Micromechanical Machining with In-Situ Optical Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current machining methods for micromechanical pieces, such as watchmaking pivot axes, face challenges in achieving high precision, concentricity, coaxiality, and low roughness due to inaccuracies in correction processes and limitations in clamping systems, leading to inefficiencies and loss of precision during the machining process.
Innovation Solution
A machine tool with integrated no-force precision machining means, a lathe spindle, and an optical measurement system that allows for real-time measurement and adjustment of machining parameters, enabling a two-phase machining process to achieve precise dimensions and low roughness, with the guidance system controlling the machining parameters to ensure extreme precision and concentricity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional machining methods with separate measurement and correction steps are used, then the machining process can be completed, but the measurement precision and manufacturing precision deteriorate due to machine tool evolution (thermal expansion, drift) between machining and measurement
Solution Approach 1:
The patent merges the measurement system and machining system into a single integrated machine tool. The optical measurement system is built into the machining center, allowing measurements to be taken in-situ on the workpiece while it remains clamped in the same fixture. This eliminates the separate measurement and machining steps that occur at different times and locations, preventing machine tool evolution from affecting the correlation between measurement and machining reference frames.
Solution Approach 2:
The patent implements a feedback loop where measurements are taken during or between machining passes, and the results are used to adjust subsequent machining operations. The control system processes measurement data and automatically modifies machining parameters to achieve the desired final dimensions and surface quality, creating a closed-loop control system that compensates for variations in real-time.
2Manufacturing precision
If multiple machining passes are performed to achieve high precision, then the manufacturing precision improves, but the productivity deteriorates due to repeated clamping and measurement operations
Solution Approach 1:
The patent uses a clamping system with preliminary centering capability that automatically positions the workpiece in the correct location and orientation before machining begins. This preliminary action ensures that the workpiece is properly aligned with the machining and measurement reference frames, eliminating the need for repeated clamping and repositioning operations during subsequent machining passes.
Solution Approach 2:
By combining multiple functions (clamping, centering, measurement, and machining) into a single integrated system, the patent eliminates the need to dismantle and reclamp the workpiece between operations. The workpiece remains secured in the same fixture throughout the entire machining process, allowing multiple machining passes to be performed efficiently without repeated setup time.
3Ease of operation
If conventional clamping systems are used to secure the workpiece, then the workpiece can be held firmly, but the manufacturing precision deteriorates due to lack of concentricity and coaxiality between clamping and machining reference frames
Solution Approach 1:
The patent replaces traditional mechanical centering methods with an optical measurement system that uses light-based measurement to detect and correct positional deviations. The optical system measures the actual position of the workpiece relative to the machining reference frame, and the control system calculates the necessary corrections to achieve the desired concentricity and coaxiality, substituting optical measurement and computational correction for mechanical centering.
Solution Approach 2:
The patent employs a clamping system with adjustable parameters that can be dynamically modified based on measured workpiece dimensions and positions. The control system adjusts clamping forces, positions, and orientations in real-time based on feedback from the optical measurement system, allowing the clamping parameters to be optimized for each specific workpiece to achieve both firm securing and high precision concentricity.
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
The machine tool achieves machined pieces with extreme qualities of concentricity, coaxiality, precision, and low roughness, with surface roughness as low as 5 nm and dimensional accuracy within ±1 μm, enhancing productivity by allowing in-situ measurement and correction without dismantling the piece.
Implementation Method 1
a first optical measurement system for the piece integrated into the first spindle and arranged to at least measure the actual dimensions of the piece when it is mounted on the first spindle
Implementation Method 2
no-force precision machining means arranged to machine the piece
Data Source
AI summary
A machine tool for machining a piece has an axis of rotation A, and includes a no-force precision machining unit to machine the piece, a first spindle, a first clamping device clamping the piece and mounting it on the first spindle, and a machine parameters guidance system. The guidance system guides a controller for the machining unit to control a first machining phase of the piece on the first spindle programmed to obtain a blank mounted on the first spindle, with target dimensions are 0.5% to 20% greater than the final dimensions, then to modify the machining parameters to control, starting from the blank on the first spindle, a second machining phase to remove a quantity of material to obtain the finished piece, with the final dimensions and a roughness of less than 40 nm. A method for machining a piece using such a machine tool is also described.