JP2002029396A - Brake control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake control device compatible with securing responsiveness for starting wheel cylinder pressure control and excellent pedal feeling at a wheel cylinder pressure control changeover point without complicating a system. SOLUTION: This brake control device is provided with a master cylinder, a braking pressure generating means, a braking pressure selecting means, a stroke simulator having a first liquid chamber for absorbing operating liquid delivered from the master cylinder and a second liquid chamber for absorbing the operating liquid delivered from the braking pressure generating means and designed so that a performance characteristic is same with a wheel cylinder, a first opening and closing valve and a check valve inserted between the master cylinder and the first liquid chamber in a row, a second opening and closing valve inserted between the braking pressure generating means and the second liquid chamber, and a brake control means for controlling the braking pressure generating means, the braking pressure selecting means, the first opening and closing valve, and the second opening and closing valve corresponding to a vehicle running condition on the basis of a result by a maser cylinder pressure detecting means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a vehicle brake control device provided with a brake operation pressure system by a brake operation and an electronic control pressure system by a control command.

[0002]

2. Description of the Related Art As a conventional brake control device, for example, one described in Japanese Patent Application Laid-Open No. 9-240465 is known.

According to this conventional publication, the pressure of a pseudo load having the same hydraulic pressure-consumption liquid amount characteristic as that of a wheel cylinder is controlled to be equal to the master cylinder pressure, and the liquid from the master cylinder is directly supplied to the wheel cylinder. When switching from a normal brake to a brake for controlling the wheel cylinder pressure by the pressure control valve, the master cylinder and the pseudo load are communicated. In this case, since the pressure of the dummy load and the pressure of the master cylinder are balanced, even if the brake pedal is depressed after switching to wheel cylinder pressure control, the characteristic of brake pedal stroke-master cylinder pressure is in a plate-depressed state. A technique is described that can prevent the occurrence of an injured person.

[0004]

However, in the conventional brake control device, the value of the slope of the pressure-liquid amount characteristic of the pseudo load (liquid amount / pressure) is equivalent to the wheel cylinder characteristic, and the low pressure At about (about 0 to 1 MPa), it is much larger than at high pressure (about 9 to 10 MPa). on the other hand,
When the wheel cylinder pressure control is started from a normal brake, a short time due to a response delay of the valve operation or a hydraulic response delay from the start determination point is set as a wheel cylinder pressure control switching point.

For this reason, as shown in FIG. 12, the pressure characteristic of the pseudo load from the wheel cylinder pressure control start judgment is as follows.
The rising gradient in the low pressure range from zero pressure, which requires fluid volume, is low and gradually increases.The rise of the pseudo load pressure is delayed, and the pseudo load pressure is lower than the master cylinder pressure. This is the point at which the wheel cylinder pressure control is switched, and as a result, the pedal stroke-master cylinder pressure characteristic changes, giving the driver an uncomfortable feeling.

Although a slight improvement in responsiveness can be seen by providing a dummy load for each pressure control valve, a switching valve and a dummy load are required for each wheel cylinder, which complicates the system and reduces the volume. -There is a problem that the weight increases.

[0007] Further, when switching to the wheel cylinder pressure control after waiting for the time until the pseudo load pressure becomes the master cylinder pressure from the point of time when the wheel cylinder pressure control is determined to start, control such as ABS control performed by the wheel cylinder pressure control is started. When the timing is delayed, for example, when the start timing of the ABS control is delayed, there is a possibility that the original ABS effect of preventing the four-wheel lock at the time of sudden braking or braking on a low μ road may not be sufficiently exhibited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. It is an object of the present invention to ensure responsiveness to start wheel cylinder pressure control and to switch wheel cylinder pressure control without complicating the system. It is an object of the present invention to provide a brake control device capable of achieving both good pedal feeling and good pedal feeling at the same point.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, a brake operation pressure corresponding to a driver's brake operation amount is generated as shown in a conceptual diagram of a claim in FIG. The master cylinder and a pressure control valve control the pressure from an external pressure source to reduce the pressure, and a brake pressure generating means for generating a desired brake pressure, or one of the pressures output from the master cylinder and the brake pressure generating means. Brake pressure selecting means for selecting and supplying to the wheel cylinder, a first fluid chamber for absorbing the hydraulic fluid output from the master cylinder, and a second fluid chamber for absorbing the hydraulic fluid output from the brake pressure generating means. A reaction force generating mechanism for applying an equal pressure to the first liquid chamber and the second liquid chamber as a reaction force in accordance with the sum of the absorption liquid amounts of the first liquid chamber and the second liquid chamber, And before A stroke simulator set such that the sum of the amounts of the absorbing liquids in the first liquid chamber and the second liquid chamber is equal to the wheel cylinder, and is inserted between the master cylinder and the first liquid chamber of the stroke simulator. A first on-off valve for intermittently controlling the flow of the hydraulic fluid, a check valve disposed in parallel with the first on-off valve and passing only the hydraulic fluid output from the stroke simulator, and the brake pressure generation Means and a second on-off valve interposed between the second fluid chambers of the stroke simulator for intermittently controlling the flow of hydraulic fluid, master cylinder pressure detecting means for detecting pressure output from the master cylinder, A block for controlling the brake pressure generating means, the brake pressure selecting means, the first opening / closing valve, and the second opening / closing valve in accordance with the vehicle traveling state based on the result of the cylinder pressure detecting means. And rk in the control unit, characterized by comprising a.

According to a second aspect of the present invention, in the brake control device according to the first aspect, the brake control means includes:
Normally, the first on-off valve is closed, the brake pressure selecting means is set to a position for selecting the pressure output from the master cylinder, and the output pressure of the master cylinder is supplied only to the wheel cylinder, After the preload is applied to the second fluid chamber of the stroke simulator by the brake pressure generating means, the second opening / closing valve is closed, and the preload is sealed in the second fluid chamber of the stroke simulator, depending on the traveling state of the vehicle. When performing wheel cylinder pressure control, based on the detection result of the master cylinder pressure detection means, after applying a pressure equal to the master cylinder pressure to the second fluid chamber of the stroke simulator by the brake pressure generation means, The second on-off valve is closed, the first on-off valve is opened, and the output pressure of the master cylinder is reduced to the third pressure of the stroke simulator. In addition to the liquid chamber, the brake pressure selecting means is set to a position for selecting the pressure output from the brake pressure generating means, and means for supplying the output pressure of the brake pressure generating means to the wheel cylinder. I do.

