Patent Publication Number: US-6986296-B2

Title: Cam apparatus

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a cam apparatus for performing processing such as punching, bending, and the like with respect to a workpiece such as a thin plate by means of a tool fitted to a cam slide by causing the cam slide to slide by a cam driver. 
   2. Description of the Related Art 
   A cam apparatus of a suspended cam type, for example, generally comprises a cam driver which is adapted to be fixedly supported by a cam-driver supporting base; a cam slide having a sliding surface with a shape complementary to the sliding surface of the cam driver so as to movably contact that sliding surface; a cam-slide supporting base for movably suspending and supporting the cam slide so that the cam slide can move while being guided by the sliding surface of the cam driver as the sliding surface of the cam slide and the sliding surface of the cam driver are brought into contact with each other; and a returning mechanism having a coil spring for generating a returning force for returning the cam slide to its initial position. 
   In such a cam apparatus of the suspended cam type, at the time of performing the operation of adjusting and confirming the position of a tip of an edge tool in the state of a bottom dead center, the operation of removing the coil spring which generates a large returning force in the state of the bottom dead center is normally effected in advance so as to facilitate the operation of the position adjustment and confirmation. 
   Incidentally, the above-described operation of removing the coil spring involves the operation of dismounting and mounting the cam slide with respect to the cam-slide supporting base. Moreover, after the operation of the position adjustment and confirmation, the operation of dismounting and mounting the cam slide with respect to the cam-slide supporting base is required again to fit the coil spring. 
   In addition, the above-described troublesome operation is required also in the maintenance, inspection, and replacement of the coil spring in the cam apparatus which involves the operation of dismounting and mounting the cam slide with respect to the cam-slide supporting base for the operation of removing the coil spring in the operation of adjusting and confirming the position of the tip of the edge tool in the state of the bottom dead center. 
   It should be noted that such a drawback does not occur only in the cam apparatus of the suspended cam type, but similarly occurs in the cam apparatus of the lower mounted type as well. 
   SUMMARY OF THE INVENTION 
   The present invention has been devised in view of the above-described aspects, and its object is to provide a cam apparatus which makes it possible to speedily and easily effect the operation of adjusting and confirming the position of the tool tip and the operation of the maintenance, inspection, and replacement of the coil spring without performing troublesome operation such as the dismounting and mounting of the cam slide with respect to the cam-slide supporting base. 
   To this end, in accordance with a first aspect of the present invention, there is provided a cam apparatus comprising: a cam driver; a cam slide adapted to move in contact with the cam driver and having a through hole; cam-slide supporting means having a cam-slide supporting base which movably supports the cam slide, has a front wall portion disposed at a forward position in a moving direction of the cam slide, and has an opening in a backward position opposing the front wall portion in the moving direction of the cam slide; and a returning mechanism for returning the cam slide to an initial position thereof, the returning mechanism including a rod which is passed through the through hole of the cam slide, a rod supporting member which supports the rod slidably in the moving direction of the cam slide and is detachably fitted to the cam slide at one open end of the through hole of the cam slide located on an opening side of the cam-slide supporting base, and a coil spring disposed between the front wall portion and the rod supporting member in such a manner as to surround the rod, so as to resiliently urge the cam slide toward the opening of the cam-slide supporting base. 
   In the cam apparatus according to the above-described first aspect of the invention, since the rod supporting member is detachably fitted to the cam slide at one open end of the through hole of the cam slide, by removing the rod supporting member from the cam slide, it is possible to prevent the occurrence of the resiliency of the coil spring in the returning direction. Thus, it is possible to eliminate the occurrence of the returning force in the operation of adjusting and confirming the position of the tip of the edge tool. 
   In the present invention, it suffices if, as in the cam apparatus in accordance with a second aspect of the invention, the rod has a rod main body and a rod subsidiary body having one end portion threadedly secured to one end portion of the rod main body. In the case of such a rod, since the rod main body and the rod subsidiary body can be easily separated from each other, the coil spring can be easily removed and fitted with respect to the rod. 
