Brake control device

Abstract

Brake control device (1), comprising: a motor (20); a housing (8) comprising a first surface (801) on which the motor (20) is arranged, a second surface (802) spaced from the first surface (801) by a predetermined distance in one direction of a rotational axis of the motor (20), and a receiving opening (81) extending from the first surface (801) towards the second surface (802) in the direction of the rotational axis and configured to receive a shaft (300) which is rotated by means of the motor (20); and a piston pump (3A) comprising a piston (36) configured to be actuated by a revolution of the motor (20) and a bearing (34A) through which the piston (36) is inserted, wherein the bearing (34A) is attached to the housing (8) such that it projects into the receiving opening (81) or is arranged coplanar with the receiving opening (81), wherein the bearing (34A) comprises on its inner circumference a sub-section (341e) with a small inner diameter and a sub-section (341f) with a large inner diameter, wherein the sub-section (341f) with a large inner diameter has a larger inner diameter than the sub-section (341e) with a small inner diameter.

Description

TECHNICAL AREA

[0001] The present invention relates to a brake control device. BACKGROUND TECHNOLOGY

[0002] PTL 1 discloses a brake control device comprising a piston pump provided in a housing. A piston of the piston pump is contained in a cylinder-containing opening of the housing and extends into a cam chamber, the distal end of which is supported by a bearing. QUOTE LIST PATENT LITERATURE PTL 1: US patent application public disclosure no. 2005-0253451 PTL 2: WO 2017 / 056690 A1 PTL 3: JP H10-81223 A PTL 4: JP 2008 - 179362 A SUMMARY OF THE INVENTIONAL PROBLEM

[0003] According to the brake control device disclosed in the patent literature PTL 1 described above, a contaminant remaining in a gap between the inner circumferential surface of the cylinder containing the opening and the outer circumferential surface of the piston can scratch or scar the piston by getting between the inner circumferential surface of the bearing and the outer circumferential surface of the piston when the piston is actuated, thereby reducing the service life of the piston pump.

[0004] PTL 2 shows a hydraulic brake control device that can suppress vibrations more effectively. A rotary drive shaft is provided in a housing, with several pumps arranged circumferentially around the axis of the rotary drive shaft within the housing and operated by the rotation of the rotary drive shaft. When the housing is installed in the vehicle, the number of pumps on the lower side (vertically) is greater than the number of pumps on the upper side (vertically) with respect to the axis of the rotary drive shaft.

[0005] PTL 3 shows a method for smoothing a suction stroke in a brake control device. The brake control device comprises a pressure booster pump as the first piston pump and an auxiliary pump as the second piston pump. The drive phases of the two piston pumps are designed to be offset by a certain amount so that the piston of the auxiliary pump enters its discharge stroke at the same time as the piston of the pressure booster pump enters its suction stroke.

[0006] PTL 4 demonstrates a fluid device with improved durability, achieved by effectively damping the pulsations generated by the pump without increasing the overall device size. A pump chamber is provided within a cylinder, in which a piston is slidably mounted and which has a variable capacity. A delivery chamber is also provided, which is connected to the pump chamber via the delivery valve. Opposite the delivery chamber, a damper chamber is provided, containing a slidable damper piston for varying the capacity of the damper chamber.

[0007] One of the objectives of the present invention is to provide a brake control device that is capable of improving the service life of a piston pump.

[0008] According to one aspect of the present invention, a brake control device includes a bearing through which a piston is inserted. The bearing is attached to a housing such that it projects into a receiving opening or is arranged coplanar with the receiving opening. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0009] Therefore, according to one aspect of the present invention, the brake control device can improve the service life of the piston pump. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view of a brake control device 1 according to a first embodiment. Fig. Figure 2 is a cross-sectional view of a housing 8 of a second unit 1B according to the first embodiment, taken along a direction perpendicular to an axis. Fig. Figure 3 is an enlarged view of main part areas of a pump part area 3A according to the first embodiment. Fig. Figure 4 is a perspective view of a guide ring 34A according to the first embodiment. Fig. Figure 5 is an axial cross-sectional view of the guide ring 34A according to the first embodiment. Fig. Figure 6 is an enlarged view of main part areas of pump part area 3A according to a second embodiment. Fig. Figure 7 is an axial cross-sectional view of the guide ring 34A according to a third embodiment. Fig. Figure 8 is an axial cross-sectional view of the guide ring 34A according to a fourth embodiment. Fig. Figure 9 is a cross-sectional view of the housing 8 of the second unit 1B according to a fifth embodiment, taken along the direction perpendicular to the axis. DESCRIPTION OF EXECUTIONS [First embodiment]

[0010] First, the configuration is described.

[0011] Fig. Figure 1 is a perspective view of a brake control device 1 according to a first embodiment, and Fig. Figure 2 is a cross-sectional view of a housing 8 of a second unit 1B according to the first embodiment, taken along a direction perpendicular to an axis.

[0012] The brake control device 1 can be used for a hybrid vehicle that includes an electric motor (a generator) in addition to an internal combustion engine, an electric vehicle that includes only an electric motor, and the like, as well as a general vehicle that includes only an internal combustion engine (a motor) as the propulsion machine driving the wheels. The brake control device 1 is a hydraulic brake control device that applies a frictional braking force to each of the vehicle's wheels based on hydraulic pressure. A brake actuation unit is provided at each of the wheels. The brake actuation unit is, for example, a disc-type brake and includes a wheel cylinder and a brake caliper. The brake caliper includes a brake disc and brake pads. The brake disc is a brake rotor that rotates integrally with a tire.The brake pads are arranged with predetermined gaps created by the brake disc and contact the brake disc by being moved by hydraulic pressure in the wheel cylinder. Through this process, the brake actuation unit generates the frictional braking force. The brake control device 1 comprises two brake line systems (a primary P-system and a secondary S-system). The brake line configuration is, for example, an X-split line configuration. The brake control device 1 can use a different line configuration, such as a front / rear split line configuration. Where a component designated according to the P-system and a component designated according to the S-system are distinguished from one another below, the indices P and S are added to the ends of the respective reference numerals.The brake control device 1 supplies each of the brake actuation units with brake fluid, which acts as a hydraulic fluid (hydraulic fluid), via the brake lines and generates the hydraulic pressure (a brake hydraulic pressure) in the wheel cylinder. Through this process, the brake control device 1 applies a hydraulic braking force to each of the wheels.

[0013] The brake control device 1 comprises a first unit 1A and a second unit 1B. The wheel cylinder at each of the wheels and the second unit 1B are connected to each other via a wheel cylinder line 10W. The first unit 1A and the second unit 1B are arranged, for example, in an engine compartment isolated from the passenger compartment of the vehicle and are connected to each other via a plurality of lines. The plurality of lines includes master cylinder lines 10M (a primary line 10MP and a secondary line 10MS), an inlet line 10R, and a back pressure line 10X. With the exception of the inlet line 10R, each of the lines 10M, 10W, and 10X is a metallic brake line (a metallic line) and, in particular, a steel tube such as a double-walled steel tube. The two end sections of each of the lines 10M, 10W, and 10X each contain a crimped push-fit connection.The inlet line 10R is a brake hose (a hose assembly) made of a material such as rubber to ensure flexibility. The end sections of the inlet line 10R are connected via nipples 10R1 and 10R2 to a fitting 873 and the like. Nipples 10R1 and 10R2 are each resin connectors with a tubular section. For the sake of simplicity, a three-dimensional orthogonal coordinate system with an X-axis, a Y-axis, and a Z-axis is defined below. The Z-axis direction is defined as the vertical direction, and a side in the positive direction of the Z-axis is defined as the upper side in the vertical direction with the first unit 1A and the second unit 1B mounted on the vehicle.An X-axis direction is defined as the longitudinal direction of the vehicle, and a side in the positive direction of the X-axis is defined as the front of the vehicle. A Y-axis direction is defined as the lateral direction of the vehicle.