According to a third aspect of the present invention, in the brake control device according to the second aspect, a wheel cylinder pressure control prediction means for predicting the start of wheel cylinder pressure control according to a vehicle running state is provided, and the brake control means is provided. When the wheel cylinder pressure control predicting means predicts the start of wheel cylinder pressure control, the brake pressure generating means applies a preload to the second fluid chamber of the stroke simulator, and then closes the second on-off valve. A means for sealing the preload in the second liquid chamber of the stroke simulator.

According to a fourth aspect of the present invention, in the brake control device of the first aspect, a wheel cylinder pressure control predicting means for predicting a start of wheel cylinder pressure control according to a vehicle running state is provided, and the brake control means is provided. Normally, the first on-off valve is closed, the brake pressure selecting means is set to a position for selecting the pressure output from the master cylinder, and the output pressure of the master cylinder is supplied only to the wheel cylinder, When the wheel cylinder pressure control predicting means predicts the start of wheel cylinder pressure control, the brake pressure generating means sets the master in the second fluid chamber of the stroke simulator based on the detection result of the master cylinder pressure detecting means. When applying a pressure equal to the cylinder pressure and performing wheel cylinder pressure control, close the second on-off valve, The first on-off valve is opened, the output pressure of the master cylinder is applied to the first liquid chamber of the stroke simulator, and the brake pressure selecting means is set to a position for selecting the pressure output from the brake pressure generating means. A means for supplying the output pressure of the brake pressure generating means to the wheel cylinder.

According to a fifth aspect of the present invention, in the brake control device according to the first aspect, the first cylinder pressure control predicting means includes: The two-stage wheel cylinder pressure control prediction means is performed in two stages by the wheel cylinder pressure control prediction means, and the second wheel cylinder pressure control prediction means is provided with a configuration for predicting the start earlier than the first wheel cylinder pressure control prediction means, Normally, the brake control unit closes the first on-off valve, sets the brake pressure selection unit to a position for selecting the pressure output from the master cylinder, and outputs the output pressure of the master cylinder only to the wheel cylinder. When the second wheel cylinder pressure control prediction means predicts the start of wheel cylinder pressure control, the brake pressure generation After applying a preload to the second fluid chamber of the stroke simulator, the second on-off valve is closed, and the preload is sealed in the second fluid chamber of the stroke simulator, thereby controlling the first wheel cylinder pressure control. When the prediction means predicts the start of the wheel cylinder pressure control,
On the basis of the detection result of the master cylinder pressure detecting means, the brake pressure generating means applies a pressure equal to the master cylinder pressure to the second fluid chamber of the stroke simulator to perform wheel cylinder pressure control. Is closed, the first on-off valve is opened, the output pressure of the master cylinder is applied to the first fluid chamber of the stroke simulator, and the brake pressure selecting means is output from the brake pressure generating means. Position to select the pressure,
A means for supplying the output pressure of the brake pressure generating means to the wheel cylinder is provided.

According to a sixth aspect of the present invention, in the brake control device according to the fourth or fifth aspect, the brake pressure generating means, the brake pressure selecting means, and the second on-off valve are each a wheel cylinder of each wheel. A plurality of brake pressure generating means capable of applying pressure to the second fluid chamber of the stroke simulator, and providing the brake control means with a second fluid chamber of the stroke simulator. When pressure is applied to the first, the pressure is first applied by all the brake pressure generating means, and after a lapse of a predetermined time, the second on-off valve is closed except for a predetermined system, and only the brake pressure generating means of the system is used. It is characterized in that it is means for continuously applying pressure.

According to a seventh aspect of the present invention, in the brake control device according to the second, third, or fifth aspect, the preload for enclosing the brake control means in the second fluid chamber of the stroke simulator is controlled by a vehicle. It is characterized in that the means is changed in accordance with the running state.

According to an eighth aspect of the present invention, in the brake control device according to the third or fourth aspect, the wheel cylinder pressure control predicting means includes: (1) a deceleration detection for detecting a deceleration in a vehicle longitudinal direction. Means for predicting the start of wheel cylinder pressure control when the rate of change of the deceleration with respect to time exceeds a predetermined threshold value. (2) Based on the detection result of the master cylinder pressure detecting means,
When the rate of change of the master cylinder pressure over time exceeds a predetermined threshold value, the start of wheel cylinder pressure control is predicted. (3) having wheel speed detection means for detecting wheel speed, determine wheel deceleration based on the wheel speed, any of the wheel deceleration,
When the predetermined threshold value is exceeded, the start of the wheel cylinder pressure control is predicted. (4) a vehicle yaw rate detecting means for detecting the yaw rate of the vehicle body, and when the deviation between the target yaw rate calculated based on the vehicle running state and the vehicle body yaw rate exceeds a predetermined threshold value, the wheel cylinder pressure Predict the start of control. (5) wheel speed detecting means for detecting wheel speed, vehicle body yaw rate detecting means for detecting the yaw rate of the vehicle body, and lateral acceleration detecting means for detecting a lateral acceleration of the vehicle body; When the vehicle body slip angle calculated based on the yaw rate and the lateral acceleration exceeds a predetermined threshold, the start of the wheel cylinder pressure control is predicted.

According to any one of the above (1) to (5), there is provided means for predicting the start of wheel cylinder pressure control.

According to a ninth aspect of the present invention, in the brake control device according to the fifth aspect, the first wheel cylinder pressure control predicting means and the second wheel cylinder pressure control predicting means are described in claim 8 ( In any one of 1) to (5),
By setting two threshold values and setting the threshold value in the second wheel cylinder pressure control prediction means smaller than the threshold value in the first wheel cylinder pressure control prediction means, the start of wheel cylinder pressure control is started. Are respectively used as prediction means.

[0019]

According to the first aspect of the present invention, the stroke simulator includes a first fluid chamber for absorbing the hydraulic fluid output from the master cylinder, and a hydraulic fluid output from the brake pressure generating means. It comprises a second liquid chamber to be absorbed, and a reaction force generating mechanism that gives equal pressure to the first liquid chamber and the second liquid chamber as a reaction force in accordance with the sum of the amount of the absorbed liquid in the first liquid chamber and the second liquid chamber. Since a second on-off valve for intermittently controlling the flow of the hydraulic fluid is interposed between the brake pressure generating means and the second fluid chamber of the stroke simulator, the second fluid of the stroke simulator is opened by opening the second on-off valve. The output pressure of the brake pressure generating means can be applied to the chamber, and then the applied pressure can be contained by closing the second on-off valve.

That is, the pressure can be sealed in the second liquid chamber in advance, so that when switching from the normal brake to the wheel cylinder pressure control by the brake pressure generating means, the stroke simulator is already determined at the time of the start of the wheel cylinder pressure control. Pressure has been raised to containment pressure. When the pressure of the stroke simulator is increased to the containment pressure at the time of the determination of the start of the wheel cylinder pressure control, from the time of the determination of the start of the wheel cylinder pressure control to the switching point of the wheel cylinder pressure control (the completion of the switching operation of the brake pressure selecting means). During the slight response delay time, the pressure of the stroke simulator can be made to follow the master cylinder pressure.

