Internal Combustion Engine Cooling Structure Bypass Passage Integration

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Solution Overview

Problem

The existing cooling structures for internal combustion engines often compromise external appearance and increase engine size due to the design of bypass passages, which can impair aesthetics and require larger engine dimensions.

Innovation Solution

A cooling structure that utilizes the in-cylinder-block lower fluid passage as part of the bypass passage, allowing for efficient coolant circulation and early engine warming without increasing the engine's size, by partitioning the fluid passage within the cylinder block and using a ring-shaped configuration around the cylinder bores, and strategically placing the thermostat and radiator to minimize external piping and component count.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the bypass passage is formed with a cylinder head-side channel portion extending from the thermostat and a cam chain chamber-side channel portion extending downward, then the bypass passage can be established to run around the radiator, but the rear wall thickness is reduced requiring a bulge in the outer wall surface which impairs external appearances

Engineering Contradiction:

Improvebypass passage functionalityVSAvoidexternal appearance

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The invention merges the bypass passage channel with the cam chain chamber by forming the channel on the inner wall of the cam chain chamber. This integration eliminates the need for separate bypass passage structures that would require external bulges, thereby maintaining smooth external surfaces and improving appearance while preserving bypass functionality.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The bypass passage channel is nested within the cam chain chamber structure. The channel is formed as an internal feature of the cam chain chamber wall, allowing the bypass passage to be contained within the existing engine structure without requiring additional external space or compromising aesthetic appearance.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If the cam chain chamber-side channel portion is formed in the inner wall of the cam chain chamber, then the bypass passage can be established, but the cam chain must be relocated outward to avoid the channel which enlarges the cam chain chamber and increases engine size

Engineering Contradiction:

Improvebypass passage functionalityVSAvoidengine size

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The invention applies local quality by forming the bypass passage channel on a specific section of the cam chain chamber inner wall that does not interfere with cam chain placement. The channel is strategically positioned in an area where it can fulfill its bypass function without requiring the cam chain to be relocated outward, thereby avoiding enlargement of the cam chain chamber and maintaining compact engine dimensions.

Inventive Principle:

Principle #3Local quality

3Reliability

If conventional bypass passage designs are used with separate channel portions, then the bypass function is achieved, but the device complexity increases with multiple channel portions and components

Engineering Contradiction:

Improvebypass passage functionalityVSAvoidbypass passage structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention combines multiple bypass passage channel portions into a single integrated channel formed on the inner wall of the cam chain chamber. This merging eliminates the need for separate cylinder head-side and cam chain chamber-side channel portions, reducing the number of components and simplifying the overall bypass passage structure while maintaining its functional integrity.

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 enables early engine warming, maintains external aesthetics, and reduces engine size while ensuring efficient cooling and reduced component count, thereby enhancing performance and appearance.

Implementation Method 1

a via-radiator passage passing through a radiator air-cooling the coolant

Methodology Applied

Scientific EffectAir cooling: Convection

Implementation Method 2

a via-radiator passage passing through a radiator air-cooling the coolant

Methodology Applied

Scientific EffectHeat transfer: Thermal Radiation

Implementation Method 3

the in-cylinder-block fluid passage through which a coolant flows around a cylinder bore, the cylinder head has an in-cylinder-head fluid passage through which the coolant flows around a combustion chamber

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS11143085B2Cooling structure for internal combustion engine

Publication Date: 2021.10.12 HONDA MOTOR CO LTD

AI summary

A cooling structure of an internal combustion engine includes a thermostat provided to switch circulation between a radiator passage and a bypass passage in an engine body, to thereby enable acceleration of early warming up via the bypass passage without impairing the external appearance or increasing the size of the internal combustion engine. The cooling structure also includes an in-cylinder-block fluid passage partitioned up and down in an axial direction of a cylinder axis into an in-cylinder-block upper fluid passage and an in-cylinder-block lower fluid passage by a partition wall. The bypass passage is partially composed of the in-cylinder-bock lower fluid passage.