[0014] A pushrod PR is rotatably connected to a brake pedal, which receives input from a driver's brake application. The pushrod PR extends from its end section on the side in the negative direction of the X-axis, which is connected to the brake pedal, towards the side in the positive direction of the X-axis. The first unit 1A is a brake actuation unit mechanically connected to the brake pedal and is a master cylinder unit containing a master cylinder 5. The first unit 1A comprises a reservoir tank 4, a housing 7, the master cylinder 5, a stroke sensor 94, and a stroke simulator 6. The reservoir tank 4 is a brake fluid source that stores the brake fluid and is a low-pressure section open to atmospheric pressure. The housing 7 contains the master cylinder 5 and the stroke simulator 6 within it.A rectangular, plate-shaped flange section 78 is provided on the end section of the housing 7 on the side in the negative direction of the X-axis. The four corners of the flange section 78 are attached to the dashboard on the side of the vehicle body by means of screws B1. The reservoir tank 4 is located on the side in the positive direction of the Z-axis of the housing 7. The master cylinder 5 is a primary hydraulic pressure source capable of supplying hydraulic pressure to the wheel cylinders and is connected to the brake pedal via the pushrod PR. It is actuated according to the driver's application of the brake pedal. The stroke sensor 94 detects the stroke of a primary piston of the master cylinder 5. The stroke simulator 6 is actuated according to the driver's brake application and provides a reaction force and stroke to the brake pedal.

[0015] The second unit 1B is a device for controlling the hydraulic pressure, located between the first unit 1A and the brake actuation unit of each wheel. The second unit 1B comprises a housing 8, a motor 20, a pump 3, a plurality of electromagnetic valves and the like, a plurality of hydraulic pressure sensors and the like, and an electronic control unit (hereinafter referred to as the ECU) 90. The housing 8 contains the pump 3 and the valve bodies of electromagnetic valves 21 and the like. The circuits (the brake hydraulic circuits) of the two systems described above (the P-system and the S-system), through which the brake fluid flows, are formed by a plurality of fluid passages within the housing 8. Furthermore, a plurality of ports are formed within the housing 8, and these ports are open to the outer surface of the housing 8.The multitude of connections is linked to the fluid passages inside the housing 8 and connects these internal fluid passages and fluid passages (the 10M lines and the like) outside the housing 8 to each other.

[0016] Motor 20 is a rotary electric motor and includes a rotating shaft for driving pump 3. Motor 20 can be a brushed motor or a brushless motor containing a resolver that detects the angle of rotation or the number of revolutions of the rotating shaft. Pump 3 is a secondary hydraulic pressure source capable of supplying hydraulic pressure to the wheel cylinders and comprises five pump sections, 3A to 3E, configured to be driven by the single motor 20. Pump 3 is shared by the S-system and the P-system. The electromagnetic valves and the like are each actuators that operate according to a control signal and each comprises a solenoid and a valve body. The stroke of the valve body is changed according to the supply of electrical power to the solenoid to switch the opening / closing of the fluid passage (to establish or shut off the connection via the fluid passage).The electromagnetic valves and similar components control the connection state of the circuit described above to adjust the flow state of the brake fluid, thereby generating hydraulic pressure for the control system. The hydraulic pressure sensors and similar components detect the outlet / delivery pressure of pump 3 and the hydraulic pressure of the master cylinder.

[0017] The second unit 1B supplies the brake fluid, pressurized by pump 3, to the brake actuation units via the wheel cylinder lines 10W, thereby generating the brake hydraulic pressures (the hydraulic pressures of the wheel cylinders). The second unit 1B can supply the hydraulic pressure of the master cylinder to each of the wheel cylinders and can also individually control the hydraulic pressure in each of the wheel cylinders using the hydraulic pressure generated by pump 3, independently of the brake application by the driver, with the connection between the master cylinder 5 and the wheel cylinders being shut off. The ECU 90 receives inputs of the values ​​detected by the stroke sensor 94, the hydraulic pressure sensors, and the like, as well as information regarding the driving condition from the vehicle side, and controls the opening / closing operations of the electromagnetic valves and the like, and the number of revolutions of the engine 20 (i.e.,The pump's delivery rate (3) is controlled based on a program installed within it, thereby controlling the hydraulic pressure of the wheel cylinders (the hydraulic braking force) at each wheel. Using this control, the ECU performs 90 different types of brake control (anti-lock braking control to prevent wheel slippage during braking, boost control to reduce the braking force required by the driver, brake control to manage vehicle movement, autonomous brake control such as following a vehicle ahead, regenerative cooperative brake control, and the like). Controlling vehicle movement includes control for stabilizing vehicle behavior, such as electronic stability control.In regenerative cooperative brake control, the ECU 90 controls the hydraulic pressures of the wheel cylinders in order to achieve a target deceleration (a target braking force) in conjunction with the regenerative brake. Next, the housing 8 of the second unit 1B will be described.

[0018] The housing 8 is a generally cuboid block made of an aluminum alloy. The outer surface of the housing 8 comprises a front surface 801, a rear surface 802, a bottom surface 803, a top surface 804, a left side surface 805, and a right side surface 806. The front surface 801 (a first surface) is a flat surface with a relatively large area. The rear surface 802 (a second surface) is a flat surface that is generally parallel to the front surface 801 and is located opposite the front surface 801 (of the housing 8). The bottom surface 803 (a third surface) is a flat surface connected to the front surface 801 and the rear surface 802.The upper surface 804 (a fourth surface) is a flat surface generally parallel to the lower surface 803 and is located opposite the lower surface 803 (of the housing 8). The left side surface 805 (a fifth surface) is a flat surface connected to the front surface 801, the rear surface 802, the lower surface 803, and the upper surface 804. The right side surface 806 (a sixth surface) is a flat surface generally parallel to the left side surface 805 and is located opposite the left side surface 805 (of the housing 8). The right side surface 806 is connected to the front surface 801, the rear surface 802, the lower surface 803, and the upper surface 804. The front surface 801 is arranged on the side in the positive direction of the Y direction and extends parallel to the X-axis and the Z-axis with the vehicle-mounted housing 8.The rear surface 802 is oriented sideways in the negative direction of the Y-axis and extends parallel to the X- and Z-axes. The upper surface 804 is oriented sideways in the positive direction of the Z-axis and extends parallel to the X- and Y-axes. The lower surface 803 is oriented sideways in the negative direction of the Z-axis and extends parallel to the X- and Y-axes. The right side surface 806 is oriented sideways in the positive direction of the X-axis and extends parallel to the Y- and Z-axes. The left side surface 805 is oriented sideways in the negative direction of the X-axis and extends parallel to the Y- and Z-axes. In actual use, the layout is...The design of the housing 8 in the XY plane is in no way restricted and the housing 8 can be arranged in any position and in any orientation in the XY plane according to the vehicle design and / or the like.

[0019] At each of the corner regions of the housing 8, a recessed sub-region 80 is formed on the side of the front surface 801 and the side of the upper surface 804. In other words, the corner formed by the front surface 801, the upper surface 804, and the right side surface 806, and the corner formed by the front surface 801, the upper surface 804, and the left side surface 805, have truncated shapes and contain first and second recessed sub-regions 80A and 80B, respectively. The first recessed sub-region 80A is open to the front surface 801, the upper surface 804, and the left side surface 805. The second recessed sub-region 80B is open to the front surface 801, the upper surface 804, and the right side surface 806.The first recessed sub-area 80A comprises a first flat surface sub-area 807, a second flat surface sub-area 808, and a third flat surface sub-area 809. The first flat surface sub-area 807 extends perpendicular to the Y-axis and parallel to the XZ-plane. The second flat surface sub-area 808 extends perpendicular to the X-axis and generally parallel to the YZ-plane. The third flat surface sub-area 809 extends in the Y-axis direction and forms an angle of approximately 50 degrees with respect to the right side face 806 in a counterclockwise direction, as viewed from the side in the positive direction of the Y-axis. The second flat surface sub-area 808 and the third flat surface sub-area 809 are seamlessly connected to each other via a concavely curved surface extending in the Y-axis direction.The second recessed sub-area 80B comprises the first flat surface sub-area 807, the second flat surface sub-area 808, and the third flat surface sub-area 809. The third flat surface sub-area 809 extends in the Y-axis direction and forms an angle of approximately 50 degrees clockwise with respect to the left side face 805, as viewed from the side in the positive direction of the Y-axis. The remaining configuration of the second recessed sub-area 80B is similar to that of the first recessed sub-area 80A. The first and second recessed sub-areas 80A and 80B are generally symmetrical about the YZ plane in the X-axis direction at the center of the housing 8.