Therefore, when switching to the wheel cylinder pressure control, the pressure is sealed in advance in the second liquid chamber at the time of the determination of the start of the wheel cylinder pressure control. It is possible to achieve both good pedal feeling and good pedal feeling at the switching point. Further, it is not necessary to provide a stroke simulator for each brake pressure generating means in order to improve responsiveness, so that the system is not complicated.

In the invention according to claim 2, usually,
In the brake control means, the first on-off valve is closed,
The brake pressure selection means is set to a position for selecting the pressure output from the master cylinder, and after applying a preload to the second fluid chamber of the stroke simulator by the brake pressure generation means, the second on-off valve is closed. Thus, the output pressure of the master cylinder generated by the brake operation is normally supplied only to the wheel cylinder in a state where the preload is sealed in the second liquid chamber of the stroke simulator.

When the wheel cylinder pressure is controlled in accordance with the running state of the vehicle, the brake control means
Based on the detection result of the master cylinder pressure detecting means, after applying a pressure equal to the master cylinder pressure to the second fluid chamber of the stroke simulator by the brake pressure generating means, the second opening / closing valve is closed, and the first opening / closing valve is opened. When the valve is opened, the brake pressure selecting means is set to a position for selecting the pressure output from the brake pressure generating means. Thus, when performing the wheel cylinder pressure control, the output pressure of the master cylinder is applied to the first liquid chamber of the stroke simulator, and the output pressure of the brake pressure generating means is supplied to the wheel cylinder.

That is, as shown in FIG. 2, since the preload has been applied at the time of determining the start of the wheel cylinder pressure control, the pressure of the second liquid chamber (= pressure of the first liquid chamber) of the stroke simulator is quickly mastered. It can match the cylinder pressure.

Therefore, at the switching point of the wheel cylinder pressure control, the fluctuation of the pedal stroke-master cylinder pressure characteristic is eliminated, so that an effect that the driver does not feel uncomfortable with the brake operation can be obtained.

According to the third aspect of the present invention, in the brake control means, when the start of the wheel cylinder pressure control is predicted by the wheel cylinder pressure control prediction means,
After applying a preload to the second fluid chamber of the stroke simulator by the brake pressure generating means, the second on-off valve is closed,
Control is performed to confine the preload in the second liquid chamber of the stroke simulator.

Therefore, in addition to the same effect as in the second aspect, the pressure is applied to the second liquid chamber of the stroke simulator only when it is predicted that the wheel cylinder pressure control will be performed. Well, reduction of energy consumption
Effects such as improvement of sound vibration and durability can be obtained.

According to the fourth aspect of the present invention, the wheel cylinder pressure control predicting means predicts the start of the wheel cylinder pressure control according to the vehicle running state. Normally, in the brake control means, the first opening / closing valve is closed, and the brake pressure selection means is set to a position for selecting the pressure output from the master cylinder. Supplied to cylinder only. In this normal state, when the start of the wheel cylinder pressure control is predicted by the wheel cylinder pressure control prediction means, based on the detection result of the master cylinder pressure detection means,
A pressure equal to the master cylinder pressure is applied to the second fluid chamber of the stroke simulator by the brake pressure generating means. When the wheel cylinder pressure control is performed, the second on-off valve is closed, the first on-off valve is opened, the output pressure of the master cylinder is applied to the first fluid chamber of the stroke simulator, and the brake pressure is increased. A position where the selection means selects the pressure output from the brake pressure generation means,
The output pressure of the brake pressure generating means is supplied to the wheel cylinder.

That is, as shown in FIG. 3, when the wheel cylinder pressure control is performed, the pressure from the brake pressure generating means is applied to the second fluid chamber of the stroke simulator from the predicted wheel cylinder pressure control start point, so that the stroke is controlled. Simulator second chamber pressure (= first chamber pressure)
At the time before the wheel cylinder pressure control switching point.

Therefore, since there is no change in the pedal stroke-master cylinder pressure characteristic at the point where the wheel cylinder pressure control is switched, an effect that the driver does not feel uncomfortable with the brake operation can be obtained.

According to the fifth aspect of the present invention, the start prediction of the wheel cylinder pressure control according to the running state of the vehicle is:
This is performed in two stages by the first wheel cylinder pressure control prediction unit and the second wheel cylinder pressure control prediction unit that predicts the start earlier than the first wheel cylinder pressure control prediction unit. Normally, in the brake control means, the first on-off valve is closed, and the brake pressure selection means is set to a position for selecting the pressure output from the master cylinder, and the output pressure of the master cylinder is supplied only to the wheel cylinder. Is done. In this normal state, when the start of the wheel cylinder pressure control is predicted by the second wheel cylinder pressure control predicting means, after the preload is applied to the second liquid chamber of the stroke simulator by the brake pressure generating means, the second Is closed, and the preload is sealed in the second liquid chamber of the stroke simulator. Further, when the start of the wheel cylinder pressure control is predicted by the first wheel cylinder pressure control predicting means, the brake fluid generating means controls the second fluid chamber of the stroke simulator based on the detection result of the master cylinder pressure detecting means. To the master cylinder pressure. When performing wheel cylinder pressure control, the second on-off valve is closed, the first on-off valve is opened, the output pressure of the master cylinder is applied to the first fluid chamber of the stroke simulator, and the brake pressure is selected. The means is positioned to select the pressure output from the brake pressure generating means, and the output pressure of the brake pressure generating means is supplied to the wheel cylinder.

Therefore, when performing the wheel cylinder pressure control, the pressure of the second liquid chamber (= the pressure of the first liquid chamber) of the stroke simulator is preliminarily and quickly changed to the master cylinder pressure by the preceding two stages of pressure containment. The variation of the master cylinder pressure-pedal stroke characteristic at the wheel cylinder pressure control switching point can be more reliably eliminated as compared with the invention according to the second to fourth aspects, and the driver can brake the vehicle. The effect of not giving a feeling of operation strangeness is obtained.

According to the present invention, a plurality of brake pressure generating means, a plurality of brake pressure selecting means, and a plurality of second on-off valves are provided for each wheel cylinder of each wheel. The pressure can be applied to the second fluid chamber of the stroke simulator also from the means, and when the pressure is applied to the second fluid chamber of the stroke simulator in the brake control means, the pressure is initially applied by all the brake pressure generating means. After a lapse of a predetermined time, all of the second on-off valves are closed except for a predetermined system, and the pressure is continuously applied only by the brake pressure generating means of the system.

