Winter Tire Sipe Structure for Ice Grip, Durability, and Noise

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Solution Overview

Problem

Tires with sipes for winter use face challenges in maintaining on-ice performance, load durability, and noise reduction due to sipe deformation and crack formation under ground load, especially with the advent of hybrid and electric vehicles that reduce overall vehicle noise.

Innovation Solution

A tire design featuring zigzag-shaped sipes with tie-bars that divide into widening portions, maintaining block rigidity and dispersing strain, combined with non-communicating circular widening sections to enhance rigidity, reduce deformation, and inhibit noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sipes are provided in the tread portion to improve on-ice performance, then ice grip is enhanced, but strain concentrates on the sipe bottoms causing cracks and reduced load durability

Engineering Contradiction:
Improveon-ice performanceVSAvoidload durability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The sipe is divided into multiple sections by tie-bars that extend from the sipe bottom toward the ground contact surface. These tie-bars segment the continuous sipe into upper and lower portions, allowing the sipe to maintain flexibility for ice grip while the tie-bars provide structural reinforcement to prevent cracking under load.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Tie-bars are pre-positioned within the sipe structure before the tire contacts the ground. These tie-bars are embedded in the rubber matrix at strategic locations to preemptively reinforce areas prone to strain concentration, preventing crack formation before it occurs during normal operation.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If sipes are provided in the tread portion to improve on-ice performance, then ice grip is enhanced, but noise is generated during vehicle operation

Engineering Contradiction:
Improveon-ice performanceVSAvoidnoise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The sipe structure is segmented by tie-bars into multiple discrete sections. This segmentation disrupts the continuous air path that would otherwise allow noise-generating air currents to flow through the sipe, thereby reducing noise while preserving the sipe's ability to conform to ice surfaces for improved grip.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4375087B1tire
Publication Date: 2025.07.23 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4375087B1 patent drawingFigure 1
  • EP4375087B1 patent drawingFigure 2
  • EP4375087B1 patent drawingFigure 3

AI summary

A tire includes first blocks with zigzag first sipes. Each first sipe includes a tie-bar locally raising radially outwardly from the sipe bottom to divide the first sipe into first and second portions. The sipe bottoms of the first and second portions extend in a zigzag shape in a cross-section parallel to the ground contact surface. The sipe bottom of the first portion communicates with a first widening portion having a circular cross-sectional shape with a groove width greater than a width of the first portion and extending in a zigzag shape along the first portion. The sipe bottom of the second portion communicates with a second widening portion having a circular cross-sectional shape with a groove width greater than a width of the second portion and extending in a zigzag shape along the second portion. The first and second widening portions do not communicate with each other.