JP2006228661A - Thermal fuse - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal fuse which can be bent easily at a predetermined position and which makes workability proper. <P>SOLUTION: In the thermal fuse, a fusible alloy 4 is formed between the inner ends of a pair of lead conductors 1, 1A, 1B, and 1C arranged facing separately from each other, and the inner ends of this fusible alloy 4 and the pair of the lead conductors 1, 1A, 1B, and 1C are stored in a housing 5. It is configured to provide a bent part to serve as the bending fulcrum A of at least either one of the pair of the lead conductors 1, 1A, 1B, and 1C which project exterior from the housing 5 so that the lead conductors 1, 1A, 1B, and 1C can be bent at the predetermined position in the exterior position of the housing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal fuse that is blown by an increase in ambient temperature.

As a thin thermal fuse, there is one shown in FIG. In this thin thermal fuse, a low melting point soluble alloy 220 is connected between the ends of a pair of strip-shaped lead conductors 211 and 212, and the low melting point soluble alloy 220 is sandwiched between cases made of resin films 231 and 232. And while sealing the periphery of the resin films 231 and 232, between each resin film 231 and 232 and the strip | belt-shaped lead conductors 211 and 212 is sealed. At this time, the resin layers 241 and 242 are coated on the sealed portions of the strip-shaped lead conductors 211 and 212, and the resin films 231 and 232 and the resin layers 241 and 242 of the sealed portions of the strip-shaped lead conductors 211 and 212 are formed. It is configured to fuse the gaps.
Japanese Patent Laid-Open No. 11-353995

  The flat lead strip 211 used in the thin thermal fuse has at least one bent portion due to its position and space when it is attached to a protected component, and is indicated by an arrow for folding. When external force is applied to the case and it is bent as shown in the figure (b), special attention should be paid to the bending position, bending method, shape, etc., taking into account damage such as poor sealing and cracking at the outer edge of the case. There is a problem that it is necessary to pay, care is taken in the bending work, and the work is complicated.

  The present invention has been proposed in view of the above, and an object of the present invention is to provide a thermal fuse that can be easily bent at a predetermined position and has good workability.

According to the first aspect of the present invention, a fusible alloy 4 is provided between inner ends of a pair of lead conductors that are spaced apart from each other and the inner ends of the fusible alloy and the pair of lead conductors are within the case. In the thermal fuse housed in, the bent portion serving as a bending fulcrum of bending is provided on at least one of the pair of lead conductors protruding outward from the case.
According to a second aspect of the present invention, in the thermal fuse according to the first aspect, the bent portion is formed of a bent portion that is bent in a substantially inverted U shape, and the root of the outer wall raised outside the bent portion. It is characterized in that the part is a bending fulcrum.
According to a third aspect of the present invention, in the thermal fuse according to the first aspect, the bent portion is composed of a protruding portion protruding substantially in the shape of a triangular pyramid, and the base portion of the central portion is used as a bending fulcrum. .
According to a fourth aspect of the present invention, in the thermal fuse according to the first aspect, the bent portion is formed by a substantially circular protruding portion, and an outer position of an outer peripheral portion outside thereof is used as a bending fulcrum. .
According to a fifth aspect of the present invention, in the thermal fuse according to the first aspect, the bent portion comprises substantially V-shaped or substantially U-shaped notches formed on both side edges of the lead conductor. It is characterized by using as a bending fulcrum.

  According to the present invention, the lead conductor protruding outward from the case is provided with a bending portion that acts as a bending fulcrum for external force, so it can be easily bent at the portion of the bending fulcrum without using any care, Since the bending external force is not applied to the case, a good sealing state can be maintained.

  Further, if the bent portion is formed by a protrusion, there is an advantage that the strength is improved.

  If the bent part is notched, it can cope with a case where high-speed response is required.

  Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1]
FIG. 1A is a perspective view of the lead conductor of the first embodiment used in the present invention, and FIG.

