Control device for four wheel drive vehicle

Abstract

Abstract PURPOSE:To continue a four-wheel driving condition even when a vehicle speed is increased and ensure stable traveling by setting vehicle speed control starting number of revolutions to a high speed side on a low friction road surface, in the captioned vehicle which is automatically shifted to two-wheel driving when a vehicle speed becomes above a set value by a vehicle speed control. CONSTITUTION:The captioned control device controls solenoids S1, S2 based on the output signals of front and rear rotation sensors 29', 29, a steering sensor 255, etc., thereby, shifting a transfer device to direct coupled four-wheel driving, differentially movable four-wheel driving, or two-wheel driving. In this case, it is detected whether a road surface is a high friction road surface or a low friction road surface based on a slip ratio which is operated from a defined formula. And, a reference vehicle speed value at the time of automatically shifting from a four-wheel driving to a two-wheel driving in accordance with a vehicle speed, is set to a low speed side at the time of high friction road surface, whereas, setting to a high speed side at the time of low friction road surface. Thereby, a four-wheel driving is continued on a low friction road surface even when the vehicle speed is increased, maintaining stable traveling.

Inventors

• 👤 Osamu Miyake
• 👤 三宅　道
• 👤 Kenji Takeuchi
• 👤 武内　賢二
• 👤 Koji Yoshiyanagi
• 👤 吉柳　考二

Bibliographic Details