulic pressure of the hydraulic pressure in the wheel cylinder, into a period for setting a steep slope and a period for setting a gentle slope. .

JP 2009-23468 A

  However, in the prior art, even if the indicated hydraulic pressure is increased at a steep slope in order to execute the sudden pressure increase control, the actual hydraulic pressure may not be able to obtain responsiveness as indicated by the indicated hydraulic pressure. Since the inclination of the pressure increase may be slightly gentler than the inclination of the indicated hydraulic pressure, it has been desired to increase the actual hydraulic pressure more quickly in the rapid pressure increase control.

  Accordingly, an object of the present invention is to provide a vehicle brake hydraulic pressure control device that can increase the hydraulic pressure more quickly in the rapid pressure increase control.

  The present invention that solves the above-described problems is provided with a normally-open proportional solenoid valve interposed in a hydraulic pressure path from a hydraulic pressure source to a plurality of wheel brakes, and a hydraulic pressure path from the wheel brake to a reservoir. A vehicle having a normally closed solenoid valve, and a control unit that controls the normally open solenoid valve and the normally closed solenoid valve to control the pressure increase and the pressure reduction of the hydraulic pressure transmitted to the wheel brake. In the brake fluid pressure control device, the control unit includes a rapid pressure increase control for increasing the hydraulic pressure at the start of pressure increase to a break point target value with a first gradient in the pressure increase control, and the break point target value. Thereafter, a slow pressure increase control is performed to increase the hydraulic pressure at a second gradient that is gentler than the first gradient. At the time of the pressure increase start of the sudden pressure increase control, the normally open proportional solenoid valve is The indicated hydraulic pressure for control corresponds to the hydraulic pressure at the start of the previous pressure reduction. Characterized by a lock corresponding hydraulic pressure.

  According to this configuration, the indicated hydraulic pressure at the start of the pressure increase in the rapid pressure increase control is set to the lock equivalent hydraulic pressure corresponding to the hydraulic pressure at the start of the previous pressure decrease, so the hydraulic pressure is increased more quickly in the rapid pressure increase control. Can be pressed.

  Further, in the above-described configuration, when the pressure increase start time of the rapid pressure increase control is set, the control unit is configured such that the difference between the hydraulic pressure at the start of pressure increase and the lock equivalent hydraulic pressure is equal to or greater than a predetermined limit value. It is desirable to limit the indicated hydraulic pressure to a value obtained by adding the limit value to the hydraulic pressure at the start of the pressure increase.

  According to this, since it is possible to limit the indicator hydraulic pressure from becoming too large by the limit value, it is possible to limit the pressure increase to an appropriate pressure increase amount when it is likely to be an excessive pressure increase.

  In the above-described configuration, it is preferable that the control unit makes the lock equivalent fluid pressure smaller than the fluid pressure at the start of the previous decompression when the previous pressure increase time is shorter than the predetermined time.

  According to this, when the previous pressure increase time is shorter than the predetermined time, the lock equivalent hydraulic pressure is made smaller than the hydraulic pressure at the start of the previous pressure reduction, so the actual pressure increased by the current rapid pressure increase control. The slope of the hydraulic pressure can be made more gradual than the previous time, and excessive pressure increase due to various factors such as failure of the pressure sensor can be suppressed.

  In the above-described configuration, when the amount of pressure reduction during the previous pressure reduction control is greater than a predetermined value, the control unit makes the lock equivalent fluid pressure smaller than the fluid pressure at the start of the previous pressure reduction. Is desirable.

  According to this, when the pressure reduction amount at the previous pressure reduction control is larger than the predetermined value, the lock equivalent fluid pressure is made smaller than the fluid pressure at the start of the previous pressure reduction, so the pressure is increased by the current sudden pressure increase control. The inclination of the actual hydraulic pressure can be made gentler than the previous time, and excessive pressure increase due to various factors such as failure of the pressure sensor can be suppressed.

  According to the present invention, the hydraulic pressure can be increased more quickly in the rapid pressure increase control.

