JP2007057089A - Small valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To protect a shape memory alloy of a small valve using the shape memory alloy from overload, and increase durability and reliability of the valve. <P>SOLUTION: The small valve is equipped with a movable valve element 3 having a sealing part 5 internally coming into contact with a guide pipe 1 to close an orifice 2, a bias coil 8 installed between the orifice 2 and the movable valve element 3, and a wire 9 formed of the shape memory alloy held between a fixed electrode 11 of the guide pipe 1 and a movable electrode 12 of the movable valve element 3. The wire 9 is heated to deform the shape memory alloy so as to move the movable valve element 3 in order to close the orifice 2. A coiled spring 7 for stress reduction is disposed in the movable valve element 3 to elastically deform the movable valve element 3 so that an overload on the movable valve element 3 due to excessive contraction of the wire 9 can be absorbed by the elastic deformation of the movable valve element 3 itself. Therefore, reoccurrence of a memorized shape can be prevented from being deteriorated by reducing the overload of the shape memory alloy, and the durability and the reliability of the valve can be increased. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a small valve for controlling various fluids such as gas and liquid using a shape memory alloy.

  Conventionally, as a small valve that performs this type of fluid adjustment, for example, as disclosed in Patent Document 1, a valve body actuator that opens and closes an orifice is formed of a shape memory alloy, and the valve body is energized, There are known normally-closed and normally-open valves that displace the valve. In the control valve of such a valve, in order to improve the sealing performance of the orifice, it is necessary to increase the pressure on the orifice. Therefore, when the valve is closed, the actuator of the shape memory alloy contracts even after contacting the orifice, Furthermore, the orifice is pressurized. Similarly, the orifice may be excessively pressurized due to variations in actuator parts. However, when the orifice is pressed by this pressurization, the actuator receives a load from the orifice fixed to the valve body. This load becomes larger as the pressure from the actuator to the orifice becomes stronger, and an overload is applied to the shape memory alloy.

  In general, an electrically heated shape memory alloy usually has an elongated shape that extends in length at normal temperature, self-heats when a DC or AC voltage is applied and is energized, and is pre-shaped when the temperature rises above a certain temperature. It becomes the memorized contraction shape. When the temperature is returned to the initial state, the original shape is recovered, and the reproducibility of the recovered shape, which is a property of the shape memory alloy, is shown. However, when an excessive pressure is applied to the shape memory alloy in the memory shape state, the memory shape shifts and the reproducibility of the recovery shape is impaired, and due to this change over time, the original memory shape state is completely restored. Has a tendency not to return.

  For this reason, even in the valve shown in Patent Document 1 described above, the shape memory alloy of the actuator is overloaded by excessive pressing on the orifice, and this is repeated to cause deterioration over time, and the initially set memory shape state is deformed. As a result, the original memory shape may not be restored. As a result, the reproducibility of the recovery shape of the shape memory alloy is deteriorated, and the valve control performance of the valve may be lowered. Further, the normally open valve disclosed in Patent Document 1 requires two shape memory alloy actuators, and has a drawback that the structure is complicated and the cost is high.

As another conventional example, as shown in Patent Document 2, when a coil spring formed of a shape memory alloy reaches a certain temperature or more, it elongates and overcomes the bias force of the bias spring to open the valve body in a valve open state. There is a valve that is pressed to forcibly close the valve. However, since this valve has a coil spring shape, the outer shape becomes large and it is difficult to reduce the size. Further, if the shape of the shape memory alloy coil spring is made thicker in order to produce a certain force, the heat capacity of the coil spring increases, and there is a possibility that the responsiveness at the time of heat radiation may deteriorate. Furthermore, as another conventional example, as shown in Patent Document 3, a small valve that realizes a closing operation of a normally open valve using a wire made of a shape memory alloy is known. However, in this valve, temperature distribution is generated at the folded portion of the wire, and there is a possibility that durability is deteriorated due to thermal stress. In addition, after the wire moves to the operation limit, the shape memory alloy is overloaded, and there is a problem that the shape memory alloy deteriorates with time as described above.
JP 05-99369 A JP 09-313363 A JP-A-11-153234

  The present invention has been made to solve the above-described problem, and is movable and includes a fixed structure that has a cylindrical shape and has an orifice built therein, and a sealing body that is inscribed in the fixed structure and seals the orifice. In a small valve that includes a movable structure and heats and deforms the shape memory alloy wire to seal the orifice, the length of the movable structure including the sealing body can be elastically deformed. An object of the present invention is to provide a highly reliable small valve that maintains the durability by reducing the stress load by elastic deformation of the movable structure, thereby eliminating the deterioration of the reproducibility of the shape memory alloy with the passage of time.

  In order to achieve the above object, the invention according to claim 1 is a movable structure having a cylindrical fixed structure having an orifice and a sealing body that is inscribed in the fixed structure and movably seals the orifice. A movable structure; a first electrode and a second electrode serving as energization electrodes; and a shape memory alloy wire held by the first electrode and the second electrode, the first electrode and the second electrode A small valve that moves the movable structure and seals the orifice by heating the wire and deforming the shape memory alloy, the movable structure including the seal Is configured such that its length is elastically deformable, and the stress load during heating of the shape memory alloy is reduced by elastic deformation of the movable structure.

  According to a second aspect of the present invention, in the small valve according to the first aspect, a part or all of the movable structure is made of an elastic material.

  According to a third aspect of the present invention, in the small valve according to the first aspect, the movable structure includes a spring body.

  According to a fourth aspect of the present invention, in the small valve according to the third aspect, the spring body is disposed so as to circumscribe the fixed structure.

  The invention according to claim 5 is the small valve according to any one of claims 1 to 4, wherein one end of the second electrode is connected to the fixed structure and the other end is connected to a wire. The movable structure is moved between the two ends by contacting the movable structure and bending the electrode.

  The invention according to claim 6 is the small valve according to any one of claims 1 to 5, wherein the first electrode is a fixed electrode fixed to the fixed structure, and the second electrode is the The movable electrode is connected to the movable structure.

  The invention according to claim 7 is the small valve according to any one of claims 1 to 4, wherein the first electrode is a fixed electrode fixed to a predetermined portion of the fixed structure, and the second electrode Is a fixed electrode fixed to a part different from the predetermined part of the fixed structure, pressing the end of the movable structure at the center of the wire, and the expansion and contraction direction of the wire is the movable structure It is orthogonal to the direction of body movement.

  The invention according to claim 8 is the small valve according to claim 7, wherein the end portion has a contact portion that contacts the movable structure and the wire, and the contact portion is made of a metal coated with a resin. It is what has been.

  The invention according to claim 9 is the small valve according to claim 7 or 8, wherein the first electrode and the second electrode are coated with a resin.

  According to the first aspect of the invention, the overload on the shape memory alloy when the valve is closed during heating can be reduced by the cushioning effect due to the elastic deformation of the movable structure. As a result, overloading due to excessive pressurization of the shape memory alloy wire can be prevented, so the durability of the shape memory alloy can be maintained without impairing the reproducibility of the shape memory of the shape memory alloy, and the reliability of the small valve can be improved. Can be increased.

  According to invention of Claim 2, a movable structure and an overload reduction elastic body can be made into one, and a number of parts can be reduced.

  According to the invention of claim 3, since the elastic function of the movable structure can be formed as an elastic part with a spring having a clear elastic specification, the design of the elastic function of the movable structure can be made with high accuracy.

  According to the invention of claim 4, since the spring body comes out of the fixed structure, the wire of the shape memory alloy between the first electrode and the second electrode can be connected without passing through the spring body. Can be easily.

  According to the invention of claim 5, since one end of the movable electrode is fixed, the connection between the lead wire for energization and the movable electrode can be strengthened, and the reliability of the connection can be improved.

