Vibration actuator and electronic device

Patent metadata

Field	Value
Publication number	US-11394285-B2
Application number	US-202016885269-A
Country	US
Kind code	B2
Filing date	May 28, 2020
Priority date	May 31, 2019
Publication date	Jul 19, 2022
Grant date	Jul 19, 2022

Abstract

A fixing body includes a coil holding part that is disposed to surround a magnet externally in a radial direction and holds the coil disposed outside the bobbin-shaped coil holding part in the radial direction. The coil holding part includes a coil protection wall portion that is disposed inside the coil in the radial direction of the coil with a gap being interposed between the coil protection wall portion and the magnet, and inhibits contact between the coil and the movable body. Elastic supporting parts are a plurality of leaf springs installed between the fixing body and the movable body to sandwich the movable body in the vibration direction, and support the movable body such that, in a non-vibration state and in a vibration state of the movable body, the movable body is freely movable in the vibration direction without making contact with the coil holding part.

First claim

What is claimed is:

1. A vibration actuator, comprising:
a fixing body including a coil including a first coil and a second coil and a bobbin-shaped coil holding part configured to hold the coil disposed outside thereof in a radial direction of the coil such that the first coil and the second coil are arranged side by side;
a movable body including a magnet that is disposed inside the coil in the radial direction to be relatively movable in a vibration direction orthogonal to the radial direction of the coil, the movable body being operable to vibrate with respect to the fixing body by cooperation of the coil supplied with electricity and the magnet; and
an elastic supporting part including at least two or more leaf springs installed between the movable body and the fixing body to sandwich the movable body in the vibration direction, the leaf springs being configured to support the movable body such that, in a non-vibration state and in a vibration state of the movable body, the movable body is freely movable with respect to the fixing body without making contact with the bobbin-shaped coil holding part, wherein
the bobbin-shaped coil holding part is disposed to surround the magnet externally in the radial direction, and comprises:
a coil protection wall portion that is disposed inside the coil in the radial direction of the coil with a gap being interposed between the coil protection wall portion and the magnet, the coil protection wall portion inhibiting contact between the coil and the movable body including the magnet; and
a flange-shaped central wall portion disposed to project in the radial direction at a central portion in the vibration direction such that the flange-shaped central wall portion is sandwiched by the first coil and the second coil in the vibration direction, and

the flange-shaped central wall portion includes:
a coil connection part to which the coil is connected; and
a groove portion disposed in an outer circumferential portion of the flange-shaped central wall portion to open outward in the radial direction, and in which a coil wire linking the first coil to the second coil is disposed.

2. The vibration actuator according to claim 1 , wherein
the fixing body includes a case for housing the bobbin-shaped coil holding part,
the elastic supporting part is fixed to the bobbin-shaped coil holding part, and
the bobbin-shaped coil holding part houses the movable body inside the coil in the radial direction of the coil via the elastic supporting part such that the movable body is freely movable in the vibration direction, the bobbin-shaped coil holding part being disposed in the case.

3. The vibration actuator according to claim 1 , wherein
the bobbin-shaped coil holding part is formed from a material containing a phenolic resin.

4. The vibration actuator according to claim 1 , further comprising:
an electromagnetic shield part disposed outside the coil in the radial direction of the coil to surround the coil, the electromagnetic shield part being formed from a magnetic material.

5. The vibration actuator according to claim 4 , wherein
the electromagnetic shield part functions as a magnetic spring together with the magnet.

6. The vibration actuator according to claim 2 , further comprising:
an electromagnetic shield part disposed outside the coil in the radial direction of the coil to surround the coil, the electromagnetic shield part being formed from a magnetic material, wherein
the electromagnetic shield part is disposed between the case and the bobbin-shaped coil holding part.

7. The vibration actuator according to claim 2 , wherein
the case includes a bottomed cylindrical case main body and a lid portion that closes an opening of the bottomed cylindrical case main body, and
a bottom portion of the bottomed cylindrical case main body and the lid portion are disposed to face each other in the vibration direction of the movable body.

