Pneumatic Tyre Carcass Plies Modulus Optimization

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Solution Overview

Problem

Pneumatic vehicle tires with a single-ply carcass lack robustness and durability, while two-ply constructions increase material costs, weight, and rolling resistance, and may have visible sidewall constrictions affecting quality.

Innovation Solution

A two-ply carcass design with a first ply having a higher modulus of elasticity and thread density product than the second ply, allowing flexible adjustment of extensibility and rigidity, reducing material usage and manufacturing costs while maintaining robustness and quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single-ply carcass is used, then manufacturing is simple and inexpensive, but the tire lacks robustness and durability

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidrobustness and durability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The carcass is divided into two plies with different reinforcement characteristics. The first ply has higher modulus and thread density for strength, while the second ply has lower values for flexibility. This segmentation allows each layer to perform its specific function optimally, achieving both robustness and ease of manufacture.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the carcass have different reinforcement properties. The first ply provides high reinforcement in critical areas for durability, while the second ply provides lighter reinforcement where flexibility is needed. This local differentiation resolves the contradiction between overall strength and manufacturing simplicity.

Inventive Principle:

Principle #3Local quality

2Reliability

If a two-ply carcass construction is used, then robustness and durability are improved, but material costs and weight increase

Engineering Contradiction:

Improverobustness and durabilityVSAvoidmaterial usage

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the parameters of reinforcement (modulus of elasticity and thread density) between the two plies rather than using uniform heavy reinforcement throughout. The first ply uses higher modulus and thread density for strength, while the second ply uses lower values, reducing overall material consumption while maintaining robustness.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The carcass uses a composite structure with two different reinforcement configurations. The combination of high-reinforcement first ply and low-reinforcement second ply creates a composite system that achieves robustness with less total material than a uniform two-ply construction would require.

Inventive Principle:

Principle #40Composite materials

3Reliability

If a two-ply carcass construction is used, then sidewall constriction is reduced, but rolling resistance increases

Engineering Contradiction:

Improvesidewall constriction reductionVSAvoidrolling resistance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The second ply with lower modulus and thread density is strategically positioned to provide localized flexibility in the sidewall region, reducing constriction effects where they occur, while the first ply maintains overall structural integrity without excessive reinforcement that would increase rolling resistance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

By changing the reinforcement parameters (lower modulus and thread density) in the second ply, the patent achieves the dual benefit of reduced sidewall constriction and reduced rolling resistance, as the lighter second ply does not add excessive stiffness that would increase energy loss.

Inventive Principle:

Principle #35Parameter changes

4Strength

If the second carcass ply has greater modulus of elasticity and thread density, then strength is increased, but extensibility decreases

Engineering Contradiction:

Improvecarcass strengthVSAvoidextensibility

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The carcass is segmented into two plies with different reinforcement characteristics. The first ply has higher modulus and thread density for strength, while the second ply has lower values for flexibility. This segmentation allows each layer to perform its specific function optimally, achieving both robustness and ease of manufacture.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP3212440B1Pneumatic vehicle tyre comprising a carcass

Publication Date: 2018.10.24 CONTINENTAL REIFEN DEUTSCHLAND GMBH

Figure 1
Figure 2~4

AI summary

Pneumatic vehicle tyre comprising a carcass (3), wherein the carcass (3) has two carcass plies (31, 32), wherein each carcass ply (31, 32) has reinforcements which are arranged inside the carcass ply (31, 32) substantially parallel to each other. The problem addressed by the invention is to provide a pneumatic vehicle tyre which likewise creates a high quality impression of sufficient robustness to a viewer and, in the process, is cheaper to produce and has a reduced rolling resistance. The invention is characterised in that the product EF1 of the average modulus of elasticity of the reinforcements, as measured with an extension of 2%, of the first carcass ply (31) and the thread density of the reinforcements of the first carcass ply (31), and the product EF2 of the average modulus of elasticity of the reinforcements of the second carcass ply (32) and the thread density of reinforcements of the second carcass ply (32), satisfy the relationship EF1 > EF2.