JPH065670Y2 - Current-carrying actuator using shape memory alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial application field" The present invention relates to a current-carrying actuator using a shape memory alloy.

“Prior Art” Conventionally, as an actuator driven by energization, there are known an actuator using a bimetal, and an actuator combining a shape memory alloy spring as shown in FIGS. 8 and 9 and a bias spring.

The bimetal is formed by joining two kinds of metals or alloys having different coefficients of thermal expansion and bending them by changing the temperature or heating by applying electricity by utilizing the difference in the coefficients of thermal expansion of the two metals.
Generally, an amber is used on the low expansion side and a copper alloy is used on the high expansion side.

Further, as a combination of a shape memory alloy spring and a bias spring, an actuator using a zigzag spring as shown in the temperature sensing device of Japanese Utility Model Laid-Open No. 61-57890 is known.

As an example of this, the actuator shown in FIG. 8 includes a spring 11 made of a shape memory alloy formed in a zigzag shape,
A bias spring 12 machined from a metal plate having elasticity. Hooks are provided at both ends of both springs 11 and 12, and the length of the shape memory alloy spring 11 is a predetermined dimension longer than the length of the bias spring 12. The springs 11 and 12 are overlapped with each other, and the pair of support shafts 13 and 14 are inserted into the hooks at both ends to form a composite structure. The shape memory alloy spring 11 is insulated so as not to come into contact with the bias spring 12 and short-circuit.

The shape memory alloy spring 11 is connected to a power supply circuit 15, and when a current flows through the circuit by energization, the shape memory alloy spring 11 generates heat, and when the transformation temperature is reached, the shape memory alloy spring 11 returns to its shape. As a result, the shape memory alloy spring 11 expands or contracts against the elastic force of the bias spring 12, and changes the distance between the support shafts 13 and 14 to perform a desired operation. Further, when the energization is released, the shape memory alloy spring 11 is cooled to the transformation temperature or lower and its rigidity is weakened, and the elastic force of the bias spring 12 restores the original shape and the distance between the support shafts 13 and 14 also returns to the original shape. .

Further, FIG. 9 shows an example of an actuator that uses a shape memory alloy spring and a bias spring to move the angle of the wind direction plate of an air conditioner or the like.

FIG. 9 is a schematic view of an air blowing portion of an air conditioner such as an air conditioner, and the wind direction plate 21 is rotatably fixed to a support shaft 22. One end of a shape memory alloy spring 23 is attached to the lower part of the wind direction plate 21 on the air blowing side, and the other end of the spring 23 is fixed to the lower part of a blowout port 25 of the air conditioner body. One end of a bias spring 26 is attached to the upper portion of the wind direction plate 21 on the air blowing side, and the other end of the spring 26 is fixed to the upper portion of the air conditioner outlet 25.

As shown in FIG. 9 (a), the shape memory alloy spring 23 is heated by the warmed air during heating, and when the temperature exceeds the transformation temperature, the shape memory alloy shape restoring force causes the spring 2 to move.
3 contracts, and at the same time, the bias spring 26 is pulled downward, and the wind direction plate 21 moves downward. As a result, the warmed air is blown downward.

Next, as shown in FIG. 9 (b), the shape memory alloy spring 23 is cooled by the cooled air during cooling, the contracting force is weakened, and the elastic force of the bias spring 26 in the expanded state is superior. Then, the shape memory alloy spring 23 is pulled upward this time, and the wind direction plate 21 moves upward. As a result, the cooled air is blown upward.

[Problems to be Solved by the Invention] However, these conventional actuators have various problems.

That is, with respect to the actuator using the bimetal, the operating stroke of the bimetal itself is small, and there is a considerable limitation in the application of the actuator.

In addition, the material used for the bimetal generally has a small electric resistance value, and a large current is required to heat the bimetal plate to operate it.

