Vulcanization Mold Blade Layout for Smooth Tire Mold Pullout
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Solution Overview
Problem
The existing vulcanization molds face difficulties in smoothly pulling out blades during mold opening due to uneven blade density and protrusion directions, leading to increased resistance and potential mold failure, such as missing parts or damage.
Innovation Solution
The vulcanization mold is designed with a varying blade density and protrusion length in circumferential central and end portions, where the blade density and sweep area are reduced in the end portions to facilitate easier pullout by decreasing the multiplication value, ensuring smooth mold opening without failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If blade density is increased in circumferential end portions to improve sipe formation, then sipe coverage is improved, but blade pullout resistance increases and mold failure occurs
Solution Approach 1:
The patent applies local quality by differentiating blade density between circumferential regions. The circumferential central portion has higher blade density for comprehensive sipe formation, while the circumferential end portion has lower blade density to reduce pullout resistance. This localized differentiation allows each region to have optimal blade density for its specific functional requirements.
Solution Approach 2:
The mold surface is segmented into two distinct circumferential regions: a central portion and an end portion. Each segment has independently optimized blade density. The central portion (first circumferential region) contains more blades per unit length, while the end portion (second circumferential region) contains fewer blades per unit length, allowing differentiated optimization for sipe formation quality and pullout reliability.
2Ease of manufacture
If uniform blade density is used across the entire mold, then manufacturing simplicity is maintained, but pullout resistance becomes excessive in end portions causing mold failure
Solution Approach 1:
Instead of uniform blade density, the patent implements local quality by varying blade density according to circumferential position. The circumferential end portions have reduced blade density specifically to address the higher pullout resistance in these regions, while maintaining adequate sipe formation capability.
3Manufacturing precision
If blade protrusion length is increased to improve sipe depth, then sipe effectiveness is improved, but pullout resistance increases causing mold damage
Solution Approach 1:
The patent applies local quality to blade protrusion length by making the blade protrusion length in the circumferential end portion shorter than in the circumferential central portion. This localized reduction in protrusion length decreases the multiplication value and pullout resistance in end portions where diagonal pullout creates higher resistance, while maintaining adequate sipe depth in the central portion.
Data Source
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AI summary
It is an object to provide a vulcanization mold, which is a mold including blades having a distal end side thick portion and pullout is performed smoothly by the mold without causing any failure, and a pneumatic tire. A vulcanization mold 1 in which a blade 6 or 7 has a blade proximal end portion 6a or 7a, a blade distal end side thick portion 6c or 7c expanded in a thicknesswise direction on the distal end side, and a blade connection portion 6b or 7b that connects the blade proximal end portion and the blade distal end side thick portion 6c or 7c to each other is a vulcanization mold in which a blade density Dc or De that is a number of blades 6 and 7 implanted on a sector mold 3 per unit length in a circumferential direction is lower at the blades 7 in circumferential end portion side regions E than at the blades 6 in a circumferential central portion side region C of the sector mold 3. Further, a pneumatic tire 20 is manufactured using the vulcanization mold 1.