JP2019189152A - Brake device for vehicle - Google Patents

Abstract

To provide a brake device for a vehicle which can accurately finish shortening control for shortening a slide-movement time of a spool within a closing range.SOLUTION: The brake device for a vehicle comprises: a high-pressure source 15b2 for supplying a working fluid having pressure equal to prescribed pressure or higher to a pressure chamber R14 via a high-pressure port PT13 in a state that the high-pressure port PT13 is opened; a pilot pressure control part 8 for performing normal control for controlling pilot pressure according to a target value of servo pressure, and shortening control for increasing a change amount of the pilot pressure per unit time more than a change amount of the pilot pressure per unit time by the normal control at different timing; a pressure detection part 15b5 for detecting the pressure of the high-pressure source 15b2; and a control changeover part 172 for finishing the shortening control on the basis of a change gradient of the pressure of the high-pressure source 15b2 which is detected by the pressure detection part 15b5.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle braking device.

  Some vehicle braking devices use a regulator as part of a booster mechanism. The regulator includes a cylinder body and a spool, and is a mechanism in which the spool is slid within the cylinder body by a pilot pressure, and the output pressure is adjusted by the position of the spool. In detail, the cylinder body is located between the pressure chamber in which the output pressure to the servo chamber of the master cylinder is generated, the high pressure port located between the high pressure source and the pressure chamber, and the low pressure source and the pressure chamber. And a low pressure port.

  In the cylinder body, the spool has a predetermined range including a closed range in which the spool closes both the high pressure port and the low pressure port, and an open range in which the spool closes one of the high pressure port and the low pressure port and opens the other. It is configured to be slidable. The hydraulic pressure (output pressure) of the pressure chamber is maintained when both the high-pressure port and low-pressure port are closed, and when only the high-pressure port is opened, the pressure is increased toward the pressure of the high-pressure source, and only the decompression port is opened. Then, the pressure is reduced toward the pressure of the low pressure source (for example, atmospheric pressure). That is, the output pressure is held when the spool is in the closed range, and is increased or reduced when the spool is in the open range.

  In this configuration, when the spool goes through the closed range to the open range in response to the pressure increase instruction or the pressure reduction instruction, the output pressure increases or decreases at a level corresponding to the operation amount while the spool slides in the closed range. Without this, the sliding section becomes an invalid section (invalid fluid amount) in which the master pressure (output pressure of the master cylinder) does not react to the pressure increase instruction or the pressure reduction instruction. On the other hand, for example, in the hydraulic pressure generating device described in Japanese Patent Application Laid-Open No. 2017-30421, when the spool passes through the closed range and goes to the open range, the shortening control is performed so that the change gradient of the pilot pressure becomes larger than normal. Has been done. Thereby, the sliding time of the invalid section of the spool is shortened, and the responsiveness to the brake operation is improved.

JP 2017-30421 A

  The end determination of the shortening control is performed based on, for example, the amount of change in servo pressure. However, with this configuration, it is difficult to determine whether the servo pressure increase is due to the spool reaching the open range (first factor) or due to the spool sliding within the closed range (second factor). Met. That is, in the conventional control, there has been a case where the shortening control is completed earlier than the target.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicular braking device capable of accurately ending the shortening control for shortening the sliding time of the closed range of the spool. To do.

  A vehicular braking apparatus according to the present invention includes a master cylinder having a master cylinder body, a master piston that slides in the master cylinder body, a servo chamber that generates servo pressure to slide the master piston, a high pressure port, and a low pressure. Sliding including a cylinder body in which a port is formed, a closed range in which both the high pressure port and the low pressure port are closed, and an open range in which one of the high pressure port and the low pressure port is closed and the other is opened A spool slidable within the cylinder body in a range, a pilot chamber in which a pilot pressure for sliding the spool is generated, and a pressure chamber that is connected to the servo chamber and whose volume is changed by sliding of the spool. A hydraulic pressure generating portion having the high pressure when the spool is located in the open range by opening the high pressure port; A high pressure source for supplying a hydraulic fluid of a predetermined pressure or higher to the pressure chamber via a port, and when the spool is located in the open range by opening the low pressure port, the pressure chamber is provided via the low pressure port. A low pressure source that is connected to be lower than the predetermined pressure, a normal control that controls the pilot pressure according to a target value of the servo pressure, and the pilot pressure that causes the spool to slide in the closed range; A pilot pressure control unit that executes a shortening control that makes the change amount per unit time larger than the change amount per unit time of the pilot pressure by the normal control, and detects the pressure of the high pressure source A pressure detection unit; and a control switching unit that terminates the shortening control based on a pressure change gradient of the high-pressure source detected by the pressure detection unit.

