Shape memory actuator

Abstract

The present invention relates to a shape memory actuator, and more specifically, to a shape memory actuator capable of restoring its shape by means of a corrugated metal strip when the temperature changes after thermal deformation of a shape memory alloy strip. The technical gist of the present invention is a shape memory actuator formed by a plate-shaped shape memory alloy strip that changes shape by heat and a corrugated metal strip coupled to both ends of one side of the shape memory alloy strip to provide elastic restoring force, wherein the shape is restored by the corrugated metal strip when the temperature changes after the shape memory alloy strip is thermally deformed.

Description

Technology Field

[0001] The present invention relates to a shape memory actuator, and more specifically, to a shape memory actuator capable of restoring a shape deformed by a corrugated metal strip when the temperature changes after thermal deformation of a shape memory alloy strip. Background Technology

[0002] An actuator is a term referring to a device that controls a system by generating driving force using energy supplied externally via an operation signal, and it is utilized in a wide variety of fields depending on its application, cost, function, and purpose.

[0003] Actuators are classified into pneumatic actuators, electric actuators, hydraulic actuators, and electro-hydraulic actuators depending on the type of energy source, such as electricity, hydraulics, compression, or air, and since each has different output torque, precision, stability, and load capacity, it is necessary to take this into consideration.

[0004] Pneumatic actuators are actuators that operate a piston inside a cylinder using compressed air or gas. Compared to other actuators, they have the advantages of a simple structure, low cost, easy maintenance, and high output, but they have the disadvantage of being difficult to control precisely.

[0005] Furthermore, electric actuators use electricity to rotate an electric motor to output rotational force and thrust. They have the advantages of being able to achieve high-capacity output with a compact structure and allowing for easy control of speed and output; however, compared to other pneumatic actuators, they have a complex structure that requires specialized personnel for repairs.

[0006] Since these conventional actuators are driven by electricity, hydraulics, compression, or air as energy sources, there is a problem of inefficient energy usage due to the additional power consumed to drive the actuators.

[0007] For example, if a conventional actuator is applied to a solar tracking device, additional devices are required, such as a light sensor to respond to sunlight, a motor to drive the actuator, and a control device capable of controlling the device's driving angle and driving speed.

[0008] There are issues such as additional installation costs and time required due to additional devices, and the inconvenience of repair and maintenance if a single additional device fails.

[0009] As a technology to solve these problems, the 'Photovoltaic power generation system (Publication No.: JP 2011-129664)' discloses a photovoltaic power generation system capable of automatically tracking the sun using a solar cell and an electrostatic actuator having a flexible mover and a flexible stator that moves the solar cell.

[0010] However, the aforementioned prior art has location constraints requiring installation in specific places, and suffers from cumbersome maintenance issues due to additional devices such as multiple position sensors for detecting the position of a mover. Furthermore, the problem of inefficient energy usage resulting from the additional power consumption to drive the actuator remains unresolved, making it necessary to develop new technology to address these issues. Prior art literature

[0011] (Patent Document 0001) JP 5521528 B2 The problem to be solved

[0012] The present invention was developed to resolve the aforementioned problems, and its technical objective is to provide a shape memory actuator that is more advantageous in terms of energy by being driven by externally supplied photothermal heat, while not being restricted by the installation location due to the lightweighting and simplification of parts of the actuator, unlike conventional actuators. means of solving the problem

[0013] To solve the above technical problem, the present invention provides a shape memory actuator characterized by being formed of: a plate-shaped shape memory alloy strip that changes shape by heat; and a corrugated metal strip coupled to both ends of one side of the shape memory alloy strip to provide elastic restoring force, wherein the shape is restored by the corrugated metal strip when the temperature changes after the shape memory alloy strip is thermally deformed.

[0014] The present invention features a shape memory actuator comprising: a corrugated metal strip that contacts the shape memory alloy strip with an 'S'-shaped convex portion and controls the shape of the shape memory alloy strip by means of elasticity; and a support portion formed between the deformation portions with an 'S'-shaped concave portion and reflects light to apply heat to the shape memory alloy strip.

