JP2015122855A - Power generation element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation element capable of suppressing the occurrence of a strange sound, the disconnection of a coil, and the disturbance of a voltage waveform.SOLUTION: A conductor is wound spirally to form a coil 13, and a magnetostrictive rod 11 is provided inside the coil 13. A magnetic loop is formed between a rigid rod 12 and the magnetostrictive rod 11 and the magnetostrictive rod 11 vibrates in the juxta position direction of the magnetostrictive rod 11 and the rigid rod 12, thereby generating power. The coil 13 is fixed to a holding member 50 but not fixed to a holding member 60, so that the interval between the magnetostrictive rod 11 and the coil 13 is kept. Since the magnetostrictive rod 11 vibrates inside the coil 13, the collision of the magnetostrictive rod 11 and the coil 13 with each other is prevented. Consequently, the occurrence of a strange sound and the disconnection of the coil 13 (conductor) due to the collision of the magnetostrictive rod 11 and the coil 13 can be prevented and the disturbance of a voltage waveform is prevented.

Description

  The present invention relates to a power generation element that performs vibration power generation using the inverse magnetostriction effect of a magnetostrictive material, and more particularly to a power generation element that can suppress generation of abnormal noise, coil disconnection, and voltage waveform disturbance.

  Conventionally, a power generation element that performs vibration power generation using the inverse magnetostriction effect of a magnetostrictive material is known (for example, Patent Document 1). In Patent Document 1, a pair of magnetostrictive rods arranged in parallel, a first holding member that holds one end of the pair of magnetostrictive rods, the other end of the pair of magnetostrictive rods, and a mass body (movable mass) are disclosed. ) Functioning as a second holding member, a coil in which a conducting wire is spirally wound and a magnetostrictive rod is provided, and a pair of magnetostrictive rods disposed at one end and the other end with different magnetic poles. A power generating element including a permanent magnet is disclosed. The power generation element disclosed in Patent Document 1 is installed with the first holding member fixed to the vibrating body and the second holding member as a free end, and the axis of the magnetostrictive rod is perpendicular to the vibration of the vibrating body. By causing the second holding member to perform a pendulum motion (free vibration or forced vibration) in the direction, axial expansion and contraction are generated in one and the other of the magnetostrictive rods, respectively. As a result, the magnetic flux density changes in a direction parallel to the axial direction of the magnetostrictive rod (inverse magnetostrictive effect), current is generated in the coil wound around the magnetostrictive rod, and power generation is performed.

International Publication No. 2011/158473 (paragraph 0078, FIG. 4A, etc.)

  However, in the above-described conventional power generating element, the magnetostrictive rod installed in the coil vibrates, so that when the magnetostrictive rod repeatedly collides with the inner peripheral surface of the coil, a collision sound (abnormal noise) is generated or the coil (conductor) is generated. There is a problem of disconnection. Further, there is a problem that the output voltage waveform is disturbed by the impact of the magnetostrictive rod colliding with the coil.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power generation element that can suppress generation of abnormal noise, disconnection of a coil, and disturbance of a voltage waveform.

Means for Solving the Problems and Effects of the Invention

  According to the power generating element of the first aspect, the coil is formed by spirally winding the conductive wire, and the magnetostrictive rod configured in a rod shape from the magnetostrictive material is disposed in the coil with a gap from the inner peripheral surface of the coil. Established. A rigid rod configured in a rod shape from a magnetic material is juxtaposed with the magnetostrictive rod, and a magnetic loop is formed with the magnetostrictive rod. Both ends of the rigid rod and the magnetostrictive rod in the axial direction are held by the pair of holding members, respectively, and one of the pair of holding members is fixed. The other of the pair of holding members vibrates in the direction in which the magnetostrictive rod and the rigid rod are juxtaposed, whereby the magnetostrictive rod expands or contracts in the axial direction to generate power.

  Since one end of the coil in the axial direction is fixed to one of the pair of holding members, the distance between the magnetostrictive rod and the coil is maintained. When one end of the coil in the axial direction is fixed to the holding member, the magnetostrictive rod vibrates inside the coil, so that the collision between the magnetostrictive rod and the coil can be prevented. As a result, there is an effect that it is possible to prevent generation of noise due to collision between the magnetostrictive rod and the coil and disconnection of the coil (conductive wire). In addition, since the magnetostrictive rod can be prevented from colliding with the coil, there is an effect that the disturbance of the voltage waveform can be suppressed.

  Furthermore, the other axial end of the coil is not fixed to either one of the pair of holding members. If both sides in the axial direction of the coil are fixed to the pair of holding members, the bending rigidity of the coil affects the bending deformation of the magnetostrictive rod. Then, in order to deform the magnetostrictive rod and vibrate the holding member, a larger excitation force is required as much as the coil intervenes than when only the magnetostrictive rod is deformed. Further, since the bending rigidity of the coil affects the natural frequency of the power generation element, it is difficult to design the natural frequency of the power generation element.

  On the other hand, it is possible to prevent the bending rigidity of the coil from affecting the bending deformation of the magnetostrictive rod by making the other axial end of the coil unfixed to one of the pair of holding members. As a result, compared to the case where both sides of the coil in the axial direction are fixed to a pair of holding members, it is possible to reduce the excitation force that can be generated and to easily design the natural frequency of the power generation element. There is.

  According to the power generating element of the second aspect, the coil has one end in the axial direction fixed to one of the fixed sides of the pair of holding members. If one end of the coil in the axial direction is fixed to one of the pair of holding members on the vibration side, the one end in the axial direction of the coil fixed to the holding member is easily detached from the holding member due to acceleration of vibration. However, since one end in the axial direction of the coil is fixed to one of the fixed members of the pair of holding members, the acceleration acting on the one end in the axial direction of the coil fixed to the holding member can be reduced. As a result, it is possible to make it difficult for one end of the coil in the axial direction to be detached from the holding member, and in addition to the effect of claim 1, there is an effect that the reliability can be improved.

  Also, if one end of the coil in the axial direction is fixed to the vibration-side holding member, the mass of the coil affects the natural frequency of the power generating element, making it difficult to design the natural frequency of the power generating element. . On the other hand, since one end in the axial direction of the coil is fixed to the holding member on the fixed side and the other end in the axial direction of the coil is not fixed to the holding member on the vibration side, the mass of the coil is added to the effect of claim 1. This has the effect of preventing the natural frequency of the power generating element from being affected and facilitating the design of the natural frequency of the power generating element.

