JP2001001885A - Fluid device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid device having excellent durability capable of effectively attenuating pulsation produced in a pump device and preventing the size of an entire device from being increased. SOLUTION: A pump chamber 20 slidably storing a plunger 19 and having a variable capacity is provided in a cylinder 10. A delivery chamber 22 communicating with the pump chamber 20 through the delivery valve 39 is provided. Then, a damper chamber 30 having a slidable damper piston 31 and variable capacity is formed toward the delivery chamber 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid device such as an anti-lock brake device for controlling a brake fluid pressure of a vehicle.

[0002]

2. Description of the Related Art A fluid device of this type includes a pump device having a pump chamber formed in a cylinder and having a capacity expanding and contracting, and a discharge chamber communicating with the pump chamber via a discharge valve. The working fluid is guided from the discharge chamber of the pump device to, for example, a wheel cylinder or the like.

In this type of fluid device, measures are taken to reduce the pulsation of the fluid generated in the pump device. For example, Japanese Patent Application Laid-Open No. 9-79134 discloses that A technology in which a damper chamber having a capacity is provided is disclosed. Japanese Patent Application Laid-Open No. Hei 9-175381 discloses
There is disclosed a technique in which an attenuator is provided in a fluid passage downstream of a discharge chamber.

[0004]

According to the technique disclosed in the former publication, the volume of the damper chamber provided in the discharge chamber of the pump device does not change. A large volume is required, and the entire apparatus may be enlarged.

[0005] Further, in the technology described in the latter publication,
An attenuator provided in a fluid passage downstream of the discharge chamber of the pump device includes an attenuator main body formed of an elastomer material, and a damping chamber defined by a seal edge of the attenuator main body. However, there is a concern that the durability of the attenuator is insufficient.

The present invention has been devised in view of the above-mentioned conventional circumstances, and can effectively attenuate the pulsation generated in the pump device, without increasing the size of the entire device.
An object of the present invention is to provide a fluid device having excellent durability.

[0007]

SUMMARY OF THE INVENTION In view of the above, the invention according to claim 1 includes a pump chamber formed in a cylinder, the capacity of which expands and contracts, and a discharge chamber communicating with the pump chamber via a discharge valve. In the fluid device in which the working fluid is led out from the discharge chamber of the pump device, a slidable damper piston is provided facing the discharge chamber to form a damper chamber whose volume can be changed. Configuration.

According to a second aspect of the present invention, in the configuration of the first aspect, the damper piston is provided with a spring member for urging the damper piston in a direction to reduce the volume of the damper chamber. Configuration.

According to a third aspect of the present invention, in the configuration of the second aspect, the spring member is formed by stacking a plurality of disc springs.

According to a fourth aspect of the present invention, in the configuration of the first aspect, an orifice is provided in a passage through which the working fluid is led out from the discharge chamber.

According to a fifth aspect of the present invention, in the configuration of the first aspect of the invention, the fluid device is an anti-lock brake device, and the damper piston is provided in a direction in which the volume of the damper chamber increases. The movement is stopped at a predetermined position.

According to a sixth aspect of the present invention, in the configuration of the first aspect, the fluid device is an anti-lock brake device, and a working fluid is supplied to the damper piston from a discharge chamber of a pump device. It is configured such that a passage that can be led out and that is not always closed is formed.

In such a configuration, when the pump device is driven, the pump chamber expands and contracts, the working fluid is sucked into the pump chamber, and is discharged from the pump chamber to the discharge chamber via the discharge valve. Specifically, when the pump device is a plunger pump, the plunger is driven to reciprocate by a driving cam. Further, when the pump device is a piston pump, the piston is reciprocated.

The pulsation of the working fluid discharged into the discharge chamber of the pump device is attenuated by the damper chamber formed facing the discharge chamber, and is led out of the discharge chamber. That is, in the damper chamber, when the hydraulic pressure fluctuates, the damper piston moves,
Its volume expands and contracts, attenuating pressure fluctuations. The pulsation of the working fluid is attenuated by the volume of the damper chamber and the sliding friction of the damper piston. Further, according to the second and third aspects of the present invention, the spring member is further obtained by mechanical friction of the spring member caused by bending deformation of the spring member. Further, according to the fourth aspect of the present invention, the working fluid is further obtained by flow resistance when passing through the orifice.

Here, the damper chamber is provided with a slidable damper piston so that the volume thereof can be changed, so that the pulsation of the working fluid is effectively attenuated by the change in the volume. . The damping action is also exerted by the sliding resistance of the damper piston.

