JP2008133835A - Three-way valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and excellently responsive three-way valve employing a shape-memory alloy made actuator. <P>SOLUTION: A three-way valve is equipped with a cylindrical guide pipe 11 containing a first and second flow passages 15, 16 and a common fluid flow passage 17, a movable valve element 12 movably accommodated in the axial direction in the guide pipe 11, a first and second electrodes 26, 27 taken as electrodes for energization and a wire 13 which is formed of a shape-memory alloy and energizably connected to the first and second electrodes 26, 27 and which can biase the movable valve element 12 in an axial direction of the guide pipe 11 through a shape change due to heat. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a three-way valve using an actuator made of a shape memory alloy.

  2. Description of the Related Art Conventionally, in a three-way valve that includes a fluid inlet and first and second outlets and selectively switches the communication between the inlet and the first or second outlet, the actuator of the valve element is a shape memory alloy. What was formed with the coil spring made from manufacture is known (for example, refer patent document 1).

  In the three-way valve described in Patent Document 1, a coil spring made of a shape memory alloy is connected to one side of the valve body. Further, a bias coil spring made of a normal spring material is connected to the other side of the valve body. Here, generally, the shape memory alloy has a property that the shape changes before and after the reference temperature. For this reason, the shape memory alloy coil spring connected to one side of the valve body changes in shape before and after the reference temperature, and as a result, the elastic coefficient of the coil spring changes before and after the reference temperature. On the other hand, the coil spring connected to the other side of the valve body has a substantially constant elastic coefficient regardless of the temperature.

Therefore, the valve body position where the urging forces of the two coil springs balance changes before and after the reference temperature. In the three-way valve described in Patent Document 1, the communication between the inlet and the first or second outlet can be selectively switched by the change in the valve element position based on the above-described temperature change.
Japanese Patent Laid-Open No. 7-4563

  By the way, in the three-way valve described in Patent Document 1, the coil spring made of shape memory alloy is a so-called side heat type in which the temperature of the coil spring changes due to the change in ambient temperature. Therefore, there exists a problem that the response of the shape change of the shape memory alloy according to temperature is comparatively slow. In order to increase the responsiveness in the side heat type, it is conceivable to increase the surface area of the actuator in order to easily receive heat from the surroundings, but this increases the size of the actuator.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a three-way valve having a small size and excellent responsiveness in a three-way valve using an actuator made of a shape memory alloy.

  In order to solve the above-mentioned problem, in the three-way valve according to the first aspect of the present invention, a cylindrical fixed structure in which first, second and third fluid inlets and outlets are formed, and an axial direction in the fixed structure. The movable structure housed movably, the first and second electrodes to be energized electrodes, and a shape memory alloy, and connected to the first and second electrodes to be energized, A first urging member capable of urging the movable structure in the axial direction of the fixed structure by a change in shape due to heat, and when the first urging member is not energized, the movable structure is The first fluid inlet / outlet is sealed and the second fluid inlet / outlet communicates with the third fluid inlet / outlet. When the first biasing member is energized, a change in the shape of the first biasing member causes the movable structure. A body is displaced and the movable structure is moved into the second fluid inlet / outlet. It said third fluid port and the first fluid inlet and outlet with seals is characterized by communicating.

  When the first urging member made of a shape memory alloy is energized, it self-heats and the temperature rises, and the shape changes due to this heat. Then, the movable structure is biased in a predetermined direction by the change in shape. As a result, the movable structure is displaced, and the communication state of the fluid inlet / outlet formed in the fixed structure is switched. Here, the first urging member is configured to be energized, and self-heats when energized. For this reason, it becomes possible to improve responsiveness compared with an indirectly heated type. Further, since it is not necessary to increase the surface area of the first biasing member in order to make it easy to receive heat from the surroundings, the size of the first biasing member made of a shape memory alloy as an actuator, and hence the size of the entire three-way valve, can be reduced. It becomes possible to reduce the size.

  According to a second aspect of the present invention, in the three-way valve according to the first aspect, the first and second fluid inlets and outlets are provided at both axial ends of the fixed structure, respectively, and the third fluid inlet / outlet is It is provided on the peripheral wall portion of the fixed structure. By moving the movable structure to one end of the fixed structure, it is possible to seal one of the first and second fluid inlets and the other. As a result, it is possible to switch between the communication state of the first and third fluid ports and the communication state of the second and third fluid ports with a simple structure.

  According to a third aspect of the present invention, in the three-way valve according to the first or second aspect, the first and second electrodes are respectively provided at positions opposed to the peripheral wall portion of the cylindrical fixed structure, One urging member is formed in a substantially V shape and both ends of the first urging member are connected to the first and second electrodes, respectively, and the first urging member is a substantially V-shaped bent portion. The movable structure is biased in the vicinity.

