Abstract:
A loading and unloading device for sheet metals for loading and unloading sheet metals to and from a sheet metal working machine, comprises: a chucking unit lifting a sheet metal by chucking the sheet metal; a loading and unloading clamping unit disposed adjacent to the chucking unit, the loading and unloading clamping unit moving in a direction of approaching to and leaving from the sheet metal working machine; and a sheet metal carrying unit carrying the sheet metal lifted by the chucking unit to the position of the loading and unloading clamping unit.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a loading and unloading device for sheet metals and relates, more particularly, to a loading and unloading device for sheet metals for automatically loading and unloading sheet metals to and from a sheet metal working machine. 
     2. Description of the Related Art 
     As a related art, there exists a sheet metals loading and unloading device for loading sheet metals to be worked to and unloading worked sheet metals from a turret punch press respectively, for example, as a sheet metal working machine. 
     This loading and unloading device for sheet metals includes a vacuum chucking unit for lifting a sheet metal by vacuum-chucking the sheet metal corresponding to a position of a movable table of a turret punch press, a loading unit for moving the vacuum chucking unit which has vacuum-chucked the sheet metal to the turret punch press, and an unloader for carrying worked sheet metal from the turret punch press. 
     At a lower side of the vacuum chucking unit, a pallet for a sheet metal to be worked loaded with a sheet metal to be worked is set, and a pallet for a worked sheet metal for loading a worked sheet metal is mounted on a lifter at a lower side of this vacuum chucking unit. 
     A supporting table is provided at a height position almost at the same height position as the movable table which is at a lower position of the vacuum chucking unit. This supporting table is capable of freely moving in both lateral directions from a lateral position of the movable table. Particularly, the supporting table can move in a direction orthogonal with a direction of loading and unloading a sheet metal to be worked to and from the turret punch press. 
     Based on the above-described structure, the vacuum chucking unit lifts a sheet metal loaded on the pallet for a sheet metal to be worked, in the state that the supporting table is moved back to a neutral position for loading and unloading a sheet metal to be worked from the turret punch press. The supporting table is returned to the neutral position to support the vacuum-chucked sheet metal, and the vacuum-chucked sheet metal is carried to the turret punch press by the loading unit. 
     Further, a worked sheet metal W is carried to the unloader and then the worked sheet metal W is unclamped and loaded on the supporting table. The supporting table is moved back again to move the worked sheet metal. The worked sheet metal is clamped by supporting clampers, the supporting table is advanced, and then the worked sheet metals are separated into individual worked sheet metals by a separation hammer. The separated individual worked sheet metals are dropped and loaded on the pallet for worked sheet metals. 
     According to the above-described relevant art, however, there is a problem that the loading unit itself has an increased weight which results in a high cost. Further, since the positions for carrying out the vacuum chucking of a sheet metal and the position for loading the sheet metal are the same, there is a problem that the sheet metal working machine has to stop its operation during a period while a next sheet metal is being vacuum-chucked after one sheet metal has been loaded to the sheet metal working machine, in order to avoid an interruption of the sheet metal being worked with the vacuum chucking unit. 
     Further, when the sheet metal working machine is to be used as a single unit, there is a problem that either the loading unit for sheet metals must be moved or the work must be done from an unnatural position. 
     SUMMARY OF THE INVENTION 
     The present invention has been achieved with such points in mind. 
     It therefore is an object of the present invention to provide a loading and unloading device for sheet metals which can carry out loading and unloading sheet metals with a simple and low-cost device and which can prepare loading sheet metals without interrupting the working. 
     To achieve the object, according to a first aspect of the present invention, there is provided a loading and unloading device for sheet metals to and from a sheet metal working machine, comprising: a chucking unit lifting a sheet metal by chucking the sheet metal; a loading and unloading clamping unit disposed adjacent to the chucking unit, the loading and unloading clamping unit moving in a direction of approaching to and leaving from the sheet metal working machine; and a sheet metal carrying unit carrying the sheet metal lifted by the chucking unit to the position of the loading and unloading clamping unit. 
