The present invention provides a fuse that has a stable fusing characteristic and is easily manufactured.A fuse 600 includes: a fuse element 100 that is provided between a pair of terminal parts 110 and has a plurality of fuse parts 120; and a casing 200 for housing the fuse parts 120, wherein the fuse element 100 includes a first flat surface 140 and a second flat surface 150 which are shaped bent along a longitudinal direction P of the fuse element 100 and which extend in a linear manner along the longitudinal direction P, wherein the first flat surface 140 and the second flat surface 150 are provided with the plurality of fuse parts 120, and wherein the first flat surface 140 and the second flat surface 150 are contiguous to one other via a bent section 131.

TECHNICAL FIELD

The present invention mainly relates to a fuse which is used in an electric circuit for an automobile or an electric circuit of an infrastructure or the like, and particularly relates to a fuse that houses a fuse element in a casing.

BACKGROUND ART

Conventionally, a fuse has been used to protect an electric circuit which is installed in an automobile, an infrastructure or the like and various electrical components which are connected to the electric circuit. More precisely, when an unintended overcurrent flows in an electric circuit, a fuse part of a fuse element built into the fuse melts under the heat generated by the overcurrent, thereby protecting the various electrical components by preventing excess current from flowing.

Further, various types of such fuses exist depending on the application, and the fuse disclosed in Patent Literature 1 for protection from comparatively large overcurrent has been known, for example.

The fuse disclosed in Patent Literature 1 is of the type that houses a fuse element inside a cylindrical casing and includes a fuse element which has a pair of terminal parts and a fuse part provided between the terminal parts. The fuse element is bent in a direction in which the overall length of the fuse element contracts and has a wave-like shape in a side elevation.

However, when the fuse element has a wave-like shape, the distance between the fuse parts provided in a plurality to the fuse element is then short, and there has been the problem that fuse parts which are close to one another exert an electrical or thermal effect on one another and degradation of the fusing characteristic occurs. In addition, because the fuse element is bent like a wave, deformation of the fuse element readily occurs due to an external force or the like which acts when the fuse is being manufactured. Hence, there has been the problem that the position and orientation of the fuse element in the casing are difficult to stabilize and that the fusing characteristic is reduced.

CITATIONS LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problems

Therefore, the present invention provides a fuse that has a stable fusing characteristic and is easily manufactured.

Solutions to Problems

In order to solve the foregoing problem, a fuse of the present invention is a fuse including: a fuse element that is provided between a pair of terminal parts and has a plurality of fuse parts; and a casing for housing the fuse parts, wherein the fuse element includes a first flat surface and a second flat surface which are shaped bent along a longitudinal direction of the fuse element and which extend in a linear manner along the longitudinal direction, wherein the first flat surface and the second flat surface are provided with the plurality of fuse parts, and wherein the first flat surface and the second flat surface are contiguous to one another via a bent section of the fuse element.

According to the foregoing feature, because the plurality of fuse parts provided to the first and second flat surfaces are arranged in a linear manner, adjacent fuse parts are not close to one another, thereby preventing fuse parts from exerting an electrical or thermal effect on one another and degradation of the fusing characteristic. In addition, the first flat surface and second flat surface, which extend in a linear manner along the longitudinal direction, are contiguous to each another via a bent section along the longitudinal direction of the fuse element, and hence the first flat surface and second flat surface are shaped so as to be bent substantially in an L shape, thereby enhancing rigidity. As a result, deformation of the fuse element due to an external force or the like which acts when the fuse is being manufactured can be prevented, and the fuse can be easily manufactured. Furthermore, by enhancing the rigidity of the fuse element, the position and orientation of the fuse element in the casing are stabilized and hence the fusing characteristic is also stable.

Further, according to the fuse of the present invention, the fuse element is shaped bent toward the center of the casing.

