Internal Combustion Engine Cooling Structure with Integrated Bypass Jacket

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Solution Overview

Problem

Traditional cooling structures for internal combustion engines with external bypass passages lead to heat dissipation and increased complexity, hindering engine warming-up and aesthetics.

Innovation Solution

The cooling structure partitions the cylinder coolant jacket into a main and sub-cylinder coolant jacket, with the bypass passage formed partly by the sub-cylinder coolant jacket, reducing external pipe usage and integrating the thermostat valve within the engine main unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the bypass passage is routed outside the engine main unit as an external pipe, then the coolant can be circulated during engine start, but heat dissipation occurs and engine warming-up is hindered

Engineering Contradiction:

Improvecoolant circulationVSAvoidengine temperature increase

Core Design Contradiction:

Ease of operationVSTemperature

Solution Approach 1:

The bypass passage is merged with the sub-cylinder coolant jacket, integrating the bypass function into the existing internal coolant circulation system. This eliminates the need for external pipes while maintaining coolant circulation capability during engine start, thereby preventing heat dissipation to outside air and expediting engine warming-up.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The bypass passage is nested within the sub-cylinder coolant jacket structure. The bypass passage utilizes the internal space of the sub-cylinder coolant jacket, allowing the bypass circulation path to be contained within the engine main unit rather than extending externally. This nesting approach prevents heat dissipation while enabling coolant circulation.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of operation

If the bypass passage is routed outside the engine main unit, then coolant circulation is enabled, but the structure becomes complicated and outer appearance is degraded

Engineering Contradiction:

Improvecoolant circulationVSAvoidstructure complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The bypass passage is merged with the sub-cylinder coolant jacket, combining two functions (bypass circulation and coolant heating) into a single integrated structure. This eliminates the need for separate external pipes and reduces the number of parts, thereby simplifying the overall structure and improving outer appearance while maintaining coolant circulation capability.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of operation

If the bypass passage uses external pipes, then coolant circulation path is established, but heat dissipation occurs due to exposure to outside air

Engineering Contradiction:

Improvecoolant circulation pathVSAvoidheat dissipation

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The bypass passage is nested within the sub-cylinder coolant jacket, placing the bypass circulation path inside the engine main unit where it is surrounded by hot engine components. This nesting prevents exposure to outside air, eliminating heat dissipation losses and enabling the bypass passage to contribute to engine warming-up rather than hinder it.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 expedites engine warming-up, simplifies the structure, reduces costs, and maintains a favorable appearance by minimizing external pipe use and pipe resistance.

Implementation Method 1

The thermostat valve includes a first valve for opening and closing the radiator-routing passage, and a second valve for opening and closing the bypass passage, the first valve and the second valve being operable concurrently

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a coolant pump for circulating coolant through a coolant circulation path formed in the cylinder coolant jacket and the cylinder head coolant jacket

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS10323565B2Cooling structure for internal combustion engine

Publication Date: 2019.06.18 HONDA MOTOR CO LTD

AI summary

In an internal combustion engine, a thermostat valve for changing over between coolant circulation through a radiator-routing passage to coolant circulation through a bypass passage, is provided with a first valve for opening and closing the radiator-routing passage, and a second valve for opening and closing the bypass passage. The first and second valves and are operable concurrently. A cylinder coolant jacket around cylinder bores of a cylinder portion is partitioned into two in a cylinder axis direction to thereby form a main cylinder coolant jacket on a side of a cylinder head portion and a sub-cylinder coolant jacket on a side of a crankcase portion. The bypass passage is formed partly by the sub-cylinder coolant jacket. The above arrangement expedites warming-up during the engine start and achieves favorable appearance by a simplified structure.