Tire Vulcanization Mold Vent Layout for Gas Discharge Control

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Solution Overview

Problem

Existing tire vulcanization molds face challenges in effectively discharging gas during the vulcanization process, leading to potential defects and failures due to rubber entering the gap between the spring vent's housing and stem, which impedes gas escape and can cause voids on the vulcanized tire surface.

Innovation Solution

The tire vulcanization mold incorporates a recess with a depth of 1.0 mm or less and a vent hole mounted with a spring vent, where the distance between the through hole edge and recess edge is equal to or less than the through hole diameter, ensuring the rubber is less likely to enter the gap and facilitating efficient gas discharge through the spring vent.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the recess depth is increased to improve gas discharge performance, then gas can escape more effectively, but rubber is more likely to enter the gap between the spring vent housing and stem

Engineering Contradiction:
Improvegas discharge performanceVSAvoidrubber intrusion prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent specifies precise parameter ranges: recess depth of 1.0 mm or less, and distance between through hole edge and recess edge equal to or less than the through hole diameter. These parameter optimizations balance gas discharge efficiency with prevention of rubber intrusion into the spring vent mechanism.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the distance between through hole edge and recess edge is increased to prevent rubber intrusion, then rubber entry is reduced, but gas discharge efficiency decreases

Engineering Contradiction:
Improverubber intrusion preventionVSAvoidgas discharge efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent optimizes the distance parameter between the through hole edge and recess edge to be equal to or less than the through hole diameter. This parameter setting ensures sufficient space to prevent rubber intrusion while maintaining adequate gas flow path for efficient discharge.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If a deeper recess is used to accommodate the spring vent, then the spring vent can be properly mounted, but gas flow path becomes longer and discharge performance decreases

Engineering Contradiction:
Improvespring vent mountingVSAvoidgas discharge performance
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent sets the recess depth to 1.0 mm or less, which is sufficient to accommodate the spring vent mounting requirements while minimizing the gas flow path length. This shallow recess design maintains short gas flow distance for efficient discharge while providing adequate space for spring vent installation.

Inventive Principle:
Principle #35Parameter changes

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 enhances gas discharge performance, reducing defects and improving the appearance quality of the vulcanized tire by minimizing rubber intrusion and ensuring uniform gas flow into the spring vent, thereby preventing vulcanization failures.

Implementation Method 1

The stem is inserted into the radially inner side of the housing and opens and closes the ventilation hole

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP4696490A1Tire vulcanization mold
Publication Date: 2026.02.18 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4696490A1 patent drawingFigure 1
  • EP4696490A1 patent drawingFigure 2
  • EP4696490A1 patent drawingFigure 3~4

AI summary

A tire vulcanization mold 10 includes a forming surface 22, a recess 26, a vent hole 28, and a spring vent 50. The forming surface 22 forms an outer shape of a tire. The recess 26 is formed in the forming surface 22. The recess 26 includes a bottom portion 26a. The vent hole 28 is formed in a part of the bottom portion 26a. The spring vent 50 is mounted in the vent hole 28. The spring vent 50 includes a tubular housing 51 having a through hole 52 formed therein and a stem 55 inserted into the through hole 52. A depth h of the recess 26 is 1.0 mm or less. A distance r between an edge 52a of the through hole 52 and an edge 26a1 of the bottom portion 26a is equal to or less than a diameter d of the through hole 52.