Break Separation of Reassembled Pieces Using Pre-Stress
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Solution Overview
Problem
Existing break separation methods often result in deviations from the desired break path due to material properties, latent stresses, and non-homogeneity, leading to inefficient separation processes, especially in precision applications like combustion engines.
Innovation Solution
Applying a compressive or bending stress perpendicular to the desired break surface to create a tensile stress that maximizes at the break plane, reducing the force required for separation and minimizing deviations from the desired break path, using methods such as wedges, shear arrangements, or bending assemblies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a force is applied perpendicular to the desired break surface to initiate break separation, then the piece breaks at the desired location, but the actual break path frequently deviates from the desired break path
Solution Approach 1:
The patent applies a pre-stress force in the direction of the break separation force before the actual break occurs. This pre-stress lies below the elastic limit of the pieces and creates a steep slope (rate of rise) of the actual break force, which positively influences the initiation of the break and the break path. However, this pre-stress cannot preclude the wandering away of the break line from the desired path due to latent stresses and material non-homogeneity.
Solution Approach 2:
The patent creates a local multi-axial stress condition through thermal treatment that embrittles the break region. This local embrittlement is achieved by conducting heat away very rapidly from the small deposition or melted area into the remainder portions of the piece, creating microscopic hard tears that should favor break separation. However, these stress conditions run into selected angles along the desired break line and cause the break line to wander away.
2Ease of manufacture
If the break region is embrittled through local thermal treatment to favor breakage, then break separation is improved, but the break line wanders away from the desired path due to multi-axial stress conditions
Solution Approach 1:
The patent changes the physical state and properties of the break region through local thermal treatment. The thermal treatment transforms the material structure in the break region, making it more brittle and favorable for break separation. The heat is conducted away very rapidly from the small deposition or melted area, creating a local multi-axial stress condition that embrittles the region. However, this same stress condition causes the break line to run into selected angles and wander away from the desired path.
3Force
If a pre-stress force is applied below the elastic limit to minimize the separation force, then the break initiation is improved, but the break line still wanders due to stress distribution in large regions
Solution Approach 1:
The patent applies a pre-stress force in the direction of the break separation force before the actual break occurs. This pre-stress lies below the elastic limit of the pieces to be separated and creates a steep slope (rate of rise) of the actual break force to be applied. The steep slope positively influences the initiation of the break and the break path. However, because the static pre-stress is effective in relatively large regions of the piece, it cannot preclude the wandering away of the break line from the desired path that results from latent stresses and material non-homogeneity.
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 ensures the break path aligns with the desired path, reduces the necessary separation force, and enhances the steepness of the break force slope, improving the efficiency and accuracy of break separation, particularly in ductile materials with poor separation properties.
Implementation Method 1
Applying a compressive or bending stress perpendicular to the desired break surface to create a tensile stress that maximizes at the break plane
Implementation Method 2
the desired break line is melted along the material, and the melt remainder is blown away or vaporized
Implementation Method 3
the melt remainder is blown away or vaporized so that there results a through groove or a line of serially arrayed blind holes
Implementation Method 4
The edge regions of the groove or the holes are embrittled via the formation of corresponding structures because the heat is conducted away very rapidly from the very small deposition or melted area into the remainder portions of the piece
Data Source
AI summary
A method for break separation of pieces that can be re-assembled or their starting materials achieves a break separation at a selected break surface. The method includes subjecting a piece to be subjected to break separation to a break force F3, F3′ perpendicular to the selected break surface. Also, the method includes applying, before the time at which the piece is subjected to the break force F3, F3′, a compressive force F1-F6′ to the piece in a manner such that a tensile stress is produced whose maximum occurs perpendicular to the plane of the break surface, the level of stress produced is below the elastic limit of the material of the piece, and the compressive force F1-F6′ continues at least until the piece is first subjected to the break force F3, F3′.