     Accordingly, a first one top sheet metal out of loaded sheet metals is lifted by chucking this sheet metal by the chucking unit as a vacuum chucking unit, and this vacuum-chucked sheet metal to be worked is carried to the loading and unloading clamping unit provided adjacent to the vacuum chucking unit by the sheet metal carrying unit. This loading and unloading clamping unit loads and unloads sheet metals carried by the sheet metal carrying unit to and from the sheet metal working machine. Since the vacuum-chucked sheet metal to be worked is carried to the loading and unloading clamping unit provided adjacent to the vacuum chucking unit by the sheet metal carrying unit, the position for vacuum-chucking one sheet metal and the position for loading and unloading the sheet metal to and from the sheet metal working machine are different. Accordingly, it is possible to carry out vacuum chucking of one sheet metal without interrupting the working of a sheet metal during the working, so that the working efficiency can be improved. Further, since the device can be simplified, the cost of the device can be lowered. 
     According to a second aspect of the present invention, as it depends from the first aspect, the sheet metal carrying unit comprises a supporting table moving between a position corresponding to the chucking unit and a position corresponding to the loading and unloading clamping unit. 
     Accordingly, the sheet metal carrying unit can freely make a reciprocating move for supplying to the loading and unloading clamping unit the sheet metals loaded to the vacuum chucking unit by the supporting table. Therefore, it is not necessary to provide a moving mechanism in the vacuum chucking unit. As a result, the overall structure of the device becomes simple, which enables a cost reduction of the device. 
     According to a third aspect of the present invention, as it depends from the second aspect, the supporting table has a brush table; and the loading and unloading clamping unit has a lower jaw moving upwards and downwards. 
     Accordingly, the brush table supports sheet metals when the sheet metals are carried by being loaded on the brush table or when the sheet metals are loaded and unloaded to and from the sheet metal working machine by the loading and unloading clamping unit. Further, in the loading and unloading clamping unit, a sheet metal is set between an upper jaw and a lower jaw and the lower jaw is moved upwards to clamp the sheet metal in co-operation with the upper jaw. Therefore, the sheet metal can be supported without being hurt and the sheet metal can be moved on the upper surface of the brush table. Further, according to the loading and unloading clamping unit, since the sheet metal is set between the upper jaw and the lower jaw and the lower jaw is moved upwards to clamp the sheet metal in co-operation with the upper jaw, it becomes unnecessary to lift the clampers after clamping the sheet metal unlike the prior-art technique. As a result, the loading and unloading of sheet metals by the loading and unloading clamping unit becomes simple for an improved working efficiency. 
    
    
     BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
     The above and further objects and novel features of the present invention will more fully appear from the following detailed description when the same is read in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a perspective view for showing the whole of a loading and unloading device for sheet metals relating to the present invention; 
     FIG. 2 is a top plan view viewed from a direction of II in FIG. 1; 
     FIG. 3 is a front view viewed from a direction of III in FIG. 1; 
     FIG. 4 is a side view viewed from a direction of IV in FIG. 1; 
     FIG. 5 is a top plan view of a loader and unloader. 
     FIG. 6 is a front view viewed from a direction of VI in FIG. 5; 
     FIG. 7 is an enlarged side view of a work clamper; 
     FIG. 8 is an enlarged front view viewed from a direction of VIII in FIG. 7; 
     FIG. 9 is a front view for showing one process of the loading operation according to the loading and unloading device of the present invention; 
     FIG. 10 is a front view for showing one process of the loading operation according to the loading and unloading device of the present invention; 
     FIG. 11 is a front view for showing one process of the loading operation according to the loading and unloading device of the present invention; 
     FIG. 12A is a plan view and FIG. 12B is a front view. FIGS. 12A and 12B show the loading operation according to the loading and unloading device of the present invention; 
     FIG. 13 is a front view for showing one process of the loading operation according to the loading and unloading device of the present invention; 
     FIG. 14 is a plan view for showing one process of the loading operation according to the loading and unloading device of the present invention; and 
     FIG. 15 is a plan view for showing one process of the loading operation according to the loading and unloading device of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     There will be detailed below the preferred embodiments of the present invention with reference to the accompanying drawings. Like members are designated by like reference characters. 
     FIGS. 1 to  4  show a whole structure of a loading and unloading device  1  for sheet metals relating to the present invention. 
     In a turret punch press  3 , a frame  5  having a gap not shown in the center is provided in a base  7 . At an upper side of this gap, an upper turret  9  loaded with a plurality of punches P is provided to be able to be exposed by rotation, and at a lower side of the gap, a lower turret  11  loaded with a plurality of dies D is provided to be able to be exposed by rotation facing the upper turret  9 . 
