Roofrail Fastening System Tolerance Compensation
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Solution Overview
Problem
Existing roof rail fastening systems require complex alignment and adjustment to compensate for manufacturing tolerances, making installation difficult, especially for curved or multi-fastener systems.
Innovation Solution
A roof rail system with a tolerance compensator that includes an oversized entry and an anchor with snap-fit and flexible arms, allowing for easy installation by expanding to span the gap between the roof and body structures without needing to realign the compensator after anchoring, and featuring fasteners with a smaller diameter than the entry to prevent side contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tolerance compensator is used to connect through both vehicle roof and body, then the roof rail can be fastened without collapsing the roof-body separation, but the installation becomes more complex due to alignment requirements
Solution Approach 1:
The fastening system is divided into separate functional components: an anchor portion that interfaces with the roof and a body portion that interfaces with the body structure, connected by a compensating element. This segmentation allows each component to be optimized independently and simplifies installation by eliminating the need for complex realignment procedures.
Solution Approach 2:
A tolerance compensator serves as an intermediary element between the roof and body structures. This compensator absorbs dimensional variations and misalignments, allowing the fastening system to accommodate manufacturing tolerances without requiring complex adjustment mechanisms or realignment procedures during installation.
2Manufacturing precision
If existing tolerance compensators are used, then manufacturing tolerances can be compensated, but realignment is required after anchoring which increases installation time
Solution Approach 1:
The fastening system is designed so that the tolerance compensator is pre-configured with an oversized entry that accommodates fasteners without requiring realignment. The anchor portion is pre-formed to engage with the roof structure in a single operation, eliminating the need for post-anchoring realignment and significantly reducing installation time.
3Measurement precision
If a tight-fitting entry is used for the fastener, then alignment precision is improved, but the installation becomes more difficult and time-consuming
Solution Approach 1:
The entry of the tolerance compensator is designed with non-uniform geometry - oversized in certain directions to facilitate easy fastener insertion, while maintaining sufficient constraint in other directions to provide adequate alignment. This local variation in dimensional tolerance allows simultaneous achievement of installation ease and alignment accuracy.
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
Facilitates easier and more efficient installation of roof rails by compensating for manufacturing tolerances without collapsing the roof-body separation, reducing assembly complexity and improving alignment accuracy.
Implementation Method 1
an anchor with snap-fit and flexible arms, allowing for easy installation by expanding to span the gap between the roof and body structures
Data Source
Figure 1~2
Figure 3~4
Figure 5a~5b
AI summary
A vehicle roof rail system includes a roof rail (102), a vehicle roof structure (240) and a vehicle body structure (242). A tolerance compensator (202, 500, 612, 712, 802) is disposed between the roof structure (240) and the body structure (242). The tolerance compensator (202, 500, 612, 712, 802) has an internal, oversized entry. The tolerance compensator (202, 500, 612, 712, 802) includes an anchor (208, 628, 716, 808) fixing the tolerance compensator (202, 500, 612, 712, 802) to the vehicle roof structure (240). A fastener (104, 872) passes through the oversized internal entry of the tolerance compensator (202, 500, 612, 712, 802) linking the roof structure (240) and body structure (242). An angle compensator (840) is attached to the tolerance compensator (202, 500, 612, 712, 802). The angle compensator (840) adjusts a contact angle of the tolerance compensator (202, 500, 612, 712, 802) with the vehicle body structure (242).