1 is a configuration diagram of a vehicle including a vehicle brake hydraulic pressure control device according to an embodiment of the present invention. It is a block diagram which shows the structure of the brake fluid pressure control apparatus for vehicles. It is a block diagram which shows the structure of a control part. It is a figure which shows the setting method of an instruction | indication hydraulic pressure. It is a figure which shows the ratio calculation table for rapid pressure increase. It is a flowchart which shows the setting method of the instruction | indication hydraulic pressure in pressure increase control. It is a flowchart which shows the setting method of the instruction | indication hydraulic pressure in rapid pressure increase control. It is a time chart which shows an example of anti-lock brake control.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, the vehicle brake fluid pressure control device 100 is a device that appropriately controls the braking force applied to each wheel T of the vehicle CR. The vehicle brake hydraulic pressure control device 100 mainly includes a hydraulic unit 10 provided with an oil passage and various parts, and a control unit 20 for appropriately controlling various parts in the hydraulic unit 10.

  Each wheel T is provided with a wheel brake FL, RR, RL, FR, and each wheel brake FL, RR, RL, FR is supplied with a hydraulic pressure supplied from a master cylinder M as an example of a hydraulic pressure source. A wheel cylinder W that generates a braking force is provided. The master cylinder M and the wheel cylinder W are each connected to the hydraulic unit 10. The brake hydraulic pressure generated in the master cylinder M in response to the depression force of the brake pedal P (the driver's braking operation) is supplied to the wheel cylinder W after being controlled by the control unit 20 and the hydraulic pressure unit 10. .

  A pressure sensor 91 that detects the hydraulic pressure in the master cylinder M and a wheel speed sensor 92 that detects the wheel speed of each wheel T are connected to the control unit 20. The control unit 20 includes, for example, a CPU, a RAM, a ROM, and an input / output circuit, and performs various calculations based on inputs from the pressure sensor 91 and the wheel speed sensor 92 and programs and data stored in the ROM. Control is executed by performing processing. Details of the control unit 20 will be described later.

  As shown in FIG. 2, the hydraulic unit 10 is disposed between the master cylinder M and the wheel brakes FL, RR, RL, FR. The two output ports M1, M2 of the master cylinder M are connected to the inlet port 121 of the hydraulic unit 10, and the outlet port 122 is connected to each wheel brake FL, RR, RL, FR. Further, since the oil passage is normally connected from the inlet port 121 to the outlet port 122 in the hydraulic pressure unit 10, the depression force of the brake pedal P is transmitted to each wheel brake FL, RR, RL, FR. It has become so.

  The hydraulic pressure unit 10 is provided with four inlet valves 1, four outlet valves 2, and four check valves 1a corresponding to the wheel brakes FL, RR, RL, FR. Further, two reservoirs 3, two pumps 4, and two orifices 5a are provided corresponding to the respective output hydraulic pressure paths 81, 82 corresponding to the output ports M1, M2, and are electrically driven for driving the two pumps 4. A motor 6 is provided.

  The inlet valve 1 is a normally open proportional solenoid valve interposed in a hydraulic pressure path from the master cylinder M to a plurality of wheel brakes FL, RR, RL, FR. Although not shown, the inlet valve 1 is moved by a spring that urges the valve body away from the valve seat, a fixed core that is excited by energizing the coil unit, and a magnetic force from the excited fixed core. And a movable core that presses the valve body against the urging force of the spring.

  The inlet valve 1 can be adjusted in its valve opening amount by the energization amount from the control unit 20 described above. The inlet valve 1 is normally open to allow the brake hydraulic pressure to be transmitted from the master cylinder M to the wheel brakes FL, RR, RL, FR. Further, the inlet valve 1 is blocked by the control unit 20 when the wheel T is about to be locked, thereby blocking the hydraulic pressure transmitted from the brake pedal P to each wheel brake FL, RR, RL, FR. Furthermore, the inlet valve 1 is controlled by the control unit 20 to have a predetermined valve closing force, thereby increasing the hydraulic pressure in each wheel brake FL, RR, RL, FR with a predetermined inclination.

