Pneumatic Tyre Sidewall Hardness Gradient and Carcass Angle
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Solution Overview
Problem
Pneumatic vehicle tires known from prior art lack optimal mechanical stability, particularly during irregular operation, and inefficient use of materials in their construction and manufacturing.
Innovation Solution
The tire carcass features a partially angled design with rubberized reinforcements forming angles of 80° to 90° in the side areas and 5° to 75° in the central area, combined with radially inner sidewalls having a Shore A hardness of 65 to 85 points and radially outer sidewalls having a Shore A hardness of 45 to 70 points, ensuring enhanced mechanical stability while optimizing material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If uniform Shore A hardness is applied across all sidewall areas, then manufacturing simplicity is maintained, but mechanical stability during irregular operation is insufficient
Solution Approach 1:
The patent applies different Shore A hardness values to different regions of the sidewall. Specifically, the equatorial region has a Shore A hardness of 65-85 points while the polar regions have a Shore A hardness of 45-70 points. This local differentiation optimizes mechanical stability in the equatorial region where it is most needed during irregular operation, while maintaining flexibility in the polar regions, thereby resolving the contradiction between reliability and construction complexity.
2Strength
If radially outer sidewall regions are made harder, then resistance to external damage is improved, but flexibility and comfort are reduced
Solution Approach 1:
The patent implements spatially varying hardness properties in the sidewall structure. The equatorial region (radially outer in the context of the tread contact area) is formulated with higher Shore A hardness (65-85 points) to provide enhanced damage resistance where it contacts the road surface and bears primary loads. The polar regions maintain lower Shore A hardness (45-70 points) to preserve flexibility for deformation during normal operation and absorption of irregularities. This local quality differentiation resolves the contradiction between strength and ease of operation.
3Reliability
If material is uniformly distributed throughout the tire carcass, then manufacturing simplicity is maintained, but mechanical stability during irregular operation is insufficient
Solution Approach 1:
The patent employs non-uniform material distribution in the tire carcass, specifically varying the Shore A hardness of the sidewall rubber compound based on spatial position. The equatorial region uses a harder compound (65-85 Shore A) while polar regions use a softer compound (45-70 Shore A). This localized material property optimization enhances mechanical stability where needed without requiring complex manufacturing processes, as the different hardness zones can be implemented through standard tire manufacturing techniques with region-specific compound formulations.
Solution Approach 2:
The patent utilizes composite material strategies by combining rubber compounds with different hardness properties in specific regions of the sidewall. This creates a functionally graded structure where the material composition varies spatially to optimize performance. The use of multiple rubber compounds with different Shore A hardness values allows the tire to exhibit both the strength needed for irregular operation resistance and the flexibility required for normal operation, resolving the contradiction between reliability and ease of manufacture.
Data Source
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AI summary
The invention relates to a vehicle pneumatic tire (1), rotatable about an axis of rotation (2), comprising: a) a tire carcass (4) with a first side region (5), a second side region (6) and a central region (7) arranged between them, comprising at least one carcass ply (7) with a plurality of rubberized reinforcing elements (9) which each extend through the first side region (5), the second side region (6) and the central region (7) of the tire carcass (4), b) a tread strip (10) located radially further outwards relative to the tire carcass (4), c) an inner tire layer (11) located radially further inwards relative to the tire carcass (4), d) tire sidewalls (12),wherein at least a part of the rubberized reinforcing elements (9) of the carcass ply (4) encloses an angle (14) in the range of 80° to 90° with respect to the circumferential direction in the first side area (5) and in the second side area (6) and encloses an angle (15) in the range of 5° to 75° in the central area (7), wherein the tire sidewalls each have a radially outer sidewall area (21) and a radially inner sidewall area (22), wherein the respective radially inner sidewall area (22) has a Shore A hardness of 65 to 85 points and the respective radially outer sidewall area (21) has a Shore A hardness of 45 to 70 points, wherein the respective radially inner sidewall area (22) has a Shore A hardness at least 5 points higher than the respective radially outer sidewall area (21).