A hybrid electric vehicle and its engine shutdown control method

Abstract

The invention provides a hybrid electric vehicle and an engine stop control method thereof. A more complete engine stop control strategy for a hybrid power system is provided. Through additional judgment on the conditions such as the increase of the water temperature of an engine and the increase of the rear exhaust temperature of a turbine, the engine stop process is determined, the engine is dragged by a BSG / ISG motor in the stop process, and the engine rotation speed reducing process is controllable. By the adoption of the hybrid electric vehicle and the engine stop control method thereof, the problems that the engine in the hybrid power system is frequently started and stopped, consequently cooling water of the engine cannot work in a normal range, a turbocharger of the engine is poorly lubricated due to urgent stops, carbon is seriously accumulated in the turbocharger, even scuffing of a cylinder bore and shoe scratching happen, and losses are serious are solved, the performance of the engine is improved, and the service life of the engine is prolonged.

Description

technical field [0001] The present application relates to a hybrid electric vehicle, in particular to the shutdown control of its engine. Background technique [0002] At present, the world's automobile industry is facing two major problems: environmental pollution and lack of oil resources. Therefore, environmental protection and energy saving are an important development direction of automobile technology in the 21st century. At the same time, the emission regulations of various countries are becoming increasingly strict. Hybrid vehicles are a new generation of clean energy vehicles featuring low pollution and low fuel consumption. A hybrid vehicle refers to a vehicle that uses both fuel-driven and electric-driven drives. The advantage of a hybrid vehicle is that when the vehicle starts and stops, it is only driven by the motor, and the engine does not work until it reaches a certain speed. Therefore, the engine can always be kept in the best working condition, with good ...

AI Technical Summary

Problems solved by technology

[0009] 1. During the actual operation of the hybrid power system, the engine shuts down too frequently, resulting in the engine cooling water temperature being too high or too low;

[0010] 2. Rapid shutdown of the engine under heavy load will also lead to excessive exhaust temperature, poor lubrication, and insufficient cooling of the turbocharger, resulting in serious carbon deposits in the turbocharger, cracking of cylinders and tiles, and even fire, which affects the life of the engine.

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