  According to the sixth aspect of the present invention, one end of the wire of the shape memory alloy can be reliably fixed at the fixed position, and the movable structure can be pulled at the other end, so that the contraction variation of the shape memory alloy during energization is ensured. It can be transmitted to the movable structure. Thereby, the structure (normal open structure) which closes a valve | bulb at the time of electricity supply, and opens a valve | bulb at the time of non-energization can be comprised simply.

  According to the invention of claim 7, a large stroke of fluctuation of the movable structure can be obtained by a slight contraction of the wire of the shape memory alloy. For this reason, the length of the wire of shape memory alloy can be shortened with respect to the required stroke of the movable structure. In addition, since the electrode to which both ends of the wire are connected is fixed without being moved, the connection reliability between the lead wire for energization connected to the electrode and the electrode can be improved.

  According to the eighth aspect of the present invention, the heat conduction to the heat contact portion of the wire generated by energization is reduced, and heat dissipation from the wire to the fixed structure can be suppressed. Efficiency can be improved and the movable response speed of the movable structure can be increased. In addition, the strength of the contact portion can be secured by using the metal member, and the price of the contact portion can be reduced.

  According to the ninth aspect of the present invention, since heat dissipation from the wire to the fixed structure can be further suppressed, the movable response speed of the movable structure by energization can be further increased.

  Hereinafter, a small valve according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2A, 2B, and 2C. In these drawings, a small valve 10 is formed of a metal or resin cylindrical guide pipe 1 (fixed structure), a metal or resin orifice 2 built in the guide pipe 1, and a guide pipe 1. A movable valve body 3 (movable structure) having a first movable portion 4 and a second movable portion 6 that are inscribed, and movably sealing the orifice 2, and a part of the first movable portion 4 that is inscribed in the guide pipe 1. A bias coil 8 (bias elastic body) of a bias spring provided between the movable valve body 3 and the orifice 2 and a guide provided between the first movable part 4 and the second movable part 6. A fixed electrode 11 (first electrode) fixed to the pipe 1, a movable electrode 12 (second electrode) installed at a terminal on the second movable portion 6 side of the movable valve body 3, a fixed electrode 11 and a movable electrode 12 Shape memory alloy (or shape memory resin, And a wire 9 of Jo storage rubber). As the shape memory alloy here, an energization heat generation type (for example, a Ti—Ni-based shape memory alloy) that contracts at a certain temperature or higher is used.

  The movable valve body 3 has a sealing part 5 (sealing body) made of resin or rubber that seals the orifice 2 at the tip of the first movable part 4 on the orifice 2 side. A coil spring 7 (overload reducing elastic body) that reduces the stress load on the shape memory alloy of the wire 9 during heating is provided between the movable parts 6. The shape memory alloy uses a specification that shrinks when the temperature exceeds a certain temperature, so when a DC voltage is applied and energized, it self-heats and the temperature rises. Recover shape. This shape recovery force is significantly larger than the elastic force of the bias coil 8 and the coil spring 7. The elastic coefficient k2 of the coil spring 7 is set smaller than the elastic coefficient k1 of the bias coil 8, as will be described later.

  The first movable part 4 includes a first cylindrical part 41 that is inscribed in the guide pipe 1 and a second cylindrical part 42 that has an outer shape smaller than the first cylindrical part 41 that extends from the first cylindrical part 41 toward the orifice 2. . The second cylindrical portion 42 has a sealing portion 5 made of resin or rubber for sealing the orifice 2 at the tip thereof. The side surface on the orifice 2 side of the first cylindrical portion 41 is pressed in the direction opposite to the orifice 2 by the bias coil 8, and the first movable portion 4 is separated from the orifice 2. Thereby, as shown to Fig.2 (a), in the state without normal electricity supply, a space | interval is opened between the orifice 2 and the sealing part 5 so that the sealing part 5 does not close the orifice 2 ( Normally open type: normally open).

  In the above configuration, the wire 9 is heated by energizing the fixed electrode 11 and the movable electrode 12, and when the temperature exceeds a certain temperature, the shape memory alloy wire 9 contracts and deforms. At this time, one end of the wire 9 is connected to the fixed electrode 11 fixed to the guide pipe 1 and does not move, and the other end of the wire 9 is connected to the movable electrode 12 of the second movable part 6, and the second movable part Move with 6. Accordingly, the second movable portion 6 moves due to the contraction of the wire 9, and this movement presses the coil spring 7, and the coil spring 7 presses and moves the first movable portion 4 toward the orifice 2, and the bias coil 8 is moved to the orifice. Press on the 2 side. Then, the sealing portion 5 at the tip of the first movable portion 4 stops in a state where the orifice 2 is pressure-sealed. Thereby, as shown in FIG.2 (b), the orifice 2 is closed.

  On the other hand, when the energization between the fixed electrode 11 and the movable electrode 12 is stopped, the temperature of the shape memory alloy wire 9 decreases, and when it returns to the original temperature, the wire 9 expands. As shown to a), the 1st movable part 4 returns to an original position, the sealing part 5 leaves | separates from the orifice 2, and the orifice 2 is open | released.

  In the above configuration, after the orifice 2 is contacted and sealed by the sealing portion 5, the wire 9 further contracts and the sealing portion 5 presses the orifice 2 in order to seal stronger. Since this pressure contact changes somewhat due to the component variation of the wire 9, the contraction of the wire 9 including the component variation is set large in advance. When the sealing portion 5 is brought into pressure contact with the orifice 2, the bias coil 8 is pressed between the end surface of the guide pipe 1 on the orifice 2 side and the first movable portion 4, and cannot be further contracted. At this time, instead of the bias coil 8, the coil spring 7 having a small elastic coefficient k2 starts to contract.

This will be described below. When the contraction force of the wire 9 is F, the contraction length of the spring is x, the elastic coefficient is k, and the length without external pressure is L, the length L of the contracted spring is
L = −x + L ₀ (L ₀ is the length before contraction)
It is represented by When the bias coil 8 and the coil spring 7 have lengths L1 and L2 after contraction, the lengths before contraction are La and Lb, and the elastic coefficients of the springs are k1 and k2, respectively.
From the relationship F = −kx,
L1 = −x + La = −F / k1 + La
L2 = −x + Lb = −F / k2 + Lb
It becomes. The relationship between the L1, L2 and the contraction force F is shown in FIG. Here, the elastic coefficient k1 of the bias coil 8 is larger than the elastic coefficient k2 of the coil spring 7. As a result, the bias coil 8 contracts before the coil spring 7, and the coil spring 7 hardly contracts until the contraction force Fr until the sealing portion 5 contacts the orifice 2, and further contracts to the orifice 2 after the contact. When force F is applied, it starts to contract.

  The contraction of the coil spring 7 plays a role of a cushioning effect that alleviates the overload directly applied to the wire 9, and the excessive load on the wire 9 can be reduced. For this reason, since the overload to the shape memory alloy can be avoided, it is possible to prevent the memory shape set at the time of high temperature of the wire 9 from being deformed, and the shape memory alloy always has the original memorized shape. Since the deterioration of the wire 9 over time can be eliminated, the reproducibility of the shape memory due to the temperature change can be improved. Further, the reproducibility of the opening / closing valve of the orifice 2 by energization of the wire 9 can be accurately performed.

  In this manner, the bias coil 8 provided between the orifice 2 and the movable valve body 3 and the overload reducing coil spring 7 provided in the movable valve body 3 are arranged in series, and the bias coil 8 By making the elastic coefficient k1 larger than the elastic coefficient k2 of the coil spring 7, the movable valve body 3 can be elastically deformed when the small valve 10 is closed. Thereby, the overload on the shape memory alloy itself due to the contraction stress of the wire 9 at the time of valve closing can be reduced, the deterioration of the reproducibility of the memory shape of this shape memory alloy with time is prevented, and the durability is improved. The reliability of the small valve 10 can be improved.

