Hydraulic pressure control unit and vehicle

Abstract

The present invention achieves a hydraulic pressure control unit which can be reduced in size compared to conventional designs and can suppress reductions in the discharge capacity of a pump. The hydraulic pressure control unit according to the present invention is provided with a pump that moves a brake fluid in an internal flow path formed in a base body, wherein: the pump is provided with a piston part in which an input-side end part, which constitutes one end thereof, is pressed by a motor, and a partition-side end part, which constitutes another end thereof, is inserted into a compression chamber so as to partition the compression chamber and reciprocally moves inside the compression chamber; the piston part has formed therein an inflow flow path for guiding the brake fluid to the compression chamber, and is provided with a first piston portion having the input-side end part, and a second piston portion having the partition-side end part; an inflow-side check valve for restricting the flow of brake fluid flowing back from the compression chamber is disposed between the first piston portion and the second piston portion; and one of the first piston portion and the second piston portion is fitted into the other and is connected thereto by press-fitting.

Description

[0001] [Document name] Statement

[0002] [Title of invention] Hydraulic pressure control unit and vehicle

[0003] [Technical Field]

[0004]

[001] The present invention relates to a hydraulic control unit for a vehicle, and a vehicle equipped with the hydraulic control unit.

[0005] [Background technology]

[0006] [. 0 0 2] Some vehicles are equipped with a hydraulic control unit that controls the hydraulic pressure of brake fluid in a hydraulic circuit filled with brake fluid. For example, when the driver of the vehicle operates an input device such as a brake lever, the hydraulic control unit increases or decreases the hydraulic pressure of the brake fluid in the hydraulic circuit to adjust the braking force generated on the wheels and perform anti-lock brake control. Such a hydraulic control unit includes a base body in which an internal flow path is formed that connects the wheel cylinders and the master cylinder, and a pump that moves the brake fluid in the internal flow path.

[0007]

[0003] The pump of the conventional hydraulic control unit includes a cylinder in which a compression chamber that compresses brake fluid is formed, and a piston portion in which an inflow passage that guides brake fluid to the compression chamber is formed. The piston portion of the conventional hydraulic control unit includes a first piston portion in which a part of the inflow passage is formed and one end of which is pressed by the motor, a second piston portion in which a part of the inflow passage is formed and which is connected to the other end of the first piston, and an inflow-side check valve that is provided between the first piston portion and the second piston portion and that restricts backflow of brake fluid in the inflow passage. In addition, in pumps of conventional hydraulic control units, the outer periphery of the end of the second piston portion on which the check valve is located defines the compression chamber and slides on the inner periphery of the compression chamber (see, for example, Patent Document 1).

[0008] [0 0 0 4] In a pump of a conventional hydraulic control unit, the first piston portion and the second piston portion are connected by a so-called snap structure. Specifically, the first connection side end, which is the connection point of the first piston portion with the second piston portion, has a convex portion that protrudes toward the outer periphery. Furthermore, a concave portion is formed in the first connection side end in an area on the opposite side of the second piston portion from the convex portion. Furthermore, the second connection side end, which is the connection point of the second piston portion with the first piston portion, has a convex portion that protrudes toward the inner periphery. Furthermore, a concave portion is formed in the second connection side end in an area on the opposite side of the first piston portion from the convex portion. By inserting the first connection side end into the second connection side end so as to spread the second connection side end apart, the convex portion of the first connection side end is inserted into the concave portion of the second connection side end, and the convex portion of the second connection side end is inserted into the concave portion of the first connection side end, whereby the convex portion of the second connection side end is caught on the convex portion of the first connection side end, and the first piston portion and the second piston portion are connected.

[0009] [Prior art documents]

[0010] [Patent documents]

[0011]

〇 0 0 5

[0012] [Patent Document 1] Japanese Patent Application Laid-Open No. 2020-011525

[0013] Summary of the Invention

[0014] [Problem to be solved by the invention]

[0015]

[0006] Compared to vehicles such as four-wheeled motor vehicles, straddle-type vehicles, which are a type of vehicle, have less freedom in component layout and therefore less freedom in mounting hydraulic control units. For this reason, there is a demand for smaller hydraulic control units mounted on straddle-type vehicles. Furthermore, in vehicles such as four-wheeled motor vehicles, there has been a demand for smaller hydraulic control units in recent years due to factors such as the reduction in engine compartment size and the increase in the number of components mounted in the engine compartment. Furthermore, when reducing the size of a hydraulic control unit, it is also necessary to avoid a reduction in the pump's discharge capacity. Thus, there has been a demand for a hydraulic control unit that can be made smaller while suppressing a reduction in the pump's discharge capacity.

[0016]

[0007] The present invention has been made in light of the above-mentioned problems, and has as its first object to provide a hydraulic control unit that can be made smaller than conventional units and that can suppress a decrease in the discharge capacity of the pump. Also, as a second object of the present invention, it is to provide a vehicle equipped with such a hydraulic control unit.

[0017] [Means for solving the problem]

[0018]

[0008] A hydraulic control unit according to the present invention is a hydraulic control unit for a brake system mounted on a vehicle, and comprises: a base body having an internal flow path formed therein that connects a wheel cylinder and a master cylinder; and a pump that moves brake fluid in the internal flow path, wherein the pump comprises: a cylinder having a compression chamber that compresses brake fluid; and a piston portion having an input side end that is one end pressed by a motor that is a drive source of the pump and a partition side end that is the other end inserted into the compression chamber to define the compression chamber, the partition side end reciprocating within the compression chamber, wherein the piston portion is formed with an inflow flow path into which brake fluid that has flowed through the internal flow path toward the pump flows and which guides the brake fluid to the compression chamber, and the piston portion comprises: a first piston portion in which a part of the inflow flow path is formed and having the input side end; and a second piston portion in which a part of the inflow flow path is formed and having the partition side end. the first piston portion has a first connection portion, which is one of a recess and a protrusion, at a first connection side end, which is an end opposite to the input side end; the second piston portion has a second connection portion, which is the other of the recess and the protrusion, at a second connection side end, which is an end opposite to the partition side end; an inlet side check valve is disposed between the first piston portion and the second piston portion to regulate the flow of brake fluid from the compression chamber toward the first piston portion; and the first piston portion and the second piston portion are connected by the protrusion being press-fit into the recess with an interference fit.

[0019]

[0009] The vehicle according to the present invention is equipped with the hydraulic control unit according to the present invention.

[0020] [Effects of the invention]

[0021] The hydraulic control unit according to the present invention is configured to partition the compression chamber at the partition end, which is the end opposite to the end where the inlet-side check valve of the second piston is located. As a result, the hydraulic control unit according to the present invention can reduce the size of the compression chamber, the cylinder in which the compression chamber is formed, and the piston, thereby making it possible to reduce the size of the pump and the hydraulic control unit compared to conventional models.

[0022]

[0011] In the conventional hydraulic control unit, as described above, the first piston portion and the second piston portion are connected by a snap structure. However, if the first piston portion and the second piston portion are made smaller, and the first piston portion and the second piston portion are connected by a snap structure as in the past, the dimensional tolerance of the connection between the first piston portion and the second piston portion becomes relatively large. Therefore, if the first piston portion and the second piston portion are connected by a snap structure as in the past, there is a concern that the reliability of the connection between the first piston portion and the second piston portion may decrease. As a result, when brake fluid is compressed in the compression chamber and sent out of the pump, there is a concern that the sealing performance of the connection between the first piston portion and the second piston portion will be reduced, resulting in a decrease in the pump's discharge capacity. However, the hydraulic control unit according to the present invention connects the first piston portion and the second piston portion by press-fitting one of the first piston portion and the second piston portion into the other with an interference fit. Therefore, the hydraulic control unit according to the present invention can achieve miniaturization while suppressing a decrease in the reliability of the connection between the first piston portion and the second piston portion and also suppressing a decrease in the pump's discharge capacity.

