Hydraulic control unit and vehicle

Abstract

A hydraulic pressure control unit is provided with: a pump that moves brake fluid in an internal flow path that connects a wheel cylinder and a master cylinder; and a motor which is a driving source of the pump. The motor is provided with an output shaft and an eccentric part arranged on the output shaft; a pump is provided with: a cylinder in which a compression chamber is formed; a plunger, one end of which is in contact with the eccentric part and the other end of which is inserted into the compression chamber so as to be reciprocally movable; and a spring for pressing the plunger toward the eccentric portion. An inflow channel for guiding the brake fluid flowing toward the pump to the compression chamber is formed in the plunger; an inflow-side check valve for restricting the flow of the brake fluid flowing out of the compression chamber is provided in the inflow flow path; the spring is provided outside the inflow passage and the compression chamber.

Description

Technical Field

[0001] The present invention relates to a hydraulic control unit for a vehicle and a vehicle equipped with the hydraulic control unit. Background Art

[0002] In conventional vehicles, there are vehicles equipped with a hydraulic control unit that controls the pressure of the brake fluid in a hydraulic circuit filled with the brake fluid. For example, in a state where an input unit such as a brake lever is operated by a driver of the vehicle, the hydraulic control unit increases or decreases the pressure of the brake fluid in the hydraulic circuit, adjusts the braking force generated at the wheels, and performs anti-lock braking control. Such a hydraulic control unit unitizes a flow path that forms part of the hydraulic circuit and units such as a pump that moves the brake fluid in the flow path (for example, refer to Patent Document 1).

[0003] Specifically, a conventional hydraulic control unit includes a base body in which an internal flow path that connects a wheel cylinder and a master cylinder is formed, a pump that moves the brake fluid in the internal flow path, and a motor that is a drive source of the pump. In addition, the pump of the conventional hydraulic control unit includes a cylinder, a plunger, and a spring. In the cylinder, a compression chamber that compresses the brake fluid and a discharge flow path that discharges the brake fluid compressed in the compression chamber are formed. One end of the cylinder abuts on an eccentric portion provided on the output shaft of the motor. The eccentric portion is a portion that eccentrically rotates with respect to the rotation center of the output shaft of the motor. In addition, the other end of the cylinder is inserted into the opening of the compression chamber. The spring is provided in the compression chamber and presses the plunger toward the eccentric portion. As a result, the plunger can follow the movement of the eccentric portion, and the other end of the cylinder reciprocates in the compression chamber. Then, the brake fluid in the compression chamber is compressed and discharged from the discharge flow path to the outside of the pump.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-109919 Summary of the Invention

[0007] Technical Problem to be Solved by the Invention

[0008] Compared with vehicles such as cross-riding vehicles and motorized four-wheel vehicles, which are a type of vehicle, the degree of freedom in component layout is low, and the degree of freedom in mounting the hydraulic control unit is low. Therefore, in the past, miniaturization of the hydraulic control unit mounted on a cross-riding vehicle has been desired. In addition, in vehicles such as motorized four-wheel vehicles, due to miniaturization of the engine room and an increase in the number of parts installed in the engine room in recent years, miniaturization of the hydraulic control unit has also been desired.

[0009] Here, in order to miniaturize the hydraulic control unit, it is necessary to reduce the compression chamber, such as by reducing the diameter of the compression chamber. At this time, as described above, in the conventional hydraulic control unit, a spring that presses the plunger toward the eccentric portion is provided in the compression chamber. Therefore, in the conventional hydraulic control unit, when reducing the diameter of the compression chamber, it is necessary to also reduce the diameter of the spring. However, if the diameter of the spring is reduced, the pressing force that presses the plunger toward the eccentric portion becomes weaker, and it becomes difficult for the plunger to follow the eccentric rotational movement of the eccentric portion. In other words, it becomes difficult for the plunger to always contact the eccentric portion. As a result, the pumping capacity of the pump decreases, and it becomes difficult to move the brake fluid of the desired volume. To solve this problem, it is necessary to lengthen the spring to increase the pressing force that presses the plunger toward the eccentric portion. However, in this case, the compression chamber also becomes longer, and the hydraulic control unit cannot be miniaturized. Thus, the conventional hydraulic control unit has a technical problem of being difficult to miniaturize.

[0010] The present invention is made based on the above technical problems. The first object is to obtain a hydraulic control unit that can be miniaturized compared to the prior art. In addition, the second object of the present invention is to obtain a vehicle equipped with such a hydraulic control unit.

[0011] Means for solving the technical problems

[0012] Regarding the hydraulic control unit of the present invention, it is a hydraulic control unit mounted on a braking system of a vehicle, and includes: a base body formed with an internal flow path that connects a wheel cylinder and a master cylinder; a pump that moves the brake fluid in the internal flow path; and a motor that is a driving source of the pump. The motor includes: an output shaft; and an eccentric portion provided on the output shaft and eccentrically rotating relative to the rotation center of the output shaft. The pump includes: a cylinder formed with a compression chamber that compresses the brake fluid and a discharge flow path that discharges the brake fluid compressed in the compression chamber; a plunger having one end in contact with the eccentric portion and the other end inserted into an opening of the compression chamber, and the other end reciprocating in the compression chamber; and a spring that presses the plunger toward the eccentric portion. An inflow flow path for the brake fluid flowing from the internal flow path toward the pump to flow in and guiding the brake fluid to the compression chamber is formed in the plunger. The plunger is provided with an inflow side check valve that is provided in the inflow flow path and restricts the flow of the brake fluid from the compression chamber toward the internal flow path. The spring is provided outside the inflow flow path and the compression chamber.

[0013] In addition, the vehicle according to the present invention includes the hydraulic control unit according to the present invention.

[0014] Advantages of the invention

[0015] In the hydraulic control unit according to the present invention, a spring that presses the plunger toward the eccentric portion is provided outside the compression chamber. Therefore, the hydraulic control unit according to the present invention can determine the diameter of the spring without being limited by the diameter of the compression chamber. Thus, the hydraulic control unit according to the present invention can miniaturize the compression chamber while suppressing a decrease in the pressing force of the spring. Therefore, the hydraulic control unit according to the present invention can be miniaturized compared with the conventional hydraulic control unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. is a diagram showing the structure of a cross-riding vehicle equipped with a braking system including a hydraulic control unit according to an embodiment of the present invention.

[0017] Figure 2 FIG. is a diagram showing the structure of a braking system including a hydraulic control unit according to an embodiment of the present invention.