  Next, a small valve according to a second embodiment of the present invention will be described with reference to FIGS. 3 (a), (b), and (c). The small valve 10 of the present embodiment is different from the above embodiment in that an elastic material is used for a part or all of the movable valve body 3.

  The small valve 10 is movable while inscribed in the guide pipe 1 and a cylindrical guide pipe 1 (fixed structure) made of metal or resin, a metal or resin orifice 2 built in the guide pipe 1, and the guide pipe 1. A movable valve body 3a for sealing the orifice 2 at the same time, a biasing coil spring 8 (bias elastic body) circumscribing the movable valve body 3a in the guide pipe 1, and a fixed electrode 11 (first electrode) fixed to the guide pipe 1 Electrode), a movable electrode 12 (second electrode) installed at the end of the movable valve body 3a opposite to the orifice 2, and a shape memory alloy wire 9 held by the fixed electrode 11 and the movable electrode 12; Is provided. As this shape memory alloy, an energization heat generation type similar to that described above, which shrinks at a certain temperature or higher is used. The movable valve body 3 a includes a resin or rubber sealing portion 5 that seals the movable portion 4 a and the orifice 2.

  The movable portion 4a is made of an elastic material such as a resin material or a rubber material, and has a cylindrical portion 44 inscribed in the guide pipe 1 at the center thereof, and a main cylinder having a smaller diameter than the cylindrical portion 44 extending from the cylindrical portion 44 to both sides. A portion 43 and a column portion 45 extending from one end of the main cylindrical portion 43 toward the orifice 2. The guide pipe 1 has a cylindrical main cavity 1 a inscribed in the cylindrical portion 44 at the center of the movable valve body 3 a and a smaller diameter than the main cavity 1 a extending from the main cavity 1 a toward the orifice 2 and connected to the orifice 2. It has a cylindrical small cavity 1b. The main cylindrical portion 43 of the movable portion 4a is inscribed in the small cavity 1b, and has a sealing portion 5 for sealing the orifice 2 at the tip of the cylindrical portion 45 at one end thereof. The bias coil 8 is provided so as to circumscribe the main cylindrical portion 43 between the end portion of the main cavity 1a in the guide pipe 1 on the small cavity 1b side and the cylindrical portion 44 of the movable portion 4a. The side surface on the orifice 2 side of the cylindrical portion 44 receives the biasing pressure from the bias coil 8 and presses the entire movable valve body 3 a to the opposite side of the orifice 2. Thereby, normally, as shown to Fig.3 (a), it sets so that the space | interval may be left between the orifice 2 and the sealing part 5 so that the sealing part 5 may not close the orifice 2. FIG. Moreover, since the movable part 4a is formed with the elastic body material, it contracts by itself by press, and the movable valve body 3a will show elasticity as a whole.

  In the above configuration, when the fixed electrode 11 and the movable electrode 12 are energized to heat the wire 9, the wire 9 of the heat generation type shape memory alloy is deformed due to the temperature rise, and the length of the wire 9 is contracted. At this time, the fixed electrode 11 to which one of the wires 9 is connected does not move because it is fixed to the guide pipe 1, but the movable electrode 12 to which the other of the wires 9 is connected is connected to the movable portion 4a. Therefore, it moves with this movable part 4a. Therefore, the movable portion 4a compresses the bias coil 8 due to the contraction of the wire 9, and the sealing portion 5 at the tip of the movable portion 4a stops in a state where the orifice 2 is in contact with and sealed. Thereby, as shown in FIG.3 (b), the orifice 2 is closed.

  On the other hand, when the energization between the fixed electrode 11 and the movable electrode 12 is stopped, the temperature of the shape memory alloy wire 9 decreases, and when it returns to the original temperature, the wire 9 expands. As shown to a), the movable part 4a of an elastic body returns to the original position, the sealing part 5 leaves | separates from the orifice 2, and the orifice 2 is open | released.

  Similarly to the above, the elastic coefficient k1 of the bias coil 8 is made larger than the elastic coefficient k3 of the elastic body of the movable part 4a. As a result, the bias coil 8 contracts before the movable portion 4a of the elastic body, and the movable portion 4a of the elastic body hardly contracts by the contraction force until the sealing portion 5 contacts the orifice 2, and after the contact When the contraction force is further applied to the orifice 2, the contraction starts.

  Then, after the orifice 2 is brought into contact with the sealing portion 5 and pressed, the wire 9 further contracts and the sealing portion 5 presses the orifice 2 in order to tightly seal the bias coil 8. Since the part 5 and the orifice 2 are already in contact with each other, it cannot be further contracted. At this time, the movable part 4a, which is an elastic body, starts to contract under the contraction pressure of the wire 9, and bends like an arcuate shape to seal the orifice 2 as shown in FIG. By this deformation, it is possible to reduce overload on the wire 9 itself from the orifice 2 due to excessive pressure on the orifice 2 due to contraction of the wire 9.

  As described above, the movable portion 4a is made of an elastic material, so that the movable portion 4a itself can be contracted with respect to an excessive load, and the movable portion 4a reduces the direct overload on the wire 9. It plays the role of a cushioning effect, and an excessive load on the wire 9 can be reduced. Therefore, by integrating the overload reducing elastic body of the movable portion 4a so that the movable valve body 3a also has an overload reducing action, the reliability of the small valve 10 can be improved and the number of parts of the small valve can be reduced. it can. Here, the entire movable valve body 3a is formed of an elastic material, but the same effect can be obtained even if a part of the movable valve body 3a is formed of an elastic material.

  Next, a small valve according to a third embodiment of the present invention will be described with reference to FIGS. 4 (a), (b), and (c). The small valve 10 of this embodiment is basically the same as that of FIG. 3 of the above embodiment, and differs from the above embodiment in that the sealing portion 5 of the movable valve body 3b is formed using an elastic material.

  4A, a small valve 10 includes a metal or resin cylindrical guide pipe 1 (fixed structure), a metal or resin orifice 2 built in the guide pipe 1, and a guide pipe. 1, a movable valve body 3 b that is in contact with the movable body 3 so as to be movably sealed, a bias coil 8 (bias elastic body) for circumscribing the movable valve body 3 b, and a fixed electrode fixed to the guide pipe 1. 11 (first electrode), a shape memory alloy held by the movable electrode 12 (second electrode) installed at the end opposite to the orifice 2 of the movable valve body 3b, the fixed electrode 11 and the movable electrode 12 The wire 9 is provided. The movable valve body 3b includes a movable portion 4b made of a metal or a resin member, and a sealing portion 5 for sealing the orifice 2 at the tip thereof. The sealing portion 5 is an elastic body made of resin or rubber and having elasticity. It is formed.

  By providing the sealing portion 5 formed of this elastic body, the movable valve body 3b becomes an elastic body showing elasticity as a whole. Therefore, if the elastic coefficient of the entire movable valve body 3b is k3, as described above, the bias coil 8 contracts until the wire 9 contracts when the sealing portion 5 contacts the orifice 2 as described above. When it contracts further, the elastic body of the sealing portion 5 starts to contract.

  That is, the movable valve body 3b is moved to the orifice 2 side by receiving the contraction pressure of the wire 9 by energization, and the sealing portion 5 contacts the orifice 2 as shown in FIG. When is contracted, the sealing portion 5 is compressed and thinned as shown in FIG. Due to the deformation of the sealing portion 5, excessive contraction force of the wire 9 is absorbed. That is, the pressure contact of the sealing portion 5 to the orifice 2 due to excessive contraction of the wire 9 generates a repulsive force from the orifice 2 to the wire 9, and an overload on the wire 9 itself due to the repulsive force is caused by the sealing portion 5. It is reduced by deformation.

