Abstract:
There is provided a rail attachment apparatus for an electrical device in which a biasing elastic function is imparted to a slider itself, whereby the slider can be adjusted to be thin and the number of components can be decreased. The rail attachment apparatus includes a nipping portion that nips one side edge of an attaching rail fixed to an attaching surface of the electrical device, and a slider that is opposed to the nipping portion and slidably held at the other side edge of the attaching rail in a direction intersecting with this attaching rail. The slider is provided with integrally formed bending elastic portions which bias the slider in a direction to enable nipping the attaching rail.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a rail attachment apparatus for an electrical device in which the electrical device including an electromagnetic contactor and the like is attachable to and detachable from an attaching rail. 
       BACKGROUND ART 
       [0002]    As this type of rail attachment apparatus for an electrical device, for example, rail attachment apparatuses described in Patent Literatures 1 and 2 have been suggested. 
         [0003]    A conventional example described in Patent Literature 1 comprises a slider which includes a coil spring disposed on a rear side of a frame of an electromagnetic contactor and is biased toward a rail side, and a support column having a hook portion at its tip is disposed adjacent to a rail on an inner bottom surface of a case, this hook portion being engaged in a hook hole of the slider. 
         [0004]    A conventional example described in Patent Literature 2 comprises a first engaging portion and a second engaging portion opposed to engage with both side edges of a rail, and a wire spring which presses the side edge of the rail engaged with the first engaging portion, a spring biasing force of this wire spring being given to the rail so that the other rail edge is pressed by the second engaging portion. 
       CITATION LIST 
       [0005]    Patent Literature 
         [0006]    PTL 1: JP H06-139893 A 
         [0007]    PTL 2: JP 2011-44285 A 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0008]    However, in a conventional example described in Patent Literature 1, a coil spring is disposed in a slider, and thus, a thickness of the slider increases and accordingly a height of an electromagnetic contactor also increases. Furthermore, there is also an unsolved problem that the slider and the coil spring have to be disposed as separate members and the number of components increases. Additionally, a conventional example described in 
         [0009]    Patent Literature 2 has a constitution in which any sliders are not disposed and a side edge of a rail is pressed by a wire spring, and hence a thickness of a rail attaching portion can be decreased, but on the other hand, there is an unsolved problem that a posture of the wire spring becomes unstable and the pressing of the rail side edge by the wire spring cannot exactly be performed. 
         [0010]    Thus, the present invention has been developed in view of the above unsolved problems of the conventional examples, and an object thereof is to provide a rail attachment apparatus for an electrical device in which an biasing elastic function is imparted to a slider itself, whereby the slider can be adjusted to be thin and the number of components can be decreased. 
       Solution to Problem 
       [0011]    To achieve the above object, a rail attachment apparatus for an electrical device according to the present invention includes a nipping portion that nips one side edge of an attaching rail fixed to an attaching surface of the electrical device, and a slider that is opposed to the nipping portion and slidably held at the other side edge of the attaching rail in a direction intersecting with this attaching rail. Further, the slider is provided with integrally formed bending elastic portions which bias the slider in a direction to enable nipping the attaching rail. 
       Advantageous Effects of Invention 
       [0012]    According to the present invention, bending elastic portions are integrally formed in a slider, and hence it is not necessary to separately dispose an elastic member that biases the slider, and it is also not necessary to dispose a coil spring or the like in the slider, whereby a thickness of the slider itself can be decreased and a height of the whole electrical device can be decreased, so that miniaturization can be achieved. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0013]      FIG. 1  is an appearance perspective view illustrative of one example where the present invention is applied to an electromagnetic contactor; 
           [0014]      FIG. 2  is a vertical cross-sectional view of  FIG. 1 ; 
           [0015]      FIG. 3  is a perspective view of a first frame of  FIG. 1  seen from an attaching surface side; 
           [0016]      FIG. 4  is a perspective view of a state where a slider of  FIG. 3  is removed; 
           [0017]      FIG. 5  is an enlarged cross-sectional view of the slider of  FIG. 2 ; 
           [0018]      FIG. 6  is a rear view of  FIG. 1 ; 
           [0019]      FIG. 7  is a rear view illustrating that the slider of  FIG. 1  is attached; and 
           [0020]      FIGS. 8A to 8D  are views illustrative of the slider, FIG. A is a perspective view, FIG. B is a front view, FIG. C is a rear view, and FIG. D is a side view. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0021]    One embodiment of the present invention will now be described with reference to the drawings. 