Accordingly, the time for matching the pressure of the second liquid chamber (= pressure of the first liquid chamber) of the stroke simulator with the master cylinder pressure can be shortened, and the effect that the response time when the pressure rises can be greatly reduced. can get.

According to the seventh aspect of the present invention, in the brake control means, the preload sealed in the second liquid chamber of the stroke simulator is changed according to the running state of the vehicle.

Therefore, when the vehicle is in a traveling state in which the master cylinder pressure at the switching point of the wheel cylinder pressure control is predicted to be high, the preload contained in the second liquid chamber of the stroke simulator is set to be high. Pressure of second liquid chamber of stroke simulator (= pressure of first liquid chamber)
The effect of shortening the time for matching the pressure to the master cylinder pressure can be obtained.

According to the present invention, in the wheel cylinder pressure control predicting means, the start of the wheel cylinder pressure control is predicted by one of the above (1) to (5).

Therefore, when the ABS (antilock brake system) is activated, one of (1) to (3)
Predict the start of wheel cylinder pressure control, and when VDC (Vehicle Dynamics Control) is activated,
Either of (4) and (5) has an effect of predicting the start of wheel cylinder pressure control.

According to the ninth aspect of the present invention, in any one of the first to fifth aspects of the present invention, two threshold values are set, and the second wheel cylinder pressure control predicting means. Is set to be smaller than the threshold value in the first wheel cylinder pressure control predicting means, so that the first wheel cylinder pressure control predicting means and the second wheel cylinder pressure control predicting means respectively predict the start of the wheel cylinder pressure control. Wheel cylinder pressure control prediction means is configured.

Thus, the effect that the start prediction of the wheel cylinder pressure control can be performed in two stages can be obtained by a simple method of changing the threshold value.

[0041]

(Embodiment 1) Embodiment 1 is a brake control device according to the first and second aspects of the present invention. First, the configuration will be described.

FIG. 4 is an overall system diagram showing a brake control device according to the first embodiment.
5 is a wheel cylinder, 6 is a brake pedal, 7 is a pump, 8 is an accumulator, 9 to 12 are pressure control valves (hereinafter, referred to as pressure control valves 1 to 4), 13 to
16 is a master cylinder cut valve (hereinafter, MCV1 to MCV1).
Called MCV4. ) And 17 are stroke simulator valves (hereinafter referred to as SSV), 18 is a supply pressure valve (hereinafter referred to as SPV), 19 is a return valve (hereinafter referred to as RTV), 20 is a check valve, and 21 is a check valve. Pedal feel valve (hereinafter PFV1)
Called. ), 25 and 26 are master cylinder pressure sensors,
27 is a stroke simulator, and 28 is a brake control unit.

The master cylinder 1 generates a master cylinder pressure (brake operation pressure) according to the amount of brake operation of the brake pedal 6 by the driver.

The pressure control valves 1 to 4 control the pressure from the pump 7 and the accumulator 8 (external pressure source) so as to constitute a brake pressure generating means for generating a desired brake pressure.

The MCV1 to MCV4 (brake pressure selecting means) select one of the pressures output from the master cylinder 1 and the pressure control valves 1 to 4 by a switching operation, and apply the selected pressure to the wheel cylinders 2 to 5. Supply.

The stroke simulator 27 shown in FIG.
As shown in FIG. 1, a first fluid chamber 30 for absorbing the hydraulic fluid output from the master cylinder 1, a second fluid chamber 31 for absorbing the hydraulic fluid output from the pressure control valve 1, and the first fluid chamber 30
The first liquid chamber 3 according to the sum of the absorption liquid amounts in the second liquid chamber 31;
The reaction force generating mechanism (cylinder 29, first piston 32, and second piston 33)
, A spring 36 and a mechanism formed by O-rings 34 and 35), and the pedal stroke-master cylinder pressure characteristics of the stroke simulator 27, that is, the reaction force and absorption of the first liquid chamber 30 and the second liquid chamber 31. The relationship of the sum of the liquid amounts is set so as to be substantially equal to the wheel cylinders 2 to 5.

The SSV (first open / close valve) is interposed between the master cylinder 1 and the first liquid chamber 30 of the stroke simulator 27, and controls the flow of hydraulic fluid on and off.

The check valve 20 (check valve) is an SSV
And only the hydraulic fluid output from the stroke simulator 27 is passed therethrough.

The PFV 1 (second on-off valve) is connected to the pressure control valve 1 and the second liquid chamber 31 of the stroke simulator 27.
It is interposed between and intermittently controls the flow of the hydraulic fluid.

The master cylinder pressure sensors 25, 26
(Master cylinder pressure detecting means) detects the pressure output from master cylinder 1.

The brake control unit 28
Correspond to the pressure control valves 1 to 4, MCV1 to MCV4, SSV, PFV1 and SP according to the vehicle running state based on the results of the master cylinder pressure sensors 25 and 26.
V and RPV are controlled.

Next, the operation will be described.

FIG. 6 is a flowchart showing a stroke simulator control routine 1. This routine is performed for a certain time (the time is determined experimentally.
(A value of about 100 msec). However, the initial value of the counter C is set to 0.

First, in step S1, it is determined whether or not to control the wheel cylinder pressure based on the vehicle behavior and the master cylinder pressure. If NO in step S1, the process proceeds to step S6, and if YES in step S1, the process proceeds to step S6.
Proceed to 4.

In step S6, it is determined whether the value of counter C is greater than threshold value N. Here, the threshold value N is experimentally determined. If NO in step S6, the process proceeds to step S8, and if YES in step S6, the process proceeds to step S7.

In step S8, SPV: open, RTV:
Open, SSV: Closed, PFV1: Open, MCV1-4: Set to the right position in FIG. 4 and command to pressure control valve 1 is 0.3MP
a. Note that any command may be given to the pressure control valves 2 to 4, but if 0 or a constant value is input, power consumption by driving the pump is reduced.

In the following step S9, the value of the counter C is increased by one.

At step S6, it is determined that the value of the counter C is larger than the threshold value N, and the process proceeds to step S7. At step S7, SPV: closed, RTV: closed, SSV: closed,
PFV1: Closed, MCV1-4: Set to the right position in FIG. 4, and command to pressure control valves 1-4 is set to 0.

On the other hand, when it is determined in step S1 that the wheel cylinder pressure is to be controlled, the process proceeds to step S4. In step S4, SPV: open, RTV: open, SSV: close,
PFV1: open, MCV1-4: set to the right position in FIG.
Is input to the pressure control valves 3 and 4 such that the pressure becomes equal to the pressure of the master cylinder pressure sensor 26.

