Friction Stir Welding Sensor Array for Pin Breakage Avoidance
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Solution Overview
Problem
Friction pins in friction stir welding systems can break due to local material variations, such as changes in hardness, particularly in cast materials, leading to interruptions in the welding process.
Innovation Solution
A device equipped with multiple strip-like sensors, a piezo vertical adjustment, laser measuring sensors, airborne and structure-borne sound sensors, and an eddy current sensor, along with an inductive power supply, is used to monitor and manage the axial force, torque, bending moment, and temperature of the welding pin, providing real-time data to prevent breakage by optimizing the welding process parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If friction stir welding is performed on cast materials with local hardness variations, then welding quality can be achieved, but the welding pin may break due to excessive axial forces
Solution Approach 1:
The patent applies preliminary action by detecting axial forces, torque, and bending moments on the welding pin before breakage occurs. Multiple sensors monitor these parameters in real-time, and the control system adjusts welding parameters proactively to prevent pin breakage, rather than waiting for failure to occur.
Solution Approach 2:
The patent implements feedback control by continuously monitoring axial forces, torque, and bending moments with multiple sensors during friction stir welding. The control system uses this real-time data to adjust welding parameters dynamically, creating a closed-loop system that prevents pin breakage by responding to actual process conditions.
2Measurement precision
If multiple sensors are added to monitor welding pin parameters, then detection precision is improved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the monitoring function into multiple specialized sensors, each measuring specific parameters (axial force, torque, bending moment) at different locations on the welding pin. This segmented approach enables comprehensive monitoring of all critical parameters simultaneously, improving overall measurement precision despite the increased number of components.
Solution Approach 2:
The patent implements multi-functionality by designing a sensor system where multiple sensors work together within a unified control framework. The control unit processes data from all sensors to comprehensively assess pin stress states and adjust welding parameters, making the system capable of monitoring multiple parameters with a coordinated sensor array rather than separate independent systems.
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 solution effectively prevents interruptions during friction stir welding by providing timely detection of potential damage, allowing for proactive measures to avoid pin breakage and ensuring continuous operation by optimizing the welding process parameters.
Implementation Method 1
a piezoelectric force measuring sensor (25) in the longitudinal axis of the pin shaft (13)
Implementation Method 2
an inductive power supply system for supplying the measuring system from a moving, secondary winding (22) and a fixed, primary winding (23)
Implementation Method 3
frictional heat is generated in the joining region of the materials to be connected by means of the friction between a rotating tool
Data Source
AI summary
The invention relates to a device and method for avoiding an interruption in the welding process during friction stir welding, in particular breakage of the friction pin, wherein the device has: g) at least three strip-like sensors (8), oriented at an angle of 120 degrees to one another, on the long sides of a wedge-shaped tool dome (7), wherein the tool dome (7) guides a welding pin (19) by means of a tool receiving cone (28) and a welding shoe (11), and the sensors (8) are configured to determined force, pressure and travel, h) a conical evaluation means in the lower region of the tool receiving cone (28), which serves to receive a sensor (22) for sensing the axial force, the torque and the bending moment on the welding pin (19), i) a piezoelectric vertical adjustment means for the welding pin (19), j) an arrangement of a laser measuring sensor (10) in the region of the welding shoe (11), the directivity of which passes over a round hole (27) in the passage region of the pin tip (12), wherein an airborne noise sensor (3) is arranged opposite the laser measuring sensor (10) and a welding shoe temperature sensor is provided, k) a sensor signal amplifier (23) having a rotor antenna for receiving, amplifying and passing on all sensed measured values, wherein these measured values are passed on to a machine controller by a static antenna (16), l) an inductive power supply system for supplying the measuring system from a moving secondary winding (24) and a stationary primary winding (25).