WO2019239894A1 - Brake control device, brake control method and pump device to be used for brake control device - Google Patents

Abstract

According to the present invention, a control unit switches a rotation direction of a motor that drives a plunger pump.

Description

BRAKE CONTROL DEVICE, BRAKE CONTROL METHOD, AND PUMP DEVICE USED FOR BRAKE CONTROL DEVICE

The present invention relates to a brake control device, a brake control method, and a pump device used in the brake control device.

Patent Document 1 aims to suppress uneven wear between the outer circumferential surface of the eccentric cam and the end surface of the plunger in the plunger pump, and offsets the central axis of the plunger in the direction opposite to the rotational direction of the motor with respect to the rotational axis of the motor. A brake control device is disclosed.

German Patent Application Publication No. 4310062 Specification DE4310062C2

However, in the above-mentioned Patent Document 1, although an effect is recognized with respect to the uneven wear of the plunger end surface contacting the outer peripheral surface of the eccentric cam, there is a possibility that the uneven wear of the sliding portion due to the inclination of the plunger is promoted.

One of the objects of the present invention is to provide a brake control device, a brake control method, and a pump device used in the brake control device that can suppress uneven wear of the sliding portion due to the inclination of the plunger.
A brake control device according to an embodiment of the present invention includes a control unit that switches a rotation direction of a motor that drives a plunger pump.

Therefore, according to the brake control device in one embodiment of the present invention, uneven wear of the sliding portion due to the inclination of the plunger can be suppressed.

1 is a schematic diagram of a brake control device 1 according to Embodiment 1. FIG. 3 is a perspective view of a hydraulic unit housing 80 according to Embodiment 1. FIG. 3 is an axial sectional view of a hydraulic unit housing 80 according to Embodiment 1. FIG. 3 is a cross-sectional view in the axial direction of the hydraulic unit housing 80 of Embodiment 1. FIG. 2 is an enlarged cross-sectional view of a plunger pump 86 according to Embodiment 1. FIG. FIG. 3 is a diagram illustrating a control configuration of a motor 211 according to the first embodiment. 3 is a flowchart illustrating a flow of rotation direction switching control of a motor 211 in the first embodiment. 3 is a flowchart illustrating a flow of rotation direction switching control of a motor 211 in the first embodiment. 6 is a flowchart illustrating a flow of rotation direction switching control of a motor 211 in the second embodiment. 10 is a flowchart showing a flow of rotation direction switching control of a motor 211 in the third embodiment. 10 is a flowchart illustrating a flow of rotation direction switching control of a motor 211 in the fourth embodiment. FIG. 10 is a diagram illustrating a control configuration of a motor 211 according to a sixth embodiment.

Embodiment 1
FIG. 1 is a schematic diagram of a brake control device 1 according to the first embodiment.
The brake control device 1 is a general vehicle having only an internal combustion engine (engine) as a prime mover for driving wheels, a hybrid vehicle having an electric motor / generator in addition to the internal combustion engine, and an electric motor. It is mounted on an electric vehicle equipped with only. The brake control device 1 is a disc brake that is installed on each wheel (the left front wheel FL, the right front wheel FR, the left rear wheel RL, the right rear wheel RR) and operates according to the hydraulic pressure of the wheel cylinder (braking force applying portion) 2 Have The brake control device 1 applies a braking torque to each of the wheels FL to RR by adjusting the hydraulic pressure of the wheel cylinder 2. The brake control device 1 has two systems (primary P system and secondary S system) of brake piping. The brake piping format is, for example, the X piping format. Hereinafter, when distinguishing a member corresponding to the primary system (hereinafter referred to as P system) and a member corresponding to the secondary system (hereinafter referred to as S system), the suffixes P and S are added to the end of the reference numerals. Further, when distinguishing the members corresponding to the wheels FL to RR, suffixes a to d are added to the end of the reference numerals.
The brake pedal 3 is a brake operation member that receives an input of a driver's brake operation. The push rod 4 strokes according to the operation of the brake pedal 3. The master cylinder 5 operates according to the stroke amount of the push rod 4, and generates brake fluid pressure (master cylinder fluid pressure).

The master cylinder 5 is supplied with brake fluid from a reservoir tank 6 that stores brake fluid. The master cylinder 5 is of a tandem type and has a P piston 51P and an S piston 51S that stroke according to the stroke of the push rod 4. Both pistons 51P and 51S are arranged in series along the axial direction of the push rod 4. The P piston 51P is connected to the push rod 4. The S piston 51S is a free piston type. A stroke sensor 60 is attached to the master cylinder 5. The stroke sensor 60 detects the stroke amount of the P piston 51P as the pedal stroke amount of the brake pedal 3.
The stroke simulator 7 operates according to the driver's brake operation. The stroke simulator 7 generates a pedal stroke by the flow of brake fluid that has flowed out of the master cylinder 5 in response to the driver's brake operation. The piston 71 of the stroke simulator 7 operates in the axial direction against the urging force of the spring 73 in the cylinder 72 by the brake fluid supplied from the master cylinder 5. Thereby, the stroke simulator 7 generates an operation reaction force corresponding to the driver's brake operation.

The hydraulic unit 8 can apply a braking torque to each wheel FL to RR independently of the driver's brake operation. The hydraulic unit 8 receives supply of brake fluid from the master cylinder 5 and the reservoir tank 6. The hydraulic unit 8 is installed between the master cylinder 5 and the wheel cylinder 2. The hydraulic unit 8 includes a motor (pump device) 211 of the pump 21 and a plurality of electromagnetic valves (such as a shutoff valve 12) as actuators for generating a control hydraulic pressure. The pump 21 sucks brake fluid from the reservoir tank 6 and discharges it toward the wheel cylinder 2. The pump 21 is a five plunger pump. In the first embodiment, a three-phase brushless motor is employed as the motor 211. The shutoff valve 12 or the like opens and closes according to the control signal, and controls the flow of the brake fluid by switching the communication state of the fluid passage 11 and the like. The hydraulic unit 8 pressurizes the wheel cylinder 2 with the brake hydraulic pressure generated by the pump while the communication between the master cylinder 5 and the wheel cylinder 2 is cut off. Further, the hydraulic unit 8 includes hydraulic pressure sensors 35 to 37 that detect hydraulic pressures at various places.