Therefore, compared with the case where the damper chamber has a constant volume, the pulsation damping performance can be improved with a small volume. In addition, since the damper piston that expands and contracts the volume of the damper chamber can be formed of a synthetic resin material or a metal material having high rigidity, there is no change with time and excellent durability.

Accordingly, a pulsation generated in the pump device can be effectively attenuated, and a fluid device having excellent durability can be obtained without increasing the size of the entire device.

According to the second aspect of the present invention, the damper piston is provided with a spring member for urging the damper piston in a direction to reduce the volume of the damper chamber, so that the damper piston slides. At this time, friction occurs between the spring member and the damper piston as the spring member flexes. For this reason, since the mechanical friction of the spring member is used for damping the pulsation, more excellent damping action is exhibited.

According to the third aspect of the present invention, since the spring member is formed by stacking a plurality of disc springs, the sliding movement of the damper piston accompanies the bending deformation of the disc spring. As a result, friction occurs between the disc spring and the damper piston and between the disc springs. For this reason, since the mechanical friction of the spring member is used for damping the pulsation, a more excellent damping action is exhibited.

According to the fourth aspect of the present invention, since the orifice is provided in the passage of the working fluid from the discharge chamber, flow resistance is obtained when the working fluid passes through the orifice. Can be For this reason, since the flow resistance of the working fluid by the orifice is used for damping the pulsation, a more excellent damping action is exhibited.

Further, in the invention described in claim 5, the fluid device is an anti-lock brake device, and the movement of the damper piston in the direction in which the volume of the damper chamber increases is stopped at a predetermined position. Therefore, the damper piston does not move in the high pressure region where the discharge pressure of the pump device exceeds a predetermined value, and the hydraulic rigidity of the antilock brake device does not decrease unnecessarily.

Further, in the invention according to claim 6, the fluid device is an anti-lock brake device, and the damper piston is not always closed so that a working fluid can be led out from a discharge chamber of a pump device. Since the passage is formed, when the anti-lock brake device is filled with the brake fluid as the working fluid (vacuum filling), the discharge chamber is not sealed, and the filling operation can be performed easily and reliably. .

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention applied to an antilock brake device will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a fluid device showing an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a housing, and the housing 1 is formed of an aluminum alloy or a cast iron material.

A housing hole 2 is formed through the housing 1. The accommodation hole 2 has a small-diameter portion 3 and a large-diameter portion 4 at both ends in the axial direction, and has a middle-diameter portion 5 at a substantially central portion. The small-diameter portion 3 of the housing hole 2 opens to a central hole 7 in which a driving cam 6 rotated by a driving shaft (not shown) is housed, while the large-diameter portion 4 is open to the outside.

The housing 1 is provided with a suction passage 8 communicating with a reservoir (not shown) and a discharge passage 9 communicating with a master cylinder (not shown). Each has an opening.
Specifically, the suction passage 8 opens at the middle diameter portion 5 of the accommodation hole 2, and the discharge passage 9 opens at the large diameter portion 4.

Numeral 10 is a bottomed cylindrical cylinder inserted and fixed in the accommodation hole 2. The cylinder 10 is preferably made of an iron-based material in order to prevent wear caused by sliding of a plunger described later as much as possible. Formed of a metallic material.

The cylinder 10 is formed in a stepped shape in the axial direction, and the small-diameter body 11 and the medium-diameter body 1 are sequentially arranged from the opening end side.
2. A large-diameter trunk 13 is formed, and the large-diameter trunk 13 is formed on the bottom 14 side of the cylinder 10.

The cylinder 10 is inserted and fixed in the accommodation hole 2 by inserting the small-diameter body 11 of the cylinder 10 into the small-diameter part 3 of the accommodation hole 2 and setting the medium-diameter trunk 12 to the middle diameter of the accommodation hole 2. 5, the large-diameter trunk 13 is inserted into the large-diameter portion 4 of the accommodation hole 2, and a flange 15 formed on the outer periphery of the large-diameter trunk 13 is further inserted into the accommodation hole 2 through the lid member 16. It is fixed to the open end. The opening end of the accommodation hole 2 is appropriately caulked.

That is, since the cylinder 10 is fixed in the housing hole 2 via the lid member 16 disposed on the bottom 14 of the cylinder 10, the opening end of the housing hole 2 where the bottom 14 side of the cylinder 10 is located. Is sealed by the lid member 16.

