JP2022087562A - Pump device - Google Patents

Abstract

To reduce noise caused by the pulsation of a brake fluid which occurs during the driving of a pump.SOLUTION: A pulsation-reducing part (80) provided in a pump device includes a fixed member (86) which has a hole part (83b) in the center part thereof and divides an accommodation chamber (58) into an upstream-side region and a downstream-side region. The upstream-side region includes: an upstream-side mobile member (84); an inflow opening-side damper part (81a) accommodating an inflow opening-side elastic body (92); and a fixed member-side damper part (81b) accommodating a fixed member-side elastic body (91). The downstream-side region includes: a downstream-side mobile member (85); and an outflow opening-side damper part (81c) accommodating an outflow opening-side elastic body (96). The upstream-side mobile member (84) includes a through-hole (84b) having a seat part (84d) capable of being closed by a valve member (94). The valve member (94) can come into contact with a columnar part (86d) during the movement of the upstream-side mobile member (84).SELECTED DRAWING: Figure 3

Description

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

As a conventional brake system for vehicles, a main flow path that communicates the master cylinder and the wheel cylinder, a sub-flow path that allows the brake fluid in the main flow path to escape, and a supply flow path that supplies the brake fluid in the middle of the sub-flow path. Some are equipped with a hydraulic circuit having.

For example, the upstream end of the flow of brake fluid in the sub-flow path is connected to the wheel cylinder side region of the main flow path with respect to the filling valve, and the downstream end of the sub-flow path is It is connected to the area of the main flow path on the master cylinder side with respect to the filling valve. Further, the upstream end of the brake fluid flow in the supply flow path communicates with the master cylinder, and the downstream end of the supply flow path is the downstream end of the secondary flow path with respect to the slack valve. It is a region and is connected to the suction side of the pump provided in the region. Further, the first switching valve is provided in the region of the main flow path on the master cylinder side with respect to the connection portion with the downstream end of the sub flow path, and the second switching valve is provided in the middle of the supply flow path. A switching valve is provided.

For example, a hydraulic pressure control unit is composed of a filling valve, a slack valve, a pump, a first switching valve, a second switching valve, a substrate in which they are incorporated, and a controller that controls their operation. In the hydraulic pressure control unit, the hydraulic pressure of the hydraulic pressure circuit is controlled by controlling the operations of the filling valve, the loosening valve, the pump, the first switching valve, and the second switching valve.

In particular, when it becomes necessary to increase the hydraulic pressure of the brake fluid of the wheel cylinder regardless of the state of the brake operation at the input part of the brake system (for example, the brake pedal, etc.), the filling valve opens and the release valve opens. The pump is driven with the first switching valve closed, the second switching valve open, and the second switching valve open.

When the pump is driven, the pulsation generated in the brake fluid is transmitted from the brake system to the engine room of the vehicle, which may generate noise. This noise may be so loud that the user (driver) feels uncomfortable. For this reason, a conventional hydraulic pressure control unit for a brake system has been proposed to reduce the pulsation generated when the pump is driven. For example, the hydraulic pressure control unit of the brake system described in Patent Document 1 includes one pump in one hydraulic pressure circuit, and reduces the pulsation of the brake liquid discharged from the pump on the discharge side of the pump. It is equipped with a pulsation reduction unit.

Japanese Unexamined Patent Publication No. 2017-061246

In recent brake systems, the booster may be miniaturized or omitted for the purpose of improving the mountability of the brake system on a vehicle. In such a brake system, the hydraulic pressure of the brake fluid of the wheel cylinder is often insufficient, so that the number of times the pump is driven increases. That is, in such a brake system, noise caused by pulsation generated when the pump is driven is more likely to be generated. Therefore, in recent years, there has been a demand for further reduction of pulsation generated when the pump is driven.

According to the configuration of the hydraulic pressure control unit of the brake system described in Patent Document 1, as a configuration for further reducing the pulsation generated when the pump is driven, a liquid having a pulsation damper in which a plurality of metal diaphragms are superposed. Pressure braking devices have been proposed. However, in the structure in which a plurality of the same metal diaphragms are superposed, there is a limit in dealing with the pulsation caused by the characteristics of the hydraulic pressure control unit based on the difference in the output and the rotation speed of the pump motor.

The present invention has been made against the background of the above-mentioned problems, and provides a brake system capable of reducing noise caused by pulsation generated when a pump is driven.

