JPS599292Y2 - Pressure control valve noise prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure control valve for a hydraulic circuit, and more particularly to a noise prevention device for a pressure control valve that prevents noise from a relief valve.

Conventional pilot operated pressure control valves
As shown in the figure, a valve chamber 5 communicating with the oil inlet 4a to the operating circuit and a valve chamber 6 communicating with the oil outlet 4b to the oil tank are provided inside the valve body 1, and the valve chambers 5 and 6 are connected to each other. Fitting holes 7 and 8 having different diameters are provided, and the main poppet 2 is slidably fitted into the fitting holes 7 and 8.

The main poppet 2 has a communication hole 9 in the axial center, and a communication hole 9 in the axial center.
A spring chamber 16 connected to the land is provided, and a small {L1
0 is provided to create a pressure difference between the valve chamber 5 and the valve chamber 11.

The piston 2 also has a spring 1 incorporated in the spring chamber 16.
The valve seat 1 is shaped at the lower end in the figure by the elastic force of 4.
The valve chamber 7 is seated at the valve chamber 7 and blocks the valve chambers 5 and 6.

A pilot valve body 15 is fixed to the outer end surface of the valve body 1, and a pilot passage 12 connects the valve chamber 11 and the action chamber 13 of the valve body 1.

The action chamber 13 is communicated with a valve chamber 20 via a passage 18,
The conical surface portion 24 of the pilot poppet 3 is seated on the valve seat 19 of the passage 18, and the action chamber 13 and the valve chamber 20 are closed off by the pressure regulating spring 21.

Further, the valve chamber 20 is provided with a passage 23 communicating with the fitting hole 8, and the oil in the valve chamber 20 is discharged into the oil tank via the communication hole 9.

31 is a cap, and 22 is an adjustment member provided movably in the axial direction to adjust the set elastic force of the pressure regulating spring 21.

With this structure, when the pressure in the operating circuit exceeds a predetermined pressure, pressure oil flows into the oil inlet 4a and the valve chamber 5, and a part of it flows into the small hole 10.
, from the pilot passage 12 through the valve chamber 11 to the action chamber 13;
Passage 18 is reached.

Therefore, the pressure oil is supplied by moving the pilot poppet 3 to the right against the pressure regulating spring 21 and passing through the valve chamber 20 and the passage 23 to the spring chamber 16.
, communication ``JL9'', valve chamber 6, and oil outlet 4b to flow out into the oil tank.

Therefore, the pressure inside the valve chamber 11 is reduced by the small hole 10 between the valve chambers 5 and 1.
1, the main poppet 2 rises against the spring 14, and the pressure oil in the valve chamber 5 flows out into the valve chamber 6, thereby controlling the pressure in the operating circuit.

In such an operating state, the conical surface portion 24 is disengaged from the valve seat 19 by the pressure oil in the working chamber 13 .

Regarding this separation, it is well known that the pilot poppet 3 vibrates transversely in a direction perpendicular to the axial direction depending on the shape and operating conditions of the valve.

High-frequency sounds (commonly known as beeping sounds) especially caused by lateral vibrations
Since the sound is significantly different from the sound of other mechanical vibrations, there are problems such as giving the operator a sense of discomfort and discomfort.

In view of this problem, one method for preventing the lateral vibrations of the pilot 1 to poppet 3 is to reduce the angle of the conical surface portion 24 that engages with the valve seat 19.

There is also a method of reducing the pilot flow rate.

The former method cannot be put to practical use because slight wear of the conical surface portion 24 and the valve seat 19 will extremely reduce the set pressure of the pressure control valve.

In addition, the latter has the disadvantage that the pilot flow rate tends to increase as the pressure of the hydraulic circuit increases and cannot be easily reduced.

In order to solve the above-mentioned drawbacks, the present invention provides a guide section at the rear of the pilot poppet, and a guide member that allows the guide section to slide and prevents lateral vibration. To provide a noise prevention device for a pressure control valve, which prevents lateral vibration of a pilot poppet in response to the current trend, eliminates high frequency noise caused by high pressure, and enables quiet operation.

Hereinafter, a description will be given of FIGS. 2 and 3 showing an embodiment of the present invention.

Note that the same parts as in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be avoided.