  Since the first urging member has a simple V-shape, the physique of the first urging member made of a shape memory alloy, which is an actuator, and the physique of the entire three-way valve can be downsized. Further, since the movable structure is biased in the vicinity of the V-shaped bent portion, the stroke amount in the moving direction of the movable valve body with respect to the expansion / contraction amount of the first biasing member made of the shape memory alloy is increased. Is possible.

  According to a fourth aspect of the present invention, in the three-way valve according to any one of the first to third aspects, the first urging member is applied when the second fluid inlet / outlet is sealed by the movable structure. It is characterized by comprising a load-reducing elastic body that reduces the stress load.

  In a three-way valve using an actuator made of a shape memory alloy, the pressure at the time of sealing may be set strongly in order to increase the reliability at the time of sealing the fluid inlet / outlet. In addition, actuator parts may vary in manufacturing accuracy. For this reason, when a variation occurs in the direction in which the stress load applied to the actuator increases, an excessive stress load may be applied to the shape memory alloy actuator when sealing the fluid inlet / outlet. In general, the shape memory alloy changes its shape when the temperature exceeds a reference temperature. When the temperature is returned to the initial state, the original shape is recovered, and the shape reproducibility which is a property of the shape memory alloy is exhibited. However, when an excessive stress load is applied in the memory shape state, the memory shape of the shape memory alloy is shifted, and the reproducibility of the shape tends to be impaired.

  In this regard, in the invention according to the fourth aspect, it is possible to suppress an excessive stress load from being applied to the first urging member made of the shape memory alloy by providing the load reducing elastic body. As a result, the reproducibility of the shape of the first urging member made of the shape memory alloy can be maintained satisfactorily, and the reliability of the three-way valve can be improved and the product life can be extended.

  According to a fifth aspect of the present invention, the three-way valve according to any one of the first to fourth aspects, further comprising a second biasing member that biases the movable structure toward the first fluid inlet / outlet side, When the first urging member is not energized, the movable structure is urged toward the first fluid inlet / outlet by the second urging member to seal the first fluid inlet / outlet. By providing the second urging member that urges the movable structure toward the first fluid inlet / outlet side, it is possible to improve the reliability of sealing of the first fluid inlet / outlet when the first urging member is not energized. It becomes.

  According to a sixth aspect of the present invention, in the three-way valve according to the fifth aspect, the second urging member is formed of an elastic body, and the first movable portion and the second fluid inlet / outlet sealing the first fluid inlet / outlet. And the second movable part is configured to constitute the movable structure, and the load reducing elastic body is provided between the first movable part and the second movable part, and the elasticity of the second urging member is provided. The coefficient is set smaller than the elastic coefficient of the load reducing elastic body. According to this, it has the structure which provided the load reduction structure between the movable structures comprised including the 1st and 2nd movable part. For this reason, it becomes possible to provide a load reduction elastic body, without adding changes to members, such as fixed structures other than a movable structure. Further, the elastic coefficient of the second urging member was set smaller than the elastic coefficient of the load reducing elastic body. For this reason, due to the force generated by the deformation of the first urging member, the second urging member is deformed before the load reducing elastic body, and the movable structure is displaced. As a result, it is possible to suppress the displacement of the movable structure from being inhibited by the load reducing elastic body.

  According to a seventh aspect of the present invention, in the three-way valve according to the fifth aspect, a convex portion is provided on one of the first and second movable portions, a concave portion is provided on the other, and the convex portion is inserted into the concave portion. In this state, the movable structure is movable in the axial direction of the fixed structure, and the first and second movable parts are relatively movable. Thereby, the movement of a movable structure and the relative movement of a 1st movable part and a 2nd movable part become smooth.

  According to an eighth aspect of the present invention, in the three-way valve according to the fifth aspect, the second urging member is formed of an elastic body, the first and second electrodes are provided on the fixed structure, and the first And at least one of the second electrode is formed of an elastic body, the load reducing elastic body is formed of an electrode formed of the elastic body, and an elastic coefficient of the second urging member is an elastic coefficient of the load reducing elastic body. It is characterized by having been set smaller than. According to this, since it is not necessary to change the movable structure in order to install the load reducing elastic body, the structure of the movable structure is simplified and the manufacture of the movable structure is facilitated. In addition, since the electrode also serves as a load reducing elastic body, the number of parts can be reduced. Furthermore, since the elastic coefficient of the second urging member is set smaller than the elastic coefficient of the load reducing elastic body, the second urging member is moved ahead of the load reducing elastic body by the force generated by the deformation of the first urging member. The movable structure is displaced by deformation. For this reason, it can suppress that the displacement of a movable structure is inhibited by the load reduction elastic body.

  According to a ninth aspect of the present invention, in the three-way valve according to the fifth aspect, the second urging member is formed of an elastic body, and at least one of the first and second electrodes is attached to the fixed structure. The load reducing elastic body is provided between the fixed structure and the electrode provided to be relatively movable with respect to the fixed structure, and the elastic coefficient of the second biasing member is set to the load It is characterized by being set smaller than the elastic coefficient of the reduced elastic body.

