Purge Device Passage Deviation Detection Using Ejector Pressure Amplification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing purge devices for internal combustion engines have difficulty detecting deviations in the connection of the purge passage end to the intake passage, especially during supercharging, due to minimal pressure changes within the purge passage.

Innovation Solution

A purge device equipped with a sensor to detect internal pressure downstream of the supply unit in the purge passage, a throttle to limit gas inflow, and a control device to determine passage end deviation based on pressure thresholds set according to supercharge pressure or discharge amount, allowing for accurate detection of passage end deviations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a purge passage is connected to the upstream side of a compressor in the intake passage during supercharging, then the purge gas can be introduced into the intake passage, but the passage end deviation becomes difficult to detect due to minimal pressure changes

Engineering Contradiction:

Improvepurge gas introductionVSAvoidpassage end deviation detection

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

An ejector is introduced as an intermediary device in the purge passage to amplify the pressure difference between connected and disconnected states. The ejector uses pressurized gas from the compressor to create a significant pressure drop when the passage is properly connected, making the pressure change detectable by the sensor even during supercharging operations.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the pressure parameter within the purge passage by using the ejector to create a large pressure difference between the upstream and downstream sides of the ejector. This parameter change amplifies the detectable pressure signal, allowing reliable detection of passage end deviation despite the challenging supercharging conditions.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If the passage end of the purge passage deviates from the intake passage, then the connection is faulty, but the pressure change is too small to reliably detect the deviation

Engineering Contradiction:

Improvedeviation detection sensitivityVSAvoidpressure detection system

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The ejector serves as a mechanical amplifier that converts the binary state of passage connection (connected/disconnected) into a large, easily detectable pressure difference. This intermediary device magnifies the signal without requiring complex sensor systems or multiple measurement points.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of using a complex mechanical detection system to directly observe passage connection, the invention substitutes a simple pressure sensor that detects pressure changes created by the ejector. This replaces potential mechanical complexity with a simpler pressure-based detection mechanism.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables reliable detection of passage end deviations, ensuring proper operation and preventing misconnection issues during supercharging, with adjustable pressure thresholds based on supercharge pressure or discharge amount.

Implementation Method 1

a sensor configured to detect internal pressure downstream of the supply unit in the purge passage

Methodology Applied

Scientific EffectPressure detection:

Implementation Method 2

a throttle configured to be provided in a portion of the intake passage connected with the purge passage and limit an inflow of gas from the purge passage

Methodology Applied

Scientific EffectFlow restriction:

Implementation Method 3

a supply unit configured to supply purge gas within the purge passage to the upstream side of the compressor in the intake passage during supercharging using the supercharger

Methodology Applied

Scientific EffectGas compression: Gas Compressor

Data Source

PatentUS10190514B2Purge device, and internal combustion engine provided with the same

Publication Date: 2019.01.29 TOYOTA JIDOSHA KK

AI summary

A purge device includes a canister; a purge passage configured to extend from the canister and be connected to an upstream side of a compressor of a supercharger in an intake passage; a supply unit configured to supply purge gas to the upstream side of the compressor in the intake passage during supercharging; a throttle configured to be provided in a portion of the intake passage connected with the purge passage and limit an inflow of gas from the purge passage; a sensor configured to detect internal pressure downstream of the supply unit in the purge passage; and a control device configured to determine that a passage end of the purge passage deviates from the intake passage, in a case where a detection value obtained by the sensor during the operation of the supply unit is lower than a predetermined pressure.