JP2008179362A - Fluid device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid device that can effectively attenuate pulsation generated in a pump device and is excellent in durability without increasing the size of the entire device.
SOLUTION: A cylinder 19 is provided with a pump chamber 20 in which a plunger 19 is slidably accommodated and the volume thereof is expanded and contracted. A discharge chamber 22 communicating with the pump chamber 20 through a discharge valve 39 is provided. Facing the discharge chamber 22, a slidable damper piston 31 is provided to form a damper chamber 30 whose volume can be changed.
[Selection] Figure 1

Description

  The present invention relates to a fluid device such as an anti-lock brake device for controlling a brake fluid pressure of a vehicle.

  This type of fluid device has a pump device that is formed in a cylinder and has a pump chamber whose volume expands and contracts, and a discharge chamber that communicates with the pump chamber via a discharge valve. The working fluid is guided from the chamber to, for example, a wheel cylinder.

Further, in this type of fluid device, a device for reducing the pulsation of the fluid generated in the pump device is provided. For example, in Patent Document 1, a damper chamber having a constant volume is provided in the discharge chamber. A technique is disclosed, and Patent Document 2 discloses a technique in which an attenuator is provided in a fluid passage on the downstream side of the discharge chamber.
Japanese Patent Laid-Open No. 9-79134 Japanese Patent Laid-Open No. 9-175381

  In the technique described in Patent Document 1, since the volume of the damper chamber provided in the discharge chamber of the pump device does not change, a large volume is required to improve the pulsation damping performance. May increase in size.

  In the technique described in Patent Document 2, an attenuator provided in a fluid passage downstream of the discharge chamber of the pump device includes an attenuator body formed of an elastomer material, and the attenuator body. There is a fear that the durability of this attenuator is insufficient.

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

  The present invention includes a cylinder inserted into a housing hole formed in a housing, a pump chamber formed in the 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 in which the working fluid is led out from the discharge chamber of the pump device, a damper chamber whose volume can be changed is formed in the housing hole at a position facing the discharge chamber. It is configured.

  According to the present invention, it is possible to effectively attenuate the pulsation generated in the pump device, and to obtain a fluid device excellent in durability without increasing the size of the entire device.

  Hereinafter, an embodiment of the present invention applied to an antilock brake device will be described in detail with reference to the drawings.

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

  In the figure, reference numeral 1 denotes a housing, which is made of an aluminum alloy or cast iron material.

  A housing hole 2 is formed through the housing 1. The housing hole 2 has a small diameter portion 3 and a large diameter portion 4 on both end sides in the axial direction, and a medium diameter portion 5 in a substantially central portion. The small-diameter portion 3 of the housing hole 2 opens into a central hole 7 in which a drive cam 6 that is rotated by a drive shaft (not shown) is housed, while the large-diameter portion 4 is open to the outside.

  The housing 1 is formed with a suction passage 8 communicating with a reservoir (not shown) and a discharge passage 9 communicating with a master cylinder (not shown). The suction passage 8 and the discharge passage 9 are opened in the receiving hole 2, respectively. is doing. Specifically, the suction passage 8 opens to the middle diameter portion 5 of the accommodation hole 2, and the discharge passage 9 opens to the large diameter portion 4.

  Reference numeral 10 denotes a bottomed cylindrical cylinder inserted and fixed in the receiving hole 2, and this cylinder 10 is preferably an iron-based metal material in order to prevent wear caused by sliding of a plunger, which will be described later, as much as possible. Formed from.

  The cylinder 10 is formed in a stepped shape in the axial direction, and a small-diameter barrel portion 11, a medium-diameter barrel portion 12, and a large-diameter barrel portion 13 are formed in order from the opening end side. It is formed on the bottom 14 side.

  The cylinder 10 is inserted and fixed in the receiving hole 2 by inserting the small-diameter barrel 11 of the cylinder 10 into the small-diameter portion 3 of the receiving hole 2 and the medium-diameter barrel 12 in the medium-diameter portion 5 of the receiving hole 2. The large-diameter body portion 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 body portion 13 is connected to the opening end of the accommodation hole 2 via the lid member 16. It is fixed. It should be noted that caulking or the like is appropriately applied to the opening end of the accommodation hole 2.

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

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

  A plunger 19 is slidably accommodated inside the cylinder 10 and a pump chamber 20 is formed on the bottom 14 side of the cylinder 10.

