Press machine and pressing method

Abstract

A press machine includes a lower die having a step portion for forming a bent portion on a side surface, a pad portion supported by a spring and disposed adjacent to the lower die in the horizontal direction, being movable upward and downward, an upper die disposed opposing the pad portion in the vertical direction, and a regulation portion. When the upper die moves downward and presses a steel plate between the upper die and the pad portion to form a bent portion in an edge portion of the steel plate, the regulation portion moves together with the upper die and regulates the motion of the edge portion of the steel plate protruding from the lower die in the horizontal direction, thereby preventing a wrinkle from forming in the edge portion of the steel plate.

What is claimed is: 
     
         1 . A press machine comprising:
 a lower die having a step portion on a side surface thereof;   a pad portion supported by a spring and disposed adjacent to the lower die in a horizontal direction, the pad portion being movable upward and downward in a vertical direction;   an upper die disposed opposing the pad portion in the vertical direction; and   a regulation portion movable together with the upper die upward and downward in the vertical direction,   wherein the upper die and the pad portion are configured to hold a steel plate therebetween,   the lower die is configured to form a bent portion at an edge portion of the steel plate held between the upper die and the pad portion, when the upper die and the regulation portion move downward, and   the regulation portion is configured to regulate a movement of the edge portion of the steel plate protruding from the lower die in the horizontal direction, when the bent portion is formed.   
     
     
         2 . The press machine of  claim 1 , wherein the regulation portion is disposed away from the lower die in the horizontal direction so as not to contact the lower die when the regulation portion moves downward, and a lower end surface of the regulation portion lies higher than a lower end surface of the upper die in the vertical direction. 
     
     
         3 . The press machine of  claim 1 , wherein the regulation portion is disposed away from an end of the upper die in the horizontal direction. 
     
     
         4 . The press machine of  claim 3 , wherein a distance between the regulation portion and the lower die in the horizontal direction is larger than a thickness of the steel plate. 
     
     
         5 . The press machine of  claim 1 , wherein the lower die and the regulation portion are curved as a whole along the edge portion of the steel plate. 
     
     
         6 . A pressing method comprising:
 providing a press machine comprising a lower die having a step portion on a side surface thereof, a pad portion supported by a spring and disposed adjacent to the lower die in a horizontal direction, an upper die disposed opposing the pad portion in a vertical direction, and a regulation portion movable together with the upper die upward and downward in the vertical direction, the pad portion being movable upward and downward in the vertical direction;   heating a steel plate to an austenitizing temperature or higher;   mounting the heated steel plate on the lower die and the pad portion;   moving the upper die and the regulation portion downward so as to hold the steel plate between the upper die and the pad portion;   moving the upper die and the regulation portion further downward so as to form a bent portion at an edge portion of the steel plate between the lower die and the upper die that is moved further downward; and   regulating a movement of the edge portion of the steel plate protruding from the lower die in the horizontal direction so as to prevent a wrinkle from forming in the edge portion of the steel plate, when the bent portion is formed.   
     
     
         7 . The pressing method of  claim 6 , wherein the regulation portion is disposed away from the lower die in the horizontal direction so as not to contact the lower die when the regulation portion moves downward, and a lower end surface of the regulation portion lies higher than a lower end surface of the upper die in the vertical direction. 
     
     
         8 . The pressing method of  claim 6 , wherein the regulation portion is disposed away from an end of the upper die in the horizontal direction. 
     
     
         9 . The pressing method of  claim 8 , wherein a distance between the regulation portion and the lower die in the horizontal direction is larger than a thickness of the steel plate. 
     
     
         10 . The pressing method of  claim 6 , wherein the lower die and the regulation portion are curved as a whole along the edge portion of the steel plate.