3a is a pilot poppet corresponding to the pilot poppet 3 in FIG. 1, which is pressed against the valve seat 19 by a pressure regulating spring 21 and an adjusting member 22 like the one in FIG.
The pressure in the action chamber 13 causes it to move to the right against the pressure regulating spring 21.

This pilot poppet 3a is provided with a guide portion 30 at the rear, and the guide portion 30 is provided with grooves for forming a plurality of passages along the axial direction.

The sliding surface of the guide member 25 that allows the guide portion 30 of the pilot poppet 3a to slide in the axial direction against the pressure regulating spring 21 and prevents transverse vibration in the right angle direction is the same as that of the pilot poppet 3a. A passage 28 is provided by the groove provided in the guide part 30, and a valve chamber 20a is provided before and after the guide part 30.
, 20 b.

The guide member 25 is provided with passages 26 and 27 corresponding to the valve chambers 20a and 20b, communicating with a chamber 29, and connected from the passage 23 to an oil tank via a communication hole 9.

Next, the operation of this device will be explained.

Note that the operation of the piston 2 is the same as that shown in FIG. 1, so a description thereof will be omitted.

When the pressure oil in the action chamber 13 becomes higher than the set pressure of the pressure control valve and the force applied to the pressure receiving area of the conical surface portion 24 overcomes the elastic force of the pressure regulating spring 21, the conical surface portion 24 disengages from the valve seat 19. Then the pilot poppets}3a is moved to the right.

Due to this rightward movement, the guide member 25 restricts the lateral vibration of the guide portion 30 in the right angle direction, so that the guide portion 30 can be smoothly moved only in the axial direction.

Furthermore, the guide portion 30 is provided with a passage 28 and has a small sliding area, so the sliding resistance is extremely low, and since the valve chambers 20a and 20b are in communication, the air in the valve chamber 20b can easily escape. ing.

Also, due to the movement of the pilot poppet 3a, the pressure oil in the valve chambers 20a and 20b flows through the respective passages 26.
, 27 to join the chamber 29, the passage 23 spring chamber 16,
The pressure is controlled because it flows out from the communication hole 9 and the valve chamber 6 into the oil tank.

As described above, the conventional pilot poppet 3 shown in FIG. 1 generates lateral vibrations and generates noise, whereas in FIG. This can prevent noise and eliminate noise.

FIG. 4 is an analysis diagram of the octave of the pressure control valve showing the occurrence of beeping noise in the conventional pressure control valve shown in FIG. 1, and FIG. 30 and a guide member 25 to reduce sliding resistance and prevent lateral vibration. FIG.

As shown in these figures, compared to FIG. 4, FIG. 5 clearly shows that the noise in the high frequency portion is smaller.

As described above, according to the present invention, a guide part is provided at the rear of the pilot poppet, and an axial groove is provided in the guide part to provide a passage with the guide member, thereby achieving a very simple structure. This has the effect of preventing lateral vibration and eliminating harmful noise, resulting in quiet operation.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional pressure control valve, FIG. 2 is a sectional view showing an embodiment of the present invention, and FIG.
4 is a 3-octave noise analysis diagram of a conventional pressure control valve, and FIG. 5 is a 2-octave noise analysis diagram of the pressure control valve of the present invention. 1... Valve body, 2... Main poppet, 3, 3a.
...Pilot poppet, 14...Spring, 15...
Pilot valve main body, 21... pressure regulating spring, 25... guide member.

Claims (1)

[Scope of utility model registration request] A pilot poppet 3 is actuated by a valve body 1, a main poppet 2 fitted into the valve body 1, and a pressure oil in an action chamber 13 formed at one end in hydraulic equilibrium with the main poppet 2. In a pressure control valve that controls the pressure of the operating circuit by discharging pressure oil laterally from its tip to slide the main poppet 2, the valve has an axial direction for providing a plurality of passages at the rear of the pilot poppet 3. A guide member 25 is provided which allows the guide member 30 to slide in the axial direction and prevents transverse vibration in the right angle direction. Noise prevention for a pressure control valve characterized by forming a passage 28 communicating with valve chambers 20a, 20b at the front and rear of a poppet 3, and providing passages 26, 27 communicating both valve chambers 20a, 20b with an oil tank. Device.