JPS59147881A - Thermo-mechanical converting element - Google Patents

Abstract

PURPOSE:To improve energy conversion efficiency by inserting an arm slidably into a cylindrical shaft body then winding helical wire composed of shape memory alloy around the arm and securing one end to the tip of arm while the other end to the shaft body. CONSTITUTION:A through-hole 2 is made through a cylindrical shaft body 1 then an arm 5 is inserted slidably through said hole 2 and helical wire 7 composed of shape memory alloy is wound around the arm 5 to secure one end to the tip 6 of arm 5 while the other to the other tip 6. When floating this system on hot water 8, the wire 7 immersed with hot water is heated to return to original shape and contract. Consequently the arm 5 will slide in arrow direction (L) to rotate the shaft body 1 in arrow direction. Since thermal energy is taken out as rotary motion of shaft body 1, thermal energy can be converted efficiently into mechanical energy.

Description

TECHNICAL FIELD The present invention relates to an S-mechanical conversion element for a heat engine that converts mechanical energy into mechanical energy.

Conventional technology In order to reduce the burden of energy demand, which is increasing year by year, we are trying to utilize the enormous amount of thermal energy contained in the large amounts of heated wastewater and thermal streams that are wastefully dumped by steel plants and power plants, which has not been given much attention in the past. , and the endless amount of solar heat that showers the earth are being reconsidered. Several heat engines have already been developed to effectively utilize such thermal energy, and heat engines using shape memory alloys, which are easy to manufacture and maintain afterward, are attracting attention in particular.

Shape memory alloy is an alloy that has a shape memory effect, and since the shape memory effect of Ti-Ni alloy was discovered in the United States in 1963, copper-based alloys such as copper-zinc and copper-zinc have been used. - Seven or eight types are known, including aluminum, lead, zinc, and tin.

The shape memory effect is a phenomenon in which when a metal material that is in a martensitic state at a low temperature is heated after being deformed, the metal material returns to its original shape before deformation. However,
A small number of metal materials are known to exist, which memorize their shape in a low-temperature state and return to their original state before deformation upon cooling. Therefore, in the following description, when referring to shape memory alloys and shape memory effects, the latter case is also included.

A thermomechanical conversion element using a shape memory alloy converts thermal energy into mechanical energy by utilizing the stretching force due to the shape memory effect. When making a thermomechanical conversion element using a shape memory alloy, there are three main methods as follows.

(1) A method in which a shape memory alloy wire is bent into a bow shape and uses the force that tries to return to its true shape when immersed in hot water (Hanks type). (2) A method in which the shape memory alloy wire is stretched and contracts in hot water. (3) After the shape memory alloy wire is memorized in the coil shape at high temperature,
One method (Tohoku University) involves creating a loop of helical wire by pulling it, then pouring warm water over it and using the contraction force when it returns to its original coil shape (Tohoku University).

However, none of the conventional methods using the -1=method described above has achieved sufficient energy conversion efficiency.

Purpose An object of the present invention is to provide a thermomechanical conversion element using a shape memory alloy that eliminates the above-mentioned problems and improves mechanical conversion efficiency.

Example Hereinafter, the present invention will be described in detail with reference to the drawings.

(First Example) FIG. 1 shows a first example of the thermomechanical conversion element of the present invention. In this example, thermal energy is converted into mechanical vibration energy.

In FIG. 1(A), 1 is a cylindrical shaft body, and 2 is a through hole bored in the outer circumferential wall 3 of the shaft body, passing through the axis 4 of the shaft body. 5 is an arm slidably inserted into this through hole 2, and 518 (flR) is attached to both ends of the arm.

1(L) is installed. ? (7R, ?L) is a helical wire made of a shape memory alloy wound around the arm 5, one end of which is fixed to the tip of the arm 5 (weights 8R, 8L),
The other end is fixed to the shaft body 1.

