CN116568576A

CN116568576A - Pump device

Info

Publication number: CN116568576A
Application number: CN202180080774.8A
Authority: CN
Inventors: 坂本贵纪
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2020-12-01
Filing date: 2021-11-05
Publication date: 2023-08-08
Also published as: DE112021006292T5; JPWO2022118113A1; JP7476350B2; JP2022087561A; WO2022118113A1; KR20230113366A

Abstract

The invention attenuates noise caused by pulsation of brake fluid generated during driving of a pump. A pulsation damping section (80) provided in a pump device is provided with a fixing member (86) that divides a housing chamber (58) into an upstream region and a downstream region, and the fixing member (86) is provided with a fixing member hole (86 b). The upstream region is provided with an upstream movable member (84), an inflow opening side damper portion (81 a) for accommodating an inflow opening side elastic body (92), and a fixed member side damper portion (81 b) for accommodating a fixed member side elastic body (91). The downstream region is provided with an outflow opening side damper (81 c) for accommodating the outflow opening side elastic body (90), and a downstream movable member (85) provided with a downstream side hole (85 c). The fixed member (86) has a cylindrical portion (86 d) extending toward the cover (82) and capable of abutting against the valve member (94), and the upstream movable member (84) has a through hole (84 b), the through hole (84 b) having a seat (84 d) capable of being closed by the valve member (94).

Description

Pump device

Technical Field

The present invention relates to a pump device provided in a hydraulic circuit of a brake.

Background

As a conventional brake system for a vehicle, there is a brake system including the following hydraulic circuit: the hydraulic circuit includes a main passage that communicates the master cylinder with the wheel cylinders, a sub-passage that discharges the brake fluid in the main passage, and a supply passage that supplies the brake fluid to a middle portion of the sub-passage.

For example, an upstream end of the flow of the brake fluid in the auxiliary flow passage is connected to a region of the main flow passage on the wheel cylinder side with respect to the inlet valve, and a downstream end of the auxiliary flow passage is connected to a region of the main flow passage on the master cylinder side with respect to the inlet valve. The upstream end of the flow of the brake fluid in the supply passage communicates with the master cylinder, and the downstream end of the supply passage is connected to a region of the sub-passage downstream of the outlet valve and to a suction side of a pump provided in the region. In the main flow path, a 1 st switching valve is provided in a region on the master cylinder side with respect to a connection portion connected to a downstream end portion of the sub flow path, and a 2 nd switching valve is provided in a middle portion of the supply flow path.

For example, the hydraulic control unit is constituted by an inlet valve, an outlet valve, a pump, a 1 st switching valve and a 2 nd switching valve, a base body equipped with these devices, and a controller for managing the operations of these devices. In the hydraulic control unit, the hydraulic pressure of the hydraulic circuit is controlled by controlling the operations of the inlet valve, the outlet valve, the pump, the 1 st switching valve, and the 2 nd switching valve.

In particular, when a need arises to raise the hydraulic pressure of the brake fluid of the wheel cylinder irrespective of the state of the brake operation of the input portion (for example, a brake pedal or the like) of the brake system, the pump is driven in a state in which the inlet valve is opened, the outlet valve is closed, the 1 st switching valve is closed, and the 2 nd switching valve is opened.

When the pump is driven, pulsation generated in the brake fluid may be transmitted from the brake system to the engine room of the vehicle, and noise may be generated. The noise may be of such a magnitude that the user (driver) feels uncomfortable. Therefore, a conventional hydraulic control unit for a brake system has also been proposed to attenuate pulsation generated during driving of a pump. For example, the hydraulic control unit of the brake system described in patent document 1 includes one pump in one hydraulic circuit, and a pulsation damping section for damping pulsation of brake fluid discharged from the pump is provided on a discharge side of the pump.

Patent document 1: japanese patent application laid-open No. 2017-061246.

Problems to be solved by the invention

In recent brake systems, in order to improve the mountability of the brake system to a vehicle, there are cases where a force multiplier is miniaturized or omitted. In such a brake system, the hydraulic pressure of the brake fluid in the wheel cylinder is often insufficient, and therefore the number of times of driving the pump increases. That is, in such a brake system, noise due to pulsation generated at the time of driving the pump becomes more likely to occur. Therefore, in recent years, it has been demanded to further attenuate pulsation generated at the time of driving the pump.

As a configuration for realizing further attenuation of pulsation generated at the time of driving a pump, according to the configuration of the hydraulic control unit of the brake system described in patent document 1, a hydraulic brake device having a pulsation damper in which a plurality of metal films are superimposed is proposed. However, when a plurality of identical metal films are superimposed, there is a limit in coping with pulsation caused by characteristics of the hydraulic control unit depending on the output and rotation speed of the pump motor.

Disclosure of Invention

The present invention has been made in view of the above-described problems, and provides a brake system capable of attenuating noise caused by pulsation generated during driving of a pump.

