CONTROLLER FOR QUANTITY OF DISCHARGE FROM PUMP OF HYDRAULIC CLOSED CIRCUIT

摘要

PURPOSE:To prevent the sudden change of speed in case of the falling of an activator for one-rod cylinder by detecting the position of the activator and regulating the acceleration of the one-rod cylinder in case of the falling of the activator. CONSTITUTION:A position detector 30 detects the angle of rotation of a boom 1 as the activator, and outputs the detecting value as electrical signals. A controller 17 is subject to the electrical signals, and electrically operates a control mechanism 13 for the quantity of discharge of a variable-capacity pump 3 by an output device 21. The sudden change of speed in case of the falling of the one- rod cylinder is prevented because the maximum quantity of variation in aptitude which can change the quantity of operation command of the control mechanism 13 for the quantity of discharge of the variable-capacity pump 3 is set to a value within a range that the acceleration of a boom cylinder 2 does not exceed the gravity of the boom 1.