JP2018144673A - Brake device, method for controlling brake device and brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake device that can inhibit shortage of pressurization responsiveness of a wheel cylinder, and to provide a method for controlling a brake device and a brake system.SOLUTION: A brake device includes: a stroke simulator connected to a master cylinder and capable of generating pseudo-manipulation reaction force of a brake operation member; and a shutoff valve 21 provided in a connection liquid passage on a side of a wheel cylinder. The brake device delays the timing of closing a valve from an open valve state for the shutoff valve when operation speed of the brake operation member is high relative to that when it is low.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a brake device, a control method for the brake device, and a brake system.

  Patent Document 1 discloses a brake device in which a shutoff valve is provided in a connecting fluid path that connects a master cylinder and a wheel cylinder, and a pump discharge unit is connected between the shutoff valve and the wheel cylinder. In this brake device, when the brake operation of the driver is performed, the shut-off valve is closed and the pump is driven to pressurize the wheel cylinder.

JP 2016-52809 A

However, in the above-described prior art, when the brake operation speed of the driver is high, there is a problem that the pressurization response of the wheel cylinder by the pump is insufficient.
One of the objects of the present invention is to provide a brake device, a brake device control method, and a brake system that can suppress a lack of pressurization response of a wheel cylinder.

  In the brake device according to the embodiment of the present invention, when the operation speed of the brake operation member is high, the timing for switching the shut-off valve from opening to closing is delayed as compared to when the operation speed is low.

  Therefore, the lack of pressurization response of the wheel cylinder can be suppressed.

1 shows a schematic configuration of a brake system 1 according to a first embodiment. 3 is a flowchart showing a flow of a sudden depression pressurization control process by the sudden depression pressurization control unit 106 according to the first embodiment. 3 is a time chart illustrating a pressurization control operation during sudden depression according to the first embodiment. 6 is a flowchart showing a flow of a sudden depression pressurization control process by a sudden depression pressurization control unit 106 according to the second embodiment. 10 is a setting map of a delay time Td corresponding to a pedal stroke speed ΔSp / Δt immediately after the brake is turned on in the second embodiment. 12 is a flowchart showing a flow of a sudden depression pressurization control process by a sudden depression pressurization control unit 106 according to the third embodiment. 10 is a time chart showing a pressurization control action during a sudden stepping of Embodiment 3. 10 is a flowchart illustrating a flow of a sudden depression pressurization control process by a sudden depression pressurization control unit according to a fourth embodiment. FIG. 10 is a setting map of a delay time Td according to a master cylinder hydraulic pressure change speed ΔPm / Δt immediately after brake ON in the fourth embodiment. 10 is a flowchart showing a flow of a sudden depression pressurization control process by a sudden depression pressurization control unit 106 according to the fifth embodiment. 10 is a time chart showing a pressurization control action during sudden depression of Embodiment 5.

Embodiment 1
FIG. 1 shows a schematic configuration of a brake system 1 according to the first embodiment.
The brake system 1 is a brake system suitable as a brake system for an electric vehicle such as a hybrid vehicle provided with a motor generator in addition to an engine or an electric vehicle provided only with a motor generator as a prime mover for driving wheels. The brake system 1 may be applied to a vehicle that uses only the engine as a driving force source. The brake system 1 supplies the brake fluid to the wheel cylinders 8 provided on the wheels FL to RR of the vehicle to generate brake fluid pressure (wheel cylinder fluid pressure Pw), thereby controlling the fluid pressure on the wheels FL to RR. Give power. Here, the wheel cylinder 8 may be a cylinder of a hydraulic brake caliper in a disc brake mechanism in addition to a wheel cylinder of a drum brake mechanism. The brake system 1 has brake piping of two systems, that is, a P (primary) system and an S (secondary) system, and adopts, for example, an X piping format. In addition, you may employ | adopt other piping formats, such as front and rear piping. In the following, when distinguishing between members provided corresponding to the P system and members corresponding to the S system, the suffixes P and S are added to the end of each symbol.

  The brake pedal 2 is a brake operation member that receives an input of a driver's brake operation. One end of the push rod 30 is rotatably connected to the base side of the brake pedal 2. The master cylinder 5 is actuated by an operation (brake operation) of the brake pedal 2 by a driver, and generates a brake fluid pressure (master cylinder fluid pressure Pm). The brake system 1 does not include a negative pressure type booster that boosts or amplifies the brake operation force (stepping force Fp of the brake pedal 2) using intake negative pressure generated by the vehicle engine. The master cylinder 5 is connected to the brake pedal 2 via the push rod 30 and receives a supply of brake fluid from the reservoir tank 4. The reservoir tank 4 is a brake fluid source that stores brake fluid, and is a low pressure portion that is opened to atmospheric pressure. The master cylinder 5 is a tandem type, and includes a primary piston 52P connected to the push rod 30 and a free piston type secondary piston 52S as a master cylinder piston that moves in the axial direction in response to a brake operation. A pedal stroke sensor 90 that detects the amount of axial displacement of the primary piston 52P is provided inside the master cylinder 5. The axial displacement of the primary piston 52P corresponds to the displacement of the brake pedal 2 (pedal stroke Sp). The pedal stroke Sp may be detected by providing the pedal stroke sensor 90 on the push rod 30 or the brake pedal 2.

The brake system 1 includes a hydraulic unit 6 and an electronic control unit 100. The hydraulic pressure unit 6 is a braking control unit that receives supply of brake fluid from the reservoir tank 4 or the master cylinder 5 and can generate brake fluid pressure independently of the brake operation by the driver. An electronic control unit (hereinafter referred to as ECU) 100 is a control unit that controls the operation of the hydraulic unit 6.
The hydraulic unit 6 is provided between the wheel cylinder 8 and the master cylinder 5, and can supply the master cylinder hydraulic pressure Pm or the control hydraulic pressure to each wheel cylinder 8 individually. The hydraulic unit 6 includes a motor 7a of a pump (hydraulic pressure source) 7 and a plurality of control valves (such as an electromagnetic valve 21) as hydraulic equipment for generating a control hydraulic pressure. The pump 7 sucks the brake fluid from the reservoir tank 4 and discharges it toward the wheel cylinder 8. In the first embodiment, a gear pump excellent in sound vibration performance and the like, specifically, an external gear type pump unit is used as the pump 7. A plunger pump may be used. The pump 7 is used in common in both systems and is rotationally driven by an electric motor 7a as the same drive source. As the motor 7a, for example, a motor with a brush can be used. The output shaft of the motor 7a is provided with a resolver that detects its rotational position (rotational angle). The solenoid valve 21 or the like opens and closes according to the control signal, and controls the flow of the brake fluid by switching the communication state of the fluid path 11 and the like. The hydraulic unit 6 is provided so that the wheel cylinder 8 can be pressurized by the hydraulic pressure generated by the pump 7 with the communication between the master cylinder 5 and the wheel cylinder 8 blocked. The hydraulic unit 6 includes a stroke simulator 22. The stroke simulator 22 operates in response to a driver's brake operation, and generates a pedal stroke Sp when brake fluid flows from the master cylinder 5. The hydraulic pressure unit 6 includes hydraulic pressure sensors 91 to 93 that detect hydraulic pressures at various locations such as the discharge pressure of the pump 7 and the master cylinder hydraulic pressure Pm.

