JPH09123330A - Shape-recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain excellent shape-recovery force by forming a shape-memory composite body consisting of a shape-memory alloy and a shape-memory polymer by layering a shape-memory composite body, a Peltier element, and a shape-memory composite body in the described order. SOLUTION: A shape-memory composite body 5 is formed of a shape-memory alloy which stores a certain shape-recovery operation and a shape-memory polymer which stores a shape-recovery operation in a direction different from the recovery operation of the shape-memory alloy. For example, the shape-memory alloy, in which a shape treated with heat and folded is stored, is stretched so as to put it in a straight line state, on which the shape-memory polymer is put in a covering manner. The shape-memory composite body 5 is arranged on both faces of a Peltier element 6 and one end thereof is fixed so as to form a shape-recovery device. When electric current is supplied to the Peltier element 6 in a certain direction, the shape-memory composite body 5 at a heating face side is folded and the shape-memory composite body 5 at a heat absorbing face side is stretched. When electric current is supplied inversely, the heating face and the heat absorbing face are inverted, so that the shape- memory composite body 5 which has been folded is stretched and the other is folded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape recovery device excellent in shape recovery force, and a microactuator excellent in shape recovery force.

[0002]

BACKGROUND OF THE INVENTION In recent years,
Drive devices using shape memory materials such as shape memory alloys (hereinafter referred to as SMA) and shape memory polymers (hereinafter referred to as SMP) are used as actuators of various machines and devices. These shape memory materials are heated to have a desired constant shape, and are cooled to return to their original shapes. In this case, as a heating method, there are methods such as a heater and heat conversion from light, but a cooling method is often cooled by natural cooling from the viewpoint of downsizing of the apparatus. However, in that case, since the cooling rate is slow, there is a problem in responsiveness in the device that repeats the recovery operation in a short time.
Since the temperature control is not accurate, it is difficult to control the speed of the shape recovery operation, and the function as an actuator is very limited.

Further, with SMA and SMP alone, the shape recovery operation is unidirectional (irreversible) which occurs in only one direction. It is possible to impart bidirectionality (reversibility) to SMA by subjecting it to heat treatment or processing conditions. It was difficult to restore the original shape. In other words, since it cannot return to the shape before recovery by itself, in order to repeatedly operate it as a drive device, a component that acts to return to the shape before recovery is required, which is a problem in terms of downsizing and weight saving of the device. was there.

In order to solve the above problem, a driving device in which an SMA, a Peltier element and an SMA are laminated in this order, that is,
A drive device has been proposed in which SMAs are installed on both sides of a Peltier element, the heating surface and the cooling surface of the Peltier element are used, and the SMA is used as a component that acts to restore the shape before recovery. (Sho 61-14770). However, the SMA recovery operation of the drive device using the Peltier device is unidirectional (irreversible) that occurs in only one direction. Further, when SMA is used as the driving device, there is a problem that it cannot be used in a device that requires a further driving force because the shape recovery force of SMA is small.

An object of the present invention is to provide a shape recovery device excellent in shape recovery force.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a shape recovery device having an excellent shape recovery force by stacking a shape memory composite, a Peltier element and a shape memory composite in this order. Furthermore, the shape memory composite is composed of a shape memory alloy that remembers a certain shape recovery action and a shape memory polymer that stores a shape recovery action in a direction different from the recovery action of the shape memory alloy. The recovery temperature (martensite reverse transformation temperature, Af) is higher than the shape recovery temperature (glass transition temperature, Tg) of the shape memory polymer, and the (recovery stress x cross-sectional area) or the generating force of the shape memory alloy is (recovery of the shape memory polymer By setting the temperature at which (Stress x cross-sectional area) becomes the same between Af and the martensitic transformation temperature (Mf) of the shape memory alloy,
Provided is a shape recovery device that performs a bidirectional shape recovery operation. Further, the present invention comprises a shape memory composite comprising a shape memory alloy and a shape memory polymer, which are laminated in the order of a shape memory composite, a Peltier element and a shape memory composite, wherein the two shape memory composites are heated. Sometimes a shape recovery operation is performed in the same direction, and a connecting rod (1) is connected to one end of each of the two shape memory composites, and the connecting rod (1) is rotatable via a pin (2). By connecting to the attached rotary rod (3), a microactuator having an excellent shape recovery force is provided.
Further, the present invention comprises a shape memory composite comprising a shape memory alloy and a shape memory polymer, which are laminated in the order of a shape memory composite, a Peltier element and a shape memory composite, wherein the two shape memory composites are heated. By sometimes performing shape recovery operations in different directions, and connecting rods (1) are respectively connected to one ends of the two shape memory composites, and the connecting rods (1) are connected to the actuating body (4). The present invention provides a microactuator having an excellent shape recovery force.

