JPS59153216A - Proportional control valve of gas - Google Patents

Abstract

PURPOSE:To reduce an actuator part at its size by fitting a shape storing alloy- made spring to a load device acting on a diaphragm and arranging a heater close to the spring. CONSTITUTION:A valve body 5 is attached to a housing 1 on which a gas inlet 2, a valve hole 3 and a gas outlet 4 are formed so that the valve body 5 is opposed to the valve hole 3, and the upper end of the valve body 5 is unitedly coupled with the diaphragm 6. A control spring 8A acting on the valve opening side and a bias spring 8B acting on the valve closing side are fitted to the diaphragm 6 to apply force balancing with gas pressure as a load device. The control spring 8A is made of the shape storing alloy and the cylindrical heater 9 is arranged on a cylinder part. The heater 9 is heated by current supply from a terminal 10 to control the opening of the valve body 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a gas proportional control valve that can arbitrarily control the flow rate of fuel gas.

Conventional configuration and its problems As shown in FIG. 1, a gas proportional control valve that controls gas flow rate in accordance with electrical input moves integrally with a valve seat 102 in a gas passage 101 and a corresponding valve body 103. diaphragm 104
On the other hand, there is a configuration in which force is applied by an electromagnetic device 1o8 consisting of a movable core 105, a coil 106, and a fixed yoke 107.

The opening degree of the valve body 103 is such that the force due to the gas pressure and the force due to the electromagnetic device 108 are balanced, and the gas pressure can be controlled by the force of the electromagnetic device 108. In this method, in order to ensure high stability of the gas flow rate against changes in gas supply pressure, it is necessary to increase the diameter of the diaphragm 104, and this increase in diameter is directly related to the increase in size of the electromagnetic device 10B. .

Therefore, in order to ensure high performance, there is a limit to the miniaturization of the electromagnetic drive unit 108, and it has been difficult to reduce the price. Further, as seen in US Pat. No. 3,811,466, the above-mentioned problem is also the same when a moving coil type drive unit is used. Furthermore, in the same patent, there is an example of forming a diaphragm with a bimetallic material and heating it with an external heater, but it is extremely difficult to design a bimetallic material that can be displaced and controlled by the pressure of household gas, and has little feasibility. .

Purpose of the Invention The present invention solves the above-mentioned conventional problems.
The purpose is to downsize the actuator section that applies force to the diaphragm.

Structure of the Invention To achieve this object, the present invention provides a loading device that acts on a diaphragm with at least one spring made of a shape memory alloy, and a heater in the vicinity of the spring. With this configuration, the characteristics of the shape memory alloy spring as a spring are changed by changing the amount of heat generated by the heater, so the load acting on the diaphragm is changed and the gas pressure number is controlled.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

In the figure, 1 is the gas population 2. Valve hole 3. The housing 6 forming the gas outlet 4 is a valve body corresponding to the valve hole 3, and its upper end is integrally connected to the diaphragm 6. 7 is an upper case that protects the upper surface of the diaphragm 6. diaphragm 6
A control spring 8B made of shape memory alloy that acts on the valve opening side and a bias spring 8B made of ordinary needle material that acts on the valve closing side are provided, and these springs are synthesized. The load device 8 applies a force that balances the gas pressure.A cylindrical heater 9 is disposed on the inner diameter of the control spring 8A, and generates heat when energized from the terminal 10.

In FIG. 2, the bias spring 8B acts on the valve body 6, but in the embodiment shown in FIG.
It is acting against. 2 and 3 are the same in that the control spring 8A and the bias spring 8B act in opposite directions.

Further, while FIG. 2 shows a heater in which a heating wire is wound around a cylindrical bobbin, FIG. 3 shows a ceramic heater having a heating portion formed by printing a heater pattern on a ceramic cylinder.

The control spring 8A made of an alloy material subjected to shape memory treatment changes its repulsive force as a spring at the same installation length depending on the temperature. Therefore, bias spring 8
The load that is combined with B and balanced with the gas pressure will also change. For example, if the material is shape memory treated to elongate at high temperatures, the load can be increased by increasing the amount of heater heating, thereby increasing the gas pressure to balance this load. In this way, the gas pressure, that is, the gas flow rate, can be controlled by controlling the supply of electricity to the heater.

Effects of the invention The gas flow rate is controlled by controlling the energization of the heater, and a shape memory alloy is used as its actuator. 1. The structure is simple and it is easy to obtain a relatively large force. . Therefore, even if a large diaphragm with good characteristics as a gas governor is used, the driving portion can be made small.

2. Contains no mechanical sliding parts and does not use magnetic elements, so there is no hysteresis and excellent controllability.

3. Since the heating pin and the control spring face each other in the direction of the cylindrical surface, it is easy to receive radiant heat from the heater, while the control spring has a wide surface area with no coil winding, making it easy to cool. Therefore, the responsiveness can be made as high as the temperature change of the heater itself.

4. Since the mass of the part that applies the load is small, the mounting direction has little effect.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a conventional gas proportional control valve, FIG. 2 is a configuration sectional view showing a gas proportional control valve which is an embodiment of the present invention, and FIG. 3 is a configuration diagram showing another embodiment of the present invention. It is a configuration sectional view. 5...Valve body, 6...Diaphragm, 8
... Loading device, 8A ... Control spring, 9 ... Heater 0

Claims (2)

[Claims] (1) A loading device including a valve body that adjusts a gas passage area, a diaphragm that interlocks with the valve body in response to gas pressure, and at least one control spring made of a shape memory alloy that acts on the diaphragm. and a heater provided near the control spring made of the shape memory alloy. (2) The gas proportional nailing valve according to claim 1, wherein the control spring made of a shape memory alloy has a coil-wound shape, and a cylindrical heater is arranged inside or outside the coil.