  According to the power generating element of the third aspect, the locking portion along the direction intersecting with the direction in which the magnetostrictive rod and the rigid rod are juxtaposed is provided on the axial end surface of the holding member. Since one end of the coil in the axial direction is locked and fixed to the locking portion, when the holding member vibrates in the direction in which the magnetostrictive rod and the rigid rod are juxtaposed, the one end in the axial direction of the coil is opposed to the holding member. This makes it difficult to shift the position. Therefore, in addition to the effect of Claim 1 or 2, there exists an effect which can improve reliability.

  According to the power generating element of the fourth aspect, the buffer portion is interposed between the coil and the locking portion, and the buffer portion is configured to be elastically deformable in a direction in which the magnetostrictive rod and the rigid rod are arranged in parallel. Yes. Since it can suppress that a coil falls from a latching | locking part by elastically deforming a buffer part, in addition to the effect in any one of Claims 1-3, there exists an effect which can improve reliability.

  According to the power generating element of claim 5, the coil has an inner diameter in a direction in which the magnetostrictive rod and the rigid rod on the other axial end side that are not fixed to the other of the pair of holding members are arranged side by side. It is expanded from the inner diameter in the direction in which the magnetostrictive rod and the rigid rod on one end side in the direction are arranged side by side. Therefore, in addition to the effect of any one of claims 1 to 4, even when the holding member vibrates greatly and the amount of bending deformation of the magnetostrictive rod increases, it is difficult to cause the magnetostrictive rod to collide with the other axial end of the coil. effective.

(A) is a top view of the electric power generation element in 1st Embodiment of this invention, (b) is a side view of the electric power generation element in the arrow Ib direction view. (A) is a front view of a fixing member, (b) is a side view of the fixing member as viewed in the direction of arrow IIb in FIG. 2 (a), and (c) is along a line IIc-IIc in FIG. 2 (b). It is sectional drawing of a fixing member. (A) is a front view of a holder member, (b) is a side view of the holder member in the arrow IIIb direction view of FIG. 3 (a). (A) is an axial sectional view of the fixing member when the coil, the magnetostrictive rod and the rigid rod are mounted, and (b) is an axial sectional view of the fixing member to which the coil, the magnetostrictive rod and the rigid rod are mounted. . (A) is a side view of the fixing member of the electric power generating element in 2nd Embodiment, (b) is sectional drawing of the fixing member in the Vb-Vb line | wire of Fig.5 (a), (c) is FIG. It is sectional drawing of the fixing member which expanded and illustrated a part of (b). (A) is a top view of the electric power generation element in 3rd Embodiment, (b) is a side view of the electric power generation element in the arrow VIb direction view. It is a figure which shows the generated voltage with respect to the excitation amplitude of the electric power generating element in an Example and a comparative example. It is a figure which shows the voltage waveform which generate | occur | produced with the electric power generation element in an Example and a comparative example.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Fig.1 (a) is a top view of the electric power generation element 1 in 1st Embodiment of this invention, FIG.1 (b) is a side view of the electric power generation element 1 in the arrow Ib direction view. In FIG. 1, in order to facilitate understanding of the orientation of the magnetic poles of the permanent magnets 14 and 15, the magnetism is illustrated in the drawing for convenience using the notation “N” and “S”.

  As shown in FIG. 1, the power generating element 1 is installed in a state where one holding member 50 of the pair of holding members 50 and 60 is fixed to the vibrating body V and the other holding member 60 is a free end. As the vibrating body V vibrates, the other holding member 60 is used in a pendulum motion (free vibration or forced vibration) in the direction perpendicular to the axis of the magnetostrictive rod 11 and the rigid rod 12 (vertical direction in FIG. 1B). Is done. In this case, axial expansion and contraction occur in the magnetostrictive rod 11 due to bending deformation accompanying the pendulum motion, so that the magnetic flux density changes in a direction parallel to the axial direction of the magnetostrictive rod 11 and current is generated in the coil 13. Thus, power generation is performed.

  The power generating element 1 includes a magnetostrictive rod 11 made of a magnetostrictive material and a rigid rod 12 made of a magnetic material, a coil 13 wound around the magnetostrictive rod 11, and one axial end side of the magnetostrictive rod 11 and the rigid rod 12. A pair of permanent magnets 14 and 15 sandwiched between the opposing of the magnetostrictive rod 11 and the rigid rod 12 on the left side (FIG. 1 (b) left side) and the other end side (right side of FIG. 1 (b)), A pair of holding members 50 and 60 that are attached to one end and the other end in the axial direction of the rigid rod 12 and hold the permanent magnets 14 and 15 sandwiched between the magnetostrictive rod 11 and the rigid rod 12, respectively; Is provided.

  The magnetostrictive rod 11 and the rigid rod 12 have a rectangular shape with a large width (Fig. 1 (a) vertical dimension) relative to the thickness (Fig. 1 (b) vertical size) (that is, the cross section has a long side (in the width direction). (Long side) and a short side (a rectangle having a side along the thickness direction)).

  The magnetostrictive rod 11 and the rigid rod 12 are formed in the same shape (dimension) with each other, and are arranged in parallel so that side surfaces having a large area (that is, side surfaces including long sides in the cross section) face each other. The rigid rod 12 is made of a magnetic material having a lower magnetostrictive effect than the magnetostrictive rod 11. In the present embodiment, the magnetostrictive rod 11 is made of an iron gallium alloy, and the rigid rod 12 is made of a steel material.

  The coil 13 is obtained by winding a wire (conductive wire) made of copper wire around the magnetostrictive rod 11 in a spiral shape, and a gap is provided between the coil 13 and the magnetostrictive rod 11. In the present embodiment, the coil 13 is an air-core coil in which conductive wires made of self-bonding wires are bonded and fixed, and is formed in a cylindrical shape having a substantially elliptical cross section that is flattened according to the cross-sectional shape of the magnetostrictive rod 11. .

  The permanent magnets 14 and 15 are members for applying a bias magnetic field to the magnetostrictive rod 11 and are each formed in a bar shape having a rectangular cross section. In addition, as for the permanent magnets 14 and 15, the dimension of the opposing direction (FIG.1 (b) up-down direction) of the clamping opposing parts 22 and 23 is made into a thickness dimension. The permanent magnets 14 and 15 are arranged with different magnetic poles. That is, the permanent magnet 14 has an N pole on the surface side connected to the magnetostrictive rod 11 (upper side in FIG. 1B) and an S pole on the surface side connected to the rigid rod 12 (lower side in FIG. 1B). On the other hand, on the contrary, the permanent magnet 15 has an S pole on the surface connected to the magnetostrictive rod 11 and an N pole on the surface connected to the rigid rod 12.

