Patent Publication Number: US-2015077212-A1

Title: Fuse

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of PCT Application No. PCT/JP2013/064633, filed on May 27, 2013, and claims the priority of Japanese Patent Application No. 2012-124706, filed on May 31, 2012, the content of both of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a fuse, and particularly to a fuse mounted on a vehicle. 
     BACKGROUND ART 
     Conventionally, a vehicle such as a car uses a plurality of fuses to protect electric circuits of various types of electronic devices. Each of such types of fuses includes a pair of terminal connecting portions to be connected to a counterpart terminal, a fusible portion provided between the pair of terminal connecting portions and breaking a current not less than a rated current (i.e., overcurrent), and a cover member covering the fusible portion with a part of the terminal connecting portion being exposed. The terminal connecting portions and the fusible portion are integrally formed with a conductive plate. 
     Generally, the fusible portion includes a fusible conductor portion connecting the pair of terminal connecting portions with each other, a low-melting point metal provided on the fusible conductor portion and including metal having a lower melting point than the fusible conductor portion (e.g., tin or its alloy), and a swaging portion for swaging and fixing the low-melting point metal. 
     The swaging portion of the fuse disclosed in the patent literature 1 is formed by rising from the both side edges of the fusible conductor portion, and it is referred to as a so-called open barrel type. The swaging portion is swaged in such a manner as to enclose the low-melting point metal from the both side edges of the fusible conductor portion to fix the low-melting point metal onto the fusible conductor portion. 
     CITATION LIST 
     Patent Literature  
     Patent Literature 1: Japanese Patent Laid-Open Publication No. 7-130277 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, in the fuse disclosed in the patent literature 1, since the swaging portion is swaged in such a manner as to enclose the low-melting point metal from the both side edges of the fusible conductor portion, the low-melting point metal and the swaging portion are protruded from the fusible conductor portion, thereby making the fuse larger. Therefore, it has been desired to make as less as possible an amount of protrusion of the low-melting point metal and the swaging portion from the fusible conductor portion. 
     Thus, it is an object of the present invention to provide a fuse capable of reducing the amount of the protrusion of the low-melting point metal and the swaging portion from the fusible conductor portion to realize miniaturization. 
     Solution to Problem  
     To solve the above described problem, the present invention has features described as below. First, a first feature of the present invention is a fuse including a pair of terminal connecting portions to be connected to a counterpart terminal and a fusible portion provided between the pair of terminal connecting portions and breaking a current not less than a rated current; the pair of the terminal connecting portions and the fusible portion being integrally formed with a conductive plate; each of the terminal connecting portions includes a main body face and a bent face bent from the main body face and brought into contact with the main body face; and the fusible portion includes a fusible conductor portion connecting a pair of the main body faces with each other, a low-melting point metal provided on the fusible conductor portion and having a lower melting point than the fusible conductor portion, and a swaging portion for swaging and fixing the low-melting point metal, in which the swaging portion is bent toward a side of the bent face to fix the fusible conductor portion. 
     According to the above described feature, the swaging portion is bent toward a side of the bent face to fix the fusible conductor portion. With this arrangement, compared with a case where the swaging portion is bent toward an opposite side of the bent face, the swaging portion can have a thickness much closer to that of the terminal connecting portion (main body face and bent face). Therefore, the amount of the protrusion of the low-melting point metal and the swaging portion from the bent face can be reduced, thereby realizing miniaturization of the fuse. 
     In addition, the terminal connecting portion includes the main body face and the bent face bent from the main body face and brought into contact with the main body face. With this arrangement, even when a thickness of a plate used to manufacture the fuse is made thinner to realize a lighter fuse, rigidity of the terminal connecting portion can be ensured. 
     A second feature of the present invention is the fuse according to the first feature of the present invention, wherein the terminal connecting portion is formed long along a direction orthogonal to an extending direction of the fusible conductor portion; and wherein the swaging portion is formed with a swaging piece protruded along the terminal connecting portion from both side edges of the fusible conductor portion, and is swaged in such a manner as to enclose the low-melting point metal from the both side edges of the fusible conductor portion. 
     According to the above described feature, the swaging portion is formed with a swaging piece and is swaged in such a manner as to enclose the low-melting point metal from the both side edges of the fusible conductor portion. With this arrangement, compared with a case where the swaging portion encloses the low-melting point metal from one side edge of the fusible conductor portion, the low-melting point metal can be fixed more reliably. 