  When the high pressure source supplies the brake fluid to the servo chamber via the pressure chamber, the pressure change gradient of the high pressure source increases. According to the present invention, by detecting this change gradient, the cause of the increase in servo pressure can be specified, and the shortening control can be completed with high accuracy.

It is a lineblock diagram of the brake device for vehicles of this embodiment. It is a time chart which shows an example of control of this embodiment.

  Hereinafter, an embodiment in which a hydraulic control device according to the present invention is applied to a vehicle will be described with reference to the drawings. The vehicle includes a vehicle braking device 1 that directly applies a hydraulic braking force to each wheel W to brake the vehicle. As shown in FIG. 1, the vehicle braking device 1 of the present embodiment includes a brake pedal 11, a master cylinder 12, a stroke simulator unit 13, a reservoir 14, a booster mechanism 15, an actuator 16, a brake ECU 17, and a wheel cylinder WC. I have.

  The wheel cylinder WC regulates the rotation of the wheel W, and is provided in the caliper. The wheel cylinder WC is a braking force applying mechanism that applies a braking force to the wheels W of the vehicle based on the pressure of the hydraulic fluid from the actuator 16. The brake pedal 11 is a brake operation member. The brake pedal 11 is connected to the stroke simulator unit 13 and the master cylinder 12 via the operation rod 11a.

  A stroke sensor 11 c that detects a stroke (operation amount) of the brake pedal 11 is provided in the vicinity of the brake pedal 11. The stroke sensor 11c is connected to the brake ECU 17 and configured to output the detection result to the brake ECU 17.

  The master cylinder 12 supplies brake fluid to the actuator 16 according to the stroke of the brake pedal 11, and includes a master cylinder body 12a, an input piston 12b, a first master piston 12c, a second master piston 12d, and the like. ing.

  The master cylinder body 12a is formed in a substantially cylindrical shape with a bottom. A partition wall 12a2 protruding in an inward flange shape is provided on the inner periphery of the master cylinder body 12a. A through hole 12a3 penetrating in the front-rear direction is formed at the center of the partition wall 12a2. A first master piston 12c and a second master piston 12d are disposed on the inner peripheral portion of the master cylinder body 12a at a portion in front of the partition wall portion 12a2 so as to be liquid-tight and movable along the axial direction.

  An input piston 12b is disposed on the inner peripheral portion of the master cylinder body 12a at a portion rearward of the partition wall 12a2 so as to be liquid-tight and movable along the axial direction. The input piston 12b is a piston that slides in the master cylinder body 12a in accordance with the operation of the brake pedal 11.

  An operation rod 11a that is linked to the brake pedal 11 is connected to the input piston 12b. The input piston 12b is urged by the compression spring 11b in the direction of expanding the first hydraulic chamber R3, that is, backward (rightward in the drawing). When the brake pedal 11 is depressed, the operation rod 11a moves forward against the urging force of the compression spring 11b. As the operating rod 11a moves forward, the input piston 12b also moves forward. When the depression operation of the brake pedal 11 is released, the input piston 12b is retracted by the urging force of the compression spring 11b and is positioned in contact with the restricting convex portion 12a4.

  The first master piston 12c is formed integrally with a pressure cylinder portion 12c1, a flange portion 12c2, and a protruding portion 12c3 in order from the front side. The pressurizing cylinder portion 12c1 is formed in a substantially cylindrical shape with a bottom having an opening at the front, and is disposed so as to be liquid-tight and slidable between the inner peripheral surface of the master cylinder body 12a. A coil spring 12c4, which is an urging member, is disposed in the internal space of the pressure cylinder portion 12c1 between the second master piston 12d. The first master piston 12c is urged rearward by the coil spring 12c4. In other words, the first master piston 12c is urged rearward by the coil spring 12c4, and finally comes into contact with the restricting convex portion 12a5 and is positioned. This position is the initial position (original position) of the first master piston 12c, and is the position when the depression operation of the brake pedal 11 is released.

  The flange portion 12c2 is formed to have a larger diameter than the pressure cylinder portion 12c1, and is disposed on the inner peripheral surface of the large diameter portion 12a6 in the master cylinder body 12a so as to be liquid-tight and slidable. The protruding portion 12c3 is formed to have a smaller diameter than the pressurizing cylinder portion 12c1, and is disposed so as to slide liquid-tightly in the through hole 12a3 of the partition wall portion 12a2. The rear end portion of the protruding portion 12c3 passes through the through hole 12a3, protrudes into the inner space of the master cylinder body 12a, and is separated from the inner peripheral surface of the master cylinder body 12a. The rear end surface of the protruding portion 12c3 is separated from the bottom surface of the input piston 12b, and the separation distance can be changed.