  A discharge hole 21 that opens to the pump chamber 20 and a discharge chamber 22 that communicates with the pump chamber 20 through the discharge hole 21 are formed at the bottom 14 of the cylinder 10. The discharge chamber 22 is opened to the opening end side of the receiving hole 2 for the purpose of forming the discharge chamber 22 and the discharge hole 21 in the bottom portion 14 of the cylinder 10, and the opening end of the discharge chamber 22 is the lid member 16. It is sealed by.

  A radial passage 23 communicating with the discharge chamber 22 is formed at the bottom 14 of the cylinder 10, and an orifice 24 is formed at the 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 accommodation 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 contracted.

  The damper piston 31 is made of a highly rigid synthetic resin material or metal material, and the working fluid can be led out from the discharge chamber 22 to the end surface of one side (left side in FIG. 1) of the damper piston 31. A passage 32 that is not normally closed is formed. In this embodiment, the passage 32 is formed as a radial groove. Further, a stopper 33 is formed on the end surface on the other side (right side in FIG. 1) so that the movement in the direction in which the volume of the damper chamber 30 increases is stopped at a predetermined position. The stopper 33 is formed in a protruding shape 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 attached with a spring member 34 that urges the damper piston 31 in a direction in which the volume of the damper chamber 30 is reduced. In this embodiment, the spring member 34 is formed by superposing two frustoconical disc springs, and is arranged on the outer peripheral side of the stopper 33.

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

  Further, a small diameter body portion 11 of the cylinder 10 is formed with a diametrical through hole 41 which communicates with the cylindrical interior of the cylinder 10 so as to face the suction passage 8 formed in the housing 1.

  In the pump chamber 20 formed on the bottom portion 14 side of the cylinder 10, a compression spring 42 having one end in contact with the plunger 19 and the other end in contact with the bottom portion 14 of the cylinder 10 is accommodated. 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, a diametrical through hole 44 opening at the bottom of the circumferential groove 43, and a communication with the through hole 44. Thus, an axial blind hole 45 that opens toward the pump chamber 20 is formed. A suction valve 49 is provided at the open end of the blind hole 45 so that the ball valve 46 is biased by a check spring 47 and adapted to the valve seat 48 of the blind hole 45.

  51 is a seal ring provided on the outer periphery of the plunger 19, and this seal ring 51 is provided closer to the central hole 7 of the housing 1 than the circumferential groove 43.

  52 is a seal ring provided on the outer periphery of the small-diameter barrel portion 11 of the cylinder 10, 53 is a seal ring similarly provided on the outer periphery of the large-diameter barrel portion 13, and 54 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 rotation center of the drive shaft (not shown). In this embodiment, a pair of pump devices are arranged opposite to both sides of the central hole 7.

  In such a configuration, the drive cam 6 is rotated through a drive shaft by a motor or the like (not shown), and the plunger 19 is driven to reciprocate by the drive cam 6 to perform a pumping action.

  That is, when the plunger 19 moves in the cylindrical hole direction of the cylinder 10 toward the central hole 7 by the spring force of the compression spring 42 in the pump chamber 20, the inside of the pump chamber 20 becomes negative pressure. As a result, the working fluid in the reservoir (not shown) is guided from the suction passage 8 into the inside diameter portion 5 of the accommodation hole 2, and further, the through hole 41 of the cylinder 10, the circumferential groove 43 of the plunger 19, the through hole 44, The air passes through the blind hole 45, opens the suction valve 49, and is 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 and seated on the valve seat 38 of the discharge hole 21.

  The plunger 19 is moved in the direction of the pump chamber 20 against the spring force of the compression spring 42 by the drive cam 6, so that the ball valve 46 of the suction valve 49 is moved to the valve seat 48 of the blind hole 45 by the spring force of the check spring 47. The suction valve 49 is closed and the working fluid in the pump chamber 20 is prevented from flowing into the blind hole 45, so that the pressure in the pump chamber 20 becomes high. As a result, the working fluid in the pump chamber 20 is discharged from the discharge hole 21 into the discharge chamber 22 by opening the discharge valve 39.

  The working fluid discharged into the discharge chamber 22 is pulsated by the damper chamber 30 and discharged from the discharge chamber 22. That is, in the damper chamber 30, the damper piston 31 moves when the fluid pressure varies, and its volume expands and contracts to attenuate the pressure variation.

  When the damper piston 31 slides in the damper chamber 30, the damper piston 31 receives the spring force of the spring member 34 and the pressure of 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 stops 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 is reduced stops when the damper piston 31 comes into contact with 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.