In the following step S2, SPV: open, RT
V: open, SSV: open, PFV1: closed, MCV1-4: left position in FIG. 4, and input command values calculated by the brake control unit 28 from vehicle behavior and master cylinder pressure to the pressure control valves 1-4. Then, the process proceeds to step S5, where the value of the counter C is set to 0, and the execution of the present routine ends.

[Stroke Simulator Control Action] According to the stroke simulator control routine 1 of the first embodiment, when the wheel cylinder pressure control is performed by the pressure control valves 1 to 4, when the wheel cylinder pressure control is started, When the PFV 1 is opened and a command is input to the pressure control valve 1 so as to be equal to the pressure of the master cylinder pressure sensor 25, the master cylinder is placed in the second liquid chamber 2 of the stroke simulator 27 as shown in FIG. Pressure sensor 2
5 is applied, and the spring 36 contracts until the pressure of the second liquid chamber 31 and the reaction force of the spring 36 are balanced.
Thereafter, the wheel cylinder pressure is controlled by the pressure control valves 1 to 4, and as shown in FIG.
V: Even if the master cylinder pressure is supplied to the first liquid chamber 30 of the stroke simulator 27 when the brake pedal 6 is opened and the brake pedal 6 is depressed in this state, the reaction force of the spring 36 is balanced with the master cylinder pressure. As shown in FIG. 8, a constant master cylinder pressure-pedal stroke characteristic is obtained, and a good pedal feeling is obtained.

Further, since the minute liquid pressure (about 0.3 MPa) is stored in the second liquid chamber 31 of the stroke simulator 27 while the wheel cylinder pressure control is not performed, the second liquid chamber 31 of the stroke simulator 27 is The amount of liquid required for making the pressure equal to the master cylinder pressure can be greatly reduced. Therefore, the responsiveness of causing the hydraulic pressure of the second liquid chamber 31 of the stroke simulator 27 to follow the master cylinder pressure can be improved.

In the first embodiment, the case where the second liquid chamber 31 of the stroke simulator 27 is connected to the pressure control valve 1 has been described, but the pressure control valve connected to the second liquid chamber 31 of the stroke simulator 27 is Any is fine. Then, the pressure value stored in the second liquid chamber 31 of the stroke simulator 27 may be any value. Further, the stroke simulator 27 may be provided at any system at the master cylinder outlet.

(Embodiment 2) The configuration of Embodiment 2 is the same as that of Embodiment 1, and illustration and description are omitted.

The operation of the second embodiment will be described.

FIG. 9 is a flowchart showing a stroke simulator control routine 2. This routine is performed for a certain period of time.
(A value of about 100 msec). However, the initial value of the counter C is set to 0.

First, in step S101, the second wheel cylinder pressure control predicting means determines whether or not it is predicted that the wheel cylinder pressure control will be performed. If NO in step S101, the process proceeds to step S102,
The value of the counter C is set to 0, the process proceeds to step S103, and S
PV: closed, RTV: closed, SSV: closed, PFV1: closed, M
CV1 to CV4: Right positions in FIG.
The command to 4 is set to 0, and the execution of this routine ends.

If YES in step S101, the flow advances to step S104 to determine whether the first wheel cylinder pressure control predicting means predicts that the wheel cylinder pressure control will be performed. On the other hand, N
In the case of O, the process proceeds to step S110, and it is determined whether the value of the counter C is larger than the threshold value N. Here, the value of the threshold value N is experimentally determined. Step S110
If YES in step S103, the process proceeds to step S103, where SPV:
Closed, RTV: Closed, SSV: Closed, PFV1: Closed, MCV1
To 4: The right position in FIG. 4, the command to the pressure control valves 1 to 4 is set to 0, and the execution of this routine is ended. If NO in step S110, the process proceeds to step S111 and S
PV: open, RTV: open, SSV: closed, PFV1: open, M
CV1-4: set to the right position in FIG. 4, set the command to the pressure control valve 1 to about 0.3 MPa, proceed to step S112, increase the value of the counter C by 1, and end the execution of this routine.

On the other hand, if YES in step S104, the flow advances to step S105 to determine whether or not to control the vehicle behavior and the wheel cylinder pressure from the master cylinder pressure. If NO in step S105, step S105
Proceeding to 108, it is determined whether or not the brake pedal 6 is depressed based on the values of the master cylinder pressure sensors 25 and 26. If YES in step S108, step S108
109, SPV: open, RTV: open, SSV: closed,
PFV1: open, MCV1-4: set to the right position in FIG. 4, input a command to the pressure control valves 1 and 2 so as to be equal to the pressure of the master cylinder pressure sensor 25,
In step S107, a command for making the pressure equal to the pressure of the master cylinder pressure sensor 26 is input, the process proceeds to step S107, the value of the counter C is set to 0, and the execution of this routine ends.

If NO in step S108, the flow advances to step S102, where the value of the counter C is set to 0, and the flow advances to step S103, where SPV: closed, RTV: closed, SSV:
Closed, PFV1: closed, MCV1-4: set to the right position in FIG. 4, set the commands to the pressure control valves 1-4 to 0, and end the execution of this routine.

If YES in step S105, the process proceeds to step S106, where SPV: open, RTV: open, SS
V: Open, PFV1: Closed, MCV1-4: Left position in FIG. 4, command values calculated by brake control unit 28 from vehicle behavior and master cylinder pressure are input to pressure control valves 1-4, and step S107 Then, the value of the counter C is set to 0, and the execution of this routine is terminated.

[Stroke Simulator Control Operation] According to the stroke simulator control routine 2 of the second embodiment, it is predicted that the wheel cylinder pressure control will be performed by the first wheel cylinder pressure control prediction means, and the brake pedal is depressed. When the PFV1 is open, a command is input to the pressure control valve 1 so as to be equal to the pressure of the master cylinder pressure sensor 25. Therefore, the pressure of the master cylinder pressure sensor 25 is set to the second liquid chamber 31 of the stroke simulator 27. The same pressure is applied, and the spring 36 contracts until the pressure of the second liquid chamber 31 and the reaction force of the spring 36 balance. Thereafter, even if the wheel cylinder pressure is controlled by the pressure control valves 1 to 4 and the master cylinder pressure is supplied to the first liquid chamber 30 of the stroke simulator 27 by opening SSV: the reaction force of the spring 36 balances with the master cylinder pressure. Therefore, even if the brake pedal 6 is depressed in this state, a constant master cylinder pressure-brake pedal stroke characteristic is obtained, and a good pedal feel is obtained.

When the first wheel cylinder pressure control predicting means predicts that the wheel cylinder pressure control will be performed, the purpose of inputting a command to the pressure control valves 2 to 4 so as to be equal to the master cylinder pressure is as follows. This is to improve the responsiveness of the wheel cylinder pressure control when switching to the wheel cylinder pressure control.