  According to this, the load reducing elastic body is provided between the fixed structure and the electrode provided so as to be movable relative to the fixed structure. For this reason, since it is not necessary to change a movable structure in order to install a load reduction elastic body, the structure of a movable structure becomes simple and manufacture of a movable structure becomes easy. Further, the elastic coefficient of the second urging member was set smaller than the elastic coefficient of the load reducing elastic body. For this reason, due to the force generated by the deformation of the first urging member, the second urging member is deformed before the load reducing elastic body, and the movable structure is displaced. For this reason, it can suppress that the displacement of a movable structure is inhibited by the load reduction elastic body.

[First Embodiment]
Hereinafter, a three-way valve according to a first embodiment of the present invention will be described with reference to FIG. Here, FIG. 1A is an axial sectional view showing the state of the three-way valve when the wire is not energized, and FIG. 1B is an axial sectional view showing the state of the three-way valve when the wire is energized. FIG.

  As shown in FIG. 1A, the three-way valve 10 includes a guide pipe 11, a movable valve body 12 accommodated in the guide pipe 11, and a wire 13 as an actuator for driving the movable valve body 12. It consists of

  The guide pipe 11 is formed in a substantially cylindrical shape from metal or resin. An accommodating portion 14 is formed inside the guide pipe 11, and the movable valve body 12 is accommodated so as to be movable in the axial direction of the guide pipe 11. First and second fluid flow paths 15 and 16 are provided at both ends of the guide pipe 11 in the axial direction. In addition, a common fluid channel 17 is provided on the peripheral wall portion on one end side (first fluid channel 15 side) of the guide pipe 11.

  The movable valve body 12 is formed in a substantially cylindrical shape from metal or resin. The movable valve body 12 is formed so that fluid can pass through it. As described above, the movable valve body 12 is movable in the axial direction in the accommodating portion 14, and the flange portion 18 having a larger diameter than the other portions is provided in the central portion in the movement direction of the movable valve body 12. It has been. The flange 18 is provided at a position where the end of the movable valve body 12 is in contact with the first fluid channel 15 and does not block the common fluid channel 17. The flange portion 18 forms a guided portion that is inscribed and guided by the inner peripheral wall surface of the housing portion 14 when the movable valve body 12 moves in the housing portion 14 in the axial direction. Since the flange 18 is guided by the inner wall surface of the housing 14, the movable valve body 12 can move smoothly in the housing 14. A through-hole 19 that penetrates the movable valve body 12 in the radial direction is formed in the flange portion 18. Further, in the through hole 19, a biased portion 20 is provided that extends in a direction orthogonal to the through direction of the through hole 19 and the moving direction of the movable valve body 12.

  First and second sealing portions 21 and 22 are provided at both ends of the movable valve body 12 in the axial direction. The first and second sealing portions 21 and 22 are for abutting and sealing the opening portions 23 and 24 on the accommodating portion 14 side in the first and second fluid flow paths 15 and 16. is there. The first and second sealing portions 21 and 22 are preferably formed of an elastic resin material such as rubber in order to improve the sealing performance of the openings 23 and 24.

  A first coil spring 25 is provided between the end of the accommodating portion 14 on the second fluid flow path 16 side and the flange 18 of the movable valve body 12, and the movable valve body 12 is connected to the first fluid flow path 15 side. Is energized. Moreover, the 1st and 2nd electrodes 26 and 27 are being fixed to the position which opposes in the surrounding wall part of the guide pipe 11, respectively.

  The three-way valve 10 is provided with a wire 13 bent in a substantially V shape. The wire 13 is disposed in the through hole 19, and both end portions thereof are protruded from the through hole 19, and the bent portion is in a direction protruding toward the first fluid flow path 15. Further, both ends of the wire 13 are connected to the first and second electrodes 26 and 27, respectively. By applying a voltage between the first and second electrodes 26 and 27, the wire 13 can be energized. ing. As shown in FIG. 1A, the bent portion of the wire 13 is disposed closer to the first fluid flow path 15 than the biased portion 20 in the through hole 19, and is not connected to the wire 13. When energized, the wire 13 and the biased portion 20 are not in contact with each other.

  The wire 13 is formed of a shape memory alloy (for example, a Ti—Ni type shape memory alloy). In general, a shape memory alloy has an elongated shape whose full length is extended at room temperature, but when it reaches a certain reference temperature or higher, it has a previously memorized contraction shape. And if it returns temperature to an initial state, it has the property to recover to the original shape. The shape change force due to the temperature change of the shape memory alloy is significantly larger than the elastic force acting on the first coil spring 25. Therefore, when a voltage is applied to the first and second electrodes 26 and 27 and the wire 13 is energized, the wire 13 self-heats, and when the temperature of the wire 13 exceeds the reference temperature, the wire 13 is stored in advance. Shrink shape. In this contracted state, as shown in FIG. 1B, the wire 13 is in contact with the first fluid flow path 15 side of the biased portion 20 in the vicinity of the bent portion, and the movable valve body 12 is moved to the second fluid. The movable valve element 12 is moved by energizing the flow path 16 side.

