Leakage diagnosis method and device for fuel evaporative emission system

A technology of evaporative emission and diagnosis method, applied in the field of vehicles, can solve the problems of inability to diagnose leakage, inability to meet the leakage diagnosis of fuel evaporative emission system, etc.

Active Publication Date: 2020-07-31
BYD CO LTD
View PDF8 Cites 14 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] In the prior art, there are control programs and failure diagnosis programs for the high-pressure fuel tank system of PHEV models during the refueling process, but there is no mention of the program control for OBD II fuel evaporation system leakage diagnosis, and the leakage cannot be diagnosed, which cannot meet the requirements of the National VI regulations. Requirements for Leak Diagnosis of Fuel Evaporative Emission System

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Leakage diagnosis method and device for fuel evaporative emission system
  • Leakage diagnosis method and device for fuel evaporative emission system
  • Leakage diagnosis method and device for fuel evaporative emission system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach

[0053] As an implementation manner, when the internal combustion engine state of the vehicle is obtained in a non-driving state, the fuel tank pressure value is obtained, including:

[0054] When the state of the internal combustion engine of the vehicle is turned off, obtain the vehicle water temperature and intake air temperature;

[0055] When the temperature difference between the vehicle temperature and the intake air temperature is less than the preset temperature, the fuel tank pressure value is acquired.

[0056] Among them, the determination of the status of the vehicle is mainly to confirm that the vehicle is in a period of time after the engine is turned off. The water temperature sensor and the intake air temperature sensor are collected by the ECU, and compared and judged. If the two temperatures are similar, it means that the vehicle has been turned off. After a while, you can proceed to the next step.

[0057] The embodiment of the present application is specif...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a leakage diagnosis method and device for a fuel evaporative emission system. The leakage diagnosis method includes the steps that when an acquired internal combustion engine state of a vehicle is a non-driving state, a fuel tank pressure value is acquired, and the leakage condition of the fuel evaporative emission system is diagnosed with a first control strategy or a second control strategy according to the fuel tank pressure value, wherein the first control strategy is to diagnose the leakage condition of the fuel evaporative emission system, and the second control strategy is to diagnose the leakage conditions of two sides of a fuel tank isolation valve respectively. According to the technical scheme, by acquiring the fuel tank pressure value and diagnosing the leakage condition of the fuel evaporative emission system with the different strategies according to the fuel tank pressure value, accurate diagnosis of the leakage condition of the fuel evaporative emission system is realized.

Description

technical field [0001] The present application relates to the technical field of vehicles, in particular to a method and device for diagnosing leakage of a fuel evaporative emission system. Background technique [0002] In the prior art, there are control programs and failure diagnosis programs for the high-pressure fuel tank system of PHEV models during the refueling process, but there is no mention of the program control for OBD II fuel evaporation system leakage diagnosis, and the leakage cannot be diagnosed, which cannot meet the requirements of the National VI regulations. Requirements for diagnostics of fuel evaporative emissions system leaks. Contents of the invention [0003] The purpose of this application is to provide a leak diagnosis method and device for a fuel evaporative emission system, which can realize the leak diagnosis of the fuel evaporative emission system. [0004] This application is achieved in this way. The first aspect of this application provid...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): F02M25/08F02B77/08
CPCF02B77/083F02M25/0809
Inventor 王珂苏清炎
Owner BYD CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap