| 摘要 |
PURPOSE:To make it possible to prevent unexpected belt slip at tire slip on the road having low mu value by maintaining high line pressure during a prescribed time after releasing an accelerator at tire slip. CONSTITUTION:When a wheel speed rises suddenly at acceleration on the road having low mu value and the acceleration becomes over the prescribed value unable to generate on the dry road surface, a tire slip judging part 171 judges it as tire slip. In the condition of this tire slip and the accelerator opening, an action mode judging part 162 selects a high pressure setting part 168 by means of output from a high pressure control part 173. Hereby, a solenoid valve 97 is not supplied with electric current, line pressure is changeovered to a high pressure level, and the line pressure is controlled in high pressure at the tire slip. Hereupon, when a driver finds out tire slip and release an accelerator, a high pressure control condition can be maintained by means of the high pressure control part 173 during the prescribed time due to a timer 172. Thus, belt slip accompanied with rapid rotation variation can be surely prevented. |