  Next, the operation of the three-way valve 10 in this embodiment will be described. As shown to Fig.1 (a), when the electric current is not sent through the wire 13, the wire 13 made from a shape memory alloy is in the expansion | extension state. In this state, the wire 13 and the urged portion 20 are not in contact, and the urging force of the wire 13 against the movable valve body 12 is not acting. On the other hand, the first coil spring 25 urges the movable valve body 12 toward the first fluid flow path 15. For this reason, the first sealing portion 21 of the movable valve body 12 contacts and seals the opening 23 on the accommodating portion 14 side in the first fluid flow path 15. As a result, the second fluid channel 16 and the common fluid channel 17 communicate with each other when the wire 13 is not energized.

  When a current is passed through the wire 13, the wire 13 self-heats when energized. When the temperature of the wire 13 becomes equal to or higher than the reference temperature, the wire 13 enters a prestored contracted state. For this reason, the bent part vicinity of the wire 13 contacts the to-be-biased part 20, and the movable valve body 12 is urged | biased to the 2nd fluid flow path 16 side. Here, the shape changing force of the wire 13 made of shape memory alloy is remarkably large with respect to the elastic force of the first coil spring 25, and the urging force of the wire 13 is larger than the urging force of the first coil spring 25. For this reason, the movable valve body 12 is moved to the second fluid passage 16 side, and the second fluid passage 16 is sealed by the second sealing portion 22. As a result, the first fluid channel 15 and the common fluid channel 17 communicate with each other when the wire 13 is energized.

  According to the embodiment described in detail above, the following excellent effects are obtained.

  In this embodiment, when the shape memory alloy wire 13 is energized, it self-heats and the temperature rises, and the shape changes due to this heat. And the movable valve body 12 is urged | biased by the 2nd fluid flow path 16 side by the change of this shape. As a result, the movable valve body 12 is displaced to switch the communication state of the fluid flow paths 15, 16 and 17 formed in the guide pipe 11. Here, the wire 13 is configured to self-heat when energized. For this reason, it becomes possible to improve responsiveness compared with an indirectly heated type. Further, unlike the indirectly heated type, it is not necessary to increase the surface area of the wire 13 in order to make it easier to receive heat from the surroundings. It becomes possible to reduce the overall physique.

  In the present embodiment, the first and second fluid flow paths 15 and 16 are provided at both ends of the cylindrical guide pipe 11. For this reason, by moving the movable valve body 12 to one end of the guide pipe 11, one of the openings 23 and 24 of the first and second fluid flow paths 15 and 16 is sealed and the other is opened. Is possible. As a result, it is possible to switch between the communication state of the first fluid channel 15 and the common fluid channel 17 and the communication state of the second fluid channel 16 and the common fluid channel 17 with a simple structure.

  Moreover, in this embodiment, the wire 13 is made into the simple shape of substantially V shape. For this reason, the physique of the actuator made of shape memory alloy, and thus the physique of the entire three-way valve 10 can be reduced in size, and the manufacture of the actuator is facilitated. Further, since the movable valve body 12 is biased in the vicinity of the V-shaped bent portion, the stroke amount in the moving direction of the movable valve body 12 with respect to the expansion / contraction amount of the wire 13 made of shape memory alloy can be increased. It becomes possible.

  In the present embodiment, a first coil spring 25 is provided between the movable valve body 12 and the second fluid flow path 16. Therefore, when the shape memory alloy wire 13 is in a non-energized state and the urging force is not applied to the movable valve body 12 by the wire 13, the movable valve body 12 is moved by the first coil spring 25 to the first fluid flow. It is biased toward the road 15 side. Thereby, it is possible to improve the certainty of sealing the first fluid flow path 15 when the wire 13 is not energized.

[Second Embodiment]
A three-way valve according to a second embodiment of the present invention will be described with reference to FIG. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. Here, FIG. 2A is an axial sectional view showing the state of the three-way valve when the wire is not energized, and FIG. 2B is an axial sectional view showing the state of the three-way valve when the wire is energized. FIG.

  The movable valve body 30 according to the second embodiment includes a first movable part 32 having a first sealing part 31 and a second movable part 33 having a second sealing part 34. And between the 1st and 2nd movable parts 32 and 33, the 2nd coil spring 35 as a load reduction elastic body is provided.

