摘要 |
<p>Method to control the lowering movement of the lifting cylinder or cylinders (1, 2) of a truck. When a lowering is to take place the pump (5) is started in the pumping direction for increasing the pressure between the pump and a loadholding valve (3, 4) until essentially the pressure has been achieved as in the hydraulic cylinder (1, 2), whereafter the pump with its motor is switched over to regenerative operation, that is the pump works as motor and the motor as generator. The holding valve (3, 4) is opened so that the oil while driving the pump can flow back through this.</p> |