The materials used in the present invention will be described in detail below. As the SMP used in the present invention, SMP
There is no particular limitation as long as it is a commonly used material, and examples thereof include polyurethane, polynorbornene, polyisoprene, and styrene-butadiene copolymer, but the glass transition temperature (hereinafter referred to as Tg) which is the shape recovery temperature is arbitrary. Polyurethane is particularly preferable because it can be set to Polyurethane usually used as SMP is a block copolymer composed of a polyol, a diisocyanate, and a chain extender such as a short-chain glycol or amine, and by changing the molar ratio of these components,
The shape recovery temperature Tg can be freely set from -30 ° C to 60 ° C. In the present invention, Tg is JIS
It is a value measured according to K7121.

The SMA used in the present invention is not particularly limited as long as it is usually used as the SMA.
The martensite reverse transformation temperature (hereinafter referred to as Af), which is the shape recovery temperature of MA, is the molding temperature of SMP (120 to 2).
00 ° C) or less is preferable, and in particular, Af is S
Ti-Ni-based SMA and copper-based SMA which are considerably lower than the molding temperature of MP are preferably used. Ti-Ni type SMA
Examples thereof include a Ti-Ni binary alloy, a Ti-Ni-Cu alloy, a Ti-Ni-Nb alloy, and a Ti-Ni-Fe alloy. These Ti-Ni-based SMAs have an Af of -10 ° C.
１００100 ° C. Also, as a copper-based SMA, Cu-Z
Examples include n-Al alloys and Cu-Al-Ni alloys, and the Af of these copper-based SMAs is -100 ° C to 100 ° C.

SMA has a martensite phase (hereinafter referred to as M phase) structure at a low temperature, and is a material that undergoes phase transformation into a matrix structure at a certain temperature or higher. The shape recovery effect utilizes this phase transformation. When the M-phase SMA is heated, transformation to the parent phase (martensite reverse transformation) gradually occurs,
Eventually, he becomes a perfect mother. Generally, the temperature at which this parent phase transformation ends is called the Af point, and this Af point is the shape recovery temperature of the SMA. On the contrary, when cooling from the temperature range of the matrix phase, the martensitic transformation gradually occurs and eventually becomes a complete M phase. The end temperature of the martensitic transformation is called the Mf point.

In the present invention, the above-mentioned SMA and SMP
It can be arbitrarily selected from and combined. However,
Due to the two-way nature, SM is already used when the shape of SMA is recovered.
Since P needs to be softened, the Af point of SMA is preferably higher than the Tg of SMP. further,
From the point of bidirectionality, when the temperature is lowered from the Af point, it is necessary that the shape recovery force of the SMP be larger than the shape recovery force of the SMA before the SMP is cured. Tg is preferably below the SMA Mf point. The difference between the shape recovery temperatures of SMA and SMP is not particularly limited, but in view of practicality, Tg is preferably Tg.
Is 10 ° C. or more lower than the Mf point, more preferably Tg is M
It is preferably 20 to 40 ° C. lower than the point f. A preferred combination of SMA and SMP has, for example, a Tg of 2
Shape memory polyurethane of 0 ~ 40 ℃ and Af point of 50 ~
Ti-Ni SMA at 80 ° C and Mf point of 30 to 60 ° C,
In particular, a combination with a Ti-Ni binary alloy and a Ti-Ni-Cu-based SMA can be mentioned.

The shape memory composite comprising SMA and SMP used in the present invention stores a shape recovery motion in the SMA and a shape recovery motion in the same direction as the shape recovery motion of the SMA. It has a better shape recovery than SMA alone. Further, in the shape memory composite of SMA and SMP used in the present invention, when a shape recovery operation in the SMA is stored and a shape recovery operation in a direction different from the shape recovery operation of the SMA is stored, that is, When performing a bidirectional shape recovery operation, the shape retained by the SMA is maintained at high temperature (above Af point of SMA), but at low temperature (below the Mf point of SMA, SM
Above Tg of P), SMP becomes softer SMA
It is preferable to overcome the shape retention force of (1) and make the SMA conform to its own shape. In this case, the balance between the shape recovery forces of SMA and SMP is the shape recovery force of SMA, that is, (recovery stress x cross-sectional area) or generated force and (recovery stress x of SMP).
The temperature at which the cross-sectional areas are equal can be set by setting the temperature between the Af point and the Mf point of the SMA. If the temperature is higher than the Af point, the SMA may not be in a state where the shape is sufficiently recovered during heating, and if the temperature is lower than the Mf point, the SMP may not be in a state where the shape is sufficiently recovered during cooling. , The amount of displacement of the shape memory complex tends to decrease, or the bidirectionality tends to be lost.

