Hydraulic control system and control method for torque limiting clutch of hybrid electric vehicle

Abstract

The invention provides a moment-limiting clutch hydraulic control system of a hybrid electric vehicle. The moment-limiting clutch hydraulic control system comprises a hydraulic cylinder, a hydraulic pump, a motor, a controller and a hydraulic oil tank and further comprises an energy accumulator communicated with the hydraulic pump, a first switch valve, a second switch valve, an oil-return switch valve, a decompression valve and a connection port, wherein the first switch valve, the second switch valve and the oil-return switch valve are respectively arranged on different branch pipelines and communicated with the energy accumulator and the hydraulic cylinder; the decompression valve is arranged on the pipeline where any one of the first switch valve and the second switch valve is located; and the connection port is communicated with the energy accumulator. By means of the energy accumulator, a motor small in size and power can be adopted, and influence caused by heat is reduced; a plurality of branch pipelines are communicated with the energy accumulator and the hydraulic cylinder, so that influence on normal driving is avoided; and the decompression valve is arranged, so that starting of the engine is stable, and dynamic property of a finished automobile is improved. Therefore, the moment-limiting clutch hydraulic control system improves using performance of the hybrid electric vehicle in city working conditions. The invention further provides a control method of the moment-limiting clutch hydraulic control system of the hybrid electric vehicle.

Description

technical field [0001] The present invention relates to the technical field of hybrid electric vehicles, and more specifically, relates to a hydraulic control system for a torque-limiting clutch of a hybrid electric vehicle. The present invention also relates to a control method for the hydraulic control system for a torque-limiting clutch of a hybrid electric vehicle. Background technique [0002] The torque limiting clutch is an important transmission device in the power coupling mechanism of a severe hybrid electric vehicle. Its setting position is between the electric motor and the engine, and the three are coaxially set. [0003] A severe hybrid vehicle has all the functions of a hybrid system such as idling start and stop, pure electric driving, parallel drive, starting the engine while driving, and braking energy recovery. Through the switching of the above modes, the vehicle's power and fuel consumption can be improved. economy. When the hybrid vehicle is running at...

AI Technical Summary

Problems solved by technology

However, since hybrid vehicles are mostly used in urban conditions with frequent start and stop, the start and stop operations of the electric motor in the torque limiting clutch control system and the operation of starting and stopping the engine through the torque limiting clutch are very frequent, which has caused this realization. The method has the following disadvantages: since the torque-limiting clutch is directly supplied with pressure, the engagement time of the clutch needs to be strictly controlled, so a high-power motor is required to drive the hydraulic control system, and the high-power motor is large in size, takes up a large space, and is frequently started. The calorific value is also large when stopped, which is not only inconvenient to install, but also has a certain impact on the service life of the hydraulic control system due to heat problems; when external factors cause an urgent change in the starting torque required by the engine, it may occur The situation that the engine cannot be started through the torque-limiting clutch affects the normal driving of the hybrid vehicle; the direct pressure supply method cannot accurately control the pressure in the hydraulic cylinder of the torque-limiting clutch, and may affect the normal driving of the vehicle when the engine is started. Cause excessive impact and affect the dynamic performance of the vehicle

[0005] Therefore, the above-mentioned shortcomings have caused a greater impact on the normal driving of hybrid electric vehicles in urban operating conditions, which is not conducive to the normal use of hybrid electric vehicles in cities.

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