V-ribbed belt and method for manufacturing same

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Solution Overview

Problem

V-ribbed belts used in engines with ISG drives face challenges in maintaining core wire pitch order and durability due to high dynamic tension, leading to potential core wire damage and reduced tensile strength during the mold-patterning production method.

Innovation Solution

A V-ribbed belt design featuring a twisted cord made from high-elongation aramid fibers with an intermediate elongation of 0.8-3% and a tensile modulus of 50-100 GPa, mixed with low-modulus fibers, which are thermally stretched and bonded to prevent core wire disorder and enhance durability under high dynamic tension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If low-elongation aramid fibers are used as core wires to maintain low belt elongation under high dynamic tension, then the tensile modulus is improved, but the laminated body cannot be sufficiently extended during mold-patterning production, resulting in rib shape failures and core wire damage

Engineering Contradiction:
Improvetensile modulusVSAvoidmanufacturability during mold-patterning
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent changes the elongation parameter of aramid fibers from low elongation (conventional) to high elongation (0.8-3.0%), enabling sufficient extension during mold-patterning production while maintaining low belt elongation through the specific elongation range selection that balances manufacturability and performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining high-elongation aramid fibers with low-modulus fibers in a twisted cord structure, where the high-elongation aramid fibers provide extension capability during production and the low-modulus fibers contribute to overall belt flexibility and manufacturability

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If low-elongation aramid fibers are used as core wires, then the belt elongation under high dynamic tension is reduced, but the core wires are damaged or pitch disorder occurs during production, decreasing tensile strength and durability

Engineering Contradiction:
Improvebelt elongation stabilityVSAvoidcore wire integrity and durability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent changes the elongation parameter of aramid fibers to a specific range (0.8-3.0%) that provides sufficient extension capability during production to prevent core wire damage and pitch disorder, while still maintaining low belt elongation under operating conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary extension of the laminated body during mold-patterning production by using high-elongation aramid fibers, which allows the core wires to be properly positioned and arranged before the final curing process, preventing pitch disorder and damage

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If high-elongation aramid fibers are used to enable sufficient extension during mold-patterning production, then the ease of manufacture is improved, but the tensile modulus and durability under high dynamic tension may be reduced

Engineering Contradiction:
Improveextension capability during productionVSAvoidtensile modulus
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent optimizes the elongation parameter to a specific range (0.8-3.0%) that provides sufficient extension capability during production while maintaining adequate tensile modulus, representing a balanced parameter selection that satisfies both manufacturability and performance requirements

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining high-elongation aramid fibers with low-modulus fibers, where the high-elongation aramid fibers provide extension capability during production and the low-modulus fibers contribute to overall belt flexibility and manufacturability while the aramid fibers maintain tensile strength

Inventive Principle:
Principle #40Composite materials

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 solution effectively inhibits core wire disorder and damage during production, while maintaining noiselessness and durability even under high dynamic tension conditions, extending the belt's running life and maintaining its tensile strength.

Implementation Method 1

thermally stretched and bonded to prevent core wire disorder and enhance durability

Methodology Applied
Scientific EffectThermal stretching: Thermal Expansion

Data Source

PatentEP3643945B1V-ribbed belt and method for manufacturing same
Publication Date: 2022.08.31 MITSUBOSHI BELTING LTD
  • EP3643945B1 patent drawingFigure 1
  • EP3643945B1 patent drawingFigure 2
  • EP3643945B1 patent drawingFigure 3

AI summary

The present invention relates to a V-ribbed belt that has a medium elongation of 0.8% or more when the load of 4 cN/dtex is applied, and that contains a twisted cord in which a high-elongation aramid fiber having a tensile modulus of 50-100 GPa and a low-modulus fiber having a lower tensile modulus than the high-elongation aramid fiber are blended and twisted.