[0020] The housing 8 contains a cam-containing opening (receiving opening) 81, a plurality of (five) cylinder-containing openings 82A to 82E, a first fluid pool chamber 83, a second fluid pool chamber 84, a plurality of mounting openings 85, a plurality of valve-containing openings, a plurality of sensor-containing openings, an opening 86 for an electrical power source, a plurality of ports 87, the plurality of fluid passages, and the like. These openings and ports are formed using a drill or the like. The cam-containing opening 81 has a cylindrical shape with a base extending in the Y-axis direction and is open towards the front surface 801.A central axis O of the opening 81 containing a cam is arranged at a position on the front surface 801 that is approximately central in the X-axis direction and slightly offset laterally in the negative direction of the Z-axis. The lower surface 803 is positioned laterally in the negative direction of the Z-axis with respect to the central axis O, and the first recessed sub-area 80A and the second recessed sub-area 80B are positioned laterally in the positive direction of the Z-axis with respect to the central axis O.

[0021] Each of the cylinder-containing openings 82 has a stepped cylindrical shape and a central axis extending in the radial direction of the cam-containing opening 81 (the radial direction around the central axis O). The opening 82 comprises a small-diameter sub-section 820 on a side closer to the cam-containing opening 81, a large-diameter sub-section 821 on the side farther from the cam-containing opening 81, and an intermediate-diameter sub-section 822 between the small-diameter sub-section 820 and the large-diameter sub-section 821. A portion 823 of the intermediate-diameter sub-section 822 on the side closer to the cam-containing opening 81 serves as the inlet port, and the large-diameter sub-section 821 serves as the outlet port.The plurality of openings 82A to 82E is arranged approximately uniformly (at approximately uniform intervals) circumferentially around the central axis O. The angle formed by the central axes of adjacent openings 82 circumferentially around the central axis O is approximately 72 degrees (lies within a predetermined range enclosing 72 degrees). The plurality of openings 82A to 82E is arranged in a single row along the Y-axis direction and is located on the side in the positive direction of the Y-axis of the housing 8. In other words, the central axes of these openings 82A to 82E lie in the same plane α, which is generally perpendicular to the central axis O. The plane α generally extends parallel to the front surface 801 and the rear surface 802 of the housing 8 and lies on a side closer to the side of the front surface 801 than to the rear surface 802.The respective inlet ports 823 of openings 82A to 82E are connected to each other via a first connecting fluid passage. The respective outlet ports 821 of openings 82A to 82E are connected to each other via a second connecting fluid passage.

[0022] Each of the openings 82A to 82E is arranged within the housing 8 as follows. Opening 82A extends from the lower surface 803 towards the side in the positive direction of the Z-axis. Opening 82B extends from a portion of the left side surface 805, positioned with respect to the central axis O on the lower side in the negative direction of the Z-axis, to the side in the positive direction of the X-axis and the side in the positive direction of the Z-axis. Opening 82C extends from the first recessed portion 80A to the side in the positive direction of the X-axis and the side in the negative direction of the Z-axis. Opening 82D extends from the second recessed portion 80B to the side in the negative direction of the X-axis and the side in the negative direction of the Z-axis.The opening 82E extends from a portion of the right-hand side surface 806, positioned on the lower side in the negative Z-axis direction relative to the central axis O, to the side in the negative X-axis direction and the side in the positive Z-axis direction. On the side in the negative Z-axis direction relative to the central axis O, the opening 82A is positioned at approximately the same position in the X-axis direction as the central axis O, and the openings 82B and 82E are arranged on both sides of the central axis O (of the opening 82A) in the X-axis direction. On the side in the positive Z-axis direction relative to the central axis O, the openings 82C and 82D are arranged on both sides of the central axis O in the X-axis direction. The small-diameter portion 820 of each of the openings 82A to 82E opens towards the inner circumferential surface of the opening 81 containing a cam.The end portion of opening 82A on the side of the large-diameter sub-area 821 opens towards a sub-area of ​​the lower surface 803 that is approximately central in the X-axis direction and located on the side in the positive direction of the Y-axis. The end portion of opening 82B on the side of the large-diameter sub-area 821 opens towards a sub-area of ​​the left side surface 805 that is located on the side in the positive direction of the Y-axis and on the side in the negative direction of the Z-axis. The end portion of opening 82E on the side of the large-diameter sub-area 821 opens towards a sub-area of ​​the right side surface 806 that is located on the side in the positive direction of the Y-axis and on the side in the negative direction of the Z-axis. The end portions of openings 82C and 82D on the sides of the large-diameter sub-area 821 open towards the first and second recessed sub-areas 80A and 82D, respectively.80B opens towards. More precisely, more than half of the end portion on the side of the large-diameter portion 821 opens towards the third flat surface portion 809, and its remaining portion opens towards the second flat surface portion 808. The third flat surface portion 809 generally extends perpendicular to the central axes of openings 82C and 82D.

[0023] The first fluid pool chamber 83 has a cylindrical shape with a bottom, its central axis extending in the Z-axis direction. The first fluid pool chamber 83 opens towards a portion of the upper surface 804 that is approximately central in the X-axis direction and offset in the positive direction of the Y-axis, and is arranged from the upper surface 804 into the housing 8. The first fluid pool chamber 83 (whose lower or bottom portion is located on the side in the negative direction of the Z-axis) is located on the side in the positive direction of the Z-axis with respect to the inlet port 823 of each of the cylinder-containing openings 82. The first fluid pool chamber 83 is formed in a region between the cylinder-containing openings 82C and 82D, which are adjacent to each other circumferentially around the central axis O, on the side in the positive direction of the Z-axis with respect to the central axis O.The first fluid pool chamber 83 and the openings 82C and 82D partially overlap each other in the Y-axis direction (as viewed from the X-axis direction). The first fluid pool chamber 83 and the inlet port 823 of each of the openings 82A to 82E are connected to each other via an inlet fluid passage 12. The second fluid pool chamber 84 has a cylindrical shape with a bottom, the central axis of which runs in the Z-axis direction. The second fluid pool chamber 84 is open to a portion of the lower surface 803 that lies on the side in the negative direction of the X-axis and is offset in the positive direction of the Y-axis, and is arranged from the lower surface 803 into the housing 8. The second fluid pool chamber 84 is formed in an area between the cylinder-containing openings 82A and 82B, which are adjacent to each other in the circumferential direction around the central axis O, on the side in the negative direction of the Z-axis with respect to the central axis O.The cylinder-containing opening 82A and the second fluid pool chamber 84 partially overlap each other in the Y-axis direction (as viewed from the X-axis direction). The cam-containing opening 81 and the second fluid pool chamber 84 are connected to each other via a drain fluid passage 19. One end of the drain fluid passage 19 opens to a sub-region on the inner circumferential surface of the cam-containing opening 81, located on the side opposite the Y-axis and the side opposite the Z-axis, and the other end of the drain fluid passage 19 opens to the outer circumferential edge of the bottom surface of the second fluid pool chamber 84 on the side opposite the Z-axis.

[0024] The plurality of valve-containing openings each has a cylindrical shape with a base and extends in the Y-axis direction so that they open towards the rear surface 802. The plurality of valve-containing openings is a single row along the Y-axis direction and is arranged on the side opposite the Y-axis of the housing 8. The cylinder-containing openings 82 and the valve-containing openings are arranged along the Y-axis direction. The plurality of valve-containing openings overlaps at least partially the cylinder-containing openings 82, as viewed from the Y-axis direction. Most of the plurality of valve-containing openings are contained within a circle that includes the ends of the plurality of cylinder-containing openings 82 on the sides of the large-diameter sub-area 821 (the other sides farther from the central axis O).Alternatively, the outer circumference of this circle and the openings containing a valve overlap at least partially. The valve portion of the electromagnetic valve is fitted, and its valve body is contained within each of the openings containing a valve. The plurality of openings containing a sensor each has a cylindrical shape with a base, its central axis extending in the Y-axis direction, and is open towards the rear surface 802. A pressure-sensitive portion, such as the hydraulic pressure sensor, is contained within each of the sensor-containing portions. The opening 86 for an electrical power source has a cylindrical shape and extends through the housing 8 (between the front surface 801 and the rear surface 802) in the Y-axis direction.The opening 86 is located at a position on the housing 8 that is approximately central in the X-axis direction and situated on the side in the positive direction of the Z-axis. The opening 86 is located in a region between the adjacent cylinder-containing openings 82C and 82D.