  The outlet valve 2 is a normally closed electromagnetic valve interposed in a hydraulic pressure path from the wheel brakes FL, RR, RL, FR to the reservoir 3. Although the outlet valve 2 is normally closed, the hydraulic pressure applied to the wheel brakes FL, RR, RL, FR is applied to the reservoir 3 by being opened by the control unit 20 when the wheel T is about to be locked. Let it go.

  The check valve 1a is connected to each inlet valve 1 in parallel. The check valve 1a is a valve that allows only the brake fluid to flow from the wheel brake FL, RR, RL, FR side to the master cylinder M side, and the inlet valve 1 when the input from the brake pedal P is released. Even when is closed, the brake fluid is allowed to flow from the wheel brakes FL, RR, RL, FR side to the master cylinder M side.

The reservoir 3 has a function of temporarily storing brake fluid that is released when each outlet valve 2 is opened.
The pump 4 has a function of sucking the brake fluid stored in the reservoir 3 and returning the brake fluid to the master cylinder M through the orifice 5a.

  The opening and closing states of the inlet valve 1 and the outlet valve 2 are controlled by the control unit 20, so that the hydraulic pressure (hereinafter referred to as “caliper pressure”) transmitted to the wheel cylinders W of the wheel brakes FL, RR, RL, FR Control). For example, in a normal state in which the inlet valve 1 is open and the outlet valve 2 is closed, if the brake pedal P is depressed, the hydraulic pressure from the master cylinder M is transmitted to the wheel cylinder W as it is to increase the pressure. When the valve 1 is closed and the outlet valve 2 is opened, the brake fluid flows out from the wheel cylinder W to the reservoir 3 side so that the pressure is reduced. When both the inlet valve 1 and the outlet valve 2 are closed, the caliper pressure is maintained. Will be held. Further, in a state where a current is supplied to the inlet valve 1 and a predetermined valve closing force is generated, the caliper pressure is in a pressure increasing state where the pressure gradually increases with a predetermined inclination. The control unit 20 then applies a predetermined amount to each inlet valve 1 or each outlet valve 2 in order to switch between the above-described pressure increasing state, pressure reducing state, and holding state according to the target brake fluid pressure in each wheel cylinder W. Output current or control signal.

Next, the control unit 20 will be described in detail.
As shown in FIG. 3, the control unit 20 includes an antilock brake control unit 21, a valve drive unit 22, and a storage unit 23.

  The antilock brake control means 21 appropriately selects and executes a pressure reduction control for reducing the caliper pressure, a holding control for holding the caliper pressure, and a pressure increase control for increasing the caliper pressure according to the state of the vehicle CR. It has a function. Specifically, for example, the anti-lock brake control means 21 has a slip ratio determined based on the wheel speed detected by the wheel speed sensor 92 and the vehicle body speed estimated based on each wheel speed equal to or greater than a predetermined value. When the wheel acceleration is 0 or less, it is determined that the wheel T is about to be locked, and the pressure reduction control is executed. Here, the wheel acceleration is calculated from the wheel speed, for example.

  Further, the antilock brake control means 21 performs holding control when the wheel acceleration is greater than zero. Further, the antilock brake control means 21 executes pressure increase control when the slip ratio is less than a predetermined value and the wheel acceleration is 0 or less.

  The anti-lock brake control means 21 is configured to increase the caliper pressure with a relatively steep first gradient, the second gradient and the second gradient that are gentler than the first gradient, in the pressure increase control. 3 has a function of executing a slow pressure increase control for increasing the caliper pressure at a gradient of 3. Specifically, the antilock brake control means 21 includes an estimated caliper pressure calculation means 21a, a target command pressure calculation means 21b, a break point target value calculation means 21c, a sudden pressure increase control means 21d, and a slow pressure increase control means 21e. And have.

  The estimated caliper pressure calculating means 21a calculates the estimated caliper pressure based on the master cylinder pressure detected by the pressure sensor 91 and the control history of the inlet valve 1 and the outlet valve 2 controlled by the antilock brake control means 21. It has a function.

