Self-Disabling Ejector for Evaporative Leak Prevention

Solution Overview

Problem

Existing evaporative emission systems in vehicles fail to detect leaks downstream of the ejector outlet, leading to undetected fuel vapor leakage into the atmosphere, and current solutions like hard-mounting or break-points increase costs and complexity.

Innovation Solution

A self-disabling ejector system is designed with an air induction passage, an inlet flow port, an external protrusion, a constriction, and inlets, where the evacuation port uncouples from the protrusion if the outlet becomes disconnected, preventing vacuum generation and fuel vapor flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the ejector outlet is positioned outside the air induction system, then engine packaging flexibility is improved, but fuel vapor leakage risk increases when the ejector disconnects

Engineering Contradiction:

Improveengine packaging flexibilityVSAvoidfuel vapor leakage

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The ejector system automatically disables itself when disconnected by allowing compressed air to escape through the evacuation port, preventing fuel vapor leakage without requiring external monitoring systems or manual intervention. The system serves its own diagnostic and protective function.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The potential harmful effect of disconnection is converted into a beneficial self-protective mechanism. When the outlet disconnects, the escaped compressed air through the evacuation port creates a pressure equalization effect that prevents vacuum formation and stops fuel vapor ingestion, turning a fault condition into a safety feature.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If sensors and monitoring systems are added to detect ejector leaks, then fuel vapor leakage detection is improved, but device complexity and cost increase

Engineering Contradiction:

Improvefuel vapor leakage detectionVSAvoidmonitoring system complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The ejector system automatically disables itself when disconnected by allowing compressed air to escape through the evacuation port, preventing fuel vapor leakage without requiring external monitoring systems or manual intervention. The system serves its own diagnostic and protective function.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The potential harmful effect of disconnection is converted into a beneficial self-protective mechanism. When the outlet disconnects, the escaped compressed air through the evacuation port creates a pressure equalization effect that prevents vacuum formation and stops fuel vapor ingestion, turning a fault condition into a safety feature.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Difficulty of detecting and measuring

If break-points are implemented in the ejector, then leak detection capability is improved, but manufacturing complexity and cost increase

Engineering Contradiction:

Improveleak detection capabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

Difficulty of detecting and measuringVSEase of manufacture

Solution Approach 1:

The ejector system automatically disables itself when disconnected by allowing compressed air to escape through the evacuation port, preventing fuel vapor leakage without requiring external monitoring systems or manual intervention. The system serves its own diagnostic and protective function.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The potential harmful effect of disconnection is converted into a beneficial self-protective mechanism. When the outlet disconnects, the escaped compressed air through the evacuation port creates a pressure equalization effect that prevents vacuum formation and stops fuel vapor ingestion, turning a fault condition into a safety feature.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The self-disabling ejector system effectively prevents fuel vapor leakage into the atmosphere by disabling vacuum generation when disconnected, reducing the need for costly monitoring systems and simplifying engine control, while maintaining engine packaging efficiency.

Implementation Method 1

ejectors may be coupled to the air induction system of the engine and the evaporative emissions system in order to generate vacuum when the intake manifold of the engine is pressurized

Methodology Applied

Scientific EffectVenturi effect: Venturi Effect

Data Source

PatentUS10145339B1Systems and method for a self disabling ejector of an air induction system

Publication Date: 2018.12.04 FORD GLOBAL TECH LLC

AI summary

Methods and systems are provided for a self-disabling ejector of an air induction system and evaporative emissions systems. In one example, an ejector may include an outlet coupled to an inlet flow port of an air induction passage, upstream of a compressor, an evacuation port coupled to an external protrusion arranged adjacent to the inlet flow port on the air induction passage, a constriction arranged between the outlet and evacuation port, and first and second inlets positioned on either side of the constriction. If the outlet becomes disconnected from the inlet flow port, the evacuation port may disconnect from the external protrusion, thereby disabling the vacuum generating capabilities of the ejector.