Snap-Fit Retaining Element for PV Support Rail on Trapezoidal Sheet
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for attaching a support rail to a trapezoidal rib on a trapezoidal sheet are inefficient, requiring individual manufacturing for different rib shapes and involving complex screwing processes, which are difficult and time-consuming.
Innovation Solution
A support rail with an undercut groove and a retaining element that includes a fastening section on the rib's sloping side, allowing for screw-free attachment via an engagement projection that inserts into the groove, providing a stable and easy-to-assemble connection suitable for various rib shapes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If holding elements surround the ribs on three sides and are fastened to both oblique sides, then the connection stability is improved, but the assembly difficulty increases and screwing becomes difficult
Solution Approach 1:
The holding element is divided into functional segments: a fastening section for attachment to the rib and a support section for bearing the rail. This segmentation allows the fastening section to be simplified for easy assembly while the support section maintains structural stability, resolving the contradiction between connection reliability and assembly ease.
Solution Approach 2:
The screwing operation is extracted and eliminated by replacing threaded fasteners with a snap-fit mechanism. The engagement projection inserted into the undercut groove provides secure attachment without requiring screws, thereby improving ease of operation while maintaining connection stability through the geometric interlocking design.
2Adaptability or versatility
If individual holding elements are manufactured for differently shaped ribs, then the adaptability to various rib shapes is improved, but the manufacturing complexity increases
Solution Approach 1:
The holding element is designed as a universal component with a standardized fastening section geometry that can accommodate various rib shapes. The fastening section attaches to the oblique sides of ribs with different cross-sections, while the support section provides universal support for the mounting rail, eliminating the need for individually manufactured holding elements for each rib shape.
Solution Approach 2:
The holding element features local adaptation through its fastening section geometry, which is designed to interface with the specific geometry of trapezoidal ribs. The fastening section has characteristics suited for attaching to oblique sides, while the support section maintains a standardized form for rail support, allowing one design to serve multiple rib configurations.
3Productivity
If a screw-free attachment with engagement projection inserted into undercut groove is used, then the assembly speed is improved, but the connection strength may be compromised
Solution Approach 1:
The undercut groove is pre-formed in the support rail with geometry designed to mechanically interlock with the engagement projection. This preliminary preparation of the groove shape ensures that when the projection is inserted, it automatically engages behind the groove base, providing strong mechanical retention without requiring additional fastening operations, thus maintaining both assembly speed and connection strength.
Solution Approach 2:
The undercut groove features an asymmetric cross-section with a narrower base than opening, creating a geometric lock where the engagement projection engages behind the groove base. This asymmetric geometry provides strong mechanical retention in the assembled state while allowing easy insertion from the open end, achieving both high assembly speed and strong connection strength.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The fastening of a support rail (1) for a photovoltaic module onto a trapezoidal rib (3) of a trapezoidal sheet (5) comprises a material-efficient retaining element (8). The retaining element (8) has a fastening section (10), which is fastened either on the left or right to a slanted side (15a) of the rib (3). An engaging extension is irremovably arranged on the fastening section (10). In an engaging position, the engaging extension reaches behind a groove (6) in the underside (20) of the support rail (1). In a loose position rotated from the engaging position, the engaging extension can be inserted through the groove opening into the groove (6). The support rail (1) can be held against the upper side (17) of the rib (3) by means of the engaging extension.