Pneumatic Tire Tread Land Portions with Rough-Surface Projections
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Solution Overview
Problem
Existing pneumatic tire tread structures with line grooves face issues of uneven wear, increased rolling resistance, and compromised wet grip performance due to compressive deformation and sliding contact between land portions and projecting portions, which weakens support and obstructs drainage.
Innovation Solution
The implementation of tapered-off projections with rough surfaces on the end surfaces of projecting portions that contact each other, forming high-friction engagement to firmly support land portions and maintain rigidity, thereby reducing deformation and enhancing drainage properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If projecting portions are formed to project from side surfaces of land portions toward the land portion on the other side, then rigidity of the land portions is maintained and deformation is suppressed, but the end surfaces may slip on each other during sliding contact, weakening the support force and making it difficult to suppress deformation effectively
Solution Approach 1:
The end surfaces of the projecting portions are given a rough surface treatment specifically at the contact regions, while other parts of the projecting portions maintain their original smooth surface. This localized modification increases friction only where contact occurs, preventing sliding without affecting the overall structure or adding excessive complexity.
Solution Approach 2:
The sliding contact between opposing projecting portions, which initially causes harmful effects through reduced support force, is converted into a beneficial engagement mechanism. By providing rough surfaces at the end surfaces, the sliding contact transforms into a high-friction engagement that firmly couples the projecting portions together, converting the potential harm of sliding into a beneficial locking effect that enhances support stability.
2Reliability
If the end surfaces of projecting portions make sliding contact with each other, then the force with which the projecting portions support the land portions is weakened, but the rough surface treatment increases friction and prevents sliding
Solution Approach 1:
The rough surface treatment is applied only to the end surfaces of the projecting portions where contact occurs, rather than treating the entire surface. This localized approach prevents sliding contact while minimizing the extent of the additional structure, thereby reducing complexity compared to comprehensive surface treatments.
3Strength
If projecting portions are formed to support land portions, then deformation is suppressed and rolling resistance is reduced, but the deformation and deformation of projecting portions may obstruct the draining property of line grooves, lowering wet grip performance
Solution Approach 1:
The rough surface treatment is confined to the end surfaces of the projecting portions, leaving the grooves and other drainage-critical areas with their original smooth surfaces. This localized modification ensures that drainage pathways remain unobstructed while still achieving the anti-sliding effect where needed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively suppresses compressive deformation, reduces rolling resistance, and maintains wet grip performance by ensuring even contact and engagement between projecting portions, preventing slipping and maintaining the draining properties of the line grooves.
Implementation Method 1
rough surfaces on the end surfaces of projecting portions that contact each other, forming high-friction engagement to firmly support land portions
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A pneumatic tire includes a tread (1) formed with a plurality of land portions (5) defined by a plurality of line grooves (2, 3) . Projecting portions (6, 6) are formed to project from both of opposed side surfaces of the land portions (5) located adjacent to each other with the line groove (2, 3) therebetween toward each other, the projecting portions (6, 6) each being formed in that region of the land portion (5) which is deeper than a tread surface (5f). Closely opposed end surfaces (6s, 6s) of the projecting portions (6, 6) facing each other are both formed to be rough surfaces having a high frictional resistance. This ensures that the projecting portions (6, 6) making contact with each other due to compressive deformation of the land portions (5) due to grounding of the tread (1) firmly support the land portions (5) on both sides thereof, deformation of the land portions (5) is suppressed, and rolling resistance is reduced while maintaining wet grip performance.