Further, in the second embodiment, the second
If the wheel cylinder pressure control predicting means predicts that the wheel cylinder pressure control will be performed, the minute hydraulic pressure (0.3MP) is applied to the second liquid chamber 31 of the stroke simulator 27.
a) is stored, it is possible to greatly reduce the amount of fluid required to make the fluid pressure in the second fluid chamber 31 of the stroke simulator 27 equal to the master cylinder pressure.

Thus, even when the brake pedal 6 is quickly depressed, the responsiveness of causing the hydraulic pressure in the second hydraulic chamber 31 of the stroke simulator 27 to follow the master cylinder pressure can be improved.

Here, the first and second wheel cylinder pressure control predicting means include, for example, the following methods. (1) When the gradient of the values of the master cylinder pressure sensor and the front and rear G sensors with respect to the time axis exceeds a threshold value, it is predicted that the wheel cylinder pressure control will be performed. (2) If any of the wheel decelerations exceeds a threshold value, it is predicted that the wheel cylinder control will be performed. (3) When the deviation between the target yaw rate value calculated in the brake control unit 28 and the value of the yaw rate sensor exceeds a threshold value, it is predicted that the wheel cylinder pressure control will be performed. (4) It is predicted that the wheel cylinder pressure control will be performed when the vehicle body slip angle exceeds the threshold value. The vehicle body slip angle is calculated, for example, as follows.

If the value of the yaw rate sensor is w, the value of the lateral G sensor is G, and the value of the wheel speed sensor is V, the vehicle body slip angular speed B becomes B = w−G / V, and the vehicle body slip angle is the vehicle body slip angular speed. B can be obtained by integration.

However, the value of the threshold value is (first wheel cylinder pressure control predicting means)> (second wheel cylinder pressure control predicting means).

Therefore, when performing the wheel cylinder pressure control, the pressure in the second liquid chamber 31 of the stroke simulator 27 can be made to match the master cylinder pressure in advance and quickly by the preceding two stages of pressure containment action. At the cylinder pressure control switching point, the variation of the master cylinder pressure-pedal stroke characteristic can be more reliably eliminated as compared with the first embodiment, and an effect that the driver does not feel uncomfortable with the brake operation can be obtained.

In the second embodiment, the case where the second liquid chamber 31 of the stroke simulator 27 is connected to the pressure control valve 1 has been described, but the pressure control valve connected to the second liquid chamber 31 of the stroke simulator 27 is Any is fine. Further, the stroke simulator 27 may be provided at any system at the master cylinder outlet. Furthermore, although the above (1) to (4) have been described as examples of the first and second wheel cylinder pressure control prediction means, the first and second wheel cylinder pressure control prediction means are not limited to this. is not.
Further, the pressure stored in the second liquid chamber 31 of the stroke simulator 27 may be changed by the value of the second wheel cylinder pressure control predicting means.

(Embodiment 3) FIG. 10 shows the configuration of Embodiment 3, wherein 1 is a master cylinder, 2 to 5 are wheel cylinders, 6 is a brake pedal, 7 is a pump, 8 is an accumulator, and 9 to 9 12 is a pressure control valve, 13 to 16 are MCV, 17 is SSV, 18 is SPV, 19 is RTV,
20 is a check valve, 21 to 24 are PFV1 to PFV4,
25 and 26 are master cylinder pressure sensors, 27 is a stroke simulator, and 28 is a brake control unit. That is, the PFV 1 is provided only for the pressure control valve 1 in the first embodiment, whereas the PFV 1 is provided for each of the pressure control valves 1 to 4 in the second embodiment.
PFV4.

The structure of the stroke simulator 27 is the same as that of the first embodiment. The characteristic of the master cylinder pressure-pedal stroke of the stroke simulator 27 is the master cylinder pressure of the wheel cylinders 1 to 4 minus the pedal stroke. It is set to be approximately equal to the characteristic.

The operation of the third embodiment will be described.

FIG. 11 is a flow chart showing the stroke simulator control routine 3. This routine is repeated every certain time (the time is experimentally determined, for example, about 1 to 100 msec). However, in this routine, the counters C1 and C2
Is set to 0.

First, step S201 is executed, and the second
It is determined whether the wheel cylinder pressure control predicting means predicts that the wheel cylinder pressure control will be performed.
If NO in step S201, the process proceeds to step S202, where the value of the counter C1 is set to 0, and the process proceeds to step S203, where SPV: closed, RTV: closed, SSV: closed, PFV
1: closed, MCV1-4: set to the right position in FIG. 10, set the commands to the pressure control valves 1-4 to 0, proceed to step S208, set the value of the counter C2 to 0, and end the execution of this routine.

If YES in step S201, the process proceeds to step S204, where it is determined whether the first wheel cylinder pressure control predicting unit predicts that the wheel cylinder pressure control will be performed.

If NO in step S204, the process advances to step S215 to determine whether the value of the counter C1 is larger than the threshold value N1. Here, the value of the threshold value N1 is experimentally determined. In the case of YES in step S215, the process proceeds to step S203, where SPV: closed, RTV:
Closed, SSV: closed, PFV1-4: closed, MCV1-4: set to the right position in FIG. 10, set the command to the pressure control valves 1-4 to 0, proceed to step S208, set the value of the counter C2 to 0, and set The execution of the routine ends. Step S21
If NO in step 5, the process proceeds to step S216, where SPV:
Open, RTV: Open, SSV: Closed, PFV1: Open, MCV1
To 4: the right position in FIG. 10, the command to the pressure control valve 1 is set to about 0.3 MPa, and the process proceeds to step S217.
The value of the counter C1 is increased by 1, and the process proceeds to step S208,
The value of the counter C2 is set to 0, and the execution of this routine ends.

If YES in step S204, S2
In step 05, it is determined whether to control the wheel cylinder pressure based on the vehicle behavior or the master cylinder pressure.

