JP2009061815A - Brake control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake control device capable of enhancing pedal feeling. <P>SOLUTION: The brake control device presumes whether or not there is possibility of getting into a state in which a vehicle is pushed out, and starts driving of a pump substantially simultaneously with operation of a brake pedal by a driver when it is presumed that there is possibility of getting into the state in which the vehicle is pushed out. Further, when it is determined whether or not the vehicle has been actually pushed out and it is determined that the vehicle is in the state of being pushed out, an operation fluid pressurized by the pump is fed to the wheel cylinder by adjusting a linear control valve to increase the wheel cylinder pressure. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a brake control device that controls braking force applied to wheels provided in a vehicle.

  As a brake control device for controlling the braking force of a vehicle such as an automobile, for example, one described in Patent Document 1 is known. Patent Document 1 discloses a vehicle having a pump unit that pressurizes the working fluid and an automatic braking mechanism that generates a braking force by supplying the working fluid pressurized by the pump unit to the wheel cylinder in accordance with the traveling state of the vehicle. In this braking device, there is disclosed a braking device having a predicting means for predicting the start of operation of the automatic braking mechanism and a control means for starting the driving of the pump means when the start of operation of the automatic braking mechanism is predicted.

According to the braking device described in Patent Document 1, when the start of the operation of the automatic braking mechanism is predicted, the driving of the pump unit is started by the braking unit. Is in a state. Thereby, even if the accumulator is not provided, it is possible to ensure good responsiveness of the braking force control.
JP-A-8-150919

  By the way, on low μ roads (road surfaces with a low friction coefficient) such as snowy roads, the braking force is insufficient with only the booster pressure generated by the driver's brake pedal operation with respect to the crepe force, even though the brake pedal is depressed. There is a possibility that the vehicle gradually moves (hereinafter referred to as an pushed-out state). In order to suppress such a state of being pushed out, it is determined whether or not the vehicle is pushed out. If it is judged that the vehicle is pushed out, the pump is driven to increase the wheel cylinder pressure to control the vehicle. It is preferable to perform control to increase power.

  However, if the pump starts driving while the driver is operating the brake pedal, the phenomenon that the brake pedal is sucked in due to the fluid flowing out of the master cylinder occurs, and the pedal feeling becomes worse.

  This invention is made | formed in view of such a condition, The objective is to provide the brake control apparatus which can improve pedal feeling.

  In order to solve the above-described problems, a brake control device according to an aspect of the present invention includes a pump that pressurizes a working fluid and an electromagnetic flow control valve that adjusts a wheel cylinder pressure. And a brake control device that supplies a pressurized working fluid to the wheel cylinder to generate a braking force, and the automatic braking device determines whether the vehicle is likely to be pushed out. Predicting means for predicting and pump control means for starting driving of the pump substantially simultaneously with the operation of the brake operating means by the driver when the predicting means predicts that the vehicle is likely to be pushed out. Determining means for determining whether or not the vehicle is actually pushed out, and electromagnetic flow control when the judging means determines that the vehicle is pushed out. By adjusting the comprises a solenoid valve control means for increase the wheel cylinder pressure of the pressurized working fluid in the pump is supplied to the wheel cylinder, the.

  According to this aspect, since the driving of the pump is started almost simultaneously with the operation of the brake operating means by the driver, the pump is not driven in the middle of operating the brake operating means. Therefore, the phenomenon that the brake operating means is sucked in while the driver is operating the brake operating means can be suppressed, so that pedal feeling can be improved.

  When the brake operating means is operated in a state in which it is determined that the vehicle is pushed out by the determining means, the electromagnetic valve control means does not change the electromagnetic pressure even if the target differential pressure before and after the electromagnetic flow control valve decreases. When there is a differential pressure greater than or equal to a predetermined reference differential pressure before and after the flow control valve, control for maintaining the opening of the electromagnetic flow control valve may be performed.

