Shoulder Sipe Chamfer Layout for Tire Braking and Noise Balance

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Solution Overview

Problem

Tires with shoulder sipes face challenges in achieving improved braking performance while maintaining noise performance, as existing designs tend to compromise noise quality during braking and cornering.

Innovation Solution

The tire design incorporates a tread portion with continuous circumferential grooves and a shoulder land region featuring chamfered shoulder sipes, where the second chamfered portion has a larger volume than the first, extending from the longitudinal edge to the tread edge, enhancing braking and cornering performance while minimizing noise deterioration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If shoulder sipes are provided in the shoulder land region to improve braking performance, then braking performance is improved, but noise performance deteriorates

Engineering Contradiction:
Improvebraking performanceVSAvoidnoise performance
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by creating asymmetric chamfered portions at different locations of the shoulder sipes. The first chamfered portion (at the inner side) has a smaller volume while the second chamfered portion (at the outer side) has a larger volume. This localized differentiation allows the sipe to provide effective braking grip through controlled ground contact while suppressing noise generation by reducing air turbulence at critical locations.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the geometric parameters of the shoulder sipes by introducing chamfered portions with specific volume ratios. The second chamfered portion is designed to have 0.5 to 2.0 times the volume of the first chamfered portion. This parameter optimization enables the sipe to maintain effective ground contact for braking while controlling air flow to minimize noise, thus resolving the contradiction between braking performance and noise performance.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If chamfered portions are made larger to improve ground contact for braking, then braking performance improves, but noise generation increases

Engineering Contradiction:
Improveground contactVSAvoidnoise generation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by strategically placing chamfered portions of different volumes at specific locations of the shoulder sipes. The inner side (first chamfered portion) has a smaller volume to minimize noise, while the outer side (second chamfered portion) has a larger volume to ensure adequate ground contact. This localized differentiation resolves the contradiction by optimizing each location's function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs asymmetry by making the chamfered portions unequal in volume. The second chamfered portion is deliberately designed to be larger (0.5 to 2.0 times) than the first chamfered portion. This asymmetric configuration allows the sipe to achieve both adequate ground contact for braking and controlled air flow to minimize noise, resolving the contradiction between ground contact quality and noise generation.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP4245574B1tire
Publication Date: 2024.10.09 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4245574B1 patent drawingFigure 1
  • EP4245574B1 patent drawingFigure 2
  • EP4245574B1 patent drawingFigure 3

AI summary

A tire has a tread portion including a first shoulder land region. The first shoulder land region is provided with first shoulder sipes. Each of the first shoulder sipes is provided with a chamfered portion over an entire lengthwise range from a first longitudinal edge to a first tread edge. Each of the chamfered portions includes a first chamfered portion defined between a shoulder center position and the first longitudinal edge and a second chamfered portion defined between the shoulder center position and the first tread edge. The second chamfered portion has a chamfer volume larger than a chamfer volume of the first chamfered portion.