JP2013206806A - Fuse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuse which can prevent a housing from melting, even if the fuse body is heated to a high temperature.SOLUTION: A fuse 100 includes a fuse body 110 interrupting a current of rating or higher, a housing 120 for housing the fuse body 110, and a heat dissipation member 130 formed of a material having a heat conductivity higher than that of the housing 120, and dissipating heat generated from the fuse body 110 to the outside of the housing 120. The fuse body 110 includes a second elastic engaging piece 111D projecting from the fuse body 110 toward the inner surface of the housing 120. An insertion hole 121E engaging with the second elastic engaging piece 111D and into which the heat dissipation member 130 can be inserted is formed in the housing 120. The heat dissipation member 130 is inserted into the insertion hole 121E and abuts against the second elastic engaging piece 111D, and at least a part of which is provided at a position higher than the end face 5A of an attachment part 5 on the outside of the housing 120.

Description

  The present invention relates to a fuse, and more particularly to a fuse mounted on a vehicle.

  Conventionally, various electronic devices are mounted on vehicles such as automobiles, and many power transmission lines for supplying desired electric power to these electronic devices have been routed. The power transmission line is provided with an electrical connection box (so-called fuse box) provided so that a plurality of fuses can be extracted in order to protect the electrical circuit of each electronic device.

  A fuse used in such an electrical junction box includes a conductive fuse body and an insulating housing that houses the fuse body. The fuse body includes a pair of terminal portions having a box shape and a fusible portion that melts a current exceeding a rating (so-called overcurrent), and these are integrally formed of metal. The pair of terminal portions includes a spring piece that is connected to a mating terminal provided in the electrical connection box, and a locking piece that is located on the outer side and is locked to the inner surface of the housing. The fusible portion includes a fusible conductor portion that connects the terminal portions to each other and a low melting point metal that is attached to the fusible conductor portion.

  In such a fuse, a pair of terminal portions are connected to a counterpart terminal in the mounting portion by mounting the housing on the mounting portion of the electrical junction box. When a current exceeding the rating (so-called overcurrent) is passed through the fusible part of the fuse, the low melting point metal melts, and the melted low melting point metal diffuses into the fusible conductor part and is soluble Reduce the melting point of the conductor. Thereby, heat_generation | fever of a soluble conductor part is accelerated | stimulated and a soluble conductor part melts | disconnects and can interrupt | block electricity_supply.

JP 2004-281078 A

  However, in the conventional fuse described above, for example, in the case of a high rating (100 amperes, 120 amperes, 140 amperes, etc.), it is assumed that the pair of terminal portions and the fusible portion tend to generate heat, and the fuse body itself becomes hot. The In this case, high-temperature heat generated in the fuse main body is transmitted from each locking piece to the inner surface of the housing, and the housing may be melted.

  Accordingly, an object of the present invention is to provide a fuse capable of preventing the housing from being melted even when the fuse body is at a high temperature.

  In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention is a fuse (fuse 100) attached to a mounting portion (mounting portion 5) of an electrical connection box (electrical connection box 1), and a counterpart terminal provided in the mounting portion. A fuse body (fuse body 110) that is connected to the (tab terminal 7) and interrupts a current exceeding the rated value, a housing (housing 120) that houses the fuse body, and a material having a higher thermal conductivity than the housing. And a heat radiating member (heat radiating member 130) for releasing heat generated in the fuse main body to the outside of the housing, the fuse main body protruding from the fuse main body toward the inner surface of the housing, and on the inner surface of the housing An elastic locking portion (second elastic locking piece 111D) that can be locked is provided, and the elastic locking portion is locked to the housing. An insertion portion (insertion hole 121E) through which the heat dissipation member can be inserted is formed, the heat dissipation member passes through the insertion portion and contacts the elastic locking portion, and at least a part thereof is outside the housing. The gist is that the mounting portion is provided at a position higher than the end surface (end surface 5A).

