JP3537115B2 - Wheel brake pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake pressure generator for generating a brake fluid pressure corresponding to an applied operating force and applying it to a wheel brake. The present invention relates to a wheel brake pressure control device including a pump for applying a brake hydraulic pressure.

[0002]

2. Description of the Related Art Conventionally, this type of pump avoids a complete stop of wheel rotation (wheel lock) during braking by a driver (driver), for example, in order to ensure running stability and steering performance of a vehicle body. And then increase the braking pressure so that the braking distance is as short as possible.
Further, anti-skid control (ABS control) that repeatedly reduces and increases the pressure as necessary, wheel brake force distribution control between wheels to suppress the vehicle's side slip, head swing or butt swing during braking, or In order to compensate for insufficient brake fluid pressure for subsequent pressure increase by reducing wheel brake pressure, such as traction slip control for suppressing wheel slip (acceleration slip) during vehicle acceleration, or a driver A brake valve is provided for generating brake fluid pressure when no braking operation is performed by the brake pedal, and an electromagnetic valve for increasing or decreasing the wheel brake pressure is connected to the wheel brake.

[0003]

A typical example of a brake pressure generator is a brake pedal, and a negative pressure booster which is connected to an input rod and increases the force applied to the input rod to apply the force to the output rod. And a brake master cylinder driven by the output rod, wherein the negative pressure booster has a diaphragm for separating a negative pressure chamber and a variable pressure chamber.
The diaphragm is provided with a pressure difference between the negative pressure chamber and the variable pressure chamber, that is, a negative pressure of an in-vehicle engine intake manifold, and a brake.
It is driven by a differential pressure from a pressure (in the range from the negative pressure to the atmospheric pressure) adjusted according to the depression amount of the key pedal.
An output rod connected to the diaphragm drives a brake master cylinder, and the output pressure of the brake master cylinder is applied to the wheel brake.

[0004] During steady-state braking that does not require computer intervention (wheel brake pressure control), the brake pressure generated by the brake master cylinder is applied to the wheel brakes.
The load applied by the diaphragm of the negative pressure booster to the output rod is determined by the product of the area of the diaphragm and the above-mentioned differential pressure, and there is a limit to both. Therefore, the maximum value of the output load of the negative pressure booster is It is determined by the area (size of the negative pressure booster) and the negative pressure given by the engine on the vehicle. By increasing the maximum value of the output load of the negative pressure booster, a large braking force can be generated during sudden braking and the vehicle can be stopped suddenly, but the size of the negative pressure booster must be increased. Must. If the size of the negative pressure booster is small, the maximum value of the output load (maximum assisting force) is small, so that the braking force at the time of sudden braking is low and the vehicle's sudden stopping performance is low.

Japanese Patent Application Laid-Open No. 4-121260 discloses a hydraulic brake device that increases the wheel brake pressure at a high speed in response to the stepping speed of the brake pedal. However, the wheel brake pressure is equal to or less than the output pressure of the brake master cylinder (FIGS. 2 and 5 of the publication),
Alternatively, the maximum brake pressure is independent of the brake operation speed and the pedaling force (FIG. 6 of the publication), and the output pressure of the brake master cylinder is substantially limited by the output load of the negative pressure booster. Therefore, even if the increasing speed of the wheel brake pressure corresponds to the pedal depression speed, the wheel brake pressure is substantially equal to or less than the output pressure of the brake master cylinder corresponding to the maximum output load of the negative pressure booster. Is limited. Alternatively, when the brake operation speed exceeds a threshold value, the speed is rapidly increased to the maximum brake pressure. However, even in the case of a high braking force at the time of sudden braking, especially in a high braking pressure region near or exceeding the boosting limit of the negative pressure booster, the braking pressure is reasonable in response to the pedal operation. It is desired to provide a technique for smooth control.

[0006] Japanese Patent Application Laid-Open No. 4-121260 discloses that
Japanese Patent Application No. 2-21053 discloses an electromagnetic valve for controlling the brake pressure of a brake pedal by detecting a brake pedal pressure by a pedal force sensor and controlling a brake fluid pressure in accordance with the detected pedal force with a reservoir, a pump, an accumulator, and a wheel brake pressure. There is a description that a hydraulic brake device that is generated by a hydraulic pressure generating device provided with and supplied to a wheel brake is presented. It is assumed that the emergency stop performance was low.

[0007] Even in a sudden braking region where a high braking force is required and a high-speed increase of the braking pressure is required, it is necessary to control the braking pressure rationally and smoothly in response to the pedal operation. preferable.

According to the present invention, the brake is performed at a speed corresponding to the operation speed.
The first object is to change the brake pressure, and the second purpose is to control the brake pressure rationally and smoothly in response to the operation applied to the brake pressure generator even in the sudden brake region. A third object of the present invention is to provide a wheel brake pressure control device having a large braking force even if the brake pressure generator generates a relatively low brake fluid pressure. It is a fourth object of the present invention to reduce the energy consumption by driving the pump as much as possible.

[0009]

[Means for Solving the Problems]

(1) The present invention provides a hydraulic pressure generating means (1) for generating a brake hydraulic pressure according to an applied operating force and applying the generated hydraulic pressure to a wheel brake (151). A hydraulic pressure source (1, 120, 12) on the vehicle including a pump (120, 121) for applying a hydraulic pressure higher than the brake pressure generated by the hydraulic pressure generating means.
1); a wheel brake provided between the hydraulic pressure source and the wheel brake (151), and provided with supply pressure adjusting means (81, 83) for increasing and reducing the wheel brake pressure. In the pressure control device, operation value detection means (103p) for detecting an operation value (Pd) applied to the hydraulic pressure generation means (1); speed detection means for detecting a change speed (dPS) of the operation value (Pd) (110); and drive / stop of the pumps (120, 121) and supply pressure adjusting means (8
When controlling the flow of (1,83) and driving the pump,
An adjustment control means (110) for driving the pump at a speed (Md-compatible speed) corresponding to the change speed (dPS) of the operation value. In addition, in order to facilitate understanding, in the parentheses, corresponding elements or corresponding items of the embodiment shown in the drawings and described below or their symbols are added for reference.

According to this, the operation value of the hydraulic pressure generating means (1)
(Pd) change speed (dPS) speed (motor energization duty Md
The pump (120, 121) is driven at the speed corresponding to
The wheel brake pressure increases at a speed corresponding to this.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(2) A hydraulic pressure generating means (1) on the vehicle for generating a brake hydraulic pressure according to the applied operating force and applying the generated hydraulic pressure to the wheel brake (151); For giving a hydraulic pressure higher than the brake hydraulic pressure generated by the hydraulic pressure generating means (1),
A pump (120, 121) on the vehicle;
The brake between the discharge side flow path (HPL1) for giving high brake fluid pressure to 1) and the output port (82) of the fluid pressure generating means (1).
A first pressure control valve (81) for controlling the flow of liquid; a suction side flow path (LPL1) of the pump and an output port of the hydraulic pressure generating means (1);
(82) a second pressure control valve (83) for controlling the flow of the brake fluid during the period (82); an operation value (Pd) applied to the hydraulic pressure generating means (1).
Value detection means (103p) for detecting the change of the operation value (Pd); speed detection means (110) for detecting the change speed (dPS) of the operation value (Pd); and drive / stop of the pumps (120, 121) and first and second pumps. By controlling the flow of the pressure control valve (81, 83), the pump (120,
A wheel brake pressure control device comprising: an adjustment control means (110) for driving the pumps (120, 121) at a speed corresponding to the operation value change speed (dPS) when driving the 121).

According to this, since the pumps (120, 121) generate a discharge pressure higher than the brake hydraulic pressure generated by the hydraulic pressure generating means (1), the hydraulic pressure generating means (1) can generate the hydraulic pressure. Blaze
Hydraulic pressure generating means (1) up to brake hydraulic pressure higher than the hydraulic pressure
The wheel brake pressure can be increased at a speed corresponding to the change speed (dPS) of the operation value (Pd). Therefore, the hydraulic pressure generating means (1) can be a small one having a relatively low maximum pressure.

When the pump is driven to open the second pressure control valve (83), the pump passes through the second pressure control valve (83) and causes the output port (82) of the hydraulic pressure generating means (1) to blow. The first pressure control valve (81) is provided between the discharge side flow path (HPL1) and the output port (82) of the hydraulic pressure generating means (1). Since the first pressure control valve (81) is inserted, the pump discharge pressure (high pressure) is applied to the wheel brake by closing the first pressure control valve (81), and the first pressure control valve (81) is opened. Thus, the pump discharge pressure and the wheel brake pressure are connected to the suction passage (and the output port 82), and the wheel brake pressure is reduced. Therefore, by controlling the opening and closing of the first pressure control valve (81), the wheel brake pressure can be adjusted. The first pressure control valve (81) may be an open / close valve or a flow control valve. (3) A hydraulic pressure generating means (1) on the vehicle for generating a brake hydraulic pressure corresponding to the applied operating force and applying the hydraulic pressure to the wheel brake (151); A pump (120, 121) on the vehicle for applying a hydraulic pressure higher than the brake hydraulic pressure generated by the generating means;
A first pressure control valve (81) for controlling the flow of the brake fluid between a discharge-side flow path for applying a hydraulic pressure and an output port of the hydraulic pressure generating means; a suction side of the pump; A second pressure control valve (83) for controlling the flow of the brake fluid between the flow path and the output port of the hydraulic pressure generating means; the discharge side flow path (HPL1) and the wheel brake;
Pressure increasing control valve (131) inserted between the key (121); pressure reducing control valve (132) inserted between the suction side flow path (LPL1) and the wheel brake (121); Operating value applied to hydraulic pressure generating means (1)
Operating value detecting means (103p) for detecting (Pd); the operating value (Pd)
Speed detecting means (110) for detecting the change speed (dPS) of the pump; and controlling the driving / stopping of the pumps (120, 121) and the flow of the first and second pressure control valves (81, 83). When driving the pump, the pump is driven at a speed corresponding to the change speed (dPS) of the operation value (Pd). The flow of the brake fluid between the discharge side flow path (LPL1) and the output port (82) of the hydraulic pressure generating means (1) is stopped via the control valve (81), and the second pressure control valve In (83), the flow of the brake fluid between the suction side flow path (LPL1) and the output port (82) of the hydraulic pressure generating means (1) is stopped, and the pressure is increased with the pressure reducing control valve (132). Pressure control valve (131)
To adjust the wheel brake pressure by operating the
10); a wheel brake pressure control device comprising:

According to this, since the pumps (120, 121) generate a discharge pressure higher than the brake hydraulic pressure generated by the hydraulic pressure generating means (1), the hydraulic pressure generating means (1) can generate the hydraulic pressure. Blaze
Hydraulic pressure generating means (1) up to brake hydraulic pressure higher than the hydraulic pressure
The wheel brake pressure can be increased at a speed corresponding to the change speed (dPS) of the operation value (Pd). Therefore, the hydraulic pressure generating means (1) can be a small one having a relatively low maximum pressure.

