CN-121989905-A - Protection method and device for crankshaft of range-extended engine

CN121989905ACN 121989905 ACN121989905 ACN 121989905ACN-121989905-A

Abstract

The application discloses a protection method of a range-extending engine crankshaft of a hybrid vehicle, which comprises the steps of obtaining the N-th friction torque of the range-extending engine crankshaft of the hybrid vehicle when the N-th torque obtaining condition of the hybrid vehicle is met, enabling the range-extending engine to be used for charging a power battery of the hybrid vehicle, determining an N-th friction torque change value according to the difference value of the N-th friction torque and the N-1-th friction torque, and removing a quick response mode from available response modes of the range-extending engine when the N-th friction torque change value is between a first threshold value and a second threshold value.

Inventors

CHEN HUI
XUE LIXIN
WANG PENGPENG
NIE SHUYI
JIAO YUFU
TANG PEIDONG

Assignees

上海汽车集团股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241106

Claims (10)

1. A method of protecting a range-extending engine crankshaft of a hybrid vehicle, the range-extending engine crankshaft being coaxially connected with a motor shaft, the method comprising: When the N-th friction torque of a crankshaft of a range-extending engine of the hybrid vehicle meets a torque acquisition condition, acquiring the N-th friction torque of the crankshaft of the range-extending engine of the hybrid vehicle, wherein the range-extending engine is used for charging a power battery of the hybrid vehicle; determining an nth friction torque variation value according to the difference value of the nth friction torque and the (N-1) th friction torque; And when the Nth friction torque change value is between a first threshold value and a second threshold value, removing a quick response mode from available response modes of the range-extending engine, wherein the first threshold value is used for identifying a normal range upper limit value of friction torque change during the process of acquiring the friction torque of the crankshaft of the range-extending engine in two adjacent times, the second threshold value is used for identifying an abnormal range upper limit value of friction torque change, and the quick response mode is a response mode in which the abrasion influence on the crankshaft of the range-extending engine is larger than a preset condition in the response modes of the range-extending engine.
2. The method according to claim 1, wherein the method further comprises: and when the range-extending engine is in a stop stage, the rotating speed of the range-extending engine crankshaft is equal to the rotating speed of the motor shaft, and the rotating speed of the range-extending engine crankshaft reaches a set value, determining that the torque acquisition condition is met.
3. The method of claim 1, wherein the obtaining the nth friction torque of the extended range engine crankshaft of the hybrid vehicle comprises: And determining the Nth friction torque according to the torque of the motor shaft, the rotational inertia of the crankshaft of the range-extending engine, the angular acceleration of the crankshaft of the range-extending engine and the pumping loss torque constant of the range-extending engine.
4. The method of claim 1, wherein the fast response mode is included in the available response modes when the nth friction torque variation value is less than the first threshold.
5. The method according to claim 1, wherein the method further comprises: And when the Nth friction torque change value is larger than the second threshold value, alarming.
6. The method according to claim 1, wherein the method further comprises: And when the Nth friction torque is larger than the maximum friction torque of the crankshaft of the range-extending engine, alarming is carried out.
7. The device for protecting the extended-range engine crankshaft of the hybrid vehicle is characterized in that the extended-range engine crankshaft is coaxially connected with a motor shaft, and comprises an acquisition unit, a determination unit and a removal unit: The acquisition unit is used for acquiring the nth friction torque of a crankshaft of a range-extending engine of the hybrid vehicle when the torque acquisition condition is met for the nth time of the hybrid vehicle, and the range-extending engine is used for charging a power battery of the hybrid vehicle; The determining unit is used for determining an nth friction torque change value according to the difference value of the nth friction torque and the (N-1) th friction torque; The removing unit is used for removing a quick response mode from available response modes of the range-extending engine when the Nth friction torque change value is between a first threshold value and a second threshold value, wherein the first threshold value is used for identifying a normal range upper limit value of friction torque change during the process of acquiring the friction torque of the crankshaft of the range-extending engine in two adjacent times, the second threshold value is used for identifying an abnormal range upper limit value of friction torque change, and the quick response mode is a response mode of the range-extending engine, wherein the abrasion influence on the crankshaft of the range-extending engine is larger than a preset condition in the response mode of the range-extending engine.
8. An electronic device, the electronic device comprising: a memory for storing a computer program or computer instructions; A processor for executing a computer program or computer instructions stored in the memory, causing the electronic device to perform the method of any one of claims 1 to 6.
9. A computer program product, characterized in that the computer program product, when run on a computer, causes the computer to perform the method according to any of claims 1 to 6.
10. A computer readable storage medium comprising computer instructions that instruct a computer to perform the method of any one of claims 1 to 6.

