Brake fluid pressure control device and straddle-type vehicle

Abstract

To provide a brake fluid pressure control device capable of reducing torque required for driving a pump.SOLUTION: A first pump 27 of the brake fluid pressure control device 10 includes: a plunger 27f that is pressed by the eccentric body 52 and reciprocates inside a cylinder 27a; a spring 27m that is provided inside the cylinder 27a and presses the plunger 27f toward the eccentric body 52; a seal member 27k that seals between the cylinder 27a and the plunger 27f. The plunger 27f includes a small diameter portion 27fa and a large diameter portion 27fb having an outer diameter larger than that of the small diameter portion 27fa. The seal member 27k is disposed on the outer periphery of the small diameter portion 27fa. The large diameter portion 27fb is disposed closer to the spring 27m than the seal member 27k. Inside the cylinder 27a, a first chamber A1 formed on the spring 27m side by the large diameter portion 27fb and the second chamber A2 formed on the eccentric body 52 side by the large diameter portion 27fb communicate with each other.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a brake fluid pressure control device that controls the hydraulic pressure of brake fluid in a brake system of a saddle-type vehicle, and a saddle-type vehicle equipped with the brake fluid pressure control device.

Background Art

[0002] Conventionally, some saddle-type vehicles (for example, motorcycles, etc.) are equipped with a brake fluid pressure control device that controls the hydraulic pressure of brake fluid in a brake system for braking wheels. As such a brake fluid pressure control device, for example, there is a configuration including a pump that reciprocates a plunger in a cylinder to compress the brake fluid, and a push-back body is disposed at an end of the plunger in the cylinder to reduce the volume of a compression chamber effective for compressing the brake fluid and improve the compression efficiency of the pump (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the pump of the brake fluid pressure control device as described in Patent Document 1, since the push-back body receives fluid resistance from the brake fluid when the plunger reciprocates, for example, when the push-back body is expanded in the radial direction of the plunger to increase its volume, there is a risk that the torque required to drive the pump increases.

[0005] The present invention has been made against the background of the above problems, and an object thereof is to provide a brake fluid pressure control device capable of reducing the torque required to drive a pump.

Means for Solving the Problems

[0006] The brake hydraulic pressure control device according to the present invention is a brake hydraulic pressure control device that controls the brake fluid of a brake system mounted on a saddle-type vehicle, and includes a base body in which a liquid passage of the brake fluid is formed, a pump that pumps the brake fluid in the liquid passage, and an electric motor that is erected on the base body and drives the pump. The electric motor includes an output shaft that is rotationally driven by a motor main body portion, and an eccentric body that is provided on the output shaft and rotates eccentrically with respect to the rotation center of the output shaft. The pump includes a plunger that is pressed by the eccentric body and reciprocates inside a cylinder, a spring that is provided inside the cylinder and presses the plunger toward the eccentric body, and a seal member that seals between the cylinder and the plunger. The plunger has a small-diameter portion and a large-diameter portion having an outer diameter larger than that of the small-diameter portion. The seal member is disposed on the outer periphery of the small-diameter portion, and the large-diameter portion is disposed on the spring side with respect to the seal member. Inside the cylinder, a first chamber formed on the spring side by the large-diameter portion and a second chamber formed on the eccentric body side by the large-diameter portion communicate with each other.

[0007] According to such a configuration, since the first chamber formed on the spring side by the large-diameter portion of the plunger and the second chamber formed on the eccentric body side communicate with each other inside the cylinder, in the compression process of the pump, when the plunger is pressed by the eccentric body and moves toward the spring side, the communication portion between the first chamber and the second chamber allows the brake fluid in the cylinder to flow from the spring side to the seal member side, and the fluid resistance received by the plunger from the brake fluid can be reduced, and the torque required for the electric motor to drive the pump can be reduced.

[0008] The saddle-type vehicle according to the present invention has a configuration including the above brake hydraulic pressure control device. According to such a configuration, in the saddle-type vehicle, the same effect as that of the above brake hydraulic pressure control device can be achieved.

[0009] Note that the present invention may have only the invention-specific matters described in the claims, or may have configurations other than the invention-specific matters together with the invention-specific matters.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0011] Examples of embodiments of the brake hydraulic control device according to the present invention and a saddle-riding type vehicle equipped with the brake hydraulic control device will be described with reference to the drawings. In the embodiments, an example in which a brake hydraulic control device is mounted on a motorcycle as a saddle-riding type vehicle will be described. However, the brake hydraulic control device according to the present invention may be mounted on other saddle-riding type vehicles other than motorcycles. The saddle-riding type vehicle generally means a vehicle on which a rider rides straddling. The saddle-riding type vehicle includes, for example, motorcycles, buggies, bicycles, etc. Motorcycles include motorcycles, three-wheelers, etc. having an engine or an electric motor as a propulsion source, and include, for example, motorcycles, scooters, electric scooters, etc. Also, a bicycle generally means a vehicle that can be propelled by the pedaling force of a rider applied to the pedals. Bicycles include ordinary bicycles, electric assist bicycles, electric bicycles, etc.

[0012] In addition, in the embodiment, an example of a configuration in which the brake hydraulic control device includes two hydraulic circuits and two pumps will be described. However, the brake hydraulic control device may have a configuration including only one hydraulic circuit, or a configuration including three or more hydraulic circuits, and may have a configuration including only one pump, or a configuration including three or more pumps. Further, in the present embodiment, a case where the brake hydraulic control device is applied to a brake system that brakes the front and rear wheels of a motorcycle will be described. However, the brake hydraulic control device may be applied to a brake system that brakes only one of the front or rear wheels.

[0013] In addition, the configuration, operation, etc. of the brake hydraulic control device described in the embodiment are merely examples, and the brake hydraulic control device according to the present invention is not limited to such a configuration, operation, etc. Further, in each figure, the same or similar members or parts may be denoted by the same reference numerals or the assignment of reference numerals may be omitted. Also, the detailed structure may be appropriately simplified or omitted in the illustration.

