A torque distribution method, system and device in the light-off stage of a catalytic converter

Abstract

The present invention provides a torque distribution method in the ignition stage of a catalytic converter, which is used in a hybrid vehicle including a control system and an exhaust system, including: obtaining the vehicle driving demand torque and the first temperature of the first catalytic converter, and judging the first catalytic converter Whether the light-off temperature is reached; if the light-off temperature is not reached, compare the driving demand torque with the motor torque output threshold, and when the driving demand torque is less than or equal to the motor torque output threshold, the motor control module controls the output torque of the motor to be the driving demand Torque, to control the engine to heat the first catalytic converter; on this basis, the present invention also provides a system and device; the present invention designs different output torque distribution strategies, so that the engine works in an appropriate working condition to improve the first catalytic converter respectively. The temperature of the catalytic converter and the second catalytic converter, while limiting the torque output range of the engine, avoiding situations that are not conducive to fuel consumption and emissions such as many transient engine conditions and heavy loads of the cold engine, and improve vehicle fuel economy.

Description

technical field [0001] The invention relates to the field of hybrid vehicle control, in particular to a torque distribution method, system and device in the ignition-off stage of a catalytic converter. Background technique [0002] The three-way catalytic converter is the most important purification device for automobile exhaust emissions. Its conversion efficiency of harmful gases such as CO, HC and NOx produced by the operation of automobile engines is directly related to temperature. In general, the light-off temperature of the catalytic converter refers to the temperature at which the conversion efficiency of the catalytic converter to harmful gases reaches 50%. The conversion efficiency can reach more than 90%. Another study shows that the harmful gas emissions of the engine during its cold phase account for 50% to 80% of the total emissions of the entire emission test cycle. Therefore, shortening the light-off time of the catalytic converter and at the same time cont...

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Problems solved by technology

[0003] The main measures to shorten the ignition of the catalytic converter in traditional cars are: increasing the fuel injection volume and de-ignition angle, thereby increasing the exhaust temperature of the engine, but this method will lead to higher CO and HC emissions during the ignition of the catalytic converter; The auxiliary electric heating device of the catalytic converter requires special modification of the catalytic converter. The installation of a catalytic converter coating temperature sensor and a high-voltage electric heating device not only increases the difficulty of the design and processing of the catalytic converter, but also increases the design of the high-voltage wiring harness of the vehicle. It also increases the R&D and production costs and safety risks of the whole vehicle. In addition, there is a risk of battery power feeding; by optimizing the structural layout of the exhaust pipe, the three-way catalytic converter is closer to the engine exhaust. The air port uses higher temperature exhaust to heat the catalyst, but this method will accelerate the aging of the catalyst and affect the service life of the catalyst

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