In the present invention, when the SMA is processed into a coil shape, its shape-recovering force is not (recovery stress × cross-sectional area). In that case, therefore, the shape-recovering force is referred to as a generating force. In the shape memory composite used in the present invention, when the SMA processed into a coil shape is coated with SMP to perform a bidirectional shape recovery operation, SMA is used.
The generated force of SMP is calculated and measured, and the temperature at which (recovery stress x cross-sectional area) of SMP is equal to the generated force is SM.
Type of SMP so that it is between Af point and Ms point of A,
It is preferable to determine the thickness of the sheet.

The shape memory composite used in the present invention can be manufactured by various methods. First, it is preferable to process the SMA into a plate shape, a wire material, a coil shape, etc., and then coat the SMP. The shape of the SMA is not particularly limited, but it is particularly preferably processed into a coil shape because a large amount of displacement for shape recovery can be obtained. Further, as a coating method of SMP, SMA is used.
Examples of the method include a method of coating the surface of the SMP with heat-melted SMP, a method of applying SMP dissolved in a solvent and drying, a method of extruding and coating SMP on SMA, a method of hot pressing, and the like. SMP
There is also a method of covering with a sheet and hot pressing. In addition,
When the shape memory composite used in the present invention is subjected to a bidirectional shape recovery operation, the SMP preferably stores a shape different from that of SMA.
Before the MP is coated, it is preferable that the SMA be deformed into a shape different from the shape memorized by itself, that is, the shape to be stored in the SMP. Further, when heat is applied to mold the SMP into a desired shape, heat of 400 ° C. or higher may cause SMA re-memory, so heat of preferably 300 ° C. or lower, more preferably 200 ° C. or lower. multiply.

In the present invention, the shape memory composites are arranged on both sides of the Peltier element, and the shape memory composite arranged on the heat absorbing surface of the Peltier element is cooled, and at the same time, the shape memory composite is arranged on the heat generating surface of the Peltier element. Heat the complex. The Peltier element utilizes a phenomenon in which heat is generated or absorbed at the junction when a current is passed through the junction between two kinds of metals or semiconductors, and the heat absorption surface and the heat generation surface are reversed depending on the direction of the current flow. It is a thing. The Peltier device used in the present invention is not particularly limited as long as it is a commonly used Peltier device.

In the present invention, it is preferable to fix one end of the shape memory composite to the Peltier device in order to effectively utilize the displacement amount of the shape memory composite. The fixing method is not particularly limited, and examples thereof include a method of fixing with a jig such as an adhesive or wire.

FIG. 1 shows one embodiment of the microactuator of the present invention. The microactuator of the present invention comprises a shape memory composite (5) composed of a shape memory alloy and a shape memory polymer, which are laminated in the order of the shape memory composite, the Peltier element (6) and the shape memory composite. The two shape memory composites perform a shape recovery operation in the same direction when heated, and a connecting rod (1) is connected to one end of each of the two shape memory composites, and the connecting rod (1) is connected to the pin (2). ) Rotating rod (3) rotatably mounted via
Is connected to That is, the microactuator causes the rotary rod to rotate by causing the two shape memory composites to simultaneously perform shape recovery operations in different directions. This rotating motion is
From the case of the shape recovery operation of one shape memory complex,
It can be operated with twice the shape recovery force. Also,
From the case of the shape recovery operation of one shape memory complex,
Large objects can also be rotated.

FIG. 2 shows one embodiment of another microactuator of the present invention. Another microactuator of the present invention is formed by laminating a shape memory composite (5) composed of a shape memory alloy and a shape memory polymer in the order of a shape memory composite, a Peltier element (6) and a shape memory composite. The two shape memory composites perform shape recovery operations in different directions when heated, and a connecting rod (1) is connected to one end of each of the two shape memory composites, and the connecting rod (1) operates. It is connected to the body (4). That is, the microactuator causes the actuating body to reciprocate in the front-rear direction by causing the two shape memory composites to simultaneously perform the shape recovery operation in the same direction. This reciprocating operation can be performed with twice the shape recovery force as compared with the case of the shape recovery operation of one shape memory composite.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The shape recovery device and the microactuator of the present invention are used for an air conditioner outlet wind direction deflection flap drive mechanism, an actuator for a bending mechanism of an endoscope such as a gastric camera or an industrial end scope, and electromagnetic cooking. Applicable to actuator temperature display actuators, valve switching actuators for automobile fuel evaporative emission prevention devices, pressure regulator actuators for siphon coffee makers, shutter opening / closing actuators for dry units in autodesicators, damper switching actuators for fire dampers, etc. To be done.

