JP2002272151A - Magnetostrictive vibration motor and its drive method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetostriction vibration motor which can easily change rotation characteristics of its rotor. SOLUTION: This magnetostrictive vibration motor has a stator 1 and a rotor 2. The stator 1 has a pair of sub-stators 3 and 4. The respective sub- stators 3 and 4 have magnetostriction devices 9, which generate vibrations due to the changes in the magnetic fields, magnetic field coils 10 which generate alternating magnetic fields according to AC currents, bias magnetic field coils 11 which generate one-directional bias magnetic fields, and vibration planes 7e, which vibrate respectively according to vibrations generated by the magnetostriction devices 9. The rotor 2 has different planes, which are brought into pressure-contact with respective vibration planes 7e and is turned by the vibration transmitted, by at least one of the respective vibration planes 7e. If the magnetic field coil 10, to which the AC current is supplied, is switched, the rotation direction of the rotor 2 is switched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetostrictive vibration motor using a magnetostrictive element and a driving method thereof.

[0002]

2. Description of the Related Art In recent years, various actuators using magnetostrictive elements (giant magnetostrictive elements) which generate distortion (expansion and contraction) when a magnetic field is changed have been proposed. As for a vibration type motor in which a rotor is rotated by vibration, a magnetostrictive vibration motor utilizing vibration caused by expansion and contraction of a magnetostrictive element has been proposed.

[0003]

However, the proposed magnetostrictive vibration motor is a proposal in which a magnetostrictive element is used in place of the piezoelectric element, and has a structure for changing the rotational characteristics of the rotor and a driving method thereof. No consideration is given, especially how to switch the rotational direction of the rotor.

An object of the present invention is to provide a magnetostrictive vibration motor capable of easily changing the rotation characteristics of a rotor and a driving method thereof.

[0005]

According to a first aspect of the present invention, a plurality of magnetostrictive elements for generating vibration by a change in a magnetic field based on an alternating current are provided for each of the magnetostrictive elements. A stator having a plurality of vibrating surfaces each vibrating based on vibration generated by the element,
A magnetostrictive vibration motor comprising: a rotor that is pressed into contact with each of the vibrating surfaces of the stator on different surfaces, and that rotates based on vibration transmitted from at least one of the vibrating surfaces.

According to a second aspect of the present invention, in the magnetostrictive vibration motor according to the first aspect, the rotor is provided with a vibration conversion unit for generating a torsional vibration for rotating itself based on the vibration of the vibration surface. Provided.

According to a third aspect of the present invention, in the magnetostrictive vibration motor according to the second aspect, the vibration conversion section is a vibration conversion slit formed on an outer peripheral surface of the rotor. According to a fourth aspect of the present invention, in the magnetostrictive vibration motor according to the third aspect, a pair of the plurality of vibration surfaces are arranged so as to sandwich the rotor in the rotation axis direction of the rotor, and the vibration conversion slit is provided. The rotor was formed in a linear shape inclined with respect to the rotation axis of the rotor and a direction orthogonal to the rotation axis.

According to a fifth aspect of the present invention, in the magnetostrictive vibration motor according to the fourth aspect, an annular circumferential slit is formed at a central portion of a rotation axis on an outer peripheral surface of the rotor. According to a sixth aspect of the present invention, in the magnetostrictive vibration motor according to the second or third aspect, a pair of the plurality of vibration surfaces are arranged so as to sandwich the rotor in the rotation axis direction of the rotor. The shape of the vibrating surface was formed in a different shape.

[0009] The invention according to claim 7 is the invention according to claims 4 to 6.
In the magnetostrictive vibration motor according to any one of the above, an output shaft that penetrates the stator in a direction of the rotor rotation axis and that penetrates the through hole and protrudes to the outside of the stator. Was provided.

[0010] The invention described in claim 8 is the invention according to claims 2 to 7.
In the magnetostrictive vibration motor according to any one of the above, the stator is provided so as to surround each of the magnetostrictive elements, and a magnetic field coil that generates an alternating magnetic field based on an alternating current, and surrounds each of the magnetostrictive elements. A bias magnetic field generating means for generating a bias magnetic field in one direction, and a yoke for holding at least each of the magnetostrictive elements in the axial direction and forming a magnetic path together with the magnetic field coil and the bias magnetic field generating means. .

According to a ninth aspect of the present invention, in the magnetostrictive vibration motor of the eighth aspect, the vibrating surface is formed on the yoke. According to a tenth aspect of the present invention, there are provided a plurality of magnetostrictive elements that generate vibration by a change in a magnetic field, a magnetic field coil that is provided for each of the magnetostrictive elements, and generates an alternating magnetic field based on an alternating current. A stator, which is provided for each of the magnetostrictive elements and has a plurality of vibrating surfaces that vibrate based on vibrations generated by the respective magnetostrictive elements, is pressed against different surfaces on the respective vibrating surfaces of the stator, A rotor that rotates based on vibration transmitted from at least one of the vibration surfaces, and a method of driving the magnetostrictive vibration motor, wherein the magnetic field coil that supplies an alternating current is changed, Change the rotation characteristics.

