Valve arrangement for control of hydraulic equipment of e.g. lifting gear of land cultivator

摘要

The arrangement consists of a control valve (18) which connects the lifting gear to a pump (P) or to a tank (T), an orifice plate flowmeter which is used to control the volume flow of hydraulic fluid to or from the user and a non-return valve (22) which is mounted between the user and the control valve. A load relay (40) is used too monitor the load on the user. The load relay incorporates a section of control line (28) which, taken in the direction of build-up of pressure, connects a section upstream of the orifice plate to a section downstream of it. A choke (30) is mounted in a section of the control line, separating the load pressure from the input pressure. The flow in the direction of the orifice plate is blocked by a non-return valve (36).