In response to a large braking slip on the wheels, the pressure reduction control valve (132) is opened to reduce the wheel brake pressure and wait for the wheel speed to return. When the braking slip is reduced, the pressure reduction control valve (132) is released. ), And in the ABS control for increasing the wheel brake pressure by opening the pressure increase control valve (131), both the first pressure control valve (81) and the second pressure control valve (83) must be closed. As a result, the wheel brake pressure is reduced by pump suction to increase the speed, and the subsequent pressure increase is performed by the pump discharge pressure to increase the speed. At high speed, and the reliability of the ABS control is improved.

(4) The adjustment control means (110) reads the operation value (Pd) at a predetermined cycle (Ts), and changes the operation value and the integrated value of the change speed. The pump is driven at a high speed when the change speed is high and at a high speed, and at a low speed when the integrated value is low and the change speed is low. More specifically, when the operation value (Pd) is the depression amount (stroke) of the brake pedal, for example, when the vehicle is depressed at a rapid speed, as shown in FIG. As shown in the figure and when the pedal is depressed at a slow speed, the depression amount PSe reaches the boosting limit of the negative pressure booster (1b) in a short time, a medium time and a long time, respectively. PSa on the vertical axis (stepping amount Pd) in FIG. 19 is the stepping amount for play allowance from the release of the brake pedal to the application of the brake pressure to the wheel brake, and PSe is the negative pressure booster (1b). It is the stepping amount at the boosting limit of.

Here, the operation value (Pd) is read in the Ts cycle, the difference dPS between the current read value and the previous read value is calculated, and this is used as the stepping speed (correctly, dPS / Ts. In FIG. 19, dPS is expressed as a speed value), and the stepping speed dPS changes in a time series, for example, as shown in FIG. The instantaneous depression speed dPS immediately before the pedal depression amount Pd reaches the value PS (Pds) at which the pump starts driving is a region where the depression speed dPS is nonlinear with respect to the passage of time, and the value of the instantaneous velocity value is small.
In addition, since it varies when viewed microscopically, there is a large error in specifying (detecting) the stepping speed. Also, the maximum value dPSm of the instantaneous stepping speed dPS in one step (or)
Generally corresponds to one stepping characteristic (or), but the driver sometimes changes the stepping force (speed) during stepping.

Therefore, in an embodiment to be described later, the current pedal depression speed (curve) is calculated using the maximum depression speed dPSm during the current depression operation and the integrated value ΣPd of the four instantaneous depression speed values dPS immediately before the start of control. ) Or) (the current braking speed). The integrated value ΔPd of the stepping speed dPS read four times in the Ts cycle (that is, during 4Ts) is a large value at the time of high-speed stepping, because the stepping speed dPS is high as shown in FIG. On the other hand, when the pedal is depressed at a low speed, the pedaling speed dPS is low, and thus the value is small. The stepping speed in the brake pressure increasing process is such that as the maximum stepping speed dPSm is higher and the integrated value ΔPd is larger,
It can be said that it is high.

In this embodiment, when the integrated value (ΣPd) is high and the maximum stepping speed dPSm is high, the pump (120-200) is operated at high speed when the integrated value (ΣPd) is low and the maximum stepping speed dPSm is low.
122), the pump drive speed setting corresponding to the operation speed is highly reliable.

(5) When the change speed (dPS) of the operation value is negative (return operation), the adjustment control means (110) operates at a high speed when the absolute value of the change speed (dPS) is high and at a low speed when the absolute value of the change speed (dPS) is low. Reduce the wheel brake pressure.

According to this, the wheel brake pressure is reduced at a speed corresponding to the return operation speed of the hydraulic pressure generating means (1).
During high-speed return operation, especially when the brake pedal is released immediately after the brake pressure has been increased to a high brake pressure exceeding the boosting limit of the negative pressure booster, the pressure reduction response of the wheel brake pressure is reduced. High. When the return operation speed is low, excessive pressure reduction is not performed.

(6) When the change speed is negative (return operation) and the absolute value is lower than the set value (nPS1), the adjustment control means controls the wheel brake (151) to the hydraulic pressure source (1, 120, 121). When the pressure is equal to or greater than the set value, the pressure reduction and the hold are alternately repeated in a fixed cycle, and the pressure reduction period in this cycle is lengthened when it is high in accordance with the absolute value of the change speed. .

According to this, the return operation speed becomes equal to the set value (nPS).
1) At the time above, the wheel brake pressure is reduced at the speed (FIG. 11) corresponding thereto. During high-speed return operation, especially when the brake pedal is released immediately after the brake pressure has been increased to a high brake pressure exceeding the boosting limit of the negative pressure booster, the pressure reduction response of the wheel brake pressure is reduced. High.

When the return operation speed is lower than the set value (nPS1), the decompression does not stop and the pressure is not excessively reduced. When the return operation speed is low, the operation speed thereafter becomes 0
There is a high possibility that the vehicle will turn to (pedal depression holding) or positive (step depression), but the wheel brake pressure holding or pressure increase at this time will be prompt.

(7) means (110) for detecting the deceleration (Gd) of the vehicle, wherein the adjustment control means (110) is adapted to detect when the deceleration (Gd) is equal to or greater than a set value (Gds). The pumps (120, 121) are driven. If the hydraulic pressure generating means (1) has a negative pressure booster (1b), the set value (Gds) is set to the high value at the boosting limit (maximum assisting force output) of the negative pressure booster (1b). If the friction coefficient is set to the deceleration of the vehicle while traveling on the road surface or a value slightly lower than the deceleration (Gds), the negative pressure booster can be used when traveling on the road surface with a high friction coefficient.
When (1b) approaches the boost limit, the vehicle deceleration is set to the set value (G
ds), and the adjustment control means (110)
(120, 121) is driven at a speed corresponding to the brake pedal depression speed so far, and the vehicle deceleration (Gd) matches the target deceleration (Go) corresponding to the brake pedal operation amount. When the shutoff / flow of the first pressure control valve (81) or the pressure increase control valve (131) is controlled, the change of the wheel brake pressure corresponding to the brake pedal depression speed and the operation amount is smooth and stable. It will be.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0027]

FIG. 1 shows an embodiment of the present invention. The hydraulic pressure generator 1 comprises a master cylinder 1a and a negative pressure booster 1b. When the brake pedal 103 is depressed beyond a stepping play amount, the input shaft of the negative pressure booster 1b is pushed and the negative pressure booster is pressed.
The output shaft of the star 1b is connected to a negative pressure of an intake manifold of an on-vehicle engine (not shown) and an adjustment pressure (a value between the negative pressure and the atmospheric pressure) corresponding to a pushing amount of the input shaft. The operating shaft (piston rod) of the master cylinder 1a is pushed with a strong force proportional to the difference, whereby the wheels FR, FL, RR and R
Wheel cylinder (wheel brake) 15 disposed on L
A brake fluid pressure proportional to the output of the negative pressure booster 1b is applied to 1 to 154.

Pumps 121 and 122, reservoirs (low-pressure accumulators) 123 and 124, and solenoid valves are provided between the pipe 82 to which the output port of the brake master cylinder 1a communicates and the wheel brakes 151 to 154. 81, 83, 9
1, 93, 131 to 138, relief valves 88, 98 and check valves 77, 79, 84 to 87, 94 to 97 are connected or inserted. The wheel FR indicates the front right wheel as viewed from the driver's seat, the wheel FL indicates the front left wheel, the wheel RR indicates the rear right wheel, and the wheel RL indicates the rear left wheel. As shown in FIG. Piping is configured.

One pipe 82 for supplying and discharging brake fluid pressure to the wheel brakes 151 and 154 of the front right wheel FR and the rear left wheel RL is connected to one output port of the master cylinder 1a. ing. A first pressure control valve 81 (in this embodiment, an electromagnetic switching valve) and check valves 77 and 87 are inserted in series between the pipe 82 and the wheel brakes 151 and 154, and are connected to the wheel brake 151. The check valve 77 is connected in parallel with a pressure increase control valve 131 (in this embodiment, an electromagnetic switching valve), and the check valve 87 connected to the wheel brake 154 is connected in parallel with a pressure increase control valve 133. Pressure reduction control valves 132 and 134 are interposed between the wheel brakes 151 and 154 and the reservoir 123.