     A fixed table  13  is provided at a lower side of the gap, and a number of free bearings  15  are provided on the upper plane of the fixed table  13 . On both left and right sides (both left and right sides in FIG. 2) of the fixed table  13 , movable tables  17  are provided to be able to move and be positioned in a Y axis direction along a pair of guide rails  19  extended in the Y axis direction. A carriage base  21  for connecting the left and right side movable tables  17  is provided to be able to move and be positioned in a Y axis direction, and, in this carriage base  21 , an X axis carriage  23  is provided to be able to move and be positioned in an X axis direction. The X axis carriage  23  is provided with a pair of work clampers  25  so as to be able to adjust distance therebetween. 
     Based on the above-described structure, a work W loaded and positioned at an original point is clamped by the work clampers  25 , the X axis carriage  23  is moved and positioned in the X axis direction and the carriage base  21  is moved and positioned in the Y axis direction so that a desired position of the work W is matched with a working position of the turret punch press  3  and the punches P are blown by a blower not shown to carry out punching by the co-operation between the punches P and the dies D. 
     Referring to FIG. 2, a loading and unloading unit  1  for sheet metals is provided at the right hand side of the turret punch press  3 . In this loading and unloading unit  1  for sheet metals, a loading and unloading frame  27  with a height extending above the upper plane of the movable tables  17  is provided in the range from the front end of the movable tables  17  (the lower end in FIG. 2) when the carriage base  21  is positioned at the original point to the front exceeding the position of the carriage base  21  (upper side in FIG.  2 ). 
     The loading and unloading frame  27  has a U-shape viewed from the top, and has a space  29  within a range adjacent to the movable table  17 . A supporting groove  31  is built in the center portion of the upper plane at an upper side of the space  29  in FIG. 2. A machine accommodation section is provided in a right hand frame  27 R of the loading and unloading frame  27 . 
     A sheet taking-up unit  33  as a chucking unit capable of lifting each one work W of sheet metals to be worked is provided at a portion of a lateral side or upper side of the carriage base  21  of the loading and unloading frame  27  in FIG.  2 . The one sheet taking-up unit  33  is hung with a plurality of vacuum pads  37  so-called vacuum chucks at a lattice point of a sheet taking-up frame  35  built in a lattice shape. At the center of the one sheet taking-up frame  35 , a post  41  mounted with a rack  39  is provided in a vertically upward direction. A driving monitor  45  mounted with a pinion  43  engaged with this rack  39  is provided at an upper side of the supporting groove  31 . Accordingly, the post  41  mounted with the rack  39  is moved up and down by rotating the pinion  43  by a driving motor  45 , to thereby move the one sheet taking-up frame  35  up and down. 
     A guide rails  47  for table is provided along the whole length in a Y axis direction at one stage below the one sheet taking-up unit  33  in the left and right frames  27 L and  27 R respectively of the loading and unloading frame  27 . The guide rails  47  slidably guide a supporting table  49  in the Y axis direction. The supporting table  49  and the guide rails  47  constitute a sheet metal carrying unit which is movably loading sheet metals to be worked W to be loaded and worked sheet metals W to be unloaded. Further, an endless chain to be run in rotation by a motor not shown, for example, is provided along the guide rails  47  for moving the supporting table  49  in the Y axis direction. A brush table  50  is installed on the supporting table  49  as shown in FIG.  6 . The upper plane of the brush table  50  has a height almost the same as the height of the upper plane of the movable table  17 . Accordingly, when the motor runs the chain in rotation, the brush table  50  can make a reciprocating move in a Y axis direction from a lateral side position of the movable tables  17  to a lower position of the one sheet taking-up unit  33 . 
     Referring to FIGS. 5 and 6, a loader and unloader guide rail  51  is provided across the loading and unloading frame  27  in an X axis direction at a position corresponding to the original point position of the turret punch press  3  of the loading and unloading frame  27 . This loader and unloader guide rail  51  is provided movably in an X axis direction with a loader and unloader  53  as a loading and unloading clamping unit for loading and unloading sheet metals to be worked or worked sheet metals W. 