  As a result, a magnetic loop is formed by the magnetostrictive rod 11, the rigid rod 12, and the permanent magnets 14 and 15, and a bias magnetic field generated by the magnetomotive force of the permanent magnets 14 and 15 is applied to the magnetostrictive rod 11. As a result, the easy magnetization direction (the direction of magnetization or the direction in which magnetization is likely to occur) of the magnetostrictive rod 11 is set to the axial direction (longitudinal direction) of the magnetostrictive rod 11.

  The permanent magnets 14 and 15 are disposed in the accommodation spaces formed (recessed) in the fixing members 20 and 30. The inner surface of the housing space (opposing surfaces 22b and 23b of the clamping opposing portions 22 and 23, the opposing surface of the restricting portion 24 and the opposing surface of the connecting portion 25, see FIG. 2), the side surfaces of the magnetostrictive rod 11 and the rigid rod 12, and the permanent A gap is formed between the opposing surfaces (side surfaces) of the magnets 14 and 15, and the permanent magnets 14 and 15 are fixed to the fixing members 20 and 30 by an adhesive filled in the gap.

  The holding members 50, 60 are press-fitted with a pair of fixing members 20, 30 attached to one end side and the other end side in the axial direction of the magnetostrictive rod 11 and the rigid rod 12, respectively. The holder member 40 is provided. The fixing members 20 and 30 and the holder member 40 are made of a nonmagnetic material (in this embodiment, an aluminum alloy). Here, with reference to FIG.2 and FIG.3, the detailed structure of the fixing members 20 and 30 and the holder member 40 is demonstrated.

  2 (a) is a side view of the fixing member 20, FIG. 2 (b) is a side view of the fixing member 20 as viewed in the direction of arrow IIb in FIG. 2 (a), and FIG. 2 (c) is FIG. It is sectional drawing of the fixing member 20 in the IIc-IIc line | wire of (b). The fixing member 30 is configured similarly to the fixing member 20 except that the locking portion 26 is omitted. Therefore, the fixed member 30 attaches | subjects the same code | symbol to the same part as the fixed member 20, and abbreviate | omits the following description.

  As shown in FIG. 2, the fixing member 20 is provided with a base portion 21 formed in a block shape and a side surface of the base portion 21 (a front side surface in FIG. 2 (a)) and at a predetermined interval. The opposing sandwiching facing parts 22 and 23 are connected to each other, and the regulation part 24 projecting from the side surface of the base part 21 while being located between the sandwiching facing parts 22 and 23 is opposed to the sandwiching facing parts 22 and 23. However, a connecting portion 25 that protrudes from the side surface of the base portion 21 is provided. The fixing member 20 is formed symmetrically with respect to a virtual plane (not shown) located in the center in the height direction (the vertical direction in FIG. 2A).

  The sandwiching facing portions 22 and 23 are portions that sandwich and sandwich the magnetostrictive rod 11 and the rigid rod 12 in the direction toward the permanent magnets 14 and 15 (see FIG. 1). The facing surfaces 22a and 22b and the facing surfaces 23a and 23b include They are formed to face each other. The magnetostrictive rod 11, the rigid rod 12, and the permanent magnets 14 and 15 are accommodated in spaces formed between the opposing surfaces 22a and 22b and the opposing surfaces 23a and 23b, respectively (see FIG. 1).

  The facing surfaces 22a and 23a are parallel to each other, and the facing distance between the facing surfaces 22a and 23a (the vertical dimension in FIG. 2A) is the thickness of the magnetostrictive rod 11, the rigid rod 12, and the permanent magnets 14 and 15. This is made larger by a predetermined amount (0.02 mm in the present embodiment) than the total (FIG. 1 (b) vertical dimension). Similarly, the facing surfaces 22b and 23b are parallel to each other, and the facing distance between the facing surfaces 23a and 23b is larger than the thickness of the permanent magnets 14 and 15 by a predetermined amount (in this embodiment, 0.02 mm). .

  Press fitting when the fixing member 20 is press-fitted into the holder member 40 on the upper surface side and the lower surface side (upper side or lower side in FIG. 2A) of the base portion 21 and the sandwiching facing portions 22 and 23 (that is, the fixing member 20). An inclined surface 22c and an inclined surface 23c that are inclined along the direction are formed. The inclined surface 22c and the inclined surface 23c are inclined in different directions from the restricting portion 24 toward the connecting portion 25 (in the side view shown in FIG. 2A, the inclined surface 22c is a downward inclination, and the inclined surface 23c is an upward inclination). It is formed as an inclined surface. Due to this inclination (gradient), the fixing member 20 (the base portion 21 and the sandwiching facing portions 22 and 23) has an axial end from the axial center of the magnetostrictive rod 11 and the rigid rod 12 in the side view shown in FIG. It is formed in a shape that tapers as it goes to the part (see FIG. 1). In addition, the inclined surfaces 22c and 23c are inclined at an inclination angle θ1 with respect to a horizontal plane (a virtual plane that is a symmetric plane of the fixing member 20 described above).

  The restricting portion 24 is a portion having a rectangular shape in a side view shown in FIG. 2A, and is disposed at a predetermined interval with respect to the facing surfaces 22 a and 23 a of the sandwiching facing portions 22 and 23. The distance between the restricting portion 24 and the opposing surfaces 22a, 23a of the sandwiching opposing portions 22, 23 (Fig. 2 (a) vertical dimension) is the thickness of the magnetostrictive rod 11 and rigid rod 12 (Fig. 1 (b) vertical). Direction dimension) or slightly larger. Further, in the restricting portion 24, the thickness W <b> 1, which is the dimension in the facing direction of the sandwiching facing portions 22 and 23 (the vertical direction in FIG. 2A), is made larger than the thickness of the permanent magnets 14 and 15. In the present embodiment, the thickness W1 of the restricting portion 24 is set to be equal to the facing distance (the vertical dimension in FIG. 2A) of the facing surfaces 22b and 23b located on the connecting portion 25 side.

  The sandwiching facing portions 22 and 23 and the restricting portion 24 are formed so that the end surface (the left side surface in FIG. 2A) located on the opposite side of the connecting portion 25 is flush with each other, and the shafts of the magnetostrictive rod 11 and the rigid rod 12 It is formed as a flat surface perpendicular to the direction (see FIG. 1).

