Partially Threaded Projection Weld Nut for Low-Force Sealing
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Solution Overview
Problem
Conventional weld nuts in automotive manufacturing require significant insertion force due to smooth inner bores, often leading to suboptimal watertight and grounded seals, and ergonomic installation challenges.
Innovation Solution
A partially-threaded projection weld nut with an annular flange and body structure, featuring a tapered entry end and partially threaded inner bore, which reduces insertion force by engaging threads and providing a watertight, grounded seal through circumferential weld protrusions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the inner bore is smooth and devoid of threads, then a watertight and grounded seal is achieved, but significant insertion force is required
Solution Approach 1:
The patent divides the inner bore into two distinct zones: a smooth lower portion for sealing and grounding, and a threaded upper portion for reduced insertion force. This segmentation allows each zone to perform its specific function optimally without compromise
Solution Approach 2:
Different portions of the inner bore are given different surface characteristics - the lower portion remains smooth for seal integrity while the upper portion has threads for easier screw engagement. This local differentiation resolves the contradiction between sealing reliability and insertion ease
2Ease of operation
If threads are added to the inner bore to reduce insertion force, then ergonomic installation is improved, but the watertight and grounded seal may be compromised
Solution Approach 1:
The inner bore is segmented vertically into threaded and smooth zones, allowing the threaded portion to handle screw engagement while the smooth lower portion maintains the grounding path and watertight seal
Solution Approach 2:
Instead of threading the entire inner bore, only the upper portion is threaded while the lower portion remains smooth. This partial application of threading provides enough insertion force reduction while preserving the seal integrity that requires a smooth surface
3Ease of operation
If a tapered entry end is added to facilitate screw insertion, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The tapered entry end acts as a guiding chamfer that preliminarily positions and aligns the screw before it engages the threaded portion. This preliminary action facilitates smoother insertion without requiring complex adjustment mechanisms
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 minimizes insertion force, ensures a solid watertight seal, and allows for electrical grounding, optimizing ergonomic installation conditions while preventing screw backout.
Implementation Method 1
The weld nut is typically welded to the body panel or other structure via the application of a predetermined current to the weld nut for a predetermined period of time, such that the weld nut is heated and bonded to the body panel or other structure
Data Source
AI summary
A weld nut assembly, including: an annular flange structure; and an annular body structure coupled to the annular flange structure; wherein the annular flange structure and the annular body structure collectively define an inner bore, wherein at least a portion of the inner bore defined proximate the annular flange structure defines threads adapted to receive a screw disposed within the inner bore. The weld nut assembly further includes an annular washer or bottom structure coupled to the annular flange structure. Optionally, the weld nut assembly further includes an annular ring projection and a plurality of circumferential weld protrusions coupled to the annular flange structure. The annular flange structure is adapted to be welded to a surface of a body panel or other structure of a vehicle with the inner bore aligned with a hole formed through the body panel or other structure, the hole adapted to receive the screw therethrough.