Unvulcanized Rubber Ring Bonding with Width-Dependent Elongation Control

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Solution Overview

Problem

Existing methods for producing unvulcanized ring-shaped rubber members struggle to bond the longitudinal end portions of unvulcanized band-like rubber members evenly and reliably across the entire width direction on the outer circumferential surface of a forming drum.

Innovation Solution

A device and method that control the movement of the rear edge portion of the band-like rubber member to adjust its elongation, using distribution data of the band's length in the width direction, to ensure an allowable bonding margin before bonding it to the front edge portion on the forming drum.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the angle of the rear end edge is adjusted to match the front end edge angle, then bonding alignment is improved, but bonding uniformity across the entire width direction is not achieved

Engineering Contradiction:
Improvebonding alignmentVSAvoidbonding uniformity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The bonding mechanism is divided into multiple independent movable portions (first movable portion and second movable portion) that can be adjusted separately in the width direction. Each movable portion corresponds to a specific width position, allowing independent control of elongation at different locations to achieve uniform bonding across the entire width.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different elongation amounts are applied to different width positions based on the actual contraction characteristics at each location. The control unit calculates required elongation amounts for each movable portion based on distribution data of contraction portions, enabling localized adjustment to achieve uniform bonding margins across the width direction.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the front edge portion is stretched to compensate for contraction, then the contraction is corrected, but the angle of the front end edge becomes non-uniform in the width direction

Engineering Contradiction:
Improvecontraction correctionVSAvoidedge angle uniformity
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The stretching operation is segmented into multiple independent movable portions that can be adjusted individually. Each movable portion applies stretching force only to its corresponding width position, correcting local contraction without affecting the angle uniformity at other positions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stretching operation is performed before bonding to pre-correct the contraction and establish proper edge angles. By adjusting each movable portion independently before the bonding step, the system ensures both contraction correction and angle uniformity are achieved simultaneously.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If simple angle adjustment is used for bonding, then the process is simple, but gaps occur in bonding across the width direction

Engineering Contradiction:
Improvebonding process simplicityVSAvoidbonding completeness
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The bonding mechanism transitions from a static fixed-position design to a dynamic system where multiple movable portions can be independently adjusted in the width direction. This dynamic adjustment capability allows the system to adapt to variations in rubber member contraction while maintaining bonding completeness across the entire width.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit uses distribution data of contraction portions to calculate and determine the optimal elongation amount for each movable portion. This feedback-based control ensures that bonding is achieved without gaps across the width direction while maintaining process automation and simplicity.

Inventive Principle:
Principle #23Feedback

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 approach allows for the production of unvulcanized ring-shaped rubber members with even and reliable bonding across the entire width direction, effectively addressing the limitations of previous methods.

Implementation Method 1

the degree of elongation around the held portion of the rear edge portion in the front-rear direction which is held by each of the holding portions

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3984730B1Device and method for producing unvulcanized ring-shaped rubber member
Publication Date: 2025.02.19 THE YOKOHAMA RUBBER CO LTD
  • EP3984730B1 patent drawingFigure 1
  • EP3984730B1 patent drawingFigure 2
  • EP3984730B1 patent drawingFigure 3

AI summary

Provided are a device and a method for producing an unvulcanized ring-shaped rubber member by bonding a front edge portion and a rear edge portion of a band-like rubber member on an outer circumferential surface of a forming drum over an entire width direction evenly and more reliably. A front edge portion (4a) of a band-like rubber member (R) conveyed by a transport conveyor (2) is disposed on an outer circumferential surface (13a) of a forming drum (13), and the forming drum (13) is rotated to wind a predetermined length of the band-like rubber member (R) on the outer circumferential surface (13a) and a rear edge portion (Rb) is held by a plurality of rear edge holding portions (8) arranged side by side in a width direction (W). Using the distribution data on a length of the band-like rubber member (R) in the width direction (W), the amount of movement of respective movement portions (9a) in a front-rear direction (L) is controlled by a control unit (12), to adjust the degree of elongation around the held portion of the rear edge portion (Rb) in the front-rear direction (L) that is held by each of the rear edge holding portions (8), and thereafter the front edge portion (Ra) and the rear edge portion (Rb) are bonded by a preset allowable bonding margin (S), to produce a ring-shaped rubber member (RC).