OPERATING DEVICE FOR WORKING MACHINE

PURPOSE:To accurately detect the neutral position of an operating lever without using a limit switch by detecting a load generated in an operating mechanism by operating the operating lever at the neutral position. CONSTITUTION:When the operating lever 2 is operated in resisting the spring force of a spring 2S, stress F is caused in the operating lever 2, and small deformation is generated in the operating lever 2. A detection/comparison part 11 detects the value of the stress F by the change of the resistance value of a strain gage 10. A relay 8L of 8R is opened by this detection output, and its contact is closed, and the output of control arithmetic part 4 calculated on the basis of the output of a potentiometer 3' is supplied to an actuator 1L or 1R. Then, when the stroke of the operating lever 2 becomes below a definite value, the comparison output of the detection/comparsion part 11 comes to '0'. Thus, the neutral position of the operating lever can be surely detected even without using the limit switch which requires labor and time for fitting and adjusting it.