The pump device according to the present invention is
In a pump device provided in a substrate and provided with a pulsation reducing portion for reducing the pulsation of the brake fluid discharged from the pump.
The pulsation reducing part is
A cylindrical storage chamber provided on the substrate and
The accommodation chamber is divided into an upstream area and a downstream area, and a fixing member having a hole in the center and a fixing member.
An axially slidable upstream movable member provided in the upstream region communicates with an inflow opening into which the brake fluid flows, and is between the upstream movable member and the lid of the accommodation chamber. The inflow opening side damper portion formed, the fixing member side damper portion formed between the upstream side movable member and the fixing member, and the fixing member side damper portion.
An axially movable downstream movable member provided in the downstream region communicates with an outflow opening through which the brake fluid flows, and an outflow formed between the fixing member and the bottom of the accommodation chamber. Opening side damper part and
An inflow opening side elastic body provided in the inflow opening side damper portion to urge the upstream side movable member toward the fixing member side.
A fixing member-side elastic body provided on the fixing member-side damper portion to urge the upstream-side movable member toward the lid portion.
An outflow opening side elastic body provided in the outflow opening side damper portion, which can close the hole portion of the fixing member by urging the downstream side movable member toward the fixing member side.
A columnar member having a columnar portion formed on the central axis of the accommodation chamber, penetrating the downstream movable member, and extending from the bottom portion to the fixed member side damper portion.
Including
The upstream movable member includes a through hole having a seat portion that can be closed by seating a valve member pressed from the lid portion side.
In the process of moving the upstream movable member to the fixing member side due to the pressure of the brake fluid flowing into the inflow opening side damper portion, the valve member abuts on the cylindrical portion and separates from the seat portion. As a result, the brake fluid flows in from the through hole, and the pressure of the damper portion on the fixing member side rises.
Due to the pressure increase of the fixing member side damper portion, the downstream side movable member that was in contact with the fixing member moves to the bottom side, the brake fluid passes through the outflow opening side damper portion, and the outflow opening. It is configured to flow out from.

In the brake system, it is possible to reduce the noise caused by the pulsation of the brake fluid generated when the pump is driven.

It is a figure which shows the example of the system configuration of the brake system which concerns on embodiment of this invention. It is a partial cross-sectional view which shows the example of the mounting state of the pump and the damper unit on the substrate in the hydraulic pressure control unit of the brake system which concerns on embodiment of this invention. It is sectional drawing of the pulsation reduction part in the state which a pump is not driving which concerns on embodiment of this invention. FIG. 5 is an enlarged cross-sectional view of a pulsation reducing portion in a state in which the upstream movable member is in the process of moving after the start of pump drive according to the embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of a pulsation reducing portion in a state in which brake fluid flows out from an outflow opening after the start of pump drive according to an embodiment of the present invention.

Hereinafter, the hydraulic pressure control unit according to the present invention will be described with reference to the drawings. In the following, a case where the brake system including the hydraulic pressure control unit according to the present invention is mounted on a four-wheeled vehicle will be described. However, the brake system including the hydraulic pressure control unit according to the present invention is described in four parts. It may be mounted on a vehicle other than a wheeled vehicle (motorcycle, truck, bus, etc.). Further, the configuration, operation, and the like described below are examples, and the brake system including the hydraulic pressure control unit according to the present invention is not limited to such a configuration, operation, and the like. Further, in each figure, the same or similar members or parts are designated by the same reference numerals, or the reference numerals are omitted. Further, for the fine structure, the illustration is simplified or omitted as appropriate.

<Configuration and operation of brake system 1>
The configuration and operation of the brake system 1 according to 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 the vehicle 100, and has a main flow path 13 that communicates the master cylinder 11 and the wheel cylinder 12, a sub flow path 14 that allows the brake fluid in the main flow path 13 to escape, and a sub flow path. A hydraulic circuit 2 having a supply flow path 15 for supplying the brake fluid to the flow path 14 is included. The hydraulic circuit 2 is filled with brake fluid.

The brake system 1 according to the present embodiment includes two hydraulic circuits 2a and 2b as the hydraulic pressure circuit 2. The hydraulic pressure circuit 2a is a hydraulic pressure circuit that communicates the master cylinder 11 with the wheel cylinders 12 of the wheels RL and FR by the main flow path 13. The hydraulic pressure circuit 2b is a hydraulic pressure circuit that communicates the master cylinder 11 with the wheel cylinders 12 of the wheels FL and RR by the main flow path 13. These hydraulic circuits 2a and 2b have the same configuration except that the wheel cylinders 12 that communicate with each other are different.

The master cylinder 11 has a built-in piston (not shown) that reciprocates in conjunction with the brake pedal 16 which is an example of the input unit of the brake system 1. A booster 17 is interposed between the brake pedal 16 and the piston of the master cylinder 11, and the pedaling force of the user is boosted and transmitted to the piston. The wheel cylinder 12 is provided on the brake caliper 18. When the hydraulic pressure of the brake fluid of the wheel cylinder 12 increases, the brake pad 19 of the brake caliper 18 is pressed against the rotor 20 to brake the wheels.

The upstream end of the sub-flow path 14 is connected to the first halfway portion 13a of the main flow path 13, and the downstream end of the sub-flow path 14 is on the upstream side of the first halfway portion 13a in the main flow path 13. , Is connected to the second intermediate portion 13b. Further, the upstream end of the supply flow path 15 communicates with the master cylinder 11, and the downstream end of the supply flow path 15 is connected to the third intermediate portion 14a of the sub flow path 14.

A filling valve (EV) 31 is provided in the region of the main flow path 13 between the second intermediate portion 13b and the first intermediate portion 13a. A slack valve (AV) 32 is provided in the region of the auxiliary flow path 14 between the first intermediate portion 13a and the third intermediate portion 14a. An accumulator 33 is provided in the region of the auxiliary flow path 14 between the loosening valve 32 and the third intermediate portion 14a. The filling valve 31 is, for example, a solenoid valve that opens in a non-energized state and closes in an energized state. The release valve 32 is, for example, a solenoid valve that closes in a non-energized state and opens in an energized state.

