Tire Bead Vent Line Layout to Prevent Rim Spew Jamming
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Solution Overview
Problem
The existing tire molds and production methods fail to prevent whisker-shaped spews from being jammed between the bead portions and the rim, which can lead to compromised appearance quality and internal pressure maintenance of the tire.
Innovation Solution
A tire design featuring a bead portion with a first vent line, a second vent line, a columnar protrusion, and a saw cut, along with a corresponding tire mold that includes vent line grooves, a vent hole, and a saw cut groove, is used to prevent spews from being jammed by effectively guiding air discharge during the vulcanization process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bead rings with vent holes are used, then air can be discharged during vulcanization, but whisker-shaped spews are formed and easily jammed between bead portions and the rim
Solution Approach 1:
The single vent hole is segmented into multiple vent lines (first vent line, second vent line) with distributed vent holes. This segmentation reduces the formation of large spews while maintaining effective air discharge, as the air escapes through multiple smaller pathways rather than one large opening
Solution Approach 2:
A saw cut groove is introduced as an intermediary feature between the vent lines and the bead portion. This saw cut acts as a barrier that prevents spews from extending outward and jamming on the rim, while still allowing air to pass through the vent lines during vulcanization
2Shape
If the rim surface is formed with micro irregularities to impart metallic appearance, then aesthetic quality is improved, but spews are more easily jammed between bead portions and the rim
Solution Approach 1:
The invention converts the potential harm of spew formation into a benefit by controlling spew location and shape. The saw cut groove captures spews in a controlled manner, preventing them from jamming on the rim while the vent lines maintain necessary air discharge. The micro irregularities on the rim can now be used purely for aesthetic purposes without compromising fitment
3Object-affected harmful factors
If a spew-less mold is used to prevent spew formation, then spew jamming is eliminated, but a new facility must be installed for mold cleaning
Solution Approach 1:
Instead of implementing a complex spew-less mold system requiring new cleaning facilities, the invention uses a simpler approach with vent lines and saw cut grooves that work with conventional molds. The saw cut grooves capture minimal spew material that can be removed with existing mold maintenance procedures, avoiding the need for expensive new equipment
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
The solution effectively prevents spews from being jammed on the rim while maintaining good appearance quality and internal pressure, as demonstrated by the improved ratios and configurations of the vent lines and protrusions in the tire design.
Implementation Method 1
the bead rings are provided with vent holes... A first vent line groove for forming the first vent line, a second vent line groove for forming the second vent line, and a saw cut groove for forming the saw cut are provided on the bead-forming surface
Implementation Method 2
A tire is obtained by pressurizing and heating a green tire within a mold... (2) pressurizing and heating the green tire within a mold
Data Source
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AI summary
A tire 2 includes a bead portion 2B to be fitted onto a rim R. The bead portion 2B includes a first vent line 50 extending in a circumferential direction, a second vent line 52 located outward of the first vent line 50 and extending in the circumferential direction, a columnar protrusion 54 located outward of the second vent line 52, and a saw cut 56 extending between the first vent line 50 and the columnar protrusion 54 and intersecting the second vent line 52. The first vent line 50, the second vent line 52, the columnar protrusion 54, and the saw cut 56 project from an outer surface of the bead portion 2B. The second vent line 52 is located on the columnar protrusion 54 side with respect to a midpoint LC between the first vent line 50 and the columnar protrusion 54.