Controlling energy characteristics of power press - by energy transfer between air-hydraulic intensifier and hydraulic cylinder linked to drive connecting rods

摘要

In a conventional power press drive energy is normally lost in the form of heat emitted by the clutch and brake during the press working cycle. In the new system a power press for drawing operations has a hydraulic cylinder (18) linked across the two connecting rods (7a, 7b) of the press eccentric drive shafts (6a, 6b). The chambers of the cylinder are connected by way of directional control valve (19) to a pressure intensifier (28) which acts as an energy storage unit. Also connected to the high pressure side of the pressure intensifier is the hydraulic cylinder (25) for loading the draw ring (21) of the drawing tool. Under valve control the intensifier releases energy allowing hydraulic cylinder to close and accelerate the press ram at the start of the press cycle. Conversely, the cylinder returns oil to the intensifier towards the end of the cycle, thus decelerating the ram. ADVANTAGE - Reduced wear of clutch and brake. More efficient energy usage. Reduced noise.