Internal Combustion Engine Cooling Passage Simplification

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Solution Overview

Problem

The complexity of the cooling passage structure in internal combustion engines due to the need for a connection hose between the water pump unit and the cylinder portion complicates the engine's design.

Innovation Solution

The internal combustion engine design includes a water pump unit mounted on the side surface of the cylinder head with a direct connection to the coolant inlet and outlet portions, eliminating the need for a hose and simplifying the cooling path structure by protruding these components externally, allowing for a more straightforward layout without compromising the cam chain chamber or other components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a connection hose is used to connect the water pump unit with the cylinder portion, then the cooling system can be assembled with separate components, but the structure of the cooling passage becomes complicated

Engineering Contradiction:
Improveassembly flexibilityVSAvoidcooling passage structure
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges the water pump unit with the cylinder portion by providing a direct connection between the discharge port of the water pump and the coolant inlet portion of the cylinder, eliminating the need for a separate connection hose and simplifying the cooling passage structure

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If the coolant inlet and outlet portions are integrated into the cylinder portion, then the number of separate components is reduced, but the space arrangement becomes more constrained

Engineering Contradiction:
Improvenumber of componentsVSAvoidspace arrangement
Core Design Contradiction:
Device complexityVSShape

Solution Approach 1:

The patent resolves the space arrangement constraint by having the coolant inlet and outlet portions protrude from the wall surface of the cylinder portion in a direction extending from the cylinder axis, utilizing the radial dimension to achieve direct connection with the water pump unit while maintaining compact integration

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

3Device complexity

If the coolant inlet and outlet portions protrude externally from the cylinder portion, then direct connection with the water pump unit is achieved, but the cam chain chamber space may be compromised

Engineering Contradiction:
Improvecooling passage structureVSAvoidcam chain chamber space
Core Design Contradiction:
Device complexityVSVolume of stationary object

Solution Approach 1:

The patent applies asymmetry by positioning the coolant inlet and outlet portions at specific locations on the cylinder portion wall surface, with the inlet portion disposed below the cam chain chamber and the outlet portion disposed above it, allowing direct connection without interfering with the cam chain chamber volume

Inventive Principle:
Principle #4Asymmetry

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 simplifies the engine's structure, enhances coolant flow management through a thermo-actuator unit that switches between normal and bypass paths, and efficiently uses space for compact component placement, such as the catalyst unit, while maintaining effective cooling without the need for additional hoses.

Implementation Method 1

a thermo-actuator unit (84) that changes flow paths of coolant

Methodology Applied
Scientific EffectThermal actuation: Thermal Expansion

Data Source

PatentEP3524793B1Internal combustion engine
Publication Date: 2020.09.30 HONDA MOTOR CO LTD
  • EP3524793B1 patent drawingFigure 1
  • EP3524793B1 patent drawingFigure 2
  • EP3524793B1 patent drawingFigure 3

AI summary

[Object] To simplify a structure of a cooling passage in an internal combustion engine. [Solving Means] An internal combustion engine includes a cylinder portion 44 that includes a cylinder 45 and a cylinder head 46; and a water pump unit 81 disposed on a side wall portion 67R of the cylinder head 46. In the internal combustion engine, the cylinder portion 44 includes a coolant inlet portion 85 with which a port 93 of the water pump unit 81 is directly connected. In a side view facing the side wall portion 67R of the cylinder head 46, the coolant inlet portion 85 protrudes to an outside from a lower surface 46a of the cylinder portion 44.