(Operation) According to the first aspect of the present invention,
Vibration is generated in the magnetostrictive element by a change in the magnetic field based on the alternating current, and the vibrating surface vibrates based on the vibration. Then, the rotor is rotationally driven based on the vibration from the vibration surface. Since a plurality of magnetostrictive elements and vibrating surfaces are provided, and the rotor is pressed into contact with each vibrating surface on different surfaces, the rotation characteristics of the rotor can be changed by changing the magnetostrictive element that changes the magnetic field. . Therefore, the rotation characteristics of the rotor can be easily changed. Thus, for example, by switching the magnetostrictive element that changes the magnetic field, the rotation direction of the rotor can be switched without changing the frequency of the alternating current that generates the magnetic field.

According to the second aspect of the present invention, the rotor is provided with the vibration conversion unit that generates torsional vibration for rotating itself based on the vibration of the vibration surface. Therefore, the rotor itself can be efficiently rotated by the torsional vibration generated by the rotor itself.

According to the third aspect of the present invention, since the vibration conversion section is the vibration conversion slit formed on the outer peripheral surface of the rotor, the vibration conversion section can be easily formed. According to the invention described in claim 4, the plurality of vibration surfaces are:
A pair of vibration converting slits are arranged so as to sandwich the rotor in the direction of the rotation axis of the rotor, and the vibration conversion slits are formed in a linear shape inclined with respect to the rotation axis of the rotor and a direction orthogonal to the rotation axis. With this configuration, the inclination directions of the vibration conversion slits viewed from the respective vibration surfaces are the same, and the respective vibration surfaces viewed from the rotor are arranged in opposite directions in the rotation axis direction. The rotation characteristics differ only in the rotation direction, and the rotation speed and the rotation torque are the same. Therefore, for example, if the stator is formed symmetrically with respect to the center of the rotor in the direction of the rotation axis, by switching the magnetostrictive element that changes the magnetic field, the rotation speed and rotation can be changed without changing the frequency of the AC current that generates the magnetic field. With the same torque, only the rotation direction of the rotor can be switched. or,
Since the vibration conversion slit is formed in a linear shape that is inclined with respect to the rotation axis of the rotor and a direction orthogonal to the rotation axis, the vibration conversion section can be easily formed.

According to the fifth aspect of the present invention, since an annular circumferential slit is formed at the center of the rotation axis on the outer peripheral surface of the rotor, the rotor itself is formed based on the vibration of one of the vibrating surfaces. When a torsional vibration is generated, the fin portion that is pressed against one vibration surface and divided by the vibration conversion slit and the circumferential slit does not contact the other vibration surface,
The torsional vibration is less likely to be inhibited on the other vibration surface.

According to the sixth aspect of the present invention, the plurality of vibrating surfaces are arranged in a pair so as to sandwich the rotor in the rotation axis direction of the rotor, and the shapes of the pair of vibrating surfaces are different. It is formed. With this configuration, the rotation characteristics of the rotor with respect to the vibration of each vibration surface, that is, the rotation direction,
The rotation speed, the rotation torque, and the like can be made different for each vibration surface. Thus, for example, if the stator is formed symmetrically with respect to the center of the rotor in the direction of the rotation axis except for the vibration surface, by switching the magnetostrictive element that changes the magnetic field, without changing the frequency of the AC current that generates the magnetic field, Rotation characteristics of the rotor, that is, rotation direction, rotation speed, rotation torque, and the like can be changed.

According to the seventh aspect of the present invention, a through hole is formed in the stator in the direction of the axis of rotation of the rotor, and the rotor has an output through the through hole and protruding outside the stator. A shaft is provided. Therefore, even if a plurality of vibrating surfaces are arranged in a pair so as to sandwich the rotor in the rotation axis direction of the rotor, the rotational force of the rotor can be transmitted to the outside with a simple configuration.

According to the present invention, a bias magnetic field is generated by the bias magnetic field generating means, and an alternating magnetic field is generated by the magnetic field coil based on the alternating current. Then, vibration is generated in the magnetostrictive element due to a change in the magnetic field. Then, the vibration surface vibrates based on the vibration, and the rotor is rotationally driven based on the vibration from the vibration surface. Then, at least the magnetostrictive element is held by the yoke and a magnetic path is formed by the yoke, so that generation of leakage magnetic flux is suppressed. Therefore, the output with respect to the supplied alternating current can be increased, and higher efficiency can be achieved.

According to the ninth aspect of the present invention, since the vibrating surface is formed on the yoke, an increase in the number of components can be suppressed. According to the tenth aspect of the present invention, an alternating magnetic field is generated by the magnetic field coil based on the alternating current, a vibration is generated by the magnetostrictive element by a change in the magnetic field, and the vibration surface vibrates based on the vibration. . Then, the rotor is rotationally driven based on the vibration from the vibration surface. And
By changing the magnetic field coil that supplies the alternating current, the rotation characteristics of the rotor are changed. Therefore, the rotation characteristics of the rotor can be easily changed. This allows, for example,
By switching the magnetic field coil that supplies the AC current, the rotation direction of the rotor can be switched without changing the frequency of the AC current.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. As shown in FIG. 1, the magnetostrictive vibration motor includes a stator 1 and a rotor 2. The stator 1 is formed symmetrically with respect to the center of the rotor 2 in the rotation axis direction. Specifically, the stator 1 includes a pair of similarly configured sub-stators 3 and 4, and similar ends of the sub-stators 3 and 4 are arranged to face each other.