  The ECU 100 receives information relating to the detected values sent from the resolver, the pedal stroke sensor 90 and the hydraulic pressure sensors 91 to 93 and the traveling state sent from the vehicle side. The ECU 100 performs information processing according to a built-in program based on these various types of information. Further, according to the processing result, a control command is output to each actuator of the hydraulic unit 6 to control them. Specifically, the opening / closing operation of the solenoid valve 21 and the like and the rotation speed of the motor 7a (that is, the discharge amount of the pump 7) are controlled. Thus, various brake controls are realized by controlling the wheel cylinder hydraulic pressure Pw of each of the wheels FL to RR. For example, boost control that assists brake operation by generating hydraulic braking force that is insufficient with the driver's brake operation force, anti-lock control for suppressing slip (lock tendency) of wheels FL to RR due to braking, vehicle Brake control for vehicle motion control (control of vehicle behavior such as prevention of skidding; hereinafter referred to as ESC), automatic brake control such as preceding vehicle tracking control, and target deceleration (target braking force) in cooperation with regenerative braking Regenerative cooperative brake control that controls the wheel cylinder hydraulic pressure Pw is realized.

  The master cylinder 5 is a hydraulic pressure source that can be connected to the wheel cylinder 8 via a first liquid path 11 to be described later and pressurize the wheel cylinder 8. The master cylinder 5 is capable of pressurizing the wheel cylinders 8a and 8d via the P system fluid passage (first fluid passage 11P) by the master cylinder fluid pressure Pm generated in the primary fluid pressure chamber 51P, and the secondary fluid pressure. The wheel cylinders 8b and 8c can be pressurized via the S system liquid path (first liquid path 11S) by the master cylinder hydraulic pressure Pm generated in the chamber 51S. The piston 52 of the master cylinder 5 is inserted into the bottomed cylindrical cylinder 50 so as to be axially movable along the inner peripheral surface thereof. The cylinder 50 includes a discharge port (supply port) 501 and a replenishment port 502 for each of the P and S systems. The discharge port 501 is connected to the hydraulic unit 6 so as to communicate with the wheel cylinder 8. The replenishment port 502 is connected to and communicates with the reservoir tank 4. A coil spring 53P as a return spring is installed in a compressed state in the primary hydraulic chamber 51P between the pistons 52P and 52S. In the secondary hydraulic chamber 51S between the piston 52S and the axial end of the cylinder 50, the coil spring 53S is installed in a compressed state. A discharge port 501 is always open in each hydraulic chamber 51P, 51S.

  A piston seal 54 (corresponding to 541 and 542 in the figure) is provided on the inner periphery of the cylinder 50. The piston seal 54 is in sliding contact with the pistons 52P and 52S to seal between the outer peripheral surface of the pistons 52P and 52S and the inner peripheral surface of the cylinder 50. Each piston seal 54 is a well-known cup-shaped seal member (cup seal) having a lip portion on the inner diameter side. In a state where the lip portion is in contact with the outer peripheral surface of the piston 52, the flow of the brake fluid in one direction is allowed and the flow of the brake fluid in the other direction is suppressed. The first piston seal 541 allows the flow of brake fluid from the replenishment port 502 toward the hydraulic pressure chamber 51 (discharge port 501) and suppresses the flow of brake fluid in the reverse direction. The second piston seal 542P suppresses the flow of brake fluid from the supply port 502P toward the brake pedal 2 side. The second piston seal 542S suppresses the flow of brake fluid from the primary hydraulic chamber 51P toward the replenishment port 502S. The hydraulic chamber 51 is reduced in volume when the piston 52 is stroked in the axial direction opposite to the brake pedal 2 by the depression operation of the brake pedal 2 by the driver, and generates a hydraulic pressure (master cylinder hydraulic pressure Pm). As a result, the brake fluid is supplied from the hydraulic chamber 51 to the wheel cylinder 8 through the discharge port 501. Note that substantially the same hydraulic pressure is generated in both hydraulic pressure chambers 51P and 51S.

Hereinafter, the brake hydraulic circuit of the hydraulic unit 6 will be described with reference to FIG.
The members corresponding to the wheels FL to RR are appropriately distinguished by adding suffixes a to d at the end of the reference numerals. The first liquid path (connection liquid path) 11 connects the discharge port 501 (hydraulic pressure chamber 51) of the master cylinder 5 and the wheel cylinder 8. The cut valve (shutoff valve) 21 is a normally open electromagnetic valve (opened in a non-energized state) provided in the first liquid passage 11. The first liquid path 11 is separated by a cut valve 21 into a liquid path 11A on the master cylinder 5 side and a liquid path 11B on the wheel cylinder 8 side. The solenoid-in valve (SOL / V IN) 25 is located on the wheel cylinder 8 side (liquid path 11B) from the cut valve 21 in the first liquid path 11, corresponding to each wheel FL to RR (in the liquid paths 11a to 11d). ) This is a normally open solenoid valve. Note that a bypass liquid path 110 is provided in parallel with the first liquid path 11 by bypassing the SOL / V IN 25. The bypass fluid passage 110 is provided with a check valve 250 that allows only the flow of brake fluid from the wheel cylinder 8 side to the master cylinder 5 side.

  The suction liquid path 15 is a low pressure part that connects the reservoir tank 4 and the suction part 70 of the pump 7. The discharge liquid path 16 connects the discharge part 71 of the pump 7 and the cut valve 21 and the SOL / V IN 25 in the first liquid path 11 (liquid path 11B). The check valve 160 is provided in the discharge liquid passage 16 and allows only the flow of brake fluid from the discharge portion 71 side (upstream side) to the first liquid passage 11 side (downstream side). The check valve 160 is a discharge valve provided in the pump 7. The discharge liquid path 16 is branched downstream of the check valve 160 into a P-system discharge liquid path 16P and an S-system discharge liquid path 16S. The liquid passages 16P and 16S are connected to the first liquid passage 11P of the P system and the first liquid passage 11S of the S system, respectively. The discharge liquid paths 16P and 16S constitute a communication path that connects the first liquid paths 11P and 11S to each other. The communication valve 26P is a normally closed electromagnetic valve (closed in a non-energized state) provided in the discharge liquid passage 16P. The communication valve 26S is a normally closed electromagnetic valve provided in the discharge liquid passage 16S. The pump 7 is a fluid pressure source capable of generating fluid pressure in the first fluid path 11 by the brake fluid supplied from the reservoir tank 4. The pump 7 is connected to the wheel cylinders 8a to 8d via the communication path (discharge liquid paths 16P and 16S) and the first liquid paths 11P and 11S, and brakes to the communication path (discharge liquid paths 16P and 16S). The foil cylinder 8 can be pressurized by discharging the liquid.