8. The vibration actuator according to claim 7 , wherein
the bottomed cylindrical case main body and the lid portion are fixed to each other by welding.

9. The vibration actuator according to claim 1 , wherein
the magnet is configured with single-pole-pair magnetization in the vibration direction, and
a winding direction of a winding of the coil forming the first coil and the second coil is reversed in the groove portion in an opposite direction.

10. The vibration actuator according to claim 1 , wherein
the groove portion has a bottom wall portion forming a bottom portion of the groove portion, and one side wall portion extending outward in the radial direction from an end portion of the bottom wall portion, the end portion being situated on a far side from the coil connection part, and
the bottom wall portion and the one side wall portion are disposed to form an acute angle on a side of the coil connection part with respect to a normal to an outer diameter of the flange-shaped central wall portion, the normal extending through a joint portion between the one side wall portion and the bottom wall portion.

11. The vibration actuator according to claim 1 , wherein
the coil connection part protrudes outward from the outer diameter of the flange-shaped central wall portion.

12. The vibration actuator according to claim 11 , further comprising:
a cylindrical electromagnetic shield part disposed outside the coil in the radial direction of the coil to surround the coil, the cylindrical electromagnetic shield part being formed from a magnetic material, wherein
the cylindrical electromagnetic shield part centrally includes an opening portion through which the coil connection part is inserted.

13. The vibration actuator according to claim 12 , wherein
the cylindrical electromagnetic shield part is a cylindrical body surrounding the bobbin-shaped coil holding part that holds the coil, and
the opening portion in the cylindrical electromagnetic shield part is formed to open at an opening edge portion on one side.

14. The vibration actuator according to claim 13 , wherein
the flange-shaped central wall portion includes a coil guide portion for guiding a winding of the coil from the coil connection part to a first winding position in a coil winding portion of the bobbin-shaped coil holding part.

15. The vibration actuator according to claim 1 , wherein
the fixing body includes a case for housing the bobbin-shaped coil holding part,
the elastic supporting part is fixed to the bobbin-shaped coil holding part,
the bobbin-shaped coil holding part houses the movable body inside the coil in the radial direction of the coil via the elastic supporting part such that the movable body is freely movable in the vibration direction, the bobbin-shaped coil holding part being disposed in the case, and
a protruding portion for wire fixation is disposed on an outer circumferential surface of the case.

16. The vibration actuator according to claim 15 , wherein
the protruding portion includes a protruding piece protruding from the outer circumferential surface of the case, and an orthogonal piece protruding orthogonally to the protruding piece from a tip of the protruding piece, and
the protruding piece and the orthogonal piece, together with the outer circumferential surface, form a groove through which a wire is passable.

17. The vibration actuator according to claim 15 , wherein
a cable as the wire is adhesively fixed to the protruding portion.

18. The vibration actuator according to claim 1 , further comprising:
a cable including a U-shaped or ring-shaped end portion, wherei

Assignees

• Takahashi Yuki
• Sekiguchi Chikara
• Shimomura Shigeyuki
• Kumanomido Yoshihiro
• Kodama Daisuke
• Yoshii Yuta
• Inamoto Shigenori
• Minebea Mitsumi Inc

Inventors

• Takahashi Yuki
• Sekiguchi Chikara
• Shimomura Shigeyuki
• Kumanomido Yoshihiro
• Kodama Daisuke
• Yoshii Yuta
• Inamoto Shigenori

Classifications

• G08B6/00

  Tactile signalling systems, e.g. tactile personal calling systems · CPC title

• H02K33/04 Primary

  wherein the frequency of operation is determined by the frequency of uninterrupted AC energisation · CPC title

• H02K11/01

  for shielding from electromagnetic fields {, i.e. structural association with shields} (means for preventing or reducing eddy-current losses in the winding heads by shielding H02K3/42) · CPC title

• H02K33/14 Primary

  wherein the alternate energisation and de-energisation of the two coil systems are effected or controlled by movement of the armatures · CPC title

• H02K33/02 Primary

  with armatures moved one way by energisation of a single coil system and returned by mechanical force, e.g. by springs · CPC title