JPS621150B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic fluid control valve that continuously and proportionally controls the flow rate of a fluid such as gas using an electric current.
In particular, the present invention relates to a structure in which vibration does not occur in the valve body in a controlled state.

A conventional example is shown in FIG.

A lower leaf spring mounting base 6 is attached to the upper part of the valve body 4 having a fluid inlet 1, a fluid outlet 2, and a valve seat 3 via a gasket 5, and a box-shaped yoke 7 and an auxiliary yoke 8 are attached to the upper part of the lower plate spring mounting base 6. A lid 11 is attached via an upper plate spring mounting base 9 and a gasket 10. A pipe 13 passes through the center of the yoke 7 and the coil 12, and both ends thereof are inserted into the upper leaf spring mount 9 and the lower leaf spring mount 6, and are sealed with an O-ring 14.
One leaf spring is attached to the upper and lower leaf spring mounting bases respectively.
5 is attached, and its free end is fastened to a support rod 17 made of a non-magnetic material, which is press-fitted into the lower part of the plunger 16 and the other into the upper part of the plunger 16, and the plunger 16 is connected to the pipe 13.
It is supported so that it does not touch the center of the A valve body 18 is swingably attached to the lower part of the plunger 16 and faces the valve seat 3. A coil spring 19 and an adjustment screw 20 are provided at the top of the plunger 16,
The adjustment screw 20 is screwed into a female screw provided in the center of the lid 11 to adjust the force of the coil spring 19. A blind cap 21 is applied with a sealant and press-fitted into the opening of the internally threaded portion of the lid 11 for sealing.

A plan view of the leaf spring 15 is shown in FIG. The fixed part is provided with a mounting hole 151 and a positioning hole 152, and the free end is provided with a support hole 153 for fastening to the support rod 17 or plunger 16.

In the above configuration, FIG. 1 shows a state in which no current is flowing through the coil 12, and the valve body 18 is pressed against the valve seat 3 by the coil spring 19 (hereinafter, this force is referred to as valve closing pressure), and the valve is closed. state. The spring force acting on the plunger 16 is the sum of the forces of the two leaf springs 15 and the coil spring 19, but the purpose of the leaf spring 15 is to support the plunger 16 at the center of the pipe 13 without contacting it. The force is sufficiently weak compared to the force of the coil spring 19. Next, when a current is gradually increased from zero to the coil 12, a magnetic force is generated and the plunger 1
When the current generates a magnetic force stronger than the valve closing pressure, the valve element 18 floats up from the valve seat 3. When the current is further increased, the valve lift increases in proportion to the current, and when the current reaches a predetermined value, the valve lift reaches its maximum and becomes fully open.
Therefore, an arbitrary valve lift can be obtained depending on the magnitude of the current, and the flow rate of the fluid can be controlled steplessly.

The problem with this conventional example is that the movable parts centering on the plunger 16 are supported by the leaf spring 15 and the coil spring 19, so when the valve body 18 is floating above the valve seat 3, it is affected by the flow of fluid. This means that there may be vibrations. As a result, this vibration significantly impairs the function of the control valve.

The present invention solves the above-mentioned conventional drawbacks, and aims to ensure operational stability of the valve body so that the valve body does not vibrate under the influence of fluid flow.

In order to achieve the above object, the present invention includes a plunger equipped with a valve body facing a valve seat, a coil,
The plunger is comprised of a yoke, one end of which is supported by a leaf spring, and the other end of which is slidably supported in the axial direction by a sliding member provided on the leaf spring. This configuration makes the control characteristics of the fluid control valve stable. An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.
This will be explained based on the diagram. Note that the same members as those in the conventional example are given the same numbers and their explanations will be omitted.

As is clear from FIG. 3, in the present invention, a sliding portion is formed in the stepped support rod 17A fastened to the plunger 16 to support the upper part of the plunger 16, and this stepped support rod 17A is connected to the upper leaf spring 15A. It is slidably supported in the axial direction with a sliding member 15B made of Teflon resin or the like which is fitted into the sliding member 15B.

In the above configuration, when the current flowing through the coil 12 is increased, the stepped support rod 17A overcomes the downward frictional force generated between the sliding portion and the sliding member 15B and rises. Moreover, if the current is decreased, it will descend while opposing the upward frictional force.

Therefore, even if the valve body 18 tries to oscillate under the influence of fluid flow or the like while the valve body 18 is floating above the valve seat 3, the frictional force acts as a vibration damping effect. In addition, by fitting the sliding member 15B to the free end of the leaf spring 15A, the leaf spring 15A absorbs subtle changes in frictional force, so even if the current applied to the coil 12 is increased or decreased, the valve body remains unchanged. 18 or the stepped support rod 17A does not move up and down, that is, there is no dead zone.

As is clear from the above description, the fluid control valve of the present invention supports one end of the plunger so as to be slidable in the axial direction with a sliding member made of resin or the like fitted to a leaf spring, and By absorbing the frictional force and subtle changes in the frictional force using leaf springs, it provides stable control characteristics with a simple configuration and no dead zones or vibrations.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional fluid control valve, Fig. 2 is a plan view of a conventional plate spring, Fig. 3 is a sectional view of a fluid control valve of an embodiment of the present invention, and Fig. 4 is the same. It is a top view of the leaf spring which fitted the sliding member. 3...Valve seat, 7...Yoke, 12...Coil, 15A
...Plate spring, 15B...Sliding member, 16...Plunger, 18...Valve body.

Claims (1)

[Claims] 1. Consisting of a plunger with a valve body mounted opposite to a valve seat, a coil and a yoke, the valve body is driven by a current flowing through the coil, and one end of the plunger is supported by a leaf spring. A fluid control valve that is slidably supported in the axial direction by a sliding member whose other end is attached to a leaf spring. 2. The fluid control valve according to claim 1, wherein the sliding member is made of fluorine resin. 3. The fluid control valve according to claim 1, wherein the sliding member is made of an oil-impregnated alloy.