JP2989030B2 - Fluid pressure pulsation reduction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for reducing fluid pressure pulsations.

[0002]

2. Description of the Related Art In a hydraulic power steering apparatus, for example, when pressure pulsation occurs in pressure oil sent from a pump to the power steering apparatus, the housing of the power steering apparatus vibrates to generate noise, or the piping is damaged by resonance. There's a problem.

In order to reduce such pulsation of the fluid pressure, there has been proposed an apparatus in which an elastic body is provided in a fluid passage and the pulsation of the pressure is absorbed by elastic deformation of the elastic body (Japanese Patent Application Laid-Open No. 63-186096). reference).

[0004]

When an attempt is made to reduce the pressure pulsation of a fluid by an elastic body, the elastic body becomes large when the fluid pressure is large, and the space is limited in a space where the installation space is limited like a power steering device. Not available to those deployed. In addition, 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 capable of reliably reducing the pulsation of fluid pressure.

[0006]

SUMMARY OF THE INVENTION A feature of the present invention is to provide a fluid passage and a fluid chamber partitioned by a partition member from the fluid passage, wherein the fluid pressure in the fluid passage is controlled by the fluid pressure in the fluid chamber. A valve allowing fluid to flow from the fluid passage to the fluid chamber when the pressure is greater than the fluid 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. And one valve and the other valve are arranged along the flow direction of the fluid.

[0007]

FIG. 1 schematically shows a configuration example of the present invention, in which a fluid having a pressure pulsation flows rightward in a fluid passage 1 in the drawing, and a partition member 2 Is filled with a stationary fluid.
When the fluid pressure in the fluid passage 1 is higher than the fluid pressure in the fluid chamber 3 on the downstream side (the right side in FIG. 1) of the partition member 2, the fluid from the fluid passage 1 to the fluid chamber 3 A valve 14 is provided to allow the inflow of water. In addition, a valve 15 is provided upstream of the partition member 2 to allow the fluid to flow from the fluid chamber 3 to the fluid passage 1 when the fluid pressure in the fluid chamber 3 is higher than the fluid pressure in the fluid passage 1. Have been.

When the fluid flowing through the fluid passage 1 has a pressure pulsation, the pressure wave can be represented as a compression wave as shown by a chain line in the figure. The dense part of the compression wave, that is, the pressure wave higher than the fluid pressure in the fluid chamber 3 is introduced into the fluid chamber 3 from the fluid passage 1 by the downstream valve 14. This pressure wave propagates in 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, at the position of the valve 15 on the upstream side, when 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,
The pressure wave propagating in the fluid chamber 3 is introduced into the fluid passage 1 by the valve 15 on the upstream side. Therefore, in this case, the pressure of the low pressure portion of the pressure wave propagating in the fluid passage 1 increases.
At the position of the valve 15 on the upstream side, the fluid passage 1
When the pressure of the pressure wave propagating in the fluid chamber is equal to or greater than the pressure of the pressure wave propagating in the fluid chamber 3, the pressure wave propagating in the fluid chamber 3 is transmitted from the upstream valve 15 to the fluid passage. The pressure wave propagating in the fluid passage 1 is not affected. Thereby, the pressure difference between the high pressure portion and the low pressure portion of the pressure wave propagating through the fluid passage 1 is reduced, and the pressure pulsation is reduced.

[0010]

Embodiments of the present invention will be described below 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.

As shown in FIG. 2, the pulsation reducing device 9 includes an outer tube 10 and an inner tube (partition member) 11 inserted into the outer tube 10. Cylindrical connection fittings 12 and 13 are fitted to both ends of the outer tube 10, and each connection fitting 1
Internal threads 12 a and 13 a for connection to the pipe 8 are formed on the inner circumferences of the pipes 2 and 13. In this embodiment, the inner tube 11 is made of rubber and is elastically deformable. Both ends of the inner tube are sandwiched between the connection fittings 12 and 13 and the outer tube 10. Thereby, the inner peripheral side of the inner pipe 11 is used as the fluid passage 1, and the pressure oil supplied from the vane pump 7 to the hydraulic power steering device 6 flows. The fluid chamber 3 is defined between the inner pipe 11 and the outer pipe 10 and stores the same oil as the oil flowing through the fluid passage 1.

When the fluid pressure in the fluid passage 1 is higher than the fluid pressure in the fluid chamber 3, a plurality of valves 14 that allow the fluid to flow from the fluid passage 1 to the fluid chamber 3 are provided in the inner pipe 11 in the circumferential direction. It is provided along. As shown in FIG. 3, the valve 14 is formed integrally with a rubber-made inner tube 11 with a radially outwardly projecting convex portion 14a. When the pressure is greater than the pressure on the outer side, the opening opens against the elastic force of the rubber, and when the pressure on the radially inner side of the inner tube 11 becomes lower than the pressure on the outer side, the through hole 14b is closed by the elastic force of the rubber. Is formed. That is, as shown in FIG. 5, when the pressure on the radially inner side of the inner tube 11 becomes larger than the pressure on the radially outer side, the through hole 14b opens, and the inflow of fluid from the fluid passage 1 to the fluid chamber 3 is allowed. Is done. As shown in FIG. 2, when the pressure on the radially inner side of the inner pipe 11 becomes lower than the pressure on the radially outer side, the through hole 14b closes, and the inflow of the fluid from the fluid passage 1 to the fluid chamber 3 is restricted. Is done.

