JP6973065B2 - Vehicle braking device - Google Patents

Description

The present invention relates to a vehicle braking device.

A vehicle braking device provided with a regenerative braking unit that applies regenerative braking force to the wheels has an input piston and an input piston that move forward in response to the operation of the brake operating member in the master cylinder in order to obtain the maximum regenerative energy. A master piston separated from the front is arranged. This separation distance prevents the direct advance of the master piston due to the normal operation of the brake operating member, and while maximizing the regenerative braking force, the drive of the master piston is electrically controlled by another drive source. can do. Such a configuration is disclosed in, for example, Japanese Patent Application Laid-Open No. 2012-214091.

Japanese Unexamined Patent Publication No. 2012-214091

In the above configuration, the input piston and the master piston are designed so as not to come into contact with each other as much as possible when the stroke of the brake operating member is increased so that the brake feeling is not deteriorated. Here, in a situation where the required braking force is satisfied only by the regenerative braking force, the master piston does not move forward, so that both pistons approach each other by the stroke of the brake operating member. For example, if a further sudden operation (sudden stepping) is performed in this situation, both pistons may come into contact with each other. In order to avoid this, for example, it is conceivable to increase the size of the master cylinder to increase the separation distance. However, according to this, the entire device becomes large. On the other hand, the vehicle braking device needs to exhibit appropriate braking performance, that is, braking force (and more preferably vehicle stability) according to the operating amount (required braking force) of the brake operating member.

The present invention has been made in view of such circumstances, and is a vehicle capable of suppressing contact between the input piston and the master piston without increasing the size of the device and exhibiting appropriate braking performance. It is an object of the present invention to provide a braking device for a vehicle.

The vehicle braking device of the present invention is disposed of an input piston that advances in a predetermined direction in a cylinder in response to an increase in the stroke of a brake operating member, and an input piston in the cylinder that is separated from the input piston in the predetermined direction. A master piston, a drive unit that generates a master pressure corresponding to the hydraulic braking force applied to the wheels by driving the master piston in the predetermined direction, and a regenerative braking unit that applies a regenerative braking force to the wheels. A vehicle braking device that coordinates and controls the regenerative braking unit and the drive unit while increasing the regenerative braking force of the regenerative braking unit in response to an increase in the stroke. The stroke is predetermined. When the value exceeds the value, the drive unit includes a control unit that increases the drive amount of the master piston by a specified value and executes adjustment control to reduce the regenerative braking force by the regenerative braking unit according to the specified value.

According to the present invention, when the stroke becomes a predetermined value or more, the master piston is driven in a predetermined direction, that is, in a direction away from the input piston by adjustment control. As a result, the contact between the input piston and the master piston is suppressed. In addition, the hydraulic braking force increases as the master pressure increases as the master piston advances in the predetermined direction, but the regenerative braking force decreases, so the braking force does not become too large and the braking force according to the required braking force can be exerted. Will be. Further, as a vehicle braking device, a regenerative braking unit is generally provided for the front wheels or the rear wheels, and the master pressure corresponds to the hydraulic braking force of both the front and rear wheels. However, even in this configuration, the regenerative braking force is generated. By reducing the braking force of one of the front wheels and the rear wheels, it is suppressed that the braking force becomes excessively larger than that of the other, and appropriate vehicle stability can be exhibited.

It is a block diagram of the braking device for a vehicle of 1st Embodiment. It is a block diagram of the actuator of 1st Embodiment. It is a time chart which shows an example of the adjustment control of 1st Embodiment. It is explanatory drawing which shows the braking force distribution of 1st Embodiment. It is explanatory drawing which shows the relationship between deceleration and the amount of regeneration of 1st Embodiment. It is a time chart which shows another example of the adjustment control of 1st Embodiment. It is a block diagram of the control device of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each figure used for explanation is a conceptual diagram, and the shape of each part may not always be exact.
<First Embodiment>
As shown in FIGS. 1 and 2, the vehicle braking device BF includes a master cylinder 1, a reaction force generator 2, a first control valve 22, a second control valve 23, and a servo pressure generator (“drive”). A unit 4), an actuator 5, wheel cylinders 541 to 544, various sensors 71 to 77, an upstream side ECU 6, and a downstream side ECU 6A are provided.

Further, since the vehicle of the first embodiment is a hybrid vehicle, the vehicle braking device BF has a regenerative braking device (“regenerative braking unit”) that generates a regenerative braking force on the wheels W and executes coordinated control with the actuator 5. 8) is provided. The regenerative braking device 8 is provided for the rear wheel Wr, and includes a hybrid ECU 81, a generator 82, an inverter 83, and a battery 84. Details of the regenerative braking device 8 are known and will be omitted. The vehicle of the first embodiment is a rear-wheel drive vehicle. In the description, the wheels Wfl, Wfr, Wrl, and Wrr may be referred to as wheels W, the front wheels Wfl and Wfr may be referred to as front wheels Wf, and the rear wheels Wrl and Wrr may be referred to as rear wheels Wr. For example, a brake pad Z1 and a brake rotor Z2 are installed on each wheel W.

The master cylinder 1 is a portion that supplies the brake fluid to the actuator 5 according to the operation amount of the brake pedal (corresponding to the "brake operation member") 10, and is a main cylinder 11, a cover cylinder 12, an input piston 13, and a first. It includes a master piston 14 and a second master piston 15. The brake pedal 10 may be any brake operating means that allows the driver to operate the brake.

The main cylinder 11 is a bottomed substantially cylindrical housing that is closed at the front and opens at the rear. An inner wall portion 111 projecting in an inward flange shape is provided near the rear side of the inner peripheral side of the main cylinder 11. The center of the inner wall portion 111 is a through hole 111a penetrating in the front-rear direction. Further, small diameter portions 112 (rear) and 113 (front) having a slightly smaller inner diameter are provided in front of the inner wall portion 111 inside the main cylinder 11. That is, the small diameter portions 112 and 113 project inwardly annularly from the inner peripheral surface of the main cylinder 11. Inside the main cylinder 11, a first master piston 14 is disposed so as to be slidably contacted with the small diameter portion 112 and movable in the axial direction. Similarly, the second master piston 15 is disposed so as to be slidably contacted with the small diameter portion 113 and movable in the axial direction.