         [0022]    An electromagnetic contactor  10  as an electrical device according to the present invention is configured by coupling a first frame  11 A and a second frame  11 B with each other as illustrated in  FIG. 1 . 
         [0023]    As illustrated in  FIG. 2 , an operating electromagnet  12  is disposed in the first frame  11 A. In the second frame  11 B, as illustrated in  FIG. 2 , there is disposed a contact mechanism  13  that is driven to be on and off by the operating electromagnet  12 . 
         [0024]    The contact mechanism  13  includes a pair of fixed contacts  14   a  and  14   b  fixed to keep a predetermined distance therebetween, and a contact support  17  supported to be movable in a forward-backward direction so that a movable contact  15  held by a contact spring  16  becomes contactable and separable to these fixed contacts  14   a  and  14   b.    
         [0025]    Additionally, in the second frame  11 B, as illustrated in  FIG. 1 , a front end face is provided with a power source side terminal portion  18   a  and an auxiliary terminal portion  19   a  which are connected to the fixed contact  14   a,  and a load side terminal portion  18   b  and an auxiliary terminal portion  19   b  which are connected to the fixed contact  14   b.    
         [0026]    The first frame  11 A has a bottomed square tubular portion  21  that contains the operating electromagnet  12 . The operating electromagnet  12  is configured of, for example, an AC electromagnet. As illustrated in  FIG. 2 , the operating electromagnet  12  has a fixed core  12 F, a movable core  12 M. and a spool  12 S around which an excitation coil  12   a  is wound. 
         [0027]    The fixed core  12 F is integrally formed of a laminated steel plate having a coupling plate portion  12 Fa, a central projecting plate portion  12 Fb and upper and lower projecting plate portions  12 Mc and  12 Md, and is formed into an E-shape seen from a left side surface, and the coupling plate portion  12 Fa is fixed and supported by a bottom surface of the bottomed square tubular portion  21 . 
         [0028]    The movable core  12 M. is integrally formed of a laminated steel plate having a coupling plate portion  12 Ma, a central projecting plate portion  12 Mb and upper and lower projecting plate portions  12 Mc and  12 Md, and the movable core is formed into an E-shape seen from a right side surface, and is coupled with the contact support  17  supported to be slidable forward and backward in the second frame  11 B so that the movable core is movable forward and backward. Here, the fixed core  12 F and the movable core  12 M are biased by an unillustrated return spring so that the central projecting plate portion  12 Fb and the upper and lower projecting plate portions  12 Fc and  12 Fd of the fixed core  12 F face the central projecting plate portion  12 Mb and the upper and lower projecting plate portions  12 Mc and  12 Md of the movable core  12 M. to keep a predetermined space therebetween. 
         [0029]    The spool  12 S is mounted around the central projecting plate portion  12 Fb of the fixed core  12 F. The spool  12 S has a coil terminal  22  that projects upward from, for example, an upper end of the first frame  11 A. Therefore, a suction force is not generated in the fixed core  12 F in a non-excitation state of the excitation coil  12   a  in which an 
         [0030]    AC power is not supplied to the coil terminal  22 , but the suction force to suck the movable core  12 M against the return spring is generated in the fixed core  12 F in an excitation state of the excitation coil  12   a  in which the AC power is supplied to the coil terminal  22 . 
         [0031]    Additionally, at upper and lower positions of the first frame  11 A in front end open end faces of right and left side surfaces of the bottomed square tubular portion  21 , as illustrated in  FIG. 1 ,  FIG. 3  and  FIG. 4 , there are formed hook portions  26  which extend forward to engage with engaging portions  25  formed in the second frame  11 B, thereby constituting snap fit portions, respectively. As illustrated in  FIG. 3 , each of the hook portions  26  includes a comparatively wide projecting piece  26   a  that has a flexibility and extends forward from a front end of the bottomed square tubular portion  21 , and an engaging portion  26   b  projected toward a tip inner side of the projecting piece  26   a.    