[0018] Figure 3 FIG. is a cross-sectional view of the periphery of a pump and a motor of a hydraulic control unit according to an embodiment of the present invention.

[0019] Figure 4 FIG. is a cross-sectional view of the periphery of a pump and a motor of a modified example of a hydraulic control unit according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, a hydraulic control unit and a vehicle according to the present invention will be described with reference to the drawings.

[0021] In addition, an example in which the hydraulic control unit according to the present invention is mounted on a motorized two-wheeler, which is an example of a cross-riding vehicle, will be described below. However, the hydraulic control unit according to the present invention can also be mounted on other cross-riding vehicles other than motorized two-wheelers. Other cross-riding vehicles other than motorized two-wheelers are, for example, bicycles (e.g., two-wheelers, three-wheelers, etc.), motorized three-wheelers, buggies, etc. having at least one of an engine and an electric motor as a drive source. In addition, a bicycle refers to all transportation means that can be propelled on the road by the pedaling force applied to the pedals. That is, bicycles include ordinary bicycles, electric assist bicycles, electric bicycles, etc. In addition, motorized two-wheelers or motorized three-wheelers refer to so-called motorcycles, and motorcycles include mopeds, small motorcycles, electric small motorcycles, etc. In addition, the hydraulic control unit according to the present invention can also be mounted on other vehicles other than cross-riding vehicles such as motorized four-wheelers having at least one of an engine and an electric motor as a drive source.

[0022] In addition, the following description uses an example of the hydraulic control unit according to the present invention in a vehicle braking system having a two-system hydraulic circuit. However, the number of hydraulic circuits of the vehicle braking system using the hydraulic control unit according to the present invention is not limited to two systems. The vehicle braking system using the hydraulic control unit according to the present invention may have only one system of hydraulic circuit, or may have three or more systems of hydraulic circuits.

[0023] In addition, the structures, operations, etc. described below are examples, and the present invention is not limited to such structures, operations, etc. In addition, in each figure, the same or similar components or parts may be given the same reference numerals or the assignment of reference numerals may be omitted. In addition, the detailed structures are appropriately simplified or omitted in the drawings.

[0024] Embodiment.

[0025] <Structure and Operation of Vehicle Braking System>

[0026] The structure and operation of the braking system having the hydraulic control unit according to the present embodiment will be described.

[0027] Figure 1 It is a diagram showing the structure of a cross-type vehicle equipped with a braking system having a hydraulic control unit according to an embodiment of the present invention. Figure 2 It is a diagram showing the structure of a braking system having a hydraulic control unit according to an embodiment of the present invention.

[0028] As Figure 1 and Figure 2 shown, the braking system 10 is mounted on a cross-type vehicle 200 which is an example of a vehicle. The cross-type vehicle 200 is, for example, a motor two-wheeler driven by an engine. The cross-type vehicle 200 includes a vehicle body 1, handlebars 2 that are turnably held by the vehicle body 1, a front wheel 3 that is turnably held by the vehicle body 1 together with the handlebars 2, and a rear wheel 4 that is rotatably held by the vehicle body 1.

[0029] The braking 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 the handlebars 2 and is operated by the driver's hand. The first hydraulic circuit 12 generates a braking force corresponding to the operation amount of the brake lever 11 on a rotor 3a that rotates together with the front wheel 3. The brake pedal 13 is provided at the lower part of the vehicle body 1 and is operated by the driver's foot. The second hydraulic circuit 14 generates a braking force corresponding to the operation amount of the brake pedal 13 on a rotor 4a that rotates together with the rear wheel 4.

[0030] In addition, the brake lever 11 and the brake pedal 13 are examples of the input parts for braking. For example, as an input part for braking in place of the brake lever 11, a brake pedal different from the brake pedal 13 provided on the vehicle body 1 may be adopted. Further, for example, as an input part for braking in place of the brake pedal 13, a brake lever different from the brake lever 11 provided on the handlebar 2 may be adopted. In addition, the first hydraulic circuit 12 may also be configured to generate a braking force corresponding to the operation amount of the brake lever 11 or the operation amount of a brake pedal different from the brake pedal 13 provided on the vehicle body 1 on the rotor 4a that rotates together with the rear wheel 4. In addition, the second hydraulic circuit 14 may also be configured to generate a braking force corresponding to the operation amount of the brake pedal 13 or the operation amount of a brake lever different from the brake lever 11 provided on the handlebar 2 on the rotor 3a that rotates together with the front wheel 3.

[0031] The first hydraulic circuit 12 and the second hydraulic circuit 14 have the same structure. Therefore, the structure of the first hydraulic circuit 12 will be described below as a representative.

[0032] The first hydraulic circuit 12 includes a master cylinder 21 with a piston (not shown) built therein, a reservoir 22 attached to the master cylinder 21, a brake caliper 23 having a brake pad (not shown), and a wheel cylinder 24 that actuates the brake pad (not shown) of the brake caliper 23.

[0033] In the base body 101 of the hydraulic control unit 100, an internal flow path 40 is formed to communicate the wheel cylinder 24 with the master cylinder 21. Specifically, the internal flow path 40 communicates with the master cylinder 21 via a liquid pipe 15 described later and communicates with the wheel cylinder 24 via a liquid pipe 16 described later. In the present embodiment, in the base body 101, a main flow path 41, a sub-flow path 42, and a pressure boosting flow path 43 are formed as the internal flow path 40. In the first hydraulic circuit 12, the master cylinder 21 and the wheel cylinder 24 communicate via a liquid pipe 15 connected between the master cylinder 21 and the master cylinder port MP formed in the base body 101, the main flow path 41 formed in the base body 101, and a liquid pipe 16 connected between the wheel cylinder 24 and the wheel cylinder port WP formed in the base body 101. In addition, the brake fluid in the wheel cylinder 24 is discharged to the middle part of the main flow path 41, i.e., the middle part 41a of the main flow path, via the sub-flow path 42. In addition, the brake fluid in the master cylinder 21 is supplied to the middle part of the sub-flow path 42, i.e., the middle part 42a of the sub-flow path, via the pressure boosting flow path 43.