The cover cylinder 12 is composed of a substantially cylindrical cylinder portion 121, a bellows tubular boot 122, and a cup-shaped compression spring 123. The cylinder portion 121 is arranged on the rear end side of the main cylinder 11 and is coaxially fitted to the opening on the rear side of the main cylinder 11. The inner diameter of the front portion 121a of the cylinder portion 121 is larger than the inner diameter of the through hole 111a of the inner wall portion 111. Further, the inner diameter of the rear portion 121b of the cylinder portion 121 is smaller than the inner diameter of the front portion 121a.

The dustproof boot 122 has a bellows cylinder shape and can be expanded and contracted in the front-rear direction, and is assembled so as to be in contact with the rear end side opening of the cylinder portion 121 on the front side thereof. A through hole 122a is formed in the center behind the boot 122. The compression spring 123 is a coil-shaped urging member arranged around the boot 122, and the front side thereof abuts on the rear end of the main cylinder 11 and the rear side is compressed so as to be close to the through hole 122a of the boot 122. It is diametered. The rear end of the boot 122 and the rear end of the compression spring 123 are coupled to the operating rod 10a. The compression spring 123 urges the operating rod 10a rearward.

The input piston 13 is a piston that slides in the cover cylinder 12 in response to the operation of the brake pedal 10. The input piston 13 is a bottomed substantially cylindrical piston having a bottom surface in the front and an opening in the rear. The bottom wall 131 constituting the bottom surface of the input piston 13 has a larger diameter than other parts of the input piston 13. The input piston 13 is slidably and liquid-tightly arranged in the rear portion 121b of the cylinder portion 121 in the axial direction, and the bottom wall 131 enters the inner peripheral side of the front portion 121a of the cylinder portion 121.

Inside the input piston 13, an operation rod 10a interlocked with the brake pedal 10 is arranged. The pivot 10b at the tip of the operating rod 10a can push the input piston 13 forward. The rear end of the operating rod 10a projects outward through the opening on the rear side of the input piston 13 and the through hole 122a of the boot 122, and is connected to the brake pedal 10. When the brake pedal 10 is depressed, the operating rod 10a advances while pushing the boot 122 and the compression spring 123 in the axial direction. As the operation rod 10a advances, the input piston 13 also advances in conjunction with it.

The first master piston 14 is slidably disposed on the inner wall portion 111 of the main cylinder 11 in the axial direction. The first master piston 14 is formed by integrally forming a pressure cylinder portion 141, a flange portion 142, and a protruding portion 143 in order from the front side. The pressure cylinder portion 141 is formed in a substantially cylindrical shape with a bottom having an opening in the front, has a gap between the pressure cylinder portion 141 and the inner peripheral surface of the main cylinder 11, and is in sliding contact with the small diameter portion 112. In the internal space of the pressure cylinder portion 141, a coil spring-like urging member 144 is disposed between the pressure cylinder portion 141 and the second master piston 15. The first master piston 14 is urged rearward by the urging member 144. In other words, the first master piston 14 is urged by the urging member 144 toward the set initial position.

The flange portion 142 has a larger diameter than the pressure cylinder portion 141 and is in sliding contact with the inner peripheral surface of the main cylinder 11. The protruding portion 143 has a smaller diameter than the flange portion 142, and is arranged so as to slide liquid-tightly in the through hole 111a of the inner wall portion 111. The rear end of the protruding portion 143 passes through the through hole 111a, protrudes into the internal space of the cylinder portion 121, and is separated from the inner peripheral surface of the cylinder portion 121. The rear end surface of the protrusion 143 is separated from the bottom wall 131 of the input piston 13, and the separation distance d is configured to be variable. As described above, in the initial state, the first master piston 14 is arranged in front of the input piston 13 at a distance d from the input piston 13.

Here, the "first master chamber 1D" is partitioned by the inner peripheral surface of the main cylinder 11, the front side of the pressure cylinder portion 141 of the first master piston 14, and the rear side of the second master piston 15. Further, the rear chamber behind the first master chamber 1D is partitioned by the inner peripheral surface (inner peripheral portion) of the main cylinder 11, the small diameter portion 112, the front surface of the inner wall portion 111, and the outer peripheral surface of the first master piston 14. ing. The front and rear ends of the flange portion 142 of the first master piston 14 divide the rear chamber into front and rear, the "second hydraulic chamber 1C" is partitioned on the front side, and the "servo chamber 1A" is on the rear side. It is partitioned. The volume of the second hydraulic chamber 1C decreases as the first master piston 14 advances, and the volume increases as the first master piston 14 retracts. Further, the inner peripheral portion of the main cylinder 11, the rear surface of the inner wall portion 111, the inner peripheral surface (inner peripheral portion) of the front portion 121a of the cylinder portion 121, the protruding portion 143 (rear end portion) of the first master piston 14, and the input. The "first hydraulic chamber 1B" is partitioned by the front end portion of the piston 13.

The second master piston 15 is arranged on the front side of the first master piston 14 in the main cylinder 11 so as to be slidably in contact with the small diameter portion 113 and movable in the axial direction. The second master piston 15 is integrally formed with a tubular pressure cylinder portion 151 having an opening in the front and a bottom wall 152 that closes the rear side of the pressure cylinder portion 151. The bottom wall 152 supports an urging member 144 with the first master piston 14. In the internal space of the pressure cylinder portion 151, a coil spring-shaped urging member 153 is arranged between the main cylinder 11 and the closed inner bottom surface 111d. The second master piston 15 is urged rearward by the urging member 153. In other words, the second master piston 15 is urged by the urging member 153 toward the set initial position. The "second master chamber 1E" is partitioned by the inner peripheral surface of the main cylinder 11, the inner bottom surface 111d, and the second master piston 15.