         [0032]    Furthermore, attaching plate portions  27  having attaching holes are formed at four corners of a bottom portion of the bottomed square tubular portion  21  of the first frame  11 A. 
         [0033]    Additionally, in the bottom surface of the bottomed square tubular portion  21  of the first frame  11 A which becomes an attaching surface, as illustrated in  FIGS. 3 to 5 , a rail attachment apparatus  31  is attached to an attaching rail  30  fixed to a wall surface or the like. 
         [0034]    As illustrated by a two-dot chain line in  FIG. 2 , the attaching rail  30  includes an attaching plate portion  30   a  that extends in a right-left direction, horizontal plate portions  30   b  and  30   c  which extend forward from upper and lower end portions of the attaching plate portion  30   a,  respectively, an upper flange portion  30   d  that extends upward from a front end of the horizontal plate portion  30   b,  and a lower flange portion  30   e  that extends downward from a front end of the horizontal plate portion  30   c.    
         [0035]    The rail attachment apparatus  31  has a rail mounting concave portion  32  that has a width equal to a width of the attaching rail  30  extended in the right-left direction in the bottom surface of the bottomed square tubular portion  21 . Nipping portions  33   a  and  33   b  which project and face a bottom surface of the rail mounting concave portion  32  of the bottomed square tubular portion  21  are formed to nip the upper flange portions  30   d  of the attaching rail  30  which are formed on both right and left end sides in a front end portion of an upper wall surface that forms the rail mounting concave portion  32 . 
         [0036]    Additionally, at a central position of a lower wall surface that forms the rail mounting concave portion  32 , there is formed a slider receiving concave portion  34  that reaches a lower end face of the bottomed square tubular portion  21  from an upper position at as much as a predetermined distance from the lower wall surface of the rail mounting concave portion  32 , to intersect with the rail mounting concave portion  32 , and the slider receiving concave portion extends at a depth larger than that of the rail mounting concave portion  32  in a vertical direction. As illustrated in  FIG. 3 , in the slider receiving concave portion  34 , a protrusion  35  is projected forward from a central portion in the right-left direction of an upper end side in a bottom portion that becomes a slider attaching surface, and is extended downward as much as a predetermined distance. 
         [0037]    In the slider receiving concave portion  34 , guide plate portions  36   a  and  36   b,  which vertically slidably guide the slider  40  opposed to the nipping portions  33   a  and  33   b,  are formed in rear end portions of right and left side wall portions on the upper end side and a lower end side, respectively, to project into the slider receiving concave portion  34 . Furthermore, between the guide plate portions  36   a  and  36   b,  bending elastic portion receiving spaces  37   a  and  37   b  are formed in which bending elastic portions  43   a  and  43   b  of the slider  40  which will be described later are received. Lower end side walls which form the bending elastic portion receiving spaces  37   a  and  37   b  are defined as engaging portions  38   a  and  38   b  which engage with engaging plate portions  44   e  and  45   e  of the bending elastic portions  43   a  and  43   b.    
         [0038]    As illustrated in  FIGS. 8A to 8D , the slider  40  is configured by injection forming of a thermoplastic synthetic resin material such as polyamide (PA)  66 , polyphenylene sulfide (PPS) or polytetrafluoroethylene (PTFE). The slider  40  has a main plate portion  41  extending in a direction intersecting with the rail mounting concave portion  32  in which the attaching rail  30  is mounted, and having, at its tip, an engaging portion  41   a  that engages with the lower flange portion  30   e  of the attaching rail  30 . The main plate portion  41  includes a comparatively wide upper plate portion  42   a  on the upper end side, an intermediate plate portion  42   b  that is connected to a lower end of the upper plate portion  42   a  and has a width smaller than that of the upper plate portion  42   a,  and a lower plate portion  42   c  that is connected to a lower end of the intermediate plate portion  42   b,  has a width larger than that of the upper plate portion  42   a,  and projects forward. 