That is, as shown in FIG. 1(B), the axis 4 of the shaft l
The helical wires 7R and 7L are arranged symmetrically with respect to each other to maintain left and right balance around the axis. Here, the helical wire 7 is one in which a coil shape is memorized in advance at a high temperature, and then stretched at room temperature to form a helical loop.

Next, the principle of operation of the thermomechanical transducer configured as described above will be explained with reference to FIGS. 1(C) and 1(I).

First, as shown in Figure 1(C), the thermomechanical conversion element I is 1
Then, float it in hot water 8 as a heating means for the linear wire 7. Helical wire 7 made of shape memory alloy
Among them, the wire 7R immersed in hot water is heated and tries to return to a pre-stored coil state. This restoring force generates a contractile force in the wire 7R. On the other hand, since the helical wire 7L is hinged at room temperature, no restoring force is generated. As a result, the arm 5 slides within the through hole 2 in the direction of the arrow in the figure due to the contraction force of the wire 7R. FIG. 1(C) shows the state after such movement. Due to this movement, the shaft 6L moves further from the shaft 4 than the weight 6R, and the balance around the shaft is broken, producing a counterclockwise rotational moment as shown, which causes the shaft 1 to rotate in the direction of the arrow. do.

Due to this rotation, the helical wire 7L is immersed in the hot water 8, and the wire 7R, which has been in the warm water, comes out into the air. As a result, a restoring force is generated in the wire 7L heated by the hot water, and the wire 7R radiates heat in the air and loses its restoring force. As a result, arm 5 moves to arrow R.
318R is pushed back in the direction of axis 4 than 1leL.
, and a clockwise rotational moment is generated. FIG. 1 (I) shows the state at this time. As a result, the shaft body 1 will rotate in the direction of the arrow.

As described above, as long as thermal energy is applied to and taken away from the helical wire made of a shape memory alloy, the above-mentioned vibration with one period of normal rotation and one reversal continues.

Here, the temperature at which the shape of the shape memory alloy recovers to its memorized shape is generally 30°C or higher, but the recovery temperature can be controlled by changing its composition.

In addition, instead of using hot water as in the -J series, the f stage for imparting thermal energy to the shape memory alloy may be heated oil, or in some cases, hot air or sunlight may be used. good.

Furthermore, the shape of the shape memory alloy is different from the normal state and memory shape.
The shape is not limited to two helical wires and coils, but may be any shape as long as it generates a restoring force that causes the arm to move when heated.

Furthermore, %8R and SL in the present embodiment and example are not necessarily required, and ν is not necessary if sufficient torque to rotate the shaft l is obtained only by movement of the arm 5.

In addition, if the shaft l is supported by a support so that it is located near the boundary between the high-temperature side and the low-temperature side, and if there is no hindrance to the generation of rotational force to the shaft, then the main It is not necessary to float on the liquid level as in the embodiment. Rather, when utilizing the mechanical energy generated by a heat engine, it is customary to be supported and supported by a support. When supported by a support,
For example, if the heat energy supply/removal means is configured by exposing the lower half of the horizontal line passing through the axis of the shaft 1 to solar heat and cutting off the upper half of the horizontal line, as in this embodiment, , mechanical energy can be extracted without using liquid.

In the above embodiment, the helical wire returns to the coil in the memorized shape in hot water. However, by using cold water instead of hot water and setting the atmospheric temperature in the air to a high temperature, the coil returns to the coil in the air. Of course, it is also possible to return to the memorized shape (elongated helical wire). That is, the operation of the thermomechanical conversion element according to this example is as follows:
Thermal energy is alternately applied to and taken away from the shape memory alloy, and the resulting restoring force of the shape memory alloy generates rotational force in the shaft body.

Therefore, in order to realize such an operating principle, the use is not limited to the use of a shape memory alloy that has a shape memory effect that restores its memorized shape when heated to a high temperature as in the above-mentioned embodiment.
Shape memory alloys having the opposite shape memory effect can also be used in the same manner as in this embodiment. In this case, cold water may be used as the cooling means instead of hot water as the heating means, and the shape memory alloy may be configured to restore its memorized shape in the cold water.

