WO2024079955A1

WO2024079955A1 - Fuse

Info

Publication number: WO2024079955A1
Application number: PCT/JP2023/025806
Authority: WO
Inventors: 健太中本; 哲高槻; 聖也山内; 健司長田
Original assignee: 太平洋精工株式会社
Priority date: 2022-10-12
Filing date: 2023-07-13
Publication date: 2024-04-18
Also published as: JP2024057230A

Abstract

The invention of the present application provides a fuse that effectively prevents a housing from expanding due to internal pressure.　The present invention is a fuse 500 comprising a fuse element 400 having a fusion part 420 provided between a pair of terminal units 410, and a housing 300 that accommodates the fuse element 400, and is characterized in that the housing 300 is provided with wall parts, and the housing 300 is provided with at least one reinforcement part (350, 360) that connects the wall parts.

Description

fuse

The present invention relates to fuses that are primarily used in automotive electrical circuits, and in particular to fuses that house a fuse element within a casing.

　Traditionally, fuses have been used to protect electrical circuits installed in automobiles and the various electrical equipment connected to the electrical circuits. More specifically, when an unintended overcurrent flows through an electrical circuit, the melting part of the fuse element built into the fuse melts due to heat generated by the overcurrent, protecting the various electrical equipment from excessive current flowing through them.

There are various types of fuses depending on the application, for example, the fuse described in Patent Document 1 is known.

The fuse described in Patent Document 1 is a type that houses a fuse element inside a housing, and includes a fuse element having a pair of terminal parts and a fusing part provided between the terminal parts. Furthermore, in recent years, in order to accommodate higher voltages and larger currents, it has been desired to increase the number of fusing parts and increase the fuse capacity. Furthermore, when the number of fusing parts is increased, there is a possibility that the housing will expand due to the internal gas pressure that is generated when the fusing part melts.

JP 2021-93323 A

The present invention provides a fuse that effectively prevents the housing from expanding due to internal pressure.

The fuse of the present invention is a fuse comprising a fuse element having a melting portion provided between a pair of terminal portions, and a housing that contains the fuse element, the housing having a wall portion, and the housing having at least one reinforcing portion that connects the wall portions.

According to the above characteristics, the reinforcing portion strongly reinforces the housing so that it does not expand and deform due to internal pressure.

Furthermore, the fuse of the present invention is characterized in that the housing comprises one housing segment and the other housing segment, and the reinforcing portion is provided so as to cross the housing segments on both sides.

The above feature effectively prevents the reinforcing portion from expanding the housing halves in a direction away from each other due to internal pressure.

Furthermore, the fuse of the present invention is characterized in that the reinforcing portion comprises one divided portion and the other divided portion, the one divided portion is provided on the one housing divided piece and the other divided portion is provided on the other housing divided piece, and the one divided portion and the other divided portion are configured to be connected and fixed to each other.

According to the above features, each housing segment can be formed at the same time as each housing segment is formed using a conventional method for forming each housing segment (e.g., injection molding, etc.).

Furthermore, the fuse of the present invention is characterized in that the tip of one of the divided parts and the tip of the other divided part are connected and fixed by fitting together.

The above features allow one housing segment to be easily connected and fixed by simply sandwiching the two housing segments together so that one segment fits directly into the other segment.

Furthermore, the fuse of the present invention is characterized in that the reinforcing portion is provided on one of the housing segments, and the tip of the reinforcing portion is connected and fixed to the other housing segment.

Furthermore, the fuse of the present invention is characterized in that the reinforcing portion is spaced apart from the inner surface of the storage space.

According to the above characteristics, the reinforcing portion does not divide the storage space into left and right parts, and the storage space around the reinforcing portion is connected by a communicating space. Therefore, the arc-extinguishing material poured into one part of the storage space flows around the reinforcing portion and reaches the entire storage space, even though the reinforcing portion is present, so that the entire storage space is filled securely with no gaps.

As described above, the fuse of the present invention can effectively prevent the housing from expanding due to internal pressure.

