Tire Vulcanization Mold Vent Plug Narrow Concave Portion
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Solution Overview
Problem
The existing tire vulcanization molds with spring vents face the issue of 'biting of rubber,' where unvulcanized rubber flows into the exhaust passage of the spring vent before it becomes closed during vulcanization molding, leading to quality issues and appearance deterioration.
Innovation Solution
A tire vulcanization mold design featuring a concave portion with a narrow section that matches the outer diameter of the vent plug housing, where the vent plug is positioned, preventing unvulcanized rubber from entering the exhaust passage and ensuring the spring vent remains closed, thereby suppressing rubber flow into the exhaust passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring vent is used to discharge air during vulcanization molding, then air discharge function is improved, but rubber flows into the exhaust passage causing biting of rubber
Solution Approach 1:
The concave portion is designed with a narrow portion at its bottom that restricts rubber flow in advance. This preliminary structural constraint prevents rubber from reaching the exhaust passage before the vent plug closes, thereby solving the contradiction between air discharge function and rubber intrusion prevention
Solution Approach 2:
The narrow portion of the concave portion acts as an intermediary barrier between the rubber and the exhaust passage. It allows air to pass through while blocking rubber flow, mediating between the conflicting requirements of air discharge and rubber prevention
2Productivity
If the vent plug is positioned in a wide concave portion, then air discharge is effective, but unvulcanized rubber flows into the exhaust passage before the vent plug closes
Solution Approach 1:
The concave portion is designed with different local qualities: a wider upper portion for effective air discharge and a narrow bottom portion for rubber flow restriction. This local differentiation allows the structure to simultaneously achieve both air discharge efficiency and rubber flow control
3Reliability
If the stem is urged toward the molding surface side, then the vent plug opens for air discharge, but rubber can enter the exhaust passage before closure
Solution Approach 1:
The narrow portion of the concave portion provides preliminary anti-action against rubber flow. It creates a physical barrier that counteracts the rubber's tendency to flow into the exhaust passage, allowing the vent to remain open for air discharge without rubber intrusion
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 configuration effectively prevents rubber from entering the exhaust passage, reducing the occurrence of 'biting of rubber' and maintaining the appearance quality of the tire by ensuring the spring vent remains closed during vulcanization molding.
Implementation Method 1
an urging member for urging the stem toward a cavity side
Data Source
AI summary
The tire vulcanization mold includes a molding surface for molding a tire surface of a pneumatic tire set in a cavity, a concave portion provided on the molding surface, and a vent plug provided in the concave portion. The vent plug includes a housing having a cylindrical shape and including an exhaust passage, a stem that is inserted in the housing and configured to open and close the exhaust passage of the housing, and an urging member urging the stem toward the cavity side. The concave portion has a narrow portion having a width substantially equal to the outer diameter of the housing of the vent plug, and the vent plug is disposed in the narrow portion.