Cylinder Liner Chamfer and Anti-Polishing Cuff Retention
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Solution Overview
Problem
Internal combustion engines face issues with liner polishing due to hard carbon deposits and particles accumulating on the piston's upper rim, leading to increased blow-by of combustion gases and lubricating oil consumption, which existing solutions like anti-polishing cuffs do not adequately address in terms of installation and structural integrity.
Innovation Solution
A cylinder liner assembly with an anti-polishing cuff featuring an annular cuff body and a cuff head with an angled undercut that abuts a chamfer on the fire dam of the cylinder liner, ensuring secure positioning and effective scraping of deposits without requiring additional machining, allowing for thinner liner construction and improved engine power-to-weight ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional anti-polishing cuff with steps or shoulders is used, then the cuff can be retained at the top of the cylinder liner, but the liner construction becomes thicker and heavier
Solution Approach 1:
The invention applies a chamfer only at the specific location where the anti-polishing cuff needs to be retained, rather than making the entire liner thicker. The chamfer creates a localized retention feature that allows the cuff to be secured at the top of the liner without increasing the overall liner thickness or weight significantly.
2Weight of moving object
If the cylinder liner is made thinner to reduce weight, then the power-to-weight ratio improves, but the structural integrity and ability to retain components like anti-polishing cuffs becomes compromised
Solution Approach 1:
The invention segments the liner structure by adding a localized chamfer feature at the top of the liner where the anti-polishing cuff is retained. This segmented approach allows the majority of the liner to remain thin for weight reduction, while the specific retention area has enhanced structural features to maintain integrity and secure the cuff.
3Reliability
If additional machining is performed to create retention features for the anti-polishing cuff, then the cuff can be securely positioned, but the manufacturing complexity and cost increase
Solution Approach 1:
The invention merges the retention feature creation into the existing liner manufacturing process by forming the chamfer as part of the liner itself during casting or machining. This eliminates the need for separate additional machining operations to create retention features, reducing manufacturing complexity while ensuring reliable cuff positioning.
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
The solution effectively reduces liner polishing by securely positioning the anti-polishing cuff to scrape deposits, preserving the cylinder head gasket and enabling lighter, more compact engines with improved power density and simplified rebuilding processes.
Implementation Method 1
The cuff head includes an upper annular cuff surface and an angled undercut that is configured to adjacently abut the correspondingly configured chamfer when the cylinder liner and the anti-polishing cuff are mated together
Implementation Method 2
The hard particles may accumulate and abrasively rub against the inner surface of the cylinder liner thereby polishing or wearing away the inside of the liner
Data Source
AI summary
A cylinder liner assembly for inclusion in the cylinder bore of an internal combustion engine includes a sleeve-like cylinder liner and an anti-polishing ring to scrape combustion deposits from a piston reciprocally movable along an axis line of the cylinder liner. A fire dam may axially protrude from a first liner end of the cylinder liner and may have an obliquely angled chamfer disposed therein circumscribing the axis line. To locate the anti-polishing ring proximate to the top land of the piston when at the top dead center position, the anti-polishing ring can include a cuff header disposed at the first cuff end that is generally triangular and has an angled undercut corresponding to the obliquely angled chamfer. When mated, the chamfer and angled undercut abut against each other.