According to the foregoing feature, the fuse parts are disposed further toward the center of the casing than the inner wall of the casing, and it is thus difficult for an arc generated by a fuse part to reach the inner wall of the casing; as a result, damage to the casing can be prevented. In addition, because the fuse parts are arranged near the center of the casing, the arc generated by the fuse part can be extinguished effectively by an arc-extinguishing material.

Furthermore, according to the fuse of the present invention, the fuse parts are provided to each of the first flat surface and the second flat surface such that the bent section is sandwiched between the fuse parts.

According to the foregoing feature, the fuse parts, which are provided to each of the first and second flat surfaces such that the bent section is sandwiched between the fuse parts, may be close to the center of the casing. As a result, an arc generated by a fuse part can be extinguished effectively by an arc-extinguishing material.

Furthermore, according to the fuse of the present invention, the fuse element is constituted from a flat metal plate, and the first flat surface and the second flat surface are formed by being bent along the longitudinal direction of the fuse element.

According to the foregoing feature, the first flat surface and the second flat surface, which are molded bent from a metal plate, have enhanced rigidity and are easy to manufacture.

Advantageous Effects of Invention

As mentioned earlier, the fuse of the present invention has a stable fusing characteristic and is easy to manufacture.

REFERENCE SIGNS LIST

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described hereinbelow using the drawings. Note that the shape and material properties and the like of each member of a fuse according to the embodiments described hereinbelow are illustrative examples and the present invention is not limited to or by such shapes and material properties and the like. Note that the “longitudinal direction of the fuse element” disclosed in this specification is a direction parallel to an axis linking the terminal parts at both ends of the fuse element. Furthermore, “up-down direction” denotes a direction perpendicular to the longitudinal direction of the fuse element.

First Embodiment

FIG.1illustrates the process of manufacturing a fuse element100of a fuse according to a first embodiment of the present invention. Note thatFIG.1(a)is a plan view of a state where the fuse element100is expanded;FIG.1(b)is a plan view of a state where the fuse element100is molded bent;FIG.1(c)is a front elevation of the fuse element100in said state;FIG.1(d)is a side elevation of the fuse element100of said state; andFIG.2is an overall perspective view of the fuse element100.

First, a flat plate of uniform thickness formed from a conductive metal such as copper or a copper alloy is stamped using a press machine or the like into the shape illustrated inFIG.1(a). A metal plate made in a predetermined shape as illustrated inFIG.1(a)are formed with a terminal part110at both ends, a flat middle section130between the terminal parts110, and a plurality of fuse parts120. Describing same in specific terms, the fuse part120is constituted from a fuse part120a, a fuse part120b, a fuse part120c, and a fuse part120dwhich form a line with a locally narrower width in the middle section130, and when an unintended overcurrent flows in an electric circuit or the like, the fuse parts (120ato120d) each melt under heat generation so as to interrupt the overcurrent. Note that the fuse parts120are not limited to being constituted from fuse parts (120ato120d) in the form of a line of narrow width, rather, as long as the fuse parts melt under heat generation so as to interrupt the overcurrent when an unintended overcurrent flows in an electric circuit or the like, the configuration may be such that small holes are provided in the middle section130and the fuse parts120are sections of narrow width, or any configuration may be adopted such as a configuration in which a metallic material that readily melts is disposed locally in the middle section130.

Next, as illustrated inFIGS.1(b) to1(d)andFIG.2, the middle section130is bent at a fold line L1which is parallel to the longitudinal direction P of the fuse element100. Note that the longitudinal direction P of the fuse element100is a direction parallel to an axis linking the terminal parts110at both ends. Hence, the fold line L1is also parallel to the axis linking the terminal parts110at both ends.

Thus, the middle section130includes a first flat surface140which extends in a linear manner along the longitudinal direction P; and a second flat surface150which bends so as to rise from the first flat surface140and extends in a linear manner along the longitudinal direction P. The first flat surface140and the second flat surface150are contiguous to one other via a bent section131which is bent at the fold line L1, and the first flat surface140and the second flat surface150intersect substantially at right angles to one another. A state thus results where a plurality of fuse parts120are provided on the first flat surface140and the second flat surface150. More specifically, the fuse part120ais provided on the second flat surface150, and the fuse part120b, the fuse part120c, and the fuse part120dare provided on the first flat surface140.

