JP2003282991A - Giant magnetostrictive linear actuator - Google Patents

Abstract

(57) [Problem] To provide a giant magnetostrictive linear actuator with small vibration. SOLUTION: An exciting coil 1 for generating a magnetic field of alternating polarity, a giant magnetostrictive element 2 whose length is elastically changed by the strength of the magnetic field of alternating polarity by the exciting coil 1,
A pair of movable portions 3 provided on both sides of the giant magnetostrictive element 2 in a direction in which the length of the giant magnetostrictive element 2 elastically changes.
And a pair of preload disc springs 4 for applying a preload to the pair of movable parts 3 on the giant magnetostrictive element 2 side. The giant magnetostrictive element 2 has an arrangement in which both ends of the giant magnetostrictive element 2 are in contact with both movable parts 3 near a fulcrum between one end, which is the point of action 32 of each movable part 3, and the other end 31.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to 0.1 mm to 1 m.
The present invention relates to a giant magnetostrictive linear actuator capable of large displacement vibration of about m.

[0002]

2. Description of the Related Art FIG. 19 is a block diagram of a conventional giant magnetostrictive actuator. This giant magnetostrictive actuator includes a giant magnetostrictive element 2 that generates a driving force, an output shaft 3X that is arranged so as to be in contact with the giant magnetostrictive element 2 and that transmits an output to the outside, and a magnetic bias that applies to the giant magnetostrictive element 2. Permanent magnet 8 and
It comprises a yoke 7X forming a magnetic circuit, a preload spring 4X for applying a preload to the giant magnetostrictive element 2, and an exciting coil 1 for applying a magnetomotive force.

When an alternating current such as a sine wave or a rectangular wave is applied to the exciting coil 1, as shown in FIG. 20, the magnetic flux passing through the magnetic path formed by the yoke 7X and the giant magnetostrictive element 2 also changes in an alternating manner. . As a result, magnetostriction occurs and minute vibration having the same frequency as the driving frequency occurs. The vibration output is transmitted to the outside through the output shaft 3X.

FIG. 21 is a block diagram of a giant magnetostrictive linear actuator (Japanese Patent Application No. 2001-262875). This giant magnetostrictive linear actuator uses an L-shaped movable portion 3Y and has an amplitude enlargement mechanism utilizing the lever principle and mechanical resonance. Further, as shown in FIG. 22, there is also proposed a giant magnetostrictive linear actuator that realizes a counter operation by using a pair of L-shaped movable portions 3Y. In addition, 4 in FIGS. 21 and 22 is a preload disc spring.

[0005]

In the actuator of FIG. 19, the output coil 3 is excited by exciting the exciting coil 1.
Although a small vibration is generated as an output at X, the output displacement is the amplitude itself of the displacement due to the expansion / contraction of the giant magnetostrictive element 2, and the maximum is 1000 to 200 with respect to the axial length of the giant magnetostrictive element 2.
Only 0ppm of minute vibration can be taken out. For example, assuming that the axial length of the giant magnetostrictive element is 10 mm, the maximum is 10 to 2
The vibration is about 0 μm.

In the actuator shown in FIG. 21, a large-amplitude linear drive can be performed by an amplitude expansion mechanism utilizing the lever principle and mechanical resonance, but the movable portion 3Y is substantially orthogonal to the expansion / contraction direction of the giant magnetostrictive element 2. Since it moves in the direction, vibration occurs.

In the actuator shown in FIG. 22, since the pair of movable portions 3Y move in opposite directions to each other, vibration in the moving direction of the movable portion 3Y can be greatly reduced, but vibration in the expansion / contraction direction of the giant magnetostrictive element 2 can be suppressed. Can not.

The actuators shown in FIGS. 21 and 22 have an open magnetic circuit structure, and there is a problem that the magnetic efficiency is poor.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a giant magnetostrictive linear actuator with small vibration.