  The connecting portion 25 is located on the tapered side of the fixing member 20 (opposite side of the restricting portion 24, right side in FIG. 2A), and the height from the side surface of the base portion 21 (FIG. 2B) dimension in the left-right direction. ) Is set to be the same as the heights of the sandwiching facing portions 22 and 23 and the restricting portion 24. When the connecting portion 25 is interposed between the opposing surfaces 22b and 23b, the permanent magnet can be used even when there is a dimensional tolerance when the fixing member 20 is press-fitted into the holder member 40 or when the accuracy of the press-fitting process is insufficient. It can suppress that 14 and 15 are pressed by opposing surface 22b, 23b, and can suppress that the permanent magnets 14 and 15 are damaged.

  As shown in FIG. 2B, the fixing member 20 is provided with a locking portion 26 on the end surface in the axial direction. The locking portion 26 is a portion where the axial end of the coil 13 is locked, and a direction (FIG. 2 (b) vertical direction) intersecting the direction in which the magnetostrictive rod 11 and the rigid rod 12 are juxtaposed (FIG. 2 (b)). 2 (b) in the left-right direction) and is formed on the end faces in the axial direction of the sandwiching facing portion 22 and the restricting portion 24. In the present embodiment, the locking portion 26 is formed continuously from the sandwiching facing portion 22 and the restricting portion 24 to the base portion 21, and has an elliptical substantially C shape when viewed in the axial direction.

  As shown in FIG. 2C, the locking portion 26 is recessed in the axial end surface of the fixing member 20 and is formed in a groove shape. Both ends of the groove-shaped locking portion 26 (see FIG. 2B) open to the opposing surfaces 22a and 24a, respectively, and the groove width of the locking portion 26 is slightly smaller than the thickness (diameter) of the wire of the coil 13. It is formed larger. The locking portion 26 is set to have the same shape as viewed in the axial direction as the shape of the axial end portion of the coil 13 as viewed in the axial direction. As a result, the end of the coil 13 is fitted to the engaging portion 26 at the end in the axial direction, and movement in the direction perpendicular to the axis (the direction parallel to the plane of FIG. 2B) is restricted.

  Next, the holder member 40 will be described with reference to FIG. 3A is a side view of the holder member 40, and FIG. 3B is a side view of the holder member 40 as viewed in the direction of arrow IIIb in FIG. 3A.

  The holder member 40 has a substantially rectangular parallelepiped base portion 41 and a press-fitting opposing surface that protrudes from one side of the base portion 41 (left side in FIG. 3 (a)) and is opposed to each other at a predetermined interval. Parts 42 and 43. The holder member 40 is formed symmetrically with respect to a virtual plane (not shown) located in the center in the height direction (the vertical direction in FIG. 3A).

  The press-fitting opposing portions 42 and 43 are portions into which the fixing members 20 and 30 are press-fitted, and the fixing members 20 and 30 are press-fitted into the holder member 40 on the mutually opposing surfaces of the press-fitting opposing portions 42 and 43. Inclined surfaces 42a and 43a are formed which are inclined along the press-fitting direction. The inclined surfaces 42a and 43a are inclined in different directions from the projecting tip side of the press-fitting facing portions 42 and 43 toward the base portion 41 (in the side view shown in FIG. 3A, the inclined surface 42a is inclined downward) The inclined surface 43a is formed as an inclined surface that is inclined upward). Due to this inclination (gradient), the interval between the inclined surfaces 42 a and 43 a becomes narrower toward the base portion 41.

  The inclined surfaces 42a and 43a are inclined at an inclination angle θ2 with respect to a horizontal plane (a virtual plane that is a symmetric plane of the holder member 40 described above). In the present embodiment, the inclination angle θ2 is the same as the inclination angle θ1 of the fixing members 20 and 30 (see FIG. 2A).

  Next, an assembly method for the power generating element 1 will be described with reference to FIG. 4A is an axial sectional view of the fixing member 20 when the coil 13, the magnetostrictive rod 11 and the rigid rod 12 are attached, and FIG. 4B is an attachment of the coil 13, the magnetostrictive rod 11 and the rigid rod 12. It is an axial sectional view of the fixed member 20 made.

  As shown in FIG. 4 (a), the magnetostrictive rod 11 is inserted into a coil 13 (air core coil) in which conductive wires made of self-bonding wires are bonded and fixed. As shown in FIG. 4 (b), the magnetostrictive rod is inserted. 11 and one end side of the rigid rod 12 in the axial direction are inserted between the sandwiching facing portions 22 and 23 of the fixing member 20 and the restricting portion 24. The coil 13 is fitted to the locking portion 26 at one end in the axial direction, and the axial end of the coil 13 and the fixing member 20 (the locking portion 26) are bonded and fixed with an adhesive. Next, the permanent magnet 14 is disposed in the accommodation space of the fixing member 20 (between the magnetostrictive rod 11 and the rigid rod 12 facing each other), and is bonded and fixed with an adhesive. Subsequently, the fixing member 20 is press-fitted between the opposed portions 42 and 43 of the holder member 40 with the axial direction of the magnetostrictive rod 11 and the rigid rod 12 (the left-right direction in FIG. 4B) as the press-fitting direction.

  Similarly, the other axial ends of the magnetostrictive rod 11 and the rigid rod 12 are inserted between the clamping facing portions 22 and 23 and the restricting portion 24 of the fixing member 30 (see FIG. 1B). Next, the permanent magnet 15 is disposed in the accommodation space of the fixing member 30 (between the magnetostrictive rod 11 and the rigid rod 12 facing each other) and bonded and fixed with an adhesive. Next, the fixing member 30 is press-fitted between the opposed portions 42 and 43 of the holder member 40 with the axial direction of the magnetostrictive rod 11 and the rigid rod 12 (the left-right direction in FIG. 4B) as the press-fitting direction. Thereby, the power generation element 1 is assembled. However, the attachment of the permanent magnets 14 and 15 to the accommodation space (adhesion fixation with an adhesive) may be performed after the press-fitting into the holder member 40 is completed.

  According to the power generating element 1 assembled as described above, one end in the axial direction of the magnetostrictive rod 11 and the rigid rod 12 is fixed to the vibrating body V via the holding member 50, and the magnetostrictive rod 11 and the The other end side in the axial direction vibrates in the direction in which the rigid rods 12 are juxtaposed (the vertical direction in FIG. 1B), whereby the magnetostrictive rod 11 extends or contracts in the axial direction to generate power. One end of the coil 13 in the axial direction is bonded and fixed to the fixing member 20 (holding member 50), and the other end in the axial direction of the coil 13 is not fixed to the fixing member 30 (holding member 60). The distance between the coil 11 and the coil 13 is maintained.