One (lower in the figure) sub-stator 3 is
A housing yoke 5, a holding yoke 6, a block yoke 7, a linear slider 8, a giant magnetostrictive element 9 as a magnetostrictive element, a magnetic field coil 10, a bias magnetic field coil 11 as a bias magnetic field generating means, and a disc spring 12 are provided. In the present embodiment, the storage yoke 5, the holding yoke 6, and the block yoke 7 constitute a yoke.

The storage yoke 5 is formed in a substantially cylindrical shape with a bottom, and has a base 5a which is circular and protrudes upward at the bottom. A through hole 5b is formed in the center of the bottom (pedestal) of the storage yoke 5 so as to penetrate in the axial direction.

The holding yoke 6 has a cylindrical portion 6a having an outer diameter substantially equal to the inner diameter of the housing yoke 5, and a disk portion extending radially inward from one end (upper end in the figure) of the cylindrical portion 6a. 6b and a small cylindrical portion 6c extending from the tip of the disk portion 6b to the other end (the lower end in the figure) of the cylindrical portion 6a. The outer diameter of the small cylinder portion 6c is set to be the same as the outer diameter of the pedestal portion 5a.

The block yoke 7 is formed in a substantially cylindrical shape having a through hole 7a having the same diameter as the through hole 5b of the storage yoke 5 at the center. The block yoke 7 has an outer diameter (indicated by a broken line in the figure) at one end (upper end in the figure) of which is set to be the same as the outer diameter of the small cylindrical portion 6c of the holding yoke 6, and the other end (in the figure, The outer diameter on the (lower end) side is set to be substantially the same as the inner diameter of the small cylindrical portion 6c of the holding yoke 6. or,
On the outer periphery of the block yoke 7, an annular engagement recess 7b is formed at the center in the axial direction. On the outer periphery of one end (the upper end in the figure) of the block yoke 7, a long detent protrusion 7c protruding radially outward along the axial direction.
Are formed in the circumferential direction.

A circular concave portion 7d is formed at the center of one end (the upper end in the figure) of the block yoke 7, and one end surface excluding the concave portion 7d is a vibrating surface 7e. The linear slider 8 is formed in a substantially cylindrical shape whose outer diameter is the same as the outer diameter of the holding yoke 6 (the cylindrical portion 6a) and whose inner diameter is the same as the outer diameter of the pedestal portion 5a. An annular support recess 8 a is formed at a radially inner end of one end (the lower end in the figure) of the linear slider 8. Further, on the inner peripheral surface of the linear slider 8 excluding the support concave portion 8a, a plurality of detent concave portions 8b which are continuous from one end to the other end and which can accommodate the detent convex portions 7c are formed in the circumferential direction. .

The giant magnetostrictive element 9 is formed in a substantially cylindrical shape having a through hole 9a having the same diameter as the through hole 5b of the housing yoke 5 at the center thereof. The outer diameter of the giant magnetostrictive element 9 is set to be the same as the outer diameter of the small cylindrical portion 6c of the holding yoke 6. The giant magnetostrictive element 9 is an element that generates distortion (expansion and contraction movement) due to a change in the magnetic field, and generates vibration by repeating the change in the magnetic field.

The outer diameter of the magnetic field coil 10 is smaller than the inner diameter of the cylindrical portion 6 a of the holding yoke 6, and the inner diameter is set to be substantially the same as the outer diameter of the giant magnetostrictive element 9. Also, the magnetic field coil 10
Is set to have substantially the same axial length as that of the cylindrical portion 6a. The end of the winding of the magnetic field coil 10 is connected to a first AC terminal of an external control device (not shown). Then, the magnetic field coil 10 generates an alternating magnetic field based on the alternating current supplied from the control device.

The bias magnetic field coil 11 has an outer diameter substantially equal to the inner diameter of the cylindrical portion 6 a of the holding yoke 6 and an inner diameter substantially equal to the outer diameter of the magnetic field coil 10. The end of the winding of the bias magnetic field coil 11 is connected to a DC terminal of an external control device (not shown). The bias magnetic field coil 11 generates a unidirectional bias magnetic field based on a DC current supplied from the control device.

The giant magnetostrictive element 9 is disposed on the pedestal 5a of the housing yoke 5, and the giant magnetostrictive element 9
The magnetic field coil 10 is provided to surround the giant magnetostrictive element 9 on the outer peripheral side of the magnetic field coil 10, and the bias magnetic field coil 11 is provided on the outer peripheral side of the magnetic field coil 10.
(Giant magnetostrictive element 9).

The other end (the lower end in the figure) of the cylindrical portion 6a of the holding yoke 6 is arranged to surround the magnetic field coil 10 and the bias magnetic field coil 11 together with the bottom of the housing yoke 5. The inner yoke 5 is fitted and fixed in the housing yoke 5 until it comes into contact with the bottom of the yoke 5.

The linear slider 8 is fitted and fixed in the accommodation yoke 5 until one end (lower end in the drawing) of the linear slider 8 contacts one end (upper end in the drawing) of the holding yoke 6. At this time, the other end of the linear slider 8 (in the figure,
The (upper end) side protrudes outside the storage yoke 5.

