Arrangement of controlling the output torque of an automatic transmission

US5407401A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Wolfgang Bullmer · Bietigheim-Bissingen, DE
• Martin Streib · Leinfelden, DE
• Richard Schottle · Mühlacker, DE
• Hong Zhang · Schwieberdingen, DE

Key dates

• Filing date: Oct 14, 1993
• Grant date: Apr 18, 1995
• Expiry date: Oct 14, 2013

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H2306/52
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

An arrangement for controlling the output torque (M.sub.ab) of an automatic transmission (10) during the sequence of a shift operation in a motor-driven vehicle to a value pregiven by the driver is suggested with the transmission (10) having at least two transmission stages (11, 12) which can be alternately shifted into via clutches (16, 17). During upshifting, the clutch (17) assigned to the higher transmission stage is continuously closed in a time-controlled manner with the motor torque being increased correspondingly for holding the output torque (M.sub.ab) constant. The first clutch (16) is assigned to the lower transmission stage and is opened when this first clutch (16) no longer transmits torque. Thereafter, the second clutch (17) is brought to its synchronous rpm by reducing the motor torque (M.sub.m) and then driven further without slippage. The downshifting operation takes place in a changed sequence in a like manner. A great shift comfort while avoiding any jolts is obtained when shifting with the shift operations being configured as above.