[0025] The inlet port 873 is an opening portion of the first fluid pool chamber 83 on the upper surface 804 and is open vertically towards the top. The port 873 opens towards a portion of the upper surface 804 that lies on the central side in the X-axis direction and is offset in the positive direction of the Y-axis. The port 873 is located on the side in the positive direction of the Z-axis with respect to the inlet port 823 of each of the cylinder-containing openings 82A to 82E. The cylinder-containing openings 82C and 82D surround the port 873 in a sandwich-like manner when viewed from the Y-axis direction. The openings of the cylinder-containing openings 82C and 82D and the port 873 partially overlap each other in the Y-axis direction (as viewed from the X-axis direction).The main cylinder ports 871 each have a cylindrical shape with a base and a central axis extending in the Y-axis direction. They are open towards a partial area that forms an end portion of the front surface 801 on the side in the positive direction of the Z-axis and is sandwiched between the recessed partial areas 80A and 80B. The primary port 871P is located on the side in the positive direction of the X-axis, and the secondary port 871S is located on the side in the negative direction of the X-axis. The two ports 871P and 871S are arranged in the X-axis direction and sandwich the first fluid pool chamber 83 in the X-axis direction (as viewed from the Y-axis direction). The ports 871P and 871S are sandwich-like arranged between the first fluid pool chamber 83 and the cylinder-containing openings 82D and 82C respectively in the circumferential direction around the central axis O (as seen from the Y-axis direction).The wheel cylinder ports 872 each have a cylindrical shape with a base, their central axis extending in the Z-axis direction, and are open laterally in the negative direction of the Y-axis of the upper surface 804 (a position closer to the rear surface 802 than to the front surface 801). The ports 872 are arranged in a row in the X-axis direction. The two ports 872 of the P-system are arranged laterally in the positive direction of the X-axis, and the two ports 872 of the S-system are arranged laterally in the negative direction of the X-axis. The first fluid pool chamber 83 is located in a region surrounded by the main cylinder ports 871 and the wheel cylinder ports 872.The multitude of fluid passages and the like connect the ports 87, the fluid pool chambers 83 and 84, the cylinder-containing openings 82, the valve-containing openings and the hydraulic pressure sensor openings to each other.

[0026] The multiple mounting openings 85 comprise screw openings 851 to 853 for mounting the engine, screw openings 854 to 857 for mounting the ECU, and a screw opening 858 for mounting the housing. Screw openings 851 to 853 are each cylindrical with a base, their central axis running in the Y-axis direction, and open towards the front surface 801. Openings 851 to 853 are located on the side in the positive direction of the Y-axis of the housing 8 and partially overlap the cylinder-containing openings 82 in the Y-axis direction. Openings 851 to 853 are positioned in locations that are generally symmetrical with respect to the central axis O of the cam-containing opening 81. The respective distances from the central axis O to openings 851 to 853 are approximately equal.Openings 852 and 853 are located on both sides of the central axis O in the X-axis direction and on the side in the positive direction of the Z-axis with respect to the central axis O. Openings 852 and 853 are each adjacent to the cylinder-containing openings 82C and 82D (whose large-diameter sub-areas 821) and are also adjacent to the third flat surface sub-areas 809 of the recessed sub-areas 80A and 80B on the sides of the side surfaces 805 and 806 with respect to the cylinder-containing openings 82C and 82D (on the opposite sides of the cylinder-containing openings 82 from the first fluid pool chamber 83). Opening 851 is located on the side in the positive direction of the X-axis with respect to the cylinder-containing opening 82A and on the side in the negative direction of the Z-axis with respect to the central axis O.The opening 851 is adjacent to the cylinder-containing opening 82A (whose large-diameter section 821) and is also adjacent to the lower surface 803 on the side of the cylinder-containing opening 82A opposite the second fluid pool chamber 84. The screw openings 854 to 857 are each cylindrical, with their central axis running in the Y-axis direction, and extend through the housing 8. Openings 854 and 855 are located on the side of the lower surface 803, and openings 856 and 857 are located on the side of the upper surface 804. Openings 854 and 855 are positioned at the corner sections sandwiched between the lower surface 803 and the side surfaces 806 and 805, and are open towards the front surface 801 and the rear surface 802.Openings 856 and 857 are positioned at the corner sections, sandwiched between the upper surface 804 and the second flat surface sections 808 of the recessed sections 80, as viewed from the Y-axis direction, and open towards the first flat surfaces 807 of the recessed sections 80 and the rear surface 802. Opening 856 is adjacent to the wheel cylinder connection 872b and sandwiched between connections 872b and 872c in the X-axis direction. Opening 857 is adjacent to the wheel cylinder connection 872a and sandwiched between connections 872a and 872d. Screw openings 858A and 858B are positioned on the side opposite the Z-axis with respect to the central axis O.The screw openings 858A and 858B each have a cylindrical shape with a base, their central axis extending in the Y-axis direction, and are open towards the two ends of the front surface 801 in the X-axis direction. The openings 858A and 858B are located on the side in the positive direction of the Y-axis of the housing 8 and partially overlap the cylinder-containing openings 82 in the Y-axis direction. The openings 858A and 858B are each adjacent to the side surfaces 805 and 806 and are sandwiched between the cylinder-containing openings 82B and 82E and the screw openings 855 and 854 in the Z-axis direction. The opening 858A on the side in the negative direction of the X-axis is sandwiched between the left side surface 805 and the second fluid pool chamber 84. The opening 858A is positioned on the side of the vicinity of the central axis O opposite the primary terminal 871 P.The opening 858B on the side in the positive direction of the X-axis is positioned on the side of the vicinity of the central axis O opposite the secondary connection 871S. The screw opening 858C is positioned on the side in the negative direction of the Z-axis with respect to the central axis O. The opening 858C has a cylindrical shape with a base, its central axis extending in the X-axis direction, and is open towards an approximately central sub-region of the right side surface 806 in the Y-axis direction. The opening 858C is open while adjacent to the corner sub-region that is sandwiched between the first flat surface sub-region 807 and the third flat surface sub-region 809 of the second recessed sub-region 80B, as viewed from the X-axis direction. The opening 858C is positioned on the side of the vicinity of the central axis O opposite the opening 858A.

[0027] The ECU 90 is located and mounted on the rear surface 802 of the housing 8. In other words, the ECU 90 is integrally integrated with the housing 8. The ECU 90 comprises a control board and a control unit housing 901. The control board manages the electrical power supply to the motor 20 and the solenoids of the electromagnetic valves, among other components. Various types of sensors that detect the vehicle's motion, such as an accelerometer that detects the vehicle's acceleration and an angular velocity sensor that detects the vehicle's angular velocity (yaw rate or speed), can be mounted on the control board. Furthermore, a combined sensor (a combined sensor) that integrates these sensors into a single unit can be mounted on the control board. The control board is contained within the housing 901.The housing 901 is a cover component that is attached to the rear surface 802 (the screw openings 854 to 857) of the housing 8 using screws b2. The rear surface 802 serves as the mounting surface for the housing. The screw openings 854 to 857 serve as the mounting area for attaching the ECU 90 to the housing 8. The head portions of the screws b2 are located on the side of the front surface 801 of the housing 8. The shank portions of the screws b2 extend through the screw openings 854 to 857, and externally threaded screws on the distal ends of the shank portions engage with internally threaded screws on the side of the housing 901. The housing 901 is firmly attached to the rear surface 802 of the housing 8 by means of the axial forces exerted by the screws b2. The head sections b21 of the screws b2 protrude into the first recessed section 80A or.the second recessed sub-area 80B. The head section areas b21 are contained within the recessed sub-areas 80 and do not project beyond the front surface 801 in the direction of the side in the positive direction of the Y-axis.