[0034] In a region of the main flow path 41 on the wheel cylinder 24 side with respect to the middle part 41a of the main flow path, a filling valve 25 is provided. By the opening and closing operation of the filling valve 25, the flow path portion at the installation position of the filling valve 25 in the main flow path 41 is opened and closed, and the flow rate of the brake fluid flowing in this region is controlled. In a region of the sub-flow path 42 on the upstream side with respect to the middle part 42a of the sub-flow path, a release valve 26 and a reservoir 27 for storing the brake fluid are provided in sequence from the upstream side. By the opening and closing operation of the release valve 26, the flow path portion at the installation position of the release valve 26 in the sub-flow path 42 is opened and closed, and the flow rate of the brake fluid flowing in this region is controlled. In addition, in a region of the sub-flow path 42 on the downstream side with respect to the middle part 42a of the sub-flow path, a pump 50 for applying pressure to the brake fluid in the sub-flow path 42 and moving the brake fluid is provided. That is, the pump 50 moves the brake fluid in the internal flow path 40. In addition, hereinafter, the part of the sub-flow path 42 on the upstream side with respect to the pump 50 may sometimes be referred to as the first sub-flow path 42b. In addition, the part of the sub-flow path 42 on the downstream side with respect to the pump 50 may sometimes be referred to as the second sub-flow path 42c.

[0035] In a region of the main flow path 41 on the master cylinder 21 side with respect to the middle part 41a of the main flow path, a switching valve 28 is provided. By the opening and closing operation of the switching valve 28, the flow path portion at the installation position of the switching valve 28 in the main flow path 41 is opened and closed, and the flow rate of the brake fluid flowing in this region is controlled. A pressure boosting valve 29 is provided in the pressure boosting flow path 43. By the opening and closing operation of the pressure boosting valve 29, the flow path portion at the installation position of the pressure boosting valve 29 in the pressure boosting flow path 43 is opened and closed, and the flow rate of the brake fluid flowing in the pressure boosting flow path 43 is controlled.

[0036] In addition, in a region of the main flow path 41 on the master cylinder 21 side with respect to the switching valve 28, a master cylinder hydraulic sensor 30 for detecting the hydraulic pressure of the brake fluid in the master cylinder 21 is provided. In addition, in a region of the main flow path 41 on the wheel cylinder 24 side with respect to the filling valve 25, a wheel cylinder hydraulic sensor 31 for detecting the hydraulic pressure of the brake fluid in the wheel cylinder 24 is provided.

[0037] That is, the main flow path 41 connects the master cylinder port MP and the wheel cylinder port WP via the filling valve 25. In addition, the sub-flow path 42 is defined as a part or all of the flow path for discharging the brake fluid in the wheel cylinder 24 to the master cylinder 21 via the release valve 26. In addition, the pressure boosting flow path 43 is defined as a part or all of the flow path for supplying the brake fluid in the master cylinder 21 to the upstream side of the pump 50 in the sub-flow path 42 via the pressure boosting valve 29. That is, the sub-flow path 42 and the pressure boosting flow path 43 also connect the master cylinder port MP and the wheel cylinder port WP.

[0038] The filling valve 25 is, for example, an electromagnetic valve that, when changing from a non-energized state to an energized state, switches the flow of the brake fluid at its installation position from open to closed. The release valve 26 is, for example, an electromagnetic valve that, when changing from a non-energized state to an energized state, switches the flow of the brake fluid passing through its installation position toward the middle part 42a of the sub-flow path from closed to open. The switching valve 28 is, for example, an electromagnetic valve that, when changing from a non-energized state to an energized state, switches the flow of the brake fluid at its installation position from open to closed. The pressure boosting valve 29 is, for example, an electromagnetic valve that, when changing from a non-energized state to an energized state, switches the flow of the brake fluid passing through its installation position toward the middle part 42a of the sub-flow path from closed to open.

[0039] 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. That is, the motor 90 is the drive source of the pump 50.

[0040] The hydraulic control unit 100 is composed of a base body 101, various components provided on the base body 101 (filling valve 25, release valve 26, reservoir 27, switching valve 28, pressure boosting valve 29, master cylinder hydraulic sensor 30, wheel cylinder hydraulic sensor 31, pump 50, motor 90, etc.), and a control device (ECU) 105.

[0041] The control device 105 is a device that controls the filling valve 25, the release valve 26, the switching valve 28, the pressure boosting valve 29, and the motor 90. The control device 105 can be one unit or divided into multiple units. In addition, the control device 105 can be installed on the base body 101 or on other components outside the base body 101. In addition, part or all of the control device 105 can be composed of, for example, a microcomputer, a microprocessor unit, etc., or can be composed of updatable elements such as firmware, or can be a program module executed according to instructions from a CPU, etc.

[0042] For example, in the normal state, the control device 105 controls the filling valve 25, the release valve 26, the switching valve 28, and the pressure boosting valve 29 to be in a non-energized state. In this state, if the brake lever 11 is operated, in the first hydraulic circuit 12, the piston (not shown) of the master cylinder 21 is pushed in, the hydraulic pressure of the brake fluid in the wheel cylinder 24 increases, and the brake pad (not shown) of the brake caliper 23 is pressed against the rotor 3a of the front wheel 3, and the front wheel 3 is braked. In addition, if the brake pedal 13 is operated, in the second hydraulic circuit 14, the piston (not shown) of the master cylinder 21 is pushed in, the hydraulic pressure of the brake fluid in the wheel cylinder 24 increases, and the brake pad (not shown) of the brake caliper 23 is pressed against the rotor 4a of the rear wheel 4, and the rear wheel 4 is braked.

[0043] For the control device 105, the outputs of various sensors (master cylinder hydraulic pressure sensor 30, wheel cylinder hydraulic pressure sensor 31, wheel speed sensor, acceleration sensor, etc.) are input. Corresponding to its output, the control device 105 outputs commands responsible for the operations of the filling valve 25, release valve 26, switching valve 28, pressure increasing valve 29, and motor 90, and executes a pressure reducing control operation, a pressure increasing control operation, etc.

[0044] For example, when there is an excess or a possibility of excess in the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic circuit 12, the control device 105 executes a pressure reducing control operation to reduce the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic circuit 12. At this time, in the first hydraulic circuit 12, the control device 105 drives the motor 90 while controlling the filling valve 25 to the energized state, the release valve 26 to the energized state, the switching valve 28 to the non-energized state, and the pressure increasing valve 29 to the non-energized state. Thereby, the brake fluid in the wheel cylinder 24 of the first hydraulic circuit 12 flows into the sub-flow path 42 through the main flow path 41, and the hydraulic pressure of the wheel cylinder 24 decreases. Then, the brake fluid flowing from the wheel cylinder 24 into the sub-flow path 42 flows into the reservoir 27 through the release valve 26 and is accumulated in the reservoir 27. In addition, the brake fluid accumulated in the reservoir 27 is sent back to the master cylinder 21 by the pump 50 driven by the motor 90.

