JPH04312288A - Pulsation attenuating device for fluid pressure - Google Patents

Abstract

PURPOSE:To attenuate the pulsation of fluid pressure in a compact and simple configuration by lessening the difference in pressure wave propagating within a fluid passage between a high and a low pressure section. CONSTITUTION:A device is provided with a fluid passage 1 and with a fluid chamber 3 which is partitioned by a partitioning member 11 with respect to the fluid passage 1. The device is also provided with valves 14 which permit fluid to flow in the fluid chamber 3 from the fluid passage 1 when fluid within the fluid passage is higher in pressure than the fluid chamber 3, and with valves 15 which permit fluid to flow in the fluid passage 1 from the fluid chamber 3 when fluid in the fluid chamber 3 is higher in pressure than the fluid passage 1. The valves 14 and the other valves 15 are disposed along the flow of fluid.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to a device for reducing fluid pressure pulsations.

0002

[Prior Art] For example, in a hydraulic power steering system, if there is pressure pulsation in the pressure oil sent from the pump to the power steering system, the housing of the power steering system may vibrate, producing noise, or the piping may be damaged due to resonance. There's a problem.

In order to reduce such fluid pressure pulsations, it has been proposed to provide an elastic body in the fluid passage and absorb the pressure pulsations through elastic deformation of the elastic body (Japanese Patent Laid-Open No. 186096/1983). reference).

0004

[Problem to be Solved by the Invention] If an attempt is made to reduce fluid pressure pulsations using an elastic body, the elastic body will become large if the fluid pressure is large, making it difficult to use in places with limited installation space, such as in power steering devices. It was not available for those placed. Further, there is a problem that the cost increases due to the increase in size.

An object of the present invention is to provide a compact device that can reliably reduce fluid pressure pulsations.

[0006]

[Means for Solving the Problems] The present invention is characterized by comprising a fluid passage and a fluid chamber partitioned from the fluid passage by a partition member, and the fluid pressure in the fluid passage is equal to the fluid pressure in the fluid chamber. a valve that allows fluid to flow from the fluid passageway into the fluid chamber when the fluid pressure in the fluid chamber is greater than the fluid pressure in the fluid passageway; One valve and the other valve are arranged along the flow direction of the fluid.

[0007]

[Operation] FIG. 1 schematically shows a configuration example of the present invention, in which a fluid having pressure pulsations flows through a fluid passage 1 toward the right in the figure, and a partition member 2 is attached to the fluid passage 1. A fluid chamber 3 partitioned by is filled with stationary fluid. Then, on the downstream side (the right side in FIG. 1) of the partition member 2, when the fluid pressure in the fluid passage 1 is higher than the fluid pressure in the fluid chamber 3, fluid is transferred from the fluid passage 1 to the fluid chamber 3. A valve 14 is provided to allow the inflow of. Further, a valve 15 is provided on the upstream side of the partition member 2 to allow fluid to flow from the fluid chamber 3 into the fluid passage 1 when the fluid pressure in the fluid chamber 3 is higher than the fluid pressure in the fluid passage 1. It is being

[0008] When the fluid flowing through the fluid passage 1 has pressure pulsations, the pressure waves can be expressed as compressional waves as shown by the chain lines in the figure. The dense portion of the compressional wave, that is, the pressure wave having a higher pressure than the fluid pressure in the fluid chamber 3, is introduced from the fluid passage 1 into the fluid chamber 3 by the downstream valve 14. This pressure wave propagates through the fluid in the fluid chamber 3, as shown by the chain line in the figure, and reaches the valve 15 on the upstream side.

In this case, if the pressure of the pressure wave propagating in the fluid passage 1 is smaller than the pressure of the pressure wave propagating in the fluid chamber 3 at the position of the valve 15 on the upstream side,
The pressure wave propagating within the fluid chamber 3 is introduced into the fluid passage 1 by the upstream valve 15. Therefore, in this case, the pressure in the low pressure portion of the pressure wave propagating within the fluid passage 1 increases. Further, at the position of the valve 15 on the upstream side, the fluid passage 1
If the pressure of the pressure wave propagating inside the fluid chamber 3 is equal to or greater than the pressure of the pressure wave propagating inside the fluid chamber 3, the pressure wave propagating inside the fluid chamber 3 flows from the valve 15 on the upstream side to the fluid passage. 1 and the pressure waves propagating within the fluid passage 1 are not affected. Thereby, the pressure difference between the high pressure part and the low pressure part of the pressure wave propagating through the fluid passage 1 is reduced, and pressure pulsations are reduced.

