Air Intake Pathway Structure with Backflow Preventer

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In internal combustion engines with a supercharger and bypass pathway, reverse flow of intake air can reach the air flow meter, causing measurement errors due to backflow components being detected.

Innovation Solution

An air intake pathway structure with an extended section and inner tube configuration between the bypass pathway and air flow meter, where the inner tube and extended section define a space section with a partition to block reverse flow, preventing backflow from reaching the air flow meter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a bypass pathway is provided to allow downstream and upstream sides of the supercharger to communicate, then the supercharging pressure can be relieved during low load states, but reverse flow of intake air may reach the air flow meter causing measurement errors

Engineering Contradiction:

Improvesupercharging pressure controlVSAvoidair flow meter measurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The air intake pathway is segmented into a main pathway and a bypass pathway, with the bypass pathway further divided into a first bypass pathway (leading to the air flow meter) and a second bypass pathway (leading to the supercharger). This segmentation allows independent control of air flow through different pathways, enabling pressure relief while preventing reverse flow from reaching the air flow meter.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A one-way valve is introduced as an intermediary component in the first bypass pathway. This valve allows air to flow from the bypass pathway to the air flow meter during normal operation but prevents reverse flow during supercharger operation, thus mediating between the need for pressure relief and measurement accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 3:

Different sections of the bypass pathway are given different qualities: the first bypass pathway is designed to communicate with the air flow meter for pressure equalization, while the second bypass pathway is designed to communicate with the supercharger for pressure relief. The one-way valve provides directional flow control specifically in the first bypass pathway section.

Inventive Principle:

Principle #3Local quality

2Reliability

If the bypass valve opens to relieve supercharging pressure, then the supercharger can be protected from excessive pressure, but intake air backflow components are detected by the air flow meter causing measurement errors

Engineering Contradiction:

Improvesupercharger pressure protectionVSAvoidair flow meter measurement accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The one-way valve acts as a mediator that allows the bypass pathway to function for pressure relief while blocking the reverse flow path to the air flow meter. This enables the supercharger to be protected from excessive pressure without causing measurement errors in the air flow meter.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The bypass pathway is segmented into two separate pathways with different functions: the first bypass pathway connects to the air flow meter for pressure equalization, while the second bypass pathway connects to the supercharger for pressure relief. This segmentation allows independent operation of each pathway.

Inventive Principle:

Principle #1Segmentation

3Adaptability or versatility

If a bypass pathway is provided in parallel with the supercharger, then the system can operate in different modes (supercharging and pressure relief), but the complexity of the air intake pathway increases

Engineering Contradiction:

Improveoperating mode flexibilityVSAvoidair intake pathway structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The first and second bypass pathways are merged into a single bypass structure that branches into two separate channels. This merging reduces the overall complexity compared to having completely separate pathways, while still providing the necessary functional separation for different operating modes.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The bypass pathway structure serves multiple functions: it provides pressure relief during high load conditions, allows pressure equalization during low load conditions, and enables the system to switch between supercharging and non-supercharging modes. This multi-functionality reduces the need for additional separate components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9605588B2Air intake pathway structure for internal combustion engine

Publication Date: 2017.03.28 NISSAN MOTOR CO LTD

AI summary

A supercharger (15) is provided with a bypass pathway (17). A backflow preventer (20) is provided to the air intake pathway (8) between an airflow meter (10) and the bypass pathway (17). The backflow preventer (20) has: a casing (41) formed by locally expanding the cross-sectional area of the air intake pathway; and an inner tube (42) substantially constructing a duct for the mainstream of air intake. The inner tube (42) is supported by a flange portion (50) and the downstream end (42a) opens within the casing (41). During backflow when the bypass pathway (17) opens, a portion of the intake air enters into an exit-side space section (55), and the flow is prevented by the flange portion (50). Consequently, reverse flow is suppressed.