Description

Protection method and device for crankshaft of range-extended engine Technical Field The application relates to the technical field of range-extending hybrid electric vehicles, in particular to a method and a device for protecting a crankshaft of a range-extending engine. Background The range-extending electric automobile is provided with a driving force by the storage battery, and under the condition of insufficient electric quantity, the range-extending engine drives the range-extending generator to charge the storage battery, so that the mileage anxiety is solved, and the range-extending electric automobile becomes one of the main directions of the development of the current new energy automobile. Compared with the traditional internal combustion engine, the start-stop times of the range-extended engine are obviously increased by the upper and lower limit values and the change of the State of Charge (SOC) of the battery in terms of control, and more abrasion of the range-extended engine shafting can occur in the frequent start-stop process. For the whole vehicle application, the range-extending engine has two response modes, namely a steady-state response mode, a fast power battery discharging probability reduction mode and a battery life, wherein the steady-state response mode is used for preferentially guaranteeing oil consumption, noise, vibration and harshness (Noise, vibration, harshness, NVH) and running stability, and the range-extending engine life is facilitated. The extent of wear of the range extender engine crankshaft varies when different response modes are executed. At present, how to reduce the abrasion of a crankshaft of an extended-range engine is a problem to be solved. Disclosure of Invention In order to solve the technical problems, the application provides a protection method and a protection device for a crankshaft of a range-extending engine, which effectively slow down the abrasion of the crankshaft of the range-extending engine and prolong the service life of the crankshaft of the range-extending engine. The embodiment of the application discloses the following technical scheme: In a first aspect, the present application provides a method for protecting a range-extending engine crankshaft of a hybrid vehicle, the range-extending engine crankshaft being coaxially connected with a motor shaft, the method comprising: When the N-th friction torque of a crankshaft of a range-extending engine of the hybrid vehicle meets a torque acquisition condition, acquiring the N-th friction torque of the crankshaft of the range-extending engine of the hybrid vehicle, wherein the range-extending engine is used for charging a power battery of the hybrid vehicle; determining an nth friction torque variation value according to the difference value of the nth friction torque and the (N-1) th friction torque; And when the Nth friction torque change value is between a first threshold value and a second threshold value, removing a quick response mode from available response modes of the range-extending engine, wherein the first threshold value is used for identifying a normal range upper limit value of friction torque change during the process of acquiring the friction torque of the crankshaft of the range-extending engine in two adjacent times, the second threshold value is used for identifying an abnormal range upper limit value of friction torque change, and the quick response mode is a response mode in which the abrasion influence on the crankshaft of the range-extending engine is larger than a preset condition in the response modes of the range-extending engine. Optionally, the method further comprises: and when the range-extending engine is in a stop stage, the rotating speed of the range-extending engine crankshaft is equal to the rotating speed of the motor shaft, and the rotating speed of the range-extending engine crankshaft reaches a set value, determining that the torque acquisition condition is met. Optionally, the nth friction torque is determined by: And determining the Nth friction torque according to the torque of the motor shaft, the rotational inertia of the crankshaft of the range-extending engine, the angular acceleration of the crankshaft of the range-extending engine and the pumping loss torque constant of the range-extending engine. Optionally, the quick response mode is included in the available response modes when the nth friction torque variation value is smaller than the first threshold value. Optionally, the method further comprises: And when the Nth friction torque change value is larger than the second threshold value, alarming. Optionally, the method further comprises: And when the Nth friction torque is larger than the maximum friction torque of the crankshaft of the range-extending engine, alarming is carried out. In a second aspect, the present application provides a protection device for an extended range engine crankshaft of a hybrid vehicle, the extended range engine