| 摘要 |
PURPOSE: A hydraulic control circuit is provided to stably lift or land a hydraulic elevator, to prevent a start shock without cavitation and to detect an abnormal operation of a main check valve during a stop control. CONSTITUTION: A hydraulic control circuit for an inverter control hydraulic elevator comprises an oil hydraulic cylinder(1) lifting a car; a driver(100) containing an oil hydraulic pump(6) pumping oil from an oil tank(9) to drive the oil hydraulic cylinder, an electric motor(7) rotating the hydraulic pump and an encoder(8) sensing the RPM(revolution per minute) of the electric motor; a control valve(200) containing an open solenoid valve(24) controlling the pressure of a pilot pressure chamber in a main check valve(26) discharged to an oil hydraulic cylinder line, a close solenoid valve(25) controlling the pressure of the pilot pressure chamber discharged to an oil hydraulic pump line, an emergency close solenoid valve(22) connected between the open solenoid valve and the hydraulic cylinder line and an emergency control valve(23) connected between the emergency close solenoid valve and the hydraulic cylinder line at one end and connected between the emergency close solenoid valve and the open solenoid valve at the other end; a pressure gauge(16) connected to the oil hydraulic cylinder line; a pressure sensor(18) measuring the pressure of a cylinder; a hand pump(15); and a pressure sensor(19) measuring the pressure of the oil hydraulic pump.
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