Pump 12 driven by electric motor 120
Check valve 8 between suction port 1 and reservoir 123
4, 85 are inserted in series, and both check valves 84,
A second pressure control valve 83 (an electromagnetic switching valve in this embodiment) is interposed between the pipe 85 and the pipe 82. A check valve 7 is provided between the discharge port of the pump 121 and the high-pressure line HPL1.
6, a damper 80 and an orifice 89 are inserted. The check valve 76 is connected to the high pressure line HPL1 through the pump 1
The backflow of the brake fluid to 21 is prevented, and damper 80 and orifice 89 absorb (smooth) the high-frequency vibration (pulsation) of the discharge pressure applied by pump 121 to high-pressure line HPL1. A check valve 86, a relief valve 88, and the aforementioned first pressure control valve 8 are provided between the pipe 82 and the high-pressure line HPL1.
1 are connected in parallel.

There is no depression of the brake pedal 103 and acceleration slip (traction control for suppressing this)
When the wheel brake pressure distribution control for maintaining the vehicle body posture stably is not performed, the first and second pressure control valves 81 and 83, the pressure increase control valves 131 and 133, and the pressure reduction control valve 132, As shown in FIG. 1, the first pressure control valve 81 and the pressure increase control valves 131 and 133 are open (flow) and the second pressure control valve 83 is turned off.
And the pressure reduction control valves 132 and 134 are closed (cut off).
That is, the first pressure control valve 81 and the pressure increase control valve 13
Reference numeral 1 133 denotes a normally open solenoid valve, and the second pressure control valve 83 and the pressure reduction control valves 132 and 134 are normally closed solenoid valves.

In this embodiment, the discharge pressure of the pump 121 is higher than the brake hydraulic pressure applied to the pipe 82 by the master cylinder 1a when the boosting limit of the negative pressure booster 1b is at the limit (the maximum assisting force output). . If the brake pedal 103 is depressed at or near the boosting limit of the negative pressure booster 1b,
In order to apply a pressure higher than the brake fluid pressure corresponding to the boosting limit to the wheel brake, a pump 121 is provided by the electric motor 120.
To turn on (energize) the first pressure control valve 81 to close (cut off the flow path) and turn on (energize) the second pressure control valve 83 to open (flow through the flow path). As a result, the pump 121 sucks the brake fluid from the master cylinder 1a and discharges it to the high-pressure pipe HPL1, and the wheel brake 151 passes through the off (non-energized) and open (flow) pressure increasing control valves 131 and 133. , 154.

At this time, the opening and closing of the first pressure control valve 81 is controlled to control the bypass amount of the brake fluid from the high-pressure pipe HPL1 to the pipe 82, so that the wheel brake 15 is controlled.
1,154 increase, decrease and brake pressure can be controlled. For example, if the control cycle of ON (closed: increased pressure) / OFF (open: reduced pressure) of the first pressure control valve 81 is Tds, and the on-duty is defined as ON time / Tds within Tds, then ON (pressure increase) ) By increasing the duty, the pressure of the high pressure pipe HPL1 increases, and the wheel brakes 151, 154
Brake pressure rises. That is, the wheel brake pressure increases. Conversely, lowering the on-duty reduces wheel blur.
The key pressure is reduced. The increase and decrease of the wheel brake pressure due to the on-duty control of the first pressure control valve 81 act on the wheel brakes 151 and 154 simultaneously. That is, the on-duty control of the first pressure control valve 81 is performed by setting the wheel brakes 151 and 154 to one group, and individually increasing the wheel brakes 151 and 154.
Pressure reduction control cannot be performed. However, with the first pressure control valve 81 being on (closed: shut off), the pressure increase control valve 13
1 (on: closed: shut off) / off (open: flow), and the control cycle of on / off of the pressure increase control valve 131 is Tds.
The off (pressure increase) duty is calculated as follows: Off time in Tds / Td
When defined as s, the brake pressure of the wheel brake 151 increases at a high speed by increasing the off (pressure increase) duty. By turning on the pressure increasing control valve 131 (closed: shut off) and turning on the pressure reducing control valve 132 (opening: flowing), the hydraulic pressure of the wheel brake 151 is increased by the pump 121 or the reservoir 12.
It falls to 3 and falls. If the ON / OFF control cycle of the pressure reduction control valve 132 is defined as Tds and the ON (pressure reduction) duty is defined as ON time / Tds in Tds, the wheel brake is increased by increasing the ON (pressure reduction) duty. Key 1
The brake pressure at 51 drops at high speed. Similarly, the pressure increase rate of the wheel brake 154 can be controlled by the off (pressure increase) duty control of the pressure increase control valve 133, and the ON (pressure decrease) duty of the pressure reduction control valve 134 is controlled. Thus, the pressure reduction speed of the wheel brakes 154 can be controlled, and the brake pressures of the wheel brakes 151 and 154 and the pressure increasing speed and the pressure reduction speed are individually controlled for each wheel brake. sell.

The pump 121 is operated by a wheel brake or a brake.
The brake fluid is sucked out from the master cylinder 1a and discharged to the high pressure pipeline HPL1. A relief valve 88 is provided to prevent an excessive rise in the pressure of the high-pressure line HPL1. When the hydraulic pressure of the high-pressure line HPL1 exceeds a set pressure, the brake of the high-pressure line HPL1 is passed through the relief valve 88. Liquid is in line 82
(Master cylinder 1a).

Another pipe 92 for supplying and discharging the brake hydraulic pressure to the wheel brakes 152 and 153 of the front left wheel FL and the rear right wheel RR is connected to another output port of the master cylinder 1a. It is connected to the. Between the pipe 92 and the wheel brakes 152 and 153, the pipe 82
Elements and fluid circuits interposed or added between the wheel brakes 151 and 154 are similarly connected. The description thereof will be omitted because it is the same as described above. For the sake of simplicity, the brake pressure control of the wheel brake 151 will be described below as a typical example. However, unless otherwise specified, the brake pressure of the other wheel brakes is also controlled. Of the wheel brake 151
Control is performed at substantially the same time as the key pressure control.

As described above, the wheel brake device shown in FIG. 1 can increase and decrease the pressure of the wheel brake 151 together with the wheel brake 154 paired with the wheel brake by the first pressure control valve 81. The pressure increase and the pressure reduction of the wheel brake 151 alone can be performed by the pressure increase control valve 131 and the pressure decrease control valve 132.

In ABS control, traction control (acceleration slip control) and braking force distribution control, individual control of each wheel brake pressure is preferred. The wheel brake device shown in FIG. 1 drives the electric motor 120 (pumps 121 and 122) when the brake pressure control of any of the wheel brakes 151 to 154 becomes necessary. The first pressure control valve 81 is turned on (closed: shut off), and the second pressure control valve 83 is turned off (closed: closed).
Shut off), and the pressure increase control valve 131 and the pressure decrease control valve 13
By controlling the pressure-increasing duty and the pressure-decreasing duty of No. 2, it is possible to control the pressure of the wheel brake 151 as well as the pressure increasing speed and the pressure decreasing speed.

In the embodiment of the present invention, as will be described later, the electronic control unit 110 controls the wheel brake pressure, that is, the ABS control, for suppressing the wheel slip rate from increasing when the wheel is braked. When there is no need for control and the brake pedal is depressed at or near the boosting limit of the negative pressure booster 1b, the electric motor 12 is depressed.
0 (pumps 121 and 122) to drive the wheel brake pressure to a pressure higher than a value corresponding to the boosting limit;
Perform The ABS control has a higher priority than the steady control. In the ABS control, the electric motor 120 (pump 12) is used.
, 122) to turn on the first pressure control valve 81 (closed:
Shut off), the second pressure control valve 83 is turned off (closed: shut off), and the duty of the pressure reduction control valve 132 and the pressure increase control valve 131 is reduced and the pressure of the wheel brake 151 is reduced and increased. When the wheel slip ratio decreases, the second pressure control valve 83 is turned on (opened: flowing) to suck the brake fluid from the master cylinder 1a and refill it into the high-pressure line HPL1 (wheel brake 151). However, in the above-described steady control, the second pressure control valve 83 is turned on (open: flow), the pressure of the wheel brake 151 is controlled by the duty control of the first pressure control valve 81, and the pressure increase control valve 131 is controlled. And the pressure reducing control valve 132 is normally off (1
(31 open, 132 closed).

FIG. 2 shows the configuration of the electronic control unit 110. The control valves 81, 83, 91, 93, 131 to 13
Numeral 8 is connected to the electronic control unit 110 to control energization and non-energization of each solenoid coil. The electric motor 120 is also connected to the electronic control unit 110, and is thereby driven and controlled. Further, wheel speed sensors 141 to 144 are provided for the wheels FR, FL, RR, and RL, respectively, and these are connected to the electronic control unit 110, and the rotation speed of each wheel, that is, the wheel speed signal is transmitted to the electronic control unit. It is configured to be input to 110. Wheel speed sensors 141-
144 is a toothed rotor that rotates with the rotation of each wheel,
This is a well-known electromagnetic induction type sensor comprising a pickup provided opposite to the tooth portion of the rotor, and outputs a pulse voltage having a frequency proportional to the rotation speed of each wheel. Alternatively, a Hall IC, an optical sensor, or the like may be used.

A potentiometer 103p is connected to the pedal shaft integral with the brake pedal 103 as a stroke sensor for detecting the amount of pushing of the input rod of the booster 1b, and the potentiometer 103p is connected to the pedal shaft. An analog signal indicating the amount of depression of the brake pedal 103 (the rotation angle of the pedal 103) is given to the electronic control unit 110. The electronic control unit 110 converts the analog signal into a stepping amount data and reads the pedaling amount.

