JPS60125778A - Rotary driving device utilizing shape memory alloy - Google Patents

Abstract

PURPOSE:To permit to convert the force of a spring into a torque immediately by a method wherein the spring of shape memory alloy, for generating the torque, is attached so as to be expanded and contracted only but not to be moved especially in order not to generate a resistant force which preclude the rotation of the device. CONSTITUTION:When low-temperature fluid is supplied into first cylinder 6a and high-temperature fluid is supplied into fifth cylinder 6e, three sets of coil springs 9 in fifth - seventh cylinders 6e-6g are contracted and respective coil springs 9 in the first - third cylinders 6a-6c are expanded. Accordingly, the component of their tensions is changed into the axial direction of the seventh cylinder 6g and a ring member 4 moves to the direction of the component whereby a disc 3 rotates clock-wise about an output shaft 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotational drive device that converts thermal energy into rotational force that is mechanical energy, and in particular, a spring made of a shape memory alloy is heated above its transformation point to restore its memorized shape. This relates to a device that obtains rotational force by the force used when rotating.

As is well known, shape memory alloys have the unique property of returning to their original shape by being deformed at a temperature below the transformation point and then heated to a temperature above the transformation point. Shape memory alloys have traditionally been used to control the opening and closing of doors and pulp, as well as eyeglass frames to fix plastic lenses, because the force that causes deformation is large when the force is below the transformation point.
Research is also being carried out on its use in thermally driven engines and micro actuators for robots.

By the way, when converting thermal energy into rotational motion using a shape memory alloy, it is necessary to continuously deform and restore the shape memory alloy. Usually, one of the springs is heated and restored (shrinked), thereby deforming (expanding) the other springs.

However, this conventional rod device has a configuration in which multiple springs made of shape memory alloy are stretched at equal intervals and are alternately immersed in a bath of hot water. There was a problem in that the rotational force was reduced due to the resistance force caused by the hot water.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotary drive device using a shape memory alloy that can obtain a large driving force.

A feature of this invention is that a plurality of cylinders each having a rod that is protruded or retracted by a shape memory alloy spring is mounted around an eccentric rotating disk that is supported to rotate at a location off center. arranged radially,
A ring member is fitted into the outer circumference of the disk so as to be slidable relative to the disk, and the rods of each cylinder are rotatably connected to the outer circumference of the ring member at equal intervals,
The present invention is characterized in that a high-temperature fluid with a temperature above the transformation point of the shape memory alloy spring and a low-temperature fluid with a temperature below the transformation point are alternately and periodically supplied to each cylinder.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 are schematic diagrams showing one embodiment of the present invention, in which a rotary output shaft l is rotatably supported at a predetermined height by a bearing 2, and the output shaft 1 is a disc plate. The two are integrated by penetrating through a point deviating from the center of 3 by a predetermined distance l,
Therefore, the disk 3 is an eccentric rotating disk whose rotation center is at a location off the center. A ring member 4 is provided on the outer periphery of the disc 3 so as to rotate freely relative to the disc 3, and the output 111 is provided around the disc 3.
A circular frame 5 is arranged coaxially with 111,
A plurality of (eight in the figure) cylinders 6a, 6b, 6c, 6d, and 6e are provided on the inner peripheral surface of the circular frame 5.

6ft 6g, 6h are rotatably attached at the rear end and at equal intervals, and rods 7a of each cylinder 6a to 6h are attached.
, 7b, 7c, 7d, 7e, 7f, 7g.

7h are rotatably connected to the ring member 4 via pins 8 at equal intervals.

Here, the cylinders 63 to 6h all have the same configuration, one of which is illustrated in FIG. 3. That is, cylinder 6a
~6h is a rod 7a that protrudes toward its tip side.
~7h, and incorporates a shape memory alloy coil spring 9 that memorizes a predetermined shape (for example, a contracted state),
One end of the coil spring 9 is fixed to the end of the rod 7a to 711, and the other end is fixed to the bottom inner surface of the cylinder 6a to 6h. The rods 7a to 7h are retracted into the cylinders 6a to 611 by moving the rods 7a to 7h. Each of the cylinders 6a to 6hK has a spring 9
An inlet 1° through which a high-temperature fluid having a temperature above the transformation point and a low-temperature fluid having a temperature below the transformation point flow in, and an outlet 11 through which these fluids are discharged are provided. The inlet 1o is connected to a high temperature fluid source such as steam/H2S via a high temperature fluid valve 12 on the one hand, and to a low temperature fluid source such as a water supply pipe 15 via a low temperature fluid valve 14 on the other hand. Further, the discharge port 11 is connected to a discharge pipe 16 that communicates with a wastewater treatment facility, a water discharge pipe, or the like.

In short, the high-temperature fluid may be any fluid having a high temperature T1 higher than the transformation point of the shape memory alloy constituting the coil spring 9, and if steam or hot water produced by a waste heat boiler is used as the high-temperature fluid, it will save money. Effective in terms of energy. In short, the low-temperature fluid may be any fluid having a low temperature T2 below the deformation point of the shape memory alloy, and for example, commonly used factory water can be used.

