Water-Cooled Engine Casting with Two Opening Portions

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Solution Overview

Problem

The existing water-cooled four-cycle engines require three opening portions for casting the water jacket, leading to complex die structures, high costs, and increased components and assembly steps, making it difficult to create a compact engine.

Innovation Solution

The engine design is modified to form a water jacket using only two opening portions, allowing for two lid plates to close them securely, simplifying casting and reducing components and assembly steps, while maintaining efficient cooling by forming the cylinder jacket and head jacket in orthogonal directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If three opening portions are provided to form the water jacket by casting out, then the water jacket can be formed completely, but the structure of the casing dies becomes complicated and costs increase

Engineering Contradiction:

Improvewater jacket formationVSAvoidcasing die structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The water jacket formation process is segmented into two separate casting operations. First, the cylinder jacket is formed by casting out through the first opening portion in the side surface of the cylinder block. Second, the head jacket is formed by casting out through the second opening portion in the upper surface of the cylinder head. This segmentation allows each opening portion to serve a specific function, simplifying the overall die structure compared to forming all water jacket portions through a single complex operation.

Inventive Principle:

Principle #1Segmentation

2Reliability

If three opening portions are provided to form the water jacket, then the water jacket can be formed completely, but the number of lid plates and assembling steps increases

Engineering Contradiction:

Improvewater jacket formationVSAvoidnumber of components and assembly steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The water jacket formation is segmented into two distinct casting operations through two opening portions, which requires only two lid plates instead of three. This reduces the number of components and assembly steps while still achieving complete water jacket formation around both the cylinder and combustion chamber.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The formation of the cylinder jacket and head jacket is merged into a coordinated two-step casting process. The first opening portion forms the cylinder jacket, and the second opening portion forms the head jacket, with both operations combined to achieve complete water jacket formation using only two lid plates instead of three separate operations.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If three opening portions are provided to form the water jacket, then the water jacket can be formed completely, but it becomes difficult to make the engine compact

Engineering Contradiction:

Improvewater jacket formationVSAvoidengine size

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The water jacket formation is segmented into two directional casting operations: horizontal casting for the cylinder jacket through the first opening portion, and vertical casting for the head jacket through the second opening portion. This orthogonal segmentation allows efficient use of space and contributes to a more compact engine overall structure.

Inventive Principle:

Principle #1Segmentation

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 reduces costs and complexity by minimizing the number of components and assembly steps, while ensuring effective cooling and enhancing combustion efficiency by optimizing the cylinder jacket thickness.

Implementation Method 1

a water jacket including a cylinder jacket and a head jacket is formed in the engine core, the cylinder jacket surrounding the cylinder bore, and the head jacket communicating with the cylinder jacket and surrounding the combustion chamber

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentUS8887673B2Water-cooled four-cycle engine

Publication Date: 2014.11.18 HONDA MOTOR CO LTD

AI summary

In a water-cooled four-cycle engine, an engine core including a cylinder block, a cylinder head and a first crankcase half body is formed as a unitary part cast integrally; a water jacket including a cylinder jacket surrounding a cylinder bore and a head jacket surrounding a combustion chamber is formed in the engine core; and a timing-belt chamber being adjacent to the cylinder jacket is provided in a side portion of the engine core. A first opening portion for forming a first semi-peripheral portion of the cylinder jacket on a side opposite from the timing-belt chamber by casting out is provided in a side surface of the cylinder block. A second opening portion for forming a second semi-peripheral portion of the cylinder jacket and the head jacket by casting out is provided in an upper surface of the cylinder head.