  Specifically, as shown in FIG. 2A, the first and second movable parts 32 and 33 are formed in a cylindrical shape, and are arranged with their axial end faces facing each other. And on the opposing surface side of the 1st movable part 32 and the 2nd movable part 33, the collar parts 36 and 37 with a larger diameter than another part are each provided. The flanges 36 and 37 of both movable parts are covered and guided by the inner peripheral wall surface of the accommodating part 14 when the first and second movable parts 32 and 33 move in the accommodating part 14 in the axial direction. A guide part is formed. Then, the first and second movable portions 32 and 33 can move smoothly in the housing portion 14 by the flange portions 36 and 37 being guided by the inner wall surface of the housing portion 14.

  Also in the present embodiment, a substantially V-shaped wire 13 made of shape memory alloy is used as an actuator for driving the movable valve body 30. The first movable part 32 is formed with a through hole 19 penetrating in the radial direction. The through hole 38 extends in a direction perpendicular to the through direction of the through hole 38 and the moving direction of the first movable part 32. An urging portion 39 is provided.

  The wire 13 is disposed in the through-hole 38, and both end portions thereof are projected, and the bent portion is disposed in a direction that protrudes toward the first fluid flow path 15. Further, both ends of the wire 13 are connected to the first and second electrodes 26 and 27, respectively. By applying a voltage between the first and second electrodes 26 and 27, the wire 13 can be energized. ing. 2A, in the through hole 38, the bent portion of the wire 13 is disposed on the first fluid flow path 15 side with respect to the biased portion 39, and the wire 13 At the time of non-energization, the wire 13 and the biased portion 20 are not in contact with each other.

  The end portions of the second coil spring 35 are connected to both flange portions 36 and 37, respectively. By the expansion and contraction of the coil spring, the relative distance between the first movable part 32 and the second movable part 33 is variable. The second coil spring 35 is for suppressing an excessive load on the wire 13 made of shape memory alloy, and the elastic coefficient of the second coil spring 35 is set sufficiently larger than the elastic coefficient of the first coil spring 25. ing.

  Next, the operation of the three-way valve 10 in this embodiment will be described. As shown in FIG. 2A, when no current is passed through the wire 13, the shape memory alloy wire 13 is in an elongated state. In this state, the wire 13 and the biased portion 39 are not in contact, and the biasing force by the wire 13 does not act on the first movable portion 32. On the other hand, the first coil spring 25 urges the second movable portion 33 toward the first fluid flow path 15. The urging force acting on the second movable part 33 is transmitted to the first movable part 32 via the second coil spring 35, and the first movable part 32 moves to the first fluid flow path 15 side. As a result, when the wire 13 is not energized, the first sealing portion 31 of the movable valve body 30 comes into contact with the opening 23 on the accommodating portion 14 side in the first fluid flow path 15 to seal it, and the second The fluid channel 16 and the common fluid channel 17 communicate with each other.

  When a current is passed through the wire 13, the wire 13 self-heats due to energization. When the temperature of the wire 13 becomes equal to or higher than the reference temperature, the wire 13 enters a prestored contracted state. Therefore, the vicinity of the bent portion of the wire 13 contacts the biased portion 39 and biases the first movable portion 32 toward the second fluid flow path 16 (second movable portion 33 side). The biasing force that has acted on the first movable part 32 is transmitted to the second movable part 33 via the second coil spring 35, and is transmitted from the second movable part 33 to the first coil spring 25.

  Here, the elastic coefficient of the second coil spring 35 is set sufficiently larger than the elastic coefficient of the first coil spring 25. For this reason, in a state where the second sealing portion 34 is not in contact with the accommodating portion 14 side opening 24 in the second fluid flow path 16, the second coil spring 35 hardly contracts and the first coil spring 25 contracts. . Then, the second movable portion 33 moves to the second fluid flow path 16 side, and the second sealing portion 34 comes into contact with the opening 24. As a result, the second fluid passage 16 is sealed by the second sealing portion 34, and the first fluid passage 15 and the common fluid passage 17 communicate with each other when the wire 13 is energized. After the second sealing portion 34 comes into contact with the second fluid flow path 16, when a biasing force further acts on the first movable portion 32 toward the second fluid flow path 16, the second coil spring 35 starts to contract. To do. The contraction of the second coil spring 35 serves as a cushioning effect that alleviates the overloading of the wire 13 directly, and reduces the excessive load on the wire 13.

  Here, in general, when an excessive pressure is applied in a memory shape state, the shape memory alloy has a tendency that the memory shape shifts and the reproducibility of the shape is lost, and the shape does not completely return to the original shape. In this regard, in the present embodiment, a second coil spring 35 is provided for suppressing an excessive load from being applied to the shape memory alloy wire 13. For this reason, it can suppress that an excessive load is applied to the wire 13 made of the shape memory alloy, and it is possible to prevent the shape reproducibility of the wire 13 made of the shape memory alloy from being impaired. As a result, deterioration with the passage of time can be suppressed, the reproducibility of the shape due to temperature change can be improved, and the switching accuracy of the communication state by energization of the wire 13 can be increased.

