Abstract:
Disclosed is a metal joint having improved electrical characteristics and mechanical strength. A center swaged part ( 2 ) formed by putting metal plates ( 11, 12 ) on top of each other, cutting the metal plates ( 11, 12 ) along a first to a fourth cut lines (L 1  to L 4 ), and depressing a part surrounded by the first to the fourth cut lines (L 1  to L 4 ). Metal joint parts are formed on cut surfaces of the first to the fourth cut lines (L 1  to L 4 ) because the cut surfaces of the first to forth cut lines (L 1  to L 4 ) are, while rubbing each other, depressed.

Description:
TECHNICAL FIELD 
     This invention relates to metal joint bodies, more particular to metal joint bodies which two or more plates are joined together to form. 
     BACKGROUND ART 
     Conventionally, as a method of jointing metal plates together is known the one that the metal plates are swaged and crimped. The joint by using the above method, however, depends on residual stress or contact by the crimp, and thus has insufficient electric characteristics. Furthermore there have been posed drawbacks that the above contact of the metal plates has many spaces, making it difficult to secure longitudinal electric characteristics in view of corrosion. Furthermore, in order to secure electric characteristics to melt metal plates, for example, with gas or plasma so as to weld the metal plates to each other, it is perceived there also has been posed drawback that its difficulty to automate the method ill-adapts to mass product, and this makes it expensive to make. 
     Thereby, in order to resolve the aforementioned drawbacks, in the PTL 1, as a method of jointing metal plates together is suggested a method of jointing the metal plates together  110 ,  111  as shown in  FIGS. 7 and 8 , by cutting the two metal plates  110 ,  111 , with their stacked, along a cut line L 12  extending from one end of a bend line L 11  passing the side away from the bend line L 11  to the other end of the bend line L 11 , and by pressing, like bending, a part surrounded by the cut line L 12  and the bend line L 11  of the two metal plates  110 ,  111  along the bend line L 11 , jointing the metal plates  110 ,  111  together. 
     This method allows the part surrounded by the cut line L 12  and the bend line L 11  of the two metal plates  110 ,  111  to depress while a cut surface inside the cut line L 12  rubs on a cut surface outside the cut line L 12 . This friction makes oxidation layer of the cut surface removed, its new surface exposed, an outside and an inside of the cut line L 12  adhered, and metal plates jointed together. The metal plate joint body  101  with the metal joint is provided with a pair of projections  113  projecting in a press direction (namely, the arrow Z) by pressing the part surrounded by the cut line L 12  and the bend line L 11 . The projection  113  is formed so as its top view is trapezoidal-shaped, and short width sides of the pair of trapezoidal-shaped projections (namely, the bend line L 11 ) are each arranged opposed to each other in an interval. 
     Furthermore, a die using for pressing the two metal plates  110 ,  111  has a pair of press jigs tapered gradually toward tip thereof. This pair of press jigs is arranged in an interval where the pair of trapezoidal-shaped projections  113  are each formed. 
     The metal joint described in the PTL 1 was capable of good electrical characteristics by providing metal joint. Disadvantageously, when the metal joint set forth in the PTL 1 experiences drop and impact test, joint thereof disengaged, or some good electric characteristics may worsen. Namely, there has been posed drawback that mechanical strength is insufficient while the metal joint set forth in the PTL 1 may have good electric characteristics. 
     The PTL 2 discloses that as a method of jointing metal plates together as shown in  FIG. 9  is advocated metal joint of forming swaged joint  114  by like plastically deforming such as, with two metal plates  110 ,  111  stacked together, a local thereof is circularly depressed. The swaged joint  114  has a part of the metal plate  110  engaged in the side of the metal plate  111 . The metal joint described in the PTL 2, however, has posed drawbacks that rotation force exerting thereon made it easy to disengage. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] 
     Japanese Patent Application Laid-Open Publication No. 2006-66515 
     [PTL 1] 
     Japanese Patent Application Laid-Open Publication No. 2010-279961 
     SUMMARY OF INVENTION 
     Technical Problem 
     Accordingly, an object of the present invention is to provide metal joint having both improved electric characteristics and mechanical strength. 
