JP2018001805A - Brake control device and brake control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake control device that can inhibit brake fluid flowing out from a stroke simulator in operating a brake pedal from leaking on an outside, and to provide a brake control method.SOLUTION: When liquid leakage is detected in a wheel cylinder W/C of S circuit connected to a back pressure chamber 602 of a stroke simulator 6 and operation to a brake pedal 100 is detected while P circuit is under P circuit booster control by a pump 3, a brake control device closes SOL/V IN22b, 22c of S circuit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a brake control device and a brake control method.

  2. Description of the Related Art Conventionally, there is known a brake control device including a stroke simulator that supplies a brake fluid of the same amount as a brake fluid supplied from a master cylinder to a wheel cylinder when a brake pedal is operated (for example, Patent Document 1). .

JP 2005-170287 A

  An object of the present invention is to provide a brake control device and a brake control method capable of suppressing leakage of brake fluid that has flowed out of a stroke simulator to the outside during operation of the brake pedal.

  The brake control device according to an embodiment of the present invention detects a liquid leak in the braking force generation unit of one system connected to the second chamber of the stroke simulator, and performs one-system boost control by a hydraulic pressure source in the other system. When the operation of the brake pedal is detected in the state of being operated, the pressure increase control valve of one system is closed.

  Therefore, it is possible to suppress the leakage of the brake fluid that has flowed out of the stroke simulator when the brake pedal is operated.

It is a figure which shows schematic structure of the brake control apparatus of Embodiment 1 with a hydraulic circuit. 1 is a perspective view of a brake control device according to Embodiment 1. FIG. 3 is a flowchart illustrating a flow of single system boost control processing according to the first embodiment. 3 is a time chart showing a liquid leakage suppressing action of the first embodiment.

Embodiment 1
FIG. 1 is a diagram illustrating a schematic configuration of a brake control device according to a first embodiment together with a hydraulic circuit, and FIG. 2 is a perspective view of the brake control device according to the first embodiment.
The brake control device of Embodiment 1 is mounted on an electric vehicle. The electric vehicle is a hybrid vehicle including an engine and a motor / generator as a prime mover for driving wheels, and an electric vehicle including only a motor / generator as a prime mover. In an electric vehicle, regenerative braking that brakes the vehicle by regenerating kinetic energy of the vehicle into electric energy can be executed by a regenerative braking device including a motor / generator. The brake control device applies friction braking force by hydraulic pressure to each wheel FL to RR of the vehicle. Each wheel FL to RR is provided with a brake operation unit. The brake operation unit is a braking force generator including the wheel cylinder W / C. The brake operation unit is, for example, a disc type and has a caliper (hydraulic brake caliper). The caliper includes a brake disc and a brake pad. The brake disc is a brake rotor that rotates integrally with the tire. The brake pad is disposed with a predetermined clearance with respect to the brake disc, and moves by the hydraulic pressure of the wheel cylinder W / C to contact the brake disc. A friction braking force is generated when the brake pad contacts the brake disc. The brake control device has two systems (primary system and secondary system, hereinafter also referred to as P system and S system). The brake piping format is, for example, the 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 control device supplies brake fluid to each brake operation unit via the brake pipe, and generates brake fluid pressure of the wheel cylinder W / C. Thereby, a hydraulic braking force is applied to each of the wheels FL to RR.

The brake control device has a first unit 1A and a second unit 1B. The first unit 1A and the second unit 1B are installed in a motor room isolated from the cab of the vehicle. Both units 1A and 1B are connected to each other by a plurality of pipes. Plural pipes are: master cylinder pipe (first liquid path) 10M (primary pipe (primary system liquid path) 10MP, secondary pipe (secondary system liquid path) 10MS), wheel cylinder pipe 10W, back pressure chamber pipe (first 3 liquid passages, second stroke simulator communication liquid passage) 10X and suction pipe 10R. Each of the pipes 10M, 10W, and 10X, excluding the suction pipe 10R, is a metal brake pipe (metal pipe), specifically, a steel pipe such as a double winding. Each of the pipes 10M, 10W, 10X has a straight portion and a bent portion, and is arranged between the ports by changing the direction at the bent portion. Both ends of each pipe 10M, 10W, 10X have male pipe joints that are flared. The suction pipe 10R is a brake hose (hose pipe) formed flexibly by a material such as rubber. The end of the suction pipe 10R is connected to the port 873 and the like via nipples 10R1 and 10R2. The nipples 10R1 and 10R2 are synthetic resin connection members having a tubular portion.
The brake pedal 100 is a brake operation member that receives an input of a driver's brake operation. The input rod 101 is connected to the brake pedal 100 so as to be rotatable in the vertical direction. The first unit 1 </ b> A is a master cylinder unit having a brake operation unit mechanically connected to the brake pedal 100 and a master cylinder 5. The first unit 1A includes a reservoir tank (reservoir) 4, a master cylinder housing 7, a master cylinder 5, a stroke sensor 94, and a stroke simulator 6. The reservoir tank 4 is a brake fluid source that stores brake fluid, and is released to atmospheric pressure. The reservoir tank 4 is provided with a supply port 40 and a supply port 41. A suction pipe 10R is connected to the supply port 41. The master cylinder housing 7 is a housing that houses (incorporates) the master cylinder 5 and the stroke simulator 6 therein. The master cylinder housing 7 includes therein a cylinder 70 for the master cylinder 5, a cylinder 71 for the stroke simulator 6, and a plurality of liquid passages. The cylinder 70 has a large diameter portion 70a and a small diameter portion 70b. The large diameter portion 70a is provided closer to the input rod 101 than the small diameter portion 70b, and the inner diameter thereof is longer than the inner diameter of the small diameter portion 70b. The axis of the large diameter portion 70a and the axis of the small diameter portion 70b are the same (axis O). The input rod 101 has a stopper plate 101a for preventing it from falling off the cylinder 70. The plurality of liquid paths are a replenishment liquid path 72, a supply liquid path (first liquid path, primary system liquid path) 73P, a supply liquid path (first liquid path, secondary system liquid path) 73S, and a positive pressure liquid path ( (Second liquid path, first stroke simulator liquid path) 74. The master cylinder housing 7 has a plurality of ports therein, and each port opens on the outer peripheral surface of the master cylinder housing 7. The plurality of ports include supply ports 75P and 75S, a supply port 76, and a back pressure port 77. The supply ports 75P and 75S are connected to the supply ports 40P and 40S of the reservoir tank 4, respectively. A master cylinder pipe 10M is connected to the supply port 76, and a back pressure chamber pipe 10X is connected to the back pressure port 77. One end of the replenishment liquid path 72 is connected to the replenishment port 75, and the other end is connected to the cylinder 70.

