JPH0324942Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a check valve that allows fluid to flow in only one direction.

"Prior art and its problems" Check valves of various structures are known in the past, and are fully functionally satisfied. However, when looking at the specific structure, there are problems such as a large number of parts and poor assembly efficiency, and as this type of functional component tends to be subject to price competition, it has not always been satisfactory in terms of cost.

``Purpose of the invention'' This invention has a small number of parts, a simple structure,
The purpose of the present invention is to obtain a check valve that is easy to assemble and is therefore inexpensive.

``Summary of the invention'' This invention forms a small diameter flow path of a certain length with a valve seat at one end and a retaining wall at the other end, and makes contact with the valve seat of this small diameter flow path. A separable valve body and a retainer that can move toward and away from a retaining wall and allow fluid flow are provided, and a connecting shaft that protrudes into the small diameter flow path is integrally provided on the valve body and the retainer,
The connecting shafts are connected via a coil spring that brings the valve body and retainer into elastic contact with the valve seat and the retaining wall, respectively.

According to this configuration, a check valve can be constructed simply by positioning the valve body and the retainer on both sides of the small-diameter flow path and locking them to the coil spring. The coil spring and the connecting shaft of the valve body and retainer can be locked with any locking means such as adhesive, but the connecting shaft of the valve body and retainer must have the same pitch as the coil spring. If a thread is formed, the two can be connected by rotating the valve body or retainer and screwing it into the coil spring.

``Embodiments of the invention'' The invention will be described below with reference to illustrated embodiments. 1 to 4 show an embodiment of the present invention, which is an embodiment applied to a part of a speed control valve. The speed control valve 10 is a directional control valve 11 that controls pressure fluid from the pump P.
and the pressure chamber 13 of the cylinder device 12, and the free flow V from the direction control valve 11 toward the pressure chamber 13 is substantially controlled via the check valve 20, which is a feature of the present invention. A controlled flow C of the fluid discharged from the pressure chamber 13 without restricting the flow path.
is the flow control valve 40 without passing the check valve 20.
This narrows the flow path.

The check valve 20 is provided within the main flow path 22 of the control valve block 21 in a small diameter flow path 23 formed with a smaller diameter than the main flow path. Small diameter channel 23
has a valve seat 24 at one end (the left end in FIG. 1) and a retaining wall 25 at the other end. 26, 2
Reference numeral 7 indicates connection taper threads for piping formed at both ends of the main flow path 22.

The valve body 28 and the retainer 33 move toward and away from the valve seat 24 and the retaining wall 25, and are made of separate members. The valve body 28 includes a valve portion 29 made of an elastic body that directly contacts and separates from the valve seat 24, and a small diameter flow path 23.
It has a connecting shaft 30 that extends while keeping a gap therein. The retainer 33 has a plurality of ribs 34 that come into contact with and separate from the retaining wall 25, and a connecting shaft 35 that similarly extends within the small-diameter flow path 23 while maintaining a gap. rib 3
4 secures a flow path between the retainer 33 and the small diameter flow path 23.

As shown in FIG. 4, spiral locking grooves 31 and 36 are formed in the connecting shaft 30 and the connecting shaft 35, respectively, for locking the coil spring 37. Then, the valve body 28 and the retainer 33 are connected by the coil spring 37.

That is, when assembling the check valve 20 having the above structure, the coil spring 37 is connected to the connecting shaft 30 of the valve body 28, for example, the valve body 28 is positioned on the valve seat 24 side, and the coil spring 37 is made small. Insert from the radial flow path 23. On the other hand, a retainer 33 is positioned on the side of the retaining wall 25, and the retainer 33 is rotated with its connecting shaft 35 aligned with the coil spring 37. Then, the connecting shaft 35 is screwed into the coil spring 37 by the locking groove 36, and the valve body 28 and the connecting shaft 35 are coupled. In this connected state, the tensile force of the coil spring 37 causes the valve body 28 to attach to the valve seat 24 and the retainer 33 to the retaining wall 25.
They collide with each other.

In addition to the above, the coil spring 37 and the connecting shafts 30 and 35 can be connected to each other by using an adhesive or by simply pushing the connecting shaft 30 or 35 into the coil spring 37 to connect the locking groove 31 and the coil around the coil spring 37. It is also possible to engage the spring 37.

