Operating force controlling device for operating lever.

摘要

An operating force controlling device comprises a pair of reactive force mechanisms (70, 70 min ) disposed in an opposing relationship to each other in the direction of operation of an operating lever (60). A load pressure of a motor (30) is detected by a detecting means (91, 91 min ), and a controlling signal is outputted from a controller (90) in response to the load pressure. A pilot pressure is outputted from an electromagnetic proportional pressure reducing valve (80) in response to the control signal. The pilot pressure is inputted into one of chambers of the reactive force mechanisms (70, 70 min ) which moves a rod (72, 72 min ) to project to apply an operation reactive force to the lever (60). The operation reactive force is controlled such that the rate of change thereof may be high when the load pressure of the motor (30) is low but may be low when the load pressure is high. A plurality of control patterns wherein the rate of change of the operation reactive force to the load pressure is different from each other are set to a controller. As an operator senses a change of the operation reactive force with a hand which is operating the lever (60), a change of the load pressure is sensed and initiation of movement of a suspended cargo is sensed.