  When the target differential pressure before and after the electromagnetic flow control valve decreases, if the opening of the electromagnetic flow control valve is increased while there is a differential pressure before and after the electromagnetic flow control valve, the working fluid flows back to the master cylinder and the brake operating means The reaction force may suddenly change and pedal feeling may deteriorate. Therefore, when the brake operation means is operated in a state where the determination means determines that the vehicle is pushed out, even if the target differential pressure before and after the electromagnetic flow control valve decreases, By controlling the opening of the electromagnetic flow control valve when there is a differential pressure greater than a predetermined reference differential pressure, the sudden change in the reaction force of the brake operating means when the brake operating means is operated is suppressed. Yes, pedal feeling can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the brake control apparatus which can improve pedal feeling can be provided.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a brake control device 10 according to an embodiment of the present invention. The hydraulic circuit in the brake control device 10 shown in FIG. 1 is configured as a diagonal system in which a system for the left front wheel and the right rear wheel and a system for the right front wheel and the left rear wheel are independent. Thereby, even if some trouble is caused in one system, the function of the other system is reliably maintained.

  The brake control device 10 includes a master cylinder 14 that sends out fluid as a working fluid from first and second ports based on a depression operation of a brake pedal 12 by a driver. A brake hydraulic pressure control conduit 16a for the rear wheel is connected, and a brake hydraulic pressure control conduit 16b for the right front wheel and the left rear wheel is connected to the second port. A brake booster 15 is provided between the brake pedal 12 and the master cylinder 14 to increase a driver's pedaling force and generate a large braking force. The brake pedal 12 is provided with a brake switch 72 that is turned on when the pedal is depressed.

  The brake control device 10 also supplies a pump 22a for supplying high-pressure fluid to the high pressure conduit 20a for the left front wheel and the right rear wheel via the check valve 23a, and a high pressure conduit 20b for the right front wheel and the left rear wheel. It has a pump 22b that discharges high-pressure fluid through a check valve 23b. The pumps 22a and 22b are driven by a motor 24 to pump fluid from the reservoirs 30a and 30b through supply conduits 28a and 28b, respectively. Hereinafter, the pumps 22a and 22b are collectively referred to as “pump 22” as appropriate, and the high-pressure conduits 20a and 20b are collectively referred to as “high-pressure conduit 20”.

  A linear control valve 32a and a check valve 33a are provided between the brake hydraulic control conduit 16a and the high pressure conduit 20a for the left front wheel and the right rear wheel. The linear control valve 32a is a normally open electromagnetic flow control valve that is in an open state when not energized and whose opening can be adjusted as necessary. By adjusting the opening degree of the linear control valve 32a, a differential pressure can be created between the hydraulic pressure of the brake hydraulic control conduit 16a and the hydraulic pressure of the high-pressure conduit 20a, that is, before and after the linear control valve 32a. Further, the brake hydraulic pressure control conduit 16a is connected to the reservoir 30a.

  Similarly, a linear control valve 32b and a check valve 33b are provided between the brake hydraulic control conduit 16b and the high pressure conduit 20b for the right front wheel and the left rear wheel. The linear control valve 32b is a normally open electromagnetic flow control valve that is in an open state when not energized and whose opening can be adjusted as necessary. By adjusting the opening degree of the linear control valve 32b, a differential pressure can be created between the hydraulic pressure of the brake hydraulic control conduit 16b and the hydraulic pressure of the high-pressure conduit 20b before and after the linear control valve 32b. Further, the brake hydraulic pressure control conduit 16b is connected to the reservoir 30b. In the following description, the linear control valves 32a and 32b are collectively referred to as “linear control valve 32” as appropriate.

