KR20230113366A - pump unit - Google Patents

Abstract

Reduces the noise caused by the pulsation of the brake fluid generated when the pump is driven. The pulsation reducing unit 80 provided in the pump device includes a fixing member 86 that divides the storage chamber 58 with the fixing member orifice 86b into an upstream region and a downstream region. The upstream region includes an upstream movable member 84, an inflow opening side damper portion 81a accommodating the inflow opening side elastic body 92, and a stationary member side damper portion accommodating the stationary member side elastic body 91 ( 81b). The downstream area includes a downstream movable member 85 having a downstream orifice 85c and an outflow opening side damper portion 81c accommodating the outflow opening side elastic body 90 . The fixing member 86 extends toward the cover portion 82 side and has a cylindrical portion 86d capable of abutting the valve member 94, and the upstream movable member 84 is closed by the valve member 94. A through hole 84b having an enabling seat portion 84d is provided.

Description

pump unit

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

As a conventional vehicle brake system, a main fluid passage for communicating a master cylinder and a wheel cylinder, a secondary fluid passage for discharging brake fluid from the main fluid passage, and a supply fluid passage for supplying brake fluid to a midway portion of the auxiliary fluid passage Some have a hydraulic circuit.

For example, the upstream end of the auxiliary fluid passage in the flow of brake fluid is connected to the area of the main fluid passage on the wheel cylinder side relative to the inlet valve, and the downstream end of the auxiliary fluid passage is the main fluid passage. It is connected to an area on the master cylinder side with respect to the inlet valve in the fluid passage. Further, the upstream end of the supply fluid passage in the flow of brake fluid communicates with the master cylinder, and the downstream end of the supply fluid passage is a downstream region of the auxiliary fluid passage with respect to the outlet valve. , connected to the suction side of the pump installed in that area. In addition, a first selector valve is provided in an area of the main fluid passage on the master cylinder side based on the connection with the downstream end of the auxiliary fluid passage, and a second selector valve is provided in the midway portion of the supply fluid passage. has been

For example, a hydraulic pressure control unit is constituted by an inlet valve, an outlet valve, a pump, a first selector valve, and a second selector valve, a base body in which they are contained, and a controller in charge of their operation. In the hydraulic pressure control unit, the hydraulic pressure in the hydraulic circuit is controlled by controlling the operations of the inlet valve, the outlet valve, the pump, the first selector valve, and the second selector valve.

In particular, when it is necessary to increase the hydraulic pressure of the brake fluid in the wheel cylinder regardless of the state of brake operation at the input part of the brake system (eg brake pedal, etc.), the inlet valve is opened and the outlet valve is closed, The pump is driven with the first selector valve closed and the second selector valve open.

When the pump is driven, pulsations generated in the brake fluid are transmitted from the brake system to the engine compartment of the vehicle, and noise may be generated. This noise may be so loud that the user (driver) feels uncomfortable. For this reason, in the conventional hydraulic pressure control unit of the brake system, one aimed at reducing the pulsation generated during pump driving has been proposed. For example, the hydraulic pressure control unit of a brake system described in Patent Document 1 includes one pump in one hydraulic circuit, and a pulsation reducing unit for reducing pulsation of the brake fluid discharged from the pump on the discharge side of the pump. are equipped

[Patent Document 1] Japanese Unexamined Patent Publication No. 2017-061246

In today's brake systems, for the purpose of improving mountability of the brake system on a vehicle, there are cases where the booster is downsized or omitted. In such a brake system, since the hydraulic pressure of the brake fluid in the wheel cylinder is often insufficient, 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 occur. For this reason, in recent years, there has been a demand for further reduction of pulsation generated during driving of the pump.

As a configuration for realizing further reduction of pulsation generated during pump driving, according to the configuration of a hydraulic pressure control unit of a brake system described in Patent Document 1, a hydraulic braking device having a pulsation damper in which a plurality of metal diaphragms are overlapped is proposed. there is. However, in a structure in which a plurality of identical metal diaphragms are overlapped, there is a limit to responding to pulsation caused by the characteristics of the hydraulic pressure control unit based on the output of the pump motor or the difference in rotational speed.

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 during driving of a pump.

The pump device according to the present invention,

In the pump device having a pulsation reducing unit installed in the base body to reduce the pulsation of the brake fluid discharged from the pump,

The pulsation reducing unit,

A cylindrical accommodation chamber installed in the base body;

a fixing member dividing the accommodation chamber into an upstream region and a downstream region;

An upstream side movable member provided in the upstream region and capable of sliding in the axial direction communicates with an inflow opening through which the brake fluid flows, and is formed between the upstream side movable member and the lid portion of the accommodation chamber. a fixed member-side damper portion formed between the upstream-side movable member and the fixed member;

A downstream movable member provided in the downstream region and capable of sliding in the axial direction communicates with an outflow opening through which the brake fluid flows out, and is formed between the downstream movable member and the bottom of the accommodation chamber. wealth,

a fixing member orifice formed in the fixing member;

a downstream orifice formed in the downstream movable member;

an inlet-opening-side elastic body that presses the upstream-side movable member provided in the inlet-side damper portion toward the fixing member;

a fixing member-side elastic body for pressing the upstream-side movable member provided in the fixing-member-side damper portion toward the lid portion;

an outflow opening side elastic body for pressing the downstream movable member provided in the outflow opening side damper unit toward the fixing member side;

The fixing member has a cylindrical portion extending toward the cover portion,

The upstream movable member has a through hole having a seat portion configured to be closed by seating a valve member pressed from the lid portion side,

In the process of moving the upstream movable member toward the fixing member due to the pressure caused by the brake fluid flowing into the inlet opening side damper unit, the valve member abuts on the cylindrical portion and displaces from the seat portion.座), the brake fluid flows in from the through hole and the pressure of the damper unit on the fixing member side increases,

As a result of a pressure increase in the damper portion on the stationary member side, the downstream movable member that is in contact with the stationary member moves toward the bottom portion, so that the brake fluid passes through the stationary member orifice and the downstream orifice, It is configured so that it flows out from the outflow opening.