FIG. 3 shows an outline of wheel brake pressure control by the computer 111. The wheel brake pressure control (steps 2 to 13) shown in FIG. 3 is repeatedly executed at a substantially constant cycle Ts. When the ignition switch is turned on, initial settings are made in step 1 as a preliminary process in FIG. 3, and counters, timers, and the like are cleared. Further, an interrupt process executed for each pulse of the pulse voltage generated by the wheel speed sensors 141 to 144 is permitted. For example, when the wheel speed sensor 141 generates one pulse, the CPU 114 of the computer 111 executes an interrupt process in response to the pulse, and stores a count value of a clock pulse (clock pulse) in a pulse cycle register addressed to the front right wheel FR. Write and clear the clock pulse counter. Since the clock pulse counter always counts up the clock pulse while the interrupt processing is permitted, the pulse cycle register addressed to the front right wheel FR stores the latest pulse voltage generated by the wheel speed sensor 141 in the pulse cycle register. Cycle (reciprocal of wheel speed)
Is always held. Wheel speed sensors 142-144
The same processing is performed by the CPU 114 for the voltage pulse generated by the wheel speed sensor. Therefore, after the interruption processing is permitted, the data of the latest one cycle of the voltage pulse generated by the wheel speed sensors 141 to 144 is obtained. It is always maintained in each pulse period register. In the "calculation of each wheel speed" (step 4) described later, C
The PU 114 calculates the wheel speed by multiplying the reciprocal of the data in the pulse period register by a coefficient (cycle / speed conversion coefficient).

Here, a counter, a timer, and the like used in the present embodiment will be generally described. First, a mode register and a flag register are provided as internal registers, and at least the following control modes are set in the former. That is, in addition to the pressure reduction mode for increasing or decreasing the brake fluid pressure in the wheel cylinders 151 to 154, the pressure increase mode, or the holding mode, the pulse pressure increase modes 1, 2, 3, and the pulse pressure decrease mode 1 , 2, and 3 are set. The contents of the wheel brake pressure control mode (ABS control mode, steady control mode) and the variable pressure mode are as follows.

-ABS control mode- The combination of the slip ratio S of any of the wheels and the wheel deceleration DWD is in the antilock control start region [(a) of FIG. 14].
Then, the pressure reduction of the wheel brake of the wheel is started, the pumps 121 and 122) are driven, and thereafter, the combination of the slip ratio S and the wheel deceleration DWD is maintained (hold), and the pressure is increased or reduced. Depending on which area (FIG. 14A) the wheel brake is held, increased or reduced in pressure. A
During the BS control, the pump is driven and the first pressure control valve 81 is kept on (closed: shut off), and the second pressure control valve 83 is off (closed: shut off). During this period, the second control valve 83 is turned on (open: flow).

-Transformation mode in ABS control mode-Pressure reduction output 3 (pulse pressure reduction 3): first pressure control valve 81 on (closed: shut off), second pressure control valve 83 off (closed: shut off) On / off control (PWM energization) of the pressure reduction control valve 132 at a high on (pressure reduction) duty with the pressure increase control valve 131 turned on (closed: shut off), pressure reduction output 2 (pulse pressure reduction 2): medium ON / OFF control of the pressure reducing control valve 132 at ON (pressure reducing) duty, pressure reducing output 1 (pulse pressure reducing 1): low ON (pressure reducing) duty
ON / OFF control of the pressure-reducing control valve 132 in the tee.

Hold (hold): First pressure control valve 81 on (closed: shut off), second pressure control valve 83 off (closed: shut off)
And the pressure increase control valve 131 is turned on (closed: shut off), and the pressure decrease control valve 1
32 off (closed: shut off).

Pressure increase output 1 (pulse pressure increase 1): The first pressure control valve 81 is turned on (closed: cut off), the second pressure control valve 83 is turned off (closed: cut off), and the pressure reduction control valve 132 is turned off (closed: cut off). Pressure increasing control valve 13 at low off (pressure increasing) duty
1, ON / OFF control (PWM energization), boost pressure output 2 (pulse boost 2): first pressure control valve 81 on (closed: shut off), second pressure control valve 83 on (open: flow), and pressure reduction The control valve 132 is turned off (closed: shut off), and the pressure increase control valve 131 is turned on / off at a medium off (pressure increase) duty.
Off control (PWM energization), boost pressure output 3 (pulse boost 3): first pressure control valve 81 on (closed: shut off), second pressure control valve 83 on (open: flow), and pressure reduction control valve 132 off (Close: shut off), on / off control (PWM energization) of the pressure increase control valve 131 at a high off (pressure increase) duty.

FIG. 10 schematically shows a change in the wheel brake pressure during the repetitive execution of the above-described boosting outputs 1 to 3, and FIG.
The wheel brake during the repetitive execution of the above-described reduced pressure outputs 1 to 3
The change of the key pressure is simulated.

When the vehicle deceleration Gd reaches the set value Gds when the vehicle is not in the ABS control mode, the pump is driven at a speed corresponding to the brake pedal depression speed up to the set value Gds. The second pressure control valve 83 is turned on (open: flowing), the pressure increase control valve 131 is turned off (open:
Flow), the pressure reduction control valve 132 is turned off (closed: shut off), and the wheel brake 1 is set according to the deviation of the vehicle deceleration Gd from the target deceleration Go corresponding to the brake pedal depression amount Pd.
The pressure is increased and reduced by 51 (FIG. 22).

-Transformation mode in steady-state control mode-Rapid pressure increase: first pressure control valve 81 on (closed: shut off), second pressure control valve 83 on (open: flow), brake pedal operation The pump is driven at a speed corresponding to the stepping speed. Pulse pressure: ON / OFF control (PWM energization) of the first pressure control valve 81 at an ON (pressure increasing) duty.

Hold: The first pressure control valve 81 is turned on (closed:
Shut off), second pressure control valve 83 on (open: flow), pump stop, pressure increase control valve 131 on (close: shut off).

Pulse pressure reduction (pulse pressure reduction 2): first pressure control valve 81 on (closed: shut off), second pressure control valve 83 on (open: flow), pump stop, pressure increase control valve 131 on (closed: ON / OFF control (PWM energization) of the first pressure control valve 81 at ON (pressure increase) duty, pulse pressure reduction 1: ON (pressure increase) duty is higher than the above "pulse pressure reduction". High on / off control of the first pressure control valve 81, rapid pressure reduction: first pressure control valve 81 off (open: flow), second pressure control valve 83 on (open: flow), pump stop.

There are flags indicating each of the above-mentioned transformation modes. When any one of the flags is set, control for realizing the transformation mode corresponding to the set flag is performed. As a counter,
It has at least a slow pressure reduction counter and a slow pressure increase counter, and the slow pressure reduction counter is a continuous time of the slow pressure reduction mode (pressure reduction output 1) (the number of pressure reduction pulses generated during the pressure reduction output 1)
The slow pressure increase counter measures the continuous time of the slow pressure increase mode (pressure increase output 1) (the number of pressure increase pulses generated while the pressure increase output 1 continues).

Referring again to FIG. 3, when the initial setting is completed in step 1, the process from step 2 to step 13 is performed, and then the process returns to step 2. In step 2, T
Start timer for s time period. In step 3, the analog signal of the potentiometer 103p is converted into digital data (brake pedal depression amount data Pd) and written into a register, and the above-mentioned wheel speed sensors 141-1 are output.
The data of a pulse period register (four addresses for FR, FL, RR and & RL) storing the cycle data of the pulse generated by 44 is read out and written in the input register. In step 4, the wheel speeds (peripheral speeds) VWFL, VWFR, VWRR and VWRL of each of the wheels FL, FR, RL and RR are calculated and written in the wheel speed registers. Each wheel deceleration DVWFL, DVWFR, DVWRR and DVWRL (positive value is deceleration, negative value is acceleration) is calculated and written in the wheel deceleration register. Then, in step 6, the road surface friction coefficient μ is estimated.

FIG. 4 shows the contents of the “estimation of road surface friction coefficient μ” (step 6). Here, the CPU 114 determines that the brake pedal depression amount Pd read in step 3 is in a small area,
It is checked whether the area is in the middle area or the multi-area, and data indicating which area it belongs to is generated (step 2).
1). Next, the deceleration of the maximum wheel speed is read out from the wheel deceleration register, and the deceleration is calculated in the small area, the middle area,
It is checked which of the large areas it belongs to, and data indicating which area it belongs to is generated (step 22). Then, based on the area data of the brake pedal depression amount Pd and the deceleration area data, the pedal depression amount & deceleration small,
During pedal depression and deceleration or when pedal depression and deceleration are large, the road surface friction coefficient μ is estimated to be in the middle range,
Otherwise, when the pedal depression amount is small or medium & deceleration is large or medium, the road surface friction coefficient μ is estimated to be in a low region, otherwise, the road surface friction coefficient μ is estimated to be in a high region and indicates the estimated region. The data is written to the friction coefficient register (steps 23 to 27).

Referring back to FIG. Next, the CPU 114
Calculates the vehicle speed VSO (n) in the "estimated vehicle speed calculation" (step 7A). Note that n of VSO (n) means the current calculated value, and n-1 appearing later means the calculated value of the previous time (before Ts).

FIG. 5 shows "Calculation of estimated vehicle speed" (step 7).
The contents of A) are shown. Here, firstly, corresponding to the estimated road surface friction coefficient μ (high, medium or low), the body deceleration αDN is determined to be 1.1G when it is high, 0.6G when it is medium, and If it is low, it is determined to be 0.4G (step 3
1 to 35). Then, the vehicle body acceleration αUP is determined to be 0.5 G (step 36). Next, the wheel speeds VWFL, VWFR, VWR
R, VWRL, the highest wheel speed is selected, and the current vehicle speed VWO (n-1) -αDN · Ts estimated from the previously calculated value VWO (n-1) and the deceleration αDN is calculated. The calculated value VWO (n-
1) and the current vehicle speed VWO (n-
1) + αUP · Ts is calculated, an intermediate value (average value) of these three is calculated, and this is set as the current vehicle speed VWO (n) (step 37).

