Control apparatus for hydraulically operated vehicular transmission

• Main Authors: TSUBOI; YOSHIHIRO, KAWAUCHI; MASAYA, WAKAMATSU; HIDEKI, SAKAI; TAKAFUMI
• Format: Patent
• Language: English
• Published: 28.11.1995
• Edition: 6
• Subjects: BLASTING; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; LIGHTING; MECHANICAL ENGINEERING; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; THERMAL INSULATION IN GENERAL; WEAPONS

The transmission is of a type that a low-speed transmission train is established in cooperation with one-way clutch. A high-speed transmission train is established by hydraulic oil supply via a shift valve in a condition in which the hydraulic oil is kept supplied to the low-speed hydraulic engaging element. A pressure adjusting valve and a hydraulic oil pressure control valve control, to increase or reduce, the supply pressure of the hydraulic oil to the high-speed hydraulic engaging element. A speed change controller at an initial stage maintains the shift valve, at the time of speed changing from a high-speed transmission train to a low-speed transmission train, in a condition in which the hydraulic oil is supplied to the high-speed hydraulic engaging element. The supply pressure of the hydraulic oil is reduced in this condition until the high-speed hydraulic engaging element gives rise to a slip. The supply pressure of the hydraulic oil is maintained in the condition of reduced pressure until the one-way clutch is engaged and thereafter the shift valve is changed over to a condition in which the hydraulic oil is discharged from the high-speed hydraulic engaging element.