| 摘要 |
PURPOSE:To prevent lowering of the transmission efficiency and deterioration of the durability of a belt, by preventing the speed ratio from increasing or decreasing infinitely. CONSTITUTION:A maximum value -emax and a minimum value -emin of the speed ratio of a CVT are preset. At a step 59, a desired speed ratio e* is calculated from a desired revolutional speed Nin* on the input side and the actual revolutional speed Nout on the output side. At a step 60, comparison is made between e* and -emax. Here, if e* is equal to or greater than -emax, the procss proceeds to a step 70, where -emax is set at the desired speed ratio e*. Further, at a step 64, comparison is made between e* and -emin. Here, if e* is equal to or smaller than -emin, the process proceeds to a step 71 and -emin is set at the desired speed ratio e*. Resultantly, the speed ratio of the CVT is set at a value between -emin and -emax, so that it is enabled to prevent the speed ratio from increasing or decreasing infinitely. |
