Control device for a hydraulic elevator drive

摘要

A control device (1) for a hydraulic elevator drive (11) with a first and second control valve (21, 22) for controlling the volume flow of a working fluid wherein the flow is detected (610) and compared (52) with a reference value (51) and a pilot (3) with a first and second pilot valve (31, 32) to control the first and second control valve in which the pilot has an actuator (4) and a coupler (33) that can activate and decouple each pilot valve. A hydraulic drive system (16) for an elevator having the control device and a method for retrofitting such a drive system. The control device is simple in design and operation and provides for cost advantages and an increased reliability. The hydraulic drive system with the control device permits an overall improvement in the starting quality of an elevator by automatic compensation of drive-side and output-side interference variables and load-induced fluctuations in the working fluid pressure.

主权项

1. A control device for a working fluid for the operation of a hydraulic drive comprising a flow path for conducting a volume flow of the working fluid in a first direction and in a second direction, a first control valve and a second control valve for controlling the volume flow in the flow path, a flow measuring device to detect the volume flow in the flow path, a comparator to compare the detected volume flow with a volume flow reference value which can be preset, and a pilot control to actuate the first control valve and the second control valve, wherein the flow path, the flow measuring device, the comparator, the pilot control, and the first control valve, and the second control valve form a control circuit for maintaining the volume flow of the working fluid in the flow path in dependence on the volume flow reference value, and the pilot control has a first pilot valve and a second pilot valve for controlling the first control valve and the second control valve, wherein the pilot control comprises an electric actuator to actuate and a coupler to couple each of the first pilot valve and of the second pilot valve, wherein said coupler is formed with a coupling region for moving to and fro between a first position and a second position, wherein in the first position the first pilot valve and the second pilot valve are coupled by the coupling region and can be actuated by the electric actuator so that the second control valve allows the volume flow of the working fluid in the flow path in the second direction, and wherein in the second position the first pilot valve and the second pilot valve are decoupled and only the first pilot valve can be actuated by the electric actuator so that the first control valve allows the volume flow of the working fluid in the flow path in the first direction.