JP2018039447A - Vehicle brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle brake device capable of facilitating adjustment of a compression amount between upstream and downstream sides, and improving responsiveness in sudden brake operation time.SOLUTION: A vehicle brake device comprises: a first control part 6 for executing control to an actuator 5; and a second control part 7 for executing control to a piston drive part 15. One of the first control part 6 and the second control part 7 calculates a first target wheel pressure on the basis of a detection result acquired from a detection part 11c, and executes control on the basis of the first target wheel pressure. The other of the first control part 6 and the second control part 7 executes control on the basis of the first target wheel pressure received from one of the first control part 6 and the second control part 7, when a determination result of a determination part 71 is a negative result, and calculates a second target wheel pressure on the basis of a detection result acquired from the detection part 11c and executes control based on the second target wheel pressure when a determination result of the determination part 71 is an affirmative result.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vehicle braking device.

  As an example, a vehicular braking device is disposed between a piston drive unit that drives a piston slidably disposed in a master cylinder, a master chamber formed in the master cylinder, and a wheel cylinder. And an actuator for adjusting the wheel pressure, which is the hydraulic pressure in the wheel cylinder, on the basis of the master pressure, which is the hydraulic pressure in the master chamber generated in response to the control, and a detection unit for detecting the brake operation. Normally, in a vehicle braking device that increases and decreases the master pressure by controlling the drive of the piston, the actuator does not have a pressurizing function from the viewpoint of cost reduction, etc., and the wheel pressure increase is realized on the premise of the master pressure increase Has been. That is, in this configuration, the pressure source is only the piston drive unit. An example of a vehicle braking device including such a piston drive unit and an actuator is described in JP-A-2015-85872.

Japanese Patent Laying-Open No. 2015-85872

  However, in the configuration having one pressurization source as described above, the pressurization configuration is not redundant as a system. Therefore, the present inventor has newly developed a configuration in which the actuator is provided with a pressurizing function, and the wheel pressure is generated by two pressurization sources of the piston drive unit and the actuator.

  Here, in the configuration in which there are pressure sources on both the upstream and downstream sides as described above, two independent control units (for example, ECUs) are provided to control two different pressure sources. Therefore, for example, when control such as skid prevention control, ABS control, or regenerative cooperative control is performed, adjustment of the pressurization amount between the upstream and downstream may be complicated. On the other hand, even with such a configuration, high responsiveness is required during a sudden braking operation.

  The present invention has been made in view of such circumstances, and it is possible to easily adjust the amount of pressurization between the upstream and downstream sides, and to improve vehicle responsiveness during a sudden braking operation. An object is to provide an apparatus.

  The vehicle brake device according to the present invention is disposed between a piston drive unit that drives a piston slidably disposed in a master cylinder, a master chamber formed in the master cylinder, and a wheel cylinder, and the piston An actuator that adjusts wheel pressure that is hydraulic pressure in the wheel cylinder based on a master pressure that is hydraulic pressure generated in response to the movement of the master chamber, and a detection unit that detects information related to brake operation. In the vehicular braking apparatus, a determination unit that determines whether or not the brake operation corresponds to a sudden braking operation based on a detection result of the detection unit, and a control unit that is connected to the detection unit and that controls the actuator A first control unit and a second control unit connected to the detection unit and executing control on the piston drive unit; The actuator is configured to be able to pressurize the wheel pressure, and the first control unit and the second control unit are connected to be communicable, and one of the first control unit and the second control unit is Calculating a first target wheel pressure which is a target value of the wheel pressure based on a detection result acquired from the detection unit, executing the control based on the first target wheel pressure, and the first control unit and When the determination result of the determination unit is negative, the other of the second control unit is based on the first target wheel pressure received from one of the first control unit and the second control unit. If the determination result of the determination unit is affirmative, a second target wheel pressure that is a target value of the wheel pressure is calculated based on the detection result acquired from the detection unit, and the first 2 Based on target wheel pressure before To run the control.

  According to the present invention, when the brake operation does not correspond to the sudden braking operation, the target wheel pressures of the first control unit and the second control unit are calculated by the first control unit by communication between the control units. Commonized by wheel pressure. As a result, even when various controls such as skid prevention control are executed, the upstream and downstream hydraulic pressures are controlled by substantially one target value, so that adjustment of the amount of pressurization between the upstream and downstream becomes easy. On the other hand, when the brake operation corresponds to a sudden braking operation, each control unit independently calculates a target wheel pressure based on the acquired detection result of the detection unit, and a corresponding device based on the calculation result To control. That is, the control of each device is executed regardless of the information communicated between the control units. Thereby, it is excluded that the delay in information acquisition of the receiving side control unit caused by communication affects the responsiveness. That is, according to the present invention, the responsiveness at the time of a sudden braking operation can be improved.

It is a block diagram which shows the structure of the vehicle braking device of 1st embodiment. It is a block diagram which shows the structure of the actuator of 1st embodiment. It is a conceptual diagram for demonstrating a differential pressure control valve. It is explanatory drawing for demonstrating the setting of the target wheel pressure of 1st embodiment. It is explanatory drawing for demonstrating the gradient correction | amendment of the 2nd target wheel pressure of 1st embodiment. It is a flowchart for demonstrating the flow of the setting of the target wheel pressure of 1st embodiment. It is explanatory drawing for demonstrating the gradient correction | amendment of the 2nd target wheel pressure of 2nd embodiment. It is a block diagram which shows the structure of 1st ECU and 2nd ECU of 3rd embodiment. It is explanatory drawing for demonstrating the raising process of the 1st target wheel pressure of 3rd embodiment. It is explanatory drawing for demonstrating the setting of the target wheel pressure in the deformation | transformation aspect of 1st embodiment. It is explanatory drawing for demonstrating the deformation | transformation aspect of 1st embodiment.

Hereinafter, an embodiment in which a vehicle braking device according to the present invention is applied to a vehicle will be described with reference to the drawings. Each drawing is a conceptual diagram. Further, in FIG. 1, a part of the communication line connecting the various sensors and the ECU is not shown.
As shown in FIG. 1, the vehicle braking device 100 according to the first embodiment includes a brake pedal 11, a stroke sensor (corresponding to a “detection unit”) 11 c, a master cylinder 12, a stroke simulator unit 13, and a reservoir. 14, a booster mechanism (corresponding to “piston drive part”) 15, an actuator 5, a first ECU (corresponding to “first control part”) 6, and a second ECU (corresponding to “second control part”). 7) and wheel cylinders WCfl, WCfr, WCrl, WCrr (hereinafter also collectively referred to as wheel cylinder WC).

  The wheel cylinder WC regulates the rotation of the wheels W (Wfl, Wfr, Wrl, Wrr) and is provided in the caliper CL. The wheel cylinder WC is a braking force application mechanism that is supplied with brake fluid from the actuator 5 and applies a braking force to the wheels W of the vehicle based on the wheel pressure that is the hydraulic pressure in the wheel cylinder WC. When brake fluid is supplied to the wheel cylinder WC, each piston (not shown) of the wheel cylinder WC presses a pair of brake pads (not shown) that are friction members, and the disc is a rotating member that rotates integrally with the wheel W. The rotor DR is sandwiched from both sides to restrict its rotation. In the first embodiment, a disc type brake is employed, but a drum type brake may be employed.

