JP2598149Y2 - Piston for solenoid valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston for an electromagnetic valve used for an electromagnetic valve for controlling the operation of a predetermined hydraulic device by switching the flow path of a working fluid by displacing a spool shaft.

[0002]

2. Description of the Related Art A solenoid valve operated by electromagnetic operation is provided with a spool shaft provided by a plunger attracting action of a column magnetized by energizing a solenoid coil and a sliding action of a solenoid valve piston provided at an end of the spool shaft. , Thereby switching the flow path of the working fluid. Therefore, the sealing material mounted on the solenoid valve piston needs to have a sufficient sealing property so that leakage does not occur when the working fluid flows in and the fluid chamber is pressurized. . In particular, when an inert gas such as carbon dioxide is used as the working fluid, it is required to ensure the sealing performance from the viewpoint of cost.

However, as shown in FIG. 4 and FIG. 5, which is a cross-sectional view taken along the line V--V, in the conventional solenoid valve piston 44, the sealing material 47 falls off on one side of the cylindrical main body 46a. Since the stopper portion 46d for prevention has a shape in which the flange portion 46b is formed on the other side,
The mold for molding this must have a structure in which the piston body 46 is divided into two parts in the axial direction. In this case, the part where the molds are joined during molding (hereinafter, referred to as a “parting line”) 48
The seal member 47 is formed at both ends, and a part of the inner peripheral surface of the mounted seal member 47 may float up from the main body 46a, leak the working fluid, and impair the sealability.

[0004] In such a case, it is conceivable to apply grease to the floating portion, but the effect is diminished by repeated sliding of the piston for electromagnetic valve 44 or the like, so that it cannot be a permanent measure. .

Therefore, in the prior art, a part which comes into contact with the sealing material 47, that is, a parting line 48 formed in the main body 46a is cut with a tool, thereby bringing the main body 46a into close contact with the sealing material 47 and operating. Fluid leakage was prevented.

[0006]

[Problem to be Solved by the Invention] However, the main body 46a
The parting line 48 formed in the piston body 4
Cutting after forming 6 is not efficient, and it is desirable that leakage of the working fluid between the piston body 46 and the seal member 47 can be prevented without passing through such a cutting process.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a technique related to a piston for an electromagnetic valve which can completely prevent the leakage of a working fluid without cutting a parting line.

[0008] The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0009]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, typical ones will be outlined as follows.

That is, the solenoid valve piston according to the present invention comprises a piston body and a sealing material. The piston main body includes a cylindrical main body, a flange formed at one end of the main body, and an annular fitting groove formed between the main body and the flange. In addition, the sealing material is such that a convex portion formed on a part of the inner peripheral surface in the circumferential direction is fitted with the fitting groove, and the other inner peripheral surface is attached to the piston body in close contact with the main body portion. It is.
The parting line is formed only in the flange portion and the fitting groove of the piston main body, and does not exist on the outer peripheral surface of the main body, and is flat.

[0011]

According to the piston for a solenoid valve having the above-described structure, the inner peripheral surface of the sealing material mounted on the piston body is in close contact with the body without cutting the parting line. . Therefore, the leakage of the working fluid between the piston body and the seal member can be completely prevented without the seal member falling out of the piston body due to the fitting of the protrusion of the seal member and the fitting groove.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in more detail with reference to the drawings.

FIG. 1 is a sectional view showing an electromagnetic valve using a solenoid valve piston according to an embodiment of the present invention, FIG. 2 is a sectional view showing the solenoid valve piston, and FIG.
It is sectional drawing in the -III line.

The valve block 2 of the solenoid valve 1 has an air supply opening 3 to which a working fluid from a fluid pressure supply device (not shown) is supplied, and an operation for controlling the operation of a predetermined fluid pressure operation device. First and second output openings 4a, 4 through which fluid flows out
b, and first and second exhaust openings 5a and 5b through which the working fluid is discharged are formed facing the shaft hole 6, respectively.

A spool shaft 7 is accommodated in the axial direction of the shaft hole 6, and spool grooves 7a are formed at predetermined intervals in the spool shaft 7, and O-rings 8a to 8d are mounted thereon. And O-rings 8a to 8d constitute a spool portion.

