Underdrive-type press

Abstract

[Object] An underdrive-type single action press capable of saving energy, saving space, and realizing high-precision formability in a well-balanced manner is provided. Particularly, a press capable of shortening a forming stroke, reducing overall height, exactly correcting the deflection of the slide or dies to improve adhesion of the dies to a workpiece, and realizing pressure equalization of a wrinkle holder is provided. [Means for Resolution] An underdrive-type press includes a forming press unit including a lower die located inside an annular wrinkle holder fixedly disposed on a bed, and a drive mechanism disposed within the bed to raise or lower a slide supporting the lower die, a slide raised or lowered by a drive mechanism loaded on the side of a crown, a die-clamping press unit including an upper die having a clamping portion pinching a workpiece in cooperation with the wrinkle holder at its peripheral edge, and a device applying a pressing force to the upper die from its back after the last stage of the descent of the slide of the die-clamping press unit and the upper die for improvements in forming precision.

1 . An underdrive-type press comprising:
 an annular wrinkle holder fixedly disposed on a bed;   a forming press unit including a lower die located inside the wrinkle holder, a slide supporting a lower die, and a drive mechanism disposed within the bed to raise or lower the slide;   a drive mechanism loaded on the side of a crown, and a slide raised or lowered by the drive mechanism;   a die-clamping press unit including an upper die having a clamping portion pinching a workpiece in cooperation with the wrinkle holder at its peripheral edge; and   a device applying a pressing force to the upper die from its back after the last stage of the descent of the slide of the die-clamping press unit and the upper die for improvements in forming precision.   
   
   
       2 . The underdrive-type press according to  claim 1 ,
 wherein the device applying a pressing force to the upper die from its back for improvements in forming precision includes:   a disk-like base disposed between a lower surface of the slide and the upper die;   a pressurizing portion built in the base;   a pressing member having a pressing surface against the lower surface of the slide, or the back surface of the upper die, and an opposite surface to the pressure surface facing the pressurizing portion;   a pressure generating means disposed in a place outside the base to feed a pressurizing medium to the pressurizing portion; and   a means disposed in a place outside the base to control the pressure of the pressurizing medium fed to the pressurizing portion from the pressure generating means.   
   
   
       3 . The underdrive-type press according to  claim 2 ,
 wherein the pressing member includes a disk-like body with a size enough to cover a wrinkle holding region.   
   
   
       4 . The underdrive-type press according to  claim 2 ,
 wherein the pressing member has a first body in its central region, and a second body in a position corresponding to the wrinkle holding region, the pressurizing portion has a first pressurizing portion corresponding to the first body, and a second pressurizing portion corresponding to the second body, and the pressure generating means is composed of a first pressure generating means for the first pressurizing portion, and a second pressure generating means for the second pressurizing portion.   
   
   
       5 . The underdrive-type press according to  claim 4 ,
 wherein the first body has a disk shape, and the second body has an annular frame shape in plan view.   
   
   
       6 . The underdrive-type press according to  claim 4 ,
 wherein the first body has a disk shape, or the first body and the first pressurizing portion are composed of any of a plurality of fluid pressure cylinders which are connected with each other and are disposed at required intervals, and the second body and the second pressurizing portion is composed of a plurality of fluid pressure cylinders which are connected with each other and are disposed at required intervals.   
   
   
       7 . The underdrive-type press according to  claim 2 ,
 wherein the pressurizing portion is composed of a chamber body, and an elastic body built in the chamber body.   
   
   
       8 . The underdrive-type press according to  claim 2 ,
 wherein the pressurizing portion is composed of a chamber body, and a fluid which fills the chamber body.   
   
   
       9 . The underdrive-type press according to  claim 2 ,
 wherein a sensor for adjusting the pressure to be fed to the pressurizing portion from the pressure generating means is interposed between the lower surface of the slide and the back surface of the upper die or between the base and the back surface of the upper die.   
   
   
       10 . The underdrive-type press according to  claim 2 ,
 wherein the pressure generating means has a servo motor as a driving source.   
   
   
       11 . The underdrive-type press according to  claim 1 ,
 wherein the drive mechanism of the die-clamping press unit includes a digital system motor and links, and the drive mechanism of the forming press unit includes a digital system motor and links.