In a brake system, noise caused by pulsation of brake fluid generated when a pump is driven can be reduced.

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 sectional view showing an example of a state in which a pump and a damper unit are mounted on a base body in a hydraulic control unit of a brake system according to an embodiment of the present invention.
3 is an enlarged cross-sectional view of a pulsation reducing unit in a state in which a pump is not driven according to an embodiment of the present invention.
4 is an enlarged cross-sectional view of a pulsation reducing unit in a state in which an upstream movable member is moving after a pump drive starts according to an embodiment of the present invention.
5 is an enlarged cross-sectional view of a pulsation reducing unit in a state in which brake fluid flows out from an outflow opening after a pump drive starts according to an embodiment of the present invention.

Hereinafter, a hydraulic control unit according to the present invention will be described using drawings. Further, in the following description, a case in which the brake system including the hydraulic control unit according to the present invention is mounted on a four-wheeled vehicle is described, but the brake system including the hydraulic control unit according to the present invention is applied to a vehicle other than a four-wheeled vehicle (two-wheeled vehicle). , a truck, a bus, etc.). In addition, the configuration, operation, etc. 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, etc. In addition, in each figure, the same code|symbol is attached|subjected to the same or similar member or part, or the code|symbol is abbreviate|omitted. In addition, about a detailed structure, illustration is simplified or abbreviate|omitted suitably.

<Configuration and operation of brake system 1>

The configuration and operation of the brake system 1 according to the present embodiment will be described. 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 includes a main fluid passage 13 mounted on a vehicle 100 and communicating a master cylinder 11 and a wheel cylinder 12, and a main fluid passage 13 and a hydraulic circuit (2) having an auxiliary fluid passage (14) for discharging brake fluid and a supply fluid passage (15) for supplying brake fluid to the auxiliary fluid passage (14). The hydraulic circuit 2 is filled with brake fluid.

Furthermore, the brake system 1 according to the present embodiment includes two hydraulic circuits 2a and 2b as the hydraulic circuit 2 . The hydraulic circuit 2a is a hydraulic circuit that connects the master cylinder 11 and the wheel cylinders 12 of the wheels RL and FR through the main fluid passage 13 . The hydraulic circuit 2b is a hydraulic circuit that connects the master cylinder 11 and the wheel cylinders 12 of the wheels FL and RR through the main fluid passage 13 . These hydraulic circuits 2a and 2b have the same configuration except that the communicating wheel cylinders 12 are different.

In the master cylinder 11, a piston (not shown) reciprocating in association with a brake pedal 16, which is an example of an input unit of the brake system 1, is incorporated. A booster 17 is interposed between the brake pedal 16 and the piston of the master cylinder 11, and the user's foot force is boosted and transmitted to the piston. The wheel cylinder 12 is installed on the brake caliper 18. When the hydraulic pressure of the brake fluid in the wheel cylinder 12 increases, the brake pad 19 of the brake caliper 18 is pushed against the rotor 20 to brake the wheel.

The upstream end of the auxiliary fluid passage 14 is connected to the first middle part 13a of the main fluid passage 13, and the downstream end of the auxiliary fluid passage 14 is higher than the first middle part 13a. It is connected to the 2nd middle part 13b which is an upstream side. Further, the upstream end of the supply fluid passage 15 communicates with the master cylinder 11, and the downstream end of the supply fluid passage 15 connects to the third middle part 14a of the auxiliary fluid passage 14. are connected

An inlet valve (EV) 31 is provided in a region between the second intermediate portion 13b and the first intermediate portion 13a in the main fluid passage 13 . An outlet valve (AV) 32 is provided in a region of the auxiliary fluid passage 14 between the first intermediate portion 13a and the third intermediate portion 14a. An accumulator 33 is installed in a region of the auxiliary fluid passage 14 between the outlet valve 32 and the third intermediate portion 14a. The inlet valve 31 is, for example, an electromagnetic valve that opens in a non-energized state and closes in an energized state. The outlet valve 32 is, for example, an electromagnetic valve that is closed in a non-energized state and opened in an energized state.

Further, a pump 60 is installed in a region of the auxiliary fluid passage 14 between the third intermediate portion 14a and the second intermediate portion 13b. The suction side of the pump 60 communicates with the third middle portion 14a. The discharge side of the pump 60 communicates with the second middle portion 13b of the main fluid passage 13 . A pulsation reducing unit 80 is installed in a region between the discharge side of the pump 60, which is a part of the auxiliary fluid passage 14, and the second middle part 13b.