The lid member 16 is formed of a metal material in this embodiment. Preferably, the surface of the lid member 16 is subjected to corrosion-resistant plating such as zinc plating, nickel plating, and chromium plating. You.

A plunger 19 is slidably housed in the cylindrical interior of the cylinder 10,
A pump chamber 20 is formed on the side.

A discharge hole 21 opening to the pump chamber 20 and a discharge chamber 22 communicating with the pump chamber 20 through the discharge hole 21 are formed in the bottom portion 14 of the cylinder 10.
The discharge chamber 22 is open on the opening end side of the housing hole 2 for convenience of forming the discharge chamber 22 and the discharge hole 21 on the bottom portion 14 of the cylinder 10. Is sealed by.

Further, on the bottom portion 14 of the cylinder 10,
A radial passage 23 communicating with the discharge chamber 22 is formed, and an orifice 24 is formed at an end of the passage 23. The passage 23 and the orifice 24 allow the inside of the discharge chamber 22 to communicate with the discharge passage 9 via the inside of the large-diameter portion 4 of the housing hole 2 formed in the housing 1.

A damper chamber 30 is formed facing the discharge chamber 22. The damper chamber 30 is formed in the discharge chamber 22 in this embodiment, and a slidable damper piston 31 is provided in the discharge chamber 22 so that the volume thereof can be expanded and reduced.

The damper piston 31 is made of a rigid synthetic resin material or a metal material.
In FIG. 1, a non-always-closed passage 32 through which the working fluid can be led out from the discharge chamber 22 is formed on one end surface (the left side in FIG. 1). In this embodiment, the passage 32 is formed as a radial groove. Further, a damper chamber 3 is provided on the other end surface (right side in FIG. 1).
The stopper 33 is formed so that the movement in the direction in which the volume of 0 increases is stopped at a predetermined position. Stopper 3
Reference numeral 3 denotes a protrusion formed in this embodiment, and the stopper 33 comes into contact with the lid member 16 so that the damper piston 31 stops moving.

The damper piston 31 is provided with a spring member 34 for urging the damper piston 31 in a direction in which the volume of the damper chamber 30 decreases. In this embodiment, the spring member 34 is formed by stacking two frusto-conical disc springs, and is disposed on the outer peripheral side of the stopper 33.

In the discharge chamber 22, a discharge valve 39 in which the ball valve 36 is biased by a check spring 37 and adapted to the valve seat 38 of the discharge hole 21 is accommodated. In this case, the damper piston 31 also serves as a spring receiver for the check spring 37.

The small-diameter body portion 11 of the cylinder 10 is formed with a diametric through hole 41 communicating with the inside of the cylinder of the cylinder 10 facing the suction passage 8 formed in the housing 1.

A compression spring 42 having one end in contact with the plunger 19 and the other end in contact with the bottom 14 of the cylinder 10 is accommodated in the pump chamber 20 formed on the bottom 14 side of the cylinder 10. Plunger 1 by
9 is pressed by the drive cam 6.

The plunger 19 has a circumferential groove 43 facing the through hole 41 formed in the small diameter body portion 11 of the cylinder 10.
And a diametrical through hole 4 opening at the bottom of the peripheral groove 43.
4, and an axial blind hole 45 communicating with the through hole 44 and opening toward the pump chamber 20 is formed. At the open end of the blind hole 45, there is provided a suction valve 49 in which the ball valve 46 is biased by a check spring 47 and adapted to the valve seat 48 of the blind hole 45.

Reference numeral 51 denotes a seal ring provided on the outer periphery of the plunger 19, and the seal ring 51
Rather than the central hole 7 of the housing 1.

Reference numeral 52 denotes a seal ring provided on the outer periphery of the small-diameter body 11 of the cylinder 10, and 53 denotes a large-diameter body 13.
Is a seal ring provided on the outer periphery of the damper piston 31.

The drive cam 6 is provided eccentrically with respect to the center of rotation of the drive shaft (not shown). Further, in this embodiment, a pair of pump devices are provided so as to face both sides of the central hole 7.

In such a configuration, the rotating cam 6 is rotated via a drive shaft by a motor or the like (not shown), and the plunger 19 is reciprocated by the driving cam 6 to act as a pump.