The brake pedal 11 is a kind of brake operation member, and is connected to the stroke simulator unit 13 and the master cylinder 12 via an operation rod 11a.
In the vicinity of the brake pedal 11, a stroke sensor 11 c that detects a brake pedal stroke (operation amount: hereinafter, sometimes referred to as a stroke) that is a brake operation state when the brake pedal 11 is depressed is provided. This stroke sensor 11c is connected to each ECU 7, and is configured such that a detection signal (detection result) is output to each ECU 7 via an individual communication line.

  The master cylinder 12 supplies brake fluid to the actuator 5 in accordance with the operation amount of the brake pedal 11, and includes a cylinder body 12a, an input piston 12b, a first master piston 12c, a second master piston 12d, and the like. ing.

  The 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 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 cylinder body 12a in a portion in front of the partition wall 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 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 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 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 original position (preset) 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 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 internal space of the cylinder body 12a, and is separated from the inner peripheral surface of the 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 cylinder body 12a. The second master piston 12d is formed in a substantially bottomed cylindrical shape having an opening on the front side. In the internal space of the second master piston 12d, a coil spring 12d1, which is an urging member, is disposed between the inner bottom surface of the 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 original 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 (hydraulic chamber) R5. In the description, the first master room R1 and the second master room R2 may be collectively referred to as master rooms R1 and R2. The first master chamber R1 is defined by the inner peripheral surface of the 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 5 via an oil passage 22 connected to the port PT5.

  The second master chamber R2 is defined by the inner peripheral surface of the 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 5 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. The inner peripheral surface of the cylinder body 12a, the partition wall portion 12a2, the protruding portion 12c3 of the first master piston 12c, and the input piston 12b. It is divided by. The second hydraulic pressure chamber R4 is formed on the side of the pressurizing cylinder portion 12c1 of the first master piston 12c, and the inner peripheral surface of the large diameter portion 12a6 on the inner peripheral surface of the cylinder body 12a and the pressurizing cylinder portion 12c1. And the flange portion 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. The servo chamber R5 has an inner peripheral surface of the cylinder body 12a, the partition wall portion 12a2, and a protruding portion 12c3 of the first master piston 12c. And a pressure cylinder portion 12c1. 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 26 a transmits a detection signal (detection result) to each ECU 6, 7. 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 (actual hydraulic pressure).

The stroke simulator unit 13 includes a 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 stroke (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 electromagnetic valve 25a which is a normally closed electromagnetic valve. The oil passage 28 connecting the oil passage 25 and the reservoir 14 is provided with a second electromagnetic valve 28a which is a normally open type electromagnetic valve. When the first electromagnetic valve 25a is in the closed state, the first hydraulic chamber R3 and the second hydraulic chamber R4 are blocked. 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 electromagnetic 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 oil passage 25 is provided with a pressure sensor (corresponding to a “detection unit”) 25 b. The pressure sensor 25b is a sensor that detects reaction force hydraulic pressures in the second hydraulic chamber R4 and the first hydraulic chamber R3. 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 an operation amount of the brake pedal 11. The pressure sensor 25b detects the pressure of the second hydraulic pressure chamber R4 when the first electromagnetic valve 25a is closed, and communicates with the first hydraulic pressure chamber R3 when the first electromagnetic valve 25a is open. The pressure (or reaction force hydraulic pressure) is also detected. The pressure sensor 25 b transmits a detection signal (detection result) to each ECU 6, 7.

(Boost mechanism)
The booster mechanism 15 generates a servo pressure corresponding to the operation amount of the brake pedal 11. The booster mechanism 15 is a hydraulic pressure generator that outputs an output pressure (servo pressure in the first embodiment) by the input pressure (pilot pressure in the first embodiment) acting thereon. The booster mechanism 15 includes a regulator 15a and a pressure supply device 15b.
The regulator 15a includes a cylinder body 15a1 and a spool 15a2 that slides in 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 a cylinder body 15a1 and a 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 restriction 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 a cylinder body 15a1, a small diameter portion 15a2c of the spool 15a2, a rear end surface of the second large diameter portion 15a2b, and a front end surface of the first large diameter portion 15a2a. The output chamber R12 is connected to the servo chamber R5 of the master cylinder 12 through an oil passage 26 connected to the port PT12 and the port PT2. The output chamber R12 can be connected to the accumulator 15b2 via an oil passage 32 connected to the port PT13.

  The third hydraulic chamber R13 is defined by a cylinder body 15a1 and a rear end surface of the first large diameter portion 15a2a of the spool 15a2. The third hydraulic chamber R13 can be connected to the reservoir 15b1 via the oil passage 33 connected to the port PT14. In addition, a spring 15a3 that urges the third hydraulic pressure chamber R13 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.
The spool 15a2 is formed with a communication passage 15a5 that communicates the output chamber R12 and the third hydraulic chamber R13.

  The pressure supply device 15b is also a drive unit that drives the spool 15a2. The pressure supply device 15b is a reservoir 15b1 that is a low pressure source, an accumulator 15b2 that is a high pressure source and accumulates brake fluid (corresponding to “fluid”), and sucks brake fluid in the reservoir 15b1 and pumps it 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 low pressure source is at a lower pressure than the high pressure source. The pressure supply device 15b includes a pressure sensor 15b5 that detects the pressure of the brake fluid supplied from the accumulator 15b2 and outputs the detected pressure to the second ECU 7.

  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 second ECU 7. 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 second ECU 7. 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 original position (see FIG. 1). The original position of the spool 15a2 is a position where the front end surface of the spool 15a2 comes into contact with the restricting convex portion 15a4 and is positioned and fixed, and the position immediately before the rear end surface of the spool 15a2 closes the port PT14.
Thus, when the spool 15a2 is in the original position, the port PT14 and the port PT12 communicate with each other via the communication path 15a5, and the port PT13 is closed by the spool 15a2.

  When the pilot pressure formed according to the operation amount of the brake pedal 11 is increased by the pressure reducing valve 15b6 and the pressure increasing valve 15b7, the spool 15a2 is moved backward (to the right in FIG. 1) against the urging force of the spring 15a3. Move towards. Then, the spool 15a2 moves to a position where the port PT13 closed by the spool 15a2 is opened. The opened 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 port PT13 and the port PT12 communicate with each other via the output chamber R12.

  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. At this time, the position of the spool 15a2 is defined as a “holding position”. In the holding position, the port PT13 and the port PT14 are closed by the spool 15a2.