The first decompression liquid path 17 connects the suction liquid path 15 between the check valve 160 and the communication valve 26 in the discharge liquid path 16. The pressure regulating valve 27 is a normally open type electromagnetic valve provided in the first pressure reducing liquid passage 17. The second decompression liquid path 18 connects the wheel cylinder 8 side and the suction liquid path 15 with respect to the SOL / VIN 25 in the first liquid path 11 (liquid path 11B). The solenoid-out valve (SOL / V OUT) 28 is a normally closed electromagnetic valve provided in the second decompression liquid path 18. In the first embodiment, the first decompression fluid path 17 on the suction fluid passage 15 side from the pressure regulating valve 27 and the second decompression fluid passage 18 on the suction fluid passage 15 side from the SOL / V OUT 28 are partially In common.
The stroke simulator 22 has a piston 220 and a spring 221. The piston 220 is a partition that separates the inside of the cylinder 22a of the stroke simulator 22 into two chambers (a positive pressure chamber R1 and a back pressure chamber R2), and is provided so as to be movable in the axial direction within the cylinder 22a. The axial direction refers to the direction in which the spring 221 is deformed. A seal member (not shown) is installed on the outer peripheral surface of the piston 220 facing the inner peripheral surface of the cylinder 22a. This seal member seals the outer peripheral side of the piston 220, thereby suppressing the flow of brake fluid between the positive pressure chamber R1 and the back pressure chamber R2, and maintaining the fluid tightness between the two chambers R1, R2. The spring 221 is a coil spring installed in a compressed state in the back pressure chamber R2, and always urges the piston 220 toward the positive pressure chamber R1. The spring 221 is provided so as to generate a reaction force according to the displacement amount (stroke amount) of the piston 220.

  The second fluid passage 12 branches from the discharge port 501P (primary fluid pressure chamber 51P) of the master cylinder 5 and the cut valve 21P (fluid passage 11A) in the first fluid passage 11P, and the positive pressure of the stroke simulator 22 A branch liquid path connected to the chamber R1. The third liquid path (simulator liquid path) 13 connects the back pressure chamber R2 of the stroke simulator 22 and the first liquid path 11. Specifically, the third liquid path 13 branches from the cut valve 21P and the SOL / V IN 25 in the first liquid path 11P (liquid path 11B) and is connected to the back pressure chamber R2. The stroke simulator-in valve (SS / V IN) 23 is a normally open type electromagnetic valve provided in the third liquid passage 13. The third liquid path 13 is separated by SS / V IN 23 into a liquid path 13A on the back pressure chamber R2 side and a liquid path 13B on the first liquid path 11 side. A bypass liquid path 130 is provided in parallel with the third liquid path 13 by bypassing the SS / V IN 23. The bypass liquid path 130 connects the liquid path 13A and the liquid path 13B. The bypass fluid passage 130 allows the flow of brake fluid from the back pressure chamber R2 side (fluid passage 13A) toward the first fluid passage 11 side (fluid passage 13B) and suppresses the flow of brake fluid in the reverse direction. A check valve (stroke simulator in valve) 230 is provided.

  The fourth liquid path 14 connects the back pressure chamber R2 of the stroke simulator 22 and the reservoir tank 4. The fourth fluid passage 14 is provided to allow both the flow of brake fluid from the back pressure chamber R2 and the flow of brake fluid from the reservoir tank 4. Specifically, the fourth fluid passage 14 is provided between the back pressure chamber R2 and the SS / V IN 23 (fluid passage 13A) in the third fluid passage 13 and the suction fluid passage 15 (or the suction from the pressure regulating valve 27). The first depressurizing liquid path 17 on the liquid path 15 side and the second depressurizing liquid path 18 on the suction liquid path 15 side from the SOL / V OUT28 are connected. The fourth liquid passage 14 may be directly connected to the back pressure chamber R2 or the reservoir tank 4. In the first embodiment, a part of the fourth liquid path 14 on the back pressure chamber R2 side is shared with the third liquid path 13 (13A), and a part of the fourth liquid path 14 on the reservoir tank 4 side is used as the suction liquid path 15. Therefore, the configuration of the liquid channel can be simplified as a whole. The stroke simulator out valve (SS / V OUT) 24 is a normally closed electromagnetic valve provided in the fourth liquid passage 14. When the fourth liquid path 14 is grasped as a liquid path directly connected to the back pressure chamber R2, the third liquid path 13 is connected to the back pressure chamber R2 and the SS / V OUT 24 in the fourth liquid path 14. Is connected to the liquid path 11B.

  The fourth liquid path 14 is in series with SS / V OUT24 and is closer to the reservoir tank 4 (suction liquid path 15) than SS / V OUT24 and has a throttle portion (orifice) having a predetermined flow path resistance. ) 24A is provided. Specifically, the aperture 24A is provided in the SS / V OUT 24, and is provided integrally with the SS / V OUT 24 unit. In the SS / V OUT24, the throttle section 24A is located closer to the reservoir tank 4 (suction fluid path 15) than the SS / V OUT24 valve body, and the cross-sectional area of the flow path in the opened SS / V OUT24 It is provided to squeeze (shrink). The throttle portion 24A may not be integrated with the SS / V OUT 24 unit but may be provided on the fourth liquid path 14 formed in the housing of the second unit 62. Further, a bypass liquid path 140 is provided in parallel with the fourth liquid path 14 by bypassing the throttle portion 24A and the SS / V OUT 24. The bypass fluid passage 140 allows the brake fluid to flow from the reservoir tank 4 (suction fluid passage 15) side to the third fluid passage 13 (fluid passage 13A) side, that is, the back pressure chamber R2, and brakes in the reverse direction. A check valve 240 that suppresses the flow of liquid is provided.

  Cut valve 21, SS / V IN23, SOL / V IN25, and pressure regulating valve 27 are proportional control valves in which the valve opening is adjusted in accordance with the current supplied to the solenoid. The other valves, that is, SS / V OUT24, communication valve 26 and SOL / V OUT28 are two-position valves (on / off valves) whose opening and closing are controlled in a binary manner. It is also possible to use a proportional control valve as the other valve. Between the cut valve 21P and the master cylinder 5 in the first fluid passage 11P (fluid passage 11A), the fluid pressure at this location (master cylinder fluid pressure Pm and fluid pressure in the positive pressure chamber R1 of the stroke simulator 22) is A hydraulic pressure sensor (master cylinder hydraulic pressure sensor) 91 for detection is provided. The hydraulic pressure sensor 91 may be provided in the second liquid path 12 or the S-system liquid path 11A. Between the cut valve 21 and the SOL / V IN 25 in the first fluid passage 11, a fluid pressure sensor (primary system pressure sensor, secondary system pressure sensor) 92 that detects the fluid pressure (wheel cylinder fluid pressure Pw) at this location. Is provided. Between the discharge part 71 (check valve 160) of the pump 7 and the communication valve 26 in the discharge liquid path 16, a hydraulic pressure sensor 93 for detecting the hydraulic pressure (pump discharge pressure) at this point is provided. Note that a hydraulic pressure sensor 93 may be provided between the connection portion of the discharge liquid passage 16 in the first reduced pressure liquid passage 17 and the pressure regulating valve 27.