Means for solving the problems

The pump device of the present invention is provided in a base body, and includes a pulsation damping section for damping pulsation of brake fluid discharged from a pump, wherein the pulsation damping section includes a housing chamber, a fixed member, an upstream movable member, an inflow opening side damping section, a fixed member side damping section, a downstream movable member, an outflow opening side damping section, a fixed member hole, a downstream side hole, an inflow opening side elastic body, a fixed member side elastic body, and an outflow opening side elastic body, the housing chamber is provided in the base body, the housing chamber is cylindrical, the fixed member divides the housing chamber into an upstream side region and a downstream side region, the upstream movable member is provided in the upstream side region so as to be axially slidable, the inflow opening side damping section is provided in the upstream side region and communicates with an inflow opening into which the brake fluid flows, the stationary member side damper portion is provided between the upstream side movable member and the stationary member, the downstream side movable member is provided in the downstream side region so as to be slidable in the axial direction, the outflow opening side damper portion is provided in the downstream side region so as to communicate with the outflow opening through which the brake fluid flows out, the stationary member hole is formed in the stationary member, the downstream side hole is formed in the downstream side movable member, the inflow opening side elastomer is provided in the inflow opening side damper portion so as to urge the upstream side movable member to the stationary member side, the stationary member side elastomer is provided in the stationary member side damper portion, the upstream side movable member is biased toward the lid portion, the outflow opening side elastic body is provided in the outflow opening side damping portion, the downstream side movable member is biased toward the fixed member side, the fixed member has a cylindrical portion extending toward the lid portion side, the upstream side movable member has a through hole having a seat portion which is configured to be closed by seating a valve member pressed from the lid portion side, the upstream side movable member is brought into contact with the cylindrical portion and separated from the seat portion during movement of the valve member toward the fixed member side by a pressure of the brake fluid flowing into the inflow opening side damping portion, and thereby the brake fluid flows in from the through hole, the pressure of the fixed member side damping portion increases, the downstream side movable member in contact with the fixed member moves toward the bottom portion side due to the pressure increase of the fixed member side damping portion, and the brake fluid flows out from the side hole and the downstream side opening through the fixed member.

Effects of the invention

In the brake system, noise caused by pulsation of the brake fluid generated at the time of driving the pump can be reduced.

Drawings

Fig. 1 is a diagram showing an example of a system configuration of a brake system according to an embodiment of the present invention.

Fig. 2 is a partial cross-sectional view showing an example of a mounting state of a pump and a damper unit of a hydraulic control unit of a brake system according to an embodiment of the present invention on a base.

Fig. 3 is an enlarged sectional view of the pulsation damping section in a state where the pump according to the embodiment of the present invention is not driven.

Fig. 4 is an enlarged sectional view of the pulsation damping section in a state in which the upstream movable member is moving after the start of the pump driving according to the embodiment of the present invention.

Fig. 5 is an enlarged sectional view of the pulsation damping section in a state where the brake fluid flows out from the outflow opening after the start of the pump driving according to the embodiment of the present invention.

Detailed Description

Hereinafter, the hydraulic control unit according to the present invention will be described with reference to the drawings. In the following, a description is given of a case where a brake system including the hydraulic control unit of the present invention is mounted on a four-wheel vehicle, but the brake system including the hydraulic control unit of the present invention may be mounted on a vehicle other than the four-wheel vehicle (such as a two-wheel vehicle, a truck, and a bus). The configuration, operation, and the like described below are examples, and the brake system including the hydraulic control unit according to the present invention is not limited to such a configuration, operation, and the like. In the drawings, the same or similar components or portions are denoted by the same reference numerals or the same reference numerals are omitted. Further, the detailed construction is appropriately simplified or omitted.

< construction and operation of brake System 1 >

The structure and operation of the brake system 1 of the present embodiment will be described. Fig. 1 is a diagram showing an example of a system configuration of a brake system according to an embodiment of the present invention.

As shown in fig. 1, the brake system 1 is mounted on a vehicle 100, and includes a hydraulic circuit 2, and the hydraulic circuit 2 includes a main flow path 13 that communicates a master cylinder 11 and a wheel cylinder 12, a sub flow path 14 that discharges brake fluid in the main flow path 13, and a supply flow path 15 that supplies brake fluid to the sub flow path 14. The hydraulic circuit 2 is filled with a brake fluid.

The brake system 1 of the present embodiment is configured such that the hydraulic circuit 2 includes two hydraulic circuits 2a and 2b. The hydraulic circuit 2a is a hydraulic circuit that communicates the master cylinder 11 with the wheel cylinders 12 of the wheels RL and FR via the main flow path 13. The hydraulic circuit 2b is a hydraulic circuit that communicates the master cylinder 11 with the wheel cylinders 12 of the wheels FL and RR via the main flow path 13. These hydraulic circuits 2a, 2b have the same configuration except that the communicating wheel cylinders 12 are different.

The master cylinder 11 incorporates a piston (not shown) that reciprocates in conjunction with a brake pedal 16 as an example of an input unit of the brake system 1. The force multiplier 17 is located between the brake pedal 16 and the piston of the master cylinder 11, and transmits the amplified pedal force of the user to the piston. The wheel cylinder 12 is provided to a brake caliper 18. When the hydraulic pressure of the brake fluid in the wheel cylinder 12 increases, the brake pads 19 of the caliper 18 are pressed against the rotor 20, and the wheels are braked.

The upstream end of the sub-channel 14 is connected to the 1 st intermediate portion 13a of the main channel 13, and the downstream end of the sub-channel 14 is connected to the 2 nd intermediate portion 13b of the main channel 13 upstream of the 1 st intermediate portion 13 a. The upstream end of the supply channel 15 communicates with the master cylinder 11, and the downstream end of the supply channel 15 is connected to the 3 rd intermediate portion 14a of the sub-channel 14.

An inlet valve (EV) 31 is provided in the main flow path 13 in a region between the 2 nd intermediate portion 13b and the 1 st intermediate portion 13 a. An outlet valve (AV) 32 is provided in the sub-flow path 14 in a region between the 1 st intermediate portion 13a and the 3 rd intermediate portion 14 a. A reservoir 33 is provided in the sub-passage 14 in a region between the outlet valve 32 and the 3 rd intermediate portion 14 a. The inlet valve 31 is, for example, a solenoid valve that is opened in a non-energized state and closed in an energized state. The outlet valve 32 is, for example, a solenoid valve that is closed in a non-energized state and opened in an energized state.

In the sub-channel 14, a pump 60 is provided in a region between the 3 rd intermediate portion 14a and the 2 nd intermediate portion 13 b. The suction side of the pump 60 communicates with the 3 rd intermediate portion 14 a. The discharge side of the pump 60 communicates with the 2 nd intermediate portion 13b of the main flow path 13. A pulsation damping section 80 is provided in a region between the discharge side of the pump 60, which is a part of the sub flow path 14, and the 2 nd intermediate section 13 b.