The master cylinder 1 is formed with ports 11a to 11i that communicate the inside and the outside. The port 11a is formed behind the inner wall portion 111 of the main cylinder 11. The port 11b is formed at a position similar to that of the port 11a in the axial direction so as to face the port 11a. The port 11a and the port 11b communicate with each other via an annular space between the inner peripheral surface of the main cylinder 11 and the outer peripheral surface of the cylinder portion 121. Ports 11a and 11b are connected to pipe 161 and to reservoir 171 (low voltage source).

Further, the port 11b communicates with the first hydraulic chamber 1B by a passage 18 formed in the cylinder portion 121 and the input piston 13. The passage 18 is shut off when the input piston 13 advances, thereby shutting off the first hydraulic chamber 1B and the reservoir 171. The port 11c is formed behind the inner wall portion 111 and in front of the port 11a, and communicates the first hydraulic chamber 1B with the pipe 162. The port 11d is formed in front of the port 11c and communicates the servo chamber 1A and the pipe 163. The port 11e is formed in front of the port 11d and communicates the second hydraulic chamber 1C with the pipe 164.

The port 11f is formed between the sealing members G1 and G2 of the small diameter portion 112, and communicates the reservoir 172 with the inside of the main cylinder 11. The port 11f communicates with the first master chamber 1D via a passage 145 formed in the first master piston 14. The passage 145 is formed at a position where the port 11f and the first master chamber 1D are cut off when the first master piston 14 advances. The port 11g is formed in front of the port 11f and communicates the first master chamber 1D with the pipeline 31.

The port 11h is formed between the sealing members G3 and G4 of the small diameter portion 113, and communicates the reservoir 173 with the inside of the main cylinder 11. The port 11h communicates with the second master chamber 1E via a passage 154 formed in the pressure cylinder portion 151 of the second master piston 15. The passage 154 is formed at a position where the port 11h and the second master chamber 1E are cut off when the second master piston 15 advances. The port 11i is formed in front of the port 11h and communicates the second master chamber 1E with the pipeline 32.

Further, a sealing member such as an O-ring is appropriately arranged in the master cylinder 1. The seal members G1 and G2 are arranged in the small diameter portion 112 and are in liquid-tight contact with the outer peripheral surface of the first master piston 14. Similarly, the seal members G3 and G4 are arranged at the small diameter portion 113 and are in liquid-tight contact with the outer peripheral surface of the second master piston 15. Further, the seal members G5 and G6 are also arranged between the input piston 13 and the cylinder portion 121.

The stroke sensor 71 is a sensor that detects an operation amount (stroke) in which the brake pedal 10 is operated by the driver, and transmits a detection signal to the upstream side ECU 6 and the downstream side ECU 6A. The brake stop switch 72 is a switch that detects the presence / absence of operation of the brake pedal 10 by the driver with a binary signal, and transmits the detection signal to the upstream ECU 6.

The reaction force generating device 2 is a device that generates a reaction force that opposes the operating force when the brake pedal 10 is operated, and is mainly composed of the stroke simulator 21. The stroke simulator 21 generates reaction force hydraulic pressure in the first hydraulic chamber 1B and the second hydraulic chamber 1C in response to the operation of the brake pedal 10. The stroke simulator 21 is configured by slidably fitting the piston 212 to the cylinder 211. The piston 212 is urged rearward by the compression spring 213, and a reaction force hydraulic chamber 214 is formed on the rear surface side of the piston 212. The reaction hydraulic pressure chamber 214 is connected to the second hydraulic pressure chamber 1C via the pipe 164 and the port 11e, and the reaction force hydraulic pressure chamber 214 is further connected to the first control valve 22 and the second control via the pipe 164. It is connected to the valve 23.

The first control valve 22 is a solenoid valve having a structure that closes in a non-energized state, and its opening and closing is controlled by the upstream ECU 6. The first control valve 22 is connected between the pipe 164 and the pipe 162. Here, the pipe 164 communicates with the second hydraulic pressure chamber 1C via the port 11e, and the pipe 162 communicates with the first hydraulic pressure chamber 1B via the port 11c. Further, when the first control valve 22 is opened, the first hydraulic pressure chamber 1B is opened, and when the first control valve 22 is closed, the first hydraulic pressure chamber 1B is closed. Therefore, the pipe 164 and the pipe 162 are provided so as to communicate the first hydraulic pressure chamber 1B and the second hydraulic pressure chamber 1C.

The first control valve 22 is closed in a non-energized state, and at this time, the first hydraulic chamber 1B and the second hydraulic chamber 1C are shut off. As a result, the first hydraulic chamber 1B is sealed and there is no place for the brake fluid to go, and the input piston 13 and the first master piston 14 are interlocked with each other while maintaining a constant separation distance. Further, the first control valve 22 is open in the energized state, and at this time, the first hydraulic chamber 1B and the second hydraulic chamber 1C are communicated with each other. As a result, the volume change of the first hydraulic chamber 1B and the second hydraulic chamber 1C due to the advance / retreat of the first master piston 14 is absorbed by the movement of the brake fluid.

The pressure sensor 73 is a sensor that detects the reaction force hydraulic pressure of the second hydraulic pressure chamber 1C and the first hydraulic pressure chamber 1B, and is connected to the pipe 164. The pressure sensor 73 detects the pressure in the second hydraulic chamber 1C when the first control valve 22 is in the closed state, and communicates with the first hydraulic chamber 1B when the first control valve 22 is in the open state. Pressure will also be detected. The pressure sensor 73 transmits a detection signal to the upstream ECU 6.

The second control valve 23 is a solenoid valve having a structure that opens in a non-energized state, and its opening and closing is controlled by the upstream ECU 6. The second control valve 23 is connected between the pipe 164 and the pipe 161. Here, the pipe 164 communicates with the second hydraulic chamber 1C via the port 11e, and the pipe 161 communicates with the reservoir 171 via the port 11a. Therefore, the second control valve 23 communicates between the second hydraulic chamber 1C and the reservoir 171 in a non-energized state and does not generate reaction force hydraulic pressure, but shuts off in the energized state to generate reaction force hydraulic pressure. Let me.