  The target command pressure calculation means 21b has a function of calculating the target command pressure based on the hydraulic pressure at the start of the previous pressure reduction. Specifically, in the present embodiment, as shown in FIG. 4, the target command pressure calculation means 21b sets the estimated caliper pressure CP1 at the start of the previous pressure reduction (time t1) as the target command pressure CP2. Note that since the antilock brake control starts from the pressure reduction control, the target command pressure is surely set even when the first pressure increase control is started.

  The breakpoint target value calculation means 21c is based on the estimated caliper pressure CP3 at the start of the pressure increase shown in FIG. 4 and the target command pressure CP2, and the breakpoint target value CP4 (the hydraulic pressure that is predicted not to end the pressure increase state). ). Specifically, the breakpoint target value calculation means 21c is calculated by multiplying a value (CP2−CP3) obtained by subtracting the estimated caliper pressure CP3 at the start of the pressure increase from the target command pressure CP2 by a predetermined ratio. The break point target value CP4 is calculated by adding the value to the estimated caliper pressure CP3 at the start of pressure increase.

  The sudden pressure increase control means 21d executes sudden pressure increase control (between times t2 and t3) for increasing the estimated caliper pressure at the first gradient G1 from the estimated caliper pressure CP3 at the start of pressure increase to the break point target value CP4. Has a function of setting the reference hydraulic pressure. Here, the reference hydraulic pressure is a target value (future value) of the caliper pressure obtained by calculation, whereas the estimated caliper pressure is an estimated value of the current caliper pressure obtained by calculation. Is approximately the same value as the estimated caliper pressure.

  Note that the first gradient G1, the second gradient G2, and the third gradient G3, which will be described later, may be fixed values determined in advance, or may be calculated appropriately. As a calculation method, for example, the difference between the hydraulic pressures at the start and end of the rapid pressure increase control (or first slow pressure increase control and second slow pressure increase control described later) is divided by a predetermined time. Thus, there is a method for calculating the gradient.

  Then, the sudden pressure increase control means 21d changes the command hydraulic pressure for controlling the inlet valve 1 from the reference hydraulic pressure to the lock equivalent hydraulic pressure RP corresponding to the estimated caliper pressure CP1 at the start of the previous pressure reduction in the rapid pressure increase control. It has a function to change. Specifically, in the present embodiment, the rapid pressure increase control unit 21d is configured to set the larger one of the reference hydraulic pressure and the lock equivalent hydraulic pressure RP as the command hydraulic pressure in the rapid pressure increase control.

  When the lock equivalent hydraulic pressure RP is selected as the command hydraulic pressure at the time of starting the pressure increase in the rapid pressure increase control, the caliper pressure can be increased more quickly in the rapid pressure increase control.

  Further, the rapid pressure increase control means 21d has a case where the difference between the reference fluid pressure (the fluid pressure at the time of the pressure increase start) and the lock equivalent fluid pressure RP is equal to or greater than a predetermined limit value LM at the time of the pressure increase start of the rapid pressure increase control Has a function of limiting the indicated hydraulic pressure to a value obtained by adding the limit value LM to the reference hydraulic pressure. Thereby, since it can be limited by limit value LM that the indicator hydraulic pressure becomes too large, it is possible to limit the pressure increase amount to an appropriate amount when excessive pressure increase is likely.

  Furthermore, the rapid pressure increase control unit 21d determines that the previous pressure increase time TU (time required for pressure increase control in the series of pressure reduction-holding-pressure increase control) is shorter than a predetermined time or the previous pressure reduction control. When the pressure reduction amount ΔP at the time is larger than a predetermined value, the lock equivalent fluid pressure RP is made smaller than the fluid pressure CP1 at the start of the previous decompression (for example, a value CP5 smaller than the fluid pressure CP1). have. Accordingly, when the previous pressure increase time TU is shorter than the predetermined time, or when the pressure reduction amount ΔP at the time of the previous pressure reduction control is larger than the predetermined value, the lock equivalent hydraulic pressure RP is decreased. The slope of the actual caliper pressure in the rapid pressure increase control can be made gentler than the previous time, and excessive pressure increase due to various factors such as a failure of the pressure sensor 91 or a characteristic that the inlet valve 1 is easy to open is suppressed. It is possible.