The pulsation damping section 80 dampens pulsation of the brake fluid discharged from the pump 60. Specifically, the discharge side of the pump 60 is connected to an inflow opening 95b (see fig. 2) into which the brake fluid of the pulsation damping section 80 flows, and an outflow opening 95c (see fig. 2) into which the brake fluid temporarily stored in the pulsation damping section 80 flows is connected to the 2 nd intermediate section 13b of the main flow path 13. In the following description, a flow path between the discharge side of the pump 60 and the inflow opening 95b is referred to as a 1 st discharge flow path 140a, and a flow path between the outflow opening 95c and the 2 nd intermediate portion 13b of the main flow path 13 is referred to as a 2 nd discharge flow path 140b.

A 1 st switching valve (USV) 35 is provided in the main channel 13 in the region on the master cylinder 11 side with respect to the 2 nd intermediate portion 13 b. The supply channel 15 is provided with a 2 nd switching valve (HSV) 36 and a damper unit 37. The damper unit 37 is provided in the supply channel 15 in a region between the 2 nd switching valve 36 and the 3 rd intermediate portion 14a of the sub-channel 14. The 1 st switching valve 35 is, for example, a solenoid valve that is opened in a non-energized state and closed in an energized state. The 2 nd switching valve 36 is, for example, a solenoid valve that is closed in a non-energized state and opened in an energized state.

The inlet valve 31, the outlet valve 32, the accumulator 33, the pump 60, the 1 st switching valve 35, the 2 nd switching valve 36, the damping unit 37, and the pulsation damping section 80 are provided in the base body 51, and the base body 51 is internally formed with flow paths for configuring the main flow path 13, the sub flow path 14, and the supply flow path 15. The components (the inlet valve 31, the outlet valve 32, the accumulator 33, the pump 60, the 1 st switching valve 35, the 2 nd switching valve 36, the damping unit 37, and the pulsation damping section 80) may be provided in a single body 51 in a collective manner, or may be provided separately in a plurality of bodies 51.

The hydraulic control unit 50 is constituted by at least a base 51, components provided on the base 51, and a controller (ECU) 52. In the hydraulic pressure control unit 50, the operation of the inlet valve 31, the outlet valve 32, the pump 60, the 1 st switching valve 35, and the 2 nd switching valve 36 is controlled by the controller 52, whereby the hydraulic pressure of the brake fluid in the wheel cylinder 12 is controlled. That is, the controller 52 manages the operations of the inlet valve 31, the outlet valve 32, the pump 60, the 1 st switching valve 35, and the 2 nd switching valve 36.

The controller 52 may be one or a plurality of controllers. The controller 52 may be mounted on the base 51, or may be mounted on another component. The controller 52 may be constituted partially or entirely by a personal computer, a microprocessor unit, or the like, may be constituted by a part capable of being updated such as firmware, or may be a program module or the like executed in accordance with instructions from a CPU or the like.

The controller 52 performs the following hydraulic control operation in addition to the well-known hydraulic control operation (ABS control operation, ESP control operation, etc.), for example. When the brake pedal 16 of the vehicle 100 is operated with the inlet valve 31 open, the outlet valve 32 closed, the 1 st switching valve 35 open, and the 2 nd switching valve 36 closed, the controller 52 starts the active supercharging control operation if a possibility of a shortage or shortage of the hydraulic pressure of the hydraulic circuit 2 is detected from the detection signal of the position sensor of the brake pedal 16 and the detection signal of the hydraulic sensor of the hydraulic circuit 2.

In the active pressure increasing control operation, the controller 52 opens the inlet valve 31 to allow the brake fluid to flow from the 2 nd intermediate portion 13b of the main flow passage 13 to the wheel cylinders 12. The controller 52 restricts the flow of brake fluid from the wheel cylinder 12 to the reservoir 33 by closing the outlet valve 32. Further, the controller 52 restricts the flow of the brake fluid from the master cylinder 11 to the flow path of the 2 nd intermediate portion 13b of the main flow path 13 without passing through the pump 60 by closing the 1 st switching valve 35. The controller 52 opens the 2 nd switching valve 36 to allow the brake fluid to flow from the master cylinder 11 to the flow path of the 2 nd intermediate portion 13b of the main flow path 13 via the pump 60. Further, the controller 52 drives the pump 60 to raise (increase) the hydraulic pressure of the brake fluid of the wheel cylinder 12.

When the release or avoidance of the shortage of the hydraulic pressure in the hydraulic circuit 2 is detected, the controller 52 opens the 1 st switching valve 35, closes the 2 nd switching valve 36, and stops the driving of the pump 60, thereby ending the active supercharging control operation.

Here, when the pump 60 is driven, pulsation generated in the brake fluid may pass through the auxiliary flow path 14 and the main flow path 13 and may be transmitted to the wheel cylinders 12. Further, the pulsation may be transmitted to an engine room in which the hydraulic control unit 50 of the brake system 1 is housed, and noise may be generated. The noise may be of such a magnitude that the user (driver) feels uncomfortable. Therefore, it is important to realize attenuation of pulsation generated when the pump 60 is driven.

As a result, in the brake system 1, that is, the hydraulic control unit 50 of the present embodiment, the brake fluid discharged from the pump 60 flows into the pulsation damping section 80. Then, the brake fluid flowing into the pulsation damping section 80 is pulsation-damped by the pulsation damping section 80, and then flows downstream from the pulsation damping section 80. Therefore, the brake system 1, that is, the hydraulic control unit 50 of the present embodiment can attenuate pulsation generated at the time of driving the pump 60.

