Piston Cooling Gallery Segmentation for Thermal Management
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Solution Overview
Problem
High-performance internal combustion engines face increased wear and reduced piston life due to excessive heat buildup and compression loads in the upper combustion surface and piston ring regions, which existing cooling methods fail to adequately address.
Innovation Solution
A piston design featuring a first cooling gallery with a contained cooling medium and a second cooling gallery facilitated by an insert member, where oil is injected to actively dissipate heat from the upper combustion wall and ring belt region through an oil jet, providing an active heat sink mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If temperature and compression loads within the combustion chambers are increased to improve engine efficiency and performance, then fuel economy and fuel combustion are improved, but wear and physical demands on the piston are increased, thereby reducing its potential useful life
Solution Approach 1:
The cooling system is segmented into two distinct cooling galleries: a first cooling gallery radially aligned with the ring belt region and a second cooling gallery axially aligned beneath it. This segmentation allows targeted cooling of different high-heat zones independently, effectively managing thermal loads while maintaining structural integrity and extending piston life under high compression conditions.
Solution Approach 2:
A cooling medium (typically oil or liquid coolant) serves as an intermediary substance that absorbs excess heat from the combustion chamber through the first cooling gallery and transfers it to the second cooling gallery, which then dissipates the heat to the piston skirt or external cooling system. This intermediary mechanism protects the piston from direct thermal damage while enabling high-temperature operation for improved fuel economy.
2Use of energy by moving object
If temperature and compression loads within the combustion chambers are increased to improve engine efficiency and performance, then fuel combustion is improved, but excessive heat buildup and associated wear within the upper combustion surface region and piston ring region of the piston are increased
Solution Approach 1:
The cooling system provides localized cooling quality to specific high-heat zones: the first cooling gallery is positioned radially aligned with the ring belt region to address heat generation from piston ring friction and combustion, while the second cooling gallery is positioned axially beneath it to cool the upper combustion surface. This localized cooling approach directly addresses heat buildup and wear in these critical regions without requiring system-wide temperature reduction, thereby maintaining efficient fuel combustion while protecting against localized thermal damage.
3Device complexity
If a single cooling gallery is used to cool the piston, then the structure is simpler, but the cooling effectiveness in both the ring belt region and upper combustion surface region is insufficient
Solution Approach 1:
The cooling system transitions from a single-plane (radial) cooling gallery to a two-dimensional cooling architecture by adding the second cooling gallery in the axial dimension beneath the first cooling gallery. This dimensional expansion enables comprehensive cooling coverage of both the ring belt region (via radial cooling) and the upper combustion surface (via axial cooling), significantly improving heat dissipation effectiveness while maintaining relatively simple structural integration within the piston body.
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 the operating temperature of the upper combustion wall and ring belt region, enhancing engine performance and extending piston life by actively dissipating heat generated during engine operation.
Implementation Method 1
The first cooling gallery has an upper wall adjacent the upper combustion surface and a lower wall. A cooling medium is contained in the first cooling gallery. The insert member bounds a second cooling gallery between the insert member and the lower wall of the first cooling gallery. The inlet opening is configured in alignment with the oil jet to allow the oil injected from the oil jet to flow into the second cooling gallery against the lower wall of the first cooling gallery.
Implementation Method 2
an oil jet configured to inject oil into the second cooling gallery against the lower wall of the first cooling gallery. The outlet opening is configured to allow the oil to flow outwardly from the second cooling gallery.
Data Source
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AI summary
An internal combustion engine and piston therefor is provided. The piston has a body including an upper combustion wall, a cylindrical outer wall including a ring belt region depending from the upper combustion wall, and a pair of pin bosses having axially aligned pin bores. The piston has a first cooling gallery in radial alignment with the ring belt region with a cooling medium contained therein. An insert member is fixed to the body in axially spaced relation beneath a lower wall of the first cooling gallery. The insert member bounds a second cooling gallery beneath the lower wall of the first cooling gallery. The insert member has an inlet opening configured to allow oil to flow into the second cooling gallery against the lower wall of the first cooling gallery and a separate outlet opening configured to allow the oil to flow outwardly from the second cooling gallery.