   In addition, in the present invention, it suffices if, as in the cam apparatus in accordance with a third aspect of the invention, the rod has one enlarged-diameter end portion abutting against the front wall portion of the cam-slide supporting base and another enlarged-diameter end portion located on the opening side of the cam-slide supporting base. In the case of such a rod, it is possible to reliably prevent the rod from coming off the rod supporting member. 
   In addition, in the present invention, it suffices if, as in the cam apparatus in accordance with a fourth aspect of the invention, the coil spring abuts against, at one end thereof, the one enlarged-diameter portion and, at another end thereof, against one of the rod supporting member and an adjusting plate disposed between the coil spring and the rod supporting member. In the case of such a coil spring, if the returning mechanism is pulled out from the opening side of the cam-slide supporting base, the coil spring can also be pulled out reliably. Moreover, in a case where the adjusting plate is disposed between the rod supporting member and the other end of the coil spring, it is possible to optimally adjust the resiliency and, hence, the returning force of the coil spring by using the adjusting plate of an appropriate thickness. 
   In accordance with a fifth aspect of the present invention, in the cam apparatus according to any one of the above-described aspects, the cam slide has a recessed portion in an end face located on the opening side of the cam-slide supporting base, and the rod supporting member is detachably fitted to the cam slide in the recessed portion of the cam slide by means of a bolt. 
   In accordance with the cam apparatus according to the fifth aspect, it is possible to reduce or eliminate the projection of the rod supporting member from the end face of the cam slide. Accordingly, even if the rod supporting member is added, the length of the apparatus in the moving direction of the cam slide does not become long. 
   In accordance with a sixth aspect of the present invention, in the cam apparatus according to any one of the above-described aspects, the cam-slide supporting base includes both side wall portions arranged on both sides of the cam slide and a suspending and supporting mechanism for movably suspending and supporting the cam slide at the both side wall portions. Further, the cam-slide supporting means has a drop preventing mechanism for preventing the cam slide from dropping off the cam-slide supporting base, the drop preventing mechanism having drop preventing plates which are removably secured respectively to one of the front wall portion and the both side wall portions on a front wall portion side and to the both side wall portions on the opening side, so as to receive the end portions of the rod when the cam slide drops. 
   In accordance with the cam apparatus according to the sixth aspect, the drop preventing mechanism has the drop preventing plates which are removably secured respectively to one of the front wall portion and both side wall portions on the front wall portion side and to both side wall portions on the opening side so as to receive the respective end portions of the rod when the cam slide drops. Therefore, even if the suspending and supporting mechanism fails to function, it is possible to prevent an unintentional drop of the cam slide from the cam-slide supporting base, so that the apparatus is extremely fail-safe. 
   As in the cam apparatus in accordance with a seventh aspect, the drop preventing plates are removably secured respectively to one of a lower surface of the front wall portion and lower surfaces of the both side wall portions on the front wall portion side and to the lower surfaces of the both side wall portions on the opening side by means of bolts. 
   In accordance with the cam apparatus according to the seventh aspect, since the drop preventing plates are secured to the lower surfaces by means of the bolts, by loosening the bolts from below and by removing them, it is possible to remove the drop preventing plates simply, and the pulling-out operation of the returning mechanism can be effected with greater ease without difficulty. 
   In accordance with an eighth aspect of the present invention, in the cam apparatus according to the above-described sixth or seventh aspect, the cam slide includes a cam slide body and slide plates which are respectively fitted to both side surfaces of the cam slide body so as to be brought into sliding contact with the respective side wall portions of the cam-slide supporting base, the suspending and supporting mechanism has suspending members which are removably secured respectively to lower surfaces of the both side wall portions, and distal ends of the suspending members are disposed on lower surfaces of the slide plates of the cam slide, thereby movably suspending the cam slide. 
   In accordance with a ninth aspect of the present invention, in the cam apparatus according to any one of the above-described aspects, the cam driver is adapted to be fixedly supported by the cam-driver supporting base, the cam slide has a sliding surface with a shape complementary to a sliding surface of the cam driver so as to movably contact the sliding surface of the cam driver, and the cam-slide supporting base is adapted to movably suspend and support the cam slide so that the cam slide can move while being guided by the sliding surface of the cam driver as the sliding surface of the cam slide and the sliding surface of the cam driver are brought into contact with each other. 