In the above-described active supercharging control, the pump 60 is driven in a state where the user operates (depresses) the brake pedal 16 and the 2 nd switching valve 36 is opened. Therefore, pulsation generated in the brake fluid propagates to the brake pedal 16 via the supply channel 15 and the master cylinder 11, and causes a user to feel uncomfortable. Therefore, the brake system 1, that is, the hydraulic control unit 50 of the present embodiment is preferably provided with the damping unit 37 as shown in fig. 1. This is because pulsation of the brake fluid traveling from the pump 60 to the brake pedal 16 can be damped by the damping unit 37.

In the case where the damper unit 37 is provided in the brake system 1 in which the force multiplier 17 is omitted, the damper unit 37 may be provided in a region between the upstream end portion of the supply passage 15 and the 2 nd switching valve 36. By providing the damper unit 37 at such a position, when the user depresses the brake pedal 16, the brake fluid can flow into the damper unit 37, and the reaction force of the brake fluid transmitted to the hydraulic circuit 2 of the brake pedal 16 is reduced. Therefore, when the user depresses the brake pedal, the same amount of depression of the brake pedal 16 as in the brake system 1 provided with the force multiplier 17 is obtained. Therefore, the user can obtain the same feeling of use as the brake system 1 provided with the force multiplier 17 in the brake system 1 in which the force multiplier 17 is omitted.

< mounting Structure of Pump 60 and pulsation damping section 80 on base body 51 >

An example of a configuration in which the pump 60 and the pulsation damping section 80 are mounted on the base 51 in the hydraulic control unit 50 of the brake system 1 according to the present embodiment will be described. Fig. 2 is a partial cross-sectional view showing an example of a mounting state of the pump 60 and the pulsation damping section 80 on the base member in the hydraulic control unit of the brake system according to the embodiment of the present invention. Fig. 2 shows a state in which the drive shaft 57 that drives the piston 62 of the pump 60 is removed. Accordingly, in fig. 2, the driving shaft 57 and the eccentric portion 57a formed on the driving shaft 57 are illustrated with virtual lines (two-dot chain lines).

As shown in fig. 2, a drive shaft housing chamber 59 is formed in the base body 51, and the drive shaft housing chamber 59 is provided with a drive shaft 57 that drives a piston 62 of the pump 60. The drive shaft accommodation chamber 59 is a bottomed hole formed in the outer wall of the base 51. Further, a pump housing chamber 53 for housing the pump 60 is formed in the base 51. The pump housing chamber 53 is a cylindrical stepped hole penetrating from the outer wall of the base 51 to the drive shaft housing chamber 59.

The pump 60 accommodated in the pump accommodating chamber 53 includes a cylinder 61, a piston 62, and the like. The pressure cylinder 61 is formed in a cylindrical shape having a cylinder bottom 61 b. One end side of the piston 62 is accommodated in the cylinder 61. The space surrounded by the inner peripheral surface of the cylinder 61 and the one end of the piston 62 is a pump chamber 63. The piston 62 is free to reciprocate in the axial direction of the cylinder 61. Further, an end 62a, which is the other end side end of the piston 62, protrudes into the drive shaft accommodating chamber 59. Further, an annular cylinder side seal member 66 is attached to a portion of the piston 62 stored in the cylinder 61. The brake fluid is prevented from leaking between the outer peripheral surface of the piston 62 and the inner peripheral surface of the cylinder 61 by the cylinder side seal member 66.

In addition, in the pressure cylinder 61, a piston spring 67 is accommodated between the cylinder bottom 61b and the piston 62, that is, in the pump chamber 63. By this piston spring 67, the piston 62 is always biased toward the drive shaft accommodating chamber 59. Thus, the end 62a of the piston 62 abuts against the eccentric portion 57a of the drive shaft 57 formed in the drive shaft accommodating chamber 59. The center position of the eccentric portion 57a is eccentric with respect to the rotation center of the drive shaft 57. Therefore, when the drive shaft 57 is rotated by a drive source, not shown, the eccentric portion 57a moves eccentrically with respect to the rotation center of the drive shaft 57. That is, by the eccentric rotary motion of the eccentric portion 57a, the piston 62 whose end portion 62a abuts against the eccentric portion 57a reciprocates in the axial direction of the cylinder 61.

The portion of the piston 62 protruding from the pressure cylinder 61 is slidably guided by a piston guide member 68 provided on the inner peripheral surface of the pump housing chamber 53. An annular drive shaft side seal member 69 is attached to the pump housing chamber 53 adjacent to the piston guide member 68. The brake fluid is prevented from leaking from the outer peripheral surface of the piston 62 to the drive shaft accommodation chamber 59 side by the drive shaft side seal member 69.

A bottomed hole 62b that opens in the axial direction toward the pump chamber 63 side of the cylinder 61 is formed in the piston 62. A suction port 62c is also formed in the piston 62 to communicate the outer peripheral surface thereof with the bottomed hole 62b. A suction valve, not shown, is provided in the piston 62 to open and close the opening of the bottomed hole 62b. The suction valve includes a suction valve member as a ball valve for closing an opening of the bottomed hole 62b, and a suction valve spring for biasing the suction valve member from the cylinder 61 side. A cylindrical filter 70 is attached to an end of the cylinder 61 on the piston 62 side so as to cover an opening of the suction port 62c of the piston 62.

A communication hole 61c for communicating the pump chamber 63 with the outside of the cylinder 61 is formed in the cylinder bottom 61 b. An opening-side discharge valve 64 is provided on the opening side of the communication hole 61c opposite to the pump chamber 63. The opening-side discharge valve 64 includes an opening-side valve member 64a as a ball valve, an opening-side valve seat 64b formed at the opening end periphery of the communication hole 61c so that the opening-side valve member 64a can be seated and unseated, and an opening-side spring 64c for biasing the opening-side valve member 64a in a direction in which the opening-side valve seat 64b is seated. The opening-side discharge valve 64 is disposed between the cylinder 61 and the cover 65.