The master cylinder 5 is connected to the brake pedal 100 via the input rod 101, and generates a master cylinder hydraulic pressure in accordance with the operation of the brake pedal 100 by the driver. The master cylinder 5 has a piston 51 that moves in the axial direction in response to an operation of the brake pedal 100. The piston 51 is accommodated in the cylinder 70 and defines the hydraulic chamber 50. The master cylinder 5 is a tandem type, and has, as a piston 51, a primary piston 51P that is pressed by the input rod 101 and a free piston type secondary piston 51S. Both pistons 51P and 51S are arranged in series. A primary chamber (first chamber) 50P is defined by the pistons 51P and 51S, and a secondary chamber (second chamber) 50S is defined by the secondary piston 51S. One end of the supply liquid path 73 is connected to the hydraulic chamber 50, and the other end is connected to the supply port 76. The hydraulic chambers 50P and 50S are supplied with brake fluid from the reservoir tank 4 and generate master cylinder hydraulic pressure by the movement of the piston 51. A coil spring 52P as a return spring is interposed between the pistons 51P and 51S in the primary chamber 50P. A coil spring 52S as a return spring is interposed between the bottom of the cylinder 70 and the piston 51S in the secondary chamber 50S. Piston seals 541 and 542 are provided on the inner periphery of the small diameter portion 70b of the cylinder 70. The piston seals 541 and 542 are a plurality of seal members that are in sliding contact with the pistons 51P and 51S and seal between the outer peripheral surfaces of the pistons 51P and 51S and the inner peripheral surface of the small diameter portion 70b. Each piston seal 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 51, 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 40 toward the primary chamber 50P and the secondary chamber 50S, and suppresses the flow of brake fluid in the reverse direction. The second piston seal 542P suppresses the flow of brake fluid to the cylinder large diameter portion 70a, and the second piston seal 542S suppresses the flow of brake fluid to the primary chamber 50P.
The stroke sensor 94 outputs a sensor signal corresponding to the movement amount (stroke) of the primary piston 51P. The stroke sensor 94 has a detection unit 95 and a magnet 96. The detection unit 95 is attached to the left outer peripheral surface of the master cylinder housing 7. The magnet 96 is attached to the primary piston 51P. The detection unit 95 and the magnet 96 are arranged close to each other. The detection unit 95 is a Hall IC having a Hall element. When a constant current is passed through the Hall element, a voltage approximately proportional to the magnitude of the magnetic flux density is generated. The detection unit 95 outputs a sensor signal having a voltage corresponding to the magnitude of the generated voltage.

