JPS59110978A - Control valve - Google Patents

Abstract

PURPOSE:To obtain a control valve with an excellent thermal response characteristic, by winding a coil around an iron core made of magnetic material. CONSTITUTION:If a coil 8 is electrified, magnetic flux is generated in an iron core 1 by allowing the iron core 1 to magnetically form a closed circuit, and an electric current is induced in a ring 7. Then Joule heat is generated in the ring 7, causing a temperature of the ring itself to rapidly increase. A driving unit 6, also receiving heat conducted from the ring 7, starts to extend as a temperature of the driving unit 6 of shape memory alloy rises from a reverse transformation start point and completes extension as the temperature further rises to reach a reverse transformation end point. The iron core 1 containing a valve part 5 is displaced upward, opening a valve hole 4 and holding a flow passage 3 in an open condition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control valve that controls the opening of a valve hole by utilizing the displacement of a driving body made of a shape memory alloy due to temperature changes.

Shape memory alloys utilize the phenomenon that occurs when the low-temperature phase generated by thermoelastic martensitic transformation is deformed and then reversely transformed into the high-temperature phase by heating. It changes to an austenite structure on the side, and changes to a martensitic structure on the low temperature side. When this shape memory alloy is cooled from the high temperature side, the austenitic structure transforms to the martensitic structure, and it has superelasticity.On the other hand, when it is heated from the low temperature side, the martensitic structure transforms to the austenite structure, and the forming process It returns to the memorized shape. The alloys that exhibit such a shape memory effect include nickel-chip, copper-aluminum disol,
Copper-aluminum, etc. are known, and those in which the valve hole is opened and closed by changing the temperature of these shape memory alloys are disclosed in Japanese Utility Model Application Publication No. 56-56969 and Japanese Patent Application Laid-Open No. 1987-57.
It is known from Publication No. 25572 and the like.

However, in the operating means for opening and closing the valve shown in Japanese Utility Model Application Publication No. 56-56969, the opening/closing means is formed of a shape memory alloy and is dependent on the temperature of the control fluid flowing down the valve body. However, since the temperature change of the control fluid becomes necessary and unavoidable, it is unsuitable for applications in which such temperature change cannot be obtained, and is unsuitable for use with wide control valves.

Furthermore, Japanese Patent Laid-Open No. 57-25572 discloses a structure in which the opening and closing of the valve hole is controlled by directly heating a valve driving element made of a shape memory alloy with a heater. Therefore, a large amount of electric power is required, and heaters with small diameter wires are generally used, but heater breakage occurs due to repeated heating and cooling and reciprocating movement of the valve drive element. The opening/closing control function of the restrictor valve was poor.

Furthermore, in a structure in which the heater is directly wound around the valve drive element, it is necessary to place an insulating film in order to insulate the heater from those elements.1 This makes efficient heating difficult. Met.

The control valve using the shape memory alloy of the present invention was created in view of the above-mentioned disadvantages, and it can be used directly without heating or cooling the driving body that drives the valve body by the environmental temperature of the control fluid, etc. , and can be widely used as a control valve, and generates a large amount of heat with a small amount of electric power compared to a control valve that opens and closes the valve by directly heating the driver with a heater. The object of the present invention is to obtain a control valve that can obtain a large amount of heat, heat the driving body directly from the ring, and has excellent heating characteristics and good controllability of opening and closing of the valve.

Hereinafter, one embodiment of a control valve using a shape memory alloy according to the present invention will be described with reference to FIG.

1 is an iron core made of a magnetic material, and the iron core has a magnetically closed circuit formed by an upper core IA made of a magnetic material and a lower flat plate IB. This iron core 1 is guided and movably erected in the center between the upper core IA and the lower flat Buddha, and the lower end of the iron core 1 has a valve installed in the flow path 3 of the valve body 2. A valve portion 5 for controlling opening and closing of the hole 4 is arranged. Also, around the iron core 1 is a driving body 6 made of a shape memory alloy.
The lower end of this coil spring is locked to the lower flat plate IB, while the upper end is locked to the upper flange 10 of the iron core 1. A ring 7 made of a conductive material is arranged around the driving body 6, and a coil 8 is arranged roughly surrounding the ring 7.

