Cylinder Head Flat Surface Machining EGR Integration

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Solution Overview

Problem

Existing cylinder head designs that integrate components like EGR passages, intake manifolds, and thermostats create a steplike surface, making 6-face machining difficult and costly.

Innovation Solution

A cylinder head design where exhaust ports, EGR gas inlets, and fresh air inlets are arranged side-by-side on flat surfaces, facilitating 6-face machining, and incorporating a water jacket with a unique cooling water passage configuration to enhance cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of moving object

If the cylinder head is integrally formed with EGR passage, intake manifold, and thermostat, then the components are integrated into a single structure, but the surface becomes steplike making 6-face machining difficult

Engineering Contradiction:
Improvecomponent integrationVSAvoid6-face machining
Core Design Contradiction:
Area of moving objectVSEase of manufacture

Solution Approach 1:

The patent resolves the machining difficulty by strategically arranging ports and passages in three-dimensional space rather than attempting flat 2D layouts. The EGR passage inlet and exhaust ports are positioned at different heights and locations on the cylinder head surface, allowing 6-face machining to proceed on a flat surface while the EGR passage routes through the internal volume of the cylinder head to connect these distributed openings.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If the EGR gas passage is arranged inside the cylinder head, then the structure is compact, but the surface shape becomes complex with steps

Engineering Contradiction:
Improvestructural compactnessVSAvoidsurface geometry
Core Design Contradiction:
Volume of moving objectVSShape

Solution Approach 1:

The EGR passage is nested within the internal volume of the cylinder head, utilizing the existing structural space. The passage is formed as an internal cavity that routes EGR gas from the exhaust manifold connection point through the cylinder head body to the intake manifold connection point, effectively hiding the complex routing inside the compact cylinder head structure without adding external complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Adaptability or versatility

If multiple ports and passages are integrated into the cylinder head, then functionality is enhanced, but manufacturing complexity increases

Engineering Contradiction:
Improvefunctional integrationVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the functional elements (exhaust ports, intake ports, EGR passage, water jacket) into distinct but integrated components within the cylinder head. Each element is designed with its own specific geometry and routing, allowing independent optimization of each function while maintaining overall integration. The EGR passage is segmented from the main combustion chamber volume, and the water jacket is segmented into regions for different cooling requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cylinder head is designed as a multi-functional component that simultaneously serves as a structural element, a fluid distribution system (for exhaust, intake, and EGR gases), and a thermal management system (via the water jacket). The integral formation of these multiple functions within a single component reduces the number of separate parts and assembly operations, thereby reducing overall manufacturing complexity despite the enhanced functionality.

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

The design simplifies 6-face machining, reduces costs, and improves engine cooling efficiency by ensuring effective air removal and water flow within the cylinder head.

Implementation Method 1

a water jacket configured to cool the combustion chambers with cooling water

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

a water jacket configured to cool the combustion chambers with cooling water

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

a cooling water passage communicating with the thermostat case and the water jacket, wherein the water jacket is formed so that the cooling water flows from an exhaust side to an intake side

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

the EGR gas passage is connected to an exhaust manifold through an EGR cooler

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3726044B1Cylinder head and engine
Publication Date: 2025.04.09 YANMAR POWER TECH CO LTD
  • EP3726044B1 patent drawingFigure 1
  • EP3726044B1 patent drawingFigure 2
  • EP3726044B1 patent drawingFigure 3A

AI summary

A cylinder head 4 includes: a plurality of exhaust ports 41 configured to lead out exhaust gas from combustion chambers; a plurality of intake ports 42 configured to introduce fresh air into the combustion chambers; an intake air aggregate part 43 configured to aggregate the plurality of intake ports 42; and a second EGR pipe 21b in which EGR gas flows, wherein exhaust outlets 41b of the plurality of exhaust ports 41 and an EGR gas inlet 44a of the second EGR pipe 21b are arranged side-by-side on a flat left side surface 4a, and a fresh air inlet 43a of the intake air aggregate part 43 and an EGR gas outlet 44b of the second EGR pipe 21b are arranged side-by-side on a flat right side surface 4b.