| 摘要 |
The invention pertains to a control valve unit (28) for an hydraulic elevator. It contains two control valves (5, 15) with which the flow of hydraulic oil from a tank to a lifting cylinder driving an elevator cabin and/or from said lifting cylinder to said tank can be controlled. In case of upward movement of said elevator cabin hydraulic oil is conveyed by means of a pump driven by an electromotor, from said tank through said control valve unit (28) to said lifting cylinder, whereas in case of downward movement of said elevator cabin said hydraulic oil flows through said control valve unit (28) to the tank without the pump working. In accordance with the present invention for control of the upward movement and the downward movement of said elevator cabin in said control valve unit (28) one single pilotable control valve (5, 15) respectively is provided for, each of which acts as check valve as well as as proportional valve. In each of said control valves (5, 15) one single flow restrictor (35; 55) is present which is shiftable with respect to a seat (36; 56). Therein, a return spring (37; 57) on one hand and a pilot valve (5v; 15v) on the other hand act on said flow restrictor (35; 55), each of them being actuable by an electrically controllable proportional magnet (5M; 15M). Said control valve unit (28) thus is of very simple construction and can be manufactured in correspondingly cost-saving manner. Therein it is particularly advantageous that setting elements are not required. |