  The lead conductor 1 is made of a conductive material such as nickel, and a first bent portion 2 for reinforcement is formed at the inner end thereof. The first bent portion 2 is bent in a substantially U shape over the width direction (direction orthogonal to the length direction). The convex bent portion 2 can be easily formed by press working.

  In addition, a rising portion b having a groove-shaped notch a at the center is bent at the inner end of the lead conductor 1.

  Further, a second bent portion 3 having substantially the same shape is formed outside the first bent portion 2, and the strength can be further improved by the second bent portion 3 having the convex shape. In addition, the bent portion 3 is used as a bent portion, and when the root portion of the outer wall 3b that rises outside of the bent portion 3 applies an external force to bend the lead conductor 1 at the outer position, the external force is dispersed and becomes a bending fulcrum A. I am doing so.

  Preferably, notches 2a and 3a having a substantially arc shape or a substantially V shape are formed on both sides of the first and second bent portions 2 and 3, respectively. By doing so, when the first bent portion 2 is positioned in the mold resin, the flow of the resin is made good through the notch portion.

  FIG. 2 shows a state in which a low-melting-point soluble alloy 4 is welded to a notch portion a between the rising portions b and b of the pair of lead conductors 1 and 1 that are arranged to face each other with their inner ends spaced apart from each other. The fusible alloy 4 is a rod-like or strip-like metal that is soluble as the ambient temperature rises. For example, one kind of Sn, Ag, Cu, or an alloy obtained by appropriately mixing them is used. The rosin applied around is applied to promote melting of the soluble alloy 1. This is known.

  In this embodiment, the end of the fusible alloy 4 is positioned and held in the notch a of the rising part b. Therefore, the attachment of the fusible alloy 4 to the lead conductor 1 and the welding operation of both can be performed easily and quickly.

  Further, since the fusible alloy 4 is attached between the notch portions a of the pair of rising portions b and in contact with the inner end portions of the lead conductors 2A, the heat transfer surface in the vicinity of the fusible alloy 4 is increased. In addition, the surface on which the melt of the fusible alloy 4 spreads out is configured in three dimensions, so that the operation accuracy can be improved.

  FIG. 3 shows a thin thermal fuse having a fusible alloy 4 and lead conductors 1 and 1 provided in a case 5. Case 5 may have any form, such as a cylindrical shape having both ends open, a case in which a resin film having an upper and lower split structure is integrated from above and below, a type in which a fusible alloy 4 is molded with an insulating resin, etc. Absent. In this embodiment, the first bent portions 2 and 2 of the lead conductors 1 and 1 are accommodated in the case 5, and the second bent portions 3 and 3 are out of the case 5.

  This thin thermal fuse protects equipment by detecting abnormal temperature increases such as overcharge and overdischarge of secondary batteries such as lithium ion batteries mounted on small electronic equipment such as mobile phones and video cameras. Used for.

  As shown in FIG. 4 (a), when an external force is applied to one of the lead conductors 1 as shown by an arrow, the bending fulcrum A as shown in FIG. 4 (b). This part can be easily folded, and the external force does not reach the case 5.

[Embodiment 2]
FIG. 5A is a perspective view of a second embodiment of the lead conductor 1A used in the present invention, and FIG.

  In this example, the outer rising portion 2a of the first bent portion 2 is inclined outward, and a substantially triangular pyramid-shaped protrusion 6 is formed outside the central portion of the outer wall of the rising portion 2a. It is characterized by having a reinforced portion and a bent portion.

  The protrusion 6 can be formed by raising from the inside. Alternatively, a separate member having a triangular pyramid shape may be welded. The base portion of the central portion 6 a that protrudes toward the outside of the protrusion 6 is a bending fulcrum A.

  FIG. 6A is an explanatory view showing a state in which the fusible alloy 4, the first bent part 2, and the inner part of the protrusion 6 are housed in the case 5.

  The base portion of the central portion 6 a of the protrusion 6 is located outside the case 5. As shown by the arrows, when an external force is applied, the bending fulcrum A can be bent as shown in FIG.

