Press Brake Stroke Compensation for Deflection-Aware Bending
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Solution Overview
Problem
Existing press brake systems face challenges in achieving accurate bending angles for sheet metal due to deflections in side frames, upper, and lower tables, despite corrections, leading to suboptimal bending accuracy.
Innovation Solution
A press brake control device and method that calculates a corrected stroke by considering spring back, bending load, and deflection amounts of the punch, punch holder, and die, incorporating deflection coefficients to adjust the depth value for precise metal bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the punch is lowered by a calculated stroke to achieve desired bending angle, then the bending process can be completed, but the bending accuracy deteriorates due to deflection of side frames, upper table, and lower table
Solution Approach 1:
The patent calculates and compensates for deflection amounts of the punch, punch holder, die, and machine structure before performing the bending operation. By pre-determining the depth value that accounts for these deflections, the system ensures accurate bending angles are achieved despite the inherent deflections that occur during the bending process.
2Manufacturing precision
If the stroke is corrected by considering deflection of side frames and tables, then bending accuracy is improved, but it is still not possible to achieve desired bending angle due to punch and punch holder deflection
Solution Approach 1:
The patent divides the total deflection compensation into separate components: punch deflection, punch holder deflection, die deflection, and machine structure deflection. Each component is calculated independently based on its specific deflection coefficient and the applied load, then summed to determine the total depth value correction. This segmentation allows for more precise compensation while maintaining manageable calculation complexity.
3Manufacturing precision
If multiple deflection components are considered for correction, then bending accuracy is further improved, but the calculation and control complexity increases
Solution Approach 1:
The patent introduces deflection coefficients for each component (punch, punch holder, die) that characterize their respective deflection behaviors. By using these coefficients along with the applied load, the system calculates specific deflection amounts for each component. This parameter-based approach allows the control system to accurately compensate for multiple deflection sources without requiring complex mechanical modifications, thereby improving precision while managing control complexity through software-based calculations.
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 significantly enhances bending accuracy by accounting for various deflections and spring back, ensuring the sheet metal is bent at the desired angle with improved precision.
Implementation Method 1
a punch holder deflection amount calculation unit configured to calculate a punch holder deflection amount that is a deflection amount of the punch holder according to the bending load
Data Source
AI summary
When a sheet metal is sandwiched between a punch held by a punch holder and a die held by a die holder to bend the sheet metal at a set bending angle by moving the punch toward the die, a stroke calculation unit calculates a stroke of the punch for bending the sheet metal at the bending angle in consideration of a spring back amount of the bent sheet metal. A bending load calculation unit calculates a bending load required to bend the sheet metal at the bending angle. A punch deflection amount calculation unit calculates a punch deflection amount according to the bending load. A punch holder deflection amount calculation unit calculates a punch holder deflection amount according to the bending load. A depth value calculation unit calculates a depth value by adding at least the punch deflection amount and the punch holder deflection amount to the stroke.