[0014] Hereinafter, the brake hydraulic control device according to the present embodiment will be described with reference to FIGS. 1 to 7. FIG. 1 is a diagram for explaining a motorcycle on which the brake hydraulic control device of the present embodiment is mounted. FIG. 2 is a diagram for explaining a brake system controlled by the brake hydraulic control device. FIGS. 3 and 4 are diagrams for explaining the brake hydraulic control device. FIG. 5 is a diagram for explaining a pump included in the brake hydraulic control device. FIG. 6 is a diagram for explaining the shape of a plunger of the pump. FIG. 7 is a diagram for explaining a modified example of the shape of the plunger of the pump.

[0015] <Regarding a saddle-type vehicle and a brake system> A motorcycle 1 as a saddle-type vehicle on which the brake hydraulic control device 10 is mounted and a brake system 100 of the motorcycle 1 controlled by the brake hydraulic control device 10 will be described with reference to FIGS. 1 and 2.

[0016] As shown in FIG. 1, the motorcycle 1 includes a body 2, a handlebar 3 rotatably provided with respect to the body 2, a front wheel 4 rotatably provided with respect to the body 2 together with the handlebar 3, a rear wheel 5 rotatably provided with respect to the body 2 and driven by a drive source (not shown, for example, an engine, an electric motor, etc.), a front wheel disc rotor 4a that rotates together with the front wheel 4, a rear wheel disc rotor 5a that rotates together with the rear wheel 5, a brake system 100 that brakes the front wheel 4 and the rear wheel 5, and a brake hydraulic control device 10 that controls the brake system 100.

[0017] As shown in FIG. 2, the brake system 100 includes a first operator 6 and a second operator 7 operated by the rider, a front wheel braking mechanism 20 that brakes the front wheel 4, a rear wheel braking mechanism 30 that brakes the rear wheel 5, a front wheel friction member 25 that generates a frictional force on the front wheel disc rotor 4a, a rear wheel friction member 35 that generates a frictional force on the rear wheel disc rotor 5a, and a brake hydraulic control device 10.

[0018] In the present embodiment, as the first operator 6, for example, a brake lever provided on the handlebar 3 and operated by the rider's hand is applied. Further, as the second operator 7, for example, a brake pedal provided at the lower part of the body 2 and operated by the rider's foot is applied.

[0019] As shown in FIG. 2, the front-wheel braking mechanism 20 includes a first master cylinder 21 to which the movement of the first operator 6 is transmitted, a first reservoir 22 for brake fluid attached to the first master cylinder 21, a first wheel cylinder 24 connected to the first master cylinder 21 via a first liquid passage 23 filled with brake fluid, a front-wheel friction member 25 pressed against the front-wheel disk rotor 4a by the hydraulic pressure of the brake fluid in the first wheel cylinder 24, and a brake fluid pressure control device 10 described later. The rear-wheel braking mechanism 30 includes a second master cylinder 31 to which the movement of the second operator 7 is transmitted, a second reservoir 32 for brake fluid attached to the second master cylinder 31, a second wheel cylinder 34 connected to the second master cylinder 31 via a second liquid passage 33 filled with brake fluid, a rear-wheel friction member 35 pressed against the rear-wheel disk rotor 5a by the hydraulic pressure of the brake fluid in the second wheel cylinder 34, and the brake fluid pressure control device 10. As will be described later, a part 23b, 23c, 33b, 33c of the first liquid passage 23 and the second liquid passage 33 is formed as an internal liquid passage in the base body 60 of the brake fluid pressure control device 10. The brake fluid pressure control device 10 is disposed, for example, on the body 2 of the motorcycle 1 (see FIG. 1).

[0020] The front-wheel braking mechanism 20 is configured to press the front-wheel friction member 25 against the front-wheel disk rotor 4a according to the operation amount of the first operator 6 to generate a frictional force, and generate a braking force corresponding to the operation amount of the first operator 6 on the front wheel 4. The rear-wheel braking mechanism 30 is configured to press the rear-wheel friction member 35 against the rear-wheel disk rotor 5a according to the operation amount of the second operator 7 to generate a frictional force, and generate a braking force corresponding to the operation amount of the second operator 7 on the rear wheel 5.

[0021] In the present embodiment, the braking system 100 includes a brake lever as the first operator 6 and a brake pedal as the second operator 7. However, the braking system is not limited to this example. For example, it may include a brake pedal as the first operator and a brake lever as the second operator. Alternatively, for example, as the first operator and the second operator, it may be configured to include one or more brake levers, or for example, as the first operator and the second operator, it may be configured to include one or more brake pedals.

[0022] In the present embodiment, the front-wheel braking mechanism 20 and the rear-wheel braking mechanism 30 are configured to press a friction member against a disk rotor to generate frictional force. However, the front-wheel braking mechanism and the rear-wheel braking mechanism may, for example, be configured to press a friction member of a brake shoe against a brake drum that rotates with the wheel to generate frictional force. Alternatively, for example, it may be configured such that an actuator that is electrically communicatively connected to the operator and operates in response to the operation of the operator presses a friction member against a disk rotor or a brake drum to generate frictional force. Further, the braking system may be configured to include only one of the front-wheel braking mechanism or the rear-wheel braking mechanism.

[0023] <Regarding the Brake Hydraulic Control Device> The brake hydraulic control device 10 will be described with reference to FIGS. 2 to 5. The brake hydraulic control device 10 includes first to fourth solenoid valves 40a to 40d, a first pump 27, a second pump 37, and a motor 50 as a hydraulic control mechanism for controlling the hydraulic pressure of the brake fluid in the braking system 100. The first to fourth solenoid valves 40a to 40d and the motor 50 as the hydraulic control mechanism are controlled to be in an energized state and a non-energized state by a control board 70, and by controlling their operations, the hydraulic pressure of the brake fluid in the braking system 100 is controlled. The brake hydraulic control device 10 can control the anti-lock operation for the front wheel 4 and the rear wheel 5 of the motorcycle 1 as will be described later by controlling the operation of the hydraulic control mechanism by the control board 70.