  On the other hand, when the energization between the fixed electrode 11 and the movable electrode 12 is stopped, the temperature of the shape memory alloy wire 9 decreases, and when the temperature returns to the original temperature, the wire 9 expands. As shown to a), the movable part 4a returns to the original position, the sealing part 5 leaves | separates from the orifice 2, and the orifice 2 is open | released.

  Thus, since the sealing part 5 itself is formed of an elastic material, the sealing part 5 itself contracts against an excessive load, so that the movable valve pair 3b overloads the wire 9. It can play a role of a cushion effect to alleviate the above, and an excessive load on the wire 9 can be reduced. Thus, by forming the sealing portion 5 itself from an elastic material, the movable valve body 3b can be easily formed as an elastic body having an overload reducing action, and the number of parts of the small valve can be reduced. .

  Next, a small valve according to a fourth embodiment of the present invention will be described with reference to FIGS. 5 (a), 5 (b), and 5 (c). The small valve 10 of this embodiment is basically the same as that of the above embodiment, and is different from the above embodiment in that the movable valve body 3c (movable structure) is provided with a spring body.

  In FIG. 5A, a small valve 10 includes a metal or resin cylindrical guide pipe 1 (fixed structure), a metal or resin orifice 2 built in the guide pipe 1, and a guide pipe. A metal or resin movable valve body 3c that is in contact with 1 and movably seals the orifice 2, and a bias bias that is inscribed in the guide pipe 1 and provided between the orifice 2 and the movable valve body 3c. A coil 8 (bias elastic body), a fixed electrode 11 (first electrode) fixed to the guide pipe 1, and a movable electrode 12 (second electrode) installed at the end of the movable valve body 3c opposite to the orifice 2 And a wire 9 of an electrically heated shape memory alloy held by the fixed electrode 11 and the movable electrode 12.

  The movable valve body 3c holds a cylindrical movable portion 4c having a cylindrical cylindrical portion 45 at the tip thereof, a sealing portion 5 for sealing the orifice 2 joined to the tip of the cylindrical portion 45, and the movable electrode 12. And a small coil spring 7a (spring body) for reducing overload sandwiched between the electrode holding plate 13 and the end of the movable portion 4c. By having this coil spring 7a, the movable valve body 3c can have elastic characteristics.

  In the above configuration, the wire 9 is heated by energizing the fixed electrode 11 and the movable electrode 12, and when the temperature exceeds a certain temperature, the shape memory alloy wire 9 is deformed and the length of the wire 9 is contracted. At this time, the fixed electrode 11 to which one of the wires 9 is connected is fixed to the guide pipe 1 and does not move, and the movable electrode 12 to which the other of the wires 9 is connected is connected to the movable portion 4c. It moves with the movable part 4c. Due to the contraction of the wire 9, the movable portion 4 c presses the bias coil 8, presses and moves the bias coil 8 toward the orifice 2, and presses the bias coil 8 toward the orifice 2. As a result, the sealing part 5 at the tip of the movable part 4c seals the orifice 2 in pressure contact, and the orifice 2 is closed. At this time, similarly to the above, the elastic coefficient k1 of the bias coil 8 is set larger than the elastic coefficient k2 of the coil spring 7a, so that the coil spring 7a contracts before the coil spring 7a. It hardly shrinks until it touches.

  On the other hand, when the energization between the fixed electrode 11 and the movable electrode 12 is stopped, the temperature of the shape memory alloy wire 9 decreases, and when returning to the original temperature, the wire 9 expands. Returns to the original position, the sealing portion 5 is separated from the orifice 2, and the orifice 2 is opened.

  After the orifice 2 is brought into contact with the sealing portion 5 and sealed, the wire 9 further contracts and the sealing portion 5 presses against the orifice 2 in order to make a stronger seal. It is pressed between the end surface of the pipe 1 on the orifice 2 side and the movable portion 4c so that it cannot be further contracted. At this time, instead of the bias coil 8, the coil spring 7a starts to contract.

  As described above, the small valve 10 according to the present embodiment is provided with a small coil spring 7a on the movable valve body 3c, so that the movable valve body 3c is formed as an elastic body having a small and simple configuration whose total length varies due to pressurization. can do. And the movable valve body 3c plays the role of the cushion effect which relieve | moderates overloading to the wire 9 by contraction of the coil spring 7a at the time of an overload, and can act as an overload reduction elastic body. In the small valve 10 here, the over-load reducing elastic coil spring 7a and the bias bias coil 8 are configured by using a spring body with a clear elastic coefficient, thereby easily designing the valve valve with high accuracy. can do. Further, similarly to the above, since overload to the shape memory alloy can be avoided, deterioration of the reproducibility of the shape change with respect to the temperature change of the shape memory alloy is prevented, and the durability of the wire 9 is improved. The orifice 2 can be opened and closed accurately by energization.

  Next, FIG. 5B shows a modification of the fourth embodiment in which the movable valve body 3d (movable structure) includes a spring body. The small valve 10 of this modification is basically the same as that of the above embodiment, and the movable valve body 3d (movable structure) includes a coil spring 7b (spring body) on the side wall of the central portion of the movable body 4d. This is different from the above embodiment.

  In FIG. 5 (b), the movable valve body 3d includes a movable portion 4d in which a coil spring 7b is incorporated in a part of the central side wall. Similarly to the above, since the elastic coefficient k2 of the coil spring 7b is set smaller than the elastic coefficient k1 of the bias coil 8, the bias coil 8 first contracts, and the coil spring 7b has the sealing portion 5 in contact with the orifice 2. Almost no shrinkage until

  With the above configuration, the movable valve body 3d can operate as an elastic body whose total length varies due to pressurization because the movable portion 4d has elasticity. And since the coil spring 7b is integrated and incorporated in the movable part 4d, the small and compact movable valve body 3d can be formed, and the whole valve can be miniaturized. In the same manner as described above, the movable valve body 3d plays a role of a cushioning effect that alleviates the overloading of the wire 9, and can reduce an excessive load on the wire 9.

  Next, FIG. 5C shows another modification of the fourth embodiment in which the movable valve body 3e (movable structure) includes a spring body. The small valve 10 of this modification is basically the same as that of the above embodiment, and the movable valve body 3e (movable structure) is a coil spring between the cylindrical portion 45 and the sealing portion 5 of the movable portion 4c. (Spring body) It differs from the said embodiment by the point provided with 7a.

  In FIG. 5 (c), the movable portion 4 c of the movable valve body 3 e includes a cylindrical movable portion 4 c having a cylindrical cylindrical portion 45 at the tip thereof, and a seal that is joined to the tip of the cylindrical portion 45 and seals the orifice 2. A stop portion 5 and an overload reducing coil spring 7a provided between the sealing portion 5 and the cylindrical portion 45 of the movable portion 4c are provided. Thus, the movable valve body 3e can be compactly formed by integrating the coil spring 7a on the sealing portion 5 side of the movable portion 4c. Moreover, the overload from the orifice 2 at the time of valve closing can be directly received by the coil spring 7a via the sealing part 5 before the movable part 4c. Therefore, even when the movable portion 4c is made of resin or the like and the pressure transmission response is slow with respect to the overload, the overload reduction action can be quickly operated by the coil spring 7a regardless of the expansion / contraction response of the movable portion 4c. The load reduction response can be accelerated. As a result, similarly to the above, the movable valve body 3e can play a role of a cushioning effect for reducing the direct overload on the wire 9, and can speed up the response of the overload reduction to the wire 9.

