Fuse

Abstract

To provide a fuse in which a housing is hardly damaged when the fuse is attached.SOLUTION: A fuse 900 includes a fuse element 100 and a housing 500 that houses a fuse portion 120 of the fuse element 100, wherein a mounting protrusion 400 of the housing 500 is inserted into a mounting hole 130 of the fuse element 100 to couple the fuse element 100 and the housing 500, the mounting protrusion 400 includes a base end portion 410 and a leading end portion 420, and a cross-sectional area S1 of the base end portion 410 is larger than a cross-sectional area S2 of the leading end portion 420.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a fuse that is used primarily in automotive electrical circuits. [Background technology]

[0002] Fuses have traditionally been used to protect electrical circuits in automobiles and other vehicles, as well as various electrical components connected to the electrical circuits. Specifically, when an unintended overcurrent flows through an electrical circuit, the fuse generates heat due to the overcurrent and melts, protecting the electrical components from excessive current.

[0003] There are various types of fuses depending on the application. For example, the fuse disclosed in Patent Document 1 includes a fuse element and a housing that houses the fusing portion of the fuse element. When the fuse is connected to an electrical circuit or the like that needs to be protected, a fixing member such as a bolt is attached to a part of the fuse element (e.g., a terminal portion of the fuse element) to electrically connect the fuse element. However, when attaching the fixing member to a part of the fuse element, an external force is applied to the fuse element. If a strong external force is applied carelessly, stress may concentrate at the connection point between the fuse element and the housing, potentially damaging the housing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2017-10823 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0005] In view of the above problems, the present invention provides a fuse whose housing is less likely to be damaged when the fuse is installed. [Means for solving the problem]

[0006] The fuse of the present invention is a fuse comprising a housing that accommodates the melting portion of the fuse element, wherein the fuse element and the housing are connected by inserting a mounting protrusion of the housing into a mounting hole of the fuse element, and the mounting protrusion has a base end and a tip end, and the cross-sectional area of ​​the base end is larger than the cross-sectional area of ​​the tip end.

[0007] The above features improve and optimize the strength of the mounting protrusion, increasing the strength of the area where the mounting protrusion connects to the mounting hole, thereby preventing damage to the housing when fastening members such as bolts to secure the fuse.

[0008] The fuse of the present invention is characterized in that the mounting hole has an elongated hole shape.

[0009] According to the above feature, since the mounting hole is elongated, the area of ​​the connection point between the mounting protrusion and the mounting hole is increased compared to when the mounting hole is a simple circular hole, and the strength of the connection point is increased.

[0010] The fuse of the present invention is characterized in that the mounting hole extends in the longitudinal direction of the fuse element.

[0011] According to the above feature, the mounting hole is unlikely to obstruct the flow of current along the longitudinal direction of the fuse element, and is unlikely to affect the electrical characteristics of the fuse element. [Effects of the Invention]

[0012] As described above, according to the fuse of the present invention, the housing is less likely to be damaged when the fuse is installed. [Brief explanation of the drawings]

