JPH0227737Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a solenoid valve that opens and closes a fluid passage by operating a plunger.

Conventional technology The life of a plunger type solenoid valve is generally 2
It is said that it is sufficient to guarantee a life of 1 million operations per second cycle, but there are also solenoid valves that operate at ultra-high speeds that must guarantee a life of 10 million operations within the same period of time.

However, in ultra-high-speed operating solenoid valves, when the plunger operates, the inner circumferential surface of the pipe, which acts as a plunger guide, is strongly affected, so by applying a resin coating such as Teflon as an anti-friction material to the plunger surface, This is intended to prevent the plunger from seizing up.

Problems that the invention aims to solve If there is even a slight coating defect on the plunger surface, the resin film tends to peel off immediately under ultra-high speed operation as mentioned above, so the resin coating method cannot be used with confidence. However, if this method is implemented, there is a problem of increased costs.

Furthermore, this type of plunger-type solenoid valve can be set at any angle within a range of ±15 degrees from the vertical state of the plunger, but there is a problem in that it cannot be set at an angle greater than that. This is because the sliding portion of the plunger relative to the inner circumferential surface of the pipe is limited to only a portion on the inclined side, causing extremely abnormal wear, making it impossible to expect smooth operation.

The present invention was developed in view of the above circumstances, and is constructed at low cost, and allows the plunger to operate smoothly at ultra-high speed over a long period of time, regardless of whether the plunger is set vertically or in any tilted position. The purpose is to provide a solenoid valve that can be used.

Means for Solving the Problems In order to achieve the above object, the present invention includes a sphere that rolls in contact with the inner circumferential surface of the pipe on the outer circumference of the plunger body that is inserted into the pipe as a plunger guide. At the same time, a guide sleeve for the plunger body protruding outside the pipe was provided at the end of the pipe.

Action When the plunger operates, the sphere rolls on the inner surface of the pipe. The sphere and the guide sleeve thus prevent the plunger and the pipe from coming into contact with each other.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a longitudinal sectional front view of a solenoid valve according to an embodiment of the present invention. In this figure, a valve seat 4 located between a fluid inlet 2 and a fluid outlet 3 is located inside the valve body 1.
is formed. A yoke 5 made of a bottomless cylindrical body is attached to the upper part of the valve body 1 via a base 6. The core 7 having a circular cross section is the yoke 5
A vertically long cylindrical pipe 8 fixed at the center of the
It is inserted into the yoke 5 and fixed to the upper wall 5a of the yoke 5 by caulking. A plunger 9 having a circular cross section is further inserted into the pipe 8 below the core 7 so as to be able to pivot freely in the vertical direction. Core bottom surface (magnetic pole surface)
Plunger upper surface portion (magnetic pole portion) 9a facing 7a
A buffer body 10 made of an elastic material such as rubber is fitted into the housing. The lower shaft portion 9f of the plunger leg portion 9b protruding outside the pipe 8 passes through the center portion of the valve body 11 made of an elastic material such as rubber so as to be able to pivot in the vertical direction. A support member 12 that supports the lower surface is provided on the shaft portion 9f.
The plate 13 placed on the top surface of the valve body 11 includes
A compression spring 1 that presses the lower surface of the valve body 11 against the valve seat 4
The lower end of 4 is acting. Further, a coil 15 is wound around the outer circumferential portion of the pipe 8 via a bobbin 16, spanning both the core 7 and the plunger 9.

Furthermore, as shown in FIG. 2, three recesses 9d are formed at an interval of 120 degrees in the circumferential direction on the outer circumference near the top of the plunger body 9c inserted into the pipe 8. And pipe inner peripheral surface 8a
A steel ball 17 that rolls in contact with the plunger leg 9 is fitted into and held in each of the recesses 9d.
A guide sleeve 18 into which b is fitted so as to be freely axially movable.
is provided at the lower end of the pipe 8, so that the second
As shown in the figure, a gap G is formed between the outer circumferential surface 9e of the plunger body 9c and the pipe inner circumferential surface 8a, and direct contact between the plunger 9 and the pipe 8 is prevented. Therefore, the guide sleeve 18 is
While fitting the upper half into the pipe 8,
The upper end of the compression spring 14 is received by the flange 18a, so that it is semi-fixedly fitted to the lower end of the pipe 8.

Next, the operation of the above configuration will be described.

When the coil 15 is excited, the plunger 9 is magnetically pulled up and attracted to the core lower surface 7a against the compression spring 14. At this time, the impact sound of the plunger 9 against the core 7 is prevented by the shock absorber 10 coming into contact with the core lower surface 7a. Also, by pulling up the plunger 9, the valve body 11
is separated from the valve seat 4, and the inlet 2 and outlet 3 communicate with each other.

On the other hand, as the coil 15 is de-energized, the compression spring 14 expands, the valve body 11 and the plunger 9 integrally return downward, and the valve body 11 is pressed against the valve seat 4. That is, the inlet 2 and outlet 3 are blocked.

Therefore, when the plunger 9 moves up and down inside the pipe 8 as described above, each sphere 17 contacts and rolls on the inner circumferential surface 8a of the pipe, and the plunger leg 9b moves into the shaft hole of the guide sleeve 18. By sliding the outer peripheral surface 9 of the plunger body 9c
Mutual contact between e and the inner circumferential surface 8a of the pipe is prevented. That is, the plunger 9 operates smoothly without touching the inner peripheral surface 8a of the pipe.

Note that the set number of spheres 17 is arbitrary, and the recess 9d can be changed according to the set number of spheres 17. For example, the recess 9d may be an annular groove in the circumferential direction of the plunger body 9c, and a large number of spheres 17 may be arranged in this groove.

Effects of the Invention As explained above, according to the solenoid valve of the present invention, a sphere that rolls in contact with the inner peripheral surface of the pipe is provided on the outer circumference of the plunger body, and a plunger leg is provided at the end of the pipe. Since a guide sleeve is provided, the plunger will not touch the inner circumferential surface of the pipe, regardless of whether the plunger is set vertically or at any inclination, allowing the plunger to operate smoothly at ultra-high speed over a long period of time. can do. In addition, such spheres can be obtained relatively inexpensively, and the concave portion of the plunger body into which the spheres are inserted and the guide sleeve can be easily formed by machining, so the present invention has the advantage that it can be implemented at low cost. be.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of a solenoid valve according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view taken along line A--A in FIG. 4... Valve seat, 7... Core, 8... Pipe, 8a
...Pipe inner peripheral surface, 9...Plunger, 9b...
Plunger leg, 9c...Plunger body, 9d
... Recessed portion, 9e ... Outer peripheral surface, 11 ... Valve body, 14
... Spring, 15 ... Coil, 17 ... Sphere, 18
...Guide sleeve, G...Gap.

Claims (1)

[Scope of utility model registration request] A cylindrical pipe, a core inserted into the pipe and fixed therein, a plunger opposed to the core and inserted into the pipe so as to be freely axially movable, and a magnet wrapped around the outer circumference of the pipe, with the plunger around the core. a spring that returns the plunger when the coil is de-energized and presses the valve body provided on the plunger leg that protrudes outside the pipe against the valve seat; A recess is provided on the outer circumference of the plunger body to be inserted into the pipe, and a sphere that rolls in contact with the inner circumferential surface of the pipe is fitted and held in the recess, and the guide sleeve of the plunger leg is inserted into the pipe end. 1. A solenoid valve characterized in that a gap is formed between an outer circumferential surface of a plunger body and an inner circumferential surface of a pipe by being fitted and held in the plunger body.