JPS626147B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas flow control valve used in gas combustion equipment.

FIG. 1 shows a conventional example. Fluid inlet 1 and outlet 2
A valve body 5 is provided on a body 4 provided with a valve seat 3 so as to interlock with a diaphragm 6, and the outer periphery of the diaphragm 6 is held between the body 4 and a diaphragm retainer 7. A spring 8 is provided at the bottom of the valve body 5 so as to act on the valve body 5 in a closing direction, and the valve body 5 is sealed with a bottom cover 9.

A plunger 10 is connected to a guide cylinder 11 on the upper part of the valve body 5.
The yokes 12, 13, and 14 and the electromagnetic coil 15 are provided on the outside.

When the electromagnetic coil 15 is energized, a downward attracting electromagnetic force acts on the plunger 10, pushing the valve body 5 downward, and due to the balance between the electromagnetic force, the fluid pressure, the force of the spring 8, etc. Fluid outlet pressure can be controlled.

The problem with this conventional example is that the plunger 10
The control characteristics were deteriorated due to sliding friction between the guide tube 11 and the guide tube 11. That is, the electromagnetic force generated by the electromagnetic coil 15 attracts the plunger 10 downward and simultaneously attracts the plunger 10 in the radial direction. This radial force is applied to the plunger 1.
Increase sliding friction for 0 axial movement,
As a result, as shown in Figure 2, when the current I is increased or decreased, the hysteresis a-c-d-f and the dead zone b
-gives rise to e.

Various efforts have been made in the past to solve this problem, and one solution is to reduce the sliding friction as much as possible, for example by forming a low-friction film on the plunger. Another solution is to support the plunger without sliding, for example by supporting the plunger with a leaf spring. However, the former measure had limitations in improving control characteristics and was insufficient. Although the latter measure can solve the sliding friction, it has other problems such as complicating the support structure of the plunger.

The purpose of the present invention is to eliminate hysteresis and dead zones caused by sliding friction of a plunger with a simple structure in a proportional control valve that electrically controls fluid pressure. is fixed to form magnetic poles at both ends of the plunger, a yoke and an electromagnetic coil are provided so that the same poles act on the magnetic pole of the plunger, and the plunger is supported non-slidingly at the center of the yoke by the repulsive force of the magnetic force. The shape of the magnetic pole is tapered or stepped so that the repulsive force also acts in the axial direction of the plunger, and the pressure of the fluid is controlled according to the current of the electromagnetic coil.

FIG. 3 shows an embodiment of the present invention. The part forming the fluid passage is the same as in the conventional example shown in FIG. is held between the body 4 and the diaphragm retainer 7. At the bottom of the valve body 5,
A spring 8 is provided so as to act in a direction to close the valve body 5, and the valve body 5 is sealed with a bottom cover 9.

A permanent magnet 16 and a magnetic pole piece 17 are mounted on the upper part of the valve body 5.
The plunger 19 consisting of 18 is connected to the yokes 20, 2
1, 22 and the center of the electromagnetic coil 23,
The upper end of the plunger 19 is formed in a tapered shape, and the hole in the yoke 20 opposing this is also formed in a tapered shape. Then, a direct current is applied to the electromagnetic coil 23 in a direction such that the opposing portions of the plunger 19 and the yokes 20 and 22 have the same polarity. As an example, a plunger 1 with a permanent magnet 16
9 is an upper N pole and a lower S pole, when the electromagnetic coil 23 is not energized, the magnetizing force of the permanent magnet forms an S pole on the yoke 20 facing the plunger 19 and an N pole on the lower yoke 22. and adsorb each other. As the current is gradually increased, the magnetization effect of the current eventually causes the upper yoke 20 to
becomes the N pole, and the lower yoke 22 becomes the S pole, and the plunger 19 separates from the yokes 20 and 22. At the same time, the plunger 19 begins to receive downward force due to the action of the upper tapered portion. The force increases with the increase in the current flowing through the electromagnetic coil 23, and the
Press down to increase the fluid outlet pressure. That is, the current causes the plunger 19 to be connected to the yoke 20,
The outlet pressure of the fluid can be controlled while floating from 22.

