DETECTOR FOR TURNING ANGLE OF SLEWING BASE TABLE OF BACK- HOE WORKING VEHICLE

摘要

PURPOSE:To detect the turning direction of a slewing base table by information from a rotary encoder by using two rotary encoders of a low frequency. CONSTITUTION:Two rotary encoders 10a and 10b to detect the turning angle of a slewing base 2 are set and connected to the slewing base 2 in an interlocking manner such that pulse signals sig.1 and sig.2 to be sent out with the turning operation are sent out with nearly equal pulse width W and a pulse repeating period T and also such that the phases of the signals sig.1 and sig.2 are differentiated from each other with a smaller width than the pulse width W. On the basis of the leading and trailing detection of the signals sig.1 and sig.2, the turning direction of the slewing base table 2 is judged and pulse signals of pulse repeating frequency (f=1/T) four times greater than pulse from the encoders 10a and 10b is sent out from a circuit 15. Since inexpensive rotary encoders of low frequency are used, the turning angle detector of high detection accuracy can be obtained at low cost.