Pneumatic Tire Block Slits for Noise Reduction
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Solution Overview
Problem
Pneumatic tires with block patterns experience impact noise, columnar resonance, and air-pumping noise due to block end impacts and deformation, making it difficult to reduce pattern noise effectively while maintaining tire performance.
Innovation Solution
The tire features blocks with inclined transverse grooves and slits on the block wall surface, where the distance from the acute-angled corner to the nearest slit is greater than from the obtuse-angled corner to the nearest slit, allowing for gradual impact reduction and effective air exhaust, thereby suppressing impact noise, columnar resonance, and air-pumping noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If soft rubber is used for the blocks to reduce impact noise, then impact noise is reduced, but air-pumping noise increases due to high block deformation
Solution Approach 1:
The block is segmented by introducing slits that divide the block wall surface into multiple regions. These slits allow controlled deformation and air release, reducing both impact noise and air-pumping noise by preventing excessive block deformation while providing pathways for air escape.
Solution Approach 2:
The slits are positioned at specific locations on the block wall surface (at distances P1 and P2 from corners) to create localized deformation zones. This local quality modification allows the block to have different compliance characteristics in different regions, reducing overall impact noise while controlling air-pumping noise through strategic air release points.
2Object-affected harmful factors
If the block rubber is made too soft to reduce impact, then impact noise decreases, but uneven wear occurs and air-pumping noise increases
Solution Approach 1:
The slits segment the block structure to control deformation distribution. By creating specific deformation zones at the slits, the block can soften to reduce impact noise while maintaining structural integrity and uniform wear characteristics through controlled flexibility distribution.
Solution Approach 2:
The slit dimensions (width of 0.3 to 2.0 mm) and positioning (distances P1 and P2) are optimized to achieve the desired balance between softness for impact reduction and structural stability for uniform wear. The parameters are carefully selected to prevent excessive deformation while allowing sufficient compliance.
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 comprehensively reduces pattern noise by minimizing impact noise, columnar resonance, and air-pumping noise while maintaining tire performance and preventing uneven wear.
Implementation Method 1
the at least two slits are provided on the block wall surface facing the transverse groove... effective air exhaust, thereby suppressing impact noise, columnar resonance, and air-pumping noise
Implementation Method 2
allowing for gradual impact reduction and effective air exhaust, thereby suppressing impact noise
Implementation Method 3
a vibration at the time of the impact causes exciting the air in the circumferential groove and generates columnar resonance... suppressing impact noise, columnar resonance
Data Source
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AI summary
A pneumatic tire comprises a tread portion provided with a plurality of blocks, each of the block having a block wall surface facing a transverse groove inclined at an angle (theta) of from 5 to 40 degrees with respect to the tire axial-direction so as to define an acute-angled corner and an obtuse-angled corner on the block. The block wall surface between the acute-angled corner and the obtuse-angled corner is provided with at least two slits having a width of from 0.3 to 2.0 mm. A distance P2 measured from the acute-angled corner to one of the at least two slits which is nearest to the acute-angled corner is more than a distance P1 measured from said obtuse-angled corner to one of said at least two slits which is nearest to the obtuse-angled corner; each distance is measured along the radially outer edge of the block wall surface to the widthwise center of the slit.