[0045] In addition, when there is an excess or a possibility of excess in the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the second hydraulic circuit 14, the control device 105 executes a pressure reducing control operation to reduce the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the second hydraulic circuit 14. At this time, in the second hydraulic circuit 14, the control device 105 drives the motor 90 while controlling the filling valve 25 to the energized state, the release valve 26 to the energized state, the switching valve 28 to the non-energized state, and the pressure increasing valve 29 to the non-energized state. Thereby, the brake fluid in the wheel cylinder 24 of the second hydraulic circuit 14 flows into the sub-flow path 42 through the main flow path 41, and the hydraulic pressure of the wheel cylinder 24 decreases. Then, the brake fluid flowing from the wheel cylinder 24 into the sub-flow path 42 flows into the reservoir 27 through the release valve 26 and is accumulated in the reservoir 27. In addition, the brake fluid accumulated in the reservoir 27 is sent back to the master cylinder 21 by the pump 50 driven by the motor 90.

[0046] In addition, for example, when there is a shortage or a possibility of shortage of the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic circuit 12, the control device 105 performs a pressure increasing control operation to increase the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic circuit 12. At this time, in the first hydraulic circuit 12, the control device 105 controls the filling valve 25 to the non-energized state, the release valve 26 to the non-energized state, the switching valve 28 to the energized state, and the pressure increasing valve 29 to the energized state, while driving the motor 90. Thus, by means of the pump 50 driven by the motor 90, the brake fluid in the master cylinder 21 of the first hydraulic circuit 12 flows from the middle part 42a of the sub-flow path into the sub-flow path 42 through the main flow path 41 and the pressure increasing flow path 43. The brake fluid flowing into the sub-flow path 42 flows from the middle part 41a of the main flow path into the main flow path 41, and flows into the wheel cylinder 24 of the first hydraulic circuit 12 through the filling valve 25. Thus, the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic circuit 12 increases.

[0047] In addition, when there is a shortage or a possibility of shortage of the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the second hydraulic circuit 14, the control device 105 performs a pressure increasing control operation to increase the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the second hydraulic circuit 14. At this time, in the second hydraulic circuit 14, the control device 105 controls the filling valve 25 to the non-energized state, the release valve 26 to the non-energized state, the switching valve 28 to the energized state, and the pressure increasing valve 29 to the energized state, while driving the motor 90. Thus, by means of the pump 50 driven by the motor 90, the brake fluid in the master cylinder 21 of the second hydraulic circuit 14 flows from the middle part 42a of the sub-flow path into the sub-flow path 42 through the main flow path 41 and the pressure increasing flow path 43. The brake fluid flowing into the sub-flow path 42 flows from the middle part 41a of the main flow path into the main flow path 41, and flows into the wheel cylinder 24 of the second hydraulic circuit 14 through the filling valve 25. Thus, the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the second hydraulic circuit 14 increases.

[0048] That is, the hydraulic control unit 100 can control the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic circuit 12 to perform the pressure reducing control operation (in other words, the anti-lock braking operation) of the first hydraulic 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 to perform the pressure reducing control operation (in other words, the anti-lock braking operation) of the second hydraulic circuit 14. In addition, the hydraulic control unit 100 can control the hydraulic pressure of the brake fluid in the wheel cylinder 24 of the first hydraulic circuit 12 to perform the pressure increasing operation of the first hydraulic 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 to perform the pressure increasing operation of the second hydraulic circuit 14.

[0049] <Structure of the hydraulic control unit>

[0050] The structure of the hydraulic control unit according to this embodiment will be described.

[0051] Figure 3 It is a cross-sectional view of the periphery of the pump and the motor of the hydraulic control unit according to the embodiment of the present invention. The Figure 3 The shown pump 50 is the pump 50 of the first hydraulic circuit 12. The structure of the pump 50 of the second hydraulic circuit 14 is the same as that of the pump 50 of the first hydraulic circuit 12.

[0052] The hydraulic control unit 100 includes the pump 50 and the motor 90 as described above. The pump 50 and the motor 90 are provided on a base 101 formed of a metal such as aluminum alloy, for example.

[0053] The motor 90 includes an output shaft 91 and an eccentric portion 92. The output shaft 91 is rotationally driven by the rotor and stator of the motor 90. In addition, Figure 3 This is a view of the hydraulic control unit 100 cut along a cross-section perpendicular to the rotation center of the output shaft 91, and is the viewing direction without showing the rotor and stator. The eccentric portion 92 is provided on the output shaft 91 and eccentrically rotates with respect to the rotation center of the output shaft 91.

[0054] The pump 50 is buried in a recess 102 formed in the base 101. The pump 50 includes a cylinder 51, a plunger 55, and a spring 60.

[0055] In the cylinder 51, a compression chamber 52 for compressing the brake fluid is formed. In addition, in the cylinder 51, a discharge flow path 53 for discharging the brake fluid compressed by the compression chamber 52 is formed. The brake fluid discharged into the discharge flow path 53 flows into the second sub-flow path 42c of the sub-flow path 42. In this embodiment, the structure is such that the brake fluid discharged into the discharge flow path 53 flows into the second sub-flow path 42c via the discharge flow path 62. That is, the discharge flow path 53 communicates with the second sub-flow path 42c via the discharge flow path 62.

[0056] Specifically, the pump 50 according to this embodiment includes a cover portion 61 adjacent to the cylinder 51. The cover portion 61 is buried in a region of the recess 102 closer to the opening of the recess 102 than the cylinder 51. Moreover, the discharge flow path 62 is formed between the cylinder 51 and the cover portion 61. In this embodiment, the discharge flow path 62 is composed of at least one groove formed in at least one of the end portion of the cylinder 51 on the cover portion 61 side and the end portion of the cover portion 61 on the cylinder 51 side, and at least one groove formed in at least one of the outer peripheral surface of the cylinder 51 and the outer peripheral surface of the cover portion 61.

