Method of controlling clutch in continuously variable transmission

Abstract

Abstract PURPOSE:To make it possible to realize a clutch engagement condition expected by the driver by controlling a hydraulic circuit when a control section receiving detection signals indicating various operating conditions determines a hold mode, so as to control the clutch pressure to a predetermined pressure. CONSTITUTION:A belt drive type continuously variable transmission 2 is composed of a primary pressure control valve 34 as a speed change control valve, a constant pressure control valve 38, a line pressure control valve 44 and a clutch pressure control valve 52 in a hydraulic circuit, and the valves 34, 44, 52 are controlled by a control section 82 through a solenoid valves 42, 50, 58, respectively. The clutch pressure control valve 52 is provided so as to control the clutch pressure of a hydraulic start clutch 62. In this arrangement, if the control section 82 determines such a hold mode that a shift lever is located at a running position, the engine rotational speed is less than a predetermined value (about 100rpm) while the vehicle speed is less than a predetermined value (about 8km/h), and an accelerator pedal gives an opening condition, the clutch pressure control valve 52 is controlled so as to set the clutch pressure to a predetermined pressure.

Inventors

• 👤 Katsuaki Murano
• 👤 Sadayuki Hirano
• 👤 Yoshinobu Yamashita
• 👤 Takumi Tatsumi
• 👤 Hiroaki Yamamoto

Bibliographic Details