Referring again to FIG. 3, the CPU 114 next calculates the vehicle body deceleration Gd (step 7B). In this case, the current vehicle speed V calculated in step 7A
Gd = VWO (n-1) -VWO (n) is calculated from WO (n) and the previously calculated vehicle speed VWO (n-1). The positive value of the deceleration Gd is the deceleration, and the negative value is the acceleration.

Next, the CPU 114 calculates the estimated vehicle speed of each wheel (step 8). The contents are shown in FIG.
Here, the current value VWFR (n) of the front right wheel speed, the previous value VWF
From R (n-1), deceleration amount αDN · T during Ts at deceleration αDN
The value VWFR (n-1) −αDN · Ts obtained by subtracting s and the previous value VWFR (n−1) are added to the speed increase amount αUP during Ts at the acceleration αUP.
Calculates an intermediate value of the three values, VWFR (n-1) + αUP · Ts, to which Ts has been added, and calculates the estimated vehicle speed VSOFR as the front right wheel portion.
(n) (step 41). Similarly, the front left wheel portion estimated vehicle speed VSOFL (n), the current value VWRR (n) of the rear right wheel speed, and the rear left wheel portion estimated vehicle speed VSORL (n) are calculated (steps 42 to 44).

Referring again to FIG. 3, the CPU 114 next performs “front left wheel FL control calculation” (step 9FL), “front right wheel FR control calculation” (9FR), “rear left wheel FL control calculation” (9RL), and "Rear right wheel FR control calculation" (9R
R). These contents are substantially the same except that the target wheels are different.
The contents of “L control calculation” (9FL) will be described with reference to FIG.

The "Front left wheel FL control calculation" shown in FIG.
In L), first, the data of the flag register FRF is "1".
(ABS control of the front left wheel FL is started) (step 51). If it is "0" (not started), the ABS control of the wheel brake of the front left wheel FL is started. It is checked whether it is necessary (step 52). Here, the slip ratio S of the left front wheel FL = [VSOFL (n) −VWFL (n)] × 100 / VSOFL (n)% is calculated, and the slip ratio S and the wheel deceleration DVWFL (n) are calculated as follows.
A check is made to see if the control start area is indicated by hatching in FIG.

If it is in the control start area, step 53
Then, the transformation mode for the left front wheel FL is set to a reduced pressure, and "1" is written to the flag register FRF. Thus, the transformer
Is set, the "control output" of step 11 in FIG.
Then, an instruction signal to a brake pressure circuit for reducing the wheel brake of the front left wheel FL is output. This is the “first decompression”
Is the start of If the ABS control is being performed on any of the wheels in the "control output" (step 11) (FRF = "1"), the CPU 114 controls the electric motor 120 (pumps 121 and 122). A driving signal is given to the motor driver 118a.

When the ABS control is started, it is checked in step 54 whether the estimated front left wheel portion vehicle speed VSOFL (n) is equal to or less than a set value or the wheel slip ratio S is equal to or less than a set value. Is established, it is determined that the ABS control is terminated. Then, the transformation mode to the left front wheel FL is set to end, and "0" is written to the flag register FRF (flag register clear). When the end is set in this manner, the left front wheel FL is obtained by the “control output” in step 11 of FIG.
To the brake pressure circuit (continuous pressure increase: the output pressure of the master cylinder is applied to the wheel brake as it is, and the brake pressure circuit is connected without computer intervention). Is output. In the “control output”, the ABS control is completed for all wheels (FRF =
If "0"), the CPU 114 causes the electric motor 120
A signal for stopping the pumps 121 and 122 is given to the motor driver 118a.

If the ABS control of the front left wheel FL has been started and the end condition is not satisfied, the CPU 11
4 is a front left wheel F with reference to the data of the flag register.
It is checked whether or not L is "control first pressure increase output state" (step 56), and if so, "control mode 1" (step 57), otherwise "control mode 2" (step 56). Step 58) is executed.

FIG. 8 shows the contents of "control mode 1" (step 57), and FIG. 9 shows the contents of "control mode 2" (step 58). Here, please refer to FIG. 7, FIG. 8 and FIG. 9 together. Start the above “initial decompression” (step 5
1 to 53-11), and after Ts, the process proceeds to “front left wheel FL control calculation” (9FL) again. If the ABS control end condition is not satisfied, the CPU 114 proceeds to steps 51-54-56.
The routine proceeds to "control mode 1" (step 57) at a route of -57, and "control mode determination 1" (step 61) is executed with reference to FIG. Here, the slip ratio S and the wheel acceleration (a value obtained by multiplying the wheel deceleration DVWFL (n) by a negative sign)
Is located in the pressure reduction region, the holding region, or the pressure increase region in FIG. 14B. If it is determined that the pressure is reduced, the variable pressure mode (output mode) is set to "pressure reduced output 3".
Is determined.

Thereafter, while the pressure reduction is determined in the "control mode determination 1" (step 61), the output "pressure reduction 3" is determined, and the output is determined relatively quickly by the "pulse pressure reduction mode 3". Then, the wheel brake pressure of the front left wheel FL decreases. The wheel speed recovers due to this rapid pressure reduction, and "control mode determination 1"
If it is determined in step 61 that the wheel brake is to be held, the wheel brake is disconnected from the brake pressure circuit, and the wheel brake is held so that no brake fluid flows in and out (steps 75 and 7).
6). If it is determined that the pressure is to be increased, the data (data representing low, medium or high) in the friction coefficient register is referred to (step 77), and if it is not "low", "pressure increase output 2" is determined. (Step 80) Information “1” indicating that the pressure increase output 2 has been determined is written to the flag register IIF.

If it is "low", the transformation mode is set to "pressure increase output 1" (step 78). Then, the information of the flag register is set to the “state after control first-time pressure increase output” (79).
This "pressure-increasing output 1" corresponds to the aforementioned "pulse pressure-increasing mode 1".
Is meant. Thereafter, since the state is the "state after the control initial pressure increase output", the process proceeds from step 56 to 58, and while the pressure increase is determined in "control mode determination 2" (step 81), "pressure increase output 1". And the output are determined (step 81
-91-96-98-100), the wheel brake pressure of the front left wheel FL rises relatively slowly by the "pulse pressure increase mode 1". The continuous time of this “pressure-increasing output 1” (the number of times that the pressure-increasing output 1 is determined to be continuous) is measured.

As described above, the “state after control initial pressure increase output”
After that, if it is determined that the pressure is to be reduced in "control mode determination 2" (step 81), the output is determined as "pressure reduction output 1" (step 92), and the "pressure increase" is a pressure increase with a very high pressure increasing speed. Check that "Output 3" has been executed (step 9
3) During execution (IIF2 = 1), the brake pressure is excessively increased due to the pressure increase by the "pressure increase output 3". The state before the control first pressure increase output is set (step 94).
Thereby, next time (after Ts), steps 56 to 5
When the control proceeds to step 7 and the pressure reduction is determined in "control mode determination 1" (step 61), the variable pressure mode is changed to "pressure reduction output 3" (step 72). Control.

After the above-described first pressure reduction is started, the "pressure increase output 1" is executed, then "control mode determination 2" (step 81) determines that the pressure is reduced, and the "pressure reduction output 1" is changed to the pressure reduction mode. -, The CPU 114 sets the "pressure-reduction output 1"
Is measured (the number of times that the pressure reduction output is determined to be 2 consecutively), and when the continuous time exceeds the set value T1, the information in the flag register is set to the “state before control first pressure increase output” (step 93-). 95-94). As a result, the next time (Ts
Thereafter, the process proceeds from step 56 to step 57, and if it is determined that the pressure is reduced in "control mode determination 1" (step 61), the pressure change mode is changed to "pressure reduction output 3" (step 72), and the above-described operation is performed. Control similar to the first pressure reduction is performed.

Further, "control mode judgment 2" (step 8)
When the pressure increase is continuously determined in 1) and “pressure increase output 1” (step 100) is continued, the continuous time is set to the set value T.
If it exceeds 2, the transformation mode is changed to "pressure increase output 3" and "1" is written to the flag register IIF2 (step 9).
9). Thereafter, "control mode determination 2" (step 81).
When it is determined that the pressure is reduced, the output is determined as "pressure reduced output 1" (step 92), and "pressure increased output 3", which is a pressure increase with a relatively high boosting speed, has been executed (IIF2 = 1).
Therefore, the brake pressure is excessively increased by the "pressure increase output 3", and it is determined that rapid pressure reduction is necessary, and the information in the flag register is set to "the state before the control first pressure increase output" (step 94). As a result, the next time (after Ts), the process proceeds from step 56 to step 57, and if it is determined that the pressure is reduced in "control mode determination 1" (step 61), the voltage is reduced to "pressure reduction output 3".
Is changed (step 72), and the same control is performed as immediately after the start of the first pressure reduction.

Next, the "front left wheel FL control calculation" (9)
The processing of the CPU 114 in FL) and the change in the rotational speed of the front left wheel FL that appears due to the processing will be described with reference to FIGS.

1. Lock pressure holding logic at the start of control (see FIG. 12A) When the wheel brake pressure exceeds the lock pressure (the brake pressure at which wheel rotation stops), the wheel speed drops. Therefore, the pressure is reduced (decompression output) by observing the drop speed (deceleration) and the drop amount (slip rate). 3 & Reduced pressure output 2). B. Once the wheel speed is recovered, the pressure is increased to the lock pressure by the pressure increase (pressure increase output 1 or pressure increase output 2). C. The above B. When the drop in the wheel speed is small as compared with, the pressure is reduced (pressure reduction output 1) to recover the wheel speed. D. The above B. (Intensified output 1 or increased pressure output 2). Is determined to be substantially at the lock pressure, and the above C.I. The pressure is reduced very slowly and the holding time is lengthened, and the pressure is increased very slowly in a pattern in which the pressure increase is reduced (pressure increase output 2). E. FIG. The above D. If a drop in wheel speed occurs in the pressure increase pattern (pressure increase output 1), slight pressure reduction (pressure reduction output 1) is performed, the wheel speed is restored, and the above D.C. In the pressure increase pattern (pressure increase output 1).