  The second master piston 12d is disposed on the front side of the first master piston 12c in the master cylinder body 12a. The second master piston 12d is formed in a substantially bottomed cylindrical shape having an opening on the front side. A coil spring 12d1 that is an urging member is disposed in the internal space of the second master piston 12d between the inner bottom surface of the master cylinder body 12a. The second master piston 12d is urged rearward by the coil spring 12d1. In other words, the second master piston 12d is urged by the coil spring 12d1 toward the set initial position.

  The master cylinder 12 includes a first master chamber R1, a second master chamber R2, a first hydraulic chamber R3, a second hydraulic chamber R4, and a servo chamber R5. The first master chamber R1 is partitioned by the inner peripheral surface of the master cylinder body 12a, the first master piston 12c (the front side of the pressure cylinder portion 12c1), and the second master piston 12d. The first master chamber R1 is connected to the reservoir 14 via an oil passage 21 connected to the port PT4. The first master chamber R1 is connected to the actuator 16 via an oil passage 22 connected to the port PT5.

  The second master chamber R2 is partitioned by the inner peripheral surface of the master cylinder body 12a and the front side of the second master piston 12d. The second master chamber R2 is connected to the reservoir 14 via an oil passage 23 connected to the port PT6. The second master chamber R2 is connected to the actuator 16 via an oil passage 24 connected to the port PT7.

  The first hydraulic chamber R3 is formed between the partition wall portion 12a2 and the input piston 12b, and has an inner peripheral surface of the master cylinder body 12a, the partition wall portion 12a2, the protruding portion 12c3 of the first master piston 12c, and the input piston. 12b. The second hydraulic chamber R4 is formed on the side of the pressurizing cylinder portion 12c1 of the first master piston 12c, the inner peripheral surface of the large diameter portion 12a6 of the inner peripheral surface of the master cylinder body 12a, and the pressurizing cylinder portion. 12c1 and the flange part 12c2. The first hydraulic pressure chamber R3 is connected to the second hydraulic pressure chamber R4 via the oil passage 25 connected to the port PT1 and the port PT3.

  The servo chamber R5 is formed between the partition wall portion 12a2 and the pressure cylinder portion 12c1 of the first master piston 12c, and has an inner peripheral surface of the master cylinder body 12a, a partition wall portion 12a2, and a protruding portion of the first master piston 12c. 12c3 and the pressurization cylinder part 12c1 are divided and formed. The servo chamber R5 is connected to the output chamber R12 via an oil passage 26 connected to the port PT2.

  The pressure sensor 26a is a sensor that detects the servo pressure supplied to the servo chamber R5, and is connected to the oil passage 26. The pressure sensor 26a transmits a detection signal (detection result) to the brake ECU 17. The servo pressure detected by the pressure sensor 26a is an actual value of the hydraulic pressure in the servo chamber R5, and is hereinafter referred to as an actual servo pressure.

  The stroke simulator unit 13 includes a master cylinder body 12a, an input piston 12b, a first hydraulic pressure chamber R3, and a stroke simulator 13a communicated with the first hydraulic pressure chamber R3. The first hydraulic chamber R3 communicates with the stroke simulator 13a through oil passages 25 and 27 connected to the port PT1. The first hydraulic pressure chamber R3 communicates with the reservoir 14 via a connection oil passage (not shown).

  The stroke simulator 13 a causes the brake pedal 11 to generate a reaction force having a magnitude corresponding to the operation state of the brake pedal 11. The stroke simulator 13a includes a cylinder portion 13a1, a piston portion 13a2, a reaction force hydraulic chamber 13a3, and a spring 13a4. The piston portion 13a2 slides liquid-tightly in the cylinder portion 13a1 in accordance with the brake operation for operating the brake pedal 11. The reaction force hydraulic chamber 13a3 is defined between the cylinder portion 13a1 and the piston portion 13a2. The reaction force hydraulic chamber 13a3 communicates with the first hydraulic chamber R3 and the second hydraulic chamber R4 via the connected oil passages 27 and 25. The spring 13a4 biases the piston portion 13a2 in a direction to reduce the volume of the reaction force hydraulic chamber 13a3.

  The oil passage 25 is provided with a first control valve 25a which is a normally closed electromagnetic valve. The oil passage 28 that connects the oil passage 25 and the reservoir 14 is provided with a second control valve 28a that is a normally open type electromagnetic valve. When the first control valve 25a is in the closed state, the first hydraulic pressure chamber R3 and the second hydraulic pressure chamber R4 are shut off. Thereby, the input piston 12b and the first master piston 12c are interlocked with each other while maintaining a constant separation distance. Further, when the first control valve 25a is in the open state, the first hydraulic chamber R3 and the second hydraulic chamber R4 are communicated. Thereby, the volume change of 1st hydraulic pressure chamber R3 and 2nd hydraulic pressure chamber R4 accompanying the advance / retreat of 1st master piston 12c is absorbed by the movement of brake fluid.

