Press-Fit Cap Nut Sealing Without Anti-Rotation Damage
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Solution Overview
Problem
Existing press-in nut technologies face challenges in achieving a media-tight connection with low manufacturing costs and effort, particularly in applications requiring sealing against liquids and gases, due to the complexity of producing cap nuts and the risk of damaging anti-rotation elements during high-force assembly.
Innovation Solution
A pre-assembled press-in nut design featuring a cap nut with a partially bent annular collar that is further secured in a two-step process, allowing for low-force initial fixation and subsequent high-force sealing, avoiding damage to anti-rotation elements and enabling cost-effective, space-optimized, and lightweight production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cap nut is manufactured from two parts and welded together to achieve media-tight connection, then sealing performance is improved, but manufacturing complexity and cost increase due to welding precautions and post-treatment steps
Solution Approach 1:
The patent merges the cap and nut body into a single integrated component manufactured from a single piece of material. This eliminates the need for welding or other joining processes between separate parts, thereby reducing manufacturing complexity while maintaining media-tight sealing performance through the integrated design and controlled forming process.
2Reliability
If high forcing is applied during assembly to achieve media-tight connection, then sealing performance is improved, but anti-rotation features may be damaged
Solution Approach 1:
The patent performs preliminary forming of the annular collar in a first forming step before the final assembly. This preliminary action pre-positioned and partially shapes the collar, allowing the subsequent assembly to complete the media-tight connection with reduced forcing, thereby protecting the anti-rotation features from damage while achieving the required sealing performance.
3Stability of the object's composition
If a two-step forming process is used to prevent damage to anti-rotation elements, then component integrity is improved, but production time increases
Solution Approach 1:
The patent segments the forming process into two distinct steps: a first forming step that pre-shapes the annular collar with low force, and a second forming step that completes the media-tight connection. This segmentation allows each step to be optimized for its specific function, preventing damage to anti-rotation elements while maintaining production efficiency through systematic process organization.
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 solution achieves a media-tight connection that meets stringent sealing requirements, such as IP67 and IP68 standards, while minimizing production costs and avoiding damage to anti-rotation features, facilitating efficient assembly and ensuring reliable sealing in various applications.
Implementation Method 1
the annular collar is bent radially inward in such a way that a positive connection is formed with the cap
Implementation Method 2
a fastening collar on the underside of the self-clinching nut can be deformed so that a positive and/or frictional connection is formed with the edge of the hole
Implementation Method 3
the component can be deformed in such a way that the material from the component flows into an undercut area of the self-clinching nut
Data Source
Figure 1~4
Figure 5~7
Figure 8A~8E
AI summary
The press-fit nut (2) is designed as a cap nut and has a nut body (4) with a through hole (10) which is closed by a cap (6) forming a blind hole (11). This cap is designed to create a media-tight connection with the nut body (4). The nut body (4) has a ring collar (16) on its upper side. In its pre-assembled state, the ring collar (16) is only partially bent over, so that the cap (6) is merely held securely without creating a media-tight connection. The desired media-tight connection is only formed when the nut is pressed into a component (36).