Stamping method and stamping apparatus

Abstract

A stamping method includes: punching out a product from a workpiece by using a die on which the conveyed workpiece is placed, a punch, and a back pressure portion; displacing the workpiece upward with respect to the die when the punch moves away from the die; before the product is punched out, providing a protrusion that protrudes downward and is located at a part of the workpiece, the part being on the upstream side in a workpiece conveying direction of a punch-out portion and aligned with the punch-out portion; and using the protrusion, which is displaced downstream in the conveying direction together with the workpiece, to push the product downstream in the conveying direction, so that the product is ejected to the outside.

What is claimed is: 
     
         1 . A stamping method for punching out a product from a workpiece that is conveyed intermittently, the method comprising:
 punching out the product from the workpiece by using a die on which the conveyed workpiece is placed, a punch that is arranged to approach and move away from the die, and a back pressure portion that is provided in the die and is urged toward the punch to apply a back pressure to the workpiece;   displacing the workpiece upward with respect to the die when the punch moves away from the die;   before the product is punched out, providing a protrusion that protrudes downward and is located at a part of the workpiece, wherein the part is on an upstream side in a workpiece conveying direction of a punch-out portion, from which the product is punched out, and is aligned with the punch-out portion; and   using the protrusion, which is displaced downstream in the conveying direction together with the workpiece, to push the product downstream in the conveying direction, so that the product is ejected to the outside.   
     
     
         2 . The stamping method according to  claim 1 , comprising providing the protrusion by performing half-blanking on the workpiece. 
     
     
         3 . The stamping method according to  claim 1 , comprising providing the protrusion at a position that corresponds to opposite ends in a width direction of the punch-out portion,
 wherein the width direction is orthogonal to both the conveying direction and a direction in which the punch approaches and moves away from the die.   
     
     
         4 . A stamping apparatus for punching out a product from a workpiece that is conveyed intermittently, the apparatus comprising:
 a punch-out mechanism that includes
 a die on which the conveyed workpiece is placed, 
 a punch that is arranged to approach and move away from the die, and 
 a back pressure portion that is provided in the die and is urged toward the punch to apply a back pressure to the workpiece, 
 wherein the punch-out mechanism is configured to punch out the product from the workpiece by using the die, the punch, and the back pressure portion; 
   a protrusion providing mechanism that is configured to provide a protrusion that protrudes downward and is located at a part of the workpiece, wherein the part is on an upstream side in a workpiece conveying direction of a punch-out portion, from which the product is punched out, and is aligned with the punch-out portion; and   a displacing mechanism that is configured to displace the workpiece to a position where the protrusion and the product are aligned with each other in the conveying direction when the punch moves away from the die.