The servo pressure generator 4 is a so-called hydraulic booster (boost booster), and includes a pressure reducing valve 41, a pressure boosting valve 42, a pressure supply unit 43, and a regulator 44. The pressure reducing valve 41 is a normally open type solenoid valve (normally open valve) that opens in a non-energized state, and the flow rate (or pressure) is controlled by the upstream ECU 6. One of the pressure reducing valves 41 is connected to the pipe 161 via the pipe 411, and the other of the pressure reducing valves 41 is connected to the pipe 413. That is, one of the pressure reducing valves 41 communicates with the reservoir 171 via the pipes 411 and 161 and the ports 11a and 11b. By closing the pressure reducing valve 41, the brake fluid is prevented from flowing out from the pilot chamber 4D. Although not shown, the reservoir 171 and the reservoir 434 communicate with each other. Reservoir 171 and reservoir 434 may be the same reservoir.

The pressure boosting valve 42 is a normally closed solenoid valve (normally closed valve) that closes in a non-energized state, and the flow rate (or pressure) is controlled by the upstream ECU 6. One of the booster valves 42 is connected to the pipe 421, and the other of the booster valves 42 is connected to the pipe 422. The pressure supply unit 43 is a portion that mainly supplies a high-pressure hydraulic fluid to the regulator 44. The pressure supply unit 43 includes an accumulator 431, a hydraulic pump 432, a motor 433, and a reservoir 434. The pressure sensor 75 detects the hydraulic pressure of the accumulator 431. Since the structure of the pressure supply unit 43 is known, the description thereof will be omitted.

The regulator 44 is a mechanical regulator, and a pilot chamber 4D is formed inside the regulator 44. Further, a plurality of ports 4a to 4h are formed in the regulator 44. The pilot chamber 4D is connected to the pressure reducing valve 41 via the port 4f and the pipe 413, and is connected to the pressure increasing valve 42 via the port 4g and the pipe 421. By opening the pressure boosting valve 42, high-pressure brake fluid is supplied from the accumulator 431 to the pilot chamber 4D via the ports 4a, 4b, and 4g, the piston moves, and the pilot chamber 4D expands. The valve member moves in response to the expansion, the port 4a and the port 4c communicate with each other, and the high-pressure brake fluid is supplied to the servo chamber 1A via the pipe 163. On the other hand, when the pressure reducing valve 41 is opened, the hydraulic pressure (pilot pressure) of the pilot chamber 4D is reduced, and the flow path between the port 4a and the port 4c is blocked by the valve member. In this way, the upstream ECU 6 controls the pilot pressure corresponding to the servo pressure by controlling the pressure reducing valve 41 and the pressure increasing valve 42, and controls the servo pressure. The actual servo pressure is detected by the pressure sensor 74. The first embodiment has a by-wire configuration in which the brake operation mechanism and the pressure adjusting mechanism are separated.

The actuator 5 is arranged between the first master chamber 1D and the second master chamber 1E where the master pressure is generated and the wheel cylinders 541 to 544. The actuator 5 and the first master chamber 1D are connected by a pipeline 31, and the actuator 5 and the second master chamber 1E are connected by a pipeline 32. The actuator 5 is a device that adjusts the hydraulic pressure (wheel pressure) of the wheel cylinders 541 to 544 in response to an instruction from the downstream ECU 6A. The actuator 5 executes pressurization control, pressurization control, depressurization control, or holding control for further pressurizing the brake fluid from the master pressure in response to a command from the downstream ECU 6A. The actuator 5 executes anti-skid control (ABS control), sideslip prevention control (ESC control), or the like by combining these controls based on the command of the downstream ECU 6A.

Specifically, as shown in FIG. 3, the actuator 5 includes a hydraulic circuit 5A and a motor 90. The hydraulic circuit 5A includes a first piping system 50a and a second piping system 50b. The first piping system 50a is a system that controls the hydraulic pressure (wheel pressure) applied to the front wheels Wfl and Wfr. The second piping system 50b is a system that controls the hydraulic pressure (wheel pressure) applied to the rear wheels Wrl and Wrr. Further, a wheel speed sensor 76 is installed for each wheel W. In the first embodiment, front and rear piping is adopted.

The first piping system 50a includes a main pipe line A, a differential pressure control valve 51, pressure boosting valves 52 and 53, a pressure reducing pipe line B, pressure reducing valves 54 and 55, a pressure regulating reservoir 56, and a recirculation pipe line C. , A pump 57, an auxiliary pipe D, an orifice portion 58, and a damper portion 59. In the description, the term "pipeline" can be replaced with, for example, a hydraulic line, a flow path, an oil passage, a passage, a pipe, or the like.

The main pipeline A is a pipeline connecting the pipeline 32 and the wheel cylinders 541 and 542. The differential pressure control valve 51 is an electromagnetic valve provided in the main pipeline A and controlling the main pipeline A in a communication state and a differential pressure state. The differential pressure state is a state in which the flow path is restricted by the valve, and can be said to be a throttled state. The differential pressure control valve 51 controls the differential pressure between the hydraulic pressure on the master cylinder 1 side centered on itself and the hydraulic pressure on the wheel cylinders 541 and 542 according to the control current based on the instruction from the downstream ECU 6A. In other words, the differential pressure control valve 51 determines the differential pressure between the hydraulic pressure of the master cylinder 1 side portion of the main pipeline A and the hydraulic pressure of the wheel cylinders 541 and 542 side portions of the main pipeline A according to the control current. It is configured to be controllable.

