Composite Bicycle Rim Wing Reinforcement for Stronger Tire Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bicycle rims made of composite materials face challenges in achieving optimal strength and lightness due to variable and diversified stresses, and existing molding techniques require multiple separable mold parts and inserts, which can complicate the manufacturing process and increase costs.
Innovation Solution
A bicycle rim design featuring a radially outer peripheral channel with an inner layered structure and a wrapping layered structure at the ends, creating a box-like structure that enhances strength and protection, combined with a method of forming using a radial mold and pression elements to minimize mechanical processing and exposure of structural fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If traditional axial or radial molds with multiple separable parts and inserts are used, then the rim can be formed with complex geometries including wings and pockets, but the manufacturing process becomes more complex and costly
Solution Approach 1:
The mold is divided into a fixed part and a movable part that can separate from each other. The movable part includes a pressing element that can be extracted independently, allowing complex geometries to be formed without requiring multiple separable mold parts and inserts. This segmentation enables the pressing element to take up the shape of the pocket and facilitate extraction of the cured composite material.
Solution Approach 2:
The mold transitions from a static multi-part structure to a dynamic two-part system where the movable part can change position. The pressing element within the movable part can be extracted in the extraction direction after curing, dynamically adapting the mold cavity to enable removal of complex geometries including wings and pockets without compromising structural integrity.
2Strength
If composite material is compressed and cured in traditional molds, then the rim achieves structural strength, but mechanical processing is required which exposes structural fibers and may compromise integrity
Solution Approach 1:
The mold design incorporates a movable part with an extractable pressing element that is removed before the composite material is fully cured. This preliminary action creates expansion space that allows the cured rim to be extracted without mechanical processing, preventing exposure of structural fibers and maintaining integrity. The pressing element extraction happens at the optimal moment during the curing process.
Solution Approach 2:
The movable part and pressing element act as intermediaries during the curing and extraction process. The pressing element temporarily occupies the pocket space during forming, then is extracted to create the necessary clearance for removing the finished rim. This intermediary mechanism enables extraction of complex geometries without compromising the structural fibers of the cured composite material.
3Reliability
If the rim design includes wings for holding the tyre, then the rim can securely hold the tyre, but the structural fibers at the wing ends are vulnerable to damage
Solution Approach 1:
The movable part is extracted from the mold cavity before the composite material completes its curing process. This preliminary extraction creates expansion space that prevents the wing ends from being constrained during final curing, allowing the structural fibers to settle into their optimal positions without damage. The timing of extraction is critical to maintaining fiber integrity while enabling proper wing formation.
Solution Approach 2:
The curing process parameters are managed through the movable part extraction timing. By extracting the pressing element at the optimal moment during curing, the patent allows the composite material to transition from a deformable state to a cured state with preserved fiber integrity. This parameter control ensures the wings maintain both tyre-holding capability and structural fiber 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
The design achieves significant structural strength and stiffness, reduces the need for mechanical processing, and facilitates easier mold extraction while maintaining the integrity of the structural fibers, resulting in a lighter and stronger rim.
Implementation Method 1
the mold with the composite material is then subjected to a heat treatment (also called curing) that causes the cross-linking (polymerization) of the matrix of polymeric material and therefore the locking of the structural fibres in the predetermined position
Data Source
AI summary
A bicycle rim is made with a plurality of layered, each of which is formed of structural fibres incorporated in a polymeric material. The rim has a radially outer peripheral channel with an upper bridge extending between the wings for holding a tyre. The peripheral channel comprises an inner layered structure, extending between wings and at least one wrapping layered structure, wound on the inner layered structure at least at the end of the wings, the inner layered structure and the wrapping layered structure being included in the plurality of layered structures.