[0024] As shown in FIG. 2, the brake hydraulic control device 10 includes a first main hydraulic passage 23b that connects a first master cylinder 21 and a first wheel cylinder 24, a first electromagnetic valve 40a disposed in the first main hydraulic passage 23b, and a first sub-hydraulic passage 23c that branches from a region on the first wheel cylinder 24 side of the first electromagnetic valve 40a in the first main hydraulic passage 23b and is connected to a region on the first master cylinder 21 side of the first electromagnetic valve 40a in the first main hydraulic passage 23b. A second electromagnetic valve 40b disposed in the first sub-hydraulic passage 23c, and a first accumulator 26 disposed in a region on the first master cylinder 21 side of the second electromagnetic valve 40b in the first sub-hydraulic passage 23c for temporarily storing brake fluid, and a first pump 27 disposed in a region on the first master cylinder 21 side of the first accumulator 26 in the first sub-hydraulic passage 23c. The first main hydraulic passage 23b and the first sub-hydraulic passage 23c constitute a part of the first hydraulic passage 23 described above.

[0025] Further, the brake hydraulic control device 10 includes a second main hydraulic passage 33b that connects a second master cylinder 31 and a second wheel cylinder 34, a third electromagnetic valve 40c disposed in the second main hydraulic passage 33b, and a second sub-hydraulic passage 33c that branches from a region on the second wheel cylinder 34 side of the third electromagnetic valve 40c in the second main hydraulic passage 33b and is connected to a region on the second master cylinder 31 side of the third electromagnetic valve 40c in the second main hydraulic passage 33b. A fourth electromagnetic valve 40d disposed in the second sub-hydraulic passage 33c, and a second accumulator 36 disposed in a region on the second master cylinder 31 side of the fourth electromagnetic valve 40d in the second sub-hydraulic passage 33c for temporarily storing brake fluid, and a second pump 37 disposed in a region on the second master cylinder 31 side of the second accumulator 36 in the second sub-hydraulic passage 33c. The second main hydraulic passage 33b and the second sub-hydraulic passage 33c constitute a part of the second hydraulic passage 33 described above.

[0026] The first to fourth electromagnetic valves 40a to 40d are controlled such that the first to fourth coils 42a to 42d (see FIG. 4) corresponding to the respective electromagnetic valves are controlled to be in an energized state or a non-energized state by a control board 70, and the operations of the first to fourth valve bodies 41a to 41d corresponding to the respective coils are controlled to open or close the respective hydraulic passages.

[0027] The first pump 27 pumps up the brake fluid stored in the first accumulator 26 and outputs it toward the first main liquid passage 23b. The second pump 37 pumps up the brake fluid stored in the second accumulator 36 and outputs it toward the second main liquid passage 33b. The first pump 27 and the second pump 37 are driven by a common electric motor 50. The operation (stop state and rotation state) of the motor 50 is controlled by controlling the energized state and non-energized state thereof by the control board 70. Hereinafter, the first to fourth solenoid valves 40a to 40d, the first pump 27, the second pump 37, and the motor 50 may be referred to as a hydraulic control mechanism for controlling the hydraulic pressure of the brake fluid.

[0028] The control board 70 of the brake hydraulic pressure control device 10 includes a controller 71. By executing a predetermined program or the like by the controller 71, the hydraulic control mechanisms 40a to 40d, 27, 37, 50, etc. are controlled. The controller 71 may be one, or may be configured to be divided into a plurality. Part or all of the controller 71 may be configured by, for example, a microcomputer, a microprocessor unit, etc., or may be configured to be updatable by software such as firmware, or may be a program module executed according to a command from a CPU or the like. Further, the controller 71 may be provided on one control board 70, or may be provided on a plurality of control boards.

[0029] Further, the controller 71 includes an acquisition unit 71a that acquires detection results of various sensors (for example, a hydraulic pressure sensor that detects the hydraulic pressure of the brake fluid, a wheel speed sensor that detects the rotational speed of the wheel, an acceleration sensor that detects the acceleration of the roll, pitch, and yaw directions of the motorcycle 1, etc.), and an execution unit 71b that executes control of the operation of the brake system 100 (for example, the normal operation, the pressure reduction operation, etc. described later) based on various information and the like acquired by the acquisition unit 71a (see FIG. 4).

[0030] During normal operation, for example, the control board 70 controls the first solenoid valve 40a and the third solenoid valve 40c to be in the open state, and controls the second solenoid valve 40b and the fourth solenoid valve 40d to be in the closed state. In this state, when the first operator 6 is operated by the rider, the plunger 27f of the first master cylinder 21 is pushed in according to the operation amount of the first operator 6, the hydraulic pressure of the brake fluid in the first master cylinder 21 rises, and the increased hydraulic pressure is supplied to the first wheel cylinder 24 through the first main hydraulic line 23b, causing the hydraulic pressure of the brake fluid in the first wheel cylinder 24 to rise. Then, the front wheel friction member 25 is pressed against the front wheel disc rotor 4a according to the hydraulic pressure of the first wheel cylinder 24, generating a frictional force and braking the front wheel 4. Also, when the second operator 7 is operated by the rider, the plunger (not shown) of the second master cylinder 31 is pushed in according to the operation amount of the second operator 7, the hydraulic pressure of the brake fluid in the second master cylinder 31 rises, and the increased hydraulic pressure is supplied to the second wheel cylinder 34 through the second main hydraulic line 33b, causing the hydraulic pressure of the brake fluid in the second wheel cylinder 34 to rise. Then, the rear wheel friction member 35 is pressed against the rear wheel disc rotor 5a according to the hydraulic pressure of the second wheel cylinder 34, generating a frictional force and braking the rear wheel 5.

[0031] Also, for example, as control of the anti-lock brake operation of the front wheels, when it is determined based on the detection results of various sensors or the like that the rotation of the front wheels 4 is locked or there is a possibility of locking, the control board 70 executes a pressure reduction operation to reduce the hydraulic pressure of the brake fluid in the first wheel cylinder 24. When performing the pressure reduction operation of the first wheel cylinder 24, the controller 71 controls the first solenoid valve 40a to the closed state, controls the second solenoid valve 40b to the open state, and controls to drive the motor 50. As a result, the brake fluid is discharged from the first wheel cylinder 24 to the first accumulator 26, the hydraulic pressure of the brake fluid in the first wheel cylinder 24 is reduced, and the braking force of the front wheels 4 is decreased, thereby releasing the lock of the rotation of the front wheels 4 or avoiding the occurrence of locking. Also, the brake fluid discharged to the first accumulator 26 is pumped up by the first pump 27 driven by the motor 50 and returned to the region on the first master cylinder 21 side of the first solenoid valve 40a in the first main hydraulic passage 23b.