The stroke simulator 6 operates in accordance with the driver's braking operation, and applies a reaction force and a stroke to the brake pedal 100. The stroke simulator 6 includes a cylinder 60, a piston 61, a positive pressure chamber (one chamber) 601, a back pressure chamber (the other chamber) 602, and an elastic body (first spring 64, second spring 65, damper 66). The cylinder 60 is provided separately from the cylinder 70 in the master cylinder housing 7. The cylinder 60 has a large diameter part 60a and a small diameter part 60b. The positive pressure chamber 601 and the back pressure chamber 602 are defined by a piston 61 provided in the small diameter portion 60b of the cylinder 60. The elastic body is provided in the large-diameter portion 60a of the cylinder 60 and biases the piston 61 in the direction in which the volume of the positive pressure chamber 601 is reduced. A bottomed cylindrical retainer member 62 is interposed between the first spring 64 and the second spring 65. One end of the positive pressure liquid path 74 is connected to the secondary supply liquid path 73S, and the other end is connected to the positive pressure chamber 601. When brake fluid flows from the master cylinder 5 (secondary chamber 50S) into the positive pressure chamber 601 according to the driver's brake operation, a pedal stroke occurs and the driver's brake operation reaction force is generated by the urging force of the elastic body. Is generated. The first unit 1A does not include an engine negative pressure booster that boosts the brake operation force by using the intake negative pressure generated by the vehicle engine.
The second unit 1B is provided between the first unit 1A and the brake operation unit. The second unit 1B is connected to the primary chamber 50P via the primary pipe 10MP, connected to the secondary chamber 50S via the secondary pipe 10MS, connected to the wheel cylinder W / C via the wheel cylinder pipe 10W, and back pressure It connects to the back pressure chamber 602 via the chamber piping 10X. The second unit 1B is connected to the reservoir tank 4 via the suction pipe 10R. The second unit 1B includes a second unit housing 8, a motor 20, a pump (hydraulic pressure source) 3, a plurality of solenoid valves 21, etc., a plurality of hydraulic pressure sensors 91, etc., and an electronic control unit (control unit) 90 (hereinafter referred to as an ECU). Said). The second unit housing 8 is a housing that houses (incorporates) valve bodies such as the pump 3 and the electromagnetic valve 21 therein. The second unit housing 8 has therein the above-described two systems (P system and S system) (brake hydraulic circuit) through which brake fluid flows. Two circuits are composed of a plurality of liquid paths. The plurality of liquid paths are the supply liquid path 11, the suction liquid path 12, the discharge liquid path 13, the pressure adjustment liquid path (reflux liquid path) 14, the decompression liquid path 15, and the back pressure liquid path (third liquid path, second stroke). (Simulator communication liquid path) 16, first simulator liquid path (third liquid path, second stroke simulator communication liquid path) 17, and second simulator liquid path 18. Further, the second unit housing 8 has a reservoir (internal reservoir) 120 and a damper 130 which are liquid reservoirs therein. A plurality of ports are formed inside the second unit housing 8, and these ports open to the outer surface of the second unit housing 8. The plurality of ports include a master cylinder port 871 (primary port 871P, secondary port 871S), a suction port 873, a back pressure port 874, and a wheel cylinder port 872. A primary pipe 10MP is connected to the primary port 871P. A secondary pipe 10MS is connected to the secondary port 871S. A suction pipe 10R is connected to the suction port 873. A back pressure chamber pipe 10X is connected to the back pressure port 874. A wheel cylinder pipe 10W is connected to the wheel cylinder port 872.

  The motor 20 is a rotary electric motor and includes a rotation shaft for driving the pump 3. The motor 20 may be a brushless motor equipped with a rotational speed sensor such as a resolver that detects the rotational angle or rotational speed of the rotating shaft, or may be a motor with a brush. The pump 3 sucks the brake fluid in the reservoir tank 4 by the rotational drive of the motor 20, and discharges it toward the wheel cylinder W / C. In the first embodiment, a plunger pump having five plungers excellent in sound vibration performance and the like is employed as the pump 3. The pump 3 is commonly used in both the S system and the P system. The solenoid valve 21 or the like is a solenoid valve that operates in response to a control signal, and the valve body strokes in response to energization of the solenoid to switch opening / closing of the liquid path (connecting / disconnecting the liquid path). The solenoid valve 21 and the like generate a control hydraulic pressure by controlling the communication state of the circuit and adjusting the flow state of the brake fluid. A plurality of solenoid valves 21 and the like include a shut-off valve 21, a pressure increasing valve (a pressure increasing control valve, hereinafter referred to as SOL / V IN) 22, a communication valve 23, a pressure regulating valve 24, a pressure reducing valve (hereinafter referred to as SOL / V OUT). 25), a stroke simulator in valve (which is a stroke simulator valve, hereinafter referred to as SS / V IN) 27 and a stroke simulator out valve (hereinafter referred to as SS / V OUT) 28. The shut-off valve 21, SOL / V IN22, and pressure regulating valve 24 are normally open solenoid valves that open in a non-energized state. The communication valve 23, the pressure reducing valve 25, SS / V IN27 and SS / V OUT28 are normally closed solenoid valves that close in a non-energized state. The shut-off valve 21, the SOL / V IN 22, and the pressure regulating valve 24 are proportional control valves in which the opening degrees of the valves are adjusted according to the current supplied to the solenoid. The communication valve 23, the pressure reducing valve 25, the SS / V IN 27, and the SS / V OUT 28 are on / off valves that are controlled to be switched in a binary manner. In addition, it is also possible to use a proportional control valve for these valves. The hydraulic pressure sensor 91 and the like detect the discharge pressure of the pump 3 and the master cylinder hydraulic pressure. The plurality of hydraulic pressure sensors include a master cylinder hydraulic pressure sensor 91, a discharge pressure sensor 93, and a wheel cylinder hydraulic pressure sensor 92 (primary pressure sensor 92P and secondary pressure sensor 92S).

