This invention relates to a V-belt type continuously variable transmission for vehicles and particularly relates to a reduction ratio detecting mechanism adapted to detect the reduction ratio between the input and output shafts for selectively supplying pressure oil to the oil-hydraulic control circuit of the V-belt type continuously variable transmission corresponding to the reduction ratio between the input and output shafts.
In a vehicle equipped with a V-belt type continuously variable transmission, the engine power consumption by the oil pump generating the oil pressure applied to the oil-hydraulic servo-system can be reduced and, thereby, improvement of the specific fuel consumption of the engine is possible when the oil pressure applied to the oil-hydraulic servo-system for driving the movable flange of the pulley controlling the reduction ratio is controlled to the lowest necessary pressure corresponding to the reduction ratio between the input and output shafts. For such a purpose, it is necessary to provide a reduction ratio detecting mechanism capable of converting the position of the movable flange corresponding to the reduction ratio into an oil-hydraulic signal.