[0032] Also, for example, as control of the anti-lock brake operation of the rear wheels, when it is determined based on the detection results of various sensors or the like that the rotation of the rear wheels 5 is locked or there is a possibility of locking, the control board 70 executes a pressure reduction operation to reduce the hydraulic pressure of the brake fluid in the second wheel cylinder 34. When performing the pressure reduction operation of the second wheel cylinder 34, the controller 71 controls the third solenoid valve 40c to the closed state, controls the fourth solenoid valve 40d to the open state, and controls to drive the motor 50. As a result, the brake fluid is discharged from the second wheel cylinder 34 to the second accumulator 36, the hydraulic pressure of the brake fluid in the second wheel cylinder 34 is reduced, and the braking force of the rear wheels 5 is decreased, thereby releasing the lock of the rotation of the rear wheels 5 or avoiding the occurrence of locking. Also, the brake fluid discharged to the second accumulator 36 is pumped up by the second pump 37 driven by the motor 50 and returned to the region on the second master cylinder 31 side of the fourth solenoid valve 40d in the second main hydraulic passage 33b.

[0033] Note that the brake hydraulic pressure control device 10 may be configured to include a hydraulic pressure sensor that detects the hydraulic pressure of the brake fluid input from the first master cylinder 21 and the second master cylinder 31, and / or a hydraulic pressure sensor that detects the hydraulic pressure of the brake fluid output to the first wheel cylinder 24 and the second wheel cylinder 34. Such a hydraulic pressure sensor may be arranged, for example, in the main flow path or the sub-flow path of the brake hydraulic pressure control device, or in a pipe or the like for the brake fluid connected to the main flow path, or in the master cylinder or the wheel cylinder.

[0034] Also, the brake hydraulic pressure control device 10 may be configured to include, for example, a liquid passage that can suck the brake fluid from the first reservoir 22 by the first pump 27 and output the brake fluid to the first wheel cylinder 24. In such a configuration, the control board 70, for example, based on the detection results of various sensors, etc., when it is determined that the braking force of the front wheels 4 is insufficient or there is a possibility of insufficiency, may be configured to perform a front-wheel pressure increasing operation to increase the hydraulic pressure of the brake fluid in the first wheel cylinder 24 with the brake fluid output by the first pump 27. In such a configuration, the braking force of the front wheels 4 can be increased by the pressure increasing operation to compensate for the insufficiency of the braking force.

[0035] Also, the brake hydraulic pressure control device 10 may be configured to include, for example, a liquid passage that can suck the brake fluid from the second reservoir 32 by the second pump 37 and output the brake fluid to the second wheel cylinder 34. In such a configuration, the control board 70, for example, based on the detection results of various sensors, etc., when it is determined that the braking force of the rear wheels 5 is insufficient or there is a possibility of insufficiency, may be configured to perform a rear-wheel pressure increasing operation to increase the hydraulic pressure of the brake fluid in the second wheel cylinder 34 with the brake fluid output by the second pump 37. In such a configuration, the braking force of the rear wheels 5 can be increased by the rear-wheel pressure increasing operation to compensate for the insufficiency of the braking force.

[0036] As shown in FIGS. 3 and 4, the brake hydraulic control device 10 includes a base body 60 in which a part of the above-described brake fluid passage is formed as an internal passage, first to fourth solenoid valves 40a to 40d, a first pump 27 and a second pump 37, a first accumulator 26 and a second accumulator 36, a motor 50, a control board 70, and a housing 80 that houses the control board 70 and the like, which are unitized.

[0037] The base body 60 is formed of, for example, a rectangular parallelepiped block material made of aluminum. Inside the base body 60, the above-described first main passage 23b, first sub-passage 23c, second main passage 33a, and second sub-passage 33c are formed.

[0038] At approximately the center of the first surface 60A that constitutes the appearance of the base body 60, a motor hole 61H for housing the motor 50 is formed. Around the motor hole 61H on the first surface 60A of the base body 60, four valve holes 62H for housing the first to fourth solenoid valves 40a to 40d are formed. Further, on the first surface 60A of the base body 60, a bolt hole 63H for engaging a bolt 18 that fixes the housing 80 to the base body 60 is formed. On the second surface 60B that constitutes the appearance following the first surface 60A of the base body 60 and the third surface 60C facing the second surface 60B, pump holes 64H for housing the plungers (not shown) of the first pump 27 and the second pump 37 are formed, respectively. On the fourth surface 60D that constitutes the appearance following the first to third surfaces 60A to 60C of the base body 60, accumulator holes 65H for housing the first accumulator 26 and the second accumulator 36 are formed. Note that each surface that constitutes the appearance of the base body 60 may include a stepped portion or a curved surface portion.

[0039] On the fifth surface 60E that constitutes the appearance facing the fourth surface 60D of the base body 60, there are formed a first master cylinder port P1 to which a brake fluid pipe 23a that forms a part of the first liquid passage 23 and connects the first master cylinder 21 and the first main liquid passage 23b is connected, a second master cylinder port P2 to which a brake fluid pipe 33d that forms a part of the second liquid passage 33 and connects the second master cylinder 31 and the second main liquid passage 33b is connected, a first wheel cylinder port P3 to which a brake fluid pipe 23e that forms a part of the first liquid passage 23 and connects the first wheel cylinder 24 and the first main liquid passage 23b is connected, and a second wheel cylinder port P4 to which a brake fluid pipe 33e that forms a part of the second liquid passage 33 and connects the second wheel cylinder 34 and the second main liquid passage 33b is connected.

[0040] One end side of the output shaft 51 rotated by the motor main body of the motor 50 is inserted into the motor hole 61H and attached to the base body 60. An eccentric body 52 that rotates together with the output shaft 51 is attached to one end side of the output shaft 51. Further, the motor 50 includes an electrical terminal 53 that is electrically connected to the control board 70 at an end portion on the side opposite to the side where the output shaft 51 is provided. In the present embodiment, the motor 50 is configured to be attached to the base body 60, but the motor may be configured to be attached to a housing, for example.

[0041] Inside each pump hole 64H, as will be described later, the plungers of the first pump 27 and the second pump 37 are respectively arranged so as to be pressed against the outer peripheral surface of the eccentric body 52. When the eccentric body 52 rotates, the plungers of the first pump 27 and the second pump 37 reciprocate in the axial direction of the pump hole 64H, so that brake fluid is conveyed from the suction sides to the discharge sides of the first pump 27 and the second pump 37.