Hereinafter, the brake hydraulic circuit of the second unit 1B 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. One end side of the supply liquid path (first liquid path, primary system liquid path) 11P is connected to the primary port 871P. The other end side of the supply liquid path 11P is a front left wheel liquid path (first liquid path, primary system liquid path) 11a and a rear right wheel liquid path (first liquid path, primary system liquid path) 11d. Branch to. Each fluid passage 11a, 11d is connected to a corresponding wheel cylinder port 872. One end side of the supply liquid path (first liquid path, secondary system liquid path) 11S is connected to the secondary port 871S. The other end side of the supply liquid path 11S includes a front right wheel liquid path (first liquid path, secondary system liquid path) 11b and a rear left wheel liquid path (first liquid path, secondary system liquid path) 11c. Branch to. Each fluid passage 11b, 11c is connected to a corresponding wheel cylinder port 872. A shutoff valve 21 is provided on the one end side of the supply liquid passage 11. A SOL / V IN 22 is provided in each liquid path 11 on the other end side. A bypass liquid path 110 is provided in parallel with each liquid path 11 by bypassing the SOL / V IN 22, and a check valve 220 is provided in the bypass liquid path 110. The check valve 220 allows only the flow of brake fluid from the wheel cylinder port 872 side toward the master cylinder port 871 side.
The suction liquid path 12 connects the reservoir 120 and the suction port 823 of the pump 3. One end side of the discharge liquid passage 13 is connected to the discharge port 821 of the pump 3. The other end side of the discharge liquid path 13 branches into a P system liquid path (communication liquid path) 13P and an S system liquid path (communication liquid path) 13S. Each liquid path 13P, 13S is connected between the shutoff valve 21 and the SOL / V IN 22 in the supply liquid path 11. A damper 130 is provided on the one end side of the discharge liquid passage 13. A communication valve (first communication valve) 23P and a communication valve (second communication valve) 23S are provided in the liquid passages 13P and 13S on the other end side. Each of the liquid paths 13P and 13S functions as a communication path that connects the supply liquid path 11P of the P system and the supply liquid path 11S of the S system. The pump 3 is connected to each wheel cylinder port 872 via the communication path (discharge liquid paths 13P, 13S) and the supply liquid paths 11P, 11S. The pressure adjusting fluid path 14 connects the reservoir 120 and the damper 130 and the communication valve 23 in the discharge fluid path 13. A pressure regulating valve 24 is provided in the pressure regulating fluid path 14. The decompression liquid path 15 connects the reservoir 120 between the SOL / V IN 22 and the wheel cylinder port 872 in each of the liquid paths 11a to 11d of the supply liquid path 11. The decompression liquid path 15 is provided with SOL / V OUT25.

One end side of the back pressure liquid passage 16 is connected to the back pressure port 874. The other end side of the back pressure liquid passage 16 branches into a first simulator liquid passage 17 and a second simulator liquid passage 18. The first simulator liquid path 17 is connected between the shutoff valve 21S and the SOL / V INs 22b and 22c in the supply liquid path 11S. The first simulator liquid path 17 is provided with SS / V IN27. Bypassing the SS / V IN 27, a bypass liquid path 170 is provided in parallel with the first simulator liquid path 17, and a check valve (stroke simulator valve) 270 is provided in the bypass liquid path 170. The check valve 270 allows only the flow of brake fluid from the back pressure fluid passage 16 side toward the supply fluid passage 11S side. The second simulator liquid path 18 is connected to the reservoir 120. The second simulator liquid path 18 is provided with SS / V OUT28. Bypassing the SS / V OUT 28, a bypass liquid path 180 is provided in parallel with the second simulator liquid path 18, and a check valve 280 is provided in the bypass liquid path 180. The check valve 280 allows only the flow of brake fluid from the reservoir 120 side toward the back pressure fluid path 16 side.
Between the shutoff valve 21S and the secondary port 871S in the supply fluid path 11S, a fluid pressure sensor 91 that detects the fluid pressure at this location (the fluid pressure in the positive pressure chamber 601 of the stroke simulator 6 and the master cylinder fluid pressure). Is provided. Between the shutoff valve 21 and the SOL / V IN 22 in the supply fluid path 11, a fluid pressure sensor 92 that detects the fluid pressure at this location (corresponding to the wheel cylinder fluid pressure) is provided. Between the damper 130 and the communication valve 23 in the discharge fluid passage 13, a fluid pressure sensor 93 for detecting the fluid pressure (pump discharge pressure) at this location is provided.

Hereinafter, for convenience of explanation, a three-dimensional orthogonal coordinate system having an X axis, a Y axis, and a Z axis is set. In a state where the first unit 1A and the second unit 1B are mounted on the vehicle, the Z-axis direction is the vertical direction, and the positive Z-axis direction is the upper side in the vertical direction. The X-axis direction is the vehicle front-rear direction, and the X-axis positive direction is the vehicle front side. The Y-axis direction is the lateral direction of the vehicle.
In the first unit 1A, the input rod 101 extends from the end on the X axis negative direction side connected to the brake pedal 100 to the X axis positive direction side. A square plate-like flange portion 78 is provided at the end of the master cylinder housing 7 on the negative side of the X axis. Bolt holes are provided at four corners of the flange portion 78. A bolt B1 for fixing and attaching the first unit 1A to the dash panel on the vehicle body side passes through the bolt hole. A reservoir tank 4 is installed on the positive side of the master cylinder housing 7 in the Z-axis direction.
In the second unit 1B, the second unit housing 8 is a substantially rectangular parallelepiped block made of aluminum alloy. The second unit housing 8 is fixed to the vehicle body side (bottom surface of the motor chamber) via an insulator and a mount (not shown). The motor 20 is disposed on the left side surface 801 of the second unit housing 8, and the motor housing 200 is attached thereto. An ECU 90 is attached to the right side surface of the second unit housing 8. That is, the ECU 90 is provided integrally with the second unit housing 8. The ECU 90 includes a control board (not shown) and a control unit housing 901. The control board controls the energization state to the solenoids such as the motor 20 and the electromagnetic valve 21. Various sensors for detecting the motion state of the vehicle, for example, an acceleration sensor for detecting the acceleration of the vehicle and an angular velocity sensor for detecting the angular velocity (yaw rate) of the vehicle may be mounted on the control board. Moreover, you may mount the composite sensor (combine sensor) by which these sensors were unitized on the control board. The control board is accommodated in the case 901. The case 901 is a cover member that is fastened and fixed to the back surface of the second unit housing 8 with bolts.