     Solution to Problem 
     According to one aspect of the invention to achieve the above mentioned object, there is provided A metal joint including two or more metal plates jointed together, comprising: a pair of first cut lines arranged on the metal plates at an interval in an arrangement direction and extending in the arrangement direction; a pair of second cut lines arranged opposed to the pair of first cut lines in a direction perpendicular to the arrangement direction of the first cut lines and extending in the arrangement direction; a pair of third cut lines extending from ends of the first cut lines adjacent to each other along a direction separating from the second cut lines; a pair of fourth cut lines extending from ends of the second cut lines adjacent to each other in a direction separating from the first cut lines; a center swaged part formed by cutting the metal plates along the first to the fourth cut lines with their stacked together and depressing a part surrounded by the first to the fourth cut lines; and a metal joint part formed on cut surfaces of the first to the fourth cut lines. 
     Preferably, a part of the metal plates surrounded by the pair of third cut lines and a part of the metal plates surrounded by the fourth cut lines are tapered to be deeper as their approaching a center of the center swaged part. 
     Preferably, a part of the metal plates surrounded by the pair of first cut lines and the second cut lines is recessed perpendicular to a plane of the metal plates. 
     Preferably, widths between the pair of third cut lines and between the pair of fourth cut lines are each formed to be narrower as their separating from the first cut lines and the second cut lines, respectively. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a metal joint according to the present invention. 
         FIG. 2  is a top view of the metal plate shown in  FIG. 1 . 
         FIG. 3  is a cross-sectional view taken along I-I line of the metal joint shown in  FIG. 1 . 
         FIG. 4  is a cross-sectional view taken along II-II line of the metal joint shown in  FIG. 1 . 
         FIG. 5  is a cross-sectional view taken along line of the metal joint shown in  FIG. 1 . 
         FIG. 6  is a perspective view of the metal joint apparatus making the metal joint shown in  FIGS. 1 to 5 . 
         FIG. 7  is a perspective view illustrating one example of a conventional metal joint. 
         FIG. 8  is a top view of the metal joint shown in  FIG. 7 . 
         FIG. 9  is a cross-sectional perspective view of one example of the metal conventional joint. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter with reference now to  FIGS. 1 to 5 , a metal joint according to the present invention is discussed.  FIG. 1  is a perspective view of a metal joint according to the present invention.  FIG. 2  is a top view of the metal plate shown in  FIG. 1 .  FIG. 3  is a cross-sectional view taken along I-I line of the metal joint shown in  FIG. 1 .  FIG. 4  is a cross-sectional view taken along II-II line of the metal joint shown in  FIG. 1 .  FIG. 5  is a cross-sectional view taken along line of the metal joint shown in  FIG. 1 . 
     As shown in the figures, a metal joint  1  is composed of the same metals, and is provided with a two metal plated  10 ,  11  formed in the same thickness. As shown in  FIGS. 1, 2 , these metal plates  10 ,  11  is provided with a pair of cut line L 1 , a pair of cut line L 2 , a pair of cut line L 3 , and a pair of cut lines L 4 . 
     The above pair of first cut lines L 1  is arranged on the metal plates at an interval and extends along its arrangement direction Y 1 . The pair of second line L 2  is arranged opposed to the pair of first lines L 1  in a perpendicular direction Y 2 . The perpendicular direction Y 2  is defined as that perpendicular to the arrangement direction Y 1 . The pair of second cut line L 2  also extends along the arrangement direction Y 1 . In the present embodiment the first cut line L 1  and the second cut line L 2  are arranged parallel to each other. 
     The pair of third line L 3  extends from ends adjacent to each other of the first cut lines L 1  in a direction separating from the second cut line L 2 . A width of the third cut lines L 3  is formed narrower as their separating from the first cut line L 1 . The pair of fourth cut line L 4  extends from ends adjacent to each other of the second cut lines L 2  in a direction separating from the first cut line L 1 . A width of the fourth cut lines L 4  is formed narrower as their separating from the second cut line L 2 . 
     The metal joint  1  is provided with a center swaged part  2  and a metal joint  3 . The center metal swaged part  2  is, with the metal plates  10 ,  11  stacked together, formed by cutting the metal plates  10 ,  11  along the first to fourth cut lines L 1  to L 4 , and depressing a center part surrounded by the these first to fourth cut lines L 1  to L 4 . The center swaged part  2  has the plates  10 ,  11  plastically deformed and a part of the metal plate  10  engaged with the side of the metal plate  11 . 