  A return conduit 44a for the left front wheel and the right rear wheel is connected to the supply conduit 28a for the left front wheel and the right rear wheel, and a connection conduit for the left front wheel is connected between the return conduit 44a and the high pressure conduit 20a. A connection conduit 46RR for 46FL and the right rear wheel is connected. The connection conduit 46FL is provided with a pressure increasing valve 48FL which is a normally open solenoid valve and a pressure reducing valve 50FL which is a normally closed solenoid valve. The connection conduit 46RR is provided with an increase which is a normally open solenoid valve. A pressure valve 48RR and a pressure reducing valve 50RR which is a normally closed solenoid valve are provided.

  The connection conduit 46FL between the pressure increasing valve 48FL and the pressure reducing valve 50FL is connected to the wheel cylinder 54FL of the left front wheel by the connection conduit 52FL, and the pressure between the connection conduit 52FL and the high pressure conduit 20a is higher than that of the wheel cylinder 54FL. A check valve 56FL is provided which allows only fluid flow toward the conduit 20a.

  Similarly, the connection conduit 46RR between the pressure increasing valve 48RR and the pressure reducing valve 50RR is connected to the wheel cylinder 54RR of the right rear wheel by the connection conduit 52RR, and between the connection conduit 52RR and the high pressure conduit 20a, the wheel A check valve 56RR that allows only fluid flow from the cylinder 54RR toward the high-pressure conduit 20a is provided.

  As with the left front wheel and right rear wheel side, the right front wheel and left rear wheel reservoir 30b is connected with a return conduit 44b for the right front wheel and the left rear wheel, and between the return conduit 44b and the high pressure conduit 20b. The left rear wheel connection conduit 46RL and the right front wheel connection conduit 46FR are connected to each other. The connection conduit 46RL is provided with a pressure increasing valve 48RL which is a normally open solenoid valve and a pressure reducing valve 50RL which is a normally closed solenoid valve. The connection conduit 46FR is provided with an increase which is a normally open solenoid valve. A pressure valve 48FR and a pressure reducing valve 50FR which is a normally closed solenoid valve are provided. In the following, the return conduits 44a and 44b are collectively referred to as “return conduit 44” as appropriate.

  A connection conduit 46RL between the pressure increasing valve 48RL and the pressure reducing valve 50RL is connected to the wheel cylinder 54RL of the left rear wheel by a connection conduit 52RL, and between the connection conduit 52RL and the high pressure conduit 20b, from the wheel cylinder 54RL. A check valve 56RL that allows only fluid flow toward the high pressure conduit 20b is provided. Similarly, the connection conduit 46FR between the pressure increasing valve 48FR and the pressure reducing valve 50FR is connected to the wheel cylinder 54FR of the right rear wheel by the connection conduit 52FR, and between the connection conduit 52FR and the high pressure conduit 20b, the wheel A check valve 56FR that allows only fluid flow from the cylinder 54FR toward the high-pressure conduit 20b is provided.

  Hereinafter, the wheel cylinders 54FL, 54RR, 54RL, and 54FR are collectively referred to as “wheel cylinders 54” as appropriate. Further, the pressure increasing valves 48FL, 48RR, 48RL, and 48FR are collectively referred to as “pressure increasing valve 48”, and the pressure reducing valves 50FL, 50RR, 50RL, and 50FR are collectively referred to as “pressure reducing valve 50”.

  A disc brake unit is provided for each wheel of the vehicle, and each disc brake unit generates a braking force by pressing a brake pad against the disc by the action of the wheel cylinder 54.

  Wheel cylinder pressure sensors 51FL, 51RR, 51RL and 51FR for detecting the wheel cylinder pressure are provided in the vicinity of the wheel cylinders 54FL to 54FR for the left front wheel, the right rear wheel, the left rear wheel and the right front wheel. Hereinafter, the wheel cylinder pressure sensors 51FL to 51FR will be collectively referred to as “wheel cylinder pressure sensor 51” as appropriate. The wheel cylinder pressure sensor 51 is not an essential component in the embodiment of the present invention and may not be provided.

