PATTERN CONTROLLER OF CONSTRUCTION MACHINE

PURPOSE:To perform expansion and contraction operation of a hydraulic cylinder automatically by setting the rotational speed and amplitude angle of a working machine to a controller, and outputting command signals to an electromagnetic switching valve and an electromagnetic proportional reducing valve according to a detected angle. CONSTITUTION:There are provided angle detecting means 9-11 which detect a rotation angle in the refraction part of a working machine 2. An electromagnetic switching valve 32 and an electromagnetic proportional reducing valve 33 are installed on an oil passage which communicates a pilot operation directional control valve 15 changing over the operating direction of a hydraulic actuator for working machine with a pilot pressure source 24. A controller 35 is provided with a pattern operation switch 37 and setters 38, 39 which set the rotational speed and amplitude angle of the working machine 2 respectively. The pattern operation switch 37 is operated and the controller 35 outputs command signals to the electromagnetic switching valve 32 and electromagnetic proportional reducing valve 33 according to a detected angle so that the working machine 2 is pattern-operated according to a preset rotational speed and the amplitude angle.