     A this time as shown in  FIGS. 1 and 2 , ends of the first and second cut lines L 1  and L 2  away from the third cut lines L 3  and the fourth curt lines L 4  are each connected with line to be bend lines L 5 , ends of the third cut lines L 3  and the fourth curt lines L 4  in the first and second cut lines L 1  and L 2  are each connected with line to be bend lines L 6  (see  FIG. 1 ). Then these bend lines L 5 , L 6  are bent so that a part surrounded by the pair of first cut lines L 1  and the pair of second cut lines L 2  becomes perpendicular to a plane of the metal plates  10 , as shown in  FIG. 4 . 
     As shown in  FIGS. 1 and 2 , ends of the pair of third cut lines L 3  away from the first cut lines L 1  and ends of the pair of fourth cut lines L 4  away from the second cut lines L 2  are each connected with line to be bend lines L 7 , and ends of the pair of third cut lines L 3  at the side of the first cut lines L 1  and ends of the pair of fourth cut lines L 4  at the side of second cut lines L 2  are each connected with line to be bend lines L 8 . These bend lines L 7  and L 8  are bent so that parts each surrounded by the third cut lines L 3  and the fourth cut lines L 4  of the metal plates  10 ,  11 , as shown in  FIG. 3 , are tapered to be deeper as their approaching center of the center swaged part  2 . 
     When a center part surrounded by the first to fourth cut lines L 1  to L 4  is depressed, a cut surface inside the third cut lines L 3 , as shown in  FIG. 3 , is rubbed by a cut surface outside the third cut lines L 3 . Thereby, friction makes oxidation layer of the cut surface of the pair of third cut lines L 3  removed, its new surface exposed, the cut surface inside the third cut lines L 3  and the cut surface outside the third cut lines L 3  adhered as shown in  FIG. 5 , and metal plate joint  3  obtained. Likewise, the metal joint  3  is obtained also on the cut surface of the pair of forth cut lines L 4 . 
     Furthermore, on the cut surface of the first and the second cut lines L 1 , L 2  is in part obtained the metal joints  3 . 
     Then, the inventor made an inventive product as shown in  FIG. 1  and a conventional product shown in  FIG. 7 , performed drop and impact test, and checked the effect of the present invention. In the result, the conventional product shown in  FIG. 7  exhibited its joint being disengaged, and the conventional one shown in  FIG. 9  electrical characteristics being degraded such as increase of resistance value, whereas the invention exhibited its joint and electric characteristics being kept. 
     Then, with reference to  FIG. 6  a metal joint apparatus for manufacturing the aforementioned metal joint body  1  is discussed. As shown in  FIG. 6 , the metal joint apparatus  20  is provided with a first die  21  and a second die  22 , and a guide  23 . 
     The aforementioned first die  21  is, for example, cuboid-shaped, and has a press hole  24  on an upper face thereof. The press hole  24  is formed in the same shape as the part surrounded by the first to the fourth cut lines L 1  to L 4 , and the bend line L 5  and L 7 . The press hole  24  is arranged such that its depth is made shallower as its approaching an edge  24   b  where the bend line L 7  overlaps from a part  24   a  where the bend line L 8  overlaps. Furthermore, the press hole  24  is made deep vertically from the an edge  24   c  where the bend line L 5  overlaps. 
     The aforementioned second die  22  is formed into a bar for example. The second die  22  is formed in the same shape as the part surrounded by the first to the fourth cut lines L 1  to L 4 , and the bend line L 5  and L 7 . The second die  22  is tapered away from the first die  21  as its approaching an edge  22   b  where the bend line L 7  overlaps from a part  22   a  where the bend line L 8  overlaps. 
     The aforementioned guide  23  is, for example, cuboid-shaped, and has a guide hole  23   a  to be stacked on the press hole  24 . The guide hole  23   a  passes through the guide  23  in a pressing direction. The guide hole  23   a  is also formed in the same shape as the part surrounded by the first to the fourth cut lines L 1  to L 4 , and the bend line L 5  and L 7 , and passes through and guides the second guide  22  into the guide hole  24  of the first die  21 . 