The pulsation reducing unit 80 damps the pulsation of the brake fluid discharged from the pump 60 . In detail, the discharge side of the pump 60 is connected to the inflow opening 95b (see FIG. 2) through which the brake fluid of the pulsation reducing unit 80 flows, and the brake fluid temporarily stored in the pulsation reducing unit 80 is discharged. The outflow opening 95c (see Fig. 2) and the second intermediate portion 13b of the main fluid passage 13 are connected. In the following description, the fluid passage constituting between the discharge side of the pump 60 and the inflow opening 95b is the first discharge fluid passage 140a, the outflow opening 95c and the main fluid passage 13 are the first. The fluid passage constituting between the two intermediate portions 13b is referred to as a second discharge fluid passage 140b.

A first selector valve (USV) 35 is provided in an area of the main fluid passage 13 on the side of the master cylinder 11 based on the second intermediate portion 13b. A second selector valve (HSV) 36 and a damper unit 37 are installed in the supply fluid passage 15 . The damper unit 37 is installed in a region between the second switching valve 36 in the supply fluid passage 15 and the third intermediate portion 14a of the auxiliary fluid passage 14 . The 1st switching valve 35 is an electromagnetic valve which opens in a non-energized state and closes in an energized state, for example. The second switching valve 36 is an electromagnetic valve that is closed in a non-energized state and opened in an energized state, for example.

Inlet valve 31, outlet valve 32, accumulator 33, pump 60, first switching valve 35, second switching valve 36, damper unit 37, and pulsation reducing unit 80 is installed in the base body 51 in which fluid passages for constituting the main fluid passage 13, the auxiliary fluid passage 14, and the supply fluid passage 15 are formed therein. Each member (inlet valve 31, outlet valve 32, accumulator 33, pump 60, first selector valve 35, second selector valve 36, damper unit 37 and pulsation reducing unit (80)) may be collectively installed in one base body 51, or may be divided and installed in a plurality of base bodies 51.

At least, the hydraulic pressure control unit 50 is constituted by the base body 51, each member installed on the base body 51, and the controller (ECU) 52. In the hydraulic control unit 50, the operation of the inlet valve 31, the outlet valve 32, the pump 60, the first selector valve 35, and the second selector valve 36 is controlled by the controller 52. By being controlled by, the hydraulic pressure of the brake fluid in the wheel cylinder 12 is controlled. That is, the controller 52 manages the operation of the inlet valve 31, the outlet valve 32, the pump 60, the first selector valve 35, and the second selector valve 36.

The controller 52 may be one or may be divided into a plurality. Further, the controller 52 may be attached to the base body 51 or may be attached to another member. Further, part or all of the controller 52 may be configured with, for example, a microcomputer, a microprocessor unit, or the like, or may be configured with an updateable component such as firmware, and is executed by instructions from a CPU or the like. A program module or the like may be used.

The controller 52 performs, for example, the following hydraulic pressure control operation in addition to well-known hydraulic pressure control operation (ABS control operation, ESP control operation, etc.). In the state where the inlet valve 31 is open, the outlet valve 32 is closed, the first selector valve 35 is open, and the second selector valve 36 is closed, the vehicle 100 When the brake pedal 16 is operated, the lack of hydraulic pressure in the hydraulic circuit 2 or the possibility of the shortage 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 circuit 2. Then, the controller 52 starts an active pressure increasing control operation.

In the active pressure increasing control operation, the controller 52 keeps the inlet valve 31 open, so that the brake fluid flows from the second intermediate portion 13b of the main fluid passage 13 to the wheel cylinder 12. makes it possible Further, the controller 52 restricts the flow of brake fluid from the wheel cylinder 12 to the accumulator 33 by keeping the outlet valve 32 closed. In addition, the controller 52 closes the first switching valve 35, so that the fluid passage from the master cylinder 11 to the second intermediate portion 13b of the main fluid passage 13 without passing through the pump 60 restricts the flow of brake fluid. In addition, the controller 52 opens the second switching valve 36, thereby controlling the flow of the fluid passage from the master cylinder 11 through the pump 60 to the second middle part 13b of the main fluid passage 13. Allows the flow of brake fluid. Further, the controller 52 increases (increases) the hydraulic pressure of the brake fluid in the wheel cylinder 12 by driving the pump 60 .

When the solution or avoidance of the hydraulic pressure shortage in the hydraulic circuit 2 is detected, the controller 52 opens the first selector valve 35, closes the second selector valve 36, and furthermore pumps 60 By stopping the driving of , the active pressure-increasing control operation ends.

Here, when the pump 60 is driven, the pulsation generated in the brake fluid may be transmitted to the wheel cylinder 12 through the auxiliary fluid passage 14 and the main fluid passage 13. And this pulsation is also transmitted to the engine room accommodating the hydraulic 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. For this reason, it is important to reduce the pulsation generated when the pump 60 is driven.

Therefore, in the brake system 1 according to the present embodiment, that is, the hydraulic pressure control unit 50, the brake fluid discharged from the pump 60 flows into the pulsation reducing unit 80. The brake fluid introduced into the pulsation reducing unit 80 flows downstream from the pulsation reducing unit 80 after the pulsation is attenuated in the pulsation reducing unit 80 . For this reason, the brake system 1 according to the present embodiment, that is, the hydraulic pressure control unit 50 can reduce the pulsation generated when the pump 60 is driven.

