Phase Shift Detection for Thermally Assisted Piercing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting punctures during thermally assisted piercing of workpieces face challenges due to background noise, plasma capsule formation, and material deviations, leading to inaccurate and delayed detection.
Innovation Solution
A differential measurement method using a phase shift between a measurement signal and a reference signal is employed, where a first alternating signal is applied to the workpiece, and the phase shift is monitored to determine if the puncture has occurred by being within a predetermined fluctuation range, thereby eliminating measurement errors and improving signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a safety buffer is added to the piercing time to account for material deviations and process changes, then the reliability of the piercing process is improved, but the productivity decreases due to increased total processing time and unnecessary energy input
Solution Approach 1:
The patent applies feedback by continuously monitoring the phase shift signal during the piercing process and using this information to dynamically adjust the piercing duration. The control unit receives real-time signals about the puncture status and adjusts the energy input accordingly, eliminating the need for fixed safety buffers while maintaining reliable piercing across varying material conditions.
2Measurement precision
If optical sensors are placed close to the workpiece to improve signal detection, then the measurement precision is improved, but the sensors are exposed to high thermal stresses that degrade their reliability
Solution Approach 1:
The patent uses an intermediary approach by measuring the phase shift of electromagnetic signals rather than directly detecting optical properties near the hot workpiece. The measuring electrode and control unit remain at a safe distance from thermal stresses while still achieving accurate puncture detection through electrical signal phase analysis, which is less susceptible to thermal interference.
3Manufacturing precision
If the piercing time is extended to ensure complete penetration, then the manufacturing precision is improved, but the energy consumption increases and material properties change
Solution Approach 1:
The control unit uses real-time feedback from the phase shift signal to determine when puncture is achieved and automatically stops or reduces energy input at that precise moment. This eliminates both insufficient piercing and excessive energy input, optimizing the balance between manufacturing precision and energy efficiency by adapting the piercing duration to actual process conditions.
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 method enables early and accurate detection of punctures, allowing for precise control of the piercing process and maintaining consistent cutting quality by adjusting energy input into the piercing crater.
Implementation Method 1
detecting a second alternating signal caused by the first alternating signal in a measuring electrode spaced apart from the workpiece
Implementation Method 2
determining the phase shift between the first and the second alternating signal with the output of a phase shift signal
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In known methods for puncture detection during thermally assisted piercing of a workpiece (208), the workpiece (208) is subjected to a first alternating signal.To provide a method that enables fast and accurate detection of a successful puncture, it is proposed that the method comprises the following steps: a) detecting a second alternating signal generated by the first alternating signal in a measuring electrode (207) spaced apart from the workpiece (208), b) determining the phase shift between the first and second alternating signals and outputting a phase shift signal, c) detecting the temporal profile of the phase shift signal or a measured quantity derived therefrom in a predetermined time interval, whereby a successful puncture of the workpiece is detected by the fact that the phase shift signal or the measured quantity derived therefrom lies within a predetermined fluctuation range in the time interval.