  Further, since the elastic coefficient of the first coil spring 25 is set to be smaller than the elastic coefficient of the second coil spring 35, the first coil spring 25 is deformed and movable before the second coil spring 35 by the force generated by the deformation of the wire 13. The valve body 30 is displaced. For this reason, it is possible to suppress the displacement of the movable valve body 30 from being inhibited by the second coil spring 35.

  In the present embodiment, the movable valve body 30 is divided into a first movable portion 32 and a second movable portion 33, and a second coil spring 35 is disposed between both movable portions. For this reason, it becomes possible to arrange | position the 2nd coil spring 35 as a load reduction elastic body, without adding a change to structures other than the movable valve body 30 with respect to the three-way valve 10 of 1st Embodiment.

[Third Embodiment]
A three-way valve according to a third embodiment of the present invention will be described with reference to FIG. In addition, about the structure similar to 2nd Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. 3A is an axial sectional view showing the state of the three-way valve when the wire is not energized, and FIG. 3B is an axial sectional view showing the state of the three-way valve when the wire is energized. FIG.

  In the present embodiment, the first movable portion 32 is formed with a convex portion 40 that protrudes toward the second movable portion 33. Further, the second movable portion 33 is formed with a concave portion 41 that is recessed toward the anti-first movable portion 32 side. The first movable portion 32 and the second movable portion 33 move together in the housing portion 14 in a state where the convex portion 40 is inserted into the concave portion 41, and the first movable portion 32 and the second movable portion move together. It is comprised so that the part 33 may move relatively.

  As shown in FIGS. 3A and 3B, in the present embodiment, when the first and second movable parts 32 and 33 move integrally, the convex part 40 is inserted into the concave part 41. Move in the state. That is, since the convex portion 40 is in a state of being fitted into the concave portion 41, it is easy to ensure the integrity of both, and the movable valve body 30 can be moved smoothly. Moreover, when the 1st and 2nd movable parts 32 and 33 move relatively, both move relatively in the state where the convex part 40 was inserted in the concave part 41. That is, when both move relatively, the sliding direction of the convex portion 40 is regulated by the concave portion 41, and the relative movement between the two can be performed smoothly.

[Fourth Embodiment]
A three-way valve according to a fourth embodiment of the present invention will be described with reference to FIG. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. 4A is an axial cross-sectional view showing the state of the three-way valve when the wire is not energized, and FIG. 4B is an axial cross-section showing the state of the three-way valve when the wire is energized. FIG.

  In the present embodiment, the first and second electrodes 42 and 43 are made of a conductive resin. And both ends of the wire 13 made of a shape memory alloy formed in a substantially V shape are connected to both electrodes 42 and 43 made of conductive resin. The elastic coefficients of the conductive resin electrodes 42 and 43 are set to be sufficiently larger than the elastic coefficient of the first coil spring 25.

  Next, the operation of the three-way valve 10 in this embodiment will be described. As shown in FIG. 4A, when no current is passed through the wire 13, the shape memory alloy wire 13 is in an elongated state. In this state, the wire 13 and the urged portion 20 are not in contact, and the urging force of the wire 13 is not acting on the movable valve body 12. On the other hand, the first coil spring 25 urges the movable valve body 12 toward the first fluid flow path 15. And the movable valve body 12 moves to the 1st fluid flow-path 15 side by this urging | biasing force. As a result, when the wire 13 is not energized, the first sealing portion 21 of the movable valve body 12 comes into contact with the opening 23 on the accommodating portion 14 side in the first fluid flow path 15 to seal it, and the second The fluid channel 16 and the common fluid channel 17 communicate with each other.

  When a current is passed through the wire 13, the wire 13 self-heats due to energization. When the temperature of the wire 13 becomes equal to or higher than the reference temperature, the wire 13 enters a prestored contracted state. For this reason, the bent part vicinity of the wire 13 contacts the to-be-biased part 20, and the movable valve body 12 is urged | biased to the 2nd fluid flow path 16 side. Further, the force generated with the deformation of the wire 13 also acts on the first and second electrodes 42 and 43.

  Here, the elastic coefficient of the first and second electrodes 42 and 43 made of conductive resin is set to be sufficiently larger than the elastic coefficient of the first coil spring 25. Therefore, in a state where the second sealing portion 22 is not in contact with the accommodating portion 14 side opening 23 in the second fluid flow path 16, the first and second electrodes 42 and 43 are hardly deformed, and the first One coil spring 25 contracts. Then, the movable valve body 12 moves to the second fluid flow path 16 side, and the second sealing portion 22 comes into contact with the opening portion 23. As a result, the second fluid channel 16 is sealed by the second sealing portion 22, and the first fluid channel 15 and the common fluid channel 17 communicate with each other. After the second sealing portion 22 comes into contact with the opening 23, when a force accompanying the deformation of the wire 13 further acts on the first and second electrodes 42 and 43, as shown in FIG. The first and second electrodes 42 and 43 start to deform. The deformation of the first and second electrodes 42 and 43 serves as a cushioning effect that alleviates the direct overloading of the wire 13 and reduces the excessive load on the wire 13.