In addition, in the active pressure increasing control described above, the user operates (steps on) the brake pedal 16, and the pump 60 is driven with the second selector valve 36 open. For this reason, the pulsation generated in the brake fluid is propagated to the brake pedal 16 through the supply fluid passage 15 and the master cylinder 11, giving a user a sense of discomfort. For this reason, it is preferable that the brake system 1 according to the present embodiment, that is, the hydraulic pressure control unit 50 includes a damper unit 37 as shown in FIG. 1 . This is because the pulsation of the brake fluid propagating from the pump 60 to the brake pedal 16 can be damped by the damper unit 37 .

In addition, when the damper unit 37 is installed in the brake system 1 in which the booster 17 is omitted, the upstream end and the second switching valve in the supply fluid passage 15 (36) It may be provided in the area between. By installing the damper unit 37 in such a position, when the user steps on the brake pedal 16, brake fluid can flow into the damper unit 37, and the hydraulic circuit 2 transmitted to the brake pedal 16 ) The reaction force of the brake fluid inside is reduced. Accordingly, when the user depresses the brake pedal, the same depression amount of the brake pedal 16 as that of the brake system 1 provided with the booster 17 is obtained. For this reason, in the brake system 1 in which the boost device 17 is omitted, the user can obtain the same feeling of use as that of the brake system 1 provided with the boost device 17 .

<Mounting configuration of the pump 60 and the pulsation reducing unit 80 to the base body 51>

In the hydraulic pressure control unit 50 of the brake system 1 according to the present embodiment, an example of a configuration when the pump 60 and the pulsation reducing unit 80 are mounted on the base body 51 will be described. 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 a base body in the hydraulic control unit of the brake system according to the embodiment of the present invention. 2 shows a state where the drive shaft 57 that drives the piston 62 of the pump 60 is removed. For this reason, in FIG. 2, the drive shaft 57 and the eccentric part 57a formed in the said drive shaft 57 are shown by a virtual line (double-dotted line).

As shown in FIG. 2 , a drive shaft accommodation chamber 59 in which a drive shaft 57 for driving the piston 62 of the pump 60 is installed is formed in the base body 51 . The drive shaft accommodation chamber 59 is a bottomed hole formed in the outer wall of the base body 51 . In addition, the base body 51 is formed with a pump accommodating chamber 53 for accommodating the pump 60 . The pump housing chamber 53 is a stepped hole in a cylindrical shape penetrating from the outer wall of the base body 51 to the drive shaft housing chamber 59 .

The pump 60 housed in the pump housing chamber 53 includes a cylinder 61 and a piston 62 and the like. The cylinder 61 is formed into a cylindrical shape having a cylinder bottom 61b. One end side of the piston 62 is accommodated in the cylinder 61 . The space surrounded by the inner circumferential surface of the cylinder 61 and the one end of the piston 62 becomes the pump chamber 63 . This piston 62 is capable of reciprocating motion in the axial direction of the cylinder 61 . Further, an end portion 62a, which is an end portion on the other end side of the piston 62, protrudes into the driving shaft accommodation chamber 59. Further, an annular cylinder side seal member 66 is attached to a portion of the piston 62 accommodated in the cylinder 61. The leakage of brake fluid between the outer circumferential surface of the piston 62 and the inner circumferential surface of the cylinder 61 is prevented by this cylinder side seal member 66 .

Further, in the 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 urged toward the drive shaft accommodating chamber 59 side. Thereby, the end part 62a of the piston 62 abuts on the eccentric part 57a formed in the drive shaft 57 in the drive shaft accommodation chamber 59. The center of the eccentric portion 57a is eccentric with respect to the rotational center of the driving shaft 57 . For this reason, when the drive shaft 57 is rotated by a drive source (not shown), the eccentric portion 57a rotates eccentrically with respect to the rotation center of the drive shaft 57 . That is, when the eccentric part 57a rotates eccentrically, the piston 62, the end part 62a of which is in contact with the eccentric part 57a, reciprocates in the axial direction of the cylinder 61.

A portion of the piston 62 protruding from the cylinder 61 is guided so as to be slidable by a piston guide member 68 provided on the inner circumferential surface of the pump housing chamber 53 . Further, an annular driving shaft side seal member 69 is attached to the pump housing chamber 53 adjacent to the piston guide member 68 . The leakage of brake fluid from the outer circumferential surface of the piston 62 to the drive shaft accommodating chamber 59 side is prevented by this drive shaft side seal member 69 .

The piston 62 is formed with a bottomed hole 62b that opens in the axial direction to the pump chamber 63 side of the cylinder 61 . The piston 62 is also formed with a suction port 62c that communicates its outer circumferential surface with the bottomed hole 62b. In addition, the piston 62 is provided with an intake valve (not shown) that closes the opening of the bottomed hole 62b so as to be able to open and close. This intake valve includes an intake valve member that is a ball valve that closes the opening of the bottomed hole 62b, and an intake valve spring that presses the intake valve member from the cylinder 61 side. Further, a cylindrical filter 70 is attached to an end portion of the cylinder 61 on the side of the piston 62 so as to cover the opening of the suction port 62c of the piston 62 .

A communication hole 61c communicating the outside of the pump chamber 63 and the cylinder 61 is formed in the cylinder bottom 61b. An opening side discharge valve 64 is provided on the opening side of the communication hole 61c on the opposite side to the pump chamber 63. The opening side discharge valve 64 is formed on the circumferential edge of the opening end of the opening side valve member 64a, which is a ball valve, and the communication hole 61c, and the opening side valve seat on which the opening side valve member 64a can be seated/relocated. 64b, and an opening side spring 64c for biasing the opening side valve member 64a in a direction to seat the opening side valve seat 64b. This opening side discharge valve 64 is disposed between the cylinder 61 and the cover 65 .