Specifically, the cover 65 is attached to the cylinder bottom 61b side by press fitting, for example. A bottomed hole 65a is formed in the cover 65, and the bottomed hole 65a has an opening portion at a position opposed to the communication hole 61c of the cylinder bottom 61 b. The opening side spring 64c of the opening side discharge valve 64 is accommodated in the bottomed hole 65a. The inner diameter of the bottomed hole 65a is larger than the outer diameter of the opening-side valve member 64 a. Therefore, when the opening-side valve member 64a is separated from the opening-side valve seat 64b, the opening-side valve member 64a moves into the bottomed hole 65a. That is, when the hydraulic pressure of the brake fluid in the pump chamber 63 of the pressure cylinder 61 increases and the force with which the brake fluid presses the opening-side valve member 64a becomes larger than the urging force of the opening-side spring 64c, the opening-side valve member 64a is separated from the opening-side valve seat 64b, and the pump chamber 63 and the bottomed hole 65a of the cover 65 communicate with each other via the communication hole 61c. The brake fluid in the pump chamber 63 flows into the bottomed hole 65a. A groove for communicating the outside of the cover 65 with the bottomed hole 65a is formed as the discharge port 65b in the cover 65. The brake fluid flowing into the bottomed hole 65a of the cover 65 passes through a discharge chamber 54 described later from the discharge port 65b and is discharged to the outside of the pump 60.

The pump 60 thus constructed is accommodated in the pump accommodating chamber 53 formed in the base 51 as described above. Specifically, the pump 60 is pressed into a position where an annular protruding portion 61a formed on the outer peripheral portion of the cylinder 61 abuts against the stepped portion 53a of the pump accommodating chamber 53, and is fixed in the pump accommodating chamber 53 of the base body 51.

When the pump 60 is accommodated in the pump accommodating chamber 53 in this manner, a discharge chamber 54, which is a space communicating with the discharge port 65b of the pump 60, is formed between the outer peripheral surface of the pump 60 and the inner peripheral surface of the pump accommodating chamber 53. The discharge chamber 54 is a space formed annularly on the outer peripheral side of the pump 60 so as to communicate with the discharge port 65b of the pump 60. The discharge chamber 54 is connected to the 1 st discharge channel 140a as described later.

Further, at the pump 60, a space between the annular protruding portion 61a of the pressure cylinder 61 and the cover 65 is partitioned into two spaces by the partition portion 71. The space closer to the cover 65 than the partition 71 is the discharge chamber 54. In the present embodiment, an O-ring (not shown) is provided in the annular groove formed in the spacer 71.

In the present embodiment, when the pump 60 is accommodated in the pump accommodating chamber 53, the annular flow path 56, which is a space communicating with the suction port 62c of the pump 60, is formed between the outer peripheral surface of the pump 60 and the inner peripheral surface of the pump accommodating chamber 53. That is, the annular flow passage 56 is a space formed annularly on the outer peripheral side of the pump 60 so as to communicate with the suction port 62c of the pump 60. The annular flow passage 56 is formed between an annular protruding portion 61a of the pressure cylinder 61 and the drive shaft side seal member 69. In other words, the annular flow passage 56 is formed on the outer peripheral side of the filter 70 so as to cover the opening of the suction port 62c.

The annular flow passage 56 communicates with the 3 rd intermediate portion 14a of the sub flow passage 14 in fig. 1 via an internal flow passage, not shown, formed in the base body 51. In other words, the annular flow passage 56 constitutes a part of the sub flow passage 14. When the pump 60 is accommodated in the pump accommodating chamber 53, the suction port 62c of the pump 60 and the 3 rd intermediate portion 14a need to communicate with each other. Because of the annular flow passage 56, there is no need for positioning for communicating the suction port 62c of the pump 60 with the 3 rd intermediate portion 14a when the pump 60 is accommodated in the pump accommodating chamber 53. Therefore, the assembly of the hydraulic control unit 50 is facilitated by the annular flow passage 56. Further, since the annular flow passage 56 is provided, when the pump housing chamber 53 is processed on the base 51, a part of the sub flow passage 14 is also processed. Therefore, the processing cost of the base body 51, that is, the manufacturing cost of the hydraulic control unit 50 can also be reduced. Further, since the annular flow passage 56 is provided, the space on the outer peripheral side of the pump 60 can be effectively utilized as the sub flow passage 14, and therefore, the base 51, that is, the hydraulic control unit 50 can be miniaturized.

The accommodation chamber 58 accommodates the pulsation damping section 80, and is a bottomed hole formed in the outer wall of the base 51. As described above, the discharge chamber 54 formed on the outer peripheral surface side of the pump 60 is connected to the 1 st discharge flow path 140a that constitutes a part of the discharge flow path 140. The discharge chamber 54 is connected to the inflow opening 95b of the pulsation damping section 80 via the 1 st discharge channel 140 a. In fig. 2, the brake fluid flows into the housing chamber 58 of the pulsation damping section 80 from the lateral direction. And the outflow opening 95c at the bottom of the accommodating chamber 58 is connected to the 2 nd discharge flow path 140b. The 2 nd discharge flow path 140b communicates with the 2 nd intermediate portion 13b of the main flow path 13 in fig. 1 via an internal flow path not shown formed in the base body 51.

When the pump 60 and the pulsation damping section 80 are mounted on the base 51 as shown in fig. 2, the brake fluid flows as follows when the pump 60 is driven.

When the drive shaft 57 is rotated by a drive source, not shown, and the eccentric portion 57a formed on the drive shaft 57 is biased toward the piston 62, the piston 62 is pushed toward the cylinder 61 against the urging force of the piston spring 67. Accordingly, the pressure of the pump chamber 63 increases, the opening-side valve member 64a is separated from the opening-side valve seat 64b, and the opening-side discharge valve 64 opens. Thereby, the brake fluid in the pump chamber 63 passes through the communication hole 61c and the bottomed hole 65a of the cover 65, and is discharged from the discharge port 65b to the discharge chamber 54.