[0057] One end of the plunger 55, namely the end portion 55a, abuts against the eccentric portion 92 of the motor 90. In addition, the other end of the plunger 55, namely the end portion 55b, is inserted into the opening portion 52a of the compression chamber 52. Further, the other end of the plunger 55, namely the end portion 55b, reciprocates in the compression chamber 52. Here, when the brake fluid is compressed by the compression chamber 52, in order to suppress the outflow of the brake fluid from between the outer peripheral surface 55c of the plunger 55 (more specifically, the outer peripheral surface of the portion of the plunger 55 inserted into the compression chamber 52) and the inner peripheral surface 52b of the compression chamber 52, the portion of the plunger 55 inserted into the compression chamber 52 is formed as follows. The outer diameter of the portion of the plunger 55 inserted into the compression chamber 52 is slightly larger than the inner diameter of the compression chamber 52, so that the portion of the plunger 55 inserted into the compression chamber 52 is press-fitted into the compression chamber 52 in a state where it can reciprocate when inserted into the compression chamber 52. In other words, the portion of the plunger 55 inserted into the compression chamber 52 is in a state where it is lightly press-fitted into the compression chamber 52 in a state where it can reciprocate when inserted into the compression chamber 52. The plunger 55 is formed of resin, for example, at least in the portion inserted into the compression chamber 52.

[0058] In addition, the number of parts constituting the plunger 55 is not particularly limited, but in the present embodiment, the plunger 55 is composed of three parts. Specifically, the plunger 55 includes a first part 56, a second part 57, and a third part 58. The first part 56 is a part having the end portion 55a. The second part 57 is mounted on the end portion of the first part 56 on the side opposite to the end portion 55a. In the present embodiment, the first part 56 is press-fitted into the second part 57, and the second part 57 is mounted on the first part 56. The third part 58 is a part having the end portion 55b. The third part 58 is mounted on the end portion of the second part 57 on the side opposite to the end portion where the first part 56 is mounted. In the present embodiment, the second part 57 is press-fitted into the third part 58, and the third part 58 is mounted on the second part 57.

[0059] In addition, the brake fluid flowing toward the pump 50 in the internal flow path 40 flows into the plunger 55, and an inflow flow path 59 for guiding the brake fluid to the compression chamber 52 is formed. Specifically, in the present embodiment, the end portion on the inflow side of the brake fluid in the inflow flow path 59 opens on the side surface of the first part 56. In addition, the end portion on the outflow side of the brake fluid in the inflow flow path 59 opens at the end portion 55b of the third part 58. That is, the end portion on the outflow side of the brake fluid in the inflow flow path 59 opens inside the compression chamber 52. Moreover, the brake fluid flowing toward the pump 50 in the first sub-flow path 42b of the sub-flow path 42 flows into the inflow flow path 59 and flows out to the compression chamber 52 through the inflow flow path 59. In addition, in order to suppress the brake fluid flowing toward the pump 50 in the first sub-flow path 42b of the sub-flow path 42 from flowing through the outer periphery of the first part 56 of the plunger 55 to the arrangement space of the eccentric portion 92, in the present embodiment, the outer peripheral surface of the first part 56 of the plunger 55 and the base body 101 are sealed by a sealing member 87 such as an O-ring.

[0060] In addition, the plunger 55 includes an inflow side check valve 70 provided in the inflow flow path 59 for restricting the flow of the brake fluid from the compression chamber 52 toward the internal flow path 40 (more specifically, the first sub-flow path 42b). In the present embodiment, the inflow side check valve 70 is configured as follows. The inflow side check valve 70 includes a valve seat 71, a valve body 72, and a spring 73. The valve seat 71 is provided at the end portion on the second part 57 side of the portion formed in the first part 56 in the inflow flow path 59. The valve body 72 is, for example, spherical and is movably provided in the direction approaching the valve seat 71 and the direction away from the valve seat 71. In a state where the valve body 72 approaches the valve seat 71 and contacts the valve seat 71, the valve body 72 closes the inflow flow path 59. In addition, in a state where the valve body 72 is away from the valve seat 71, the valve body 72 opens the inflow flow path 59. The spring 73 biases the valve body 72 toward the valve seat 71.

[0061] The spring 60 is a member that pushes the plunger 55 toward the eccentric portion 92 of the motor 90. Here, in the hydraulic control unit 100 according to the present embodiment, the spring 60 is provided outside the inflow flow path 59 and the compression chamber 52. For example, the spring 60 is provided on the outer peripheral side of the plunger 55. Specifically, the spring 60 is clamped by the cylinder 51 and the third part 58 of the plunger 55 on the outer peripheral side of the plunger 55 in a state shorter than the natural length of the spring 60. When the spring 60 is provided outside the inflow flow path 59 and the compression chamber 52, by providing the spring 60 on the outer peripheral side of the plunger 55, the arrangement of the spring 60 becomes easy, and the manufacture of the hydraulic control unit 100 becomes easy.

[0062] In the pump 50 configured in this way, as the outer peripheral surface of the eccentric portion 92 of the motor 90 approaches the compression chamber 52, the plunger 55 is pushed to be inserted into the compression chamber 52. As a result, the volume of the compression chamber 52 decreases. Further, when the outer peripheral surface of the eccentric portion 92 of the motor 90 moves away from the compression chamber 52, the plunger 55 pushed toward the eccentric portion 92 by the spring 60 maintains the state where the end portion 55a is in contact with the eccentric portion 92. Thus, the plunger 55 moves following the outer peripheral surface of the eccentric portion 92 of the motor 90, in other words, moves following the eccentric rotational movement of the eccentric portion 92 of the motor 90, and operates in a manner of being pulled out from the compression chamber 52. Therefore, the volume of the compression chamber 52 increases.

[0063] When the 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 inflow path 59 formed in the plunger 55. For example, during the decompression control operation, the brake fluid in the wheel cylinder 24 flows into the inflow path 59 through the main flow path 41 and the first sub-flow path 42b. Further, during the pressure increase control operation, the brake fluid in the master cylinder 21 flows into the inflow path 59 through the main flow path 41, the pressure increase flow path 43, and the first sub-flow path 42b.

[0064] At this time, in the stage where the volume of the compression chamber 52 increases, the pressure of the brake fluid existing on the compression chamber 52 side with respect to the inflow side check valve 70 is low. Therefore, the brake fluid flowing into the inflow path 59 moves the valve body 72 in a direction away from the valve seat 71, and sets the inflow side check valve 70 in an open state. As a result, the brake fluid flowing into the inflow path 59 flows into the compression chamber 52 through the inflow side check valve 70. On the other hand, in the stage where the volume of the compression chamber 52 decreases, with respect to the inflow side check valve 70, the pressure of the brake fluid existing on the compression chamber 52 side becomes high. Therefore, the brake fluid flowing into the inflow path 59 cannot move the valve body 72 in a direction away from the valve seat 71. As a result, the inflow side check valve 70 becomes a closed state, and the brake fluid flowing into the inflow path 59 does not flow into the compression chamber 52.