In detail, the cover 65 is attached to the cylinder bottom 61b side by press fitting, for example. The cover 65 is formed with a bottomed hole 65a having an opening at a position opposite to the communicating hole 61c of the cylinder bottom 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 valve member 64a on the opening side. For this reason, when the opening side valve member 64a displaces 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 cylinder 61 rises, and the force of the brake fluid pressing the opening side valve member 64a is greater than the urging force of the opening side spring 64c, the opening side valve The member 64a moves away from the valve seat 64b on the opening side, and the pump chamber 63 and the hole 65a with the bottom of the cover 65 communicate with each other through the communication hole 61c. Then, the brake fluid in the pump chamber 63 flows into the bottomed hole 65a. The cover 65 is formed with a groove communicating the outside of the cover 65 and the bottomed hole 65a as a discharge port 65b. The brake fluid flowing into the bottom hole 65a of the cover 65 is discharged from the discharge port 65b to the outside of the pump 60 through a discharge chamber 54 described later.

The pump 60 configured in this way is accommodated in the pump accommodation chamber 53 formed in the base body 51 as described above. Specifically, the annular protruding portion 61a formed on the outer periphery of the cylinder 61 is press-fitted to a position in contact with the stepped portion 53a of the pump accommodation chamber 53, so that the pump 60 is formed on the base body 51. It is fixed in the pump receiving chamber 53.

When the pump 60 is accommodated in the pump accommodating chamber 53 in this way, the space between the outer circumferential surface of the pump 60 and the inner circumferential surface of the pump accommodating chamber 53 communicates with the discharge port 65b of the pump 60. A discharge chamber 54 is formed. 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 . As will be described later, the discharge chamber 54 is connected to the first discharge fluid passage 140a.

Further, in the pump 60, the space between the annular projection 61a of the cylinder 61 and the cover 65 is partitioned into two spaces by the partition 71. And the space on the side of the cover 65 rather than the partition part 71 becomes the discharge chamber 54. In this embodiment, an O-ring (not shown) is provided in the annular groove formed in the partition portion 71 .

Moreover, in this embodiment, when the pump 60 is accommodated in the pump accommodation chamber 53, between the outer peripheral surface of the pump 60 and the inner peripheral surface of the pump accommodation chamber 53, the suction port 62c of the pump 60 ), and an annular fluid passage 56, which is a space communicating with, is formed. That is, the annular fluid passage 56 is an annular space formed on the outer peripheral side of the pump 60 so as to communicate with the inlet 62c of the pump 60 . The annular fluid passage 56 is formed between the annular projection 61a of the cylinder 61 and the drive shaft side seal member 69. In other words, the annular fluid passage 56 is formed on the outer circumferential side of the filter 70 so as to cover the opening of the inlet 62c.

The annular fluid passage 56 communicates with the third intermediate portion 14a of the auxiliary fluid passage 14 in FIG. 1 by means of an internal fluid passage (not shown) formed in the base body 51 . In other words, the annular fluid passage 56 constitutes a part of the auxiliary fluid passage 14 . When the pump 60 is accommodated in the pump housing chamber 53, the suction port 62c of the pump 60 and the third middle part 14a need to communicate with each other. By having the annular fluid passage 56, when the pump 60 is accommodated in the pump accommodation chamber 53, positioning for communicating the suction port 62c of the pump 60 and the third intermediate portion 14a is improved. It becomes unnecessary. For this reason, by having the annular fluid passage 56, assembling of the hydraulic pressure control unit 50 becomes easy. In addition, by having the annular fluid passage 56, when processing the pump housing chamber 53 into the base body 51, a part of the auxiliary fluid passage 14 is also processed. For this reason, the processing cost of the base body 51, that is, the manufacturing cost of the hydraulic pressure control unit 50 can also be reduced. In addition, by having the annular fluid passage 56, the space on the outer peripheral side of the pump 60 can be effectively used as the auxiliary fluid passage 14, so that the base body 51, that is, the hydraulic pressure control unit 50 can be downsized. may be

The storage chamber 58 is a storage chamber for accommodating the pulsation reducing unit 80 and is a bottomed hole formed in the outer wall of the base body 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 fluid passage 140a constituting a part of the discharge fluid passage 140 . The discharge chamber 54 is connected to the inflow opening 95b of the pulsation reducing unit 80 via the first discharge fluid passage 140a. In FIG. 2 , the brake fluid flows in from the horizontal direction with respect to the axis of the housing chamber 58 of the pulsation reducing unit 80 . And the outflow opening 95c located at the bottom of the accommodating chamber 58 is connected to the 2nd discharge fluid passage 140b. The second discharge fluid passage 140b communicates with the second middle portion 13b of the main fluid passage 13 in FIG. 1 by means of an internal fluid passage (not shown) formed in the base body 51 .