When the drive shaft 57 further rotates and the eccentric portion 57a formed on the drive shaft 57 starts to rotate in the direction away from the piston 62, the piston 62 moves in the direction away from the cylinder 61 by the urging force of the piston spring 67. Accordingly, the pressure of the pump chamber 63 becomes low, the opening-side valve member 64a is seated on the opening-side valve seat 64b, the opening-side discharge valve 64 is closed, and a suction valve, not shown, which openably closes the opening of the bottomed hole 62b of the piston 62, is opened. Thus, the brake fluid in the annular passage 56 flows into the pump chamber 63 through the filter 70, the suction port 62c, and the bottomed hole 62b.

When the drive shaft 57 is further rotated and the eccentric portion 57a formed on the drive shaft 57 is biased toward the piston 62, the piston 62 is pressed toward the cylinder 61 as described above, and the brake fluid in the pump chamber 63 is discharged from the discharge port 65b to the discharge chamber 54. As described above, the piston 62 repeatedly reciprocates in the axial direction of the cylinder 61, and the suction valve and the opening-side discharge valve 64, not shown, selectively open and close, whereby the brake fluid whose hydraulic pressure has been raised, that is, the brake fluid whose pressure has been raised, is discharged from the discharge port 65b to the discharge chamber 54. Therefore, pulsation occurs in the brake fluid that is boosted by the pump 60. The brake fluid accompanied by the pulsation flows into the pulsation damping section 80 through the 1 st discharge channel 140 a.

< structural example and operation of pulsation damping section 80 >

The configuration and operation of the pulsation damping section 80 will be described below with reference to fig. 3 to 5. As described above, the pulsation damping section 80 is configured to damp pulsation of the brake fluid generated during driving of the pump 60, and to damp noise caused by the pulsation.

Fig. 3 shows the pulsation damping section 80 in a state where the pump 60 is not driven. A cylindrical accommodating chamber 58 accommodating the pulsation damping section 80 is formed in the base 51. The pulsation damping section 80 includes an inflow opening 95b into which the brake fluid flows and an outflow opening 95c from which the brake fluid flows. The pulsation damping section 80 further includes a fixing member 86, and the fixing member 86 divides the pulsation damping section 80 into an upstream side region on the inflow opening 95b side and a downstream side region on the outflow opening 95c side.

The cylindrical shape forming the housing chamber 58 is a stepped shape having a small diameter portion 58b and a large diameter portion 58 d. A large diameter portion 58d is formed on the lid portion 82 side of the opening portion 58e of the housing chamber 58, and a small diameter portion 58b is formed on the bottom portion 58a side of the housing chamber 58 on the opposite side of the opening portion 58 e. A stepped portion 58c is formed between the small diameter portion 58b and the large diameter portion 58d in parallel with the bottom portion 58a, in other words, in a direction orthogonal to the longitudinal axis Axc of the pulsation damping portion 80. The inflow opening 95b is formed in the large diameter portion 58d, and the outflow opening 95c is formed in the bottom portion 58a.

The fixing member 86 is fixed to the small diameter portion 58b side of the housing chamber 58. The fixing member 86 includes a fixing member disk portion 86a having a disk shape, a fixing member outer cylindrical portion 86c having a cylindrical shape formed from the outer peripheral portion of the fixing member disk portion 86a toward the bottom portion 58a side, and a cylindrical portion 86d having a cylindrical shape formed toward the lid portion 82 side at the center portion of the fixing member disk portion 86 a. The fixing member disc portion 86a includes a fixing member hole 86b penetrating the fixing member disc portion 86a in the direction of the axis Axc of the housing chamber 58 at a position circumferentially outside the cylindrical portion 86d and circumferentially inside the fixing member outer cylindrical portion 86 c.

The pulsation damping section 80 includes a guide member 87. The guide member 87 is a stepped hollow cylindrical member having a small diameter portion guide portion 87a covering the inner surface of the small diameter portion 58b of the housing chamber 58, a bottom guide portion 87b covering the surface of the bottom portion 58a of the housing chamber 58, and an outflow opening guide portion 87c covering the inner surface of the outflow opening 95c. The fixing member outer cylindrical portion 86c is fixed to the small diameter portion guide portion 87a of the guide member 87 by a suitable method such as press fitting or welding.

The upstream movable member 84 having a disk shape and slidable in the direction of the axis Axc of the housing chamber 58 is provided on the fixed member 86 side of the inflow opening 95b of the large diameter portion 58 d. A sliding member 84a is attached to the side of the upstream movable member 84 facing the large diameter portion 58 d. When the upstream movable member 84 moves, the slide member 84a slides with respect to the large diameter portion 58 d. For smooth sliding, PTFE, for example, is used as a material of the sliding member 84a.

The upstream movable member 84 has a through hole 84b penetrating in the direction of the axis Axc of the housing chamber 58 at the center. The through hole 84b includes a seat 84d on the cover 82 side, on which the valve member 94 can be seated. The valve member 94 is pressed against the seat 84d with a predetermined attachment force by a valve spring 93 provided between the cover inner surface 82a, which is the surface of the cover 82 on the upstream side of the movable member 84, and the valve member 94. On the outer side in the radial direction of the through hole 84b, a plurality of upstream side holes 84c having a smaller diameter than the through hole 84b are formed so as to penetrate the upstream side movable member 84 in the direction of the axis Axc of the housing chamber 58.