Further, a pump 60 is provided in a region of the sub-flow path 14 between the third intermediate portion 14a and the second intermediate portion 13b. The suction side of the pump 60 communicates with the third intermediate portion 14a. The discharge side of the pump 60 communicates with the second intermediate portion 13b of the main flow path 13. A pulsation reducing portion 80 is provided in a region between the discharge side of the pump 60, which is a part of the auxiliary flow path 14, and the second intermediate portion 13b.

The pulsation reducing unit 80 attenuates the pulsation of the brake fluid discharged from the pump 60. Specifically, the discharge side of the pump 60 is connected to the inflow opening 95b (see FIG. 2) into which the brake fluid of the pulsation reducing unit 80 flows, and the outflow opening through which the brake fluid temporarily stored in the pulsation reducing unit 80 flows out. The 95c (see FIG. 2) and the second intermediate portion 13b of the main flow path 13 are connected. In the following description, the flow path constituting between the discharge side of the pump 60 and the inflow opening 95b is defined as the first discharge flow path 140a, and the outflow opening 95c and the second intermediate portion 13b of the main flow path 13 are defined. The constituent flow path will be referred to as a second discharge flow path 140b.

A first switching valve (USV) 35 is provided in a region of the main flow path 13 on the master cylinder 11 side with respect to the second intermediate portion 13b. The supply flow path 15 is provided with a second switching valve (HSV) 36 and a damper unit 37. The damper unit 37 is provided in the region of the supply flow path 15 between the second switching valve 36 and the third intermediate portion 14a of the sub-flow path 14. The first switching valve 35 is, for example, a solenoid valve that opens in a non-energized state and closes in an energized state. The second switching valve 36 is, for example, a solenoid valve that closes in a non-energized state and opens in an energized state.

The filling valve 31, the loosening valve 32, the accumulator 33, the pump 60, the first switching valve 35, the second switching valve 36, the damper unit 37, and the pulsation reducing unit 80 are the main flow path 13, the sub flow path 14, and the supply flow. A flow path for forming the path 15 is provided on the substrate 51 formed inside. Each member (filling valve 31, loosening valve 32, accumulator 33, pump 60, first switching valve 35, second switching valve 36, damper unit 37, and pulsation reducing unit 80) is collectively provided on one substrate 51. It may be provided separately, or it may be provided separately in a plurality of substrates 51.

At least, the hydraulic pressure control unit 50 is configured by the substrate 51, each member provided on the substrate 51, and the controller (ECU) 52. In the hydraulic pressure control unit 50, the brake fluid of the wheel cylinder 12 is controlled by the operation of the filling valve 31, the loosening valve 32, the pump 60, the first switching valve 35, and the second switching valve 36 by the controller 52. Hydraulic pressure is controlled. That is, the controller 52 controls the operation of the filling valve 31, the loosening valve 32, the pump 60, the first switching valve 35, and the second switching valve 36.

The controller 52 may be one or may be divided into a plurality of controllers 52. Further, the controller 52 may be attached to the substrate 51, or may be attached to another member. Further, a part or all of the controller 52 may be configured by, for example, a microcomputer, a microprocessor unit, or the like, or may be configured by an updatable one such as firmware, or a command from a CPU or the like. It may be a program module or the like executed by.

The controller 52, for example, performs the following hydraulic pressure control operation in addition to the well-known hydraulic pressure control operation (ABS control operation, ESP control operation, etc.). When the brake pedal 16 of the vehicle 100 is operated with the filling valve 31 opened, the loosening valve 32 closed, the first switching valve 35 opened, and the second switching valve 36 closed. When it is detected from the detection signal of the position sensor of the brake pedal 16 and the detection signal of the hydraulic pressure sensor of the hydraulic pressure circuit 2 that the hydraulic pressure of the hydraulic pressure circuit 2 is insufficient or may be insufficient, the controller 52 determines. The active boost control operation is started.

In the active boost control operation, the controller 52 keeps the filling valve 31 in the open state, thereby allowing the brake fluid to flow from the second intermediate portion 13b of the main flow path 13 to the wheel cylinder 12. Further, the controller 52 limits the flow of the brake fluid from the wheel cylinder 12 to the accumulator 33 by keeping the release valve 32 in the closed state. Further, the controller 52 closes the first switching valve 35 to limit the flow of the brake fluid in the flow path from the master cylinder 11 to the second intermediate portion 13b of the main flow path 13 without going through the pump 60. Further, the controller 52 opens the second switching valve 36 to enable the flow of the brake fluid in the flow path from the master cylinder 11 to the second intermediate portion 13b of the main flow path 13 via the pump 60. Further, the controller 52 raises (increases) the hydraulic pressure of the brake fluid of the wheel cylinder 12 by driving the pump 60.

When the elimination or avoidance of the insufficient hydraulic pressure of the hydraulic pressure circuit 2 is detected, the controller 52 opens the first switching valve 35, closes the second switching valve 36, and stops the drive of the pump 60. By doing so, the active pressure boost control operation is terminated.

Here, when the pump 60 is driven, the pulsation generated in the brake fluid may be transmitted to the wheel cylinder 12 through the sub flow path 14 and the main flow path 13. Then, this pulsation is also transmitted to the engine room accommodating the hydraulic pressure control unit 50 of the brake system 1, and noise may be generated. This noise may be so loud that the user (driver) feels uncomfortable. Therefore, it is important to reduce the pulsation generated when the pump 60 is driven.