[0015] The present invention features a shape memory actuator in which the deformation part and the support part have different degrees of curvature, and the support part has a less degree of deformation than the deformation part. Effects of the invention

[0016] According to the shape memory actuator based on the means for solving the above problem, unlike conventional actuators, it does not generate noise or vibration, and has the effect of making the actuator lighter by minimizing additional devices such as sensors.

[0017] In addition, the reduction in actuator weight and the simplification of parts have the effect of not being restricted by the actuator installation location.

[0018] While conventional actuators are driven by electricity, hydraulics, or compressed air, this device is driven by externally supplied photothermal energy, offering a more advantageous effect in terms of energy. Brief explanation of the drawing

[0019] FIG. 1 is a top view of the shape memory actuator of the present invention. FIG. 2 is a cross-sectional view showing a shape memory actuator of the present invention. FIG. 3 is an enlarged view showing the deformation part and the support part of the present invention. FIG. 4 is a graph showing the driving angle when thermal deformation and restoration of a shape memory actuator according to an embodiment of the present invention are repeated. Specific details for implementing the invention

[0020] The present invention will be examined below with reference to the drawings. In describing the present invention, if it is determined that a detailed description of related known technologies or configurations may unnecessarily obscure the essence of the invention, such detailed description will be omitted.

[0021] Furthermore, the terms described below are defined in consideration of their functions in the present invention; since these may vary depending on the intentions or practices of the user or operator, their definitions should be based on the content throughout this specification describing the present invention.

[0022] First, FIG. 1 is a top view of the shape memory actuator of the present invention, and FIG. 2 is a cross-sectional view of the shape memory actuator of the present invention. As shown, the shape memory actuator (10) according to an embodiment of the present invention includes a shape memory alloy strip (20) and a corrugated metal strip (30).

[0023] The shape memory alloy strip (20) is in the shape of a plate-shaped strip, and the material is made of a shape memory alloy (SMA) that can change its shape according to temperature changes.

[0024] The shape memory alloy that constitutes the shape memory alloy strip (20) is a metal that has the characteristic of remembering the shape it was in when it was first formed even after deformation occurs, and returning to that shape when it reaches a certain temperature. When it is restored to its original shape, it requires about 5 times more force than the force required for deformation. Due to this characteristic, it is being applied in various fields such as medical devices, space development devices, and electronic devices.

[0025] Here, the shape memory alloy strip (20) of the present invention is a shape memory material and includes all materials capable of changing shape by heat, such as elastic materials, wires, cylinders, rubber, metals, ceramics, and polymers, without any special limitation on the material.

[0026] In addition, in the embodiments of the present invention, an alloy whose shape changes at a minimum of 45° is exemplified.

[0027] And, the corrugated metal strip (30) is in the shape of a plate with a corrugation formed in the center.

[0028] There are no special limitations on the material of the corrugated metal strip (30), but it is preferable that it be made of an elastic material capable of providing angle control of the shape memory actuator (10), or a metal material with high light reflectivity.

[0029] These corrugated metal strips (30) are joined to the shape memory alloy strips (20) at each end, and for this purpose, the corrugated metal strips (30) and the shape memory alloy strips (20) are connected in various ways that do not interfere with the operation, such as soldering, adhesive, or adhesive tape.

[0030] As shown in FIG. 3, the corrugated metal strip (30) may further include a deformation portion (32) and a support portion (34).

[0031] The deformation part (32) corresponds to the convex part of the fold formed in an 'S' shape, and the shape restoration of the shape memory alloy strip (20) is controlled by the elastic force of the deformation part (32).

[0032] And the support portion (34) corresponds to the concave part of the fold formed in an 'S' shape and is formed between each deformation portion (32), and when the shape memory actuator (10) is driven by photothermal heat, it reflects light to further increase the temperature of the shape memory alloy strip (20).

[0033] Here, in order to create a difference in the degree of deformation between the support part (34) and the deformation part (32), the degree of curvature of the deformation part (32) and the support part (34) is different.