The coil spring as the driving body 6 made of the shape memory alloy has a martensitic transformation starting point (M, point).
When the temperature decreases, the driving body 6 starts shrinking and deforming, and this deformation stops when it reaches the end point of martensitic transformation (M+ point). On the other hand, as the humidity and temperature rise, the reverse transformation LT4tM
At the starting point (point A), restoration of the shape begins and stretching deformation begins, and at the end point of reverse transformation (point Ar), stretching ends and the set shape is restored.

A spring 9 biases the iron core 1 with a spring force in the -F direction in the figure, and is in a compressed state with one end engaged with the lower flat plate IB and the bottom end engaged with the valve portion 5.

Next, to explain its operation, when the coil 8 is de-energized, no heat is applied to the drive body 6 made of a shape memory alloy, so the drive body 6 reaches the reverse temperature (9 points). ), and therefore the driving body 6 is kept in a contracted state. In this state, the tension of the spring 9 is set to be large compared to the tension of the driving body 3, so that the valve part 4 is The iron core 1 contained therein is pressed downward, the valve hole 4 is closed by the valve portion 5, and the flow path 3 is maintained in a blocked state.

Next, when the coil 8 is energized, the iron core! By forming a magnetically closed circuit, a magnetic flux passes through the iron core 1, and a current is induced in the ring 7 by this passing magnetic flux.

As a result, Joule heat is generated in the ring 7 due to the induced current flowing in the ring 8, and the temperature of the inner body of the ring 7 is rapidly increased. According to this temperature rise of ring 7,
The drive body 6 disposed close to the ring 7 is also connected to the ring 7.
As the temperature of the driving body 6 rises from the reverse transformation starting point (point A), the driving body 6 starts to expand, and the temperature rises further and the reverse transformation occurs. The extension is completed when the end point (Ar point) is reached,
By setting the tension associated with the expansion of drive #-6 to be greater than the tension of spring 9, iron core 1 including valve portion 5
is displaced upward in the figure to open the valve hole 4 and maintain the flow path 3 in an open state.

In addition, in this example, the martensitic transformation starting point (M, point)
When the temperature drops to the bottom at The driving body 6 may be expanded and deformed when the bottom falls to the bottom.

According to the control valve using a driving body made of a shape memory alloy as described above, an induced current is generated in the ring 7 by the magnetic flux generated in the iron core 1 when the coil 8 is energized, thereby causing the ring 7 to self-heat. Therefore, the heat generated by ring 7 is due to the fact that a large heat generating wax can be obtained with a small current.Furthermore, since the tunyuan current is not directly connected to ring 7, ring 7 and drive #$6 are There is no need to place an insulating film between the drive body 6 and the large open heat fence described above.
It was possible to achieve the same heating characteristics as above. Therefore, it is possible to provide a control valve that consumes less power and has good valve opening/closing controllability. In addition, since the heating part is ring-shaped compared to a heater made of wire, the danger of wire breakage due to repeated heating and cooling and external vibrations can be eliminated, and a control valve with stable controllability over a long period of time can be provided.

Further, according to a structure in which a ring 7 is arranged around the iron core l and a driving body 6 is further arranged around the outer periphery of the ring 7 as shown in FIG.
Since the circumference of the ring 7 can be shortened close to the iron core 1, it is possible to obtain a large induced current;
It is possible to provide a control valve that can increase the amount of heat generated, improve heating characteristics, and have excellent responsiveness.

Roughly speaking, as shown in FIG. 3, the iron core l is made into a rectangular shape, a coil 8 is wound around one iron core IA, a driving body 6 and a ring 7 are arranged around the other iron core IB, and the driving body 6 The operating body 1O is equipped with a valve portion 4 at the end of the coil 8.
This increased the degree of design freedom.