         [0039]    At a central position of the upper plate portion  42   a , there is formed an opening  42   d  that reaches a front surface from a rear side, and there is formed an elastic engaging projection  42   e  that projects and extends upward and forward from a front side of a lower end wall surface of the opening  42   d.  A free end of the elastic engaging projection  42   e  is projected forward from the front surface of the upper plate portion  42   a.    
         [0040]    Additionally, in the upper plate portion  42   a,  guide pieces  42   f,  which project to the right and left, respectively, are formed on the front side of the upper end side, and in the lower plate portion  42   c,  guide pieces  42   g,  which project to the right and left, respectively, are similarly formed on the front side of the lower end side. 
         [0041]    Furthermore, at right and left side edges at a connected position of the upper plate portion  42   a  and the intermediate plate portion  42   b,  the outwardly projecting bending elastic portions  43   a  and  43   b  are integrally formed being outwardly projecting, respectively. Each of the bending elastic portions  43   a  and  43   b  is horizontally symmetrically formed. The bending elastic portion  43   a  is formed into bellows and includes a substrate portion  44   a  which has, in a left direction from the main plate portion  41 , a height substantially equal to a height (e.g., 3 mm) of the main plate portion  41  in the forward-backward direction projecting and extending in a direction orthogonal to a longitudinal direction of the main plate portion  41  and whose thickness is decreased to be about ¼ to ⅕ of the height; a first U-shaped and folded portion  44   b  that is connected to a left end portion of the substrate portion  44   a  and folded back substantially in parallel with the substrate portion  44   a  in the form of a U-shape seen from the front surface; a parallel plate portion  44   c  that is connected to the first U-shaped and folded portion  44   b  and is substantially parallel to the substrate portion  44   a;  a second U-shaped and folded portion  44   d  that is folded back from a right end portion of the parallel plate portion  44   c  in the vicinity of a coupled position of the intermediate plate portion  42   b  with the lower plate portion  42   c  in parallel with the substrate portion  44   a  and the parallel plate portion  44   c,  in the form of a U-shape seen from the front surface; and an engaging plate portion  44   e  that substantially extends in parallel with the substrate portion  44   a  and the parallel plate portion  44   c  in the left direction from the second U-shaped and folded portion  44   d.    
         [0042]    Similarly, the bending elastic portion  43   b  is also formed linearly symmetrically with the bending elastic portion  43   a , formed into bellows, with a substrate portion  45   a,  a first U-shaped and folded portion  45   b,  a parallel plate portion  45   c , a second U-shaped and folded portion  45   d  and an engaging plate portion  45   e.  Here, a distance between upper surfaces of the substrate portions  44   a  and  45   a  of the bending elastic portions  43   a  and  43   b  and lower surfaces of the engaging plate portions  44   e  and  45   e  is set to be substantially equal to a distance in a vertical direction of the bending elastic portion receiving spaces  37   a  and  37   b  formed on both the right and left sides of the slider receiving concave portion  34  of the bottomed square tubular portion  21 . 
         [0043]    Furthermore, a tool inserting hole  43  that extends through the lower plate portion  42   c  in the forward-backward direction is formed in the lower plate portion. 
         [0044]    Further, to attach the slider  40  to the bottom surface of the bottomed square tubular portion  21 , first, the main plate portion  41  of the slider  40  is received in the slider receiving concave portion  34  as illustrated in  FIG. 7 . At this time, the elastic engaging projection  42   e  is brought into contact with the protrusion  35  of the slider receiving concave portion  34 , the guide pieces  42   f  and  42   g  are brought into contact with the upper end side and lower end side of the bottom portion of the slider receiving concave portion  34 , and the bending elastic portions  43   a  and  43   b  are received in the bending elastic portion receiving spaces  37   a  and  37   b.  Here, the engaging plate portions  44   e  and  45   e  of the bending elastic portions  43   a  and  43   b  are disposed upward away from the engaging portions  38   a  and  38   b  as illustrated in  FIG. 7 , and the bending elastic portions  43   a  and  43   b  are in a free length state where any repulsive force is not generated. 
