JPS5744441A - Impact cylinder - Google Patents

Abstract

PURPOSE: To improve the striking efficiency of a press machine, by providing the press machine with returning cylinder equipped with such construction that a reacting force exerted on a striking piston can be reduced at the time when said piston is moved in the direction for its striking operation.

CONSTITUTION: After being pushed downward with the aid of pressurized air flowing from a pressure accumulator 27 into a valve chamber 33, a striking piston 29 moves down rapidly and strikes a large-diameter rod 7 of a cylinder 1 and then conducts a stamping work through a small-diameter rod 8. Accompanied with the downward motion of the striking piston 29, the pessurized air in the pressure accumulator 27 flows into the valve chamber 33 and the pressurized air in a pressure chamber 43 of a returning cylinder 40 flows into the pressure accumulator 27 through a commutating passage 45, an opening port 46 and pipings 47 and because the volume increase of valve chamber 33 is larger than the volume decrease of the pressure chamber 43, the pressures in both the air accumulator 27 and pressure chamber 43 are reduced. Accordingly, the reacting force against the striking force of the striking piston 29, namely the force for pushing up the striking piston 29 originated by pressurized air contained in the pressure chamber 43 can be reduced.

COPYRIGHT: (C)1982,JPO&Japio