[0028] The housing 901 is a cover component made of a resin material and comprises a circuit board-containing sub-section 902 and a connector sub-section 903. The circuit board-containing sub-section 902 contains the control board and parts of the solenoids of the electromagnetic valves and the like (hereinafter referred to as the control board and the like). The control board is generally mounted parallel to the rear surface 802 in the circuit board-containing sub-section 902. The terminals of the solenoids of the electromagnetic valves and the like, the terminals of the hydraulic pressure sensors and the like, and the conductive component from the motor 20 protrude from the rear surface 802. The terminals described above and the conductive component extend laterally in the negative direction of the Y-axis to connect to the control board.The connector section 903 is located on the side opposite the X-axis of the circuit board-containing section 902 with respect to the connections and conductive component described above, and projects towards the side opposite the Y-axis of the circuit board-containing section 902. The connector section 903 is located on the slightly outer side (the side opposite the X-axis) with respect to the left side face 805 of the housing 8, as viewed from the Y-axis direction. Connections of the connector section 903 are exposed towards the side opposite the Y-axis and also extend towards the side opposite the Y-axis to connect to the control board.Each of the terminals of connector section 903 (exposed to the side in the positive direction of the Y-axis) can be connected to an external device or the stroke sensor 94 (hereinafter referred to as the external device and the like). An electrical connection between the external device and the like and the control board (the ECU 90) is established by inserting another connector, connected to the external device and the like, into connector section 903 from the side in the positive direction of the Y-axis. Furthermore, electrical power is supplied to the control board from an external electrical power source (a battery) via connector section 903.The conductive component serves as a connecting part area that electrically connects the control board and the motor 20, and the electrical power is supplied from the control board to the motor 20 via the conductive component.

[0029] The motor 20 is arranged on the front surface 801 of the housing 8, and a motor housing 200 is attached to it. The front surface 801 serves as a mounting surface for the motor. The screw openings 851 to 853 serve as the fastening area for attaching the motor 20 to the housing 8. The motor 20 encompasses the motor housing 200. The motor housing 200 has a cylindrical shape with a base and contains, for example, a magnet as a stator, a rotor, and the like on its inner circumferential side, assuming that the motor 20 is a DC brushed motor. The conductive component for an electrical power supply is connected to the rotor via a brush. The central axis (the axis of rotation) of the rotating shaft of the motor 20 approximately coincides with the central axis O of the opening 81 containing a cam.A rotary drive shaft 300, which is the drive shaft and the drive shaft of the pump 3, and a cam assembly 30 are contained in the opening 81 (within the housing 8) which contains a cam. The rotary drive shaft 300 is the drive shaft of the pump 3. The rotary drive shaft 300 is rigidly coupled to the drive shaft of the motor 20 in such a way that its central axis runs on an extension of the central axis of the drive shaft of the motor 20, and is set in rotation by the motor 20. The central axis of the rotary drive shaft 300 is approximately the same as the central axis O. The rotary drive shaft 300 rotates integrally with the drive shaft of the motor 20 about the central axis O. The cam assembly 30 is provided on the rotary drive shaft 300. The cam unit 30 comprises a cam 301, a drive component 302 and a multitude of rolling elements 303.The cam 301 is a columnar eccentric cam and has a central axis P that is eccentric with respect to the central axis O of the rotary drive shaft 300. The central axis P generally runs parallel to the central axis O. The cam 301 oscillates as it rotates integrally with the rotary drive shaft 300 about the central axis O. The drive component 302 has a cylindrical shape and is arranged on the outer circumferential side of the cam 301. The central axis of the drive component 302 is approximately congruent with the central axis P. The drive component 302 is rotatable about the central axis P with respect to the cam 301. The drive component 302 is configured similarly to the outer race of a rolling bearing. The plurality of rolling elements 303 is arranged between the outer circumferential surface of the cam 301 and the inner circumferential surface of the drive component 302.The rolling elements 303 are needle rollers and extend along the direction of the central axis of the drive shaft 300.

[0030] Pump 3 is a radial piston pump in the form of a fixed cylinder and comprises the housing 8, the rotary drive shaft 300, the cam unit 30, and the plurality of (five) pump subsections 3A to 3E. Each pump subsection 3A to 3E is a piston pump (reciprocating piston pump) and is actuated by the rotation of the rotary drive shaft 300. The brake fluid, as the hydraulic fluid, is drawn in and expelled according to the reciprocating movements of the pistons 36. The cam unit 30 converts the rotary motion of the rotary drive shaft 300 into the reciprocating movements of the pistons 36. To distinguish the respective configurations of the pump subsections 3A to 3E, indices A to E are added to their reference numbers. The respective pistons 36 are arranged around the cam unit 30 and are each contained in the opening 82 containing the cylinder.A central axis 360 of each of the pistons 36 coincides approximately with the central axis of the cylinder-containing opening 82 and extends in the radial direction of the rotary drive shaft 300. In other words, as many pistons 36 as there are cylinder-containing openings 82 (five) are provided and extend radially with respect to the central axis O. The pistons 36A to 36E are arranged circumferentially around the rotary drive shaft 300 at approximately equal intervals in the direction of rotation of the rotary drive shaft 300. The central axes 360A to 360E of these pistons 36A to 36E lie in the same plane α. These pistons 36A to 36E are driven by the same rotary drive shaft 300 and the same cam unit 30.

[0031] The pump section 3A comprises a cylinder sleeve 31, a filter component 32, a plug component 33, a guide ring (a bearing) 34, a first sealing ring 351, a second sealing ring 352, the piston 36, a return spring 37, an inlet valve 38, and an outlet valve 39, and these components are arranged in the cylinder-containing opening 82. The cylinder sleeve 31 has a cylindrical shape with a base, and an opening 311 extends through its base section 310. The cylinder sleeve 31 is secured in the cylinder-containing opening 82. The central axis of the cylinder sleeve 31 is approximately aligned with the central axis 360 of the cylinder-containing opening 82. An end section 312 of the cylinder sleeve 31 on the opening side is arranged in the section 822 with an intermediate diameter (the inlet port 823), and the bottom section 310 is arranged in the section 821 with a large diameter (exhaust port).The filter component 32 has a cylindrical shape with a base, and an opening 321 extends through its base section 320, while multiple opening sections also extend through its side wall section. A filter is placed on each of these opening sections. An end section 323 of the filter component 32 on the opening side is attached to the end section 312 of the cylinder sleeve 31 on the opening side. The base section 320 is located in the small-diameter section 820. The central axis of the filter component 32 approximately coincides with the central axis 360 of the cylinder-containing opening 82. A gap is created between the outer circumferential surface, where the opening section of the filter component 32 is open, and the inner circumferential surface of the cylinder-containing opening 82 (the inlet port 823). The first connecting fluid passage is connected to the inlet port 823 and the gap described above.The plug component 33 has a column-like shape and comprises a recessed section 330 and a depression on one end face in the direction of its central axis. This depression extends radially to connect the recessed section 330 and the outer circumferential surface of the plug component 33 and is connected to the outlet port 821. The end face of the plug component 33, described above, is attached to the bottom section 310 of the cylinder sleeve 31. The central axis of the plug component 33 approximately coincides with the central axis 360 of the cylinder-containing opening 82. The plug component 33 is attached to the large-diameter section 821 and closes the opening of the cylinder-containing opening 82 on the outer circumferential surface of the housing 8. The second connecting fluid passage is connected to the outlet port 821 and the depression of the plug component 33 described above.The guide ring 34 has a cylindrical shape and is attached to the side of the opening 81 containing a cam (the small-diameter section 820) of the cylinder-containing opening 82 with respect to the filter component 32. The guide ring 34 is made of a resin material. The central axis of the guide ring 34 approximately coincides with the central axis 360 of the cylinder-containing opening 82. The first sealing ring 351 is arranged between the guide ring 34 and the filter component 32 in the cylinder-containing opening 82 (the small-diameter section 820).