The control unit (pump device) 9 controls the operation of the hydraulic unit 8. In addition to the detection values sent from the stroke sensor 60 and the hydraulic pressure sensors 35 to 37, the control unit 9 receives information (wheel speed and the like) related to the running state sent from the vehicle side. The control unit 9 performs information processing in accordance with a built-in program based on various input information, and calculates the target wheel cylinder hydraulic pressure of the wheel cylinder 2. The control unit 9 outputs a command signal to each actuator of the hydraulic unit 8 so that the wheel cylinder hydraulic pressure of the wheel cylinder 2 becomes the target wheel cylinder hydraulic pressure. Accordingly, various brake controls (such as boost control, antilock control, brake control for vehicle motion control, automatic brake control, and regenerative cooperative brake control) can be realized. The boost control assists the brake operation by generating a brake fluid pressure that is insufficient for the driver's brake pedal force. Anti-lock control suppresses braking slip (lock tendency) of each wheel FL to RR. Vehicle motion control is vehicle behavior stabilization control that prevents skidding and the like. The automatic brake control is a preceding vehicle following control, an automatic emergency brake, or the like. The regenerative cooperative brake control controls the wheel cylinder hydraulic pressure so as to achieve the target deceleration in cooperation with the regenerative brake.

A P hydraulic chamber 52P is defined between the pistons 51P and 51S of the master cylinder 5. A compression coil spring 53P is installed in the P hydraulic chamber 52P. An S hydraulic pressure chamber 52S is defined between the S piston 51S and the bottom portion 541 of the cylinder 54. A compression coil spring 53S is installed in the S hydraulic chamber 52S. A fluid passage (connection fluid passage) 11 is opened in each of the fluid pressure chambers 52P and 52S. Each of the hydraulic chambers 52P and 52S is connected to the hydraulic unit 8 through the liquid path 11, and can communicate with the wheel cylinder 2.
As the driver depresses the brake pedal 3, the piston 51 strokes, and the master cylinder hydraulic pressure is generated as the volume of the hydraulic pressure chamber 52 decreases. Approximately the same master cylinder hydraulic pressure is generated in both hydraulic pressure chambers 52P and 52S. As a result, the brake fluid is supplied from the hydraulic chamber 52 to the wheel cylinder 2 via the fluid path 11. The master cylinder 5 pressurizes the P system wheel cylinders 2a and 2d through the P system fluid path (fluid path 11P) by the master cylinder fluid pressure generated in the P fluid pressure chamber 52P. The master cylinder 5 pressurizes the S- system wheel cylinders 2b and 2c through the S-system liquid path (liquid path 11S) by the master cylinder hydraulic pressure generated in the S-hydraulic chamber 52S.

The stroke simulator 7 has a cylinder 72, a piston 71, and a spring 73. The cylinder 72 has a cylindrical inner peripheral surface. The cylinder 72 has a piston housing part 721 and a spring housing part 722. The piston housing part 721 has a smaller diameter than the spring housing part 722. On the inner peripheral surface of the spring accommodating portion 722, a liquid path 27 described later is always open. The piston 71 is movable in the axial direction within the piston housing portion 721. The piston 71 separates the inside of the cylinder 72 into a positive pressure chamber 711 and a back pressure chamber 712. The liquid path 26 is always open in the positive pressure chamber 711. The liquid passage 27 is always open in the back pressure chamber 712. A piston seal 75 is installed on the outer periphery of the piston 71. The piston seal 75 is in sliding contact with the outer peripheral surface of the piston 71 and seals between the inner peripheral surface of the piston housing portion 721 and the outer peripheral surface of the piston 71. The piston seal 75 is a separation seal member that seals between the positive pressure chamber 711 and the back pressure chamber 712 to separate them liquid-tightly, and complements the function of the piston 71. The spring 73 is a compression coil spring installed in the back pressure chamber 712 and biases the piston 71 from the back pressure chamber 712 side toward the positive pressure chamber 711 side. The spring 73 generates a reaction force according to the compression amount. The spring 73 has a first spring 731 and a second spring 732. The first spring 731 is smaller in diameter and shorter than the second spring 732 and has a smaller wire diameter. The first spring 731 and the second spring 732 are arranged in series via the retainer member 74 between the piston 71 and the spring accommodating portion 722.

The fluid path 11 connects between the fluid pressure chamber 52 of the master cylinder 5 and the wheel cylinder 2. The liquid path 11P branches into a liquid path 11a and a liquid path 11d. The liquid path 11S branches into the liquid path 11b and the liquid path 11d. The shut-off valve (shut-off valve portion) 12 is a normally open type solenoid valve (opened in a non-energized state) provided in the liquid passage 11. The electromagnetic proportional valve can realize any opening degree according to the current supplied to the solenoid. The liquid path 11 is separated by a shutoff valve 12 into a liquid path 11A on the master cylinder 5 side and a liquid path 11B on the wheel cylinder 2 side.
The solenoid-in valve 13 is a normally open electromagnetic valve provided on the wheel cylinder 2 side (liquid path 11B) with respect to each wheel FL to RR (liquid paths 11a to 11d) with respect to the shutoff valve 12 in the liquid path 11. It is a proportional valve. The liquid path 11 is provided with a bypass liquid path 14 that bypasses the solenoid-in valve 13. The bypass fluid passage 14 is provided with a check valve 15 that allows only the flow of brake fluid from the wheel cylinder 2 side to the master cylinder 5 side.

The suction pipe 16 connects the reservoir tank 6 and the internal reservoir 17. The liquid path 18 connects the internal reservoir 17 and the suction side of the pump 21. The liquid path 19 connects the discharge side of the pump 21 and between the shut-off valve 12 and the solenoid-in valve 13 in the liquid path 11B. The liquid path 19 branches into a P-system liquid path 19P and an S-system liquid path 19S. Both liquid paths 19P and 19S are connected to the liquid paths 11P and 11S. Both liquid passages 19P and 19S function as communication passages that connect the liquid passages 11P and 11S to each other. The communication valve 20 is a normally closed type (closed in a non-energized state) on / off valve provided in the liquid passage 19. The on / off valve is binaryly switched according to the current supplied to the solenoid.
The pump 21 generates a hydraulic pressure in the liquid passage 11 by the brake fluid supplied from the reservoir tank 6 to generate a wheel cylinder hydraulic pressure. The pump 21 is connected to the wheel cylinders 2a to 2d via the liquid passages 19P and 19S and the liquid passages 11P and 11S, and pressurizes the wheel cylinder 2 by discharging brake fluid to the liquid passages 19P and 19S.