  The hydraulic unit 6 includes a first unit 61 and a second unit 62. The first unit 61 is a pump unit including a pump 7 and a motor 7a. The second unit 62 is a valve unit that accommodates each valve 21 and the like. The first and second units 61 and 62 control each actuator in accordance with a control command from the ECU 100. The second unit 62 includes the stroke simulator 22 and the sensors 90 to 93, and the master cylinder 5 is integrally provided. In addition, the reservoir tank 4 is integrally installed in the second unit 62. In other words, the master cylinder 5 and the stroke simulator 22 are provided in the same housing and constitute one master cylinder unit. From another viewpoint, the valve unit is integrally installed in the master cylinder unit, and these constitute a single unit as a whole. Specifically, the master cylinder 5, the stroke simulator 22, the valve 21 and the like are provided in the same housing. It should be noted that how the actuators and sensors of the hydraulic unit 6 are unitized is arbitrary. For example, in addition to the stroke simulator 22, SS / V IN23 and SS / V OUT24, a stroke simulator unit having a P-system cut valve 21P and a hydraulic pressure sensor 91 may be provided. In this case, other actuators and sensors, that is, valve units and pump units having the valves 21S, 25 to 28 and hydraulic pressure sensors 92, 93 other than those described above, and the pump 7 and the motor 7a, are separated from the master cylinder 5. Can be provided on the body. These units and the master cylinder 5 may be installed integrally or connected to each other via piping.

A liquid reservoir 15A having a predetermined volume is provided on the suction liquid passage 15. The liquid reservoir 15A is a reservoir inside the hydraulic pressure unit 6. The liquid reservoir 15A is provided inside the first unit 61 and in the vicinity of a portion to which a brake pipe constituting the suction liquid passage 15 is connected (upper side in the vertical direction of the first unit 61). The pump 7 sucks brake fluid from the reservoir tank 4 through the liquid reservoir 15A. The first and second reduced pressure liquid passages 17 and 18 and the fourth liquid passage 14 are connected to the liquid reservoir 15A. The brake fluid in the first and second decompression fluid passages 17 and 18 and the fourth fluid passage 14 is returned to the reservoir tank 4 through the fluid reservoir 15A.
A brake system (first fluid path 11) that connects the hydraulic chamber 51 of the master cylinder 5 and the wheel cylinder 8 in a state where the cut valve 21 is controlled in the valve opening direction constitutes a first system. This first system creates a wheel cylinder hydraulic pressure Pw by the master cylinder hydraulic pressure Pm generated using the pedal effort Fp, and realizes a pedal brake (non-boosting control). On the other hand, with the cut valve 21 controlled in the valve closing direction, the brake system including the pump 7 and connecting the reservoir tank 4 (liquid reservoir 15A) and the wheel cylinder 8 (suction liquid path 15, discharge liquid path 16, etc.) Constitutes the second system. This second system constitutes a so-called brake-by-wire device that creates the wheel cylinder hydraulic pressure Pw by the hydraulic pressure generated using the pump 7, and realizes boost control or the like as brake-by-wire control.

  During the brake-by-wire control, the stroke simulator 22 creates an operation reaction force accompanying the driver's brake operation. Hereinafter, the hydraulic pressure in the positive pressure chamber R1 of the stroke simulator 22 is referred to as positive pressure (primary side pressure) P1, and the hydraulic pressure in the back pressure chamber R2 or the third liquid passage 13 (liquid passage 13A) is referred to as back pressure (secondary side pressure). ) P2. When the cut valve 21 is controlled in the valve closing direction and communication between the master cylinder 5 and the wheel cylinder 8 is cut off, the driver performs a brake operation (depresses or returns the brake pedal 2), the stroke simulator 22 The pedal stroke Sp is generated by sucking and discharging the brake fluid from the master cylinder 5. Specifically, an amount of brake fluid corresponding to the pedal stroke Sp flows from the master cylinder 5 (primary hydraulic pressure chamber 51P) to the first fluid passage 11P. The brake fluid that has flowed out flows into the positive pressure chamber R1 of the stroke simulator 22 through the second fluid passage 12. Here, positive pressure P1 (as master cylinder hydraulic pressure Pm) acts on the pressure receiving surface of piston 220, thereby causing piston 220 to move to one side in the axial direction (the volume of positive pressure chamber R1 is expanded and the volume of back pressure chamber R2 is increased). F1 is the force that pushes in the direction to reduce. The back pressure P2 acts on the pressure receiving surface of the piston 220, and the force pushing the piston 220 to the other side in the axial direction (the direction in which the volume of the positive pressure chamber R1 is reduced and the volume of the back pressure chamber R2 is increased) is F2. . A force by which the spring 221 biases the piston 220 toward the other side in the axial direction is defined as F3. If F1 is larger than the sum of F2 and F3 (F2 + F3), the piston 220 strokes toward the one side in the axial direction while compressing the spring 221. As a result, the volume of the positive pressure chamber R1 is increased, and at the same time as the brake fluid flows into the positive pressure chamber R1, the amount of brake fluid equivalent to the amount that flows into the positive pressure chamber R1 (according to the pedal stroke Sp) is reduced. It flows out from the pressure chamber R2 to the third liquid path 13 (liquid path 13A). In a state where the SS / V OUT 24 is controlled in the valve opening direction and the back pressure chamber R2 and the reservoir tank 4 communicate with each other, the brake fluid is discharged from the back pressure chamber R2 to the reservoir tank 4 through the fourth liquid passage 14. Note that the fourth fluid passage 14 need only be connected to a low-pressure portion through which brake fluid can flow, and need not necessarily be connected to the reservoir tank 4. When F1 becomes smaller than the sum of F2 and F3, the piston 220 returns toward the initial position.

Note that when the change in the pedal stroke speed ΔSp / Δt is small (for example, not in a sudden braking state), and therefore the change in the volume expansion speed of the positive pressure chamber R1 (the stroke speed of the piston 220) is small, F1 is F2 and F3 It can be considered that it is roughly balanced with the sum of. At this time, the force F2 due to the back pressure P2 corresponds to the magnitude obtained by subtracting F3 from F1. Here, the urging force F3 of the spring 221 acting on the piston 220 is a value obtained by multiplying the stroke amount of the piston 220 (compression amount of the spring 221) by the elastic coefficient (spring constant) k of the spring 221. Further, the stroke amount of the piston 220 can be equated with the pedal stroke Sp. Therefore, F3 can be calculated from the pedal stroke Sp. F1 can be calculated from the master cylinder hydraulic pressure Pm. Therefore, the back pressure P2 can be estimated from the detection value Sp of the pedal stroke sensor 90 and the detection value Pm of the hydraulic pressure sensor 91.
The master cylinder hydraulic pressure Pm acts on the pressure receiving surface of the piston 52P of the master cylinder 5 to generate a reaction force of the brake pedal 2 (hereinafter referred to as a pedal reaction force). That is, the force F1 due to Pm corresponds to a pedal reaction force. The pedal reaction force corresponds to the pedal effort Fp. When F1 can be regarded as roughly balanced with the sum of F2 and F3, the pedal reaction force Fp (corresponding to F1) is equal to the magnitude of the back pressure P2 (corresponding to F2) and the spring 221 (corresponding to F3). It is determined by the compression amount (stroke amount of piston 220). For example, an increase in the pedal stroke Sp (an increase in the stroke amount of the piston 220) causes an increase in F1 through an increase in F3, which is reflected in the driver's pedal feel (pedal feeling) as an increase in the pedal reaction force Fp. Is done. In this way, a pedal reaction force corresponding to the operation of the brake pedal 2 is created. As described above, the stroke simulator 22 reproduces an appropriate pedal depression feeling by simulating the fluid rigidity of the wheel cylinder 8 by sucking the brake fluid from the master cylinder 5 and generating a pedal reaction force.
The first fluid passage 11, the cut valve 21, the pump 7, the stroke simulator 22, the third fluid passage 13, and the ECU 100 constitute the brake device of the first embodiment.