[0032] The piston 36 has a column-like shape and comprises an end face (hereinafter referred to as the piston end face) 361 on one side in the direction of its central axis and, on the other side in the direction of its central axis, a flanged portion 362 on its outer circumference. The piston end face 361 is flat and extends in a direction generally perpendicular to the central axis 360 of the piston 36. It is generally circular and centered on the central axis 360. The piston 36 includes an axial opening 363 and a radial opening 364. The axial opening 363 extends along the central axis 360 such that it opens towards the end face of the piston 36 on the other side described above, in the direction of the central axis.The radial opening 364 extends radially along the piston 36 such that it opens towards the outer circumferential surface of the one side described above in the direction of the central axis with respect to the flange section 362 and is also connected to the one side of the axial opening 363 described above in the direction of the central axis. A check valve housing 365 is attached to the end section of the piston 36 on the other side described above in the direction of the central axis. The check valve housing 365 has a cylindrical shape with a base consisting of a thin plate and comprises a flange section 366 on the outer circumference of its end section on the opening side and a plurality of openings 368 extending through its side wall section and base section 367.The end section of the check valve housing 365 on the opening side is adapted to the end section of the piston 36 on the other side described above, in the direction of the central axis. The second sealing ring 352 is arranged between the flange section 366 of the check valve housing 365 and the flange section 362 of the piston 36. The other side of the piston 36, described above, in the direction of the central axis, is inserted into the inner circumferential side of the cylinder sleeve 31, and the piston section 362 is guided and supported by the cylinder sleeve 31. The one side of the piston 36 described above, in the direction of the central axis with respect to the radial opening 364, is inserted into the inner circumferential side (the opening 321) of the bottom part area 320 of the filter component 32, the inner circumferential side of the first sealing ring 351 and the inner circumferential side of the guide ring 34, and is guided and supported by them.The central axis 360 of the piston 36 coincides approximately with the central axis of the cylinder sleeve 31 and the like (the cylinder-containing opening 82). The end portion of the piston 36 on the side described above, in the direction of the central axis (the piston end face 361), projects inside the opening 81 containing a cam.

[0033] The return spring 37 is a compression spring and is located on the inner circumferential side of the cylinder sleeve 31. One end and the other end of the return spring 37 bear against the base section 310 of the cylinder sleeve 31 and the flange section 366 of the check valve housing 365, respectively. The return spring 37 constantly biases the piston 36 in the direction of the cam-containing opening 81 relative to the cylinder sleeve 31 (the cylinder-containing opening 82). The inlet valve 38 comprises a ball 380 as the valve body and a return spring 381, and these are located on the inner circumferential side of the check valve housing 365. A valve seat 369 is provided around the opening of the axial opening 363 on the end face of the piston 36 on the other side described above, in the direction of the central axis. The ball 380 sits on the valve seat 369, thereby closing the axial opening 360.The return spring 381 is a compression spring, and one end and the other end of it rest against the base section 367 of the check valve housing 365 and the ball 380, respectively. The return spring 381 constantly pre-tensions the ball 380 towards the side of the valve seat 369 with respect to the check valve housing 365 (the piston 36). The exhaust valve 39 contains a ball 390 as the valve body and a return spring 391, and these are contained in the recessed section 330 of the plug component 33. A valve seat 313 is provided around the opening section of the through-hole 311 on the base section 310 of the cylinder sleeve 31. The ball 390 rests on the valve seat 313, thereby closing the through-hole 311. The return spring 391 is a compression helical spring, and one end and the other end of it lie against the bottom surface of the recessed part 330 or the ball 390.The return spring 391 constantly pre-tensions the ball 390 towards the side of the valve seat 313.

[0034] Within the cylinder-containing opening 82, a space R1 is located on the side of the cam-containing opening 81, in relation to the flange section 362 of the piston 36. This space is on the inlet side and is connected to the first connecting fluid passage. More precisely, a space, serving as the inlet-side space R1, extends from the gap described above between the outer circumferential surface of the filter component 32 and the inner circumferential surface (the inlet port 823) of the cylinder-containing opening 82, through the plurality of openings of the filter component 32 and a gap between the outer circumferential surface of the piston 36 and the inner circumferential surface of the filter component 32, leading to the radial opening 364 and the axial opening 363 of the piston 36. The connection of this inlet-side space R1 with the cam-containing opening 81 is sealed by the first sealing ring 351.Inside the cylinder containing the opening 82, a space R3 between the cylinder sleeve 31 and the plug component 33 is an outlet-side space connected to the second connecting fluid passage. More precisely, a space extending from the recess of the plug component 33 described above to the outlet port 821 serves as the outlet-side space R3. On the inner circumferential side of the cylinder sleeve 31, the volume of a space R2 between the flange section 362 of the piston 36 and the bottom section 310 of the cylinder sleeve 31 changes due to a reciprocating movement (a stroke) of the piston 36 relative to the cylinder sleeve 31. This space R2 is connected to the inlet-side space R1 corresponding to the opening of the inlet valve 38 and to the outlet-side space R3 corresponding to the opening of the outlet valve 39. The piston 36 of pump section 3A performs a pumping function by moving back and forth.More precisely, when the piston 36 performs a stroke as it approaches the opening 81 containing the cam (central axis O), the volume of chamber R2 increases and the pressure in R2 decreases. Corresponding to the closing of the outlet valve 39 and the opening of the inlet valve 38, the brake fluid, as the hydraulic fluid, is introduced from the inlet-side chamber R1 into chamber R2, and the brake fluid from the first connecting fluid passage is supplied to chamber R2 via the inlet port 823. When the piston 36 performs a stroke as it moves away from the opening 81 containing the cam to the other side, the volume of chamber R2 decreases and the pressure in R2 increases.Due to the closing of the inlet valve 38 and the opening of the outlet valve 39, the brake fluid is transferred from chamber R2 to the outlet-side chamber R3 and fed into the second connecting fluid passage via the outlet port 821. The other pump sections 3B to 3E are configured similarly. The brake fluid discharged by each of the pump sections 3A to 3E to the second connecting fluid passage is collected in a single outlet fluid passage 13 and used jointly by the two hydraulic circuit systems.

[0035] Fig. Figure 3 is an enlarged view of main part areas of pump part area 3A according to the first embodiment. Fig. Figure 4 is a perspective view of the guide ring 34A according to the first embodiment. Fig. Figure 5 is an axial cross-sectional view of the guide ring 34A according to the first embodiment.

[0036] The guide ring 34A comprises a cylindrical section 341 and a flanged section 342. The cylindrical section 341 is cylindrical and includes a first end section 341a and a second end section 341b at its two axial ends. The guide ring 34A is attached to the housing 8 by the first end section 341a, which projects into the opening 81 containing a cam. The flanged section 342 projects radially outward from the second end section 341b of the cylindrical section 341. The outer circumference of the guide ring 34A, with the exception of the flanged section 342, is a section 341c with a small outer diameter. Furthermore, the outer circumference of the flanged section 342 is a section 341d with a large outer diameter, the outer diameter of which is larger than that of the section 341c with a small outer diameter.A subsection 824 with the smallest diameter and a smaller inner diameter than the subsection 820 with the smallest diameter is provided at a position of the cylinder-containing opening 82A that is closer to the opening 81 containing a cam than the subsection 820 with the smallest diameter. The cylindrical subsection 341 of the guide ring 34A is press-fitted into the subsection 824 with the smallest diameter. The inner diameter of the subsection 820 with the smallest diameter is larger than the outer diameter of the flange subsection 342.

[0037] The cylindrical section 341 comprises, on its inner circumference, a section 341e with a small inner diameter and a section 341f with a large inner diameter. The section 341e with the small inner diameter is located on the side of the first end section 341a, and the section 341f with the large inner diameter is located on the side of the second end section 341b. The section 341f with the large inner diameter has a larger inner diameter than the section 341e with the small inner diameter. Furthermore, the axial length of the section 341f with the large inner diameter is longer than the stroke of the piston 36A. The first end section 341a includes an R-shaped section 341g on the outer circumference of its distal end.

[0038] The guide rings 34B to 34E of the pump sections 3B to 3E do not project into the cam receiving opening 81. In other words, the distal ends of the guide rings 34B to 34E lie on the radial inner surfaces and on the radial outer surfaces with respect to the inner circumferential surface of the opening 81 containing a cam.

[0039] Next, the functions will be described.

[0040] When pump 3 is actuated, contamination such as abrasion is generated by the sliding contact between each of the pistons 36A to 36B and the drive component 302. This contamination, which mixes with the brake fluid leaked or escaped from the cylinder-containing openings 82A to 82E, is deposited in the opening 81 containing a cam. The cylinder-containing opening 82A of pump section 3A is now open upwards at the lower end of the opening 81 containing the cam, located beneath these cylinder-containing openings 82A to 82E. In other words, when the brake control device 1 is mounted on the vehicle, pump section 3A is positioned on its lower side in the vertical direction with respect to the center of the opening 81 containing the cam.Therefore, the contaminant deposited in the opening 81 containing the cam is carried by the reciprocating sliding motion of the piston 36A into a gap between the outer circumferential surface of the piston 36A and the inner circumferential surface of the guide ring 34, causing scarring on the piston 36A. As a result, the scar (the unevenness) created on the outer circumferential surface of the piston 36A can damage the first sealing ring 351, thereby reducing the service life of the piston section 3A. In particular, the problem described above occurs noticeably in newer vehicles equipped with autonomous driving functionality or brake-by-wire systems, because the pump 3 is operated very frequently and contamination is generated in large quantities in these vehicles.