Therefore, in the brake system 1, that is, the hydraulic pressure control unit 50 according to the present embodiment, the brake fluid discharged from the pump 60 flows into the pulsation reducing unit 80. Then, the brake fluid that has flowed into the pulsation reducing unit 80 will flow from the pulsation reducing unit 80 to the downstream side after the pulsation is attenuated in the pulsation reducing unit 80. Therefore, the brake system 1, that is, the hydraulic pressure control unit 50 according to the present embodiment can reduce the pulsation generated when the pump 60 is driven.

In the above-mentioned active pressure boosting control, the user operates (steps on) the brake pedal 16 and the pump 60 is driven with the second switching valve 36 open. Therefore, the pulsation generated in the brake fluid propagates to the brake pedal 16 via the supply flow path 15 and the master cylinder 11, which gives the user a sense of discomfort. Therefore, it is preferable that the brake system 1, that is, the hydraulic pressure control unit 50 according to the present embodiment includes the damper unit 37 as shown in FIG. This is because the damper unit 37 can attenuate the pulsation of the brake fluid propagating from the pump 60 to the brake pedal 16.

When the damper unit 37 is provided in the brake system 1 in which the booster 17 is omitted, the damper unit 37 is located between the upstream end portion of the supply flow path 15 and the second switching valve 36. It may be provided in the area. 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 brake fluid in the hydraulic circuit 2 transmitted to the brake pedal 16 can be discharged. The reaction force is reduced. Therefore, when the user depresses the brake pedal, the depressing amount of the brake pedal 16 similar to that of the brake system 1 provided with the booster 17 can be obtained. Therefore, the user can obtain the same usability as the brake system 1 provided with the booster 17 in the brake system 1 in which the booster 17 is omitted.

<Pump 60 and pulsation reducing unit 80 mounted on the substrate 51>
An example of the configuration when the pump 60 and the pulsation reducing unit 80 are mounted on the substrate 51 in the hydraulic pressure 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 state in which the pump 60 and the pulsation reducing unit 80 are mounted on the substrate in the hydraulic pressure 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 for driving the piston 62 of the pump 60 is removed. Therefore, in FIG. 2, the drive shaft 57 and the eccentric portion 57a formed on the drive shaft 57 are illustrated by an imaginary line (dashed-dotted line).

As shown in FIG. 2, the substrate 51 is formed with a drive shaft accommodating chamber 59 provided with a drive shaft 57 for driving the piston 62 of the pump 60. The drive shaft accommodating chamber 59 is a bottomed hole formed in the outer wall of the substrate 51. Further, the substrate 51 is formed with a pump accommodating chamber 53 accommodating the pump 60. The pump accommodating chamber 53 is a cylindrical, stepped hole that penetrates from the outer wall of the substrate 51 to the drive shaft accommodating chamber 59.

The pump 60 housed in the pump housing chamber 53 includes a cylinder 61, a piston 62, and the like. The cylinder 61 is formed in a cylindrical shape having a cylinder bottom portion 61b. One end side of the piston 62 is housed in the cylinder 61. The space surrounded by the inner peripheral surface of the cylinder 61 and the one end of the piston 62 becomes the pump chamber 63. The piston 62 is reciprocating in the axial direction of the cylinder 61. Further, the end portion 62a, which is the end portion on the other end side 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 housed in the cylinder 61. The cylinder-side seal member 66 prevents the brake fluid from leaking between the outer peripheral surface of the piston 62 and the inner peripheral surface of the cylinder 61.

Further, in the cylinder 61, a piston spring 67 is housed between the cylinder bottom portion 61b and the piston 62, that is, in the pump chamber 63. The piston 62 is constantly urged toward the drive shaft accommodating chamber 59 by the piston spring 67. As a result, the end portion 62a of the piston 62 is in contact with the eccentric portion 57a formed on the drive shaft 57 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 undergoes an eccentric rotational movement with respect to the rotation center of the drive shaft 57. That is, the eccentric rotation of the eccentric portion 57a causes the piston 62 whose end portion 62a is in contact with the eccentric portion 57a to reciprocate in the axial direction of the cylinder 61.

The portion of the piston 62 protruding from the cylinder 61 is slidably guided by a piston guide member 68 provided on the inner peripheral surface of the pump accommodating chamber 53. Further, in the pump accommodating chamber 53, an annular drive shaft side seal member 69 is attached adjacent to the piston guide member 68. The drive shaft side seal member 69 prevents the brake fluid from leaking from the outer peripheral surface of the piston 62 to the drive shaft accommodating chamber 59 side.

The piston 62 is formed with a bottomed hole 62b that opens in the axial direction on the pump chamber 63 side of the cylinder 61. The piston 62 is also formed with a suction port 62c that communicates the outer peripheral surface thereof with the bottomed hole 62b. Further, the piston 62 is provided with a suction valve (not shown) for closing the opening of the bottomed hole 62b so as to be openable and closable. The suction valve includes a suction valve member that is a ball valve that closes the opening of the bottomed hole 62b, and a suction valve spring that urges the suction valve member from the cylinder 61 side. Further, a cylindrical filter 70 is attached to the end of the cylinder 61 on the piston 62 side so as to cover the opening of the suction port 62c of the piston 62.

A communication hole 61c is formed in the bottom portion 61b of the cylinder to communicate the pump chamber 63 and the outside of the cylinder 61. 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 which is a ball valve, and an opening side valve seat 64b which is formed on the peripheral edge of the opening end of the communication hole 61c and on which the opening side valve member 64a can be attached and detached. The opening-side valve member 64a is provided with an opening-side spring 64c that urges the opening-side valve seat 64a to be seated on the opening-side valve seat 64b. The opening side discharge valve 64 is arranged between the cylinder 61 and the cover 65.

