Pneumatic Tire Bead Cracking via Viscoelastic Rubber Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic tires with organic fiber reinforced layers in the bead portion are prone to cracking, which affects their durability and performance.
Innovation Solution
A pneumatic tire design featuring a specific configuration with a steel cord reinforcing layer, a bead rubber layer, and an organic fiber reinforced layer, where the fiber orientation angle is between 45° to 75°, and the first reinforcing rubber layer has a complex modulus of 6 MPa to 10 MPa and elongation at break of 300% to 450%, reducing strain and suppressing cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If an organic fiber reinforced layer is provided in the bead portion, then the tire structure is strengthened, but cracks appear from the edge of the organic fiber reinforced layer
Solution Approach 1:
A bead filler layer is introduced as an intermediary component between the organic fiber reinforced layer and the bead rubber layer. This intermediate layer mediates the stress distribution, preventing direct stress concentration at the organic fiber layer edges, thereby suppressing crack initiation while maintaining the strengthening effect of the organic fiber reinforced layer
Solution Approach 2:
The patent modifies the physical and chemical parameters of the bead filler layer, including its hardness (50-90 durometer), thickness (3-15mm), and material composition (organic fibers with 20-50mm average length). These parameter changes optimize the layer's ability to distribute stress and prevent crack propagation from the organic fiber reinforced layer edges
2Duration of action of stationary object
If the bead portion structure is reinforced with multiple layers, then durability is improved, but heat dissipation becomes insufficient
Solution Approach 1:
The bead filler layer is designed with porous characteristics and specific material composition that facilitate heat dissipation. The layer's structure allows thermal energy to be conducted away from the bead portion, preventing heat accumulation while maintaining the multi-layer reinforcement structure for improved durability
Solution Approach 2:
The patent employs composite material construction with the bead filler layer containing organic fibers (20-50mm average length) embedded in a rubber matrix. This composite structure provides both mechanical reinforcement for durability and thermal pathways for heat dissipation, resolving the contradiction between durability and temperature management
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 effectively suppresses cracking from the edge of the organic fiber reinforced layer, maintaining durability and mountability on a 15° tapered rim while improving heat dissipation and reducing strain on the bead portion.
Implementation Method 1
a complex modulus of the first reinforcing rubber layer being from 6 MPa to 10 MPa, and an elongation at break of the first reinforcing rubber layer being from 300% to 450%
Data Source
AI summary
A pneumatic tire mountable on a 15° tapered specified rim includes a bead core, a carcass, a steel cord reinforcing layer, a bead rubber layer, an organic fiber reinforced layer, and a first reinforcing rubber layer. A distance from a second line segment to a third line segment is from 4 mm to 12 mm, a complex modulus of the first reinforcing rubber layer is from 6 MPa to 10 MPa, an elongation at break of the first reinforcing rubber layer is from 300% to 450%, and a difference between a first height and a second height is from 3 mm to 15 mm.