  The ECU 100 includes a brake operation state detection unit 101, a target wheel cylinder hydraulic pressure calculation unit 102, a pedal effort brake creation unit 103, and a wheel cylinder hydraulic pressure control unit 104. The brake operation state detection unit 101 receives an input of a detection value of the pedal stroke sensor 90, and detects a pedal stroke Sp as a brake operation amount by the driver. Specifically, Sp is calculated by obtaining the output value of the pedal stroke sensor 90 (the axial displacement of the primary piston 52P). Further, based on Sp, it is detected whether or not the driver is operating the brake (whether or not the brake pedal 2 is operated), and the brake operating speed of the driver is detected or estimated. Specifically, the brake operation speed is detected or estimated by calculating the changing speed of Sp (pedal stroke speed ΔSp / Δt). A pedal force sensor for detecting the pedal force Fp may be provided, and the brake operation amount may be detected or estimated based on the detected value. Further, the brake operation amount may be detected or estimated based on the detection value of the hydraulic pressure sensor 91. That is, the brake operation amount used for control is not limited to Sp, and other appropriate variables may be used.

The target wheel cylinder hydraulic pressure calculation unit 102 calculates a target foil cylinder hydraulic pressure Pw *. For example, during boost control, based on the detected Sp (brake operation amount), an ideal value between Sp and the driver's required brake fluid pressure (vehicle deceleration requested by the driver) according to a predetermined boost ratio. Pw * that realizes the relational characteristic is calculated. In the first embodiment, for example, in a brake device including a normal-size negative pressure booster, a predetermined relationship characteristic between Sp and Pw (braking force) realized when the negative pressure booster is operated is as follows. The ideal relational characteristic for calculating Pw * is used. Further, during anti-lock control, Pw * of each wheel FL to RR is calculated so that the slip amount of each wheel FL to RR (the amount of deviation of the speed of the wheel with respect to the pseudo vehicle speed) becomes appropriate. At the time of ESC, Pw * of each wheel FL to RR is calculated so as to realize a desired vehicle motion state based on, for example, the detected vehicle motion state amount (lateral acceleration or the like). During regenerative cooperative brake control, Pw * is calculated in relation to the regenerative braking force. For example, Pw * is calculated such that the sum of the regenerative braking force input from the control unit of the regenerative braking device and the hydraulic braking force corresponding to the target wheel cylinder hydraulic pressure satisfies the vehicle deceleration required by the driver.
The pedal force brake generating unit 103 controls the cut valve 21 in the valve opening direction so that the state of the hydraulic unit 6 can be generated by the master cylinder hydraulic pressure Pm so that the wheel cylinder hydraulic pressure Pw can be generated. Is realized. At this time, by controlling SS / V OUT 24 in the valve closing direction, the stroke simulator 22 is deactivated in response to the driver's brake operation. SS / V IN 23 may also be controlled in the valve closing direction.

  The wheel cylinder hydraulic pressure control unit 104 controls the cut valve 21 in the valve closing direction so that the state of the hydraulic unit 6 can be changed to a state in which the wheel cylinder hydraulic pressure Pw can be created (pressurization control) by the pump 7. To do. In this state, hydraulic pressure control (for example, boost control) for controlling each actuator of the hydraulic pressure unit 6 to realize Pw * is executed. Specifically, the cut valve 21 is controlled in the valve closing direction, the communication valve 26 is controlled in the valve opening direction, the pressure regulating valve 27 is controlled in the valve closing direction, and the pump 7 is operated. By controlling in this way, it is possible to send desired brake fluid from the reservoir tank 4 to the wheel cylinder 8 via the suction fluid passage 15, the pump 7, the discharge fluid passage 16, and the first fluid passage 11. . At this time, a desired braking force can be obtained by feedback control of the rotation speed of the pump 7 and the valve opening state (opening degree, etc.) of the pressure regulating valve 27 so that the detection value of the hydraulic pressure sensor 92 approaches Pw *. it can. That is, Pw can be adjusted by controlling the valve opening state of the pressure regulating valve 27 and appropriately leaking the brake fluid from the discharge fluid path 16 to the first fluid path 11 through the pressure regulating valve 27 to the suction fluid path 15. . In the first embodiment, basically, Pw is controlled by changing the valve opening state of the pressure regulating valve 27, not the rotational speed of the pump 7 (motor 7a). For example, in addition to setting the command value Nm * for the rotation speed of the motor 7a to a predetermined large constant value during Pw pressurization, the minimum required pump discharge pressure is generated during Pw holding or pressure reduction (pump discharge Hold a predetermined small constant value to supply). In the first embodiment, since the pressure regulating valve 27 is a proportional control valve, fine control is possible and smooth control of Pw can be realized. By controlling the cut valve 21 in the valve closing direction and shutting off the master cylinder 5 side and the wheel cylinder 8 side, Pw can be controlled independently of the driver's brake operation.

The wheel cylinder hydraulic pressure control unit 104 basically performs boost control during normal braking in which a braking force corresponding to the driver's braking operation is generated in the front and rear wheels FL to RR. In normal boost control, SOL / V IN25 of each wheel FL to RR is controlled in the valve opening direction, and SOL / V OUT28 is controlled in the valve closing direction. With the cut valves 21P and 21S controlled in the valve closing direction, control the pressure regulating valve 27 in the valve closing direction (feedback control of the degree of opening, etc.), control the communication valve 26 in the valve opening direction, and the rotational speed of the motor 7a The command value Nm * is set to a predetermined constant value, and the pump 7 is operated. Operate SS / V OUT24 in the valve opening direction (control in the valve opening direction), and operate SS / V IN23 in the valve closing direction (control in the valve closing direction).
The wheel cylinder hydraulic pressure control unit 104 includes an auxiliary pressurization control unit 105. In the auxiliary pressurization control, the brake fluid flowing out from the back pressure chamber R2 of the stroke simulator 22 in accordance with the brake operation of the driver is supplied to the wheel cylinder 8 through the third fluid passage 13, whereby the wheel cylinder fluid by the pump 7 is supplied. This is a control for assisting the generation of the pressure Pw and improving the pressure response of the wheel cylinder 8. The auxiliary pressurization control is positioned as a backup (backup) control of the wheel cylinder pressurization control by the pump 7. Auxiliary pressurization control unit 105 performs Pw of each wheel FL to RR according to the depression operation of brake pedal 2 (increase in pedal stroke Sp) by the driver at the time of boost control (normal brake) by wheel cylinder hydraulic pressure control unit 104 Is increased (according to wheel cylinder pressurization control by the pump 7), auxiliary pressurization control is executed in accordance with the brake operation state of the driver. Specifically, SS / V IN23 is deactivated (controlled in the valve opening direction), and SS / V OUT24 is deactivated (controlled in the valve closing direction). The other actuator control details such as operating the pump 7 are the same as in normal boost control.