The block yoke 7 has one end (upper end in the figure) side accommodated inside the linear slider 8 and the other end side (lower end in the figure) inside the small cylindrical portion 6c of the holding yoke 6. Is housed in The block yoke 7 has a rotation-preventing projection 7c that is a linear slider 8
By being accommodated in the rotation stopper recess 8b, the rotation of the linear slider 8 is stopped, and the linear slider 8 is movable in the axial direction. The block yoke 7 has its other end (the lower end in the drawing) whose other end (the lower end in the figure) is urged by the engagement recess 7 b against the other end of the disc spring 12 having one end supported by the support recess 8 a of the linear slider 8. It is in pressure contact with the giant magnetostrictive element 9. Thereby, the giant magnetostrictive element 9 is sandwiched between the block yoke 7 and the pedestal portion 5a of the storage yoke 5, and the giant magnetostrictive element 9 is applied with a pressure for increasing the amplitude of its own vibration. I have.

The other (upper in the figure) sub-stator 4 is
It has the same members as the sub-stator 3 configured as described above, and has the same configuration. The winding end of the magnetic field coil 10 of the sub-stator 4 is connected to a second AC terminal of an external control device (not shown). The sub-stator 4 includes a housing 13 and a housing cover 14.
In the inside, similarly configured ends are disposed opposite to each other at one end (upper end) in the axial direction of the sub-stator 3.

More specifically, the housing 13 is formed in a substantially cylindrical shape with a bottom, and a bearing holding hole 13a for holding the bearing 15 is formed at the bottom. Housing cover 14
Is formed in a lid shape fitted into the opening of the housing 13, and has a bearing holding hole 14 in the center of which a bearing 16 is held.
a is formed. The sub stators 3 and 4 are accommodated in the housing 13 and the housing cover 14 so as to face each other. Here, the sub-stator 4 is biased toward the sub-stator 3 at the other end of the disc spring 17 whose one end is supported by the housing cover 14. At this time, the rotor 2 is interposed between the two sub stators 3 and 4, and the rotor 2
Is held between the two sub-stators 3 and 4 so as to be pressed against the two vibrating surfaces 7e of the two sub-stators 3 and 4.

The rotor 2 has an outer diameter of the block yoke 7.
Is formed in a substantially columnar shape having the same diameter as the outer diameter (the outer diameter of the vibrating surface 7e) on one end (the upper end in the figure) of the oscillating member. A plurality of vibration conversion slits (recesses) 2a are formed in the outer peripheral surface of the rotor 2 in the circumferential direction as a vibration conversion unit that generates torsional vibration for rotating itself based on vibration. The vibration conversion slit 2a is formed in a linear shape inclined with respect to the rotation axis of the rotor 2 and a direction orthogonal to the rotation axis. The vibration conversion slit 2a of the present embodiment is formed so as to be inclined clockwise toward the substator 4 side end when viewed from the substator 3 side end (vibration surface 7e). An annular circumferential slit 2b is formed at the center of the rotation axis on the outer peripheral surface of the rotor 2.

The rotor 2 is integrally formed with an output shaft 2c protruding in the axial direction (vertical direction in the figure). The output shaft 2c is connected to the through holes 5b, 7a,
9a so as to protrude outside the stator 1 and to be supported by the bearings 15 and 16.
Projecting out of the housing 13 and the housing cover 14 through the housings 5 and 16.

In the magnetostrictive vibration motor configured as described above, the rotation characteristics of the rotor 2 are changed by changing the magnetic field coil 10 (the magnetic field coil 10 of the sub-stator 3 or the sub-stator 4) for supplying an alternating current. . still,
Here, the rotation characteristics of the rotor 2 include a rotation direction, a rotation speed, and a rotation torque.

In this embodiment, when an alternating current having a predetermined frequency is supplied to the magnetic field coil 10 of the sub-stator 3 and a direct current is supplied to the bias magnetic field coil 11 of the sub-stator 3, the rotor 2 is driven to rotate forward. You. or,
When an alternating current of a predetermined frequency is supplied to the magnetic field coil 10 of the sub-stator 4 and a direct current is supplied to the bias magnetic field coil 11 of the sub-stator 4, the rotor 2 is driven to rotate in the reverse direction.

More specifically, when an alternating current having a predetermined frequency is supplied to the magnetic field coil 10 of the sub-stator 3, an alternating magnetic field is generated based on the alternating current. At this time, a DC current is supplied to the bias magnetic field coil 11 of the sub-stator 3, and a one-way bias magnetic field is generated based on the DC current. Then, the giant magnetostrictive element 9 of the sub-stator 3 generates a longitudinal vibration due to a change in the magnetic field based on the alternating magnetic field. Then, based on the longitudinal vibration, the sub stator 3
Vibrating surface 7e vibrates. Then, torsional vibration is generated in the vibration conversion slit 2a of the rotor 2 based on (resonates) the vibration from the vibration surface 7e, and the rotor 2 is driven to rotate forward by the propulsive force of the torsional vibration component.

