JPH029156Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an improvement of a joint valve in which a valve is incorporated into a piping joint such as a hydraulic cylinder.

(Prior art and its problems to be solved) For example, in a single-acting hydraulic cylinder, if oil leaks due to damage to piping while supplying pressure oil to the oil chamber, It is necessary to prevent the hydraulic cylinder (piston rod) from dropping suddenly, and for this purpose a joint valve as shown in FIG. 1 is attached to the hydraulic cylinder.

The cylindrical joint body 1 has coupling threads 2 and 3 at both ends.
The main body 1 has an intercept valve 4 incorporated therein.

In the intercept valve 4, a valve seat 6 having an orifice 6a is fitted into a stepped portion of a stepped hole 5, and a sleeve poppet 7, which is housed so as to be able to come into and out of the valve seat 6, is engaged by a spring 8 with a retaining ring 9. is biased in the direction of contact with.

Therefore, as long as the differential pressure between ports A and B does not exceed the set value of the spring 8, the sleeve poppet 7 is kept open. When the pressure at which a crack occurs suddenly drops and the differential pressure with the port A side exceeds the spring setting value, the sleeve poppet 7 contacts the seat 6 and closes, preventing the high pressure inside the cylinder from escaping suddenly. Then, the hydraulic cylinder is stopped at that position.

However, due to the structure of such a joint valve, the valve seat 6 and sleeve poppet 7 are housed inside the stepped hole 5 of the joint body 1, so it is difficult to secure a predetermined valve flow rate. The outer diameter of the joint body 1 is large, and the structure is complicated, making machining and assembly difficult, resulting in high production costs.

In addition, known documents regarding this type of valve include JP-A No. 53-18032, JP-A-49-521, and JP-U-T-KOKAI No. 39-1803.
There are various publications of No. 24541. The valves disclosed in these documents all have a structure in which a poppet and a spring are housed inside the member itself that connects the piping, and therefore have the problems described above.

The present invention aims to solve these conventional problems.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes integrally forming a valve seat on the end face of one threaded part of the joint body which has coupling threaded parts on both outer circumferential surfaces. A poppet that comes into contact with and separates from the seat is slidably housed inside a cap coaxially caulked to the end of the threaded portion, and the poppet is biased in a direction opposing the fluid pressure acting on the poppet. Installed a spring.

(Function) In the above configuration, the poppet and spring are housed inside the cap which is caulked to the end of the threaded part, so the inner diameter of the accommodation space inside this thin cap is approximately the diameter of the threaded part. In this case, the joint body only needs to have a passage, so its outer diameter can be minimized and the structure can be simplified.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 2 shows a state in which the joint valve 10 of the present invention is attached to a passage 13 communicating with a lower oil chamber 12 of a hydraulic cylinder 11.

In the figure, 15 is the joint body, 16 is the nut head, 17 and 18 are the connecting screw parts, and the joint body 1
5 has a straight through hole 19 formed therein.

A valve seat 2 is integrally provided on the inner periphery of the shaft end 22 of the threaded portion 17 that is screwed into the hydraulic cylinder 11 side.
0 is formed.

A poppet 21 faces this valve seat 20.
is arranged, and this poppet 21 is housed in a cap 23 on the outside thereof via a collar 24 so as to be freely slidable.

The cylindrical cap 23 is caulked coaxially to the shaft end 22, and the outer diameter of the shaft end 22 is adjusted so that its outer diameter in the joined state corresponds to the root diameter of the threaded portion 17. is also set.

An orifice hole 25 is formed through the center of the poppet 21, and a valve hole 26 is formed in the guide collar 24.The poppet 21 is connected to the cap 23 by a spring 27.
The valve is biased to open so as to come into contact with the distal end locking portion 28 of the valve.

The device is configured as described above, and its operation will be explained next.

When threading the threaded portion 17 into the passage 13 of the hydraulic cylinder 11, the valve portion at the tip of the threaded portion 17
Since the cap 23 has a smaller diameter, it has no effect on this tightening. A pipe (not shown) is screwed to the threaded portion 18 on the opposite side.

Pressure oil from the piping side is transferred to the oil chamber 1 of the hydraulic cylinder 11.
When supplying to cap 2, poppet 21
The valve is opened by being pressed by a spring 27 and hydraulic pressure to a position where it contacts the tip locking portion 28 of No. 3,
To smoothly introduce high pressure oil into an oil chamber 12.

Also, when lowering the oil chamber cylinder 11,
As long as the differential pressure across the poppet 21 does not exceed the set value in the spring 27 due to circuit resistance (not shown), the poppet 21 is held at the same position as above, allowing the return oil from the oil chamber 12 to be smoothly discharged. .

On the other hand, when the pressure on the piping side suddenly decreases and the differential pressure across the poppet 21 becomes significantly large,
The poppet 21 moves against the spring 27 until it comes into close contact with the valve seat 20, and the valve is closed.

In this state, the hydraulic oil flows only through the orifice hole 25, so the descending speed of the hydraulic cylinder 11 is very slow, and a sudden fall can be prevented.

In the embodiment shown in FIG. 3, a joint valve 1 is connected to a hydraulic cylinder 11 through an elbow-shaped joint 30.
0 can be combined to make the cylinder axis and joint valve axis parallel.

Figures 4 and 5 show joint valves 10A and 10B with different valve functions, respectively.
In FIG. 4, the poppet 21A is urged by a spring 27 in the direction of contacting the valve seat 20, and the poppet 21A is always pressed against the return oil from the cylinder side.
1A is closed and hydraulic oil is passed only through the orifice hole 25 to control the descending speed. (However, in this case, it also functions as a delay valve.) Fig. 5 shows an example in which the poppet 21B is not provided with the orifice 25 as shown in Fig. 4, but merely functions as a check valve. .

(Effects of the invention) As described above, the present invention integrally forms a valve seat on the end face of one threaded part of a joint body having coupling threaded parts on both outer peripheral surfaces, and a poppet that comes into contact with and separates from this valve seat. It is housed in a cap that is coaxially caulked to the end of the threaded part and can be slid freely inside.
Since a spring is provided that biases the poppet in a direction opposed to the fluid pressure acting on the poppet, the present invention allows the joint body to be made compact in the radial direction. Since there is no need to incorporate the inside of the joint body, the structure is simplified, assembly is easy, and productivity is improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional device. 2 to 5 are sectional views showing embodiments of the present invention, respectively. 10...Joint valve, 11...Hydraulic cylinder,
15...Joint body, 17, 18...Threaded part, 19
...Through hole, 20...Valve seat, 22...Shaft end, 21, 21A, 21B...Poppet, 23...
...cap, 25...orifice hole, 27...spring.

Claims (1)

[Scope of utility model registration request] A cap in which a valve seat is integrally formed on the end face of one threaded part of a joint body that has coupling threaded parts on both outer peripheral surfaces, and a poppet that comes into contact with and separates from this valve seat is coaxially caulked to the end of the threaded part. 1. A joint valve comprising a spring that is slidably housed inside the poppet and biases the poppet in a direction opposed to the fluid pressure acting on the poppet.