FIG. 2 is an overall perspective view of one housing split piece of the fuse according to the present invention. 4A is a plan view of a housing split piece, and FIG. 4B is a front view of the housing split piece. 2A is a cross-sectional view taken along line A-A in FIG. 2A, and FIG. 2B is a cross-sectional view taken along line B-B in FIG. 11 is an overall perspective view of the other housing split piece of the fuse according to the present invention. FIG. 4A is a plan view of a housing split piece, and FIG. 4B is a front view of the housing split piece. 5A is a cross-sectional view taken along line CC of FIG. 5A, and FIG. 5B is a cross-sectional view taken along line DD of FIG. 5A. FIG. 2 is an exploded perspective view of the fuse according to the present invention. FIG. 2A is a plan view of the fuse in an assembled state, and FIG. 2B is a front view of the fuse in an assembled state. 8A is a cross-sectional view taken along line E-E of FIG. 8A, and FIG. 8B is a cross-sectional view taken along line F-F of FIG. 8A.

300 Housing 340 Storage space 350 Reinforcement portion 360 Reinforcement portion 400 Fuse element 410 Terminal portion 420 Melting portion 500 Fuse

Below, each embodiment of the present invention will be described with reference to the drawings. Note that the shapes and materials of each component of the fuse in the embodiments described below are merely examples and are not intended to be limiting.

FIGS. 1 to 3 show housing split pieces 100 constituting a housing 300 of a fuse according to the present invention. FIG. 1 is an overall perspective view of the housing split piece 100, FIG. 2(a) is a plan view of the housing split piece 100, FIG. 2(b) is a front view of the housing split piece 100, FIG. 3(a) is a cross-sectional view taken along line A-A in FIG. 2(a), and FIG. 3(b) is a cross-sectional view taken along line B-B in FIG. 2(a).

The housing split piece 100 is made entirely of synthetic resin and has a roughly rectangular parallelepiped shape, with an upper wall 110 forming the top surface, side walls 120 forming the sides, and front and rear walls 130 forming the front and rear surfaces, respectively. The housing split piece 100 also has a storage space 140 surrounded on all sides by the upper wall 110, the left and right walls 120, and the front and rear walls 130. The lower side of the storage space 140 forms an opening surface 141, which is arranged to face the opening surface 241 of the storage space 240 of the housing split piece 200, which will be described later. Furthermore, the ends of the

walls

120 and 130 are provided with mating protrusions 121 that protrude downward, and this mating protrusion 121 fits into a mating recess 222 of the housing split piece 200, which will be described later. The ends of the

walls

120 and 130 are provided with inwardly recessed mating recesses 122 into which mating protrusions 221 of the housing segments 200, described below, fit. The end of the wall 130 is also formed with a recessed insertion portion 131 so that a terminal portion 410 of the fuse element 400, described below, can be inserted therethrough.

Furthermore, the housing space 140 of the housing split piece 100 is provided with a central split section 150 and split sections 160 on both sides of the split section 150. The central split section 150 and the split sections 160 on both sides are connected and fixed to the central split section 250 and the split sections 260 on both sides of the housing split piece 200, which will be described later, respectively, to form a single reinforcing section. The base 151 of the split section 150 is fixed to approximately the center of the wall section 110 that constitutes the top surface, and the tip 152 hangs down linearly downward. The tip 152 is further provided with a mating protrusion 153 that is convex downward, and the mating protrusion 153 is configured to fit into the mating recess 253 of the housing split piece 200, which will be described later. Similarly, the base 161 of the split section 160 is fixed to the vicinity of the end of the wall section 110 that constitutes the top surface, and the tip 162 hangs down linearly downward. Furthermore, the tip 162 is provided with a downwardly protruding mating protrusion 163, which is configured to fit into a mating recess 263 of the housing split piece 200 described below. The split portion 160 is also connected and fixed to the inside of the wall portion 130. Furthermore, the base 151 of the split portion 150 and the base 161 of the split portion 160 are connected and fixed to each other by a base reinforcement body 159 that extends along the wall portion 110 that forms the top surface.

Next, Figs. 4 to 6 show the housing split pieces 200 constituting the housing 300 of the fuse according to the present invention. Fig. 4 is an overall perspective view of the housing split piece 200, Fig. 5(a) is a plan view of the housing split piece 200, Fig. 5(b) is a front view of the housing split piece 200, Fig. 6(a) is a cross-sectional view taken along line C-C in Fig. 5(a), and Fig. 6(b) is a cross-sectional view taken along line D-D in Fig. 5(a).

