Water-Cooled Engine Cylinder Block Guide Walls

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Solution Overview

Problem

Conventional water-cooled engine cooling structures face a trade-off between maintaining compact engine length and achieving sufficient cooling performance, particularly between cylinders, where high thermal loads require enhanced cooling without increasing engine length.

Innovation Solution

The implementation of guide walls that direct cooling water flow between cylinders in opposite or the same directions within the water jacket, promoting efficient water intake and flow rates in inter-bore flow paths without widening the cylinder arrangement, utilizing arc-shaped rib walls and strategically placed drilled holes to enhance cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If core chaplet or similar structures are used to clearly separate adjacent cylinders and provide a clear water jacket between bores, then cooling performance between cylinders is improved, but engine length increases

Engineering Contradiction:
Improvecooling performanceVSAvoidengine length
Core Design Contradiction:
TemperatureVSLength of moving object

Solution Approach 1:

The water jacket is segmented into multiple flow paths including inter-bore flow paths and main flow paths, with guide walls directing water flow to specific segments. This segmentation allows efficient cooling of inter-bore regions without requiring increased separation between cylinders, thus maintaining compact engine length while improving cooling performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling water flow is directed in multiple dimensions through guide walls that create opposite-direction flows in adjacent inter-bore paths. This multi-dimensional flow arrangement maximizes heat transfer efficiency within the available space, achieving superior cooling without increasing engine length

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

2Temperature

If drilled holes are made in portions between bores to form water paths, then cooling performance between cylinders is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvecooling performanceVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The guide walls and water path structures are formed as integral parts of the cylinder block during the initial molding process. This preliminary formation eliminates the need for subsequent drilling operations, reducing manufacturing complexity while ensuring precise geometry for optimal cooling performance

Inventive Principle:
Principle #10Preliminary action

3Temperature

If guide walls are formed to guide cooling water to inter-bore flow paths in opposite directions, then cooling efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidwater jacket structure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

Multiple functions are merged into the guide walls: they serve as flow directors, structural supports, and integral parts of the water jacket. By combining these functions into a single integrated component formed during molding, the structure achieves improved cooling efficiency without proportionally increasing device complexity

Inventive Principle:
Principle #5Merging (Combining)

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 configuration ensures effective cooling between cylinders while maintaining engine length, achieving a balance between cooling performance and compactness by ensuring a sufficient flow rate and efficient heat absorption without increasing the distance between cylinders.

Implementation Method 1

the guide wall capable of guiding the cooling water flowing in the main flow path to the inter-bore flow path is provided, thereby promoting the water intake action that promotes taking more cooling water into the inter-bore flow path

Methodology Applied
Scientific EffectFluid flow guidance:

Implementation Method 2

cooling water is circulated... a sufficient flow rate (a flow rate per unit time of cooling water) is ensured in the inter-bore flow path, and even a place between the bores, which is difficult to be cooled, can be efficiently cooled

Methodology Applied
Scientific EffectConvection cooling: Convection

Implementation Method 3

a water jacket is provided around a cylinder or a cylinder head which is a heat generating portion, and cooling water is circulated

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3342999B1Water-cooled engine
Publication Date: 2021.06.02 KUBOTA CORP
  • EP3342999B1 patent drawingFigure 1
  • EP3342999B1 patent drawingFigure 2
  • EP3342999B1 patent drawingFigure 3

AI summary

There is provided a cooling structure of a water-cooled engine which enables sufficient cooling between bores without causing an increase in engine length by a further structural device, to achieve reduction in engine length as well as cooling performance. A cooling structure of a water-cooled engine includes: a plurality of cylinders 2 arranged in a cylinder block 1; and a water jacket W formed around the plurality of cylinders 2. The water jacket W includes a pair of main flow paths 7, 8 formed in a state of extending in a cylinder arrangement direction outside the cylinders, and inter-bore flow paths 9, 10 formed between adjacent cylinders 2 in a state of connecting the pair of main flow paths 7, 8. Guide walls 11h, 13h, capable of guiding the cooling water flowing in the main flow paths 7, 8 to the inter-bore flow paths 9, 10, are formed in the cylinder block 1.