  Specifically, in the present embodiment, the rapid pressure increase control unit 21d decreases the lock equivalent hydraulic pressure RP based on the following mathematical formulas (1) to (3) and the rapid pressure increase ratio calculation table illustrated in FIG. It is configured as follows.

RP = CP1- (CP1-CP3) × RA (1)
RA = SV + CV (2)
CV = CVp + RAb (3)
RP: Lock equivalent hydraulic pressure CP1: Estimated caliper hydraulic pressure CP3 at the start of previous pressure reduction CP3: Estimated caliper pressure RA at the start of pressure increase RA: Rapid increase ratio SV: Initial value (constant)
CV: Correction amount CVp: Previous value of correction amount RAb: Table calculation value of ratio for rapid pressure increase

  Here, the magnitude relationship of the values in FIG. 5 is −α1 <0 <α1 <α2 <α3, ΔP1 <ΔP2 <ΔP3, and T1 <T2 <T3 <T4. That is, as the previous pressure increase time TU is shorter, a larger value is selected as the table calculation value RAb for the rapid pressure increase ratio, and as a result, the lock equivalent hydraulic pressure RP is calculated to be a smaller value. . Further, as the pressure reduction amount ΔP at the previous pressure reduction control is larger, a larger value is selected as the table calculation value RAb for the sudden pressure increase ratio, and as a result, the lock equivalent hydraulic pressure RP is calculated to a smaller value. It has become.

  As shown in FIGS. 3 and 4, the slow pressure increase control means 21e increases the estimated caliper pressure from the break point target value CP4 to the target command pressure CP2 with a second gradient G2 that is gentler than the first gradient G1. First slow pressure increase control (between times t3 and t4) to be performed and second slow pressure increase control that is increased from the target command pressure CP2 to the end of the pressure increase at a third gradient G3 that is gentler than the second gradient G2 ( (Between time t4 and time t5).

  Further, the slow pressure increase control means 21e sets the command fluid pressure so as to follow the set reference fluid pressure in the first slow pressure increase control and the second slow pressure increase control (time t3 to t5). Then, the anti-lock brake control means 21 calculates a current value for controlling the inlet valve 1 based on the set command hydraulic pressure and master cylinder pressure, and outputs this current value to the valve drive unit 22. In the pressure reduction control and the holding control, the antilock brake control means 21 determines a current value that flows to the inlet valve 1 or the outlet valve 2 by a known method, and outputs the current value to the valve drive unit 22.

The valve drive unit 22 controls the inlet valve 1 and the outlet valve 2 based on the current value output from the antilock brake control means 21.
The storage unit 23 stores the above-described rapid pressure increase ratio calculation table (see FIG. 5), mathematical expressions (1) to (3), and the like.

Next, a method for setting the indicated hydraulic pressure during the pressure increase control by the antilock brake control means 21 will be described in detail with reference to FIGS.
The antilock brake control means 21 first calculates an estimated caliper pressure (S1), a target command pressure (S2), and a breakpoint target value (S3). After step S3, the antilock brake control means 21 determines whether or not the estimated caliper pressure is equal to or greater than the breakpoint target value (S4).

  In step S4, when the estimated caliper pressure is not equal to or greater than the breakpoint target value (No), the antilock brake control means 21 shifts to control for setting the command hydraulic pressure for rapid pressure increase control (S5). In step S5, as shown in FIG. 7, the anti-lock brake control means 21 first calculates a lock equivalent hydraulic pressure (S11) and calculates a reference hydraulic pressure from the first gradient (S12).

  After step S12, the anti-lock brake control means 21 determines whether or not the lock equivalent hydraulic pressure is greater than the reference hydraulic pressure (S13). In step S13, if the lock equivalent hydraulic pressure is greater than the reference hydraulic pressure (Yes), the anti-lock brake control means 21 sets the lock equivalent hydraulic pressure as the indicated hydraulic pressure (S14), and the lock equivalent hydraulic pressure is If it is not greater than the reference hydraulic pressure (No), the indicated hydraulic pressure is set so as to follow the reference hydraulic pressure (S15). After step S14 or step S15, the antilock brake control means 21 returns to the flowchart of FIG. 6 and ends this control.