Housing split piece 200 is made entirely of synthetic resin and has a roughly rectangular parallelepiped shape, with a lower wall 210 forming the bottom, side walls 220 forming the sides, and front and rear walls 230 forming the front and rear, respectively. Housing split piece 200 also has a storage space 240 surrounded on all sides by lower wall 210, left and right walls 220, and front and rear walls 230. The upper side of storage space 240 is an opening surface 241, which is positioned opposite opening surface 141 of storage space 140 of housing split piece 100. Furthermore, the ends of wall 220 and wall 230 are provided with mating protrusions 221 that protrude upward, and this mating protrusion 221 fits into mating recess 122 of housing split piece 100. Additionally, the ends of the

walls

220 and 230 are provided with inwardly recessed mating recesses 222 into which the mating protrusions 121 of the housing segments 100 fit. Additionally, the end of the wall 230 is formed with a recessed insertion portion 231 so that the terminal portion 410 of the fuse element 400 described below can be inserted.

Furthermore, the housing split piece 200 has a central split part 250 and split parts 260 on both sides of the split part 250 in the storage space 240. The base part 251 of the split part 250 is fixed to approximately the center of the wall part 210 constituting the bottom surface, and the tip 252 protrudes linearly upward. The tip 252 has a downwardly concave mating recess 253 that is configured to fit with the mating protrusion 153 of the housing split piece 100. Similarly, the base part 261 of the split part 260 is fixed to the end of the wall part 210 constituting the bottom surface, and the tip 262 protrudes linearly upward. The tip 262 has a downwardly concave mating recess 263 that is configured to fit with the mating protrusion 163 of the housing split piece 100. The split part 260 is connected and fixed to the inside of the wall part 230. Furthermore, the base 251 of the division 250 and the base 261 of the division 260 are connected and fixed to each other by a base reinforcement 259 that extends along the wall 210 that constitutes the bottom surface.

Next, the manner in which the fuse 500 of the present invention is assembled will be described with reference to Figures 7 to 9. Note that Figure 7 is an exploded perspective view of the fuse 500, Figure 8(a) is a plan view of the fuse 500 in an assembled state, Figure 8(b) is a front view of the fuse 500 in an assembled state, Figure 9(a) is a cross-sectional view taken along line E-E in Figure 8(a), and Figure 9(b) is a cross-sectional view taken along line F-F in Figure 8(a).

First, as shown in FIG. 7, the fuse element 400 is formed into an elongated shape from a single thin metal plate, and includes a pair of terminal portions 410 and a flat, elongated circuit portion 430 between the terminal portions 410. The circuit portions 430 of the fuse element 400 are connected in parallel with each other, and each circuit portion 430 has a plurality of melting portions 420 formed therein. The melting portions 420 are formed with a plurality of small holes 421.

Note that the fuse element 400 has two circuit parts 430, but is not limited to this and may have one circuit part 430, or three or more circuit parts 430. Also, the fusing part 420 is formed by drilling a plurality of small holes 421, but is not limited to this and may be formed, for example, by locally thinning the thickness of the circuit part 430 to form the fusing part, or by depositing a low melting point metal such as tin, lead, silver, nickel, or an alloy of these into a narrow part of the circuit part 430 to form the fusing part.

Then, as shown in FIG. 7, when assembling the fuse 500, the housing split

pieces

100 and 200 are attached so as to sandwich the fuse element 400 from above and below, and the melting portion 420 of the fuse element 400 is housed inside the housing 300. Specifically, the fuse element 400 is placed on the opening surface 241 of the accommodation space 240 of the lower housing split piece 200, and the terminal portion 410 of the fuse element 400 is fitted into the insertion portion 231 of the housing split piece 200. The central split portion 250 and the split portions 260 on both sides are located in the gaps 440 between the circuit portions 430 of the fuse element 400.

Next, the housing split piece 100 is placed over the housing split piece 200 so that the opening surface 141 of the storage space 140 of the upper housing split piece 100 covers the fuse element 400, and the insertion portion 131 of the housing split piece 100 is fitted into the terminal portion 410 of the fuse element 400. The central split piece 150 and the split pieces 160 on both sides are located in the gap 440 between the circuit portion 430 of the fuse element 400, and the mating protrusion 153 of the upper split piece 150 fits into the mating recess 253 of the lower split piece 250, and are firmly fixed to each other. In particular, simply by assembling the upper housing split piece 100 and the lower housing split piece 200 so that they face each other and are sandwiched between them, the mating protrusion 153 of the upper split piece 150 fits directly into the mating recess 253 of the lower split piece 250, making it easy to connect and fix one split piece 150 to the other split piece 250.