As shown in FIG. 2 , when the pump 60 and the pulsation reducing unit 80 are mounted on the base body 51 and 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 moves toward the piston 62, the piston 62 resists the pressing force of the piston spring 67. and is pressed toward the cylinder 61 side. For this reason, the pressure in the pump chamber 63 increases, the opening-side valve member 64a displaces 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 starts to rotate in a direction away from the piston 62 side, the piston 62 responds to the urging force of the piston spring 67. As a result, it moves in a direction away from the cylinder 61. For this reason, the pressure in the pump chamber 63 is lowered, the opening side valve member 64a is seated on the opening side valve seat 64b, and the opening side discharge valve 64 is closed, and at the same time, the bottomed hole of the piston 62 is closed. A suction valve (not shown) that closes the opening of 62b so as to be able to open and close is opened. Thus, the brake fluid in the annular fluid 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 further rotates and the eccentric portion 57a formed on the drive shaft 57 moves toward the piston 62 again, the piston 62 is pushed toward the cylinder 61 side as described above, and the pump chamber 63 The brake fluid in ) is discharged from the discharge port 65b to the discharge chamber 54. In this way, the piston 62 is repeatedly reciprocated in the axial direction of the cylinder 61 to selectively open and close the intake valve and outlet side discharge valve 64 (not shown), thereby increasing the hydraulic pressure, that is, the increased brake fluid. It is discharged to the discharge chamber 54 from the discharge port 65b. For this reason, pulsation occurs in the brake fluid boosted by the pump 60 . The brake fluid accompanying this pulsation flows into the pulsation reducing unit 80 through the first discharge fluid passage 140a.

<Configuration example and operation of pulsation reducing 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 reduces the pulsation of the brake fluid generated when the pump 60 is driven, and reduces noise caused by the pulsation.

3 shows the pulsation reducing unit 80 in a state where the pump 60 is not driving. A cylindrical accommodation chamber 58 accommodating the pulsation reducing unit 80 is formed in the base body 51 . The pulsation reducing unit 80 includes an inflow opening 95b through which brake fluid flows in and an outflow opening 95c through which brake fluid flows out. Further, the pulsation reducing unit 80 includes a fixing member 86 that divides the inside of the pulsation reducing unit 80 into an upstream area on the inflow opening 95b side and a downstream area on the outflow opening 95c side.

The cylindrical shape forming the housing chamber 58 has a stepped shape having a small diameter portion 58b and a large diameter portion 58d. A large-diameter portion 58d is formed on the side of the cover portion 82 that closes the opening 58e of the storage chamber 58, and a small-diameter portion is formed on the side of the bottom portion 58a opposite to the opening 58e of the storage chamber 58. (58b) is formed. Between the small-diameter portion 58b and the large-diameter portion 58d, there is a stepped portion 58c parallel to the bottom portion 58a, in other words, in a direction orthogonal to the longitudinal axis Axc of the pulsation reducing portion 80. ) is formed. 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 storage chamber 58 . The fixing member 86 includes a fixing member disk portion 86a forming a disk shape, and a cylindrical fixing member outer cylindrical portion 86c formed from an outer circumferential portion of the fixing member disk portion 86a toward the bottom portion 58a side. ) and a cylindrical columnar portion 86d formed toward the cover portion 82 side in the central portion of the fixing member disk portion 86a. Further, the fixing-member disk portion 86a is outside the cylindrical portion 86d in the circumferential direction, and further, the fixing-member disk portion 86a is provided on the inside of the fixing-member outer cylindrical portion 86c in the circumferential direction. A fixing member orifice 86b penetrating the housing chamber 58 in the direction of the axis Axc is provided.

The pulsation reducing unit 80 includes a guide member 87 . The guide member 87 includes a small diameter guide portion 87a covering the inner surface of the small diameter portion 58b of the storage chamber 58 and a bottom guide portion covering the surface of the bottom portion 58a of the storage chamber 58. It is a stepped hollow cylindrical member provided with 87b and the outflow opening guide part 87c which covers the inner surface of the outflow opening 95c. The fixing member outer cylindrical portion 86c is fixed to the small-diameter guide portion 87a of the guide member 87 by an appropriate method such as press fitting or welding.

On the fixed member 86 side of the large-diameter portion 58d, rather than the inflow opening 95b, an upstream movable member 84 that forms a disc shape and is slidable in the direction of the axis Axc of the storage 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 against the large-diameter portion 58d. In order to make the sliding smooth, as the material of the sliding member 84a, for example, PTFE can be employed.

The upstream movable member 84 has a through hole 84b penetrating in the direction of the axis Axc of the storage chamber 58 at a central portion. The through hole 84b has a seat portion 84d on the side of the cover portion 82 on which the valve member 94 can be seated. The valve member 94 is formed by a valve spring 93 installed between the inner surface 82a of the lid portion 82 on the upstream movable member 84 side and the valve member 94, It is pressed by the seat portion 84d by the set force. On the outside in the radial direction of the through hole 84b, an upstream orifice 84c having a smaller diameter than the through hole 84b penetrates the upstream movable member 84 in the direction of the axis Axc of the storage chamber 58. plural are formed.

In this embodiment, the area between the upstream side movable member 84 and the lid portion 82 in the accommodation chamber 58 is formed by the inlet opening side damper portion 81a, the upstream side movable member 84 and the fixing member The area between 86 is called the fixing member side damper portion 81b, and the area between the fixing member 86 and the bottom portion 58a is called the outflow opening side damper portion 81c. That is, in the storage chamber 58, the inflow opening side damper portion 81a and the fixing member side damper portion 81b form an upstream region of the storage chamber 58, and the outflow opening side damper portion 81c constitutes a downstream region of the storage chamber 58.