[0042] The first to fourth electromagnetic valves 40a to 40d are each composed of a valve body and a coil. The first to fourth valve bodies 41a to 41d of the first to fourth electromagnetic valves 40a to 40d are inserted into the valve holes 62H, and the first to fourth coils 42a to 42d of the first to fourth electromagnetic valves 40a to 40d are erected on the first surface 60A of the base body 60, whereby the first to fourth electromagnetic valves 40a to 40d are assembled to the base body 60.

[0043] The first accumulator 26 and the second accumulator 36 are respectively housed and assembled in the accumulator holes 65H.

[0044] The control board 70 includes a board 72 as described later, and a controller 71, electrical wirings constituting an electronic circuit, and various electronic components (for example, integrated circuit chips 73, etc.) are arranged on the board 72. The electronic circuit of the control board 70 is electrically connected to the electrical terminal 53 of the motor 50, the electrical terminals 43a to 43d of the first to fourth coils 42a to 42d, the output terminals of various sensors (not shown), and a connector 75 connected to an external device (not shown) provided outside the brake hydraulic control device 10.

[0045] The housing 80 is made of, for example, resin and is formed in a substantially rectangular parallelepiped shape. The housing 80 includes a first housing 81 that houses the first to fourth electromagnetic valves 40a to 40d and the motor 50, and a second housing 87 that houses the control board 70. Note that each surface constituting the appearance of the housing 80 may be formed in a shape including a stepped portion, a curved surface portion, etc.

[0046] The first housing 81 is a member attached to the base body 60, and a silicon-based sealing material (not shown) is disposed between the first housing 81 and the base body 60, for example. The first housing 81 includes an enclosing portion 81a that encloses the first to fourth electromagnetic valves 40a to 40d and the motor 50 in a state of being attached to the base body 60, and a connector portion 81b formed on the side of the enclosing portion 81a and housing the above-described connector 75.

[0047] The surrounding portion 81a includes a first surface 82A facing the base body 60 and a second surface 82B facing the control board 70 in a state where the first housing 81 is attached to the base body 60. A first opening 84 is formed in a region facing the control board 70 on the second surface 82B side of the surrounding portion 81a. The control board 70 is housed in the surrounding portion 81a through the first opening 84. Further, a second opening 85 facing the first surface 60A of the base body 60 is formed on the first surface 82A side of the surrounding portion 81a. The first to fourth coils 42a to 42d and the motor 50 are housed in the surrounding portion 81a through the second opening 85.

[0048] A through hole 83H is formed in the surrounding portion 81a, through which the above-described bolt 18 is inserted from the first surface 82A side and penetrates to the second surface 82B side. By inserting the bolt 18 into the through hole 83H and engaging it with the bolt hole 63H of the base body 60, the first housing 81 is sandwiched and fixed between the head of the bolt 18 and the base body 60. Further, insertion holes (not shown) are formed in the surrounding portion 81a, through which the electrical terminals 53 of the motor 50 and the electrical terminals 43a to 43d of the first to fourth coils 42a to 42d are inserted from the first surface 82A side and penetrate to the second surface 82B side. Note that the number of bolts 18 for fixing the first housing 81 to the base body 60 may be one or a plurality, and the bolt holes 63H of the base body 60 and the through holes 83H of the first housing 81 may be formed corresponding to the number of the bolts. Further, the base body 60 and the housing 80 may also be fixed by an adhesive.

[0049] The second housing 87 is formed as a separate member from the first housing 81 and, in a state of being attached to the first housing 81, covers the control board 70 and closes the first opening 84 of the first housing 81. A silicon-based sealing material mainly composed of silicon is disposed between the first housing 81 and the second housing 87.

[0050] For example, with a silicon-based sealing material 95 applied to a range facing the edge of the first opening 84 of the first housing 81, the second housing 87 is moved in the mounting direction D and attached to the first housing 81. As a result, the first housing 81 and the second housing 87 are adhered to each other, and the space between the first housing 81 and the second housing 87 is sealed, suppressing the intrusion of moisture or the like into the housing 80 from between the first housing 81 and the second housing 87. That is, the silicon-based sealing material 95 also functions as an adhesive.

[0051] The first housing 81 includes a convex portion 86 provided to protrude from the outer surface, and the second housing 87 includes an engaging portion 88 that engages with the convex portion 86 of the first housing 81 in a mounted state where the second housing 87 is attached to the first housing 81. When the second housing 87 is moved in the mounting direction D (see FIG. 4) and attached to the first housing 81, the convex portion 86 is inserted into the opening formed in the engaging portion 88, and the engaging portion 88 engages with the convex portion 86, so that the second housing 87 is fixed to the first housing 81.

[0052] <Regarding the first pump and the second pump> The first pump 27 and the second pump 37 assembled to the base 60 and driven by the motor 50 will be described with reference to FIGS. 5 and 6. FIG. 5 is a cross-sectional view showing the periphery of the first pump 27 assembled to the base 60, and is a cross-sectional view in a plane perpendicular to the rotation axis of the output shaft 51 of the motor 50. FIG. 6 is a perspective view of the plunger 27f of the first pump 27. Note that since the second pump 37 has the same configuration as the first pump 27, the description thereof will be omitted. The first pump 27 and the second pump 37 may be simply collectively referred to as a pump.

[0053] As described above, the motor 50 includes an output shaft 51 and an eccentric body 52 (see FIG. 4). The output shaft 51 is rotationally driven by a rotor and a stator (not shown) of the motor 50. The eccentric body 52 is provided on one end side of the output shaft 51 and performs an eccentric rotational motion with respect to the rotation center of the output shaft 51. Further, a bearing portion 52a that rotates in the rotation direction of the eccentric body 52 is provided on the outer peripheral portion of the eccentric body 52, and the outer peripheral surface of the bearing portion 52a is configured to press the plunger 27f of the first pump 27 to cause reciprocating motion (see FIG. 5). Further, the plunger of the second pump 37 is arranged on the axis of the reciprocating motion of the plunger 27f of the first pump 27 so as to face the plunger 27f of the first pump 27 with the eccentric body 52 interposed therebetween (not shown).

