Ultrasonic Weld Endpoint Control for Variant Workpieces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional ultrasonic welding methods fail to accurately weld physically variant workpieces due to inconsistent energy directors and material variations, leading to inefficiencies and errors from frequent recalibration needs.
Innovation Solution
An ultrasonic welding method that monitors weld force or force rate of change to determine the endpoint, allowing for consistent welding of workpieces with different shapes and sizes by setting a predetermined level based on sensed parameters, eliminating the need for frequent recalibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional ultrasonic welding methods use fixed time or distance parameters to end the weld phase, then the welding process is simple to control, but the welding accuracy deteriorates when workpieces have physical variations
Solution Approach 1:
The patent applies feedback control by using a force sensor to monitor weld force in real-time during the ultrasonic welding process. The system continuously measures the force and compares it to a predetermined threshold, automatically adjusting the welding parameters based on the actual workpiece characteristics. This feedback mechanism enables accurate welding of physically variant workpieces without requiring complex manual recalibration, resolving the contradiction between welding accuracy and device complexity.
2Reliability
If traditional methods use fixed parameters for weld and hold phases, then the process is efficient and fast, but the reliability deteriorates due to frequent recalibration needs
Solution Approach 1:
The patent implements self-service through automatic force-based endpoint detection that eliminates the need for manual recalibration. The force sensor automatically adapts to each workpiece's physical characteristics by monitoring the actual weld force, and the control system autonomously adjusts the welding parameters accordingly. This self-adjusting mechanism ensures consistent welding reliability across physically variant workpieces without requiring operator intervention or recalibration time.
3Manufacturing precision
If the weld phase ends based on predetermined time or distance, then the productivity is high, but the manufacturing precision deteriorates for variant workpieces
Solution Approach 1:
The patent applies dynamics by transitioning from static fixed parameters to dynamic force-based control. Instead of using predetermined time or distance values, the system dynamically monitors weld force in real-time and automatically adjusts the welding endpoint based on actual workpiece characteristics. This dynamic adaptation maintains high productivity by avoiding manual recalibration while achieving precise endpoint detection for each physically variant workpiece.
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 ensures accurate and efficient welding of physically variant workpieces with higher accuracy and lower error rates by setting endpoints based on specific force or force rate levels, ensuring full contact between abutting surfaces.
Implementation Method 1
initiating a weld phase by outputting energy from the ultrasonic welding stack to the first workpiece
Implementation Method 2
outputting energy from the ultrasonic welding stack to the first workpiece
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
The present disclosure can provide for an ultrasonic welding method for a pair of workpieces (Wl, W2). The method can include first pressing an ultrasonic welding stack (10) against a first workpiece (Wl) in the pair so that the first workpiece (Wl) comes into contact with a second workpiece (W2) in the pair. The method can then provide for initiating a weld phase by outputting energy from the ultrasonic welding stack (10) to the first workpiece (Wl). The method can provide for monitoring, with at least one sensor, a sensed parameter. The sensed parameter can be weld force or weld force rate of change. The method can provide for determining whether the sensed parameter has reached a predetermined level. Based on determining that the sensed parameter has reached the predetermined level, the method can provide for ending the weld phase.