  Damping of the pulsation of the working fluid is caused by the volume of the damper chamber 30 that expands and contracts, the sliding friction of the damper piston 31, the friction of the seal ring 54, and the bending of the spring member 34. Obtained by mechanical friction. Further, since the orifice 24 is provided in the middle of the passage (discharge passage 9 and 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. It is done.

  The working fluid whose pulsation is 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 to a master (not shown). Discharged to the cylinder side.

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

  Here, the damper chamber 30 is provided with a slidable damper piston 31 so that the volume of the damper chamber 30 can be changed. Therefore, 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 and the like.

  For this reason, compared with the case where the damper chamber 30 has a constant volume, the pulsation damping performance can be improved with a small volume. Further, the damper piston 31 that expands and contracts the volume of the damper chamber 30 can be formed of a highly rigid synthetic resin material or metal material, and therefore has excellent durability without 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.

  Further, the damper piston 31 is attached with a spring member 34 that urges the damper piston 31 in a direction in which the volume of the damper chamber 30 is reduced. (In the form, two sheets) Since they are formed in an overlapping manner, when the damper piston 31 slides, friction occurs between the disc spring and the damper piston 31 and between the disc springs as the disc spring is bent and deformed. Produce. For this reason, since the mechanical friction of the spring member 34 is utilized for damping the pulsation, a more excellent damping action is exhibited.

  Further, since the orifice 24 is provided in the middle of the passage (discharge passage 9 and passage 23) through which the working fluid is led out from the discharge chamber 22, a flow resistance is obtained when the working fluid passes through the orifice 24. It is done. For this reason, since the flow resistance of the working fluid by the orifice 24 is used for damping the pulsation, a more excellent damping action is exhibited.

  Further, the damper piston 31 is provided with a stopper 33. The damper piston 31 is stopped at a predetermined position in the direction in which the volume of the damper chamber 30 increases. The damper piston 31 does not move in a high pressure region where the value exceeds a predetermined value, and the hydraulic rigidity of the antilock brake device is not reduced more than necessary.

  Further, since the damper piston 31 is formed with a passage 32 that is not always closed so that the working fluid can be led out from the discharge chamber 22, the antilock brake device is filled with a brake fluid as a working fluid (vacuum). When filling, the discharge chamber 22 is not sealed, and the filling operation can be performed easily and reliably.

  FIG. 2 is a drawing showing another embodiment of the present invention. This embodiment differs from the above embodiment in that the discharge chamber 22 is formed in the large diameter portion 4 of the accommodation hole 2. . Further, the discharge valve 39 is disposed in the cage 55. This embodiment will be described below. In the description, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

  That is, in the embodiment shown in FIG. 2, the cylinder 10 has an axial dimension that does not contact the lid member 16, and the 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 contracted.

  The damper piston 31 is attached with a spring member 34 that urges the damper piston 31 in a direction in which the volume of the damper chamber 30 is reduced. In this embodiment, the spring member 34 is formed in a wave shape. It is a flat leaf spring.

  The discharge chamber 22 accommodates a discharge valve 39 in which a ball valve 36 is biased by a check spring 37 and adapted to the valve seat 38 of the discharge hole 21. Arranged in the cage 55 in form. That is, the cage 55 is formed in a hat shape, the opening edge portion is attached to the outer peripheral side of the discharge hole 21 and wraps the discharge valve 39, and the bottom portion supports the check spring 37.

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

  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.

  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 gist of the invention. For example, although the embodiment in which the pump device is a plunger pump including the plunger 19 has been described, the present invention is not limited to this, and the present invention can be applied to a fluid device including various pump devices.

  As described above in detail, according to the present invention, 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. .

  In the present invention, when the pump device is driven, the pump chamber expands and contracts, and the working fluid is sucked into the pump chamber and discharged from the pump chamber to the discharge chamber via the discharge valve. Specifically, when the pump device is a plunger pump, the pump device is driven back and forth by a drive cam. Further, when the pump device is a piston pump, the piston is driven to reciprocate.

  The working fluid discharged to the discharge chamber of the pump device is led from the discharge chamber after the pulsation is attenuated by the damper chamber formed facing the discharge chamber. That is, in the damper chamber, when the hydraulic pressure varies, the damper piston moves, and its volume expands and contracts to attenuate the pressure variation. Damping of the pulsation of the working fluid is obtained by the volume of the damper chamber, the sliding friction of the damper piston, and the like. Further, the damper chamber is provided with a damper piston and a spring member for biasing the damper piston in a direction in which the volume of the damper chamber is reduced, or the spring member overlaps a plurality of disc springs. By being formed, it is obtained by mechanical friction of the spring member which is caused by the bending deformation of the spring member. Further, by providing an orifice in the middle of the passage through which the working fluid is led out from the discharge chamber, the flow resistance is obtained when the working fluid passes through the orifice.

