| 摘要 |
PURPOSE:To enable steady speed change control even when a primary pulley speed sensor is judged as disordered, by calculating changed speed on the basis of a reserve change gear ratio and a target change gear ratio using engine speed. CONSTITUTION:In speed change control for a belt type continuously variable transmission by a control unit 40, output signals from each sensor 41-44 are read in and actual car speed (i) is obtained by an actual speed calculation part 45 and a target change gear ratio (is) obtained by a target change gear ratio retrieval part 46. Then, changed speed di/dt is obtained by a speed change calculation part 48, using the values of (i) and (is) and a factor (k). The speed so obtained and the value of (i) are used to obtain a duty ratio (D) for application to the solenoid valve 28 of a speed change control system. On the other hand, when primary pulley speed 41 is judged to be disordered by a trouble judging part 52, the changed speed di/dt is calculated similarly to the aforesaid method by using a reserve change gear ratio (i) obtainable from engine speed Ne and counter pulley speed Ns given by a reserve change gear ratio calculation part 51. |