  The pressure sensor 25 b is a sensor that detects the hydraulic pressure (reaction force hydraulic pressure) of the second hydraulic pressure chamber R 4 and the first hydraulic pressure chamber R 3, and is connected to the oil passage 25. The pressure sensor 25 b is also an operation force sensor that detects an operation force with respect to the brake pedal 11, and has a correlation with the stroke of the brake pedal 11. The pressure sensor 25b detects the pressure of the second hydraulic pressure chamber R4 when the first control valve 25a is closed, and communicates with the first hydraulic pressure chamber R3 when the first control valve 25a is open. It will also detect the pressure. The pressure sensor 25b transmits a detection signal (detection result) to the brake ECU 17.

  The booster mechanism 15 generates a servo pressure corresponding to the stroke of the brake pedal 11. The booster mechanism 15 is a hydraulic pressure generator that outputs an output pressure (servo pressure in this embodiment) by the input pressure (in this embodiment, pilot pressure) that is input. The booster mechanism 15 includes a regulator (corresponding to a “hydraulic pressure generator”) 15a and a pressure supply device 15b.

  The regulator 15a includes a cylinder body 15a1 and a spool 15a2 that slides within the cylinder body 15a1. A pilot chamber R11, an output chamber R12, and a third hydraulic pressure chamber R13 are formed in the regulator 15a.

  The pilot chamber R11 is defined by the cylinder body 15a1 and the front end face of the second large diameter portion 15a2b of the spool 15a2. The pilot chamber R11 is connected to the pressure reducing valve 15b6 and the pressure increasing valve 15b7 (to the oil passage 31) connected to the port PT11. Further, on the inner peripheral surface of the cylinder body 15a1, there is provided a regulating convex portion 15a4 that is positioned by contacting the front end surface of the second large diameter portion 15a2b of the spool 15a2.

  The output chamber R12 is defined by the cylinder body 15a1, the small diameter portion 15a2c of the spool 15a2, the rear end surface of the second large diameter portion 15a2b, and the front end surface of the first large diameter portion 15a2a. The output chamber R12 is connected to the servo chamber R5 via the port PT12, the oil passage 26, and the port PT2. The output chamber R12 can be connected to the accumulator 15b2 via the high-pressure port PT13 and the oil passage 32.

  The third hydraulic chamber R13 is defined by the cylinder body 15a1 and the rear end face of the first large diameter portion 15a2a of the spool 15a2. The third hydraulic pressure chamber R13 can be connected to the reservoir 15b1 via the low pressure port PT14 and the oil passage 33. In addition, a spring 15a3 that urges the spool 15a2 in the direction of expanding the third hydraulic pressure chamber R13 is disposed in the third hydraulic pressure chamber R13.

  The spool 15a2 includes a first large diameter portion 15a2a, a second large diameter portion 15a2b, and a small diameter portion 15a2c. The first large-diameter portion 15a2a and the second large-diameter portion 15a2b are configured to slide in a liquid-tight manner in the cylinder body 15a1. The small diameter portion 15a2c is disposed between the first large diameter portion 15a2a and the second large diameter portion 15a2b, and is formed integrally with the first large diameter portion 15a2a and the second large diameter portion 15a2b. . The small diameter portion 15a2c is formed to have a smaller diameter than the first large diameter portion 15a2a and the second large diameter portion 15a2b.

  Further, the spool 15a2 is formed with a communication passage 15a5 for communicating the output chamber R12 and the third hydraulic pressure chamber R13. The output chamber R12 and the third hydraulic chamber R13 constitute a pressure chamber R14. The pressure chamber R14 is configured such that the volume decreases as the spool 15a2 moves backward, and the volume increases as the spool 15a2 moves forward. As described above, the pressure chamber R14 is a portion that is connected to the servo chamber R5 and whose volume is changed by the sliding of the spool 15a2.

  The pressure supply device 15b is also a drive unit that drives the spool 15a2. The pressure supply device 15b includes a reservoir (corresponding to “low pressure source”) 15b1, an accumulator (accumulating “high pressure source”) 15b2 that accumulates brake fluid, and sucks and discharges the brake fluid in the reservoir 15b1 to the accumulator 15b2. A pump 15b3 and an electric motor 15b4 that drives the pump 15b3 are provided. The reservoir 15b1 is open to the atmosphere, and the hydraulic pressure in the reservoir 15b1 is the same as the atmospheric pressure. The pressure in the reservoir 15b1 (here, atmospheric pressure) is lower than the pressure in the accumulator 15b2.