In addition, the point where the terminal part110is coupled to the middle section130is bent in a direction orthogonal to the longitudinal direction P at fold lines L2and L3. Thus, a step part111which is bent in a direction orthogonal to the longitudinal direction P is formed between the first flat surface140and the terminal part110. The step part111is constituted so that, when the first flat surface140is stretched along the longitudinal direction P due to heat generation during conduction of an overcurrent, stress caused by the stretching can be absorbed by the step part deforming such that the flexion angle at fold lines L2and L3changes. Furthermore, the whole fuse element100, that is, the terminal part110, the first flat surface140, and the second flat surface150are integrally molded from a flat metal plate.

Moreover, as illustrated inFIG.1(d), the first flat surface140and second flat surface150are arranged displaced laterally from the center of the fuse element100. In other words, the first flat surface140and second flat surface150are arranged displaced closer to a side end112than the center of the terminal part110. In addition, the first flat surface140and second flat surface150are arranged displaced above the terminal part110due to the step part1l1. Hence, as described subsequently, when a plurality of fuse elements100are housed in a casing200, the first flat surface140and second flat surface150of each of the fuse elements100can be prevented from interfering with each other.

Next, a method for assembling a fuse600of the present invention will be described with reference toFIGS.3and4. Note thatFIGS.3(a) and3(b)are overall perspective views of a state where a plurality of fuse elements100are combined;FIG.4(a)is an overall perspective view in which the respective members constituting the fuse600are illustrated in an exploded view; andFIG.4(b)is an overall perspective view of the finished fuse600.

As illustrated inFIG.3(a), four fuse elements100are first prepared and overlapped with orientations which are obtained by inverting the fuse elements100vertically and horizontally. Here, in order to discriminate between each of the fuse elements100, same are denoted, starting from the top, as a fuse element100a, a fuse element100b, a fuse element100c, and a fuse element100d.

Further, the fuse element100bis oriented so as to be horizontally inverted relative to the fuse element100a. In other words, the orientation of the fuse element100bis obtained by rotating the fuse element100athrough 180 degrees in a horizontal plane such that one terminal part100aof the fuse element100ain the drawing foreground is positioned on the other terminal part110ain the drawing background. Further, the terminal part110bof a fuse element100bis disposed stacked below the terminal part110aof the fuse element100a.

Next, the fuse element100cis oriented so as to be vertically inverted relative to the fuse element100a. In other words, the orientation of the fuse element100cis obtained by rotating the fuse element100athrough 180 degrees about an axis P1along the longitudinal direction thereof. Further, the terminal part110cof the fuse element100cis disposed stacked below the terminal part110bof the fuse element100b.

Further, the fuse element100dis oriented so as to be horizontally inverted relative to the fuse element100c. In other words, the orientation of the fuse element100dis obtained by rotating the fuse element100cthrough 180 degrees in a horizontal plane such that one terminal part110cof the fuse element100cin the drawing foreground is positioned on the other terminal part110cin the drawing background. Further, the terminal part110dof a fuse element100dis disposed stacked below the terminal part110cof the fuse element100c. Thus, as illustrated inFIG.3(b), the first flat surfaces (140ato140d) and the second flat surfaces (150ato150d) of the respective fuse elements (100ato100d) are arranged compactly without interfering with one another.

Next, as illustrated inFIG.4(a), the respective fuse elements100in a stacked state are inserted into the casing200via openings220at ends210thereof. The casing200has a cylindrical shape which is formed from ceramic or a synthetic resin or the like, and includes the openings220in the ends210on both sides. Further, the casing200has a length that enables the first flat surface140and second flat surface150of the fuse element100to be housed therein, and the terminal parts110of the fuse element100are in a state of protruding from the openings220on both sides of the casing200.