0010

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 4 shows a fluid pressure pulsation reducing device 9 provided in the middle of a pipe 8 connecting the vane pump 7 and the hydraulic power steering device 6.

The pulsation reduction device 9 includes an outer tube 10 and an inner tube (partition member) 11 inserted into the outer tube 10, as shown in FIG. Cylindrical connection fittings 12 and 13 are fitted to both ends of the outer tube 10, and each connection fitting 12
, 13 has a female thread 1 on the inner periphery for connection with the piping 8.
2a and 13a are formed. In this embodiment, the inner tube 11 is made of rubber and is elastically deformable. Both ends of this inner tube are sandwiched between connection fittings 12 and 13 and outer tube 10. As a result, the inner peripheral side of the inner tube 11 becomes the fluid passage 1, and the pressure oil supplied from the vane pump 7 to the hydraulic power steering device 6 flows therethrough. In addition, inner tube 1
1 and the outer tube 10 is a fluid chamber 3 in which the same oil as that flowing through the fluid passage 1 is stored.

A plurality of valves 14 are provided in the inner pipe 11 in the circumferential direction for allowing fluid to flow from the fluid passage 1 into the fluid chamber 3 when the fluid pressure in the fluid passage 1 is greater than the fluid pressure in the fluid chamber 3. It is located along the As shown in FIG. 3, this valve 14 is made by integrally molding a convex portion 14a that protrudes outward in the radial direction on the inner tube 11 made of rubber. The through hole 14b opens against the elastic force of the rubber when the pressure becomes greater than the pressure on the outer side, and closes due to the elastic force of the rubber when the pressure on the radially inner side of the inner tube 11 becomes less than the pressure on the outer side. It is formed by providing That is, as shown in FIG. 5, when the pressure on the radially inward side of the inner tube 11 becomes greater than the pressure on the radially outward side, the through hole 14b opens, allowing fluid to flow from the fluid passage 1 into the fluid chamber 3. be done. Further, as shown in FIG. 2, when the pressure on the radially inward side of the inner tube 11 becomes lower than the radially outward pressure, the through hole 14b closes, and the inflow of fluid from the fluid passage 1 to the fluid chamber 3 is restricted. be done.

Further, a plurality of valves 15 are provided around the inner pipe 11 to allow fluid to flow from the fluid chamber 3 into the fluid passage 1 when the fluid pressure in the fluid chamber 3 is greater than the fluid pressure in the fluid passage 1. located along the direction. As shown in FIG. 3, this valve 15 is made by integrally molding a convex portion 15a that protrudes radially inward on the inner tube 11 made of rubber, and the convex portion 15a is provided with a pressure on the radially outward side of the inner tube 11. When the pressure on the radially outer side of the inner tube 11 becomes lower than the pressure on the inner side, the through hole 15b opens against the elastic force of the rubber and closes due to the elastic force of the rubber. It is formed by providing That is, as shown in FIG. 6, when the pressure on the radially outward side of the inner tube 11 becomes larger than the pressure on the radially inward side, the through hole 15b opens, allowing fluid to flow from the fluid chamber 3 into the fluid passage 1. be done. Further, as shown in FIG. 2, when the pressure on the radially outer side of the inner tube 11 becomes lower than the pressure on the radially inward side, the through hole 15b closes, and the inflow of fluid from the fluid chamber 3 to the fluid passage 1 is restricted. be done.

The one valve 14 and the other valve 15 are arranged along the flow direction. In this embodiment, the fluid flows from the left to the right in FIG.
is located on the downstream side, and the other valve 15 is located on the upstream side.

According to the above structure, the pressure oil discharged from the vane pump 7 has pressure pulsations, and the pressure pulsations propagate through the fluid passage 1 as pressure waves. And the downstream valve 14
If, at the position of
A small amount of oil flows into the fluid chamber 3 from there. As a result, pressure waves propagating through the fluid passage 1 are introduced into the fluid chamber 3.