The liquid path 22 connects the branch point of both the liquid paths 19P and 19S and the liquid path 23. A pressure regulating valve 24 is provided in the liquid path 22. The pressure regulating valve 24 is a normally open type electromagnetic proportional valve. The fluid path 23 connects the wheel cylinder 2 side to the internal reservoir 17 with respect to the solenoid-in valve 13 in the fluid path 11B. The solenoid-out valve 25 is a normally closed on / off valve provided in the liquid path 23.
The liquid path 26 branches off from the P-system liquid path 11A and is connected to the positive pressure chamber 711 of the stroke simulator 7. The liquid passage 26 may directly connect the P hydraulic pressure chamber 52P and the positive pressure chamber 711 without going through the liquid passage 11P (11A).

The liquid passage 27 connects between the back pressure chamber 712 of the stroke simulator 7 and the liquid passage 11. Specifically, the liquid passage 27 branches from between the shutoff valve 12P and the solenoid-in valve 13 in the liquid passage 11P (11B) and is connected to the back pressure chamber 712. The stroke simulator-in valve 28 is a normally closed on / off valve provided in the liquid passage 27. The liquid path 27 is separated into a liquid path 27A on the back pressure chamber 712 side and a liquid path 27B on the liquid path 11 side by the stroke simulator in valve 28. A bypass liquid path 29 is provided in parallel with the liquid path 27 by bypassing the stroke simulator in valve 28. The bypass liquid path 29 connects the liquid path 27A and the liquid path 27B. A check valve 30 is provided in the bypass liquid passage 29. The check valve 30 allows the flow of brake fluid from the fluid passage 27A toward the fluid passage 11 (27B), and suppresses the flow of brake fluid in the reverse direction.
The liquid path 31 connects between the back pressure chamber 712 of the stroke simulator 7 and the liquid path 23. The stroke simulator out valve 32 is a normally closed on / off valve provided in the liquid passage 31. A bypass liquid path 33 is provided in parallel with the liquid path 31 by bypassing the stroke simulator out valve 32. The bypass fluid passage 33 is provided with a check valve 34 that allows the flow of brake fluid from the fluid passage 23 side to the back pressure chamber 712 side and suppresses the brake fluid flow in the reverse direction.

Between the shutoff valve 12P and the master cylinder 5 in the fluid path 11P (fluid path 11A), a master cylinder fluid pressure sensor that detects fluid pressure at this location (master cylinder fluid pressure and fluid pressure in the positive pressure chamber 711). 35 is provided. Between the shut-off valve 12 and the solenoid-in valve 13 in the fluid passage 11, a wheel cylinder fluid pressure sensor (P system pressure sensor, S system pressure sensor) 36 for detecting the fluid pressure (wheel cylinder fluid pressure) at this point is provided. Is provided. A discharge pressure sensor 37 is provided between the discharge side of the pump 21 in the liquid passage 19 and the communication valve 20 to detect the liquid pressure (pump discharge pressure) at this location.
The brake system (fluid path 11) that connects the hydraulic chamber 52 of the master cylinder 5 and the wheel cylinder 2 in a state where the shut-off valve 12 is opened constitutes a first system. This first system can realize a pedal force brake (non-boosting control) by generating a wheel cylinder hydraulic pressure by a master cylinder hydraulic pressure generated using a pedaling force. On the other hand, the brake system (liquid path 19, liquid path 22, liquid path 23, etc.) including the pump 21 and connecting the reservoir tank 6 and the wheel cylinder 2 with the shut-off valve 12 closed is the second system. Configure. This second system constitutes a so-called brake-by-wire device that generates the wheel cylinder hydraulic pressure by the hydraulic pressure generated using the pump 21, and can realize boost control or the like as brake-by-wire control. During the brake-by-wire control, the stroke simulator 7 generates an operation reaction force accompanying the driver's brake operation.

FIG. 2 is a perspective view of the hydraulic unit housing 80 of the first embodiment, and FIG. 3 is an axial sectional view of the hydraulic unit housing 80.
A motor case 81, a stroke simulator case 82, and a control unit case 83 are fixed to the hydraulic unit housing 80.
The hydraulic unit housing (hereinafter referred to as “housing”) 80 is made of, for example, an aluminum alloy and is a substantially rectangular housing having a front surface 801, a back surface 802, an upper surface 803, a bottom surface 804, a right side surface 805, and a left side surface 806. The housing 80 has each liquid passage (liquid passage 11 etc.) formed therein. The housing 80 accommodates the pump 21, solenoid valves (such as the shut-off valve 12), and fluid pressure sensors (such as the master cylinder fluid pressure sensor 35). On the upper surface 803 of the housing 80, four wheel cylinder ports 8031 are formed, and a nipple 8032 is attached. The wheel cylinder port 8031 is connected to the wheel cylinder 2 via a wheel cylinder pipe (not shown). A suction pipe 16 is connected to the nipple 8032. On the back surface 802 of the housing 80, a valve housing hole 8021 and four sensor housing holes 8022 for each electromagnetic valve are formed. Each valve accommodating hole 8021 accommodates a valve portion of each electromagnetic valve (such as the shutoff valve 12). Each sensor accommodation hole 8022 accommodates each hydraulic pressure sensor (master cylinder hydraulic pressure sensor 35, etc.).

The motor case 81 is a metal cylindrical member, and houses the motor 211 therein. The motor case 81 is fixed to the front surface 801 of the housing 80. Two master cylinder ports 8011 are formed on the front surface 801.
The stroke simulator case 82 is made of an aluminum alloy, and accommodates the stroke simulator 7 therein. The stroke simulator case 82 is fastened to the right side surface 805 of the housing 80 by a screw (not shown).
The control unit case 83 is formed of a resin material, and accommodates the solenoid 84 and the control board 40 of each electromagnetic valve (the cutoff valve 12 and the like). The control board 40 is the control unit 9 and controls the energization state of the motor 211 and each solenoid. The control board 40 is attached in parallel with the back surface 802. In addition to the terminal 212a of the power supply unit 212 penetrating the housing 80, the terminal 84a of each solenoid 84 and the terminals 85 of the hydraulic pressure sensors 35 to 37 are connected to the control board 40.