  Next, a small valve according to a fifth embodiment of the present invention will be described with reference to FIGS. 6 (a), (b), and (c). The small valve 10 of this embodiment is basically the same as that of the above embodiment, and the coil spring 7 constituting the movable valve body 3f and the bias coil 8 having a bias function are circumscribed on the guide pipe 1 (fixed structure). It differs from the said embodiment by the point arrange | positioned.

  In FIG. 6A, a small valve 10 is movable in a cylindrical guide pipe 1 (fixed structure) made of metal or resin, a metal or resin orifice 2 built in the guide pipe 1, and freely movable. A movable valve body 3f (movable structure) for sealing the orifice 2 at the same time, a bias coil 8 (bias elastic body) circumscribing the guide pipe 1 and serving as a bias spring for the movable valve body 3f, and the guide pipe 1 are fixed. The shape memory alloy (or shape memory) held by the fixed electrode 11 (first electrode), the movable electrode 12 (second electrode) installed at the end of the movable valve body 3f, and the fixed electrode 11 and the movable electrode 12 Resin, shape memory rubber, etc.) wire 9. The shape memory alloy used here is an energization heat generation type that shrinks when the temperature rises above a certain temperature.

  The guide pipe 1 includes a cylindrical main cavity 1 a having a large inner diameter, a small cylindrical cavity 1 b extending from the main cavity 1 a toward the orifice 2 and including the orifice 2, and a bias coil circumscribing the guide pipe 1. 8 is provided with a bowl-shaped circular projection 1c serving as a stopper. The movable valve body 3f is provided at the first movable portion 4e inscribed in the small cavity 1b of the guide pipe 1, the second movable portion 6a circumscribed in the guide pipe 1, and the tip of the first movable portion 4e on the orifice 2 side. A sealing part 5 (sealing body) made of resin or rubber for sealing the orifice 2 and a coil spring 7 (excessively provided around the guide pipe 1 and between the first movable part 4e and the second movable part 6a). Load-reducing elastic body).

  The first movable portion 4e is made of a metal or a resin material, and has a main cylindrical portion 43 that is inscribed in the small cavity 1b of the guide pipe 1, a small-diameter columnar portion 45 that extends from the main cylindrical portion 43 toward the orifice 2, and a main cylinder. A protrusion 46 is provided that protrudes outward from the end of the portion 43 on the side of the movable portion 6a perpendicularly to the guide pipe 1. A bias coil 8 that circumscribes the guide pipe 1 is disposed between the protrusion 46 and the circular protrusion 1 c of the guide pipe 1.

  The second movable portion 6a is made of a metal or a resin material, the inner surface of the second movable portion 6a circumscribes the guide pipe 1 to seal the end of the guide pipe 1, and the outer end surface has a movable electrode for energizing the wire 9 12 is provided. A coil spring 7 (overload reducing elasticity) that circumscribes the guide pipe 1 and reduces the stress load on the shape memory alloy of the wire 9 during heating is provided between the circumscribed side wall thickness of the second movable portion 6a and the protruding portion 46. Body) is disposed. Further, the elastic coefficient k2 of the coil spring 7 is set smaller than the elastic coefficient k1 of the bias coil 8 as described above.

  In the above configuration, when the wire 9 is heated by energizing the fixed electrode 11 and the movable electrode 12, the shape memory alloy wire 9 contracts, and the second movable portion 6a is pulled toward the orifice 2, the second movable portion 6a. The coil spring 7 in contact with is pressed. This pressing force is transmitted to the first movable part 4e via the coil spring 7 without contracting the coil spring 7 having a small elastic coefficient (k2), and the bias coil having a large elastic coefficient (k1) by the pressing of the first moving part 4e. Shrink 8 Then, as shown in FIG. 6B, the sealing portion 5 at the tip of the first movable portion 4e stops in a state where the orifice 2 is sealed.

  After the orifice 2 is contacted by the sealing portion 5 and closed, the wire 9 is further contracted to seal tightly, and when the sealing portion 5 further compresses the orifice 2, the sealing portion 5 and the orifice 2 are sealed. Are already in contact with each other, the bias coil 8 having a large elastic coefficient does not contract any more. Accordingly, the repulsive force from the orifice 2 is applied to the wire 9 as an overload, but here, the coil spring 7 between the first movable portion 4e and the second movable portion 6a starts to contract, thereby overloading the wire 9 Is reduced.

  On the other hand, when the energization between the fixed electrode 11 and the movable electrode 12 is stopped, the temperature of the wire 9 of the shape memory alloy decreases, returns to the original temperature, and the wire 9 expands. ), The entire movable valve body 3f including the first movable portion 4e is returned to the original position, the sealing portion 5 is separated from the orifice 2, and the orifice 2 is opened.

  Thus, by providing the coil spring 7 and the bias coil 8 so as to circumscribe the guide pipe 1, these spring portions are disposed within the entire length of the movable valve body 3f, so that the entire small valve 10 is provided. Can be further reduced in size. Further, since the shape memory alloy wire 9 can be configured without passing through the spring portion, the manufacture of the valve 10 is facilitated. Further, since the movable valve body 3f can have elasticity as a whole, as described above, the movable valve body 3f serves as a cushioning effect to alleviate the overloading of the wire 9, and exerts an excessive load on the shape memory alloy. The durability of the small valve 10 can be increased.

  Next, a small valve according to a sixth embodiment of the present invention will be described with reference to FIGS. 7 (a) and 7 (b). The small valve 10 of this embodiment is basically the same as that of the above embodiment, and one end of the movable electrode 12 (second electrode) is connected to the guide pipe 1 and the movable electrode 12 is contracted by the contraction of the wire 9. It differs from the said embodiment by the point which moves 3 g of movable valve bodies by bending.

  In FIG. 7A, a small valve 10 includes a cylindrical guide pipe 1 (fixed structure) made of metal or resin, a metal or resin orifice 2 built in the guide pipe 1, and a guide pipe. 1, a movable valve body 3 g that is slidably sealed in contact with 1, a bias bias coil 8 (bias elastic body) that circumscribes a part of the movable valve body 3 g in the guide pipe 1, and a guide pipe A fixed electrode 11 (first electrode) fixed to the outside of 1, a movable electrode 12 having one end fixed to the outside of the guide pipe 1, and a shape memory alloy held by the fixed electrode 11 and the movable electrode 12 (or Wire 9 of shape memory resin, shape memory rubber, etc.). As the shape memory alloy here, an energization heat generation type (for example, a Ti—Ni-based shape memory alloy) that contracts at a certain temperature or higher is used. The fixed electrode 11 and the movable electrode 12 are connected to a lead wire 15b for energization and a lead wire 15a, respectively.

  The guide pipe 1 has a cylindrical main cavity 1a having a large inner diameter, in which the movable valve body 3g is inscribed, and a cylindrical small cavity 1b having a small inner diameter extending from the main cavity 1a to the orifice 2 side. The movable valve body 3g includes a first movable portion 4f inscribed in the guide pipe 1, a second movable portion 6b inscribed in the guide pipe 1 and pressed against the movable electrode 12, and the orifice 2 side of the first movable portion 4f. A resin or rubber sealing portion (sealing body) 5 for sealing the orifice 2 and a coil spring 7 (overload reducing elastic body) for imparting elasticity to the movable valve body 3g are provided.