Next, the flow control valve 40 will be explained. A narrow part 39 is formed in the upper part of the control valve block 21, and a needle valve passage 41 communicating with the main passage 22 is provided in this narrow part 39.
It is perforated in a diagonal relation to the This needle valve passage 41 penetrates into the main passage 22 from the outer surface of the narrow portion 39, and forms an angle θ with the axis of the main passage 22. This θ is
The vertical and horizontal dimensions s and of the control valve block 21 are determined so as to be small. If θ is made small, s
can be made smaller, and conversely, by increasing θ, can be made smaller.

The needle valve passage 41 opens into the main passage 22 on the left side of the check valve 20 in FIG.
3 is provided with a detour passage 42 that is orthogonal to the needle valve passage 41 and penetrates through the outer surface of the narrow portion 39. The portion of this detour passage 42 outside the needle valve passage 41 is later closed off by a blind ball 43.

A needle valve 44 is inserted into the needle valve passage 41 . This needle valve 44 has a male threaded portion 46, a seal portion 48, and a needle portion 49 in this order from the top, and an O-ring 50 that makes elastic contact with the inner wall of the needle valve passage 41 is fitted into the seal portion 48. The needle portion 49 changes the flow path area between the needle valve passage 41 and the constricted portion 41a by changing its axial position.

A slit 52 is cut in the narrow portion 39 of the control valve block 21 and is perpendicular to the needle valve passage 41. A flow rate adjusting nut 53, which is screwed into the male threaded portion 46 of the needle valve 44, is fitted into the slit 52 so as not to move substantially in the axial direction. The outer diameter of the flow rate adjusting nut 53 is larger than the width of the narrow portion 39, so that the flow rate adjusting nut 53 can be easily rotated from both sides of the narrow portion 39.

In the speed control valve 10 configured as described above, the free flow V flows without being substantially throttled when the check valve 20 is opened, and the flow path area of the controlled flow C depends on the axial position of the needle valve 44. can be controlled. That is, since the free flow V causes the valve body 28 of the check valve 20 to separate from the valve seat 24 against the force of the coil spring 37, the flow path is not substantially restricted. On the other hand, when the controlled flow C occurs, the valve body 28 seats on the valve seat 24 due to the force of the coil spring 37 and the force of the controlled flow C, so the check valve 20 blocks the flow path for the controlled flow C. It works as a means. In other words, it is a check valve (one-way valve).

The flow control valve 40 controls the flow rate of this control flow C. That is, the flow rate adjustment nut 5
When the nut 53 is rotated, the axial position of the nut 53 is restricted by the slit 52.
The needle valve 44 is moved in the axial direction by the male threaded portion 45. Therefore, the needle valve 44 is connected to the main flow path 22.
If the flow rate adjusting nut 53 is rotated in a direction closer to If the flow rate adjusting nut 53 is rotated in a direction that moves the needle valve 44 away from the main flow path 22, the return of the piston 14 becomes faster.

In the above embodiment, the check valve 20 of the present invention is combined with the flow rate control valve 40 to form the speed control valve 10.
Of course, it can also be used as a standalone check valve.

"Effects of the Invention" As described above, the check valve of the present invention has an extremely simple structure and can be easily assembled because the constituent members on the valve body side are one or two members. Therefore, a low-cost check valve can be provided.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view taken along line I-I in FIG. 2, FIG. 2 is a right side view of the same, and FIG. This figure is a front view of the same, and FIG. 4 is a perspective view showing an exploded state of the valve body, retainer, and coil spring. 20... Check valve, 21... Control valve block, 2
2... Main flow path (flow path), 23... Small diameter flow path,
24... Valve seat, 25... Preventing wall, 28... Valve body, 30, 35... Connection shaft, 31, 36... Locking groove, 33... Retainer, 34... Rib, 37...
coil spring.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A small diameter flow path of a certain length is formed in the flow path with a valve seat at one end and a retaining wall at the other end, and the valve seat of this small diameter flow path is A valve body that can move toward and away from the retaining wall, and a retainer that allows fluid flow to move toward and away from the retaining wall are provided, and a connecting shaft that protrudes into the small diameter flow path is integrally attached to the valve body and the retainer. established,
A check valve characterized in that the connecting shafts are connected via a coil spring that brings the valve body and retainer into elastic contact with a valve seat and a retaining wall, respectively. (2) The check valve according to claim 1 of the utility model registration claim, wherein a locking groove having the same pitch as that of a coil spring is formed on a connecting shaft of a valve body and a retainer.