Electrohydraulic pressure control of an automatic transmission using a PWM switching valve

Autor:	Yoshiaki Katoh, Hirohisa Tanaka
Rok vydání:	1990
Předmět:	Engineering Power transmission Automatic transmission Pressure control business.industry Ocean Engineering Valve actuator Electrohydraulic servo valve law.invention Control theory law Control system Torque business Pulse-width modulation
Zdroj:	Hydraulics & Pneumatics. 21:169-174
ISSN:	2185-5285 0286-6900
Popis:	An automatic power transmission has some pressure control valves for wet-clutch engaging or band-brake tightening control. Recent transmissions are being changed from hydromechanical control systems to electrohydraulic systems for improvement of shifting quality and control flexibility. A conventional hydromechanical system has a large accumulator for the smooth pressure control.; however, the size is sometimes a problem during installation on vehicles.In this paper, a two-stage pressure control valve is applied to the control system, consisting of a PWM control switching valve and a secondary pressure control valve. The secondary valve is provided with a hydraulic position limiting mechanism for reducing the pressure surge. The electrohydraulic pressure control system is applied to advanced automatic transmissions. The system reduced the torque change at gear-stage shifting by half.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::74186d680dabcabf1e37217b1c4882d0 https://doi.org/10.5739/jfps1970.21.169 Zobrazit plný text záznamu