When an alternating current having a predetermined frequency is supplied to the magnetic field coil 10 of the sub-stator 4, an alternating magnetic field is generated based on the alternating current. At this time, the sub stator 4
A DC current is supplied to the bias magnetic field coil 11, and a unidirectional bias magnetic field is generated based on the DC current. Then, the giant magnetostrictive element 9 of the sub-stator 4 generates a longitudinal vibration due to a change in the magnetic field based on the alternating magnetic field. Then, the vibrating surface 7e of the sub stator 4 vibrates based on the longitudinal vibration. Then, based on the vibration from the vibration surface 7e (resonating), the vibration conversion slit 2a of the rotor 2
, A torsional vibration is generated, and the rotor 2 is driven to rotate in the reverse direction by the propulsive force of the torsional vibration component. Here, each vibration surface 7e
The inclination direction of the vibration conversion slit 2a viewed from the same is the same (inclined clockwise in the direction away from the vibration surface 7e), and each vibration surface 7e viewed from the rotor 2 rotates. Since the rotors 2 are arranged in opposite directions in the axial direction, the rotation characteristics of the rotor 2 with respect to the vibration of each vibration surface 7e differ only in the rotation direction, and the rotation speed and the rotation torque are the same. Therefore, when the sub-stator 4 is driven, the rotor 2 is driven in reverse rotation at the same rotation speed and the same rotation torque as during normal rotation.

Next, the characteristic operation and effect of the first embodiment will be described below. (1) Since the stator 1 is provided with a plurality of giant magnetostrictive elements 9 and vibrating surfaces 7e, and the rotor 2 is pressed against the vibrating surfaces 7e on different surfaces, the giant magnetostrictive element 9 that changes the magnetic field is changed. That is, by changing the magnetic field coil 10 that supplies the alternating current (the magnetic field coil 10 of the sub stator 3 or the sub stator 4), the rotation characteristics of the rotor 2 can be changed. Therefore, the rotation characteristics of the rotor 2 can be easily changed. In the present embodiment, the rotation direction of the rotor 2 can be switched by switching the magnetic field coil 10 that supplies the alternating current.

(2) The rotor 2 is provided with a vibration conversion slit 2a for generating torsional vibration for rotating itself based on the vibration of the vibration surface 7e. Therefore, the rotor 2 itself can be efficiently rotated by the torsional vibration generated by the rotor 2 itself.

(3) Since the vibration converting portion that generates torsional vibration for rotating itself is the vibration converting slit 2a, the vibration converting portion can be easily formed by cutting or the like.

(4) A plurality of vibrating surfaces 7e are arranged in a pair so as to sandwich the rotor 2 in the direction of the axis of rotation of the rotor 2, and the vibration converting slit 2a is arranged in the direction of the axis of rotation of the rotor 2 and the direction orthogonal to the axis of rotation. It is formed in an inclined linear shape. Therefore, the inclination direction of the vibration conversion slit 2a as viewed from each vibration surface 7e is the same (inclined clockwise in a direction away from the vibration surface 7e), and as viewed from the rotor 2. Since the vibrating surfaces 7e are arranged in directions opposite to each other in the direction of the rotation axis, the rotational characteristics of the rotor 2 with respect to the vibration of the vibrating surfaces 7e differ only in the rotational direction, and the rotational speed and the rotational torque are the same. Also, stator 1
The (sub-stators 3, 4) are formed symmetrically with respect to the center of the rotor 2 in the rotation axis direction.
The same vibration occurs in e. Therefore, only by switching the magnetic field coil 10 that supplies the alternating current (the magnetic field coil 10 of the sub-stator 3 or the sub-stator 4), the frequency of the alternating current is not changed (the control device does not need to generate a plurality of types of alternating current), and It is possible to switch only the rotation direction of the rotor 2 with the same rotation speed and rotation torque. Further, since the vibration conversion slit 2a is formed in a linear shape, the vibration conversion section can be easily formed by cutting or the like. Further, since the stator 1 is formed symmetrically and includes the sub-stators 3 and 4 having the same configuration, different types of components are not required for each of the sub-stators 3 and 4, and an increase in the types of components is suppressed. Furthermore, since the sub stators 3 and 4 are arranged in the rotation axis direction of the rotor 2, the magnetostrictive vibration motor (stator 1) does not increase in size in the direction orthogonal to the rotation axis of the rotor 2 (radial direction).

(5) Since an annular circumferential slit 2b is formed at the center of the rotation axis on the outer peripheral surface of the rotor 2, the rotor 2 itself generates torsional vibration based on the vibration of one of the vibrating surfaces 7e. When this occurs, the fin portion which is pressed against one vibrating surface 7e and divided by the vibration converting slit 2a and the circumferential slit 2b does not contact the other vibrating surface 7e, and the torsional vibration is applied to the other vibrating surface 7e. And it is hard to be disturbed. Therefore, the efficiency of the magnetostrictive vibration motor can be improved.

(6) Stator 1 (sub-stator 3, 4)
Have through holes 5b, 7 penetrating in the direction of the rotor rotation axis.
a, 9a are formed, and the rotor 2 has through holes 5b, 7
a, an output shaft 2 penetrating through 9a and protruding outside the stator 1
c is provided. Therefore, even if a plurality of vibrating surfaces 7e are arranged in a pair so as to sandwich the rotor 2 in the direction of the rotation axis of the rotor 2, the rotational force of the rotor 2 can be transmitted to the outside with a simple configuration.

(7) Since a bias magnetic field in one direction is generated by the bias magnetic field coil 11, the giant magnetostrictive element 9 is formed while reducing the size of the magnetic field coil 10 and the value of the alternating current supplied at a predetermined frequency. A large magnetic field in one direction that can be sufficiently extended can be generated. Therefore,
Further, higher efficiency can be achieved.

