Fine blanking V-shaped projection for smooth cutting surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fine blanking processes often result in tears and edge rollover at cutting surfaces, especially when dealing with thicker materials and sharper contours, leading to reduced part functionality and increased material costs due to the need for thicker raw materials and additional machining operations.
Innovation Solution
A method that involves clamping a flat strip between a shearing punch and a cutting die with a V-shaped projection, applying compressive stress by a tool element moving slightly retarded to the shearing punch, and pressing additional material into the cutting zone perpendicular to the cutting direction, ensuring a consistent compressive stress throughout the cutting process to prevent tears and rollover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If fine blanking is performed on thicker materials with sharper contours, then manufacturing precision is improved, but tears and edge rollover occur at cutting surfaces
Solution Approach 1:
The V-shaped projection is pressed into the material before the cutting process begins, creating preliminary compressive stress and preventing continuous material flow during cutting. This preliminary action prepares the material to resist tearing and rollover during the subsequent shearing process
Solution Approach 2:
The invention changes the stress state parameter by applying high compressive stress through the V-shaped projection during cutting. This parameter change transforms the material's response to cutting forces, enabling smooth cutting surfaces on thicker materials with sharper contours without tears or significant rollover
2Manufacturing precision
If additional machining operations are performed to remove tears and rollover, then cutting surface quality is improved, but productivity decreases and material loss increases
Solution Approach 1:
The V-shaped projection prevents tears and rollover formation during the initial cutting process itself, eliminating the need for subsequent machining operations to remove defects. This preliminary preventive action maintains high productivity while achieving smooth cutting surfaces
Solution Approach 2:
The invention converts the potentially harmful material flow that causes rollover into a beneficial controlled deformation by applying compressive stress through the V-shaped projection. This transforms what would be a defect-creating process into a defect-preventing process, eliminating the need for additional machining
3Strength
If thicker raw materials are used to compensate for rollover, then part strength is improved, but material loss increases and cost increases
Solution Approach 1:
By changing the stress state through the V-shaped projection, the invention enables use of thinner materials while maintaining part strength. The controlled compressive stress prevents rollover that would otherwise require thicker materials to compensate for functional length loss and edge quality issues
Solution Approach 2:
The preliminary pressing of the V-shaped projection into the material prevents rollover formation, allowing use of optimal thickness without excessive material loss. This preliminary action ensures that the full thickness of the material contributes to part strength rather than being lost to rollover
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 method enables smooth, tear-free cutting surfaces and reduced edge rollover, allowing for the fine blanking of thicker parts with sharp edges without additional finishing and minimizing material shifting, thus enhancing the quality and functionality of parts across various dimensions and geometries.
Implementation Method 1
a compressive stress acts on the flat strip to be cut
Implementation Method 2
by superposition of high hydrostatic pressure is enforced, a cut by shearing
Implementation Method 3
a cut by shearing, i.e. a plastic deformation
Implementation Method 4
prevents continuous flow of the material during the cutting process
Data Source
AI summary
A method and device for production of stampings with an almost smooth cutting and enlarged functional surface, especially fine blanking and/or forming a workpiece out of a flat strip, wherein flat strip is clamped between an upper part consisting of a shearing punch, a pressure pad, a V-shaped projection and an ejector arranged on the pressure pad, and a lower part consisting of cutting die, ejector and an inner form stamp. By adjusting the state of stress in the cutting zone to a position oriented compressive stress by movement slightly retarded with regard to movement of the shearing punch additionally pressing in material in a direction almost perpendicular to the cutting direction by a tool element acting with controlled force depending on the part geometry and thickness of the workpiece parallel to the cutting line between shearing punch and cutting die, tears at cutting and reduced rollover are achieved.