Vibration-Decoupled Counter Tool for Ultrasonic Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ultrasonic welding devices with cylindrical sonotrodes struggle to process thicker materials continuously due to insufficient energy transfer, resulting in discontinuous processing and longer processing times.
Innovation Solution
The ultrasonic welding device employs a vibration-decoupled counter-tool with a distinct natural frequency, allowing both the sonotrode and counter-tool to oscillate independently, enhancing energy transfer and welding performance by ensuring maximum vibration on the sealing surface during processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional ultrasonic welding devices with cylindrical sonotrodes are used, then the device structure is simple, but the energy transfer is insufficient for processing thicker materials continuously
Solution Approach 1:
The system is segmented into two independent ultrasonic oscillating units: a sonotrode and a counter-tool, each capable of generating ultrasonic vibrations. This segmentation allows both components to actively participate in energy transfer to the material, doubling the effective energy input and enabling continuous processing of thicker materials that would be impossible with a single sonotrode.
Solution Approach 2:
The invention utilizes mechanical vibration at ultrasonic frequencies from both the sonotrode and counter-tool. By resonating both components at their respective natural frequencies, the system maximizes vibration amplitude and energy transfer efficiency, generating sufficient frictional heat to process thicker materials continuously without the energy limitations of conventional single-sonotrode devices.
2Power
If the counter-tool is made to oscillate at its natural frequency, then the vibration on the sealing surface is maximized, but vibration transmission to the holder increases
Solution Approach 1:
A vibration-decoupling element (elastomeric material or damping element) is introduced as an intermediary between the counter-tool and its holder. This intermediary absorbs and isolates vibration energy, preventing transmission to the holder while allowing the counter-tool to oscillate at its natural frequency with maximum amplitude on the sealing surface, thus maintaining high power output without energy loss to the support structure.
Solution Approach 2:
The system changes the mechanical parameters of the counter-tool holder assembly by introducing damping materials with specific loss factors. This parameter change allows the holder to accommodate the oscillating counter-tool while minimizing vibration transmission, effectively decoupling the useful vibration (on the sealing surface) from the harmful vibration (transmitted to the holder).
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 configuration enables continuous processing of thicker materials with reduced energy consumption, improving welding performance and efficiency by utilizing the counter-tool's vibration to assist in material processing.
Implementation Method 1
Such ultrasonic frequencies are often generated from electrical energy with the aid of piezoelectric sound transducers (converters).
Implementation Method 2
The sonotrode, which is in contact with the material to be processed, then transmits the ultrasonic energy to the material to be processed, which is thereby welded or separated, for example. The heat required to plasticize the webs of material is generated by converting ultrasonic vibrations into frictional energy.
Implementation Method 3
The heat required to plasticize the webs of material is generated by converting ultrasonic vibrations into frictional energy. Due to the interfacial and molecular friction, heat is generated that melts the plastic.
Implementation Method 4
In order to effectively transmit the ultrasonic vibration using the ultrasonic vibrating unit, it is necessary to resonate the ultrasonic vibrating unit. Depending on the structure of the ultrasonic oscillating unit, it has a large number of natural frequencies. Resonant oscillation of the ultrasonic oscillating unit occurs only when the converter generates a natural frequency of the ultrasonic oscillating unit.
Data Source
AI summary
The invention relates to an ultrasound welding device (1) for ultrasonic machining of a material by means of a sonotrode (2) mounted in a vibration-decoupled manner, which sonotrode comprises a sealing surface having a cylinder barrel shape, and a counter tool (8), wherein a converter is connected to the sonotrode (2) optionally via a first amplitude transformation unit and the sonotrode (2) and the first converter are designed in such a manner that the sonotrode (2) can be set into vibration by means of a natural vibration of the ultrasonic frequency fs.