JP3060015B1 - Attitude control drive device using shape memory alloy and method of diagnosing state of deterioration of shape memory alloy - Google Patents

Abstract

A solar cell paddle is automatically provided by a function of a shape memory alloy without providing a light receiving sensor, a motor, a control circuit, a power supply, and the like, and without having to worry about a storage location of these elements. Enables efficient attitude control. SOLUTION: A shape memory alloy 4 is fixed at its distal end to a disk 2 on which a solar battery paddle 1 is erected by a fixture 3, and its proximal end is attached to an artificial satellite body 8 to which the solar battery paddle 1 is attached. The solar cell paddle is fixed, and is heated by solar heat to shrink and constantly control the attitude of the solar cell paddle in the direction of the sun.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an attitude control driving device for directing an object to be controlled in the direction of an external heat source, for example, an artificial satellite, a solar cell vehicle, a solar cell power generator or the like. The present invention relates to a posture control drive device for controlling the posture of a battery panel or the like. More specifically, the present invention relates to a mechanism that uses a shape memory alloy as a driving member, to which a heat source including the sun can be added to change the direction spontaneously. Further, the present invention relates to a diagnostic method which can easily diagnose the deterioration state of a shape memory alloy used as a component such as a drive mechanism of such an apparatus by measuring an electric resistance value.

[0002]

2. Description of the Related Art When controlling the attitude of a solar cell panel or the like attached to an apparatus body such as an artificial satellite, a solar cell car, or a solar cell power generator, conventionally, the direction of sunlight is detected by a light receiving sensor. A mechanism that uses a motor as a driving force to control the posture to an optimum posture by a driving mechanism is used.

[0003]

In such a mechanism using a conventional light receiving sensor and a motor, a control circuit and a power source for driving the motor are required, and where the energy resources are small or the storage space is limited. Had a problem. In addition, there is a problem that the deterioration state is not known until the motor stops operating, and sudden failure occurs when unexpected.

The present invention focuses on a shape memory alloy having a property of being deformed by heat such as sunlight, and uses the shape memory alloy as a driving member in a driving mechanism. It is an object of the present invention to realize a very simple and reliable attitude control drive device without providing a sensor, a motor, a control circuit, a power supply, and the like, and with no particular restrictions on their storage locations.

In a device using a shape memory alloy, if the shape memory alloy deteriorates over time, it is not only unfavorable for maintaining the function of the device but also causes a failure of the device using the shape memory alloy. However, replacing a shape memory alloy that has not deteriorated is a problem in terms of cost performance. Therefore, it is necessary to check the deterioration with time of the shape memory alloy and replace it with a new one at an optimal timing to solve the above-mentioned problem. However, this work for checking the deterioration of the shape memory alloy over time can be done by removing it from the device using the shape memory alloy, or by heating or heating the shape memory alloy.
It is extremely troublesome to obtain deformation characteristic data.

The present invention makes it possible to easily diagnose the deterioration state of a shape memory alloy without removing and checking the shape memory alloy from an apparatus, and to easily determine the optimum timing to replace the shape memory alloy. It is an object of the present invention to provide a method for diagnosing the state of deterioration of a shape memory alloy, which can reduce the maintenance cost as well as maintain the performance and prevent the failure of the apparatus using the method.

In particular, when the shape memory alloy is used in an attitude control device of a solar cell panel in an artificial satellite, a solar cell vehicle, a solar cell power generation device or the like as described above, the shape memory alloy is accessed. Since it is not always easy to check the state of deterioration, a method that can diagnose the state of deterioration of the shape memory alloy remotely is important.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention utilizes a driving member made of a shape memory alloy, and a movable object mounted on an apparatus body in the direction of an external heat source. A posture control driving device for directing a control body, wherein the driving member has a distal end portion fixed to a posture control body or a support member supporting the posture control body, and a base end portion of the driving member is attached to the device main body. A posture control drive device, which is fixed, and controls the posture of the posture-controlled body by being expanded or contracted by being heated by the heating source.

[0009] At least one or more driving members are provided.

A plurality of the driving members may be provided corresponding to a plurality of directions extending radially from the center of the plane of the posture-controlled body.

According to the present invention, the driving member has a coil portion stored at the base end thereof so as to shrink when heated, and has a wire portion at the tip end, and the coil portion is provided with the posture control. The wire portion is located between the support member for supporting the body or the posture-controlled body and the device main body, the wire portion is guided and extended by a guide attached to the tip of the support, and the tip of the wire portion is extended from the partial position. It may be configured to be fixed to a remote position control body or another part of the support member that supports the position control body.

The distal end and the proximal end of the driving member are connected to a circuit including a power supply and a resistance meter, and the electric resistance value of the driving member is measured to diagnose the deterioration state of the driving member. It may be configured as possible.