  Further, wheel speed sensors 18FL, 18RR, 18RL and 18FR for detecting the wheel speeds of the respective wheels are provided on the left front wheel, the right rear wheel, the left rear wheel and the right front wheel. Hereinafter, the wheel speed sensors 18FL, 18RR, 18RL, and 18FR are collectively referred to as “wheel speed sensor 18” as appropriate.

  The linear control valve 32, the pressure increasing valve 48, the pressure reducing valve 50, the pump 22 and the like described above constitute a hydraulic actuator 80 of the brake control device 10. The hydraulic actuator 80 is controlled by an electronic control unit (hereinafter referred to as “ECU”) 200.

  The ECU 200 is a nonvolatile memory such as a CPU that executes various arithmetic processes, a ROM that stores various control programs, a RAM that is used as a work area for data storage and program execution, and a backup RAM that can retain stored contents even when the engine is stopped. An A / D converter for converting an analog signal input from a memory, an input / output interface, various sensors, and the like into a digital signal and taking it in, a timer for timing, and the like are provided.

  Various types of actuators including the hydraulic actuator 80 such as the linear control valve 32, the pressure increasing valve 48, the pressure reducing valve 50, and the motor 24 are electrically connected to the ECU 200.

  The ECU 200 is electrically connected to various sensors and switches that output signals for use in control. That is, the ECU 200 receives a signal indicating the wheel cylinder pressure in the wheel cylinder 54 from the wheel cylinder pressure sensor 51.

  Further, the ECU 200 receives a signal indicating the wheel speed of each wheel from the wheel speed sensor 18, a signal indicating the yaw rate from the yaw rate sensor, and a signal indicating the steering angle of the steering wheel from the steering angle sensor. A signal indicating the traveling speed of the vehicle is input from the vehicle speed sensor.

  Further, the ECU 200 receives a signal indicating the master cylinder pressure from the master cylinder pressure sensor 13, and receives a signal indicating whether or not the switch is on from the brake switch 72. The ECU 200 receives a signal from a sensor that detects a high pressure conduit pressure (not shown), and calculates a differential pressure P before and after the linear control valve 32 from the master cylinder pressure and the high pressure conduit pressure.

  In the brake control device 10 configured as described above, in the normal traveling state, the linear control valve 32 is opened, the pressure increasing valve 48 is opened, and the pressure reducing valve 50 is closed. The same hydraulic pressure as the master cylinder pressure generated when the person steps on the brake pedal 12 is generated in the wheel cylinder pressure to generate a braking force.

  Further, the brake control device 10 monitors the running state of the vehicle based on signals from various sensors connected to the ECU 200, and controls the pump 22 and the linear control valve 32 according to the running state of the vehicle. It has a function of automatically generating a braking force. Examples of such automatic braking control include traction control (TRC), vehicle stability control (VSC), and the like. Since such control is known, description thereof is omitted here.

  The brake control device 10 according to the present embodiment can perform an extrusion suppression control, which will be described later, as one of the automatic braking controls. When being pushed out and subjected to suppression control, the hydraulic pressure of the high-pressure conduit 20 is regulated by driving the pump 22 and controlling the open / close state of the linear control valve 32 to generate a braking force larger than normal. it can.

  FIG. 2 is a diagram for explaining the extrusion suppression control. In FIG. 2, the horizontal axis represents time, and the vertical axis represents the state of push-out prediction, brake switch, pump drive, push-out determination, linear control valve supply current, and wheel cylinder pressure from the top. .

  Extrusion suppression control described here is control performed on a low μ road such as a snowy road. As described above, on a low μ road, there is a possibility that the braking force is insufficient and the vehicle is pushed out only by the braking force generated when the driver steps on the brake pedal 12. By performing the extrusion suppression control according to the present embodiment, the extruded state can be suppressed.