The differential pressure control valve 51 is a normally open type that is in a communicating state in a non-energized state. The larger the control current applied to the differential pressure control valve 51, the larger the differential pressure. When the differential pressure control valve 51 is controlled to the differential pressure state and the pump 57 is driven, the hydraulic pressure on the wheel cylinders 541 and 542 side becomes larger than the hydraulic pressure on the master cylinder 1 side according to the control current. .. A check valve 51a is installed for the differential pressure control valve 51. The main pipeline A is branched into two pipelines A1 and A2 at a branch point X on the downstream side of the differential pressure control valve 51 so as to correspond to the wheel cylinders 541 and 542.

The booster valves 52 and 53 are solenoid valves that open and close according to the instructions of the downstream ECU 6A, and are normally open type solenoid valves that are in an open state (communication state) in a non-energized state. The pressure booster valve 52 is arranged in the pipeline A1, and the pressure booster valve 53 is arranged in the pipeline A2. The pressure boosting valves 52 and 53 are opened in a non-energized state during pressure boost control to communicate with the wheel cylinders 541 to 544 and the branch point X, and are energized and closed during holding control and depressurization control. And the branch point X are blocked.

The pressure reducing line B connects between the pressure boosting valve 52 and the wheel cylinders 541 and 542 in the line A1 and the pressure adjusting reservoir 56, and adjusts between the pressure increasing valve 53 and the wheel cylinders 541 and 542 in the line A2. It is a pipeline connecting to the pressure reservoir 56. The pressure reducing valves 54 and 55 are solenoid valves that open and close according to the instructions of the downstream ECU 6A, and are normally closed type solenoid valves that are closed (closed) in a non-energized state. The pressure reducing valve 54 is arranged in the pressure reducing pipe line B on the wheel cylinders 541 and 542. The pressure reducing valve 55 is arranged in the pressure reducing pipe line B on the wheel cylinders 541 and 542. The pressure reducing valves 54 and 55 are mainly energized during decompression control to be in an open state, and the wheel cylinders 541 and 542 and the pressure regulating reservoir 56 are communicated with each other via the pressure reducing pipe line B. The pressure regulating reservoir 56 is a reservoir having a cylinder, a piston, and an urging member.

The reflux pipe C is a pipe connecting the pressure reducing pipe B (or the pressure regulating reservoir 56) and the differential pressure control valve 51 and the pressure increasing valves 52 and 53 (here, the branch point X) in the main pipe A. be. The pump 57 is provided in the reflux pipe C so that the discharge port is arranged on the branch point X side and the suction port is arranged on the pressure regulating reservoir 56 side. The pump 57 is a gear-type electric pump (gear pump) driven by a motor 90. The pump 57 causes the brake fluid to flow from the pressure regulating reservoir 56 to the master cylinder 1 side or the wheel cylinders 541 and 542 sides via the reflux pipe C. Further, for example, during anti-skid control, the pump 57 pumps the brake fluid in the wheel cylinders 541 and 542 back to the master cylinder 1 via the pressure reducing valves 54 and 55 in the open state. In this way, the pump 57 is arranged between the master cylinder 1 and the wheel cylinders 541 and 542, and can discharge the brake fluid in the wheel cylinders 541 and 542 to the outside of the wheel cylinders 541 and 542.

The pump 57 is configured to repeat a discharge process of discharging the brake fluid and a suction process of sucking the brake fluid. That is, when the pump 57 is driven by the motor 90, the discharge process and the suction process are alternately and repeatedly executed. In the discharge process, the brake fluid sucked from the pressure regulating reservoir 56 in the suction process is supplied to the branch point X. The motor 90 is energized and driven via a relay (not shown) according to the instruction of the downstream ECU 6A. The pump 57 and the motor 90 can also be said to be electric pumps.

The orifice portion 58 is a throttle-shaped portion (so-called orifice) provided in a portion between the pump 57 of the return pipe C and the branch point X. The damper portion 59 is a damper (damper mechanism) connected to a portion of the return pipe C between the pump 57 and the orifice portion 58. The damper unit 59 absorbs and discharges the brake fluid according to the pulsation of the brake fluid in the return pipe line C. The orifice portion 58 and the damper portion 59 can be said to be a pulsation reducing mechanism for reducing (damping, absorbing) pulsation.

The auxiliary pipeline D is a pipeline connecting the pressure regulating hole 56a of the pressure regulating reservoir 56 and the upstream side (or master cylinder 1) of the differential pressure control valve 51 in the main pipeline A. The pressure adjusting reservoir 56 is configured so that the valve hole 56b is closed as the inflow amount of the brake fluid into the pressure adjusting hole 56a increases due to the increase in the stroke. A reservoir chamber 56c is formed on the pipe lines B and C sides of the valve hole 56b.

By driving the pump 57, the brake fluid in the pressure regulating reservoir 56 or the master cylinder 1 is brought into the portion between the differential pressure control valve 51 and the pressure boosting valves 52 and 53 in the main pipe line A via the return pipe line C (branch point X). ). Then, the wheel pressure is pressurized according to the control state of the differential pressure control valve 51 and the pressure boosting valves 52 and 53. In this way, in the actuator 5, pressurization control is executed by driving the pump 57 and controlling various valves. That is, the actuator 5 is configured to be able to pressurize the wheel pressure. A pressure sensor 77 for detecting the hydraulic pressure (master pressure) of the portion is installed in a portion between the differential pressure control valve 51 and the master cylinder 1 in the main pipeline A. The pressure sensor 77 transmits the detection result to the upstream side ECU 6 and the downstream side ECU 6A.

