Spiral Unit Fin Bonding via Electromagnetic Induction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing spiral units face challenges in efficiently and safely bonding fins of any shape to the outer peripheral surface of base tubes, with limitations in bonding methods such as UV adhesive, solvent-based bonding, RF welding, and induction welding, which restrict shape flexibility and increase production time and costs.
Innovation Solution
A spiral unit design where a fin with a strip portion containing magnetic material is bonded to the base tube using electromagnetic waves, allowing for easy and safe bonding without the need for adhesives or solvents, and enabling bonding of fins with complex shapes without the requirement for a planar surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If UV adhesive is used to bond the fin to the base tube, then bonding is achieved, but the adhesive has a short shelf time and dispensing issues occur
Solution Approach 1:
The patent replaces chemical bonding (UV adhesive) with electromagnetic induction heating to melt and bond the thermoplastic fin to the base tube. This substitution eliminates adhesive shelf life limitations and dispensing issues by using a physical heating process instead of chemical adhesives.
Solution Approach 2:
The patent utilizes phase transition of the thermoplastic fin material from solid to molten state through electromagnetic induction heating, enabling bonding without adhesives. The fin material melts and bonds to the base tube, then cools to form a strong joint, eliminating the need for time-sensitive adhesive materials.
2Ease of manufacture
If solvent-based bonding is used to attach the fin to the base tube, then bonding is achieved, but the process requires a long time and solvent safety concerns arise
Solution Approach 1:
The patent replaces solvent-based chemical bonding with electromagnetic induction heating and melting of thermoplastic materials. This eliminates the need for solvents and their associated safety concerns while significantly reducing bonding time through direct thermal processing.
Solution Approach 2:
The patent uses electromagnetic induction heating to rapidly heat and melt the thermoplastic fin material, accelerating the bonding process compared to slow solvent evaporation and re-solidification. The intense localized heating enables quick bonding without safety hazards of solvent vapors.
3Productivity
If RF welding is used to bond the fin to the base tube, then rapid bonding is achieved, but the fin bonding surface must be planar which restricts fin shape flexibility
Solution Approach 1:
The patent applies electromagnetic induction heating locally to the fin material at the bonding interface, allowing the fin to have complex three-dimensional shapes while still achieving rapid bonding. Only the bonding surface needs to contact the base tube, while the rest of the fin can maintain its complex shape for functional purposes.
Solution Approach 2:
The patent changes the bonding mechanism from RF welding (which requires planar surfaces for uniform electric field distribution) to electromagnetic induction heating (which can heat any shape through eddy currents). This parameter change in the heating method enables bonding of fins with complex cross-sections and three-dimensional shapes.
4Adaptability or versatility
If induction welding or electromagnetic welding is used to bond the fin to the base tube, then bonding of complex shapes is possible, but filler members must be provided which increases production time and costs
Solution Approach 1:
The patent extracts and eliminates the filler member requirement from the induction welding process by using electromagnetic induction heating to melt and bond the thermoplastic fin directly to the base tube. The fin material itself serves as the bonding medium, removing the need for additional filler materials and associated production steps.
Solution Approach 2:
The thermoplastic fin material serves its dual function of providing the spiral structure and acting as the bonding material through melting and adhesion to the base tube. This self-service approach eliminates the need for separate filler members and reduces production complexity.
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 allows for efficient and safe bonding of fins with any shape to the base tube, reducing production time and costs, while ensuring the safety of manufacturers and enabling flexible fin shapes without the need for filler members or planar surfaces.
Implementation Method 1
a strip portion (79) extended along the fin axis F is provided in the fin 72. In the strip portion 79, a magnetic material is mixed with the second resin. When an electromagnetic wave is applied, the second resin is melted by heating the magnetic material
Implementation Method 2
the second resin is melted by heating the magnetic material
Implementation Method 3
the second resin is melted by heating the magnetic material when an electromagnetic wave is applied
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A spiral unit includes a base tube extended along a longitudinal axis and made of a first thermoplastic resin, and a fin disposed on an outer peripheral surface of the base tube along a fin axis spirally extended around the longitudinal axis and made of a second thermoplastic resin. The fin includes a strip portion provided in a state of being bonded to the outer peripheral surface of the base tube and spirally extended along the fin axis. The second resin being mixed with a magnetic material in the strip portion.