GB1151996A - High Speed Forging Hammer Apparatus - Google Patents

Abstract

1,151,996. Forging hammers. NIHON SEIKOSHO K.K. 19 Aug., 1966 [19 Aug., 1965], No. 37261/66. Heading B3H. A high speed forging hammer has a vertical cylinder 18 containing a piston 22 connected to the hammer tup 28, 30 and which divides the cylinder into upper and lower spaces 24, 25, which are interconnected in the fluid circuit to form a closed loop system. The lower space 25 is connected through conduit 69 with a low pressure reservoir 66 and the upper space 24 is connected through ports 48, annular chamber 46, valve 50 and conduit 77 with a high pressure reservoir 67. The two reservoirs are interconnected by a compressor 72 and the upper and lower cylinder spaces are interconnected by a bleed duct 42 in piston 22. In operation, the piston 22 in its upper position closes upon a seat 44. An extension 26 of the piston actuates a starting device 58, which opens valve 50 to admit high pressure gas into chamber 46. Valve 50 then closes and device 58 moves piston 22 from its seat, Fig. 3 (not shown), whereby the high pressure acts instantly in cylinder space 24 to effect the forging stroke, Fig. 4 (not shown). After impact the pressure in the cylinder spaces 24, 25 becomes equalized through bleed duct 42 whereby the piston 22 is raised by the upward thrust due to differential piston areas. The compressor 72. includes an unloader for setting the pressure and means are provided to make up for loss of fluid in the system. The starting device 58 may act as a sequence programming device and both the starting device and the valve 50 may be controlled mechanically, electrically or pneumatically. In another embodiment, Fig. 5 (not shown) the bleed duct 42 is replaced by external ducts (78) which may include a valve (80) for varying the lifting speed. The valve may be replaced by an orifice.