Pneumatic Tire Non-Symmetrical Tread Groove Bottom Cracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-symmetrical tread patterns in pneumatic tires with different see-through void areas on each side lead to non-uniform ground pressure, causing excessive distortion and cracking at groove bottoms, which existing designs fail to adequately address.
Innovation Solution
The tire design features main grooves with varying groove sectional areas and ground contact surfaces of land portions that swell outward from a datum contour line, with the amount of swelling adjusted to balance pressure distribution, ensuring that the side with a larger see-through void area has reduced swelling to prevent increased pressure and cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a non-symmetrical tread pattern with different see-through void areas is used, then steering stability and ground contact are improved, but ground pressure becomes non-uniform causing distortion and cracking at groove bottoms
Solution Approach 1:
The patent applies different swelling amounts to different land portions based on their local characteristics. Specifically, land portions adjacent to main grooves with larger see-through void areas are given smaller swelling amounts, while other land portions receive larger swelling amounts. This localized differentiation of swelling characteristics allows the tire to maintain non-uniform ground pressure distribution that prevents excessive distortion at groove bottoms while preserving the steering stability benefits of the non-symmetrical tread pattern.
Solution Approach 2:
The patent changes the swelling parameter of land portions to control ground pressure distribution. By adjusting the swelling amount of each land portion according to the see-through void area of adjacent main grooves, the patent transforms the harmful non-uniform ground pressure into a controlled distribution pattern that prevents groove bottom cracking while maintaining the overall non-symmetrical tread pattern configuration.
2Productivity
If main grooves with large groove widths are provided, then drainage and heat dissipation are improved, but ground pressure increases at adjacent land portion edges causing excessive distortion
Solution Approach 1:
The patent applies different swelling amounts to land portions based on the groove width characteristics. Land portions adjacent to main grooves with large groove widths receive smaller swelling amounts, while other land portions receive larger swelling amounts. This localized quality differentiation ensures that drainage performance is maintained through large groove widths while preventing excessive ground pressure concentration at land portion edges through reduced swelling in specific locations.
Solution Approach 2:
The patent preemptively reduces the swelling amount of land portions adjacent to large groove width main grooves before ground contact occurs. This preliminary anti-action prevents the formation of excessive ground pressure at these critical locations, countering the potential harmful effect of large groove widths before they can cause distortion or cracking at groove bottoms.
3Area of stationary object
If ground contact surfaces swell outward uniformly, then ground contact area is increased, but ground pressure non-uniformity cannot be corrected in non-symmetrical patterns
Solution Approach 1:
The patent implements non-uniform swelling across different land portions, with each land portion having a swelling amount tailored to its specific location and the characteristics of adjacent main grooves. This localized quality approach allows the overall ground contact area to be increased through swelling while simultaneously correcting ground pressure non-uniformity by applying different swelling magnitudes to different regions, thereby resolving the contradiction between area expansion and pressure uniformity.
Data Source
AI summary
There is provided a pneumatic tire with a tread portion having a plurality of main grooves extending in a tire circumferential direction, and a plurality of land portions partitioned by the main grooves. The tread portion is formed in such a manner that a see-through void area on a first side relative to an equatorial plane of the tire in a tire width direction is greater than a see-through void area on a second side in the tire width direction. Ground contact surfaces of the plurality of land portions formed between the main grooves swell outward from a datum contour line of the tread portion in a tire radial direction, and the amount of swelling of a land portion, positioned on the first side on which the see-through void area is large, relative to the datum contour line is smaller than that of a land portion positioned on the second side.