Bending Tool Assembly with Optical Angle Detection

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Solution Overview

Problem

Existing bending angle measurement techniques face challenges in accurately determining the bending angle during the bending process, especially with metal surfaces that strongly reflect or absorb light, leading to unreliable detection due to cramped spatial conditions and surface properties.

Innovation Solution

A bending tool arrangement with a punch and die setup, incorporating an optical image acquisition device with lenses of discrete focal lengths, including fan or Fresnel lenses, and a beam splitter, which captures a section of the sheet metal surface parallel to the bending line, ensuring reliable contactless measurement independent of surface quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a light pattern is projected onto the sheet metal surface to determine the bending angle, then the bending angle can be measured, but the measurement becomes unreliable due to strong reflection or absorption by metal surfaces

Engineering Contradiction:
Improvebending angle measurementVSAvoiddetection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

A magnetic marking device is introduced as an intermediary between the sheet metal surface and the optical detection system. The device applies magnetic markings directly to the metal surface, which then serve as the optical pattern for angle measurement. This intermediary approach eliminates the problem of light reflection/absorption from the metal surface itself, as the markings provide high-contrast optical features that are reliably detectable by the camera system.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the parameter being measured from direct optical properties of the metal surface to the position of magnetic markings applied to the surface. By transforming the measurement from detecting native surface properties (which reflect/absorb light) to detecting the positions of applied magnetic markers (which provide consistent optical contrast), the measurement becomes reliable regardless of the underlying metal surface properties.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If lighting and image capturing devices are added to measure bending angle, then measurement capability is achieved, but the cramped spatial conditions in the bending tool area complicate the process

Engineering Contradiction:
Improvebending angle measurementVSAvoidtool arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The magnetic marking device and the optical detection system are merged into a single integrated bending tool. The marking device is positioned on one tool component while the camera is positioned on another, allowing both functions to be performed within the existing bending tool footprint without requiring separate standalone devices. This integration reduces overall system complexity while maintaining measurement capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The bending tool is enhanced with multi-functionality by incorporating both the magnetic marking capability and the optical detection capability into the same tool assembly. This allows the tool to perform both the marking function and the measurement function, eliminating the need for separate dedicated devices and reducing the overall complexity of the measurement system.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If the lens is positioned to capture the bending area, then the bending angle can be recorded, but the maximum achievable bending angle may be impaired

Engineering Contradiction:
Improvebending angle recordingVSAvoidmaximum bending angle
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The optical detection system is positioned in a different spatial dimension relative to the bending plane. By placing the camera and marking device in a configuration that utilizes the third dimension (perpendicular to the bending plane), the system can capture the bending angle without interfering with the maximum bending angle achievable in the primary bending direction. The lens captures the bending area from an optimized angle that does not constrain the workpiece.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Enables precise contactless determination of the bending angle, accommodating various surface conditions and ensuring accurate measurement throughout the bending process without impairing the maximum achievable bending angle.

Implementation Method 1

an optical image acquisition device with a lens is arranged in the punch arrangement or in the die arrangement, the lens being aligned with a section parallel to the bending line and the lens having a plurality of discrete focal lengths

Methodology Applied
Scientific EffectLens focusing: Lens

Implementation Method 2

the lens is designed as a fan lens or Fresnel lens. A lens designed in this way enables a compact realization of small focal lengths

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

the lens has a beam splitter. Since the section is captured by a lens with multiple focal lengths or by multiple lenses, it is advantageously possible with this development to deflect the individual incoming light beams in a targeted manner

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3041617B1Bending tool assembly for determining the bending angle
Publication Date: 2017.06.14 TRUMPF MASCHEN AUSTRIA
  • EP3041617B1 patent drawingFigure 1a~1b
  • EP3041617B1 patent drawingFigure 2
  • EP3041617B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a bending tool assembly (1) for determining the bending angle, said assembly comprising a punch assembly (2) and a die assembly (3), the punch assembly (2) consisting of at least one press brake punch and the die assembly (3) consisting of at least one bending die. A bending contact surface (4) of the punch assembly (2) and at least one bending contact surface (5) of the die assembly (3) are oriented in parallel and parallel to a bending line (6). An optical image capture device (7) comprising a lens (8) is located in the punch assembly (2) or in the die assembly (3), the lens (8) being oriented towards a section (9) running parallel to the bending line (6) and said lens (8) having multiple discrete focal lengths (10).