[0013] [Figure 1]FIG. 1( a ) is an overall perspective view of a fuse element 100 , and FIG. 1( b ) is a plan view of the fuse element 100 . [Figure 2] 2(a) is a perspective view of the outside of the housing split piece 200, and FIG. 2(b) is a plan view of the outside of the housing split piece 200. FIG. [Figure 3] 3(a) is a perspective view of the inside of the housing split piece 200, and FIG. 3(b) is a plan view of the inside of the housing split piece 200. As shown in FIG. [Figure 4] 4(a) is a perspective view of the inside of the housing split piece 300, and FIG. 4(b) is a plan view of the inside of the housing split piece 300. As shown in FIG. [Figure 5] 5(a) is a side view of the housing split piece 300, FIG. 5(b) is a cross-sectional view taken along line AA, and FIG. 5(c) is a cross-sectional view taken along line BB. [Figure 6] FIG. 6(a) is a perspective view of the cover member 600, and FIG. 6(b) is a plan view of the cover member 600. As shown in FIG. [Figure 7] Figure 7(a) is an oblique view of the state in which the cover member 600 is attached to the housing segment 300, and Figure 7(b) is an oblique view of the state in which the fuse element 100 is attached to the housing segment 300, and the cover member 600 and the housing segment 200 are attached. [Figure 8] 8(a) is a perspective view of the assembled fuse 900, FIG. 8(b) is a plan view of the fuse 900, and FIG. 8(c) is a front view of the fuse 900. FIG. [Figure 9] 9(a) is a cross-sectional view taken along CC in FIG. 8(b), FIG. 9(b) is an enlarged cross-sectional view of the periphery of the viewing window 240 in FIG. 9(a), and FIG. 9(c) is a cross-sectional view taken along DD in FIG. 8(b). [Explanation of symbols]

[0014] 100 fuse elements 120 fused part 130 Mounting hole 400 Mounting protrusion 240 Viewing window 500 Housing 600 Cover member 610 Main body 613 Protrusion 620 Legs 900 fuse X1 Ventilation space DETAILED DESCRIPTION OF THE INVENTION

[0015] The following describes embodiments of the present invention with reference to the drawings. Note that the shapes and materials of the components of the fuse in the embodiments described below are merely examples and are not intended to limit the scope of the present invention.

[0016] 1 shows a fuse element 100 of a fuse 900 according to the present invention. FIG. 1(a) is an overall perspective view of the fuse element 100, and FIG. 1(b) is a plan view of the fuse element 100.

[0017] As shown in FIG. 1 , fuse element 100 includes terminal portions 110 that can be electrically connected to an external electric circuit, and fusing portions 120 located between terminal portions 110 on both sides. Fuse element 100 is integrally formed by punching a flat, uniform-thickness plate made of a conductive metal such as copper or its alloy into the shape shown in FIG. 1 using a press or other machine. Fusing portion 120 is formed by bending elongated linear body 121, which is narrower than fuse element 100 and has a Z-shape, and is provided with welded portion 122 made of a low-melting-point metal such as tin, silver, lead, nickel, or an alloy thereof. When an unintended overcurrent flows through an electric circuit or the like, fusing portion 120 generates heat and melts, interrupting the overcurrent. Furthermore, when an overcurrent flows, the molten welded portion 122 bonds with the linear body 121, lowering the melting point of the linear body 121 and allowing the linear body 121 to melt more quickly and effectively. Note that the fusing portion 120 is configured to generate heat and melt to cut off the overcurrent when the narrowed linear body 121 causes an unintended overcurrent to flow in an electric circuit or the like, but is not limited to this, and any configuration can be adopted, such as providing a small hole in part of the fusing portion 120 to melt the narrowed portion, as long as it can generate heat, melt, and cut off the overcurrent when an unintended overcurrent flows in an electric circuit or the like.

[0018] The terminal portion 110 is provided with a connection hole 111 for connection to an electric circuit or the like. The terminal portion 110 is also provided with a mounting hole 130 for inserting and fixing a mounting protrusion of a housing 500 (described later). The mounting hole 130 has a generally elliptical elongated hole shape, and the length L1 of the mounting hole 130 is greater than the width W1 (length L1 > width W1). The mounting hole 130 extends so as to be elongated in a longitudinal direction P1 (i.e., the direction along the length L1). The longitudinal direction P1 of the mounting hole 130 coincides with a longitudinal direction P2 of the fuse element 100 (the axial direction of a line connecting the terminal portions 110 on both sides). In other words, the mounting hole 130 extends in the longitudinal direction P2 of the fuse element 100. Therefore, the mounting hole 130 is unlikely to obstruct the flow of current along the longitudinal direction of the fuse element 100 and is unlikely to affect the electrical characteristics of the fuse element 100.