That is, the plunger 19 is connected to the pump chamber 20.
By moving the inside of the cylinder of the cylinder 10 in the direction of the center hole 7 by the spring force of the compression spring 42 in the inside, the pump chamber 2
The inside of 0 becomes a negative pressure. Thereby, the working fluid in the reservoir (not shown) is guided from the suction passage 8 into the middle diameter portion 5 of the accommodation hole 2, and further, the through hole 41 of the cylinder 10, the plunger 1
9 through the circumferential groove 43, the through hole 44, and the blind hole 45,
9 is opened to be sucked into the pump chamber 20. At this time, the discharge valve 39 closes the discharge hole 21 by the ball valve 36 being urged by the spring force of the check spring 37 to be seated on the valve seat 38 of the discharge hole 21.

When the plunger 19 is moved by the driving cam 6 toward the pump chamber 20 against the spring force of the compression spring 42, the ball valve 46 of the suction valve 49 is closed by the spring force of the check spring 47. After sitting on the valve seat 48, the suction valve 49 is closed to prevent the working fluid in the pump chamber 20 from flowing into the blind hole 45, so that the pressure in the pump chamber 20 becomes high. Thereby, the pump chamber 2
The working fluid in 0 is discharged into the discharge chamber 22 by opening the discharge valve 39 from the discharge hole 21.

The pulsation of the working fluid discharged into the discharge chamber 22 is attenuated by the damper chamber 30, and
Is discharged from. That is, in the damper chamber 30, when the hydraulic pressure changes, the damper piston 31 moves, and its volume expands and contracts to attenuate the pressure fluctuation.

The damper piston 31 is provided in the damper chamber 30.
When sliding inside, it receives the spring force of the spring member 34 and the pressure of the air sealed between the damper piston 31 and the lid member 16. The movement of the damper piston 31 in the direction in which the volume of the damper chamber 30 increases is stopped at a predetermined position where the stopper 33 of the damper piston 31 contacts the lid member 16. Further, the movement of the damper piston 31 in the direction in which the volume of the damper chamber 30 decreases is stopped when the damper piston 31 contacts the cylinder 10. At this time, since the passage 32 is formed in the damper piston 31, the inside of the discharge chamber 22 is not blocked by the discharge passage 9 and the passage 23.

The pulsation of the working fluid is attenuated by the volume of the damper chamber 30 whose volume expands and contracts, the sliding friction of the damper piston 31, the friction of the seal ring 54, and the spring member 34.
And the mechanical friction of the spring member 34 caused by the bending deformation of the spring member 34. Further, since the orifice 24 is provided in the passage (the discharge passage 9 and the passage 23) through which the working fluid is led out from the discharge chamber 22, it is obtained by the flow resistance when the working fluid passes through the orifice 24. Can be

The working fluid whose pulsation has been attenuated by the damper chamber 30 and the orifice 24 is guided from the discharge chamber 22 to the inside of the large diameter portion 4 of the housing 1 through the passage 23, and further from the discharge passage 9. Discharged to the outside master cylinder side.

Thus, the pump device pumps the working fluid flowing into the reservoir from the wheel cylinder (not shown) to the master cylinder side.

Since the damper chamber 30 is provided with a slidable damper piston 31 so that the volume thereof can be changed, the pulsation of the working fluid is effectively attenuated by the change in the volume. Is done. The damping action is also exerted by the sliding resistance of the damper piston 31 and the like.

Therefore, the pulsation damping performance can be improved with a small volume as compared with the case where the damper chamber 30 has a constant volume. The damper chamber 30
Since the damper piston 31 which expands and contracts the volume can be formed of a rigid synthetic resin material or a metal material,
Has excellent durability with no change over time.

Therefore, the pulsation generated in the pump device can be effectively attenuated, and a fluid device having excellent durability can be obtained without increasing the size of the entire device.

The damper piston 31 is provided with a spring member 34 for urging the damper piston 31 in a direction to reduce the volume of the damper chamber 30. The spring member 34 includes a plurality of disc springs ( In this embodiment, 2
When the damper piston 31 slides, friction occurs between the disc spring and the damper piston 31 and between the disc springs when the damper piston 31 slides due to the bending deformation of the disc spring. For this reason, the mechanical friction of the spring member 34 is used for damping the pulsation, so that a more excellent damping action is exhibited.

Since an orifice 24 is provided in the passage (discharge passage 9 and passage 23) through which the working fluid is discharged from the discharge chamber 22, the working fluid flows when passing through the orifice 24. Resistance is obtained. For this reason, the flow resistance of the working fluid by the orifice 24 is used for damping the pulsation, so that a more excellent damping action is exhibited.

