CONTROL CIRCUIT FOR EXCAVATOR HAS PROGRAMMED CONTROL FOR HYDRAULIC SERVO-CYLINDERS WITH OVERLOAD PROTECTION

摘要

The control process for maintaining position of the bucket during several operations by the excavator, such as an excavating operation, is provided. The desired angular position of the loaded bucket with respect to the absolute horizontal line of the ground surface is automatically controlled not to change even when another actuators except for the bucket cylinder are actuated upon positing the control level for the bucket cylinder at the neutral position, thereby preventing the objects contained in the bucket from being dropped. The process removes difficulty in handling the control levers/pedals for the actuators at the same time.