4 is a cross-sectional view in the direction perpendicular to the axis of the hydraulic unit housing 80, and FIG. 5 is an enlarged cross-sectional view of the plunger pump (pump device) 86.
The pump 21 of the first embodiment has five plunger pumps 86A to 86E. Each plunger pump 86A to 86E is housed in five cylinder housing holes 80a formed in the housing 80. Two cylinder receiving holes 80a are arranged on the right side 805 of the housing 80 (80aD, 80aE), two on the left side 806 (80aB, 80aC), and one on the bottom 804 (80aA). Line up at equal pitches in the surrounding direction. Each cylinder accommodation hole 80a is connected to the cam chamber 80b. The cam chamber 80 b extends in a direction along the rotation axis of the motor 211 and opens on the front surface 801 of the housing 80. The cam chamber 21b accommodates a cam unit 21a that is rotationally driven by the rotational drive shaft 300 of the motor 211. The cam unit 21a includes an eccentric cam 301, a drive member 302 (outer ring), and a plurality of rolling elements 303. The eccentric cam 301 is a cylindrical eccentric cam, and has a rotation axis P that is eccentric with respect to the rotation axis O of the rotation drive shaft 300. The rotation axis P extends substantially parallel to the rotation axis O. The eccentric cam 301 swings while rotating around the rotation axis O integrally with the rotation drive shaft 300. The drive member 302 (outer ring) has a cylindrical shape and is disposed on the outer peripheral side of the eccentric cam 301. The drive member 302 (outer ring) can rotate around the rotation axis P with respect to the eccentric cam 301. The drive member 302 (outer ring) is an eccentric bearing having the same configuration as the outer ring of the rolling bearing. The plurality of rolling elements 303 are disposed between the outer peripheral surface of the eccentric cam 301 and the inner peripheral surface of the drive member 302 (outer ring). The rolling element 303 is a needle roller and extends along the direction of the rotation axis O. The eccentric cam 301 and the rotation drive shaft 300 of the motor 211 may be integrally configured, and a general rolling bearing may be used for the cam unit 21a, for example, a needle bearing having needle rollers on the rolling element 303 or the like. .

The plunger pumps 86A to 86E are plunger pumps (piston pumps) as reciprocating pumps, and are operated by the rotation of the rotary drive shaft 300. As the plunger 86a reciprocates, the brake fluid as the hydraulic fluid is sucked and discharged. The cam unit 21a has a function of converting the rotary motion of the rotary drive shaft 300 into the reciprocating motion of the plunger 86a. When the configurations of the plunger pumps 86A to 86E are distinguished from each other, suffixes A to E are added to the reference numerals. Each plunger 86a is arranged around the cam unit 21a, and is accommodated in each cylinder accommodation hole 80a. The central axis 360 of the plunger 86a substantially coincides with the central axis of the cylinder accommodation hole 80a and extends in the radial direction of the rotary drive shaft 300. The central axes 360A to 360E of the plungers 86aA to 86aE are in the same plane. These plungers 86aA to 86aE are driven by the same rotation drive shaft 300 and the same cam unit 21a.

The plunger pump 86A includes a cylinder sleeve 304, a filter member 305, a plug 306, a guide ring 307, a first seal ring 351, a second seal ring 352, a plunger 86a, a return spring 308, and a suction valve 38. And a discharge valve 39, which are installed in the cylinder accommodation hole 80a. The cylinder sleeve 304 has a bottomed cylindrical shape, and a through hole 311 passes through the bottom portion 310. The cylinder sleeve 304 is fixed to the cylinder accommodation hole 80a. An end 312 on the opening side of the cylinder sleeve 304 is disposed at the medium diameter portion 822 (suction port 823), and the bottom portion 310 is disposed at the large diameter portion (discharge port) 821. The filter member 305 has a bottomed cylindrical shape, and a hole 321 passes through the bottom 320 and a plurality of openings penetrates the side wall. A filter is installed in the opening. An end 323 on the opening side of the filter member 305 is fixed to an end 312 on the opening side of the cylinder sleeve 304. The bottom part 320 is disposed in the small diameter part 820. There is a gap between the outer peripheral surface where the opening of the filter member 305 opens and the inner peripheral surface of the cylinder accommodation hole 80a (suction port 823). The first communication liquid path communicates with the suction port 823 and the gap. That is, the first communication liquid path is between the liquid path 18 and the suction port 823. The plug 306 has a columnar shape, and has a bottomed cylindrical discharge chamber 330 and a discharge passage 331 on one end side in the central axis direction. The discharge passage 331 extends in the radial direction, connects the discharge chamber 330 and the outer peripheral surface of the plug 306, and communicates with the discharge port 821. One end of the plug 306 in the axial direction is fixed to the bottom 310 of the cylinder sleeve 304. The plug 306 is fixed to the large diameter portion 821 and closes the opening of the cylinder accommodation hole 80a on the outer peripheral surface of the housing 80. The second communication liquid path communicates with the discharge port 821 and the discharge passage 331 of the plug 306. That is, the second communication liquid path is between the discharge port 821 and the liquid path 19. The guide ring 307 has a cylindrical shape and is fixed to the cam chamber 80b side (small diameter portion 820) with respect to the filter member 305 in the cylinder accommodation hole 80a. The first seal ring 351 is installed between the guide ring 307 and the filter member 305 in the cylinder accommodation hole 80a (small diameter portion 820).