[0034] First, when heat is applied to the shape memory actuator (10), thermal deformation of the shape memory alloy strip (20) occurs, causing the angle of the actuator (10) to change. Accordingly, the deformation part (32) having elastic force is pressed by the shape memory alloy strip (20), and the degree of curvature becomes smooth. At this time, the degree of curvature of the deformation part (32) is within a certain range, and since the degree of deformation of the support part (34) is small, it acts as a support for the deformation part (32). In addition, the support part (34) reflects incident light to generate reflected light, thereby applying more heat to the shape memory alloy strip (20) and increasing the heat collection efficiency of the shape memory alloy strip (20).

[0035] Therefore, the shape memory actuator (10) according to the present invention can undergo thermal deformation through this operation.

[0036] And, when heat is cut off from the shape memory actuator (10), the shape memory and the compressed deformation part (32) of the corrugated metal strip (30) that attempts to return to the initial shape of the shape memory alloy strip (20) are restored by elastic restoring force.

[0037] Therefore, the shape memory actuator (10) according to the present invention can restore its shape through this operation.

[0038] Thus, it can be seen that the deformation part (32) is an area having elasticity for shape restoration, and the support part (34) is an area that reflects light for the heat collection efficiency of the shape memory alloy strip (20) and supports the deformation part (32) for constant movement.

[0039] In the shape memory actuator (10) of the present invention as described above, the shape of the actuator (10) is deformed due to a temperature change of the shape memory alloy strip (20), and when heat is cut off, the temperature of the shape memory alloy strip (20) is lowered, and the initial shape can be restored by the elastic force of the corrugated metal strip (30).

[0040] Figure 4 shows a graph representing the driving angle when thermal deformation and restoration of a shape memory actuator are repeated according to an embodiment of the present invention.

[0041] First, the horizontal axis represents the angle of the initial shape of the shape memory actuator (10), and the vertical axis represents the driving angle of the shape memory actuator (10) formed during thermal deformation, and is indicated by color when thermal deformation and restoration are repeated. When viewed as a graph, it was confirmed through experiments that a constant driving angle is maintained when thermal deformation and restoration are repeated.

[0042] That is, it can be confirmed that the shape memory actuator (10) enables high precision and stability in driving angle control.

[0043] Unlike conventional actuators, such an actuator (10) does not generate noise or vibration, and can be made lighter by minimizing additional devices such as sensors, and is not restricted in the installation location of the actuator due to the lightweighting of the actuator and simplification of parts.

[0044] In addition, while conventional actuators are driven by electricity, hydraulics, or compressed air, this device is driven by externally supplied photothermal energy, offering a more advantageous effect in terms of energy.

[0045] The drawings illustrated above for the purpose of explaining the present invention are one embodiment in which the present invention is embodied, and it can be seen that various combinations are possible to realize the gist of the present invention as illustrated in the drawings.

[0046] Therefore, the present invention is not limited to the embodiments described above, and the technical spirit of the present invention extends to the scope in which various modifications can be made by anyone with ordinary knowledge in the field to which the invention belongs, without departing from the essence of the invention as claimed in the following patent claims. Explanation of the symbols

[0047] 10 : Shape memory actuator 20 : Shape memory alloy strip 30: Corrugated metal strip 32 : Deformation part 34 : Support

Claims

Claim 1 A shape memory actuator characterized by being formed by: a plate-shaped shape memory alloy strip that changes shape by heat; and a corrugated metal strip coupled to both ends of one side of the shape memory alloy strip to provide elastic restoring force, wherein when the temperature changes after thermal deformation of the shape memory alloy strip, the shape is restored by the corrugated metal strip, and the corrugated metal strip comprises a deformation part that contacts the shape memory alloy strip and controls the shape of the shape memory alloy strip by elasticity, and a support part formed between each of the deformation parts and reflecting light to apply heat to the shape memory alloy strip. Claim 2 delete Claim 3 A shape memory actuator according to claim 1, characterized in that the deformation part and the support part have different degrees of curvature, and the support part has a smaller degree of deformation than the deformation part.

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