[0010]

A giant magnetostrictive linear actuator according to a first aspect of the present invention for solving the above problems is an exciting coil for generating a magnetic field having alternating polarities, and the polarities of the exciting coils are alternating. A giant magnetostrictive element whose length changes elastically depending on the strength of the magnetic field, a pair of movable parts provided on both sides of the giant magnetostrictive element in the direction in which the length of this giant magnetostrictive element changes elastically, and a pair of these movable parts. And an additional means for applying a preload to the giant magnetostrictive element side, and both ends of the giant magnetostrictive element are in contact with both movable portions near the fulcrum between one end and the other end, which are the action points of each movable portion. It is characterized by

According to a first aspect of the present invention, in the giant magnetostrictive linear actuator according to the first aspect, the exciting coil and the giant magnetostrictive element are composed of two sets of exciting coil and giant magnetostrictive element provided on both sides of the fixing member, One of the sets of giant magnetostrictive elements and one end of the other set of giant magnetostrictive elements are in contact with the pair of movable portions, respectively.

The invention according to claim 3 is characterized in that, in the giant magnetostrictive linear actuator according to claim 2, a preload is applied to the giant magnetostrictive element using the lever principle.

The invention according to claim 4 is the invention according to claim 1 or 2.
In the giant magnetostrictive linear actuator described above, a pair of movable portions are provided between the movable body and a support body that supports the exciting coil and the giant magnetostrictive element between the movable portions and the pair of movable portions. The pair of movable portions and the support body are magnetic bodies, and the pair of movable portions and the support body are magnetic bodies. The pair of movable portions and the support body are magnetic bodies. It is characterized in that a closed magnetic circuit is formed by the members.

According to a fifth aspect of the present invention, in the giant magnetostrictive linear actuator according to the fourth aspect, the gap between the magnetic member and the pair of movable portions is arranged to be constant regardless of the movement of the movable portions. It is characterized by

A giant magnetostrictive linear actuator according to a sixth aspect of the present invention includes a yoke formed of a magnetic material in a C-shaped cross section having one opening point, and an exciting coil for generating a magnetic field having alternating polarities. And a giant magnetostrictive element whose length elastically changes depending on the strength of a magnetic field whose polarity is alternated by this exciting coil, a movable part partially protruding outside from the opening point of the yoke, and the length of the giant magnetostrictive element being elastic. An additional means for applying a preload to both sides of the giant magnetostrictive element in the changing direction is provided inside the yoke, and the exciting coil and the giant magnetostrictive element are provided with two sets of exciting coils and supermagnets provided on both sides of the rest of the movable part. The addition means is composed of a magnetostrictive element, and the adding means is fixed to the inner wall of the yoke to apply a preload to one end of one set of supermagnetostrictive elements and one end of the other set of supermagnetostrictive elements, so that the movable part is self-contained. Characterized in that it is sandwiched by two sets of super-magnetostrictive element in parts tip-sided.

Here, in the present invention, the vibration is reduced by the amplitude enlarging mechanism in which the moving direction of the movable portion and the expanding / contracting direction of the giant magnetostrictive element coincide with each other. Further, the closed magnetic circuit structure realizes high efficiency.

A general magnetostrictive element is pure Ni or Fe-Ni.
It is formed using a material such as a Ni-based alloy or ferrite (iron oxide) to which Ni or Zn is added, and its total length is several tens pp due to magnetostriction.
Elasticity changes about m. On the other hand, the giant magnetostrictive material is made of an alloy of rare earth elements such as terbium (Tb) and dysprosium (Dy) and iron, and elastically changes by 1000 to 2000 ppm of the total length due to magnetostriction.
Such a giant magnetostrictive element was developed by the US Navy,
Commercialized by ETREMA, Terfenol
Such as _{-D (Tb 0.3 Dy 0.7 Fe 1.91} ) is known.
In the present invention, such a giant magnetostrictive element or the like is used.

According to the present invention having the above-mentioned structure, since the output amplitude is obtained by multiplying the amplification factor by the lever mechanism and the amplification factor by the resonance system, a large-amplitude linear actuator can be realized, and the movement of the output of the movable part can be realized. Vibration can be suppressed by the amplitude magnifying mechanism in which the direction and the expansion / contraction direction of the giant magnetostrictive element are matched, and the efficiency can be improved by the closed magnetic circuit structure.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a block diagram of a giant magnetostrictive linear actuator according to a first embodiment of the present invention.