The effect of this embodiment is that the plunger 19 is moved between the yokes 20 and 22 by the repulsion between the permanent magnet 16 and the electromagnetic force.
By floating the plunger and supporting it without sliding, it is possible to prevent deterioration of control characteristics due to sliding friction of the plunger, that is, increase in hysteresis and generation of a dead zone, which were problems in the conventional example. Furthermore, since no plunger support member such as a leaf spring is required, the structure is extremely simple and easy to assemble. Furthermore, in this embodiment, when the electromagnetic coil 23 is not energized, the permanent magnet 1
Due to the suction force of 6, the plunger 19 is moved by the yoke 20,
22 and enters a so-called locked state, which is convenient when transporting products.

However, depending on the applied equipment, a smaller proportional control valve with lower power consumption may be desired rather than the above locking effect. Another embodiment of the present invention that meets this purpose is shown in FIG. In this example, yoke 2
A permanent magnet 23 was provided between 1a and 21b. The other configurations are the same as the embodiment of the present invention shown in FIG. The permanent magnet 23 forms the same polarity as the plunger 19 in the yokes 20 and 22 even when the electromagnetic coil 23 is not energized. Therefore, the plunger 19 is always floating above the yokes 20 and 22, and the electromagnetic coil 2
The control state can be entered as soon as power starts to be applied to 3. Therefore, compared to the embodiment shown in FIG. 3, the current is smaller, resulting in lower power consumption and smaller size.

FIG. 5 shows the main part of another embodiment of the present invention. The end of the plunger 19' is stepped, and the yoke 2
The configuration is inserted into the hole 0', and the other configurations are the same as in FIG. 3 or 4. In this embodiment, a radial repulsive force is generated at the small diameter portion of the plunger 19', and an axial repulsive force is generated at the stepped portion. and the third
This embodiment has the same effect as the embodiment shown in FIGS. 4 and 4, but is suitable for a control valve with a relatively small stroke and has the advantage of being easy to process.

As described above in detail in the conventional example and the embodiment of the present invention, the present invention fixes a permanent magnet to the plunger,
By floating and non-slidingly supporting the plunger using repulsive magnetic force, sliding friction is completely eliminated, and a proportional control valve with good control characteristics with small hysteresis and no dead zone can be realized. Furthermore, a large stroke can be obtained efficiently due to the angle of the tapered part at the end of the plunger, the structure is extremely simple as the plunger is supported and driven at the same time by magnetic repulsion, and the plunger itself is accurately supported on the axis of motion. Since the valve body acts on the valve body, it has many effects such as smooth operation of the valve body.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional electromagnetic proportional control valve.
Fig. 2 is a control characteristic diagram of a conventional example, Fig. 3 is a sectional view of an electromagnetic type and proportional control valve of an embodiment of the present invention, Fig. 4 is a sectional view of another embodiment of the invention, and Fig. 5 FIG. 2 is a sectional view of a main part of another embodiment of the present invention. 5...Valve body, 6...Pressure receiving thin film (diaphragm), 1
6 to 23... Electromagnetic drive unit, 16, 23... Permanent magnet,
19... Plunger, 20, 21, 22... Yoke,
23...Electromagnetic coil.

Claims (1)

[Scope of Claims] 1. A valve body that varies a fluid passage area, a pressure-receiving thin film that receives fluid pressure and interlocks with the valve body, and an electromagnetic drive unit that applies an electromagnetic force to the valve body, The electromagnetic drive unit includes an electromagnetic coil, a plunger having at least one end formed in a tapered or stepped shape and a permanent magnet fixed thereto, and magnetic poles at both ends of the plunger, and a magnetic pole that is energized by the electromagnetic coil. An electromagnetic proportional control valve consisting of a yoke on which repulsive electromagnetic force acts in the axial and radial directions. 2. The electromagnetic proportional valve according to claim 1, wherein a permanent magnet is provided in a part of the yoke so that a repulsive magnetic force acts on the plunger even when the electromagnetic coil is not energized.