ENGINE AUXILIARY MACHINE DRIVING CONTROLLER

PURPOSE:To make each auxiliary machine operatable in an efficient manner as well as to aim at the promotion of power-saving, by controlling a driving speed of the auxiliary machine in response to a pressure signal at the low pressure side of an air conditioner, besides an on-off signal out of a compressor of the air conditioner. CONSTITUTION:A device bearing the above caption drives auxiliary machines such as a compressor 5, an oil pump 6, an alternator 3 and a fan 4 via a variable speed pulley 7 and driving belts 19-21 rolled on firs - third pulleys 8-10 of the said pulley 7. In this case, there is provided with a control unit 69 which inputs each detection signal out of an engine speed sensor 51, an on-off detector 54 of the compressor 5 and a low pressure side pressure detector 55 of the compressor 5, etc. And, at the said control unit 69, a proper speed conversion characteristic by the variable speed pulley 7 is selected on the basis of the said detection signal, and according to the selected speed conversion characteristic, a solenoid valve 13 in the variable speed pulley 7 is made so as to be controlled for its on-off operation.