  Further, when the pilot pressure formed according to the operation amount of the brake pedal 11 is reduced by the pressure reducing valve 15b6 and the pressure increasing valve 15b7, the spool 15a2 at the holding position moves forward by the urging force of the spring 15a3. To do. Then, the port PT13 that has been blocked by the spool 15a2 is maintained in the closed state. Further, the blocked port PT14 is opened. The position of the spool 15a2 in this state is referred to as a “decompression position”. At this time, the port PT14 and the port PT12 communicate with each other through the communication path 15a5.

  The booster mechanism 15 described above forms a pilot pressure according to the stroke of the brake pedal 11 by the pressure reducing valve 15b6 and the pressure increasing valve 15b7, and generates a servo pressure according to the stroke of the brake pedal 11 by the pilot pressure. The generated servo pressure is supplied to the servo chamber R5 of the master cylinder 12, and the master cylinder 12 supplies the master pressure generated according to the stroke of the brake pedal 11 to the wheel cylinder WC. The pressure reducing valve 15b6 and the pressure increasing valve 15b7 constitute a valve portion that adjusts the inflow and outflow of the brake fluid with respect to the servo chamber R5.

  Thus, the vehicle braking device 100 of the first embodiment is configured by a by-wire system. That is, the vehicle braking device 100 is configured to be able to adjust the master pressure independently of the operation of the brake pedal (brake operation member) 11, and the configuration in which fluctuations in the master pressure do not directly affect the brake pedal 11. It has become.

(Actuator)
The actuator 5 is a device that adjusts the hydraulic pressure (wheel pressure) of the wheel cylinder WC in accordance with an instruction from the second ECU 7. Specifically, the actuator 5 includes a hydraulic circuit 5A and a motor 8 as shown in FIG. The hydraulic circuit 5A includes a first piping system 50a and a second piping system 50b. The first piping system 50a is a system that controls the hydraulic pressure (wheel pressure) applied to the rear wheels Wrl and Wrr. The second piping system 50b is a system that controls the hydraulic pressure (wheel pressure) applied to the front wheels Wfl, Wfr. A wheel speed sensor S is provided for each wheel W.

  The first piping system 50a includes a main line A, a differential pressure control valve 51, pressure increasing valves 52 and 53, a pressure reducing line B, pressure reducing valves 54 and 55, a pressure regulating reservoir 56, and a reflux line C. The pump 57, the auxiliary pipe D, the orifice part 41, and the damper part 42 are provided. In the description, the pipe line can be replaced with, for example, a hydraulic pressure path, a flow path, an oil path, or a pipe.

  The main pipeline A is a pipeline connecting the oil passage 24 and the wheel cylinders WCrl and WCrr. The differential pressure control valve 51 is an electromagnetic valve that is provided in the main pipeline A and controls the main pipeline A to a communication state and a differential pressure state. The differential pressure state is a state where the flow path is restricted by a valve, and can be said to be a throttle state. The differential pressure control valve 51 responds to a control current based on an instruction from the first ECU 6, and a differential pressure between the hydraulic pressure on the master cylinder 12 side and the hydraulic pressure on the wheel cylinders WCrl and WCrr sides (hereinafter referred to as “first pressure”). (Also referred to as “differential pressure”). In other words, the differential pressure control valve 51 is configured to be able to control the differential pressure between the hydraulic pressure in the portion of the main pipeline A on the master cylinder 12 side and the hydraulic pressure in the portions of the main pipeline A on the wheel cylinders WCrl and WCrr. Yes.

  The differential pressure control valve 51 is a normally open type that is in a communication state in a non-energized state. The first differential pressure increases as the control current applied to the differential pressure control valve 51 increases. When the differential pressure control valve 51 is controlled to be in the differential pressure state and the pump 57 is driven, the hydraulic pressure on the wheel cylinders WCrl and WCrr side is larger than the hydraulic pressure on the master cylinder 12 side according to the control current. .

  For the differential pressure control valve 51, a check valve 51a is provided. The main pipeline A branches into two pipelines A1 and A2 at a branch point X on the downstream side of the differential pressure control valve 51 so as to correspond to the wheel cylinders WCrl and WCrr.

  Here, the configuration of the differential pressure control valve 51 will be conceptually described. As shown in FIG. 3, the differential pressure control valve 51 mainly includes a valve seat 511, a ball valve 512, a spring 513, a solenoid 514, and a flow path 51A. The differential pressure control valve 51 is configured such that the flow path 51A is blocked when the ball valve 512 is seated on the valve seat 511, and the flow path 51A is communicated when the ball valve 512 is separated. The flow path 51 </ b> A is a flow path that connects a pipe line on the master cylinder 12 side of the differential pressure control valve 51 and a pipe line on the wheel cylinders WCrl and WCrr side of the differential pressure control valve 51. The ball valve 512 is disposed on the master cylinder 12 side of the valve seat 511, and is fixed to the spring 513 while being separated from the valve seat 511. When a control current is applied to the solenoid 514, the ball valve 512 is pressed against the valve seat 511 by electromagnetic force. When the ball valve 512 abuts (sits) the valve seat 511 by electromagnetic force, the flow path 51A is blocked. The ball valve 512 is returned to the initial position by the spring 513 when the control current is not applied to the solenoid 514, and the flow path 51A communicates.

  Consider a case where the pump 57 is driven while the differential pressure control valve 51 is in a differential pressure state, that is, in a state where a control current corresponding to the target differential pressure is applied. In this case, if the hydraulic pressure on the wheel cylinders WCrl, WCrr side of the differential pressure control valve 51 is larger than the hydraulic pressure on the master cylinder 12 side of the differential pressure control valve 51 and the differential pressure becomes larger than the target differential pressure, The pressing force due to the differential pressure with respect to the valve 512 becomes larger than the pressing force due to the electromagnetic force, and the ball valve 512 moves slightly toward the master cylinder 12 and is separated. Thereby, the brake fluid moves to the master cylinder 12 side through the flow path 51A due to the separation of the ball valve 512, and the hydraulic pressure on the wheel cylinders WCrl, WCrr side decreases. Then, the pressing force due to the differential pressure decreases, and the ball valve 512 is seated. By repeating this, the target differential pressure is maintained.

  The pressure increasing valves 52 and 53 are electromagnetic valves that are opened and closed according to instructions from the first ECU 6, and are normally open type electromagnetic valves that are opened (communicated) when not energized. The pressure increasing valve 52 is disposed in the line A1, and the pressure increasing valve 53 is disposed in the line A2. The pressure-increasing valves 52 and 53 are opened in a non-energized state during pressure-increasing control to communicate with the wheel cylinder WC and the branch point X, and are energized and closed in holding control and pressure-reducing control. And shut off. Note that, like the differential pressure control valve 51, the pressure increasing valves 52 and 53 may be electromagnetic valves that switch between a communication state and a differential pressure state based on an instruction from the first ECU 6. In this case, for example, the pressure increasing valves 52 and 53 are arranged such that the “wheel cylinder side” in FIG. 3 is the “differential pressure control valve side” and the “master cylinder side” is the “wheel cylinder side”.

