Zigzag Circumferential Groove Tread for Mud and Noise Trade-off
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pneumatic tires for four-wheel-drive vehicles face a trade-off between improving mud performance, noise performance, and steering stability, as increasing the grooved area to enhance mud performance typically deteriorates noise and steering stability.
Innovation Solution
A tread pattern featuring zigzag circumferential grooves with alternating inner and outer segments, connected by oblique segments, and a specific number and width of axial grooves to maximize shearing force while maintaining a balanced ground pressure distribution, thereby improving mud performance without compromising noise and steering stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the percentage of the grooved area is increased to improve mud performance, then mud performance is improved, but noise performance deteriorates
Solution Approach 1:
The patent applies local quality by making the circumferential groove width variable rather than uniform. The groove width is larger at the tire center and smaller at the shoulders, optimizing mud ejection where needed while reducing noise and maintaining stability at the edges. This localized variation resolves the contradiction between mud performance and noise performance.
Solution Approach 2:
The patent changes the parameter of groove width along the circumferential direction, transitioning from a constant width to a variable width that tapers toward the shoulders. This parameter change allows the groove to perform multiple functions: effective mud ejection at the center and noise reduction at the shoulders, thereby resolving the technical contradiction.
2Reliability
If the percentage of the grooved area is increased to improve mud performance, then mud performance is improved, but steering stability deteriorates
Solution Approach 1:
The patent applies local quality by concentrating the grooved area at the tire center where mud ejection is most needed, while reducing groove width at the shoulders where stability is critical. This localized distribution improves mud performance without sacrificing steering stability.
Solution Approach 2:
The patent changes the groove width parameter along the tread width, creating a gradient from center to shoulder. This parameter variation optimizes the balance between mud performance (requiring larger grooved area) and steering stability (requiring smaller grooved area at shoulders).
3Reliability
If the width of axial grooves is increased to improve mud performance, then mud performance is improved, but block rigidity decreases
Solution Approach 1:
The patent extracts the primary mud ejection function from the axial grooves and assigns it to the circumferential groove. The axial grooves are reduced to minimal width, serving only to guide mud into the circumferential groove, thereby maintaining block rigidity while preserving mud performance.
Solution Approach 2:
The patent changes the width parameter of axial grooves from conventional large width to minimal width, fundamentally altering their function. This parameter change allows the blocks to maintain rigidity while the circumferential groove handles the primary mud ejection task.
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 described tread pattern enhances mud traction by ensuring efficient mud self-ejection and penetration, while maintaining low noise levels and stable steering through optimized groove configurations and ground pressure distribution.
Implementation Method 1
the mud within the groove is hard to slide in the groove and a shearing force from the mud on the road surface occurs to produce traction. As to the self-ejection of mud, the circumferential groove is superior to the axial grooves
Implementation Method 2
a shearing force from the mud on the road surface occurs to produce traction
Data Source
AI summary
A pneumatic tire is provided in the tread portion with zigzag circumferential grooves and axial grooves so that a row of circumferentially arranged blocks is formed on each side of each of the zigzag circumferential grooves. Each of the zigzag circumferential grooves is composed of axially inner and outer circumferential segments and oblique segments. The axially inner and outer circumferential segments are arranged alternately in the tire circumferential direction. The oblique segments connect between the axially inner and outer circumferential segments, whereby the zigzag circumferential groove extends in the form of a trapezoidal wave. The zigzag amplitude is in a range of from 4 to 15% of a half tread width (Tw/2). The width of the zigzag circumferential groove is in a range of from 7 to 13% of the half tread width (Tw/2). The number of the axial grooves connected to each of the zigzag circumferential grooves on both side thereof is in a range of from 8 to 12 when counted in a tire footprint. The axial grooves each have a groove width WY of from 8 to 25% of a pitch length Py between the axial groove and the circumferentially adjacent axial groove.