Furthermore, the high-temperature fluid and the low-temperature fluid are alternately supplied into the cylinders 6a to 6h at a predetermined period, and the periods in each cylinder 68 to 6h are sequentially shifted slightly. The valve 12.14 is a solenoid valve, and the cholera pal 7-12.14'
It is configured to open and close in response to a finger signal from an appropriate control device (not shown) such as a z-sequence controller.

The output shaft 1 is connected to a screw shaft 19 of a screw feeder set 18 for ore powder 17 by a shaft coupling 2.
Connected via 0.

Next, the operation of the apparatus configured as described above will be explained.

First, the internal temperature of each cylinder 63 to 6h and the state of the coil spring 9 provided therein are set to change periodically from process I to process (2) as shown in Table 1. This is the high temperature fluid valve 12 in each cylinder 63 to 6h.
This can be done by slightly shifting the timing of opening and closing of the low-temperature fluid valve 14 from the first cylinder 6a to the eighth cylinder 6h.

The state shown in Table 1 and Figure 1 is the state of Step 1 in Table 1,
High-temperature fluid is supplied into the sixth to eighth cylinders 6f to 6h, and the coil springs 9 are gradually contracted to the pre-memorized shape, and the coil springs 9 in the second to fourth cylinders 6b to 6d are gradually expanded. There is. Furthermore, the inside of the first cylinder 6a is in the stage of switching from high-temperature fluid to low-temperature fluid, and the coil spring 9 is in a state of transition from contraction to expansion. Furthermore, the inside of the fifth cylinder 6e is in the stage of switching from low-temperature fluid to high-temperature fluid, and its coil spring 9
is a state in which there is a transition from elongation to contraction.

When moving from this state to step (2), the valves 12 of the first and fifth cylinders 6a and 6e are switched to supply low temperature fluid to the first cylinder 6a, and the fifth cylinder 6e is supplied with low temperature fluid. When high temperature fluid is supplied to the cylinders 6e to 6g, the three coil springs 9 in the fifth to seventh cylinders 6e to 6g contract, and the first to third cylinders 63 to 6c contract.
As each coil spring 9 stretches, the resultant force of its tensile force changes in the axial direction of the seventh cylinder 6g, and as a result, the ring member 4 moves in the direction of the resultant force, causing the disc 3 to move toward the output shaft 1. Rotate clockwise in Figure 1 around . From then on, high temperature fluid is supplied similarly.
Among these cylinders, the valve 12.14 of the one cylinder located on the rear side in the direction in which the output shaft 1 should be rotated is switched to supply low-temperature fluid, and the valve 12. Valve 1 of one cylinder in
2. By switching 14 and supplying high-temperature fluid to the cylinders, the three cylinders set to the high temperature T state are changed 11' quaternically in the rotational direction of the output shaft 1, and the transformation point is reached. Since the three coil springs 9 that are heated and restored are switched sequentially, the output +ll+1 is the same as the disk 3.
It can be rotated clockwise in the figure. Therefore, since the scree i11+19 of the cutting device 18 is rotated together with the output shaft l, a predetermined amount of the ore powder 17 can be cut out.

In addition, the valves 12 in all cylinders 63 to 6h,
If the opening/closing of 14 is stopped, the output shaft stops rotating 10 times. Furthermore, if the order of the cylinders in which the fluid to be supplied is switched from the low-temperature fluid to the high-temperature fluid, that is, the order of the coil springs 9 to be heated and restored, is reversed from the above case, the output shaft l can be moved in the opposite direction as shown in FIG. It can be rotated clockwise.

As is clear from the above explanation, according to the device of the present invention, the shape memory alloy spring that generates the rotational force simply expands and contracts and does not move, so a resistance force that prevents rotation is generated. First, the number of flt'i sheets in the rotating portion is small, and as a result, the force of the spring can be immediately converted into rotational force, so a large rotational driving force can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic front view showing one embodiment of the present invention, FIG. 2 is a vertical side view thereof, and FIG. 3 is a schematic exploded sectional view showing one of the cylinders. 3... Disk, 4... Ring member, 5... Circular frame, 68-6h... Cylinder, 7a-7h...
Lot, 9...Shape memory alloy coil spring, 10...
- Inlet, 11... Outlet, 12... Valve for high temperature fluid, 13... Steam pipe, 14... Pulp for low temperature fluid, 15... Water supply pipe. Figure 3

Claims (1)

[Claims] A ring member is slidably attached to the outer periphery of an eccentric rotating disk that is rotatably supported at a location off the center, and one end of a plurality of rods is attached to the outer periphery of the ring member. are rotatably mounted at equal intervals,
The other end of each rod is inserted into a cylinder that is rotatably attached at equal intervals to a fixed part on the circumference of the eccentric rotating disk, and one end is inserted into the cylinder. A shape memory alloy spring fixed to the rod and fixed to the inner surface of the cylinder at the other end and having a predetermined shape memorized is provided in each cylinder, and each cylinder is further provided with a high temperature above the transformation point of the spring. A shape memory alloy characterized in that a fluid source and a low temperature fluid source at a temperature below the transformation point of the spring are connected via a valve, and each cylinder is provided with a discharge port for discharging these fluids. Rotary drive device used.