         [0045]    Thus, in a state where the elastic engaging projection  42   e  is in contact with the surface of the protrusion  35  of the slider receiving concave portion  34 , the elastic engaging projection  42   e  projects from the surface of the main plate portion  41 , and hence the guide pieces  42   f  face the guide plate portion  36   a  from the upside, and the guide pieces  42   g  face a lower space of the guide plate portion  36   b.    
         [0046]    In this state, the slider  40  is pressed toward the bottom surface of the slider receiving concave portion  34  to bend the elastic engaging projection  42   e  in the opening  42   d , whereby the guide pieces  42   f  face the lower space of the guide plate portion  36   a.    
         [0047]    Further, when the slider  40  that remains to be pressed toward the bottom surface is slid downwardly, the guide pieces  42   f  and  42   g  are interposed between the guide plate portions  36   a  and  36   b  and the bottom surface of the slider receiving concave portion  34 . Simultaneously, the engaging plate portions  44   e  and  45   e  of the bending elastic portions  43   a  and  43   b  are engaged with the engaging portions  38   a  and  38   b , whereby portions between the substrate portions  44   a  and  45   a  of the bending elastic portions  43   a  and  43   b  and the engaging plate portions  44   e  and  45   e  bend in a contracting direction, thereby generating the repulsive force to return the slider  40  upward. 
         [0048]    Furthermore, when the slider  40  is slid downward to obtain a state where the elastic engaging projection  42   e  faces the lower end face of the protrusion  35  as illustrated in  FIG. 5 , the elastic engaging projection  42   e  projects toward the front surface to engage with the lower surface of the protrusion due to its own elasticity. When the pressing of the slider  40  is released in this state, the slider  40  is held in the slider receiving concave portion  34  without falling upward or rearward as illustrated in  FIG. 6  and  FIG. 7 . 
         [0049]    Next, a rail attaching operation of the above embodiment will be described. 
         [0050]    First, as illustrated in  FIG. 2 , the attaching rail  30  is extended in the right-left direction and fixed to the wall surface or the like. 
         [0051]    To support the electromagnetic contactor  10  by the attaching rail  30 , first, the nipping portions  33   a  and  33   b  of the rail attachment apparatus  31  are hooked to nip the upper flange portion  30   d  of the attaching rail  30  from the upside. 
         [0052]    Next, a minus screwdriver as a tool is inserted from a front surface side into the tool inserting hole  43  of the slider  40  to slide the slider  40  downward against the repulsive force of the bending elastic portions  43   a  and  43   b , and in a state where the engaging portion  41   a  of the main plate portion  41  is retained to be back on the lower side of the rail mounting concave portion  32  or to be flush with a lower flat surface thereof, a slider  40  side of the electromagnetic contactor  10  is rotated to an attaching rail  30  on a contact point of the nipping portion  33   a  or  33   b  with the upper flange portion  30   d  as a rotation center. 
         [0053]    Further, in a state where the bottom surface of the rail mounting concave portion  32  is in contact with the lower flange portion  30   e,  a force to slide the slider  40  downward is released. In consequence, the slider  40  moves upward by the repulsive force of the bending elastic portions  43   a  and  43   b,  to obtain a state where the lower flange portion  30   e  is nipped by the engaging portion  41   a  of the main plate portion  41  as illustrated in  FIG. 2  and  FIG. 5 , whereby the electromagnetic contactor  10  is held by the attaching rail  30 . 
         [0054]    When the electromagnetic contactor  10  is removed from the attaching rail  30  in the held state of the electromagnetic contactor  10  by the attaching rail  30 , for example, the minus screwdriver is inserted into the tool inserting hole  43  of the slider  40  to slide the slider  40  downward against the repulsive force of the bending elastic portions  43   a  and  43   b , and the engaging portion  41   a  is moved to the lower side of the lower flange portion  30   e  of the attaching rail  30 . 
         [0055]    In this state, the slider  40  side of the electromagnetic contactor  10  is rotated in a direction away from the attaching rail  30  based on the rotation center of the contact point of the nipping portion  33   a  or  33   b  with the upper flange portion  30   d  of the attaching rail  30 , thereby obtaining a state where the engaging portion  41   a  does not face the lower flange portion  30   e.  Afterward, a downward sliding force of the slider  40  is released and then the nipping of the upper flange portion  30   d  of the attaching rail  30  by the nipping portions  33   a  and  33   b  is released, so that the electromagnetic contactor  10  can be removed from the attaching rail  30 . 
