Tire Vulcanization Mold Evacuation Path for Air Pocket Reduction
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Solution Overview
Problem
The existing tire vulcanization molds face issues with air pocket formation due to poor air discharge during vulcanization, leading to poor molding quality, especially when protrusions are present at the groove bottom of lateral grooves.
Innovation Solution
A tire vulcanization mold design with mold parting lines located in the tread portion and a lateral groove molding rib that includes a protrusion molding recess and an evacuation path from the recess to the mold parting plane, allowing for effective air discharge and enhanced moldability of protrusions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mold parting lines are disposed to the sidewall portion, then rubber squeezed out from the mold parting lines may set at easy-to-notice spots, but this arrangement is simpler than disposing to the tread portion
Solution Approach 1:
The mold is divided into multiple sectors that can be radially separated in the mold open state and gather together in the mold close state. This segmentation allows the mold parting lines to be disposed to the tread portion rather than the sidewall portion, preventing rubber from setting at easy-to-notice spots while maintaining manufacturing precision.
2Reliability
If a protrusion is disposed at a groove bottom of a lateral groove, then stone trapping is prevented, but air pocket formation occurs due to poor air discharge
Solution Approach 1:
An evacuation path is created to extract air from the protrusion molding recess during the vulcanization process. This allows the protrusion to be disposed at the groove bottom for stone trapping prevention while simultaneously removing air pockets that would otherwise form, maintaining both reliability and molding quality.
Solution Approach 2:
The evacuation path is designed to be opened before the mold closes, allowing air to be evacuated from the protrusion molding recess in advance. This preliminary action prevents air pocket formation during vulcanization while maintaining the protrusion's stone trapping function.
3Manufacturing precision
If the evacuation path is provided from the protrusion molding recess to the mold parting plane, then air discharge is improved, but the mold structure becomes more complex
Solution Approach 1:
The evacuation path is integrated into the existing mold structure by utilizing the lateral groove molding rib and the mold parting plane. This merging of functions allows air discharge to be improved without significantly increasing structural complexity, as the evacuation path shares space with existing mold components.
Data Source
AI summary
A tire vulcanization mold disclosed herein includes sectors molding a tread portion of the tire and a pair of upper and lower side plates molding a sidewall portion of the tire. Mold parting lines formed by the sectors and a pair of the upper and lower side plates are located in the tread portion. A lateral groove molding rib molding a lateral groove in the tread portion is provided to bridge from the sector to the side plate and a protrusion molding recess used to mold a protrusion at a groove bottom of the lateral groove is provided to the lateral groove molding rib. Mold parting planes including the mold parting lines are provided to divide the lateral groove molding rib where the protrusion molding recess is not provided. An evacuation path from the protrusion molding recess to the mold parting plane is provided to the lateral groove molding rib.