  According to this feature, the heat dissipation member is formed of a material having a higher thermal conductivity than the housing. The heat dissipating member is inserted through the insertion portion and comes into contact with the elastic locking portion, and at least a part thereof is provided at a position higher than the end surface of the mounting portion outside the housing. Thereby, for example, even in the case of high ratings (100 amperes, 120 amperes, 140 amperes, etc.), high-temperature heat generated in the fuse body is conducted to the heat dissipation member and released to the outside of the housing. For this reason, it is possible to prevent the housing from being melted and to prevent the mounting portion of the electrical connection box to which the fuse is mounted from being melted.

  A second feature of the present invention is the fuse according to the first feature of the present invention, wherein the heat dissipation member extends along an insertion direction (insertion direction ID) of the heat dissipation member into the insertion portion, and A contact portion (contact portion 131) that is inserted through the insertion portion and contacts the elastic locking portion; a tip portion (tip portion 132) that extends along the insertion direction and is located outside the housing; A connecting portion (connecting portion 133) that extends along a direction orthogonal to the insertion direction and connects the contact portion and the tip portion is provided, and the tip portion is provided at a position higher than the end surface of the mounting portion. The main point is that

  According to this feature, the heat dissipation member includes a contact portion, a tip portion, and a connecting portion. Thereby, the area which can be radiated by the heat radiating member is increased, and the high temperature heat generated in the fuse body can be efficiently discharged.

  The tip is provided at a position higher than the end surface of the mounting part. As a result, when the fuse is attached to or detached from the electrical junction box, the tip portion also serves as a gripping portion (handle), and the fuse can be easily attached to or detached from the electrical junction box.

  According to the characteristics of the present invention, it is possible to provide a fuse capable of preventing the housing from being melted even when the fuse body is at a high temperature.

FIG. 1 is an exploded perspective view showing an electrical junction box and a fuse according to the present embodiment. FIG. 2 is an assembled perspective view showing the electrical junction box and the fuse according to the present embodiment. FIG. 3 is a cross-sectional view showing the electrical junction box and the fuse according to the present embodiment. FIG. 4 is an exploded perspective view showing the fuse according to the present embodiment. FIG. 5 is a front, side, and plan view showing the fuse body according to this embodiment. FIG. 6 is a front, side, and plan view showing the housing body according to the present embodiment.

  Next, an embodiment of a fuse according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, the part from which the relationship and ratio of a mutual dimension differ also in between drawings may be contained.

(Configuration of electrical junction box)
First, the configuration of the electrical junction box 1 to which the fuse 100 according to the present invention is mounted will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing an electrical junction box 1 and a fuse 100 according to the present embodiment. FIG. 2 is an assembled perspective view showing the electrical junction box 1 and the fuse 100 according to the present embodiment. FIG. 3 is a cross-sectional view showing the electrical junction box 1 and the fuse 100 according to the present embodiment.

  As shown in FIGS. 1 to 3, the electrical junction box 1 includes a box-shaped (a part in the drawing) box body 3 and a wiring board (not shown) housed in the box body 3. The box body 3 is provided with a mounting portion 5 that is open at the top and to which the fuse 100 is mounted, and a connector fitting portion (not shown) into which a connector of a wire harness routed in a vehicle such as an automobile is fitted. It has been.

  The mounting portion 5 is formed in a cylindrical shape having an open top, and a plurality of mounting portions 5 are provided on the box body 3. Inside the mounting portion 5, a strip-like tab terminal 7 (mating terminal) provided on a bus bar of a wiring board (not shown) is provided.

  Such an electrical junction box 1 is provided on a power transmission line for supplying desired power to various electronic devices by being provided between a power source such as a battery mounted on the vehicle and various electronic devices. Will be.

(Fuse configuration)
Next, the configuration of the fuse 100 described above will be described with reference to the drawings. FIG. 4 is an exploded perspective view showing the fuse 100 according to the present embodiment. FIG. 5 is a view showing the fuse body 110 according to the present embodiment. FIG. 6 is a view showing the housing main body 121 according to the present embodiment.

