Vibration actuator with movable body and fixing body with gap and fluid and pipe resistance to fluid

Patent metadata

Field	Value
Publication number	US-12424916-B2
Application number	US-202318140011-A
Country	US
Kind code	B2
Filing date	Apr 27, 2023
Priority date	Apr 28, 2022
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

Provided is a vibration actuator including: a movable body including a magnet having a pillar shape; and a fixing body including a coil and a main body part. The main body part includes an inner peripheral surface, which surrounds the movable body with a gap between the inner peripheral surface and an outer peripheral surface of the movable body inside the coil, and supports the movable body via an elastic support part such that the movable body is vibratable in an axial direction of the movable body. The vibration actuator is configured to cause a flow of a fluid in a direction opposite to a direction of movement of the movable body in the gap and to generate a pipe resistance to the fluid.

First claim

The invention claimed is:

1. A vibration actuator, comprising:
a movable body including a magnet having a pillar shape; and
a fixing body including a coil and a main body part, the main body part including an inner peripheral surface and supporting the movable body via an elastic support part such that the movable body is vibratable in an axial direction of the movable body, the inner peripheral surface surrounding the movable body with a gap between the inner peripheral surface and an outer peripheral surface of the movable body inside the coil, wherein
the vibration actuator is configured to cause a flow of a fluid in a direction opposite to a direction of movement of the movable body in the gap and to generate a pipe resistance to the fluid,
the outer peripheral surface of the movable body has a length protruding from the inner peripheral surface of the main body part on both sides of the outer peripheral surface in the axial direction over an entire movable field of the movable body,
the movable body includes the magnet in a center part of the movable body in the axial direction, includes a pair of weight parts in both end parts of the movable body in the axial direction, and includes a pair of yokes between the magnet and the pair of weight parts,
the magnet, the pair of yokes, and the pair of weight parts are each formed in a cylindrical shape with an identical diameter and are joined to each other such that outer peripheral surfaces of the magnet, the pair of yokes, and the pair of weight parts are flush with each other, and
a joined part between the magnet and each of the pair of yokes or a joined part between each of the pair of yokes and a corresponding one of the pair of weight parts is provided with a gathering part that gathers an adhesive or a welding material.

2. The vibration actuator according to claim 1 ,
wherein each of the outer peripheral surface of the movable body and the inner peripheral surface of the main body part is flat in the axial direction such that the gap has a constant width in the axial direction when the movable body does not move and is maintained constant in the axial direction when the movable body moves, and each of the outer peripheral surface of the movable body and the inner peripheral surface of the main body part maintains generation of a straight pipe loss to the fluid over the entire movable field.

3. An electric apparatus that is a hand-carry electric apparatus or a wearable electric apparatus, the electric apparatus comprising a configuration in which the vibration actuator according to claim 1 is implemented in a contact part which comes into contact with a user.

4. A vibration actuator, comprising:
a movable body including a magnet having a pillar shape; and
a fixing body including a coil and a main body part, the main body part including an inner peripheral surface and supporting the movable body via an elastic support part such that the movable body is vibratable in an axial direction of the movable body, the inner peripheral surface surrounding the movable body with a gap between the inner peripheral surface and an outer peripheral surface of the movable body inside the coil, wherein
the vibration actuator is configured to cause a flow of a fluid in a direction opposite to a direction of movement of the movable body in the gap and to generate a pipe resistance to the fluid,
the outer peripheral surface of the movable body has a length protruding from the inner peripheral surface of the main body part on both sides of the outer peripheral surface in the axial direction over an entire movable field of the movable body,
the fixing body includes a pair of fluid housing chambers communicating with the gap at both end parts of the fixing body in the axial direction, and
the pair of fluid housing chambers steeply expands in diameter with respect to the inner peripheral surface such that a loss due to a change in a shape of a flow path at an entrance of the gap and at an exit of the gap is generated over the entire movable field of the movable body.

5. The vibration actuator according to claim 4 , wherein the pair of fluid housing chambers is a pair of hermetically sealed spaces having a plane-symmetrical shape with respect to a normal section through a center position of the pair of hermetically sealed spaces in the axial direction.

6. The vibration actuator according to claim 4 , wherein:
the movable body includes the magnet in a center part of the movable body in the axial direction, includes a pair of weight parts in both end parts of the movable body in the axial direction, and includes a pair of yokes between the magnet and the pair of weight parts, and
the magnet, the pair of yokes, and the pair of weight parts are each formed in a cylindrical shape with an identical diameter and are joined to each other such that outer peripheral surfaces of the magnet, the pair of yokes, and the pair of weight parts are flush with each other.

7. The vibration actuator according to claim 4 , wherein
a joined part between the magnet and each of the pair of yokes or a joined part between each of the pair of yokes and a corresponding one of the pair of weight parts is provided with a gathering part that gathers an adhesive or a welding material.

8. The vibration actuator according to claim 4 , wherein
each of the outer peripheral surface of the movable body and the inner peripheral surface of the main body part is flat in the axial direction such that the gap has a constant width in the axial direction when the movable body does not move and is maintained constant in the axial direction when the movable body moves, and each of the outer peripheral surface of the movable body and the inner peripheral surface of the main body part maintains generation of a straight pipe loss to the fluid over the entire movable field.

9. An electric apparatus that is a hand-carry electric apparatus or a wearable electric apparatus, the electric apparatus comprising a configuration in which the vibration actuator according to claim 4 is implemented in a contact part which comes into contact with a user.

Assignees

• Shimomura Shigeyuki
• Ogihara Yuki
• Kinoshita Yosuke
• Minebea Mitsumi Inc

Inventors

• Shimomura Shigeyuki
• Ogihara Yuki
• Kinoshita Yosuke

Classifications

• G08B6/00

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

• H02K33/18 Primary

  with coil systems moving upon intermittent or reversed energisation thereof by interaction with a fixed field system, e.g. permanent magnets · 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