The plunger 86a has a cylindrical shape, and has an end surface (hereinafter referred to as a plunger end surface) 361 on one side in the central axis direction and a flange portion 362 on the outer periphery on the other side in the central axis direction. The plunger end surface 361 has a planar shape extending in a direction substantially orthogonal to the central axis 360 of the plunger 86a, and has a substantially circular shape centering on the central axis 360. The plunger 86a has an axial hole 363 and a radial hole 364 therein. The axial hole 363 extends on the central axis 360 and opens on the end surface of the plunger 86a on the other side in the central axial direction. The radial hole 364 extends in the radial direction of the plunger 86 a, opens on the outer peripheral surface on one side in the central axis direction than the flange portion 362, and connects to the one side in the central axis direction of the axial hole 363. A check valve case 365 is fixed to the other end of the plunger 86a on the other side in the central axis direction. The check valve case 365 has a bottomed cylindrical shape made of a thin plate, has a flange portion 366 on the outer periphery of the end portion on the opening side, and a plurality of holes 368 pass through the side wall portion and the bottom portion 367. The end of the check valve case 365 on the opening side is fitted to the other end of the plunger 86a on the other side in the central axis direction. The second seal ring 352 is installed between the flange portion 366 of the check valve case 365 and the flange portion 362 of the plunger 86a. The other side in the central axis direction of the plunger 86 a is inserted into the inner peripheral side of the cylinder sleeve 304, and the flange portion 362 is guided and supported by the cylinder sleeve 304. One side in the central axis direction of the plunger 86a from the radial hole 364 is on the inner peripheral side (hole 321) of the bottom 320 of the filter member 305, the inner peripheral side of the first seal ring 351, and the inner peripheral side of the guide ring 307. It is inserted in and guided and supported by these. One end (plunger end surface 361) of the plunger 86a on one side in the central axis direction protrudes into the cam chamber 80b.

The return spring 308 is a compression coil spring and is installed on the inner peripheral side of the cylinder sleeve 304. One end of the return spring 308 is installed on the bottom 310 of the cylinder sleeve 304, and the other end is installed on the flange 366 of the check valve case 365. The return spring 308 always urges the plunger 86a toward the cam chamber 80b with respect to the cylinder sleeve 304 (cylinder accommodation hole 80a). The suction valve 38 has a ball 380 as a valve body and a return spring 381, which are accommodated on the inner peripheral side of the check valve case 365. A valve seat 369 is provided around the opening of the axial hole 363 on the end surface on the other side in the central axial direction of the plunger 86a. When the ball 380 is seated on the valve seat 369, the axial hole 363 is closed. The return spring 381 is a compression coil spring, one end of which is installed on the bottom 367 of the check valve case 365 and the other end of which is installed on the ball 380.
The return spring 381 always urges the ball 380 toward the valve seat 369 with respect to the check valve case 365 (plunger 86a). The discharge valve 39 includes a ball 390 as a valve body and a return spring 391, which are accommodated in a discharge chamber 330 of the plug 306. A valve seat 313 is provided around the opening of the through hole 311 in the bottom 310 of the cylinder sleeve 304. When the ball 390 is seated on the valve seat 313, the through hole 311 is closed. The return spring 391 is a compression coil spring, one end of which is installed on the bottom surface of the discharge chamber 330 and the other end is installed on the ball 390. The return spring 391 always urges the ball 390 toward the valve seat 313.

Inside the cylinder housing hole 80a, the space R1 closer to the cam chamber 80b than the flange portion 362 of the plunger 86a is a suction side space communicating with the first communication liquid path. Specifically, from the gap between the outer peripheral surface of the filter member 305 and the inner peripheral surface (suction port 823) of the cylinder housing hole 80a, a plurality of openings of the filter member 305, and the outer peripheral surface of the plunger 86a and the filter member A space that passes through the gap between the inner peripheral surface of 305 and reaches the radial hole 364 and the axial hole 363 of the plunger 86a functions as the suction-side space R1. The suction-side space R1 is prevented from communicating with the cam chamber 80b by the first seal ring 351.
Inside the cylinder accommodation hole 80a, a space R3 between the cylinder sleeve 304 and the plug 306 is a discharge side space communicating with the second communication liquid path. Specifically, the space from the discharge passage 331 of the plug 306 to the discharge port 821 functions as the discharge side space R3. On the inner peripheral side of the cylinder sleeve 304, the volume of the space R2 between the flange portion 362 of the plunger 86a and the bottom portion 310 of the cylinder sleeve 304 changes due to the reciprocating movement (stroke) of the plunger 86a with respect to the cylinder sleeve 304. This space R2 communicates with the suction side space R1 by opening the suction valve 38, and communicates with the discharge side space R3 by opening the discharge valve 39.

The plunger 86aA of the plunger pump 86A reciprocates to perform the pumping action. That is, when the plunger 86aA strokes closer to the cam chamber 80b (rotation axis O), the volume of the space R2 increases and the pressure in R2 decreases. When the discharge valve 39 is closed and the suction valve 38 is opened, the brake fluid as the working fluid flows from the suction side space R1 into the space R2, and the space R2 passes through the suction port 823 from the first communication fluid path. Brake fluid is supplied to When the plunger 86aA strokes away from the cam chamber 80b, the volume of the space R2 decreases and the pressure in R2 increases. When the suction valve 38 is closed and the discharge valve 39 is opened, the brake fluid flows out from the space R2 to the discharge side space R3 through the through hole 311 and goes to the second communication liquid path through the discharge port 821. Brake fluid is supplied. The same applies to the other plunger pumps 86B to 86E. The brake fluid discharged from each plunger pump 86A to 86E to the second communication fluid passage is collected in one fluid passage 19, and is used in common in two systems of hydraulic circuits.

In the brake control device 1 according to the first embodiment, the control unit 9 switches the rotation direction of the motor 211 every time the driver performs a brake operation with the aim of suppressing uneven wear of the sliding portion due to the inclination of the plunger 86a. The sliding portion is a contact portion of the drive member 302 (outer ring) of the cam unit 21a, the cylinder sleeve 304, the first seal ring 351 and the second seal ring 352, and the guide ring 307 with respect to the plunger 86a.
FIG. 6 is a diagram illustrating a motor control configuration according to the first embodiment.
The control unit 9 controls driving of the motor 211 via the driving circuit 10. The drive circuit 10 includes switching elements Q1 to Q6 configured with, for example, a three-phase bridge of an Nch FET. The drain terminals of the switching elements Q1 to Q3 on the upper arm side are connected to the DC power source Vcc. The source terminals of the switching elements Q4 to Q6 on the lower arm side are connected to the ground GND. The source terminal of the switching element Q1 on the upper arm side and the drain terminal of the switching element Q4 on the lower arm side are connected, and the connection point of the switching elements Q1 and Q4 is connected to the U phase of the motor 211 via the output power line Lu. It is connected to the coil terminal. The source terminal of the switching element Q2 on the upper arm side and the drain terminal of the switching element Q5 on the lower arm side are connected, and the connection point between the switching elements Q2 and Q5 is connected to the V phase of the motor 211 via the output power line Lv. It is connected to the coil terminal. The source terminal of the switching element Q3 on the upper arm side and the drain terminal of the switching element Q6 on the lower arm side are connected, and the connection point of the switching elements Q3 and Q6 is connected to the W phase of the motor 211 via the output power line Lw. It is connected to the coil terminal.
A diode Dx (parasitic diode or the like) is connected in parallel to each of the switching elements Q1 to Q6 so that the cathode is in the direction of the DC power supply Vcc and the anode is in the direction of the ground GND as shown in the figure. Switching elements Q1 to Q6 may be IGBTs or bipolar transistors. In addition, although the motor 211 is a delta connection, it may be a star connection.
The control unit 9 detects the rotor rotation speed or rotor rotation angle (position) from the output of the Hall IC 211a installed in the motor 211, and sets the switching elements Q1 to Q6 so that the desired rotation speed and rotation direction are obtained. To drive.