  In step S4, when the estimated caliper pressure is not less than the breakpoint target value (Yes), the antilock brake control means 21 determines whether or not the estimated caliper pressure is not less than the target command pressure (S6). In step S6, when the estimated caliper pressure is not equal to or higher than the target command pressure (No), the antilock brake control means 21 calculates the reference hydraulic pressure from the second gradient (S7).

  In step S6, when the estimated caliper pressure is equal to or higher than the target command pressure (Yes), the antilock brake control means 21 calculates the reference hydraulic pressure from the third gradient (S8). After step S8 or step S9, the anti-lock brake control means 21 sets the command hydraulic pressure so as to follow the calculated reference hydraulic pressure (S9), and ends this control.

  Next, an example of the antilock brake control by the antilock brake control means 21 will be described in detail. Specifically, the antilock brake control when the estimated caliper pressure and the actual caliper pressure deviate due to a failure of the pressure sensor 91 or the like will be described.

  As shown in FIG. 8, when the driver depresses the brake pedal P (time t10), the actual caliper pressure increases with a larger slope than the estimated caliper pressure due to a failure of the pressure sensor 91 or the like. Thereafter, when the decompression conditions are met, the antilock brake control means 21 starts decompression control (time t11).

  After the pressure reduction control, the holding control is executed when the conditions for the holding control are met (time t12), and then the first pressure increasing control is executed when the conditions for the pressure increasing control are met (time t13). In this first pressure increase control, since the previous pressure increase time and pressure reduction amount cannot be obtained, the anti-lock brake control means 21 refers to the above-described mathematical expressions (1) to (3) and the sudden pressure increase ratio calculation table. Instead, the hydraulic pressure CP11 at the start of the previous pressure reduction (time t11) is set to the lock equivalent hydraulic pressure RP1 as it is. That is, in the first pressure increase control, the antilock brake control means 21 always sets the lock equivalent hydraulic pressure RP1 to the hydraulic pressure CP11 at the start of the previous pressure reduction.

  Thereafter, the anti-lock brake control means 21 sets the larger lock equivalent hydraulic pressure RP1 of the lock equivalent hydraulic pressure RP1 and the reference hydraulic pressure to the indicated hydraulic pressure, and executes the sudden pressure increase control (between times t13 and t14). After the rapid pressure increase control, the reference fluid pressure is set to the indicated fluid pressure and the first slow pressure increase control is executed (between times t14 and t15).

  Thereafter, as described above, after the pressure reduction control and the holding control are executed, the second pressure increase control is started (time t16). In the second pressure increase control, when the anti-lock brake control means 21 calculates the sudden pressure increase ratio RA1 based on the previous pressure increase time, the pressure reduction amount, etc., the lock equivalent liquid is calculated based on the rapid pressure increase ratio RA1. The pressure is set to a value RP2 smaller than the hydraulic pressure CP12 at the start of the previous pressure reduction.

  Thereafter, in the third pressure increase control (time t17), when the anti-lock brake control means 21 calculates a sudden pressure increase ratio RA2 larger than the previous rapid pressure increase ratio RA1, the lock equivalent hydraulic pressure is the same as that at the start of the previous pressure decrease. It is set to a value RP3 obtained by reducing the hydraulic pressure CP13 by a large rate. In this way, in the second and third pressure increase control, the lock equivalent hydraulic pressure is changed to a small value, so that the slope of the actual caliper pressure during the sudden pressure increase control can be gradually reduced. It is possible to suppress excessive pressure increase.

  After that, when the previous pressure increase time and the amount of pressure decrease gradually return to appropriate values, the rapid pressure increase ratio gradually decreases in the fourth and fifth pressure increase control (time t18, t19). Thus, the lock equivalent hydraulic pressure gradually returns to large values RP4 and RP5. As a result, the slope of the actual caliper pressure during the sudden pressure increase control gradually increases, and good braking control is realized.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and can be appropriately modified as shown below.