2 and 3 show a modification of the embodiment of FIG. 1. FIG.

The example shown in FIG. 2 is intended to increase the generated rotational force, and a plurality of arms 5 each having a shape memory alloy wire (helical wire) 7 wound thereon as means for rotating the shaft body 1 are used in the example shown in FIG. 2) are installed.

As a result, a rotational force approximately twice as large as that in the example shown in FIG. 1 can be obtained.

In the example shown in FIG. 3, an arm 5 is placed inside the helical wire 7.
It is designed so that it does not pass through.

That is, both ends of the two arms 5 are connected by a connecting member 9, and one end of the helical wire 7 is fixed to this connecting member 8. If the connecting material 81 θ is made of a material with a large specific gravity, it becomes a weight. It can have a role as

By using the thermomechanical conversion element configured as described above, thermal energy can be converted into mechanical energy. However, the converted mechanical energy is the normal and reverse intersection m of the shaft l
It is extracted as a rotational motion of. Therefore, a second embodiment will be described below in which the mechanical energy is extracted as rotational motion of the shaft body 1.

(Second Embodiment) FIG. 4 CA) shows a second embodiment of the present invention, which is constructed so that the supplied thermal energy is extracted as continuous rotational movement of the shaft body 1.

As shown in the figure, through holes 2-1 and 2-2 passing through the shaft core 4 are formed in the outer circumferential wall 3 of the shaft body 1 at positions spaced apart from each other in the axial direction. Furthermore, both page holes 2-1 and 2-2
shall be formed so as to be shifted from each other by a predetermined angle. These page holes 2-1, 2-2 have screws 8R and S on both ends.
Arms 5-i and 5-2 to which L is attached are slidably inserted. Further, in each arm 5-1, 5-2, helical wires made of a shape memory alloy are arranged symmetrically with respect to the axis. Install (7R, 7L),
One end of the wire 7 is fixed to a weight, and the other end is fixed to the shaft body 1. The helical wire 7 is formed by memorizing a coil shape in advance at high temperature and then stretching it at high temperature to form a helical loop.

The operating principle of the thermomechanical conversion element constructed in this way will be explained based on FIGS. 4(B) to 4(D).

First, the principle of sustained rotational motion is the shape memory alloy 7R-1
, 7R-2, 7L-1, and 7L-2, the rotational force about the axis 4 of the shaft body is generated in one direction. In other words, the first rotation, for example, clockwise rotation, regardless of whether it is self-inflicted or external! 5- Suppose that the surface of the hot water reaches the state shown in Figure 4 (B). In this state, the shape memory alloy wire 7R-2 has just been immersed in the hot water 8, so sufficient restoring force (contraction force) has not yet been generated1. X. On the other hand, since the wire 7L-2 has just come out of the hot water 8, there still remains a force to maintain the contracted state.

Therefore, the arm 5-2 is connected to the wire 7 from the wire 7R-2 side.
It is only slightly pushed back to the L-2 side, and a clockwise rotational force still acts. However, since the shape memory alloy wire 7R-1 has been sufficiently heated, a large restoring force (contraction force) acts, and the wire 7L-1 has been sufficiently cooled, so there is no remaining force to maintain the memorized shape.

Therefore, the arm 5-1 is strongly pushed toward the wire 7L-1, the balance around the axis is broken, and a clockwise rotational force is generated. In this way, clockwise rotational force is applied by the arms 5-1 and 5-2, and the shaft body 1 continues to rotate clockwise. As a result, the state shown in Fig. 4(B) changes from the state shown in Fig. 4(B) to
Move to state C).

In the state shown in FIG. 4(C), the shape memory alloy wire 7R-2 is sufficiently heated and contracts, and the arm 5-2
is pushed toward the wire 7L-2, so a clockwise rotational force is generated on the shaft body 1 by the arm 5-2. On the other hand, shape memory alloy wire? L-1 is gradually heated and its restoring force is gradually increased accordingly, but since the wire 7R-1 still has residual heat, a slight force remains to maintain the memorized shape.