  That is, in this embodiment, by forming the first and second electrodes 42 and 43 with a conductive resin, it is possible to suppress an excessive load from being applied to the wire 13 made of shape memory alloy. It is possible to prevent the shape reproducibility of the alloy wire 13 from being impaired. As a result, deterioration with the passage of time can be suppressed, the reproducibility of the shape due to temperature change can be improved, and the switching accuracy of the communication state by energization of the wire 13 can be increased.

  Further, since the elastic coefficient of the first coil spring 25 is set to be smaller than the elastic coefficient of the electrodes 42 and 43 made of conductive resin, the first coil spring 25 is preceded by the force generated by the deformation of the wire 13 before the electrodes 42 and 43. Is deformed and the movable valve body 12 is displaced. For this reason, it can suppress that the displacement of the movable valve body 12 is inhibited by the deformation of the electrodes 42 and 43.

  In this embodiment, it is not necessary to change the movable valve body 12 in order to install the load reducing elastic body. For this reason, the structure of the movable valve body 12 is simplified, and the manufacture of the movable valve body 12 is facilitated. Further, since the electrodes 42 and 43 also serve as a load reducing elastic body, the number of parts can be reduced.

[Fifth Embodiment]
A three-way valve according to a fifth embodiment of the present invention will be described with reference to FIG. In addition, about the structure similar to said each embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. Here, FIG. 5A is an axial sectional view showing a state of the three-way valve when the wire is not energized, and FIG. 5B is an axial sectional view showing a state of the three-way valve when the wire is energized. FIG.

  In the present embodiment, the first electrode 44 is fixed to the guide pipe 11, and the second electrode 45 is provided to be movable relative to the guide pipe 11. Specifically, a hole 46 is formed in the radial direction at the position where the second electrode 45 is disposed on the inner peripheral wall surface of the guide pipe 11. The second electrode 45 is movable in the perspective direction with respect to the first electrode 44 in the hole 46. A stopper 47 is formed at the end of the hole 46 on the side of the accommodating part 14 so that the second electrode 45 is prevented from protruding into the accommodating part 14. A second coil spring 48 as a load reducing elastic body is disposed between the stopper portion 47 and the second electrode 45, and both end portions of the second coil spring 48 are fixed to the stopper portion 47 and the second electrode 45, respectively. ing. The elastic coefficient of the second coil spring 48 is set sufficiently larger than the elastic coefficient of the first coil spring 25.

  Also in this embodiment, when the wire 13 shown in FIG. 5A is not energized, the first sealing portion 21 of the movable valve body 12 seals the first fluid channel 15 and the second fluid channel 16. And the common fluid flow path 17 communicate with each other. When energization of the wire 13 is started, the movable valve body 12 and the second electrode 45 are biased by deformation of the wire 13 as shown in FIG. Here, since the elastic coefficient of the first coil spring 25 is set to be smaller than the elastic coefficient of the second coil spring 48, the movement of the movable valve body 12 is started before the movement of the second electrode 45. Then, after the second sealing portion 22 of the movable valve body 12 seals the second fluid flow path 16, when a biasing force is applied to the movable valve body 12 and the second electrode by the wire 13, the second coil spring 48 Expansion starts. Thereby, it is suppressed that an excessive load is applied to the wire 13.

  Also in the present embodiment, the second electrode is provided so as to be movable relative to the guide pipe 11, and the second coil spring 48 is disposed between the stopper portion 47 and the second electrode 45. As a result, it is possible to prevent an excessive load from being applied to the shape memory alloy wire 13 and to prevent the shape reproducibility of the shape memory alloy wire 13 from being impaired. As a result, deterioration with the passage of time can be suppressed, the reproducibility of the shape due to temperature change can be improved, and the switching accuracy of the communication state by energization of the wire 13 can be increased.

[Other Embodiments]
In the first embodiment, the structure that abuts against the biased portion 20 only when the wire 13 contracts may be configured such that the V-shaped portion of the wire 13 is fixed to the movable valve body 12. In this case, when the wire 13 is extended, the movable valve body 12 is biased toward the first fluid flow path 15 by the wire 13, and when the wire 13 is contracted, the movable valve body 12 is moved toward the second fluid flow path 16 by the wire 13. The position and the shape of the wire 13 are set so as to be urged by. Also by this, it is possible to switch the communication state of the fluid flow path by switching the energization state to the wire 13.

  In each of the above embodiments, the substantially V-shaped wire 13 made of shape memory alloy is used as the actuator that drives the movable valve bodies 12 and 30. That is, a shape memory alloy actuator was used as a linear body. However, the shape of the shape memory alloy actuator is not limited to this, and may be a plate-like body.

