Segmented Tire Mold With Rotating Tread Parts for Undercut Release
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Solution Overview
Problem
Conventional tire molds with projections on the tread design surface cause high undercut resistance during mold release, leading to defects such as permanent deformation and projection failure, especially in tires with complex tread patterns.
Innovation Solution
The mold is designed with segments that include rotatable design surface dividing mold parts supported by a shaft, allowing them to rotate when the mold is opened, reducing undercut resistance by facilitating the release of the tire from the projections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If projections such as ribs or blades are provided on the tread design surface to form tread patterns, then the tread pattern with recesses and protrusions can be formed on the tire tread, but high undercut resistance is caused during mold releasing, leading to permanent deformation and projection failure
Solution Approach 1:
The tread molding part is divided into multiple segments arranged in the circumferential direction, with each segment further divided into multiple design surface dividing mold parts. This segmentation allows each mold part to be independently rotated around a rotatable shaft during mold releasing, reducing undercut resistance and preventing projection failure while maintaining tread pattern formation quality.
Solution Approach 2:
The design surface dividing mold parts are configured to rotate around a rotatable shaft parallel to the axis of the tread molding part when the mold is opened. This dynamic movement transforms the static mold structure into a dynamic one, allowing the mold parts to adjust their position during releasing to minimize undercut resistance and prevent damage to the projections.
2Ease of operation
If the tread molding part is divided into multiple segments to enable opening and closing motion, then the mold can be opened for tire releasing, but high undercut resistance occurs at the sides of both ends of the segments due to projections
Solution Approach 1:
Each segment is further divided into multiple design surface dividing mold parts that can be independently rotated around rotatable shafts. This additional segmentation level allows for more precise control of the releasing process, enabling each small mold part to rotate and reduce undercut resistance at the segment ends where high resistance occurs.
Solution Approach 2:
The mold parts are given rotational freedom around a shaft parallel to the tread molding part axis, adding a rotational dimension to the traditional linear opening motion. This dimensional change allows the mold parts to escape from the undercut condition by rotating away from the tire tread surface during releasing.
3Adaptability or versatility
If projections are used to form complex tread patterns, then the desired tread design can be achieved, but the undercut resistance becomes excessively high causing defects in the tire tread
Solution Approach 1:
The complex tread pattern is formed by multiple design surface dividing mold parts within each segment, with each part capable of independent rotation. This segmentation allows the mold to accommodate complex tread designs while managing undercut resistance through controlled rotation of individual mold parts during releasing.
Solution Approach 2:
The rotatable configuration of the design surface dividing mold parts enables dynamic adjustment during the releasing process. As the mold opens, each part can rotate to an optimal position that minimizes undercut resistance, allowing complex tread patterns to be released without defects or permanent deformation.
Data Source
AI summary
Provided are a mold for forming a tire including an annular tread molding part which is configured to be opened and closed by moving a plurality of segments in a radial direction, and a tire production method using the same. In the mold for forming the tire, each of the segments includes a plurality of design surface dividing mold parts, each of the plurality of the design surface dividing mold parts includes a tread design surface for forming a tread of a tire, the plurality of the design surface dividing mold parts are arranged in a circumferential direction of the segments, and the plurality of the design surface dividing mold parts are configured to rotate around a rotatable shaft parallel to an axis of the tread molding part when the tread molding part is opened after vulcanization molding of the tire.