Wedge-Shaped Rubber End Forming via Drum Inversion

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Solution Overview

Problem

Existing methods for forming a belt-like rubber member struggle to directly affix and form a rear end with a wedge-shaped cross section on a forming surface, particularly due to difficulties in holding the winding end part during the rotation of a rotary drum.

Innovation Solution

A method involving an extruder that gradually increases and then decreases the extrusion amount, movement speed, and distance to form a wedge-shaped front and rear end, with a gear pump for controlled rubber supply, allowing the rear end to be affixed directly on the forming surface by reversing the gear rotation and maintaining the extrusion end distance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If the winding end part is formed by gradually decreasing the extrusion amount of rubber and gradually decreasing the distance between the extruder and the rotary drum while the rotary drum is rotated, then the rear end with wedge-shaped cross section can be formed, but it is difficult to affix and hold the winding end part on the rotary drum

Engineering Contradiction:

Improvewedge-shaped cross section of rear endVSAvoidaffixing and holding of winding end part

Core Design Contradiction:

ShapeVSReliability

Solution Approach 1:

The patent applies inversion by stopping the rotary drum during the formation of the rear end portion, reversing the conventional approach where the drum continues to rotate. This allows the extruded rubber to be directly affixed to the stationary forming surface, solving the problem of holding the winding end part while maintaining the wedge-shaped cross section.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent employs preliminary action by forming the rear end portion with a wedge-shaped cross section before the drum rotation resumes. The rear end is formed and affixed to the stationary forming surface first, creating a stable base that eliminates height differences at the joint portion, after which normal drum rotation and extrusion resume.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the rotary drum is stopped during rear end formation, then the rear end can be directly affixed to the forming surface, but the overall production efficiency decreases

Engineering Contradiction:

Improvedirect affixing of rear endVSAvoidproduction efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies partial action by stopping the rotary drum only for the brief period necessary to form the rear end portion, rather than stopping the entire production process. This minimal interruption allows direct affixing of the rear end while maintaining high overall production efficiency, as the drum resumes rotation immediately after the rear end is formed.

Inventive Principle:

Principle #16Partial or excessive action

3Shape

If the extrusion amount and distance are gradually adjusted during rear end formation, then the wedge-shaped cross section is achieved, but the process complexity increases

Engineering Contradiction:

Improvewedge-shaped cross sectionVSAvoidcontrol of extrusion amount and distance

Core Design Contradiction:

ShapeVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical adjustment systems with a simpler control approach. Instead of using complex mechanisms to gradually adjust extrusion amount and distance, the invention uses a control unit that coordinates the extruder and drum rotation, achieving the wedge-shaped cross section through controlled variation of extrusion parameters and drum speed rather than mechanical adjustments.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Enables the direct formation and affixing of a rear end with a wedge-shaped cross section on the forming surface, effectively eliminating height differences at the joint portion by overlapping it with the front end, ensuring a seamless joint.

Implementation Method 1

the gear in the gear pump may be reversely rotated for a predetermined time at a predetermined rotation speed in the rear end affixing step

Methodology Applied

Scientific EffectGear pump reverse rotation: Gear

Implementation Method 2

a front end forming step for forming a front end having a wedge-shaped cross section by gradually increasing an extrusion amount of the rubber from zero to a predetermined extrusion amount

Methodology Applied

Scientific EffectExtrusion: Extrusion

Data Source

PatentUS11975472B2Method for forming belt-like rubber member

Publication Date: 2024.05.07 TOYO TIRE CORP

AI summary

A method for forming a belt-like rubber sheet S by extruding rubber on a drum outer peripheral surface 3a by an extruder 2 includes: a front end forming step for forming a front end S1 having a wedge-shaped cross section; an intermediate part forming step for forming an intermediate part S2 having a desired thickness; and a rear end forming step for forming a rear end S3 having a wedge-shaped cross section by gradually decreasing an extrusion amount of the rubber to zero from a predetermined extrusion amount in a predetermined time, gradually decreasing the rotational speed of the drum outer peripheral surface 3a to zero from a predetermined rotational speed in the predetermined time, and gradually decreasing a distance from the drum outer peripheral surface 3a to a die 21 to an extrusion end distance from a predetermined distance in the predetermined time.