  If the amplitude of the vibrating body V and the interval between the coil 13 and the magnetostrictive rod 11 are set such that the magnetostrictive rod 11 is bent and deformed within a range where the magnetostrictive rod 11 does not collide with the coil 13, the magnetostrictive rod 11 and the coil 13 are set. Collisions are prevented. As a result, it is possible to prevent the generation of noise due to the collision between the magnetostrictive rod 11 and the coil 13 and the disconnection of the coil 13 (conductive wire). Moreover, since it is possible to prevent the magnetostrictive rod 11 from colliding with the coil 13, disturbance of the voltage waveform can be suppressed.

  Here, by injecting a caulking agent or the like between the coil 13 and the magnetostrictive rod 11, it is possible to prevent a collision between the coil 13 and the magnetostrictive rod 11 (shock is shocked by an elastic body such as a caulking agent). is there. However, in this case, the vibration of the magnetostrictive rod 11 may be input to the coil 13 through the elastic body, and the bending load may be input to the coil 13 due to the vibration (bending deformation) of the magnetostrictive rod 11. There is. If it does so, there exists a possibility that the coil 13 (conductor) may be disconnected by the bending load input into the coil 13.

  On the other hand, according to the power generating element 1, the magnetostrictive rod 11 can freely vibrate without interfering with the coil 13 in the hollow portion of the coil 13 (air core coil), and therefore the coil 13 is vibrated by the vibration (bending deformation) of the magnetostrictive rod 11. It is possible to prevent the bending load from being input to the. Therefore, it is possible to prevent the coil 13 (conductive wire) from being disconnected by a bending load input to the coil 13. Further, since the vibration of the magnetostrictive rod 11 can be prevented from being suppressed by the rigidity of the coil 13, it is possible to suppress a decrease in power generation efficiency (ratio of the amount of electric power to the excitation energy input to the power generation element 1).

  Various adhesives such as epoxy resin, acrylic resin, silicone rubber, chloroprene rubber, and cyanoacrylate are used as the adhesive for bonding and fixing the coil 13 and the fixing member 20 (locking portion 26). it can. By adhering the one axial end side of the coil 13 and the fixing member 20 and unfixing the other axial end side of the coil 13 and the fixing member 30, the degree of freedom of the adhesive that can be employed can be improved.

  Temporarily, when it is set as the structure which adhere | attaches the axial direction one end side of the coil 13 to the fixing member 20, and adhere | attaches the axial direction other end side of the coil 13 to the fixing member 30, when using the adhesive agent which cannot be elastically deformed after hardening, In order to deform the magnetostrictive rod 11 and vibrate the holding member 60 (see FIG. 1B), a larger excitation force is required as compared with the case where only the magnetostrictive rod 11 is deformed. . Further, since the bending rigidity of the coil 13 affects the natural frequency of the power generating element 1 (inversely proportional to the square root of the spring constant of the magnetostrictive rod 11), it is difficult to design the natural frequency of the power generating element 1.

  Therefore, when both ends in the axial direction of the coil 13 are bonded to the fixing members 20 and 30, respectively, in order to suppress the bending rigidity of the coil 13 from affecting the bending deformation of the magnetostrictive rod 11, as much as possible. An elastic adhesive that can be elastically deformed later is preferably employed. As the elastic adhesive, one containing a high molecular compound such as silicone, modified silicone, polyurethane, nitrile rubber, or synthetic rubber is used.

  On the other hand, the other end in the axial direction of the coil 13 is not fixed to the holding member 60 as in this embodiment, thereby preventing the bending rigidity of the coil 13 from affecting the bending deformation of the magnetostrictive rod 11. it can. As a result, the adhesive that fixes the one end side of the coil 13 in the axial direction and the fixing member 20 is not limited to an elastic adhesive, and various adhesives can be freely employed. Since an adhesive having a high curing speed, such as a cyanoacrylate, can be used, the assembly time of the power generating element 1 can be shortened when such an adhesive having a high curing speed is used.

  Further, since the other axial end of the coil 13 is not fixed, one axial end of the coil 13 is bonded to the fixing member 20 and the other axial end of the coil 13 is bonded to the fixing member 30. Compared to the case, the man-hour required for bonding the coil 13 and the amount of adhesive used can be reduced by the amount that the other axial end of the coil 13 is not bonded to the fixing member 30.

  Further, since the bending rigidity of the coil 13 can be prevented from affecting the bending deformation of the magnetostrictive rod 11, the magnetostrictive rod is compared with the case where both axial sides of the coil 13 are fixed to the pair of holding members 50, 60. An increase in excitation energy necessary for vibrating 11 can be suppressed. As a result, the power generation efficiency of the power generation element 1 can be improved. Furthermore, since the increase in the bending rigidity (spring constant) of the magnetostrictive rod 11 by the coil 13 can be suppressed, the natural frequency of the magnetostrictive rod 11 can be prevented from deviating from the design value, and the design of the natural frequency can be facilitated.

  According to the power generation element 1, since the one axial end side of the coil 13 is fixed to the holding member 50 (fixing member 20), until the axial other end side of the coil 13 contacts the holding member 60 (fixing member 30), The axial length of the coil 13 can be extended to the other axial end side. As a result, the number of turns of the coil 13 can be increased as compared with the case where the coil 13 is disposed in the central portion of the magnetostrictive rod 11 and the rigid rod 12 in the axial direction. As a result, the generated voltage can be increased.

  Further, since the axial end of the coil 13 is fixed to the holding member 50 fixed to the vibrating body V, the axial end of the coil 13 is fixed to the holding member 60 that vibrates with respect to the holding member 50. As compared with the above, the acceleration (magnitude of vibration) on one end side (holding member 50 side) in the axial direction of the coil 13 to be fixed can be reduced. As a result, it is possible to make it difficult for the coil 13 to be detached from the holding member 50 as compared with the case where the coil 13 is fixed to the vibration-side holding member 60. As a result, the reliability of the power generation element 1 can be improved.

  If the axial end of the coil 13 is fixed to the holding member 60 on the vibration side, the mass of the coil 13 is proportional to the natural frequency of the power generating element 1 (proportional to the square root of the mass of the holding member 60). Therefore, it is difficult to design the natural frequency of the power generating element 1. On the other hand, since one end in the axial direction of the coil is fixed to the holding member 50 on the fixed side and the coil 13 is not fixed to the holding member 60 on the vibration side, the mass of the coil 13 becomes the natural frequency of the power generating element 1. The natural frequency of the power generating element 1 can be easily designed by preventing the influence.