  The pressure reducing line B connects the pressure increasing reservoir 52 between the pressure increasing valve 52 and the wheel cylinder WCrl in the line A1, and connects the pressure adjusting reservoir 56 between the pressure increasing valve 53 and the wheel cylinder WCrr in the line A2. It is a pipeline to For example, the pressure increase valves 52 and 53 are controlled to be closed during pressure reduction control, and shut off the master cylinder 12 and the wheel cylinders WCrl and WCrr.

  The pressure reducing valves 54 and 55 are electromagnetic valves that are opened and closed in accordance with an instruction from the first ECU 6, and are normally closed electromagnetic valves that are closed (shut off) when not energized. The pressure reducing valve 54 is disposed in the pressure reducing line B on the wheel cylinder WCrl side. The pressure reducing valve 55 is disposed in the pressure reducing line B on the wheel cylinder WCrr side. The pressure reducing valves 54 and 55 are energized mainly during the pressure reducing control and are opened, and the wheel cylinders WCrl and WCrr and the pressure regulating reservoir 56 are communicated with each other via the pressure reducing pipe B. The pressure regulation reservoir 56 is a reservoir having a cylinder, a piston, and an urging member.

  The reflux line C is a line that connects the pressure reducing line B (or the pressure regulating reservoir 56) and the pressure difference control valve 51 and the pressure increasing valves 52 and 53 (here, the branch point X) in the main line A. is there. The pump 57 is provided in the reflux line C so that the discharge port is located on the branch point X side and the suction port is located on the pressure regulating reservoir 56 side. The pump 57 is a piston type electric pump driven by the motor 8. The pump 57 causes the brake fluid to flow from the pressure regulating reservoir 56 to the master cylinder 12 side or the wheel cylinders WCrl, WCrr side via the reflux line C.

  The pump 57 is configured to repeat a discharge process for discharging brake fluid and a suction process for sucking brake fluid. That is, when the pump 57 is driven by the motor 8, the discharge process and the suction process are alternately repeated. In the discharge process, the brake fluid sucked from the pressure regulating reservoir 56 in the suction process is supplied to the branch point X. The motor 8 is energized and driven via a relay (not shown) according to an instruction from the first ECU 6. The pump 57 and the motor 8 can be said to be an electric pump. The pump 57 may be always driven while the vehicle is starting up.

  The orifice portion 41 is a throttle-shaped portion (so-called orifice) provided in a portion of the reflux conduit C between the pump 57 and the branch point X. The damper portion 42 is a damper (damper mechanism) connected to a portion of the reflux conduit C between the pump 57 and the orifice portion 41. The damper unit 42 absorbs and discharges the brake fluid in accordance with the pulsation of the brake fluid in the reflux conduit C. The orifice part 41 and the damper part 42 can be said to be a pulsation reduction mechanism that reduces (attenuates, absorbs) pulsation.

  The auxiliary pipeline D is a pipeline that connects the pressure regulation hole 56 a of the pressure regulation reservoir 56 and the upstream side (or the master cylinder 12) of the main pipeline A relative to the differential pressure control valve 51. The pressure regulating reservoir 56 is configured such that the valve hole 56b is closed as the amount of brake fluid flowing into the pressure regulating hole 56a increases due to an increase in stroke. A reservoir chamber 56c is formed on the pipe lines B and C side of the valve hole 56b.

  When the pump 57 is driven, the brake fluid in the pressure regulating reservoir 56 or the master cylinder 12 passes through the reflux line C and the portion between the differential pressure control valve 51 and the pressure increasing valves 52 and 53 in the main line A (branch point X ). The wheel pressure is increased according to the control state of the differential pressure control valve 51 and the pressure increasing valves 52 and 53. Thus, in the actuator 5, pressurization control is executed by driving the pump 57 and controlling various valves. That is, the actuator 5 is configured to be able to pressurize the wheel pressure. A pressure sensor Y that detects the fluid pressure (master pressure) in the portion of the main line A between the differential pressure control valve 51 and the master cylinder 12 is installed. The pressure sensor Y transmits the detection result to the first ECU 6 and the second ECU 7.

  The second piping system 50b has the same configuration as the first piping system 50a, and is a system that adjusts the hydraulic pressures of the wheel cylinders WCfl and WCfr of the front wheels Wfl and Wfr. The second piping system 50b corresponds to the main pipeline A and connects the oil passage 22 and the wheel cylinders WCfl and Wfr, the differential pressure control valve 91 corresponding to the differential pressure control valve 51, the pressure increasing valve 52, The pressure increasing valves 92 and 93 corresponding to 53, the pressure reducing line Bb corresponding to the pressure reducing line B, the pressure reducing valves 94 and 95 corresponding to the pressure reducing valves 54 and 55, and the pressure adjusting reservoir 96 corresponding to the pressure adjusting reservoir 56 A reflux line Cb corresponding to the reflux line C, a pump 97 corresponding to the pump 57, an auxiliary line Db corresponding to the auxiliary line D, an orifice part 43 corresponding to the orifice part 41, and a damper part. And a damper portion 44 corresponding to 42. About the detailed structure of the 2nd piping system 50b, since description of the 1st piping system 50a can be referred, description is abbreviate | omitted. The piping configuration may be X piping or front and rear piping.

  The pressure adjustment of the wheel pressure by the actuator 5 includes a pressure increase control for providing the master pressure to the wheel cylinder WC, a holding control for sealing the wheel cylinder WC, a pressure reduction control for causing the fluid in the wheel cylinder WC to flow out to the pressure adjustment reservoir 56, or This is done by executing pressurization control for increasing the wheel pressure by the throttle by the differential pressure control valve 51 and driving of the pump 57.

(ECU)
The first ECU 6 is an electronic control unit that includes a CPU, a memory, and the like. The first ECU 6 performs control on the actuator 5 based on the target wheel pressure that is the target value of the wheel pressure. The first ECU 6 performs pressure increase control, pressure reduction control, holding control, or pressure control on the actuator 5 based on the target wheel pressure.

  The control state by the first ECU 6 will be briefly described by taking the control with respect to the wheel cylinder WCrl as an example. In the pressure increase control, the differential pressure control valve 51 and the pressure increase valve 52 are opened, and the pressure reduction valve 54 is closed. In the pressure reducing control, the pressure increasing valve 52 is closed and the pressure reducing valve 54 is opened. In the holding control, the pressure increasing valve 52 and the pressure reducing valve 54 are closed. In the pressurization control, the differential pressure control valve 51 is in a differential pressure state (throttle state), the pressure increasing valve 52 is opened, the pressure reducing valve 54 is closed, and the pump 57 is driven.

  Various sensors such as a stroke sensor 11c, pressure sensors Y and 25b, and a wheel speed sensor S are connected to the first ECU 6. The first ECU 6 acquires stroke information, master pressure information, reaction force hydraulic pressure information, wheel speed information, and the like from these sensors. The various sensors and the first ECU 6 are connected by, for example, a communication line (CAN communication). The first ECU 6 performs skid prevention control and ABS control on the actuator 5 according to the situation and request. Further, the first ECU 6 is connected to be communicable with the second ECU 7 by, for example, a communication line. Setting of the target wheel pressure in the first ECU 6 will be described later.