The second piping system 50b has the same configuration as the first piping system 50a, and is a system for adjusting the hydraulic pressure of the wheel cylinders 543 and 544 of the rear wheels Wrl and Wrr. The second piping system 50b includes a main pipeline Ab corresponding to the main pipeline A and connecting the pipeline 31 and the wheel cylinders 543 and 544, a differential pressure control valve 91 corresponding to the differential pressure control valve 51, and a pressure boosting valve 52. Pressure-increasing valves 92 and 93 corresponding to 53, pressure reducing pipes Bb corresponding to pressure reducing pipe B, pressure reducing valves 94 and 95 corresponding to pressure reducing valves 54 and 55, and pressure adjusting reservoir 96 corresponding to pressure adjusting reservoir 56. , The recirculation line Cb corresponding to the recirculation line C, the pump 97 corresponding to the pump 57, the auxiliary line Db corresponding to the auxiliary line D, the orifice part 58a corresponding to the orifice part 58, and the damper part. It is provided with a damper portion 59a corresponding to 59. As for the detailed configuration of the second piping system 50b, the description of the first piping system 50a can be referred to, and thus the description thereof will be omitted. Further, in the following description, the reference numerals of the first piping system 50a are used for the description of each part of the actuator 5, and the reference numerals of the second piping system 50b are omitted.

The upstream side ECU 6 and the downstream side ECU 6A are electronic control units (ECUs) including a CPU, a memory, and the like. The upstream ECU 6 is an ECU that executes control to the servo pressure generator 4 based on the target wheel pressure (or target deceleration) which is the target value of the wheel pressure. The upstream ECU 6 executes pressure increase control (pressurization control), depressurization control, or holding control for the servo pressure generator 4 based on the target wheel pressure. In the pressure increase control, the pressure increase valve 42 is opened and the pressure reducing valve 41 is closed. In the pressure reducing control, the pressure increasing valve 42 is closed and the pressure reducing valve 41 is opened. In the holding control, the pressure boosting valve 42 and the pressure reducing valve 41 are closed.

Various sensors 71 to 77 are connected to the upstream ECU 6. The upstream ECU 6 acquires stroke information, master pressure information, reaction force hydraulic pressure information, servo pressure information, and wheel speed information from these sensors. The sensor and the upstream ECU 6 are connected by a communication line (CAN) (not shown). Further, the upstream side ECU 6 acquires information (during anti-skid control, etc.) regarding the control status of the actuator 5 from the downstream side ECU 6A.

The downstream side ECU 6A is an ECU that executes control to the actuator 5 based on a target wheel pressure (or a target deceleration) which is a target value of the wheel pressure. The downstream side ECU 6A executes pressure increasing control, depressurizing control, holding control, or pressurizing control with respect to the actuator 5 based on the target wheel pressure. The downstream ECU 6A acquires information from various sensors 71 to 77 via or directly from the upstream ECU 6. The upstream ECU 6 and the downstream ECU 6A may be composed of one ECU.

Here, to briefly explain each control state by the downstream ECU 6A by taking the control for the wheel cylinder 541 as an example, in the pressure increase control, the pressure increase valve 52 (and the differential pressure control valve 51) is opened and the pressure reducing valve 54 is closed. It becomes a state. The check valve 51a installed in parallel with the differential pressure control valve 51 allows the flow of brake fluid from upstream to downstream, and vice versa. Therefore, when the hydraulic pressure on the upstream side is higher than the hydraulic pressure on the downstream side, the brake fluid is supplied downstream via the check valve 51a without control to the differential pressure control valve 51. In the pressure reducing control, the pressure increasing valve 52 is closed and the pressure reducing valve 54 is opened. In the holding control, the pressure boosting valve 52 and the pressure reducing valve 54 are closed. Further, the holding control can also be executed by closing (squeezing) the pressure reducing valve 54 and the differential pressure control valve 51 without closing the pressure increasing valve 52. Further, in the holding control, from the viewpoint of pressurization responsiveness, control is also performed in which the differential pressure is maintained while the brake fluid is leaked from the differential pressure control valve 51 to the upstream side while the motor 90 and the pump 57 are being driven. That is, the differential pressure control valve 51 and / or the pressure boosting valve 52 corresponds to a holding valve that holds the wheel pressure. In the pressurization control, the differential pressure control valve 51 is in the differential pressure state (throttle state), the pressure booster valve 52 is in the open state, the pressure reducing valve 54 is in the closed state, and the motor 90 and the pump 57 are driven.

Briefly explaining an example of coordinated control of both ECUs 6 and 6A, the upstream ECU 6 sets a target deceleration (target value for deceleration) based on the stroke information, and downstream the target deceleration information via a communication line. It is transmitted to the side ECU 6A. The target master pressure and the target wheel pressure are determined based on the target deceleration. The upstream side ECU 6 and the downstream side ECU 6A control the hydraulic pressure of the brake fluid so that the wheel pressure approaches the target wheel pressure (deceleration approaches the target deceleration) by coordinated control. The upstream ECU 6 calculates the target deceleration based on the stroke to calculate the target master pressure, and the downstream ECU 6A calculates the target wheel pressure based on the target deceleration, and the detected master pressure (or target master pressure) and the target. The pressurization amount (control amount) is set based on the wheel pressure.

Further, both ECUs 6 and 6A execute cooperative control (regenerative cooperative control) with the hybrid ECU 81. In the regenerative cooperative control, for example, from the start of the brake operation to a predetermined situation, the target deceleration is achieved by the regenerative braking force of the regenerative braking device 8 and the pressurization of the wheel pressure (hydraulic braking force) by the actuator 5. Then, after a predetermined situation, the master pressure is also applied as the hydraulic braking force by the servo pressure generating device 4, and the target deceleration is achieved together with the regenerative braking force. Near the end of the brake operation, for example, the target deceleration is achieved only by the regenerative braking force, and then, at a predetermined timing, the replacement control for switching from the regenerative braking force to the hydraulic braking force (pressurization by the actuator 5) is executed. The hybrid ECU 81 sets a target regenerative braking force according to the situation and transmits information on the actually generated regenerative braking force to both ECUs 6 and 6A, and both ECUs 6 and 6A request the regenerative braking force and the hydraulic braking force. The servo pressure generator 4 and the actuator 5 are controlled so that the braking force (required deceleration) is achieved.