(Embodiment 1) FIG. 3 shows an embodiment of the shape recovery apparatus of the present invention. Ti-Ni with a cross-sectional area of 1.0 mm ²
Binary alloy SMA wire (Af point: 80 ° C, Mf point: 50
C.) was heat-treated to memorize the bent shape as shown in FIG. This SMA wire rod is stretched into a straight line, and polyurethane SMP (Tg: 30 ° C) with a thickness of 4.5
It was coated to have a thickness of mm. The molding temperature is 200 ° C. The shape memory composites (5) were placed on both sides of the Peltier device (6), and one end was fixed. When a current was applied to the Peltier element in a certain direction, the shape memory composite on the heat generating surface side was bent, and the shape memory composite on the heat absorbing surface side was still expanded. Next, when an electric current is applied in the opposite direction, the heat-generating surface and the heat-absorbing surface are reversed, so that the bent shape memory complex begins to expand, and the shape memory complex that has been kept bent begins to bend.

(Embodiment 2) FIG. 1 shows one embodiment of the microactuator of the present invention. SMA wire rod of Ti-Ni-Cu alloy (Af point: 70 ° C, with a cross-sectional area of 0.3 mm ²
Shape memory heat treatment was performed in a state where the Mf point: 58 ° C.) was a roughly wound coil having an outer diameter of 1.2 mm. This coil is compressed (closely wound), and in that state, polyurethane-based S
A sheet of MP (Tg: 40 ° C.) (thickness: 0.2 mm) was wound into a cylindrical shape as shown in FIG. 2, heated and fixed in this shape (molding temperature is 200 ° C.). The two shape memory composites (5) are arranged on both sides of the Peltier element (6), and the connecting rod (1) is connected to one end of the shape memory composite, and the connecting rod (1) is connected to the pin (2). Via a rotary rod (3) mounted rotatably. First, when an electric current was applied to the Peltier device in a certain direction, the shape memory composite on the heat generating surface side expanded and the shape memory composite on the heat absorbing surface side remained contracted. Next, when an electric current is applied in the opposite direction, the heat-generating surface and the heat-absorbing surface are reversed, so that the shape memory complex that has been expanded begins to contract, and the shape memory complex that has been contracted has expanded. In other words, this microactuator causes the rotary rod to rotate by causing the two shape memory composites to simultaneously perform shape recovery operations in different directions.

[0021]

The shape recovery device of the present invention has a shape memory composite comprising a shape memory alloy and a shape memory polymer, and the shape memory composite, the Peltier element and the shape memory composite are laminated in this order to obtain a shape. Since it has excellent recovery power, it can be used for an apparatus that requires a larger driving force than before. Further, the shape memory composite is composed of a shape memory alloy that memorizes a shape recovery operation and a shape memory polymer that stores a shape recovery operation in a direction different from the recovery operation of the shape memory alloy. (Martensite reverse transformation temperature, Af) is higher than the shape recovery temperature (glass transition temperature, Tg) of the shape memory polymer, and the (recovery stress x cross-sectional area) or generating force of the shape memory alloy is (recovery stress x of the shape memory polymer). The temperature that becomes the same as
And the shape memory alloy's martensitic transformation temperature (Mf) are set so that the shape memory composite performs a bidirectional shape recovery operation, and therefore a member for returning to the original shape is used. It is possible to reduce the size and weight of the element without the need. Further, by coating the SMA with SMP, the corrosion resistance and the insulating property are excellent, so that the range of applications such as medical applications is expanded. Further, by covering the outer circumference of the SMA coil with SMP, it is possible to obtain a shape recovery device having a better shape recovery force. In addition, SMP
By using one or more polymers selected from polyurethane, polynorbornene, polyisoprene and styrene-butadiene copolymer, the shape recovery temperature can be easily set. In addition, when the SMA is a Ti-Ni-based shape memory alloy or a copper-based shape memory alloy, the Af point is considerably lower than the SMP molding temperature, so that the shape memory composite can be easily manufactured. Further, the microactuator of the present invention is formed by laminating a shape memory composite comprising a shape memory alloy and a shape memory polymer in the order of a shape memory composite, a Peltier element and a shape memory composite. The body performs a shape recovery operation in the same direction when heated, and a connecting rod (1) is connected to one end of each of the two shape memory composites, and the connecting rod (1) is connected via a pin (2). Rotatably mounted rotating rod (3)
Since it is excellent in shape recovery by being connected to, it can be used in a device that requires a larger driving force than in the past. Another microactuator of the present invention is formed by laminating a shape memory composite composed of a shape memory alloy and a shape memory polymer in the order of a shape memory composite, a Peltier element, and a shape memory composite. The memory complex makes a different shape recovery action when heated,
A connecting rod (1) is connected to one end of each of the two shape memory composites, and the connecting rod (1) is an actuator (4).
Since it is excellent in shape recovery by being connected to, it can be used in a device that requires a larger driving force than in the past.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a microactuator of the present invention.