  The pressure supply device 15b includes a pressure sensor (corresponding to a “pressure detection unit”) 15b5 that detects the pressure of the brake fluid supplied from the accumulator 15b2 and outputs a detection result to the brake ECU 17. That is, the pressure supply device 15b includes a pressure sensor 15b5 that detects the pressure of the accumulator 15b2. When the detection result of the pressure sensor 15b5 is smaller than a predetermined lower limit value (corresponding to “predetermined pressure”), the brake ECU 17 drives the electric motor 15b4 and the pump 15b3 to maintain the pressure of the accumulator 15b2 above the predetermined lower limit value. . The accumulator 15b2 is configured to supply brake fluid from a pump 15b3 driven by the electric motor 15b4 when the detection result of the pressure sensor 15b5 becomes less than a predetermined lower limit value. The pressure of the accumulator 15b2 is maintained, for example, within a predetermined pressure range (between a predetermined lower limit value and a predetermined upper limit value). The reservoir 15b1 is maintained at a pressure lower than a predetermined pressure.

  Furthermore, the pressure supply device 15b includes a pressure reducing valve 15b6 and a pressure increasing valve 15b7. Specifically, the pressure reducing valve 15b6 is an electromagnetic valve having a structure that opens in a non-energized state (normally open type), and the flow rate is controlled by a command from the brake ECU 17. One of the pressure reducing valves 15b6 is connected to the pilot chamber R11 via the oil passage 31, and the other of the pressure reducing valves 15b6 is connected to the reservoir 15b1 via the oil passage 34. The pressure increasing valve 15b7 is a solenoid valve having a structure (normally closed type) that closes in a non-energized state, and the flow rate is controlled by a command from the brake ECU 17. One of the pressure increase valves 15b7 is connected to the pilot chamber R11 via the oil passage 31, and the other end of the pressure increase valve 15b7 is connected to the accumulator 15b2 via the oil passage 35 and the oil passage 32 to which the oil passage 35 is connected. Yes.

  Here, the operation of the regulator 15a will be briefly described. When the pilot pressure (hydraulic pressure in the pilot chamber R11) is not supplied from the pressure reducing valve 15b6 and the pressure increasing valve 15b7 to the pilot chamber R11, the spool 15a2 is biased by the spring 15a3 and is in the initial position (see FIG. 1). The initial position of the spool 15a2 is a position where the front end surface of the spool 15a2 comes into contact with the regulating convex portion 15a4 and is positioned and fixed, and the rear end surface of the spool 15a2 is a position adjacent to the front end portion of the low pressure port PT14.

  Thus, when the spool 15a2 is in the initial position, the low pressure port PT14 and the port PT12 communicate with each other via the pressure chamber R14, and the high pressure port PT13 is closed by the spool 15a2.

  The pilot pressure is formed according to the stroke of the brake pedal 11 by the pressure reducing valve 15b6 and the pressure increasing valve 15b7. When the pilot pressure is increased, the spool 15a2 moves rearward (to the right in FIG. 1) against the biasing force of the spring 15a3. Then, the spool 15a2 moves to a position where the high-pressure port PT13 closed by the spool 15a2 is opened. Further, the opened low pressure port PT14 is closed by the spool 15a2. The position of the spool 15a2 in this state is referred to as a “pressure increasing position”. At this time, the pressure chamber R14 and the accumulator 15b2 communicate with each other via the high-pressure port PT13 (pressure increase state). Further, the rear end surface of the second large diameter portion 15a2b of the spool 15a2 receives a force corresponding to the servo pressure.

  The spool 15a2 is positioned by the balance between the pressing force of the front end surface of the second large diameter portion 15a2b of the spool 15a2 and the resultant force of the force corresponding to the servo pressure and the urging force of the spring 15a3. The position of the spool 15a2 where the high pressure port PT13 and the low pressure port PT14 are closed by the spool 15a2 is referred to as a “holding position”. At this time, the connection between the pressure chamber R14, the accumulator 15b2, and the reservoir 15b1 is cut off (holding state).

  Further, when the pilot pressure is reduced, the spool 15a2 located at the holding position moves forward by the urging force of the spring 15a3. Then, the high pressure port PT13 closed by the spool 15a2 is maintained in the closed state, and the closed low pressure port PT14 is opened. The position of the spool 15a2 in this state is referred to as a “decompression position”. At this time, the pressure chamber R14 and the reservoir 15b1 communicate with each other via the low pressure port PT14 (depressurized state). At the initial position of the spool 15a2 (pilot pressure = pressure of the reservoir 15b1), the high-pressure port PT13 is closed and the low-pressure port PT14 is opened, and the initial position corresponds to the decompression position.

