Spindle Deflection Measurement Using Clamped Laser Source

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Solution Overview

Problem

Current methods for determining spindle deflection in machine tools are influenced by inaccuracies in the position of the spindle relative to the clamping table and require complex setups, making them unreliable for pre-installation measurements and prone to errors due to additional load on the spindle.

Innovation Solution

A method involving a laser beam source clamped to the spindle, with points of incidence recorded at different optical distances, allowing continuous determination of deflection by analyzing vertical components of shift, using electronic optical sensors to accurately measure deflection independently of other machine tool parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a flange with conic reflective face and four laser beams is used to measure spindle rotation errors, then measurement capability is provided, but the equipment complexity increases and measurement accuracy is reduced due to impurities on the flange face and additional strain on the spindle

Engineering Contradiction:
Improvespindle deflection measurement accuracyVSAvoidmeasurement equipment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts the measurement function from the complex flange-with-mirrors system and implements it directly on the spindle nose using only a laser beam source and electronic optical sensors. This eliminates the conic reflective face flange, beam splitters, and multiple mirrors, retaining only the essential measurement capability while removing sources of error and complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical/optical complex system with a laser-based measurement system. Instead of using physical mirrors and beam splitters that require precise mechanical alignment and are sensitive to surface impurities, the patent uses a laser beam source clamped to the spindle and electronic optical sensors to detect spindle deflection through optical field interactions.

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

2Reliability

If measurement is performed after headstock installation and adjustment on the machine tool, then the measurement reflects actual operating conditions, but the measurement cannot be performed on test benches or during headstock installation

Engineering Contradiction:
Improvemeasurement reliability under operating conditionsVSAvoidmeasurement applicability during installation and testing
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention enables preliminary measurement of spindle deflection characteristics before the headstock is installed on the machine tool. By clamping the laser beam source directly to the spindle nose, measurements can be performed on test benches during headstock assembly and adjustment, allowing deflection characteristics to be determined in advance rather than only after installation.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If the spindle is tilted upwards in the headstock to compensate for gravity-induced deflection, then machining accuracy is improved, but the setup complexity increases and requires precise knowledge of the deflection process

Engineering Contradiction:
Improvemachining accuracyVSAvoidheadstock tilting mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention provides a method to accurately measure and determine the spindle deflection process at different extension positions. By clamping the laser beam source to the spindle and using electronic optical sensors to detect the position of the laser beam, the system generates feedback information about actual deflection characteristics, enabling precise calculation of the required compensating tilt angle.

Inventive Principle:
Principle #23Feedback

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 provides accurate and independent measurement of spindle deflection, reducing errors and enabling pre-installation assessment without distorting the spindle, thus improving machining precision.

Implementation Method 1

a laser beam source clamped to a spindle, with points of incidence recorded

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3029416B1Method for determination of sinking and/or the process of sinking and/or determination of the inclination angle and/or the process of the bending of a horizontal or inclined spindle, particularly of a horizontal or inclined spindle of a machine tool and a detection device for performing it
Publication Date: 2020.06.17 VUTS AS
  • EP3029416B1 patent drawingFigure 1~2a
  • EP3029416B1 patent drawingFigure 2b
  • EP3029416B1 patent drawingFigure 3

AI summary

The invention relates to a method for determination of deflection (y) and/or the process of deflection of a horizontal or angular spindle (1) and/or to determination of the angle (α) of inclination and/or the process of the bending of a horizontal or angular spindle (1), especially a horizontal or angular spindle (1) of a machine tool. Its principle consists in that a laser beam (2) source is clamped to a spindle (1) and at least at two different optical distances (b), (c) from the end of the spindle (1) with at least two different extensions (w1), (w2) of the spindle (1) out of a headstock, the points of incidence of the laser beam (2) or of its components (21), (22), or the geometric shapes drawn by the laser beam (2) or by its components (21), (22) are successively or simultaneously recorded, whereby the deflection (y) of the spindle (1) in its movement and/or the inclination angle (α) of the spindle (1) is determined, or continuously determined, or the process of deflection of the spindle (1) and/or the process of bending of the spindle (1) is determined, or continuously determined, from the vertical components or components oriented downwards of the shifts (yb), (yc) of the points of incidence of the laser beam (2) or of its components (21), (22), or of the centers of the geometric shapes drawn by the laser beam (2) or by its components (21), (22) at these optical distances (b), (c) from the end of the spindle (1). In addition, the invention relates to a detection device (3) for performing this method.