Case 901 is a cover member made of synthetic resin. The case 901 has a substrate housing part 902 and a connector part 903. The board accommodating portion 902 accommodates a part of the solenoid such as the control board and the electromagnetic valve 21. The connector part 903 protrudes further toward the Y axis positive direction side than the board housing part 902. When viewed from the X-axis direction, the terminal of the connector portion 903 is exposed toward the Y-axis positive direction side and extends to the Y-axis negative direction side to connect to the control board. Each terminal (exposed toward the Y axis positive direction side) of the connector unit 903 can be connected to an external device or a stroke sensor 94 (hereinafter referred to as an external device or the like). Another connector connected to the external device or the like is inserted into the connector portion 903 from the Y axis positive direction side, thereby realizing electrical connection between the external device or the like and the control board (ECU 90). In addition, power is supplied from an external power source (battery) to the control board via the connector unit 903. The conductive member functions as a connecting portion that electrically connects the control board and the motor 20, and power is supplied from the control board to the motor 20 through the conductive member.
In the first embodiment, no solenoid valve or the like is provided in the first unit 1A, and SS / V IN27 and SS / V OUT28 for switching the operation of the stroke simulator 6 are provided in the second unit 1B. Thereby, the controller for driving the solenoid valve is not required for the first unit 1A. Further, no electromagnetic valve control wiring is required between the first unit 1A and the second unit 1B. Therefore, cost can be suppressed. Further, when connecting the stroke simulator 6 in the first unit 1A and the second unit 1B as piping, the positive pressure chamber 601 and the second unit 1B of the stroke simulator 6 are not connected, and the back pressure chamber 602 and the back pressure are not connected. It was only connected through the room piping 10X. Therefore, since the operation of the stroke simulator 6 can be switched without providing a plurality of pipes, the cost can be suppressed.

The ECU 90 receives detection values from the stroke sensor 94, the hydraulic pressure sensor 91, etc., and information related to the running state from the vehicle side. The ECU 90 controls the wheel cylinder hydraulic pressure of each wheel FL to RR by operating the solenoid valve 21 and the motor 20 using the input information in accordance with a built-in program. As a result, various brake controls (anti-lock brake control to suppress wheel slip due to braking, boost control to reduce driver's brake operation force, brake control for vehicle motion control, preceding vehicle, etc. Automatic brake control such as follow-up control, regenerative cooperative brake control, etc.) can be executed. Vehicle motion control includes vehicle behavior stabilization control such as skidding prevention. In regenerative cooperative brake control, the wheel cylinder hydraulic pressure is controlled so as to achieve the target deceleration (target braking force) in cooperation with the regenerative brake.
The ECU 90 is configured to execute the brake control described above as a brake operation amount detection unit 90a, a target wheel cylinder hydraulic pressure calculation unit 90b, a boost control unit 90c, a sudden brake operation state determination unit 90d, and a second pedal force brake creation. Part 90e. The brake operation amount detection unit 90a receives the sensor signal from the stroke sensor 94 and detects the stroke (movement amount) of the input rod 101. The target foil cylinder hydraulic pressure calculation unit 90b calculates a target foil cylinder hydraulic pressure. Specifically, the target wheel cylinder hydraulic pressure calculation unit 90b determines a predetermined boost ratio based on the detected pedal stroke, that is, the pedal stroke and the driver's required brake hydraulic pressure (the vehicle deceleration G requested by the driver). ) To calculate the target wheel cylinder hydraulic pressure that realizes the ideal relationship characteristics. Further, the target wheel cylinder hydraulic pressure calculation unit 90b calculates the target wheel cylinder hydraulic pressure in relation to the regenerative braking force during the regenerative cooperative brake control. For example, the target wheel cylinder hydraulic pressure in which 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. Is calculated. At the time of motion control, the target wheel cylinder hydraulic pressure 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).