In the present embodiment, the region between the upstream movable member 84 and the cover 82 of the housing chamber 58 is referred to as an inflow opening side damper 81a, the region between the upstream movable member 84 and the fixed member 86 is referred to as a fixed member side damper 81b, and the region between the fixed member 86 and the bottom 58a is referred to as an outflow opening side damper 81c. That is, in the housing chamber 58, the inflow opening side damper portion 81a and the fixed member side damper portion 81b constitute an upstream side region of the housing chamber 58, and the outflow opening side damper portion 81c constitutes a downstream side region of the housing chamber 58.

The inflow opening side damper portion 81a includes an inflow opening side elastic body 92 which is an elastic body that biases the upstream side movable member 84 toward the fixed member 86 side. The fixed member side damper portion 81b includes a fixed member side elastic body 91 that is an elastic body that biases the upstream side movable member 84 toward the cover 82 side.

A coil spring can be used as the inflow opening side elastic body 92. The inflow opening side elastic body 92 is disposed on the outer side in the circumferential direction than the valve spring 93 and the upstream side hole 84c.

The fixing member side elastic body 91 may be a cylindrical cushion member. As a material of the buffer member, for example, ethylene Propylene Diene Monomer (EPDM) and/or a material such as silicon can be used. The fixing member side elastic body 91 is disposed radially outward of the fixing member hole 86b and the upstream side hole 84c.

In the case of using the cushioning member as the elastic body, the cushioning member may be formed of one material or may be formed of a plurality of materials. For example, it may be constituted by sandwiching EPDM having a relatively low rebound rate with silicon having a relatively high rebound rate. By combining the materials, the rebound rate of the damper member can be adjusted in accordance with the natural pulsation frequency of the brake fluid due to the performance of the pump.

The outflow opening side damper 81c is provided with a downstream side movable member 85 slidable in the direction of the axis Axc of the housing chamber 58. The downstream movable member 85 includes a cylindrical downstream hole 85c facing the outflow opening 95c at the center, and a 1 st disk portion 85a capable of abutting against the fixed member disk portion 86a of the fixed member 86 at the outer side of the downstream hole 85c in the circumferential direction. The downstream hole 85c may be a through hole penetrating the 1 st disc 85a, instead of a cylindrical shape.

Further, at the downstream side movable member 85, a cylindrical movable member cylindrical portion 85e formed from the outer peripheral portion of the 1 st dish portion 85a toward the bottom portion 58a side and a 2 nd dish portion 85d extending radially outward from the upper end portion of the movable member cylindrical portion 85e are integrally formed. The movable member cylindrical portion 85e forms a space on the top surface of the 1 st dish portion 85a. Further, the outer peripheral portion of the 2 nd disc portion 85d is guided by the small diameter portion guide portion 87a of the guide member 87.

The 2 nd dish portion 85d is formed at the following positions: the 1 st disc portion 85a is in contact with the fixing member disc portion 86a of the fixing member 86, and is kept at a predetermined distance from the bottom guide portion 87b of the guide member 87. In a state where the 1 st disk portion 85a is in contact with the fixing member disk portion 86a, the fixing member hole 86b of the fixing member 86 is closed by the 1 st disk portion 85a, and the downstream side hole 85c of the downstream side movable member 85 is closed by the fixing member disk portion 86 a.

A hollow cylindrical outflow opening side elastic body 90 that biases the downstream side movable member 85 toward the fixed member 86 is provided between the 1 st dish portion 85a of the downstream side movable member 85 and the bottom guide portion 87b of the guide member 87. The outflow opening side elastic body 90 is provided at a position outside the downstream side hole 85c in the circumferential direction and inside the movable member cylindrical portion 85e in the circumferential direction. The outflow opening side elastic body 90 can be made of an elastic body having the same conditions as those of the fixing member side elastic body 91.

In the state of fig. 3, that is, in the state in which the pump 60 is not driven, the upstream movable member 84 receives a force in the direction of the cover 82 from the fixed member side elastic body 91, while receiving a force in the direction of the fixed member 86 from the valve spring 93 and the inflow opening side elastic body 92. As a result, the urging force of each elastic body is adjusted so that the upstream side movable member 84 is located between the stepped portion 58c and the inflow opening 95b at the large diameter portion 58 d. In this state, the valve member 94 and the cylindrical portion 86d do not abut. Further, the 1 st disc portion 85a of the downstream movable member 85 abuts against the fixed member disc portion 86a of the fixed member 86.

When the pump 60 starts to drive, the brake fluid flows in from the inflow opening 95b, and the pressure of the inflow opening side damper 81a increases. When the pressure flowing into the opening-side damper portion 81a increases, the valve member 94 and the upstream-side movable member 84 move toward the fixed member 86 in a state where the valve member 94 is seated on the seat portion 84d.

Next, the valve member 94 abuts against the cylindrical portion 86d of the fixed member 86, but the upstream movable member 84 continues to move. Thereby, the valve member 94 is disengaged from the seat 84d at this time. After that, the upstream movable member 84 abuts against the stepped portion 58c, and the movement ends. That is, the dimensions of the respective members are set in advance so that the movement amount of the upstream movable member 84 is larger than the movement amount of the valve member 94.

Fig. 4 shows a state in which the valve member 94 is in contact with the cylindrical portion 86d but is also in contact with the seat portion 84d. After this state, the upstream movable member 84 moves further to come into contact with the stepped portion 58c.

The valve member 94 and the upstream movable member 84 rise, and thus the pressure of the fixed member side damper portion 81b also rises. Then, the valve member 94 is disengaged from the seat portion 84d, and the brake fluid flows from the inflow opening side damper portion 81a to the fixed member side damper portion 81b through the through hole 84b, so that the pressure of the fixed member side damper portion 81b further increases. The pressure rise of the fixed member side damper portion 81b acts on the downstream side movable member 85 through the fixed member hole 86b, and moves the downstream side movable member 85 toward the bottom portion 58a against the urging force of the outflow opening side elastic body 90.