[0019] Furthermore, although the mounting hole 130 extends in the longitudinal direction P2 of the fuse element 100, this is not a limitation, and the mounting hole 130 can extend in a direction perpendicular to the longitudinal direction P2 of the fuse element 100, or the mounting hole 130 can extend in any direction intersecting the longitudinal direction P2 of the fuse element 100. Furthermore, although the mounting hole 130 has a generally elliptical elongated hole shape, this is not a limitation, and the mounting hole 130 can have any shape, such as a generally rectangular shape, as long as the length L1 of the mounting hole 130 is greater than the width W1. Furthermore, a claw 112 that protrudes toward the fusing portion 120 is provided on a portion of the terminal portion 110 of the fuse element 100.

[0020] Next, the housing segment 200 of the housing 500 of the fuse 900 according to the present invention will be described with reference to Figures 2 and 3. The housing 500 is composed of a pair of housing segments 200 and 300. Figure 2(a) is a perspective view of the outside of the housing segment 200, Figure 2(b) is a plan view of the outside of the housing segment 200, Figure 3(a) is a perspective view of the inside of the housing segment 200, and Figure 3(b) is a plan view of the inside of the housing segment 200.

[0021] As shown in Figures 2 and 3, the housing split piece 200 is made of synthetic resin and has a generally rectangular shape. It includes an accommodating section 210 that accommodates the fusing portion 120 of the fuse element 100, and a fixing section 220 that clamps and fixes a portion of the terminal section 110 of the fuse element 100. An outer wall 230 that surrounds the outside of the accommodating section 210 is provided with a viewing window 240 in the form of a hole that penetrates vertically. This viewing window 240 is provided in a position opposite the fusing portion 120 of the fuse element 100 accommodated in the accommodating section 210, allowing the fusing portion 120 to be viewed from the outside. A protrusion 231 that protrudes inward is provided on the inner surface (toward the accommodating section 210) of the outer wall 230. This protrusion 231 is inserted into a mounting hole of a cover member, which will be described later.

[0022] Further, a recess 251 recessed outward is provided on the inner surface of a side wall 250 surrounding the side surface of the storage section 210. This recess 251 is a portion where the legs of a cover member described later are disposed, and extends linearly from an end 252 of the side wall 250 toward the outer wall 230 so as to follow the legs.

[0023] The front side of the fixing portion 220 is formed with a recess 221, which is provided with a fixing hole 260 that penetrates vertically. The fixing hole 260 is configured to allow the insertion of a mounting protrusion 400 of a housing segment 300 (described later). Specifically, the fixing hole 260 includes a first fixing hole 261 through which the tip of the mounting protrusion 400 is inserted, and a second fixing hole 262 that extends laterally from the first fixing hole 261. Furthermore, a cutout 263 is provided in a portion of the inner wall of the first fixing hole 261, and the cutout 263 communicates with the accommodating portion 210. Therefore, gas generated when the fusing portion 120 of the fuse element 100 melts passes from the accommodating portion 210 through the cutout 263 and the second fixing hole 262 of the fixing hole 260 to the outside. This prevents the housing 500 from being damaged due to an increase in internal pressure when the fusing portion 120 melts. Even when the mounting projections 400 are inserted into the fixing holes 260 and fixed, there is still a small gap that allows gas to be discharged.

[0024] Next, the housing segment 300 of the housing 500 of the fuse 900 according to the present invention will be described with reference to Figures 4 and 5. Figure 4(a) is a perspective view of the inside of the housing segment 300, Figure 4(b) is a plan view of the inside of the housing segment 300, Figure 5(a) is a side view of the housing segment 300, Figure 5(b) is a cross-sectional view taken along A-A, and Figure 5(c) is a cross-sectional view taken along B-B.