   In accordance with a tenth aspect of the present invention, in the cam apparatus according to any one of the above-described aspects, the rod has a maximum diameter smaller than a diameter of the through hole, and the coil spring has a maximum diameter smaller than the diameter of the through hole. 
   In accordance with the cam apparatus according to the tenth aspect, the rod, which is passed through the through hole in the cam slide, has a maximum diameter smaller than the diameter of the through hole, and the coil spring, which is disposed between the front wall portion and the rod supporting member in such a manner as to surround the rod, has a maximum diameter smaller than the diameter of the through hole. Thus, the returning mechanism formed as a unit composed of the rod supporting member, the rod, and the coil spring can be pulled out from the opening side of the cam-slide supporting base. Consequently, it is possible to speedily and easily effect the operation of adjusting and confirming the position of the tool tip and the operation of the maintenance, inspection, and replacement of the coil spring without performing troublesome operation such as the dismounting and mounting of the cam slide with respect to the cam-slide supporting base. 
   In accordance with the present invention, it is possible to provide a cam apparatus which makes it possible to speedily and easily effect the operation of adjusting and confirming the position of the tool tip and the operation of the maintenance, inspection, and replacement of the coil spring without performing troublesome operation such as the dismounting and mounting of the cam slide with respect to the cam-slide supporting base. 
   Hereafter, a description will be given of the present invention with reference to the embodiment shown in the drawings. It should be noted that the present invention is not limited to the embodiment. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an explanatory diagram, partly in section, of a preferred embodiment of the present invention; 
       FIG. 2  is a cross-sectional view taken in the direction of arrows along line II—II of  FIG. 1 ; 
       FIG. 3  is a left side elevational view of a portion shown in  FIG. 1 ; 
       FIG. 4  is a cross-sectional view taken in the direction of arrows along line IV—IV of  FIG. 1 ; 
       FIG. 5  is a diagram explaining the operation of the embodiment shown in  FIG. 1 ; and 
       FIG. 6  is a diagram explaining the operation of the embodiment shown in FIG.  1 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   In  FIGS. 1  to  4 , a cam apparatus  1  of a suspended cam type of this embodiment comprises a cam driver  3  which is adapted to be fixedly supported by a cam-driver supporting base  2 ; a cam slide  7  having a sliding surface  5  with a shape complementary to a sliding surface  4  of the cam driver  3  and having a through hole  6 , so as to movably contact the sliding surface  4 ; a cam-slide supporting means  11  having a cam-slide supporting base  10  for movably supporting the cam slide  7  in a direction X and a direction Y so that the cam slide  7  can move in the direction X while being guided by the sliding surface  4  of the cam driver  3  as the sliding surface  5  of the cam slide  7  and the sliding surface  4  of the cam driver  3  are brought into contact with each other, the cam-slide supporting base  10  having a front wall portion  8  disposed at a forward position as viewed in the moving direction X of the cam slide  7  and having an opening with a recessed portion  9  in a backward position opposing the front wall portion  8  as viewed in the moving direction X of the cam slide  7 ; and a returning mechanism  12  for returning the cam slide  7  to its initial position (position shown in FIG.  1 ). 
   The cam driver  3  includes a base body  15  fixed to the cam-driver supporting base  2  by means of bolts or the like and a projecting portion  17  formed integrally with an inclined upper surface  16  of the base body  15 . The sliding surface  4  in this embodiment is formed in an inverse V-shape and is provided on the projecting portion  17 . 
