Dual-Diameter Joint Fitting for Precise Adhesive Bonding
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Solution Overview
Problem
Glued-in rods (GIRs) used in timber buildings experience positioning inaccuracies due to gaps between the rod and the hole, leading to potential displacement and misalignment of building components.
Innovation Solution
A metal joint with a small diameter portion and two large diameter portions, each with a spring ring, is fitted into a hole in a building component, using adhesive injection and fill check holes to ensure precise positioning and bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a gap is left between the GIR and the hole for adhesive filling, then the adhesive can be properly applied, but the positioning accuracy of the GIR with respect to the hole deteriorates
Solution Approach 1:
The patent introduces positioning protrusions on the GIR that engage with positioning recesses in the hole before adhesive application. This preliminary positioning action ensures accurate alignment is established prior to filling the gap with adhesive, preventing displacement during the adhesive setting process while maintaining the necessary gap for proper adhesive application.
2Manufacturing precision
If the GIR outer diameter is made close to the hole inner diameter to reduce gap, then positioning accuracy improves, but the adhesive cannot be properly injected and filled
Solution Approach 1:
The patent employs a dual-diameter structure where the GIR has a larger diameter portion for positioning accuracy and a smaller diameter portion that creates adequate gap space for adhesive injection. This local variation in diameter allows the positioning function and adhesive application function to be simultaneously satisfied without compromise.
3Strength
If a simple cylindrical GIR is used, then the device complexity is low, but the bonding strength and positioning stability are insufficient
Solution Approach 1:
The patent divides the GIR into distinct functional segments: a larger diameter positioning portion that ensures accurate alignment and a smaller diameter bonding portion that provides sufficient gap for adhesive application. This segmentation allows each portion to optimize its specific function, thereby enhancing overall bonding strength without excessive complexity.
Solution Approach 2:
The patent combines the metal GIR structure with adhesive material to create a composite bonding system. The GIR provides mechanical positioning and structural strength, while the adhesive fills the gap and creates a bonded connection, resulting in a composite joint that leverages the advantages of both materials for enhanced bonding strength.
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 provides improved positioning accuracy and enhanced bonding strength between the metal joint and the building component, minimizing gaps and ensuring accurate alignment of structural members.
Implementation Method 1
each spring ring being capable of retaining a position with respect to the hole by elastic force
Implementation Method 2
fixed to the building component with an adhesive such as an epoxy resin
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A metal joint adapted to be fitted into a hole formed in a building component and fixed to the hole with an adhesive includes: a small diameter portion having an elongated shape and an outer diameter smaller than an inner diameter of the hole; and two large diameter portions fixed to the small diameter portion individually at two locations spaced apart from each other in a longitudinal direction of the small diameter portion, each large diameter portion having an outer diameter corresponding to the inner diameter of the hole. Furthermore, irregularities are formed on an outer peripheral surface of the small diameter portion in a section between the two large diameter portions.