Protection element

Patent metadata

Field	Value
Publication number	US-12261007-B2
Application number	US-202218276310-A
Country	US
Kind code	B2
Filing date	Feb 15, 2022
Priority date	Feb 19, 2021
Publication date	Mar 25, 2025
Grant date	Mar 25, 2025

Abstract

A protection element includes: a fuse element configured to be energized in a first direction, which is a direction from a first end portion of the fuse element to a second end portion of the fuse element; a shielding member including a plate-shaped part, configured to rotate around a rotation axis extending in a second direction orthogonal to the first direction, wherein the plate-shaped part viewed from the fuse element is divided to a first portion and a second portion at a contact position between the plate-shaped part and the rotation axis, and an area of the first portion and an area of the second portion are different from each other; and a case having therein a housing portion. Pressure elevation in the housing portion due to an arc discharge causes the shielding member to rotate around the rotation axis and the shielding member divides the housing portion.

First claim

The invention claimed is:

1. A protection element, comprising:
a fuse element configured to be energized in a first direction, which is a direction from a first end portion of the fuse element to a second end portion of the fuse element;
a shielding member composed of an insulating material, configured to rotate to a rotated position around a rotation axis extending in a second direction orthogonal to the first direction, and comprising a plate-shaped part which comprises a first surface and a second surface, the first surface facing the fuse element and a second surface being in contact with the rotation axis, wherein the plate-shaped part viewed from the fuse element is divided to a first portion and a second portion at a contact position between the plate-shaped part and the rotation axis, and an area of the first portion and an area of the second portion are different from each other; and
a case composed of an insulating material, and having therein a housing portion in which the fuse element and the shielding member are stored,
wherein pressure elevation in the housing portion due to an arc discharge generated when the fuse element fuses causes the first surface to be pressed so that the shielding member to rotate around the rotation axis and the shielding member divides the housing portion.

2. The protection element according to claim 1 , wherein an inner surface of the case facing the fuse element has a shielding member housing groove in which a part of the shielding member is housed in the rotated position.

3. The protection element according to claim 1 , wherein the fuse element further comprises a constricted portion between the first end portion and the second end portion, and a cross-sectional area of the constricted portion in the second direction is narrower than each of a cross-sectional area of the first end portion and a cross-sectional area of the second end portion in the second direction.

4. The protection element according to claim 3 , wherein a width of the constricted portion in the second direction is narrower than each of a width of the first end portion and a width of the second end portion in the second direction.

5. The protection element according to claim 1 , wherein the fuse element is composed of a laminated body in which an inner layer comprising a low-melting-point metal and an outer layer comprising a high-melting-point metal are laminated in a thickness direction of the laminated body.

6. The protection element according to claim 5 , wherein the low-melting-point metal is Sn or a metal comprising Sn as a main component thereof, and the high-melting-point metal is Ag, Cu, or a metal comprising Ag or Cu as a main component thereof.

7. The protection element according to claim 1 , wherein the fuse element comprises a bent portion bent along a direction intersecting the first direction.

8. The protection element according to claim 1 , wherein at least one of the shielding member and the case is composed of a resin material which is a nylon-based resin, a fluorine-based resin, or a polyphthalamide resin.

9. The protection element according to claim 8 , wherein the resin material has a tracking resistance index CTI of 600 V or more.

10. The protection element according to claim 8 , wherein the nylon-based resin comprises no benzene ring.

11. The protection element according to claim 1 , further comprising a first terminal and a second terminal,
wherein the first end portion is electrically connected to the first terminal, the second end portion is electrically connected to the second terminal, and
a portion of the first terminal and a portion of the second terminal are exposed from the case.

12. The protection element according to claim 1 , wherein the second surface of the plate-shaped part is provided with a member having elasticity configured to apply force on the shielding member in a rotation direction.

13. The protection element according to claim 1 , wherein the shielding member comprises: a first shielding member and a second shielding member having a same shape as the first shielding member; and
the first shielding member and the second shielding member are disposed symmetrically in the first direction with respect to a center of the fuse element in the first direction.

14. The protection element according to claim 13 ,
wherein the fuse element comprises a cut portion between the first end portion and the second end portion,
the first shielding member and the second shielding member are disposed symmetrically in the first direction with respect to the cut portion,
the second shielding member is disposed facing a surface of an opposite side to a surface of the fuse element facing the first shielding member, and
a rotation direction of the first shielding member and a rotation direction of the second shielding member are opposite with respect to the fuse element.

15. The protection element according to claim 1 , wherein the case comprises a first case and a second case having a same shape as the first case, and
the first case and the second case are disposed facing each other with respect to the fuse element.

16. The protection element according to claim 1 , further comprising a cover,
wherein a part of the case is covered by the cover,
the protection element is provided with an internal pressure buffer space surrounded by an outer surface of the case and an inner surface of the cover,
the case has a vent passing through the case and communicating the housing portion and the internal pressure buffer space, and
a volume of the internal pressure buffer space is equal to or greater than a volume of the fuse element.

17. The protection element according to claim 1 , wherein the housing portion has a concave portion having a step which works as the rotation axis, and
the first surface of the plate-shaped part has a first end edge and a second end edge, the first end edge being closer to the rotation axis than the second end edge in the first direction, and the shielding member rotates in a direction in which the second end edge moves away from the fuse element.

18. The protection element according to claim 1 , further comprising a heat generation member configured to heat the fuse element is installed on the first surface of the plate-shaped part.

19. The protection element according to claim 18 , wherein the heat generation member comprises an element-connecting electrode electrically connected to the fuse element.

20. The protection element according to claim 19 , wherein the heat generation member further comprises:
a heat generation unit composed of a resistive material; and
power supply wire electrodes each electrically connected to the heat generation unit at each end portion opposite to each other with respect to a center of the heat generation unit.

21. The protection element according to claim 20 , wherein the heat generation member further comprises:
an insulated substrate on which the heat generation unit is provided; and
an insulating layer provided on the heat generation unit,
wherein the element-connecting electrode is provided at a position on the insulating layer where at least a part of the element-connecting electrode overlaps the heat generation unit.

22. The protection element according to claim 20 , wherein the heat generation member further comprises:
an insulated substrate on which the heat generation unit is provided; and
an insulating layer is provided on the heat generation unit,
wherein

Assignees

• Dexerials Corp

Inventors

• Yoneda Yoshihiro

Classifications

• H01H85/1755

  composite casing · CPC title

• H01H2223/044

  Protecting cover · CPC title

• H01H85/17

  characterised by the casing material · CPC title

• H01H85/10 Primary

  with constriction for localised fusing (H01H85/11 takes precedence) · CPC title

• H01H85/06 Primary

  characterised by the fusible material (H01H85/11 takes precedence) · CPC title