In the giant magnetostrictive linear actuator of the first embodiment, as shown in FIG. 1, an exciting coil 1 for generating a magnetic field having alternating polarities and an exciting coil 1 provided in the axis of the exciting coil 1 are used. A rod-shaped giant magnetostrictive element 2 whose length elastically changes depending on the strength of a magnetic field of alternating polarity, and a pair of giant magnetostrictive elements 2 provided on both sides of the giant magnetostrictive element 2 in the direction in which the length of the giant magnetostrictive element 2 elastically changes. Movable part 3, a pair of preload disc springs 4 for applying a preload to the pair of movable parts 3 toward the giant magnetostrictive element 2, and a pair of movable parts 3
And an exciting coil 1 and a support 5 for supporting the giant magnetostrictive element 2.

The support 5 has a U-shaped cross section, and the preload disc spring 4 is fixed to the inner surface of each end 51 of the support 5. Further, both ends of the giant magnetostrictive element 2 are in contact with both movable parts 3 near the fulcrum between one end serving as the action point 32 of each movable part 3 and the other end 31.
However, in the example of FIG. 1, hemispherical driving force transmission members 21 are provided at both ends of the giant magnetostrictive element 2, and the poles of these driving force transmission members 21 are operating points and contact both movable parts 3. . Further, the giant magnetostrictive linear actuator is configured such that the action point 32 side of each movable portion resonates with the vibration due to the expansion and contraction of the giant magnetostrictive element 2. Further, the fulcrum is provided above the operating point (on the side of the action point 32) and near the operating point.

Here, twice the exciting frequency of the exciting coil 1
Each movable part 3 moves at the frequency of. Amplitude changes from fulcrum
The length to the point is l₁, Length from fulcrum to action point 32
L ₂Then, expansion / contraction of the giant magnetostrictive element 2 × 0.5 × l₂/
l₁× Expanded by resonance amplification factor.

According to the giant magnetostrictive linear actuator having such a structure, the vibration direction of the action point 32 of the movable portion 3 and the expansion / contraction direction of the giant magnetostrictive element 2 coincide with each other, and the pair of movable portions 3
Move in directions opposite to each other, so that the vibrations caused by the respective motions are canceled and a giant magnetostrictive linear actuator with small vibration can be realized.

In the first embodiment, the disc spring is used as the addition means for applying the preload, but the addition means of the present invention is not limited to this, and other means such as a coil spring may be used. It may be an elastic body.

Although the magnetic bias is not applied, the magnetic bias may be applied by a magnet or a direct current. When a magnetic bias is applied, the movable part moves at the same frequency as the exciting current frequency.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
It is a block diagram of the giant magnetostrictive linear actuator of embodiment.

As shown in FIG. 2, the giant magnetostrictive linear actuator of the second embodiment differs from the giant magnetostrictive actuator of the first embodiment in that the exciting coil and the giant magnetostrictive element are formed in a plate shape in which the support 5 is continuously provided. It is composed of two sets of exciting coils 1A and 1B and giant magnetostrictive elements 2A and 2B provided on both sides of the fixing member 52, and one end of one pair of giant magnetostrictive element 2A and one end of the other pair of giant magnetostrictive element 2B are provided. The structure is such that it contacts the pair of movable parts 3, respectively.

According to the giant magnetostrictive linear actuator having such a structure, since the other ends of the two giant magnetostrictive elements 2A and 2B are fixed to the fixing member 52, the adjustment of the preload by the preload disc spring 4 can be adjusted to the left and right. Can be done independently. This facilitates initial adjustment and improves productivity.

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention.
It is a block diagram of the giant magnetostrictive linear actuator of embodiment.

The difference from the second embodiment is that the giant magnetostrictive linear actuator of the third embodiment has a structure in which a preload is applied to the giant magnetostrictive element using the lever principle. In the example of FIG. 3, a hole 3a is formed in each movable part 3 of the exciting coils 1A and 1B and the giant magnetostrictive elements 2A and 2B on the side of the action point 32, and a rod-shaped preloading member 4A is inserted into both holes 3a. Has been done. Then, the end portions 41A having large outer dimensions are fixed to both ends of the preload applying member 4A.
A preload addition spring 42A inserted through the preload addition member 4A is provided between 1A and the movable portion 3.

