Shift controller of vehicle automatic transmission

Abstract

To provide a shift control device for an automatic transmission preventing uncomfortable feeling caused by down shift unintended by a driver associated with return from a high fluid temperature gear shift diagram to a basic gear shift diagram. An electronic control device (38) as the shift control device includes a low output state determination means (78) for determining whether or not a target throttle opening ([theta]TH*) used for gear shift determination is in a low output state below a low output determination value ([theta]TH1); and with a gear shift diagram switch control means (80) for returning a gear shift diagram from the high fluid temperature gear shift diagram to the basic gear shift diagram when it is determined that working fluid temperature (TOIL) is below a fluid temperature determination value (TOIL1) and in a low output state. Thus, since a down shift line of the basic gear shift diagram and a down shift line of the high fluid temperature gear shift diagram are common to each other in the lower output side region than the low output determination value ([theta]TH1), this prevents uncomfortable feeling caused by down shift unintended by a driver associated with the return from the high fluid temperature gear shift diagram to the basic gear shift diagram.

Description

technical field [0001] The present invention relates to a high temperature shift line switching control in which a shift line for automatic shift control is shifted to a low speed side when a hydraulic fluid temperature of the automatic transmission is high in an automatic transmission equipped vehicle. Background technique [0002] A known shift controller of an automatic transmission for a vehicle includes a shift control unit and a shift map switching control unit. The shift control unit automatically shifts the gear position of the automatic transmission based on the state of the vehicle with reference to a pre-stored basic shift line map. When the hydraulic fluid temperature in the automatic transmission is higher than a predetermined fluid temperature judgment value, the shift map switching control unit switches from the basic shift map to the high fluid temperature shift map, the high fluid temperature shift map It is set on the lower vehicle speed side with respect ...

AI Technical Summary

Problems solved by technology

Therefore, when the vehicle state falls in the higher speed side region with respect to the high fluid temperature shift line due to switching back to the basic shift line map, there is a case that indicates the vehicle speed represented by the vehicle speed and the required power related value The point of the running state crosses the downshift line relatively toward the lower vehicle speed side in the shift line diagram, so the automatic transmission downshifts unexpectedly

Images