The auxiliary pressurization control unit 105 determines whether or not the driver's brake operation state is a predetermined sudden brake operation, and determines that the sudden brake operation is being performed (the brake pedal 2 is depressed at a high speed). Allows pressurization control to be executed. If it is determined that the sudden braking operation has not been performed (the brake pedal 2 is not depressed at a high speed), the auxiliary pressurization control is not executed. Specifically, when the brake operation speed (pedal stroke speed ΔSp / Δt) detected or estimated by the brake operation state detection unit 101 is equal to or higher than a predetermined value α (a threshold value for determining start and end of auxiliary pressurization control) It is determined that the predetermined sudden braking operation is being performed, and if ΔSp / Δt is less than α, it is determined that the predetermined sudden braking operation has not been performed. If the auxiliary pressurization control unit 105 determines that the sudden braking operation is being performed, the rotational speed Nm of the motor 7a detected or estimated based on the detection signal of the resolver is a predetermined value Nm0 (determination of the end of the auxiliary pressurization control) When the detected pedal stroke Sp is equal to or smaller than a predetermined value Sp0 (judgment threshold for termination of auxiliary pressure control), the auxiliary pressure control is executed as described above. On the other hand, even if it is determined that the sudden braking operation is being performed, if Nm is greater than Nm0 or Sp is greater than Sp0, it is determined that the auxiliary pressurization control termination condition is satisfied, and the auxiliary Does not execute pressurization control. In this case, the wheel cylinder hydraulic pressure control unit 104 controls SS / V IN23 in the valve closing direction and SS / V OUT24 in the valve opening direction, so that normal boost control (foil cylinder pressurization by the pump 7) is performed. Control). Thereby, auxiliary pressurization control is complete | finished.
The wheel cylinder hydraulic pressure control unit 104 has a sudden depression pressurization control unit 106. Pressurization control during sudden depression is the pedal stroke speed ΔSp when the pedal stroke speed ΔSp / Δt is greater than or equal to the predetermined value β higher than the predetermined value α during auxiliary pressurization control (SS / V IN23 open state). The cut valve 21 remains open until / Δt becomes less than β. β is a pedal stroke speed at which the response of auxiliary pressurization exceeding the maximum flow rate of SS / V IN23 and check valve 230 is required. In other words, the pressurization control at the time of sudden depression is performed by delaying the timing of switching the cut valve 21 from opening to closing when the pressurization response of the wheel cylinder 8 is insufficient only by the auxiliary pressurization control. This is a control for improving the pressure response of the wheel cylinder 8 by supplying the master cylinder hydraulic pressure Pm generated by the operation from the first liquid passage 11 to the wheel cylinder 8.

FIG. 2 is a flowchart illustrating the flow of the sudden depression pressurization control process by the sudden depression pressurization control unit 106 according to the first embodiment. This process is repeatedly executed at a predetermined calculation cycle.
In step S1, the pedal stroke Sp is acquired from the pedal stroke sensor 90.
In step S2, it is determined whether or not the pedal stroke Sp is greater than or equal to a predetermined value a (brake ON determination). If YES, the process proceeds to step S3. If NO, the process proceeds to step S4. a is a pedal stroke by which it can be determined that the brake pedal 2 has been depressed.
In step S3, an elapsed time T1 after brake ON is calculated.
In step S4, the cut valve 21 is controlled in the valve opening direction.
In step S5, it is determined whether the elapsed time T1 after brake ON is equal to or less than a predetermined value b (brake ON initial determination) and whether the cut valve 21 has been opened in the previous calculation cycle. If YES, the process proceeds to step S6. If NO, the process proceeds to step S7.
In step S6, it is determined whether or not the pedal stroke speed ΔSp / Δt calculated by the brake operation state detection unit 101 is equal to or greater than a predetermined value β. If YES, the process proceeds to step S8. If NO, the process proceeds to step S7.
In step S7, the cut valve 21 is controlled in the valve closing direction.
In step S8, the cut valve 21 is controlled in the valve opening direction.

Next, the effect of Embodiment 1 is demonstrated.
FIG. 3 is a time chart showing the sudden pressurization pressurization control operation of the first embodiment. In addition, as a comparative example, the case where the sudden pressurization pressurization control is not performed (only the auxiliary pressurization control is performed) is indicated by a broken line.
At time t0, the driver starts depressing the brake pedal 2. Since the pedal stroke Sp does not reach the predetermined value a, in the sudden depression pressurization control process shown in FIG. 2, the flow is S1 → S2 → S4, and the cut valve 21 is controlled in the valve opening direction.
At time t1, the brake ON determination (Sp ≧ a) and the brake ON initial determination (T1 ≦ b, the previous cut valve 21 is opened) were made, and the pedal stroke speed ΔSp / Δt exceeded the predetermined value β, so S1 → S2 → S3 → S5 → S6 → S8, and the open state of the cut valve 21 is maintained.
At time t2, since the pedal stroke speed ΔSp / Δt has fallen below the predetermined value β, the flow goes from S1, S2, S3, S5, S6, and S7, and the cut valve 21 is controlled in the valve closing direction.

  In FIG. 3, in the comparative example, the cut valve 21 is controlled in the valve closing direction at time t1 when the pedal stroke speed ΔSp / Δt exceeds the predetermined value α. At this time, if excessive braking operation exceeding the maximum flow rate of SS / V IN23 and check valve 230 is performed, there is insufficient pressure assistance of wheel cylinder 8 by auxiliary pressure control, and the vehicle requested by the driver There was a possibility that deceleration could not be obtained. On the other hand, in the sudden depression pressurization control of the first embodiment, the open state of the cut valve 21 is maintained while the pedal stroke speed ΔSp / Δt is equal to or greater than the predetermined value β (delay time Td) at the initial stage of brake ON. maintain. That is, when the driver's brake operation speed (≈ pedal stroke speed ΔSp / Δt) is high, the timing at which the cut valve 21 is closed is delayed by the delay time Td from the brake ON (time t1) as compared with the low speed. As a result, the brake fluid supplied from the master cylinder 5 can be sent from the first fluid passage 11 to the wheel cylinder 8, and the wheel cylinder 8 can be pressurized using the master cylinder hydraulic pressure Pm generated by the brake operation. Therefore, it is possible to suppress a decrease in the pressurization response of the wheel cylinder 8 in response to the driver's sudden braking operation exceeding the pressurization assisting ability due to the opening of the SS / V IN 23 and the check valve 230. As a result, the vehicle deceleration required by the driver is obtained.