[0025] As shown in FIG. 4 , housing segment 300 has essentially the same configuration as housing segment 200. Specifically, housing segment 300 is made of synthetic resin and has a generally rectangular shape. It includes a storage section 310 that stores fusing portion 120 of fuse element 100 and a fixing section 320 that clamps and fixes a portion of terminal portion 110 of fuse element 100. An outer wall 330 that surrounds the outside of storage section 310 is provided with a viewing window 340 in the form of a hole that penetrates vertically. This viewing window 340 is located opposite to the fusing portion 120 of fuse element 100 stored in storage section 310, allowing the fusing portion 120 to be viewed from the outside. An inward-protruding protrusion 331 is provided on the inner surface of outer wall 330 (toward storage section 310). This protrusion 331 is inserted into a mounting hole of a cover member, which will be described later.

[0026] Further, recesses 351 recessed outward are provided on the inner surface of sidewall 350 surrounding the lateral side of storage section 310. These recesses 351 are portions where legs of a cover member (described later) are disposed, and extend linearly from end 352 of sidewall 350 toward outer wall 330 so as to follow the legs. Furthermore, end 352 aligned linearly with recess 351 is recessed more toward outer wall 330 than the adjacent end portions 352 on either side, so that recessed mounting portions 353 are formed. These mounting portions 353 are portions where fixing portions of the legs of a cover member (described later) are clamped and fixed.

[0027] Additionally, mounting protrusions 400 are provided on the inner surfaces of the fixing portions 320 on both sides of the housing segment 300, protruding inward. The mounting protrusions 400 include a base end 410 connected to the fixing portion 320 and a tip end 420 protruding from the base end 410. The base end 410 of the mounting protrusion 400 has a generally oval shape in plan view, and is shaped to closely match the shape of the mounting hole 130 of the fuse element 100 so that it can be inserted through the mounting hole 130. Furthermore, the tip end 420 of the mounting protrusion 400 is configured to be able to be inserted through the fixing hole 260 of the housing segment 200. Furthermore, the upper end 411 of the base end 410 is inclined, making it easier to insert through the second fixing hole 262 of the fixing hole 260 of the housing segment 200. Furthermore, the tip portion 420 of the mounting projection 400 has a substantially circular shape in a plan view, and is configured so as to be able to be inserted into the first fixing hole 261 of the fixing hole 260 of the housing segment 200. Furthermore, the upper end 421 of the tip portion 420 is inclined, making it easier to insert into the fixing hole 260 of the housing segment 200.

[0028] As shown in FIG. 5, the cross-sectional area S1 of the base end 410 of the mounting projection 400 is larger than the cross-sectional area S2 of the tip end 420 of the mounting projection 400. When the fuse 900 is assembled as described below, the mounting projection 400 extends in a direction perpendicular to the longitudinal direction P2 of the fuse element 100. An axis P3 in the height direction of the mounting projection 400 is perpendicular to the longitudinal direction P2 of the fuse element 100. As shown in FIG. 5(b), the cross-sectional area S1 of the base end 410 of the mounting projection 400 is the cross-sectional area obtained when the base end 410 is cut in a cross section perpendicular to the axis P3. As shown in FIG. 5(c), the cross-sectional area S2 of the tip end 420 of the mounting projection 400 is the cross-sectional area obtained when the tip end 420 is cut in a cross section perpendicular to the axis P3.

[0029] Although the base end 410 of the mounting projection 400 has a generally oval cross section, this is not limited thereto and may have any cross-sectional shape, such as a generally rectangular shape, as long as it can be inserted into the mounting hole 130 of the fuse element 100. Furthermore, although the tip end 420 of the mounting projection 400 has a generally circular cross section, this is not limited thereto and may have any cross-sectional shape, such as a generally square shape, as long as it can be inserted into the fixing hole 260 of the housing segment 200.

[0030] Next, the cover member 600 of the fuse 900 according to the present invention will be described with reference to Fig. 6. Fig. 6(a) is a perspective view of the cover member 600, and Fig. 6(b) is a plan view of the cover member 600.