Further, in the energizing actuator and the temperature sensing device using the shape memory alloy spring and the bias spring, the operating stroke is large, but the movement direction can be limited to the expansion and contraction direction of the spring, and in that respect the application as an actuator is restricted. There is.

Further, in the temperature sensing device as shown in FIG. 9,
Since it is necessary to attach the shape memory alloy spring and the bias spring separately, the number of parts inevitably increases, the structure becomes complicated, the production cost increases, and the production cannot be rationalized.

Therefore, it is an object of the present invention to provide a current-carrying actuator using a shape memory alloy, which is capable of deforming in both directions, such as bimetal, and which operates even with a relatively small current.

[Means for Solving the Problem] In order to achieve the above object, the current-carrying actuator according to the present invention is elastically bendable with a shape memory alloy plate formed into a continuous linear pattern that is folded back at a predetermined length. A flat substrate and a linear pattern of the shape memory alloy plate so as not to short-circuit so that the surface shape of the substrate in a state without external force is different from the stored surface shape of the shape memory alloy plate. And a shape in which at least one surface shape is curved by drawing a bending line intersecting with the line direction in which the linear patterns are arranged in parallel, and the shape memory alloy is energized when the linear pattern of the shape memory alloy plate is energized. By the shape restoring force, the surface is deformed against the elastic force of the substrate, and when the energization is released, the elastic force of the substrate restores the original shape.

[Operation] The present invention provides an actuator that deforms in the surface direction by using a shape memory alloy, and increases the energization resistance by operating the shape memory alloy pattern as long as possible to operate even at a small current. It was made with an eye on what can be done.

In the present invention, the surface shape of the substrate without external force,
Because the shape of the shape memory alloy plate is different from the memorized surface shape, when the shape memory alloy plate is energized to generate heat and transform, the surface of the shape memory alloy plate resists the elastic force of the substrate due to the shape restoring force of the shape memory alloy plate. Deform. For example, if the substrate is a flat surface, it can be deformed into a curved shape in either direction, and if the substrate is curved, it can be deformed into a flat surface or a curved shape in the opposite direction. Further, when the power supply is released, the elastic force of the substrate can restore the original shape.

In this case, in the present invention, at least one of the surface shapes has a curved shape by drawing a bending line intersecting the line direction in which the linear patterns are arranged in parallel, so that the surface deformation due to energization and deenergization is a linear pattern. It is designed to perform a bending operation by drawing a bending line intersecting with the parallel line directions of. Therefore, the deforming forces of the plurality of linear portions of the linear pattern can be made to act in cooperation with each other, and the deforming force can be increased.

As described above, an actuator that uses a shape memory alloy to perform surface deformation has not been known so far, and it is used in various fields such as a mechanism for switching a wind direction plate of an air conditioner and a mechanism for adjusting an angle of a fan or a propeller blade. It is expected that these mechanisms will be further simplified by applying to.

Further, since the shape memory alloy plate is formed into a continuous linear pattern that is folded back at a predetermined length, connecting a power circuit to both ends of this pattern to energize the pattern allows a long current path. The energization resistance can be increased, and thereby the temperature can be raised to the temperature required for transformation even with a relatively small current. As a result, a high voltage-low current circuit configuration can be adopted, and the cost of parts and devices used in the circuit can be reduced.

Further, as the shape of the shape memory alloy plate, various shapes such as a so-called zigzag spring-like shape and a shape in which slits are alternately formed from opposite sides of a rectangular plate can be adopted.

[Embodiment] FIGS. 1, 2, and 3 show an embodiment of a current-carrying actuator using a shape memory alloy spring according to the present invention.

As shown in FIG. 1, the energizing actuator 31 is
The shape memory alloy plate 32 is formed into a zigzag shape, and an elastically bendable substrate 33 is included.

Although the shape memory alloy plate 32 has a zigzag pattern in which the shape memory alloy plate 32 is folded back in a U shape with a predetermined length, the folded back portion may be rounded like the zigzag spring shown in FIG.