   The cam slide  7  has a recessed portion  20  in an end face  19  located on the side of an opening  18  defined by the recessed portion  9  of the cam-slide supporting base  10 , and is adapted to move in contact with the cam driver  3 . The cam slide  7  includes a cam slide body  25  in which the aforementioned through hole  6  and the recessed portion  20  communicating with the through hole  6  are respectively formed; slide plates  30  and  31  which are respectively fitted to side surfaces  28  and  29  of the cam slide body  25  by means of stud bolts or the like in such a manner as to come into sliding contact with side wall portions  26  and  27 , respectively, of the cam-slide supporting base  10 ; a slide plate  34  fitted to an upper surface  33  of the cam slide body  25  by means of stud bolts or the like in such a manner as to come into sliding contact with a base portion  32  of the cam-slide supporting base  10 ; and a bifurcating projecting portion  36  formed integrally with an inclined lower surface  35  of the cam slide body  25 . The sliding surface  5  in this embodiment is formed in an inverse V-shape and is provided on the projecting portion  36 . A tool such as an edge tool is mounted on a front surface  37  of the cam slide body  25  by means of bolts or the like. 
   The cam-slide supporting means  11  has, in addition to the cam-slide supporting base  10 , a drop preventing mechanism  41  for preventing the cam slide  7  from dropping off the cam-slide supporting base  10 . 
   The cam-slide supporting base  10  includes the base portion  32 ; both side wall portions  26  and  27  arranged on both sides of the cam slide body  25  of the cam slide  7  and formed integrally on both sides of the base portion  32 ; the front wall portion  8  formed integrally with both side wall portions  26  and  27  and the base portion  32  in such a manner as to bridge both side wall portions  26  and  27 ; and a suspending and supporting mechanism  42  for movably suspending and supporting the cam slide  7  at both side wall portions  26  and  27 . The base portion  32  is secured to a foundation bed  43 , which is attached to a hydraulic ram or the like, by means of bolts or the like. A cavity  44  is defined by the front wall portion  8 , both side wall portions  26  and  27 , and the base portion  32 . An upper portion of the cam slide body  25  is disposed in the cavity  44 , which is open at the opening  18 , in such a manner as to be movable in the X and Y directions. 
   The suspending and supporting mechanism  42  has a pair of plate-like suspending members  47  and  48  secured to lower surfaces  45  and  46  of respective both side wall portions  26  and  27  in such a manner as to be removable by stud bolts or the like. Distal ends of the suspending members  47  and  48  are disposed on lower surfaces  49  and  50  of the slide plates  30  and  31  of the cam slide  7 , thereby suspending the cam slide  7  movably in the X and Y directions. 
   The cam-slide supporting base  10  is adapted to suspend and support the cam slide  7  movably in the X and Y directions by means of the suspending and supporting mechanism  42 , such that the cam slide  7  can move in the X and Y directions while being guided by the sliding surface  4  of the cam driver  3  as the sliding surface  5  of the cam slide  7  and the sliding surface  4  of the cam driver  3  contact each other. 
   The drop preventing mechanism  41  has a pair of drop preventing plates  59  and  60  which are removably secured respectively to the front wall portion  8  or both side wall portions  26  and  27  on the front wall portion  8  side, i.e., to the front wall portion  8  in this embodiment, and to both side wall portions  26  and  27  on the opening  18  side by means of bolts  58 , so as to receive enlarged-diameter end portions  56  and  57  at both ends of a rod  55  when the cam slide  7  drops unintentionally. 
   The drop preventing plate  59  is removably secured to a lower surface  61  of the front wall portion  8  by means of the bolts  58  on the front wall portion  8  side. Meanwhile, the drop preventing plate  60  is removably secured to the lower surfaces  45  and  46  of both side wall portions  26  and  27  by means of the bolts  58  on the opening  18  side in such a manner as to bridge the side wall portions  26  and  27 . 
   Even if the bolts securing the suspending members  47  and  48  of the suspending and supporting mechanism  42  to the lower surfaces  45  and  46  of the side wall portions  26  and  27  are loosened, and the suspending members  47  and  48  drop off the lower surfaces  45  and  46  of the side wall portions  26  and  27 , the drop preventing mechanism  41  is adapted to prevent the cam slide  7  from dropping off the cam-slide supporting base  10  by receiving the enlarged-diameter end portions  56  and  57  of the rod  55  from below by the drop preventing plates  59  and  60 . Further, the drop preventing plates  59  and  60  are adapted to be removed from the front wall portion  8  and the side wall portions  26  and  27 , respectively, by loosening and removing the bolts  58 . 