  Similar to the first ECU 6, the second ECU 7 is an electronic control unit that includes a CPU, a memory, and the like. The second ECU 7 executes control on the booster mechanism 15 based on the target wheel pressure that is the target value of the wheel pressure. The second ECU 7 executes pressure increase control, pressure reduction control, or holding control for the boost mechanism 15 based on the target wheel pressure. The control of the second ECU 7 will be briefly described by taking the control for the wheel cylinder WCrl as an example. In the pressure increasing control, the pressure increasing valve 15b7 is opened and the pressure reducing valve 15b6 is closed. In the pressure reduction control, the pressure increasing valve 15b7 is closed and the pressure reducing valve 15b6 is opened. In the holding control, the pressure increasing valve 15b7 and the pressure reducing valve 15b6 are closed.

  Various sensors such as a stroke sensor 11c, pressure sensors Y, 25b, 26a, and 15b5, and a wheel speed sensor S are connected to the second ECU 7. The second ECU 7 acquires stroke information, master pressure information, reaction force hydraulic pressure information, servo pressure information, wheel speed information, and the like from these sensors. The sensor and the second ECU 7 are connected by, for example, a communication line. The setting of the target wheel pressure in the second ECU 7 will also be described later. In the first embodiment, the stroke sensor 11c and the first ECU 6 are connected by, for example, the communication line Z1, the stroke sensor 11c and the second ECU 7 are connected by, for example, the communication line Z2, and the first ECU 6 and the second ECU 7 are connected by the communication line Z3. Connected with. The other communication lines are not shown in FIG.

  As described above, the vehicle braking device 100 according to the first embodiment includes the booster mechanism 15 that drives the master pistons 12c and 12d that are slidably disposed in the master cylinder 12, and the master formed in the master cylinder 12. The fluid in the wheel cylinder WC is arranged between the chambers R1, R2 and the wheel cylinder WC, and is based on the master pressure that is the fluid pressure in the master chambers R1, R2 generated according to the movement of the master pistons 12c, 12d. An actuator 5 that adjusts the wheel pressure that is a pressure, a stroke sensor 11c and a pressure sensor 25b that detect information related to a brake operation, a first ECU 6 that is connected to the stroke sensor 11c and the pressure sensor 25b, and that controls the actuator 5; The booster mechanism 15 is connected to the stroke sensor 11c and the pressure sensor 25b. It includes a first 2ECU7 for executing control, an against.

(Set target wheel pressure)
Here, the setting of the target wheel pressure in the first ECU 6 and the second ECU 7 will be described. The first ECU 6 includes, as functions, a target calculation unit 61, a wheel pressure estimation unit 62, an operation control unit 63, and a transmission unit 64.

  The target calculation unit 61 calculates the first target wheel pressure based on the acquired detection result of the stroke sensor 11c and / or the pressure sensor 25b. The target calculation unit 61 stores, for example, a first map indicating a relationship between a stroke (and / or reaction force hydraulic pressure) and a first target wheel pressure.

  The wheel pressure estimation unit 62 estimates the current wheel pressure based mainly on the master pressure information received from the pressure sensor Y and the control state of the actuator 5. That is, the wheel pressure estimation unit 62 calculates the estimated wheel pressure. The operation control unit 63 basically controls each part of the actuator 5 based on the first target wheel pressure and the estimated wheel pressure so that the estimated wheel pressure approaches the first target wheel pressure. The transmission unit 64 transmits the first target wheel pressure calculated by the target calculation unit 61 to the second ECU 7. The signal (information) is periodically transmitted in synchronization with the synchronous clock.

  The second ECU 7 includes a determination unit 71, a target calculation unit 72, an operation control unit 73, and a target correction unit 74 as functions. Based on the received detection result (stroke information) of the stroke sensor 11c, the detection result of the pressure sensor 25b (reaction force hydraulic pressure information), and the detection result of the wheel speed sensor S (wheel speed information), the determination unit 71 It is determined whether or not the operation corresponds to a sudden braking operation.

  Specifically, the determination unit 71 determines that the brake operation corresponds to the sudden braking operation when the start determination condition is satisfied. In other words, when the start determination condition is satisfied, the determination result of the determination unit 71 becomes positive. The start determination condition of the first embodiment is that the wheel speed is equal to or higher than the first determination speed and the stroke increasing gradient is equal to or higher than the first predetermined value or the reaction force hydraulic pressure increasing gradient is equal to the second predetermined value. That is all. On the other hand, when the start determination condition is not satisfied, the determination unit 71 determines that the brake operation does not correspond to the sudden braking operation. In other words, if the start determination condition is not satisfied, the determination result of the determination unit 71 is negative.

  In addition, after determining that the brake operation corresponds to the sudden braking operation, the determination unit 71 determines whether the sudden braking operation has been released based on the various pieces of information described above. Specifically, the determination unit 71 determines that the sudden braking operation (positive determination) has been released when the release determination condition is satisfied after making a positive determination. The release determination condition of the first embodiment is that the wheel speed is less than the second determination speed and the stroke increasing gradient is less than the third predetermined value or the reaction force hydraulic pressure increasing gradient is the fourth predetermined value. Is less than. The second determination speed is smaller than the first determination speed, the third predetermined value is smaller than the first predetermined value, and the fourth predetermined value is smaller than the second predetermined value. On the other hand, when the release determination condition is not satisfied, the determination unit 71 determines that the sudden braking operation has not been released. Each determination of the determination unit 71 is performed periodically.

  The target calculation unit 72 calculates the second target wheel pressure based on the received detection result of the stroke sensor 11c and / or the pressure sensor 25b when the determination result of the determination unit 71 is affirmative, that is, during a sudden braking operation. To do. The target calculation unit 72 stores, for example, a second map indicating the relationship between the stroke (and / or reaction force hydraulic pressure) and the second target wheel pressure. The second map is the same as the first map. If the determination result of the determination unit 71 is negative, the target calculation unit 72 stops calculating the second target wheel pressure. That is, when the normal brake operation is performed, the function of the target calculation unit 72 is stopped.

  When the determination result of the determination unit 71 is negative (during normal operation), the operation control unit 73 controls each unit of the booster mechanism 15 based on the first target wheel pressure received from the first ECU 6. That is, when a normal brake operation is performed, the first ECU 6 and the second ECU 7 set a common target wheel pressure (first target wheel pressure).

  On the other hand, when the determination result of the determination unit 71 is affirmative (during a sudden braking operation), as shown in FIG. 4, the operation control unit 73 is not the first target wheel pressure but the first calculation calculated by the target calculation unit 72. The booster mechanism 15 is controlled based on the two target wheel pressure. Then, when the determination unit 71 makes a positive determination and then cancels the positive determination, that is, when the sudden braking operation is finished, the operation control unit 73 performs the first target wheel pressure as in the normal braking operation. Based on the control, the booster mechanism 15 is controlled. Thus, the target wheel pressure of the second ECU 7 is set to the first target wheel pressure during normal braking operation, and is set to the second target wheel pressure during sudden braking operation. In the drawing, a case where the determination unit 71 makes a positive determination is described as “rapid operation determination ON”, and a case where the determination unit 71 makes a negative determination or a case where the positive determination is canceled Is described as “abrupt operation determination OFF”.