As the substrate 33, a metal plate, a synthetic resin plate, or the like can be adopted. In the case of a metal plate, when a shape memory alloy plate is joined, it is electrically insulated so that the pattern of the shape memory alloy plate does not short-circuit. Need to be joined.

The substrate 33 may have various shapes such as a rectangle, a circle, and an ellipse, but a rectangle such as a rectangle or a square is preferably used. In this case, the shape memory alloy plate 3
It is more preferable that the outer circumference of the second folded portion is sized and shaped to match the outer circumference of the substrate 33.

The shape of the shape memory alloy plate 32 can be arbitrarily selected such as a curved shape or a flat surface shape. When the memory shape of the shape memory alloy plate 32 is curved, the substrate 33 is bonded as a flat surface shape or a shape curved on the opposite side. In addition, the shape memory alloy plate 32
When the memory shape of 1 is a flat plate shape, the substrate 33 is joined as a curved shape.

However, in the present invention, at least one surface shape of the memorized shape of the shape memory alloy plate 32 and the shape of the substrate 33 in the state without external force is bent so as to intersect the line direction in the parallel portion of the pattern of the shape memory alloy plate 32. It is necessary to draw a line to form a curved shape. In this embodiment, the memorized shape of the shape memory alloy plate 32 is stored in a curved shape such that the direction perpendicular to the line direction of the patterns, that is, the longitudinal direction of the substrate 33 is a bending line. Further, the substrate 33 is made to be a flat surface without any external force.

In this embodiment, as shown in FIGS. 2 and 3, a shape memory alloy plate 32 is superposed on a substrate 33, and an adhesive agent is interposed between them to adhere them.

However, as a method of joining the shape memory alloy plate 32 and the substrate 33, various methods such as bonding, fitting, screwing, and embedding can be adopted. For example, as shown in FIG. 4, a structure in which a shape memory alloy plate 32 is superposed on a substrate 33, and opposing edges along the respective longitudinal directions are held and joined by a frame 34 having a U-shaped cross section. Can also be adopted. Also, the substrate 3
When 3 is made of a synthetic resin plate, a structure in which the shape memory alloy plate 32 is sandwiched and fixed by two synthetic resin plates can be adopted.

As shown in FIG. 1, this energizing actuator 31 has
A power supply circuit 35 is connected to both ends of the linear pattern of the shape memory alloy plate 32, and the power supply circuit 35 energizes or deenergizes the shape memory alloy plate 32 to operate.

5A and 5B show the energizing actuator 31.
Shows the operating state of. In this embodiment, as described above, the substrate 33 has a planar shape without any external force, and the shape memory alloy plate 32 is stored in a curved shape by drawing a bending line orthogonal to the line direction in which the patterns are arranged in parallel. The structure is adopted.

As shown in FIG. 7A, the rigidity of the substrate 33 keeps the shape memory alloy plate 32 flat as a whole when the shape memory alloy plate 32 is not energized.

Further, as shown in FIG. 3B, when the shape memory alloy plate 32 is energized, heat is generated by the energization resistance and the shape memory alloy plate 32 returns to the memorized shape and resists the elastic force of the substrate 33. To bend.

Then, when the energization is released again, the rigidity of the shape memory alloy plate 32 decreases, so that the elastic force of the substrate 33 restores the planar shape shown in FIG.

Such an action may, for example, actuate other members associated therewith or alter the flow of fluid.

FIG. 6 shows another embodiment of the current-carrying actuator of the present invention.

In this embodiment, the shape of the shape memory alloy plate 32 as a whole is a rectangular shape suitable for the substrate 33 as in the above-described embodiments. Then, the shape memory alloy plate 32
Have slits 36 which are staggered from opposite sides, thereby forming a linear pattern that is folded back in zigzag. The slit 36 has a predetermined width so that a short circuit does not occur between the opposing straight line portions in the state where a current is flowing in the circuit. Dimensions and shape of substrate 33, joint structure with shape memory alloy plate 32, and power supply circuit 35
The connection structure and the like are similar to those in the above-described embodiment.