  Based on signals from various sensors, ECU 200 performs prediction (hereinafter referred to as “push-out prediction”) as to whether or not the vehicle may be pushed out. For example, the ECU 200 calculates the slip ratio based on the vehicle speed signal from the vehicle speed sensor and the wheel speed signal from the wheel speed sensor 18, and when the slip ratio is a predetermined value or more, the ECU 200 may be pushed out. Predict that there is. This is because when the slip ratio is high, the friction coefficient of the road surface is low and the possibility of being pushed out is high. In FIG. 2, at time t1, it is predicted that the vehicle may be pushed out, and the vehicle is pushed out and the prediction flag is on.

  Thereafter, at time t2, it is assumed that the brake pedal 12 is operated by the driver and the brake switch 72 is turned on. At this time, the ECU 200 issues a command to the motor 24 and starts driving the pump 22 substantially simultaneously with the operation of the brake pedal 12 by the driver, that is, substantially simultaneously with the brake pedal 12 being turned on. To do. In this state, since the linear control valve 32 is in an open state, the fluid discharged by the pump 22 is circulated to the reservoir 30 via the linear control valve 32. Accordingly, the wheel cylinder pressure is increased by an amount corresponding to the increase in the master cylinder pressure that is increased by the driver's depression of the brake pedal 12.

  Thereafter, the ECU 200 determines whether or not the vehicle is actually pushed out (hereinafter referred to as push-out determination) based on signals from various sensors. The ECU 200 is pushed and determined based on a wheel speed signal from the wheel speed sensor 18, for example. Specifically, when the wheel speed detected by the front wheel speed sensors 18FL and 18FR is zero and the wheel speed detected by the rear wheel speed sensors 18RR and 18RL is not zero, the vehicle is pushed out. Is determined. Here, at time t3, it is determined that the vehicle is pushed out, and the push-out determination flag is on.

  When it is determined that the vehicle is pushed out at time t3, the ECU 200 calculates the optimum target differential pressure Pr before and after the linear control valve 32 so that the pushed-out state is eliminated, Supply of current to the linear control valve 32 is started so that the actual differential pressure P becomes the target differential pressure Pr. Thereby, since the opening degree of the linear control valve 32 becomes small and the differential pressure P becomes large, the wheel cylinder pressure can be increased more than the master cylinder pressure.

  In FIG. 2, a current is supplied to the linear control valve 32 with a certain degree of gradient from time t3 to time t4. Thus, supplying a current to the linear control valve 32 with a gradient is preferable from the viewpoint of preventing hydraulic pulsation.

  As described above, the brake control device 10 determines whether or not the vehicle is pushed out, and if it is determined that the vehicle is in the pushed state, the pump 22 supplies the current to the linear control valve 32, thereby The pressurized fluid was supplied to the wheel cylinder 54. Thereby, since a hydraulic pressure higher than the master cylinder pressure is generated in the wheel cylinder pressure and a large braking force can be generated, the pushed-out state can be suppressed.

  Here, in the brake control device 10 according to the present embodiment, the push pedal is predicted before being pushed out, and the brake pedal 12 is operated when there is a possibility that the vehicle is pushed out and enters a state. The pump 22 is configured to be driven substantially simultaneously.

  For example, when the pump 22 is driven after the brake pedal 12 is depressed and pushed and judged, the fluid flows out of the master cylinder 14 due to the driving of the pump 22, so that the brake pedal 12 is sucked. The pedal feeling will get worse.

  In the present embodiment, since the pump 22 starts to be driven almost simultaneously with the depression of the brake pedal 12, the pump 22 is not driven with the brake pedal 12 depressed. Therefore, a phenomenon in which the brake pedal 12 is sucked in while the driver is operating the brake pedal 12 can be suppressed, so that pedal feeling can be improved.

  FIG. 3 shows a flowchart of the extrusion suppression control. This control flow is continuously executed at predetermined time intervals.

  First, the ECU 200 predicts whether or not the vehicle is likely to be pushed out (S10). If it is determined that there is no possibility of being pushed out (N in S10), the control flow ends.