  Specifically, the operation control unit 73 calculates a target servo pressure (or target master pressure) based on the set target wheel pressure (first target wheel pressure or second target wheel pressure). Since the wheel pressure is related to the master pressure, and the master pressure is related to the servo pressure, the target wheel pressure can be converted into the target servo pressure (or target master pressure). Based on the target servo pressure and the detection result (actual servo pressure) of the pressure sensor 26a, the operation control unit 73 controls the booster mechanism 15 so that the actual servo pressure approaches the target servo pressure. A dead zone is set for the target servo pressure. The dead zone is a region from the lower dead zone value lower than the target servo pressure to the upper dead zone value higher than the target servo pressure. When the actual servo pressure is within the dead band, holding control is executed, and when the actual servo pressure is lower than the dead band lower limit value, pressure increase control is executed and the actual servo pressure is higher than the dead band upper limit value. In some cases, pressure reduction control is performed.

  Here, since the first ECU 6 and the second ECU 7 directly acquire the operation information from the stroke sensor 11c and / or the pressure sensor 25b, there may be a difference between the acquired operation information. That is, even if the maps are the same, if the input information is different, the calculated first target wheel pressure and second target wheel pressure are different. In the first embodiment, when the first target wheel pressure and the second target wheel pressure are different during the sudden braking operation, the wheel pressure is consequently larger of both target wheel pressures by the control of each device. It is controlled to approach the target wheel pressure.

  The target correction unit 74 is a case where the determination result of the determination unit 71 is affirmative (during sudden braking operation) and the second target wheel pressure is greater than the first target wheel pressure, and a predetermined condition is satisfied. The gradient of the second target wheel pressure is made smaller than the gradient of the second target wheel pressure calculated by the target calculation unit 72. The predetermined condition of the first embodiment includes “the second target wheel pressure being equal to or higher than the predetermined pressure”. That is, when the second target wheel pressure is larger than the first target wheel pressure during the sudden braking operation, the target correction unit 74 reduces the gradient of the second target wheel pressure when the second target wheel pressure becomes equal to or higher than a predetermined pressure.

  For the corrected second target wheel pressure gradient, for example, the corrected target gradient, a gradient subtraction value to be subtracted from the second target wheel pressure gradient calculated by the target calculation unit 72, or a target calculation A gain value (gain value <1) for multiplying the gradient of the second target wheel pressure calculated by the unit 72 is set.

  A correction target gradient is set in the target correction unit 74 of the first embodiment. For example, as illustrated in FIG. 5, the target correction unit 74 corrects the second target wheel pressure so that the gradient of the second target wheel pressure becomes the corrected target gradient when a predetermined condition is satisfied. The corrected target gradient is set to a value sufficiently smaller than the gradient of the second target wheel pressure assumed at the time of the sudden braking operation. The target correction unit 74 transmits the corrected second target wheel pressure to the operation control unit 73. The target correction unit 74 continuously limits the gradient of the second target wheel pressure by the gradient correction until the sudden braking operation is finished, that is, until the positive determination by the determination unit 71 is cancelled. It can be said that the target correction unit 74 limits the second target wheel pressure after the predetermined condition is satisfied under the above situation.

  When the correction by the target correction unit 74 is performed, the operation control unit 73 performs control of the booster mechanism 15 based on the corrected second target wheel pressure. The predetermined pressure, the corrected target gradient, the gradient subtraction value, and / or the gain value in the target correction unit 74 are determined based on a previously performed calculation (estimation), simulation, or the like before the sudden braking operation is released. The wheel pressure is set to be equal to or lower than the first target wheel pressure.

  An example of the flow of setting the target wheel pressure in the second ECU 7 will be briefly described with reference to FIG. When the determination result of the determination unit 71 is affirmative (S101: Yes), the second ECU 7 sets the second target wheel pressure calculated by itself as the target wheel pressure, and executes control based on the second target wheel pressure. (S102). Then, the second ECU 7 compares the received first target wheel pressure with the second target wheel pressure during the control based on the second target wheel pressure (S103). When the second target wheel pressure is larger than the first target wheel pressure (S103: Yes), the second ECU 7 determines whether or not a predetermined condition is satisfied (S104). When the predetermined condition is satisfied (S104: Yes), the second ECU 7 corrects and decreases the gradient of the second target wheel pressure (S105). Then, when the positive determination is canceled (S106: Yes), the second ECU 7 changes the value of the target wheel pressure from the second target wheel pressure to the first target wheel pressure (S107).

  On the other hand, when the determination result of the determination unit 71 is negative (S101: No), the second ECU 7 sets the first target wheel pressure received from the first ECU 6 as the target wheel pressure (S107). The second ECU 7 monitors whether or not the positive determination is canceled after the determination unit 71 makes a positive determination. Further, the first ECU 6 and the second ECU 7 are configured to be able to communicate in both directions, and information can be transmitted from the second ECU 7 to the first ECU 6.

  According to the first embodiment, during a normal braking operation that is not a sudden braking operation, the target wheel pressures of the first ECU 6 and the second ECU 7 are shared by the first target wheel pressure calculated by the first ECU 6 by communication. As a result, even when various controls such as ABS control are executed, the upstream and downstream hydraulic pressures are controlled by substantially one target value, so that adjustment of the pressurization amount between the upstream and downstream becomes easy.

  On the other hand, when the brake operation corresponds to the sudden braking operation, the second ECU 7 independently calculates the second target wheel pressure based on the detection results acquired from the stroke sensor 11c and the pressure sensor 25b, and the calculation result Based on the above, the booster mechanism 15 is controlled. That is, control of the booster mechanism 15 is executed regardless of the first target wheel pressure transmitted from the first ECU 6. Thereby, it is excluded that a delay in information acquisition of the receiving ECU (second ECU 7 in this case) caused by communication affects the response of the brake. In communication between ECUs, communication according to a synchronous clock is performed, and a communication delay of at least the clock cycle occurs. In normal brake operation, the gradient of the target wheel pressure is relatively gentle, and it can be said that there is almost no influence on control and response due to communication delay. As described above, according to the first embodiment, the adjustment of the pressurization amount between the upstream and the downstream can be facilitated, and the responsiveness during the sudden braking operation can be improved.

  Further, according to the first embodiment, during normal braking operation, the control target (first target wheel pressure) to the actuator 5 that can cope with relatively fine pressure increase / decrease control is shared by both ECUs 6 and 7. Therefore, it is possible to control the wheel pressure with high accuracy. In the control of the actuator 5, for example, no dead zone is set, and more direct control is possible. During a sudden braking operation, the second target wheel pressure based on a unique calculation without transmission delay is set as a control target for the booster mechanism 15 that can handle relatively quick pressure increase / decrease control. Control becomes possible. In the control for the booster mechanism 15, since the accumulator 15b2 accumulated in advance is used, quick control is possible.