     Then, a method of manufacturing the metal joint body  1  is described using the aforementioned metal joint apparatus  20 . At the first place, the metal plates  10 ,  11  which are stacked together are laid on the upper surface of the first die  21 . Then, the second die  22  is moved along the guide hole  23   a  of the guide  23  in the pressing direction, between these first die  21  and second die  22  is placed the metal plates  10 ,  11  which are stacked together. 
     Furthermore, moving the second die  22  in the pressing direction allows the metal plates  10 ,  11  stacked together to be cut along the first to fourth cut lines L 1  to L 4  by an edge of the second die  22  along the first to fourth cut lines L 1  to L 4  and press hole  24 . At the same time, the center part surrounded by the first to fourth cut lines L 1  to L 4  is depressed so as the center swaged part  2  and the metal joint part  3  are formed, completing the metal joint body  1 . 
     According to the aforementioned metal joint body  1 , provision of the center swaged part  2  for securing mechanical strength and the metal joint  3  for improving electric characteristics allows both the electrical characteristics and the mechanical strength to improve. Also, only pressing the joint makes completion thereof easier and lower cost than using particular welding means. 
     According to the metal joint body  1 , in the metal plates  10 ,  11 , parts each surrounded by the pair of third cot lines L 3  and the pair of fourth cut lines L 4  are tapered deeper as their approaching the center of the center swaged part  2 . It follows from this that cut surfaces inside and outside the third cut lines L 3  and the forth cut lines L 4  assuredly contact to each other, and thereby surface of the metal joint  3  can be made larger, making it possible further to improve its electric characteristics. 
     According to the metal joint body  1 , the aforementioned metal joint  1 , in the metal plates  10 ,  11 , arrangement of the part surrounded by the pair of first cut lines L 1  and the part surrounded by the second cut lines L 2  vertical to the plane of the metal plates  10 ,  11  allows the mechanical strength to further improve. 
     According to the metal joint body  1 , since the width between the pair of third cut lines L 3  and the width between the pair of fourth cut lines L 4  are formed to become narrower as their separating from the first cut lines L 1  and the second cut lines L 2 , respectively, the part surrounded by the pair of third cut lines L 3  and the part surrounded by the fourth cut lines L 4  are depressed so as to further improve its electric characteristics. 
     Note that according to the above-mentioned embodiment, the part surrounded by the first cut lines L 1  and the second cut lines L 2  is arranged such as, but not limited to, vertical to the plane the metal plates  10 ,  11 . For example, in the case of requirement for electric characteristics more than mechanical strength, the part surrounded by the first cut lines L 1  and the second cut lines L 2  is tapered deeper as its approaching the center of the center swaged part  2 . 
     Note that according to the above-mentioned embodiment, the third cut lines L 3  and the fourth cut lines L 4  is arranged such as, but not limited to, tapered. For example, in the case of requirement for mechanical strength more than electric characteristics, the part surrounded by the third cut lines L 3  and the fourth cut lines L 4  is arranged vertical to the plane of the metal plates  10 ,  11 . 
     Note that according to the above-mentioned embodiment, the first cut lines L 1  and the second cut lines L 2  is arranged, but not limited to, parallel to each other. The first cut lines L 1  and the second cut lines L 2  are only arranged to extend in the arrangement direction Y, but not in parallel with each other. 
     Note that according to the above-mentioned embodiment, the distance between the pair of third cut lines L 3  and that between the pair of fourth cut lines L 4  are formed to become such as, but not limited to, shorter as their separating from the first cut lines L 1  and the second cut lines L 2 , respectively. The pair of third cut lines L 3  and the pair of fourth cut lines L 4  may each be formed parallel to each other. 
     Note that according to the above-mentioned embodiment, jointed are such as, but not limited to, two metal plates. The number of metal plates is only required of more than two, but e.g., of three of four. 
     Note that the aforementioned embodiments merely show such as, but not limited to, typical embodiment of the present invention. Namely, it is to be understood that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention hereafter defined, they should be construed as being included therein. 
     REFERENCE SIGNS LIST 
     
         
           1  metal joint 
           2  center swaged part 
           3  metal joint 
           10  metal plate 
           11  metal plate 
         L 1  first cut line 
         L 2  second cut line 
         L 3  third cut line 
         L 4  fourth cut line 
         Y 1  arrangement direction 
         Y 2  perpendicular direction (direction perpendicular to arrangement direction)