Specifically, the cover 65 is attached to the cylinder bottom 61b side by, for example, press fitting. The cover 65 is formed with a bottomed hole 65a having an opening at a position facing the communication hole 61c of the cylinder bottom portion 61b. The opening side spring 64c of the opening side discharge valve 64 is housed in the bottomed hole 65a. Further, the inner diameter of the bottomed hole 65a is larger than the outer diameter of the opening side valve member 64a. 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 liquid in the pump chamber 63 of the cylinder 61 rises and the force by which the brake liquid pushes the opening side valve member 64a becomes larger than the urging force of the opening side spring 64c, the opening The 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 through the communication hole 61c. Then, the brake fluid in the pump chamber 63 will flow into the bottom hole 65a. The cover 65 is formed with a groove as a discharge port 65b that communicates the outside of the cover 65 with the bottomed hole 65a. The brake fluid that has flowed into the bottomed hole 65a of the cover 65 is discharged from the discharge port 65b to the outside of the pump 60 through the discharge chamber 54 described later.

The pump 60 configured in this way is housed in the pump storage chamber 53 formed in the substrate 51 as described above. Specifically, since the annular protruding portion 61a formed on the outer peripheral portion of the cylinder 61 is press-fitted into a position where it abuts on the stepped portion 53a of the pump accommodating chamber 53, the pump 60 is inside the pump accommodating chamber 53 of the base 51. Is fixed to.

When the pump 60 is accommodated in the pump accommodating chamber 53 in this way, the discharge chamber 54 is a space that communicates with the discharge port 65b of the pump 60 between the outer peripheral surface of the pump 60 and the inner peripheral surface of the pump accommodating chamber 53. Is formed. The discharge chamber 54 is a space formed in an annular shape 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 first discharge flow path 140a as described later.

Further, in the pump 60, the space between the annular protrusion 61a of the cylinder 61 and the cover 65 is divided into two spaces by the partition portion 71. The space on the cover 65 side of the partition portion 71 is the discharge chamber 54. In the present embodiment, an O-ring (not shown) is provided in the annular groove formed in the partition portion 71.

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

The annular flow path 56 communicates with the third intermediate portion 14a of the sub-flow path 14 in FIG. 1 by an internal flow path (not shown) formed on the substrate 51. In other words, the annular flow path 56 constitutes a part of the sub-flow path 14. When the pump 60 is housed in the pump storage chamber 53, it is necessary that the suction port 62c of the pump 60 and the third intermediate portion 14a communicate with each other. By having the annular flow path 56, when the pump 60 is accommodated in the pump accommodating chamber 53, it is not necessary to align the suction port 62c of the pump 60 with the third intermediate portion 14a. Therefore, having the annular flow path 56 facilitates the assembly of the hydraulic pressure control unit 50. Further, by having the annular flow path 56, when the pump accommodating chamber 53 is processed into the substrate 51, a part of the sub-flow path 14 is also processed. Therefore, the processing cost of the substrate 51, that is, the manufacturing cost of the hydraulic pressure control unit 50 can be reduced. Further, by having the annular flow path 56, the space on the outer peripheral side of the pump 60 can be effectively used as the sub-flow path 14, so that the substrate 51, that is, the hydraulic pressure control unit 50 can be miniaturized.

The accommodation chamber 58 is an accommodation chamber for accommodating the pulsation reducing portion 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 first discharge flow path 140a forming a part of the discharge flow path 140. The discharge chamber 54 is connected to the inflow opening 95b of the pulsation reducing unit 80 via the first discharge flow path 140a. In FIG. 2, the brake fluid is configured to flow from the lateral direction with respect to the axis of the accommodation chamber 58 of the pulsation reducing unit 80. The outflow opening 95c located at the bottom of the accommodation chamber 58 is connected to the second discharge flow path 140b. The second discharge flow path 140b communicates with the second intermediate portion 13b of the main flow path 13 in FIG. 1 by an internal flow path (not shown) formed on the substrate 51.

When the pump 60 and the pulsation reducing unit 80 are mounted on the substrate 51 as shown in FIG. 2, when the pump 60 is driven, the brake fluid flows as follows.

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

When the drive shaft 57 further rotates and the eccentric portion 57a formed on the drive shaft 57 begins to rotate in a direction away from the piston 62, the piston 62 moves away from the cylinder 61 due to the urging force of the piston spring 67. I will move. Therefore, the pressure in the pump chamber 63 becomes low, the opening side valve member 64a sits on the opening side valve seat 64b, the opening side discharge valve 64 closes, and the opening of the bottomed hole 62b of the piston 62 is closed. A suction valve (not shown) that closes freely opens and closes. As a result, the brake fluid in the annular flow path 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 further rotates and the eccentric portion 57a formed on the drive shaft 57 approaches the piston 62 again, the piston 62 is pressed toward the cylinder 61 as described above, and the inside of the pump chamber 63. Brake fluid is discharged from the discharge port 65b to the discharge chamber 54. In this way, 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) are selectively opened and closed, so that the hydraulic pressure is increased, that is, the pressure is increased. The brake fluid is discharged from the discharge port 65b to the discharge chamber 54. Therefore, pulsation is generated in the brake fluid boosted by the pump 60. The brake fluid accompanied by this pulsation flows into the pulsation reducing unit 80 via the first discharge flow path 140a.

