HYDRAULIC CIRCUIT DEVICE

摘要

A load pressure detection oil passage (7-1) branches from an oil passage (30-1) between the outlet passageway (5b) of a flow dividing valve (5-1) and a hold check valve (6-1) and is connected to a signal detection oil passage (9), the latter being connected to a tank (T) via a restrictor (14) (with an area at), while a control oil passage (10-1) branches from the load pressure detection oil passage (7-1) and is connected to a control chamber (70), with a check valve (8-1) placed in an oil passage portion (7a) between the oil passage (30-1) of the load pressure detection oil passage (7-1) and the branch point at which the control oil passage (10-1) branches, with a restrictor (11) (with an area ac) placed in an oil passage portion (7b) between a branch point at which the control oil passage (10-1) of the load pressure detection oil passage (7-1) branches and the signal detection oil passage (9). Thereby, in the hydraulic circuit device having a load sensing system, smooth starting characteristics are obtained irrespective of the size of an inertial body to be driven, and the arrangement is simple and can be readily applied even in the case of a spool type control valve.