As described above, the vehicle braking device BF is arranged in the main cylinder 11 so as to be separated forward from the input piston 13 in the main cylinder 11 and the input piston 13 that advances in the main cylinder 11 in response to the increase in the stroke of the brake pedal 10. The servo pressure generator 4 that generates the master pressure corresponding to the hydraulic braking force applied to the wheel W by driving the first master piston 14 and the first master piston 14 forward, and the wheel W are regenerated. A device including a regenerative braking device 8 that applies braking force, and a device that cooperatively controls the regenerative braking device 8 and the servo pressure generator 4 while increasing the regenerative braking force of the regenerative braking device 8 in response to an increase in stroke. be. Further, the regenerative braking device 8 applies a regenerative braking force to the front wheel Wf or the rear wheel Wr of the wheels W, and the servo pressure generator 4 applies the front wheel Wf and the rear wheel Wf by the hydraulic pressure (wheel pressure) based on the master pressure. A hydraulic braking force is applied to the wheel Wr.

(Adjustment control)
Here, an adjustment control for suppressing contact (collision) between the input piston 13 and the first master piston 14 and exhibiting appropriate braking performance will be described. Here, it can be said that each of the ECUs 6, 6A, and 81 constitutes one control device 60 because the control is executed in cooperation with each other. As a function, the control device 60 increases the drive amount of the first master piston 14 by a specified value (predetermined drive amount) by the servo pressure generator 4 when the stroke of the brake pedal 10 exceeds a predetermined value, and the specified value. A control unit 61 for executing adjustment control for reducing the regenerative braking force by the regenerative braking device 8 is provided.

The adjustment control can be said to be a control in which the regenerative braking force is reduced by a predetermined amount with a decreasing gradient according to a predetermined increasing gradient while increasing the servo pressure with a predetermined increasing gradient. The predetermined increase gradient is set to a constant value or a value corresponding to the increase gradient of the stroke. The predetermined pressure is set to a value larger than the driving hydraulic pressure (hydraulic pressure corresponding to the set load) of the first master piston 14. The predetermined amount is, for example, a preset constant value (fixed value), a value corresponding to an increasing gradient of the stroke (for example, an increasing gradient immediately before the stroke reaches a predetermined value), or a driving amount of the first master piston 14. It is a value corresponding to the hydraulic braking force of the front wheel Wf or the rear wheel Wr that increases when the specified value is increased. The increasing gradient of the servo pressure corresponds to the increasing gradient of the driving amount of the first master piston 14. Further, the adjustment control is executed during the regenerative braking in which the regenerative braking force is generated.

An example of adjustment control will be described with reference to FIGS. 3 and 4. As shown in FIG. 3, first, in t1 to t2 at the initial stage of braking operation, the required braking force is realized only by the regenerative braking force of the rear wheel Wr, and in t2 to t3, the actuator 5 controls the front wheel Wf by pressurization control. The required braking force is realized by the hydraulic braking force generated in the vehicle and the regenerative braking force of the rear wheel Wr. Then, when the stroke of the brake pedal 10 (input piston 13) reaches a predetermined value at t3, the adjustment control is executed, the servo pressure generator 4 operates, and the master pressure (servo pressure) has an increasing gradient according to the stroke fluctuation. Increases, and the regenerative braking force decreases by a predetermined amount with a decreasing gradient having the same gradient (absolute value: inclination) as the increasing gradient of the master pressure (t3 to t4). The predetermined amount here is a preset constant value. By increasing the servo pressure at t3 with a predetermined increasing gradient, when the servo pressure reaches the driving hydraulic pressure of the first master piston 14, the first master piston 14 momentarily advances by a specified value.

In t3 to t4, the servo pressure increases in response to the adjustment control and the increase in the stroke, so that the first master piston 14 advances. Further, at this time, since the stepping operation is continued, the input piston 13 is also moving forward. In t3 to t5, the increase in the required braking force and the decrease in the regenerative braking force of the rear wheel Wr are compensated for by increasing the master pressure and controlling the pressurization of the rear wheel Wr of the actuator 5. After that, the replacement control is executed immediately before the vehicle stops.

According to this adjustment control, since the first master piston 14 advances in a situation where the separation distance d is small, the separation distance d is increased (or the decrease in the separation distance d is suppressed), and the input piston 13 and the first master piston are suppressed. Contact with 14 is suppressed. Further, as shown in FIG. 4, the braking force distribution between the front wheel Wf and the rear wheel Wr can be kept good. For example, when the stroke reaches a predetermined value (t3) and the control is performed so as to increase the servo pressure without decreasing the regenerative braking force, the braking force is high as shown by the two-dot chain line in FIG. The braking force will increase in the region away from the ideal distribution line. The braking force distribution in the region where the braking force is high has a great influence on the running stability as compared with the region where the braking force is low.

However, in the adjustment control of the first embodiment, since the regenerative braking force is reduced according to the increase of the master pressure and the increase of the braking force of the rear wheel Wr is suppressed, the adjustment control is being executed (t3 to t4). , The distribution state moves toward the ideal distribution line. After that, when the control unit 61 keeps the regenerative braking force constant in t4 to t5, the hydraulic braking force of the front wheel Wf and the rear wheel Wr increases evenly due to the increase in the master pressure, and the braking force increases along the ideal distribution line. do. As a result, in the region where the braking force is high, it is suppressed that the braking force of one of the front wheel Wf and the rear wheel Wr is excessively increased as compared with the other, and the vehicle stability is kept good. As a vehicle braking device, a regenerative braking device 8 is generally provided for the front wheel Wf or the rear wheel Wr as in the first embodiment, and the master pressure corresponds to the hydraulic braking force of both the front and rear wheels. Also in this configuration, by reducing the regenerative braking force, it is suppressed that the braking force of one of the front wheel Wf and the rear wheel Wr becomes excessively larger than that of the other, and appropriate vehicle stability can be exhibited. Further, even if the adjustment control is performed, the generated braking force also becomes a value corresponding to the required braking force due to the increase in the hydraulic braking force and the decrease in the regenerative braking force.

