Tire Belt Structure Balancing Rolling Resistance and Durability
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Solution Overview
Problem
Existing tires face a challenge in achieving a balance between reducing rolling resistance for improved fuel efficiency and maintaining durability, particularly in heavy-duty applications.
Innovation Solution
A tire design incorporating a belt structure with specific belt angles and widths, including a radially inner cross belt, a radially outer cross belt, and a circumferential reinforcing layer, along with circumferential main grooves and land portions, to enhance rigidity and durability while minimizing rolling resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the belt structure is optimized to reduce rolling resistance, then fuel efficiency is improved, but durability decreases
Solution Approach 1:
The belt layer is divided into three distinct segments: radially inner cross belt (45° or more), circumferential reinforcing layer (±5°), and radially outer cross belt (45° or less with opposite sign). Each segment performs a specific function - the inner cross belt provides structural support, the circumferential layer reduces rolling resistance, and the outer cross belt maintains durability, resolving the contradiction between fuel efficiency and durability
Solution Approach 2:
Different belt sections have different cord angles and widths tailored to local requirements. The circumferential reinforcing layer with ±5° angle is positioned where rolling resistance reduction is most beneficial, while the cross belts with 45° angles are positioned where structural support and durability are critical, achieving local optimization of both fuel efficiency and durability
2Use of energy by moving object
If the circumferential reinforcing layer width W1 is increased to reduce rolling resistance, then fuel economy performance improves, but the structural balance of the belt layer is disrupted
Solution Approach 1:
The patent specifies precise parameter ranges: W1/W2 between 0.3-1.0, W1/W3 between 0.3-1.0, and circumferential belt angle within ±5°. These parameter changes optimize the circumferential reinforcing layer's contribution to reducing rolling resistance while maintaining the overall structural balance and functionality of the multi-layer belt system
Data Source
AI summary
A belt layer includes an inner cross belt having a belt cord angle with an absolute value of 45 degrees or more relative to the circumferential direction, an outer cross belt having a belt cord angle with an absolute value of 45 degrees or less relative to the circumferential direction with an opposite sign as the belt cord angle of the inner cross belt and outward of the inner cross belt in the radial direction, and a circumferential reinforcing layer including a belt cord having a belt angle within ±5 degrees relative to the circumferential direction and disposed between the inner and outer cross belts. A width W1 of the circumferential reinforcing layer in the width direction, a width W2 of the inner cross belt in the width direction, and a width W3 of the outer cross belt in the width direction satisfy a relationship W1<W3<W2.