Studless Tire Micro Sipe Layout for Ice Grip and Rigidity

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Solution Overview

Problem

Existing pneumatic tires, particularly studless tires, face a challenge in balancing the rigidity of the land portion with the discharge of water by sipes, which limits the improvement of on-ice gripping performance.

Innovation Solution

A pneumatic tire design featuring land portions with inclined width direction edges and micro sipes, where the micro sipes have first and second elements with specific orientations and dimensions, and combined with long sipes, to enhance drainage and maintain rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If sipes are arranged at high density to improve water discharge, then on-ice gripping performance is improved, but the rigidity of the land portion decreases

Engineering Contradiction:
Improvewater discharge capabilityVSAvoidrigidity of land portion
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The sipes are divided into multiple elements (first element, second element, third element) with different orientations and lengths. This segmentation allows each element to serve specific functions: the first element provides water discharge capability, while the second and third elements with shorter lengths and different orientations help maintain land portion rigidity, thus resolving the contradiction between water discharge and rigidity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the sipe structure are given different properties. The first element extends in the tire circumferential direction for effective water discharge, while the second and third elements have shorter extensions in different directions to maintain structural rigidity. This local differentiation allows the sipe to simultaneously achieve water discharge functionality and structural strength.

Inventive Principle:
Principle #3Local quality

2Reliability

If sipes are arranged at high density to enhance on-ice gripping, then water discharge is improved, but the structure becomes more complex

Engineering Contradiction:
Improveon-ice gripping performanceVSAvoidsipe structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sipe structure is segmented into multiple elements with specific orientations and length ratios. This segmentation enables the sipe to achieve complex water discharge patterns and rigidity maintenance functions through a structured yet manageable design, balancing functionality with manufacturing feasibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sipe structure combines multiple elements with different geometric properties (different lengths, orientations, and positions) to create a composite sipe structure that achieves enhanced on-ice gripping performance while maintaining a level of complexity that is manageable for manufacturing and design purposes.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP4699820A1Pneumatic tire
Publication Date: 2026.02.25 BRIDGESTONE CORP
  • EP4699820A1 patent drawingFigure 1
  • EP4699820A1 patent drawingFigure 2~3
  • EP4699820A1 patent drawingFigure 4

AI summary

A pneumatic tire has at least one land portion on a tread surface. The land portion has a width direction edge extending inclined with respect to a tire width direction. A plurality of micro sipes are disposed in at least one of the land portions. The micro sipes each have a first element and a second element. The first element extends in the same direction as the width direction edge closest to the first element. The second element extends from one end of the first element in a direction different from the first element. An extension length of the second element is shorter than an extension length of the first element. The other end of the first element terminates within the land portion, one end of the second element communicates with the one end of the first element, and the other end of the second element terminates within the land portion.