Water Jacket Cooling Groove Inclined Transition

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Solution Overview

Problem

The existing water jacket designs for internal combustion engine cylinder blocks face issues with thermal and compressive stress concentration when slits are introduced between adjacent cylinders to improve cooling performance, leading to variations in temperature and stress generation.

Innovation Solution

A water jacket design featuring a cooling channel and a cooling groove between adjacent cylinders, where the end portion of the groove is continuous with the inner wall via an inclined portion and positioned on a flat surface, dispersing thermal and compressive stress, and ensuring that the groove is disposed at a flat wall surface to prevent stress concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a slit is disposed between adjacent cylinders to improve cooling performance, then cooling performance is improved, but thermal stress and compressive stress concentration are generated

Engineering Contradiction:

Improvecooling performanceVSAvoidstress concentration

Core Design Contradiction:

TemperatureVSStress or pressure

Solution Approach 1:

The patent applies curvature by forming the cooling groove with a curved cross-section instead of a straight slit, and by creating an inclined portion at the end of the groove that transitions smoothly to the cooling channel. This curved geometry eliminates stress concentration points while maintaining effective cooling between adjacent cylinders.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Temperature

If a slit is disposed between adjacent cylinders, then cooling performance is improved, but variations in temperatures of parts of the cylinder block are large

Engineering Contradiction:

Improvecooling performanceVSAvoidtemperature uniformity

Core Design Contradiction:

TemperatureVSStability of the object's composition

Solution Approach 1:

The patent implements local quality by creating a cooling groove with varying cross-sectional area along its length, with the widest section positioned at the center between adjacent cylinders where cooling demand is highest. The groove gradually tapers toward the ends, providing localized cooling intensity where needed while reducing temperature variations across the cylinder block.

Inventive Principle:

Principle #3Local quality

3Temperature

If a slit is disposed between adjacent cylinders, then cooling performance is improved, but a compressive stress against expansion is generated at the slit

Engineering Contradiction:

Improvecooling performanceVSAvoidresistance to compressive stress

Core Design Contradiction:

TemperatureVSStrength

Solution Approach 1:

The curved cross-section of the cooling groove and the inclined transition portion distribute compressive stresses generated during cylinder expansion more evenly throughout the structure, preventing stress concentration at the groove location while maintaining cooling effectiveness.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 reduces stress at the cylinder block by dispersing thermal and compressive stress through the inclined portion and preventing concentration on the cooling groove, thereby enhancing cooling performance without excessive stress generation.

Implementation Method 1

the end portion of the cooling groove and an inner wall of the cooling channel are continuous with each other via an inclined portion inclined so as to become thicker toward the inner wall of the cooling channel. Accordingly, the end portion of the cooling groove and the inner wall of the cooling channel are continuous with each other via the inclined portion, and the thermal stress and the compressive stress generated at the cooling groove are dispersed via the inclined portion.

Methodology Applied

Scientific EffectStress dispersion:

Implementation Method 2

a cooling channel through which a coolant flows, the cooling channel being formed in a cylinder block in which a plurality of cylinders are formed such that the cooling channel is positioned outside the cylinders; and a cooling groove through which the coolant flows, the cooling groove being formed between adjacent ones of the cylinders

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS11339741B2Water jacket

Publication Date: 2022.05.24 HONDA MOTOR CO LTD

AI summary

A water jacket includes: a cooling channel through which a coolant flows, the cooling channel being formed in a cylinder block in which a plurality of cylinders are formed such that the cooling channel is positioned outside the cylinders; and a cooling groove (slit) through which the coolant flows, the cooling groove being formed between adjacent ones of the cylinders. When a slit end portion is viewed in sectional view in a direction in which the cylinders are arranged, the slit end portion and a cylinder-block inner wall are continuous with each other via an inclined portion inclined so as to become thicker toward the cylinder-block inner wall.