Therefore, since the force for pushing arm 5-1 toward wire 7R-1 is insufficient, clockwise and counterclockwise rotational forces are generated as arm 5-1 moves. but,
Since the rotational force is small, a clockwise rotational force is generated on the shaft l as a whole in this case as well. Therefore, the shaft body 1 rotates clockwise #, >" as shown in Fig. 4 (D).
Transition to the state shown in .

In the state shown in FIG. 4(D), the shape memory alloy wire 7L-1 is sufficiently heated and shrinks to the maximum extent, so that the arm 5-1 is heated to the maximum extent possible. Pushed to the R-1 side. At this time, the horizontal line (hot water level) and arm 5-1
Since the angle between the On the other hand, the arm 5-2 is pushed toward the wire 7R-2, and a counterclockwise rotational force is generated.
Since the angle between -2 and the horizontal line is close to a right angle, only a small rotational force is generated in the counterclockwise direction. Therefore, in this case as well, the clockwise rotational force prevails as a whole, so
The shaft 1 continues to rotate clockwise and returns to the state shown in FIG. 4(B). A continuous rotation of the shaft l is thus obtained.

In addition, although the above-mentioned Example described the case where two arms were arranged, it is of course not limited to this only, and the number can be increased as needed. Further, it is preferable that the positional relationship between the arms and the tail be determined by considering the length of the arm, the weight, the restoring characteristics of the shape memory alloy, etc. so that the shaft body can be smoothly rotated.

Next, FIG. 5 shows an improvement of the example shown in FIG. 4 so that the shaft body can be rotated more efficiently.

To this end, in this embodiment, the shaft body 1 is supported by a support member (not shown) so that its shaft center is located at the hot water level, and a retaining wall 51 is provided to prevent the counterclockwise movement that occurs in the example shown in FIG. Converts rotational force in the rotation direction into clockwise rotational force.

For this purpose, the arm 5 is brought into contact with the curved surface 52 of the holding wall 51 with a predetermined pressing force due to the restoring force of the shape memory alloy wire 7. Further, when the arm 5 presses the curved surface 52 vertically, no tangential force of the pressing force is generated, so the arm 5 always presses the curved surface 52 from an oblique direction. Further, the curvature of the curved surface 52 is set so that the generated tangential force rotates the shaft body 1 clockwise.

In the example shown in FIGS. 5(A) to 5(C), the angle between the tangent of the curved surface 52 at the contact point of the arm 5 and the arm 5 is 0.
The curvature of the curved surface 52 is set so that the angle is always an acute angle.

Incidentally, the installation range of the holding wall 51 is, of course, as shown in FIGS.
Although not limited to the example shown in C), it is preferable to provide it in a range where counterclockwise rotational force is generated by the arm 5.

Next, FIG. 6 shows a pulley 1317F that also serves as a weight at the tip of the arm 5 in order to reduce the loss of rotational energy due to friction.
t is provided.

By doing so, the friction between the curved surface 52 and the arm 5 can be reduced, and the rotation efficiency can be further improved.

(Third Embodiment) In FIG. 7(A), 71 shows a water toy to which the thermomechanical conversion element shown in FIG. It is. A curved arm 74 is slidably inserted into a through hole 75 formed in the hull 71, and its both ends are fixed to the paddles 72 and 73.

Moreover, 76 and 77 are helical wires made of a shape memory alloy wound around the arm 74, and one end thereof is fixed to the paddles 72 and 73, respectively, and the other end is fixed to the hull l. Note that the wires 76 and 77 have coil shapes memorized at high temperatures.