Similarly, the mating protrusion 163 of the upper split portion 160 fits into the mating recess 263 of the lower split portion 260, and they are firmly fixed to each other. In addition, the mating protrusion 121 of the housing split piece 100 fits into the mating recess 222 of the housing split piece 200, and the mating protrusion 221 of the housing split piece 200 fits into the mating recess 122 of the housing split piece 100, so the fit between the housing split

pieces

100 and 200 becomes stronger.

Note that the mating protrusion 153 of the upper division 150 is fitted into the mating recess 253 of the lower division 250, but this is not limited thereto, and as long as the upper division 150 and the lower division 250 can be connected and fixed to each other, any method can be used, such as a method of connecting and fixing one division 150 and the other division 250 with adhesive, a method of connecting and fixing one division 150 and the other division 250 with a fastening member such as a screw, or a method of connecting and fixing one division 150 and the other division 250 with a locking member such as a hook. Similarly, the mating protrusion 163 of the upper division 160 is fitted into the mating recess 263 of the lower division 260, but this is not limited thereto, and as described above, any fixing method can be used.

In this way, the housing 300, which includes one housing split piece 100 and the other housing split piece 200, accommodates the fusing portion 420 of the fuse element 400 by sandwiching it from above and below, and the fuse 500 is assembled. Then, as shown in Figures 8 and 9, the accommodation space 340, which is composed of the upper and lower accommodation spaces (140, 240), accommodates the fusing portion 420 of the circuit section 430 of the fuse element 400 so as to surround the periphery of the fusing portion 420.

The storage space 340 is filled with granular arc-extinguishing material (not shown) in the same manner as in the past. For example, the arc-extinguishing material is poured into the storage space 340 through the filling hole 301 of the housing 300, and then the filling hole 301 is sealed. At this time, the reinforcing part 350, which is formed by connecting and fixing the split part 150 and the split part 250, is located approximately in the center of the storage space 340 and is separated from the inner surface 341 around the storage space 340, so that a communication space 342 is secured between the periphery of the reinforcing part 350 and the inner surface 341 of the storage space 340. In other words, the reinforcing part 350 does not divide the storage space 340 into left and right parts, and the storage space 340 around the reinforcing part 350 is communicated with the communication space 342. Therefore, even if the reinforcing portion 350 is present, the arc-extinguishing material poured into one part of the storage space 340 flows around the reinforcing portion 350 and reaches the entire storage space 340, filling the entire storage space 340 tightly and without any gaps.

The fuse 500 is mounted by connecting the terminal portion 410 protruding laterally from the housing 300 to an external electric circuit. When an unintended overcurrent flows through an electric circuit, the melting portion 420 of the fuse element 400 generates heat and melts, interrupting the overcurrent. In addition, the arc that is generated when the melting portion 420 melts is quickly extinguished by the surrounding arc-extinguishing material.

Here, in order to accommodate high voltages and large currents, the fuse 500 is provided with multiple fusing parts 420. Then, as shown in FIG. 9, the internal pressure P of the gas generated when the fusing parts 420 melt is increased, and a load is applied to the housing 300 to expand it. However, in the fuse 500 of the present invention, a reinforcing part 350 is provided that connects the walls of the housing 300, so that the housing 300 is strongly reinforced so that it does not expand and deform due to the internal pressure P. Similarly, in the fuse 500, the reinforcing part 360, which is formed by connecting and fixing the upper and

lower division parts

160 and 260, connects the walls, so that the housing 300 is strongly reinforced so that it does not expand and deform due to the internal pressure P.

8 and 9, the fuse 500 includes a reinforcing portion 350 located approximately in the center of the storage space 340 and a reinforcing portion 360 located on the side, but is not limited to this, and may include only one of the reinforcing portion 350 or the reinforcing portion 360. However, by providing the reinforcing portion 350 spaced apart from the inner surface 341 around the storage space 340, the weak portion of the storage space 340, that is, the portion away from the inner surface 341, can be reinforced by the reinforcing portion 350, so that the housing 300 can be more effectively prevented from expanding and deforming due to the internal pressure P. Also, the fuse 500 shown in FIG. 8 and 9 includes three reinforcing portions (350, 360), but is not limited to this, and may include any number of reinforcing portions, such as two, four or more. Furthermore, in the fuse 500 shown in Figures 8 and 9, the reinforcing parts (350, 360) connect the upper wall part 110 and the lower wall part 120, but this is not limited thereto, and each reinforcing part (350, 360) may connect any two walls of the housing 300. Furthermore, in the fuse 500 shown in Figures 8 and 9, the reinforcing parts (350, 360) are configured in a columnar shape that connects the walls, but this is not limited thereto, and the reinforcing parts may be configured in any shape, such as a wall shape that separates the storage space 340 of the housing 300 into both sides.