     A third feature of the present invention is the fuse according the first or second feature of the present invention, and the main body face includes an inside edge portion to which the fusible conductor portion is connected and an outside edge portion located at an outside of the inside edge portion being opposed to the inside edge portion, wherein the bent face is connected to the outside edge portion. 
     According to the above described feature, the bent face is connected to the outside edge portion. With this arrangement, when the plate used to manufacture the fuse is punched out, the plate can be used more efficiently when compared with a case where the bent face is connected to an upper side portion or a lower side portion. Therefore, unnecessary part of the plate can be reduced, thereby reducing a manufacturing cost of the fuse. 
     A fourth feature of the present invention is the fuse according to the first or second feature of the present invention, in which the main body face includes an inside edge portion to which the fusible conductor portion is connected, an outside edge portion located at an outside of the inside edge portion being opposed to the inside edge portion, and a side portion connecting the inside edge portion with the outside edge portion; and the bent face is connected to the side portion. 
     According to the above described feature, the bent face is connected to a side portion. In other words, a leading end of the terminal connecting portion in an insertion direction to the counterpart terminal is formed on a bent face. With this arrangement, the terminal connecting portion can be easily inserted into the counterpart terminal. Therefore, an insertion force of the terminal connecting portion to the counterpart terminal is reduced, thereby easily mounting the fuse to the counterpart terminal. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view illustrating a fuse according to the present embodiment. 
         FIG. 2  is an exploded perspective view illustrating the fuse according to the present embodiment. 
         FIG. 3A  is a front view of the fuse according to the present embodiment. 
         FIG. 3B  is a plan view of the fuse according to the present embodiment. 
         FIG. 3C  is a side view of the fuse according to the present embodiment. 
         FIG. 4A  is a front view of a terminal connecting portion and a fusible portion according to the present embodiment. 
         FIG. 4B  is a plan view of a terminal connecting portion and a fusible portion according to the present embodiment. 
         FIG. 4C  is a side view of a terminal connecting portion and a fusible portion according to the present embodiment. 
         FIG. 5  is an exploded view illustrating the terminal connecting portion and the fusible portion according to the present embodiment. 
         FIG. 6A  is a perspective view of the terminal connecting portion and the fusible portion according to a modification example. 
         FIG. 6B  is an expanded view of the terminal connecting portion and the fusible portion according to a modification example. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Next, with reference to drawings, the embodiments of the fuse according to the present invention will be described. In the descriptions in the drawings illustrated below, same or similar reference numerals are provided to same or similar parts. However, the drawings are schematically illustrated, and thus it should be noted that ratios of dimensions are different from actual ones. Therefore, specific dimensions should be determined in consideration of descriptions described below. Further, the diagrams may include parts having mutually different relationships in dimensions and ratios. 
     (Structure of Fuse) 
     First, with reference to the drawings, the structure of a fuse  1  according to the present embodiment will be described.  FIG. 1  is a perspective view illustrating the fuse  1  according to the present embodiment.  FIG. 2  is an exploded perspective view illustrating the fuse  1  according to the present embodiment.  FIGS. 3A to 3C  illustrate the fuse  1  according to the present embodiment, in which  FIG. 3A  is a front view,  FIG. 3B  is a plan view, and  FIG. 3C  is a side view.  FIGS. 4A to 4C  illustrate a terminal connecting portion  10  and a fusible portion  20  according to the present embodiment, in which  FIG. 4A  is a front view,  FIG. 4B  is a plan view, and  FIG. 4C  is a side view.  FIG. 5  is an exploded view illustrating the terminal connecting portion  10  and the fusible portion  20  according to the present embodiment. The fuse  1  according to the present embodiment is connected to a counterpart terminal (e.g., diapason terminal) (not illustrated). 
     As illustrated in  FIG. 1  to  FIGS. 3A to 3C , the fuse  1  includes a pair of terminal connecting portions  10  to be connected to the counterpart terminal, the fusible portion  20  integrally formed with the pair of terminal connecting portions  10  and breaking a current not less than a rated current (i.e., overcurrent), and a cover member  30  covering the fusible portion  20  with a part of the terminal connecting portion  10  being exposed. The terminal connecting portions  10  and the fusible portion  20  described above are integrally formed with a conductive plate (refer to  FIG. 5 ). 