When the spool shaft 7 is in the first position as shown in FIG. 1, the air supply opening 3 is
The first output opening 4 is closed by the rings 8a and 8c.
a, and the second output opening 4b and the second exhaust opening 5b communicate with each other. Also, this spool shaft 7 is shown in FIG.
When the air supply opening 3 is displaced rightward to the second position, the air supply opening 3 is closed by the O-rings 8b and 8d of the spool shaft 7, communicates with the second output opening 4b, and the first output The opening 4a and the first exhaust opening 5a communicate with each other.

Next, the structure of the solenoid portion 9 for operating the spool shaft 7 to the first position shown in FIG. 1 and the second position displaced rightward will be described.

A bobbin 10 of the solenoid portion 9 has a solenoid 11 formed by winding a conductor or the like around the outer periphery thereof, and a yoke 12 is provided outside these. A column 13 is fitted to the rear part of the bobbin 10, and a plunger 14 is mounted to the front part so as to be slidable in the axial direction. The members constituting these solenoid parts 9 are sealed by a housing 15 made of, for example, resin.

The distal end of the plunger 14 has a communicating flow path 1
6, a valve seat 18 for closing the air supply hole 17 communicating with the air supply opening 3 is fitted, and the plunger 14 is provided with a resilient force in a direction of retracting the compression coil spring 19. Powered by Therefore, when the solenoid 11 is not energized, the air supply hole 17 is closed by the valve seat 18 by the elastic force of the compression coil spring 19.

At the front of the plunger 14, that is, at one end of the spool shaft 7, a valve 23 for opening and closing the discharge passage 22 by an interlocking pin 20 and a compression coil spring 21 interlocking with the axial movement of the plunger 14 is provided. The first fluid chamber 25 is formed by disposing the first solenoid valve piston 24. When the solenoid 11 is energized, the plunger 14 moves backward to release the air supply hole 17, and the working fluid from the air supply opening 3 flows into the first fluid chamber 25, so that the first fluid chamber 25 is formed. When pressurized, the first solenoid valve piston 24 slides and contacts one end surface of the spool shaft 7 to displace it.

As shown in FIGS. 2 and 3, the first solenoid valve piston 24 is made up of a piston body 26 made of resin and a V-ring (seal material) 27 having a substantially V-shaped cross section. It is configured. The piston main body 26 includes a cylindrical main body 26a, a flange 26b formed at one end of the main body 26a, and a main body 26.
a and an annular fitting groove 26c formed between the flange portion 26b and the base portion of the inner peripheral surface of the V-ring 27. Is formed.

The main body 26a of the piston main body 26
By providing the flange portion 26b and the fitting groove 26c on one side of the mold, a mold (not shown) for molding the piston main body 26 has one side on the main body section 26a side and the other on the flange section 26b and the fitting section. It is divided into three grooves 26c and further divided into a flange 26b and a fitting groove 26c. Therefore, the parting line 28, which is a part where the molds are joined at the time of molding, is
6b and only the fitting groove 26c are formed, the outer peripheral surface of the main body 26a becomes flat, and the inner peripheral surface of the mounted V ring 27 is in close contact with the main body 26a.

The other end of the spool shaft 7 has a spool shaft 7
Is provided in the opposite direction, and a second fluid chamber 30 for sliding the second solenoid valve piston 29 is connected to the air supply opening 3 by the communication flow path 31. It is formed in communication. The shape of the piston 29 for the second solenoid valve is the same as the shape of the piston 24 for the first solenoid valve.

The pressure receiving area of the second solenoid valve piston 29 is set smaller than that of the first solenoid valve piston 24, so that the working fluid from the air supply opening 3 is supplied to both solenoid valves. When acting on the pistons 24, 29, the first solenoid valve piston 24 displaces the spool shaft 7, overcoming the second solenoid valve piston 29.

When the solenoid 11 of the solenoid section 9 is not energized, the working fluid is supplied only to the second fluid chamber 30, so that the spool shaft 7 is pressurized to the second fluid chamber 30. It is displaced by the second solenoid valve piston 29 that slides and comes into contact, and assumes the first position shown in FIG.
At this time, the air supply opening 3 communicates with the first output opening 4a, and the second output opening 4b and the second exhaust opening 5b.
And are in communication.

On the other hand, when the solenoid 11 is energized, the plunger 14 moves backward against the elastic force of the compression coil spring 19. As a result, the air supply hole 17 is opened, and the discharge passage 22 is closed by the valve body 23.
6, and is also supplied to the first fluid chamber 25,
The spool shaft 7 is displaced by the first solenoid valve piston 24 to be in the second position. At this time, the air supply opening 3 is connected to the second output opening 4b and the first output opening 4a is set to the first output opening 4b.
It communicates with the exhaust opening 5a.

