Cylinder Liner Fire Ring Contact Geometry for Stable Gas Sealing
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Solution Overview
Problem
The existing gas sealing structure for internal combustion engines experiences relative slip between the gasket and the cylinder head due to uneven surface pressures, leading to roughened surfaces and reduced gas sealing performance.
Innovation Solution
A gas sealing structure is designed with a gasket that includes a fire ring, where the contact areas between the cylinder liner and the fire ring, and between the cylinder head and the fire ring, are made equal by using grooves on the cylinder liner and cylinder head to adjust the contact areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gasket is disposed between the cylinder head and cylinder liner with different contact areas, then the sealing function is achieved, but the surface pressure becomes uneven causing relative slip and surface roughening
Solution Approach 1:
The invention applies local quality by creating different surface conditions on the cylinder head and cylinder liner contact surfaces. Specifically, one surface is made smooth while the other is made rough, allowing each surface to have optimized properties for its specific function - the smooth surface reduces friction while the rough surface enhances mechanical interlocking and sealing pressure distribution.
Solution Approach 2:
The invention inverts the conventional approach by making one contact surface rough instead of smooth. Traditionally, both surfaces are made smooth for minimal friction, but this invention makes one surface rough to prevent relative slip and maintain uniform surface pressure, thereby improving sealing reliability.
2Adaptability or versatility
If the cylinder head and cylinder liner have different rigidities, then they can be manufactured with appropriate materials, but relative slip occurs on the contact surface during operation
Solution Approach 1:
The invention addresses the stability issue by creating asymmetric surface qualities - one smooth and one rough - which compensates for the different rigidities of the cylinder head and cylinder liner. This local differentiation allows the system to accommodate material flexibility while maintaining contact surface stability through enhanced mechanical interlocking on the rough surface.
3Ease of manufacture
If the contact area between gasket and cylinder head is large, then the assembly is easier to manufacture, but the surface pressure becomes low causing relative slip
Solution Approach 1:
The invention resolves this contradiction by creating localized surface roughness on one contact surface. This allows the overall contact area to remain large for ease of manufacture and assembly, while the rough surface texture locally increases surface pressure through enhanced mechanical interlocking, preventing relative slip.
Data Source
AI summary
An internal combustion engine includes a cylinder block that includes a space part formed in a columnar shape; a cylinder liner that is formed in a cylindrical shape and that is disposed in the space part; a piston that is movably supported in an axial direction by the cylinder liner; a cylinder head that is fastened to the top of the cylinder block; and a gasket that is disposed between the cylinder block and the cylinder head and between the cylinder liner and the cylinder head. A contact area between the cylinder liner and the gasket and a contact area between the cylinder head and the gasket are the same.