Pneumatic Tire Tread Pattern with Chamfered Acute-Angle Portions
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Solution Overview
Problem
Pneumatic tires face challenges in achieving a balance between drainage properties, driving stability, resistance to uneven wear, and noise reduction due to the rigidity issues at acute-angle portions between circumferential and slant grooves, with existing designs either compromising on drainage or stability.
Innovation Solution
A tread pattern with a center main groove, steep grooves, and chamfered portions that gradually increase in depth and decrease in height, providing adjacent inclined and chamfered surfaces for enhanced rigidity and drainage, along with arcuate side walls for improved water flow and reduced noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If slant grooves open to the circumferential groove in the tread center region to enhance drainage properties, then drainage properties are improved, but rigidity of land portions at acute-angle portions is reduced, causing deterioration of driving stability and probable occurrence of uneven wear
Solution Approach 1:
The patent applies local quality by providing chamfered portions specifically at the acute-angle portions between circumferential grooves and slant grooves, while maintaining the overall groove pattern. This localized structural modification strengthens only the critical weak points without altering the drainage function of the grooves, thereby resolving the contradiction between drainage properties and driving stability.
2Stability of the object's composition
If the slant groove extends to be inclined at a relatively large angle with respect to the tire circumferential direction to improve driving stability, then driving stability and resistance to uneven wear are improved, but pattern noises and drainage properties deteriorate
Solution Approach 1:
The patent maintains the relatively large inclination angle of slant grooves for driving stability while locally adding chamfered portions at the acute-angle portions. This localized reinforcement reduces pattern noises caused by the interaction between the groove edges and road surface, without requiring a change in the overall groove angle that would compromise drainage properties.
3Reliability
If the groove width is made wider to increase a percentage of grooves in the tire contact ground for improving drainage properties, then drainage properties are improved, but rigidity of the land portions is reduced, causing deterioration in driving stability
Solution Approach 1:
The patent maintains the groove width for adequate drainage properties while locally strengthening the land portions at acute-angle portions through chamfered portions. This localized reinforcement compensates for the reduced rigidity caused by wider grooves, thereby maintaining driving stability without sacrificing drainage performance.
Data Source
Figure 1
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AI summary
The present invention provides a pneumatic tire which suppresses pattern noise and uneven wear, with improving both drainage properties and driving stability at the same time. The pneumatic tire, having in each half-section obtained by dividing a tread portion 1 into two by the pattern center a center main groove 3, a side main groove, steep grooves 7 and a center land portion 6 demarcated into a number of substantial blocks 14 to form a block row 15, is characterized in that: the steep groove 7 is provided with an inclined groove bottom portion 8 where the groove depth gradually increases from the center main groove 3 toward the first side main groove 5; a first acute-angle portion interposed by the center main groove 3 and each steep groove 7 is provided with a first chamfered portion 9 where the height of the land portion gradually decreases toward a tip end 9c thereof; and the inclined groove bottom portion 8 and the first chamfered portion 9 are located adjacent to each other in the tire width direction W.