Further, in order to solve the above-mentioned problems, the present invention provides a method of diagnosing a deterioration state of a shape memory alloy by measuring an electric resistance value of the shape memory alloy.

When the shape memory alloy is a part of the above-mentioned device incorporated in an arbitrary device, the deterioration state of the shape memory alloy can be diagnosed without disassembling the device.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an attitude control drive device and a method of diagnosing a shape memory alloy according to the present invention will be described based on embodiments with reference to the drawings. An embodiment in which a controlled object to be controlled by the attitude control drive device according to the present invention is a solar battery paddle of an artificial satellite will be described with reference to FIGS.
FIGS. 1A and 1B are a side view and a plan view of a solar cell paddle 1 and an attitude control driving device according to the present invention, respectively.
FIG. 1C shows a mounting structure of the pulley 6.

The disk 2 as a support member is attached to the artificial satellite body 8 of the present invention at an interval so as to freely rotate about its center as an axis. The solar cell paddle 1 is fixed vertically to the outer surface of the disk 2. In short, the solar cell paddle 1 is rotatably attached to the artificial satellite main body 8 via the disk 2.

On the outer surface of the artificial satellite body 8, a column 5 is vertically provided so as to correspond to the inner peripheral edge of the disk 2 at intervals of 90 degrees. A coil portion of four shape memory alloys 4a, 4b, 4c, 4d, which are driving members, is wound around each of the columns 5, and functions as a support guide when the coil portions expand and contract. The base ends of the four shape memory alloys 4a, 4b, 4c, 4d are fixed to the outer surface of the satellite body 8, respectively.

The tips of the four shape memory alloys 4a, 4b, 4c and 4d are formed as straight wire portions, respectively, and guided by four pulleys attached to the column 5, respectively. It extends along the peripheral surface, and its tip end is converged and fixed at a predetermined position (a part different from the above-mentioned part) on the side peripheral surface of the disk by the fixture 3.

The shape memory alloy stores its shape so that the coil partial spring contracts when the temperature becomes high. With such a structure, when the coil portion of the shape memory alloy 4 expands and contracts, the disk is pulled or loosened via the pulley 6 attached to the tip of the column 5 to generate a rotational driving force for the disk 2, The disk 2 is rotated efficiently.

A reflector 7 is arranged between the satellite body 8 and the disk 2 along the inside of the coil portions 4a, 4b, 4c, 4d of the shape memory alloy so as to stand on the outer surface of the satellite body 8. I do. The reflecting plate 7 has a function of promoting heating of the shape memory alloy from a specific direction and suppressing heating from another direction.

The distal end portions of the four shape memory alloys are assembled by the fixture 3, and a common electrode is provided at a converging portion which is bundled and fixed to a disk.
Electrodes are provided for each of 9a, 9b, 9c, and 9d, and the electrical resistance between the common electrode and each electrode at the base end can be measured. That is, the distal end portion and the proximal end portion of the driving member are connected to a circuit including a power supply and a resistance meter, and the deterioration state of the driving member can be diagnosed by measuring the electric resistance value of the driving member. It is configured to be

The operation of the embodiment of the present invention having the above configuration will be described. The solar battery paddle has its surface oriented in the direction of the sun, and the power obtained by the solar battery is used for the operation of various devices mounted on the artificial satellite body 8.

As shown in FIG. 1, when the solar battery paddle 1 is facing the sunlight, a sufficient electromotive force is generated by the solar battery and there is no problem. However, for example, in FIG. 1, when the direction of sunlight is in the direction of the coil portion of the shape memory alloy 4b (when the sun irradiates from a direction perpendicular to the paper surface of FIG. , The sunlight is not sufficiently irradiated on the solar cell surface, and the electromotive force is small.

According to the present invention, however, in this case, since the shape memory alloy 4b faces the sun,
The shape memory alloy 4b is sufficiently irradiated with sunlight or the reflection plate 7
Is reflected and heated. And shape memory alloy 4
The coil portions of the shape memory alloy other than b are illuminated and reflected only by the coil portion of the shape memory alloy 4b without being irradiated or reflected because the sunlight is blocked by the correspondingly provided reflector. .

Then, only the shape memory alloy 4b is heated and deformed to the memorized shape (the shape of the contracted spring). The other shape memory alloys 4a, 4c, and 4d have low rigidity at low temperatures, so they cannot fully withstand the tensile force of the shape memory alloy 4b that has become high in temperature, and are stretched, so that the shape memory alloy 4b becomes stable in the shortest shape. As a result, as shown in FIGS. 2A and 2B, the coil portion of the shape memory alloy 4b contracts,
Is rotated so as to draw the fixture 3 of the disk 2 through the.

