GB1260586A - Hydraulic high pressure forging apparatus - Google Patents

Abstract

1,260,586. Forging. TOKYU SHARYO SEIZO K.K. 14 Jan., 1969 [30 Jan., 1968; 31 Jan., 1968; 15 March, 1968], No. 2223/69. Heading B3H. A high-pressure forging apparatus comprises a set of die segments, Figs. 7-12, arranged around a central die cavity and an hydraulic chamber into which a plunger is movable to generate hydraulic pressure which is transmitted through the hydraulic fluid to at least some of the die segments to move them simultaneously. The plunger 3, Fig. 1, may seal the chamber or close the chamber at the end of its stroke, Figs. 3 and 5. The plunger is driven by compressed air. The separation of the die segments may be adjustable by hydraulic positioning mechanism 16, Fig. 1, or by hydraulically operated toggle mechanism, Fig. 2 (not shown). The adjusting mechanism is shown for illustration with a two die arrangement which is used to describe the pressuregenerating method. The hydraulic liquid may be water or glycerine. An air punch may be used to give impact to the hammer. In one embodiment of the invention, Fig. 7, the die segments are arranged to enclose a die cavity 43 and are moved by a high pressure impulse transmitted from a common impact hydraulic pressure generator. Four die segments 42 surround the cavity on a horizontal plane and a fifth die segment 44 is moved between the die segments 42 by the hydraulic pressure impulse to abut a base block (46), Fig. 8 (not shown). In a similar embodiment, Fig. 9, the bottom die segment 53 co-operates with four side die segments 80 and an upper die segment 60. The die segment 53 is held in position by wedges 57. This apparatus may be used with only one opposed pair of die segments operative. The side die segments may be three, five or more to forge polygonal prism shapes. In a final embodiment, Figs. 11 and 12 (not shown), the side die segments serve merely for defining a closed die cavity 62. The upper die segment 60 produces the high forging pressure and an exhaust port (75) communicates with the cavity. A workpiece surrounded by semisolid pressure medium is placed on the lower die segment (53). The medium may be a mixture of grease and graphite or talc. The hydraulic pressure is simultaneously applied to the upper and side die segments whereby the pressure medium flows and fills the cavity. Part of the medium flows out of the exhaust port (75) and the remainder is pressurized in the cavity. Using the above method with the pressure medium such materials as stainless steel can be forged. The workpiece may be shaped into elements for a watch band.