Pneumatic Tire Tread Segmentation for Rolling Resistance and Braking
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Solution Overview
Problem
There is a conflict in improving both rolling resistance and braking and handling properties in pneumatic vehicle tires, where enhancing rolling resistance typically deteriorates braking and handling, and vice versa.
Innovation Solution
The central tread part is made of a rubber material with higher rebound elasticity at 70°C and a smaller loss factor, occupying most of the ground contact area for low rolling resistance, while the shoulder-side tread parts, with a higher loss factor at 70°C and 0°C, enhance braking and handling by increasing energy absorption and adhesion during braking and cornering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the tread is made of uniform rubber material, then manufacturing is simple, but rolling resistance and braking properties cannot be simultaneously optimized
Solution Approach 1:
The tread is divided into multiple segments (central tread part and shoulder-side tread parts) with different rubber material compositions. The central part uses material optimized for low rolling resistance while shoulder parts use material optimized for braking and handling, allowing simultaneous optimization of conflicting performance requirements through spatial segmentation of material properties.
Solution Approach 2:
Different regions of the tread are assigned different material qualities: the central tread part has rubber material with properties optimized for reducing rolling resistance, while the shoulder-side tread parts have rubber material with properties optimized for braking and handling. This local differentiation of material properties allows each region to perform its specific function optimally.
2Loss of energy
If the central tread part uses material with low loss factor for low rolling resistance, then energy loss is reduced, but braking and handling properties deteriorate
Solution Approach 1:
The tread is segmented into a central part for rolling resistance optimization and shoulder parts for braking optimization. The central tread part uses rubber material with low loss factor to minimize energy loss during rolling, while the shoulder-side tread parts use rubber material with higher loss factor to maximize energy absorption during braking and cornering, thus resolving the contradiction between low rolling resistance and good braking properties.
Solution Approach 2:
The central tread part is assigned rubber material with specific properties (lower loss factor) for low rolling resistance, while the shoulder-side tread parts are assigned rubber material with different properties (higher loss factor) for superior braking and handling. This local quality differentiation ensures that each region's material properties match its functional requirements.
3Reliability
If the shoulder-side tread parts use material with high loss factor for good braking, then braking properties improve, but rolling resistance increases
Solution Approach 1:
The tread is divided into functional segments where shoulder-side tread parts use rubber material with high loss factor optimized for braking energy absorption, while the central tread part uses material with low loss factor for rolling efficiency. This segmentation isolates the high energy loss to only the braking-relevant regions, preventing overall rolling resistance increase.
Solution Approach 2:
The shoulder-side tread parts are assigned rubber material with high loss factor specifically where braking forces are applied, while the central tread part maintains low loss factor material for rolling. This localized application of high loss factor material improves braking without significantly increasing overall rolling resistance.
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 design achieves significantly reduced rolling resistance and improved braking and handling properties by optimizing the rubber materials' properties for each tread part, ensuring the central tread part dominates straight driving for low resistance and shoulder-side tread parts contribute to better braking and cornering performance.
Implementation Method 1
the rubber material(s) of the central tread part has or have a smaller loss factor at 70° C. than the rubber material of the shoulder-side tread parts
Implementation Method 2
the rubber material(s) of the central tread part has or have a greater rebound elasticity at 70° C. than the rubber material of the shoulder-side tread parts
Implementation Method 3
the rubber material of the shoulder-side tread parts has a larger loss factor at 70° C. and at 0° C. than the rubber material(s) of the central tread part
Implementation Method 4
the rubber material of the shoulder-side tread parts has a larger loss factor at 0° C. than the rubber material(s) of the central tread part
Data Source
Figure 1
AI summary
The invention relates to a radial-type pneumatic tire for vehicles, comprising a tread (1) with a central tread section (1a) and two shoulder-side tread sections (1b) that each adjoin the central tread section (1a) in the axial direction, wherein the tread sections (1a, 1b) each have a constant width over the circumference of the tread, wherein the central tread section (1a) is a single piece and consists of a first rubber material, or wherein the central tread section (1a) is multi-part and consists of several first rubber materials, wherein the shoulder-side tread sections (1b) consist of a second rubber material, and wherein the rubber material(s) of the central tread section (1a) has a smaller loss factor (tan δ) at 70°C than the rubber material of the shoulder-side tread sections (1b) according to DIN 53512.The central tread section (1a) has a width (B1) of 90% to 100% of the ground contact area width (B) of the tread (1) in the axial direction.