[0065] The brake fluid flowing into the compression chamber 52 is compressed as the volume of the compression chamber 52 decreases, and is pressured and sent to the second sub-flow path 42c of the sub-flow path 42 through the discharge path 53 and the discharge path 62. For example, during the decompression control operation, the brake fluid flowing into the second sub-flow path 42c is sent back to the master cylinder 21 through the main flow path 41. Further, during the pressure increase control operation, the brake fluid flowing into the second sub-flow path 42c flows into the wheel cylinder 24 through the main flow path 41.

[0066] In addition, compared with vehicles such as straddle-type vehicles and motor four-wheel vehicles, which are one type of vehicle, the degree of freedom in component layout is lower, and the degree of freedom in mounting a hydraulic control unit is lower. Therefore, conventionally, miniaturization has been sought for the hydraulic control unit mounted on a straddle-type vehicle. In addition, in vehicles such as motor four-wheel vehicles, miniaturization of the hydraulic control unit has also been desired in recent years due to miniaturization of the engine room and an increase in the number of components mounted in the engine room.

[0067] In order to miniaturize the hydraulic control unit, it is necessary to reduce the diameter of the compression chamber and the like to reduce the compression chamber. Here, a spring that presses the plunger toward the eccentric portion of the motor is provided in the compression chamber of the conventional hydraulic control unit. Therefore, in the conventional hydraulic control unit, when reducing the diameter of the compression chamber, it is also necessary to reduce the diameter of the spring. However, if the diameter of the spring is reduced, the pressing force that presses the plunger toward the eccentric portion becomes weak, and it is difficult for the plunger to follow the eccentric rotational movement of the eccentric portion. In other words, it is difficult for the plunger to always contact the eccentric portion. As a result, the pumping capacity of the pump decreases, and it is difficult to move the brake fluid of a desired volume. To solve this problem, it is necessary to extend the spring to increase the pressing force that presses the plunger toward the eccentric portion. However, in this case, the compression chamber also becomes longer, and the hydraulic control unit cannot be miniaturized. Thus, there is a technical problem that it is difficult to miniaturize the conventional hydraulic control unit.

[0068] On the other hand, in the hydraulic control unit 100 according to the present embodiment, a spring 60 that presses the plunger 55 toward the eccentric portion 92 of the motor 90 is provided outside the compression chamber 52. Therefore, in the hydraulic control unit 100 according to the present embodiment, the diameter of the spring 60 can be determined without being limited by the diameter of the compression chamber 52. Thus, the hydraulic control unit 100 according to the present embodiment can miniaturize the compression chamber 52 while suppressing a decrease in the pressing force of the spring 60. Therefore, the hydraulic control unit 100 according to the present embodiment can be miniaturized compared with the conventional hydraulic control unit.

[0069] In addition, in the hydraulic control unit 100 according to the present embodiment, since the spring 60 is provided outside the compression chamber 52, the compression chamber 52 is not damaged by the spring 60. Therefore, the hydraulic control unit 100 according to the present embodiment can also achieve an effect of better suppressing leakage of the brake fluid from the compression chamber 52 compared with the conventional hydraulic control unit.

[0070] In addition, in the hydraulic control unit 100 according to the present embodiment, the spring 60 is disposed outside the compression chamber 52 and outside the inflow passage 59. That is, the spring 60 is disposed outside the flow path of the brake fluid in the pump 50 that guides the brake fluid from the first sub-flow path 42b of the sub-flow path 42 to the second sub-flow path 42c. Therefore, even when foreign matter occurs due to interference between the spring 60 and surrounding parts, it is possible to suppress the inflow of the foreign matter into the internal flow path 40. Thus, the reliability of the hydraulic control unit 100 according to the present embodiment is also improved.

[0071] In addition, the method of fixing the pump 50 to the base body 101 is not particularly limited. In the present embodiment, the pump 50 is fixed to the base body 101 as follows. The base body 101 has a stepped portion 103 on the inner peripheral surface of the recess 102. The cylinder 51 of the pump 50 has a stepped portion 54 that projects from the outer peripheral surface and abuts against the stepped portion 103 of the base body 101. In addition, the base body 101 has a plastic deformation portion 104 formed by plastically deforming the peripheral edge of the opening of the recess 102. Moreover, the cover portion 61 and the cylinder 51 of the pump 50 are clamped between the stepped portion 103 and the plastic deformation portion 104, and the pump 50 is fixed to the base body 101. In addition, Figure 3 FIG. shows the base body 101 before the plastic deformation portion 104 is formed. Therefore, in Figure 3 the plastic deformation portion 104 is shown by a phantom line.

[0072] Here, it is preferable that the hydraulic control unit 100 according to the present embodiment has the following structure.

[0073] Preferably, the hydraulic control unit 100 includes a holder 85 that holds the cylinder 51, the plunger 55, and the spring 60. Thereby, at least a part of the constituent parts of the hydraulic control unit 100 can be unitized. Moreover, the unitized part in the hydraulic control unit 100 can be inserted into the recess 102 of the base body 101 at once. Therefore, by providing the hydraulic control unit 100 with the holder 85, the manufacturing of the hydraulic control unit 100 becomes easier compared to the case where the constituent parts of the hydraulic control unit 100 are inserted into the recess 102 one by one and the pump 50 is assembled.

[0074] Preferably, the holder 85 of the hydraulic control unit 100 includes a filter 86 through which the brake fluid flowing into the inflow passage 59 formed in the plunger 55 passes. By providing the holder 85 with the filter 86, it is possible to suppress the mixing of foreign matter into the compression chamber 52 and to suppress the occurrence of damage inside the compression chamber 52, so the reliability of the hydraulic control unit 100 is improved. In addition, by providing the holder 85 with the filter 86, the filter 86 can be provided when at least a part of the constituent parts of the hydraulic control unit 100 are unitized by the holder 85. Therefore, by providing the holder 85 with the filter 86, the manufacturing of the hydraulic control unit 100 becomes easier.

