Automatic two-wheel/four-wheel drive change-over mechanism for four-wheel drive vehicle

Abstract

Abstract PURPOSE:To improve the starting acceleration and reduce the fuel consumption during the two-wheel drive by a mechanism wherein the connection between the oil pressure source of a four-wheel driven vehicle with automatic speed changer and the oil pressure servo of a friction clutch for four-wheel drive are automatically made ON or OFF on the basis of the set vehicle speed to change-over from four-wheel drive to two-wheel drive. CONSTITUTION:When in two-wheel drive, the oil pressure of an oil passage 104 is supplied to the oil pressue servo 70 of a clutch 7 through an oil passage 225 to engage the clutch 7. While the vehicle speed is below the set point, the spool 231 of a change-over valve 230 locates below the connect the oil passage 104 to an oil passage 235 and to supply the oil pressure to the oil pressure servo 80 to engage the friction clutch for four-wheel drive. When the vehicle speed exceeds the set point, the spool 231 of the change-over valve 230 moves upwards to close the oil passage 104 and exhaust the oil pressure of the oil pressure servo 80 and to disengage to clutch 8, returning to two-wheel drive. Due to the mechanism mentioned above, the starting acceleration and fuel consumption during low speed two wheel drive are improved.

Inventors

• 👤 Shuzo Moroto
• 👤 Yoichi Hayakawa

Bibliographic Details