The pressure wave introduced into the fluid chamber 3 propagates through the oil in the fluid chamber 3 and reaches the valve 15 on the upstream side. If the pressure of the pressure wave propagating in the fluid passage 1 is lower than the pressure of the pressure wave propagating in the fluid chamber 3 at the position of the upstream valve 15, the pressure difference causes the passage of the upstream valve 15 to 15b opens, and oil slightly flows into the fluid passage 1 from the fluid chamber 3. Therefore, in this case, the pressure waves propagating through the fluid chamber 3 are introduced into the fluid passage 1, and the pressure of the pressure waves propagating through the fluid passage 1 is increased. Moreover, at the position of the valve 15 on the upstream side, the pressure of the pressure wave propagating in the fluid passage 1 is
If the pressure is greater than or equal to the pressure of the pressure wave propagating through the fluid chamber 3, the through hole 15b of the valve 15 will not be opened. Therefore, in this case, the pressure waves propagating in the fluid chamber 3 do not affect the pressure of the pressure waves propagating in the fluid passage 1.

[0018] As a result, the pressure difference between the high pressure part and the low pressure part of the pressure wave propagating through the fluid passage 1 is reduced, and pressure pulsations are reduced.

Further, in the above embodiment, since the inner tube 11 is made of rubber, the pressure pulsations of the pressure oil flowing through the fluid passage 1 can be absorbed by the inner tube 11.
This can be absorbed by the elastic deformation of 1 itself.

It should be noted that the present invention is not limited to the above embodiments.

For example, in the above embodiment, the fluid pressure pulsation reducing device 9 is provided in the middle of the pipe 8, but it may be provided inside the discharge port of the casing of the pump 7.

Furthermore, although the above embodiment shows the device used to reduce the pulsation of the hydraulic fluid pressure in the hydraulic power steering device 6, the present invention can be applied to any device where it is necessary to reduce the pulsation of the fluid pressure. can.

Further, in the above embodiment, the inner tube 11 is made of rubber so that it can be elastically deformed, but its material is not limited as long as it can partition the fluid passage and the fluid chamber.

Further, in the above embodiment, one valve that allows fluid to flow from the fluid passage into the fluid chamber is disposed on the downstream side,
The other valve that allows fluid to flow from the fluid chamber into the fluid passage is placed on the upstream side, but one valve may be placed on the upstream side and the other valve on the downstream side, or one valve may be placed above one valve. The other valve may be disposed downstream, or one valve may be disposed upstream and downstream of the other valve, as long as one valve and the other valve are disposed along the flow direction.

Further, in the above embodiment, the inner periphery of the double pipe is used as a fluid passage and the outer periphery is used as a fluid chamber, but the outer periphery may be used as a fluid passage and the inner periphery may be used as a fluid chamber. Further, the fluid passage and the fluid chamber may be arranged in parallel without having a double pipe structure. Further, although a liquid is shown as the fluid in the above embodiment, it may be a gas.

Further, although the fluid in the fluid chamber is shown to be stationary in the above embodiment, it may be fluid, and the fluid in the fluid chamber and the fluid in the fluid passage may be of the same quality. Not limited.

Further, the structure of the valve is not limited to the above-described embodiment, and may be any structure that allows fluid to flow in one direction depending on the pressure difference between the fluid passage and the fluid chamber.

[0028]

According to the present invention, pulsation of fluid pressure can be reliably reduced with a compact and simple structure regardless of the magnitude of fluid pressure.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the action of the fluid pressure pulsation reducing device of the present invention.

FIG. 2 is a sectional view of a fluid pressure pulsation reducing device according to an embodiment of the present invention.

FIG. 3 is a perspective view of an inner tube according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of the configuration of a hydraulic power steering device according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of the operation of one valve according to the embodiment of the present invention.

[
FIG. 6 is an explanatory diagram of the operation of the other valve according to the embodiment of the present invention

[Explanation of symbols]

1 Fluid passage 3 Fluid chamber 11 Inner pipe (partition member) 14 Valve 15 Valve

Claims (1)

[Claims] Claim 1: A fluid passageway and a fluid chamber partitioned from the fluid passageway by a partition member, wherein when the fluid pressure in the fluid passageway is greater than the fluid pressure in the fluid chamber, the fluid flow from the fluid passageway to the fluid chamber is provided. A valve that allows fluid to flow in, and a valve that allows fluid to flow from the fluid chamber to the fluid passage when the fluid pressure in the fluid chamber is greater than the fluid pressure in the fluid passage are provided. A fluid pressure pulsation reducing device characterized in that the other valve is arranged along the fluid flow direction.