  When it is determined that there is a possibility of being pushed out (Y in S10), the ECU 200 determines whether or not the brake switch 72 has been turned on (S12). If the brake switch 72 remains off (N in S12), the control flow ends.

  When the brake switch 72 is in the on state (Y in S12), the ECU 200 starts driving the pump 22 by energizing the motor 24 (S14). The pump 22 is driven substantially simultaneously with the brake switch 72 being turned on. Thereby, the phenomenon that the brake pedal 12 is sucked in is suppressed, and the pedal feeling can be improved.

  Thereafter, ECU 200 determines whether or not the vehicle is actually pushed out (S16). If it is determined that the state is not pushed out (N in S16), the control flow ends.

  When it is determined that the state is pushed out (Y in S16), the ECU 200 starts energizing the linear control valve 32 (S18). Thereby, since a hydraulic pressure higher than the master cylinder pressure is generated in the wheel cylinder pressure and a large braking force can be generated, the pushed-out state can be suppressed.

  FIG. 4 is a diagram for explaining control for improving pedal feeling while being pushed out and performing suppression control. In FIG. 4, the horizontal axis represents time, and the vertical axis represents push-out determination, brake switch, pump drive, target differential pressure Pr before and after the linear control valve 32, supply current to the linear control valve 32, Each state of wheel cylinder pressure is shown.

  When the push-out suppression control described in FIG. 2 is executed and the brake pedal 12 is operated in a state where the ECU 200 determines that the vehicle is pushed out as shown in FIG. , It is assumed that the target differential pressure Pr has decreased from the initial target differential pressure P1 set when the suppression control is started after being pushed out to P2.

  When the target differential pressure Pr is reduced during the suppression control as described above, the differential pressure P of the linear control valve 32 exists in a state where the differential pressure P exists before and after the linear control valve 32 in an attempt to make the differential pressure P follow the target differential pressure Pr. When the opening degree is increased, fluid may flow back to the master cylinder 14 and the reaction force of the brake pedal 12 may change suddenly, resulting in a worse pedal feeling.

  Therefore, in the brake control apparatus 10 according to the present embodiment, in such a case, the ECU 200 has a differential pressure P greater than or equal to a predetermined reference differential pressure Ps before and after the linear control valve 32 even if the target differential pressure Pr decreases. When this is done, control is performed to maintain the current supplied to the linear control valve 32 and maintain the opening degree of the linear control valve 32. Thereby, the sudden change of the reaction force of the brake pedal 12 in the state by which the brake pedal 12 was operated can be suppressed, and a pedal feeling can be improved. The predetermined reference differential pressure Ps may be appropriately determined by experiment in consideration of the degree of deterioration of the pedal feeling.

  In FIG. 4, the target differential pressure Pr increases from P2 to P3 at time t6. However, when the increased target differential pressure Pr is equal to or less than the initial target differential pressure Pr1, the supply current to the linear control valve 32 is kept as it is. The opening degree of the linear control valve 32 is maintained. Thereby, the phenomenon in which the brake pedal 12 is sucked in is suppressed, and the pedal feeling can be improved.

  In FIG. 4, thereafter, the target differential pressure Pr further increases from P3 to P4 at time t7. In this case, since the target differential pressure Pr is higher than the initial target differential pressure Pr1 and it is considered necessary to further increase the braking force, the linear control valve 32 is supplied by supplying current to the linear control valve 32. Reduce the opening of the cylinder and increase the wheel cylinder pressure. Thereby, an appropriate braking force can be generated.

  In the brake control device 10, when the driver finishes the operation of the brake pedal 12 and the brake switch 72 is turned off at time t8, the driving of the pump 22 is stopped and the supply of current to the linear control valve 32 is stopped. The As a result, the wheel cylinder pressure is reduced and the braking force is released.