(8) The storage yoke 5, the holding yoke 6, and the block yoke 7 form a magnetic path.
0 and bias magnetic field coil 11 → accommodation yoke 5 → giant magnetostrictive element 9 → block yoke 7 → holding yoke 6 → magnetic field coil 10 and bias magnetic field coil 11 or vice versa)
Generation of leakage magnetic flux is suppressed. Therefore, the amount of effective magnetic flux with respect to the supplied alternating current, and the output (amplitude of vibration) can be increased, and high efficiency can be achieved.

(9) Since the vibrating surface 7e is formed on the block yoke 7 constituting a part of the magnetic path, the number of components is suppressed from increasing compared to the case where the vibrating surface is formed and provided as a separate member. can do.

(10) Since the giant magnetostrictive element 9 having a large displacement is used as the magnetostrictive element, the amplitude of vibration can be increased and the rotor 2 can be rotated more efficiently. The above embodiment may be modified and implemented as follows.

In the above embodiment, it is possible to switch only the rotating direction of the rotor 2 with the same rotation speed and rotation torque without changing the frequency of the AC current, only by switching the magnetic field coil 10 for supplying the AC current. Although the present invention has been embodied as a magnetostrictive vibration motor, it may be changed to another magnetostrictive vibration motor that changes the rotation characteristics of the rotor 2 by changing the magnetic field coil 10 that supplies an alternating current.

For example, it may be changed as shown in FIG.
This magnetostrictive vibration motor mainly differs from the magnetostrictive vibration motor of the above-described embodiment in that the shape of the block yokes 23 and 24 (the respective vibrating surfaces 23a and 24a) of the sub-stators 21 and 22 provided on the stator 20 is different. Is formed in the different. More specifically, the vibrating surface 23a of one (the lower side in the figure) sub-stator 21 (the block yoke 23) is formed on the outer peripheral side of one end (the upper end in the figure), as in the above embodiment. The vibrating surface 24a of the other (upper in the figure) sub-stator 22 (block yoke 24) is formed on the inner peripheral side of one end (the lower end in the figure). Further, the rotor 25 of this magnetostrictive vibration motor has an axial length half that of the rotor 2 of the above-described embodiment, and does not have the circumferential slit 2b. On the outer peripheral surface of the rotor 25, a plurality of vibration converting slits (recesses) 25a are formed in the circumferential direction as vibration converting portions that generate torsional vibration for rotating the rotor 25 based on vibration. The holding yoke 26 of this magnetostrictive vibration motor is
Compared to the holding yoke 6 of the above embodiment, the configuration is such that the cylindrical portion 6a is omitted. Also, the linear slider 27
Of the linear slider 8 of the above embodiment is slightly shorter than that of the linear slider 8 of the above embodiment.

In the magnetostrictive vibration motor configured as described above, the load (rotor 2) viewed from each of the vibrating surfaces 23a and 24a.
5) Since the shapes are different, the rotation characteristics (at least one of the rotation direction, the rotation speed, the rotation torque, and the like) of the rotor 25 with respect to the vibration of the vibration surfaces 23a and 24a are different. Therefore, the magnetic field coil 10 that supplies an alternating current (the magnetic field coil 10 of the sub-stator 21 or the sub-stator 22)
, The rotation characteristics of the rotor 25 can be switched to different characteristics without changing the frequency of the AC current (without the need for the control device to generate a plurality of types of AC currents). For example, the magnetic field coil 1 of the sub-stator 21
0 when a predetermined frequency of alternating current is supplied to the rotor 25
Can be rotated forward with a high torque, and when an alternating current of a predetermined frequency is supplied to the magnetic field coil 10 of the sub-stator 22, the rotor 25 can be reversely rotated with a low torque. In order to obtain desired rotation characteristics in this manner, the shape (slit shape) and material of the rotor may be changed to change the resonance frequency and vibration mode (direction and pattern of vibration) of the rotor. For example, by forming a vibration conversion slit (recess) (not shown) inside the rotor 25, desired rotation characteristics can be obtained.

In the above-described embodiment and other examples, the rotation characteristics of the rotors 2 and 25 are different by switching the magnetic field coil 10 (the magnetic field coil 10 of the sub-stator 3, 21 or the sub-stator 4, 22) for supplying an alternating current. Although the characteristics have been switched, the magnetostrictive vibration motor that changes the rotation characteristics of the rotor to different characteristics by changing the magnetic field coil that supplies the alternating current may be embodied. For example, the present invention may be embodied in a magnetostrictive vibration motor in which, when an alternating current is supplied to one of the magnetic field coils, the rotor rotates forward at a low speed, and when an alternating current is supplied to the two magnetic field coils simultaneously, the rotor rotates forward at a high speed. Even in this case, the rotation characteristics of the rotor can be changed without changing the frequency of the AC current (without having to generate a plurality of types of AC currents) by simply changing the magnetic field coil that supplies the AC current. Can be switched to

In the above embodiment, the rotor 2 is formed with the vibration conversion slit 2a that generates torsional vibration for rotating itself based on the vibration of the vibration surface 7e. , Each sub-stator 3, 4
May be provided with a vibration converter for generating torsional vibration for rotating the rotor. For example, an inclined vibration conversion slit is formed on the outer periphery of each block yoke 7. Even in this case, the rotation characteristics of the rotor can be changed without changing the frequency of the AC current (without having to generate a plurality of types of AC currents) by simply changing the magnetic field coil that supplies the AC current. Can be changed to Of course, both the rotor 2 and the sub stators 3 and 4 may be provided with a vibration converter.

