DIGGING FORCE CONTROL DEVICE OF EXCAVATOR

摘要

PURPOSE:To improve digging efficiency and accuracy by comparing a digging load detected by a sensor with the set value and controlling the lowering speed of a digging device so that it is slowed down when the digging load is larger than the set value, and the lowering speed is accelerated when the load is smaller than the set value. CONSTITUTION:An optimum digging load is determined by a digging load setting device 39, and set by a setting switch 41. Then, the braking force to be given to a power transmission system is set out by operating a controller 35. Next, a digging device 15 is lowered to sit on the bottom by extending the rope of a hoisting drum 9a, and a load current detected by a digging load current detector 42 is fed back to a control computer 36, and compared with the set value preset by the setting device 39. Further, a control unit 33 outputs a command value foward an electro-hydraulic conversion valve 30 to slacken the braking when the digging load is smaller than the set value, and to increase the braking force when the load is larger than the set value.