Heavy Load Tire Widthwise Grooves Shear Force Reduction
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Solution Overview
Problem
Heavy load tires experience uneven wear due to shearing forces generated between tread rubber parts where driving and braking forces are produced, leading to increased tire diameter differences and uneven deformation, particularly in construction vehicle tires.
Innovation Solution
The tire design incorporates a specific belt layer structure with high angle belts and widthwise grooves, including inner and outer widthwise grooves with curved shapes, to reduce shearing rigidity and promote uniform wear resistance by aligning groove walls and adjusting groove angles to suppress shearing forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a high angle belt with a small angle (4 to 10°) is arranged in the belt layer to suppress tire diameter growth, then tire diameter increase is reduced, but shearing force is generated between tread rubber parts with different deformation degrees causing uneven wear
Solution Approach 1:
The patent applies local quality by creating widthwise grooves with different characteristics at different locations across the tread width. The grooves have varying depths, angles, and positions tailored to specific regions (shoulder, center, intermediate areas) to locally compensate for the shearing forces generated by the high angle belt structure, thereby preventing uneven wear while maintaining the overall small belt angle for diameter stability.
Solution Approach 2:
The patent segments the tread portion into multiple regions by introducing widthwise grooves that divide the continuous rubber structure into separate zones. This segmentation allows different regions to deform independently, reducing the shearing force between adjacent areas with different rolling radii, while the overall tire structure maintains its diameter stability through the high angle belt configuration.
2Speed
If the tire rotates with different rolling radii in center and shoulder regions, then driving force is generated in the center region, but braking force is generated in the shoulder region creating shearing force
Solution Approach 1:
The patent changes the geometric parameters of the widthwise grooves (depth, angle, position) to optimize their ability to counteract shearing forces. By carefully selecting groove depths of 0.5 to 2.0 mm and angles of 10 to 30 degrees relative to the tread surface, the grooves create controlled deformation zones that reduce the differential shearing force between regions with different rolling radii during tire rotation.
3Object-affected harmful factors
If widthwise grooves are introduced to reduce shearing rigidity and prevent uneven wear, then uneven wear resistance is improved, but block rigidity may be compromised
Solution Approach 1:
The patent applies local quality by designing widthwise grooves with specific depth ranges (0.5 to 2.0 mm) and angular orientations (10 to 30 degrees) that are optimized for different tread regions. This localized groove configuration reduces shearing rigidity precisely where needed to prevent uneven wear, while maintaining adequate block rigidity in other areas to ensure proper tire performance and handling characteristics.
Solution Approach 2:
The patent implements partial action by introducing widthwise grooves that extend only partially across the tread width and with controlled depths that do not penetrate the entire tire structure. This partial grooving approach is sufficient to reduce shearing forces and prevent uneven wear, while leaving enough rubber material intact to maintain the necessary block rigidity for tire strength and handling.
Data Source
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AI summary
A first inner widthwise groove (16i) which opens to a circumferential groove (14a) is arranged in the tire circumferential direction on at least one side of a tread portion (10). The first inner widthwise groove (16i) is provided with a widthwise linear groove (16is) that linearly extends from the circumferential groove (14c) in the tire widthwise direction, and a curved groove (16ir) which connects to the inner end in the tire widthwise direction of the widthwise linear groove (16is), extends inward in the tire widthwise direction, extends in the tire normal rotation direction (R), and reaches the tire equator line (CL). In addition, the angle (θ1) formed between the curved groove (16ir) and the tire widthwise direction (W) becomes smaller in a direction toward the tire equator line.