GB856650A - Improvements in controlling means for hydraulic presses, particularly forging presses - Google Patents

Abstract

856,650. Fluid-pressure servomotor-control systems. SCHLOEMANN A. G. March 7, 1958 [March 25, 1957], No. 7369/58. Class 135. An electro-hydraulic servomotor control system for controlling a forging press, comprises a rotary hydraulic motor 11 under the control of a slide valve 23 receiving pressure liquid from a pump 29 and actuating through a shaft 10 and a worm and worm-wheel 8, 9 a cam-shaft 5 which through cams 6 actuates the pressactuating valves 7. The slide valve 23 is in turn controlled by an hydraulic amplifier 21 having a control valve receiving pressure liquid from a pump 28 and connected by a rod 20 to the plunger coil 19 of a plunger-coil regulator 17. The plunger-coil regulator 17 receives signals through an electric amplifier 15 and a rectifier 16 from an induction rotary setter 4 having a rotor keyed to the cam-shaft 5 so that the motor 11 rotates the rotor to remove the voltage differential between the setter 4 and a desired value of voltage determining the position of the valves 7. The desired value of voltage may be set by hand-lever of a continuously variable mechanical controlling appliance 1 keyed to a shaft 2 which in turn is keyed to the rotor of an inductive rotary setter 3. When switches 41 are closed the rotor 5 of the setters 3, 4 rotate to operate the motor 11 until the differential voltage between the setters is removed. Alternatively, the desired value of voltage may be set by switching into circuit with the setter 4 one or other of resistance connections 51, 52, 53, 54 by means of push-button switches 47, 48, 49, 50.