In the above-described embodiment, the vibration conversion slit 2a is formed in the rotor 2 as a vibration conversion section for generating torsional vibration for rotating itself based on the vibration of the vibration surface 7e. If a torsional vibration for rotating itself can be generated based on the vibration, the vibration conversion unit may be changed to a configuration (shape) other than the slit.

In the above embodiment, the plurality of vibrating surfaces 7e
The (sub-stators 3, 4) are arranged in a pair so as to sandwich the rotor 2 in the direction of the rotation axis of the rotor 2. However, a plurality of giant magnetostrictive elements (magnetostrictive elements) and vibrating surfaces are provided, and the rotors have different vibrating surfaces. As long as the contact is made, the configuration may be changed to another configuration. Even in this case, the rotation characteristics of the rotor 2 can be changed by changing the giant magnetostrictive element (magnetostrictive element) that changes the magnetic field (only by changing the magnetic field coil that supplies the AC current).

In the above embodiment, the annular circumferential slit 2b is formed at the center of the rotation axis on the outer peripheral surface of the rotor 2, but the circumferential slit 2b may be omitted. Even in such a case, the effects (1) to-of the above embodiment can be obtained.
(4) The same effects as (6) to (10) can be obtained.

In the above embodiment, the through holes 5b, 7a, 9a penetrating in the direction of the rotor rotation axis are formed in the stator 1 (sub stators 3, 4), and the through holes 5
Although the output shaft 2c penetrating through b, 7a, 9a and protruding outside the stator 1 is provided, another configuration may be used as long as the torque of the rotor 2 can be transmitted to the outside. For example, the through holes 5b, 7a, 9a and the output shaft 2c are omitted,
A tooth is provided on the outer peripheral surface of the rotor 2, and a gear that meshes with the tooth and transmits torque to the outside is provided. In this case, the rotational force of the rotor 2 is transmitted to the outside via the gear. or,
Even in such a case, the effects (1) to (7) of the above-described embodiment can be obtained.
(5) The same effects as (7) to (10) can be obtained.

In the above-described embodiment, the bias magnetic field coil 11 is used as the bias magnetic field generating means for generating the one-directional bias magnetic field. May be changed. For example, the bias magnetic field coil 11 may be changed to a permanent magnet. Even in this case, effects similar to the effects (1) to (6) and (8) to (10) of the above embodiments can be obtained. In addition, since a one-way bias magnetic field is generated by the permanent magnet, the size of the magnetic field coil 10 is reduced and the value of the alternating current to be supplied is reduced, while the unidirectional large magnetic field is sufficient to extend the giant magnetostrictive element 9. A magnetic field can be generated. Also, the bias magnetic field coil 11
As compared with the case of using, there is no need to supply a direct current, and a bias magnetic field in one direction can be easily generated.

In the above embodiment, the vibrating surface 7e is formed on the block yoke 7 which forms a part of the magnetic path. However, a similar vibrating surface may be formed on another member. Even in this case, the effects (1) to (8), (1)
The same effect as in (0) can be obtained.

In the above embodiment, the giant magnetostrictive element 9 having a large displacement is used as the magnetostrictive element, but may be changed to a magnetostrictive element having a small displacement. Even in this case, effects similar to the effects (1) to (9) of the above embodiments can be obtained.

The magnetostrictive vibration motor of the above-described another example (see FIG. 2) can be a magnetostrictive vibration motor in which the rotation characteristics of the rotor 31 are constant by changing as shown in FIG. This magnetostrictive vibration motor is different from the other example shown in FIG.
(Block yoke 24) is omitted and sub-stator 21
And a stator 32 configured substantially in the same manner as the above. The rotor 31 is directly urged toward the vibrating surface 23a at the other end of the disc spring 34 whose one end is supported by the housing cover 33, and is in pressure contact with the vibrating surface 23a. In the magnetostrictive vibration motor configured as described above, when an alternating current having a predetermined frequency is supplied to the magnetic field coil 10 and a direct current is supplied to the bias magnetic field coil 11, the rotor 31 is driven to rotate forward.

The technical ideas that can be grasped from the above embodiments will be described below together with their effects. (A) The magnetostrictive vibration motor according to any one of claims 1 to 3, wherein a pair of the plurality of vibration surfaces are arranged so as to sandwich the rotor in the rotation axis direction of the rotor. Vibration motor. By doing so, the effect of the invention described in claim 1 can be obtained, and a pair of a plurality of vibration surfaces are arranged so as to sandwich the rotor in the rotation axis direction of the rotor. The stator) does not increase in size in the direction (radial direction) orthogonal to the rotation axis of the rotor.

(B) In the magnetostrictive vibration motor according to any one of (1) to (7) and (A), a magnetic field coil for generating an alternating magnetic field based on an alternating current is provided near each of the magnetostrictive elements of the stator. A magnetostrictive vibration motor characterized by being provided. With this configuration, the rotation characteristics of the rotor can be changed by changing the magnetic field coil that supplies the alternating current.

