HYDRAULIC CIRCUIT IN SWINGABLE WORKING APPARATUS.

摘要

A hydraulic circuit in a swingable type working apparatus wherein the operation of a working machine is quickened when a swingable member and the working machine are simultaneously operated. For this purpose, the delivery path of a hydraulic pump (10) is connected to a hydraulic motor (161) for swinging and a cylinder (162) for the working machine through first and second control valves (151, 152), pressure compensating valves (18) are respectively provided between the first and second control valves (151, 152) and the hydraulic motor (161) and the cylinder (162), so that load pressure of the hydraulic motor (161) for swinging and load pressure of the cylinder (162) for the working machine are introduced into a load introducing path (23) through check valves (42), respectively, so that the respective pressure compensating valves (18) are set by the load pressure of the load pressure introducing path (23), and the check valve (42) for detecting the load pressure of the hydraulic motor (161) for swinging is not operated even if the second control valve (152) is operated.