  As shown in FIGS. 1 to 3, the fuse 100 is a type of fuse that is inserted into the mounting portion 5 of the electrical junction box 1, and cuts off the power supply from the power source to the electronic device. As shown in FIGS. 3 and 4, the fuse 100 is connected to a tab terminal 7 provided in the mounting portion 5 of the electrical junction box 1 to cut off a current exceeding the rating (so-called overcurrent) 110. A housing 120 that houses the fuse body 110, and a heat dissipation member 130 that releases heat generated in the fuse body 110 to the outside of the housing 120.

  As shown in FIGS. 4 and 5, the fuse body 110 includes a pair of terminal portions 111 and a fusible portion 112 that melts when a current exceeding the rating (so-called overcurrent) is energized. Are integrally formed of metal.

  The pair of terminal portions 111 includes a box-shaped terminal main body 111A arranged in parallel to each other, a spring piece 111B provided inside the terminal main body 111A, and an outer side of the terminal main body 111A and latched to the inner surface of the housing 120. The first elastic locking piece 111C and the second elastic locking piece 111D (elastic locking portion) are provided.

  111 C of 1st elastic locking pieces are standingly arranged in the state inclined from the bottom wall of the terminal main body 111A. The second elastic locking piece 111D is erected at a right angle from the bottom wall of the terminal body 111A. Two upper and lower second elastic locking pieces 111D are provided in each terminal body 111A.

  The fusible portion 112 includes a fusible conductor portion 112A that connects the terminal bodies 111A to each other, and a low melting point metal 112B that is fixed to the fusible conductor portion 112A by caulking pieces. The low melting point metal 112B is formed of a metal (for example, tin or tin alloy) having a melting point lower than that of the soluble conductor portion 112A.

  As shown in FIGS. 4 and 6, the housing 120 includes a housing body 121 that houses the fuse body 110 from the upper opening 121A, and a housing cover 122 that is attached to the housing body 121 from the opening 121A side. Yes.

  The housing main body 121 is formed of an insulating synthetic resin, and is formed in a square cylinder shape whose lower side branches in two directions. The housing main body 121 includes a pair of terminal accommodating chambers 121 </ b> B that accommodate the pair of terminal portions 111. Each terminal accommodating chamber 121B is formed with a locking accommodating groove 121C in which the first elastic locking piece 111C provided outside the terminal main body 111A is locked and accommodated.

  Further, on the outer wall of the housing main body 121, an engagement protrusion 121D with which the housing cover 122 engages with the front and rear surfaces, and an insertion hole 121E (insertion portion) through which the heat dissipation member 130 can be inserted are formed on the side surface. The second elastic locking piece 111D is locked in the insertion hole 121E.

  The housing cover 122 is formed of a permeable material (for example, polyethersulfone (PES)) so that the soluble portion 112 can be visually recognized. The housing cover 122 is formed with an engaging portion 122 </ b> A that engages with the engaging protrusion 121 </ b> D of the housing main body 121.

  The heat radiating member 130 is made of a material (for example, ceramic) having a higher thermal conductivity than the housing 120. The heat radiating member 130 is inserted through the insertion hole 121E of the housing main body 121 and comes into contact with the second elastic locking piece 111D, and at least a part of the heat radiating member 130 is outside the housing 120 at the end surface 5A (see FIG. (See FIG. 3). The heat radiating member 130 includes a contact portion 131, a tip portion 132, and a connecting portion 133, and is formed in a substantially S shape.

  The contact portion 131 extends along the insertion direction ID of the heat radiating member 130 into the insertion hole 121E, passes through the insertion hole 121E, and contacts the second elastic locking piece 111D. The distal end portion 132 extends along the insertion direction ID, and is provided at a position higher than the end surface 5A of the mounting portion 5 of the electrical junction box 1 outside the housing 120. The connecting portion 133 extends along a direction (vertical direction) orthogonal to the insertion direction ID, and connects the contact portion 131 and the tip portion 132.

