Segmented Tire Curing Mold for Sidewall Tread Demoulding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing curing moulds are not suitable for moulding tyres with tread patterns extending onto the sidewalls, as they lack sufficient radial retraction for easy removal and require modifications to the curing press and actuating tools for different tread patterns.
Innovation Solution
A curing mould with a crown ring of circumferential segments divided into upper and lower parts, allowing simultaneous radial and axial movement, and a holding device to stabilize the lower segment parts in position, enabling use on standard curing presses without modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the crown ring segments are radially retracted to allow removal of vulcanized tyres with tread patterns extending onto sidewalls, then the tyre can be demoulded, but the segments require additional axial movement relative to each other which complicates the mould structure
Solution Approach 1:
The crown ring is divided into multiple circumferential segments that can move independently. Each segment is further divided into upper and lower parts that can move axially relative to each other, enabling complex demoulding paths while maintaining structural manageability
Solution Approach 2:
The invention adds axial movement capability to the traditionally radially-moving segments. By allowing upper and lower segment parts to move axially relative to each other while maintaining radial retraction, the system achieves demoulding in multiple dimensions without excessive complexity
2Ease of operation
If the crown ring segments are divided into upper and lower parts with independent axial movement, then demoulding of complex tread patterns is enabled, but the positioning and control of segment parts becomes more difficult
Solution Approach 1:
Guide fingers protruding from upper segments interact with orifices in facing lower segments to synchronize and control their relative axial positions. This intermediary mechanism ensures proper positioning without requiring complex active control systems
Solution Approach 2:
The segment parts self-position through their interaction with the holding device and guide fingers. The system uses the segments' own geometric features and mechanical interactions to maintain proper alignment without external intervention
3Reliability
If a holding device is added to stabilize lower segment parts in radial position, then segment positioning is improved, but the mould structure becomes more complex
Solution Approach 1:
The holding function is extracted as a separate device with specific elements (guide fingers, orifices) that can be integrated into the existing mould structure. This modular approach adds functionality while maintaining design clarity
Solution Approach 2:
The holding device elements are integrated with the segment structure itself - guide fingers are part of upper segments and orifices are part of lower segments. This merging reduces the need for separate external holding mechanisms
4Adaptability or versatility
If modifications are made to the curing press or actuating tools to accommodate different tread patterns, then versatility is improved, but the cost and complexity of equipment increases
Solution Approach 1:
The mould is designed with segments that can perform multiple functions - radial retraction for standard tyres and combined axial-radial movement for tyres with tread patterns on sidewalls. This universal design eliminates the need for different moulds or press modifications for different tread types
Data Source
AI summary
A mold (10) for curing a tire comprises: an upper shell (16a) for molding a tire sidewall, a lower shell (16b) for molding a tire sidewall, and a crown ring (20) of circumferential segments for molding a tire tread, each segment comprising an upper segment part (20a) suitable for being axially separated from a lower segment part (20b), the curing mold being suitable for interacting with means for actuating a radial movement of all of the segment parts simultaneously. Each lower segment part (20b) comprises a device (100) for holding the lower segment part (20b) in a radial position between a closed position of the mold and an open position thereof, the elements of the holding device (100) belonging to the lower segment part and to the lower shell (16b).