Furthermore, since the reinforcing portion 350 is provided so as to connect and cross one housing segment 100 and the other housing segment 200, it can effectively prevent the

housing segments

100 and 200 from expanding in a direction away from each other due to the internal pressure P. Although the housing 300 is composed of two separate parts (housing segment 100 and housing segment 200), this is not limited thereto, and the housing 300 may be composed of a single part that is molded as a whole, or the housing 300 may be composed of three or more separate parts.

Furthermore, the reinforcing portion 350 is configured by connecting and fixing two divided portions (150, 250), but is not limited to this, and the reinforcing portion 350 may be a single column body that crosses the storage space 340 and is molded as one piece. In this case, the single reinforcement portion 350 that is molded as one piece is provided on one housing split piece 100 of the housing 300, and the tip of the reinforcement portion 350 is connected and fixed to the other housing split piece 200 of the housing 300, so that the housing split piece 100 and the housing split piece 200 are firmly fixed. Similarly, the reinforcing portion 360 is configured by connecting and fixing two divided portions (160, 260), but is not limited to this, and the reinforcing portion 360 may be a single column body that crosses the storage space 340 and is molded as one piece. Furthermore, the reinforcing portion 350 that is molded as one piece is not limited to being molded as one housing split piece 100 of the housing 300, and the reinforcing portion 350 may be molded as a separate body from the housing 300. In this case, the reinforcing part 350 is fixed to the housing 300 so as to penetrate the storage space 340, thereby reinforcing the housing 300.

In addition, each divided section (150, 250) that constitutes the reinforcing section 350 is formed in each housing segment (100, 200), respectively, so that each divided section can be formed at the same time that each housing segment is formed using a conventional method for forming each housing segment (e.g., injection molding, etc.).

Also, as shown in Figures 8 and 9, each reinforcing portion (350, 360) is provided at a distance from the fusing portion 420 of the fuse element 400 so as not to come into contact with the fusing portion 420. Therefore, each reinforcing portion (350, 360) does not have a thermal or physical effect on the fusing portion 420, and the fusing characteristics of the fusing portion 420 are stable.

9, the reinforcing portion 350 extends perpendicular to the extension direction of the fuse element 400, i.e., the direction parallel to the axis X connecting the terminal portions 410 on both sides. Therefore, the reinforcing portion 350 is less susceptible to the internal pressure P and thermal effects generated from the melting portion 420, and the reinforcing portion 350 maintains its designed strength and can more effectively prevent the housing 300 from expanding and deforming due to the internal pressure P. Note that the reinforcing portion 350 extends perpendicular to the extension direction of the fuse element 400, i.e., the direction parallel to the axis X connecting the terminal portions 410 on both sides, but is not limited to this and may extend so as to be inclined at any angle with respect to the axis X. Compared to the case where the reinforcing portion 350 extends in a direction parallel to the axis X, the reinforcing portion 350 inclined at any angle with respect to the axis X is less susceptible to the internal pressure P and thermal effects generated from the melting portion 420.

The fuse of the present invention is not limited to the above examples, and various modifications and combinations are possible within the scope of the claims and the scope of the embodiments, and these modifications and combinations are also included in the scope of the rights.

Claims

A fuse comprising a fuse element having a melting portion provided between a pair of terminal portions, and a housing for accommodating the fuse element,
The housing includes a wall.
The fuse is characterized in that the housing is provided with at least one reinforcing portion connecting the wall portions.
The housing includes one housing segment and another housing segment,
2. The fuse according to claim 1, wherein the reinforcing portion is provided across the housing split pieces on both sides.
The reinforcing portion includes one divided portion and another divided portion,
the one divided portion is provided on the one housing divided piece,
the other divided portion is provided on the other housing divided piece,
3. The fuse according to claim 2, wherein the one split portion and the other split portion are configured to be connectable and fixed to each other.
4. The fuse according to claim 3, wherein a tip of the one split portion and a tip of the other split portion are connected and fixed by fitting together.
The reinforcing portion is provided on the one of the housing segments,
3. The fuse according to claim 2, wherein a tip of the reinforcing portion is connected and fixed to the other housing divided piece.
The fuse described in any one of claims 1 to 5, characterized in that the reinforcing portion is spaced apart from the inner surface of the storage space.