| 摘要 |
PURPOSE:To control the ram speed over a wide range in a quick and accurate way, by calculating the deviation between the ram speed extracted from the distance between the stop position of a target and the present position and the set speed and controlling a variable capacity type hydraulic pump with the arithmetic output corresponding to the above-mentioned deviation. CONSTITUTION:A detector 25 is set to a hydraulic forging press main body 22 to detect the residual stroke, i.e. the distance between the target stop position and the present position of a ram 20. A microcomputer 27 holds the set speed calculating relation showing the relation between the distance and the set speed of the ram 20 at an ROM35. Based on this relation, the set speed corresponding to the distance is calculated to be held at an RAM36. At the same time, the real speed of the ram 20 extracted from the distance is fed back, and an output in accordance with the deviation to the set speed and the set speed is sent out through an arithmetic part 37. Then the output of the part 37 is delivered to a hydraulic servomotor 42 to control the output degree of a variable capacity type pump 41. Thus the speed of the ram 20 is controlled. |