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

  For this reason, 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, the damper piston that expands and contracts the volume of the damper chamber can be formed of a highly rigid synthetic resin material or metal material, and therefore 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.

  Further, since the damper piston is attached with a spring member that urges the damper piston in the direction in which the volume of the damper chamber is reduced, when the damper piston slides, the spring is accompanied by the bending deformation of the spring member. Friction is generated between the member and the damper piston. For this reason, since the mechanical friction of the said spring member is utilized for attenuation | damping of a pulsation, the more outstanding damping effect | action is exhibited.

  In addition, since the spring member is formed by stacking a plurality of disc springs, when the damper piston slides, the disc spring and the damper piston are interleaved with each other as the disc spring is bent. Friction between them. For this reason, since the mechanical friction of the said spring member is utilized for attenuation | damping of a pulsation, the more outstanding damping effect | action is exhibited.

  Further, since an orifice is provided in the middle of the passage through which the working fluid is led out from the discharge chamber, a flow resistance is obtained when the working fluid passes through the orifice. 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, since the fluid device is an anti-lock brake device, and the damper piston is stopped at a predetermined position in the direction in which the volume of the damper chamber increases, the discharge pressure of the pump device is In the high pressure region exceeding the predetermined value, the damper piston does not move, and the hydraulic rigidity of the antilock brake device is not lowered more than necessary.

  The fluid device is an anti-lock brake device, and the damper piston is formed with a non-blocking passage through which the working fluid can be led out from the discharge chamber of the pump device. When the brake fluid as the working fluid is filled (vacuum filling), the discharge chamber is not sealed, and the filling operation can be performed easily and reliably.

  A cylinder inserted into a housing hole formed in the housing; a pump chamber formed in the cylinder, the volume of which is expanded and contracted; a discharge chamber communicating with the pump chamber via a discharge valve; and the discharge valve And a damper chamber which is adjacent to the discharge chamber and whose volume can be changed.

  And a pump device having a pump chamber whose volume expands and contracts, a discharge chamber communicating with the pump chamber via a discharge valve, and a damper capable of changing its volume during operation of the pump at a position facing the discharge chamber. A part is provided.

  The damper chamber can change its volume by a movable part and an elastic body provided on the outer periphery of the movable part.

It is sectional drawing of the fluid apparatus which shows embodiment of this invention. It is sectional drawing of the fluid apparatus which shows another embodiment of this invention.

Explanation of symbols

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

Claims (9)

A pump device comprising: a cylinder inserted into an accommodation hole formed in the housing; a pump chamber formed in the 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 in which the working fluid is led out from the discharge chamber of the pump device,
A fluid device characterized in that a damper chamber having a variable volume is formed in a position facing the discharge chamber in the accommodation hole.   2. The fluid device according to claim 1, wherein the damper chamber includes a damper piston and a spring member that urges the damper piston in a direction in which the volume of the damper chamber is reduced.   The fluid device according to claim 2, wherein the spring member is formed by overlapping a plurality of disc springs.   The fluid device according to claim 1, wherein an orifice is provided in the middle of a passage through which the working fluid is led out from the discharge chamber.   2. The fluid device according to claim 1, wherein the fluid device is an anti-lock brake device, and the damper piston is stopped at a predetermined position in a direction in which the volume of the damper chamber increases. Fluid device.   2. The fluid device according to claim 1, wherein the fluid device is an anti-lock brake device, and the damper piston is formed with a non-blocking passage that can draw a working fluid from a discharge chamber of a pump device. The fluidic device as described.   A cylinder inserted into a housing hole formed in the housing; a pump chamber formed in the cylinder, the volume of which is expanded and contracted; a discharge chamber communicating with the pump chamber via a discharge valve; and the discharge valve opened. A fluid device comprising: a spring member biased in a valve direction; and a damper chamber having a variable volume adjacent to the discharge chamber.   A pump device having a pump chamber whose volume expands and contracts, a discharge chamber communicating with the pump chamber via a discharge valve, and a damper portion whose volume can be changed during pump operation at a position facing the discharge chamber. A fluid device provided.   The fluid device according to claim 1 or 7, wherein the damper chamber has a volume changeable by a movable part and an elastic body provided on an outer periphery of the movable part.

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