[Embodiment 2]
Since the basic configuration of the second embodiment is the same as that of the first embodiment, only portions different from the first embodiment will be described.
FIG. 4 is a flowchart showing the flow of the sudden depression pressurization control process by the sudden depression pressurization control unit 106 according to the second embodiment.
In step S9, it is determined whether the elapsed time T1 after brake ON is equal to or shorter than the delay time Td. If YES, the process proceeds to step S8. If NO, the process proceeds to step S7. The delay time Td is a value obtained by referring to the map shown in FIG. 5 based on the pedal stroke speed ΔSp / Δt immediately after the brake is turned on, calculated by the brake operation state detection unit 101. FIG. 5 is a setting map of the delay time Td according to the pedal stroke speed ΔSp / Δt immediately after the brake is turned on. In FIG. 5, T is 0 in a region where ΔSp / Δt is equal to or smaller than a predetermined value β, and T becomes longer as ΔSp / Δt is higher in a region where ΔSp / Δt exceeds β.
In the second embodiment, the timing at which the cut valve 21 is closed is delayed as the pedal stroke speed ΔSp / Δt increases. Since the pedal stroke speed ΔSp / Δt substantially matches the brake operation speed, the higher the brake operation speed, the more brake fluid can be supplied to the wheel cylinder 8. As a result, the pressure response of the wheel cylinder 8 according to the brake operation speed can be realized.

[Embodiment 3]
Since the basic configuration of the third embodiment is the same as that of the first embodiment, only the differences from the first embodiment will be described.
The brake operation state detection unit 101 detects or estimates the brake operation speed by calculating the change speed of the master cylinder hydraulic pressure Pm (master cylinder hydraulic pressure change speed ΔPm / Δt). Since the master cylinder hydraulic pressure change speed ΔPm / Δt and the brake operation speed are in a substantially proportional relationship, the brake operation speed can be accurately estimated by calculating ΔPm / Δt.
FIG. 6 is a flowchart illustrating the flow of the sudden depression pressurization control process by the sudden depression pressurization control unit 106 according to the third embodiment.
In step S11, the master cylinder hydraulic pressure Pm is acquired from the hydraulic pressure sensor 91.
In step S12, it is determined whether or not the master cylinder hydraulic pressure Pm is equal to or greater than a predetermined value c (brake ON determination). If YES, the process proceeds to step S3. If NO, the process proceeds to step S4. c is a master cylinder hydraulic pressure at which it can be determined that the brake pedal 2 has been depressed.
In step S13, it is determined whether or not the master cylinder hydraulic pressure change rate ΔPm / Δt calculated by the brake operation state detection unit 101 is equal to or greater than a predetermined value γ. If YES, the process proceeds to step S8. If NO, the process proceeds to step S7. γ is a master cylinder hydraulic pressure that requires a response of auxiliary pressurization exceeding the maximum flow rate of SS / V IN23 and check valve 230.

Next, the function and effect of the third embodiment will be described.
FIG. 7 is a time chart illustrating the pressurization control action during sudden depression according to the third embodiment.
At time t0, the driver starts depressing the brake pedal 2. Since the master cylinder hydraulic pressure Pm does not reach the predetermined value c, in the sudden depression pressurization control process shown in FIG. 6, the flow is S11 → S12 → S4, and the cut valve 21 is controlled in the valve opening direction.
At time t1, the brake ON determination (Pm ≧ c) and the brake ON initial determination (T1 ≦ b, the previous cut valve 21 is opened) were made, and the master cylinder hydraulic pressure change rate ΔPm / Δt exceeded the predetermined value γ. The flow is S11 → S12 → S3 → S5 → S13 → S8, and the open state of the cut valve 21 is maintained.
At time t2, since the elapsed time T1 after the brake is ON exceeds the predetermined value b, the flow becomes S11 → S12 → S3 → S5 → S7, and the cut valve 21 is controlled in the valve closing direction.
In the sudden depression pressurization control of the third embodiment, the cut valve 21 is maintained in the open state while the master cylinder hydraulic pressure change rate ΔPm / Δt is equal to or greater than the predetermined value γ (delay time Td) at the initial stage of brake ON. To do. Therefore, similarly to the first embodiment, it is possible to suppress a decrease in pressurization responsiveness of the wheel cylinder 8 with respect to a driver's sudden braking operation exceeding the assisting pressurization capability by opening the SS / V IN 23 and the check valve 230.

[Embodiment 4]
Since the basic configuration of the fourth embodiment is the same as that of the third embodiment, only portions different from the third embodiment will be described.
FIG. 8 is a flowchart illustrating the flow of the sudden depression pressurization control process performed by the sudden depression pressurization control unit 106 according to the fourth embodiment.
In step S14, it is determined whether the elapsed time T1 after brake ON is equal to or shorter than the delay time Td. If YES, the process proceeds to step S8. If NO, the process proceeds to step S7. The delay time Td is a value obtained by referring to the map shown in FIG. 9 based on the master cylinder hydraulic pressure change rate ΔPm / Δt immediately after the brake is turned on calculated by the brake operation state detection unit 101. FIG. 9 is a setting map of the delay time Td according to the master cylinder hydraulic pressure change rate ΔPm / Δt immediately after the brake is turned on. In FIG. 9, T is 0 in a region where ΔPm / Δt is equal to or smaller than a predetermined value γ, and T becomes longer as ΔPm / Δt is higher in a region where ΔPm / Δt exceeds γ.
In the fourth embodiment, the timing at which the cut valve 21 is closed is delayed as the master cylinder hydraulic pressure change rate ΔPm / Δt increases. Since the master cylinder hydraulic pressure change rate ΔPm / Δt is proportional to the brake operation speed, the higher the brake operation speed, the more brake fluid can be supplied to the wheel cylinder 8. As a result, the pressure response of the wheel cylinder 8 according to the brake operation speed can be realized.

[Embodiment 5]
Since the basic configuration of the fifth embodiment is the same as that of the first embodiment, only the differences from the first embodiment will be described.
FIG. 10 is a flowchart illustrating the flow of the sudden depression pressurization control process performed by the sudden depression pressurization control unit 106 according to the fifth embodiment.
In step S21, the master cylinder hydraulic pressure Pm is acquired from the hydraulic pressure sensor 91, the pedal stroke Sp is acquired from the pedal stroke sensor 90, and the pump discharge pressure Ppump is acquired from the hydraulic pressure sensor 93.
In step S22, it is determined whether or not the master cylinder hydraulic pressure Pm is equal to or greater than a predetermined value c or the pedal stroke Sp is equal to or greater than a predetermined value a (brake ON determination). If YES, the process proceeds to step S3. If NO, the process proceeds to step S4.
In step S23, the pressure difference ΔP is calculated by subtracting the pump discharge pressure Ppump from the master cylinder hydraulic pressure Pm.
In step S24, it is determined whether or not the differential pressure ΔP is equal to or greater than a predetermined value σ. If YES, the process proceeds to step S8. If NO, the process proceeds to step S7. σ is a differential pressure (pressure difference) that requires responsiveness of auxiliary pressurization exceeding the maximum flow rate of SS / V IN23 and check valve 230.