As described above, in the solenoid valve 1, the sliding of the spool shaft 7 by the sliding of the two solenoid valve pistons 24 and 29.
Is displaced. According to the first and second solenoid valve pistons 24 and 29 as in the present embodiment, the main body 26a
Since the parting line 28 is not formed in the V ring 27, the inner peripheral surface of the V ring 27 attached to the piston main body 26 comes into close contact with the main body 26a. Therefore, the fitting of the convex portion 27a of the V-ring 27 and the fitting groove 26c prevents the V-ring 27 from falling off.
Leakage of the working fluid between the piston body 26 and the V-ring 27 is completely prevented.

Although the invention made by the present inventors has been specifically described based on the embodiments, the invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. Needless to say.

For example, in the present embodiment, the solenoid valve 1 in which the displacement of the spool shaft 7 in the right and left directions is performed by the solenoid valve pistons 24 and 29, however, the displacement in one direction is described. For example, a compression coil spring or the like can be used.

Further, the sealing material mounted on the solenoid valve pistons 24 and 29 is not limited to the V-ring 27, and various sealing materials such as a sealing material having a substantially X-shaped cross section may be used. Can be used. Further, the convex portion 27a does not necessarily need to be formed at the base end portion, and can be formed at any position as long as it is a part of the inner peripheral surface in the circumferential direction.

The piston body 26 is not necessarily made of resin, but may be made of metal.

[0032]

[Effects of the Invention] Of the ideas disclosed in the present application, the effects obtained by typical ones will be briefly described.
It is as follows.

(1) That is, the piston for the solenoid valve according to the present invention is flat without any parting line on the outer peripheral surface of the main body of the piston main body, and is formed in the circumferential direction of the inner peripheral surface of the sealing material. Can be fitted to the fitting groove, and the other inner peripheral surface can be attached to the piston main body in close contact with the main body.

(2) Therefore, leakage of the working fluid between the piston body and the seal member can be completely prevented without cutting the parting line formed in the piston body with a tool.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a solenoid valve using a solenoid valve piston according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the solenoid valve piston.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a cross-sectional view showing a conventional solenoid valve piston.

FIG. 5 is a sectional view taken along line VV in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solenoid valve 2 Valve block part 3 Air supply opening 4a First output opening 4b Second output opening 5a First exhaust opening 5b Second exhaust opening 6 Shaft hole 7 Spool shaft 7a Spool groove 8a O-ring 8b O-ring 8c O-ring 8d O-ring 9 Solenoid unit 10 Bobbin 11 Solenoid 12 Yoke 13 Column 14 Plunger 15 Housing 16 Communication channel 17 Air supply hole 18 Valve seat 19 Compression coil spring 20 Interlocking pin 21 Compression coil spring 22 Discharge path 23 Valve element 24 Piston for first electromagnetic valve 25 First fluid chamber 26 Piston main body 26a Main body 26b Flange 26c Fitting groove 27 V-ring (seal material) 27a Convex part 28 Parting line 29 For second electromagnetic valve Piston 30 Second fluid chamber 31 Communication channel 44 Piston for solenoid valve 46 Fixie Main body 46a main body 46b flange 46d stopper 47 sealing material 48 parting line

Claims (3)

(57) [Scope of request for utility model registration] A spool is displaced to switch a flow path of a working fluid to control an operation of a predetermined fluid pressure operating device. The solenoid valve is used for pressurizing a fluid chamber at at least one end of the spool shaft. A piston for an electromagnetic valve that displaces the spool shaft in the axial direction by sliding due to a cylindrical main body, a flange formed on one end side of the main body, the main body and the flange. A piston main body comprising an annular fitting groove formed between the piston body and a convex portion formed in a part of the inner peripheral surface in the circumferential direction is fitted with the fitting groove, and the other inner peripheral surface is A sealing material attached to the piston body in close contact with the main body, and a parting line, which is a joining portion of a mold during molding, is formed only in the flange and the fitting groove,
The piston for an electromagnetic valve, wherein an outer peripheral surface of the main body is flat. 2. The sealing material has a substantially V-shaped cross section.
2. The solenoid valve piston according to claim 1, wherein said convex portion is formed at a base end thereof. 3. The solenoid valve piston according to claim 1, wherein the piston body is made of resin.