According to the giant magnetostrictive linear actuator having such a structure, the preload can be amplified by the lever principle, and the range of adjustment can be widened. Further, it is not necessary to install a preload in the expansion / contraction direction of the giant magnetostrictive element, and the width can be reduced.

(Fourth Embodiment) FIG. 4 shows a fourth embodiment of the present invention.
FIG. 5 is a configuration diagram of the giant magnetostrictive linear actuator of the embodiment.
FIG. 6 is an explanatory view of a closed magnetic circuit which is a characteristic of the giant magnetostrictive linear actuator, and FIG. 6 is an explanatory view of a closed magnetic circuit which is a comparison and contrast of the giant magnetostrictive linear actuator.

The difference between the giant magnetostrictive linear actuator of the fourth embodiment and that of the first embodiment is that, as shown in FIG. 4, the exciting coil 1 and the giant magnetostriction provided between a pair of movable parts 3 are provided. Faces the support 5 through the element 2,
For example, a magnetic path bypass 6 made of iron is provided, and the pair of movable parts 3 and the support body 5 are magnetic bodies, and the giant magnetostrictive element 2, the pair of movable parts 3, the support body 5 and the magnetic path bypass 6 form a closed magnetic path. It is structured.

According to the giant magnetostrictive linear actuator having such a structure, since the closed magnetic circuit is formed as shown in FIG. 5, the magnetic resistance of the magnetic circuit is smaller than that of the open magnetic circuit shown in FIG. Since it is possible to suppress the current that generates the alternating magnetic field necessary for expanding and contracting the giant magnetostrictive element 2, it is possible to achieve high efficiency.

In the fourth embodiment, the magnetic path bypass 6
Is provided in the giant magnetostrictive linear actuator of the first embodiment, but the magnetic path bypass 6 may be provided in the giant magnetostrictive linear actuator of the second embodiment as shown in FIG. Even in this structure, since the closed magnetic circuit is formed as shown in FIG. 8, the magnetic resistance of the magnetic circuit is smaller than that of the open magnetic circuit shown in FIG. 9, and the giant magnetostrictive elements 2A and 2B are formed.
Since it is possible to suppress the current that generates the alternating magnetic field necessary for expanding and contracting, the efficiency can be improved. However, the fixing member 52 in FIG. 7 also becomes a magnetic body.

(Fifth Embodiment) FIG. 10 is an external view of a giant magnetostrictive linear actuator according to a fifth embodiment of the present invention, FIG. 11 is a configuration diagram of the giant magnetostrictive linear actuator, and FIG.
FIG. 3 is a view of the giant magnetostrictive linear actuator viewed from the output side.

The difference between the giant magnetostrictive linear actuator of the fifth embodiment and that of the fourth embodiment is that the gap between the magnetic path bypass and the pair of movable parts is constant regardless of the movement of the movable parts. Is characterized by. In the example of FIGS. 10 to 12,
The magnetic path bypass 6A is composed of two parallel magnetic bodies.

Here, from the magnetic path bypass 6A to the movable portion 3,
By making the moving direction of the movable part 3 perpendicular to the flow of the magnetic flux from the movable part 3 to the magnetic path bypass 6A, the gap in the magnetic path is made constant.

In the structures of FIGS. 4 and 7, the movement of the movable part 3 increases the air gap in the magnetic path and increases the magnetic resistance of the magnetic path. However, according to the fifth embodiment, the movement of the movable part 3 is increased. On the other hand, the air gap in the magnetic path becomes constant, and the efficiency can be stably increased.

In the fifth embodiment, the magnetic path bypass 6
Although the structure A is provided in the giant magnetostrictive linear actuator of FIG. 4, the magnetic path bypass 6A may be provided in the giant magnetostrictive linear actuator of FIG. 7 as shown in FIGS. Even with this structure, high efficiency can be stably achieved.

