JP2524662Y2 - Solenoid valve plunger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a plunger of an electromagnetic valve used for a control valve or the like of a hydraulic / pneumatic device, for example.

(Prior Art) As a conventional plunger for this type of solenoid valve, for example, there is one shown in FIG. That is, the plunger 100 includes a magnetic plunger 101 and a rubber-like elastic body 102 that is integrally baked on the plunger body 101. The plunger body 101 is provided with a through hole 103 penetrating both ends thereof,
02 is baked so as to be tightly filled in the through hole 103 and to cover both end surfaces of the plunger body 101. Of these, the end face rubber portion 104 covering the end face of the plunger main body 101 on the valve seat contact portion side is in close contact with the valve seat 105 so as to maintain the sealing property when the valve is closed.

(Problems to be Solved by the Invention) However, in the case of the above-described conventional technique, when the rubber-like elastic body 102 is baked on the plunger main body 101, the rubber-like elastic body 102 in the through-hole 103 is shrunk after molding, so that the end face rubber is shrunk. Department
The central part of 104 is pulled into the through hole 103, and the end face rubber part 10
There is a problem that rubber shrinkage 106 occurs on the sealing surface 104A of No. 4 and the sealing performance is deteriorated.

Conventionally, as a countermeasure against such a shrinkage 106, as shown in FIG.
A method of stopping the contraction of the rubber-like elastic body 102 by the squeezing portion 107 and a method of polishing the sealing surface 104A to secure the sealing property are adopted.

However, such a conventional countermeasure method has a disadvantage that the former has a small diameter of the squeezed portion 107, so that the processing is troublesome and there is no mass productivity. In the latter method,
There is a problem that the polishing step is increased by one step and leads to an increase in cost.

The present invention has been made to solve the above-mentioned problems of the prior art, and the purpose is to reduce the shrinkage of the material when the rubber-like elastic body is baked with a simple structure as much as possible. An object of the present invention is to provide a plunger for an electromagnetic valve to obtain, thereby improving sealing performance and facilitating manufacture.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, a movable plunger body comes into contact with and separates from a valve seat provided in a valve box by electromagnetic attraction of a solenoid. The plunger body is provided with a through hole penetrating both ends thereof, and a plunger of a solenoid valve which is integrally baked so as to fill the inside of the through hole with a rubber-like elastic body and cover both end surfaces of the plunger body. A plurality of recesses are provided in the vicinity of a portion corresponding to the through hole of a rubber-like elastic body baked on the end face of the plunger body on the valve seat contact portion side.

(Operation) In the plunger of the solenoid valve having the above-described configuration, the rubber covering the vicinity of the through hole and the end surface of the peripheral portion thereof is covered by a plurality of recesses provided in the rubber-like elastic body which is baked on the end surface of the plunger body. The elastic body becomes discontinuous. Therefore, the force of pulling the rubber-like elastic body at the end face into the through-hole due to the contraction force of the rubber-like elastic body in the through-hole is reduced for each step, and the occurrence of shrinkage is prevented.

(Embodiment) Hereinafter, the present invention will be described based on the illustrated embodiment. In FIGS. 1 and 2 showing a plunger of an electromagnetic valve according to an embodiment of the present invention, reference numeral 1 denotes an entire plunger, and a plunger main body 2 made of a substantially magnetic material and integrally burned to the plunger main body 2. And a rubber-like elastic body 3 to be fixed.

The plunger main body 2 is a stepped cylindrical member, which is composed of a large diameter portion 21 and a small diameter portion 22, and has a through hole 4 penetrating both end surfaces thereof. The opening of the through hole 4 on the small diameter portion 22 side is slightly reduced in diameter.

The rubber-like elastic body 3 is filled in the through hole 4 and is baked on both end surfaces 5 and 6 of the plunger body.
It is composed of a filling rubber portion 31 filled in the inside, and first and second end face rubber portions 32 and 33 on both end faces. The first end face rubber portion 32 baked on the end face 5 of the plunger body 2 on the side of the small diameter portion 2 comes into contact with the valve seat 7 of the solenoid valve.

The first end surface rubber portion 32 is formed in a flat plate shape having a diameter slightly smaller than the small diameter side end surface 5 of the plunger main body 2, and a surface closely contacting the valve seat 7 is a sealing surface 8. A concave portion 9 is formed concentrically with the through hole 4 near the through hole 4 of the plunger main body 2 of the first end face rubber portion 32.

The recess 9 has a two-step shape in this embodiment.
A first recess 91 having a diameter slightly larger than the through hole 4 and a second recess 91 having a diameter smaller than the through hole 4 formed at the center of the bottom surface of the first recess 91;
And a stepped concave portion 92. The bottom surface of the second-step concave portion 92 is located at substantially the same position as the end surface 5 of the plunger body 2.
Further, the depth of the first-step concave portion 91 is formed slightly deeper than half of the thickness of the first end face rubber portion 32. But recess 9 is 3
A multi-stage configuration of more than stages may be used. The dimensions such as the depth and the diameter may be appropriately selected as needed.