  Here, of the sliding range of the spool 15a2, a range in which both the high pressure port PT13 and the low pressure port PT14 are closed is referred to as a “closed range”, and one of the high pressure port PT13 and the low pressure port PT14 is closed and the other is opened. This range is referred to as “open range”. The fact that the spool 15a2 is located in the closed range has the same meaning as the fact that the spool 15a2 is located in the holding position. In addition, the fact that the spool 15a2 is located in the open range has the same meaning as the spool 15a2 being located in the pressure increasing position or the pressure reducing position. Thus, the spool 15a2 is configured to be slidable within the cylinder body 15a1 within a sliding range including a closed range and an open range.

  The booster mechanism 15 generates a pilot pressure corresponding to the stroke of the brake pedal 11 in the pilot chamber R11 by the pressure reducing valve 15b6 and the pressure increasing valve 15b7. Then, servo pressure corresponding to the stroke of the brake pedal 11 is generated in the servo chamber R5 by the pilot pressure. The master cylinder 12 supplies a master pressure (fluid pressure in the first master chamber R1 and the second master chamber R2) generated according to the stroke of the brake pedal 11 to the wheel cylinder WC via the actuator 16. The pressure reducing valve 15b6 and the pressure increasing valve 15b7 constitute a valve mechanism that adjusts the inflow and outflow of the brake fluid with respect to the servo chamber R5.

  The actuator 16 is a device that is disposed between the master cylinder 12 and the wheel cylinder WC and adjusts the hydraulic pressure applied to each wheel cylinder WC. The actuator 16 includes a solenoid valve, a motor, a pump, and the like (not shown). The actuator 16 performs anti-skid control (ABS control) and the like based on a command from the brake ECU 17.

  The brake ECU 17 is an electronic control unit including a CPU and a memory. The brake ECU 17 receives detection results of various sensors and controls various devices (such as solenoid valves) based on the detection results. In addition, a detection signal from a wheel speed sensor S provided for each wheel W of the vehicle is input to the brake ECU 17.

  The brake ECU 17 includes a control unit 171 and a control switching unit 172 as functions. The control unit 171 is a normal control for controlling the pilot pressure in accordance with a servo pressure target value (hereinafter referred to as a target servo pressure) and a control based on the target servo pressure, and sets the time for the spool 15a2 to slide in the closed range. The shortening control that shortens the sliding time by the normal control is executed at different timings. The controller 171 sets the target servo pressure based on the stroke of the brake pedal 11 (detected value of the stroke sensor 11c).

  In the normal control, the control unit 171 controls the pressure reducing valve 15b6 and the pressure increasing valve 15b7 so that the actual servo pressure approaches the target servo pressure, and performs pressure increasing control, holding control, or pressure reducing control on the servo chamber R5. To do. The shortening control is a control in which the amount of change per unit time of the pilot pressure for sliding the spool 15a2 in the closed range is made larger than the amount of change per unit time of the pilot pressure by the normal control. That is, the shortening control is a control for increasing the speed at which the spool 15a2 slides in the closed range when the spool 15a2 moves to the open range through the closed range, compared to the normal control. When executing the shortening control, the control unit 171 makes the inflow / outflow amount of the hydraulic fluid per unit time to the pilot chamber R11 larger than the inflow / outflow amount by the normal control. For example, when the pressure increasing control is executed when the spool 15a2 is positioned at the holding position, the control unit 171 executes the shortening control until the spool 15a2 reaches the pressure increasing position from the holding position, and the pressure increasing position is reached. After reaching, normal control is executed. As a result, the sliding time in the closed range in which the control amount to the pilot pressure is not reflected in the actual servo pressure in the sliding range of the spool 15a2 can be shortened, and the responsiveness is improved.

  It can be said that the control unit 171, the pressure reducing valve 15b6, and the pressure increasing valve 15b7 constitute a pilot pressure control unit 8 that selectively executes normal control and shortening control. That is, the pilot pressure control unit 8 includes a pressure increasing valve 15b7 provided in the flow path 35 connecting the accumulator 15b2 and the pilot chamber R11, and a pressure reducing valve provided in the flow path 34 connecting the reservoir 15b1 and the pilot chamber R11. 15b6 and a controller 171 that controls the pressure increasing valve 15b7 and the pressure reducing valve 15b6. The brake fluid supply destination of the accumulator 15b2 is the pilot chamber R11, the servo chamber R5, and the pressure chamber R14.