[Embodiment 3]
FIG. 7A is a perspective view of a third embodiment of the lead conductor 1B used in the present invention, and FIG.

  In this example, the outer raised portion 2b of the first bent portion 2 is raised almost vertically, and a protrusion 8 also serving as a circular reinforcement is formed on the outer side, and this is used as a bent portion. .

  The base portion outside the outer peripheral portion 8a of the protruding portion 8 serving as the bending portion is located outside the case 5 as in the above-described embodiment, and acts as a bending fulcrum A. The protrusion 8 can be easily formed by raising or welding another member.

[Embodiment 4]
FIG. 8 shows a perspective view of a fourth embodiment of the lead conductor 1C used in the present invention.

  In this example, substantially V-shaped or substantially U-shaped notch portions 9 are formed on both side edges of the lead conductor 1C outside the first bent portion 2 so as to bite toward the inside of the lead conductor 1C. This is a bent part. The cut-out notched portion 9 is located outside the case 5 and is characterized in that the inner end of the central portion is a bending fulcrum A.

  In each of the above-described embodiments, a part of the lead conductor is increased in strength and is used as a bending fulcrum A. However, in this embodiment, the bent portion is notched and the width of the portion is larger than the width of the other portions. Since it can be narrowed and thereby the strength can be reduced, it can be used as a bending fulcrum A, and even if a notch is provided, the electrical characteristics of the thermal fuse can be secured, and a notch is provided. Since the heat radiation area of the lead conductor can be suppressed, it is suitable when high-speed response is required.

  Although the embodiments of the present invention have been described above, the specific configuration is not limited to the present embodiments, and various design changes and the like can be made without departing from the spirit of the present invention. That is, although the thin thermal fuse has been described in the above embodiment, it is needless to say that the thin thermal fuse is not limited to the thin thermal fuse and can be applied to a general general thermal fuse.

(A) is a perspective view of the lead conductor of 1st Example of this invention, (b) is a side view. The perspective view which provided the soluble alloy in the lead conductor of the Example same as the above is shown. 1 is a configuration explanatory diagram of a first embodiment of the present invention. (A), (b) shows operation | movement explanatory drawing of 1st Example of this invention. The perspective view of the lead conductor of 2nd Example of this invention, (b) shows a side view. (A), (b) shows operation | movement explanatory drawing of 2nd Example of this invention. The perspective view of the lead conductor of 3rd Example of this invention, (b) shows a side view. The perspective view of the lead conductor of 4th Example of this invention is shown. (A) is a sectional side view of a conventional example, and (b) shows an example of a bent state of a lead conductor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C Lead conductor 2 1st bending part 2a Notch part 3 2nd bending part 3a Notch part 3b Outer wall 4 Soluble alloy 5 Case 6 Projection part 8 Projection part 9 Notch part a Notch b Rising part A Bending fulcrum

Claims (5)

In a temperature fuse in which a fusible alloy is provided between the inner ends of a pair of lead conductors that are spaced apart from each other and the inner ends of the fusible alloy and the pair of lead conductors are housed in a case,
A thermal fuse, wherein a bent portion serving as a bending fulcrum of bending is provided on at least one of the pair of lead conductors protruding outward from the case.   2. The thermal fuse according to claim 1, wherein the bent portion is formed of a bent portion that is bent substantially in an inverted U shape, and a root portion of the outer wall raised outside the bent portion serves as a bending fulcrum. Thermal fuse characterized by.   2. The thermal fuse according to claim 1, wherein the bent portion is formed of a protruding portion projecting substantially in a triangular pyramid shape, and a base portion of the central portion thereof serves as a bending fulcrum.   2. The thermal fuse according to claim 1, wherein the bent portion is formed by a substantially circular protruding portion, and an outer position of an outer peripheral portion outside thereof is a bending fulcrum.   2. The thermal fuse according to claim 1, wherein the bent portion is formed of a substantially V-shaped or substantially U-shaped cutout portion formed on both side edges of the lead conductor, and an inner end of the central portion serves as a bending fulcrum. Characteristic thermal fuse.

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