  Further, when the second target wheel pressure is larger than the first target wheel during the sudden braking operation, the master pressure is controlled based on the second target wheel pressure, the pressurization control is not performed by the actuator 5, and the wheel pressure is the second pressure. Increase based on target wheel pressure. Then, when the sudden braking operation is released and the target wheel pressure of the second ECU 7 is changed from the second target wheel pressure to the first target wheel pressure, the target wheel pressure suddenly decreases, that is, the target servo pressure suddenly increases. A decrease may occur, and the driver may feel an unexpected deceleration change. The sudden braking operation is often released after the target wheel pressure becomes constant, and a sudden change in the target servo pressure that does not depend on the brake operation tends to affect the brake feeling.

  On the other hand, in the first embodiment, the target correction unit 74 reduces the gradient of the second target wheel pressure in advance under a predetermined condition before the sudden braking operation is released. Therefore, the corrected second target wheel pressure is equal to or lower than the first target wheel pressure, or at least the second target wheel pressure is approaching the first target wheel pressure. Thereby, a sudden decrease in the target servo pressure (or target master pressure) is suppressed, and deterioration of the brake feeling is suppressed.

<Second embodiment>
The vehicle braking device of the second embodiment is different from the first embodiment in the way of gradient correction. Therefore, the different points will be described. In the description of the second embodiment, the description of the first embodiment and the drawings can be referred to as appropriate.

  The predetermined condition set in the target correction unit 74 of the second embodiment includes “the gradient of the second target wheel pressure has changed to the decreasing side”. When the second target wheel pressure is larger than the first target wheel pressure during the sudden braking operation, the target correction unit 74 multiplies the second target wheel pressure by a gain value when the gradient of the second target wheel pressure fluctuates. And reducing the second target wheel pressure.

  The target correction unit 74 monitors the gradient fluctuation of the second target wheel pressure, and corrects the second target wheel pressure when a decrease in the gradient is detected. As a result, for example, as shown in FIG. 7, when the second target wheel pressure starts to curve from a certain steep slope to a decreasing side, correction is started, and the slope of the second target wheel pressure after correction is started. Is also curved in the same way as before correction, and correction is made according to the brake operation. With this correction, the second target wheel pressure approaches the first target wheel, and the second target wheel pressure becomes equal to or lower than the first target wheel pressure before the sudden braking operation is released. Thus, also by 2nd embodiment, the effect similar to 1st embodiment is exhibited.

  Note that the predetermined condition set in the target correction unit 74 may be configured as “the gradient of the first target wheel pressure has changed to the decreasing side”. In this case, the target correction unit 74 monitors the gradient of the received first target wheel pressure, and corrects the second target wheel pressure when a decrease in the gradient is detected. Further, the predetermined condition may be configured as “a predetermined time has elapsed since the determination unit 71 made a positive determination”. The duration of the sudden braking operation can be estimated in advance by calculation or the like, and the same effect as described above is exhibited by appropriately setting the predetermined time.

<Third embodiment>
The vehicle braking device of the third embodiment is different from that of the first embodiment in terms of gradient correction. Therefore, different points will be described. In description of 3rd embodiment, description and drawing of 1st embodiment can be referred suitably.

  As shown in FIG. 8, the first ECU 6 of the third embodiment further includes a target correction unit 65 as a function. In the third embodiment, the target correction unit 74 of the second ECU 7 is omitted. The target correction unit 65 determines the first target wheel pressure when the determination result of the determination unit 71 is affirmative and the second target wheel pressure is greater than the first target wheel pressure and a predetermined condition is satisfied. Increases the first target wheel pressure so as to match the second target wheel pressure. The predetermined condition includes “the positive determination of the determination unit 71 has been released (the sudden braking operation has ended)”.

  As illustrated in FIG. 9, when the target correction unit 65 receives from the second ECU 7 that the positive determination of the determination unit 71 has been released, the target correction unit 65 raises the first target wheel pressure calculated by the target calculation unit 61. Execute the process. The raising process is a process for raising the first target wheel pressure by the raising amount. The raising amount is set based on the difference between the first target wheel pressure and the second target wheel pressure. The target correction unit 65 of the third embodiment calculates the difference between the first target wheel pressure and the second target wheel pressure, and sets the difference as the raising amount.

  According to the third embodiment, when the sudden braking operation is finished, the first target wheel pressure is raised and matched with the second target wheel pressure, so that the brake feeling is deteriorated due to a sudden decrease in the second target wheel pressure. Is suppressed. However, since the target wheel pressure is maintained at the larger second target wheel pressure, the braking force is maintained relatively large. In the third embodiment, a determination unit having the same function as the determination unit 71 may be provided in the first ECU 6. In this case, the target correction unit 65 can acquire the determination result related to the sudden braking operation without communication with the second ECU 7.

  The predetermined condition (predetermined condition regarding the start of raising) set in the target correction unit 65 is, for example, “a first target wheel pressure is constant” or “a predetermined time after the determination unit 71 makes a positive determination. It may be configured to include “elapsed time”. When the first target wheel pressure is constant (gradient = 0), it can be estimated that the sudden braking operation has been completed. Therefore, the same effect as described above is exhibited by performing the raising process at that timing. Further, the duration of the sudden braking operation can be estimated in advance by calculation or the like, and the same effect as described above is exhibited by appropriately setting the predetermined time.

<Others>
The present invention is not limited to the above embodiment. For example, when the predetermined condition set in the target correction unit 74 includes “a predetermined time has elapsed since the determination unit 71 made a positive determination”, the wheel pressure is 0 (atmospheric pressure) for the predetermined time. May be set to the arrival time from the time until the predetermined threshold is reached. The arrival time can be calculated based on the gradient of the target wheel pressure and the PV characteristics of the wheel cylinder WC. The wheel pressure may be an estimated wheel pressure, or may be a wheel pressure detected by the pressure sensor when a pressure sensor for detecting the wheel pressure is provided.

  For example, the second ECU 7 may further include a predetermined time setting unit (7) as a function. The second ECU 7 (predetermined time setting unit) calculates the arrival time based on the gradient of the second target wheel pressure, and sets the arrival time to the predetermined time. Furthermore, the predetermined threshold is set so that the predetermined time becomes longer than the invalid braking period (for example, the period until the brake pad contacts the disc rotor DR) due to the structure of the brake mechanism around the wheel W. Is preferred. Thereby, at least during the invalid braking period, the pressure is quickly increased by the gradient of the second target wheel pressure before correction, which is advantageous in terms of responsiveness.