<Structure example and operation of pulsation reduction unit 80>
Hereinafter, a configuration example and operation of the pulsation reducing unit 80 will be described with reference to FIGS. 3 to 5. As described above, the pulsation reducing unit 80 is for reducing the pulsation of the brake fluid generated when the pump 60 is driven and reducing the noise caused by the pulsation.

FIG. 3 shows a pulsation reducing unit 80 in a state where the pump 60 is not driven. The cylindrical storage chamber 58 that houses the pulsation reducing portion 80 is formed in the base 51. The pulsation reducing unit 80 includes an inflow opening 95b into which the brake fluid flows in and an outflow opening 95c in which the brake fluid flows out. Further, the pulsation reducing unit 80 includes a fixing member 83 that divides the inside of the pulsation reducing unit 80 into an upstream region on the inflow opening 95b side and a downstream region on the outflow opening 95c side.

The cylindrical shape forming the storage chamber 58 is a stepped shape including a small diameter portion 58b and a large diameter portion 58d. A large diameter portion 58d is formed on the side of the lid 82 that closes the opening 58e of the storage chamber 58, and a small diameter portion 58b is formed on the bottom portion 58a side opposite to the opening 58e of the storage chamber 58. 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 reducing portion 80. The inflow opening 95b is formed in the large diameter portion 58d. The outflow opening 95c is formed on the bottom portion 58a on the outer side in the radial direction with respect to the damper member 90 described later.

The fixing member 83 includes a fixing member disk portion 83a having a cylindrical hole portion 83b in the central portion. The hole portion 83b is formed as a cylinder extending from the fixing member disk portion 83a to the upstream region. Further, the fixing member 83 includes a fixing member outer cylindrical portion 83d extending from the outer peripheral portion of the fixing member disk portion 83a toward the bottom portion 58a. The fixing member disk portion 83a, the hole portion 83b, and the fixing member outer cylindrical portion 83d are integrally formed. The fixing member 83 is fixed to the small diameter portion 58b of the accommodation chamber 58 by an appropriate method such as press fitting or welding. At that time, the fixing member outer cylindrical portion 83d is arranged so as to abut on the small diameter portion 58b.

Further, the pulsation reducing portion 80 includes a columnar member 86 extending from the central portion of the bottom portion 58a to the upstream region. The columnar member 86 includes a columnar member fixing portion 86b for fixing the columnar member 86 to the bottom portion 58a, and a columnar portion 86d extending from the columnar member fixing portion 86b to the upstream region. The cylindrical portion 86d has a diameter smaller than the inner diameter of the hole portion 83b, and is arranged so that the tip portion is located closer to the lid portion 82 than the lower end portion of the hole portion 83b. Further, the columnar member fixing portion 86b includes a disk-shaped portion to which the columnar portion 86d is connected, and a cylindrical portion extending from the outer diameter portion of the disk-shaped portion to the side opposite to the bottom portion 58a. The disk-shaped portion and the cylindrical portion are fixed by an appropriate method such as welding while being inserted into the recess 58f formed in the bottom portion 58a. With such a configuration, the positioning of the columnar member 86 becomes easy.

On the fixing member 83 side of the large diameter portion 58d with respect to the inflow opening 95b, an upstream movable member 84 having a disk shape and slidable in the axial direction Axc of the accommodation chamber 58 is provided. A sliding member 84a is attached to the side surface of the upstream movable member 84 facing the large diameter portion 58d. When the upstream movable member 84 moves, the sliding member 84a slides with respect to the large diameter portion 58d. In order to smooth the sliding, for example, PTFE can be adopted as the material of the sliding member 84a.

The upstream movable member 84 is provided with a through hole 84b penetrating in the axis Axc direction of the accommodation chamber 58 in the central portion. The through hole 84b is provided with a seat portion 84d on which the valve member 94 can be seated on the lid portion 82 side. The valve member 94 is pressed against the seat portion 84d by a predetermined setting force by a valve spring 93 provided between the inner surface 82a of the lid portion, which is the surface of the lid portion 82 on the upstream side movable member 84 side, and the valve member 94. .. A plurality of upstream orifices 84c having a diameter smaller than that of the through hole 84b are formed on the outer side in the radial direction of the through hole 84b so as to penetrate the upstream movable member 84 in the axial direction Axc of the accommodation chamber 58.

In the present embodiment, the region between the upstream movable member 84 and the lid 82 in the accommodation chamber 58 is the inflow opening side damper portion 81a, and the region between the upstream movable member 84 and the fixing member 83 is the fixed member side damper. The region between the portion 81b, the fixing member 83 and the bottom portion 58a is referred to as an outflow opening side damper portion 81c. That is, in the accommodation chamber 58, the inflow opening side damper portion 81a and the fixing member side damper portion 81b form an upstream region of the accommodation chamber 58, and the outflow opening side damper portion 81c forms a downstream region of the accommodation chamber 58.

The inflow opening side damper portion 81a is provided with an inflow opening side elastic body 92 which is an elastic body that urges the upstream side movable member 84 toward the fixing member 83 side. The fixed member side damper portion 81b is provided with a fixed member side elastic body 91 which is an elastic body that urges the upstream side movable member 84 toward the lid portion 82 side.

