Pneumatic Tire Sidewall Geometry for Clean Rib Separation
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Solution Overview
Problem
Existing vehicle pneumatic tires suffer from material tears and uneven surfaces at the transition between circumferential ribs and sidewalls due to sharp corners and recesses in the vulcanization mold, leading to material waste and increased rolling resistance.
Innovation Solution
The tire design features a smooth, circularly circumferential flat surface transitioning into a thin, outwardly curved section of the sidewall, minimizing material usage and ensuring a seamless transition, allowing for recessed sidewall markings and designs without protrusions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If circumferential ribs are formed along mold parting lines with sharp corners, then the ribs can be cleanly defined and separated, but material tears occur at the corners and the surface becomes uneven
Solution Approach 1:
The patent applies curvature by replacing the sharp corners of the circumferential ribs with rounded transitions. The rib flanks are designed with curved surfaces that smoothly connect to the sidewall and shoulder sections, eliminating the sharp corners that cause material tears. This curvature principle resolves the contradiction by maintaining rib definition through controlled rounding while preventing material damage and surface unevenness.
2Ease of manufacture
If recesses are provided in the vulcanization mold along the parting line, then the ribs can be formed with proper shape, but material waste increases due to tears and uneven separation
Solution Approach 1:
The curved rib flanks with rounded transitions eliminate material tears during separation, directly reducing rubber material waste. The smooth curvature allows for cleaner separation without the need for excessive material compensation, resolving the contradiction between ease of manufacture and material loss.
Solution Approach 2:
The patent changes the geometric parameters of the rib flanks from sharp angles to curved surfaces with specific radius of curvature. This parameter change optimizes the separation process, reducing material waste while maintaining manufacturability. The curved geometry allows for better material flow and separation characteristics.
3Shape
If the shoulder flanks are made flush with the sidewalls, then visual uniformity is improved, but the transition areas require additional material and increase rolling resistance
Solution Approach 1:
The curved rib flanks create a smooth aerodynamic transition between the shoulder and sidewall areas, reducing turbulence and rolling resistance. The curvature principle allows the shoulder flanks to appear flush with the sidewalls for visual uniformity while maintaining optimized material distribution that reduces energy loss.
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to a pneumatic vehicle tyre having a tread (2) with shoulder flanks (2a), sidewalls (3) and bead regions (4), which tyre is vulcanised in a vulcanising mould having a plurality of segments (8) of a segment ring that are arranged movably in the radial direction in order to form the tread (2) and the shoulder flanks (2a), having sidewall shells (7) in order to form the outer sides of the sidewalls (3) and having mould partitions (Ft) between the segments (8) and the sidewall shells (7), wherein the shoulder flanks (2a) together with those regions that correspond to the positions of the mould partitions (Ft) always adjoin the outer sides of the sidewalls (3) such that the shoulder flanks (2a) align with the outer sides of the sidewalls (3). Radially within the regions that correspond to the positions of the mould partitions (Ft), one portion (3a) of the sidewall (3) is directly adjoining in each case, which portion, when the tyre is viewed from the side, forms an annularly shaped circumferential flat surface with a radial extent (a1) from 10.00 mm to 25.00 mm and which tangentially transitions into the outer side of a further portion (3b) of the sidewall (3), which portion has a 0.50 mm to 1.50 mm thin material addition (9) and curves outward in an arc-shaped manner in the radial cross section.