Radial Lip Piston Profile for Diesel Emission Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Diesel engine pistons face challenges in reducing NOx and soot emissions while maintaining efficiency and cost-effectiveness, as existing designs often require costly after-treatment systems and complex manufacturing processes.
Innovation Solution
A piston with a stepped combustion bowl design featuring a planar annular floor and inwardly sloping inner bowl with protruding radial lips, which enhances air mixing and reduces NOx emissions, allowing for a cost-effective solution that can be forged or machined without 5-axis CNC machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a conventional piston design is used, then manufacturing is simpler, but emissions (NOx and soot) are higher and after-treatment systems are required
Solution Approach 1:
The combustion bowl is divided into multiple levels (first level, second level, third level) with distinct functional zones. Each level has specific geometric features (radii, depths, profiles) that perform different combustion functions, allowing complex emission reduction geometry to be achieved through segmented construction rather than a single complex form
Solution Approach 2:
Different regions of the combustion bowl have optimized local geometries tailored to specific functions: the first level has a larger radius for initial combustion, the second level has a smaller radius for mixing enhancement, and the third level has specific profile characteristics for emission control. This local optimization allows emission reduction without requiring complex after-treatment systems
2Object-generated harmful factors
If a complex stepped bowl design is used, then emissions are reduced, but manufacturing complexity increases requiring 5-axis CNC machining
Solution Approach 1:
The combustion bowl is divided into multiple levels (first level, second level, third level) with distinct functional zones. Each level has specific geometric features (radii, depths, profiles) that perform different combustion functions, allowing complex emission reduction geometry to be achieved through segmented construction rather than a single complex form
Solution Approach 2:
The combustion bowl utilizes spherical and curved geometries (first radius R1, second radius R2, third radius R3) that are naturally formable through forging processes. These curved surfaces achieve the complex emission-reducing geometry without requiring multi-axis CNC machining, as the spherical profiles can be created through conventional forging dies
3Object-generated harmful factors
If enhanced air system designs are used for cooled EGR, then NOx emissions are reduced, but device complexity and cost increase
Solution Approach 1:
The piston's combustion bowl geometry itself performs the emission reduction function that would otherwise require complex air system designs. The multi-level bowl with specific radii and profiles creates natural mixing and combustion conditions that reduce NOx without needing additional EGR systems, turbochargers, or complex air handling equipment
4Object-generated harmful factors
If enhanced fuel injection systems are used, then soot emissions are reduced, but device complexity and cost increase
Solution Approach 1:
The piston's combustion bowl geometry itself performs the emission reduction function that would otherwise require complex fuel injection systems. The multi-level bowl design with specific geometric features creates combustion conditions that naturally reduce soot formation without needing advanced injection equipment
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 design effectively reduces NOx and soot emissions while maintaining efficiency and cost-effectiveness, eliminating the need for expensive after-treatment systems and simplifying manufacturing processes, achieving superior trade-offs in emissions and fuel consumption.
Implementation Method 1
enhanced mixing of combustion products with excess air available in the cylinder
Implementation Method 2
enhanced mixing of combustion products with excess air available in the cylinder
Data Source
AI summary
A piston for an internal combustion engine includes a piston body having a generally planar crown and a sidewall extending from the crown. A stepped combustion bowl is recessed in the crown and includes an outer bowl recessed relative to the crown and defining a generally planar annular floor surface. The stepped combustion bowl further includes an inner bowl recessed relative to the outer bowl. The inner bowl includes a sidewall that slopes continually inwardly from the outer bowl to a floor surface of the inner bowl. A plurality of protruding lips extend from the sidewall toward a central axis of the piston body.