JPH0249971A - Actuator - Google Patents

Abstract

PURPOSE:To obtain an actuator in small size and light weight applicable for use in space with a shape memory alloy utilized by providing the coil-shaped shape memory alloy, inserted to a cylinder block, and an electrification means for the shape memory alloy to be arranged in the inside of a cylinder. CONSTITUTION:To operate an actuator, a shape memory alloy 3 is electrified. That is, an electric current is conducted from an electric wire 16, serving as an electrification means, in the electric wire 16 through an inner conductive member 15, rod conductive part 19, flange conductive part 21 and a conductive bolt 22. And the shape memory alloy 3, being heated, is restored and deformed so as to be contracted in a direction of the axial center. While a rod guide 10 is slided against a bias spring 28 to a side of an opening part 6 in a cylinder 1. Further a cylinder rod 2, mounted to the rod guide 20, is extended from the cylinder 1 while an outer end part of the cylinder rod 2 is slided by a through hole 13 in a cover member 12. In this way, an operation connected part B is moved by a predetermined stroke S.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an actuator that operates by utilizing the stability of a shape memory alloy, and particularly relates to an actuator used for operating space equipment.

[Prior Art] In general, an actuator is used in a wide range of fields, such as fluid on-off valves, as an actuating device that generates a driving force using energy supplied from the outside and uses this driving force to apply force and displacement to a plunger plug. ing. The actuator is actuated by hydraulic, electrical, and combinations of drive energy. Among these, an electromagnetic actuator is known as one that uses electrical energy, for example, which uses the force of an electromagnetic solenoid to operate a plunger or the like.

FIG. 6 shows an example of a conventional electromagnetic actuator, and as shown in the figure, this electromagnetic actuator consists of a solenoid part 42 and a 1-lunger part 43. This solenoid part 42 is made up of a winding 44 and an iron core 46 fitted into a hollow part 45 formed at the center of the solenoid part 42 .

Further, the granger portion 43 is formed of, for example, a bar-shaped silicon steel plate, and is inserted so as to be freely protrusive and retractable toward the opposite end of the iron core portion 46 fitted into the hollow portion 45 of the winding 44 . A plunger lug 47 is provided at the outer tip of the first langeer portion 43, and an actuated device is connected to this. A coiled plunger spring 48 through which the plunger portion 43 is not inserted is provided between the outer end of the plunger portion 43 and the outer end of the solenoid portion 42 .

Therefore, by energizing the winding 44 of the solenoid part 42, a solenoid wave is excited in the hollow part 45,
The plunger portion 43 is drawn toward the iron core 46 against the spring force of the plunger spring 48, and the plunger plug 48 is moved in the direction of arrow F in the figure, thereby operating the actuated device.

Further, when the power to the winding 44 is cut off, the excitation is stopped, and the plunger portion 43 moves the plunger plug 47 in the direction of arrow G in the figure by the spring force of the plunger spring 48 to operate the actuated device. and was used as an actuator.

[Problems to be Solved by the Invention] Recently, research and development of space equipment has been progressing, and research on actuators for operating the members of these space equipment is also progressing. However, due to the space environment, an appropriate actuator has not yet been developed.

In particular, actuators used in space equipment cannot use fluids due to their environment, and even when using current from solar cells, for example, actuators that use conventional electromagnetic solenoids do not have windings or iron cores. Since it is used, it is heavy and requires a large current to be applied, making it unsuitable for space equipment.

On the other hand, there is a technical concept of using a shape memory alloy to operate a plunger based on the amount of displacement between the shape at room temperature and the shape restored by applying electricity and heating, but no progress has been made in the development of application to actual machines. The problem was that it was not.

The present invention has been made to solve these problems, and its purpose is to restore the original shape by energizing the shape memory alloy to generate heat, and to use this displacement as the actuation amount of the plunger. It is lightweight, compact, and
Another object of the present invention is to provide an actuator that operates with a small amount of electric power and can be applied to actual equipment.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a cylinder having a closed end, a cylinder rod slidably inserted into the cylinder, and a cylinder rod provided in the cylinder and having the above-mentioned cylinder rod. It is comprised of a coil-shaped shape memory alloy into which a cylinder rod is inserted, and an energizing means for energizing the shape memory alloy, and an opening for heat radiation is formed in the cylinder.

[Operation] A coiled shape memory alloy provided so that the cylinder rod is inserted into the cylinder is energized and heated, and the cylinder rod is actuated by the stability of this alloy,
Further, the power supply to the shape memory alloy is cut off to cool it, and the shape memory alloy is deformed by a plunger spring or the like, and the cylinder rod is operated to return to its original position. Therefore, it operates as an actuator with a small amount of electricity. At the same time, when the shape memory alloy is cooled by stopping the current supply, the opening provided in the cylinder acts to speed up the cooling and promote the operation of the cylinder rod.

