Elliptical Piston Cooling Channel for Crown Stress Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The crown of internal combustion engine pistons experiences increased temperature and stress due to higher engine output, leading to potential cracking and reduced durability, as existing cooling channels concentrate stress when positioned close to the combustion load.
Innovation Solution
The piston features a cooling channel with an elliptical cross-section, where at least one arc is configured as a quadratic curve, maximizing stress distribution by optimizing the ratio of minor to major axes, and incorporating elliptical arcs in critical areas such as the oil groove and reinforced parts to reduce stress concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the cooling channel is positioned closer to the crown surface to improve cooling performance, then the cooling efficiency increases, but stress concentration occurs at the upper side of the cooling channel leading to reduced durability
Solution Approach 1:
The cooling channel cross-section is designed with an elliptical shape having rounded corners instead of sharp angles. The elliptical shape with curvature radius R1 at the upper side and R2 at the lower side distributes stress more evenly throughout the structure, eliminating stress concentration points while maintaining effective cooling proximity to the crown surface.
Solution Approach 2:
The invention optimizes specific geometric parameters of the cooling channel including the elliptical cross-section dimensions, curvature radii (R1 and R2), and positioning distance from the crown surface. By carefully controlling these parameters, the design achieves optimal balance between cooling efficiency and stress distribution, allowing the channel to be positioned closer to the crown without causing stress concentration.
2Power
If the engine output is increased to improve power, then the driving force increases, but the crown experiences higher temperature and stress leading to cracking
Solution Approach 1:
The elliptical cross-section with rounded corners distributes the high thermal and mechanical stresses generated during high-power operation more uniformly across the crown structure. This curvature-based design prevents stress concentration that would otherwise lead to cracking under increased engine output conditions.
Solution Approach 2:
The invention converts the harmful effect of high stress and temperature from increased engine output into a beneficial reinforcement mechanism. The elliptical cooling channel design causes stresses to distribute and reinforce each other constructively throughout the crown structure, transforming the potentially damaging high-stress environment into a condition that strengthens the overall piston integrity.
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 design enhances cooling performance and increases the safety factor by distributing stress effectively, allowing the cooling channel to be positioned closer to the crown surface without compromising durability, resulting in reduced temperatures and stress levels.
Implementation Method 1
a cooling channel including a refrigerant channel provided in the body to allow a refrigerant to flow therethrough to cool the body
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a piston for an internal combustion engine. The piston includes a body (10) including, at an upper part of the body (10), a crown (11) including a combustion chamber (B) where fuel is burnt and including, at a lower part of the body (10), a piston pin boss (12) into which a piston pin is inserted and a skirt (13) corresponding to a cylinder wall, and a cooling channel (20) including a refrigerant channel, a refrigerant inlet (21) provided at a side of the refrigerant channel, and a refrigerant outlet (22) provided at the other side of the refrigerant channel, wherein a cross section of the cooling channel (20) has an overall elliptic shape to reduce stress occurring at an upper side of the cooling channel (20) when the fuel is burnt in the internal combustion engine, and at least one of arcs of the ellipse is configured as a first elliptical arc (EA-1) of a quadratic curve.