Detection device and detection method of sealing performance of automobile fuel evaporation system

Abstract

The invention discloses a detection device and a detection method of sealing performance of an automobile fuel evaporation system. The detection device comprises an engine, a carbon canister control valve, a carbon canister, a fuel tank, an ash filter, an electronic control unit, an engine water temperature sensor and an intake air temperature sensor, wherein the detection device further comprisesa pressure sensor, a carbon canister stop valve and a leakage fault indication module, the pressure sensor is installed on a connecting pipe of the carbon canister and the fuel tank, the carbon canister stop valve is connected with the carbon canister and the ash filter, and the pressure sensor, the carbon canister stop valve and the leakage fault indication module are electrically connected withthe electronic control unit; and the detection method comprises the following steps: firstly detecting whether the carbon canister stop valve has leakage under the condition that a detection condition is satisfied, then detecting whether the fuel evaporation system has large leakage, and finally detecting whether the fuel evaporation system has small leakage. By adoption of the detection device and the detection method disclosed by the invention, whether the fuel evaporation system has leakage can be detected in time during the operation of the engine so as to better avoid the air pollution caused by fuel vapor leakage.

Description

technical field [0001] The invention belongs to the field of automobile fuel evaporation systems, and in particular relates to a detection device and a detection method for the tightness of the automobile fuel evaporation system. Background technique [0002] With the gradual implementation of the requirements of the National VI regulations for automobiles, in order to make the automobile better emission reduction and environmental protection, the regulations require that the tightness of the fuel evaporation system must be tested and whether there is leakage (that is, whether there is a 1mm hole leakage), if there is leakage, then It needs to be prompted (leakage fault) for maintenance to avoid leakage of fuel vapor into the air and pollute the atmosphere. However, traditional vehicles (meeting the requirements of National V regulations) cannot detect the tightness of the fuel evaporation system, cannot judge whether there is a leak, and cannot prompt for maintenance. Once ...

AI Technical Summary

Problems solved by technology

However, traditional vehicles (meeting the requirements of National V regulations) cannot detect the tightness of the fuel evaporation system, cannot judge whether there is a leak, and cannot prompt for maintenance. Once the fuel evaporation system leaks, it will cause continuous leakage of fuel vapor into the air and not Awareness, resulting in air pollution, serious pollution, and even destruction of the natural environment

[0003] CN105156210A discloses a fuel tank evaporative emission system leak detection device and detection method, which uses a leak detection intelligent module, a leak detection air pump module to cooperate with a carbon tank, a carbon tank desorption solenoid valve (that is, a carbon tank control valve), an engine, an ECU (i.e. electronic control unit), filter, can realize 0.5mm hole leak detection, mainly suitable for PHEV models, but it has the following problems: (1) It cannot be detected when the vehicle is running, and the fuel tank can only be waited for several hours after the engine stops. It can only be detected when the temperature of the steam space does not change much. For the situation where the engine stops for a short time and the evaporative emission system of the fuel tank leaks, it is impossible to provide timely fault prompts; (2) It is necessary to use the air pump to pump air inward, and then close the steam solenoid valve to maintain pressure It takes a long time to detect leaks, and it is mainly suitable for PHEV models, because PHEV models do not use the engine most of the time; (3) Additional air pumps and temperature sensors are required, and the hardware cost is high; (4) Although 0.5 mm hole leak detection, the scope of application is wider, but the national VI regulations only require 1mm hole leak detection, which exceeds the requirements of the regulations, and is a redundant design, which makes the overall cost higher and the detection more complicated

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