The control switching unit 172 is configured to end the shortening control based on the detection result of the pressure sensor 15b5. The control switching unit 172 ends the shortening control based on the change gradient (slope) of the pressure of the accumulator 15b2 (hereinafter referred to as “accumulator pressure”) detected by the pressure sensor 15b5. The control switching unit 172 switches the control of the control unit 171 from the shortening control to the normal control when the decreasing gradient of the accumulator pressure (change gradient to the decreasing side) exceeds a predetermined gradient. The control switching unit 172 calculates a change gradient of the accumulator pressure every predetermined time. The predetermined gradient is a preset gradient threshold value.
As described above, the vehicular braking apparatus 1 of the present embodiment generates the master cylinder body 12a, the master pistons 12c and 12d that slide in the master cylinder body 12a, and the servo pressure that slides the master pistons 12c and 12d. A master cylinder 12 having a servo chamber R5, a cylinder body 15a1 in which a high pressure port PT13 and a low pressure port PT14 are formed, and a spool 15a2 capable of sliding in the cylinder body 15a1 within a sliding range including a closed range and an open range. The regulator 15a has a pilot chamber R11 in which a pilot pressure for sliding the spool 15a2 is generated, and a pressure chamber R14 connected to the servo chamber R5 and whose volume is changed by the sliding of the spool 15a2, and the spool 15a2 is a high pressure port PT13. Is located within the open range An accumulator 15b2 for supplying hydraulic fluid of a predetermined pressure or higher to the pressure chamber R14 via the pressure port PT13, and when the spool 15a2 is located in the open range by opening the low pressure port PT14, the pressure chamber R14 is entered via the low pressure port PT14. The connected reservoir 15b1 maintained at a pressure lower than a predetermined pressure, normal control for controlling the pilot pressure according to the target value of the servo pressure, and the pilot pressure per unit time for sliding the spool 15a2 in the closed range A pilot pressure control unit 8 that executes shortening control that makes the change amount larger than the change amount of pilot pressure per unit time by normal control at different timings, a pressure sensor 15b5 that detects the pressure of the accumulator 15b2, and a pressure sensor The change gradient of the pressure of the accumulator 15b2 detected by 15b5 Zui it includes a control switching unit 172 to terminate the reduction control, the.

  As shown in FIG. 2, at time t1, shortening control is started based on the pressure increasing instruction (shortening control ON), and when the pressure increasing valve 15b7 is opened (valve opening flag ON), the accumulator 15b2 enters the pilot chamber R11. High pressure brake fluid is supplied. As a result, the spool 15a2 slides and the volume of the pressure chamber R14 sealed in the closed range decreases, so that the hydraulic pressure in the pressure chamber R14 increases with a relatively small increase gradient (change gradient to the increase side), At the same time, the servo pressure increases with a relatively small increase gradient. At the same time, since the brake fluid is supplied from the accumulator 15b2 to the pilot chamber R11, the accumulator pressure also decreases with a relatively small decrease gradient Z1.

  At time t2, the spool 15a2 reaches the pressure increasing position, and high-pressure brake fluid is supplied from the accumulator 15b2 to the pressure chamber R14 via the high-pressure port PT13. The pressure chamber R14 communicates with the servo chamber R5, and the servo pressure starts to increase with a relatively large increase gradient due to the accumulator pressure. At the same time, the accumulator 15b2 supplies brake fluid to the servo chamber R5 communicating with the pressure chamber R14, and the accumulator pressure starts to decrease with a relatively large decreasing gradient Z2. Compared with the supply of the brake fluid to the pilot chamber R11, the supply of the brake fluid to the servo chamber R5 which expands with the sliding of the first master piston 12c is much larger. It can be said that the servo chamber R5 has lower rigidity (hydraulic pressure change necessary for increasing the unit volume) than the pilot chamber R11. Therefore, when the accumulator 15b2 communicates with the servo chamber R5, the accumulator pressure decreasing gradient increases.

  The decreasing gradient Z2 is larger than the predetermined gradient, and the control switching unit 172 ends the shortening control after time t2 and starts the normal control. That is, the control switching unit 172 determines that the spool 15a2 has reached the pressure increasing position after the decrease gradient Z2 is calculated after the spool 15a2 has reached the pressure increasing position, and ends the shortening control (shortening). Control OFF). In the normal control (pressure increase control), the valve opening instruction is continuously given to the pressure increase valve 15b7, but the flow rate of the brake fluid passing through the pressure increase valve 15b7 per unit time is smaller than that during the shortening control. At time t3, the pressure increase control is terminated according to the brake operation, the process proceeds to the holding control, and the pressure increase valve 15b7 is closed (the valve opening flag is OFF).