[0023] [Brief description of the drawing]

[0024] [ 0 0 1 2 ]

[0025] FIG. 1 is a diagram showing the configuration of a saddle-ride type vehicle equipped with a brake system including a hydraulic pressure control unit according to an embodiment of the present invention.

[0026] [Figure 2] A diagram showing the configuration of a brake system equipped with a hydraulic control unit according to an embodiment of the present invention.

[0027] [Figure 3] A cross-sectional view showing the area around the pump and motor of a hydraulic control unit in an embodiment of the present invention.

[0028] [Figure 4] A cross-sectional view showing a pump of a hydraulic control unit according to an embodiment of the present invention.

[0029] [Figure 5] A cross-sectional view showing a pump of a modified hydraulic control unit according to an embodiment of the present invention.

[0030] [Figure 6] A cross-sectional view showing a pump of a modified example of a hydraulic control unit according to an embodiment of the present invention.

[0031] [Figure 7] A diagram showing the configuration of a brake system equipped with a modified example of a hydraulic control unit according to an embodiment of the present invention.

[0032] [Figure 8] A diagram showing the configuration of a brake system equipped with a modified example of a hydraulic control unit according to an embodiment of the present invention.

[0033] DETAILED DESCRIPTION OF THE INVENTION

[0034]

[0013] The hydraulic control unit and vehicle according to the present invention will be described below with reference to the drawings. Hereinafter, an example will be described in which the hydraulic control unit according to the present invention is mounted on a motorcycle, which is an example of a saddle-riding vehicle. However, the hydraulic control unit according to the present invention may be mounted on saddle-riding vehicles other than motorcycles. Examples of saddle-riding vehicles other than motorcycles include bicycles (e.g., two-wheeled vehicles, three-wheeled vehicles, etc.), three-wheeled vehicles using at least one of an engine and an electric motor as a drive source, and buggies. Furthermore, the term "bicycle" refers to any vehicle that can be propelled on a road by pedaling force applied to pedals. In other words, bicycles include ordinary bicycles, electrically assisted bicycles, and electric bicycles. Furthermore, a motorcycle or three-wheeled vehicle refers to a so-called motorcycle, and a motorcycle includes a motorbike, a scooter, an electric scooter, etc. Furthermore, the hydraulic control unit according to the present invention may be mounted on vehicles other than saddle-type vehicles, such as four-wheeled motor vehicles using at least one of an engine and an electric motor as a drive source.

[0035]

[0014] In the following, an example in which the hydraulic pressure control unit according to the present invention is used in a vehicle brake system having two hydraulic circuits is described, but the number of hydraulic circuits in a vehicle brake system in which the hydraulic pressure control unit according to the present invention is used is not limited to two. A vehicle brake system in which the hydraulic pressure control unit according to the present invention is used may have only one hydraulic circuit, or may have three or more hydraulic circuits.

[0036]

[0015] Furthermore, the configurations, operations, etc. described below are merely examples, and the present invention is not limited to such configurations, operations, etc. Furthermore, in each drawing, the same or similar members or parts may be denoted by the same reference numerals or may not be denoted by the reference numerals. Furthermore, detailed structures may be appropriately simplified or omitted from the illustration.

[0037] [ 0 0 1 6 ] Embodiments.

[0038] <Configuration and Operation of Vehicle Brake System> The configuration and operation of a brake system equipped with a hydraulic pressure control unit according to this embodiment will be described. Fig. 1 is a diagram showing the configuration of a saddle-ride type vehicle equipped with a brake system equipped with a hydraulic pressure control unit according to an embodiment of the present invention. Fig. 2 is a diagram showing the configuration of a brake system equipped with a hydraulic pressure control unit according to an embodiment of the present invention.

[0039]

[0017] As shown in Fig. 1 and Fig. 2, the brake system 10 is mounted on a saddle-riding vehicle 200, which is an example of a vehicle. The saddle-riding vehicle 200 is, for example, a motorcycle powered by an engine. The saddle-riding vehicle 200 includes a body 1, a handlebar 2 rotatably held on the body 1, a front wheel 3 rotatably held on the body 1 together with the handlebar 2, and a rear wheel 4 rotatably held on the body 1.

[0040]

[0018] The brake system 10 includes a brake lever 11, a first hydraulic circuit 12 filled with brake fluid, a brake pedal 13, and a second hydraulic circuit 14 filled with brake fluid. The brake lever 11 is provided on a handlebar 2 and is operated by the driver's hand. The first hydraulic circuit 12 generates a braking force in a rotor 3 a that rotates together with the front wheels 3 according to the amount of operation of the brake lever 11. The brake pedal 13 is provided below the body 1 and is operated by the driver's foot. The second hydraulic circuit 14 generates a braking force in a rotor 4 a that rotates together with the rear wheels 4 according to the amount of operation of the brake pedal 13.

[0041]

[0019] The brake lever 11 and the brake pedal 13 are examples of a brake input unit. For example, a brake pedal other than the brake pedal 13 provided on the body 1 may be used as a brake input unit instead of the brake lever 11. Also, for example, a brake lever other than the brake lever 11 provided on the handlebars 2 may be used as a brake input unit instead of the brake pedal 13. Also, the first hydraulic circuit 12 may generate a braking force in the rotor 4 a that rotates together with the rear wheel 4 according to the amount of operation of the brake lever 11 or the amount of operation of a brake pedal other than the brake pedal 13 provided on the body 1. In addition, the second hydraulic circuit 14 may generate a braking force in the rotor 3 a that rotates together with the front wheel 3 according to the amount of operation of the brake pedal 13 or the amount of operation of a brake lever other than the brake lever 11 provided on the handlebars 2.

[0042]

[0020] The first hydraulic pressure circuit 12 and the second hydraulic pressure circuit 14 have the same configuration. Therefore, the following description will explain the configuration of the first hydraulic pressure circuit 12 as a representative. The first hydraulic pressure circuit 12 includes a master cylinder 21 incorporating a piston (not shown), a reservoir 22 attached to the master cylinder 21, a brake caliper 23 having brake pads (not shown), and a wheel cylinder 24 that operates the brake pads (not shown) of the brake caliper 23.

[0043]

[0021] An internal flow path 40 that connects the wheel cylinder 24 and the master cylinder 21 is formed in the base body 101 of the hydraulic control unit 100. Specifically, the internal flow path 40 communicates with the master cylinder 21 via a liquid pipe 15 described below, and communicates with the wheel cylinder 24 via a liquid pipe 16 described below. In this embodiment, the base body 101 is formed with a main flow path 41, a sub-flow path 42, and a pressure-boosting flow path 43 as the internal flow path 40. In the first hydraulic circuit 12, the master cylinder 21 and the wheel cylinder 24 are connected via a fluid pipe 15 connected between the master cylinder 21 and a master cylinder port MP formed in the base 101, a main flow path 41 formed in the base 101, and a fluid pipe 16 connected between the wheel cylinder 24 and a wheel cylinder port WP formed in the base 101. Brake fluid in the wheel cylinder 24 is released via a sub-flow path 42 to a main flow path intermediate portion 41a, which is a midpoint of the main flow path 41. Brake fluid in the master cylinder 21 is supplied via a pressure-boosting flow path 43 to a sub-flow path intermediate portion 42a, which is a midpoint of the sub-flow path 42.