When the fluid pressure in the fluid chamber 3 is higher than the fluid pressure in the fluid passage 1, a plurality of valves 15 permitting the fluid to flow from the fluid chamber 3 into the fluid passage 1 in the inner pipe 11. It is provided along the direction. As shown in FIG. 3, the valve 15 has a rubber inner tube 11 integrally formed with a convex portion 15a projecting inward in the radial direction, and the convex portion 15a has a pressure on the radially outer side of the inner tube 11. When the pressure becomes larger than the pressure on the inner side, the opening is opened against the elastic force of the rubber, and 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 is closed by the elastic force of the rubber. It is formed by providing. That is, as shown in FIG. 6, when the pressure on the radially outer side of the inner pipe 11 becomes larger than the pressure on the radially inner side, the through hole 15b opens, and the inflow of fluid from the fluid chamber 3 to the fluid passage 1 is allowed. Is done. Also, 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 inner side, the through hole 15b closes and the inflow of fluid from the fluid chamber 3 to the fluid passage 1 is restricted. Is done.

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

According to the above configuration, the pressure oil discharged from the vane pump 7 has a pressure pulsation, and the pressure pulsation propagates through the fluid passage 1 as a pressure wave. And the downstream valve 14
When the pressure of the pressure wave propagating through the fluid passage 1 is greater than the oil pressure in the fluid chamber 3 at the position of the flow path 1, the pressure difference causes the through hole 14b of the downstream valve 14 to open, and the fluid passage 1
Slightly flows into the fluid chamber 3 from the fluid. Thereby, the pressure wave propagating through the fluid passage 1 is 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. When the pressure of the pressure wave propagating through the fluid passage 1 is smaller than the pressure of the pressure wave propagating through the fluid chamber 3 at the position of the upstream valve 15, the pressure difference causes the passage of the upstream valve 15. 15b is opened, and the oil slightly flows into the fluid passage 1 from the fluid chamber 3. Therefore, in this case, the pressure wave propagating in the fluid chamber 3 is introduced into the fluid passage 1, and the pressure of the pressure wave propagating in the fluid passage 1 is increased. Further, at the position of the valve 15 on the upstream side, the pressure of the pressure wave propagating through the fluid passage 1 becomes
When the pressure is higher than or equal to the pressure of the pressure wave propagating through the fluid chamber 3, the through hole 15b of the valve 15 is not opened. Therefore, in this case, the pressure wave propagating through the fluid chamber 3 does not affect the pressure of the pressure wave propagating through the fluid passage 1.

As a result, the pressure difference between the high pressure portion and the low pressure portion of the pressure wave propagating through the fluid passage 1 is reduced, and pressure pulsation is reduced.

In the above embodiment, since the inner pipe 11 is made of rubber, the pressure pulsation of the pressure oil flowing through the fluid passage 1 is reduced.
1 can be absorbed by its own elastic deformation.

The present invention is not limited to the above embodiment.

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.

In the above embodiment, the hydraulic power steering device 6 is used for reducing the pulsation of the hydraulic oil pressure. However, the present invention is applicable if the pulsation of the fluid pressure needs to be reduced. it can.

In the above embodiment, the inner tube 11 is made of rubber and can be elastically deformed. However, the material is not limited, and any material can be used as long as it can separate the fluid passage from the fluid chamber.

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

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. However, 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 using a double pipe structure. Further, in the above embodiment, a liquid is shown as the fluid, but a gas may be used.

Although the fluid in the fluid chamber is stationary in the above embodiment, it may be flowing, 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-mentioned embodiment, and any structure may be used as long as it allows the fluid to flow in one direction according to the pressure difference between the fluid passage and the fluid chamber.

[0028]

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

[Brief description of the drawings]

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

FIG. 2 is a cross-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 the embodiment of the present invention.

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

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

FIG. 6 is a diagram illustrating the operation of the other valve according to the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 fluid passage 3 fluid chamber 11 inner pipe (partition member) 14 valve 15 valve

Claims (1)

(57) [Claims] A fluid passage, and a fluid chamber partitioned from the fluid passage by a partition member. When a fluid pressure in the fluid passage is larger than a fluid pressure in the fluid chamber, the fluid passage from the fluid passage to the fluid chamber is provided. A valve that permits the inflow of fluid and a valve that allows the 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; The pulsation reducing device for fluid pressure, wherein the other valve is disposed along a flow direction of the fluid.