Airless Tire Spoke Casting Device Outer Surface Positioning
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Solution Overview
Problem
The existing methods for integrally molding a spoke with a tread ring and a hub in an airless tire face challenges in achieving high positioning accuracy and circularity due to the deformation of the rubber tread ring during the molding process, leading to reduced uniformity and concentricity of the tire.
Innovation Solution
A spoke casting device with a casting mold that includes a first positioning means with an outer peripheral surface contact part to accurately position the tread ring, a vibration generator to discharge air bubbles, and a demolding mechanism to reduce resistance during tire ejection, ensuring improved circularity and concentricity by securely contacting the tread ring's outer surface and forming a cavity between the tread ring and hub.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If annular projections are provided in upper and lower molds to position the tread ring by contact with its inner peripheral surface, then positioning is attempted, but the contact surface height is insufficient and positioning accuracy is poor
Solution Approach 1:
Instead of contacting the inner peripheral surface of the tread ring (which forms the cavity and has insufficient contact height), the invention contacts the outer peripheral surface of the tread ring. This inversion of the contact surface from internal to external resolves the insufficient contact height problem and enables accurate positioning.
Solution Approach 2:
The invention transitions from two-dimensional point/line contact (annular projections contacting the inner surface) to three-dimensional surface contact (positioning means contacting the outer peripheral surface). This dimensional change provides sufficient contact area for accurate positioning.
2Ease of manufacture
If the tread ring is positioned and fixed during integral molding, then the spoke can be cast, but the rubber surface deforms under external force reducing circularity and concentricity
Solution Approach 1:
The invention inverts the positioning approach from internal contact (inner surface) to external contact (outer surface). This allows the tread ring to be positioned and fixed during casting while maintaining its circularity and concentricity, as the outer surface contact does not deform the rubber structure.
3Measurement precision
If annular projections contact the inner peripheral surface for positioning, then positioning is attempted, but poor fitting occurs when the mold is closed
Solution Approach 1:
By contacting the outer peripheral surface instead of the inner peripheral surface, the invention eliminates the poor fitting problem during mold closure. The outer surface contact provides stable positioning without the interference issues that occur with inner surface contact.
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 solution enhances the positioning accuracy and circularity of the tread ring, resulting in improved tire uniformity and reduced deformation, while preventing poor fitting and resistance issues during mold closure and tire ejection.
Implementation Method 1
a vibration generator that is configured to cause the casting mold to vibrate to discharge air bubbles in a polymer material when the polymer material is injected in the cavity
Data Source
AI summary
The present invention relates to a casting device including a casting mold that concentrically holds a tread ring and a hub between upper and lower molds and forms a cavity between the tread ring and the hub; a positioning means that concentrically positions the hub and the tread ring; and a demolding means that pushes out an airless tire after cast molding from the lower mold in a mold open state. The positioning means has a first positioning means that includes an outer peripheral surface contact part that positions the tread ring by being in contact with an outer peripheral surface of the tread ring.