[0041] To address this problem, in the brake control device 1 according to the first embodiment, the guide ring 34A of the pump section 3A projects into the opening 81 containing a cam. In other words, the guide ring 34A is fixed in the cylinder-containing opening 82A in such a way that its upper end (the distal end of the first end section 341a) is positioned in the opening 81 containing a cam on the upper side with respect to the opening edge of the cylinder-containing opening 82A. The contamination generated by the actuation of the pump 3 is deposited on the outer circumferential side of the guide ring 34A, but is insulated from the piston 36A by the guide ring 34A and is therefore less likely to adhere to the piston 36A and less likely to penetrate the inner circumferential side of the guide ring 34A.As a result, the brake control device 1 can prevent or reduce the scarring on the piston 36A caused by contamination, thereby preventing or reducing the deterioration of the sealing performance of the first sealing ring 351 and thus improving the service life of the pump part area 3A.

[0042] The guide ring 34A includes on its inner circumference the sub-section 341e with a small inner diameter and the sub-section 341f with a large inner diameter. The sub-section 341e with a small inner diameter and the sub-section 341f with a large inner diameter are located on the side of the first end section 341a and the side of the second end section 341b, respectively, in the axial direction of the guide ring 34A, and the sub-section 341f with a large inner diameter has a larger inner diameter than the sub-section 341e with a small inner diameter. The gap between the sub-section 341f with a large inner diameter and the piston 36A is large compared to the gap between the sub-section 341e with a small inner diameter, and therefore the outer circumferential surface of the piston 36A is less likely to become scarred, even if contamination gets between the inner circumferential surface of the sub-section 341f with a large inner diameter and the outer circumferential surface of the piston 36A.More precisely, even if the piston 36A moves back and forth with the contaminant fixed between the inner circumferential surface of the guide ring 34A and the outer circumferential surface of the piston 36A, the area where scars are inflicted on the piston 36A can be limited to the area where the piston 36A is in contact with the small inner diameter sub-area 341e.

[0043] The axial length of the large inner diameter section 341f of the guide ring 34A is set to be longer than the stroke of the piston 34A. Because of this setting, even if the piston 36A slides back and forth with the contaminant trapped in the gap between the small inner diameter section 341e and the piston 36A and the outer circumferential surface of the piston 36A, this contaminant does not reach the first sealing ring 351, thus preventing damage to the first sealing ring 351.

[0044] The guide ring 34A encompasses the flange section 342 on its outer circumference and the section 341f with a large inner diameter on its radially outer side. Due to this configuration, when the guide ring 34A is installed in the cylinder-containing opening 82A, the flange section 342 is brought into contact with the stepped surface between the small-diameter section 820 and the smallest-diameter section 824, and this contact enables the guide ring 34A to be positioned with improved accuracy in the axial direction of the cylinder-containing opening 82A.

[0045] The guide ring 34A includes the small outer diameter subsection 341c on its outer circumference. The outer diameter of the small outer diameter subsection 341c is smaller than that of the flange subsection 342. The small outer diameter subsection 341c is attached to the housing 8 by pressing it into the smallest diameter subsection 824 of the cylinder-containing opening 82A. As a result, the guide ring 34A can be easily attached to the housing 8.

[0046] The guide ring 34A comprises, at its two axial end regions, the first end region 341a and the second end region 341b. The first end region 341a, which is one of these end regions located on the side of the opening 81 containing a cam, then contains the R-shaped sub-region 341g, and the diameter of the first end region 341a decreases towards its distal end. Due to this configuration, the brake control device 1 can facilitate positioning in the initial phase of installation in the press fit when the guide ring 34A is pressed into the cylinder-containing opening 82A, thereby preventing or reducing tilting or jamming during pressing. Furthermore, the brake control device 1 can prevent or reduce the deposition of contaminants on the end face of the first end region 341a. [Second embodiment]

[0047] A second embodiment has a basic configuration similar to the first embodiment and is therefore described with a focus solely on differences compared to the first embodiment.

[0048] Fig. Figure 6 is an enlarged view of main part areas of pump part area 3A according to the second embodiment.

[0049] The pump section 3A according to the second embodiment differs from the first embodiment with respect to the guide ring 34A, which includes a sealing component 343. The sealing component 343 is annular and is attached to the end surface of the first end section 341a by means of adhesive bonding in close contact with the outer circumferential surface of the piston 36A. The first end section 341a has a constant outer diameter.

[0050] In the second embodiment, the amount of contamination entering the inner circumferential side of the guide ring 34A can be reduced by eliminating the gap between the inner circumferential surface of the guide ring 34A and the outer circumferential surface of the piston 36A using the sealing component 343. [Third embodiment]

[0051] A third embodiment has a basic configuration similar to the first embodiment and is therefore described with a focus solely on differences compared to the first embodiment.

[0052] Fig. Figure 7 is an axial cross-sectional view of the guide ring 34A according to the third embodiment.

[0053] The guide ring 34A according to the third embodiment differs from the first embodiment with respect to the flange section 342, which is pressed into the small-diameter section 820 containing the opening 82A. The inner diameter of the smallest-diameter section 824 is larger than the outer diameter of the cylindrical section 341. The first end section 341a of the guide ring 34A comprises a conical section 341h on the outer circumference of its distal end. The outer diameter of the conical section 341h decreases towards its distal end.

[0054] The guide ring 34A is a resin-molded product, and therefore, compared to a metal product, the inner diameter of the pressed-in section changes significantly when the guide ring 34A is pressed into the cylinder-containing opening 82A. Furthermore, there is considerable dimensional variation in the resin-molded product compared to a metal product. If the radially outer side of the small inner diameter section 341e is in sliding contact with the piston 36A in the press fit within the cylinder-containing opening 82A, the dimensions of the small inner diameter section 341e should therefore be designed taking into account deformation due to the press fit and variations in the dimensions of the cylinder-containing opening 82A and the small outer diameter section 341c.To address this difficulty, in the third embodiment, the guide ring 34A is attached to the housing 8 by pressing the radially outer side of the large-diameter sub-section 341f into the small-diameter sub-section 820. This configuration allows the dimension of the small-diameter sub-section 341e to be designed without considering deformation due to the press fit and dimensional variation in each sub-section. In other words, the third embodiment allows the dimension of the small-diameter sub-section 341 to be determined with high accuracy, thereby further reducing the gap between the small-diameter sub-section 341e and the piston 36A.As a result, the third embodiment can reduce the amount of contamination that enters the gap between the small inner diameter sub-section 341e and the piston 36A and can also reduce the inclination of the piston 36A, thereby achieving ideal actuation of the pump sub-section 3A.

[0055] The guide ring 34A comprises, as its two axial end sections, the first end section 341a and the second end section 341b. The first end section 341a, which is located on the side of the opening 81 containing a cam, contains the conical section 341h, and the diameter of the first end section 341a decreases towards its distal end. Due to this configuration, the third embodiment facilitates positioning during the initial pressing phase when the guide ring 34A is pressed into the cylinder-containing opening 82A, thereby preventing or reducing tilting or jamming during pressing. Furthermore, the third embodiment can prevent or reduce the deposition of contaminants on the end surface of the first end section 341a. [Fourth embodiment]

[0056] A fourth embodiment has a basic configuration similar to the third embodiment and is therefore described with a focus solely on differences compared to the third embodiment.

[0057] Fig. Figure 8 is an axial cross-sectional view of the guide ring 34A according to the fourth embodiment.

[0058] The guide ring 34A according to the fourth embodiment differs from the third embodiment in that the flange section is omitted. The outer diameter of the guide ring 34A is constant, with the exception of the conical section 341h. The section 824 with the smallest diameter of the cylinder-containing opening 82A is located between the small-diameter section 820 and the intermediate-diameter section 822. The guide ring 34A is pressed into the small-diameter section 824. The fourth embodiment can also achieve similarly advantageous effects as the third embodiment. [Fifth embodiment]

[0059] A fifth embodiment has a basic configuration similar to the first embodiment and is therefore described with a focus solely on differences compared to the first embodiment.