[0054] As shown in FIG. 5, the first pump 27 includes a cylinder 27a disposed in a pump hole 64H drilled in a base body 60, a plunger 27f that reciprocates inside the cylinder 27a, a seal member 27k that seals between the cylinder 27a and the plunger 27f, and a spring 27m that presses the plunger 27f toward the eccentric body 52.

[0055] The cylinder 27a is formed with a compression chamber 27b in which the plunger 27f reciprocates to compress the brake fluid, an inlet 27c through which the brake fluid flows into the compression chamber 27b, and an outlet 27d through which the brake fluid compressed in the compression chamber 27b flows out. The inlet 27c is connected to the first accumulator 26 side of the first sub-fluid passage 23c via a first check valve (not shown) provided in the base body 60. A second check valve 27e is provided at the outlet 27d, and the outlet 27d is connected to the first main fluid passage 23b side of the first sub-fluid passage 23c via the second check valve 27e. Further, the cylinder 27a is press-fitted into the pump hole 64H to seal the pump hole 64H.

[0056] One end of the plunger 27f abuts against the eccentric body 52 and is pressed by the eccentric body 52. The other end is biased toward the eccentric body 52 by the spring 27m. As the rotational motion of the eccentric body 52 is converted into linear motion, the other end reciprocates inside the compression chamber 27b to compress the brake fluid. A seal member 27k (e.g., an O-ring etc.) for sealing between the outer peripheral surface of the plunger 27f and the inner peripheral surface of the pump hole 64H is arranged, and leakage of the brake fluid from the compression chamber 27b side to the eccentric body 52 side of the motor 50 inside the pump hole 64H is suppressed.

[0057] As shown in FIGS. 5 and 6, the plunger 27f has a small-diameter portion 27fa and a large-diameter portion 27fb having an outer diameter larger than that of the small-diameter portion 27fa. The seal member 27k is arranged on the outer periphery of the small-diameter portion 27fa, and the large-diameter portion 27fb is arranged on the spring 27m side with respect to the seal member 27k. On the first surface of the large-diameter portion 27fb facing the spring 27m, at the edge outside the outer diameter of the small-diameter portion 27fa, it receives the spring 27m and is pressed toward the eccentric body 52 side. Further, a groove portion 27fc extending from the first surface side facing the spring 27m to the second surface side facing the eccentric body 52 is provided on the outer peripheral surface of the large-diameter portion 27fb. In a state where the plunger 27f is arranged inside the cylinder 27a, the large-diameter portion 27fb forms a first chamber A1 on the spring 27m side with respect to the large-diameter portion 27fb, and a second chamber A2 is formed on the eccentric body 52 side by the large-diameter portion 27fb. Also, in a state where the plunger 27f is arranged inside the cylinder 27a, the first chamber A1 and the second chamber A2 communicate with each other through the groove portion 27fc of the large-diameter portion 27fb.

[0058] Since the groove portion 27fc is formed on the outer peripheral surface of the large-diameter portion 27fb, a first chamber A1 formed on the spring 27m side by the large-diameter portion 27fb of the plunger 27f and a second chamber A2 formed on the eccentric body 52 side by the large-diameter portion 27fb communicate with each other inside the cylinder 27a. Therefore, in the compression process of the first pump 27, when the plunger 27f is pressed by the eccentric body 52 and moves toward the spring 27m side, the brake fluid in the cylinder 27a is circulated from the spring 27m side to the seal member 27k side through the communication portion between the first chamber A1 and the second chamber A2, and the fluid resistance received by the plunger 27f from the brake fluid can be reduced, and the torque required for the motor 50 to drive the first pump 27 can be reduced.

[0059] In addition, since the large-diameter portion 27fb is biased by receiving the spring 27m, it is possible to adopt a configuration in which the plunger 27f is biased by the spring 27m having an outer diameter larger than the outer diameter of the small-diameter portion 27fa. For example, even when the outer diameter of the small-diameter portion 27fa is reduced to reduce the pump flow rate, the plunger 27f can receive the end portion of the spring 27m having a diameter larger than the outer diameter of the small-diameter portion 27fa, and the degree of freedom in the pump design can be improved.

[0060] Also, as shown in FIGS. 5 and 6, an occlusion portion 27fe that occludes at least a part of the inlet 27c during the reciprocating movement of the plunger 27f is formed on the outer peripheral surface of the large-diameter portion 27fb of the plunger 27f. The occlusion portion 27fe is arranged at a position where at least a part of the occlusion portion 27fe faces the inlet 27c during the reciprocating movement of the plunger 27f.

[0061] Since the occlusion portion 27fe is formed on the large-diameter portion 27fb of the plunger 27f, by occluding at least a part of the inlet 27c in the compression process of the first pump 27, the volume of the compression chamber effective in the compression process can be reduced, and the compression efficiency of the first pump 27 can be improved.

[0062] In addition, in the present embodiment, the plunger 27f of the first pump 27 has a small-diameter portion 27fa and a large-diameter portion 27fb having an outer diameter larger than that of the small-diameter portion 27fa, and is provided with a groove portion 27fc extending on the outer peripheral surface of the large-diameter portion 27fb to communicate the first chamber A1 and the second chamber A2. However, the communication means for communicating the first chamber A1 and the second chamber A2 formed by the large-diameter portion 27fb by arranging the plunger 27f inside the cylinder 27a may be other than the groove portion 27fc formed in the large-diameter portion 27fb. For example, as shown in FIG. 7, the plunger 27f may be configured to be perforated in the large-diameter portion 27fb and include a communication hole 27fd for communicating the first chamber A1 and the second chamber A2. Even with such a configuration, in the compression process of the first pump 27, when the plunger 27f is pressed by the eccentric body 52 and moves toward the spring 27m side, the brake fluid in the cylinder 27a can be circulated from the spring 27m side to the seal member 27k side through the communication portion between the first chamber A1 and the second chamber A2.

[0063] <Regarding the effects> Conventionally, some saddle-riding type vehicles (for example, motorcycles, etc.) are provided with a brake fluid pressure control device that controls the hydraulic pressure of the brake fluid in the brake system for braking the wheels. As such a brake fluid pressure control device, for example, there is a configuration including a pump that reciprocates a plunger in a cylinder to compress the brake fluid, and a push-back body is arranged at the end of the plunger in the cylinder to reduce the actual volume of the cylinder and improve the compression efficiency of the pump. In the pump of such a brake fluid pressure control device, since the push-back body receives fluid resistance from the brake fluid when the plunger reciprocates, if the push-back body is expanded in the radial direction of the plunger to increase its volume, there is a risk that the torque required to drive the pump will increase.