A coil spring can be used as the inflow opening side elastic body 92. The inflow opening side elastic body 92 is arranged outside the valve spring 93 and the upstream orifice 84c in the circumferential direction.

The elastic body 91 on the fixing member side can be a cylindrical cushion member. As the material of the cushion member, for example, a material such as ethylene, propylene, diene rubber (EPDM) and / or silicon can be used. The elastic body 91 on the fixing member side is arranged so that the inner diameter portion is in contact with the outer diameter portion of the hole portion 83b. In other words, the elastic body 91 on the fixing member side is guided by the hole portion 83b.

When the cushion member is used as the elastic body, the cushion member may be formed of one material or may be formed of a plurality of materials. For example, EPDM having a relatively low elastic modulus may be sandwiched between silicon having a relatively high elastic modulus. The combination of materials makes it possible to adjust the elastic modulus of the cushion member according to the inherent pulsation frequency caused by the performance of the brake fluid pump.

The outflow opening side damper portion 81c is provided with a downstream side movable member 85 that can move in the axis Axc direction of the accommodation chamber 58. The downstream movable member 85 includes a downstream movable member disk portion 85a having a hole in the center portion and a downstream side movable member cylindrical portion 85b extending from the inner diameter portion of the central hole of the downstream side movable member disk portion 85a toward the bottom portion 58a. Has. Further, the downstream movable member 85 includes a downstream movable member diameter expanding portion 85c that faces the bottom 58a side from the outer peripheral portion of the downstream movable member disk portion 85a and whose diameter increases as it approaches the bottom portion 58a. The downstream side movable member disk portion 85a, the downstream side movable member cylindrical portion 85b, and the downstream side movable member enlarged diameter portion 85c are integrally formed.

The cylindrical portion 86d is inserted through the inside of the downstream movable member cylindrical portion 85b. In other words, the cylindrical portion 86d guides the movement of the downstream movable member 85.

An outflow opening side elastic body 96, which is a coil spring that urges the downstream movable member 85 toward the fixing member 83, is arranged between the downstream movable member disk portion 85a and the columnar member fixing portion 86b. As shown in FIG. 3, the outflow opening side elastic body 96 is arranged on the outer peripheral side of the downstream side movable member cylindrical portion 85b and is guided by the downstream side movable member cylindrical portion 85b.

A damper member 90 is provided between the downstream side movable member disk portion 85a and the bottom portion 58a on the outer side in the circumferential direction of the outflow opening side elastic body 96. The damper member 90 is arranged so that the outer peripheral portion is in contact with the downstream side movable member diameter expanding portion 85c, and is guided by the downstream side movable member diameter expanding portion 85c. For the damper member 90, it is possible to use an elastic body under the same conditions as the above-mentioned fixed member side elastic body 91.

In the state shown in FIG. 3, that is, in the state where the pump 60 is not driven, the upstream movable member 84 receives the urging force from the fixed member side elastic body 91 toward the lid 82, while the valve spring 93 and the inflow opening side. It receives an urging force from the elastic body 92 toward the fixing member 83 side. As a result, the urging force of each elastic body is adjusted so that the upstream movable member 84 is located between the stepped portion 58c and the inflow opening 95b in the large diameter portion 58d. Further, in this state, the valve member 94 and the cylindrical portion 86d are not in contact with each other. Further, the downstream movable member disk portion 85a of the downstream movable member 85 abuts on the fixing member disk portion 83a of the fixing member 83 by the urging force received from the outflow opening side elastic body 96 and the damper member 90, and the hole portion 83b is formed. It is blocked.

When the pump 60 starts driving, the brake fluid flows in from the inflow opening 95b, and the pressure of the inflow opening side damper portion 81a rises. When the pressure of the inflow opening side damper portion 81a rises, the valve member 94 and the upstream movable member 84 move to the fixing member 83 side with the valve member 94 seated on the seat portion 84d.

Then, the valve member 94 comes into contact with the columnar portion 86d of the columnar member 86, but the upstream movable member 84 continues to move. Therefore, the valve member 94 is separated from the seat portion 84d at this timing. After that, the upstream movable member 84 comes into contact with the stepped portion 58c, and the movement is completed. That is, the dimensions of each member are set in advance so that the amount of movement of the upstream movable member 84 is larger than the amount of movement 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 still in contact with the seat portion 84d. After passing through this state, the upstream movable member 84 moves further and comes into contact with the step portion 58c.

As the valve member 94 and the upstream movable member 84 rise, the pressure of the fixing member side damper portion 81b also rises. Then, when the valve member 94 is separated from the seat portion 84d, the brake fluid flows from the inflow opening side damper portion 81a to the fixing member side damper portion 81b through the through hole 84b, so that the pressure of the fixing member side damper portion 81b is further increased. Rise. Then, the pressure increase of the damper portion 81b on the fixing member side acts on the movable member 85 on the downstream side, and the downstream movable member 85 moves toward the bottom 58a side against the urging force of the elastic body 96 on the outflow opening side and the damper member 90. Move it.

FIG. 5 shows a state in which the downstream movable member 85 has moved to the bottom 58a side. When the downstream movable member 85 moves to the bottom 58a side, the brake fluid flows out from the fixed member side damper portion 81b to the outflow opening side damper portion 81c. The brake fluid that has flowed out to the outflow opening side damper portion 81c flows out from the outflow opening 95c to the outside of the pulsation reducing portion 80.

