Abstract: A device for hydraulically controlling a continuously variable transmission by decreasing the load exerted on an engine to improve the fuel efficiency and preventing the slipping. The device includes a belt slip detector unit 27 which forms a slip detection signal DS when a slipping state of a V-belt is detected, and a belt slip suppressing unit 25, 26, SW1 which executes a correction processing for suppressing the slipping in response to the slip detection signal. The line pressure is set to a minimum required value until the slip is detected, and the correction processing is executed for suppressing the slip only when the slip is detected.

Abstract: A device for hydraulically controlling a continuously variable transmission by decreasing the load exerted on an engine to improve the fuel efficiency and preventing the slipping. The device includes a belt slip detector unit 27 which forms a slip detection signal DS when a slipping state of a V-belt is detected, and a belt slip suppressing unit 25, 26, SW1 which executes a correction processing for suppressing the slipping in response to the slip detection signal. The line pressure is set to a minimum required value until the slip is detected, and the correction processing is executed for suppressing the slip only when the slip is detected.

Abstract: A duty solenoid valve control apparatus and a duty solenoid valve control method, in which a plurality of duty solenoid valves different in operation from each other are controlled without increase of the program capacity of a computer. The apparatus comprises a duty signal generating device for generating a duty signal corresponding to a time ratio, an overexcitation signal generating device for generating an overexcitation signal to overexcite a solenoid coil, a holding signal generating device for generating a holding signal to hold a duty solenoid valve, and a signal synthesizing device for synthesizing the duty signal, the overexcitation signal and the holding signal into a drive signal for driving the solenoid coil.

Abstract: A controller device for vehicle automatic transmission including oil-pressure driven type friction elements controls the duty factors of the solenoid valves for the respective friction elements involved in the gear shift. In the first control interval A, the duty factors are controlled in accordance with predetermined patterns, such that the friction elements engage with predetermined amounts of slip at the actual beginning of the gear shift. The first interval A is terminated either when a change in the rotational speed of the input shaft of the automatic transmission is detected or when a predetermined length of upper limit for the first interval A expires. When the first interval A terminates, the second control interval B begins, and the duty factors are controlled by a feedback control method.