[0031] As shown in FIG. 6 , the cover member 600 is made of a transparent or translucent synthetic resin and includes a flat main body 610 and legs 620 extending laterally and downward from both sides of the main body 610. The main body 610 is configured to overlap with the viewing window 240 of the housing segment 200 and includes a protrusion 611 disposed within the viewing window 240. The main body 610 is transparent or translucent so that the fusing portion 120 of the fuse element 100 housed in the housing portion 210 can be seen from the outside. Mounting holes 612 are provided at the four corners of the main body 610, into which the protrusions 231 of the housing segment 200 are inserted. The main body 610 also includes protrusions 613 protruding from the surface of the main body 610.

[0032] Legs 620 are provided on both sides of main body 610, one on each side. Legs 620 are located in the center of main body 610, and include base ends 621 extending laterally from main body 610, and tip ends 622 extending downward from base ends 621. Tip ends 622 are provided with stepped fixing portions 623 protruding laterally. Note that, although legs 620 are provided one on each side in the center of main body 610, the present invention is not limited to this. Legs 620 may be provided at each of the four corners of main body 610 (four in total), or any number of legs 620 may be provided at any location.

[0033] Next, a description will be given of how to assemble the fuse 900 according to the present invention with reference to Figures 7 and 8. Figure 7(a) is a perspective view of the state in which the cover member 600 is attached to the housing segment 300, Figure 7(b) is a perspective view of the state in which the fuse element 100 is attached to the housing segment 300 and the cover member 600 and the housing segment 200 are attached, Figure 8(a) is a perspective view of the assembled fuse 900, Figure 8(b) is a plan view of the fuse 900, and Figure 8(c) is a front view of the fuse 900.

[0034] As shown in FIG. 7( a), the cover member 600 is attached to the housing segment 300 in the accommodation space 310 inside the housing segment 300 so as to overlap the viewing window 340 of the housing segment 300. Specifically, with the cover member 600 turned upside down, the main body 610 of the cover member 600 is placed over the viewing window 340, and the protrusions 331 of the housing segment 300 are inserted into the mounting holes 612 of the main body 610 to attach the cover member 600 to the housing segment 300. The fixing portions 623 of the legs 620 of the cover member 600 rest on the recessed mounting portions 353 in the side walls 350 of the housing segment 300. Furthermore, because the outer surfaces of the legs 620 of the cover member 600 are accommodated in the recesses 351 in the side walls 350 of the housing segment 300, the portions of the legs 620 that protrude into the accommodation space 310 can be reduced. Therefore, the leg portions 620 of the cover member 600 are prevented from narrowing the space within the accommodating portion 310, and the space within the accommodating portion 310 can be kept as large as possible, thereby preventing the internal pressure within the housing 500 from becoming excessively high when the fusing portion 120 of the fuse element 100 melts, and avoiding damage to the housing 500.

[0035] 7(b), the fuse element 100 is attached to the housing segment 300 with the cover member 600 attached. Specifically, the terminal portion 110 of the fuse element 100 is placed on the fixing portion 320 of the housing segment 300, and the base end portion 410 of the mounting projection 400 is inserted into the mounting hole 130 of the fuse element 100. The fusing portion 120 of the fuse element 100 is disposed within the accommodation portion 310 of the housing segment 300.

[0036] Next, the cover member 600 is attached to the accommodation portion 210 inside the housing segment 200. The attachment method is the same as the method for attaching the cover member 600 to the housing segment 300, as shown in FIG. 7(a). The housing segment 200 with the cover member 600 attached is then attached to the housing segment 300 so as to sandwich the fuse element 100. Specifically, the fixing portion 220 of the housing segment 200 is placed on top of the terminal portion 110 of the fuse element 100, and the terminal portion 110 of the fuse element 100 is sandwiched between the fixing portion 220 of the housing segment 200 and the fixing portion 320 of the housing segment 300. The tip portion 420 of the attachment projection 400 is then inserted into the fixing hole 260 of the housing segment 200. As a result, as shown in Figure 8(a), the housing 500 composed of the housing segments 200 and 300 is connected to the fuse element 100 with the fusing portion 120 of the fuse element 100 housed inside.