[0044]

[0022] An inlet valve 25 is provided in a region of the main flow path 41 closer to the wheel cylinder 24 than the main flow path intermediate portion 41a. Opening and closing of the inlet valve 25 opens and closes the flow path portion of the main flow path 41 where the inlet valve 25 is installed, thereby controlling the flow rate of the brake fluid flowing through this region. In a region of the secondary flow path 42 upstream of the secondary flow path intermediate portion 42a, a release valve 26 and an accumulator 27 that stores brake fluid are provided, in this order from upstream to downstream. Opening and closing of the release valve 26 opens and closes the flow path portion of the secondary flow path 42 where the release valve 26 is installed, thereby controlling the flow rate of the brake fluid flowing through this region. In addition, a pump 50 is provided in the area of ​​the secondary flow path 42 downstream of the secondary flow path intermediate portion 42a, which applies pressure to the brake fluid in the secondary flow path 42 and moves the brake fluid. In other words, the pump 50 moves the brake fluid in the internal flow path 40. Note that, hereinafter, the portion of the secondary flow path 42 upstream of the pump 50 may be referred to as the first secondary flow path 42b. Furthermore, the portion of the secondary flow path 42 downstream of the pump 50 may be referred to as the second secondary flow path 42c.

[0045]

[0023] A switching valve 28 is provided in the main flow path 41 in a region closer to the master cylinder 21 than the main flow path intermediate portion 41a. The opening and closing operation of the switching valve 28 opens and closes the flow path portion of the main flow path 41 where the switching valve 28 is installed, thereby controlling the flow rate of the brake fluid flowing through this region. A pressure increase valve 29 is provided in the pressure increase flow path 43. The opening and closing operation of the pressure increase valve 29 opens and closes the flow path portion of the pressure increase flow path 43 where the pressure increase valve 29 is installed, thereby controlling the flow rate of the brake fluid flowing through the pressure increase flow path 43.

[0046]

[0024] A master cylinder hydraulic pressure sensor 30 is provided in the main flow path 41 in a region closer to the master cylinder 21 than the switching valve 28, for detecting the hydraulic pressure of the brake fluid in the master cylinder 21. A wheel cylinder hydraulic pressure sensor 31 is provided in the main flow path 41 in a region closer to the wheel cylinder 24 than the inlet valve 25, for detecting the hydraulic pressure of the brake fluid in the wheel cylinder 24.

[0047]

[0025] In other words, the main flow path 41 communicates between the master cylinder port MP and the wheel cylinder port WP via the inlet valve 25. The secondary flow path 42 is defined as a part or all of the flow path that releases the brake fluid in the wheel cylinder 24 to the master cylinder 21 via the release valve 26. The pressure-boosting flow path 43 is defined as a part or all of the flow path that supplies the brake fluid in the master cylinder 21 to the upstream side of the pump 50 of the secondary flow path 42 via the pressure-boosting valve 29. In other words, the secondary flow path 42 and the pressure-boosting flow path 43 also communicate between the master cylinder port MP and the wheel cylinder port WP.

[0048]

[0026] The inlet valve 25 is a solenoid valve that switches the flow of brake fluid at its installation location from open to closed when it is switched from a de-energized state to an energized state, for example. The release valve 26 is a solenoid valve that switches the flow of brake fluid through its installation location toward the secondary flow path intermediate portion 42a from closed to open when it is switched from a de-energized state to an energized state, for example. The switching valve 28 is a solenoid valve that switches the flow of brake fluid at its installation location from open to closed when it is switched from a de-energized state to an energized state, for example. The pressure booster valve 29 is a solenoid valve that switches the flow of brake fluid through its installation location toward the secondary flow path intermediate portion 42a from closed to open when it is switched from a de-energized state to an energized state, for example.

[0049]

[0027] The pump 50 of the first hydraulic circuit 12 and the pump 50 of the second hydraulic circuit 14 are driven by a common motor 90. In other words, the motor 90 is the drive source of the pump 50.

[0050]

[0028] A hydraulic control unit 100 is configured by a base 101, the various components provided on the base 101 (inlet valve 25, release valve 26, accumulator 27, switching valve 28, pressure booster valve 29, master cylinder hydraulic pressure sensor 30, wheel cylinder hydraulic pressure sensor 31, pump 50, motor 90, etc.), and a control device (ECU) 105.

[0051]

[0029] The control device 105 controls the inlet valve 25, the release valve 26, the switching valve 28, the pressure increase valve 29, and the motor 90. The control device 105 may be a single device or may be divided into multiple devices. The control device 105 may be attached to the base 101, or may be attached to a member other than the base 101. Some or all of the control device 105 may be configured, for example, by a microcomputer, a microprocessor unit, or the like, or may be configured with updatable firmware, or may be a program module executed by commands from a CPU, etc.

[0052] For example, under normal conditions, the control device 105 controls the inlet valve 25, the release valve 26, the switching valve 28, and the pressure-increasing valve 29 to be in a non-energized state. When the brake lever 11 is operated in this state, the piston (not shown) of the master cylinder 21 in the first hydraulic circuit 12 is pressed, increasing the hydraulic pressure of the brake fluid in the wheel cylinder 24, and the brake pad (not shown) of the brake caliper 23 is pressed against the rotor 3a of the front wheel 3, thereby braking the front wheel 3. Furthermore, when the brake pedal 13 is operated, the piston (not shown) of the master cylinder 21 in the second hydraulic circuit 14 is pressed, increasing the hydraulic pressure of the brake fluid in the wheel cylinder 24, and the brake pad (not shown) of the brake caliper 23 is pressed against the rotor 4a of the rear wheel 4, thereby braking the rear wheel 4.

[0053]

[0031] The outputs of the various sensors (master cylinder hydraulic pressure sensor 30, wheel cylinder hydraulic pressure sensor 31, wheel speed sensor, acceleration sensor, etc.) are input to the control device 105. In response to these outputs, the control device 105 outputs commands that control the operation of the inlet valve 25, the release valve 26, the switching valve 28, the pressure increase valve 29, and the motor 90, thereby performing pressure reduction control, pressure increase control, etc.

[0054]

[0032] For example, when the brake fluid pressure in the wheel cylinder 24 of the first hydraulic pressure circuit 12 is excessive or there is a possibility of excessive pressure, the control device 105 executes pressure reduction control to reduce the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic pressure circuit 12. In this case, the control device 105 controls the inlet valve 25 to an energized state, the release valve 26 to an energized state, the switching valve 28 to a de-energized state, and the pressure increase valve 29 to a de-energized state in the first hydraulic pressure circuit 12, while driving the motor 90. As a result, the brake fluid in the wheel cylinder 24 of the first hydraulic pressure circuit 12 flows into the sub-flow path 42 through the main flow path 41, and the hydraulic pressure in the wheel cylinder 24 is reduced. Then, the brake fluid that flows from the wheel cylinder 24 into the sub-flow path 42 passes through the release valve 26 and flows into the accumulator 27, where it is stored. The brake fluid stored in the accumulator 27 is returned to the master cylinder 21 by a pump 50 driven by a motor 90.

[0055]

[0033] Furthermore, when the brake fluid pressure in the wheel cylinder 24 of the second hydraulic circuit 14 is excessive or there is a possibility of excessive pressure (i.e., when the wheel is locked or there is a possibility of locking), the control device 105 executes pressure reduction control to reduce the brake fluid pressure in the wheel cylinder 24 of the second hydraulic circuit 14. At that time, the control device 105 controls the inlet valve 25 to an energized state, the release valve 26 to an energized state, the switching valve 28 to a de-energized state, and the pressure booster # 29 to a de-energized state in the second hydraulic circuit 14, while driving the motor 90. As a result, the brake fluid in the wheel cylinder 24 of the second hydraulic circuit 14 flows through the main flow path 41 into the secondary flow path 42, reducing the hydraulic pressure in the wheel cylinder 24. The brake fluid that flows from the wheel cylinder 24 into the secondary flow path 42 then flows through the release valve 26 into the accumulator 27 and is stored in the accumulator 27. The brake fluid stored in the accumulator 27 is returned to the master cylinder 21 by a pump 50 driven by a motor 90.

