| 摘要 |
PURPOSE:To decrease the line pressure as low as possible while a V-belt is prevented from slipping to enhance the durability of the V-belt, by compensating a reference line pressure determined in accordance with the operating condition of an engine, to a high line pressure upon shift-down in comparison with that upon shift-up CONSTITUTION:In a stepless speed change unit 4 in which the gear ratio is changed by adjusting the groove gaps of drive and driven pulleys having variable effective diameters, by means of hydraulic actuators, there are provided a line pressure regulating means A for regulating the line pressure fed to the hydraulic actuators, and a gear ratio regulating means B for changing the gear ratio. Further, there are provided a line pressure control means C for controlling the regulating means means A to set the line pressure to a reference value which is set in accordance with the operating condition of the engine, and a gear shift control means D which delivers a shift-up shift-down signal, for controlling the gear ratio. Further, upon shift-down a line pressure compensating means E compensates the above-mentioned reference value to a high value in comparison with that upon shift-up. |