7 and 8 are flowcharts showing the flow of the rotation direction switching control of the motor 211, which is executed by the control unit 9. 7 is executed when the motor 211 is in a driving state, and FIG. 8 is executed when the motor 211 is in a stopped state. Note that steps performing the same processing are denoted by the same step numbers and description thereof is omitted.
In step S1, various sensor values for calculating the target wheel cylinder hydraulic pressure are read. Sensor values include, for example, motor speed sensor (Hall IC211a), hydraulic pressure sensors 35-37, stroke sensor 60, wheel speed sensor, brake lamp switch, yaw rate sensor, front / rear G sensor, lateral G sensor, rudder angle sensor, etc. Sensor value.
In step S2, a target wheel cylinder hydraulic pressure is calculated based on each read sensor value.
In step S3, it is determined whether the target wheel cylinder hydraulic pressure is a positive value (> 0). If yes, go to return, if no, go to step S4.
In step S4, the motor 211 is stopped.
In step S5, the rotation direction of the motor 211 immediately before the stop is stored, and the process proceeds to return.
In step S6, it is determined whether the stored rotation direction of the previous motor 211 is CW (clockwise: clockwise direction). If YES, the process proceeds to step S7. If NO, the process proceeds to step S8. CW is the clockwise direction of the rotary drive shaft 300 when the hydraulic unit 8 is viewed from the front side (the clockwise direction in FIG. 4).
In step S7, the motor 211 is driven with the rotation direction as CCW (counterclockwise).
In step S8, the motor 211 is driven with the rotation direction as CW.

Next, the effect of Embodiment 1 is demonstrated.
In the plunger pump, when the plunger reaches the top dead center or the bottom dead center, the position where the plunger and the cylinder contact and slide with respect to the force of the eccentric cam acting on the plunger changes, and the plunger pump instantaneously Oscillation occurs. In the plunger pump in the conventional brake control device, the central axis of the plunger is opposite to the rotation direction of the motor with respect to the rotation axis of the motor, aiming to suppress the eccentric wear between the eccentric cam and the plunger due to the swing of the plunger. It is offset in the direction. However, in this prior art, the plunger repeatedly operates in a state where the plunger is always tilted by sliding with the eccentric cam. Therefore, there is a possibility that uneven wear of the sliding portion is promoted by always contacting the same portion. Further, the tightening allowance of the seal ring becomes non-uniform in the circumferential direction, which may cause a decrease in sealing performance and durability.
On the other hand, in the brake control device 1 of the first embodiment, the rotation direction of the motor 211 that drives the plunger pump 86 is switched at a predetermined timing. By switching the rotation direction of the motor 211, the position of each sliding portion changes, so that uneven wear of the sliding portion due to the inclination of the plunger 86a can be suppressed. That is, it is possible to suppress uneven wear of the sliding portions of the drive member 302 (outer ring) of the cam unit 21a, the cylinder sleeve 304, the first seal ring 351 and the second seal ring 352, and the guide ring 307 with respect to the plunger 86a. Further, by suppressing the uneven wear of the first seal ring 351 and the second seal ring 352, it is possible to suppress the tightening margin of the first seal ring 351 and the second seal ring 352 from becoming uneven in the circumferential direction, and the seal And durability can be improved. Further, by appropriately switching the rotation direction of the motor 211, it is possible to suppress the uneven distribution of the grease enclosed in the drive member 302 and the grease applied to the outer peripheral surface of the drive member 302. As a result, the durability of the plunger pump 86 can be improved.
In addition, the offset arrangement of the central axis 360 of the plunger 86a with respect to the rotational axis 0 of the motor 211 (rotational drive shaft 300) is not required, and strict dimensional accuracy is not required, so that the manufacturability of the plunger pump 86 can be improved.

Of the various brake controls that pressurize the brake fluid by the plunger pump 86, the boost control according to the brake operation is the most frequently operated. For this reason, by switching the rotation direction of the motor 211 each time the driver performs a brake operation, the position of the sliding portion is frequently switched, so that uneven wear can be effectively suppressed.
The fluid passage 11 connected to the wheel cylinder 2 for applying a braking force to each wheel FL to RR connects the master cylinder 5 and the wheel cylinder 2, and the fluid passage 11 is provided with a shut-off valve 12, and a plunger pump 86 Supplies the brake fluid to a portion (liquid passage 11B) located on the wheel cylinder 2 side with respect to the shutoff valve 12 in the liquid passage 11. The shut-off valve 12 is closed to shut off the flow of brake fluid between the master cylinder 5 and the wheel cylinder 2, and the target wheel cylinder hydraulic pressure of each wheel FL to RR is realized by the brake fluid pressurized by the pump 21. In the brake-by-wire system, the pump 21 is operated each time the driver brakes, so that the pump is operated only in the case of anti-lock control or vehicle motion control. The frequency is high. Therefore, since the pump employed in the brake-by-wire system is required to have high durability, switching of the rotation direction of the motor 211 is effective and has a remarkable effect.
In the first embodiment, since the motor 211 that drives the plunger pump 86 is a brushless motor, compared to the case where the plunger pump 86 is a brushed motor, the size and weight are reduced, the motor efficiency is improved, and the speed control range is expanded. There are advantages such as improved maintainability and improved durability.