Next, the holding piece310and holding piece320, which are made of metal, are attached to the terminal parts110protruding from the openings220of the casing200so as to pinch the terminal parts110from above and below. The holding piece310includes a gripping piece311of the same shape as the terminal part110and a locking part312which is provided so as to rise from the gripping piece311. Further, the gripping piece311is fixed to the terminal part110through screwing, welding or the like. Similarly, the holding piece320includes a gripping part321of the same size as the terminal part110and a locking part322which is provided so as to rise from the gripping part321. Further, the gripping part321is fixed to the terminal part110through screwing, welding or the like. In addition, because the widths of the locking parts312and322are longer than the width of the openings220of the casing200, the locking parts312and322lock onto an edge211around the openings220. Therefore, the locking part312of the holding piece310and the locking part322of the holding piece320which are fixed to the terminal part110on both sides of the fuse element100lock onto the edge211on both sides of the casing200, and hence the fuse elements100do not fall out from inside the casing200and are in a state of being held inside the casing200.

Next, lid plates400made of metal or a synthetic resin are attached so as to cover the openings220of the casing200. The lid plates400have a disc shape which is larger than the openings220to enable the openings220to be covered, and include a long hole410enabling insertion of the terminal parts110. Furthermore, the lid plates400also include a hole420to enable granular arc-extinguishing material, described subsequently, to flow into the openings220. Further, after the lid plates400have been attached to cover the openings220of the casing200, caps500made of metal or a synthetic resin are attached so as to cover the ends210of the casing200. The caps500have a cylindrical shape which is larger than the ends210to enable fitting to the outside of the ends210, and include along hole510enabling insertion of the terminal parts110and a hole520that overlaps the hole420.

When the caps500are attached so as to cover the ends210of the casing200, a fuse600is finished as illustrated inFIG.4(b). Note that the holes520of the fuse600are closed after the arc-extinguishing material has flowed via the holes520into the casing200, thereby encapsulating the arc-extinguishing material inside the casing200. Further, the fuse600is used such that, when a portion of the electric circuit is electrically connected to the terminal parts110protruding from the caps500and an unintended overcurrent flows in the electric circuit, the fuse parts120of the fuse element100melt and interrupt the overcurrent, thereby protecting the electric circuit.

Thus, the fuse600of the present invention includes a first flat surface140and a second flat surface150which extend in a linear manner along the longitudinal direction, and a plurality of fuse parts120provided on the first flat surface140and second flat surface150are arranged in a linear manner, as illustrated inFIG.1. Hence, adjacent fuse parts120are not close to one another, thereby preventing fuse parts from exerting an electrical or thermal effect on one another and degradation of the fusing characteristic.

In addition, the first flat surface140and second flat surface150which extend in a linear manner along the longitudinal direction are contiguous to one another in the sections thereof which are bent along the longitudinal direction of the fuse element100. Therefore, the first flat surface140and second flat surface150of the fuse element100are shaped so as to be bent substantially in an L shape, thereby enhancing rigidity. In particular, because the first flat surface140and second flat surface150extend in a linear manner along the longitudinal direction, there is the problem that same readily bend individually and have low rigidity, but said problem is solved when the first flat surface140and second flat surface150are contiguous to one another via the bent section131of the fuse element100and are substantially L-shaped. Therefore, when the rigidity of the fuse element100is high, the fuse element100can be prevented from deforming due to an external force or the like which acts when the fuse600is being manufactured, thereby facilitating manufacturing of the fuse600. Furthermore, by enhancing the rigidity of the fuse element100, the position and orientation of the fuse element100in the casing200are stabilized and hence the fusing characteristic is also stable.