FIG. 2 shows an embodiment of another microactuator of the present invention.

FIG. 3 shows an embodiment of the shape recovery device of the present invention.

[Brief description of reference numerals]

 (1) Connecting rod (2) Pin (3) Rotating rod (4) Actuator (5) Shape memory composite (6) Peltier element

Claims (13)

[Claims] 1. A shape recovery device comprising a shape memory composite comprising a shape memory alloy and a shape memory polymer, which are laminated in the order of a shape memory composite, a Peltier element and a shape memory composite. 2. A shape memory composite comprising a shape memory alloy that remembers a shape recovery action and a shape memory polymer that remembers a shape recovery action in a direction different from that of the shape memory alloy. The shape recovery temperature (martensite reverse transformation temperature, Af) is higher than the shape recovery temperature (glass transition temperature, Tg) of the shape memory polymer, and the (recovery stress x cross-sectional area) or the generating force of the shape memory alloy is ( The temperature at which recovery stress x cross-sectional area) becomes the same as Af
The shape recovery device according to claim 1, wherein the shape recovery device is set so as to be between the martensitic transformation temperature (Mf) of the shape memory alloy. 3. The shape recovery device according to claim 1, wherein the shape memory composite comprises a shape memory alloy coated with a shape memory polymer. 4. The shape memory composite, wherein the outer circumference of a coil of shape memory alloy is coated with a shape memory polymer.
3. The shape recovery device according to any one of 3 above. 5. The shape recovery device according to claim 1, wherein the shape memory polymer is one or more polymers selected from polyurethane, polynorbornene, polyisoprene and styrene-butadiene copolymer. . 6. The shape recovery device according to claim 1, wherein the shape memory alloy is a Ti—Ni-based shape memory alloy or a copper-based shape memory alloy. 7. A shape memory composite comprising a shape memory alloy and a shape memory polymer is laminated in the order of a shape memory composite, a Peltier element and a shape memory composite, wherein the two shape memory composites are heated. A shape recovery operation is performed in the same direction, and a connecting rod (1) is connected to one end of each of the two shape memory composites, and the connecting rod (1) is rotatably attached via a pin (2). Rotating rod (3)
A microactuator characterized by being connected to. 8. A shape memory composite comprising a shape memory alloy and a shape memory polymer is laminated in the order of a shape memory composite, a Peltier element and a shape memory composite, wherein the two shape memory composites are heated. A shape recovery operation in different directions is performed, and a connecting rod (1) is connected to one end of each of the two shape memory composites, and the connecting rod is an operating body (4).
A microactuator characterized by being connected to. 9. A shape memory composite comprising a shape memory alloy that remembers a shape recovery action and a shape memory polymer that remembers a shape recovery action in a direction different from that of the shape memory alloy. The shape recovery temperature (martensite reverse transformation temperature, Af) is higher than the shape recovery temperature (glass transition temperature, Tg) of the shape memory polymer, and the (recovery stress x cross-sectional area) or the generating force of the shape memory alloy is ( The temperature at which recovery stress x cross-sectional area) becomes the same as Af
And the martensitic transformation temperature (Mf) of the shape memory alloy. 10. The microactuator according to claim 7, wherein the shape memory composite comprises a shape memory alloy coated with a shape memory polymer. 11. The shape memory composite comprises a shape memory alloy coil surrounded by a shape memory polymer.
10. The microactuator according to any one of 10. 12. The shape memory polymer is polyurethane,
8. A polymer selected from polynorbornene, polyisoprene and styrene-butadiene copolymer.
11. The microactuator according to any one of 11 to 11. 13. The microactuator according to claim 7, wherein the shape memory alloy is a Ti—Ni-based shape memory alloy or a copper-based shape memory alloy.