   The returning mechanism  12  includes the rod  55  which is passed through the through hole  6  in the cam slide body  25  of the cam slide  7  and has a maximum diameter D 2  smaller than a diameter D 1  of the through hole  6 ; a rod supporting member  67  which supports the rod  55  slidably in the moving directions X and Y of the cam slide  7 , and which is detachably fitted to the cam slide body  25  of the cam slide  7  by means of a pair of bolts  66  at an open end  65  of the through hole  6  in the cam slide body  25  located on the opening  18  side of the cam-slide supporting base  10 ; and a coil spring  68  which is disposed between the front wall portion  8  and the rod supporting member  67  in such a manner as to surround the rod  55 , and has a maximum diameter D 3  smaller than the diameter D 1  of the through hole  6 , so as to return the cam slide  7  to its initial position (position shown in  FIG. 1 ) by resiliently urging the cam slide  7  toward the opening  18  of the cam-slide supporting base  10 . 
   The rod  55  has the enlarged-diameter end portion  56  abutting against the front wall portion  8  of the cam-slide supporting base  10 ; the enlarged-diameter end portion  57  located on the opening  18  side of the cam-slide supporting base  10 ; a rod main body  71  having the enlarged-diameter end portion  57  provided integrally therewith; and a rod subsidiary body  72  which is threadedly secured at one end portion thereof to one end portion of the rod main body  71  and with which the enlarged-diameter end portion  56  is provided integrally. 
   The rod supporting member  67  is detachably fitted to the cam slide body  25  of the cam slide  7  by means of the bolts  66  in the recessed portion  20  of the cam slide body  25 . 
   The coil spring  68  abuts against, at one end, the enlarged-diameter portion  56  and, at the other end, an annular adjusting plate  73  disposed between the coil spring  68  and the rod supporting member  67  and fitted over the rod main body  71 . It should be noted that in a case where the enlarged-diameter portion  56  is not provided, the one end of the coil spring  68  may abut against the front wall portion  8 . In addition, in a case where the adjusting plate  73  for adjusting the spring force of the coil spring  68  by its thickness is not provided, the other end of the coil spring  68  may abut against the rod supporting member  67 . 
   The returning mechanism  12  operates as follows: As the foundation bed  43  and the cam-slide supporting base  10  are lowered in a D direction due to the operation of the hydraulic ram (not shown) connected to the foundation bed  43 , the cam slide  7  is moved in the X direction by the cam driver  3 , as shown in FIG.  5 . Subsequently, as the cam-slide supporting base  10  together with the foundation bed  43  is raised in a U direction due to the reverse operation of the hydraulic ram, the returning mechanism  12  moves the cam slide  7  in the Y direction by means of the resiliency of the coil spring  68 , thereby returning the cam slide  7  to its initial position in which the end face  19  of the cam slide body  25  abuts against a stepped portion  75  of the base portion  32 , as shown in FIG.  1 . 
   In the above-described cam apparatus  1 , when the hydraulic ram is operated in the state in which the cam slide  7  has been returned to the initial position shown in  FIG. 1 , and the cam-slide supporting base  10  together with the foundation bed  43  is lowered in the D direction, the cam slide  7  is moved in the X direction due to the contact of its sliding surface  5  against the sliding surface  4  of the cam driver  3 , as shown in FIG.  5 . Then, a tool attached to the front surface  37  of the cam slide body  25  is adapted to effect bending, for example. 
   After the bending, in the cam apparatus  1 , if the hydraulic ram is reversibly operated, and the cam-slide supporting base  10  together with the foundation bed  43  is raised in the U direction, the cam slide  7 , in conjunction with the cancellation of the contact of its sliding surface  5  against the sliding surface  4  of the cam driver  3 , is moved in the Y direction by the resiliency of the coil spring  68  of the returning mechanism  12 , thereby returning to its initial position, as shown in FIG.  1 . 