[0064] In contrast, the brake hydraulic control device 10 of the present embodiment is a brake hydraulic control device that controls the brake fluid of a brake system 100 mounted on a motorcycle 1 as a straddle-type vehicle. The brake hydraulic control device includes a base body 60 in which a first fluid passage 23 for the brake fluid is formed, a first pump 27 that pumps the brake fluid in the first fluid passage 23, and a motor 50 that is erected on the base body 60 and drives the first pump 27. The motor 50 includes an output shaft 51 that is rotationally driven by a motor main body portion, and an eccentric body 52 that is provided on the output shaft 51 and rotates eccentrically with respect to the rotation center of the output shaft 51. The first pump 27 includes a plunger 27f that is pressed by the eccentric body 52 and reciprocates inside a cylinder 27a, a spring 27m that is provided inside the cylinder 27a and presses the plunger 27f toward the eccentric body 52, and a seal member 27k that seals between the cylinder 27a and the plunger 27f. The plunger 27f has a small-diameter portion 27fa and a large-diameter portion 27fb having an outer diameter larger than that of the small-diameter portion 27fa. The seal member 27k is disposed on the outer periphery of the small-diameter portion 27fa, and the large-diameter portion 27fb is disposed on the spring 27m side with respect to the seal member 27k. Inside the cylinder 27a, a first chamber A1 formed on the spring 27m side by the large-diameter portion 27fb of the plunger 27f and a second chamber A2 formed on the eccentric body 52 side by the large-diameter portion 27fb communicate with each other.

[0065] According to such a configuration, since the first chamber A1 formed on the spring 27m side by the large-diameter portion 27fb of the plunger 27f and the second chamber A2 formed on the eccentric body 52 side communicate with each other inside the cylinder 27a, in the compression process of the first pump 27, when the plunger 27f is pressed by the eccentric body 52 and moves toward the spring 27m side, the communication portion between the first chamber A1 and the second chamber A2 allows the brake fluid in the cylinder 27a to flow from the spring 27m side to the seal member 27k side, and the fluid resistance that the plunger 27f receives from the brake fluid can be reduced, and the torque required for the motor 50 to drive the first pump 27 can be reduced.

[0066] The brake hydraulic control device 10 of the present embodiment includes a first pump 27 that pumps the brake fluid in the first liquid passage 23. The first pump 27 is pressed by an eccentric body 52 and includes a plunger 27f that reciprocates inside a cylinder 27a. The plunger 27f has a small-diameter portion 27fa and a large-diameter portion 27fb having an outer diameter larger than that of the small-diameter portion 27fa. Further, the large-diameter portion 27fb is provided with a groove portion 27fc that extends on the outer peripheral surface of the large-diameter portion 27fb and communicates the first chamber A1 and the second chamber A2.

[0067] According to such a configuration, since the plunger 27f is provided with the groove portion 27fc in the large-diameter portion 27fb, in the compression process of the first pump 27, when the plunger 27f is pressed by the eccentric body 52 and moves toward the spring 27m side, the brake fluid in the cylinder 27a can be circulated from the spring 27m side to the seal member 27k side through the communication portion between the first chamber A1 and the second chamber A2.

[0068] The brake hydraulic control device 10 of the present embodiment includes a first pump 27 that pumps the brake fluid in the first liquid passage 23. The first pump 27 is pressed by an eccentric body 52 and includes a plunger 27f that reciprocates inside a cylinder 27a and a spring 27m that presses the plunger 27f toward the eccentric body 52. The plunger 27f has a small-diameter portion 27fa and a large-diameter portion 27fb having an outer diameter larger than that of the small-diameter portion 27fa. Further, the large-diameter portion 27fb is provided with a groove portion 27fc that extends on the outer peripheral surface of the large-diameter portion 27fb and communicates the first chamber A1 and the second chamber A2. Further, the large-diameter portion 27fb of the plunger 27f receives one end portion of the spring 27m on the outer peripheral surface facing the spring 27m and is configured to be pressed by the spring 27m.

[0069] According to such a configuration, the plunger 27f receives one end of the spring 27m on the outer peripheral surface where the large-diameter portion 27fb faces the spring 27m and is pressed by the spring 27m. Therefore, for example, even when the outer diameter of the small-diameter portion 27fa is reduced to reduce the pump flow rate, the plunger 27f can receive the end portion of the spring 27m having a diameter larger than the outer diameter of the small-diameter portion 27fa, and the degree of freedom in the pump design can be improved.

[0070] The brake hydraulic control device 10 of the present embodiment includes a first pump 27 that pumps the brake fluid in the first liquid passage 23. The first pump 27 includes a plunger 27f that is pressed by an eccentric body 52 and reciprocates inside a cylinder 27a. The plunger 27f has a small-diameter portion 27fa and a large-diameter portion 27fb having an outer diameter larger than that of the small-diameter portion 27fa. An inlet 27c for allowing the brake fluid to flow from the outside to the inside of the cylinder 27a is formed on the inner peripheral surface of the cylinder 27a. The large-diameter portion 27fb includes a closing portion 27fe that closes at least a part of the inlet 27c during the reciprocating movement of the plunger 27f.

[0071] According to such a configuration, since the large-diameter portion 27fb of the plunger 27f includes the closing portion 27fe that closes at least a part of the inlet 27c during the reciprocating movement of the plunger 27f, by closing at least a part of the inlet 27c in the compression process of the first pump 27, the volume of the compression chamber effective in the compression process can be reduced, and the compression efficiency of the first pump 27 can be improved.