[0037] As shown in FIG. 8( a), the tip 420 of the mounting projection 400 protrudes from the fixing hole 260 of the housing segment 200, and is then heated and crushed. The heated and crushed tip 420 (hereinafter referred to as the head 422) is then welded to the fixing portion 220 around the fixing hole 260 (a process known as crimping), firmly securing the housing segment 200 and the housing segment 300 together. Furthermore, the upper end 421 of the tip 420 is inclined, and therefore has a smaller volume and is more easily melted. Therefore, the upper end 421 of the tip 420 is easier to heat and crush, and the time required for welding can be shortened. Furthermore, the crushed head 422 is prevented from protruding from the fixing portion 220. As shown in FIG. 8( b), the tip 420 of all of the mounting projections 400 is heated and crushed.

[0038] 7(b), the fixing portion 623 of the cover member 600 attached to the upper housing segment 200 is disposed within the mounting portion 353 of the lower housing segment 300 and overlaps the fixing portion 623 of the cover member 600 attached to the lower housing segment 300. Then, as shown in FIG. 8(a), when the housing segments 200 and 300 are assembled, the fixing portion 623 of the upper cover member 600 and the fixing portion 623 of the lower cover member 600 are sandwiched and fixed between the housing segment 200 and the housing segment 300 in a vertically stacked state. In this way, the cover member 600 is firmly fixed within the housing 500.

[0039] 8 , in the assembled fuse 900, the terminal portions 110 of the fuse element 100 protrude laterally from both sides of the housing 500, and the fusing portion 120 of the fuse element 100 is housed within the housing 500. The fusing portion 120 of the housing 500 can be seen from the outside through the main body portion 610 of the cover member 600 that is placed over the viewing window 340 of the housing 500.

[0040] Furthermore, when connecting the fuse 900 to an electric circuit or the like to be protected, the fuse 900 is fixed to the electric circuit or the like by inserting a bolt or the like into the connection hole 111 of the terminal portion 110 of the fuse element 100 and fastening the fuse 900. When a fastening member such as a bolt inserted into the connection hole 111 of the fuse element 100 is rotated during fastening, stress F1 is applied around the connection hole 111 of the terminal portion 110 in a direction intersecting the longitudinal direction P2 of the fuse element 100. As a result, stress F1 concentrates at the connection point between the fuse element 100 and the housing 500, i.e., the connection point between the mounting hole 130 of the terminal portion 110 and the mounting protrusion 400 of the housing 500, which could damage the housing 500. Therefore, in the fuse 900 of the present invention, the mounting hole 130 is shaped like an elongated hole. This increases the area of ​​the connection point between the mounting protrusion 400 and the mounting hole 130 compared to when the mounting hole 130 is a simple circular hole, thereby increasing the strength of the connection point. As a result, when fastening members such as bolts to fix the fuse 900, damage to the housing 500 can be prevented.

[0041] Furthermore, the base end 410 side of the mounting projection 400 is inserted into and directly connected to the mounting hole 130 of the fuse element 100, and is therefore the location most susceptible to stress. For this reason, the cross-sectional area of ​​the base end 410 is made larger to provide greater strength than the tip end 420. On the other hand, the tip end 420 side is not directly connected to the mounting hole 130 of the fuse element 100, but is inserted into the fixing hole 260 of the housing segment 300, and therefore the strength of the tip end 420 may be lower than that of the base end 410. In this way, by making the cross-sectional area of ​​the base end 410 of the mounting projection 400 larger than the cross-sectional area of ​​the tip end 420, the strength of the mounting projection 400 is improved and optimized.