Note that the fuse element100of the fuse600of the present invention may have a bent shape toward the center O of the casing200as described subsequently with reference toFIG.5, that is, the fuse element100may have a shape in which the bent section131is disposed toward the center O of the casing200, but is not limited thereto and may have a shape bent toward an inner wall201of the casing200, that is, the fuse element100may have a shape in which the bent section131is disposed toward the inner wall201of the casing200. In this case also, because the first flat surface140and second flat surface150of the fuse element100are shaped so as to be bent substantially in an L shape, rigidity is enhanced, and the fuse element100can be prevented from deforming due to an external force or the like which acts when the fuse600is being manufactured, thereby facilitating manufacturing of the fuse600. In addition, the position and orientation of the fuse element100in the casing200are stabilized, and the fusing characteristic is also stable.

Furthermore, as illustrated inFIG.1, the fuse element100of the fuse600of the present invention is constituted from a flat metal plate, and the first and second flat surfaces are formed by being bent along the longitudinal direction P of the fuse element100. Hence, the rigidity of the first flat surface140and second flat surface150, which are molded bent from the metal plate, is enhanced and manufacture thereof is also straightforward.

Note that, although the fuse element100of the fuse600of the present invention is constituted from a flat metal plate inFIG.1, same is not limited to this configuration, rather, the whole fuse element100may also be manufactured by preparing the integrally molded first flat surface140and second flat surface150and coupling the terminal part110, which is separate from the first flat surface140and second flat surface150, to the first flat surface140through welding or the like. The whole fuse element100may also be manufactured by individually manufacturing all of the terminal part110, first flat surface140, and second flat surface150and then coupling the same to one another through welding or the like. In a case where the first flat surface140and second flat surface150are manufactured individually, the first flat surface140and second flat surface150are subsequently coupled substantially at right angles to one another through welding or the like, the coupling point thereof being the bent section131of the fuse element100.

Furthermore, as illustrated inFIG.3, although four fuse elements100are housed in the casing200in the case of the fuse600of the present invention, the same is not limited to such a configuration, rather, only one fuse element100may be housed in the casing200or any number of two or more fuse elements100may be housed therein.

Next, the internal structure of the fuse600of the present invention will be described with reference toFIG.5. Note thatFIG.5is a cross-sectional view along A-A inFIG.4(b).

As illustrated inFIG.5, the four fuse elements100housed in the casing200of the fuse600are each arranged around the center O of the casing200. Furthermore, the bent section131of the fuse elements100is disposed toward the center O of the casing200. That is, the fuse elements100are shaped bent toward the center O of the casing200. Hence, the fuse parts120provided to the first flat surface140and second flat surface150are arranged closer to the center O of the casing200than the inner wall201of the casing200.

Here, assuming a case where the fuse elements100are not bent and the first flat surface140and second flat surface150are contiguous in a linear manner,FIG.5illustrates, using an imaginary line, a fuse element100′ in which a first flat surface140′ and a second flat surface150′ are contiguous in a linear manner. A fuse part120′ is provided to the first flat surface140′ and second flat surface150′ of the fuse element100′, the fuse part120′ being adjacent to the inner wall201of the casing200. Further, although the fuse part120′ of the fuse element100′ melts and interrupts the overcurrent when an unintended overcurrent flows in an electric circuit or the like, an arc may be generated subsequently in the vicinity of the melted fuse part120′. Nevertheless, the fuse part120′ is close to the inner wall201of the casing200, and hence an arc which is generated by the fuse part120′ easily reaches the inner wall201of the casing200and, as a result, there is a risk of damage to the casing200.

Therefore, w % ben the fuse element100of the fuse600of the present invention is shaped bent toward the center O of the casing200, the fuse part120is then disposed closer to the center O of the casing200than the inner wall201of the casing200. Thus, the distance d2between the fuse part120and the inner wall201can be secured so as to be larger than the distance d1between the fuse part120′ and the inner wall201, and an arc generated by the fuse part120reaches the inner wall201of the casing200and, as a result, damage to the casing200can be prevented.

