Screw Cap Fastening with Sealing Element for Enamel Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fastening systems for enamelled surfaces in corrosive environments face challenges as the enamel can be damaged by screw heads or nuts, and soft-sealing elements often fail under high torque, leading to ineffective corrosion protection and material limitations.
Innovation Solution
A fastening arrangement where the screw head connects directly to a non-enamelled area of the plate, with a cap externally covering the screw head and providing independent corrosion protection, using a flexible sealing element like PTFE between the cap and the component, allowing high torque without damaging the seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a screw head is used to connect components on an enamelled surface, then a secure mechanical connection is achieved, but the enamel surface is damaged by the screw head or nut
Solution Approach 1:
A sealing element is introduced as an intermediary component between the screw head/nut and the enamelled surface. This sealing element distributes the contact pressure over a larger area and prevents direct concentrated loading on the enamel, thereby avoiding damage while maintaining connection strength
Solution Approach 2:
The sealing element provides localized protection at the contact point between the fastening system and the enamelled surface. By concentrating the protective function at the critical interface, the enamel is shielded from damage while the overall connection maintains its mechanical strength
2Object-affected harmful factors
If a soft-sealing element is used under the screw head to protect the enamel, then corrosion protection is improved, but the seal fails under high torque
Solution Approach 1:
The sealing element is constructed as a composite structure combining a soft outer layer for corrosion protection with a reinforced inner structure for torque resistance. This composite design allows the seal to withstand both corrosive environments and high tightening torques without failing
Solution Approach 2:
The sealing element is divided into functional segments: an outer soft layer that provides corrosion protection and an inner reinforced structure that provides mechanical strength for torque resistance. This segmentation allows each layer to optimize its specific function
3Strength
If the screw connection is tightened to ensure secure connection, then connection strength is improved, but the sealing element is damaged or crushed
Solution Approach 1:
The sealing element uses composite construction with an inner reinforced structure that can withstand high compression forces from tightening, while the outer soft layer maintains sealing integrity. This allows secure connection without crushing the seal
4Strength
If a metallic screw element is used for fastening, then connection strength is improved, but corrosion attack occurs at the interface with the enamelled surface
Solution Approach 1:
The sealing element acts as an intermediary barrier between the metallic screw element and the enamelled surface, preventing direct contact and thus preventing corrosion attack at the interface while allowing the metallic fastener to maintain its 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
This design ensures a secure connection without damaging the enamel and allows for flexible material choices, preventing corrosion damage and maintaining connection quality while enabling high torque applications.
Implementation Method 1
the sealing element being compressed when the screw is tightened
Implementation Method 2
an electrically conductive element, in particular a thin wire bent like a bow, is embedded in the sealing element, which forms an electrically conductive connection between the outside of the sealing element and the inside of the sealing element facing the fastening element
Data Source
Figure 1~2
Figure 3~4
Figure 5~7
AI summary
An assembly comprises a fastening element (20) that can be screwed into a component (11, 12) and has a thread (21) and a screw head (22). Furthermore, a sealing element (40) is provided for insertion into a separation joint between a sealing surface (31) of the assembly and a counter surface (13) formed by the component (11, 12). The sealing element (40) is clamped by tightening the screw connection between the sealing surface (31) and the counter surface (13). A cap (30) covers the screw head (22). The screw head (22) has an external thread (23) and the cap (30) has an internal thread (33). The external thread (23) and the internal thread (33) engage with each other and allow the cap (30) to be screwed onto the screw head (22). The sealing surface (31) of the assembly is formed by an underside of the cap (30) facing the component (11, 12).