  In the above-described embodiment, in the rapid pressure increase control, the reference hydraulic pressure is compared with the lock equivalent hydraulic pressure RP, and the larger one is set as the indicated hydraulic pressure. However, the present invention is not limited to this. For example, in the rapid pressure increase control, the control may be performed using only the lock equivalent hydraulic pressure without setting the reference hydraulic pressure. In this case, when the estimated caliper pressure reaches the breakpoint target value, the slow pressure increase control may be performed according to the reference hydraulic pressure.

  Further, when the reference hydraulic pressure is not set in the rapid pressure increase control as described above, instead of limiting the indication hydraulic pressure to a value obtained by adding the limit value LM to the reference hydraulic pressure as in the above-described embodiment, the indication hydraulic pressure is set to What is necessary is just to restrict | limit to the value which added the limit value to the hydraulic pressure at the time of a pressure increase start.

  In the above embodiment, the lock equivalent hydraulic pressure is lowered based on the sudden pressure increase ratio, but the present invention is not limited to this, and without using the sudden pressure increase ratio, the lock equivalent hydraulic pressure is always set at the start of the previous pressure reduction. You may make it set to the hydraulic pressure of.

  In the above embodiment, the slow pressure increase control is performed with the two gradients G2 and G3. However, the present invention is not limited to this, and may be performed with one gradient, or with three or more gradients. May be.

  In the above embodiment, for the sake of simplicity, the vehicle brake hydraulic pressure control device that performs only anti-lock brake control has been exemplified. However, a control valve is appropriately added to control the vehicle attitude, brake assist control, etc. Other controls may be combined.

DESCRIPTION OF SYMBOLS 1 Inlet valve 2 Outlet valve 3 Reservoir 20 Control part 21 Anti-lock brake control means 21a Estimated caliper pressure calculation means 21b Target instruction pressure calculation means 21c Point target value calculation means 21d Rapid pressure increase control means 21e Slow pressure increase control means 100 Vehicle brake Fluid pressure control device CP4 Break point target value G1 First gradient G2 Second gradient M Master cylinder RP Lock equivalent fluid pressure

Claims (4)

A normally open proportional solenoid valve interposed in a hydraulic pressure path from a hydraulic pressure source to a plurality of wheel brakes, a normally closed solenoid valve interposed in a hydraulic pressure path from the wheel brake to a reservoir, A vehicular brake hydraulic pressure control device including a control unit that controls an open proportional electromagnetic valve and the normally closed electromagnetic valve to increase and control a hydraulic pressure transmitted to the wheel brake;
The controller is
In the pressure increase control,
Rapid pressure increase control for increasing the hydraulic pressure at the start of pressure increase to the breakpoint target value with a first gradient, and the hydraulic pressure after the breakpoint target value is increased with a second gradient that is gentler than the first gradient And slowly increasing pressure control
At the time of the pressure increase start of the rapid pressure increase control, the command hydraulic pressure for controlling the normally open proportional solenoid valve is set to a lock equivalent hydraulic pressure corresponding to the hydraulic pressure at the start of the previous pressure reduction. A brake fluid pressure control device for a vehicle. The controller is
If the difference between the hydraulic pressure at the time of the pressure increase start and the hydraulic pressure corresponding to the lock is equal to or greater than a predetermined limit value at the time of the pressure increase start of the sudden pressure increase control, the indicated hydraulic pressure is set to the pressure increase start. The vehicular brake hydraulic pressure control device according to claim 1, wherein the vehicle hydraulic pressure control device is limited to a value obtained by adding the limit value to the hydraulic pressure at the time. The controller is
3. The vehicle according to claim 1, wherein when the previous pressure increase time is shorter than a predetermined time, the lock equivalent hydraulic pressure is made smaller than the hydraulic pressure at the start of the previous pressure reduction. Brake hydraulic pressure control device. The controller is
The hydraulic pressure corresponding to the lock is set to be smaller than the hydraulic pressure at the start of the previous decompression when the amount of decompression at the previous decompression control is greater than a predetermined value. The brake fluid pressure control device for a vehicle according to any one of claims.

Images