[0075] Preferably, the pump 50 of the hydraulic control unit 100 is provided with an outlet check valve 75 disposed in the discharge flow path 53 to restrict the flow of the brake fluid from the internal flow path 40 (more specifically, the second sub-flow path 42c) toward the compression chamber 52. In the present embodiment, the outlet check valve 75 is configured as follows. The outlet check valve 75 includes a valve seat 76, a valve body 77, and a spring 78. The valve seat 76 is disposed in the discharge flow path 53. The valve body 77 is, for example, spherical and is movably disposed in the direction approaching the valve seat 76 and the direction away from the valve seat 76. In a state where the valve body 77 approaches the valve seat 76 and contacts the valve seat 76, the valve body 77 closes the discharge flow path 53. Further, in a state where the valve body 77 separates from the valve seat 76, the valve body 77 opens the discharge flow path 53. The spring 78 biases the valve body 77 toward the valve seat 76. In order to suppress the backflow of the brake fluid from the internal flow path 40 (more specifically, the second sub-flow path 42c) to the compression chamber 52, there is a case where an outlet check valve 75 for restricting the flow of the brake fluid from the internal flow path 40 (more specifically, the second sub-flow path 42c) toward the compression chamber 52 is provided in the hydraulic control unit 100. In such a case, by providing the pump 50 with the outlet check valve 75, when the pump 50 is provided on the base 101, the outlet check valve 75 can also be provided on the base 101. Therefore, by providing the pump 50 with the outlet check valve 75, the manufacturing of the hydraulic control unit 100 becomes easier compared to the case where the outlet check valve 75 and the pump 50 are separately provided on the base 101.

[0076] <Modification Example>

[0077] Figure 4 is a cross-sectional view showing the periphery of the pump and the motor of a modification example of the hydraulic control unit according to the embodiment of the present invention. The Figure 4 shown pump 50 is the pump 50 of the first hydraulic circuit 12. The structure of the pump 50 of the second hydraulic circuit 14 is the same as the structure of the pump 50 of the first hydraulic circuit 12.

[0078] Figure 4 The shown hydraulic control unit 100 is provided with a sealing member 81 disposed on the outer peripheral surface 55c of the plunger 55 to suppress the outflow of the brake fluid between the outer peripheral surface 55c of the plunger 55 and the inner peripheral surface 52b of the compression chamber 52. The sealing member 81 is, for example, an O-ring. In Figure 3 In the shown hydraulic control unit 100, in order to suppress the outflow of the brake fluid between the outer peripheral surface 55c of the plunger 55 and the inner peripheral surface 52b of the compression chamber 52, the portion of the plunger 55 inserted into the compression chamber 52 is sized to be lightly press-fitted into the compression chamber 52 so as to be able to reciprocate. In the case of manufacturing such a plunger 55, a high machining accuracy is required for the portion of the plunger 55 inserted into the compression chamber 52. On the other hand, in Figure 4In the hydraulic control unit 100 shown, as long as the portion of the plunger 55 inserted into the compression chamber 52 can reciprocate within the compression chamber 52, the outer diameter of this portion can also be made smaller than the inner diameter of the compression chamber 52. That is, Figure 4 the hydraulic control unit 100 shown and Figure 3 compared with the hydraulic control unit 100 shown, a high machining accuracy is not required for the portion of the plunger 55 inserted into the compression chamber 52. Thus, Figure 4 the hydraulic control unit 100 shown and Figure 3 compared with the hydraulic control unit 100 shown, the manufacture of the hydraulic control unit 100 becomes easier.

[0079] In addition, in Figure 4 the hydraulic control unit 100 shown, since the portion of the plunger 55 inserted into the compression chamber 52 can be formed to be thinner, when the brake fluid is compressed by the compression chamber 52, the load acting on the end portion 55a of the plunger 55 and the load on the motor 90 can be reduced.

[0080] In addition, the setting manner of the sealing member 81 on the outer peripheral surface 55c of the plunger 55 is not particularly limited. For example, it can also be configured such that the sealing member 81 is buried in the portion of the outer peripheral surface 55c of the plunger 55 that faces the inner peripheral surface 52b of the compression chamber 52. In this case, the sealing member 81 reciprocates within the compression chamber 52 together with the plunger 55 and slides relative to the inner peripheral surface 52b of the compression chamber 52. In addition, for example, the hydraulic control unit 100 may also include a holding member 82 for holding the sealing member 81.

[0081] For example, the holding member 82 is configured as Figure 4 shown. Specifically, a recess 83 is formed in the holding member 82. At this recess 83, the end portion 51a of the cylinder 51 on the side where the opening 52a of the compression chamber 52 is formed is inserted. Moreover, the sealing member 81 is clamped between the bottom 83a of the recess 83 and the end portion 51a of the cylinder 51. By holding the sealing member 81 by the holding member 82, it is easy to set the sealing member 81 at an appropriate position and maintain the state where the sealing member 81 is set at an appropriate position.

[0082] <Effects of the hydraulic control unit>

[0083] The effects of the hydraulic control unit 100 according to the present embodiment will be described.

[0084] The hydraulic control unit 100 according to this embodiment is a hydraulic control unit mounted on the braking system 10 of a vehicle. The hydraulic control unit 100 includes: a base body 101, in which an internal flow path 40 that communicates the wheel cylinder 24 with the master cylinder 21 is formed; a pump 50 that moves the brake fluid in the internal flow path 40; and a motor 90 that is a driving source of the pump 50. The motor 90 includes: an output shaft 91; and an eccentric portion 92 that is provided on the output shaft 91 and performs an eccentric rotational motion with respect to the rotation center of the output shaft 91. The pump 50 includes a cylinder 51, a plunger 55, and a spring 60. In the cylinder 51, a compression chamber 52 that compresses the brake fluid and a discharge flow path 53 that discharges the brake fluid compressed in the compression chamber 52 are formed. One end of the plunger 55, i.e., the end portion 55a, abuts against the eccentric portion 92 of the motor 90. The other end of the plunger 55, i.e., the end portion 55b, is inserted into the opening 52a of the compression chamber 52. Further, the other end of the plunger 55, i.e., the end portion 55b, reciprocates in the compression chamber 52. The spring 60 presses the plunger 55 toward the eccentric portion 92 of the motor 90. In the plunger 55, an inflow flow path 59 is formed through which the brake fluid flowing toward the pump 50 in the internal flow path 40 flows in and is guided to the compression chamber 52. Further, the plunger 55 is provided with an inflow side check valve 70 that is provided in the inflow flow path 59 and restricts the flow of the brake fluid from the compression chamber 52 toward the internal flow path 40. Further, the spring 60 is provided outside the inflow flow path 59 and the compression chamber 52.

