Pneumatic Tire Carcass Layout for Low-Weight Cornering Stiffness

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Solution Overview

Problem

Existing vehicle tires face a challenge in achieving a low weight while maintaining high material stiffness and stability, particularly during cornering, as conventional designs often include multiple belt layers that increase weight without significantly enhancing stability.

Innovation Solution

A novel tire construction featuring a maximum of one belt layer beneath the tread, combined with a central carcass layer of high tensile strength and specific reinforcing element angles, along with optional side carcass layers, to enhance stability and stiffness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If multiple belt layers are used in conventional tire designs, then stability and material strength are improved, but weight increases

Engineering Contradiction:
ImprovestabilityVSAvoidweight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent removes the belt layer from the tire construction, retaining only the carcass layers. This extraction of the belt component eliminates its weight contribution while the optimized carcass layer configuration (with high-tensile-strength cords at specific angles) maintains the necessary stability and strength functions.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies different cord arrangement configurations to different regions of the tire. The first and second carcass layers have cords arranged at different angles and orientations, with the first layer providing stability in one direction and the second layer providing stability in another direction. This localized differentiation of layer properties optimizes strength distribution without requiring additional belt layers.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If multiple belt layers are used to enhance stability during cornering, then material stiffness is improved, but weight increases

Engineering Contradiction:
Improvecornering stiffnessVSAvoidweight
Core Design Contradiction:
Stability of the object's compositionVSWeight of moving object

Solution Approach 1:

The patent configures the first carcass layer with cords arranged at a first angle and orientation to provide stability in a first direction, and the second carcass layer with cords arranged at a second angle and orientation to provide stability in a second direction. This directional differentiation of layer properties optimizes cornering stiffness without requiring additional belt layers.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite cord materials with high tensile strength properties in the carcass layers. The specific cord arrangements and material selections create a composite structure that achieves high cornering stiffness equivalent to or exceeding conventional multi-layer belt designs, but with reduced weight.

Inventive Principle:
Principle #40Composite materials

3Stability of the object's composition

If the central carcass layer has high tensile strength, then lateral stiffness is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvelateral stiffnessVSAvoidmanufacturing complexity
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent specifies that the central carcass layer has a tensile strength within a particular range (20,000 to 25,000 Newtons per decimeter). By defining a specific parameter range rather than requiring extreme values, the patent achieves high lateral stiffness while maintaining manufacturability and avoiding excessive complexity in material selection and processing.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4212359B1Pneumatic tyre for vehicles
Publication Date: 2026.02.25 CONTINENTAL REIFEN DEUTSCHLAND GMBH
  • EP4212359B1 patent drawingFigure 1~2
  • EP4212359B1 patent drawingFigure 3~4

AI summary

To improve the tire construction of vehicle pneumatic tires, it is proposed that the vehicle pneumatic tire (1) has a tire belt with a maximum of one belt ply (6) or no belt ply, wherein the tire carcass (2) has at least one side carcass ply (3) with radially oriented reinforcing elements (12) in the area of ​​the sidewalls (9) and a central carcass ply (4) in the area below the tread, wherein the reinforcing elements (12) of the central carcass ply (4) are arranged at an angle in the range of 5° to 85° to the circumferential direction (11) of the vehicle pneumatic tire, wherein the central carcass ply (4) has a tensile strength of approximately 20,000 to 30,000 Newtons per decimeter to achieve high material stiffness of the tire carcass (2).