JPS6024572B2 - proportional control valve solenoid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a solenoid portion of a proportional control valve that non-slidingly supports a plunger using a leaf spring of a proportional control valve that proportionally controls fluid based on a current value.

Conventional structure and its problems Conventionally, as a support structure for the plunger of a proportional control valve, in order to prevent hysteresis caused by sliding friction of the plunger, the plunger was supported on the coil with a leaf spring without sliding. There is.

As shown in FIG. 4, the solenoid part of a conventional proportional control valve has a plunger 7 on top of a body 1, a diaphragm holding plate 2, and a retaining plate 3, and a coil 6 and a yoke 5 to form a magnetic circuit. Leaf springs 9, 9' are fixed to and movably attached to the yoke 5 with pins 12, 13, supporting the plunger 7 in the hollow part of the coil 6 without sliding.

The valve 10 is airtightly attached to the tip of the plunger 7 with a diaphragm 4. The valve seat 16 is arranged to face the valve 101, and the valve opening degree is changed by displacement of the plunger 7. With the above configuration, the plunger 7 operates by balancing the magnetic force that changes with the coil current and the elasticity generated by the deflection of the leaf spring, so when the current is always large, the magnetic force also becomes large and the leaf spring also becomes elastic. It is used in locations where the force is large, that is, where the deflection of the leaf spring is also large.

However, the magnetic pole portion 5 of the yoke 5 facing the plunger 7
′ is also acted upon by a magnetic force F that attracts it in a direction perpendicular to the axial direction of the plunger 7. If the rigidity of the leaf spring 9 does not overcome the magnetic force, the leaf spring 9 will be twisted and the plunger 7 will be pushed into the magnetic pole part 5.
A phenomenon in which the plunger 7 could not be held without sliding due to being attracted by the plunger 7 occurred when the current value was large.

This can be explained by referring to the main part of the leaf spring support part in FIG. 5. With respect to the leaf spring mounting surface A-A', the support surface of the plunger 7 of the leaf spring 9 has a deflection times the length of the arm. Due to magnetic force F,
A bending moment is generated, torsional stress is applied to the leaf spring, and even with a small magnetic force F, the plunger 7
The cause was that it was adsorbed to.

Purpose of the Invention The present invention solves the above-mentioned problems of the conventional art. By reducing the bending moment when the magnetic force is large, the deflection of the leaf spring is eliminated, and the plunger is supported without sliding by a thin leaf spring. This is to improve the stability of the proportional control valve.

Structure of the Invention The present invention provides flexibility in the cantilever leaf spring to support the plunger when the current in the electromagnetic coil is de-energized, and when the coil current in the electromagnetic coil is at its maximum, the mounting surface of the cantilever leaf spring flexes. The plunger is configured to be displaced so that the supporting points of the plunger are on the same plane.

With this configuration, there is no deflection of the leaf spring when the coil current is at its maximum, so no bending moment is generated due to magnetic force, and no torsional force is applied to the leaf spring.

Therefore, the plunger is prevented from being attracted to the penetrating portion of the yoke and unable to be held without sliding. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIGS. 1 and 2, a gas inlet 20 and a gas outlet 21
An electromagnetic coil 28 is arranged on the upper part of the valve body 25, which has a primary passage 22, a valve port 23, and a secondary passage 24 arranged between the valve body 25 and the outer periphery of a plunger 27 that adjusts the degree of closure of the valve body 26.
Around it, yoke A29, yoke B30, yoke C31
is installed to create a magnetic circuit.

Further, the plunger 27 is supported by two sheets, an upper plate spring 33 and a lower plate spring 34, so as to be able to move up and down without sliding on an airtight pipe 32 inserted into the hollow part of the electromagnetic coil 28. A coil spring 35 is provided to push down the valve body 26 and close the valve □ 23, and an adjustment screw 36 is provided to adjust the force of the coil spring 35.

37 is a block to which the lower plate spring 34 is attached, and 38 is a block to which the upper plate 1 copy 33 is attached, which are passed through with the airtight pipe 32 and made airtight with O rings 39, 39'.

Then, by increasing the coil current, the valve body 26 and the valve □
When the opening degree of 23 is increased, the stopper part 40 of the plunger 27 comes into contact with the block 38, and even if the current is further increased, the plate is placed in a position where the plunger does not move upward and the plate spring does not bend. Springs 33, 34 are secured to leaf spring mounting blocks 37, 38. 'In the above configuration, when the coil current is not flowing, the first
As shown in the figure, the leaf springs 33 and 34 support the plunger 27 without sliding with flexure against the mounting surface,
The valve port 23 is closed.