In the plunger of the solenoid valve having the above configuration, when the rubber-like elastic body 3 is baked on the plunger body 2, the sealing surface 8 is shrunk by shrinkage of the molding material of the rubber-like elastic body 3 after the baking.
The first end face rubber portion 32 constituting the above-mentioned is closed.

In the present invention, since the two-step concave portion 9 is formed in the first end surface rubber portion 32, the contraction force generated on the seal surface 8 of the first end surface rubber portion 32 when the rubber-like elastic body 3 contracts. Of these, the component in the y direction in the figure, which is parallel to the sealing surface 8, is reduced by the recess 9 for each step, and the shrinkage of the sealing surface 8 can be reduced as much as possible. That is, the shrinking force of the filling rubber portion 31 in the through hole 4 in the central axis direction (x direction in the drawing) of the through hole 4 acts in the direction of pulling the first end face rubber portion 32 into the through hole 4. The component of the contraction force in the y direction is the concave portion 9.
Therefore, it is eased step by step. Therefore, the sealing surface 8 can maintain a flat surface and can be in close contact with the valve member 7 without any gap.

FIG. 3 shows an example of a solenoid valve in which such a plunger 1 is used. That is, this solenoid valve causes the plunger 1 to move toward and away from the valve seat 7 provided on the valve box 11 by the electromagnetic attraction force of the solenoid 10, and a flow path opened to the valve seat 7.
12 is configured to control opening and closing.

The solenoid 10 is integrated with the valve box 11,
The valve seat 7 provided in the valve box 11 is disposed so as to face the center post 13 of the solenoid 10, and the plunger 1 is a spring interposed between the center post 13 and the plunger 1.
14 urges the valve in the normally closed direction. Then, when the solenoid 10 is turned on, the plunger 1 is electromagnetically attracted to the center post 13 side against the spring force of the spring 14 to separate from the valve seat 7 and open the valve. On the other hand, the solenoid
Turning off 10 causes plunger 1 to spring 14
The valve is pressed against the valve seat 7 by the spring force of (2) to close the valve. That is, the first end face rubber portion of the plunger 1
Since the valve 32 is in close contact with the valve seat 7, the sealing performance when the valve is closed is maintained. At this time, since the first end face rubber portion 32 has the two-stage concave portion 9, the fluid pressure from the flow path 12 can be held for each stage, and the holding pressure can be increased. From this, it is possible to improve the sealing performance when the valve is closed.

The solenoid 10 is a coil molded into a cylindrical shape.
15, a center post 13 inserted and fixed to one open end of the coil 15, a case 16 for accommodating the coil 15, and an upper plate 17 for coupling the center post 13 and the case 16 to each other.
And The plunger 1 is slidably guided and held via a sleeve 19 on the inner periphery of a side ring 18 molded integrally with the coil 15.

However, the solenoid valve shown in FIG. 3 is merely an example, and the solenoid valve may be configured to abut on a valve seat and close when the plunger turns on the solenoid. The invention can be widely applied to other various solenoid valves.

(Effects of the Invention) The present invention has the above-described structure and operation. Since a plurality of recesses are provided in the vicinity of the through holes of the plunger body made of rubber-like elastic material which is baked on the end face of the plunger body, the penetration at the time of baking is achieved. The influence of the contraction force of the rubber-like elastic body in the hole can be reduced step by step, and the shrinkage generated in the rubber-like elastic body on the end face of the plunger main body can be reduced. In this case, since the fluid pressure from the flow path can be held for each stage in the plurality of recesses, the holding pressure can be increased. From these,
The sealing performance at the time of closing the valve can be reliably improved, and since there is no need to form a squeezed portion on the plunger main body as in the conventional case, molding is easy and mass production is possible. No post-processing is required, and costs can be reduced.

[Brief description of the drawings]

1 and 2 show a plunger of an electromagnetic valve according to an embodiment of the present invention. FIG. 1 is an enlarged sectional view of a main part, FIG. 2 is a vertical sectional view of the entirety, and FIG. FIG. 4 is a longitudinal sectional view of a plunger of a conventional solenoid valve, and FIG. 5 is a longitudinal sectional view of a plunger of another conventional solenoid valve. is there. DESCRIPTION OF SYMBOLS 1... Plunger 2... Plunger main body 21... Large-diameter portion 22... Small-diameter portion 3... Rubber-like elastic portion 31 31 rubber filling portion 32 first end rubber portion 33. Second end surface rubber portion 4 ... through hole, 5,6 ... end surface 7 ... valve seat, 8 ... seal surface 9 ... recess 91,92 ... first stage, second stage recess 10 ... solenoid, 11 Valve seat 12 Flow path 13 Center post 14 Spring 15 Coil 16 Case 17 Upper plate 18 Side ring 19 Sleeve

Claims (1)

(57) [Scope of request for utility model registration] A movable plunger body comes into contact with and separates from a valve seat provided on a valve box by an electromagnetic attraction force of a solenoid, and the plunger body is provided with through holes penetrating both ends thereof. In a plunger of an electromagnetic valve, which is integrally baked so as to fill the inside of the through hole and cover both end faces of the plunger body, a rubber-like elastic body baked on an end face of the plunger body on the valve seat contact portion side. A plurality of recesses are provided near a portion corresponding to the through hole.