  The first movable portion 4f is made of a metal or a resin material, a main cylindrical portion 48 that is inscribed in the small cavity 1b of the guide pipe 1, a small-diameter cylindrical portion 45 that extends from the main cylindrical portion 48 toward the orifice 2, and a main cylinder. A second cylindrical portion 48 that is inscribed in the guide pipe 1 at the end of the portion 48 is provided. A bias coil 8 circumscribing the main cylindrical portion 48 is disposed between the side surface on the orifice 2 side of the second cylindrical portion 48 and the end portion on the orifice 2 side of the main cavity 1 a of the guide pipe 1.

  The second movable part 6 b is made of a metal or a resin material, and has a protrusion 61 that is inscribed in the guide pipe 1 and in contact with the movable electrode 12. The movable electrode 12 has a fixed end 14 a fixed to the guide pipe 1 and a movable end 14 b connected to the other end of the wire 9 having one end joined to the fixed electrode 11, and the movable end 14 b is a contraction of the wire 9. To move. The fixed end 14a and the movable end 14b are disposed in a substantially circular symmetrical position on the outer side surface near the end surface of the guide pipe 1 in which the second movable portion 6b is inserted. The movable electrode 12 between the fixed end 14a and the movable end 14b is pulled by the wire 9 to bend, and is bent and arranged in an arc shape so as to cover and hold the protrusion 61. Between the first movable part 4f and the second movable part 6b, a coil spring 7 (overload reducing elastic body) for reducing the stress load on the shape memory alloy of the wire 9 during heating is disposed. The coefficient k2 is set smaller than the elastic coefficient k1 of the bias coil 8 as described above.

  In the above configuration, when the fixed electrode 11 and the movable electrode 12 are energized by the lead wires 15a and 15b for energization, the movable electrode 12 is pulled toward the fixed electrode 11 due to the contraction of the wire 9 accompanying heating, The projection 61 of the second movable part 6 b is pressed near the center of the movable electrode 12. By this pressing, the second movable portion 6b is moved to the orifice side, and the coil spring 7 and the first movable portion 4f that are in pressure contact with the second movable portion 6b are moved, as shown in FIG. 7B. In addition, the orifice 2 is sealed in the sealing portion 5. Similarly to the above, the bias coil 8 is contracted until the sealing portion 5 comes into contact with the orifice 2, and almost stops when the sealing portion 5 at the tip of the first movable portion 4 f seals the orifice 2. .

  After the orifice 2 is contacted by the sealing portion 5 and closed, the wire 9 is further contracted to seal tightly, and when the sealing portion 5 further compresses the orifice 2, the sealing portion 5 and the orifice 2 are sealed. Are already in contact with each other, the bias coil 8 having a large elastic coefficient does not contract any more. Accordingly, the repulsive force from the orifice 2 is applied to the wire 9 as an overload. At this time, the coil spring 7 between the first movable portion 4f and the second movable portion 6a starts to contract, thereby reducing the overload on the wire 9.

  Thus, the movable valve body 3f becomes the movable valve body 3f having elasticity by providing the coil spring 7 between the first movable portion 4f and the second movable portion 6b, and can reduce overload. . Since the movable electrode 12 has the fixed end 14a, the strength of the joint portion between the lead wire 15a for energizing the movable electrode 12 and the movable electrode 12 can be improved, and the reliability of the small valve can be improved. .

  Next, a small valve according to a seventh embodiment of the present invention will be described with reference to FIGS. The small valve 10 of this embodiment is basically the same as that of the above embodiment, and includes a first fixed electrode 11a (first electrode) fixed to the guide pipe 1 (fixed structure), and the guide pipe 1 and the like. A second fixed electrode 12a (second electrode) fixed at the location of the wire 9, and a wire 9 is connected between the first fixed electrode 11a and the second fixed electrode 12a. Is different from the above-described embodiment in that the extending / contracting direction of the wire 9 is orthogonal to the moving direction of the movable valve body 3h.

  In FIG. 8A, a small valve 10 includes a metal or resin cylindrical guide pipe 1, a metal or resin orifice 2 built in the guide pipe 1, and an orifice 2 of the guide pipe 1. A hollow disc-shaped flange 1d provided perpendicularly to the guide pipe 1 at the open end on the opposite side, a movable valve body 3h that inscribes the guide pipe 1 and movably seals the orifice 2, and a guide pipe A bias coil 8 (bias elastic body) for biasing circumscribing a part of the movable valve body 3h in 1 and a first fixed electrode 11a arranged and fixed circularly symmetrically on the flange 1d of the guide pipe 1 (First electrode) and second fixed electrode 12a (second electrode), and wire of shape memory alloy (or shape memory resin, shape memory rubber, etc.) held by first fixed electrode 11a and second fixed electrode 12a 9 Equipped with a. The shape memory alloy used here is an energization heat generation type that shrinks when the temperature rises above a certain temperature. The wire 9 presses the end of the movable valve body 3h at its center.

  The movable valve body 3h includes a first movable portion 4g inscribed in the guide pipe 1, a second movable portion 6c inscribed in the guide pipe 1 and in contact with the wire 9 at the end thereof, and the orifice 2 side of the first movable portion 4g. Resin or rubber sealing portion (sealing body) 5 for sealing the orifice 2 provided at the tip, and the movable valve body 3h provided between the first movable portion 4g and the second movable portion 6c are elastic. A coil spring 7 (overload reducing elastic body) is provided.

  The first movable portion 4g is made of a metal or a resin material, and has a first cylindrical portion 41 inscribed in the guide pipe 1 and a first outer shape smaller than the first cylindrical portion 41 extending from the first cylindrical portion 41 toward the orifice 2. Two cylindrical portions 42 are provided. The second cylindrical part 42 has a sealing part 5 made of resin or rubber for sealing the orifice 2 at the tip thereof, and the cylindrical side surface is inscribed in the bias coil 8. The bias coil 8 is sandwiched between the side surface on the orifice 2 side of the first cylindrical portion 41 and the end surface on the orifice 2 side of the guide pipe 1, and the sealing portion 5 closes the orifice 2 when there is no energization. The 1st movable part 4g is pressed so that it may not. The elastic coefficient k2 of the coil spring 7 is set smaller than the elastic coefficient k1 of the bias coil 8 as described above.

  The second movable part 6c includes a first cylindrical part 62 inscribed in the guide pipe 1 and a second cylindrical part 63 having an outer shape smaller than the first cylindrical part 62 extending from the first cylindrical part 62 in the direction of the first movable part 4g. In addition, a cylindrical contact portion 64 is provided at the central portion of the first cylindrical portion 62 and is contacted and pressed at the central portion of the wire 9. The contact portion 64 is freely rotatable and is moved while being pressed in the axial direction of the guide pipe 1 by the expansion and contraction of the wire 9. As a result, the second movable portion 6 c is pressed along the direction of expansion and contraction of the wire 9 and moved along the guide pipe 1.

  In the above configuration, when the first fixed electrode 11a and the second fixed electrode 12a are energized, the wire 9 is heated and contracted. As a result, the contact portion 64 of the second movable portion 6c is pressed in the direction of the orifice 2, and the entire movable valve body 3h is moved in the direction of the orifice 2, so that the sealing portion 5 becomes the orifice as shown in FIG. The movement stops at the point of contact with 2. Here, when the wire 9 is further contracted and the orifice 2 is pressed by the sealing portion 5, the bias coil 8 having a large elastic coefficient is contracted first, and then a reverse load from the orifice 2 is applied to the movable valve body 3h. As a result, the wire 9 is overloaded. However, since the movable valve body 3h includes the coil spring 7 and has an elastic characteristic, the overload on the wire 9 can be reduced and the wire 9 can be protected as described above.