The damper piston 31 is provided with a stopper 33, and the movement of the damper piston 31 in the direction in which the volume of the damper chamber 30 increases is stopped at a predetermined position. In a high-pressure region where the discharge pressure exceeds a predetermined value, the damper piston 31 does not move, and the hydraulic rigidity of the antilock brake device does not decrease unnecessarily.

Since the damper piston 31 is formed with the always-closed passage 32 through which the working fluid can be led out from the discharge chamber 22, the brake fluid as the working fluid is supplied into the anti-lock brake device. When filling (vacuum filling), the discharge chamber 22 is not sealed,
The filling operation can be performed easily and reliably.

FIG. 2 is a view showing another embodiment of the present invention. This embodiment is different from the above-described embodiment in that the discharge chamber 22 is formed in the large-diameter portion 4 of the accommodation hole 2. Is a point. Another point is that the discharge valve 39 is arranged in the cage 55. Hereinafter, this embodiment will be described.
In the description, the same components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

That is, in the embodiment shown in FIG.
The cylinder 10 has an axial dimension not in contact with the lid member 16, and a discharge chamber 22 is formed in the large diameter portion 4 of the accommodation hole 2.

A damper chamber 30 is formed facing the discharge chamber 22. The damper chamber 30 is formed in the discharge chamber 22 in this embodiment, and a slidable damper piston 31 is provided in the discharge chamber 22 so that the volume thereof can be expanded and reduced.

The damper piston 31 is provided with a spring member 34 for urging the damper piston 31 in a direction in which the volume of the damper chamber 30 is reduced.
Is a leaf spring formed in a wave shape in this embodiment.

In the discharge chamber 22, the ball valve 36 is biased by the check spring 37 so that the valve seat 3 of the discharge hole 21 is formed.
A discharge valve 39 adapted to 8 is accommodated, which discharge valve 39 is arranged in the cage 55 in this embodiment. That is, the cage 55 is formed in a hat shape, and the opening edge is attached to the outer peripheral side of the discharge hole 21 so that the discharge valve 39 is formed.
, The bottom of which supports the check spring 37.

In such a configuration, the damper chamber 30
Since the slidable damper piston 31 is provided so that the volume thereof can be changed, the pulsation of the working fluid is effectively attenuated by changing the volume. The damping action is also exerted by the sliding resistance of the damper piston 31, the mechanical friction of the spring member 34, and the like.

Therefore, a pulsation generated in the pump device can be effectively attenuated, and a fluid device having excellent durability can be obtained without increasing the size of the entire device.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to this embodiment and can be changed without departing from the spirit of the invention.
For example, the embodiment in which the pump device is a plunger pump including the plunger 19 has been described. However, the present invention is not limited to this, and is applicable to a fluid device including various pump devices.

[0069]

As described above, according to the present invention, the pulsation generated in the pump device can be effectively attenuated, and the durability of the device can be improved without increasing the size of the device. A fluid device is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fluid device showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a fluid device showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Housing hole 10 Cylinder 20 Pump room 22 Discharge room 30 Damper room 31 Damper piston 32 Passage 33 Stopper 34 Spring member

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D046 BB05 BB07 BB28 CC02 EE01 LL00 LL33 LL37 LL51 LL54 3D049 BB22 CC02 HH10 HH12 HH36 HH53 3H071 AA03 BB01 CC25 CC26 CC33 DD06 DD13 DD31 DD35 DD89 EE15

Claims (6)

[Claims] 1. A pump device having a pump chamber formed in a cylinder, the volume of which expands and contracts, and a discharge chamber communicating with the pump chamber via a discharge valve. In the fluid device from which the working fluid is derived,
A fluid device, wherein a slidable damper piston is provided facing the discharge chamber to form a damper chamber whose volume can be changed. 2. The fluid device according to claim 1, wherein the damper piston is provided with a spring member for urging the damper piston in a direction to reduce the volume of the damper chamber. 3. The fluid device according to claim 2, wherein the spring member is formed by stacking a plurality of disc springs. 4. The fluid device according to claim 1, wherein an orifice is provided in a passage through which the working fluid is led out from the discharge chamber. 5. The fluid device according to claim 1, wherein the fluid device is an anti-lock brake device, wherein the damper piston is stopped at a predetermined position from moving in a direction in which the volume of the damper chamber increases. The fluid device according to claim 1. 6. The fluid device is an anti-lock brake device, wherein the damper piston is formed with a passage that can always draw out a working fluid from a discharge chamber of the pump device and that is not closed. The fluid device according to claim 1, wherein