| 摘要 |
PURPOSE:To prevent a retard in the starting motion by making rotation control of a motor which operates regularly and reversely a hydraulic pump for oil supply and exhaust to/from a hydraulic cylinder even when the elevator is at a standstill. CONSTITUTION:A hydraulic pump 5 is driven by a three-phase induction motor 6 to supply and exhaust a working oil to/from a hydraulic cylinder 2, and thereby a plunger 3 is elevated and sunk so that an elevator car 1 is elevated ans sunk through a rope 4. The motor 6 undergoes a rotation control with a control device 12 which includes an inverter. When an elevator stop command is issued, the motor 6 undergoes rotation control with the control device 32. That is, pulses from an encoder ENC1 mounted on the car 1 are sensed, and control is made so that such a revolving speed as not allowing the car 1 to move in the rising direction is generated (the revolving speed where the output pulse from the encoder ENC1 becomes zero). This makes the pressure of the cylinder approx. equal to that of the pump 5 to eliminate necessity for the starting compensation. |
