| 摘要 |
PURPOSE:To prevent the fall in transmission efficiency, the shortening of life, etc., by multiplying the square of the revolution speed of a hydraulic cylinder by a constant to obtain the product as a compensation quantity, and controlling an electromagnetic relief valve to reduce line pressure by the compensation quantity. CONSTITUTION:The revolution speed Nc of a hydraulic cylinder, to which line pressure Pl is transmitted, is detected by a revolution speed sensor. The square of the detected revolution speed Nc is multiplied by a constant K so that a compensation quantity KNc<2> is calculated. An electromagnetic relief valve is controlled to reduce the line pressure Pl by the compensation quantity KNc<2>. As a result, a line pressure rise due to the centrifugal force and a line pressure fall due to the compensation cancel each other so that the line pressure Pl in the hydraulic cylinder is put at a value corresponding to belt-transmitted motive power. This results in preventing the fall in the transmission efficiency of CVT, the increase in the drive loss of an oil pump, the shortening of life of parts of the CVT, etc. |
