Multi-port Check-valve for Turbocharged EVAP Systems

Solution Overview

Problem

In internal combustion engines with forced induction, the existing EVAP systems face challenges in withstanding high boost pressures, which can damage the purge valve and hinder the system's ability to perform both fuel evaporative emissions purge and leak detection functions, as simple check-valves do not allow two-way airflow necessary for effective leak detection.

Innovation Solution

A multi-port check-valve system is introduced, featuring a first port connected to the purge valve, a second port with a fixed orifice that opens in response to engine vacuum to bleed boost pressure, and a third port with a second check-valve to release boost pressure to the atmosphere or air box, ensuring the purge valve is protected from damage and enabling two-way airflow for leak detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a simple check-valve is employed to prevent high boost pressures from impacting the purge valve, then the purge valve is protected from damage, but the EVAP system cannot perform leak detection function because two-way airflow is blocked

Engineering Contradiction:

Improvepurge valve protectionVSAvoidleak detection capability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The check-valve is divided into multiple ports (first port, second port, third port) with separate check-valves for different functions. The first check-valve handles purge vapor flow while the second check-valve enables leak detection airflow, allowing each segment to perform its specific function independently without interfering with the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The check-valve assembly is designed to perform multiple functions simultaneously: it protects the purge valve from boost pressure damage while also enabling the leak detection function through the ESIM switch. By incorporating multiple ports and check-valves, a single component achieves both protection and diagnostic capabilities.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a check-valve allows two-way airflow to support ESIM leak detection function, then leak detection is enabled, but high boost pressures can directly impact and damage the purge valve

Engineering Contradiction:

Improveleak detection capabilityVSAvoidpurge valve protection

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The check-valve is divided into multiple ports (first port, second port, third port) with separate check-valves for different functions. The first check-valve handles purge vapor flow while the second check-valve enables leak detection airflow, allowing each segment to perform its specific function independently without interfering with the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second check-valve acts as an intermediary that allows controlled two-way airflow for leak detection while the first check-valve serves as a protective barrier against boost pressure. The intermediary structure enables necessary airflow for diagnostics without compromising the protection function.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If the EVAP system is designed to collect and transfer vapors to the purge canister, then fuel vapor emissions are controlled, but the system becomes vulnerable to damage from high boost pressures in turbocharged engines

Engineering Contradiction:

Improvefuel vapor emissions controlVSAvoidboost pressure damage

Core Design Contradiction:

Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The check-valve is divided into multiple ports (first port, second port, third port) with separate check-valves for different functions. The first check-valve handles purge vapor flow while the second check-valve enables leak detection airflow, allowing each segment to perform its specific function independently without interfering with the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system converts the potentially harmful high boost pressure into a controlled flow path through the second check-valve that releases pressure to atmosphere or air box. This transforms the harmful pressure into a controlled venting mechanism that protects the purge valve while maintaining system functionality.

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 multi-port check-valve effectively manages high boost pressures, protecting the purge valve and enabling the EVAP system to perform both emissions purge and leak detection functions, ensuring reliable operation and preventing system damage from high manifold pressures.

Implementation Method 1

the check-valve is positioned to open in response to engine vacuum

Methodology Applied

Scientific EffectVacuum: Vacuum

Implementation Method 2

the fixed orifice is arranged to bleed intake manifold boost pressure

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 3

a third port in fluid communication with the first and second ports, which includes a second check-valve arranged to release the boost pressure to atmosphere or to the engine's air box

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS7373930B1Multi-port check-valve for an evaporative fuel emissions system in a turbocharged vehicle

Publication Date: 2008.05.20 FCA US LLC

AI summary

A multi-port check-valve for a fuel vapor emissions system coupled to an intake manifold of an internal combustion engine with forced induction and of the type including a purge canister and a purge valve, comprising a first port coupled to the purge valve, a second port in fluid communication with the first port and having a first check-valve with a fixed orifice arranged to open in response to engine vacuum, and bleed intake manifold boost pressure.