Furthermore, although a granular arc-extinguishing material X is packed inside the casing200, generally speaking, the arc-extinguishing material X collects readily with increasing proximity to the center O of the casing200, and density tends to increase. That is, there is a tendency for the arc-extinguishing performance of the arc-extinguishing material X to increase with increasing proximity to the center O of the casing200. Therefore, when the fuse element100of the fuse600of the present invention is shaped bent toward the center O of the casing200, the fuse parts120are then arranged near the center O of the casing200and an arc generated by a fuse part120can be effectively extinguished by the arc-extinguishing material X. Note that the arc-extinguishing material X is not limited to granular form and that arc-extinguishing material in any form can be used.

In addition, the fuse parts120of the fuse element100are provided to each of the first flat surface140and second flat surface150such that the bent section131is sandwiched between the fuse parts. More specifically, as illustrated inFIGS.1and2, the fuse part120ais provided to the second flat surface150and the fuse parts120b,120c, and120dare each provided to the first flat surface140such that the bent section131is sandwiched between the fuse parts. In addition, the bent section131of the fuse element100is disposed toward the center O of the casing200and hence the fuse parts120, which are provided to each of the first flat surface140and second flat surface150such that the bent section131is sandwiched between the fuse parts, can approach the center O of the casing200. As a result, an arc generated by a fuse part120can be extinguished effectively by the arc-extinguishing material X.

Note that, as illustrated inFIG.1(d), the first flat surface140and second flat surface150are arranged displaced laterally from the center of the fuse element100, and the first flat surface140and second flat surface150are arranged displaced above the terminal part110due to the step part111. Hence, each of the fuse elements100which have vertically and horizontally inverted orientations as illustrated inFIG.5do not interfere with each other and can be housed in alignment around the center O in the casing200.

Second Embodiment

A fuse600A according to a second embodiment of the present invention will be described hereinbelow with reference toFIGS.6to8. Note that the specific configuration of the fuse600A is common to the fuse600according to the first embodiment, and hence a detailed description of the common configuration is omitted.

First,FIG.6illustrates the process of manufacturing a fuse element100A of a fuse600A according to a second embodiment of the present invention. Note thatFIG.6(a)is a perspective view of a state where a fuse element100A is expanded;FIG.6(b)is a perspective view of a state in which the fuse element100A is molded bent; andFIG.6(c)is an overall perspective view of a casing200A for housing the fuse element100A.

First, a flat plate of uniform thickness formed from a conductive metal such as copper or a copper alloy is stamped using a press machine or the like into the shape illustrated inFIG.6(a). A metal plate which is afforded a predetermined shape as illustrated inFIG.6(a)include a terminal part110A at both ends, a flat middle section130A between the terminal parts110A, and a plurality of fuse parts120A.

Next, as illustrated inFIG.6(b), the middle section130A is bent at a fold line L4along the longitudinal direction P of the fuse element100A. Thus, the middle section130A includes a first flat surface140A which extends along the longitudinal direction P and a second flat surface150A which is bent so as to rise from the first flat surface140A. The first flat surface140A and the second flat surface150A are contiguous to one other via a bent section131A which is bent at the fold line L4, and the first flat surface140A and the second flat surface150A intersect substantially at right angles to one other. A state thus results where a plurality of fuse parts120A are provided on the first flat surface140A and the second flat surface150A. Note that, in the case of the fuse element100according to the first embodiment illustrated inFIG.1, the widths of the first flat surface140and the second flat surface150are substantially the same. However, the present invention is not limited to this configuration, the width d4of the second flat surface150A may be larger than the width d3of the first flat surface140A as illustrated inFIGS.6(a) and6(b).

Furthermore, because the middle section130A of the fuse element100A is constituted from a metal plate, the width d3of the first flat surface140A and the width d4of the second flat surface150A can be optionally changed as long as the bending point is changed by displacing the position of the fold line L4. In particular, when a change in the width d3of the first flat surface140A and the width d4of the second flat surface150A is desired in consideration of the balance of the fuse element100A in the casing200A, the shape is easily changed because the bending point can be changed by suitably displacing the position of the fold line L4.