[0056]

[0034] For example, when the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic pressure circuit 12 is insufficient or there is a possibility of such insufficiency, the control device 105 executes pressure increase control to increase the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic pressure circuit 12. In this case, the control device 105 controls the inlet valve 25 to a non-energized state, the release valve 26 to a non-energized state, the switching valve 28 to a conductive state, and the pressure increase valve 29 to a conductive state in the first hydraulic pressure circuit 12, while driving the motor 90. As a result, the pump 50 driven by the motor 90 causes the brake fluid in the master cylinder 21 of the first hydraulic circuit 12 to flow from the sub-flow path intermediate portion 42a through the main flow path 41 and the pressure-boosting flow path 43 into the sub-flow path 42. The brake fluid that has flowed into the sub-flow path 42 flows from the main flow path intermediate portion 41a into the main flow path 41, passes through the inlet valve 25, and flows into the wheel cylinder 24 of the first hydraulic circuit 12. As a result, the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic circuit 12 increases.

[0057]

[0035] Furthermore, when the brake fluid pressure in the wheel cylinder 24 of the second hydraulic circuit 14 is insufficient or there is a possibility of such insufficiency, the control device 105 executes pressure increase control to increase the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the second hydraulic circuit 14. At this time, the control device 105 controls the inlet valve 25 to a non-energized state, the release valve 26 to a non-energized state, the switching valve 28 to a conductive state, and the pressure increase valve 29 to a conductive state in the second hydraulic circuit 14, while driving the motor 90. As a result, the pump 50 driven by the motor 90 causes the brake fluid in the master cylinder 21 of the second hydraulic circuit 14 to flow through the main flow path 41 and the booster flow path 43, and from the sub-flow path intermediate portion 42a into the sub-flow path 42. The brake fluid that has flowed into the sub-flow path 42 flows from the main flow path intermediate portion 41a into the main flow path 41, and then flows through the inlet valve 25 into the wheel cylinder 24 of the second hydraulic circuit 14. This increases the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the second hydraulic circuit 14.

[0058]

[0036] In other words, the hydraulic control unit 100 controls the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic pressure circuit 12, thereby enabling pressure reduction control of the first hydraulic pressure circuit 12 (in other words, anti-lock brake control). The hydraulic control unit 100 controls the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the second hydraulic pressure circuit 14, thereby enabling pressure reduction control of the second hydraulic pressure circuit 14 (in other words, anti-lock brake control). The hydraulic control unit 100 controls the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic pressure circuit 12, thereby enabling pressure increase control of the first hydraulic pressure circuit 12. In addition, the hydraulic control unit 100 can control the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the second hydraulic circuit 14, thereby performing pressure increase control of the second hydraulic circuit 14.

[0059]

[0037] <Configuration of hydraulic control unit> The configuration of the hydraulic control unit according to this embodiment will be described. Fig. 3 is a cross-sectional view showing the periphery of the pump and motor of the hydraulic control unit according to the embodiment of the present invention. Also, Fig. 4 is a cross-sectional view showing the pump of the hydraulic control unit according to the embodiment of the present invention. The pump 50 shown in Figs. 3 and 4 is the pump 50 of the first hydraulic circuit 12. The configuration of the pump 50 of the second hydraulic circuit 14 is the same as the configuration of the pump 50 of the first hydraulic circuit 12.

[0060]

[0038] As described above, the hydraulic control unit 100 includes the pump 50 and the motor 90. The pump 50 and the motor 90 are mounted on a base 101 made of a metal such as an aluminum alloy.

[0061]

[0039] The motor 90 has an output shaft 91 and an eccentric portion 92. The output shaft 91 is rotated by the rotor and stator of the motor 90. Note that FIG. 3 is a diagram of the hydraulic control unit 100 cut along a cross section perpendicular to the center of rotation of the output shaft 91, and the observation direction does not show the rotor and stator. The eccentric portion 92 is provided on the output shaft 91 and rotates eccentrically about the center of rotation of the output shaft 91.

[0062]

[0040] The pump 50 is embedded in a recess 102 formed in a base 101. The pump 50 includes a cylinder 51 and a piston portion 55.

[0063]

[0041] A compression chamber 52 that compresses brake fluid is formed in the cylinder 51. A discharge flow path 53 that discharges the brake fluid compressed in the compression chamber 52 is also formed in the cylinder 51. The brake fluid discharged to the discharge flow path 53 flows into the second sub-flow path 42c of the sub-flow path 42. In this embodiment, the brake fluid discharged to the discharge flow path 53 flows into the second sub-flow path 42c via the discharge flow path 68. In other words, the discharge flow path 53 is connected to the second sub-flow path 42c via the discharge flow path 68. In addition, in this embodiment, an outflow check valve 75 is provided between the discharge flow path 68 and the discharge flow path 53 to regulate the flow of brake fluid from the discharge flow path 68 to the discharge flow path 53.

[0064]

[0042] Specifically, the pump 50 according to this embodiment includes a lid portion 67 adjacent to the cylinder 51. The lid portion 67 is embedded in a region of the recess 102 that is closer to the opening of the recess 102 than the cylinder 51. The discharge flow path 68 is formed between the cylinder 51 and the lid portion 67. In this embodiment, the discharge flow path 68 is composed of a groove formed in at least one of the end of the cylinder 51 on the lid portion 67 side and the end of the lid portion 67 on the cylinder 51 side, and a groove formed in at least one of the outer circumferential surface of the cylinder 51 and the outer circumferential surface of the lid portion 67.

[0065]

[0043] An input side end 55a, which is one end of the piston portion 55, abuts against the eccentric portion 92 of the motor 90. In other words, the input side end 55a is the end that is pressed against the motor 90 via the eccentric portion 92. Furthermore, a partition side end 55b, which is the other end of the piston portion 55, is inserted into the compression chamber 52. The partition side end 55 is the end that defines the compression chamber 52. The partition side end 55b reciprocates within the compression chamber 52. At this time, the outer peripheral surface of the partition side end 55b slides on the inner peripheral surface of the compression chamber 52.

[0066]

[0044] In addition, an inlet flow path 65 is formed in the piston portion 55, through which brake fluid that has flowed through the internal flow path 40 toward the pump 50 flows and guides the brake fluid to the compression chamber 52. Specifically, in this embodiment, the end of the inlet flow path 65 on the brake fluid inlet side opens to a side surface of a first piston portion 56 of the piston portion 55, which will be described later. In addition, the end of the inlet flow path 65 on the brake fluid outlet side opens to the partition side end 55b. In other words, the end of the inlet flow path 65 on the brake fluid outlet side opens into the compression chamber 52. Then, the brake fluid that has flowed through the first sub-flow path 42b of the sub-flow path 42 toward the pump 50 flows into the inlet flow path 65 and flows out through the inlet flow path 65 into the compression chamber 52. In order to prevent the brake fluid that has flowed through the first sub-flow path 42b of the sub-flow path 42 toward the pump 50 from flowing through the outer periphery of a first piston portion 56 (described later) of the piston portion 55 into the arrangement space of the eccentric portion 92, in this embodiment, a sealing member 87 such as a ring seals the gap between the outer periphery of a first piston portion 56 (described later) of the piston portion 55 and the base body 101.

[0067]

[0045] Here, the piston portion 55 includes a first piston portion 56 and a second piston portion 61. The first piston portion 56 is a portion of the piston portion 55 that has an input side end portion 55a. A part of the inflow flow path 65 is formed in the first piston portion 56. The second piston portion 61 is made of, for example, resin, and is a portion of the piston portion 55 that has a partition side end portion 55b. A part of the inflow flow path 65 is formed in the second piston portion 61. The first piston portion 56 has a first connection portion 59 which is a convex portion at a first connection side end 56a which is the end opposite the input side end 55a. The second piston portion 61 has a second connection portion 62 which is a concave portion at a second connection side end 61a which is the end opposite the partition side end 55b. The first piston portion 56 and the second piston portion 61 are connected by press-fitting the first connection portion 59 which is a convex portion into the second connection portion 62 which is a concave portion.