[0072] The motorcycle 1 as a saddle-riding type vehicle according to this embodiment includes a brake fluid pressure control device 10 that controls the brake fluid of the brake system 100 of the motorcycle 1. The brake fluid pressure control device 10 includes a base body 60 in which a first liquid passage 23 for the brake fluid is formed, a first pump 27 that pumps the brake fluid in the first liquid passage 23, and a motor 50 that is erected on the base body 60 and drives the first pump 27. The motor 50 includes an output shaft 51 that is rotationally driven by a motor main body portion, and an eccentric body 52 that is provided on the output shaft 51 and rotates eccentrically with respect to the rotation center of the output shaft 51. The first pump 27 includes a plunger 27f that is pressed by the eccentric body 52 and reciprocates inside a cylinder 27a, a spring 27m that is provided inside the cylinder 27a and presses the plunger 27f toward the eccentric body 52, and a seal member 27k that seals between the cylinder 27a and the plunger 27f. The plunger 27f has a small-diameter portion 27fa and a large-diameter portion 27fb having an outer diameter larger than that of the small-diameter portion 27fa. The seal member 27k is disposed on the outer periphery of the small-diameter portion 27fa, and the large-diameter portion 27fb is disposed on the spring 27m side with respect to the seal member 27k. Inside the cylinder 27a, a first chamber A1 formed on the spring 27m side by the large-diameter portion 27fb of the plunger 27f and a second chamber A2 formed on the eccentric body 52 side by the large-diameter portion 27fb communicate with each other.

[0073] According to such a configuration, in the brake fluid pressure control device 10 of the motorcycle 1, since the first chamber A1 formed on the spring 27m side by the large-diameter portion 27fb of the plunger 27f and the second chamber A2 formed on the eccentric body 52 side by the large-diameter portion 27fb communicate with each other inside the cylinder 27a, in the compression process of the first pump 27, when the plunger 27f is pressed by the eccentric body 52 and moves toward the spring 27m side, the communication portion between the first chamber A1 and the second chamber A2 allows the brake fluid in the cylinder 27a to flow from the spring 27m side to the seal member 27k side, and the fluid resistance that the plunger 27f receives from the brake fluid can be reduced, and the torque required for the motor 50 to drive the first pump 27 can be reduced.

[0074] In this embodiment, the plunger 27f of the brake hydraulic control device 10 is configured to include a groove portion 27fc that extends on the outer peripheral surface of its large-diameter portion 27fb and communicates the first chamber A1 and the second chamber A2. However, the means for communicating the first chamber A1 and the second chamber A2 in the plunger 27f may be means other than the groove portion 27fc. For example, the plunger 27f may have a small-diameter portion 27fa and a large-diameter portion 27fb having an outer diameter larger than that of the small-diameter portion 27fa. Further, the large-diameter portion 27fb may be configured to include a communication hole 27fd that is drilled in the large-diameter portion 27fb and communicates the first chamber A1 and the second chamber A2.

[0075] In such a configuration, since the plunger 27f includes the communication hole 27fd in the large-diameter portion 27fb, when the plunger 27f is pressed by the eccentric body 52 and moves toward the spring 27m side in the compression process of the first pump 27, the brake fluid in the cylinder 27a can be circulated from the spring 27m side to the seal member 27k side through the communication portion between the first chamber A1 and the second chamber A2.

[0076] The brake hydraulic control device 10 of this embodiment includes a second pump 37 driven by a motor 50. The second pump 37 has the same configuration as the above-described first pump 27 and exhibits the same effects as the above-described first pump 27.

[0077] The brake hydraulic control device 60 according to this embodiment has been described above. However, the brake hydraulic control device according to the present invention is not limited to the description of this embodiment. For example, only a part of this embodiment may be implemented.

Explanation of Reference Numerals

[0078] 1 Motorcycle (straddle-type vehicle) 10 Brake hydraulic control device 23 First liquid passage (liquid passage) 27 First pump (pump) 27f Plunger 27fa Small-diameter portion 27fb Large-diameter portion 27fc Groove portion 27m Spring 37 Second Pump (Pump) 50 Motor (Electric Motor) 51 Output Shaft 52 Eccentric Body 60 Substrate 70 Control Board 100 Brake System A1 First Chamber A2 Second Chamber

Claims

1. A brake fluid pressure control device for controlling the brake fluid of a brake system (100) mounted on a saddle-type vehicle (1), a base body (60) in which a liquid passage (23) for the brake fluid is formed, a pump (27) for pumping the brake fluid in the liquid passage (23), an electric motor (50) standing upright on the base body (60) and driving the pump (27), comprising: the electric motor (50) includes an output shaft (51) rotationally driven by a motor main body portion, an eccentric body (52) provided on the output shaft (51) and rotating eccentrically with respect to the rotation center of the output shaft (51), comprising: the pump (27) includes a plunger (27f) pressed by the eccentric body (52) and reciprocating inside a cylinder (27b), a spring (27m) provided inside the cylinder (27b) and pressing the plunger (27f) toward the eccentric body (52), a seal member (27k) for sealing between the cylinder (27b) and the plunger (27f), comprising: the plunger (27f) has a small-diameter portion (27fa) and a large-diameter portion (27fb) having an outer diameter larger than that of the small-diameter portion (27fa), the seal member (27k) is disposed on the outer periphery of the small-diameter portion (27fa), the large-diameter portion (27fb) is disposed on the spring (27m) side with respect to the seal member (27k), inside the cylinder (27b), a first chamber (A1) formed on the spring (27m) side by the large-diameter portion (27fb) and a second chamber (A2) formed on the eccentric body (52) side by the large-diameter portion (27fb) communicate with each other, a brake fluid pressure control device.

2. The large-diameter portion (27fb) is provided with a groove portion (27fc) extending on the outer peripheral surface of the large-diameter portion (27fb) and communicating the first chamber (A1) and the second chamber (A2), The brake fluid pressure control device according to Claim 1.

3. The large-diameter portion (27fb) is provided with a communication hole (27fd) drilled in the large-diameter portion (27fb) and communicating the first chamber (A1) and the second chamber (A2), The brake fluid pressure control device according to Claim 1.

4. The large-diameter portion (27fb) is pressed by the spring (27fm), The brake fluid pressure control device according to any one of Claims 1 to 3.

5. The cylinder (27b) includes an inlet (27c) for allowing the brake fluid to flow from the outside to the inside of the cylinder (27b). The large-diameter portion (27fb) includes a closing portion (27fe) that closes at least a part of the inlet (27fc) during reciprocating motion. The brake fluid pressure control device according to any one of claims 1 to 3.

6. A saddle-riding type vehicle including the brake fluid pressure control device (10) according to any one of claims 1 to 3.

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