  Conventionally, the shortening control is terminated based on whether or not the servo pressure exceeds a threshold value. However, it is determined whether the servo pressure increase is due to the spool 15a2 reaching the pressure increasing position (open range) (first factor) or due to the spool 15a2 sliding in the closed range (second factor). It was difficult. That is, in the conventional control, there has been a case where the shortening control is completed earlier than the target. For example, as indicated by a two-dot chain line in FIG. 2, before the time t2 is reached, the servo pressure may exceed the threshold value, and the shortening control may end before the spool 15a2 reaches the pressure increasing position.

  However, according to the present embodiment, paying attention to a large change in the accumulator pressure when the servo chamber R5 and the accumulator 15b2 communicate with each other, the cause of the increase in the servo pressure is specified by detecting the change gradient of the accumulator pressure. And the shortening control can be finished with high accuracy. More specifically, according to the present embodiment, paying attention to the difference in rigidity of the brake fluid supply destination (control target chamber: servo chamber R5 and pilot chamber R11) of the accumulator 15b2, the change gradient of the accumulator pressure caused by the difference. By using the difference in the end determination element, the first factor and the second factor can be separated from each other as the cause of the servo pressure increase, and the shortening control can be finished with high accuracy. According to the present embodiment, it is possible to suppress a decrease in responsiveness due to the end of the shortening control earlier than the target.

  The accumulator pressure is adjusted by the pump 15b3 so as to be equal to or higher than a predetermined lower limit value (predetermined pressure), and is maintained within a predetermined pressure range, for example. It is not always constant. However, in this embodiment, since the change gradient of the accumulator pressure is used as the end determination element, the end determination can be executed regardless of the accumulator pressure at the start of the pressure increase control. The present invention is not limited to the above embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle brake device, 11 ... Brake pedal, 12 ... Master cylinder, 12a ... Master cylinder body, 12c ... First master piston, 12d ... Second master piston, 15 ... Booster mechanism, 15a ... Regulator (hydraulic pressure generation) 15a1 ... cylinder body, 15a2 ... spool, 15b1 ... reservoir, 15b2 ... accumulator, 15b3 ... pump, 15b4 ... electric motor, 15b5 ... pressure sensor (pressure detector), 15b6 ... pressure reducing valve, 15b7 ... pressure increasing valve, 16 ... Actuator, 17 ... Brake ECU, 171 ... Control part, 172 ... Control switching part, 8 ... Pilot pressure control part, PT13 ... High pressure port, PT14 ... Low pressure port, R1 ... First master room, R2 ... Second master room, R5 ... Servo chamber, R11 ... Pilot chamber, R14 ... Pressure chamber, W ... Wheel, WC Wheel cylinder.

Claims (3)

A master cylinder having a master cylinder body, a master piston sliding in the master cylinder body, and a servo chamber generating a servo pressure for sliding the master piston;
A cylinder body in which a high pressure port and a low pressure port are formed, a closed range in which both the high pressure port and the low pressure port are closed, and an open range in which one of the high pressure port and the low pressure port is closed and the other is opened A spool that is slidable within the cylinder body within a sliding range, a pilot chamber that generates a pilot pressure for sliding the spool, and a pressure that is connected to the servo chamber and that changes its volume due to sliding of the spool. A fluid pressure generating unit having a chamber;
A high-pressure source that supplies hydraulic fluid of a predetermined pressure or higher to the pressure chamber via the high-pressure port when the spool is located in the open range by opening the high-pressure port;
A low pressure source maintained at a pressure lower than the predetermined pressure, connected to the pressure chamber via the low pressure port when the spool is in the open range by opening the low pressure port;
Normal control for controlling the pilot pressure in accordance with the target value of the servo pressure, and the amount of change per unit time of the pilot pressure for sliding the spool in the closed range, the unit time of the pilot pressure by the normal control A pilot pressure control unit that executes shortening control that is greater than the per-change amount at different timings;
A pressure detector for detecting the pressure of the high pressure source;
A control switching unit for ending the shortening control based on a pressure change gradient of the high-pressure source detected by the pressure detection unit;
A braking device for a vehicle comprising:   The pilot pressure control unit includes a pressure increasing valve provided in a flow path connecting the high pressure source and the pilot chamber, a pressure reducing valve provided in a flow path connecting the low pressure source and the pilot chamber, The vehicle braking device according to claim 1, further comprising: a pressure increasing valve and a control unit that controls the pressure reducing valve.   The high-pressure source is an accumulator that accumulates brake fluid, and when the detection result of the pressure detection unit becomes less than the predetermined pressure, the brake fluid is supplied from a pump driven by an electric motor. The vehicle braking device according to 1 or 2.

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