Fig. 5 shows a state in which the downstream movable member 85 moves toward the bottom portion 58a. When the downstream movable member 85 moves toward the bottom portion 58a, the fixed member hole 86b closed by the downstream movable member 85 is opened, and the brake fluid flows out from the fixed member side damper portion 81b to the outflow opening side damper portion 81c through the fixed member hole 86b. The brake fluid flowing out to the outflow opening side damper portion 81c passes through the downstream side hole 85c formed in the downstream side movable member 85, and flows out from the outflow opening 95c to the outside of the pulsation damping portion 80.

In fig. 5, the 2 nd disc portion 85d of the downstream movable member 85 abuts against the bottom guide portion 87 b. That is, the movement amount of the downstream movable member 85 at the time of driving the pump 60 is defined based on the position of the 2 nd disc portion 85d before driving the pump 60.

In addition, immediately after the pump 60 is driven, in a state where the valve member 94 is seated on the seat portion 84d, the brake fluid flowing into the opening-side damper portion 81a also flows out little by little to the fixed-member-side damper portion 81b through the upstream side hole 84c formed in the upstream-side movable member 84. This can prevent the pressure in the fixed member side damper 81b from rapidly rising after the valve member 94 is separated from the seat 84d.

The downstream side hole 85c is disposed in the center of the downstream side movable member 85, and a plurality of fixing member holes 86b are formed on the outer side in the circumferential direction than the downstream side hole 85 c. With such a configuration, the brake fluid flowing out of each of the fixing member holes 86b collides with the vicinity of the downstream side hole 85c by flowing to the center through the plurality of fixing member holes 86b, and the flow potential of the brake fluid becomes weak. As a result, the flow of the brake fluid can be stabilized.

Further, by the action of the respective elastic bodies, the rapid operation of the upstream side movable member 84 and the downstream side movable member 85 is blocked, and the flow of the brake fluid can be smoothed.

As described above, according to the present invention, the rapid operation of the upstream side movable member 84 and the downstream side movable member 85 is blocked by the action of each elastic body, and the rapid flow of the brake fluid is blocked by the action of each hole, whereby the flow of the brake fluid in the pulsation damping section 80 can be smoothed and the pressure pulsation can be damped. As a result, noise caused by pulsation generated at the time of driving the pump 60 can be attenuated.

Description of the reference numerals

51: matrix, 58: accommodation chamber, 58a: bottom, 60: pump, 80: pulsation damping section, 81, a: inflow opening side damper portions, 81b: fixed member side damping portion 81c: outflow opening side damper portion, 82: cover portion, 84: upstream movable members, 84b: through holes, 84c: upstream side holes, 84d: seat, 85: downstream-side movable member, 85c: downstream side holes, 86: fixing member, 86b: fixing part hole, 86d: cylindrical portion, 90: outflow opening side elastic body, 91: fixing member side elastic body, 92: inflow opening side elastic body, 94: valve member, 95b: inflow opening, 95c: and out of the opening.

Claims

1. A pump device provided in a base body (51) and having a pulsation damping section (80) for damping pulsation of brake fluid discharged from a pump (60),

the pulsation damping section (80) comprises:

a cylindrical housing chamber (58) provided in the base body (51);

a fixing member (86) that divides the housing chamber (58) into an upstream side region and a downstream side region;

an upstream movable member (84) provided in the upstream region and slidable in the axial direction; an inflow opening side damper portion (81 a) which communicates with an inflow opening (95 b) into which the brake fluid flows and is formed between the upstream side movable member (84) and a cover portion (82) of the housing chamber (58); a fixed member side damper portion (81 b) formed between the upstream side movable member (84) and the fixed member (86);

a downstream movable member (85) provided in the downstream region and capable of sliding in the axial direction; an outflow opening side damper portion (81 c) which communicates with an outflow opening (95 c) through which the brake fluid flows out and is formed between the downstream side movable member (85) and a bottom portion (58 a) of the housing chamber (58);

a fixing member hole (86 b) formed in the fixing member (86);

a downstream hole (85 c) formed in the downstream movable member (85);

an inflow opening side elastic body (92) provided to the inflow opening side damper portion (81 a) for biasing the upstream side movable member (84) toward the fixed member (86);

a fixed member side elastic body (91) provided to the fixed member side damper portion (81 b) and configured to bias the upstream side movable member (84) toward the cover portion (82); and

an outflow opening side elastic body (90) provided in the outflow opening side damper portion (81 c) and urging the downstream side movable member (85) toward the fixed member (86),

the fixing member (86) has a cylindrical portion (86 d) extending toward the cover portion (82),

the upstream movable member (84) is provided with a through hole (84 b), the through hole (84 b) is provided with a seat (84 d), the seat (84 d) is configured to be capable of being closed by being seated by a valve member (94) pressed from the cover (82) side,

the upstream movable member (84) is separated from the seat (84 d) by abutting the valve member (94) against the cylindrical portion (86 d) during movement to the fixed member (86) by the pressure caused by the brake fluid flowing into the inflow opening side damper portion (81 a), whereby the brake fluid flows into the through hole (84 b), the pressure of the fixed member side damper portion (81 b) increases,

the downstream movable member (85) in contact with the fixed member (86) moves toward the bottom (58 a) by the pressure increase of the fixed member side damper (81 b), and the brake fluid flows out from the outflow opening (95 c) through the fixed member hole (86 b) and the downstream side hole (85 c).

2. The pump apparatus of claim 1, wherein,

the downstream side hole (85 c) is formed in a radially central portion of the downstream side movable member (85), and a plurality of the fixed member holes (86 b) are formed radially outward of the downstream side hole (85 c) when viewed in the axial direction.

3. A pump device according to claim 1 or 2, wherein,

the upstream movable member (84) has an upstream hole (84 c) that communicates the inflow opening side damper portion (81 a) and the fixed member side damper portion (81 b) to each other on the outer side of the through hole (84 b) in the radial direction.