The boost control unit 90c operates the pump 3, operates the shut-off valve 21 in the valve closing direction, and operates the communication valve 23 in the valve opening direction when the driver operates the brake. As a result, it is possible to create a wheel cylinder hydraulic pressure that is higher than the master cylinder hydraulic pressure using the discharge pressure of the pump 3 as a hydraulic pressure source, and to perform a boost control that generates a hydraulic braking force that is insufficient for the driver's brake operation force It becomes. Specifically, the boost control unit 90c adjusts the amount of brake fluid supplied from the pump 3 to the wheel cylinder W / C by controlling the pressure regulating valve 24 while operating the pump 3 at a predetermined rotational speed. Realize the target wheel cylinder hydraulic pressure. The brake control device of the first embodiment exhibits a boosting function that assists the brake operation force by operating the pump 3 of the second unit 1B instead of the engine negative pressure booster. Further, the boost control unit 90c operates the SS / V IN 27 in the valve closing direction and operates the SS / V OUT 28 in the valve opening direction. Thereby, the stroke simulator 6 is caused to function.
The sudden brake operation state determination unit 90d detects a brake operation state based on an input from the brake operation amount detection unit 90a and the like, and determines (determines) whether or not the brake operation state is a predetermined sudden brake operation state. For example, the sudden brake operation state determination unit 90d determines whether or not the amount of change in pedal stroke per time exceeds a predetermined threshold value. When it is determined that the brake is in the sudden brake operation state, the ECU 90 switches from the generation of the wheel cylinder hydraulic pressure by the boost control unit 90c to the generation of the wheel cylinder hydraulic pressure by the second pedal force brake generation unit 90e. The second pedal force brake generating section 90e operates the pump 3, operates the shut-off valve 21 in the valve closing direction, operates SS / V IN27 in the valve opening direction, and operates SS / V OUT28 in the valve closing direction. . Thus, the second pedal force that creates the wheel cylinder hydraulic pressure using the brake fluid flowing out from the back pressure chamber 602 of the stroke simulator 6 until the pump 3 can generate a sufficiently high wheel cylinder hydraulic pressure. Realize the brake. The shut-off valve 21 may be operated in the valve opening direction. SS / V IN27 may be operated in the valve closing direction. In this case, the brake fluid from the back pressure chamber 602 is opened (because the wheel cylinder W / C side is still at a lower pressure than the back pressure chamber 602 side). It is supplied to the wheel cylinder W / C through the check valve 270. In the first embodiment, the brake fluid can be efficiently supplied from the back pressure chamber 602 side to the wheel cylinder W / C side by operating the SS / V IN 27 in the valve opening direction. Thereafter, when it is not determined that the brake is suddenly operated or when a predetermined condition indicating that the discharge capacity of the pump 3 is sufficient is satisfied, the ECU 90 causes the wheel cylinder hydraulic pressure by the second pedal force brake generating unit 90e to be Is switched from the creation of the wheel cylinder hydraulic pressure by the boost control unit 90c. The boost control unit 90c operates the SS / V IN 27 in the valve closing direction and operates the SS / V OUT 28 in the valve opening direction. Thereby, the stroke simulator 6 is caused to function. Note that switching to regenerative cooperative brake control may be performed after the second pedal effort braking.

Booster control part (single system booster control part) 90c is normal by operating the faulty communication valve 23 in the valve closing direction when the wheel cylinder W / C of the P system or S system fails to leak. Disconnect from the brake circuit on the side and perform boost control only with the normal wheel cylinder W / C (single-system boost control). It should be noted that during one-system boost control, the wheel cylinder hydraulic pressure is not generated by the second pedal force brake generating unit 90e even in the sudden brake operation state.
The booster control unit 90c operates the communication valve 23S in the valve closing direction when the S cylinder wheel cylinder W / C (FR) or W / C (RL) fails to leak, and the P system is based on the P system alone. Performs boost control. When the driver operates the brake pedal 100 and the brake fluid flows into the positive pressure chamber 601 of the stroke simulator 6 during the P system boost control, an equal amount of brake fluid flows from the back pressure chamber 602 of the stroke simulator 6 to the back pressure chamber. It flows out to the back pressure liquid passage 16 of the second unit 1B via the pipe 10X. Here, since the internal pressure of the supply fluid passage 11S is reduced due to fluid leakage from the wheel cylinder W / C, a part of the brake fluid flowing out to the back pressure fluid passage 16 passes through the check valve 270 and is supplied to the supply fluid passage. Flows to 11S and leaks from the place where the liquid leak occurred. Along with this, the brake fluid in the back pressure chamber 602 becomes insufficient, so the brake fluid in the reservoir tank 4 flows through the suction pipe 10R, the bypass fluid path 180, the back pressure fluid path 16, and the back pressure chamber pipe 10X. Supplyed to the pressure chamber 602. As a result, the brake fluid in the reservoir tank 4 may be insufficient with respect to the required amount of brake fluid.
Therefore, in the first embodiment, the one-system boost control as described below is aimed at suppressing leakage of brake fluid to the outside due to the operation of the brake pedal 100 during the P-system boost control. Implement the process. The ECU 90 further includes a liquid leakage detection unit 90f, a pedal input detection unit 90g, and a pressure increase control valve control unit 90h as a configuration for executing the single system boost control process.