  Further, the locking portion 26 along the direction intersecting the direction in which the magnetostrictive rod 11 and the rigid rod 12 are juxtaposed (the vertical direction in FIG. 2B) is the axis of the sandwiching facing portion 22 and the regulating portion 24 of the fixing member 20. It is provided on the direction end face. Since the coil 13 has one end in the axial direction locked and fixed to the locking portion 26, when acceleration is applied to the holding member 50 (fixing member 20) in the direction in which the magnetostrictive rod 11 and the rigid rod 12 are juxtaposed. The one end side in the axial direction of the coil 13 can be made difficult to shift in the direction in which the acceleration acts. As a result, it is possible to make it difficult for the coil 13 to be detached from the holding member 50, so that reliability can be improved.

  The locking portion 26 is formed in a substantially C shape when viewed in the axial direction from the sandwiching facing portion 22 and the regulating portion 26 of the fixing member 20 to the base portion 21. Since the locking portion 26 provided on the base portion 21 is along the direction in which the magnetostrictive rod 11 and the rigid rod 12 are arranged in parallel, the holding member 50 is arranged in a direction intersecting with the direction in which the magnetostrictive rod 11 and the rigid rod 12 are arranged in parallel. Even when an acceleration acts on the (fixing member 20), it is possible to make it difficult to shift one end of the coil 13 in the axial direction in the direction in which the acceleration acts. As a result, it is possible to make it difficult for the coil 13 to be detached from the holding member 50, so that reliability can be improved.

  In addition, the locking portion 26 is formed in a concave groove shape on the fixing member 20, and the inner surface of the concave groove-shaped locking portion 26 and the axial end portion of the coil 13 are bonded, so that the locking portion 26 is formed. Compared to the case where the axial end portion of the coil 13 is bonded to the axial end surface (flat surface) of the fixing member that is not fixed, the bonding area can be increased in proportion to the depth of the locking portion 26 (concave groove). As a result, since the adhesive strength can be ensured, reliability can be ensured.

  Next, a second embodiment will be described with reference to FIG. In the first embodiment, the case where the coil 13 is bonded and fixed to the locking portion 26 that is recessed in the axial end face of the fixing member 20 has been described. On the other hand, in the second embodiment, a case will be described in which the coil 13 is press-fitted and fixed to the engaging portion 71 that is recessed in the axial end surface of the fixing member 70. In addition, about the part same as 1st Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted. FIG. 5A is a side view of the power generating element fixing member 70 according to the second embodiment, and FIG. 5B is a cross-sectional view of the fixing member 70 taken along line Vb-Vb in FIG. FIG. 5C is a cross-sectional view of the fixing member 70 shown by enlarging a part of FIG.

  As shown in FIG. 5A, the fixing member 70 has a locking portion 71 formed on the axial end surface. As shown in FIG. 5B, the locking portion 71 is a portion where the axial end of the coil 13 is locked, and the direction in which the magnetostrictive rod 11 and the rigid rod 12 are juxtaposed (FIG. 5A). It is formed in the axial direction end surface of the clamping opposing part 22 and the control part 24 along the direction (FIG. 5 (a) left-right direction) which cross | intersects the up-down direction. In the present embodiment, the locking portion 71 is formed continuously from the sandwiching facing portion 22 and the restricting portion 24 to the base portion 21, and has an elliptical substantially C shape when viewed in the axial direction.

  As shown in FIG. 5C, the locking portion 71 is formed in a concave groove shape, and is recessed on the axial end surface of the fixing member 70. The locking portion 71 (see FIG. 5A) is a portion where both ends open to the opposing surfaces 22a and 24a, respectively, and a buffer portion 72 is fixed to the inner wall. The buffer part 72 is comprised from the rubber-like elastic body in the shape of a thin film. The gap between the buffer portions 72 fixed to the inner wall of the locking portion 71 is formed smaller than the thickness (diameter) of the wire of the coil 13. Further, the shape of the locking portion 71 in the axial direction is set to be the same as the shape in the axial direction of the axial end portion of the coil 13. Thereby, the end of the axial direction of the coil 13 is press-fitted into the buffer 72, and the movement in the direction perpendicular to the axis (the direction parallel to the plane of FIG. 5A) is restricted.

  According to the second embodiment, the locking portion 71 along the direction intersecting the direction in which the magnetostrictive rod 11 and the rigid rod 12 are juxtaposed (the vertical direction in FIG. 5A) is the axial end surface of the fixing member 70. Is provided. Since the coil 13 has one end in the axial direction locked and fixed to the locking portion 71, when acceleration is applied in the direction in which the magnetostrictive rod 11 and the rigid rod 12 are juxtaposed, the one end in the axial direction of the coil 13 is It can be made difficult to come off from the fixing member 70. Therefore, reliability can be improved.

  Moreover, the buffer part 72 is interposed between the coil 13 and the latching | locking part 71, and the buffer part 72 is comprised by the rubber-like elastic body. Since the coil 13 is press-fitted between the buffer portions 72 and fixed, it is possible to eliminate the need for an adhesive operation in which an adhesive is applied and the coil 13 is left stationary.

  Further, the buffer portion 72 is configured to be elastically deformable in a direction (vibration direction) in which the magnetostrictive rod 11 and the rigid rod 12 are juxtaposed. As a result, the acceleration in the direction in which the magnetostrictive rod 11 and the rigid rod 12 are juxtaposed can be suppressed by the elastic deformation of the buffer portion 72. Therefore, since the acceleration which acts on the coil 13 can be buffered, reliability can be improved.

  Next, a third embodiment will be described with reference to FIG. In 1st Embodiment and 2nd Embodiment, the case where the coil 13 (air core coil) was set to the same internal diameter over the axial direction was demonstrated. On the other hand, in the third embodiment, the inner diameter on the other end side in the axial direction of the coil 82 not fixed to the holding member 60 is smaller than the inner diameter on one end side in the axial direction of the coil 82 fixed to the holding member 50. A case where a large value is set will be described. In addition, about the part same as 1st Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted. FIG. 6A is a plan view of the power generation element 81 in the third embodiment, and FIG. 6B is a side view of the power generation element 81 in the direction of arrow VIb.

  In the power generation element 81, one axial end side of the coil 82 is bonded and fixed to the holding member 50 (fixing member 20). The coil 82 is a spirally wound wire (conducting wire) made of a copper wire, and the magnetostrictive rod 11 is provided inside the coil 82 with a clearance from the inner peripheral surface. In the present embodiment, the coil 82 is an air-core coil in which conductive wires made of self-bonding wires are bonded and fixed, and one end in the axial direction fixed to the holding member 50 is formed in a substantially cylindrical shape, while the holding member The other axial end that is not fixed to 60 is formed in a substantially conical shape (trumpet shape) that gradually increases in diameter toward the other axial end. That is, the coil 82 has an inner diameter in the direction in which the magnetostrictive rod 11 and the rigid rod 12 are juxtaposed (the vertical direction in FIG. 6B), and the other axial end side (the right side in FIG. 6B) is the axial one end side. It is enlarged from FIG.6 (b) left side.