  In this way, by converting the force in the contraction direction of the wire 9 into the moving direction of the movable valve body 3h perpendicular to the wire 9, the movable valve body 3h can be moved with a slight contraction of the shape memory alloy wire 9 by the reverse lever principle. A stroke that greatly fluctuates can be obtained. For this reason, the length of the wire 9 of shape memory alloy can be shortened with respect to the required stroke of the movable valve body 3h. Further, since the electrodes to which both ends of the wire 9 are connected are the first fixed electrode 11a and the second fixed electrode 12a that are not movable, the energization lead wires 15a and 15b connected to these electrodes and the fixed electrodes 11a and 12a are connected. Connection reliability can be improved.

  Next, a small valve according to the eighth embodiment will be described with reference to FIG. The configuration of the small valve 10 of this embodiment is basically the same as that of the seventh embodiment, and the contact portion 64 that contacts the second movable portion 6c and the wire 9 at the end of the movable valve body 3h is provided. The difference is that the metal body 65 (metal) covered with the resin 66 is used. The first fixed electrode 11a and the second fixed electrode 12a are fixed to the flange 1d of the guide pipe 1 by resin adhesive or welding, and both ends of the wire 9 are fixed to the fixed electrodes 11a and 12a, respectively. ing.

  In FIG. 9, the contact portion 64 is formed of a columnar metal body 65 that is freely rotatable, and the surface thereof is covered with a resin 66 having low thermal conductivity. Further, it is desirable that the resin 66 has good heat resistance and wear resistance and is rich in lubricity. Specific examples include PTFE resin. The first cylindrical portion 62 of the second movable portion 6c, which is the end portion of the movable valve body 3h, has a groove 62a having a semicircular cross section that is substantially the same diameter as the radius of the contact portion 64 at the center thereof and the wire 9. They are arranged in a substantially orthogonal direction. Further, about half of the cylindrical side surface of the contact portion 64 is inscribed in the groove 62a, and the other half side surface is pressed in contact with the central portion of the wire 9. Due to the expansion and contraction of the wire 9, the contact portion 64 is pressed in the axial direction of the guide pipe 1, whereby the second movable portion 6 c is pressed perpendicularly to the expansion and contraction direction of the wire 9 and along the guide pipe 1. Moved.

  At this time, since the contact portion 64 moves while being in contact with both the second movable portion 6c and the wire 9, the heat generated by energization of the wire 9 is transferred from the wire 9 to the contact portion 64 and the second movable portion 6c. Then, heat is conducted to the guide pipe 1 via the coil spring 7 and is dissipated. However, this heat dissipation of the wire 9 is undesirable because it reduces the shrinkage efficiency of the shape memory alloy with respect to energization.

  In the contact portion 64 of the present embodiment, since the contact portion 64 is configured by coating the surface of the metal body 65 with the resin 66, a heat insulating effect by the resin coating can be obtained, whereby the heat contact portion 64 of the wire 9 is obtained. The heat conduction to the wire 9 can be reduced, and the heat dissipation of the heat generation of the wire 9 due to energization can be suppressed. Therefore, the contraction efficiency of the wire 9 with respect to energization is improved, the movable response speed of the movable valve body 3h can be increased, and the energization response of the small valve 10 to open and close can be improved. Further, the contact portion 64 receives a strong press due to the contraction of the wire 9 of the shape memory alloy, but the strength of the contact portion 64 can be hardened and strengthened by using the metal body 65 as its main body. Can be directly transmitted to the movable valve body 3h, and the transmission efficiency of the pressure is improved. Although the entire member for the contact portion 64 can be formed of a resin member, a resin member having good heat resistance and wear resistance and having high lubricity is expensive. Since the main body of the contact portion 64 is made of metal, the contact portion 64 can be manufactured at low cost.

  As described above, according to the small valve 10 of the present embodiment, the contact portion 64 is configured by the metal body 65 covered with the resin 66, thereby improving the heat shrinkage efficiency of the wire 9 with a simple configuration and being movable by energization. The movable response speed of the valve body 3h can be increased, and the contact portion 64 can be formed at a low cost.

  Next, a small valve according to the ninth embodiment will be described with reference to FIG. The configuration of the small valve 10 of this embodiment is basically the same as that of the seventh embodiment, and is different in that the surfaces of the first electrode 11a and the second electrode 12a are coated with the resins 11c and 12c.

  In FIG. 10, the first fixed electrode 11a and the second fixed electrode 12a are arranged and fixed in a circularly symmetrical manner on the flange 1d of the guide pipe 1, and the shape memory alloy wire 9 is formed by both the electrodes 11a and 12a. Holding. The first fixed electrode 11a and the second fixed electrode 12a cover a surface including a contact surface between the metal bodies 11b and 12b made of a rectangular parallelepiped and at least the flange 1d of the surfaces of the metal bodies 11b and 12b. It consists of resin 11c, 12c. Further, the first fixed electrode 11a and the second fixed electrode 12a coated with resin in this way are fixed to the flange 1d with a resin adhesive or the like.

  In this configuration, both ends of the wire 9 are fixed to the first fixed electrode 11a and the second fixed electrode 12a, and the first and second fixed electrodes 11a and 12a are fixed to the flange 1d of the guide pipe 1. Therefore, the heat generated by energization of the wire 9 is conducted from the wire 9 to the guide pipe 1 through the fixed electrodes 11a and 12a and is dissipated.

  However, in the contact part 64 of this embodiment, the heat between each fixed electrode 11a, 12a and the collar part 1d is obtained by the heat insulating effect of the resin by covering the surfaces of the first fixed electrode 11a and the second fixed electrode 12a with resin. The conduction can be reduced, and the heat of the wire 9 can be prevented from being dissipated from the guide pipe 1. Therefore, since the contraction efficiency of the wire 9 with respect to energization can be improved, the movable response speed of the movable valve body 3h can be increased, and the energization response for opening and closing the small valve 10 can be improved.

  Thus, according to the small valve 10 of the present embodiment, the first fixed electrode 11a and the second fixed electrode 12a are covered with the resins 11c and 12c, so that heat is radiated from the fixed electrodes 11a and 12a with a simple configuration. Since it can suppress, the contraction efficiency by electricity supply of the wire 9 can be improved, and the movable response speed of the movable valve body 3h by electricity supply can be raised. As a result, the energization response of the valve opening / closing of the small valve 10 can be improved.

  Next, a modification of the small valve according to the eighth embodiment will be described with reference to FIG. The configuration of the small valve 10 of this modification is basically the same as that of the eighth embodiment, and is held by the first fixed electrode 11a and the second fixed electrode 12a, and these fixed electrodes 11a and 12a. The difference is that a cover 16 covering the shape memory alloy wire 9 is provided on the flange 1d.

  The cover 16 is formed of a rectangular hollow housing using a resin member having low thermal conductivity. The cover 16 covers the first fixed electrode 11a, the second fixed electrode 12a, and the wire 9, and is substantially hermetically sealed on the flange 1d. It is attached to the collar 1d with a resin adhesive or the like. Thereby, the 1st fixed electrode 11a, the 2nd fixed electrode 12a, and the wire 9 are interrupted | blocked with external air. By this interruption, the heat of the wire 9 that has generated heat by energization and the heat of the first fixed electrode 11a and the second fixed electrode 12a heated by heat conduction from the wire 9 is suppressed from being diffused into the air. . Therefore, the heat dissipation of the heat generated by the wire 9 due to energization is suppressed, the contraction efficiency of the wire 9 against energization is improved, and the movable response speed of the movable valve body 3h can be further increased.

  Next, another modification of the small valve according to the eighth embodiment will be described with reference to FIGS. The configuration of the small valve 10 of this modification is basically the same as that of the eighth embodiment, and is arranged in a circularly symmetrical manner on the flange 1d of the guide pipe 1 and fixed by welding or a resin adhesive or the like. In the first fixed electrode 11a and the second fixed electrode 12a thus formed, a substantially inverted triangular deburring hole is formed inside the electrode from the surface of the wire outlets 11d and 12d through which the wire 9 connected to the fixed electrodes 11a and 12a is drawn. 11e and 12e are engraved to deburr the periphery of the opening.

