Piston Combustion Bowl Failure Initiation Structure
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Solution Overview
Problem
Internal combustion engines face challenges in managing over-pressures caused by incompressible liquids in the combustion chamber, which can lead to damage due to excessive forces transmitted to the piston, connecting rod, and crankshaft.
Innovation Solution
A piston assembly with a failure initiation structure in the bowl base that allows for a controlled fracture when a predetermined load or pressure is exceeded, releasing the excess pressure and preventing further engine damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the piston head is made robust to withstand high pressures, then the piston's tolerance of stress increases, but the risk of catastrophic failure increases when incompressible liquid enters the combustion chamber
Solution Approach 1:
The patent applies preliminary action by pre-configuring a failure initiation structure (such as a groove or notch) in the piston head before any abnormal condition occurs. This structure is designed to ensure that when incompressible liquid enters the combustion chamber and causes over-pressure, the fracture will initiate at the predetermined location rather than randomly, allowing for a controlled failure mode that prevents catastrophic damage to the engine.
Solution Approach 2:
The patent converts the harmful effect of incompressible liquid ingress into a beneficial controlled failure mode. Instead of allowing random catastrophic failure that could damage the entire engine, the failure initiation structure guides the fracture to occur in a predetermined, less harmful location. The harmful over-pressure condition is thus transformed into a controlled event that protects the engine from more severe damage.
2Stability of the object's composition
If the piston design prioritizes crack prevention through robust construction, then the piston can withstand normal combustion pressures, but it lacks a mechanism to safely handle over-pressure conditions from liquid ingress
Solution Approach 1:
The failure initiation structure is pre-formed in the piston head during manufacturing, creating a predetermined fracture path before any abnormal operating condition occurs. This preliminary preparation ensures that when over-pressure from liquid ingress occurs, the fracture will follow the predetermined path rather than creating random, unpredictable cracks that could compromise engine safety.
Solution Approach 2:
The patent transforms the harmful over-pressure condition caused by liquid ingress into a beneficial controlled fracture event. The failure initiation structure ensures that the harmful pressure builds up until it triggers a predetermined, controlled failure mode that releases the pressure safely, converting a potentially catastrophic harmful event into a protective mechanism.
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 controlled fracture mechanism effectively manages over-pressures by releasing incompressible liquids from the combustion chamber, preventing engine damage and ensuring continued operation.
Implementation Method 1
a failure initiation structure in the bottom surface of the bowl base configured so that a favorable fracture occurs along the failure initiation structure that separates a fragment of the bowl base from the combustion bowl when a predetermined load or pressure in the combustion bowl is exceeded
Data Source
AI summary
A piston including a piston crown, the piston crown defining a combustion bowl with a bowl base and bottom surface. A failure initiation structure is provided on the bottom surface of the combustion bowl to initiate favorable fracture at predetermined loads. Such favorable fracture may lead to the a separation of a fragment of the bowl base from the combustion bowl when a predetermined load or pressure is exceeded within the combustion bowl.