Portable Machine Tool Frame Positioning for Large Workpiece Machining

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Solution Overview

Problem

Existing machine tools face challenges in efficiently machining large, slender workpieces due to the need for long machine axes and complex propulsion devices, which are not suitable for processing components like those in aircraft construction, and are often too complex and expensive for infrequent use.

Innovation Solution

A machine tool system that allows for the movement of a machine frame relative to a workpiece without requiring long machine axes, utilizing a measuring device with laser interferometers for high accuracy positioning, and a fastening system that enables the machine frame to be moved relative to the workpiece, allowing for machining of large workpieces with high precision and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If long machine axes are used to machine large workpieces, then the machining capability is improved, but the device complexity and cost increase significantly

Engineering Contradiction:
Improvework areaVSAvoidmachine axis complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

Instead of moving the workpiece through long machine axes, the patent inverts the approach by moving the machine frame itself relative to the workpiece. The machine frame is detached and repositioned at different locations along the workpiece, allowing machining of large workpieces without requiring excessively long machine axes. This reversal of the traditional machining paradigm resolves the contradiction between work area and device complexity.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The machining process is segmented into multiple stages, with the machine frame being detached and repositioned at different locations along the workpiece. Each segment of the workpiece is machined separately by moving the machine frame to the appropriate location, avoiding the need for a single long machine axis that would span the entire workpiece length.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If generic machine tools with feed devices are used, then versatility is improved, but the device complexity increases due to complex feed devices

Engineering Contradiction:
Improvemachining versatilityVSAvoidfeed device complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical feed devices with a measurement-guided positioning system. Laser interferometers measure the position of the machine frame relative to the workpiece, and this measurement information is used to control the movement and positioning of the machine frame, substituting mechanical complexity with optical measurement and control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces laser interferometers as an intermediary between the machine frame and the workpiece. These measuring devices provide precise position information without requiring complex mechanical feed mechanisms, serving as a mediator that enables accurate positioning through measurement rather than mechanical means.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If machine tools are attached to workpieces for machining, then machining capability is improved, but the system requires specific adaptation to workpiece structure

Engineering Contradiction:
Improvemachining precisionVSAvoidworkpiece adaptability
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The machine frame is designed with universal attachment capabilities that can accommodate different workpiece structures. The fastening device can be adapted to attach the machine frame to various types of workpieces without requiring complete redesign of the machine tool system, providing both precision and versatility.

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

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 the machining of large workpieces, such as ship hulls and aircraft components, with high accuracy and flexibility, reducing the need for complex and expensive machine tools, and allows for automated processing, effectively addressing the limitations of existing technologies.

Implementation Method 1

the position of the machine frame relative to the measuring device can be determined by means of a measuring device, in particular by means of at least three, in particular four, tracking laser interferometers by means of which changes in the tool's position can be determined

Methodology Applied
Scientific EffectLaser interferometry: LIDAR

Data Source

PatentEP3074175B1Power tool
Publication Date: 2020.09.23 GOTTFRIED WILHELM LEIBNIZ UNIV HANNOVER
  • EP3074175B1 patent drawingFigure 1
  • EP3074175B1 patent drawingFigure 2
  • EP3074175B1 patent drawingFigure 3a~3d

AI summary

The invention relates to a power tool (10) having a tool receptacle (12), in particular a spindle, for receiving a tool (20), at least three machine axles (14, 16, 18) for positioning the tool receptacle (12), a machine control (22), which is designed to actuate the machine axles (14, 16, 18) such that the tool receptacle (12) is movable on a tool trajectory (W) which can be specified in a machine coordinate system, a machine frame (24) to which the machine axles (14, 16, 18) are fastened, and a fastening device (32) which is designed to fasten the machine frame (24) and a work piece (36) relative to each other. According to the invention, there is a measurement device (26) which spans a metrological frame and by means of which the position of the machine frame (24) can be determined relative to the measurement device (26), wherein the machine control (22) is configured to automatically carry out a method having the steps: measuring a position of the machine frame (24) relative to the measurement device (26), calculating the tool trajectory (W) in the machine coordinate system from a specified target trajectory (Z) in measurement frame coordinates of the measurement device (26) and moving the tool (20) along the tool trajectory (W) by means of the machine axles (14, 16, 18) such that a work piece (36) can be processed.