Tire Mold Venting Unit With Ice-Like Tread Imprint Structure
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Solution Overview
Problem
Existing venting units in vulcanization molds for pneumatic tires do not effectively replicate ice surface structures on the tire tread, resulting in minimal improvement in snow and ice performance.
Innovation Solution
The venting units feature a surface-covering, uneven peak-valley structure with specific roughness parameters (0.20 mm to 0.60 mm mean roughness Sa and 0.80 mm to 2.25 mm maximum height difference Sz) designed to mimic natural ice surfaces, produced through additive manufacturing processes like SLM, which imprint these structures onto the tire tread during vulcanization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a smooth valve plate surface is used for venting, then air release is effective, but the tread surface lacks ice-grip structures
Solution Approach 1:
The valve plate surface is given a specific local quality through the peak-valley structure with defined roughness parameters (Sa 0.20-0.60 mm, Sz 0.20-0.85 mm). This localized surface treatment allows the valve plate to simultaneously perform its venting function while imprinting ice-grip structures onto the tread surface during vulcanization.
Solution Approach 2:
The valve plate upper surface copies the microstructure of natural ice surfaces through its peak-valley structure. By replicating ice surface characteristics on the valve plate, the imprint transferred to the tire tread creates structures that enhance grip on ice and snow, effectively copying the beneficial properties of ice surfaces onto the tire contact patch.
2Ease of manufacture
If thermal spray coating is applied to create roughness, then manufacturing is simple, but the roughness parameters are insufficient for ice performance
Solution Approach 1:
The invention specifies precise parameter ranges for the peak-valley structure (Sa 0.20-0.60 mm, Sz 0.20-0.85 mm) that represent a significant change from conventional roughness values. These parameter changes ensure the imprinted structures on the tire tread are sufficient to provide meaningful ice and snow grip performance.
Solution Approach 2:
The patent replaces conventional coating methods (thermal spray, EDM, etching, turning, grinding) with additive manufacturing technology. This substitution enables direct construction of the peak-valley structure on the valve plate surface, achieving the required roughness parameters more effectively while maintaining manufacturing feasibility.
3Reliability
If numerous vent holes with venting units are installed, then air release is optimized, but the valve plate imprints cover significant positive surface area
Solution Approach 1:
By optimizing the roughness parameters (Sa and Sz) of the valve plate surface, the invention ensures that each imprint, while covering area, creates sufficiently deep and pronounced ice-grip structures. This parameter optimization maximizes the ice performance benefit per unit area of imprint coverage.
Solution Approach 2:
The peak-valley structure concentrates the functional benefit into the localized peak regions of the imprints. While the imprints cover significant area, it is the distributed peaks across this area that provide the ice-grip enhancement, effectively utilizing the available surface area for traction.
4Ease of manufacture
If conventional roughness (Sa 5-100 μm) is applied, then manufacturing is straightforward, but ice and snow performance improvement is minimal
Solution Approach 1:
The invention fundamentally changes the roughness parameter scale from conventional values (Sa 5-100 μm = 0.005-0.1 mm) to much larger values (Sa 0.20-0.60 mm, Sz 0.20-0.85 mm). This parameter transformation creates imprints with sufficient depth and prominence to provide meaningful ice and snow grip performance.
Solution Approach 2:
The valve plate upper surface copies the microstructure of natural ice surfaces through its peak-valley structure. By replicating ice surface characteristics on the valve plate, the imprint transferred to the tire tread creates structures that enhance grip on ice and snow, effectively copying the beneficial properties of ice surfaces onto the tire contact patch.
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 tire tread exhibits enhanced grip and performance on ice and snow due to the replication of ice-like structures, providing significant improvement in traction and grip on winter roads.
Implementation Method 1
The uneven peak-valley structure can be produced in particular by means of an additive manufacturing process, in particular by means of SLM (selective laser melting)
Implementation Method 2
a movable valve insert (8, 9) which is subject to spring force (7) relative to the housing (10), with a valve stem (8) and a valve plate (9)
Data Source
Figure 1~2
Figure 3~5
AI summary
Venting unit (6) for a vulcanizing mould of a pneumatic vehicle tyre, with a mould inner side (1a), a housing (10), which can be pressed into a bore in the vulcanizing mould, and a valve insert, which is positioned in the housing and is movable with respect to the latter under spring force and which has a valve stem (8) and a valve head (9), which has an upper side (11) facing the green tyre to be vulcanized, wherein the valve head comes into contact with the surface of the green tyre during the forming process of the green tyre and has a planar base area (12) on the inner side of the mould. The upper side (11) of the valve head has a surface-covering, uneven crest-and-trough structure (13) with an area-related average roughness Sa in accordance with DIN EN ISO 25178 of 0.20 mm to 0.60 mm and a maximum height difference Sz in accordance with DIN EN ISO 25178 of 0.20 mm to 2.25 mm, wherein the deepest points of the trough structures are at or above the level of the base area.