FIG. 3 is a flowchart illustrating the flow of the single system boost control process according to the first embodiment. This process is repeatedly executed at a predetermined cycle.
In step S1, the leak detection unit 90f detects brake fluid leak from the wheel cylinder W / C. If a leak is detected, the process proceeds to step S2, and if no leak is detected, the process proceeds to step S7. . The liquid leak detection unit 90f detects a liquid leak using a known method, for example, a method described in JP 2014-151806 A or JP 2015-182631 A. Step S1 is a liquid leak detection step.
In step S2, the boost control unit 90c determines whether or not the liquid leakage of the S system is detected in step S1. If YES, the process proceeds to step S3. If NO, the process proceeds to step S6.
In step S3, the boost control unit 90c operates the communication valve 23S in the valve closing direction to perform the P system boost control. Step S3 is a one-system boost control step.
In step S4, the boost control unit 90c operates the communication valve 23P in the valve closing direction to perform S system boost control.
In step S5, the pedal input detection unit 90g detects whether the brake pedal 100 has been operated. If operated, the process proceeds to step S6, and if NO, the process proceeds to return. The pedal input detection unit 90g detects that the brake pedal 100 is operated when the output value (stroke) of the stroke sensor 94 exceeds a predetermined threshold value. Step S5 is a pedal input detection step.
In step S6, the S-system SOL / V INs 22b and 22c are operated in the valve closing direction in the pressure increase control valve control unit 90h. Step S6 is a pressure increase control valve control step.
In step S7, normal boost control is performed.

FIG. 4 is a time chart showing the liquid leakage suppressing action of the first embodiment. As a premise, the fluid leakage of the wheel cylinder W / C is detected in the S system before the time t1, and the P system boost control is being performed. Therefore, in the flowchart of FIG. 3, the flow of S1->S2->S3-> S5 is repeated.
At time t1, the driver depresses the brake pedal 100, but since the stroke sensor output does not exceed the threshold value, the flow of S1 → S2 → S3 → S5 is continued in the flowchart of FIG.
At time t2, since the stroke sensor output exceeds the threshold, pedal operation is detected. In the flowchart of FIG. 3, the flow is switched to S1->S2->S3->S5-> S6, and the S-system SOL / V INs 22b, 22c are closed in S6. When the operation of the brake pedal 100 is detected, the brake fluid that has passed through the check valve 270 can be prevented from reaching the leak point of the wheel cylinder W / C by closing the SOL / V IN 22b and 22c. Therefore, leakage of brake fluid to the outside can be suppressed.
At time t3, the driver depresses the brake pedal 100 and the stroke sensor output falls below the threshold value. Therefore, in the flowchart of FIG. 3, the flow is switched to S1 → S2 → S3 → S5, and the S system SOL / V IN22b, 22c opens. When the brake pedal 100 is not operated, liquid leakage to the outside does not occur. In this case, unnecessary power consumption can be suppressed by turning off the SOL / V INs 22b and 22c.

[Embodiment 2]
Next, Embodiment 2 will be described. 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.
In the second embodiment, it is detected that the brake pedal 100 is operated when the differential value of the output value of the stroke sensor 94 exceeds a predetermined threshold value in step S5 of FIG.
Of the brake fluid that flows out from the back pressure chamber 602 to the back pressure fluid passage 16 due to the brake operation during P system boost control, the amount of brake fluid that flows out to the supply fluid passage 11S through the check valve 270 is: It increases as the flow rate of the brake fluid flowing out from the back pressure chamber 602 increases. The flow rate of the brake fluid depends on the stroke speed of the brake pedal 100. Therefore, when the brake pedal 100 is suddenly depressed during the P system boost control, the SOL / V IN22b, 22c of the S system is closed, and when the brake pedal 100 is gently depressed, the SOL / V IN22b, 22c is opened. It is possible to achieve both suppression of leakage of brake fluid to the outside during sudden depression and suppression of unnecessary power consumption.

[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 stroke simulator may be separate from the master cylinder unit.
The liquid leak detection unit 90f and the pedal input detection unit 90g may be outside the ECU 90.
The pedal input detection unit 90g may detect that the brake pedal 100 is operated when the output value of the stroke sensor 94 exceeds the threshold value and the differential value of the output value exceeds the threshold value.

FL to RR wheels
W / C wheel cylinder (braking force generator)
3 Pump (hydraulic pressure source)
4 Reservoir tank (reservoir)
5 Master cylinder
6 Stroke simulator
10MP primary piping (1st fluid path, primary system fluid path)
10MS secondary piping (1st fluid channel, secondary fluid channel)
10X Back pressure chamber piping (3rd fluid passage, 2nd stroke simulator fluid passage)
11P Supply liquid path (1st liquid path, primary system liquid path)
11S supply liquid path (1st liquid path, secondary system liquid path)
11a Fluid channel (first fluid channel, primary system fluid channel)
11b Fluid path (1st fluid path, secondary system fluid path)
11c Fluid path (1st fluid path, secondary system fluid path)
11d Fluid path (first fluid path, primary system fluid path)
13P liquid path (communication liquid path)
13S liquid path (communication liquid path)
14 Pressure regulating fluid path (refluxing fluid path)
16 Back pressure liquid path (3rd liquid path, 2nd stroke simulator communication liquid path)
17 1st simulator liquid path (3rd liquid path, 2nd stroke simulator communication liquid path)
22 Booster regulator (pressure booster control valve)
23P communication valve (first communication valve)
23S communication valve (second communication valve)
24 Pressure regulating valve
27 Stroke simulator in valve (stroke simulator valve)
50P Primary room (1st room)
50S secondary room (second room)
73P Supply liquid path (Primary system liquid path)
73S supply fluid path (secondary fluid path)
74 Positive pressure fluid passage (second fluid passage, first stroke simulator communication fluid passage)
90 Electronic control unit (control unit)
90c Boost control unit (single system boost control unit)
90h Booster control valve controller
270 Check valve (Stroke simulator valve)
601 Positive pressure chamber (one chamber)
602 Back pressure chamber (the other chamber)