[0068]

[0046] As shown in a modified example described later, the first connecting portion 59 may be a recess and the second connecting portion 62 may be a protrusion. Also, the number of parts constituting the first piston portion 56 is not particularly limited, but in this embodiment, the first piston portion 56 is composed of two parts. Specifically, the first piston portion 56 includes a first part 57 having an input side end portion 55a and a second part 58 having a first connection side end portion 56a. The parts constituting the first piston portion 56 are formed, for example, from resin or metal. Also, a part of the part constituting the first piston portion 56 may be formed from resin, and another part of the part constituting the first piston portion 56 may be formed from metal. For example, the first part 57 may be made of metal and the second part 58 may be made of resin.

[0069]

[0047] Piston portion 55 is provided with inlet-side check valve 70 that regulates the flow of brake fluid from compression chamber 52 toward first piston portion 56. Inlet-side check valve 70 is disposed between first piston portion 56 and second piston portion 61. In this embodiment, inlet-side check valve 70 is configured as follows. Inlet-side check valve 70 includes ball 71 that blocks inlet flow path 65, and spring 72. Ball 71 is provided movably. Ball 71 is pressed by spring 72 in the direction from second piston portion 61 toward first piston portion 56. The ball pressed by the spring 72 blocks the portion of the inlet flow path 65 formed in the first piston portion 56, thereby stopping the flow of brake fluid in the inlet flow path 65. Specifically, the first piston portion 56 is provided in the inlet flow path 65 and has a seat portion 60 against which the ball 71 abuts when the inlet flow path 65 is blocked. The ball pressed by the spring 72 abuts against the seat portion 60, thereby stopping the flow of brake fluid in the inlet flow path 65.

[0070]

[0048] The hydraulic control unit 100 according to this embodiment also includes a spring 66 that is provided on the outer periphery of the second piston portion 61 and presses the piston portion 55 in a direction from the partition-side end portion 55b toward the input-side end portion 55a. In other words, the spring 66 presses the piston portion 55 toward the eccentric portion 92 of the motor 90. In this embodiment, the spring 66 is configured to press the piston portion 55 as follows: The second piston portion 61 includes a flange portion 64 that is provided on the outer periphery of the second piston portion 61. The spring 66 is in contact with a first surface 64a, which is the surface of the flange 64 on the cylinder 51 side. This causes the flange 64 to be pressed in the direction from the partition-side end 55b toward the input-side end 55a, and the piston 55 to be pressed in the direction from the partition-side end 55b toward the input-side end 55a.

[0071]

[0049] Note that the method for fixing the pump 50 to the base 101 is not particularly limited, but in the present embodiment, the pump 50 is fixed to the base 101 as follows. The base 101 has a step 103 on the inner peripheral surface of the recess 102. The cylinder 51 of the pump 50 has a step 54 that protrudes from the outer peripheral surface and abuts against the step 103 of the base 101. In addition, the base 101 has a plastically deformed portion 104 formed by plastically deforming the periphery of the opening of the recess 102. The lid portion 67 and cylinder 51 of the pump 50 are sandwiched between the step portion 103 and the plastically deformed portion 104, and the pump 50 is fixed to the base body 101. Note that FIG. 3 shows the base body 101 before the plastically deformed portion 104 is formed. For this reason, the plastically deformed portion 104 is shown by an imaginary line in FIG. 3.

[0072] In the pump 50 configured in this manner, as the outer peripheral surface of the eccentric portion 92 of the motor 90 approaches the compression chamber 52, the piston portion 55 is pushed so as to be inserted into the compression chamber 52. This reduces the volume of the compression chamber 52. Furthermore, as the outer peripheral surface of the eccentric portion 92 of the motor 90 moves away from the compression chamber 52, the piston portion 55, which is pressed toward the eccentric portion 92 by the spring 66, maintains a state in which the input side end 55 a abuts the eccentric portion 92. As a result, the piston portion 55 moves in accordance with the outer peripheral surface of the eccentric portion 92 of the motor 90, in other words, moves in accordance with the eccentric rotational motion of the eccentric portion 92 of the motor 90, and operates to move out of the compression chamber 52. Therefore, the volume of the compression chamber 52 increases.

[0073]

[0051] When brake fluid flows into the first sub-flow path 42b of the sub-flow path 42, the brake fluid in the first sub-flow path 42b flows into the inlet flow path 65 formed in the piston portion 55. For example, during pressure reduction control, the brake fluid in the wheel cylinder 24 flows into the inlet flow path 65 through the main flow path 41 and the first sub-flow path 42b. During pressure increase control, the brake fluid in the master cylinder 21 flows into the inlet flow path 65 through the main flow path 41, the pressure increase flow path 43, and the first sub-flow path 42b.

[0074]

[0052] At this time, when the volume of the compression chamber 52 is increasing, the hydraulic pressure of the brake fluid present on the compression chamber 52 side relative to the inlet check valve 70 is low. Therefore, the brake fluid that has flowed into the inlet flow path 65 moves the ball 71 away from the seat 60, opening the inlet check valve 70. As a result, the brake fluid that has flowed into the inlet flow path 65 passes through the inlet check valve 70 and flows into the compression chamber 52. On the other hand, when the volume of the compression chamber 52 is decreasing, the hydraulic pressure of the brake fluid present on the compression chamber 52 side relative to the inlet check valve 70 increases. Therefore, the brake fluid that has flowed into the inlet flow path 65 cannot move the ball 71 away from the seat 60. As a result, the inlet check valve 70 is closed, and the brake fluid that has flowed into the inlet flow path 65 does not flow into the compression chamber 52.

[0075]

[0053] The brake fluid that flows into the compression chamber 52 is compressed as the volume of the compression chamber 52 decreases. When the hydraulic pressure of the brake fluid in the compression chamber 52 reaches a level that allows the outlet check valve 75 to open, the brake fluid in the compression chamber 52 is pressure-fed to the second sub-flow path 42c of the sub-flow path 42 through the discharge flow path 53 and the discharge flow path 68. For example, during pressure reduction control, the brake fluid that flows into the second sub-flow path 42c passes through the main flow path 41 and is returned to the master cylinder 21. During pressure increase control, the brake fluid that flows into the second sub-flow path 42c passes through the main flow path 41 and flows into the wheel cylinder 24.

[0076]

[0054] In the conventional hydraulic control unit, the outer circumferential portion of the end of the second piston portion on which the check valve is disposed defines the compression chamber and slides on the inner circumferential surface of the compression chamber. That is, in the conventional hydraulic control unit, the end of the second piston portion on the side corresponding to the second connection end portion 61 a according to the present embodiment defines the compression chamber and slides on the inner circumferential surface of the compression chamber.

[0077]

[0055] On the other hand, in the hydraulic control unit 100 according to this embodiment, the compression chamber 52 is defined by a partition-side end 55b, which is the end opposite to the end of the second piston portion 61 where the inlet-side check valve 70 is located. The second piston portion 61 can be formed so that the diameter of the partition-side end 55b is smaller than the diameter of the second connection-side end 61a, which is the end where the inlet-side check valve 70 is located. Therefore, in the hydraulic control unit 100 according to this embodiment, the diameter of the compression chamber 52 can be made smaller than in the past, and the compression chamber 52 can be made smaller. Furthermore, in the hydraulic control unit 100 according to this embodiment, the cylinder 51 in which the compression chamber 52 is formed can also be made smaller. Furthermore, the hydraulic control unit 100 according to this embodiment is configured so that the compression chamber 52 is defined by the partition-side end 55b of the second piston portion 61, thereby making it possible to reduce the size of the connection between the first piston portion 56 and the second piston portion 61 and also to reduce the size of the piston portion 55. In other words, the hydraulic control unit 100 according to this embodiment makes it possible to make the pump 50 smaller than conventional pumps and the hydraulic control unit 100 smaller than conventional pumps.

