Ultrasonic Sonotrode Support for Gap Height Stability
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Solution Overview
Problem
Existing ultrasonic machining devices face challenges in maintaining a constant gap height and contact pressure, leading to variations in welding quality due to fluctuating material thicknesses and difficulties in supporting the sonotrode, which can result in damage to the material web or tools.
Innovation Solution
The ultrasonic unit is mounted on a carriage that can be moved to adapt the gap height to current conditions, with a support system engaging the sonotrode perpendicularly to absorb transverse forces without affecting the welding forces, using a temperature-resistant material with low thermal expansion and low friction to prevent distortion of welding forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the sonotrode is firmly clamped to maintain constant gap height, then the gap height stability is improved, but the welding quality varies due to inability to adapt to material thickness fluctuations
Solution Approach 1:
The patent applies the dynamics principle by making the sonotrode movable rather than firmly clamped. The sonotrode is supported by a bearing that allows it to move vertically in response to material thickness variations, while a control system actively adjusts its position to maintain constant gap height. This dynamic adjustment mechanism resolves the contradiction by enabling both gap stability and adaptation to material fluctuations.
Solution Approach 2:
The patent changes the parameter of sonotrode position from fixed to variable. By introducing a motor-driven adjustment mechanism that can change the sonotrode's vertical position, the system adapts to different material thicknesses while maintaining optimal gap height for consistent welding quality.
2Strength
If the sonotrode is supported by rigid structures to absorb transverse forces, then the structural stability is improved, but the welding forces are reduced due to force absorption by supports
Solution Approach 1:
The patent introduces a bearing as an intermediary element between the sonotrode and the support structure. This bearing supports transverse forces and lateral loads without transmitting them to the sonotrode, thereby protecting the welding forces from being reduced while still providing necessary structural stability.
Solution Approach 2:
The patent extracts the function of supporting transverse forces from the sonotrode itself and assigns it to a separate bearing structure. By taking out the lateral support function from the sonotrode, the sonotrode can focus on transmitting welding forces without being burdened by lateral loads.
3Force
If the sonotrode is supported laterally by rigid holding structures, then the transverse force absorption is improved, but the sonotrode deflection increases due to force transmission
Solution Approach 1:
The bearing acts as an intermediary that absorbs transverse forces without causing sonotrode deflection. It provides lateral support while allowing the sonotrode to maintain its straight alignment, preventing force transmission that would cause bending or distortion.
4Measurement precision
If the sonotrode connection to booster is rigid to maintain positioning, then the positioning accuracy is improved, but the bending moments at connection points increase due to transverse forces
Solution Approach 1:
The patent extracts the lateral support function from the sonotrode-booster connection and assigns it to separate bearing structures. This allows the connection to remain rigid for positioning accuracy while the bearings handle the transverse forces, preventing excessive bending moments.
Solution Approach 2:
The patent introduces dynamic adjustment capability to the sonotrode positioning system, allowing it to adapt to lateral forces while maintaining accurate positioning. The motor-driven mechanism can compensate for position changes caused by lateral loads.
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 solution allows for precise control of welding forces and quality by maintaining consistent contact pressure and preventing damage to the sonotrode and material web, ensuring reliable processing across varying material thicknesses and speeds.
Implementation Method 1
the support is made of ceramic, an Invar alloy or hardened steel in order to avoid both excessive wear and unwanted heat build-up. These materials are very wear-resistant and, with suitable lubrication, have a negligible coefficient of friction compared to the sonotrode.
Implementation Method 2
the support is temperature-resistant and has a temperature expansion coefficient that is less than 10 -5
Implementation Method 3
material webs can be connected, cut, perforated, stamped, embossed, heat-treated or processed in a similar way by means of ultrasonic sonotrodes
Data Source
AI summary
The invention relates to a device (10) for machining a material web (12), comprising an ultrasound unit (22), which has a converter (42), a booster (40) and a sonotrode (20), and a counter-tool (14), wherein the material web (12) is guided through a gap between the sonotrode (20) and the counter-tool (14) and machined by the sonotrode (20), wherein the ultrasound unit (22) can be displaced with respect to the counter-tool (14) by way of a movable carriage (26) and the booster (40) is rigidly connected to the carriage (26), wherein a support (48) is provided, which engages on at least one lateral surface of the sonotrode (20) and guides the sonotrode (20) in the longitudinal direction (50) thereof.