The operation of the water toy configured in this way will be explained. As shown in FIG. 7(B), when the hull 71 is tilted, the helical wire 77 is immersed in hot water 78 and heated, and is restored to the memorized coil shape. Due to this restoring force, the arm 74 is pushed toward the wire 76 side, and the paddle 73 fixed to the arm 74 challenges the hull 71 side and scrapes the warm water (see FIG. 7 CG)). As a result, the hull 71 gains thrust and performs DQa. On the other hand, while such an operation is performed, the hull 71 maintains gravitational balance and rotates around the hull 71 in the direction of an arrow 78 shown in FIG. 7(B). As a result, the hull 71 rotates to the state shown in FIG.
The wire 77 is cooled and heated, and the wire 77 comes out into the air and becomes a heat radiating state. Therefore, a restoring force is generated that tries to restore the wire 78 to the memorized shape, and the restoring force that had been generated in the wire 77 disappears. That is, the arm 74 is connected to the wire 77.
Pushed to the side, webbed? 2 will bend and splash the hot water. Such operations are repeated, and thrust is continuously applied to the hull 71 to move it forward.

It is preferable that the members forming the paddles 72 and 73 have flexibility so that the above-mentioned paddle action can be performed smoothly. For example, if the hull 71 and the paddles 72 and 73 are connected by pins It does not have to be formed from a flexible member.

(Fourth Example) FIG. 8 shows an example of a lees equipped with a heat engine using the thermomechanical conversion element shown in FIG. 5.

Here, reference numeral 81 is a rotary engine to which a thermomechanical conversion element configured as shown in FIG. 84 is hull 8
5 is a heated wastewater storage tank constructed inside the tank, and has the same function as the hot water tank shown in FIG. 5.

In a ship having such a configuration, the thermal energy of the heated waste water is extracted as rotation of the impeller 83, and the thrust of the ship is obtained.

Effects As explained above, according to the present invention, it is possible to realize a thermomechanical conversion element with high energy conversion efficiency in a component cylinder, thereby making it possible to effectively utilize the heat energy of heated waste water and sunlight that is wastefully discarded. It is effective on

[Brief explanation of drawings]

FIG. 1(A) is a perspective view showing the first embodiment of the present invention;
Figures (B), (C), and (D) are sectional views showing the operation, respectively; Figures 2 and 3 are perspective views showing a modification of the first embodiment shown in Figure 1; Figure (A) is a perspective view showing the second embodiment of the present invention, Figures 4 (B) and (C)
and (D) are diagrams illustrating the respective operations, Fig. 5 1
:A), (B) and (C) are diagrams showing the operation of a modification of the second embodiment shown in FIG. 4<A), and FIG. 6 is a diagram showing the operation of the second embodiment shown in FIG. 4(A). Diagram showing another modification of , No. 7
Figure (A) is a perspective view showing a water bottle to which the first embodiment shown in Figure 1 (A) is applied, Figures 7 (B) and (C)
7 (A) is an elevation view and a plan view showing the operation of the toy shown in FIG. 7 (A), FIG. (B)
These are a side view and a plan view of a ship to which the second embodiment shown in FIG. 4(A) is applied. 1... Axial body. 2... Through hole, 3... Outer peripheral wall, 4... Axis core, 5... Arm, 6... Weight, 7... Helical wire (shape memory alloy), 8...
・ N crystal; 1. Water, 8... Connecting member, 51... Holding wall, 52... Curved surface, 61... Pulley, 71... Hull, 72.73... Water web, 74... Arm, 75 ...Through hole. ? +3.77...Helical wire (shape memory alloy),
7th... Hot water, 81... Heat engine, 82... Output shaft, 83... Impeller, 84... Storage tank, 85... Hull, R, L... Arrow. Figure 2/L-2 Figure 7 (B) (C) 7 et al. Figure 8 83 85

Claims (1)

[Claims] l) A member (A), a member (B) attached to the member (A) so as to be movable relative to the member (A), and a member (B) that has a restoring force to a predetermined memorized shape. 1. A thermomechanical transducer comprising: a shape memory alloy member that moves; and the movement of the member (B) generates a rotational force around the axis of the member (A). 2) The thermomechanical conversion element according to claim 1, wherein the member (A) is provided with a through hole, and the member (B) is inserted into the through hole.