2. F. Lock holding logic when a change 1 (low μ → high μ) occurs in the road surface friction coefficient μ during the ABS control (see FIG. 12B). When the road surface changes from low μ to high μ, that is, when D.
If the pressure increase pattern (pressure increase output 2) is output for a certain number of times (T2) or more, The pressure is increased suddenly (pressure increase output 3) to increase the pressure to the lock pressure at once. Since the lock pressure needs to be searched again due to the sudden increase, The above B. Then, the pressure is gradually increased (pressure increase output 2), and the lock pressure is searched again. I. The above D. Similarly, the pressure is gradually increased in the pressure increase pattern (pressure increase output 1) having a longer holding time.

3. The lock pressure holding logic when the road surface friction coefficient μ changes 2 (high μ → low μ) during control (FIG. 12)
(C) of J.). When the road surface changes from high μ to low μ, the wheel speed drops sharply, so that the pressure is largely reduced (pressure reduction output 2). As the lock pressure has to be searched again due to the sudden decrease, K. The above B. In the same manner as described above, the pressure increase pattern (pressure increase output 2) for searching for the lock pressure is set, and the lock pressure is searched again. L. The above D. Similarly, the pressure is gradually increased in the pressure increase pattern (pressure increase output 1) having a longer holding time.

4. B. Lock pressure holding logic when road friction coefficient μ is low at the start of control (see FIG. 13 (a)) If low μ is determined based on the amount of decrease in wheel speed (deceleration) when starting the first decompression, B. Search for lock pressure Instead of the pressure increase pattern (pressure increase output 2) of FIG. The pressure is slowly increased in the pressure increase pattern (pressure increase output 1) with a longer holding time. O. On low μ roads If the brake pressure control is performed in the same pattern as On the low μ road, as described in 4. above, since the second drop in wheel speed becomes large and the amount of decompression increases. The brake pressure is reduced by controlling the hydraulic pressure according to the following pattern.

As described above, 1. ~ 4. By performing the above, the pressure reduction amount of the whole ABS control is reduced, and the brake fluid pressure amount dropped to the reservoir is reduced.

Referring back to FIG. The above-mentioned "front left wheel FL
When the control calculation (step 9FL), the front right wheel FR control calculation (9FR), the rear left wheel FL control calculation (9RL), and the rear right wheel FR control calculation (9RR) elapse, C
The PU 114 executes “steady-state control calculation” (9 AW).

FIG. 15 shows the contents of the "steady-state control calculation" (9 AW). Here, first, the flag registers FRF, FL
It is checked whether the data of F, RRF and RLF are all "0" (ABS control is not performed for all wheels) (step 111). If so, it is checked whether the brake pedal depression amount Pd is within the braking effective area (the pedal 103 is depressed more than the play allowance PSa) (step 112). If so, the vehicle deceleration G calculated in step 7B (FIG. 3)
d is an output pressure slightly lower than the boosting limit of the negative pressure booster 1b, and a deceleration Gds applied to the vehicle while traveling on a road surface with high frictional resistance.
(Set value) is checked (step 11)
3). If Gd <Gds, "control mode determination 3"
(Step 114) is executed.

FIG. 16 shows the contents of "control mode determination 3" (step 114). Here, first, the brake pedal depressing speed (dPS = Pd-previous Pd) is calculated (step 121A). In this calculation, Pd is the value read in step 3 this time, and Pd is the previous value (Ts before this time)
Is the value read into.

Next, it is checked whether the stepping speed dPS is a positive value (stepping) (step 121B). If the stepping speed dPS is a positive value, the contents of dps2 are written into dps1 of the instantaneous speed register (step 122), and dps2 Is written (step 123), dps4 is written into dps3 (step 124), and the current calculated value dPS is written into the instantaneous speed register dps4 (step 125). And the instantaneous speed registers dps1 to dps4
Is calculated (126).
Next, the current calculated value dPS is stored in the maximum instantaneous speed register dP.
It is checked whether the value of Sm is equal to or more than dPSm (127).
a) If so, the current calculated value dPS is written to the maximum instantaneous speed register dPSm (127b).

Then, the data dPSm of the maximum instantaneous speed register dPSm is set to threshold values (set values) dPS1, dPS2.
(Steps 127c and 129) and ΔPd
Are compared with threshold values (set values) ΣPd1 and ΣPd2 (steps 128, 130 and 131), and according to the value of the maximum stepping speed dPSm and the integrated value ΣPd, as shown in FIG. The energization duty command value Md of 120 is set (steps 132A to 134A). The energization duty command value Md specifies the ratio (%) of the energization time in one cycle of the PWM energization of the motor 120 to one cycle.

As shown in FIG. 20, the maximum stepping speed dPS
If m is high, the energization duty command value Md is set to a high value, and if the value of the integrated value ΔPd is large, the energization duty command value Md is set to a high value. One brake pedal 103
In the process of increasing the wheel brake pressure due to the stepping in, for example, as shown in FIG. 19, when the stepping speed is high as shown in FIG. 19, the dPSm is large and the integrated value ΔPd is large. When the stepping speed is medium as shown in FIG. 19, dPSm and the integrated value ΣPd
Since both are medium, the energization duty command value Md is set to, for example, 80%. If the stepping speed is low as shown in FIG. 19, the dPSm is small and the integrated value ΔPd is small, so the energization duty command value Md is set. Is set to, for example, 60%.

While the vehicle deceleration Gd is smaller than the set value Gds, the depressing speed of the brake pedal 103 is calculated in this manner, and the energization duty command value Md is set accordingly.

When the vehicle deceleration Gd is equal to or greater than the set value Gds, a target deceleration Go corresponding to the brake pedal depression amount Pd is calculated (step 115).

The internal memory of the CPU 114 stores data (indicated by a dashed line) indicating the relationship between the brake pedal depression amount Pd (horizontal axis) and the target deceleration Go (right ordinate), as indicated by the dashed line in FIG. In step 115, this data
The target deceleration Go corresponding to the brake pedal depression amount Pd read in step 3 is read from the table.

FIG. 21 shows the relationship (solid line) between the stepping amount Pd (horizontal axis) and the load (left vertical axis) applied to the input rod 4 of the booster 1b, and the wheel shake by the electronic control unit 110. Stepping amount Pd when key pressure control is not performed
The relationship (dotted line) between (horizontal axis) and the vehicle body deceleration Gd is shown.

The pushing amount of the input rod of the booster 1b is Se.
At this time, the booster 1b reaches the boosting limit, and the booster 1b
, The rod driving force of the master cylinder due to the pressure difference between the atmospheric pressure and the negative pressure (the engine manifold pressure) becomes the maximum value (the highest assisting force). Assuming that the booster input load at this time is Fbm, the brake pedal depression amount Pd is a value PS corresponding to the depression amount Se of the input rod of the booster 1b.
e, the booster input load is Fbm as shown in FIG.
It becomes. The output load of the output rod of the booster 1b is small and the boosting function of the booster 1b is practically absent until the brake pedal depressing amount Pd exceeds Pse and reaches the pressing limit PSi.

However, in this embodiment, the pump 121,
The brake pressing force by the discharge pressure of 122 is larger than the brake pressing force obtained by the maximum value of the output load of the booster (the boosting limit value corresponding to Fbm), and the target of the vehicle body deceleration caused by the brake pressing force is obtained. The deceleration Gom is determined. The set value Gds is determined by the booster assisting force being the maximum value Fbm.
Is set slightly lower than the vehicle deceleration at the time of (the case of traveling on a road surface having a high friction coefficient). Then, as shown in FIG. 21, after the boosting limit (Fbm), the target deceleration Go is set to a deceleration higher than the vehicle deceleration (approximately Gds) when the booster output is the maximum assisting force Fbm. Specified wheel brake higher than the boosting limit of booster 1b
The pedal depression amounts PSe to PSi corresponding to the key pressure
High deceleration (wheel brake pressure) is defined.

After calculating the target deceleration Go as described above, the CPU 114 proceeds to "control mode judgment 4" (step 11).
Perform 6). This is shown in FIG. In this case, the vehicle body deceleration Gd is compared with the target deceleration Go (steps 151 to 154), and as shown in FIG. 22, the transformation mode (rapid pressure increase, pulse pressure increase, hold, pulse (Step 155)
161).

That is, if dG = Go-Gd is positive and equal to or more than the set value i, the "rapid pressure increase" and the transformation mode are set (steps 151 and 155). Otherwise, dG is positive and the set value h is set.
Is exceeded, set to “pulse pressure increase” (step 1).
52, 156) Otherwise, if the absolute value of dG is less than or equal to h, "hold" is set (steps 153, 15).
9) Otherwise, if dG is negative and its absolute value exceeds r, "rapid decompression" is set (steps 154 and 160). If dG is negative and its absolute value is less than r, a "pulse" is set. "Decompression" is set (steps 154 and 161).

When "rapid pressure increase" or "pulse pressure increase" is set, pump drive (120 ON) is set (step 157), and "1" (during steady control) is written to the register FSW (step 158). ).

When the transformation mode is set as described above, FIG.
In step 111, "control output", the control mode and the transformation mode determined as described above are executed. CPU1
14 is the energization duty command value M set as described above.
d, the electric motor 120 is energized at a duty Md.
To energize. If the pedal depression speed until Gd ≧ Gds is high, the energizing duty Md is high as described above, and the output torque of the electric motor 120 is high, so that the pumps 121, 1
22 is driven at a high speed, the braking pressure applied to the wheel brakes increases at a high speed, but if the pedal depression speed until Gd ≧ Gds is low, the energizing duty M
Since d is low and the output torque of the electric motor 120 is low, the pumps 121 and 122 are driven at a low speed, and the rising speed of the brake pressure applied to the wheel brakes is low.