FIG. 7 shows an example in which the energizing actuator according to the present invention is used as a wind direction plate for an air conditioner or the like.

In this example, the energizing actuator 31 as described above is arranged so as to traverse the flow path of the outlet 25 and the plane thereof is parallel to the flow, and both ends thereof are provided with a pair of support shafts 37.
It is fixed by. Further, the substrate 33 has a shape that is curved upward of the blowout port 25 in a state where no external force is applied, and when the shape memory alloy plate 32 is heated by energization and reaches the transformation temperature, the substrate 33 is moved downwardly of the blowout port 25. The shape is memorized so as to curve toward.

As shown in FIG. 7 (a), during cooling, the shape memory alloy plate 32 is not energized, and the rigidity of the substrate 33 causes the end portion on the blow-out side to bend upward to blow cool air upward.

In addition, as shown in FIG. 7 (b), during heating, the shape memory alloy plate 32 is energized to return to its shape and curved toward the lower side of the outlet 25 against the elastic force of the substrate 33 to warm the air. Blow downwards.

[Advantages of the Invention] As described above, according to the energizing actuator of the present invention, it is possible to provide an actuator that deforms in the surface direction by using a shape memory alloy. It can be applied to various fields such as wind direction plate switching mechanism and fan and propeller blade angle adjusting mechanism. Further, since the shape memory alloy and the substrate are joined together to form a single plate, the mounting structure for various devices can be simplified and the mounting space can be reduced. Furthermore, by making the shape of the shape memory alloy into a linear pattern that is folded back at a predetermined length, it is possible to obtain an actuator that operates with a small current by increasing the conduction resistance.
The design of the power supply circuit, etc. is also easy. In addition, the surface deformation is
Since the shape memory alloy plate is curved by drawing a bending line that intersects the parallel line direction of the pattern, each of the linear portions of the pattern cooperates to give a shape restoring force, which is strong. You can get the output.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of an energizing actuator according to the present invention, FIG. 2 is a front view of the same actuator, and FIG.
FIG. 4 is a side view of the actuator, FIG. 4 is a side view showing another example of a joint structure of a shape memory alloy plate and a substrate, and FIGS. 5 (a) and 5 (b) are side views showing an operating state of the actuator. FIG. 6 is a plan view showing another embodiment of the current-carrying actuator according to the present invention, and FIGS. 7 (a) and 7 (b) are schematic views showing an example in which the current-carrying actuator according to the present invention is applied to a wind direction plate of an air conditioner or the like. 8 and 9 are schematic explanatory diagrams showing an example of a conventional energizing actuator, and FIG. 9 is a schematic explanatory diagram showing an example in which a conventional actuator using a shape memory alloy is applied to a wind direction plate of an air conditioner or the like. In the figure, 31 is an energizing actuator, 32 is a shape memory alloy plate, 33 is a substrate, 34 is a frame, 35 is a power supply circuit, and 36 is a slit.

Claims (1)

[Scope of utility model registration request] 1. A linear pattern of a shape memory alloy plate does not short-circuit a shape memory alloy plate formed into a continuous linear pattern that is folded back at a predetermined length and an elastically bendable substrate. So that the surface shape of the substrate in a state where there is no external force is different from the stored surface shape of the shape memory alloy plate, and at least one surface shape is parallel to the linear pattern. A curved shape is drawn by drawing a bending line that intersects the line direction, and when the linear pattern of the shape memory alloy plate is energized, the surface is deformed against the elastic force of the substrate by the shape restoring force of the shape memory alloy, An energizing actuator using a shape memory alloy, characterized in that when the energization is released, the elastic force of the substrate restores the original shape.