Tyre Building Drum Synchronized Finger Drive
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Solution Overview
Problem
Conventional tire building drums face issues with uneven folding of tire side walls due to asynchronous movement of pivoting fingers, leading to faulty connections and high wear of components, resulting in production rejects and increased maintenance costs.
Innovation Solution
The design features a spindle drive system where pull and push rods, acting as spindles with spindle nuts, pivot the fingers, allowing for synchronized movement and reduced wear, with a differential gear for rotational synchronization and servo motors for axial displacement, enabling a simpler and more reliable structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pneumatic cylinders are used to spread the pivoting fingers apart, then the sidewalls can be folded up, but the spreading does not occur simultaneously due to frictional influences, leading to uneven pressing and faulty bonds
Solution Approach 1:
The patent replaces the pneumatic cylinder system with a mechanical linkage system consisting of a common drive mechanism, connecting rods, and pivoting fingers. This mechanical substitution ensures synchronous movement of fingers on both crowning heads by eliminating the frictional delays inherent in pneumatic systems, while still achieving the folding up of sidewalls.
Solution Approach 2:
The common drive mechanism serves multiple functions: it simultaneously controls the spreading of pivoting fingers on both crowning heads, ensures synchronous movement, and maintains even pressing force distribution. This multi-functional design eliminates the need for separate pneumatic cylinders for each crowning head.
2Productivity
If side camber bellows are used to press sidewalls against the carcass, then the sidewalls can be folded up, but the bellows do not penetrate the shoulder areas, requiring manual rework
Solution Approach 1:
The pivoting fingers are designed with a pivotable connection that allows them to dynamically adapt to the tire geometry. As the fingers spread apart during the folding process, they automatically penetrate the shoulder areas of the green tire, ensuring complete coverage without requiring manual rework.
3Extent of automation
If side camber bellows are used for folding sidewalls, then the process can be automated, but the bellows are subject to high wear, necessitating frequent replacement
Solution Approach 1:
The pivoting fingers are designed as simple, robust mechanical components with pivotable connections that can withstand high wear. Unlike the complex inflatable bellows, these fingers are easier to replace and maintain, improving the overall reliability and reducing downtime for maintenance.
4Adaptability or versatility
If four adjustment devices with pull/push rods are used to move crowning heads and pivoting fingers, then the system can be controlled, but the structure becomes very complex
Solution Approach 1:
The patent merges the control functions by using a common drive mechanism that simultaneously controls the pivoting fingers on both crowning heads. This is achieved through a linkage system with connecting rods that transmit motion from a single drive source, reducing the number of independent adjustment devices from four to one while maintaining full control capability.
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 solution ensures synchronized and efficient folding of tire side walls, reducing rejects and maintenance costs by using standard machine elements and minimizing wear on components, while simplifying the drive system and enhancing accessibility.
Implementation Method 1
the pull rod and the push rod are each designed as a spindle drive for pivoting the fingers
Implementation Method 2
a differential gear for rotational synchronization
Implementation Method 3
servo motors for axial displacement
Data Source
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AI summary
The invention relates to a tyre building drum for producing a green tyre, wherein the tyre building drum comprises a rotatable drum housing (2) and two crowning heads (3, 3') on the drum housing (2), which crowning heads can be displaced coaxially next to one another and relative to one another and are arranged substantially symmetrically with respect to the perpendicular bisector (M) through the drum housing (2). The crowning heads (3, 3') are equipped with pivotable fingers arranged in a ring around the periphery of the crowning heads (3, 3'), the fingers being pivotable by means of a spindle drive. A pull rod (20) and a push rod (21) are provided which extend coaxially with respect to one another, are guided axially out of the drum housing (2), and can be axially displaced in opposite directions, the push rod (21) being connected to one crowning head (3) and the pull rod (20) being connected to the other crowning head (3').