[Embodiment 2]
Since the basic configuration of the second embodiment is the same as that of the first embodiment, only portions different from the first embodiment will be described.
FIG. 9 is a flowchart showing the flow of the rotation direction switching control of the motor 211 in the second embodiment.
In step S11, it is determined whether there is a self-diagnosis execution request. If yes, go to step S6, if no, go to return. Here, the self-diagnosis is to determine whether the control unit 9 is normal by operating each actuator of the hydraulic unit 8 during running or stopping when the vehicle is powered on, for example. At this time, the motor 211 may be rotated in both directions in order to determine whether the motor 211 normally rotates in both directions.
In step S12, it is determined whether the self-diagnosis is completed. If YES, the process proceeds to step S4. If NO, the process returns to step S7.
In step S13, it is determined whether the self-diagnosis is completed. If YES, the process proceeds to step S4. If NO, the process returns to step S8.
Since the self-diagnosis of the brake control device 1 is executed multiple times during one trip (period from start to stop of the vehicle) regardless of the braking state, one trip is performed by switching the rotation direction of the motor 211 after the self-diagnosis. Uneven wear can be effectively suppressed by switching the position of the sliding portion a plurality of times. In particular, it is effective for improving the durability of the plunger pump 86 when the brake control device 1 is employed in a brake system that does not have a shut-off valve, in other words, a brake system that is not a so-called brake-by-wire.

[Embodiment 3]
Since the basic configuration of the third embodiment is the same as that of the first embodiment, only the differences from the first embodiment will be described.
FIG. 10 is a flowchart showing the flow of rotation direction switching control of the motor 211 in the third embodiment.
In step S21, it is determined whether the operating flag of each function is 1. If yes, go to return, if no, go to step S22. Each function is brake control other than boost control (anti-lock control, brake control for vehicle motion control, automatic brake control, etc.). If one of the functions is inactive, the operating flag is 0. When in operation, the in-operation flag is 1.
In step S22, it is determined whether a fixed time has elapsed since the function being operated stopped. If yes, go to step S5, if no, go to return. For example, when the rotation direction of the motor 211 is switched immediately after the end of the anti-lock control and the anti-lock control is continuously activated thereafter, the pressure increase of the wheel cylinder 2 may be delayed by the inertia of the motor 211. Specifically, in anti-lock control, the liquid necessary for re-increasing the wheel cylinder hydraulic pressure following the operation of holding (solenoid-in valve 13 is closed) and depressurization (solenoid-out valve 25 is open). The response delay of the motor 221 that drives the pump 21 to generate pressure affects the pressure increase delay of the wheel cylinder 2. Therefore, a delay in response of the antilock control can be prevented by switching the rotation direction of the motor 211 after a sufficient time has elapsed after the antilock control is completed.
In a specific function such as anti-lock control, the discharge flow rate and the discharge hydraulic pressure of the pump 21 are higher than in the boost control, so that the pump 21 operates at a high load and the durability deterioration of the plunger pump 86 is easily promoted. Therefore, switching the rotation direction of the motor 211 after the specific function is effective in improving the durability of the plunger pump 86.

[Embodiment 4]
Since the basic configuration of the fourth embodiment is the same as that of the third embodiment, only the differences from the third embodiment will be described.
FIG. 11 is a flowchart illustrating a flow of rotation direction switching control of the motor 211 in the fourth embodiment.
In step S31, the operating time T of the motor 211 in the finished function is read. When the function is started, the control unit 9 starts counting up by the counter and measures the operation time of the motor 211.
In step S32, it is determined whether the operation time T is longer than the predetermined time T1 based on whether the count value of the counter is larger than the threshold value. If yes, go to step S5, if no, go to return.
By switching the rotation direction of the motor 211 after the plunger pump 86 is continuously operated for a long time, it is possible to suppress the same part from sliding continuously for a long time, which is effective in improving the durability of the plunger pump 86.

[Embodiment 5]
Since the basic configuration of the fifth embodiment is the same as that of the first embodiment, only the differences from the first embodiment will be described.
In the rotation direction switching control of the motor 211 in the fifth embodiment, the rotation direction of the motor 211 is switched when the accumulated rotation number in the same direction of the motor 211 reaches a predetermined rotation number. In other words, the rotation direction of the motor 221 is switched so that the accumulated rotation speeds of the CW and CCW are substantially equal, or the accumulated rotation speeds of the CW and CCW are compared with each other in the smaller rotation direction. It means switching. As a result, the rotational direction of the motor 211 is switched so that the integrated rotational speed is always the same between CW and CCW, which is effective in improving the durability of the plunger pump 86.
It should be noted that the rotation direction may be switched each time the total accumulated rotational speed of CW and CCW reaches, for example, 10,000 revolutions, 20,000 revolutions,.

[Embodiment 6]
Since the basic configuration of the sixth embodiment is the same as that of the first embodiment, only the differences from the first embodiment will be described.
FIG. 12 is a diagram illustrating a motor control configuration according to the sixth embodiment.
In the sixth embodiment, a DC brush motor is employed as the motor 211. The drive circuit 10 includes switching elements Q11 to Q14 configured by, for example, an N-channel FET H-bridge. The drain terminals of the switching elements Q11 and Q12 on the upper arm side are connected to the DC power source Vcc. The source elements of the switching elements Q13 and Q14 on the lower arm side are connected to the ground GND. The source terminal of the switching element Q11 on the upper arm side and the drain terminal of the switching element Q13 on the lower arm side are connected, and the connection point of the switching elements Q11 and Q13 is connected to the first terminal of the motor 211 via the output power line L1. Connected to the terminal. The source terminal of the switching element Q12 on the upper arm side and the drain element of the switching element Q14 on the lower arm side are connected, and the connection point between the switching elements Q12 and Q14 is connected to the second terminal of the motor 211 via the output power line L2. Connected to the terminal.
As shown in the figure, a diode Dx is connected in parallel to each of the switching elements Q11 to Q14 so that the cathode is in the direction of the DC power supply Vcc and the anode is in the direction of the ground GND. Switching elements Q11 to Q14 may be IGBTs or bipolar transistors.
When the switching elements Q11 and Q14 of the drive circuit 10 are turned ON and the switching elements Q12 and Q13 are turned OFF, a current flows in the direction of the solid line arrow shown in the figure, and the rotation direction of the motor 211 is CW. On the other hand, when switching elements Q12 and Q13 are turned ON and switching elements Q11 and Q14 are turned OFF, a current flows in the direction of the broken line arrow shown in the figure, and the rotation direction of motor 211 is CCW. Therefore, even when a DC brush motor is employed as the motor 211, the rotation direction can be switched. Here, when the motor 211 is rotating, since two of the switching elements of the drive circuit 10 are in a non-energized state (OFF), heat generation of the entire switching element can be suppressed. Therefore, the heat capacity of each switching element can be reduced, and the heat dissipation structure can be simplified.