The inlet opening side damper portion 81a is provided with an inlet opening side elastic body 92 which is an elastic body that presses the upstream movable member 84 toward the fixing member 86 side. The fixed member side damper portion 81b is provided with a fixed member side elastic body 91 which is an elastic body that presses the upstream movable member 84 toward the cover portion 82 side.

As the inflow opening side elastic body 92, a coil spring can be used. The inflow opening side elastic body 92 is disposed outside the valve spring 93 and the upstream orifice 84c in the circumferential direction.

The fixing member side elastic body 91 can be a cylindrical cushioning member. As the material of the cushion member, materials such as ethylene/propylene/diene rubber (EPDM) and/or silicone can be used, for example. The fixing-member side elastic body 91 is disposed radially outside the fixing-member orifice 86b and the upstream orifice 84c.

When a cushion member is used as the elastic body, the cushion member may be formed of one material or a plurality of materials. For example, it may be configured so that EPDM having a relatively low rebound elastic modulus is sandwiched by silicone having a relatively high rebound elastic modulus. Depending on the combination of materials, it becomes possible to adjust the rebound elastic modulus of the cushion member according to the unique pulsation frequency generated due to the pump performance of the brake fluid.

The outflow opening side damper portion 81c is provided with a downstream movable member 85 capable of sliding in the direction of the axis Axc of the storage chamber 58 . The downstream movable member 85 has a downstream orifice 85c forming a cylindrical shape facing the outflow opening 95c side at its central portion, and is fixed outwardly in the circumferential direction with respect to the downstream orifice 85c. It is provided with the 1st disk part 85a which can contact the fixed member disk part 86a of the member 86. Further, the downstream orifice 85c may be not a cylindrical shape but may be a through hole penetrating the first disk portion 85a.

Further, the downstream movable member 85 includes a cylindrical movable member cylindrical portion 85e formed from the outer circumferential portion of the first disk portion 85a toward the bottom portion 58a side, and the movable member cylindrical portion 85e. A second disc portion 85d extending outward in the radial direction from the upper end of the disc is integrally formed. The movable member cylindrical portion 85e forms a space on the upper surface of the first disk portion 85a. Further, the outer peripheral portion of the second disk portion 85d is guided by the small-diameter portion guide portion 87a of the guide member 87 .

The second disk portion 85d is connected to the bottom guide portion 87b of the guide member 87 in a state where the first disk portion 85a is in contact with the fixing member disk portion 86a of the fixing member 86. It is formed at a position maintaining a predetermined distance between them. Further, in a state where the first disk portion 85a abuts against the fixing member disk portion 86a, the fixing member orifice 86b of the fixing member 86 is blocked by the first disk portion 85a, and The downstream orifice 85c of the downstream movable member 85 is blocked by the stationary member disk portion 86a.

Between the first disc portion 85a of the downstream movable member 85 and the bottom guide portion 87b of the guide member 87, there is a hollow which presses the downstream movable member 85 toward the fixing member 86 side. An outflow opening side elastic body 90 forming a cylindrical shape is provided. The outflow opening side elastic body 90 is provided outside the downstream orifice 85c in the circumferential direction and further inside the movable member cylindrical portion 85e in the circumferential direction. Also for the outflow opening side elastic body 90, it is possible to use an elastic body under the same conditions as the fixing member side elastic body 91 described above.

In the state in FIG. 3 , that is, in the state in which the pump 60 is not driving, the upstream movable member 84 receives a pressing force from the stationary member side elastic body 91 in the direction of the cover portion 82, A biasing force toward the fixing member 86 is received from the valve spring 93 and the elastic body 92 on the inflow opening side. As a result, the pressing force of each elastic body is adjusted such that the upstream movable member 84 is located between the step portion 58c and the inflow opening 95b in the large diameter portion 58d. In this state, the valve member 94 and the cylindrical portion 86d are not in contact. Further, the first disc portion 85a of the downstream movable member 85 is in contact with the fixed member disk portion 86a of the fixed member 86 .

When the pump 60 starts driving, brake fluid flows in through the inflow opening 95b, and the pressure of the inflow opening side damper portion 81a rises. When the pressure of the damper portion 81a on the inlet opening side rises, the valve member 94 and the upstream movable member 84 engage the fixing member 86 in a state where the valve member 94 is seated on the seat portion 84d. move to the side

Then, although the valve member 94 abuts against the cylindrical portion 86d of the stationary member 86, the upstream movable member 84 continues to move. Therefore, at this timing, the valve member 94 displaces from the seat portion 84d. After that, the movement of the upstream movable member 84 is ended by abutting against the step portion 58c. That is, the dimensions of each member 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 still in contact with the seat portion 84d. After passing through this state, the upstream side movable member 84 moves further and comes into contact with the stepped portion 58c.

When the valve member 94 and the upstream movable member 84 rise, the pressure of the stationary member side damper portion 81b also rises. Then, when the valve member 94 displaces from the seat portion 84d, the brake fluid flows from the inflow opening side damper portion 81a to the stationary member side damper portion 81b through the through hole 84b, so that the stationary member The pressure of the side damper part 81b further rises. Then, the pressure rise of the stationary member side damper portion 81b acts on the downstream movable member 85 via the stationary member orifice 86b to oppose the urging force of the outflow opening side elastic body 90, and the downstream movable The member 85 is moved toward the bottom portion 58a side.

