Multi-Strand Tire Cord Structure for Elastomer Penetrability
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Solution Overview
Problem
Existing multi-strand cables used in heavy industrial vehicle tires are susceptible to corrosion due to the entry and propagation of corrosive agents, and increasing cord diameter or number to enhance breaking force compromises flexibility and penetrability.
Innovation Solution
A two-layer multi-strand cable design with desaturated outer layers and specific pitch ratios (p3-p2)/p3 allows for improved penetrability by elastomer composition, maintaining mechanical strength and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the cord diameter is increased to enhance breaking force, then the breaking force is improved, but the flexibility of the cord decreases
Solution Approach 1:
The cable is divided into multiple strands (inner strand and outer strands), each strand containing multiple wires arranged in layers. This segmentation allows the cable to achieve high breaking force through the cumulative strength of many individual wires while maintaining flexibility through the modular strand structure that can bend and deform independently.
2Strength
If the number of cords is increased to enhance breaking force, then the breaking force is improved, but the penetrability of the strands by elastomer composition decreases
Solution Approach 1:
The patent applies different wire diameters at different locations within the strand structure. The inner layer contains wires of one diameter while outer layers contain wires of different diameters. This local variation in wire dimensions creates pathways of appropriate size for elastomer composition to penetrate while still achieving the required breaking force through the overall multi-layer configuration.
Solution Approach 2:
The cable structure is organized as nested layers: inner strand containing multiple wires, surrounded by outer strands, each with their own layered wire structures. The elastomer composition can penetrate through the nested structure from outer to inner layers, treating each layer as a separate penetrable unit while the cumulative effect of all layers provides the required strength.
3Strength
If the unit strength of each cord is increased to enhance breaking force, then the breaking force is improved, but the investment in cord manufacturing facilities increases significantly
Solution Approach 1:
Instead of manufacturing fewer high-strength cords requiring expensive specialized equipment, the patent segments the strength requirement across many standard-strength wires. Each wire can be manufactured using conventional, less expensive equipment, while the cumulative strength of all wires in the multi-layer structure achieves the required breaking force.
Solution Approach 2:
The patent changes the parameter of wire diameter distribution within the strand structure. By using multiple wires of optimized diameters arranged in specific layers, the overall breaking force is enhanced without requiring each individual wire to have extremely high unit strength, thereby avoiding the need for expensive manufacturing facilities.
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
The cable design effectively prevents corrosive agent ingress and propagation while maintaining breaking force and flexibility, enhancing tire lifespan.
Implementation Method 1
the elastomeric composition penetrates the capillaries present between each layer of each strand and thus prevents the spread of corrosive agents
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The disclosed cord (50) comprises an inner strand (TI) and L > 1 outer strands (TE). The inner strand (TI) comprises: an inner layer (C1) consisting of Q = 2, 3 or 4 inner wires (F1); an intermediate layer (C2) consisting of M intermediate wires (F2) wound at a pitch p2; an outer layer (C3) consisting of N outer wires (F3) wound at a pitch p3. The outer layer (CE) of the cord is wound in a winding direction of the cord (50). Each outer layer (C3, C3') of each inner and outer strand (TI, TE) is wound in a same winding direction extending opposite the winding direction of the cord (50). The outer layer (CE) of the cord (50) is desaturated. The intermediate layer (C2) of the inner strand (TI) is desaturated, and the outer layer (C3) of the inner strand (TI) is desaturated. The following applies to pitches p2 and p3: 0.33 ≤ (p3-p2)/p3 ≤ 0.45 if Q=2; 0.35 ≤ (p3-p2)/p3 ≤ 0.42 if Q=3; 0.28 ≤ (p3-p2)/p3 ≤ 0.43 if Q=4.