If NO in step S205, the process proceeds to step S209, where master cylinder pressure sensors 25, 26
It is determined whether or not the brake pedal 6 is depressed from the value of. If NO in step S209, the process proceeds to step S202, where the value of the counter C1 is set to 0, the process proceeds from step S203 to step S208, and the execution of this routine ends. When YES is determined in the step S209, the process proceeds to a step S210, where the value of the counter C1 is set to 0, and the process proceeds to a step S211.
It is determined whether it is greater than. Here, the value of the threshold value N2 is experimentally determined. When YES is determined in the step S211, the process proceeds to a step S212, and SPV: open, RT
V: Open, SSV: Closed, PFV1, 2: Open, PFV3
4: closed, MCV1-4: set to the right position in FIG. 10, input a command equal to the pressure of master cylinder pressure sensor 25 to pressure control valves 1 and 2, and apply master cylinder pressure sensors to pressure control valves 3 and 4. A command is input to make the pressure equal to the pressure of 26, and the execution of this routine ends. Step S
If NO in step 211, the flow advances to step S213 to execute SP
V: open, RTV: open, SSV: closed, PFV1-4: open,
MCV1 to MCV4: Set to the right position in FIG. 10, input a command to the pressure control valves 1 to 4 so as to be equal to the pressure of the master cylinder pressure sensor 25, proceed to step S214, increase the value of the counter C2 by 1, and The execution of the routine ends.

If YES in step S205, the flow advances to step S206 to open SPV: open, RTV: open, SS
V: open, PFV1-4: closed, MCV1-4: left position in FIG. 10, command values calculated by the brake control unit 28 from vehicle behavior and master cylinder pressure are input to the pressure control valves 1-4, Proceed to step S207,
The value of the counter C1 is set to 0, and the process proceeds to step S208,
The value of the counter C2 is set to 0, and the execution of this routine ends.

According to the stroke simulator control routine 3 of the third embodiment, the wheel cylinder pressure control is predicted to be performed by the first wheel cylinder pressure control predicting means, and when the brake pedal is depressed, the first is performed. PFV1 to 4: Open, input a command to the pressure control valves 1 to 4 so as to be equal to the pressure of the master cylinder pressure sensor 25, and then open PFV1, 2: Open the master cylinder pressure to the pressure control valves 1 and 2. Since a command to make the pressure equal to the pressure of the sensor 25 is input, the master cylinder pressure sensor 25 is provided in the second liquid chamber 31 of the stroke simulator 27.
Is applied, and the spring 36 contracts until the pressure of the second liquid chamber 31 and the reaction force of the spring 36 are balanced.
In the third embodiment, the stroke simulator 2
First, the hydraulic pressure is supplied from the pressure control valves 1 to 4 to the second liquid chamber 31 of FIG. 7, and then the hydraulic pressure is supplied from the pressure control valves 1 and 2. Two-liquid chamber 31
Is reduced until the pressure reaches the pressure of the master cylinder pressure sensor 25. Thereafter, even if the wheel cylinder pressure is controlled by the pressure control valves 1 to 4 and the master cylinder pressure is supplied to the first liquid chamber 30 of the stroke simulator 27 by opening SSV: the reaction force of the spring 36 balances with the master cylinder pressure. Therefore, even if the brake pedal 6 is depressed in this state, a constant master cylinder pressure-
The characteristics of the brake pedal stroke are obtained, and a good pedal feeling is obtained.

When the wheel cylinder pressure control is predicted to be performed, the purpose of inputting a command to the pressure control valves 3 and 4 so as to be equal to the pressure of the master cylinder pressure sensor 26 is to switch to the wheel cylinder pressure control. This is to improve the responsiveness of the wheel cylinder pressure control in the case where it is performed.
The first and second wheel cylinder pressure control prediction means are the same as in the second embodiment.

Therefore, in the third embodiment, in addition to the same operation and effect as in the first and second embodiments, the second liquid chamber 31 of the stroke simulator 27 is operated after a command is input to the pressure control valve. Pressure is the master cylinder pressure sensor 2
The effect of shortening the time required to make the pressure equal to the pressure of 5 can be obtained.

In the third embodiment, the stroke simulator 27 may be provided at any system at the outlet of the master cylinder.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a claim showing a brake control device according to the first aspect of the present invention.

FIG. 2 is a diagram showing a function of a stroke simulator in the brake control device according to claim 2;

FIG. 3 is a view showing an operation of a stroke simulator in the brake control device according to claim 4;

FIG. 4 is an overall system diagram showing a brake control device according to the first embodiment.

FIG. 5 is a detailed view showing a stroke simulator section of the brake control device according to the first embodiment.

FIG. 6 is a flowchart showing a stroke simulator control routine 1 performed by the brake control unit of the brake control device according to the first embodiment.

FIG. 7 is a diagram showing a stroke simulator control operation of the first embodiment.

FIG. 8 is a diagram showing a master cylinder pressure-pedal stroke characteristic in the first embodiment.

FIG. 9 is a flowchart showing a stroke simulator control routine 2 performed by the brake control unit of the brake control device according to the second embodiment.

FIG. 10 is an overall system diagram showing a brake control device according to a third embodiment.

FIG. 11 is a flowchart showing a stroke simulator control routine 3 performed by the brake control unit of the brake control device according to the third embodiment.

FIG. 12 is a view showing a stroke simulator operation in a conventional brake control device.

[Explanation of symbols]

 1: Master cylinder 2-5: Wheel cylinder 6: Brake pedal 7: Pump 8: Accumulator 9-12: Pressure control valve 13-16: MCV1-MCV4 17: SSV 18: SPV 19: RTV 20: Check valve 21-24 : PFV1 to PFV4 25, 26: Master cylinder pressure sensor 27: Stroke simulator 28: Brake control unit 29: Cylinder 30: First liquid chamber 31: Second liquid chamber 32, 33: Piston 34, 35: O-ring 36: Spring

Claims (9)