In the present embodiment, even when the valve member 94 is seated on the seat portion 84d immediately after the pump 60 is driven, the brake fluid of the inflow opening side damper portion 81a is formed on the upstream side movable member 84. It gradually flows out to the fixing member side damper portion 81b through the upstream side orifice 84c. Therefore, it is possible to prevent the pressure in the damper portion 81b on the fixing member side from suddenly increasing after the valve member 94 is separated from the seat portion 84d.

Further, due to the action of each elastic body, the sudden movement of the upstream movable member 84 and the downstream movable member 85 is hindered, and the flow of the brake fluid can be moderated.

Further, since the damper member 90 functions as a resistance to the elastic body 96 on the outflow opening side, the movement of the downstream movable member 85 can be stabilized.

As described above, according to the present invention, the action of each elastic body and the orifice hinders the sudden movement of the upstream movable member 84 and the downstream movable member 85, and the sudden flow of the brake fluid. Is hindered. As a result, the flow of the brake fluid in the pulsation reducing unit 80 becomes gentle, and the pressure pulsation of the brake fluid can be reduced. As a result, it is possible to reduce the noise caused by the pulsation generated when the pump 60 is driven.

51: Substrate, 58: Containment chamber, 58a: Bottom, 60: Pump, 80: Pulsation reduction part, 81a: Inflow opening side damper part, 81b: Fixing member side damper part, 81c: Outflow opening side damper part, 82: Lid Part, 83: Fixing member, 83b: Hole, 84: Upstream movable member, 84b: Through hole, 84c: Upstream orifice, 84d: Seat, 85: Downstream movable member, 86: Cylindrical member, 86d: Cylindrical part, 90: damper member, 91: fixing member side elastic body, 92: inflow opening side elastic body, 94: valve member, 95b: inflow opening, 95c: outflow opening, 96: outflow opening side elastic body

Claims (5)

In a pump device provided in the substrate (51) and provided with a pulsation reducing unit (80) for reducing the pulsation of the brake fluid discharged from the pump (60).
The pulsation reduction unit (80) is
A cylindrical storage chamber (58) provided on the substrate (51) and
The accommodation chamber (58) is divided into an upstream side region and a downstream side region, and a fixing member (83) having a hole portion (83b) in the center and a fixing member (83).
An upstream movable member (84) provided in the upstream region and slidable in the axial direction communicates with an inflow opening (95b) into which the brake fluid flows, and the upstream movable member (84) and the said. It is formed between the inflow opening side damper portion (81a) formed between the lid portion (82) of the accommodation chamber (58) and the upstream side movable member (84) and the fixing member (83). Fixing member side damper part (81b) and
The downstream movable member (85) provided in the downstream region and movable in the axial direction communicates with the outflow opening (95c) through which the brake fluid flows, and the fixing member (83) and the accommodating chamber ( The outflow opening side damper portion (81c) formed between the bottom portion (58a) of 58) and the outflow opening side damper portion (81c).
An inflow opening side elastic body (92) provided in the inflow opening side damper portion (81a) to urge the upstream side movable member (84) toward the fixing member (83) side.
A fixing member-side elastic body (91) provided on the fixing member-side damper portion (81b) to urge the upstream-side movable member (84) toward the lid portion (82).
By urging the downstream movable member (85) provided in the outflow opening side damper portion (81c) toward the fixing member (83), the hole portion (83b) of the fixing member (83) is closed. Possible outflow opening side elastic body (96) and
A columnar portion (86d) formed on the central axis of the accommodation chamber (58), penetrating the downstream movable member (85), and extending from the bottom portion (58a) to the fixing member side damper portion (81b). Cylindrical member (86) and
Including
The upstream movable member (84) has a through hole (84b) having a seat portion (84d) that can be closed by seating a valve member (94) pressed from the lid portion (82) side. Prepare,
In the process of moving the upstream movable member (84) to the fixing member (83) side by the pressure of the brake fluid flowing into the inflow opening side damper portion (81a), the valve member (94) is the columnar portion. By abutting on (86d) and separating from the seat portion (84d), the brake fluid flows in from the through hole (84b) and the pressure of the fixing member side damper portion (81b) rises.
Due to the pressure increase of the fixing member side damper portion (81b), the downstream side movable member (85) that was in contact with the fixing member (83) moves to the bottom portion (58a) side, and the brake fluid is discharged. A pump device that passes through the outflow opening side damper portion (81c) and flows out from the outflow opening (95c). The outflow opening side elastic body (96) is a coil spring, and the outflow opening side elastic body (96) is located between the downstream movable member (85) and the bottom portion (58a) of the accommodation chamber (58). The pump device according to claim 1, further comprising a damper member (90) that absorbs vibration. The outflow opening (95c) communicates with the outflow opening side damper portion (81c) on the radial outer side of the outflow opening side elastic body (96) and the damper member (90), according to claim 1 or 2. The pump device described. The upstream movable member (84) has an upstream orifice (84c) that communicates the inflow opening side damper portion (81a) and the fixing member side damper portion (81b) to the outside in the radial direction of the through hole (84b). ), The pump device according to any one of claims 1 to 3. The pump device according to any one of claims 1 to 4, wherein the columnar member (86) guides the movement of the downstream movable member (85).

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