FIG. 2 shows the case when the coil current is increased and the valve opening is at its maximum, and the plate springs 33 and 34 support the plunger without sliding, without bending with respect to the mounting surface. In other words, depending on the magnitude of the current, the magnetic force that lifts the plunger 27 changes, stopping the plunger 27 at a position that balances the force of the coil spring 35, changing the relationship between the valve body 26 and the valve □23, and proportionally adjusting the gas flow rate. controlled. Here, the plunger 27 and the yoke C31 through which the plunger 27 passes
A magnetic force F acting perpendicularly to the direction of the plunger 27 is also generated at the opposing portion of the plunger 27, and this magnetic force F also changes proportionally to the coil current, so as the coil current increases, this magnetic force F also changes proportionally. However, at this time, the leaf spring 33,
The deflection of the leaf springs 34 decreases inversely proportionally, and when the coil current is at its maximum, the leaf springs 33 and 34 do not deflect, and no torsion is applied to the leaf springs by the magnetic force F.

Therefore, when the coil current is increased, the plunger 2
7 can be prevented from being attracted to the yoke 31, and furthermore, it is also possible to make the leaf springs 33 and 34 thinner.

For this reason, since the spring constant is proportional to the cube of the plate thickness, the plunger 27 can be held without contact with a leaf spring having an extremely small spring constant, and variations in characteristics in manufacturing proportional control valves can be kept to a minimum. It has the effect of being able to In addition, in this embodiment, if only the leaf spring 37 is made so that the leaf spring support surface and the support point of the plunger 27 are on the same plane at the maximum valve opening, the other leaf spring 33 does not need to be made the same as the plunger 27. Since the upper end of the yoke 31 does not pass through the yoke 31, the magnetic attraction force in the direction perpendicular to the axis is weak, so the same effect as above can be obtained. Next, another embodiment of the present invention will be described with reference to FIG.

In FIG. 3, a valve body 53 is opposed to a valve seat 52 provided between a fluid inlet 50 and a fluid outlet 51, and the valve body 53 is fixed to a diaphragm 54 to constitute a gas governor section. An electromagnetic coil 56 is arranged around the outer periphery of the plunger 55, and a yoke A57 and a yoke B58 are provided around it to form a magnetic circuit, and the plunger 55 is supported without sliding on the electromagnetic coil 56 by plate springs 59 and 60'. . The force of the plunger 55 is transmitted to the valve body 53 by the slide bin 61. A coil spring 61 sets the minimum gas pressure of the gas governor when the coil current is zero, and the force of the spring 61 can be adjusted with an adjustment screw 62.

63 is a stopper for the valve body 53.

In this configuration, when a current is passed through the electromagnetic coil 56, a downward magnetic force is generated in the plunger 55 according to the magnitude of the current, and the diaphragm 5 is
4 and controls the pressure of the fluid flowing out from the fluid outlet 51 according to the well-known principle of a governor.

By the way, when the pressure at the fluid inlet 50 changes, the degree of opening of the valve seat 52 and the valve body 53 facing each other changes, and the pressure at the fluid outlet 51 is maintained, but even if the magnetic force generated by the coil current is constant, , coil spring 61, leaf spring 59, 6
Since 0 has a spring constant, if the valve body 53 changes, the force acting on the valve body 53 also changes, and eventually the pressure at the fluid outlet 51 also changes.

In order to reduce this change, it is desirable to make the spring constants of the coil spring 61 and leaf springs 59, 60 as small as possible.

According to this embodiment, since the spring constant of the leaf spring can be made small, changes in the pressure at the fluid outlet 51 when the pressure at the fluid inlet 50 changes can be reduced.

Effects of the Invention As described above, according to the present invention, the proportional control valve has a configuration in which the plunger is displaced so that the mounting surface of the leaf spring and the support point of the plunger are on the same plane when the current of the electromagnetic coil is maximum. Therefore, even if the magnetic force at the part facing the yoke through which the plunger passes increases, the cantilever leaf spring does not bend, so no torsional force acts, and even if the leaf spring is thin, the plunger will not be attracted to the yoke. , the plunger can be held without sliding on the coil.

Therefore, in the proportional control valve, it is possible to provide a solenoid that allows highly stable control.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a closed state of a proportional control valve using a solenoid according to an embodiment of the present invention, and FIG. 2 is a sectional view showing an open state of a proportional control valve using a solenoid of the present invention. Figure 3 is a proportional control valve showing the operating state of another embodiment using the solenoid of the present invention, Figure 4 is a sectional view of the operating state of a proportional control valve using a conventional solenoid, and Figures 5a and b. ，
c and d are a plan view, a front view, a side view, and an explanatory view of the moment, respectively, showing the relationship between the leaf spring and the mounting surface during operation of the subordinate example. 27... Plunger, 28... Electromagnetic coil, 31... Yoke, 34, 35... Leaf spring. Fin5Figure 1Figure 2Figure 3Figure 4

Claims (1)

[Claims] 1 A plunger that drives a valve body passes through a yoke made of a magnetic material, is supported in a hollow part of the electromagnetic coil by a cantilever leaf spring so as to be movable in the axial direction without contacting the electromagnetic coil, and the plunger When the coil current is de-energized,
The cantilever leaf spring is given slack to support the plunger, and when the coil current of the electromagnetic coil is maximum,
A solenoid for a proportional control valve, wherein the plunger is displaced so that a mounting surface of the cantilever spring and a support point of the plunger are on the same plane.