Patent Publication Number: US-6212930-B1

Title: Method and device for producing stamped parts

Description:
This application is a 371 of PCT/EP97/01093, filed Mar. 5, 1997. 
    
    
     The invention relates to a method and a device for producing stamped parts, especially plates. 
     BACKGROUND OF THE INVENTION 
     Stamped parts, especially plates such as used as clutch plates and brake plates in automatic transmissions, are customarily produced by the following steps: blanking, deburring, straightening and visual checking. In the blanking step the workpiece is blanked out from the raw material. In this step, burrs form in the outer and inner contours. The burrs are removed in the deburring step. In the straightening step, the workpiece is brought to a desired flatness by rolling, for example. The last mentioned method step is the visual checking. In the visual checking, the workpiece is checked for damage such as scratches or dents. Between these individual steps, the workpiece is removed from the respective tool, set in an intermediate position and transported to the next tool. By pretreating the raw material, the method steps can be reduced to blanking, deburring and visual checking. One kind of pretreatment is, for example, stress-relieving annealing. In the known production method, the elevated cost of production and the time taken are disadvantageous. 
     SUMMARY OF THE INVENTION 
     The invention solves the problem of reducing the cost of production and the time taken. According to the invention, the problem is solved by a method of production of stamped parts, especially plates, comprising only two steps. In a first step, the workpiece is blanked from raw material by fine blanking in a device and is the moved to a stamping stage by means of transfer tongs also housed in the device. The stamping stage is also inside the device. In the second step, the inner and outer contours of the workpiece are stamped so as to remove the burrs formed in the workpiece during the first step. 
     The solution, according to the invention, offers the advantage that the workpiece is produced in only one tool. Post-treatment and visual checking are eliminated. Another advantage is that placing in an intermediate position and transport are also eliminated. 
     In a development hereof, it is proposed that during a working operation in the fine blanking stage a first workpiece be blanked from the raw material and the burrs simultaneously removed in the stamping stage on a second workpiece. In another development of the invention, it is proposed that after terminating a working operation the first workpiece be automatically transported from the fine blanking stage to the stamping stage by means of transfer tongs. The second workpiece is simultaneously removed from the device and the fine blanking stage is equipped with a new raw material. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING(S) 
     FIG. 1 diagrammatically illustrates the method of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     The reference numeral  1  shows the device. The device  1  consists of a fine blanking stage  2 , transport tongs  4  and stamping stage  3 . In the blanking stage  2 , the workpiece  5  is blanked from raw material. In the drawings, the workpiece  5  is designed in cross section as one plate. In this first method step, burrs  6  form on the plate  5  both on the inner and outer contours. In this condition, the plate  5  cannot be used without post-treatment. After the first step, the plate  5  is passed by the transfer tongs  4  from the fine blanking stage  2 . Inside the device  1 , the transfer tongs  4  automatically transport the finely blanked plate  5  to the stamping stage  3 . In the stamping stage  3 , the burrs of the plate  5  are stamped in the second method step, in other words, the outer and inner contours of the plate  5  are rounded. In FIG. 1, this is shown with the reference numeral  7 . The stamping stage  3  consists of an upper die  8  and a lower die  9 . The plate  5  thus produced is ready for installation without any further working operations. A high quantity of processed workpieces is obtained by simultaneously processing during one working operation inside the device  1 , a first plate in the fine blanking stage  2  and a second plate within the stamping stage  3 . After terminating said operations, the first plate, as described above, is brought out of the fine blanking stage to the stamping stage  3 . The second plate completely processed in the stamping stage  3  is simultaneously removed from the tool. 
     Let it be pointed out that this method and the device are not limited to the production of plates. The method and the device can be used in general for producing stamped parts. 
     
       
         
           
               
             
               
                   
               
               
                 Reference numerals 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                   
                 1 device 
               
               
                   
                 2 fine blanking stage 
               
               
                   
                 3 stamping stage 
               
               
                   
                 4 transfer tongs 
               
               
                   
                 5 workpiece 
               
               
                   
                 6 burrs 
               
               
                   
                 7 stamped burr 
               
               
                   
                 8 upper die 
               
               
                   
                 9 lower die