Furthermore, by making the iron core 1 laminated and bent and laminated with silicon steel plates, it is possible to improve the magnetic flux efficiency of the iron core 1. Accordingly, the induced current can be increased and the ring 7
It is possible to increase the amount of heat generated and improve the heating characteristics.

In addition, as shown in FIG. 4, all the core IDs inside core 1 are
, branch to IB, and their core ID.

By arranging the rings 11 surrounding each of the IFi, a plurality of magnetic flux paths are formed in the iron core 1, and therefore a conductive current is generated in each of the rings 11, and the thermal properties for the rings 11 are further improved. The flow can provide a large amount of heat to the driving body 3, making it possible to provide a control valve with excellent responsiveness.

Further, as shown in FIG. 5, when the terminal pins 6B of the driving body 6 are connected to form an open circuit, an induced current is generated in the ring 7 and the driving body 6 due to the magnetic flux passing through the iron core 1. As mentioned above, in accordance with the self-heating caused by the induced current in the ring 7, the driving body 6 also generates self-heating due to the induced current, and the heating characteristics of the driving body 6 can be significantly improved. As a result of the self-heating of the drive body 6, the drive body 6 is uniformly warmed and its dynamic characteristics can be improved as the temperature rises, making it possible to provide a control valve with excellent controllability.

As described above, according to the control valve of the present invention, a coil is wound around an iron core, and a driving body made of a shape memory alloy and a ring made of a conductive material are arranged around the iron core,
The magnetic flux generated in the iron core causes the ring to generate self-heating due to an induced current, and the ring heats the driving body, and the valve hole is controlled by the valve body that moves according to the displacement of the driving body, so a small current is used to control the valve hole. It is possible to obtain a large amount of heat, and there is no need to place an insulating film between the ring and the driving body, and heat can be transferred directly from the ring to the driving body, improving heating characteristics and thermal response. This made it possible to obtain a control valve with excellent properties. Furthermore, since the heat-generating portion is ring-bound from the wire heater, there is no danger of wire breakage, and a control valve that provides stable control over a long period of time can be obtained.

In addition, the magnetic flux efficiency of the iron core can be improved by making the iron core laminated and bent and laminated, and the heat generation amount of the ring can be increased with a small current. By arranging a ring around each of these magnetic flux paths, it is possible to increase the induced current generated within the ring, thereby increasing the amount of heat generated by the ring. Furthermore, if the drive body is an electrically closed circuit, the drive body generates heat by itself, and in addition to the heat generated by the ring, it is desired to improve the heating characteristics. The body itself is heated evenly and its dynamic characteristics are further improved, and in both cases, a control valve with excellent thermal responsiveness can be obtained using a small current.

[Brief explanation of drawings]

The figure is a longitudinal sectional view showing an example of a control valve using a shape memory alloy according to the present invention, and FIGS. 1, 2, 3,
FIG. 4 and FIG. 5 show each embodiment. l... Iron core 6... Drive body 7 made of shape memory alloy... Ring 8... Coil agent Patent attorney Ike 1) Hiroshi, y-Wli,
, 7.1 Figure 4 Figure 5

Claims (1)

[Claims] l) A coil is wound around an iron core made of a magnetic material forming a magnetically closed circuit, and a driving body made of a shape memory alloy and a ring made of a conductive material are arranged around the iron core, When the coil is energized, the magnetic flux generated in the iron core causes the ring to generate self-heating due to an induced current, thereby heating the driving body, and controlling the valve hole with the valve body that moves according to the displacement of the driving body. control valve. 2) The control valve according to claim 1, in which the iron core is made of laminated layers. 3) The control valve according to claim 1, wherein a plurality of magnetic flux paths are formed by the iron core, and a ring is arranged around each of the magnetic flux paths. 4) The control valve according to claim rA1, wherein the driving body made of a shape memory alloy is an electrically closed circuit.