Oil pressure control unit of automatic speed changer having torque converter with lockup mechanism

Abstract

Abstract PURPOSE:To reduce the cost by allowing the operation stop of two speed change stages by one car speed cut valve in the said control unit having the car speed cut valve stopping the operation of a lockup mechanism at a predetermined car speed or less. CONSTITUTION:A lockup control valve 44 communicated to the lockup clutch oil chamber LC of a torque converter T/C via an oil passage 456 and a lockup timing valve 46 communicated to the port 146c of this valve 44 via an oil passage 454 are provided. In addition, a car speed cut valve 48 communicated to the port 146b of this valve 46 via an oil passage 458 is provided, the governor pressure in response to the car speed is fed to this port 148a through an oil passage 430, and the port 148c is connected to ports 144a, 146a of the valves 44, 46 via an oil passage 452. Then, a car speed cut valve 48 is formed so that the lockup release can be performed at the low car speed of the third speed and fourth speed.

Inventors

• 👤 Kunio Otsuka
• 👤 邦雄 大塚

Bibliographic Details