     A pair of idle sprockets  55  and  57  are provided at the right end portion of the loader and unloader guide rail  51 , and an idle sprocket  59  is rotatably provided at the left end portion of the loader and unloader guide rail  51 , in FIG.  6 . In FIG. 6, a driving motor  61  is provided at a lower side of the idle sprockets  55  and  57 , and a driving sprocket  63  is mounted on the rotational driving axis. 
     The driving sprocket  63  and the idle sprockets  55 ,  57  and  59  are wound with an endless chain  65 , and the loader and unloader  53  is installed at a predetermined position of this chain  65 . Accordingly, when the driving motor  61  runs the chain  65  in rotation, the loader and unloader  53  can make a reciprocating move in an X axis direction. 
     The loader and unloader  53  is provided with a slider  67  movably supported in an X axis direction along the loader and unloader guide rail  51 . A supporting member  71  reinforced by a bracket  69  is provided in the slider  67 , and a cylinder  73  is provided at the front end of the supporting member  71  (the lower end in FIG.  5 ). Further, a pair of guide receivers  75  are provided in the supporting member  71 . A clamper base  79  mounted with work clampers  77  as a plurality (three in this case) of loading and unloading clamping units is movably supported in an X axis direction by the guide receivers  75 . 
     Referring to FIGS. 7 and 8, in each of the work clampers  77 , an upper jaw  81  is fixed to the clamper base  79 , and a lower jaw  85  is provided in a clamper cylinder  83  provided integrally with the upper jaw  81 . 
     With the above-described structure, since the lower jaw  85  is raised by the clamper cylinder  83  to clamp the work W in co-operation with the upper jaw  81 , it is not necessary to raise the whole of the work clamper  77  to move after having clamped the work W by lowering the upper jaw  81 , unlike the prior-art clamper. Thus, the working efficiency can be improved. 
     Accordingly, after the work W is clamped as described above, the clamper base  79  is moved in a Y axis direction by the cylinder  73  provided at the front end of the supporting member  71 , the chain  65  is run in rotation by the driving motor  61 , and the loader and unloader  53  is moved in an X axis direction along the loader and unloader guide rail  51 , so that the work W is moved on the brush table  50  and loaded to the movable table  17 . Further, the work W as a worked sheet metal is unloaded from the movable table  17  in the opposite process. 
     In the mean time, a pair of pallet supporting brackets  87  and  89  for sheet metals to be worked are provided for each stage by two stages of the left and right frames  27 L and  27 R at a lower position of the guide rail  47  for table inside the left and right frames  27 L and  27 R, and these sheet metal pallet supporting brackets are selected according to the height of the sheet metals W loaded. These pallet supporting brackets  87  and  89  for sheet metals to be worked are fixed to a rotary axis  91  rotationally provided, for example, and can appear and disappear to the inside from each of the left and right frames  27 L and  27 R by rotating the rotary axis  91  by a driving unit  93  structured by a motor and a gear mechanism, for example. FIG. 3 shows a state that the pallet supporting brackets  87  and  89  for sheet metals to be worked appear. 
     Further, a pair of guide rails  95  are extended in a Y axis direction on the base  7  which is in contact with the lower side of the loading and unloading frame  27 , and is stretched to the lower side in excess of the loading and unloading frame  27  in FIG.  2 . The guide rail  95  is movably provided with a lifter  97  which is moved up and down directions. Accordingly, the lifter  97  can move from the front side of the loading and unloading unit  1  for sheet metals to be worked (the lower side in FIG. 2) to a lower side position of the sheet taking-up unit  33 . 
     Next, the loading and unloading operation of sheet metals by the loading and unloading unit  1  for sheet metals relating to the present invention will be explained below with reference to FIGS. 1 to  4  and FIGS. 9 to  15 . 
     At first, prior to the loading and unloading and working of a sheet metal W, the brush table  50  is moved back (moved upwards in FIG. 2) to make empty a working space  99  at a front side (a lower side in FIG. 2) of the loading and unloading unit  1  for sheet metals. In this working space  99 , a pallet  101  for a sheet metal to be worked loaded with the sheet metal W is mounted on the lifter  97 . This lifter  97  is moved to a lower side of the sheet taking-up unit  33  along the guide rail  95 , and the pallet  101  for sheet metal to be worked is lifted by the lifter  97  in the state that the pallet supporting bracket  87  for sheet metal to be worked is stored. The pallet  101  is lifted to a position higher than the pallet supporting bracket  87  or  89  for sheet metal to be worked, and the lifter  97  is lowered after the pallet supporting bracket  87  or  89  for sheet metal to be worked is taken out. Then, the pallet  101  for sheet metal to be worked is set on the pallet supporting bracket  87  or  89  for sheet metal to be worked. Further, the lifter  97  is advanced to the front side (to a lower side in FIG. 2) and the pallet  103  for worked sheet metal is mounted on the lifter  97  in the working space  99 . The pallet  103  for worked sheet metal may be set during the working of the sheet metal W. 
