Profiled Cylinder Liner Relief Geometry Against Bore Ovalization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cylinder liners in internal combustion engines experience distortion due to assembly, thermal expansion, and cylinder pressure, leading to radial growth and ovalization, which affects piston ring conformability and increases oil consumption, with existing solutions like external rib structures being inadequate and costly.
Innovation Solution
A cylinder liner with a relief feature and an optional stiffening feature on its outer surface, designed to resist distortion by reversing and reducing radial growth, and amplifying higher-order deformations, improving piston ring conformability and reducing oil consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the mid-stop height is shortened to minimize radial growth, then liner distortion is reduced, but the liner thickness cannot be increased without negatively impacting liner temperatures
Solution Approach 1:
The patent applies local quality by introducing a relief feature with a specific profile at a localized position on the liner outer surface, adjacent to the mid-stop. This localized structural modification allows the liner to resist radial growth and distortion at the critical mid-stop region without requiring a uniform increase in liner thickness, thereby maintaining heat dissipation characteristics while improving dimensional stability.
Solution Approach 2:
The patent changes the geometric parameters of the liner structure by adding a relief feature with specific dimensions (depth, width, position) on the outer surface. This parameter modification creates a stiffer local structure that resists radial growth without increasing the overall liner thickness, thus avoiding negative thermal impacts while reducing distortion.
2Stability of the object's composition
If the liner thickness is increased to minimize radial growth, then liner distortion is reduced, but liner temperatures are negatively impacted
Solution Approach 1:
Instead of uniformly increasing liner thickness, the patent introduces a localized relief feature with a specific profile on the outer surface adjacent to the mid-stop. This localized structural enhancement provides additional stiffness and distortion resistance only where needed, without increasing the overall liner thickness that would impair heat dissipation and temperature management.
3Stability of the object's composition
If an external rib structure is added to the cylinder block to control distortion, then liner stability is improved, but weight and cost increase
Solution Approach 1:
The patent extracts the distortion control function from the external cylinder block structure and relocates it to the liner itself by adding a relief feature on the liner outer surface. This transfers the stabilization function to a lighter component, eliminating the need for heavy external rib structures on the cylinder block while maintaining liner stability.
Solution Approach 2:
Instead of adding external structural elements in the radial dimension, the patent uses a relief feature that modifies the liner surface profile in a controlled geometric pattern. This dimensional approach creates stiffness through geometric design rather than through added material mass, reducing weight while maintaining stability.
4Manufacturing precision
If complex higher order distortions occur from cylinder head bolts and structural influences, then piston ring conformability deteriorates, but oil consumption increases
Solution Approach 1:
The patent applies preliminary anti-action by pre-configuring the relief feature with a specific profile on the liner outer surface before assembly. This pre-designed geometric feature creates inherent resistance to higher order distortions caused by cylinder head bolts and structural influences, maintaining bore roundness and piston ring conformability without requiring additional corrective measures, thereby preventing oil consumption issues.
Data Source
AI summary
A cylinder liner for a cylinder bore of a cylinder of an internal combustion engine. The cylinder liner includes a cylindrical casing having an outer surface and an inner surface, wherein each surface has a respective surface area. The liner includes a liner seat positioned on the outer surface wherein the liner seat engages with the cylinder bore to position the cylindrical casing in the cylinder bore. The liner includes a relief feature positioned on the outer surface either adjacent the liner seat or above a mid-stop wherein the relief feature resists distortion of the cylindrical casing from the cylinder bore. The liner can include a stiffening feature positioned above the relief feature on the outer surface. The relief feature forms a depressed surface on the outer surface and the stiffening feature forms a raised surface on the outer surface of the cylindrical casing.