Directional Tire Tread Offset Calculation for Noise and Stiffness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic vehicle tires with directional tread designs face issues of unequal positive components in tread halves, leading to uneven circumferential stiffness, increased rolling noise, and imbalanced push-pull behavior due to offset diagonal grooves.
Innovation Solution
The tread design ensures a consistent offset between diagonal grooves in all pitches, calculated as U/2, with a maximum deviation of ±2% of the shortest pitch length, to maintain equal positive components in both tread halves, allowing the tire to assume an ideal toroidal shape under pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If diagonal grooves are offset in pitches of different circumferential lengths, then rolling noise is reduced through pitch variation, but unequal positive components in tread halves cause uneven circumferential stiffness and imbalanced push-pull behavior
Solution Approach 1:
The patent applies local quality by making the offset value position-dependent - specifically, the offset is calculated based on the pitch position along the tire circumference. Pitches with different circumferential lengths have different offset values, creating a gradient distribution. This local variation in offset quality allows noise reduction through pitch variation while maintaining equal positive components in both tread halves at each local position, thus preserving circumferential stiffness uniformity.
Solution Approach 2:
The patent changes the offset parameter dynamically based on pitch position and circumferential length. The offset value is not constant but varies according to the formula that considers the pitch's circumferential length and its position in the sequence. This parameter change strategy enables the tread to achieve both noise reduction (through variation) and structural balance (through position-specific optimization).
2Duration of action of stationary object
If diagonal grooves are offset to create pitch variation, then tread wear uniformity is improved, but unequal positive proportions in tread halves lead to negative shear-traction behavior
Solution Approach 1:
The patent applies local quality by making the offset value position-dependent - specifically, the offset is calculated based on the pitch position along the tire circumference. Pitches with different circumferential lengths have different offset values, creating a gradient distribution. This local variation in offset quality allows noise reduction through pitch variation while maintaining equal positive components in both tread halves at each local position, thus preserving circumferential stiffness uniformity.
Solution Approach 2:
The patent changes the offset parameter dynamically based on pitch position and circumferential length. The offset value is not constant but varies according to the formula that considers the pitch's circumferential length and its position in the sequence. This parameter change strategy enables the tread to achieve both noise reduction (through variation) and structural balance (through position-specific optimization).
Data Source
Figure 1
AI summary
The invention relates to a pneumatic vehicle tire for passenger vehicles, comprising a directional tread pattern formed by diagonal grooves (1) that run in a V-shape as main grooves. The diagonal grooves (1) run from one tread half slightly over the circumferential central line of the tread into the other tread half where each diagonal groove opens into a diagonal groove (1) from the other tread half, such that sub-regions of positive profiles protrude out of each tread half into the other tread half. The diagonal grooves (1) together with the positive profiles arranged between the diagonal grooves form identically designed profile structures or pitches (Pi, P2, P2) over the tire circumference, said profile structures or pitches being provided in at least two different circumferential lengths. A mutual offset (v) of the diagonal grooves (1) of a pitch (Pi, P2, P3) is formed in each pitch (Pi, P2, P3) along the circumferential central line (M-M) of the tread, said offset being the mutual distance between the diagonal groove (1) which first arrives at ground level in the circumferential central line (M-M) upon rolling during forwards travel and the next diagonal groove which arrives at ground level. The tread is designed such that the offset v is calculated according to the following relationship and is the same size in all of the pitches (Pi, P2, P3): v = u 2 x n, wherein U is the circumference of the tire along the circumferential central line in mm, and n is the number of pitches P over the tire circumference. The maximum deviation is ± 2 % of the pitch length of the shortest pitch.