By the way, if Gd <Gds, and FIG.
When the depressing speed dPS is a negative value (release of pedal depression: return) in step 121B, the maximum instantaneous value register dPSm is cleared in step 121C of FIG.
In step 135 of FIG. 17, it is checked whether the data of the register FSW is "1" (during pump driving; near or above the boosting limit of the vacuum booster). Step 135). If the data of the register FSW is "1", it is checked whether the stepping speed dPS (negative value) is equal to or less than the third set value nPS3 (negative value) (the pedal return speed is high) (step 136). Is the transformation mode
Is set to "rapid decompression" (139). Third set value nPS
If it is larger than 3, it is checked whether it is equal to or less than the second set value nPS2 (the pedal return speed is medium speed) (step 13).
7) If so, the transformation mode is set to "pulse pressure reduction 2" (step 140). If it is larger than the second set value nPS2, it is checked whether it is equal to or less than the first set value nPS1 (the pedal return speed is low) (step 138), and if so, the transformation mode is set to "pulse pressure reduction 2" (step 141). ). If it is greater than the first set value nPS1, all the solenoid valves are turned off (the state shown in FIG. 1), the energization of the electric motor 120 is stopped (142), and the register FSW is cleared (143). The transformation mode is set to "hold" (step 142).

When the control mode and the transformation mode are set in this way, the control mode and the transformation mode determined as described above are executed by the "control output" of step 11 in FIG. , Due to the strong depression of the brake pedal 103,
The vehicle deceleration Gd ≧ Gds, and the pump 1 responds to this.
After driving the electric motors 21 and 122 (electric motor 120),
When d <Gds and the brake pedal 103 moves backward, it corresponds to the return movement speed. If the brake pedal 103 is at a high speed, the speed is increased by "rapid decompression", and if it is medium, it is determined by "pulse decompression 2". If the speed is medium and low, the wheel brake pressure is reduced at low speed by "pulse pressure reduction 1". When the speed is extremely low or substantially stopped, the pump driving is stopped, and the control of the wheel brake pressure by the CPU 114 is stopped.

When the brake pedal 103 is at the starting point P of the effective area
When the stepping amount returns to Sa or less, the register FSW is cleared (step 119 in FIG. 15), and the pumps 121 and 12 are reset.
2 (electric motor 120) is stopped (step 120 in FIG. 15). While the brake pedal 103 is not depressed to near the boosting limit of the negative pressure booster 1b and the vehicle deceleration Gd is less than the set value Gds, the pump is not driven and all the solenoid valves are off (see FIG. 1). Pressure increase mode)
The output pressure change speed of the negative pressure booster corresponding to the depression / return speed of the key pedal 103 is obtained.

Referring back to FIG. 9FL each wheel control calculation
~ 9RR or 9AW in steady-state control calculation
U114 outputs ON / OFF instructions to the motor driver and the solenoid drivers 118a to 118m in accordance with the calculation results of the wheel control calculations 9FL to 9RR or the steady control calculation 9AW (step 11).

When the ABS control (9FL to 9RR) or the steady control (9AW) is completed, an OFF instruction is output to the motor driver and the solenoid drivers 118a to 118m, and each timer of the holding timer, the pressure reducing timer and the pressure increasing timer is output. Is cleared, and the pulse pressure increase counter, the pulse pressure increase flag, and the rapid pressure decrease flag are cleared (step 12).

Then, it is checked whether or not the timer Ts has timed out (step 13), and an abnormality check is performed until the time is over (step 14). When an abnormality is detected, the brake pressure control is released and an alarm is generated (steps 15 and 16).

The ABS control described above (9FL to 9R)
R) is started when the wheel deceleration and the wheel slip rate of at least one wheel enter the anti-lock control start area shown in FIG. 14A, and the operation is performed until the brake pedal is released. The procedure ends when the key pedal is released. During the ABS control, the registers FRF, FLF,
The data of RRF or RLF is "1". When the ABS control is not performed, the registers FRF, FLF, R
RF and RLF data are "0", and steady control (9 AW) is performed while the brake pedal is being depressed at this time. The fact that the ABS control is not performed means that (1) the road surface is high μ, the wheel slip rate is low, and wheel lock due to sudden braking is unlikely to occur (the body braking effect is high), or (2) -Means that the depression amount of the key pedal is small and the vehicle body deceleration (wheel deceleration) is low.

In the case of the above (1), the driver sets the brake pedal 103 to the key touch point corresponding amount PSe of the booster 1b.
At the time of sudden braking, the above-described steady control (9A
By W), a brake pressure higher than the brake pressure possible with the booster 1b is applied to the wheel brake, and the vehicle body is suddenly braked. In addition, in the upper limit regions PSe to PSi in which the increase of the brake pedal pressure cannot be substantially expected with respect to the increase of the brake pedal depression amount, the wheel brake is increased in proportion to the increase of the brake pedal depression amount. When the pressure rises sharply and emergency braking is required (in such a case, the driver must
3 is pushed down to the upper limit amount) effectively.
This rapid increase in the wheel brake pressure of the rapid brake is also a speed corresponding to the pedal depression speed until the booster 1b substantially reaches the maximum assist output, and is affected by the driver's pedal operation (the depression amount and the depression speed). This results in a smooth change in wheel brake pressure.
When the brake is released immediately after the sudden braking, the wheel brake pressure is reduced at a deceleration corresponding to the pedal return speed, and the response to the release of the brake pressure is high.

The case (2) above is a gentle braking region in which the degree of urgency in driving the vehicle is low. In this region, the change in the wheel brake pressure due to the output of the booster 1b interlocked with the pedal operation causes a fluctuation. -Efficiently illuminated according to the depression amount and the depression speed of the key pedal 103.

Now, assuming that the driver depresses the brake pedal 103 while the vehicle is running, and the pedal depression amount Pd approaches or exceeds the maximum assist output (sudden braking), the "steady control calculation" ( 9AW), the wheel brake pressure is controlled so that the vehicle body deceleration Gd rises to the target deceleration Go shown in FIG. 21 at a speed proportional to the stepping speed in accordance with the pedal depression amount Pd. The key pressure is controlled; During this brake pressure control, the deceleration of each wheel is calculated by “calculation of wheel deceleration of each wheel” 5, μ of the road surface is estimated by “estimation of friction coefficient μ of road surface” 6, and “calculation of estimated vehicle speed” 7A, the vehicle speed is estimated and calculated, and the "estimated vehicle deceleration Gd calculation" 7B is estimated and calculated. In each wheel control calculation 9FL to 9RR, each wheel slip ratio S is calculated, and the slip ratio and the wheel deceleration for each wheel are in a region where the ABS control is to be started (excessive slip ratio region: FIG. Check if it is in ABS)
When the vehicle enters the control start region (that is, when the wheel slip ratio becomes excessive due to sudden braking), the ABS control is started. That is, the wheel brake pressure control is changed from the steady control 9AW to A
Switch to BS control.

The basic data for the ABS control is generated in "Estimation of road friction coefficient μ" 6, in which the brake pedal depression amount Pd is included in the parameter, and this range corresponds to the booster 1b. There is a pedal stroke (PSi-PSe) exceeding the boosting limit of the booster up to PSi which is larger than the depression amount PSe corresponding to the key touch point, and the ABS control extends to a region exceeding the boosting limit. When the steady control 9AW is switched to the ABS control, when the brake pedal depression amount Pd is in a region (PSi-PSe) exceeding the maximum assist limit for the booster (when the vehicle body deceleration is extremely high). ) Also has steady control 9
Consistent with the wheel brake pressure control by AW (continuous)
The ABS control is started, and the continuity of the wheel brake pressure control is high. The same applies when switching from the ABS control to the steady control 9AW.

In the embodiment described above, the potentiometer for detecting the depression amount Pd of the brake pedal 103 is used as the operation value detecting means (103p) for detecting the operation value applied to the hydraulic pressure generating means (1). −p 103p is used,
As shown by the solid line in FIG. 21, the brake pedal depression amount Pd
And the booster input load, there is a one-to-one relationship in the stepping amount Pd of the wheel brake pressure control range. Therefore, instead of the potentiometer 103p, a load sensor for detecting the stepping force is used. Is also good. That is, load detection may be performed instead of stroke detection. In this case, a data table storing data representing the relationship between the brake pedal depression amount Pd and the target deceleration Go is made to represent the relationship between the pedaling force and the target deceleration Go. As the treading force sensor, a sensor used for load detection, such as a strain gauge or a pressure sensor, may be used.

In the embodiment described above,
The deceleration of the vehicle body is obtained by the CPU 114 of the electronic control unit 110 estimating and calculating the vehicle body speed from the detected rotation speed of each wheel and calculating the differential value of the calculated vehicle body speed. An acceleration sensor for detecting acceleration / deceleration may be provided to detect the vehicle body deceleration. More specifically, in the above-described embodiment, the brake pressures of the four wheels are collectively controlled based on the difference between the deceleration of the vehicle body as a whole and the target deceleration. Each wheel deceleration obtained in the "deceleration calculation" 5 may be individually compared with the target deceleration, and each wheel brake pressure may be controlled based on each comparison result. In this case, the first pressure control valve 81 is turned on (closed), and the pressure increase control valve 131 and the pressure reduction control valve 132 control the increase and decrease of the wheel brake 151. In any case, when the deceleration (wheel brake pressure) becomes excessive with respect to the road surface condition and the wheel slip increases, the above-described ABS control is started, so that the wheel lock is avoided and the steering stability is improved. Secured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of an electronic control device 110 illustrated in FIG.