     Next, the work sheet W is loaded in the following procedure. The brush table  50  is advanced (moved to a lower side in FIG. 2, or to the front side in a perpendicular direction in FIG. 9) to make room at the lower side of the one sheet taking-up unit  33 , and a sheet metal to be worked on top of the pallet  101  for sheet metal to be worked is taken up by the vacuum pad  37  by lowering the one sheet taking-up frame  35  by the driving motor  45  (reference FIG.  10 ). The one sheet taking-up frame  35  is lifted by the driving motor  45  to move back the brush table  50  to below the hung sheet metal W (moved upwards in FIG. 2, reference FIG.  11 ), and the sheet metal W is released from the vacuum pad  37  and is loaded on the brush table  50 . 
     The brush table  50  loaded with the sheet metal W to be worked is advanced (moved to the front side in a perpendicular direction in FIG. 13, reference FIG.  13 ), the sheet metal W is clamped by the work clampers  77  of the loader and unloader  53  (reference FIG.  14 ), and the sheet metal W is loaded to the turret punch press  3  by moving the loader and unloader  53  to the left side in FIG. 2 (reference FIG.  15 ). The work clamper  77  is unclamped, and the loader and unloader  53  is moved to the right side in FIG. 2 after the sheet metal W is released on the movable table  17 , and is stored in the right frame  27 R. 
     Next, the unloading operation of a worked sheet metal W after completing a punching operation will be explained. The loader and unloader  53  is moved to the left in FIG.  15  and the sheet metal W is clamped by the work clampers  77  (reference FIG.  15 ). The loader and unloader  53  is moved to the right in FIG.  14  and the worked sheet metal W is taken out to the brush table  50  (reference FIG.  14 ). The brush table  50  is moved back (moved upwards in FIG. 14) in a state of being clamped by the loader and unloader  53  and the sheet metal W is dropped on the pallet  103  for worked sheet metal. In this case, since the pallet  103  for worked sheet metal is lifted to immediately below the brush table  50  by the lifter  97 , the sheet metal does not drop suddenly even when the brush table  50  has moved back. 
     Then, the lifter  97  is dropped to return to the state shown in FIG.  9 . The above-described process is repeated thereafter. 
     From the above result, it is understood that the one sheet taking-up unit  33  for a sheet metal W carries out only a vacuum chucking of the sheet metal W, and carrying unit is not necessary. Further, since the loader and unloader  53  as a carrier and unloader carries out only the carrying, the whole mechanism of the device can be simplified. Accordingly, a cost reduction can be achieved. 
     Further, since the position of the loader and unloader  53  is not same as the position of the one sheet taking-up unit  33  for the sheet metal W, the loading and the one sheet taking-up operation of the sheet metal W can be done at the same time. Therefore, the working time can be reduced. Further, at the time of working a sheet metal W larger than the working range of the turret punch press  3 , the sheet metal W does not interrupt the one sheet taking-up unit  33  even if the sheet metal W is overhung. Therefore, it is not necessary to stop the working, so that the working efficiency can be improved. In this case, since the brush table  50  is waited, this can be used for repositioning. 
     Furthermore, since the working space  99  can be made vacant, the operator can work in a safe posture without unnatural position near the turret punch press  3 . 
     The present invention is not limited to the above-described mode of implementation and can also be implemented in any other mode with a suitable modification. In other words, although the description has been made of the case where the turret punch press  3  is used as a sheet metal working machine in the above-described mode of implementation, the invention can also be applied to the case where a laser working machine is used, for example. 
     Furthermore, it is applicable that the one sheet taking-up unit  33  is hung with a plurality of magnetic chucks other than the plurality of vacuum pads  37  so-called vacuum chucks at the lattice point of a sheet taking-up frame  35  built in the lattice shape. 
     While preferred embodiments of the present invention have been described using specific terms, such description is for illustrative purposes, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.