[0078]

[0056] In a pump of a conventional hydraulic control unit, the first piston portion and the second piston portion are connected by a so-called snap structure. Specifically, the first connection side end, which is the connection point of the first piston portion with the second piston portion, has a convex portion protruding toward the outer periphery. A recess is formed in the first connection side end in an area opposite the second piston portion with respect to the convex portion. The second connection side end, which is the connection point of the second piston portion with the first piston portion, has a convex portion protruding toward the inner periphery. A recess is formed in the second connection side end in an area opposite the first piston portion with respect to the convex portion. By inserting the first connection side end into the second connection side end so as to spread the second connection side end, the convex portion of the first connection side end is inserted into the concave portion of the second connection side end, and the convex portion of the second connection side end is inserted into the concave portion of the first connection side end. As a result, the convex portion of the second connection side end is caught on the convex portion of the first connection side end, and the first piston portion and the second piston portion are connected.

[0057] However, if the first piston portion and the second piston portion of a pump of a conventional hydraulic control unit are downsized without changing the connection configuration, the dimensional tolerance of the connection portion between the first piston portion and the second piston portion becomes relatively large, which raises concerns about a decrease in the reliability of the connection between the first piston portion and the second piston portion. As a result, if the size of the pump of a conventional hydraulic control unit is reduced without changing the connection configuration between the first piston portion and the second piston portion, there is a concern that the sealing performance of the connection between the first piston portion and the second piston portion will be reduced when the brake fluid is compressed in the compression chamber and sent out of the pump, resulting in a decrease in the pump's discharge capacity.

[0079]

[0058] Specifically, for example, when the first connection end portion is inserted into the second connection end portion so as to spread the second connection end portion, the deformation of the second connection end portion may become too large, causing cracks in the second connection end portion. If a crack occurs in the second connection end portion, the sealing performance of the connection portion between the first piston portion and the second piston portion decreases, and the discharge capacity of the pump decreases.

[0080]

[0059] Furthermore, for example, in the case of a snap structure, the force with which the second connection side end holds the first connection side end in a direction perpendicular to the direction in which the first piston portion and the second piston portion face each other (the direction in which the first connection side end is inserted into the second connection side end) is small. As a result, the first piston portion may wobble relative to the second piston portion. When the first piston portion wobble relative to the second piston portion, the sealing performance of the connection between the first piston portion and the second piston portion decreases, and the discharge capacity of the pump decreases.

[0081]

[0060] Furthermore, for example, when brake fluid is compressed in the compression chamber, the compressed brake fluid may flow into the connection between the first piston portion and the second piston portion. At this time, the brake fluid that has flowed into the connection between the first piston portion and the second piston portion applies pressure to the second piston portion in a direction away from the first piston portion. Here, in the case of a snap structure, a recess is formed in the portion of the second connection side end portion where the first connection side end portion is inserted, into which the protrusion of the first connection side end portion is inserted. In other words, in the case of a snap structure, a recess that is recessed toward the outer periphery is formed on the inner circumferential surface of the second connection side end portion. Therefore, in the case of a snap structure, the area of ​​the second connection side end portion where pressure acts in a direction away from the first piston portion is wider. For this reason, in the case of a snap structure, the first piston portion and the second piston portion may separate, reducing the sealing performance at the connection between the first piston portion and the second piston portion, and the discharge capacity of the pump may decrease.

[0082]

[0061] On the other hand, in the hydraulic control unit 100 according to this embodiment, the first connecting portion 59, which is a convex portion, is press-fit into the second connecting portion 62, which is a concave portion, to connect the first piston portion 56 and the second piston portion 61. Therefore, the hydraulic control unit 100 according to this embodiment can prevent a decrease in the reliability of the connection between the first piston portion 56 and the second piston portion 61, and can also prevent a decrease in the discharge capacity of the pump 50.

[0083]

[0062] Specifically, for example, when the first connecting portion 59, which is a convex portion, is press-fitted into the second connecting portion 62, which is a concave portion, by an interference fit, the amount of deformation of the second connecting portion 62 is smaller than in a conventional snap structure. Therefore, the hydraulic control unit 100 according to this embodiment can prevent cracks from occurring in the second connecting portion 62. Therefore, the hydraulic control unit 100 according to this embodiment can prevent a decrease in the sealing performance of the connecting portion between the first piston portion 56 and the second piston portion 61, and can prevent a decrease in the discharge capacity of the pump 50.

[0084]

[0063] Furthermore, for example, when the first connecting portion 59, which is a convex portion, is press-fit into the second connecting portion 62, which is a concave portion, by an interference fit, the force with which the second connecting portion 62 holds the first connecting portion 59 can be increased in a direction perpendicular to the direction in which the first piston portion 56 and the second piston portion 61 face each other, compared to a conventional snap structure. Therefore, the hydraulic control unit 100 according to this embodiment can prevent the first piston portion 56 from wobbling relative to the second piston portion 61, compared to a conventional snap structure. Therefore, the hydraulic control unit 100 according to this embodiment can prevent a decrease in the sealing performance at the connection point between the first piston portion 56 and the second piston portion 61, and can prevent a decrease in the discharge capacity of the pump 50.

[0085]

[0064] Furthermore, for example, when the first connection portion 59, which is a convex portion, is press-fitted into the second connection portion 62, which is a concave portion, by an interference fit, there is no need to form a concave portion that is concave toward the outer periphery on the inner circumferential surface of the second connection portion 62. Therefore, the second connection portion 62 of the hydraulic pressure control unit 100 according to this embodiment can narrow the area in which pressure acts in a direction away from the first piston portion 56 due to the brake fluid compressed in the compression chamber 52, compared to a conventional snap structure. Therefore, compared to conventional snap structures, the hydraulic control unit 100 according to this embodiment can prevent the first piston portion 56 and the second piston portion 61 from separating, thereby preventing a decrease in the sealing quality at the connection point between the first piston portion 56 and the second piston portion 61, and can prevent a decrease in the discharge capacity of the pump 50.

[0086]

[0065] In the hydraulic control unit 100 according to this embodiment, the portion where the first connecting portion 59 is press-fitted into the second connecting portion 62 also serves as a seal portion. Even in this configuration, the hydraulic control unit 100 according to this embodiment has a larger seal area than a conventional snap structure, so that a decrease in the sealing performance of the connecting portion between the first piston portion 56 and the second piston portion 61 can be suppressed, and a decrease in the discharge capacity of the pump 50 can be suppressed.

[0087]

[0066] Here, it is preferable that the hydraulic control unit 100 according to this embodiment has the following configuration.

[0088]

[0067] Preferably, the tip of the first connecting portion 59, which is a convex portion, abuts the bottom 63 of the second connecting portion 62, which is a concave portion. In the hydraulic control unit 100 having this configuration, the sealing area at the connection point between the first piston portion 56 and the second piston portion 61 is increased, so that deterioration in the sealing property at the connection point between the first piston portion 56 and the second piston portion 61 can be further suppressed, and deterioration in the discharge capacity of the pump 50 can be further suppressed.

[0089]

[0068] Preferably, in the direction in which the piston portion 55 reciprocates (in other words, in the direction in which the first piston portion 56 and the second piston portion 61 face each other), the tip of the second connection portion 62 is arranged on the side away from the cylinder 51, based on the position where the ball 71 of the inlet-side check valve 70 abuts against the seating portion 60. In the hydraulic control unit 100 having this configuration, the length of the portion where the first connection portion 59 is press-fitted into the second connection portion 62 by an interference fit is long in the direction in which the piston portion 55 reciprocates. Therefore, the hydraulic control unit 100 having this configuration can further prevent a decrease in the sealing performance at the connection point between the first piston portion 56 and the second piston portion 61, and can further prevent a decrease in the discharge capacity of the pump 50.