[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 present invention is also suitable as a vehicle brake control device equipped with an automatic driving function. Since the operation frequency of the plunger pump increases in automatic operation, the effect of the present invention is remarkable.
The present invention can also be applied to brake systems other than the brake-by-wire system.

The technical idea that can be grasped from the embodiment described above will be described below.
In one aspect of the brake control device, a liquid passage portion connected to a braking force applying portion that applies a braking force to a wheel, a plunger pump that discharges brake fluid to the liquid passage portion, and the plunger pump are driven. And a control unit for switching the rotation direction of the motor.
In another preferred aspect, in the above aspect, the control unit switches the rotation direction of the motor each time the driver performs a brake operation.
In another preferred aspect, in any one of the above aspects, the control unit performs a self-diagnosis for determining soundness of the brake control device, and switches the rotation direction of the motor after the self-diagnosis.
In still another preferred aspect, in any one of the above aspects, the control unit performs predetermined brake control on the wheels, and switches the rotation direction of the motor after the brake control is performed.

In still another preferred aspect, in any one of the above aspects, the control unit switches the rotation direction of the motor every time the continuous operation time of the motor reaches a predetermined time.
In still another preferred aspect, in any one of the above aspects, the control unit switches a rotation direction of the motor when a start switch of the vehicle is turned on or off.
In still another preferred aspect, in any one of the above aspects, the control unit switches the rotation direction of the motor every time an integrated value of the number of rotations in the same direction of the motor reaches a predetermined value.
In still another preferred aspect, in any one of the above aspects, the liquid path part includes a connection liquid path that connects the master cylinder and the braking force applying part.
The liquid path part also includes a shutoff valve part provided in the connection liquid path,
The plunger pump supplies brake fluid to a portion of the connection fluid path that is located on the braking force applying portion side with respect to the shutoff valve portion.

In still another preferred aspect, in any of the above aspects, the motor is a brushless motor.
In still another preferred aspect, in any of the above aspects, the motor is a brush motor.
From another point of view, in one aspect, the brake control method performs a first rotation of a motor that drives a plunger pump that discharges brake fluid to a fluid path connected to a braking force application unit that applies braking force to a wheel. A first step of discharging the brake fluid into the fluid path by rotating in a direction, and a rotation direction of the motor in a second direction opposite to the first rotation direction, And a second step of discharging the brake fluid into the fluid path.
Furthermore, from another viewpoint, in a certain aspect, the pump device used in the brake control device includes a plunger pump that discharges brake fluid, a motor that drives the plunger pump, a control unit that switches the rotation direction of the motor, Is provided.

In addition, this invention is not limited to above-described embodiment, Various modifications are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

This application claims priority based on Japanese Patent Application No. 2018-114133 filed on Jun. 15, 2018. The entire disclosure including the specification, claims, drawings, and abstract of Japanese Patent Application No. 2018-114133 filed on Jun. 15, 2018 is incorporated herein by reference in its entirety.

FL to RR wheels
1 Brake control device
2 Wheel cylinder (braking force applying part)
5 Master cylinder
9 Control unit (pump device)
11 Fluid path (connection fluid path)
12 Shut-off valve (shut-off valve)
86 Plunger pump (pump device)
211 Motor (pump device)

Claims (12)

1. A brake control device, the brake control device comprising:
   A liquid passage portion connected to a braking force applying portion for applying a braking force to the wheel;
   A plunger pump that discharges the brake fluid to the liquid passage portion;
   A motor for driving the plunger pump;
   A control unit for switching the rotation direction of the motor;
   A brake control device comprising:
2. The brake control device according to claim 1, wherein
   The control unit is a brake control device that switches a rotation direction of the motor each time a driver performs a brake operation.
3. The brake control device according to claim 1, wherein
   The said control unit is a brake control apparatus which performs the self-diagnosis which determines the soundness of the said brake control apparatus, and switches the rotation direction of the said motor after the said self-diagnosis.
4. The brake control device according to claim 1, wherein
   The said control unit is a brake control apparatus which performs predetermined brake control with respect to the said wheel, and switches the rotation direction of the said motor after execution of the said brake control.
5. The brake control device according to claim 1, wherein
   The control unit is a brake control device that switches the rotation direction of the motor every time the continuous operation time of the motor reaches a predetermined time.
6. The brake control device according to claim 1, wherein
   The control unit is a brake control device that switches a rotation direction of the motor when a start switch of a vehicle is turned on or off.
7. The brake control device according to claim 1, wherein
   The said control unit is a brake control apparatus which switches the rotation direction of the said motor, whenever the integrated value of the rotation speed in the same direction of the said motor reaches a predetermined value.
8. The brake control device according to claim 1, wherein
   The liquid path part includes a connecting liquid path that connects the master cylinder and the braking force application part,
   The liquid path part also includes a shut-off valve part provided in the connection liquid path,
   The said plunger pump is a brake control apparatus which supplies a brake fluid to the part located in the said braking force provision part side with respect to the said cutoff valve part among the said connection liquid paths.
9. The brake control device according to claim 1, wherein
   The brake control device, wherein the motor is a brushless motor.
10. The brake control device according to claim 1, wherein
    The brake control device, wherein the motor is a brush motor.
11. A brake control method, the brake control method comprising:
    The brake fluid is discharged into the fluid passage by rotating in a first rotation direction a motor that drives a plunger pump that discharges the brake fluid to a fluid passage connected to a braking force applying portion that applies a braking force to the wheel. A first step to:
    A second step of discharging the brake fluid into the fluid path by rotating the rotation direction of the motor in a second direction opposite to the first rotation direction;
    A brake control method comprising:
12. A pump device used in a brake control device,
    A plunger pump that discharges brake fluid;
    A motor for driving the plunger pump;
    A control unit for switching the rotation direction of the motor;
    A pump device comprising:

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