[Example code] A preferred embodiment of the present invention will be described with reference to the drawings.

The actuator shown in this embodiment is used for operating space equipment in space with a high degree of vacuum.

As shown in FIGS. 1 to 3, a cylindrical cylinder 1 with a closed tip 5, a cylinder rod 2 slidably inserted into the cylinder 1, and a cylinder rod 2 provided in the cylinder 1 are shown in FIGS. A coiled shape memory alloy 3 into which the cylinder rod 2 is inserted is provided, and a current supply means 4 is provided for supplying current to the shape memory alloy 3. Also, the cylinder 1 has a heat dissipation opening for dissipating heat from the shape memory alloy. A portion 9 is provided and configured.

As shown in the figure, the tip 5, which is one end of the cylinder 1, is closed, and the tip 5 is provided with an actuating connection A as an actuator. The tip 5 of this cylinder 1
A rod guide 10 having an outer diameter substantially the same as the inner diameter of the cylinder 1 is provided inside the cylinder 1 so as to be slidable in the axial direction of the cylinder 1 .

A cylinder opening 6 is formed at the other end of the cylinder 1 . A benefit body 12 is inserted into the cylinder opening 6 via a current-carrying flange 14 and an insulating bushing 20 for power supply.
It is detachably attached using a real screw member 11. A through hole 13 through which the cylinder rod 2 slides in and out is provided in the center of the lid 12.

A cylinder rod 2 is inserted into the cylinder 1. One end of this cylinder rod 2 is attached to a rod guide 10 slidably provided within the cylinder 1, and the other end is slidably passed through a through hole 13 of an M body 12. A rod current-carrying portion 19 is provided at the inner end of the inserted cylinder rod 2.
The rod current-carrying portion 19 is screwed to the rod guide 10 by the inner current-carrying member 15.

This rod guide 10 is made of an electrical insulator,
Electric wire 16 and inner current carrying member 1 from a power source (not shown)
5, the rod energizing portion 19 of the cylinder rod 2 is configured to be energized as the energizing means 4.

Note that the electric wire 16 may not be connected to the inner current-carrying member 15, but may be connected to an operation connection portion B, which will be described later.

On the other hand, the end of the cylinder rod 2 is provided with an actuation connection B as an actuator. At the same time, the other @ side is slidably inserted into the through hole 13 of the lid 12 attached to the cylinder opening 6 of the cylinder 1.

Inside the flange 14 interposed between the cylinder opening 6 of the cylinder 1 and the lid body 12, a sgur-shaped flange current-carrying part 21 is formed as shown in the figure, and the flange current-carrying part 21 is energized. In order to
2 as a current supply means 4.

The rod current-carrying part 19 connected to the inner end of the cylinder rod 2 and the flange current-carrying part 21 of the flange 14 provided at the cylinder opening 6 of the cylinder 1 have a shape memory formed in a coil shape. Alloy 3 is attached and the cylinder rod 2 is inserted through it. Also,
This cylinder rod 2 has a coiled shape memory alloy 3.
A coil guide member 27 for insulating heat and electricity from the rod 2 and preventing buckling is provided to surround the rod 2.

The shape memory alloy 3 used in this embodiment is a known alloy, such as a T1Ni alloy or a Cu 3 A J alloy. This alloy is easily deformed at room temperature, and has the property that it can be deformed in any way, but instantly returns to its original shape with just a little heating. It is used as a source. In other words, when operating the actuator,
This coiled shape memory alloy 3 is energized and heated to restore its original shape, and the amount of displacement of the shape of the coil between the room temperature and the heating temperature is set so that the cylinder rod 2 is actuated.

The rod guide 10 attached to the tip of the cylinder rod 2 and the opening 61F of the cylinder 1! A coiled bias spring 28 is provided between the rod guide 10 and the insulating bushing portion 20 provided at I in order to reactively assist the movement of the rod guide 10 due to the expansion and contraction of the shape memory alloy 3. The coiled shape memory alloy 3 is inserted into the bias spring 28 .

In addition, when the above-mentioned shape 100 million alloy 3 is energized,
The cylinder rod 2 is heated and restored, and the cylinder rod 2 is operated, and after this operation is completed, the current supply is cut off. In order to promote thermal radiation cooling of the alloy 3 being heated at this time, an appropriate number of heat radiation openings 9 of an appropriate size are provided on the outer periphery of the cylinder 1. A heat dissipation opening 9 having a size substantially equal to the size of the memory alloy 3 is provided in the memory alloy 3 .

Next, the operation of this embodiment will be explained.

This actuator is installed between a fixed part and an actuated part of space equipment, for example, the actuation connection part A of the cylinder 1 is on the fixed part side of the equipment, and the actuation connection part B of the cylinder rod 2 is on the side of the actuated part of the equipment. Installed.