  Thereby, a large excitation energy is input, the holding member 60 is greatly displaced with respect to the holding member 50, and the magnetostriction in the direction in which the magnetostrictive rod 11 and the rigid rod 12 are juxtaposed (the vertical direction in FIG. 6B). Even when the amount of bending deformation of the rod 11 increases, it is possible to make it difficult for the magnetostrictive rod 11 to collide with the other axial end of the coil 82 (the right side in FIG. 6B).

  Hereinafter, the present invention will be described specifically by way of examples. The power generation elements of the example, comparative example 1 and comparative example 2 are all made using parts such as the magnetostrictive rod 11 and the coil 13 of the same material and the same dimensions. The present invention is not limited to these examples.

(Example)
In order to create the power generating element 1 described in the first embodiment, one end in the axial direction of the coil 13 through which the magnetostrictive rod 11 is inserted is bonded and fixed to the holding member 50 (fixing member 20). The rod 12 and the permanent magnets 14 and 15 were held by a pair of holding members 50 and 60. The other axial end of the coil 13 was not fixed to the holding member 60 (fixing member 30). This obtained the electric power generating element in an Example.

(Comparative Example 1)
After inserting the magnetostrictive rod 11 through the coil 13, the magnetostrictive rod 11, the rigid rod 12 and the permanent magnets 14 and 15 were held by a pair of holding members 50 and 60. The coil 13 was not fixed to the holding members 50 and 60 at both ends in the axial direction. Thereby, the power generation element in Comparative Example 1 was obtained. The comparative example 1 is different from the embodiment in which one axial end side of the coil 13 is fixed to the holding member 50 in that the one axial end side of the coil 13 is not fixed to the holding member 50.

(Comparative Example 2)
After inserting the magnetostrictive rod 11 through the coil 13, the magnetostrictive rod 11, the rigid rod 12 and the permanent magnets 14 and 15 were held by a pair of holding members 50 and 60. Subsequently, a synthetic resin-based (made of elastomer) adhesive was injected between the coil 13 and the magnetostrictive rod 11 from both axial ends of the coil 13 and cured. Thereby, the power generation element in Comparative Example 2 was obtained. In Comparative Example 2, the magnetostrictive rod 11 and the coil 13 do not interfere with each other in that the axial ends of the magnetostrictive rod 11 and the coil 13 are bonded to the holding members 50 and 60 via an elastic adhesive (coil 13 does not affect the bending deformation of the magnetostrictive rod 11).

(Test results)
The relationship between the excitation amplitude of the power generation element and the generated voltage in Examples, Comparative Examples 1 and 2 was measured. Of the pair of holding members 50, 60, the holding member 50 is a fixed end, the holding member 60 is a vibration end, and an excitation amplitude is given to the vibration end. FIG. 7 is a diagram showing a generated voltage (generated voltage) with respect to the excitation amplitude of the power generating element in the example and the comparative example. The horizontal axis is the excitation amplitude (mm), and the vertical axis is the generated voltage (V). As shown in FIG. 7, the power generation element in the example and the comparative example 1 generated a voltage of about 2 V when an excitation amplitude of about 0.03 mm was applied.

  On the other hand, it was found that the power generation element in Comparative Example 2 could not generate a voltage of about 2 V unless an excitation amplitude of about 0.08 mm was given. This is because the magnetostrictive rod 11 and the coil 13 have both axial ends bonded to the holding members 50 and 60 in the power generating element in the comparative example 2, so that the bending rigidity (spring constant) of the magnetostrictive rod 11 is increased, and the power generation efficiency ( This is presumably because the ratio of the amount of electric power to the excitation energy input to the power generation element has decreased.

  Next, with reference to FIG. 8, the voltage waveform of the electric power generation element in an Example and the comparative example 1 is demonstrated. FIG. 8 is a diagram showing voltage waveforms generated by the power generation elements in the examples and comparative examples. The horizontal axis is time (s), and the vertical axis is the generated voltage (V). As shown in FIG. 8, a voltage waveform of ± 4 V was obtained for the power generation element in the example with a period of about 0.007 seconds.

  On the other hand, in the power generation element in Comparative Example 1, the voltage waveform is disturbed by superimposing an AC voltage having a higher frequency on the voltage waveform (fundamental wave) of the example. Disturbances in the voltage waveform lead to excessive current flow, causing malfunction of the device and overheating. It is presumed that the disturbance of the voltage waveform is due to the impact of the magnetostrictive rod 11 colliding with the coil 13.

  As described above, in the power generating element 1 according to the embodiment, the one end side in the axial direction of the coil 13 is fixed to the holding member 50, thereby preventing collision between the vibrating magnetostrictive rod 11 and the coil 13. As a result, it became clear that the disturbance of the voltage waveform can be suppressed. Further, by preventing the collision between the magnetostrictive rod 11 and the coil 13, it is possible to prevent the generation of noise due to the collision between the magnetostrictive rod 11 and the coil 13 and the disconnection of the coil 13 (conductive wire).

  In addition, although description was abbreviate | omitted, also about the electric power generation element in 2nd Embodiment to 3rd Embodiment, it was confirmed that disorder of a voltage waveform can be suppressed similarly to an Example. Moreover, it can be inferred that by preventing the collision between the magnetostrictive rod and the coil, it is possible to prevent the generation of noise due to the collision between the magnetostrictive rod and the coil and the disconnection of the coil (conductive wire).

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed.

  In each of the above-described embodiments, the case where the holding members 50 and 60 are configured by the two members of the fixing members 20 and 30 and the holder member 40 has been described. However, the present invention is not necessarily limited thereto, and the fixing members 20 and 30 are not necessarily limited thereto. And the holder member 40 may be integrally formed. In this case, since the holding action of the magnetostrictive rod 11 or the like by press-fitting cannot be obtained, the magnetostrictive rod 11 or the like is fixed to the holding members 50 and 60 by adhesive fixing with an adhesive.

  In each of the above-described embodiments, the case where the coil 13 is wound only on the magnetostrictive rod 11 has been described. However, the present invention is not limited to this. May be. In this case, the magnetostrictive rod 11 and the rigid rod 12 are made of the same magnetostrictive material (that is, the rigid rod 12 need not be made of a material having a lower magnetostrictive effect than the magnetostrictive rod 11).