[0042] Furthermore, the claws 112 provided on the terminal portion 110 of the fuse element 100 are located adjacent to the mounting hole 130 and abut against the inner surface of the housing 500. Therefore, the claws 112 reinforce the area around the mounting hole 130 and prevent the area around the mounting hole 130 from being deformed by the stress F1 concentrated around the area.

[0043] Next, Fig. 9 shows the structure inside the housing 500. Fig. 9(a) is a cross-sectional view taken along CC in Fig. 8(b), Fig. 9(b) is an enlarged cross-sectional view of the periphery of the viewing window 240 in Fig. 9(a), and Fig. 9(c) is a cross-sectional view taken along DD in Fig. 8(b).

[0044] As shown in FIGS. 9( a) and 9(b), the protrusion 613 of the cover member 600 is in point contact with the back surface of the outer wall 230 of the housing 500. The protrusion 613 provides a ventilation space X1 between the back surface of the outer wall 230 of the housing 500 and the main body 610 of the cover member 600. Therefore, as shown in FIG. 9(b), gas G1 generated within the housing 500 when the fusing portion 120 of the fuse element 100 melts is released from the ventilation space X1 to the outside through the viewing window 240. This prevents the internal pressure of the housing 500 from increasing due to the gas G1, which could result in damage to the housing 500. The protrusion 611 of the cover member 600 is disposed within the viewing window 240 of the housing 500, but a small gap X2 is provided between the protrusion 611 and the viewing window 240, allowing the gas G1 to be released.

[0045] Furthermore, when the fusing portion 120 of the fuse element 100 melts, the gasified metal constituting the fusing portion scatters within the housing 500 and adheres to the inner surface of the housing 500. If a voltage is applied to the fuse 900 while the gasified metal constituting the fusing portion is continuously adhering to the inner surface of the housing 500, a leakage current is likely to occur within the housing 500. This reduces the insulation performance between the terminals 110, and even after the fusing portion 120 of the fuse element 100 melts, leakage current flows through the inner surface of the housing 500, maintaining electrical continuity between the terminals 110, resulting in the problem of melting damage to the housing 500 and the terminals 110.

[0046] 9(a) and 9(b), however, a ventilation space X1 is provided between the back surface side of the outer wall 230 of the housing 500 and the main body 610 of the cover member 600, so that the outer wall 230 of the housing 500 and the main body 610 of the cover member 600 are vertically spaced apart so that the gasified metal constituting the fusing portion is less likely to adhere continuously. Therefore, the ventilation space X1 prevents the gasified metal constituting the fusing portion from adhering continuously to the inner surface of the housing 500, and prevents leakage current from occurring within the housing 500.

[0047] 9(a) and 9(c), the leg portions 620 of the cover member 600 protrude inward from the inner surface of the housing 500. Therefore, the leg portions 620 prevent the gasified fusing portion metal from continuously adhering to the inner surface of the housing 500. Specifically, the fusible element metal G2 scattered from the fusing portion 120 of the fuse element 100 to the surroundings adheres to the inner surface 625 of the leg portions 620 and the inner surface of the outer wall 330, but is less likely to adhere to the side surface 626 of the leg portions 620. Therefore, the stepped leg portions 620 having the inner surface 625 and the side surface 626 prevent the gasified fusing portion metal from continuously adhering to the inner surface of the housing 500, thereby preventing leakage current from occurring within the housing 500.

[0048] Furthermore, the fusing portion 120 of the fuse element 100 is located near the center 502 of the housing 500. The leg portions 620 are disposed on the center 502 side between the ends 501 of the housing 500. Therefore, the leg portions 620 can receive the fusible metal G2 scattered from the fusing portion 120 at the positions closest above and below the fusing portion 120. This makes it even more difficult for the fusible metal G2 scattered radially from the fusing portion 120 to adhere to the side surface 626 of the leg portions 620 of the cover member 600. As a result, the gasified fusing portion metal is prevented from continuously adhering to the inner surface of the housing 500, preventing leakage current from occurring within the housing 500.