After this, the action as an actuator is performed. First, shape memory alloy 3 is used to operate cylinder rod 2.
energization is performed. This includes a power supply (not shown), an electric wire 16, an inner current-carrying member 15, and a rod current-carrying portion 1.
9, the shape memory alloy 3 is energized, and from this alloy 3, the electric wire 16 is passed through the 7 lange current-carrying portion 21, the current-carrying bolt 22, and
energized to the power supply. By being energized, the coiled shape memory alloy 3 generates heat and is restored to its original shape by its own heat, so that the total length of the alloy 3 is reduced in the axial direction shown by arrow C in the figure. It is restored and deformed like this. Due to this reduction, the shape memory alloy 3 in this state has a high elastic modulus and deforms, so the rod guide 10 resists the spring force of the bias spring 28 and moves toward the cylinder 1.
It is made to slide toward the cylinder opening 6 while sliding inside.

With this operation, the outer end of the cylinder rod 2 attached to the rod guide 10 is extended from the cylinder 1 while sliding through the through hole 13 of the lid 12, and its operating connection part B is The actuated member is moved by the stroke S, and the extension operation as an actuator is completed.

Note that a coil guide member 27 is provided surrounding the cylinder rod 2 so that the shape memory alloy 3 is deformed and moved in the axial direction of the cylinder 1 without buckling.
guided by.

The retracting operation of the actuator without returning the actuated member to its original position is performed as follows.

For this operation, first the power from the power source is cut off. As a result, the shape memory alloy 3 stops being heated and begins to cool down. Since this actuator is operated in the vacuum of space, there is no flow of cooling fluid such as air, and therefore this alloy 3 is cooled by thermal radiation. This heat radiation is performed through a suitable number of heat radiation openings 9 provided on the outer periphery of the cylinder 1.

Due to its characteristics, the elastic modulus of the shape memory alloy 3 decreases as it cools, making it easier to deform. Therefore, it is deformed by the spring force of the bias spring 28, and the length of this alloy 3 extends in the direction of the arrow in the figure. It works like this.

As a result, the rod guide 10 inside the cylinder 1 is moved while sliding in the direction of the distal end 5 of the cylinder 1.

As the rod guide 10 moves, the cylinder rod 2 attached to the rod guide 10 slides through the through hole 13 of the lid 12 and moves to be drawn into the cylinder 1. The operating connection part B attached to the shape memory alloy 3 moves by a stroke S, and in a state where heat dissipation is completed, a contraction operation is performed so that the shape memory alloy 3 returns to the state before being energized and heated.

In the case of this example, the current heating temperature ('C
) and stroke (related) This relationship is as shown in FIG. 4, and a stroke in the range of 0 to 11 mm can be operated at a temperature of 50 to 70°C.

Furthermore, at a room temperature of 25°C, the relationship between the current value (A) applied to the shape memory alloy 3 and the temperature ("C) of this alloy 3 is as shown in Figure 5, and the heat resistance of this alloy 3 is as follows. Taking into account the temperature, the current value is calculated to be energized and operated between 5.8 and 7.0 A.

Therefore, according to this embodiment, a large stroke of the cylinder rod 2 can be obtained with a small current, and it is ideal for space equipment that uses a solar cell as a power source, for example.

[Effects of the Invention] Since the present invention is as described above, it has the following excellent effects.

(1) A coiled shape memory alloy is provided in the cylinder, and the stability due to heat generated by electricity is used as the operating force of the cylinder rod, so this alloy can be operated as an actuator with a small amount of current that generates heat.

(2) Regardless of whether the actuator is actuated by electric current, the actuator can be made smaller and lighter than an electromagnetic coil or the like which is large in shape and weight.

(3) The shape memory alloy whose temperature has increased due to heat generation is
Thermal radiation cooling is provided to facilitate the retracting operation of the actuator.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment according to the present invention, and FIG.
Figure 3 is a side view of Figure 1, Figure 4 is a diagram showing the relationship between the heating temperature of the shape memory alloy used in this example and the stroke of the cylinder wood, and Figure 5 is the same heating temperature. FIG. 6 is a cross-sectional view of a conventional electromagnetic valve. In the figure, 1 is a cylinder, 2 is a cylinder wood, 3 is a shape memory alloy, 4 is a current supply means, 5 is a tip of the cylinder, and 9 is a heat radiation opening. Patent Applicant Haru Ishikawajima@Heavy Industries Co., Ltd. Agent Patent Attorney Nobu Kinuya
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Claims (1)

[Claims] 1. A cylinder with a closed tip, a cylinder rod slidably inserted into the cylinder, and a coiled shape memory alloy provided in the cylinder and into which the cylinder rod is inserted. and an energizing means for energizing the shape memory alloy. 2. Claim 1, wherein an opening for heat radiation is formed in the cylinder.
Actuator as described.