     More specifically, each terminal connecting portion  10  is formed long along a vertical direction. Each terminal connecting portion  10  is formed with a fixing hole  10 A (refer to  FIG. 2 ) through which each terminal connecting portion  10  is fixed to the cover member  30 . Each terminal connecting portion  10  includes, as illustrated in  FIGS. 4A to 4C  and  FIG. 5 , a main body face  11  connected to the fusible portion  20  (fusible conductor portion  21  described below) and a bent face  12  bent from the main body face  11  and brought into contact with the main body face  11 . 
     The main body face  11  includes an inside edge portion  11 A to which the fusible portion  20  (fusible conductor portion  21  described below) is to be connected, an outside edge portion  11 B located at an outside (a left side or a right side in the drawing) from the inside edge portion  11 A being opposed to the inside edge portion  11 A, and side portions (an upper side portion  11 C and a lower side portion  11 D) connecting the inside edge portion  11 A and the outside edge portion  11 B. 
     The bent face  12  has an approximately same shape with that of the main body face  11 . As illustrated in  FIG. 5 , the bent face  12  is connected to the outside edge portion  11 B of the main body face  11 . 
     The fusible portion  20  includes, as illustrated in  FIGS. 4A to 4C  and  FIG. 5 , a fusible conductor portion  21  connecting a pair of main body faces  11  with each other, a low-melting point metal  22  provided at the fusible conductor portion  21  and including metal having a lower melting point than the fusible conductor portion  21  (e.g., tin or its alloy), and a swaging portion  23  for swaging and fixing the low-melting point metal  22 . 
     The swaging portion  23  is, as illustrated in  FIGS. 4A to 4C  and  FIG. 5 , bent toward the side of the bent face  12  to fix the fusible conductor portion  21 . The swaging portion  23  is formed with the swaging piece protruded from the both side edges of the fusible conductor portion  21  along an extending direction of the terminal connecting portion  10 . The swaging portion  23  is swaged in such a manner as to enclose the low-melting point metal  22  from the both side edges of the fusible conductor portion  21 . 
     The cover member  30  is, as illustrated in  FIG. 1  to  FIGS. 3A to 3C , formed in a substantially T-like shape. The cover member  30  includes an upper cover  31  and a lower cover  32  to be mounted to the upper cover  31 . Each of side edges (upper and lower side edges) of the upper cover  31  is formed with a locking recessed portion  31 A. A face at a side of the terminal connecting portion  10  of the upper cover  31  is formed with a protruding portion  31 B to be inserted into a fixing hole  10 A of the terminal connecting portion  10 . On the other hand, each of side edges (upper and lower side edges) of the lower cover  32  is formed with a locking claw portion  32 A to be engaged with the locking recessed portion  31 A. Between the locking claw portions  32 A, a viewing window  32 B that is capable of viewing the fusible portion  20  is formed. 
     (Operation and Effect) 
     According to the above described present embodiment, the swaging portion  23  is bent toward the side of the bent face  12  to fix the fusible conductor portion  21 . With this arrangement, compared with a case where the swaging portion  23  is bent toward an opposite side of the bent face  12 , the swaging portion  23  can have a thickness much closer to a thickness of the terminal connecting portion  10  (main body face  11  and bent face  12 ). Therefore, the amount of the protrusion of the low-melting point metal  22  and the swaging portion  23  from the bent face  12  can be reduced, thereby realizing miniaturization of the fuse  1 . 
     In addition, the terminal connecting portion  10  includes the main body face  11  and the bent face  12  bent from the main body face  11  and brought into contact with the main body face  11 . With this arrangement, even when a thickness of a plate used to manufacture the fuse  1  is made thinner to realize a lighter fuse  1 , rigidity of the terminal connecting portion  10  can be ensured. 
     According to the present embodiment, the swaging portion  23  is formed with the swaging piece and swaged in such a manner as to enclose the low-melting point metal  22  from the both side edges of the fusible conductor portion  21 . With this arrangement, compared with a case where the swaging portion  23  encloses the low-melting point metal  22  from one side edge of the fusible conductor portion  21 , the low-melting point metal  22  can be fixed more reliably. 
