Engine Exhaust Communication Pipe for Lower Pressure Loss

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Solution Overview

Problem

Conventional engines experience increased pressure loss due to abnormal shapes in the exhaust pipe connection portions, leading to inefficiencies in the exhaust gas flow path.

Innovation Solution

The engine design incorporates an exhaust communication pipe with a first connection member having an upstream end with an abnormal-shaped inner peripheral face and a downstream end with a circular cross-section, connected to a turbocharger and an exhaust gas purifier, which includes a waste gate port and a waste gate valve to manage gas flow and reduce pressure loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the exhaust pipe connection portion has an abnormal-shaped cross-section to match the turbocharger outlet, then the assembly fit is improved, but the pressure loss increases due to irregular gas flow

Engineering Contradiction:
Improveassembly fitVSAvoidpressure loss
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The exhaust communication pipe is divided into two separate connection members: a first connection member with an abnormal-shaped cross-section that fits the turbocharger outlet, and a second connection member with a circular cross-section that provides smooth gas flow. This segmentation allows each part to optimize for its specific function, resolving the contradiction between assembly fit and pressure loss reduction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first connection member acts as an intermediary component that connects the abnormal-shaped turbocharger outlet to the circular second connection member. It transforms the irregular shape into a regular circular shape, enabling both proper assembly fit and smooth gas flow without direct connection between the abnormal outlet and circular pipe.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If the exhaust communication pipe has a constant circular cross-section, then the pressure loss is reduced, but the assembly compatibility with abnormal-shaped turbocharger outlets is poor

Engineering Contradiction:
Improvepressure lossVSAvoidassembly compatibility
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The exhaust communication pipe system employs different cross-sectional shapes at different locations: the first connection member has an abnormal-shaped cross-section localized at the turbocharger connection end to ensure compatibility, while the second connection member maintains a circular cross-section to minimize pressure loss. This local quality variation optimizes both assembly compatibility and energy efficiency.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system embraces asymmetry by using an abnormal-shaped cross-section only where needed for compatibility with the turbocharger outlet, while maintaining symmetry (circular shape) in the main pipe body for optimal fluid dynamics. This selective asymmetry resolves the contradiction between adaptability and pressure loss.

Inventive Principle:
Principle #4Asymmetry

3Volume of moving object

If the flow path cross-sectional area is reduced at the downstream end, then the connection size is minimized, but the gas flow resistance increases

Engineering Contradiction:
Improveconnection sizeVSAvoidgas flow resistance
Core Design Contradiction:
Volume of moving objectVSLoss of energy

Solution Approach 1:

The exhaust communication pipe system dynamically adapts its cross-sectional area along the flow direction: the first connection member has a smaller abnormal-shaped cross-section for compact connection, while the second connection member transitions to a larger circular cross-section to reduce flow resistance. This dynamic variation in cross-sectional area optimizes both size and flow efficiency.

Inventive Principle:
Principle #15Dynamics

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

This design effectively suppresses pressure loss in the exhaust communication pipe, enhancing the engine's efficiency by improving gas flow and facilitating easier assembly and reducing the overall size of the engine.

Implementation Method 1

forming the gas flow path of the exhaust pipe in the abnormal shape increases a pressure loss seen when the exhaust gas passes through the gas flow path of the exhaust pipe

Methodology Applied
Scientific EffectPressure loss reduction through flow path design: Pressure Drop

Data Source

PatentEP4177447B1engine
Publication Date: 2025.09.10 YANMAR HLDG CO LTD
  • EP4177447B1 patent drawingFigure 1
  • EP4177447B1 patent drawingFigure 2
  • EP4177447B1 patent drawingFigure 3

AI summary

[Problem] To provide an engine capable of suppressing a larger pressure loss in an exhaust communication pipe connecting a turbocharger with an after-treatment unit. [Solution] An engine 1 is equipped with an engine body 2, a turbocharger 20, an exhaust gas purifier 40, an exhaust communication pipe 25. The turbocharger 20 is connected to the engine body 2.The exhaust gas purifier 40 purifies exhaust gas discharged from the turbocharger 20. The exhaust communication pipe 25 connects the turbocharger 20 with the exhaust gas purifier 40. The exhaust communication pipe 25 includes: a first connection member 60 that is connected to the turbocharger 20, and a second connection member 70 that connects the first connection member 60 with the exhaust gas purifier 40. A downstream end portion 62 of the first connection member 60 has an inner peripheral face 62a having a cross-section of a circular shape. An upstream end portion 61 of the first connection member 60 has an inner peripheral face 61a having a cross-section of an abnormal-shape that is different from the inner peripheral face 62a of the downstream end portion 62.