   As described above, the cam apparatus  1  is arranged such that the rod supporting member  67  is detachably fitted to the cam slide  7  at the open end  65  of the through hole  6  of the cam slide  7 , and the rod  55  which is passed through the through hole  6  in the cam slide  7  has the maximum diameter D 2  smaller than the diameter D 1  of the through hole  6 . Further, the coil spring  68 , which is disposed between the front wall portion  8  and the rod supporting member  67  in such a manner as to surround the rod  55 , has the maximum diameter D 3  smaller than the diameter D 1  of the through hole  6 . Thus, after the drop preventing plate  60  is removed from each of the side wall portions  26  and  27  by loosening the bolts  58 , the rod supporting member  67  can be removed from the cam slide body  25  of the cam slide  7  by loosening the bolts  66 . As a result, it is, first of all, possible to prevent the occurrence of the resiliency of the coil spring  68  in the returning direction. Thus, it is possible to prevent the occurrence of the returning force in the operation of adjusting and confirming the position of the tool tip in the state of the bottom dead center shown in FIG.  5 . Moreover, as shown in  FIG. 6 , the returning mechanism  12  formed as a unit composed of the rod supporting member  67 , the rod  55 , and the coil spring  68  can be pulled out from the opening  18  side of the cam-slide supporting base  10 . Consequently, it is possible to speedily and easily effect the operation of adjusting and confirming the position of the tool tip and the operation of the maintenance, inspection, and replacement of the coil spring  68  without performing troublesome operation such as the dismounting and mounting of the cam slide  7  with respect to the cam-slide supporting base  10 . 
   In addition, with the cam apparatus  1 , since the rod  55  has the rod main body  71  and the rod subsidiary body  72  threadedly secured to the rod main body  71 , the rod main body  71  and the rod subsidiary body  72  can be easily separated from each other, so that the coil spring  68  can be easily removed and fitted with respect to the rod  55 . Furthermore, since the rod  55  has the enlarged-diameter end portions  56  and  57 , it is possible to reliably prevent the rod  55  from unintentionally coming off the rod supporting member  67 . 
   In addition, with the cam apparatus  1 , since the coil spring  68  at its one end abuts against the enlarged-diameter end portion  56 , if the returning mechanism  12  is pulled out from the opening  18  side of the cam-slide supporting base  10 , the coil spring  68  can also be pulled out reliably. Moreover, since the adjusting plate  73  is disposed between the rod supporting member  67  and the other end of the coil spring  68 , it is possible to optimally adjust the resiliency and, hence, the returning force of the coil spring  68  by using the adjusting plate  73  of an appropriate thickness. In addition, since the rod supporting member  67  is detachably fitted to the cam slide  7  at the recessed portion  20  by means of the bolts  66 , it is possible to reduce or eliminate the projection of the rod supporting member  67  from the end face  19  of the cam slide  7 . Accordingly, even if the rod supporting member  67  is added, the length of the apparatus in the moving direction of the cam slide  7  does not become long. 
   Furthermore, with the cam apparatus  1 , the drop preventing mechanism  41  consists of the drop preventing plates  59  and  60  which are removably secured respectively to the front wall portion  8  and the side wall portions  26  and  27  so as to receive the enlarged-diameter end portions  56  and  57  at both ends of the rod  55  when the cam slide  7  drops, as described above. Therefore, even if the suspending and supporting mechanism  42  fails to function, it is possible to prevent an unintentional drop of the cam slide  7  from the cam-slide supporting base  10 , so that the apparatus is extremely fail-safe. In addition, since the drop preventing plate  59  and the drop preventing plate  60  are removably secured to the lower surface  61  of the front wall portion  8  and to the lower surfaces  45  and  46  of both side wall portions  26  and  27 , respectively, by means of the bolts  58 , by loosening the bolts  58  from below and by removing them, it is possible to remove the drop preventing plates  59  and  60  simply. Also, since the drop preventing plate  60  can be removed simply, the pulling-out operation of the returning mechanism  12  can be effected with greater ease without difficulty.