Further, in the first embodiment, the predetermined value which is the threshold value of the stroke related to the execution of the adjustment control corresponds to the normal range (for example, the deceleration is 0.3 G or less) in which the normal braking operation (operation excluding the emergency brake) is performed. It is set to a value corresponding to a high deceleration range (for example, deceleration is 0.3 to 0.5 G) instead of a value. As a result, even if the adjustment control is executed, as shown in FIG. 5, the regenerative amount in the high deceleration range decreases, but the regenerative amount in the normal range does not decrease, so that the decrease in the regenerative amount is extremely small. be able to. For example, when an emergency braking operation is performed, the deceleration reaches a high deceleration range.

Further, when the braking force distribution is adjusted by the pressure adjusting function of the actuator 5 in response to the increase in the master pressure, the operating noise of various solenoid valves, the lock of the stroke, and the like are generated, so that the brake feeling is deteriorated and the brake feeling is deteriorated. It is practically difficult to realize allocation adjustment. However, according to the adjustment control of the first embodiment, it is not necessary to perform special control on the actuator 5, and these problems do not occur.

Further, in the adjustment control, the control unit 61 increases the decreasing gradient of the regenerative braking force as the increasing gradient of the stroke increases, so that the braking performance can be maintained more accurately. For example, when the stroke is kept constant after the stroke reaches a predetermined value at t3, as shown in FIG. 6, the drive amount of the first master piston 14 is a specified value with a predetermined increasing gradient by the adjustment control. The regenerative braking force decreases by a predetermined amount with a predetermined decreasing gradient so as to cancel the increase in the hydraulic braking force due to the increase. That is, even if the adjustment control is performed, the braking force corresponding to the required braking force is realized. Then, the separation distance d increases by a specified value.

<Second Embodiment>
The vehicle braking device of the second embodiment is different from the first embodiment in that the control device 60 further includes a determination unit 62. Therefore, only the different parts will be described. In the description of the second embodiment, the description and the drawings of the first embodiment can be referred to.

As shown in FIG. 7, the control device 60 includes a control unit 61 and a determination unit 62 as functions. The determination unit 62 is configured to determine the probability (large or small possibility) that the increase gradient of the stroke of the brake pedal 10 is equal to or higher than the reference value (predetermined gradient). The control unit 61 sets a larger specified value as the probability of determination by the determination unit 62 increases. The determination unit 62 determines that the higher the vehicle speed, the higher the probability. The vehicle speed can be calculated, for example, based on the detection result of the wheel speed sensor 76. When driving at high speed, the possibility of performing an emergency braking operation is higher than when driving at low speed. Therefore, the determination unit 62 determines that the probability is high when the vehicle speed is equal to or higher than the predetermined speed. When the determination unit 62 determines that the probability is high, the control unit 61 increases the specified value (for example, increases the specified value by a certain amount from the initial value). As a result, when the adjustment control is executed, the drive amount of the first master piston 14 (for example, the momentary drive amount) becomes larger than that at low speed, and the input piston 13 and the first master piston 14 are more reliably contacted with each other. Contact can be suppressed.

<Others>
The present invention is not limited to the above embodiment. For example, the control unit 61 may be configured to execute adjustment control regardless of the magnitude of the stroke when the pumping operation is executed for the brake pedal 10. The pumping operation is an operation of repeating stepping and releasing in a short period of time, and the control unit 61 can detect, for example, from the fluctuation of the stroke. In the situation where the pumping operation is performed, the separation distance d fluctuates almost periodically, but when a control delay or the like occurs there, when the input piston 13 is moving forward (when the separation distance d is small). ) It is also conceivable that the first master piston 14 retracts. Therefore, when the pumping operation is performed, the control unit 61 executes the adjustment control in advance regardless of the stroke, so that the contact between the input piston 13 and the first master piston 14 is suppressed.

Further, the actuator 5 is not limited to one having a pressurizing function, and may be one having no pressurizing function (for example, an ABS actuator). Further, the servo pressure generator 4 may be configured not to have a regulator 44. Further, the regenerative braking device 8 may be provided with respect to the front wheel Wf. Further, the predetermined direction is the direction in which the input piston 13 advances when the brake pedal 10 is depressed, and is described as forward in the present embodiment. Further, both ECUs 6 and 6A may be configured by one ECU.

10 ... Brake pedal (brake operation member), 11 ... Main cylinder (cylinder), 13 ... Input piston, 14 ... First master piston (master piston), 4 ... Servo pressure generator (drive unit), 5 ... Actuator, 61 ... Control unit, 62 ... Judgment unit, 8 ... Regenerative braking device (regenerative braking unit), BF ... Vehicle braking device, W ... Wheel.

Claims (5)

An input piston that advances in a predetermined direction in response to an increase in the stroke of the brake operating member, a master piston that is arranged in the cylinder at a distance from the input piston in the predetermined direction, and the master piston. A drive unit that generates a master pressure corresponding to the hydraulic braking force applied to the wheel by driving in the predetermined direction and a regenerative braking unit that applies the regenerative braking force to the wheel are provided to increase the stroke. A vehicle braking device that cooperatively controls the regenerative braking unit and the drive unit while increasing the regenerative braking force of the regenerative braking unit in accordance with the above.
When the stroke becomes a predetermined value or more, the drive unit increases the drive amount of the master piston by a specified value, and the regenerative braking unit reduces the regenerative braking force according to the specified value. A braking device for vehicles equipped with a part. A determination unit for determining the probability that the increase gradient of the stroke of the brake operating member will be equal to or higher than the reference value is provided.
The vehicle braking device according to claim 1, wherein the control unit sets the specified value larger as the probability determined by the determination unit increases. The vehicle braking device according to claim 2, wherein the determination unit determines that the higher the vehicle speed, the higher the probability. The vehicle according to any one of claims 1 to 3, wherein the control unit executes the adjustment control regardless of the magnitude of the stroke when the pumping operation is executed for the brake operating member. Braking device. The vehicle braking device according to any one of claims 1 to 4, wherein the control unit increases the decreasing gradient of the regenerative braking force as the increasing gradient of the stroke increases in the adjustment control.

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