US 6,669,599 B2 · Shift control apparatus for an automatic transmission

Abstract

A shift control apparatus for an automatic transmission eliminates or reduces a sense of discomfort to the driver and other occupants during slip, while maintaining the necessary driving force. When slip is determined by detection of wheel speed, a slip signal is output. A controller which receives the slip signal outputs a maintaining signal for maintaining the gear stage which existed at the time the slip signal was received, until a predetermined period of time has passed. If the slip continues after the predetermined period of time, the controller outputs a shift signal to the automatic transmission to shift it to a predetermined gear stage, thus reducing driving force and preventing slip from continuing. If the slip stops within the predetermined period of time, the slip signal is canceled such that the current gear stage is maintained and no shift is executed.

Claims24

Dependent claims

A shift control apparatus for an automatic transmission in a wheeled vehicle, comprising:

an automatic transmission for changing input speed of rotation of an input shaft to an output speed based on a running state of the vehicle and outputting rotation at the output speed to an output shaft;
wheel speed detecting means for detecting wheel speed of a wheel;
slip determining means for determining slip based on the wheel speed detected by said wheel speed detecting means and outputting a slip signal corresponding to the determined slip;
shifting means for outputting a shift signal for a predetermined gear stage which reduces driving force, when the slip signal is continuing after a predetermined time has passed since start of the slip signal;
and
maintaining means for outputting a maintaining signal for maintaining, for a predetermined time from a point at which the slip signal was input, a gear stage at the point at which the slip signal was input.

3 more elements

A shift control apparatus for an automatic transmission mounted in a vehicle, comprising:

an automatic transmission for changing input speed of rotation of an input shaft to an output speed based on a running state of the vehicle and outputting rotation at the output speed to an output shaft;
wheel speed detecting means for detecting wheel speeds of a driven wheel and a non-driven wheel;
slip determining means for determining slip based on the wheel speeds detected by said wheel speed detecting means and outputting a slip signal corresponding to the determined slip;
shifting means for outputting a shift signal for a predetermined gear stage which reduces driving force, when the slip signal is continuing after a predetermined time has passed since start of the slip signal;
and
switching means for switching from determination of the running state of the vehicle based on the speed of the driven wheel to determination of the running state of the vehicle based on the speed of the non-driven wheel, on the basis of input of the slip signal from the slip determining means.

3 more elements

Dependencies are inferred from the claim text.

Shift control apparatus for an automatic transmission

Life of this patent

Shift control apparatus for an automatic transmission

Life of this patent

Abstract

Claims24