Tire Hooping Reinforcement Axial Spacing for Noise Reduction
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Solution Overview
Problem
Despite various attempts, passenger car tires continue to emit significant noise due to the excitation of air inside the tire cavity and vibratory behavior, particularly the flexural mode at 5th order, which contributes substantially to noise generation.
Innovation Solution
A tire design featuring a specific arrangement of hooping reinforcement with varying axial distances between neighboring portions, specifically in first and second axial regions, to modify the tire's vibratory behavior and reduce noise emission through the flexural mode at 5th order.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the axial distance between neighboring portions of hooping reinforcement is kept constant, then the manufacturing process is simple, but the tire noise emission remains high due to flexural mode at 5th order
Solution Approach 1:
The patent applies local quality by varying the axial distance between neighboring portions of hooping reinforcement in specific axial regions (first and second axial regions) while maintaining constant distance in other regions. This localized modification of the hooping reinforcement arrangement targets specific areas to reduce flexural mode vibrations and noise emission without requiring complete redesign of the entire tire structure.
Solution Approach 2:
The patent changes the parameter of axial distance between hooping reinforcement portions in specific axial regions. By modifying this geometric parameter locally (creating variations in spacing), the patent alters the vibratory behavior of the tire to reduce noise emission from flexural mode at 5th order, while maintaining overall structural integrity.
2Object-affected harmful factors
If noise absorbers are provided within the tire cavity, then noise emission is reduced, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts the noise reduction function from separate noise absorber components and integrates it into the hooping reinforcement structure itself. By modifying the axial distance between hooping reinforcement portions, the structure inherently provides noise reduction through vibration control, eliminating the need for additional noise absorber components within the tire cavity.
Solution Approach 2:
The hooping reinforcement structure performs dual functions: maintaining tire structural integrity and reducing noise emission. By varying the axial distance between portions, the hooping reinforcement itself generates the noise reduction effect through modified vibratory behavior, making the system self-sufficient without requiring separate noise control components.
3Object-affected harmful factors
If the tread pattern is adapted using variable pitch technique, then noise emission is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The patent segments the noise reduction approach by applying it to the hooping reinforcement structure rather than the tread pattern. By varying the axial distance between hooping reinforcement portions in specific axial regions, the patent creates a segmented modification that is easier to manufacture with standard precision tolerances compared to variable pitch tread patterns.
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 tire design effectively reduces noise emission by altering the axial distance between hooping reinforcement elements, resulting in lower noise levels across relevant frequency ranges.
Implementation Method 1
the vibratory behaviour of the tire varies according to frequency... Between 30 Hz and 250 Hz, the tire may be considered to be a multi-mode vibratory system as it has several natural mode shapes... the flexural mode at 5th order (i.e. the flexural mode with five anti-nodes in a meridian plane)... are important contributors to tire noise
Implementation Method 2
The effects caused by acoustic resonance of the air contained in a tire, such as the 'first cavity mode' (FCM) have been studied in detail
Data Source
AI summary
A tire comprising a hooping reinforcement, wherein the axial distance between neighboring portions of the hooping reinforcement is greater than or equal to 0.7 mm and smaller than or equal to 2 mm, with the exception of one first axial region L1 and two second axial regions L2. The axial distance of each of the axial ends of the first axial region L1 from the median plane is greater than or equal to 0.05·S and smaller than or equal to 0.15·S, S being the maximum axial width of the tire. The two regions L2 are provided on both sides of the median plane, each second axial region being centered at an axial distance D2 from the median plane, D2 being greater than or equal to 0.25·S and smaller than or equal to 0.4·S. Each second axial region L2 has an axial width W2 that is greater than or equal to 0.1·S. The sum of the axial widths of the first and second axial regions is smaller than or equal to 0.5·S. The difference between the average axial distance between neighboring portions of the hooping reinforcement in the first and second axial regions L1 and L2, and the distance outside the first and second axial regions L1 and L2 is at least 0.2 mm.