| 摘要 |
Apparatus for producing an instantaneous pressure on a workpiece includes a working piston, one side of which is impinged by gas under pressure tending to move the working piston from a starting position in a direction towards the workpiece, whereas the other side of the working piston is over a control valve impingable by a pressure fluid, preferably a hydraulic fluid, whereby the working piston is returnable to the starting position. A control piston is movable from a first position extending into a space communicating with the space into which the pressure fluid is fed to a second position moved out of the space and the volume of the control piston is such so as to produce during its movement from said first to said second position an instantaneous relief of the pressure of the pressure fluid acting on the other side of the working piston, whereby a corresponding instantaneous pressure is produced on the workpiece by a piston rod projecting from the other side of the working piston in engagement with the workpiece. The apparatus is used for forging, deep drawing, coining, etc. of a workpiece. |