     According to the present embodiment, the bent face  12  is connected to the outside edge portion  11 B. With this arrangement, when the plate used to manufacture the fuse  1  is punched out, the plate can be used more efficiently when compared with a case where the bent face  12  is connected to an upper side portion  11 C or a lower side portion  11 D. Therefore, unnecessary part of the plate can be reduced, thereby reducing a manufacturing cost of the fuse. 
     In addition, each terminal connecting portion  10  is formed long along a vertical direction, and the bent face  12  is accordingly connected to the outside edge portion  11 B that is longer than the upper side portion  11 C or the lower side portion  11 D. Therefore, a fixing strength between the main body face  11  and the bent face  12  is increased, thereby reliably improving the rigidity of the terminal connecting portion  10 . 
     (Modification Example) 
     Next, with reference to the drawings, a modification example of the terminal connecting portion  10  according to the above described embodiment will be described.  FIGS. 6A and 6B  illustrate the terminal connecting portion  10  and the fusible portion  20  according to the modification example, in which  FIG. 6A  is a perspective view and  FIG. 6B  is an exploded view. The same reference numeral is provided to a part same as that in the terminal connecting portion  10  according to the above described embodiment and only different parts are mainly described. 
     According to the above described embodiment, the bent face  12  of the terminal connecting portion  10  is connected to the outside edge portion  11  B of the main body face  11 . On the other hand, according to the modification example, as illustrated in  FIG. 6B , the bent face  12  of the terminal connecting portion  10  is connected to the lower side portion  11 D of the main body face  11 . 
     Even in such a modification example, in a similar manner to the above described embodiment, a lighter fuse  1  can be realized, and even when the thickness of the plate to manufacture the fuse  1  is reduced to realize the lighter fuse  1 , the rigidity of the terminal connecting portion  10  can be ensured. 
     In addition, according to the modification example, the bent face  12  is connected to the lower side portion  11 D of the main body face  11 . In other words, a leading end of the terminal connecting portion  10  in an insertion direction to the counterpart terminal is formed on a bent face. With this arrangement, the terminal connecting portion  10  can be easily inserted into the counterpart terminal. Therefore, an insertion force of the terminal connecting portion  10  into the counterpart terminal is reduced, thereby easily mounting the fuse  1  to the counterpart terminal. 
     (Other Embodiments) 
     As described above, the description of the present invention is disclosed according to the embodiments of the present invention. However, it should not be interpreted that the descriptions and drawings included in a part of the disclosure limits the present invention. Based on the disclosure, various types of alternative embodiments, examples, and operation techniques will be clarified to those skilled in the art. 
     For example, the embodiment of the present invention can be modified as follows. More specifically, it is described that the swaging portion  23  is formed with the swaging piece protruded along the vertical direction of the terminal connecting portion  10  from the both side edges of the fusible conductor portion  21 , but, the swaging portion  23  is not limited thereto, and it may be formed with the swaging piece protruded to one side of the terminal connecting portion  10 . 
     Further, it is described that the bent face  12  of the terminal connecting portion  10  is connected to the outside edge portion  11 B or the lower side portion  11 D, but, the bent face  12  is not limited thereto, and it may be connected to the upper side portion  11 C. 
     As described above, the present invention may include various types of embodiments that are not described herein. Therefore, a technical scope of the present invention is defined only by specific matters of the invention according to an appropriate scope of claims based on the above described descriptions. 
     INDUSTRIAL APPLICABILITY 
     According to the features of the present invention, it is possible to provide a fuse that can reduce the amount of the protrusion of the low-melting point metal and the swaging portion from the fusible conductor portion to realize miniaturization. 
     REFERENCE SIGNS LIST 
     
         
           1  fuse 
           10  terminal connecting portion 
           10 A fixing hole 
           11  main body face 
           11 A inside edge portion 
           11 B outside edge portion 
           11 C upper side portion 
           11 D lower side portion 
           12  bent face 
           20  fusible portion 
           21  fusible conductor portion 
           22  low-melting point metal 
           23  swaging portion 
           30  cover member 
           31  upper cover 
           31 A locking recessed portion 
           31 B protruding portion 
           32  lower cover 
           32 A locking claw portion 
           32 B viewing window