In the example of FIGS. 10 to 15, the magnetic path bypass 6A is composed of two parallel magnetic bodies, but the magnetic path bypass 6B is formed of an H-shaped magnetic body as shown in FIG. You may Even with this structure, high efficiency can be stably achieved.

(Sixth Embodiment) FIG. 17 is an external view of a giant magnetostrictive linear actuator according to a sixth embodiment of the present invention, and FIG. 18 is a configuration diagram of the giant magnetostrictive linear actuator.

As shown in FIGS. 17 and 18, the giant magnetostrictive linear actuator of the sixth embodiment comprises a yoke 7 formed of a magnetic material in a C-shaped cross section having one opening point (fulcrum) 7a. In addition, an exciting coil 1 for generating a magnetic field of alternating polarities, a giant magnetostrictive element 2 whose length elastically changes depending on the strength of the magnetic field of alternating polarities generated by the exciting coil 1, and an opening point 7a of the yoke 7 are formed. From part 32
Inside the yoke 7, there is provided a movable portion 3A in which A projects outward, and a pair of preload disc springs 4 for preloading both sides of the giant magnetostrictive element 2 in a direction in which the length of the giant magnetostrictive element 2 elastically changes. I have it.

The exciting coil 1 and the giant magnetostrictive element 2 are composed of two sets of exciting coils 1A, 1B and giant magnetostrictive elements 2A, 2B provided on both sides of the remaining portion 31A of the movable part 7, and each preload disc spring 4 is , Is fixed to the inner wall of the yoke 7, and a preload is applied to one end of the super magnetostrictive element 2A of one set and one end of the super magnetostrictive element 2B of the other set, so that the movable portion 3A moves toward the tip of the remaining portion 31A of itself 2 Set of giant magnetostrictive elements 2A, 2
It is structured to be held by B.

Here, the giant magnetostrictive elements 2A and 2B are excited so that when one giant magnetostrictive element is extended, the other giant magnetostrictive element is in a contracted state. As a result, the movable portion 3A moves in the expansion / contraction direction according to the expansion / contraction of the two giant magnetostrictive elements. The point of the remaining portion 31A of the movable portion 3A, which is in contact with each giant magnetostrictive element, is the operating point, and the portion 32 of the movable portion 3A.
The tip of A is the point of action. The distance between the opening point (fulcrum) 7a and the action point is set longer than the distance between the opening point (fulcrum) 7a and the operating point.

In the giant magnetostrictive linear actuator having such a structure, the movable portion 3A reciprocates by alternately energizing the two sets of exciting coils 1A and 1B, but the movable portion 3A moves in either direction. Even at times, a driving force is generated by the giant magnetostrictive element. Further, since the structure is almost a closed magnetic circuit, high efficiency can be achieved.

In the sixth embodiment, the magnetic bias is not applied, but the magnetic bias may be applied by a magnet or a direct current. When a magnetic bias is applied, the movable part moves at the same frequency as the exciting current frequency.

The structure of the entire yoke is not limited to the box shape as shown in FIG. 17, but may be a C-shaped cylinder.

[0049]

As is apparent from the above, according to the invention described in claim 1, an exciting coil for generating a magnetic field having alternating polarities, and the strength of the magnetic field having alternating polarities by the exciting coil. Of a super magnetostrictive element whose length is elastically changed by a pair of movable parts provided on both sides of the super magnetostrictive element in the direction in which the length of the supermagnetostrictive element is elastically changed, and a giant magnetostrictive element for the pair of movable parts. Since the both ends of the giant magnetostrictive element are respectively in contact with both movable parts near the fulcrum between one end and the other end, which are the action points of the respective movable parts, with the addition means for applying a preload to the element side, Since the vibration direction at the point of action and the expansion / contraction direction of the giant magnetostrictive element match, and the pair of movable parts move in opposite directions, the vibration due to each motion is canceled, and the giant magnetostrictive linear actuator with small vibration is cancelled. It is possible to realize the data.

According to the invention of claim 1, in the giant magnetostrictive linear actuator of claim 1, the exciting coil and the giant magnetostrictive element are composed of two sets of exciting coil and giant magnetostrictive element provided on both sides of the fixing member. Then, one end of the super magnetostrictive element of one set and one end of the super magnetostrictive element of the other set are respectively in contact with the pair of movable parts, and this structure also reduces vibration.