(Fuse assembly method)
Next, a method for assembling the above-described fuse 100 will be described with reference to FIG.

  First, after the pair of terminal portions 111 and the fusible portion 112 are punched or bent into a single sheet metal, the low melting point metal 112B is crimped and fixed to the fusible conductor portion 112A and thermally welded. Thus, the fuse body 110 is assembled.

  Next, the fuse body 110 is mounted in the housing body 121. Then, as shown in FIG. 3, the first elastic locking piece 111C of the fuse body 110 is locked in the locking receiving groove 121C of the housing main body 121, and the second elastic locking piece 111D of the fuse main body 110 is fixed to the housing. The fuse body 110 is locked in the insertion hole 121E of the main body 121 (so-called fuse body 110 is double-locked).

  Next, the housing cover 122 is mounted from the opening 121 </ b> A side of the housing main body 121, and the engaging portion 122 </ b> A of the housing cover 122 is engaged with the engaging protrusion 121 </ b> D of the housing main body 121. Then, the contact portion 131 of the heat radiating member 130 is press-fitted and fixed in the insertion hole 121 </ b> E of the housing body 121. As a result, the housing main body 121 and the housing cover 122 are fixed, and the fuse main body 110 is accommodated in the housing 120, whereby the fuse 100 is assembled.

  Here, it has been described that the housing cover 122 is first attached to the housing main body 121, and then the heat radiating member 130 is attached. However, the order is not necessarily the order, and the order may be reversed. .

  Thereafter, when the fuse 100 is mounted on the mounting portion 5 (see FIGS. 1 to 3) of the electrical junction box 1, the tab terminal 7 is inserted into the terminal body 111A. At this time, the spring piece 111B presses the tab terminal 7 inserted into the terminal body 111A toward the inner surface of the terminal body 111A. Thereby, the terminal part 111 and the tab terminal 7 are mutually connected.

  The fuse 100 attached to the electrical junction box 1 connects the power source and the electronic device, and when a current exceeding the rating (so-called overcurrent) is applied to the fusible portion 112, the low melting point metal 112B. Is melted, and the melted low melting point metal 112B diffuses into the soluble conductor portion 112A and lowers the melting point of the soluble conductor portion 112A. Thereby, the heat generation of the soluble conductor portion 112A is promoted, the soluble conductor portion 112A is melted, and the power supply from the power source to the electronic device is interrupted.

(Action / Effect)
In the present embodiment described above, the heat radiating member 130 is formed of a material having a higher thermal conductivity than the housing 120. Further, the heat radiating member 130 is inserted through the insertion hole 121 </ b> E and comes into contact with the second elastic locking piece 111 </ b> D, and at least a part (in the embodiment, a part of the distal end portion 132 and the connecting portion 133) is electrically external to the housing 120. It is provided at a position higher than the end surface 5 </ b> A of the mounting portion 5 of the connection box 1. Thus, for example, even in the case of a high rating (100 amperes, 120 amperes, 140 amperes, etc.), high temperature heat generated in the fuse body 110 is conducted to the outside of the housing 120 through the heat radiating member 130. For this reason, the housing 120 can be prevented from being melted, and the mounting portion 5 of the electrical junction box 1 to which the fuse 100 is mounted can also be prevented from being melted.

  In the present embodiment, the second elastic locking piece 111D is locked to the inner surface of the housing 120 together with the first elastic locking piece 111C. Thereby, since the fuse body 110 is double-locked to the inner surface of the housing 120, the fuse body 110 is more reliably fixed in the housing 120.

  In the present embodiment, the heat radiating member 130 includes a contact portion 131, a tip portion 132, and a connecting portion 133. As a result, the area where heat dissipation by the heat radiating member 130 can be increased, and high-temperature heat generated in the fuse body 110 can be efficiently released.