[0090]

[0069] Preferably, the hydraulic control unit 100 includes a holder 85 that holds the cylinder 51 and the piston portion 55. By including the holder 85 in the hydraulic control unit 100, at least some of the components of the pump 50 can be unitized. The unitized parts of the pump 50 can then be inserted into the recess 102 of the base 101 all at once. For this reason, the hydraulic control unit 100 having this configuration is easier to manufacture than assembling the pump 50 by inserting the components of the pump 50 into the recess 102 one by one. This holder 85 may be provided with a filter 86 through which brake fluid flows into the inlet flow path 65 formed in the piston portion 55. By providing the holder 85 with the filter 86, it is possible to prevent foreign matter from entering the compression chamber 52 and to prevent damage to the inside of the compression chamber 52, thereby improving the reliability of the hydraulic control unit 100.

[0091] [ 0 0 7 0 ]

[0092] <Modifications> Fig. 5 is a cross-sectional view showing a pump of a modification of the hydraulic control unit according to the embodiment of the present invention. In the hydraulic control unit 100 described above, the first connection portion 59 provided at the first connection end portion 56a of the first piston portion 56 is a convex portion. Also, in the hydraulic control unit 100 described above, the second connection portion 62 provided at the second connection end portion 61a of the second piston portion 61 is a concave portion. However, this is not limiting. As shown in Fig. 5, the first connection portion 59 of the first piston portion 56 may be a concave portion. Also, the second connection portion 62 of the second piston portion 61 may be a convex portion. In other words, the first connection portion 59 may be either a concave portion or a convex portion. The second connecting portion 62 may be the other of the recessed portion and the protruding portion. In the hydraulic control unit 100 shown in Fig. 5, the second connecting portion 62, which is a protruding portion, is press-fit into the first connecting portion 59, which is a recessed portion, to connect the first piston portion 56 and the second piston portion 61. In the hydraulic control unit 100 configured as shown in Fig. 5, as in the hydraulic control unit 100 described above, a decrease in sealing quality at the connection between the first piston portion 56 and the second piston portion 61 can be suppressed, and a decrease in the discharge capacity of the pump 50 can also be suppressed.

[0093]

[0071] When the first connecting portion 59 is a recess and the second connecting portion 62 is a protrusion, the first connecting portion 59 may have to be formed as a thin annular groove, as shown in Fig. 5. For this reason, when the first connecting portion 59 is a protrusion and the second connecting portion 62 is a recess, it is easier to manufacture the piston portion 55 and the hydraulic control unit 100 than when the first connecting portion 59 is a recess and the second connecting portion 62 is a protrusion.

[0094]

[0072] Figure 6 is a cross-sectional view showing a pump of a modified example of a hydraulic control unit according to an embodiment of the present invention. Similar to the hydraulic control unit 100 shown in Figures 3 and 4, the hydraulic control unit 100 shown in Figure 6 has a first connecting portion 59 of a first piston portion 56 as a convex portion, and a second connecting portion 62 of a second piston portion 61 as a concave portion. Here, of the surfaces of the flange portion 64 of the second piston portion 61, the surface opposite to the first surface 64a is referred to as a second surface 64b. When the second surface 64 is defined in this way, in the hydraulic control unit 100 shown in Figures 3 and 4, the distance from the cylinder 51 to the second surface 64b in the direction in which the piston portion 55 reciprocates is approximately the same as the distance from the cylinder 51 to the bottom 63 of the second connection portion 62, which is a recess. On the other hand, in the hydraulic control unit 100 shown in Figure 6, the bottom 63 of the second connection portion 62, which is a recess, is positioned on the cylinder 51 side with respect to the second surface 64b in the direction in which the piston portion 55 reciprocates. Therefore, in the hydraulic control unit 100 shown in Fig. 6, the length of the portion where the first connecting portion 59 is press-fitted into the second connecting portion 62 by an interference fit is longer in the direction in which the piston portion 55 reciprocates. Therefore, the hydraulic control unit 100 shown in Fig. 6 can further prevent a decrease in the sealing performance of the connecting portion between the first piston portion 56 and the second piston portion 61, and can further prevent a decrease in the discharge capacity of the pump 50.

[0095]

[0073] Fig. 7 is a diagram showing the configuration of a brake system equipped with a modified hydraulic control unit according to an embodiment of the present invention. The hydraulic control unit 100 described above is configured to be able to perform both pressure reduction control and pressure increase control. However, the hydraulic control unit 100 may not be configured to perform pressure increase control. In this case, as shown in Fig. 7, the hydraulic control unit 100 does not have the switching valve 28, the pressure increase valve 29, and the pressure increase flow path 43, which are necessary for pressure increase control. This type of hydraulic control unit 100 can also achieve the same effects as the hydraulic control unit 100 described above.

[0096]

[0074] Figure 8 is a diagram showing the configuration of a brake system including a modified example of a hydraulic control unit according to an embodiment of the present invention. The brake system 10 described above is configured to include multiple hydraulic circuits (more specifically, the first hydraulic circuit 12 and the second hydraulic circuit 14). Therefore, multiple internal flow paths 40 are formed in the base 101 of the hydraulic control unit 100 described above. However, this is not limited to this, and the brake system 10 may include only one hydraulic circuit. In other words, the hydraulic control unit 100 may have only one internal flow path 40 formed in the base 101. Note that Figure 8 shows an example in which the brake system 10 includes only the first hydraulic circuit 12. 8 is configured not to perform pressure increase control, but may be configured to perform both pressure reduction control and pressure increase control. A hydraulic control unit 100 in which only one internal flow path 40 is formed in the base 101 can also obtain the same effect as the hydraulic control unit 100 described above.

[0097]

[0075] The above-described hydraulic control unit 100 includes the master cylinder hydraulic pressure sensor 30 and the wheel cylinder hydraulic pressure sensor 31. However, some conventional hydraulic control units do not include at least one of a hydraulic pressure sensor that detects the hydraulic pressure of the brake fluid in the master cylinder and a hydraulic pressure detection sensor that detects the hydraulic pressure of the brake fluid in the wheel cylinder. The hydraulic control unit 100 according to this embodiment may also be configured not to include at least one of the master cylinder hydraulic pressure sensor 30 and the wheel cylinder hydraulic pressure sensor 31. Such a hydraulic control unit 100 can also achieve the same effects as the above-described hydraulic control unit 100.

[0098]

[0076] <Effects of the hydraulic pressure control unit> The effects of the hydraulic pressure control unit according to this embodiment will be described.

[0099]

[0077] The hydraulic control unit 100 according to this embodiment is a hydraulic control unit for a brake system 10 mounted on a vehicle. The hydraulic control unit 100 includes a base 101 having an internal flow path 40 that connects a wheel cylinder 24 and a master cylinder 21, and a pump 50 that moves brake fluid through the internal flow path 40. The pump 50 includes a cylinder 51 having a compression chamber 52 that compresses the brake fluid, and a piston portion 55. An input end portion 55a, which is one end of the piston portion 55, is pressed against a motor 90, which is the drive source of the pump 50. The other end of the piston portion 55, a partition side end 55b, is inserted into the compression chamber 52 to define the compression chamber 52. The partition side end 55b reciprocates in the compression chamber 52. The piston portion 55 has an inlet flow path 65 into which brake fluid that has flowed through the internal flow path 40 toward the pump 50 flows and which guides the brake fluid to the compression chamber 52. The piston portion 55 includes a first piston portion 56 in which a portion of the inlet flow path 65 is formed and which has an input side end 55a, and a second piston portion 61 in which a portion of the inlet flow path 65 is formed and which has the partition side end 55b. The first piston portion 56 has a first connection portion 59, which is one of a recess and a protrusion, at a first connection side end 56a, which is the end opposite the input side end 55a. The second piston portion 61 has a second connection portion 62, which is the other of a recess and a protrusion, at a second connection side end 61a, which is the end opposite the partition side end 55b. In addition, the piston portion 55 has an inlet side check valve 70 disposed between the first piston portion 56 and the second piston portion 61, which regulates the flow of brake fluid from the compression chamber 52 toward the first piston portion 56.The first piston portion 56 and the second piston portion 61 are connected by a press fit of a convex portion, which is one of the first connecting portion 59 and the second connecting portion 62, into a concave portion, which is the other of the first connecting portion 59 and the second connecting portion 62.

