Blowby Gas Returning Apparatus Using Jet Pump

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Solution Overview

Problem

Existing blowby gas returning apparatuses increase intake resistance when trying to enhance blowby gas returning flow rate during turbocharger or supercharger operation, especially with increased boost pressure.

Innovation Solution

Incorporating a bypass passage with a jet pump that generates negative pressure to facilitate blowby gas return without increasing intake resistance, using a jet pump to connect the upstream and downstream sides of the intake passage relative to the turbocharger.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If filter density is increased to enhance blowby gas returning flow rate during turbocharger operation, then blowby gas returning flow rate is improved, but intake resistance increases

Engineering Contradiction:

Improveblowby gas returning flow rateVSAvoidintake resistance

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The blowby gas returning system is divided into two separate passages: a first blowby gas returning passage for natural return during non-turbo operation, and a second blowby gas returning passage for turbo operation. This segmentation allows each passage to be optimized for its specific operating condition without compromising the other.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A jet pump is introduced as an intermediary device in the second blowby gas returning passage to actively generate negative pressure and drive blowby gas return during turbocharger operation, replacing the passive filter-based pressure differential approach.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If pressure difference is increased to enhance blowby gas returning flow rate during turbocharger operation, then blowby gas returning flow rate is improved, but engine operation efficiency deteriorates due to increased intake resistance

Engineering Contradiction:

Improveblowby gas returning flow rateVSAvoidengine operation efficiency

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The jet pump utilizes pneumatic principles by using pressurized air or gas flow to create a vacuum effect, generating negative pressure to actively pull blowby gas through the returning passage without creating resistance in the intake passage.

Inventive Principle:

Principle #29Pneumatics and hydraulics

3Productivity

If negative pressure is generated in bypass passage during turbocharger operation, then blowby gas returning flow rate is improved, but device complexity increases

Engineering Contradiction:

Improveblowby gas returning flow rateVSAvoiddevice complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The jet pump is designed to utilize the existing pressurized air flow from the turbocharger system to generate its own driving force, making the system self-sufficient without requiring external power sources or additional complex control mechanisms.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The bypass passage serves multiple functions: it allows pressurized air to reach the jet pump for negative pressure generation, provides a return path for blowby gas during turbo operation, and can be integrated with existing engine air management systems.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 efficient blowby gas return to the engine without increasing intake resistance and enhances flow rate with increasing boost pressure, maintaining engine operation efficiency.

Implementation Method 1

a jet pump for generating negative pressure in the bypass passage

Methodology Applied

Scientific EffectNegative pressure generation: Pressure Gradient

Data Source

PatentUS8122870B2Blowby gas returning apparatus

Publication Date: 2012.02.28 AISAN IND CO LTD

AI summary

A blowby gas returning apparatus is mounted in an engine provided with a turbocharger in an intake passage and provided with a blowby gas returning passage for flowing blowby gas generated in the engine to return to the engine. This apparatus comprises an intake bypass passage connecting an upstream side and a downstream side of the intake passage with respect to the turbocharger, and a jet pump for generating negative pressure in the intake bypass passage. An exit of the first blowby gas returning passage is connected to the intake bypass passage through the jet pump. The apparatus further includes a second blowby gas returning passage connecting the intake passage downstream of the throttle valve to a head cover. In the head cover, a PCV valve is placed at an entrance of the second blowby gas returning passage.