  In each of the above embodiments, the power generation element 1 has been described as an example. However, the present invention is not necessarily limited thereto, and includes “a magnetostrictive rod made of a magnetostrictive material and a coil wound around the magnetostrictive rod, One end in the axial direction of the magnetostrictive rod is a fixed end and the other end in the axial direction is a free end capable of free vibration or forced vibration (vibration end), and the magnetostrictive rod is expanded or contracted in the axial direction. Of course, it is possible to employ other power generating elements as long as they generate electricity by the magnetostrictive effect.

  As another power generation element, for example, an element using an electromagnet can be adopted instead of the permanent magnets 14 and 15. In addition, if the magnetic flux from the outside of the power generating element 1 is generated in the magnetic circuit, a configuration in which a magnet is arranged outside the power generating element 1 is possible. It is also possible to provide a back yoke that applies bias magnetization to the magnetostrictive rod 11 and the rigid rod 12 (magnetostrictive rod) by the magnetomotive force of a permanent magnet or electromagnet.

  In each of the above-described embodiments, the case where the dimensions (that is, the thickness dimension and the width dimension) of the magnetostrictive rod 11 and the rigid rod 12 are the same has been described. On the other hand, the dimension of the rigid rod 12 may be a different value (only one or both of the thickness dimension and the width dimension are different).

  In each of the above embodiments, the case where the magnetostrictive rod 11 and the rigid rod 12 are formed to have a rectangular cross section has been described. However, the present invention is not necessarily limited to this, and other shapes are naturally possible. Examples of other shapes include a square cross section, a circular cross section, an elliptical cross section, and a polygonal cross section (for example, a hexagonal cross section).

  In addition, for example, when the magnetostrictive rod 11 or the like has a circular cross section, the permanent magnets 14 and 15 are in line contact, and when the contact area cannot be secured, the size or magnetomotive force of the permanent magnets 14 and 15 is increased, Alternatively, it is possible to secure a contact area by interposing a spacer made of a magnetic material between the magnetostrictive rod 11 and the like and the permanent magnets 14 and 15 and having a shape corresponding to the shape of both (that is, a shape in surface contact with both). preferable. This is because the bias magnetic field that can be applied can be increased.

  In each of the above embodiments, the case where one end of the coils 13 and 82 is fixed to the holding member 50 on the fixed side and the other end of the holding member 60 on the vibration side and the other ends of the coils 13 and 82 are not fixed has been described. However, the present invention is not necessarily limited to this, and the other end of the coils 13 and 82 is fixed to the vibration-side holding member 60, while the fixed-side holding member 50 and one end of the coils 13 and 82 are not fixed. Is of course possible. Also in this case, since the coils 13 and 82 can be prevented from affecting the bending deformation of the magnetostrictive rod 11, occurrence of abnormal noise, disconnection of the coils 13 and 82, and disturbance of the voltage waveform can be suppressed.

  In each of the above embodiments, the case where the recessed groove-like locking portions 26 and 71 are provided in the fixing members 20 and 70 (holding member 50) has been described. Of course, it is possible to project the locking portions in the shape of ridges or ridges on the end surfaces of the fixing members 20 and 70 in the axial direction. This is because even when the locking portion is formed in a protruding shape or a ridge shape, the movement of the axial end portions of the coils 13 and 82 along the axial end surfaces of the fixing members 20 and 70 can be restricted.

  In the second embodiment, the case where the buffer portion 72 is formed of a rubber-like elastic body and the axial one end side of the coils 13 and 82 is press-fitted into the gap of the buffer portion 72 has been described. However, the present invention is not necessarily limited to this, and it is naturally possible to configure the buffer portion 72 with an elastic adhesive that can be elastically deformed after curing. In this case, after applying an elastic adhesive in the recessed groove-shaped locking part 71, one axial end side of the coils 13 and 82 is inserted into the locking part 71. After the elastic adhesive is hardened, a buffer portion made of the elastic adhesive is formed between the locking portion 71 and the coils 13 and 82. Thereby, the effect | action and effect similar to the electric power generation element in 2nd Embodiment are realizable.

  In the third embodiment, the other axial end of the coil 82 that is not fixed to the holding member 60 is formed in a substantially conical shape (trumpet shape) that gradually increases in diameter toward the other axial end. Explained. However, the present invention is not necessarily limited to this, and it is naturally possible to expand the inner diameter at the other end in the axial direction in a step shape. Also in this case, the bending deformation of the magnetostrictive rod 11 can be prevented from being hindered by the coil 82 by enlarging the inner diameter of the coil 82 on the other end side in the axial direction than the inner diameter on the one end side in the axial direction of the coil.

DESCRIPTION OF SYMBOLS 1,81 Power generation element 11 Magnetostrictive rod 12 Rigid rod 13, 82 Coil 26, 71 Locking part 50, 60 Holding member 72 Buffer part

Claims (5)

A coil formed by winding a conductive wire in a spiral;
A magnetostrictive rod that is provided in the coil with a gap from the inner peripheral surface of the coil and is configured in a rod shape from a magnetostrictive material;
A rigid rod that is arranged in parallel to the magnetostrictive rod and is formed into a rod shape from a magnetic material, and a magnetic loop is formed between the magnetostrictive rod,
A pair of holding members that respectively hold axially opposite ends of the rigid rod and the magnetostrictive rod, one of the pair of holding members is fixed, and the other of the pair of holding members is the magnetostrictive rod and the rigid rod A power generating element in which power is generated by stretching or contracting the magnetostrictive rod in the axial direction by oscillating in a parallel direction,
One end of the coil in the axial direction is fixed to one of the pair of holding members, and the other end in the axial direction is not fixed to the other of the pair of holding members.   2. The power generating element according to claim 1, wherein one end of the coil in the axial direction is fixed to one of the fixed sides of the pair of holding members. The holding member includes a locking portion provided on an axial end surface along a direction intersecting with a direction in which the magnetostrictive rod and the rigid rod are juxtaposed,
The power generating element according to claim 1, wherein one end side of the coil in the axial direction is locked and fixed to the locking portion. Including a buffer portion interposed between the coil and the locking portion;
The power generation element according to any one of claims 1 to 3, wherein the buffer portion is configured to be elastically deformable in a direction in which the magnetostrictive rod and the rigid rod are juxtaposed.   The coil has an inner diameter in a direction in which the magnetostrictive rod and the rigid rod on the other axial end side that are not fixed to the other of the pair of holding members are arranged side by side, and the magnetostrictive rod on the one axial end side and The power generating element according to any one of claims 1 to 4, wherein the power generating element is enlarged from an inner diameter in a direction in which the rigid rods are juxtaposed.

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