AUTOMATIC CONTROL OF TILLING DEPTH BY ROTARY TILLING AND WORKING MACHINE AND REAR COVER THEREOF

摘要

PURPOSE:To maintain accuracy of control of tilling depth, by keeping action amount of advance and retreat of feed back link mechanism unchanged even by adjustment of height of hanging of rear cover. CONSTITUTION:Rotation of a rear cover 40 is transmitted through a rotary arm 62 and an advance and retreat rod 72 to a pushing arm and further a hydraulic cylinder is controlled through a pressure receiving arm to control tilling depth. The rear cover 40 can be changed by operation of a change lever 55 from the upper position wherein a connecting arm 65 is upward rotated and a flexible film 41 is bent to the lower position wherein the connecting arm 65 is downward rotated and the flexible film 41 is expanded. Since the longitudinal position of a pivot pin 67 is unchangeably set, the position of the advance and retreat rod 72 will not change. Consequently, accuracy of control of tilling depth is not influenced even by fluctuation of the rear cover position.