According to the third aspect of the invention, in the giant magnetostrictive linear actuator according to the second aspect, the preload is added to the giant magnetostrictive element by using the lever principle. Therefore, the preload is applied by the lever principle. Amplification is possible and the range of adjustment is expanded.

According to a fourth aspect of the present invention, in the giant magnetostrictive linear actuator according to the first or second aspect, the pair of movable portions are supported on the respective other end sides thereof, and the exciting coil between the pair of movable portions and The pair of movable parts and the support body are provided with a support body that supports the giant magnetostrictive element and a magnetic member that is provided between the pair of movable portions and faces the support body via the exciting coil and the giant magnetostrictive element therebetween. Since it is a magnetic material and forms a closed magnetic path with a super magnetostrictive element, a pair of movable parts, a support and a magnetic member, the magnetic resistance of the magnetic circuit is reduced compared to the open magnetic path, and it is necessary to expand and contract the super magnetostrictive element. Since it is possible to suppress the current that generates a large alternating magnetic field, it is possible to achieve high efficiency.

According to the fifth aspect of the present invention, in the giant magnetostrictive linear actuator according to the fourth aspect, the gap between the magnetic member and the pair of movable portions is constant regardless of the movement of the movable portions. Since they are arranged, high efficiency can be stably achieved.

According to the sixth aspect of the present invention, there is provided a yoke which is made of a magnetic material and has a C-shaped cross section having one opening point, and an exciting coil for generating a magnetic field of alternating polarity. A giant magnetostrictive element whose length elastically changes depending on the strength of a magnetic field in which the polarities of the exciting coil alternate.
Inside the yoke, there is provided a movable part partially protruding from the opening point of the yoke, and an addition means for applying a preload to both sides of the giant magnetostrictive element in the direction in which the length of the giant magnetostrictive element elastically changes. The exciting coil and the giant magnetostrictive element are composed of two sets of exciting coil and giant magnetostrictive element provided on both sides of the remaining part of the movable part, and the adding means is fixed to the inner wall of the yoke and is connected to one end of one pair of giant magnetostrictive element. A preload is applied to one end of the other set of giant magnetostrictive elements, and the movable part is sandwiched by the two sets of giant magnetostrictive elements near the tip of the rest of the self, so it can be moved by alternately energizing two exciting coils. Although the part reciprocates, the opposite direction driving force is generated by the giant magnetostrictive element when the movable part moves in either direction, so that a giant magnetostrictive linear actuator with small vibration can be realized. Further, since the structure is a closed magnetic circuit, high efficiency can be achieved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a giant magnetostrictive linear actuator according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a giant magnetostrictive linear actuator according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a giant magnetostrictive linear actuator according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a giant magnetostrictive linear actuator according to a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram of a closed magnetic circuit that is a feature of the giant magnetostrictive linear actuator.

FIG. 6 is an explanatory diagram of a closed magnetic circuit serving as a comparative reference of the giant magnetostrictive linear actuator.

7 is a diagram showing a structure when the magnetic path bypass shown in FIG. 4 is provided in the giant magnetostrictive linear actuator shown in FIG.

FIG. 8 is an explanatory diagram of a closed magnetic circuit that is a feature of the giant magnetostrictive linear actuator.

FIG. 9 is an explanatory diagram of a closed magnetic circuit serving as a comparison reference of the giant magnetostrictive linear actuator.

FIG. 10 is an external view of a giant magnetostrictive linear actuator according to a fifth embodiment of the present invention.

FIG. 11 is a configuration diagram of the giant magnetostrictive linear actuator.

FIG. 12 is a view of the giant magnetostrictive linear actuator seen from the output section side.

13 is an external view when the magnetic path bypass shown in FIGS. 10 to 12 is provided in the giant magnetostrictive linear actuator of FIG.

FIG. 14 is a configuration diagram of the giant magnetostrictive linear actuator.

FIG. 15 is a view of the giant magnetostrictive linear actuator seen from the output section side.

FIG. 16 is a diagram showing a structural example of another magnetic path bypass.