5 shows a state in which the downstream movable member 85 has moved toward the bottom portion 58a. When the downstream movable member 85 moves toward the bottom portion 58a, the stationary member orifice 86b blocked by the downstream movable member 85 is released, and the brake fluid flows through the stationary member orifice 86b. , It flows out from the fixing 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 of the pulsation reducing unit 80 from the outflow opening 95c through the downstream orifice 85c formed in the downstream movable member 85. .

5, the second disc portion 85d of the downstream movable member 85 is in contact with the bottom guide portion 87b. That is, the movement amount of the downstream movable member 85 when the pump 60 is driven is regulated by the position of the second disk portion 85d before the pump 60 is driven.

Further, immediately after the pump 60 is driven, even in a state where the valve member 94 is seated on the seat portion 84d, the brake fluid of the inlet-opening side damper portion 81a does not flow through the upstream movable member 84. Through the upstream side orifice 84c formed therein, it flows out to the fixing member side damper portion 81b little by little. Therefore, after the valve member 94 displaces from the seat portion 84d, it is possible to prevent the pressure in the fixing member side damper portion 81b from rapidly increasing.

Further, the downstream orifice 85c is disposed at the central portion of the downstream movable member 85, and a plurality of fixing member orifices 86b are formed outside the downstream orifice 85c in the circumferential direction. By adopting such a configuration, the brake fluid passing through the plurality of fixing member orifices 86b flows toward the center, and the brake fluid flowing from each fixing member orifice 86b collides near the downstream orifice 85c, and brakes The momentum of the liquid flow weakens. As a result, the flow of brake fluid can be made mild.

Further, by the action of each elastic body, rapid movement of the upstream-side movable member 84 and the downstream-side movable member 85 is prevented, so that the flow of brake fluid can be made mild.

As described above, according to the present invention, the rapid movement of the upstream movable member 84 and the downstream movable member 85 is prevented by the action of each elastic body, and the action of each orifice prevents the rapid flow of brake fluid. By obstructing the flow, the flow of the brake fluid in the pulsation reducing unit 80 can be calmed and pressure pulsation can be reduced. As a result, noise caused by pulsation generated when the pump 60 is driven can be reduced.

51: base body, 58: storage chamber, 58a: bottom part, 60: pump, 80: pulsation reducing part, 81a: inflow opening side damper part, 81b: fixed member side damper part, 81c: outflow opening side damper part, 82 : cover part, 84: upstream movable member, 84b: through hole, 84c: upstream orifice, 84d: seat portion, 85: downstream movable member, 85c: downstream orifice, 86: fixed member, 86b: fixed member orifice , 86d: cylindrical portion, 90: outflow opening side elastic body, 91: fixed member side elastic body, 92: inflow opening side elastic body, 94: valve member, 95b: inflow opening, 95c: outflow opening

Claims (3)

In the pump device provided with a pulsation reducing unit 80 installed in the base body 51 to reduce pulsation of the brake fluid discharged from the pump 60,
The pulsation reducing unit 80,
A cylindrical accommodation chamber 58 installed in the base body 51,
A fixing member 86 dividing the accommodation chamber 58 into an upstream region and a downstream region;
The upstream movable member 84 provided in the upstream region and capable of sliding in the axial direction communicates with the inflow opening 95b through which the brake fluid flows, and the upstream movable member 84 and the receiving chamber 58 communicate with each other. An inlet opening side damper portion 81a formed between the cover portion 82 of the ) and a fixed member side damper portion 81b formed between the upstream movable member 84 and the fixing member 86,
The downstream movable member 85 provided in the downstream region and capable of sliding in the axial direction communicates with an outflow opening 95c through which the brake fluid flows out, and the downstream movable member 85 and the receiving chamber 58 communicate with each other. An outflow opening-side damper portion 81c formed between the bottom portion 58a of ),
A fixing member orifice 86b formed in the fixing member 86;
a downstream orifice 85c formed in the downstream movable member 85;
an inlet opening-side elastic body 92 for pressing the upstream-side movable member 84 provided in the inflow-side damper portion 81a toward the fixing member 86;
a fixing member-side elastic body 91 for pressing the upstream-side movable member 84 provided in the fixing-member-side damper portion 81b toward the cover portion 82;
An outflow opening side elastic body 90 for pressing the downstream movable member 85 provided in the outflow opening side damper portion 81c toward the fixing member 86 side,
The fixing member 86 has a cylindrical portion 86d extending toward the cover portion 82,
The upstream movable member 84 has a through hole 84b having a seat portion 84d configured to be closed by seating a valve member 94 pressed from the lid portion 82 side,
In the process of moving the upstream movable member 84 toward the fixing member 86 by the pressure caused by the brake fluid flowing into the inlet opening side damper part 81a, the valve member 94 By coming into contact with the cylindrical portion 86d and moving away 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,
As the pressure of the damper portion 81b on the stationary member side rises, the downstream movable member 85, which is in contact with the stationary member 86, moves toward the bottom portion 58a side, so that the brake fluid Passing through the member orifice 86b and the downstream orifice 85c, the pump device flows out from the outflow opening 95c. The downstream orifice (85c) according to claim 1, wherein the downstream orifice (85c) is formed at a central portion in the radial direction of the downstream movable member (85), and the stationary member orifice (86b) is, viewed in an axial direction, the downstream orifice (85c). ), a pump device formed in plurality radially outside. The inflow opening side damper part (81a) and the stationary member side damper part (81b) according to claim 1 or 2, wherein the upstream side movable member (84) is radially outward of the through hole (84b). ) having an upstream orifice 84c communicating therewith.

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