Induction Ring Welding Joint for Uniform Plastic Annular Gaps
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Solution Overview
Problem
Existing electromagnetic resistance welding and induction welding methods result in nonuniform or partially absent annular gaps between plastic components due to the eccentric position of the induction ring, impairing the quality of the connection.
Innovation Solution
A connection arrangement and method where the induction ring is melted into the plastic components, forming undercuts and positive joints, ensuring a durable and integral joint by using a radially flexible induction ring design with specific geometries and materials, such as conductive plastics or metals, to improve thermal shock resistance and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the induction ring is used in electromagnetic resistance welding or induction welding, then the plastic components are joined through heating and melting, but the induction ring assumes an eccentric position after welding, resulting in nonuniform or partially absent annular gaps that impair connection quality
Solution Approach 1:
The induction ring is segmented into multiple sections (first induction ring section, second induction ring section, third induction ring section) that can move independently relative to each other. This segmentation allows the ring to accommodate thermal expansion and contraction uniformly, preventing eccentric positioning and ensuring uniform annular gaps throughout the connection area.
Solution Approach 2:
The induction ring is designed with dynamic flexibility through radial joints that enable relative movement between segments. This dynamic structure allows the ring to adapt its shape during thermal cycles, maintaining uniform contact and gap distribution with the plastic components while preventing the eccentric positioning that occurs with rigid rings.
2Ease of manufacture
If a rigid induction ring is used, then the welding process can be performed, but the different coefficients of expansion of metal and plastic cause thermal shock resistance to deteriorate
Solution Approach 1:
The induction ring incorporates radial flexibility through articulated joints between segments, enabling the ring to expand and contract radially in response to thermal changes. This dynamic adaptation accommodates the different thermal expansion coefficients of metal and plastic materials, preventing stress concentration and improving thermal shock resistance while maintaining welding capability.
Solution Approach 2:
The induction ring's structural parameters are changed from a fixed rigid configuration to a flexible segmented configuration. The radial joints allow the ring to change its effective radius and shape during thermal cycles, matching the thermal behavior of the plastic components and thereby improving thermal shock resistance without compromising the welding process.
3Strength
If the induction ring is melted into the plastic components forming undercuts, then a durable positive joint is produced, but the device complexity increases
Solution Approach 1:
The induction ring is divided into multiple segments with radial joints, which simplifies the manufacturing of each individual segment while achieving the complex function of forming undercuts and positive joints. The segmented structure allows for easier production and assembly compared to a monolithic complex ring, reducing overall device complexity while maintaining joint durability.
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 achieves a durable and high-quality joint with improved thermal shock resistance and uniformity, preventing the induction ring from being removed from the plastic components, thus enhancing the connection's reliability and quality.
Implementation Method 1
eddy currents are induced in a closed annular metallic component or in an induction ring by an alternating electromagnetic field (typically 10 kHz to 40 kHz), which is generally produced by a water-cooled coil. Owing to heat losses, the induction ring is heated
Implementation Method 2
eddy currents are induced in a closed annular metallic component or in an induction ring by an alternating electromagnetic field
Implementation Method 3
the induction ring is heated and, by virtue of heat conduction, leads to the melting of the plastic polymers of the two joining partners
Implementation Method 4
the two plastic components are then joined under pressure, and the two annular gaps provided are filled with plastic melt
Data Source
AI summary
A connection arrangement includes a first plastic component, a second plastic component, and a closed induction ring. The first plastic component has a first joining region designed as a receptacle, and at one end, the second plastic component has a second joining region introduced into the first joining region. At the joining regions, the induction ring is at least partially fused into the two plastic components such that at one contact region between a first plastic melt of the first plastic component and a second plastic melt of the second plastic melt, a material-conclusive connection is generated. In this case, the induction ring is melted into the first plastic component while forming at least one first undercut, and is melted into the second plastic component while forming at least one second undercut such that between the plastic components and the induction ring, one each form-fitting connection is created.