Next, the effect of Embodiment 5 is demonstrated.
FIG. 11 is a time chart illustrating the pressurization control action during sudden depression according to the fifth embodiment.
At time t0, the driver starts depressing the brake pedal 2. Since the master cylinder hydraulic pressure Pm is less than the predetermined value c and the pedal stroke Sp is less than the predetermined value a, the flow of S21 → S22 → S4 in the sudden depression pressurization control process shown in FIG. 21 is controlled in the valve opening direction.
At time t1, the brake ON determination (Sp ≧ a) and the brake ON initial determination (T1 ≦ b, the previous cut valve 21 is opened) are made, and the differential pressure ΔP between the master cylinder hydraulic pressure Pm and the pump discharge pressure Ppump is predetermined. Since the value σ has been exceeded, the flow is S21 → S22 → S3 → S5 → S23 → S24 → S8, and the open state of the cut valve 21 is maintained.
At time t2, since the differential pressure ΔP has fallen below the predetermined value σ, the flow proceeds from S21 → S22 → S3 → S5 → S23 → S24 → S7, and the cut valve 21 is controlled in the valve closing direction.
In the sudden pressurization pressurization control according to the fifth embodiment, the cut valve 21 is used while the differential pressure ΔP between the master cylinder hydraulic pressure Pm and the pump discharge pressure Ppump is equal to or greater than the predetermined value σ at the initial stage of brake ON. Keep the valve open. Since the pump discharge pressure Ppump substantially coincides with the wheel cylinder hydraulic pressure Pw, the necessary brake fluid amount can be accurately determined by looking at the differential pressure ΔP between the master cylinder hydraulic pressure Pm and the pump discharge pressure Ppump. Therefore, since the optimum delay time Td without excess or deficiency can be set from the differential pressure ΔP, it is possible to improve the control accuracy of the sudden depression pressurization control.

[Other Embodiments]
Although the embodiment for carrying out the present invention has been described above, the specific configuration of the present invention is not limited to the configuration of the embodiment, and there are design changes and the like within the scope not departing from the gist of the invention. Are also included in the present invention.
The pressurization control at the time of sudden depression shown in the embodiment is effective even when the auxiliary pressurization control (the pressurization assist of the wheel cylinder 8 via the SS / V IN23 and the check valve 230) is not performed in the sudden brake operation state. Yes, the lack of pressurization response of the wheel cylinder 8 by the pump 7 can be compensated.
A configuration in which SS / V IN23 is deleted and pressurization assistance is performed only by opening the check valve 230 may be adopted.

1 Brake system
2 Brake pedal (brake operating member)
5 Master cylinder
6 Hydraulic unit
7 Pump (hydraulic pressure source)
8 Wheel cylinder
11 First fluid channel (connection fluid channel)
13 Third fluid path (simulator fluid path)
21 Cut valve (shutoff valve)
22 Stroke simulator
23 Stroke simulator in valve
90 Pedal stroke sensor
91 Fluid pressure sensor (Master cylinder fluid pressure sensor)
93 Fluid pressure sensor
100 electronic control unit
230 Check valve (Stroke simulator in valve)
FL to RR wheels

Claims (9)

A connecting fluid path for connecting a master cylinder that generates a brake fluid pressure in response to an operation on a brake operation member, and a wheel cylinder that can apply a braking force to a wheel in accordance with the brake fluid pressure;
A shut-off valve provided in the connection liquid path;
A hydraulic pressure source capable of supplying brake fluid to the connecting fluid path on the wheel cylinder side with respect to the shutoff valve;
A stroke simulator connected to the master cylinder and capable of generating a pseudo operation reaction force of the brake operation member;
A simulator liquid path connecting the back pressure chamber of the stroke simulator and the connection liquid path on the wheel cylinder side to the shut-off valve;
When the operation speed of the brake operation member is high, a control unit for delaying the timing for opening the shut-off valve from the open valve than when the operation speed is low,
A brake device comprising: The brake device according to claim 1, wherein
A stroke simulator-in valve provided in the simulator liquid passage;
The control unit is a brake device for delaying the timing for opening the shut-off valve from opening to closing when the operation speed of the brake operating member is high when the stroke simulator in valve is open than when the operating speed is low . The brake device according to claim 1, wherein
A stroke sensor for detecting a stroke of the brake operation member;
The said control unit is a brake device which changes the timing which opens the said shut-off valve from a valve opening according to the increasing speed of the stroke detected by the said stroke sensor. The brake device according to claim 1, wherein
A master cylinder hydraulic pressure sensor for detecting a brake hydraulic pressure generated in the master cylinder;
The said control unit is a brake device which changes the timing which makes the said shut-off valve open from a valve opening according to the increase speed of the master cylinder hydraulic pressure detected by the said master cylinder hydraulic pressure sensor. The brake device according to claim 1, wherein
A master cylinder hydraulic pressure sensor for detecting a brake hydraulic pressure generated in the master cylinder;
A hydraulic pressure sensor for detecting a brake hydraulic pressure discharged from the hydraulic pressure source;
With
The control unit sets a timing for opening the shutoff valve from opening to closing according to a difference between a master cylinder hydraulic pressure detected by the master cylinder hydraulic pressure sensor and a discharge pressure detected by the hydraulic pressure sensor. Brake device to change. A master cylinder unit having a master cylinder that generates brake fluid pressure in response to an operation on the brake operation member;
A stroke simulator unit having a stroke simulator connected to the master cylinder and capable of generating a pseudo operation reaction force of the brake operation member;
A hydraulic unit connected to the master cylinder unit and the stroke simulator unit, the connecting fluid path connecting the master cylinder and a wheel cylinder capable of applying a braking force to a wheel according to the brake hydraulic pressure; A shutoff valve provided in the connection fluid path, a hydraulic pressure source capable of supplying brake fluid to the connection fluid path on the wheel cylinder side with respect to the shutoff valve, a back pressure chamber of the stroke simulator, A hydraulic fluid unit having a simulator fluid passage that connects the fluid passage on the wheel cylinder side to the shutoff valve;
A control unit for controlling the hydraulic pressure unit, the control unit for delaying the timing for opening the shut-off valve from opening when the operating speed of the brake operating member is high than when the operating speed is low;
Brake system with The brake system according to claim 6, wherein
A stroke simulator-in valve provided in the simulator liquid passage;
In the state where the stroke simulator in valve is opened, the control unit delays the timing for switching the shut-off valve from opening to closing when the operating speed of the brake operating member is high than when the operating speed is low. . A connecting fluid path for connecting a master cylinder that generates a brake fluid pressure in response to an operation on a brake operation member, and a wheel cylinder that can apply a braking force to a wheel in accordance with the brake fluid pressure;
A shut-off valve provided in the connection liquid path;
A hydraulic pressure source capable of supplying brake fluid to the connecting fluid path on the wheel cylinder side with respect to the shutoff valve;
A stroke simulator connected to the master cylinder and capable of generating a pseudo operation reaction force of the brake operation member;
A simulator liquid path connecting the back pressure chamber of the stroke simulator and the connection liquid path on the wheel cylinder side to the shut-off valve;
A control method of a brake device comprising:
A control method for a brake device that delays a timing for opening the shutoff valve from opening to closing when the operation speed of the brake operation member is high than when the operation speed is low. In the control method of the brake equipment according to claim 8,
The brake device includes a stroke simulator-in valve in the simulator liquid path,
A control method of a brake device that delays the timing of opening the shut-off valve from opening to closing when the operation speed of the brake operating member is high when the stroke simulator-in valve is open than when the operating speed is low.

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