Next, in order to house the fuse element100A in the casing200A illustrated inFIG.6(c), one terminal part110A of the fuse element100A is bent substantially at right angles at a fold line L6. At this stage, the other terminal part110A (in the drawing background) of the fuse element100is not bent substantially at right angles at a fold line L7. Note that the casing200A has a cylindrical shape formed from ceramic or a synthetic resin, or the like, and includes an opening220A in an end210A on both sides. Further, an inner cap230A, which is formed from a synthetic resin or the like, is attached to the end210A so as to cover the opening220A. A cross-shaped hole240A is formed in the inner cap230A. A step part242A is formed in a first hole241A arranged in a linear manner. Furthermore, a second hole243A is formed so as to intersect the first hole241A at right angles.

Next, a method for housing the fuse element100A inside the casing200A will be described with reference toFIGS.7and8. Note thatFIGS.7(a) and7(b)are overall perspective views of the casing200A;FIGS.8(a) and8(b)are perspective views in which the region close to the end of the casing200A is enlarged; andFIG.8(c)is an overall perspective view of a finished fuse600A.

First, as illustrated inFIG.7(a), the fuse element100A is housed by being inserted inside the casing200A via the cross-shaped hole240A (in the drawing foreground) of one inner cap230A. More specifically, the other terminal part110A (in the drawing background) of the fuse element100A is inserted via the cross-shaped hole240A (in the drawing foreground) of the one inner cap230A, and the fuse element100A is inserted inside the casing200A so that the first flat surface140A of the fuse element100A is made to pass through the first hole241A and the second flat surface150A of the fuse element100A is made to pass through the second hole243A. Further, the terminal part110A is made to engage with the step part242A of the first hole241A, and a point of contact between the inner cap230A and the terminal part110A is fixed through welding or the like.

Using the same method, the other three fuse elements100A are also inserted into the casing200A via the cross-shaped hole240A and the terminal part110A is made to engage with the step part242A of the first hole241A. Further, as illustrated inFIG.7(b), the point of contact between the inner cap230A and each terminal part110A is fixed through welding or the like.

The other terminal part110A (in the drawing background) of the fuse element100A is in a state of not yet being bent and hence, as illustrated inFIG.8, each terminal part110A can be inserted firmly as far as the cross-shaped hole240A of the other inner cap230A. Note that, inFIGS.8(a) and8(b), the other terminal part110A (in the drawing background) illustrated inFIG.7is displayed in the foreground. Each terminal part110A is then bent at right angles at fold line L7, made to engage with the step part242A of the cross-shaped hole240A, and the point of contact between the inner cap230A and the terminal parts110A is fixed through welding or the like.

An outer cap250is attached by being press-fitted from above one inner cap230A, thereby closing one cross-shaped hole240A, and a granular arc-extinguishing material flows into the casing200A via the cross-shaped hole240A of the other inner cap230A. Further, once the interior of the casing200A has been filled with arc-extinguishing material, if an outer cap250A is press-fitted from above the other inner cap230A, thereby closing the other cross-shaped hole240A, the fuse600A is finished. The outer cap250A includes an outer terminal part252made of metal for connecting to an electric circuit, and a disc-like base part252A made of metal which is coupled to the outer terminal part252, and the back face of the base part252A makes contact with the terminal part110A so as to be electrically connected thereto. Hence, the fuse600A is used such that, when an unintended overcurrent flows in an electric circuit or the like which is connected to the outer terminal part252, the fuse part120A of the fuse element100A melts and interrupts the overcurrent, thereby protecting the electric circuit.

Note that, according to the configurations of the fuse600illustrated inFIGS.7and8, because the cross-shaped hole240A through which arc-extinguishing material flows into the casing200A is completely closed by the outer cap250A, leakage of arc-extinguishing material from the casing200A can be effectively prevented.

Note that the fuse of the present invention is not limited to the foregoing embodiment examples, rather, various modification examples and combinations are possible within the scope of the patent claims and the scope of the embodiment, and such modification examples and combinations are also included in the scope of rights thereof.