  FIG. 5 shows a flowchart of the pedal feeling improvement control during the push-out suppression control. First, the ECU 200 determines whether or not the vehicle is pushed out (S20). When the vehicle is pushed out and is not in a state (N in S20), the control flow ends.

  When it is determined that the vehicle is pushed out (Y in S20), the ECU 200 determines whether or not the brake switch 72 is in an on state (S22). If the brake switch 72 is off (N in S22), the control flow ends.

  When the brake switch 72 is on (Y in S22), the ECU 200 determines whether or not the target differential pressure Pr is equal to or less than the initial target differential pressure P1 (S24).

  When the target differential pressure Pr is higher than the initial target differential pressure P1 (N in S24), the ECU 200 increases the energization amount to the linear control valve 32 to reduce the opening degree of the linear control valve 32 and reduce the wheel cylinder pressure. Increase (S26). Thereby, an appropriate braking force can be generated.

  On the other hand, when the target differential pressure Pr is equal to or lower than the initial target differential pressure P1 (Y in S24), the ECU 200 determines whether or not the differential pressure P before and after the linear control valve 32 is equal to or higher than a predetermined reference differential pressure Ps. (S28).

  When the differential pressure P is equal to or higher than the reference differential pressure Ps (Y in S28), the ECU 200 maintains the energization amount to the linear control valve 32 and maintains the opening degree of the linear control valve 32 (S30). Thereby, the sudden change of the reaction force of the brake pedal 12 in the state by which the brake pedal 12 was operated can be suppressed, and a pedal feeling can be improved.

  When the differential pressure P is less than the reference differential pressure Ps (N in S28), the ECU 200 decreases the energization amount to the linear control valve 32 and increases the opening degree of the linear control valve 32 (S32). Thereby, the differential pressure P decreases following the target differential pressure Pr.

  The present invention has been described above based on the embodiment. It should be understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention.

It is a figure which shows the structure of the brake control apparatus which concerns on embodiment of this invention. It is a figure for demonstrating extruded suppression control. It is a figure which shows the flowchart of extrusion control. It is a figure for demonstrating the control which improves the pedal feeling while pushing out and performing suppression control. It is a figure which shows the flowchart of the pedal feeling improvement control during extrusion control control.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Brake control apparatus, 12 Brake pedal, 14 Master cylinder, 15 Brake booster, 18 Wheel speed sensor, 20 High pressure conduit, 22 Pump, 24 Motor, 30 Reservoir, 32 Linear control valve, 48 Pressure increase valve, 50 Pressure reduction valve, 54 Wheel Cylinder, 72 brake switch, 200 ECU.

Claims (2)

A pump for pressurizing the working fluid;
A brake having an electromagnetic flow control valve for adjusting a wheel cylinder pressure, and supplying an operating fluid pressurized by the pump to the wheel cylinder according to a running state of the vehicle to generate a braking force. A control device,
The automatic braking means is
A predicting means for predicting whether or not the vehicle is likely to be pushed into a state;
A pump control means for starting driving of the pump substantially simultaneously with the operation of the brake operation means by the driver, when it is predicted that the vehicle may be pushed out by the prediction means; and
Determination means for determining whether or not the vehicle is actually pushed out;
When it is determined by the determination means that the vehicle is pushed out, the electromagnetic fluid control valve is adjusted so that the working fluid pressurized by the pump is supplied to the wheel cylinder and the wheel cylinder pressure is increased. Solenoid valve control means for increasing pressure;
A brake control device comprising:   When the brake operation unit is operated in a state where the determination unit determines that the vehicle is pushed out, the electromagnetic valve control unit reduces the target differential pressure before and after the electromagnetic flow control valve. 2. The brake according to claim 1, wherein when the pressure difference equal to or greater than a predetermined reference pressure difference exists before and after the electromagnetic flow control valve, control is performed to maintain the opening degree of the electromagnetic flow control valve. Control device.

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