Emission reduction method for controlling gear shift of automatic transmission

Abstract

The invention relates to an emission reduction method for controlling gear shift of an automatic transmission. The method comprises the following steps that: an engine control unit (ECU) recognizes a water temperature of an engine, a vehicle speed and a starting time so as to judge whether to heat a three-way catalyst, and enters an emission mode; when the water temperature of the engine is lowerthan a set temperature, the vehicle speed is lower than a set speed and the starting time is shorter than a set time, the ECU sends a signal for entering the emission mode to an automatic transmission control unit (TCU), and otherwise, quits the emission mode. In the method, different gear shift modes are configured according to a need to heat the three-way catalyst, so the gear shift can be delayed or a delay command can be released; and the need to heat the three-way catalyst is determined according to three existing signals such as the water temperature of the engine, the vehicle speed andthe starting time. The working efficiency of the three-way catalyst is improved and the emission of the engine is reduced; meanwhile, the steerability in the original automatic transmission mode cannot be influenced.

Description

technical field [0001] The invention belongs to the technical field of automatic transmission control systems of automobiles, and in particular relates to a control method for reducing engine emissions through shift control of automatic transmissions. Background technique [0002] The country has mandatory regulations on the emissions of gasoline engines, and the emissions mainly include CO, HC, and NO X There are three types, generally relying on the three-way catalytic converter for exhaust post-treatment. The working efficiency of the three-way catalytic converter is closely related to the temperature. It can only start working when it reaches a certain temperature, which is usually called the light-off temperature. When the vehicle is just started, the temperature of the three-way catalytic converter is usually low, and it is necessary to heat the three-way catalytic converter to the light-off temperature as soon as possible to reduce engine emissions. Heating the three...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a control method for shifting gears according to the working temperature of the three-way catalytic converter in addition to the D mode of the automatic transmission, so as to solve the problem of excessive emissions; at the same time, it provides a method for judging whether the three-way catalytic converter needs to be heated

Images