High Frequency Vibration Welding with Position Control
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Solution Overview
Problem
Vibration welding technologies face challenges in minimizing flash and particulate generation while maintaining adequate weld strength, with existing methods either increasing equipment costs or prolonging cycle times, and lacking control over the pressing action and speed of collapse during the weld process.
Innovation Solution
A vibration welding system operating at frequencies of 260 Hz or higher, with direct control over the relative position and speed of the workpieces using sensors and algorithms, and employing low amplitude vibrations for pre-heating, allows for reduced flash and particulate generation without compromising weld strength, and dynamically controlling the speed and force of the pressing action.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If higher vibration frequency (260 Hz or higher) is used, then flash and particulate generation is reduced, but existing systems cannot successfully operate at these frequencies
Solution Approach 1:
The patent changes the vibration frequency parameter from conventional ranges (typically below 260 Hz) to higher frequencies (260 Hz or higher). This parameter change enables reduced flash and particulate generation while the system successfully operates at these previously unsuccessful frequencies through improved control mechanisms
Solution Approach 2:
The patent implements feedback control to monitor and adjust vibration parameters in real-time, enabling the system to maintain stable operation at high frequencies (260 Hz or higher). The feedback mechanism detects variations in vibration characteristics and adjusts electromagnet energization accordingly, ensuring reliable operation that previously could not be achieved
2Object-generated harmful factors
If amplitude is reduced to minimize flash, then flash generation is reduced, but linear velocity becomes insufficient to generate adequate heat for melting
Solution Approach 1:
The patent changes the vibration frequency parameter to higher frequencies (260 Hz or higher), which alters the heating mechanism. At these frequencies, heat generation becomes more efficient through increased cyclic deformation, allowing adequate melting even at reduced amplitudes where flash generation is minimized
Solution Approach 2:
The patent utilizes periodic vibration at high frequency (260 Hz or higher) to generate heat through repeated cyclic deformation of the plastic material. This periodic action at elevated frequencies produces sufficient thermal energy for melting while maintaining low amplitude to reduce flash, resolving the contradiction between heat generation and flash control
3Manufacturing precision
If pre-heating equipment is added to reduce flash and particulate, then weld quality is improved, but equipment cost and cycle time increase significantly
Solution Approach 1:
The patent extracts the pre-heating function from the overall welding system by eliminating separate pre-heating equipment. Instead, the vibration welding process itself performs the heating function through high-frequency (260 Hz or higher) vibration, which generates sufficient heat directly at the weld interface without requiring additional heating devices or extended cycle times
Solution Approach 2:
The vibration welding system performs multiple functions: it provides both the welding action and the pre-heating function simultaneously. The high-frequency vibration (260 Hz or higher) serves dual purposes of generating heat for melting and controlling flash/particulate, eliminating the need for separate pre-heating equipment and reducing overall system complexity
4Ease of operation
If conventional vibration welding is used, then the process is simple, but there is no direct control over pressing action position and speed of collapse
Solution Approach 1:
The patent implements feedback control to directly monitor and adjust the pressing action position and collapse speed during vibration welding. Sensors detect position and motion parameters, and the control system adjusts electromagnet energization in real-time, providing direct control over previously uncontrollable parameters while maintaining operational simplicity
Solution Approach 2:
The patent transitions from static, fixed pressing action to dynamic, adjustable pressing control. The system can dynamically adjust the position and speed of collapse during the welding process by varying electromagnet energization patterns, enabling direct control over pressing action characteristics while preserving the simplicity of the vibration welding process
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 system effectively reduces flash and particulate while maintaining weld strength, enhances the accuracy and repeatability of the weld assembly, and reduces production costs by eliminating the need for additional pre-heating equipment and minimizing cycle times.
Implementation Method 1
The vibratory movement of one part relative to another part is generated by two electromagnets positioned between movable and stationary components of the welder. Both electromagnets apply force along the same coordinate line, but in opposite directions. The electromagnets are energized with a 180° phase shift
Implementation Method 2
As the parts are pressed together by force, the oscillatory motion generates heat, which melts the adjoining surfaces of the plastic parts and creates a weld after the parts cool
Implementation Method 3
the oscillatory motion generates heat, which melts the adjoining surfaces of the plastic parts
Implementation Method 4
The movable head components are physically coupled to the stationary components via a series of mechanical spring elements
Implementation Method 5
It is desirable to maintain the frequency of the energizing cycles at the resonant frequency of the movable mechanical part of the welder to allow for maximum energy transfer to the parts being welded. The resonant frequency is a function of the combined stiffness of the spring elements and the mass of all vibrating elements
Data Source
AI summary
A vibration welding system and method having an operating vibration frequency of 260 Hz or higher. A pressing action between two workpieces is effected by directly controlling, with a control system and a sensor, the relative positions of the workpieces during some or all of the weld cycle, or by controlling the speed between the workpieces during some phase of the weld cycle and controlling the force between the workpieces during other phases. An external control device can be coupled to a control system, to produce an input signal to adjust the speed of relative motion between the workpieces, the force therebetween, or both speed and force based on the input signal. A positive force can be initially applied between the workpieces, and the weld is started by initiating lateral vibrations while the relative position between the workpieces in the pressing direction is maintained, a control variable is monitored, and the second workpiece is moved relative to the first only after the monitored variable satisfies a condition.