[0060] Fig.Figure 9 is a cross-sectional view of the housing 8 of the second unit 1B according to the fifth embodiment, taken along the direction perpendicular to the axis.

[0061] The fifth embodiment differs from the first embodiment with regard to the use of the guide ring 34A according to the first embodiment for all pump sub-areas 3A to 3E.

[0062] Assembling one type of guide ring, such as guide ring 34A, for all pump sub-areas 3A to 3E allows the same assembly process to be used, thus preventing assembly errors and simplifying the process. [Other embodiments]

[0063] Having described the embodiments for implementing the present invention, the specific configuration of the present invention is not limited to the configurations of the embodiments, and the present invention also includes its design modification and the like, which is carried out within a scope that does not deviate from the spirit of the present invention, if at all.

[0064] The guide ring 34 can be coplanar with the cam mounting opening 81.

[0065] In the fifth embodiment, the guide ring 34A according to the first embodiment can be used for only the three pump sub-areas 3A, 3B and 3E.

[0066] The following description outlines technical ideas that can be identified from the embodiments described above.

[0067] A brake control device comprises, in one configuration, a motor and a housing. The housing includes a first surface on which the motor is mounted, a second surface spaced from the first surface by a predetermined distance in the direction of a rotational axis of the motor, and a receiving opening extending from the first surface to the second surface in the direction of the rotational axis and configured to receive a shaft rotated by the motor. The brake control device further includes a piston pump. The piston pump includes a piston configured to be actuated by one revolution of the motor. The piston pump includes a bearing through which a piston is inserted. The bearing is attached to the housing such that it projects into the receiving opening or is coplanar with the receiving opening.

[0068] According to another preferred configuration, in the configuration described above, the bearing comprises, on its inner circumference, a sub-region with a small inner diameter and a sub-region with a large inner diameter. The sub-region with the large inner diameter has a larger inner diameter than the sub-region with the small inner diameter.

[0069] According to another preferred configuration, in each of the configurations described above, the axial length of the large inner diameter section is equal to or longer than the stroke of the piston.

[0070] According to another preferred configuration, in any of the configurations described above, a radial outer side of the large inner diameter part of the bearing is attached to the housing.

[0071] According to another preferred configuration, in each of the configurations described above, the bearing comprises a flanged part area on its outer circumference and on the radially outer side of the part area with a large inner diameter.

[0072] According to another preferred configuration, in each of the configurations described above, the bearing includes a flange part area on its outer circumference.

[0073] According to another preferred configuration, in each of the configurations described above, the bearing includes a small-diameter sub-section on its outer circumference. This small-diameter sub-section has a smaller outer diameter than the flange sub-section. The small-diameter sub-section is attached to the housing.

[0074] According to another preferred configuration, in each of the configurations described above, the bearing comprises a small-diameter inner section and a large-diameter inner section on its inner circumference. The small-diameter inner section is positioned on a radially inner side of the small-diameter outer section. The large-diameter inner section is positioned on a radially inner side of the flange section.

[0075] According to another preferred configuration, in each of the configurations described above, at an end part region of both axial end part regions of the bearing that is located on a side closer to the receiving opening, the diameter decreases in the direction of a distal end.

[0076] According to another preferred configuration, in each of the configurations described above, the end section has an R-shape.

[0077] According to another preferred configuration, in each of the configurations described above, the end section has a tapered shape.

[0078] According to another preferred configuration, in each of the configurations described above, the bearing includes a sealing component at an end part region of its two axial end part regions, which is located on a side closer to the receiving opening.

[0079] According to another preferred configuration, in each of the configurations described above, the piston pump is located on a lower side in a vertical direction with respect to a center of the receiving opening when the brake control device is mounted on a vehicle.

[0080] According to another preferred configuration, in each of the configurations described above, the piston pump comprises a plurality of piston pumps arranged around the axis of rotation.

[0081] The present invention is not intended to be limited to the embodiments described above and includes various modifications. For example, the embodiments described above have been described in detail to facilitate a better understanding of the present invention, and the present invention is not necessarily intended to be limited to the configuration containing all the described features. Furthermore, a part of the configuration of any embodiment can be replaced by the configuration of another embodiment. Furthermore, any embodiment can also be implemented with a configuration of another embodiment added to the configuration of that embodiment. Furthermore, each of the embodiments can also be implemented with a different configuration that adds to, eliminates, or replaces a part of the configuration of that embodiment.

[0082] The present application claims priority under the Paris Agreement for Japanese patent application No. 2018-155195, filed on August 22, 2018. The entire disclosure of Japanese patent application No. 2018-155195, filed on August 22, 2018, including the description, claims, drawings, and abstract, is incorporated herein by reference in its entirety. [List of reference symbols] 3A Pump section (piston pump) 8 cases 20 engine 34A Guide ring (bearing) 36 pistons 81 cam-containing opening (receiving opening) 300 Rotary drive shaft (shaft) 801 front surface (first surface) 802 reverse surface (second surface)

Claims

[1] Brake control device (1) comprising: a motor (20); a housing (8) comprising a first surface (801) on which the motor (20) is arranged, a second surface (802) spaced from the first surface (801) by a predetermined distance in one direction of a rotational axis of the motor (20), and a receiving opening (81) extending from the first surface (801) towards the second surface (802) in the direction of the rotational axis and configured to receive a shaft (300) which is rotated by means of the motor (20); and a piston pump (3A) comprising a piston (36) configured to be actuated by a revolution of the motor (20) and a bearing (34A) through which the piston (36) is inserted, wherein the bearing (34A) is attached to the housing (8) such that it projects into the receiving opening (81) or is arranged coplanar with the receiving opening (81), wherein the bearing (34A) comprises on its inner circumference a sub-section (341e) with a small inner diameter and a sub-section (341f) with a large inner diameter, wherein the sub-section (341f) with a large inner diameter has a larger inner diameter than the sub-section (341e) with a small inner diameter. [2] Brake control device (1) according to claim 1, wherein an axial length of the part (341f) with large inner diameter is equal to or longer than a stroke range of the piston (36). [3] Brake control device (1) according to claim 1, wherein a radially outer side of the sub-area (341f) with large inner diameter of the bearing (34A) is attached to the housing (8). [4] Brake control device (1) according to claim 3, wherein the bearing (34A) comprises a flange part section (342) on its outer circumference and on the radially outer side of the part section (341f) with a large inner diameter. [5] Brake control device (1) according to claim 1, wherein the bearing (34A) comprises a flange part area (342) on its outer circumference. [6] Brake control device (1) according to claim 5, wherein the bearing (34A) comprises a sub-section (341c) with a small outer diameter on its outer circumference, wherein the sub-section (341c) with a small outer diameter has a smaller outer diameter than the flange sub-section (342), and wherein the sub-section (341c) with a small outer diameter is attached to the housing (8). [7] Brake control device (1) according to claim 6, wherein the bearing (34A) comprises a sub-section (341e) with a small inner diameter and a sub-section (341f) with a large inner diameter on its outer circumference, wherein the sub-section (341e) with a small inner diameter is positioned on a radially inner side of the sub-section (341c) with a small outer diameter, and wherein the sub-section (341f) with a large inner diameter is positioned on a radially inner side of the flange sub-section (342). [8] Brake control device (1) according to claim 1, wherein at an end part region (341a) of both axial end part regions of the bearing (34A), which is located on one side closer to the receiving opening (81), the diameter of which decreases in the direction of a distal end. [9] Brake control device (1) according to claim 8, wherein the end part area (341a) has an R-shape (341g). [10] Brake control device (1) according to claim 8, wherein the end part area (341a) has a tapered shape. [11] Brake control device (1) according to claim 1, wherein the bearing (34A) includes a sealing component (343) at an end part region (341a) of its two axial end part regions, which is located on one side closer to the receiving opening (81). [12] Brake control device (1) according to claim 1, wherein the piston pump (3A) is located on a lower side in a vertical direction with respect to a center of the receiving opening (81) when the brake control device (1) is mounted on a vehicle (10). [13] Brake control device (1) according to claim 1, wherein the piston pump (3A) comprises a plurality of piston pumps (3A) arranged around the axis of rotation.

Images