FIG. 17 is an external view of a giant magnetostrictive linear actuator according to a sixth embodiment of the present invention.

FIG. 18 is a configuration diagram of the giant magnetostrictive linear actuator.

FIG. 19 is a configuration diagram of a conventional giant magnetostrictive actuator.

FIG. 20 is a diagram showing a flow of magnetic flux of the giant magnetostrictive actuator.

FIG. 21 is a configuration diagram of a giant magnetostrictive linear actuator proposed in Japanese Patent Application No. 2001-262875.

FIG. 22 is a configuration diagram of a giant magnetostrictive linear actuator that realizes a counter operation proposed in Japanese Patent Application No. 2001-262875.

[Explanation of symbols]

1,1A, 1B Excitation coil 2,2A, 2B giant magnetostrictive element 3,3A movable part 4 Preload disc spring 4A Preload addition member 42A preload spring 5 support 52 Fixing member 6,6A, 6B Magnetic path bypass 7 York

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsuhiro Hirata             1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works             Within the corporation (72) Inventor Yasuhiro Matsui             3-1, 14 Jingumae, Shibuya-ku, Tokyo Stocks             Company Moritex (72) Inventor Tomohiko Suzuki             3-1, 14 Jingumae, Shibuya-ku, Tokyo Stocks             Company Moritex

Claims (6)

[Claims] 1. An exciting coil for generating a magnetic field of alternating polarities, a super magnetostrictive element whose length elastically changes depending on the strength of a magnetic field of alternating polarities generated by the exciting coil, and the length of the super magnetostrictive element. A pair of movable parts respectively provided on both sides of the giant magnetostrictive element in the direction in which elasticity changes,
The pair of movable parts is provided with an addition means for applying a preload to the giant magnetostrictive element side, and the movable parts of the giant magnetostrictive element are provided on both movable parts near the fulcrum between one end and the other end, which are the action points of each movable part. A giant magnetostrictive linear actuator characterized in that both ends are in contact with each other. 2. The exciting coil and the giant magnetostrictive element are composed of two sets of exciting coils and giant magnetostrictive elements provided on both sides of the fixing member, and one end of the one pair of giant magnetostrictive elements and the other pair of giant magnetostrictive elements. 2. The giant magnetostrictive linear actuator according to claim 1, wherein one end of each of the giant magnetostrictive linear actuators is in contact with each of the pair of movable portions. 3. The giant magnetostrictive linear actuator according to claim 2, wherein a preload is applied to the giant magnetostrictive element using the lever principle. 4. A support body, which is provided between the pair of movable portions, and a support body which supports the pair of movable portions at the other ends thereof and also supports the exciting coil and the giant magnetostrictive element between the pair of movable portions. Of the excitation coil and the magnetic member facing the support through the giant magnetostrictive element, the pair of movable portions and the support are magnetic bodies, and the supermagnetostrictive element, the pair of movable portions, the support and the magnetic member close the magnetic field. The giant magnetostrictive linear actuator according to claim 1 or 2, wherein a path is formed. 5. The giant magnetostrictive linear actuator according to claim 4, wherein the gap between the magnetic member and the pair of movable portions is arranged so as to be constant regardless of the movement of the movable portion. 6. A cross section C having a single opening made of a magnetic material.
An exciting coil for generating a magnetic field with alternating polarities, a giant magnetostrictive element whose length elastically changes depending on the strength of the magnetic field with alternating polarities by the exciting coil, and a yoke A movable part partially protruding from the opening point to the outside, and an addition means for applying a preload to both sides of the giant magnetostrictive element in the direction in which the length of the giant magnetostrictive element elastically changes are provided inside the yoke, The exciting coil and the super magnetostrictive element are composed of two sets of exciting coil and super magnetostrictive element provided on both sides of the remaining part of the movable part, and the adding means is fixed to the inner wall of the yoke and one end and the other end of the super magnetostrictive element of one set. A giant magnetostrictive linear actuator characterized in that a preload is applied to one end of the pair of giant magnetostrictive elements, and the movable part is sandwiched by two pairs of giant magnetostrictive elements near the tip of the rest of the self.