Thus, the direction of the battery surface of the solar battery paddle can be directed to the direction of sunlight. Therefore, in the present invention, it is possible to automatically and efficiently control the attitude of the solar battery paddle by the action of the shape memory alloy without providing a sun sensor, a motor driving mechanism, and the like. The direction of sunlight is not the shape memory alloy 4b, but the shape memory alloys 4a, 4c, 4
When facing in any direction of d, the direction of the battery surface of the solar battery paddle can be directed to the direction of sunlight in the same manner as described above.

Then, the electric resistance between the common electrode and the electrodes provided at the base ends 9a, 9b, 9c, 9d of the shape memory alloy is measured. Since the electrical resistance value of the shape memory alloy increases with aging, the degree of aging can be easily determined from this resistance value, and the shape memory alloy may be replaced as needed. As described above, since the aging can be determined only by the measured value of the electric resistance without removing the shape memory alloy 4, it is extremely effective for maintenance and the like.

The shape memory alloys 4a, 4b, 4c and 4d are
, The shape memory alloys 4a, 4b, 4
When c and 4d are respectively expanded and contracted, they operate smoothly without bending or moving in the lateral direction of the shape memory alloy.

Although the present invention has been described with reference to the embodiments, the configuration of the present invention is not limited to the above-described embodiments, and various embodiments may be made within the technical scope described in the claims. Needless to say, it is possible.

For example, by appropriately combining a shape memory alloy with a spring or the like, the shape memory alloy is stored in such a manner that it expands when the temperature of the shape memory alloy becomes high. Is also conceivable.

In the above embodiment, four shape memory alloys are provided as drive members.
May be provided corresponding to a plurality of directions extending in the radial direction from the center of the plane of the posture-controlled body, and there is no need to limit the number to four. In addition, a spring may be used instead of a driving member made of a shape memory alloy for a certain direction of the radiation direction.
The number of drive members made of the shape memory alloy may be one.

[0032]

The present invention is configured as described above.
In a solar cell paddle or the like, without providing a light receiving sensor, a motor, a control circuit, a power supply, and the like, which are required in the above-described conventional attitude control driving device, and also without having to particularly bother with the storage location of these, The effect of the shape memory alloy automatically enables efficient attitude control of the solar cell paddle.

Further, according to the present invention, a diagnosis can be made by supplying a current between the electrodes of the shape memory alloy and measuring the electric resistance value of the shape memory alloy. This makes it possible to easily diagnose the deterioration state of the shape memory alloy without having to perform it, make it easy to determine at the optimal timing to replace it, and maintain the performance of the equipment, prevent failures, and reduce maintenance costs. it can. In particular, when the shape memory alloy is used in a device body that is not easily accessible such as the above-mentioned solar cell panel, it is possible to remotely diagnose the deterioration state or to have a large effect.

[Brief description of the drawings]

FIG. 1 is a side view and a plan view of a solar battery paddle portion of an artificial satellite to which an attitude control driving device according to the present invention is applied.

FIG. 2 is a diagram illustrating an operation of a solar battery paddle section of an artificial satellite to which the attitude control driving device according to the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solar cell paddle 2 Disk 3 Fixture 4 Shape memory alloy 5 Prop 6 Pulley 7 Reflector 8 Satellite body 9 Electrode

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-57-162373 (JP, A) JP-A-61-140551 (JP, A) JP-A-4-171774 (JP, A) JP-A-3- 67800 (JP, A) JP-A-2-123772 (JP, A) JP-A-7-237599 (JP, A) JP-A-63-55156 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B64G 1/44 G01N 27/04 H01L 31/04

Claims (2)

(57) [Claims] 1. A rotatably mounted outer surface of an apparatus main body.
Was to be attitude control body, by using a plurality of driving <br/> moving member made from a shape memory alloy, a heat source in the shape memory alloy to the outside
By heating and expanding or contracting,
A posture control drive device for controlling a posture of a body and directing the body toward the heat source , wherein the drive member includes a coil portion on a proximal end side and a wire portion on a distal end side.
Consists of a, the coil unit has its base end portion is fixed to the apparatus main body, the outer surface of the apparatus main body, the rotation axis of the target attitude control member
Several pillars are suspended at intervals around the center.
The coil portion of the driving member is wound around each of the columns.
And the wire portion is connected to a pulley attached to the tip of the column.
The wire portion extends and is guided by the coil.
At another part away from the part corresponding to the strut on which
Attitude control body or support member for supporting the attitude control body
An attitude control drive device, characterized in that the attitude control drive device is fixed to the device. 2. The driving member according to claim 1, wherein said driving member has a coil portion and a wire portion.
Is connected to the circuit containing the power supply and ohmmeter
The electric resistance value of the shape memory alloy of the driving member is measured.
This makes it possible to diagnose the deterioration of the drive member over time.
2. The apparatus according to claim 1, wherein the apparatus is configured as follows.
On-board attitude control drive.