[0085] Since the hydraulic control unit 100 configured as described above can determine the diameter of the spring 60 without being limited by the diameter of the compression chamber 52 as described above, it can be miniaturized compared with the conventional hydraulic control unit.

[0086] Preferably, the vehicle equipped with the hydraulic control unit 100 is a straddle-type vehicle 200. Compared with vehicles such as motorized four-wheel vehicles, the degree of freedom of the component layout of the straddle-type vehicle 200 is lower, and the degree of freedom of mounting the hydraulic control unit 100 is lower. Therefore, conventionally, for the hydraulic control unit mounted on the straddle-type vehicle 200, it has been desired to be more miniaturized than the hydraulic control unit mounted on vehicles such as motorized four-wheel vehicles. Therefore, it is preferable to mount the hydraulic control unit 100 that can be more miniaturized than the conventional hydraulic control unit on the straddle-type vehicle 200.

[0087] As described above, the hydraulic control unit 100 according to this embodiment has been described, but the hydraulic control unit related to the present invention is not limited to the description of this embodiment. The hydraulic control unit related to the present invention may also implement only a part of this embodiment.

[0088] Description of reference numerals

[0089] 1 Vehicle body; 2 Handlebar; 3 Front wheel; 3a Rotor; 4 Rear wheel; 4a Rotor; 10 Braking system; 11 Brake lever; 12 First hydraulic circuit; 13 Brake pedal; 14 Second hydraulic circuit; 15 Liquid pipe; 16 Liquid pipe; 21 Master cylinder; 22 Reservoir; 23 Brake caliper; 24 Wheel cylinder; 25 Filling valve; 26 Release valve; 27 Storage; 28 Switching valve; 29 Boost valve; 30 Master cylinder hydraulic sensor; 31 Wheel cylinder hydraulic sensor; 40 Internal flow path; 41 Main flow path; 41a Middle part of the main flow path; 42 Sub-flow path; 42a Middle part of the sub-flow path; 42b First sub-flow path; 42c Second sub-flow path; 43 Boost flow path; 50 Pump; 51 Cylinder; 51a End part; 52 Compression chamber; 52a Opening part; 52b Inner peripheral surface; 53 Discharge flow path; 54 Step part; 55 Plunger; 55a End part; 55b End part; 55c Outer peripheral surface; 56 First part; 57 Second part; 58 Third part; 59 Inflow flow path; 60 Spring; 61 Cover part; 62 Discharge flow path; 70 Inflow side check valve; 71 Valve seat; 72 Valve body; 73 Spring; 75 Outflow side check valve; 76 Valve seat; 77 Valve body; 78 Spring; 81 Sealing member; 82 Holding member; 83 Recess; 83a Bottom part; 85 Retainer; 86 Filter; 87 Sealing member; 90 Motor; 91 Output shaft; 92 Eccentric part; 100 Hydraulic control unit; 101 Substrate; 102 Recess; 103 Step part; 104 Plastic deformation part; 105 Control device; 200 Straddle-type vehicle; MP Master cylinder port; WP Wheel cylinder port.

Claims

1. A hydraulic control unit (100) is a hydraulic control unit (100) mounted on a braking system (10) of a vehicle, characterized in that: It includes: A base body (101) formed with an internal flow path (40) that connects a wheel cylinder (24) and a master cylinder (21); A pump (50) that moves the brake fluid in the internal flow path (40); and A motor (90) that is a driving source of the pump (50); The motor (90) includes: An output shaft (91); and An eccentric part (92) provided on the output shaft (91) that performs an eccentric rotational motion with respect to the rotation center of the output shaft (91); The pump (50) includes: A cylinder (51) formed with a compression chamber (52) that compresses the brake fluid and a discharge flow path (53) that discharges the brake fluid compressed in the compression chamber (52); And A plunger (55) having one end (55a) abutted against the eccentric part (92) and the other end (55b) inserted into an opening (52a) of the compression chamber (52), and the other end (55b) reciprocates within the compression chamber (52); And A spring (60) that pushes the plunger (55) toward the eccentric part (92); An inflow flow path (59) is formed in the plunger (55) for the brake fluid flowing in the internal flow path (40) toward the pump (50) to flow in and guide the brake fluid to the compression chamber (52); The plunger (55) is provided with an inflow side check valve (70) that is provided in the inflow flow path (59) and restricts the flow of the brake fluid from the compression chamber (52) toward the internal flow path (40); The spring (60) is provided outside the inflow flow path (59) and the compression chamber (52).

2. The hydraulic control unit (100) according to claim 1, characterized in that: It includes a sealing member (81) provided on the outer peripheral surface (55c) of the plunger (55) to suppress the outflow of the brake fluid between the outer peripheral surface (55c) of the plunger (55) and the inner peripheral surface (52b) of the compression chamber (52).

3. The hydraulic control unit (100) according to claim 2, characterized in that: It includes a holding member (82) that holds the sealing member (81).

4. The hydraulic control unit (100) according to claim 3, characterized in that: A recess (83) is formed in the holding member (82); One end (51a) of the cylinder (51) where the opening (52a) of the compression chamber (52) is formed is inserted into the recess (83); The sealing member (81) is clamped between the bottom (83a) of the recess (83) and the end (51a) of the cylinder (51).

5. The hydraulic control unit (100) according to any one of claims 1 to 4, characterized in that: The spring (60) is provided on the outer peripheral side of the plunger (55).

6. The hydraulic control unit (100) according to any one of claims 1 to 4, characterized in that: A retainer (85) for holding the aforementioned cylinder (51), the aforementioned plunger (55), and the aforementioned spring (60).

7. The hydraulic control unit (100) according to claim 6, characterized in that the aforementioned retainer (85) is provided with a filter (86) through which the brake fluid flowing into the aforementioned inflow passage (59) passes.

8. The hydraulic control unit (100) according to any one of claims 1 to 4, characterized in that the aforementioned pump (50) is provided with an outflow check valve (75), and the outflow check valve (75) is provided in the aforementioned discharge passage (53) to restrict the flow of the brake fluid from the aforementioned internal passage (40) toward the aforementioned compression chamber (52).

9. A vehicle, characterized in that it is provided with the hydraulic control unit (100) according to any one of claims 1 to 4.

10. The vehicle according to claim 9, characterized in that the aforementioned vehicle is a straddle-type vehicle (200).

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