Claims (7)

Two first fluid passages connecting the master cylinder and the braking force generator of the wheel;
A pressure increase control valve provided in the first liquid passage corresponding to the braking force generation unit;
A hydraulic pressure source for discharging the brake fluid sucked from the reservoir to the first fluid path;
A stroke simulator that has two chambers separated by a partition wall and applies an operational reaction force to the brake pedal; one of the two chambers; and the first fluid path of one system of the two first fluid paths; A second fluid path connecting
A third fluid path connecting the other chamber of the two chambers and a position closer to the master cylinder than the pressure increase control valve of the first fluid path of the one system;
A hydraulic control device having
A control unit for controlling the hydraulic pressure control device,
Boost control that supplies brake fluid to the braking force generator by the brake fluid discharged from the hydraulic source in the other of the two systems when a fluid leak is detected in the braking force generator of the one system A single-system boost control unit that implements
A pressure-increasing control valve control unit for operating the pressure-increasing control valve of the one system in a valve closing direction when an operation of the brake pedal is detected during the boost control;
A control unit having
Brake control device with The brake device according to claim 1, wherein
A brake control device having a stroke simulator valve in the third liquid passage. The brake device according to claim 2,
A brake control device that detects that the brake pedal is operated when an operation speed of the brake pedal is higher than a predetermined value. A primary system fluid path having a plurality of wheel cylinders that can be pressurized by the master cylinder hydraulic pressure generated in the first chamber of the master cylinder;
A secondary system fluid path comprising a plurality of wheel cylinders that can be pressurized by a master cylinder fluid pressure generated in the second chamber of the master cylinder;
A communication liquid path connecting the liquid path of the primary system and the liquid path of the secondary system;
A first communication valve that is provided in the communication liquid path and suppresses a flow of brake fluid from the communication liquid path to the liquid path of the primary system;
A second communication valve that is provided in the communication liquid path and suppresses a flow of brake fluid from the communication liquid path to the liquid path of the secondary system;
A hydraulic pressure source for discharging brake fluid between the first communication valve and the second communication valve of the communication fluid path;
Provided between at least one of the first communication valve and the second communication valve and the fluid pressure source, the brake fluid discharged to the fluid communication path is returned to the suction side of the fluid pressure source. A reflux liquid path to
A pressure regulating valve that is provided in the reflux fluid path and adjusts the amount of brake fluid that is refluxed to the suction side of the fluid pressure source;
Corresponding to the plurality of wheel cylinders, a pressure increase control valve provided in the liquid path of the primary system and the liquid path of the secondary system;
A stroke simulator that has two chambers separated by a partition wall and applies an operational reaction force to the brake pedal;
A first stroke simulator communication liquid path that connects one of the two chambers and the liquid path of the secondary system;
A second stroke simulator communication liquid path that connects the other chamber of the two chambers and a position closer to the master cylinder than the pressure increase control valve of the liquid path of the secondary system;
A stroke simulator valve provided in the second stroke simulator communication liquid path;
A hydraulic control device having
A control unit for controlling the hydraulic pressure control device,
When fluid leakage is detected in the wheel cylinder in the secondary system fluid path, boost control is performed to supply brake fluid to the wheel cylinder by the brake fluid discharged from the fluid pressure source in the primary system fluid path. A single system boost control unit,
A pressure-increasing control valve control unit that operates the pressure-increasing control valve of the secondary system in a valve closing direction when an operation of the brake pedal is detected during the boost control;
A control unit having
Brake control device with Two first fluid passages connecting the master cylinder and the braking force generator of the wheel;
A pressure increase control valve provided in the first liquid passage corresponding to the braking force generation unit;
A hydraulic pressure source for discharging the brake fluid sucked from the reservoir to the first fluid path;
A stroke simulator that has two chambers separated by a partition wall and applies an operational reaction force to the brake pedal;
A second liquid path that connects one of the two chambers and the first liquid path of one of the two systems of the first liquid path;
A third fluid path connecting the other chamber of the two chambers and a position closer to the master cylinder than the pressure increase control valve of the first fluid path of the one system;
A control method for a brake control device comprising:
Boost control that supplies brake fluid to the braking force generator by the brake fluid discharged from the hydraulic source in the other of the two systems when a fluid leak is detected in the braking force generator of the one system A single-system boost control step for carrying out
A pressure-increasing control valve control step for operating the pressure-increasing control valve in the one system in a valve closing direction when an operation of the brake pedal is detected during the one-system boost control step;
Brake control method with The brake control method according to claim 5, wherein
The brake control device is a brake control method having a stroke simulator valve in the third liquid passage. The brake control method according to claim 6, wherein
A brake control method for detecting that the brake pedal is operated when an operation speed of the brake pedal is higher than a predetermined value.

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