Off-Road Motorcycle Tire Block Durability via Groove Recesses
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Solution Overview
Problem
Current motorcycle tires for rough terrain lack sufficient durability performance of blocks, as existing designs do not adequately alleviate stress concentration and prevent molding failures and cracks.
Innovation Solution
The tire design features multiple recess portions on the groove bottom surface between blocks, arranged axially with spaces, and a tire vulcanization mold with vent holes to prevent residual gas and improve molding quality, incorporating spews or excision marks between recess and blocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a plurality of large blocks are sparsely formed on the tread portion to provide grip on rough terrain, then traction performance is improved, but stress concentration on the block basal portions increases and durability performance deteriorates
Solution Approach 1:
The groove bottom surface is segmented into multiple recess portions arranged in the axial direction between adjacent blocks. This segmentation distributes and moderates the stress concentration that would otherwise occur at the block basal portions, thereby improving durability while maintaining the sparse block configuration needed for traction
Solution Approach 2:
Recess portions are locally formed at specific positions on the groove bottom surface between blocks. This local modification creates stress-relief zones precisely where needed at the block bases without altering the overall block structure or traction characteristics
2Reliability
If recess portions are formed on the groove bottom surface to reduce stress concentration, then durability performance is improved, but molding quality deteriorates due to residual gas and air entrapment
Solution Approach 1:
Vent holes are pre-formed in the mold at strategic locations corresponding to the recess portions. This preliminary action ensures that air and residual gas can be evacuated during vulcanization molding, preventing molding defects while the recess portions are being formed
Solution Approach 2:
The vent holes act as intermediary channels that facilitate the removal of air and residual gas from the mold cavity during molding. These channels mediate between the recess portions (which create air pockets) and the external environment, allowing controlled gas evacuation
3Reliability
If multiple recess portions are arranged in the axial direction between blocks, then stress concentration is effectively moderated and durability is improved, but device complexity increases
Solution Approach 1:
The complex stress distribution problem is solved by segmenting the groove bottom surface into multiple simple recess portions arranged axially. Each recess is a simple geometric feature, but their collective arrangement effectively moderates stress concentration across the block bases
Solution Approach 2:
Instead of making the blocks themselves more complex to distribute stress, the invention inverts the approach by modifying the groove bottom surface with simple recess features. This simpler modification achieves the stress distribution effect without complicating the block structure
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 design enhances block durability by moderating stress concentration and preventing molding failures, leading to improved traction and extended tire life.
Implementation Method 1
a spew sucked up a vent hole in a mold during vulcanization molding or its excision mark being provided between each recess portion and the block adjacent to the recess portion
Data Source
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AI summary
To provide a motorized two-wheeled vehicle tire for traveling on uneven terrain, the block durability performance of which has been improved; and a tire vulcanization mold capable of molding said tire. A motorized two-wheeled vehicle tire for traveling on uneven terrain wherein multiple blocks are provided on the tread at intervals in the tire circumference direction. Recesses are provided on the bottom surfaces of the grooves. Multiple recesses are provided at intervals in the axial direction of the tire. Spew, which was drawn up into the vent holes of the mold during vulcanization molding, or removal marks thereof are provided between each recess and the block that is adjacent in the tire circumference direction.