Piston Cooling Cavity Formation via Groove Bending
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for manufacturing internal combustion engine pistons with annular cavities for cooling fluid circulation are inefficient, costly, and prone to curled scales during pressure welding, which affect fluid flow and can lead to overheating issues.
Innovation Solution
A method involving forming an annular groove on the piston crown, creating a protruding strip, and bending it to close the groove, forming a sealed annular cavity without dividing the piston body or using complex cores, using a pressure roller to apply a bending load while rotating the piston.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pressure welding is used to join the top land and skirt to form the annular cavity, then production efficiency is improved, but curled scales form at the welding edges which reduce cavity volume and adversely affect cooling fluid flow
Solution Approach 1:
The invention extracts and removes the harmful curled scales that form during pressure welding through a dedicated scale removal step, separating the welding process from the final cavity formation. This allows the welding to proceed efficiently while eliminating the detrimental byproduct that would otherwise reduce cavity volume and disrupt cooling fluid flow.
Solution Approach 2:
The invention performs preliminary actions by first forming the annular groove and allowing curled scales to form during pressure welding, then subsequently removing these scales before finalizing the annular cavity. This sequence of preliminary actions enables efficient welding while ensuring the cavity achieves the correct volume and shape for optimal cooling fluid circulation.
2Ease of manufacture
If a readily disintegrating sand core is used to cast the annular cavity, then the cavity can be formed in a single piece, but the molding and core removal work is difficult, time-consuming and expensive
Solution Approach 1:
The invention eliminates the need for complex sand core molding and removal operations by extracting the cavity formation process from traditional casting. Instead, the annular cavity is formed by machining an annular groove and sealing it with the piston crown, completely removing the time-consuming core molding and extraction steps while maintaining ease of manufacture.
Solution Approach 2:
The invention replaces the mechanical sand core casting system with a machining and sealing system. The annular groove is machined into the piston body, and the crown is pressed onto it to form the sealed cavity, substituting complex core molding mechanics with simpler machining and pressing operations that are faster and less costly.
3Reliability
If the annular cavity volume is reduced due to curled scale formation, then the cooling fluid flow characteristics are adversely affected, but increasing pressure application to reduce scale size increases scale volume
Solution Approach 1:
The invention converts the harmful effect of curled scale formation into a beneficial process by allowing scales to form during pressure welding (which ensures good bonding) and then removing them in a controlled manner. The scales that would otherwise reduce cavity volume are eliminated, and the remaining cavity is optimized for cooling fluid flow, turning a potential defect into an opportunity for ensuring both weld quality and cavity integrity.
Solution Approach 2:
The invention performs preliminary scale removal operations after welding but before final cavity sealing, allowing the removal of harmful scales that would reduce cavity volume. This preliminary action ensures the cavity achieves the correct volume and shape for optimal cooling fluid circulation while maintaining the benefits of pressure welding.
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 approach enables efficient, high-quality piston manufacturing with improved fluid flow and prevents overheating, reducing the risk of burning and knocking phenomena.
Implementation Method 1
applying pressure to the protruding strip, so as to bend the protruding strip in the direction of the opening of the annular groove and thereby close the opening of the annular groove
Data Source
AI summary
A method is provided for efficiently manufacturing a high quality internal combustion engine piston having an annular cavity allowing for good circulation of cooling fluid. An annular groove is formed at the circumferential edge of the top face of a piston crown, or at the top of the exterior circumferential face of the crown, and an annular protruding strip is formed as a continuation of an edge of the opening of the annular groove. The protruding strip is bent in the direction of the opening of the annular groove by bringing to bear a pressure roller 11, while rotating the main piston body. Consequently, the opening of the annular groove is closed, whereby an annular cavity for circulating cooling fluid is formed so as to surround a pressure receiving recess.