  In the first to third embodiments, the first ECU 6 may control the boost mechanism 15 and the second ECU 7 may control the actuator 5. That is, the ECU that controls the booster mechanism 15 may calculate the first target wheel pressure and transmit it to the other ECU during a normal brake operation. This also makes it easy to adjust the amount of pressurization between the upstream and downstream sides and improves the responsiveness during a sudden braking operation.

  Further, the determination unit 71 may determine that the brake operation is a sudden braking operation when the brake operation is started regardless of the operation speed of the brake pedal 11. That is, the start determination condition in this case is set to detect that the brake operation has been performed, for example, to increase the stroke even a little. In this case, when the brake operation is started, the determination result of the determination unit 71 becomes positive regardless of the operation speed, and the second ECU 7 calculates the second target wheel pressure, and based on the second target wheel pressure. The booster mechanism 15 is controlled. Thereafter, when the release determination condition is satisfied, the determination result of the determination unit 71 becomes negative, and the second ECU 7 controls the booster mechanism 15 based on the received first target wheel pressure.

  According to this configuration, as shown in FIG. 10, it is possible to eliminate the determination time from when the brake operation is started until the determination unit 71 makes a positive determination. Control by the target wheel pressure is started. According to this configuration, switching from the first target wheel pressure to the second target wheel pressure at the beginning of the sudden braking operation can be eliminated, and the target wheel pressure can be increased more smoothly, thereby further improving the responsiveness. be able to.

  Further, the target calculation unit 72 may calculate the second target wheel pressure regardless of the result of the determination unit 71. In this case, the operation control unit 73 switches between the first target wheel pressure and the second target wheel pressure according to the determination result of the determination unit 71. Further, the first map and the second map may be different. When a pressure sensor for detecting wheel pressure is provided, the detection result of the pressure sensor may be used instead of the estimated wheel pressure. In this case, the wheel pressure estimation unit 62 can be omitted. Further, the determination by the determination unit 71 may be performed based only on the stroke or the reaction force hydraulic pressure. Further, the determination as to whether or not the sudden braking operation has ended may be performed by the target correction units 74 and 65. Further, the predetermined condition, the start determination condition, and the release determination condition may be configured with conditions other than those described above. The term “target wheel pressure” has the same meaning as the target hydraulic braking force and the target hydraulic braking torque, and can be said to be a concept including the target hydraulic braking force and the target hydraulic braking torque.

  Moreover, the vehicle braking device 100 may include a regenerative braking device H as shown in FIG. The regenerative braking device H is a device that applies a regenerative braking force obtained by converting the kinetic energy of the vehicle into electric energy to the wheels W, and includes an ECU, a generator, an inverter, a battery, and the like (not shown). . In this case, for example, the first ECU 6 calculates the required braking force based on the detected stroke and / or reaction force hydraulic pressure. The first ECU 6 transmits the calculated required braking force to the regenerative braking device H. The regenerative braking device H executes regenerative control using the required braking force as a target regenerative braking force, calculates an actual regenerative braking force that is actually output, and transmits it to the first ECU 6. The first ECU 6 uses the difference obtained by subtracting the effective regenerative braking force from the required braking force as the target hydraulic pressure braking force, and sets the wheel pressure corresponding to the target hydraulic pressure braking force as the target wheel pressure. The same communication as described above is possible between the regenerative braking device H and the second ECU 7. The booster mechanism 15 may be an electric booster that directly moves the first master piston 12c by driving a motor, for example.

DESCRIPTION OF SYMBOLS 12 ... Master cylinder, 12c ... 1st master piston, 12d ... 2nd master piston, R1 ... 1st master chamber, R2 ... 2nd master chamber, WC ... Wheel cylinder, 5 ... Actuator, 11c ... Stroke sensor (detection part) , 25b ... pressure sensor (detection unit), 6 ... first ECU (first control unit), 7 ... second ECU (second control unit), 71 ... determination unit, 74, 65 ... target correction unit.

Claims (6)

A piston drive section for driving a piston slidably disposed in the master cylinder;
Based on the master pressure that is disposed between the master chamber formed in the master cylinder and the wheel cylinder and is generated in response to the movement of the piston, the hydraulic pressure in the wheel cylinder An actuator that adjusts a wheel pressure;
A detection unit for detecting information on brake operation;
In a vehicle braking device comprising:
A determination unit that determines whether or not the brake operation corresponds to a sudden braking operation based on a detection result of the detection unit;
A first control unit connected to the detection unit and executing control on the actuator;
A second control unit connected to the detection unit and executing control on the piston drive unit;
Further comprising
The actuator is configured to be able to pressurize the wheel pressure,
The first control unit and the second control unit are communicably connected,
One of the first control unit and the second control unit calculates a first target wheel pressure that is a target value of the wheel pressure based on a detection result acquired from the detection unit, and sets the first target wheel pressure. Based on said control,
When the determination result of the determination unit is negative, the other of the first control unit and the second control unit receives the first target received from one of the first control unit and the second control unit. When the control is executed based on the wheel pressure, and the determination result of the determination unit is affirmative, a second target wheel pressure that is a target value of the wheel pressure based on the detection result acquired from the detection unit And the vehicle braking device that executes the control based on the second target wheel pressure. The first control unit calculates the first target wheel pressure based on a detection result acquired from the detection unit, and executes the control based on the first target wheel pressure,
When the determination result of the determination unit is negative, the second control unit executes the control based on the first target wheel pressure received from the first control unit, and the determination of the determination unit The said 2nd target wheel pressure is calculated based on the detection result acquired from the said detection part when a result is affirmative, The said control is performed based on the said 2nd target wheel pressure. Vehicle braking system. When the determination result of the determination unit is affirmative and the second target wheel pressure is greater than the first target wheel pressure, the gradient of the second target wheel pressure when a predetermined condition is satisfied, A target correction unit that makes the gradient of the second target wheel pressure calculated based on the detection result of the detection unit smaller;
The predetermined conditions include that the second target wheel pressure is greater than or equal to a predetermined pressure, that the gradient of the first target wheel pressure has changed to the decreasing side, and that the gradient of the second target wheel pressure has changed to the decreasing side. The vehicle braking device according to claim 2, wherein a predetermined time has elapsed since the determination unit made a positive determination. When the determination result of the determination unit is affirmative and the second target wheel pressure is greater than the first target wheel pressure, and when a predetermined condition is satisfied, the first target wheel pressure is the second target wheel pressure. A target correction unit that raises the first target wheel pressure so as to match the target wheel pressure;
The predetermined condition is that the positive determination of the determination unit has been canceled, the first target wheel pressure is constant, or a predetermined time has elapsed since the determination unit made a positive determination. The vehicle braking device according to claim 2, wherein A predetermined time setting unit that sets the predetermined time based on an arrival time until the wheel pressure reaches a predetermined threshold value from 0;
The vehicle braking device according to claim 3, wherein the predetermined condition includes that the predetermined time has elapsed since the determination unit made a positive determination.   The determination unit performs a positive determination when the brake operation is started, and performs a negative determination when a detection result of the detection unit satisfies a preset release determination condition. The braking device for vehicles as described.

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