  Further, the front end portion 132 is provided at a position higher than the end surface 5A of the mounting portion 5 of the electrical junction box 1. As a result, when the fuse 100 is attached to or detached from the electrical connection box 1, the distal end portion 132 also serves as a grip portion (handle), and the attachment and detachment operation of the fuse 100 to the electrical connection box 1 is facilitated.

  In the embodiment, the heat radiating member 130 is formed of ceramic. Thereby, the fuse 100 can be manufactured with an inexpensive material, which contributes to a reduction in manufacturing cost.

(Other embodiments)
Although the contents of the present invention have been disclosed through the embodiments of the present invention as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.

  For example, the embodiment of the present invention can be modified as follows. Specifically, although the heat radiating member 130 has been described as being formed of ceramic, it is not limited thereto, and any material having a higher thermal conductivity than the housing 120 may be used.

  Moreover, although the heat radiating member 130 was demonstrated as what is formed in substantially S shape by the contact part 131, the front-end | tip part 132, and the connection part 133, it is not limited to this, The 2nd elastic locking piece It suffices that at least a part is in contact with 111D and provided at a position higher than the end surface 5A of the mounting portion 5 of the electrical junction box 1 outside the housing 120. For example, the heat radiating member 130 may be provided flush with the outer wall of the housing main body 121 as long as at least a part of the heat radiating member 130 is provided at a position higher than the end surface 5A of the mounting portion 5 of the electrical junction box 1.

  Moreover, although the housing main body 121 and the housing cover 122 were demonstrated as what is fixed by latching with the engaging protrusion 121D and the engaging part 122A, it is not limited to this, By other lock mechanisms etc. It may be fixed.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is determined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 ... Electric junction box 3 ... Box main body 5 ... Mounting part 5A ... End surface 7 ... Tab terminal (mating side terminal)
DESCRIPTION OF SYMBOLS 100 ... Fuse 110 ... Fuse main body 111 ... Terminal part 111A ... Terminal main body 111B ... Spring piece 111C ... 1st elastic locking piece 111D ... 2nd elastic locking piece (elastic locking part)
DESCRIPTION OF SYMBOLS 112 ... Soluble part 112A ... Soluble conductor part 112B ... Low melting-point metal 120 ... Housing 121 ... Housing main body 121A ... Opening part 121B ... Terminal accommodation chamber 121C ... Locking accommodation groove 121D ... Engagement protrusion 121E ... Insertion hole 122 ... Housing Cover 122A ... engaging portion 130 ... heat dissipation member 131 ... abutting portion 132 ... tip portion 133 ... connecting portion

Claims (2)

A fuse attached to the mounting part of the electrical junction box,
A fuse body that is connected to a counterpart terminal provided in the mounting portion and cuts off a current exceeding a rating;
A housing for housing the fuse body;
A heat dissipation member that is formed of a material having a higher thermal conductivity than the housing, and that releases heat generated in the fuse body to the outside of the housing;
The fuse body includes an elastic locking portion that protrudes from the fuse body toward the inner surface of the housing and can be locked to the inner surface of the housing.
The housing is formed with an insertion portion through which the elastic locking portion is locked and the heat dissipation member can be inserted,
The fuse, wherein the heat dissipating member is inserted through the insertion portion and abuts against the elastic locking portion, and at least a part thereof is provided at a position higher than the end surface of the mounting portion outside the housing. The fuse of claim 1,
The heat dissipation member is
An abutting portion that extends along an insertion direction of the heat dissipation member into the insertion portion, and is inserted through the insertion portion and contacts the elastic locking portion;
A tip portion extending along the insertion direction and located outside the housing;
Extending along a direction orthogonal to the insertion direction, and comprising a connecting part for connecting the contact part and the tip part,
The fuse is characterized in that the tip portion is provided at a position higher than an end surface of the mounting portion.

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