         [0056]    In this way, according to the above embodiment, the bending elastic portions  43   a  and  43   b  are integrally formed in the slider  40  of the rail attachment apparatus  31 , whereby it is not necessary to separately dispose an elastic member that biases the slider  40  toward the attaching rail  30 , and accordingly the number of components can be decreased. 
         [0057]    Additionally, in the slider  40  made of the thermoplastic synthetic resin material, the main plate portion  41  and the bending elastic portions  43   a  and  43   b  are integrally formed, and hence a thickness of the slider can be decreased as compared with a conventional example where a coil spring is disposed or the slider is biased by a wire spring. Consequently, a height of the rail attachment apparatus  31  can be decreased, a height of the whole electromagnetic contactor  10  can be decreased, and miniaturization of the electromagnetic contactor  10  can be achieved. 
         [0058]    Furthermore, in the slider  40  made of the thermoplastic synthetic resin material, the main plate portion  41  and the bending elastic portions  43   a  and  43   b  are integrally formed, and the bending elastic portions  43   a  and  43   b  are formed into the bellows and configured of at least the substrate portions  44   a  and  45   a  and the U-shaped and folded portions  44   b  and  45   b . Consequently, heat resisting properties of the bending elastic portions  43   a  and  43   b  can improve, and life of the slider  40  can be lengthened by inhibiting permanent set in fatigue. Additionally, the U-shaped and folded portions are formed, whereby a bend amount of the bending elastic portions  43   a  and  43   b  when sliding the slider  40  can be dispersed, and a durability can further improve. 
         [0059]    It is to be noted that in the above embodiment, there has been described the case where the bending elastic portions  43   a  and  43   b  are disposed on both right and left sides of the main plate portion  41 , but the present invention is not limited to this embodiment, and one of the bending elastic portions may be omitted and the bending elastic portion may be disposed only on one side of the main plate portion  41 . 
         [0060]    Additionally, in the above embodiment, there has been described the case where the bending elastic portions  43   a  and  43   b  are formed into the bellows and includes the first U-shaped and folded portions  44   b  and  45   b  and the second U-shaped and folded portions  44   d  and  45   d,  but one or three or more U-shaped and folded portions may be formed. 
         [0061]    Furthermore, in the above embodiment, there has been described the case where the present invention is applied to the electromagnetic contactor in which the AC electromagnet is used, but the present invention is not limited to this embodiment, and the present invention is also applicable to an electromagnetic contactor in which a DC electromagnet is used. Furthermore, when an electrical device such as a breaker, a relay or a breaker unit except the electromagnetic contactor is attached to the attaching rail, the rail attachment apparatus according to the present invention is applicable. 
       REFERENCE SIGNS LIST 
       [0062]      10  . . electromagnetic contactor,  11 A . . . first frame,  11 B . . . second frame,  12  . . . operating electromagnet,  13  . . . contact mechanism,  21  . . . bottomed square tubular portion,  30  . . . attaching rail,  30   a  . . . attaching plate portion,  30   b  and  30   c  . . . horizontal plate portion,  30   d  . . . upper flange portion,  30   e  . . . lower flange portion,  31  . . . rail attachment apparatus,  32  . . . rail mounting concave portion,  33   a  and  33   b  . . . nipping portion,  34  . . . slider receiving concave portion,  35  . . . protrusion,  36   a  and  36   b  . . . guide plate portion,  38   a  and  38   b  . . . engaging portion,  40  . . . slider,  41  . . . main plate portion,  41   a  . . . engaging portion,  42   e  . . . elastic engaging projection,  42   f  and  42   f  . . . guide piece,  43   a  and  43   b  . . . bending elastic portion,  44   a  and  45   a  . . . substrate portion,  44   b  and  45   b  . . . first U-shaped and folded portion,  44   c  and  45   c  . . . parallel plate portion,  44   d  and  45   d  . . . second U-shaped and folded portion, and  44   e  and  45   e  . . . engaging plate portion.