[Claims] A pressure control valve for reducing a pressure from an external pressure source by a master cylinder for generating a brake operation pressure according to a driver's brake operation amount;
Brake pressure generating means for generating a desired brake pressure; brake pressure selecting means for selecting one of the pressures output from the master cylinder and the brake pressure generating means and supplying the selected pressure to the wheel cylinder; and output from the master cylinder. A first fluid chamber that absorbs hydraulic fluid, a second fluid chamber that absorbs hydraulic fluid output from the brake pressure generating means, and a first fluid chamber and a second fluid chamber. And a reaction force generating mechanism for applying the same pressure to the first liquid chamber and the second liquid chamber as a reaction force, and the relationship between the reaction force and the sum of the amounts of the absorbing liquid in the first liquid chamber and the second liquid chamber. A stroke simulator set so as to be equal to the wheel cylinder; a first on-off valve interposed between the master cylinder and the first fluid chamber of the stroke simulator for intermittently controlling the flow of hydraulic fluid; A check valve disposed in parallel with the first opening / closing valve and passing only the hydraulic fluid output from the stroke simulator, and interposed between the brake pressure generating means and the second fluid chamber of the stroke simulator; A second on-off valve for intermittently controlling the flow of the hydraulic fluid, a master cylinder pressure detecting means for detecting a pressure output from the master cylinder, and a vehicle traveling state based on a result of the master cylinder pressure detecting means. And a brake control means for controlling the brake pressure generation means, the brake pressure selection means, the first opening / closing valve, and the second opening / closing valve. 2. The brake control device according to claim 1, wherein the brake control means normally closes the first on-off valve, and the brake pressure selection means selects a pressure output from the master cylinder. And applying the output pressure of the master cylinder only to the wheel cylinder and applying a preload to the second fluid chamber of the stroke simulator by the brake pressure generating means, and then closing the second on-off valve. A preload is sealed in the second fluid chamber of the stroke simulator, and when performing wheel cylinder pressure control according to the vehicle running state, based on the detection result of the master cylinder pressure detection means, the brake pressure generation means, After applying a pressure equal to the master cylinder pressure to the second liquid chamber of the stroke simulator, the second on-off valve is closed, and the Opening one on-off valve, applying the output pressure of the master cylinder to the first liquid chamber of the stroke simulator, and setting the brake pressure selecting means to a position for selecting the pressure output from the brake pressure generating means, A brake control device comprising means for supplying an output pressure of a pressure generating means to the wheel cylinder. 3. The brake control device according to claim 2, further comprising: a wheel cylinder pressure control predicting unit that predicts a start of wheel cylinder pressure control according to a vehicle running state, wherein the brake control unit controls the wheel cylinder pressure control. When the predicting means predicts the start of the wheel cylinder pressure control, the brake pressure generating means applies a preload to the second fluid chamber of the stroke simulator, and then closes the second on-off valve. A brake control device characterized in that a preload is contained in the two-liquid chamber. 4. The brake control device according to claim 1, further comprising: a wheel cylinder pressure control prediction unit that predicts a start of a wheel cylinder pressure control according to a vehicle running state. One of the on-off valves is closed, the brake pressure selecting means is set to a position for selecting the pressure output from the master cylinder, the output pressure of the master cylinder is supplied only to the wheel cylinder, and the wheel cylinder pressure control prediction is performed. When the means predicts the start of the wheel cylinder pressure control, based on the detection result of the master cylinder pressure detecting means, the brake pressure generating means applies a pressure equal to the master cylinder pressure to the second fluid chamber of the stroke simulator. In addition, when performing wheel cylinder pressure control, the second on-off valve is closed and the first on-off valve is opened. , Together with the added output pressure of the master cylinder to the first fluid chamber of the stroke simulator,
A brake control device, wherein the brake pressure selecting means is located at a position for selecting a pressure output from the brake pressure generating means, and means for supplying the output pressure of the brake pressure generating means to the wheel cylinder. 5. The brake control device according to claim 1, wherein the prediction of the start of the wheel cylinder pressure control according to the vehicle traveling state is performed by a first wheel cylinder pressure control prediction unit,
A configuration in which the second wheel cylinder pressure control prediction means performs the prediction in two stages, and the second wheel cylinder pressure control prediction means predicts the start earlier than the first wheel cylinder pressure control prediction means. The brake control means is normally closed with the first on-off valve, the brake pressure selection means is set at a position for selecting the pressure output from the master cylinder, and the output pressure of the master cylinder is adjusted to the wheel When the second wheel cylinder pressure control predicting means predicts the start of wheel cylinder pressure control while supplying only to the cylinder, and after applying a preload to the second fluid chamber of the stroke simulator by the brake pressure generating means, Closing the second on-off valve,
A preload is sealed in the second fluid chamber of the stroke simulator, and when the first wheel cylinder pressure control predicting unit predicts the start of wheel cylinder pressure control, based on the detection result of the master cylinder pressure detecting unit, The brake pressure generating means applies a pressure equal to the master cylinder pressure to the second fluid chamber of the stroke simulator, and when performing wheel cylinder pressure control, closes the second on-off valve and closes the first on-off valve. Open, applying the output pressure of the master cylinder to the first fluid chamber of the stroke simulator, and setting the brake pressure selection means to a position for selecting the pressure output from the brake pressure generation means; A brake control device comprising means for supplying an output pressure to the wheel cylinder. 6. The brake control device according to claim 4, wherein the brake pressure generating means, the brake pressure selecting means, and the second on-off valve are provided in a plurality corresponding to each wheel cylinder of each wheel. It is provided, and it is configured to be able to apply pressure to the second fluid chamber of the stroke simulator from any brake pressure generating means, When applying the brake control means to the second fluid chamber of the stroke simulator, At first, the pressure is applied by all the brake pressure generating means, and after a lapse of a predetermined time, the second on-off valve is closed except for a predetermined system, and the pressure is continuously applied only by the brake pressure generating means of the system. A brake control device characterized by the following. 7. The method of claim 2, claim 3, or claim 5.
The brake control device according to any one of claims 1 to 3, wherein the brake control means is means for changing a preload sealed in the second liquid chamber of the stroke simulator in accordance with a vehicle running state. 8. The brake control device according to claim 3, wherein the wheel cylinder pressure control predicting means includes: (1) a deceleration detecting means for detecting a deceleration in a vehicle longitudinal direction; When the rate of change of the deceleration with respect to time exceeds a predetermined threshold, the start of wheel cylinder pressure control is predicted. (2) Based on the detection result of the master cylinder pressure detecting means,
When the rate of change of the master cylinder pressure over time exceeds a predetermined threshold value, the start of wheel cylinder pressure control is predicted. (3) having wheel speed detection means for detecting wheel speed, determine wheel deceleration based on the wheel speed, any of the wheel deceleration,
When the predetermined threshold value is exceeded, the start of the wheel cylinder pressure control is predicted. (4) a vehicle yaw rate detecting means for detecting the yaw rate of the vehicle body, and when the deviation between the target yaw rate calculated based on the vehicle running state and the vehicle body yaw rate exceeds a predetermined threshold value, the wheel cylinder pressure Predict the start of control. (5) wheel speed detecting means for detecting wheel speed, vehicle body yaw rate detecting means for detecting the yaw rate of the vehicle body, and lateral acceleration detecting means for detecting a lateral acceleration of the vehicle body; When the vehicle body slip angle calculated based on the yaw rate and the lateral acceleration exceeds a predetermined threshold, the start of the wheel cylinder pressure control is predicted. A brake control device characterized in that it is means for predicting the start of wheel cylinder pressure control according to any one of the above (1) to (5). 9. The brake control device according to claim 5, wherein the first wheel cylinder pressure control prediction means and the second wheel cylinder pressure control prediction means are shown in claim 8.
In any one of (1) to (5), two threshold values are set, and the threshold value in the second wheel cylinder pressure control predicting means is set to be larger than the threshold value in the first wheel cylinder pressure control predicting means. A brake control device characterized in that the start of the wheel cylinder pressure control is predicted by setting the wheel cylinder pressure to be small.