[0100]

[0078] As described above, the hydraulic control unit 100 configured in this manner can be made smaller than conventional hydraulic control units. Furthermore, as described above, the hydraulic control unit 100 configured in this manner can suppress a decrease in the reliability of the connection between the first piston portion 56 and the second piston portion 61, and can also suppress a decrease in the discharge capacity of the pump 50.

[0101]

[0079] Preferably, the vehicle equipped with hydraulic control unit 100 is a saddle-ride type vehicle 200. Compared to vehicles such as four-wheeled automobiles, saddle-ride type vehicles 200 have less freedom in component layout and therefore less freedom in mounting hydraulic control unit 100. For this reason, hydraulic control units mounted on saddle-ride type vehicles 200 have traditionally been desired to be smaller than hydraulic control units mounted on vehicles such as four-wheeled automobiles. For this reason, it is preferable to mount hydraulic control unit 100, which can be made smaller than conventional hydraulic control units, on saddle-ride type vehicles 200. In other words, since the hydraulic control unit 100 is a hydraulic control unit mounted on the saddle-type vehicle 200, the effect of miniaturization is significantly achieved.

[0102]

[0080] Although the hydraulic control unit 100 according to the present embodiment has been described above, the hydraulic control unit according to the present invention is not limited to the description of the present embodiment. The hydraulic control unit according to the present invention may be implemented as only a part of the present embodiment.

[0103] [Explanation of symbols]

[0104] [ 0 0 8 1 ]

[0105] ! Fuselage, 2 Handle, 3 Front wheel, 3a Rotor, 4 Rear wheel, 4a Rotor, 10 Brake system, !1 Brake lever, 12 First hydraulic circuit, 13 Brake pedal, !4 Second hydraulic circuit, 15 Fluid pipe, 16 Fluid pipe, 21 Master cylinder, 22 Reservoir, 23 Brake caliper, 24 Wheel cylinder, 25 Fill valve, 26 Release valve, 27 Accumulator, 28 Switching valve, 29 Pressure booster valve, 3 〇 Master cylinder fluid pressure sensor, 31 Wheel cylinder fluid pressure sensor, 4 〇 Internal flow path, 41 Main flow path, 41a Main flow path intermediate portion, 42 Sub-flow path, 42a Sub-flow path intermediate portion, 42b First secondary flow passage, 42c Second secondary flow passage, 43 Pressure booster flow passage, 5〇 Pump, 51 Cylinder, 52 Compression chamber, 53 Discharge flow passage, 54 Step portion, 55 Piston portion, 55a Input side end, 55 Partition side end, 56 First piston portion, 56a First connection side end, 57 First part, 58 Second part, 59 First connection portion, 6〇 Seat portion, 61 Second piston portion, 61a Second connection side end, 62 Second connection portion, 63 Bottom portion, 64 Flange portion, 64a First surface, 64b Second surface, 65 Inlet flow path, 66 spring, 67 lid portion, 68 discharge flow path, 7〇 inlet side check valve, 71 ball, 72 spring, 75 outlet side check valve, 85 holder, 86 filter, 87 sealing member, 9〇 motor, 91 output shaft, 92 eccentric portion, 100 hydraulic control unit, 101 base, 102 recess, 1〇3 stepped portion, 1〇4 plastically deformed portion, 1〇5 control device, 200 saddle-type vehicle, Mp master cylinder port, wP wheel cylinder port.

Claims

[Document name] Scope of claims

1. A hydraulic control unit (100) for a brake system (10) mounted on a vehicle, comprising: a base (101) in which an internal flow path (40) for communicating a wheel cylinder (24) with a master cylinder (21) is formed; and a pump (50) for moving brake fluid in the internal flow path (40), wherein the pump (50) has a cylinder (51) in which a compression chamber (52) for compressing brake fluid is formed, and an input side end (55a) of the pump (50) is pressed by a motor (90) which is a drive source of the pump (50), and a partition side end (55b) of the pump (50) is inserted into the compression chamber (52) to compress the brake fluid. and a piston portion (55) which divides an internal passage (40) of the pump (50) and whose division-side end portion (55b) reciprocates within the compression chamber (52), and an inflow passage (65) into which the brake fluid flowing through the internal passage (40) toward the pump (50) flows and which guides the brake fluid to the compression chamber (52) is formed in the piston portion (55), and the piston portion (55) comprises a first piston portion (56) in which a part of the inflow passage (65) is formed and which has the input-side end portion (55a), and a second piston portion (61) in which a part of the inflow passage (65) is formed and which has the division-side end portion (55b), The first piston portion (56) has a first connection portion (59) which is one of a recess and a protrusion at a first connection side end (56a) which is an end opposite to the input side end (55a), and the second piston portion (61) has a second connection portion (62) which is the other of the recess and the protrusion at a second connection side end (61a) which is an end opposite to the partition side end (55b), and the compression chamber (52) is formed between the first piston portion (56) and the second piston portion (61).an inlet-side check valve (70) for regulating the flow of brake fluid from the first piston portion (56) to the first piston portion (56), and the first piston portion (56) and the second piston portion (61) are connected by press-fitting the convex portion into the concave portion with an interference fit.

2. The hydraulic control unit (100) according to claim 1, wherein the tip of the convex portion abuts against the bottom of the concave portion (63).

3. The inlet-side check valve (70) includes a ball (71) that closes the inlet flow passage (65), the first piston portion (56) is provided in the inlet flow passage (65), and the inlet flow passage (65) 2. The hydraulic control unit (100) according to claim 1, further comprising a seat (60) against which the ball (71) abuts when the cylinder (51) is closed, and a tip of the second connection part (62) is disposed on a side farther from the cylinder (51) in the reciprocating direction, based on a contact position between the ball (71) and the seat (60).

4. The hydraulic control unit (100) according to any one of claims 1 to 3, wherein the first connection portion (59) is the convex portion, and the second connection portion (62) is the concave portion.

5. The second piston portion (61) includes a spring (66) that is provided on the outer circumferential side of the second piston portion (61) and presses the piston portion (55) in a direction from the partition-side end (55b) to the input-side end (55a). The second piston portion (61) includes a flange portion (64) that is provided on the outer circumferential side of the second piston portion (61), the spring (66) abuts against a first surface (64a) that is a surface on the cylinder (51) side, and is pressed by the spring (66) in a direction from the partition-side end (55b) to the input-side end (55a). The flange portion (64) 5. The hydraulic control unit (100) according to claim 4, wherein, when a surface opposite to the first surface (64a) is defined as a second surface (64b), a bottom (63) of the recess is disposed on the cylinder (51) side with respect to the second surface (64b) in the reciprocating direction.

6. A hydraulic control unit (100) according to any one of claims 1 to 3, comprising a holder (85) that holds the cylinder (51) and the piston portion (55). [Claim ?] A hydraulic pressure control unit (100) according to any one of claims 1 to 3, which is a hydraulic pressure control unit (100) for a brake system (10) mounted on a saddle-ride type vehicle (200).

8. A vehicle equipped with a hydraulic control unit (100) according to any one of claims 1 to 3.

9. The vehicle according to claim 8, wherein the vehicle is a saddle-type vehicle (200).

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