[0049] Furthermore, cover member 600 is provided with only the minimum number of legs 620 necessary to support cover member 600, that is, one on each side of main body 610. This prevents legs 620 from narrowing the space inside housing 500 more than necessary, and maintains the space inside housing 500 as large as possible. This prevents the internal pressure inside housing 500 from becoming excessively high when fusing portion 120 of fuse element 100 melts, and prevents damage to housing 500.

[0050] Furthermore, leg portions 620 of cover member 600 are provided continuously around the entire periphery of the inner surface of housing 500 via main body portion 610. Main body portion 610 protrudes inward from the inner surface of housing 500, preventing the gasified metal constituting the fusing portion from continuously adhering to the inner surface of housing 500. As a result, the gasified metal constituting the fusing portion is reliably prevented from continuously adhering around the entire periphery of the inner surface of housing 500, preventing the occurrence of leakage current within housing 500.

[0051] Furthermore, cover member 600 is subjected to outward pressure by gas G1 that is generated when fusing portion 120 melts. However, because cover member 600 is disposed inside housing 500, cover member 600 is unlikely to come off housing 500 even when pressure is applied. Although cover member 600 is disposed inside housing 500, cover member 600 may be attached to the outside of housing 500 as long as cover member 600 is configured to be unlikely to come off housing 500.

[0052] Note that, although a ventilation space X1 is provided between the back surface side of the outer wall 230 of the housing 500 and the main body portion 610 of the cover member 600 by a protrusion 613, the present invention is not limited to this. If the protrusion 613 is not provided, the back surface side of the outer wall 230 of the housing 500 and the main body portion 610 of the cover member 600 will be in contact with each other. However, to form the ventilation space X1, a groove 614 is provided in the main body portion 610 of the cover member 600 instead of the protrusion 613. The groove 614 is recessed from the surface of the main body portion 610, and one end 615 of the groove 614 communicates with the interior of the housing 500, and the other end 616 of the groove 614 communicates with the viewing window 240. Therefore, the groove 614 forms the ventilation space X1 that connects the inside and outside of the housing 500. Then, within the housing 500, gas G1 generated when the fusing portion 120 of the fuse element 100 melts passes from one end 615 to the other end 616 of the groove 614 that forms the ventilation space X1, and is released to the outside through the viewing window 240.

[0053] Furthermore, if the protrusion 613 is not provided, the back surface of the outer wall 230 of the housing 500 and the main body 610 of the cover member 600 will be in contact with each other. However, to form the ventilation space X1, a groove 617 may be provided on the back surface of the outer wall 230 of the housing 500 instead of the protrusion 613. The groove 617 is recessed from the back surface of the outer wall 230 of the housing 500, with one end 618 of the groove 617 communicating with the interior of the housing 500 and the other end 619 of the groove 617 communicating with the viewing window 240. Therefore, the groove 617 forms the ventilation space X1 that connects the inside and outside of the housing 500. When the fusing portion 120 of the fuse element 100 melts within the housing 500, the gas G1 generated passes from one end 618 to the other end 619 of the groove 617 that forms the ventilation space X1 and is released to the outside via the viewing window 240.

[0054] Furthermore, 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 rights.

Claims

1. A fuse comprising a fuse element and a housing that accommodates a melting portion of the fuse element, The fuse element and the housing are connected by inserting the mounting protrusion of the housing into the mounting hole of the fuse element, The mounting projection has a base end and a tip end, The cross-sectional area of ​​the base end is larger than the cross-sectional area of ​​the tip end. A fuse characterized by:

2. 2. The fuse according to claim 1, wherein the mounting hole is an elongated hole.

3. 3. The fuse according to claim 1, wherein the mounting hole extends in the longitudinal direction of the fuse element.

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