FIG. 3 is a flowchart showing an outline of wheel brake pressure control of the microcomputer 111 shown in FIG. 2;

FIG. 4 is a flowchart showing the content of “calculation of road friction coefficient μ” (step 6) shown in FIG. 3;

FIG. 5 is a flowchart showing the contents of “calculation of estimated vehicle speed” (step 7A) shown in FIG. 3;

FIG. 6 is a flowchart showing the content of “calculation of estimated vehicle speed of each wheel portion” (step 8) shown in FIG. 3;

FIG. 7 is a flowchart showing the content of “front left wheel FL control calculation” (step 9FL) shown in FIG. 3;

FIG. 8 shows a “control mode 1” (step 5) shown in FIG.
This is a flowchart showing the contents of 7).

FIG. 9 shows “control mode 2” (step 5) shown in FIG.
This is a flowchart showing the contents of 8).

10A and 10B show three modes of boosting outputs 1 to 3 (pulse boosting) when the boosting control valve 131 shown in FIG. 1 is turned on / off, and FIG. -The pressure rise rate, (b) the "pressure boost output 2"
(C) shows the result of the “pressure increase output 3”.

FIG. 11 shows three modes of pressure reduction outputs 1 to 3 (pulse pressure reduction) by turning on / off the pressure reduction control valve 132 shown in FIG. 1, and FIG. (B) shows the result of “decompression output 2”,
(C) shows the result based on the “reduced pressure output 3”.

12 is a time chart showing the relationship between the wheel brake pressure and the wheel speed of the front left wheel FL appearing in the "front left wheel FL control calculation" (step 9FL) shown in FIG.
(A) shows a case where the friction coefficient μ of the road surface is low at the start of braking, and (b) shows a case where the friction coefficient μ of the road surface is high μ during the ABS control.
(C) shows a case where the friction coefficient μ of the road surface changes from a high μ to a low μ with a relatively large change during the ABS control. .

FIG. 13 is a time chart showing the relationship between the wheel brake pressure and the wheel speed of the front left wheel FL appearing in “Front left wheel FL control calculation” (step 9FL) shown in FIG. 7;
(A) shows a case where the friction coefficient μ of the road surface is low at the start of braking, and (b) shows a case where the friction coefficient μ of the road surface changes from high μ to low μ during braking.

FIG. 14A shows an example in which the CPU 114 shown in FIG.
FIG. 4B is a graph showing a region where control is started, and FIG. 4B is a graph showing a region where pressure reduction and pressure increase output during ABS control is performed.

FIG. 15 is a flowchart showing the contents of the “steady control calculation” 9AW shown in FIG.

FIG. 16 shows “control mode determination 3” 114 shown in FIG.
Is a flow chart showing a part of the contents of FIG.

FIG. 17 shows “control mode determination 3” 114 shown in FIG.
Is a flow chart showing the rest of the contents of FIG.

FIG. 18 shows “control mode determination 4” 116 shown in FIG.
Is a flowchart showing the contents of the above.

FIG. 19 is a graph showing three examples of the depressing speed of the brake pedal 103 shown in FIG.

20 is a diagram showing a depression speed dPS of the brake pedal 103 and an integrated depression amount ΔPd, and a motor energization duty Md determined by “control mode determination 3” 114 shown in FIG.
3 is a graph showing the relationship with the value of.

21 is a graph showing a relationship between a depression amount Pd of a brake pedal 103 shown in FIG. 1 and an input load of a brake booster 1b.

FIG. 22 is a graph showing an area of a pressure change mode determined by the CPU 114 in accordance with “control mode determination 4” 116 of FIG. 18 in accordance with the vehicle body deceleration Gd and the target deceleration Go.

[Description of Signs] 1: Hydraulic pressure generator 1a: Master cylinder 1b: Boosters 80, 90: Dampers 89, 99: Orifices 81, 91: First pressure control valves 83, 93: Second pressure control valve 103: Brake pedal 103p: Potentiometer 110: Electronic control unit 111: Microcomputer 112: Input port 113: Output port 114: CPU 115: ROM 116: RAM 117a to 17e: Amplifier circuit 118a to 18i :
Driver 120: Electric motors 121, 22: Pumps 123, 124: Reservoirs 131, 133, 135, 137: Pressure increasing control valves 132, 134, 136, 138: Pressure reducing control valves 141 to 144: Wheel speed sensor 151 154: wheel brake FR: front right wheel FL: front left wheel RR: rear right wheel RL: rear left wheel

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Chief Hayashi 2-1-1 Asahi-cho, Kariya-shi, Aichi Aisin Seiki Co., Ltd. (72) Inventor Akihide Kamiya 2-1-1 Asahi-cho, Kariya-shi, Aichi Aisin Seiki Co., Ltd. (72) Inventor Mitsunari Takeuchi 2-1-1 Asahicho, Kariya City, Aichi Prefecture Aisin Seiki Co., Ltd. (72) Inventor Asao Sakai 2-1-1 Asahicho, Kariya City, Aichi Prefecture Address Aisin Seiki Co., Ltd. (56) References JP-A-7-81540 (JP, A) JP-A-8-207726 (JP, A) JP-A-3-136693 (JP, A) JP-A-8-815 295224 (JP, A) JP-A-9-123892 (JP, A) JP-A-5-270384 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T 8 / 00-13 / 74

Claims (7)

(57) [Claims] 1. A hydraulic pressure generating means for generating a brake hydraulic pressure in accordance with an applied operating force and applying the hydraulic pressure to a wheel brake, and the hydraulic pressure generating means generates the wheel brake by the hydraulic pressure generating means. A hydraulic source on the vehicle, including a pump for providing a hydraulic pressure higher than the brake pressure; and increasing and reducing the wheel brake pressure between the hydraulic pressure source and the wheel brake. A wheel brake pressure control device comprising: an operation value detection unit for detecting an operation value applied to the hydraulic pressure generation unit; a speed detection unit for detecting a change speed of the operation value; And adjusting control means for controlling the driving / stopping of the pump and the flow of the supply pressure adjusting means, and driving the pump at a speed corresponding to the change speed of the operation value when driving the pump. Wheel brake suppression Apparatus. 2. A hydraulic pressure generating means on a vehicle for generating a brake hydraulic pressure according to an applied operating force and applying the generated hydraulic pressure to a wheel brake; A pump on the vehicle for applying a hydraulic pressure higher than the brake pressure to be applied; a pump for applying a high brake hydraulic pressure to the wheel brake; Output port
A first pressure control valve for controlling the flow of the brake fluid between the pump and the suction port of the pump and the output port of the hydraulic pressure generating means; A second pressure control valve for controlling; an operating value detecting means for detecting an operating value applied to the hydraulic pressure generating means; a speed detecting means for detecting a changing speed of the operating value; A wheel brake pressure control device comprising: a flow control means for controlling the flow of a second pressure control valve and driving the pump to drive the pump at a speed corresponding to a change speed of the operation value. . 3. A hydraulic pressure generating means on a vehicle for generating a brake hydraulic pressure according to an applied operating force and applying the generated hydraulic pressure to a wheel brake; the hydraulic pressure generating means generates the wheel brake by the hydraulic pressure generating means. A pump on the vehicle for applying a hydraulic pressure higher than the brake pressure to be applied; a pump for applying a high brake hydraulic pressure to the wheel brake; Output port
A first pressure control valve for controlling the flow of the brake fluid between the pump and the suction port of the pump and the output port of the hydraulic pressure generating means; A second pressure control valve to be controlled; a pressure increase control valve interposed between the discharge side flow path and the wheel brake; a pressure reduction control valve interposed between the suction side flow path and the wheel brake Operating value detecting means for detecting an operating value applied to the hydraulic pressure generating means; speed detecting means for detecting a changing speed of the operating value; and driving / stopping of the pump and first and second pressure control valves. When controlling the flow and driving the pump, the pump is driven at a speed corresponding to the change speed of the operation value, and when the braking slip of the wheels is increased, the pump is driven at a specified speed. 1 Brake between the discharge side flow path and the output port of the hydraulic pressure generating means via the pressure control valve The flow of the brake fluid is stopped, and the flow of the brake fluid between the suction side flow path and the output port of the hydraulic pressure generating means is stopped by the second pressure control valve, and the pressure reduction control valve and the pressure increase control are stopped. A wheel brake pressure control device comprising: an adjustment control means for adjusting a wheel brake pressure by operating a valve. 4. The adjustment control means reads the operation value at a predetermined cycle, and in response to a change speed of the operation value and an integrated value of the change speed, the adjustment value is high when the integrated value is high and the change speed is high.
4. The wheel brake pressure control device according to claim 1, wherein the pump is driven at a low speed when the integrated value is low and the change speed is low. 5. The adjustment control means according to claim 1, wherein when the speed of change of the operation value is negative, the wheel brake pressure is reduced at a high speed when the absolute value of the speed of change is high and at a low speed when the absolute value of the speed of change is low. 5. The wheel brake pressure control device according to claim 2, 3 or 4. 6. The adjustment control means sets a hold for shutting off the wheel brake from the hydraulic pressure source when the change speed is negative and the absolute value is lower than a set value, and when the change speed is equal to or higher than the set value. , Depressurization and hold are repeated alternately in a certain cycle,
6. The wheel brake pressure control device according to claim 5, wherein the pressure reduction period within the cycle is lengthened when the pressure reduction period is high corresponding to the absolute value of the change speed. 7. The vehicle according to claim 1, further comprising: means for detecting a deceleration of the vehicle, wherein the adjustment control means drives the pump when the deceleration is equal to or greater than a set value. Wheel brake according to claim 4, claim 5, or claim 6.
Pressure control device.