Tire Forming Arm Dynamics for Consistent Press Force
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Solution Overview
Problem
Conventional tire forming apparatuses face challenges in consistently applying the right press force during the folding back step of tire members, leading to defects like air entering between the bead core and carcass ply, and unevenness on the attachment surface due to varying arm angles and biasing forces.
Innovation Solution
A tire forming apparatus with a drum spindle body, arms, and pushing means, where the arm is configured with a slidable contact portion, press portion, and connecting portion, allowing for adjustable press force by varying the arm angle, thereby reducing the press force as the arm opens radially, ensuring a consistent and suitable force application across different positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the arm pushes the outer zone in the radial direction with a larger arm angle, then the press force increases, but the press force becomes excessive causing unevenness defects on the attachment surface
Solution Approach 1:
The arm angle is made variable rather than fixed, allowing the press force to be dynamically adjusted according to the position being pressed. The arm angle changing mechanism enables the system to adapt the pressing characteristics to different zones of the tire member, applying appropriate force to each location rather than a uniform force throughout.
Solution Approach 2:
The arm angle parameter is changed based on the pressing position. By varying the arm angle, the press force parameter is consequently varied - smaller angles for outer zones requiring less force, and larger angles for the bead core vicinity requiring greater force. This parameter adjustment resolves the contradiction between sufficient press force and preventing excessive force defects.
2Force
If the arm pushes the vicinity of the bead core with a smaller arm angle, then the press force decreases, but the press force becomes insufficient allowing air to enter between the bead core and carcass ply
Solution Approach 1:
The arm angle is dynamically adjusted to be larger when pressing the bead core vicinity, which increases the press force at this critical location. This dynamic adjustment ensures sufficient press force is applied where needed to prevent air entry and ensure proper bonding, while avoiding excessive force elsewhere that would cause surface defects.
Solution Approach 2:
The arm angle parameter is specifically increased for the bead core vicinity to generate the higher press force required for reliable bonding. This parameter change directly addresses the reliability concern by ensuring adequate pressing force is applied at the most critical bonding location.
3Device complexity
If a spring member bundles the arms, then the structure is simplified, but the press force varies with arm opening movement causing folding back defects
Solution Approach 1:
While maintaining the simple spring member structure for bundling arms, the system introduces dynamic control through variable arm angles. This allows the press force to be modulated according to position rather than solely depending on spring tension, thereby preventing folding back defects while preserving structural simplicity.
Solution Approach 2:
The arm angle parameter is varied to compensate for the press force variations inherent in the spring member system. By adjusting the arm angle according to position, the system maintains consistent pressing effectiveness despite the simple elastic structure, preventing folding back defects without adding complex control mechanisms.
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 apparatus effectively reduces folding back defects by maintaining a consistent press force across the tire member, preventing air entry and minimizing unevenness, with the press force decreasing as the arm angle increases, allowing for precise control of the pressing force based on the arm angle and pushing force.
Implementation Method 1
a spring member such as a rubber band 35 that bundles the arms 32
Implementation Method 2
a press force resulting from a biasing force T (indicated with a spring symbol in the drawing) due to tension of the rubber band 35
Implementation Method 3
the arm 32 is moved about a rear end portion 32B of the arm 32 as a fulcrum and opened outward in a radial direction of the drum spindle body 31 while pressing the carcass ply 30
Data Source
Figure 1A~1B
Figure 2
Figure 3A~3B
AI summary
A tire forming apparatus including: a drum spindle body; a plurality of arms arranged in annular shape on an outer circumferential side of the drum spindle body; and pushing means configured to push the arms in a direction approaching an unvulcanized tire member, along an extending direction of the drum spindle body, wherein each arm includes: a slidable contact portion provided on one end side of the arm and configured to slidably contact the pushing means; a press portion provided on the other end side of the arm and configured to contact the unvulcanized tire member and press the unvulcanized tire member; and a connecting portion provided between the slidable contact portion and the press portion in the arm extending direction and connected to the drum spindle body, on the drum spindle body side with respect to a line segment connecting the slidable contact portion and the press portion.