  12A and 12B, the fixed electrodes 11a and 12a are formed of rectangular metal bodies 11b and 12b, and both ends of the wire 9 are fixed in the metal bodies 11b and 12b by welding or the like. Deburring holes 11e and 12d for drawing out the wire 9 from the metal bodies 11b and 12b of the fixed electrodes 11a and 12a have deburring holes 11e and 12e formed on their surfaces. By providing the deburring holes 11e and 12e, contact between the metal bodies 11b and 12b and the wire 9 at the outlets 11d and 12d can be reduced. Moreover, the metal bodies 11b and 12b are disposed with a flange surface and an inclination so that the outlets 11d and 12d are aligned with the direction in which the wire 9 is pulled out. Thereby, since the pulling direction of the wire 9 and the directions of the outlets 11d and 12d of the metal bodies 11b and 12b are substantially the same direction, the wire 9 can be further prevented from coming into contact with the metal bodies 11b and 12b.

  As described above, by providing the deburring holes 11e and 12e, contact friction between the wire 9 and the outlets 11b and 12b due to the position change of the wire 9 at the outlets 11d and 12d due to the contraction of the wire 9 is reduced. be able to. Thereby, the disconnection by the friction with the fixed electrodes 11a and 12a of the wire 9 can be prevented, and reliability can be improved.

  According to the above-described various embodiments and the small valves 10 according to the modified examples thereof, the movable valve having the sealing portion 5 that is inscribed in the guide pipe 1 and seals the orifice 2 in the guide pipe 1 that contains the orifice 2. A flexible movable valve body 3 is provided, a coil spring 7 for reducing overload is provided on the movable valve body 3, and the elastic coefficient k2 of the coil spring 7 is made smaller than the elastic coefficient k1 of the bias coil 8, whereby the shape memory alloy When the orifice 2 is closed due to the contraction of the wire 9, the overload from the orifice 2 due to the excessive contraction of the wire 9 can be absorbed by the elastic deformation of the coil spring 7 of the movable valve body 3. Due to the cushion effect of the movable valve body 3 as an overload reducing elastic body, it is possible to reduce the overload on the shape memory alloy in the valve closing at the time of energization heating. Therefore, deformation of the memory shape due to overload on the shape memory alloy when the valve is closed can be prevented, so that shape memory reproducibility of the shape memory alloy due to repeated overload is not deteriorated over time. The durability of the alloy can be improved and the reliability of the small valve can be increased.

  In addition, by forming a part or all of the movable valve body from an elastic material, the movable valve body can be integrally formed as an overload reducing elastic body, a coil spring is not required, and the number of parts is reduced. be able to. In addition, by forming the elastic body as a spring body using a bias coil or a coil spring, the specification of the elastic coefficient becomes clear and the accuracy of valve control design can be improved. Further, by disposing the spring body outside the guide pipe, the shape memory alloy wire can be connected without passing through the spring body, and the manufacture of the small valve can be facilitated.

  Furthermore, by pressing the end of the movable valve body at the center of the wire and making the contraction direction of the wire orthogonal to the moving direction of the movable valve body, the stroke of the large movable valve body with a slight contraction of the shape memory alloy wire Variations can be obtained. For this reason, the length of the wire of the shape memory alloy can be shortened with respect to the necessary stroke of the movable valve element. In addition, by covering the end portion and the fixed electrode with a resin, heat dissipation from the wire can be suppressed, and the energization response sensitivity of the valve opening / closing valve of the shape memory alloy can be increased.

Sectional drawing of the small valve | bulb which concerns on the 1st Embodiment of this invention. (A), (b) is sectional drawing at the time of valve opening of each of the said valve | bulb, and a valve closing time, respectively, (c) is a contraction characteristic figure of a coil spring and a bias coil. (A) is sectional drawing of the small valve | bulb which concerns on the 2nd Embodiment of this invention, (b), (c) is sectional drawing at the time of valve closing of the valve, and at the time of overload closing. (A) is sectional drawing of the small valve | bulb which concerns on the 3rd Embodiment of this invention, (b), (c) is sectional drawing at the time of valve closing of the valve, and at the time of overload closing. (A) is sectional drawing of the small valve | bulb which concerns on the 4th Embodiment of this invention, (b), (c) is sectional drawing which shows the modified example from which the valve respectively differs. (A) is sectional drawing of the small valve | bulb which concerns on the 5th Embodiment of this invention, (b) is sectional drawing at the time of valve closing of the valve. (A) is sectional drawing of the small valve | bulb which concerns on the 6th Embodiment of this invention, (b) is sectional drawing at the time of valve closing of the valve. (A) is sectional drawing of the small valve | bulb which concerns on the 7th Embodiment of this invention, (b) is sectional drawing at the time of valve closing of the valve. Sectional drawing of the small valve | bulb which concerns on the 8th Embodiment of this invention. Sectional drawing of the small valve | bulb which concerns on the 9th Embodiment of this invention. Sectional drawing of the small valve | bulb which concerns on the modification of the said 8th Embodiment. (A) is sectional drawing of the small valve | bulb which concerns on the other modification of the said 8th Embodiment, (b) is an enlarged view of the A section of (a).

Explanation of symbols

1 Guide pipe (fixed structure)
2 Orifice 3, 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h Movable valve body (movable structure)
5 Sealing part (sealing body)
7, 7a, 7b Coil spring (overload reducing elastic body, spring body)
9 Wire (shape memory alloy)
10 Small valve 11 Fixed electrode part (first electrode)
12 Movable electrode part (second electrode)
11c, 12c Resin 64 Contact part 65 Metal body (metal)
66, resin

Claims (9)

A fixed structure having an orifice in a cylindrical shape;
A movable movable structure having a sealing body that seals the orifice movably in contact with the fixed structure;
A first electrode and a second electrode to be energized electrodes;
A wire of shape memory alloy held by the first electrode and the second electrode,
A small valve that energizes the first electrode and the second electrode, heats the wire and deforms the shape memory alloy, thereby moving the movable structure and sealing the orifice;
The movable structure including the sealing body is configured such that its length is elastically deformable, and the stress load during heating of the shape memory alloy is reduced by the elastic deformation of the movable structure. A small valve characterized by being configured as follows.   The small valve according to claim 1, wherein a part or all of the movable structure is made of an elastic material.   The small valve according to claim 1, wherein the movable structure includes a spring body.   The small valve according to claim 3, wherein the spring body is disposed so as to circumscribe the fixed structure.   One end of the second electrode is connected to the fixed structure, the other end is connected to a wire, and the movable structure is brought into contact with both ends of the second electrode, whereby the movable structure is deformed by bending the electrode. The small valve according to any one of claims 1 to 4, wherein the small valve is moved.   5. The first electrode according to claim 1, wherein the first electrode is a fixed electrode fixed to the fixed structure, and the second electrode is a movable electrode connected to the movable structure. The small valve as described in any one.   The first electrode is a fixed electrode fixed to a predetermined part of the fixed structure; the second electrode is a fixed electrode fixed to a part different from the predetermined part of the fixed structure; The end portion of the movable structure is pressed at the center of the wire, and the expansion / contraction direction of the wire is orthogonal to the moving direction of the movable structure. Small valve as described in The end portion has a contact portion that contacts the movable structure and the wire,
The small valve according to claim 7, wherein the contact portion is made of a metal coated with a resin.   The small valve according to claim 7 or 8, wherein a resin is coated on surfaces of the first electrode and the second electrode.

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