(C) Claims 1 to 9 and (a),
(2) The magnetostrictive vibration motor according to any one of (1) to (3), wherein the magnetostrictive element is a giant magnetostrictive element. By doing so, the amplitude of the vibration can be increased, and the rotor can be more efficiently rotated.

[0067]

As described in detail above, according to the first to ninth aspects of the present invention, it is possible to provide a magnetostrictive vibration motor capable of easily changing the rotation characteristics of the rotor.

Further, according to the tenth aspect of the present invention, it is possible to provide a method of driving a magnetostrictive vibration motor capable of easily changing the rotation characteristics of a rotor.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a magnetostrictive vibration motor according to an embodiment.

FIG. 2 is a sectional view of a main part of a magnetostrictive vibration motor according to another example.

FIG. 3 is a sectional view of a main part of a magnetostrictive vibration motor according to another example.

[Explanation of symbols]

1, 20: stator, 2, 25: rotor, 5: storage yoke (yoke), 6, 26: holding yoke (yoke), 7,
23, 24: block yokes (yoke), 9: giant magnetostrictive element (magnetostrictive element), 10: magnetic field coil, 11: bias magnetic field coil (bias magnetic field generating means), 2a, 25a: vibration conversion slit (vibration conversion unit), 2b: circumferential slit, 2c: output shaft, 5b, 7a, 9a: through hole, 7e,
23a, 24a: vibrating surface.

Claims (10)

[Claims] A plurality of magnetostrictive elements (9) for generating vibrations by a change in a magnetic field based on an alternating current; and a plurality of magnetostrictive elements (9) provided for each of the magnetostrictive elements (9).
A stator (1, 20) having a plurality of vibrating surfaces (7e, 23a, 24a) each vibrating based on the vibration generated by the vibrator; and the vibrating surfaces (7e, 23) of the stator (1, 20).
a, 24a) being in pressure contact with different surfaces, and having a rotor (2, 25) rotating based on vibration transmitted from at least one of the vibrating surfaces (7e, 23a, 24a). Magnetostrictive vibration motor. 2. The magnetostrictive vibration motor according to claim 1, wherein said rotor (2, 25) has said vibrating surface (7e, 23).
A magnetostrictive vibration motor provided with a vibration converter (2a, 25a) for generating a torsional vibration for rotating itself based on the vibration of (a, 24a). 3. The magnetostrictive vibration motor according to claim 2, wherein the vibration conversion unit (2a, 25a) includes the rotor (2, 25).
25) A magnetostrictive vibration motor characterized in that it is a vibration conversion slit formed on the outer peripheral surface. 4. The magnetostrictive vibration motor according to claim 3, wherein the plurality of vibrating surfaces (7e) are arranged in a pair so as to sandwich the rotor (2) in a rotation axis direction of the rotor (2). A magnetostrictive vibration motor, wherein the vibration conversion slit (2a) is formed in a linear shape inclined with respect to the rotation axis of the rotor (2) and a direction orthogonal to the rotation axis. 5. The magnetostrictive vibration motor according to claim 4, wherein an annular circumferential slit (2b) is formed at the center of the rotation axis on the outer peripheral surface of the rotor (2). . 6. The magnetostrictive vibration motor according to claim 2, wherein the plurality of vibrating surfaces (23a, 24a) are paired so as to sandwich the rotor (25) in the rotation axis direction of the rotor (25). And a pair of vibrating surfaces (23a,
24. A magnetostrictive vibration motor characterized in that the shape of 24a) is formed in a different shape. 7. The magnetostrictive vibration motor according to claim 4, wherein a through hole (5b, 7a, 9a) penetrating in a direction of the rotor rotation axis is formed in the stator (1, 20). Forming the through holes (5b, 7a,
9a) An output shaft (2c) penetrating through 9a) and projecting outside the stator (1, 20). 8. The magnetostrictive vibration motor according to claim 2, wherein the stator (1, 20) is provided so as to surround each of the magnetostrictive elements (9), and based on an alternating current. A magnetic field coil (10) for generating an alternating magnetic field, and a bias magnetic field generating means (11) provided to surround each of the magnetostrictive elements (9) and generating a unidirectional bias magnetic field.
And a yoke (5-7, 2) that holds at least each of the magnetostrictive elements (9) in the axial direction and forms a magnetic path together with the magnetic field coil (10) and the bias magnetic field generating means (11).
3, 24, 26). 9. The magnetostrictive vibration motor according to claim 8, wherein the vibrating surface (7e, 23a, 24a) is formed on the yoke (7, 23, 24). 10. A plurality of magnetostrictive elements (9) for generating vibration by a change in a magnetic field, and a magnetic field coil (10) provided for each of the magnetostrictive elements (9) for generating an alternating magnetic field based on an alternating current. ) And a plurality of vibrating surfaces (7e, 23a, 24a) provided for the respective magnetostrictive elements (9) and vibrating based on the vibrations generated in the respective magnetostrictive elements (9). Stator (1, 2
0) and the respective vibrating surfaces (7e, 23) of the stator (1, 20).
and a rotor (2, 25) that is pressed against different surfaces of the vibration surfaces (a, 24a) and rotates based on vibration transmitted from at least one of the vibration surfaces (7e, 23a, 24a). The method of driving a magnetostrictive vibration motor according to claim 1, wherein the rotational characteristics of the rotor (2, 25) are changed by changing the magnetic field coil (10) for supplying an alternating current.