  In the third embodiment, the convex portion 40 is formed in the first movable portion 32 and the concave portion 41 is formed in the second movable portion 33. However, the concave portion 41 may be formed in the first movable portion 32 and the convex portion 40 may be formed in the second movable portion 33.

It is sectional drawing which shows the structure of the three-way valve concerning 1st Embodiment of this invention, (a) is at the time of the electricity supply to a wire, (b) shows the time at the time of electricity supply to a wire. It is sectional drawing which shows the structure of the three-way valve concerning 2nd Embodiment of this invention, (a) is at the time of the electricity supply to a wire, (b) shows the time at the time of electricity supply to a wire. It is sectional drawing which shows the structure of the three-way valve concerning 3rd Embodiment of this invention, (a) is at the time of the electricity supply to a wire, (b) shows the time at the time of electricity supply to a wire. It is sectional drawing which shows the structure of the three-way valve concerning 4th Embodiment of this invention, (a) is at the time of the electricity supply to a wire, (b) shows the time at the time of electricity supply to a wire. It is sectional drawing which shows the structure of the three-way valve concerning 5th Embodiment of this invention, (a) is at the time of the electricity supply to a wire, (b) shows the time at the time of electricity supply to a wire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Three-way valve 11 Guide pipe 12 Movable valve body 13 Wire 14 Accommodating part 15 1st fluid flow path 16 2nd fluid flow path 17 Common fluid flow path 18 Gutter part 19 Through-hole 20 Energized part 21 1st sealing part 22 Second sealing portion 23, 24 Opening portion 25 First coil spring 26 First electrode 27 Second electrode

Claims (9)

A cylindrical fixing structure in which first, second and third fluid ports are formed;
A movable structure housed movably in the axial direction in the fixed structure;
First and second electrodes to be energized electrodes;
A first attachment formed of a shape memory alloy, connected to the first and second electrodes so as to be energized, and capable of urging the movable structure in the axial direction of the fixed structure by a change in shape due to heat. A force member,
When the first biasing member is not energized, the movable structure seals the first fluid inlet / outlet and the second fluid inlet / outlet communicates with the third fluid inlet / outlet;
When the first urging member is energized, the movable structure is displaced due to a change in the shape of the first urging member so that the movable structure seals the second fluid inlet / outlet and the first fluid inlet / outlet. And the third fluid inlet / outlet communicate with each other.   The said 1st and 2nd fluid inlet / outlet was provided in the both ends of the axial direction of the said fixed structure, respectively, and the said 3rd fluid inlet / outlet was provided in the surrounding wall part of the said fixed structure. The three-way valve described. The first and second electrodes are respectively provided at positions opposed to the peripheral wall portion in the cylindrical fixing structure,
Forming the first biasing member in a substantially V shape and connecting both ends of the first biasing member to the first and second electrodes, respectively;
The three-way valve according to claim 1 or 2, wherein the first urging member urges the movable structure in the vicinity of a substantially V-shaped bent portion.   The load reducing elastic body for reducing a stress load applied to the first urging member when the second fluid inlet / outlet is sealed by the movable structure is provided. The three-way valve according to item. A second biasing member that biases the movable structure toward the first fluid inlet / outlet;
The said movable structure is urged | biased by the said 2nd urging | biasing member to the said 1st fluid inlet / outlet side at the time of the deenergization to the said 1st urging | biasing member, The said 1st fluid inlet / outlet is sealed, It is characterized by the above-mentioned. The three-way valve according to any one of claims 1 to 4. Forming the second biasing member with an elastic body;
The movable structure is configured to include a first movable part that seals the first fluid inlet / outlet and a second movable part that seals the second fluid inlet / outlet, and the first movable part and the second movable part, The load reducing elastic body is provided between
The three-way valve according to claim 5, wherein an elastic coefficient of the second urging member is set smaller than an elastic coefficient of the load reducing elastic body. A convex portion is provided on one of the first and second movable portions and a concave portion is provided on the other,
The movable structure is movable in the axial direction of the fixed structure and the first and second movable parts are relatively movable in a state where the convex portion is inserted into the concave portion. The three-way valve according to claim 6. Forming the second biasing member with an elastic body;
Providing the first and second electrodes on the fixed structure and forming at least one of the first and second electrodes with an elastic body;
The load reducing elastic body is composed of an electrode formed of the elastic body,
The three-way valve according to claim 5, wherein an elastic coefficient of the second urging member is set smaller than an elastic coefficient of the load reducing elastic body. Forming the second biasing member with an elastic body;
At least one of the first and second electrodes is provided so as to be relatively movable with respect to the fixed structure, and between the fixed structure and the electrode provided to be relatively movable with respect to the fixed structure. Provide a load reducing elastic body,
The three-way valve according to claim 5, wherein an elastic coefficient of the second urging member is set smaller than an elastic coefficient of the load reducing elastic body.

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