Dual Ignition Plug Cylinder Head Layout for Compact Engine Design
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Solution Overview
Problem
In internal combustion engines, the conventional placement of two ignition plugs often compromises engine performance and increases the size of the engine body, as it requires additional space for valve systems and cooling mechanisms, limiting the compactness and efficiency of the engine.
Innovation Solution
The engine design incorporates a first ignition plug positioned centrally between intake and exhaust valves and a second ignition plug inclined relative to the cylinder axis, with a communicating passage to guide rainwater and enhance cooling, allowing for optimal ignition timing and compact valve system control while maintaining engine size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If two ignition plugs are provided on a cylinder head with conventional placement, then engine performance is enhanced, but the size of the engine main body increases
Solution Approach 1:
The patent changes the spatial arrangement of ignition plugs from a conventional horizontal placement to a vertical arrangement where one plug is positioned higher than the other. The first ignition plug is disposed at a higher position than the second ignition plug when viewed from the front, allowing both plugs to be accommodated within the cylinder head's vertical space rather than requiring additional horizontal space, thus enhancing engine performance without increasing engine main body size.
Solution Approach 2:
The patent employs asymmetric positioning of the two ignition plugs, with the first plug located at a higher position and the second plug at a lower position. This asymmetric arrangement optimizes the combustion chamber geometry and ignition timing while maintaining a compact engine structure, resolving the contradiction between performance enhancement and size control.
2Productivity
If two ignition plugs are provided on a cylinder head, then engine performance is enhanced, but the valve driving mechanism space is compromised
Solution Approach 1:
By positioning the ignition plugs at different vertical heights within the cylinder head, the patent creates three-dimensional space utilization that separates the ignition system from the valve driving mechanism space. The first ignition plug is disposed at a higher position than the second ignition plug, allowing the valve driving mechanism to be arranged in the lower region without spatial conflict, thus maintaining both enhanced engine performance and adequate valve driving mechanism space.
3Productivity
If ignition plugs are positioned to optimize combustion, then engine performance is enhanced, but cooling efficiency is reduced
Solution Approach 1:
The patent segments the cooling system into separate cooling passages for each ignition plug. The first cooling passage is provided in the cylinder head to cool the first ignition plug, and the second cooling passage is provided in the cylinder block to cool the second ignition plug. This segmented cooling approach allows optimized thermal management for each plug's specific thermal environment, maintaining both combustion performance and cooling efficiency.
Solution Approach 2:
The patent implements localized cooling solutions tailored to each ignition plug's thermal requirements. The first cooling passage in the cylinder head provides cooling for the first ignition plug, while the second cooling passage in the cylinder block provides cooling for the second ignition plug. This local quality approach ensures each plug receives appropriate cooling based on its specific thermal conditions, resolving the contradiction between combustion optimization and cooling efficiency.
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 enhances engine performance, reduces fuel adhesion, prevents abnormal combustion, and improves emission performance by optimizing ignition timing and compactness, even with lean fuel mixtures, while simplifying the draining structure and maintaining efficient cooling.
Implementation Method 1
a communicating passage extending from a bottom portion of the first plug hole to the second plug hole
Implementation Method 2
A cooling water passage for communicating the water jacket of the cylinder head and a water jacket of a cylinder main body
Implementation Method 3
a first ignition plug disposed on the inner side of an area surrounded by the plural intake valves and the plural exhaust valves... A second ignition plug is inclined with respect to the cylinder axial line
Data Source
AI summary
An internal combustion engine can include a first ignition plug disposed on the inner side of a range surrounded by a plurality of intake valves and a plurality of exhaust valves with a cylinder head viewed in parallel to a cylinder axial line and standing uprightly along the cylinder axial line. A second ignition plug is inclined with respect to the cylinder axial line on the outer side of the range. The second ignition plug is disposed on the opposite side to a valve driving mechanism with respect to the cylinder axial line on the outer side of the range.