Transversal Sipe Profile for Heavy Load Tire Traction and Wear

Solution Overview

Problem

The design of tread bands for heavy load vehicle tires faces a trade-off between optimal traction, acceleration, and lateral stability on snowy or wet surfaces, which can lead to increased wear, noise, and vibrations due to excessive friction between adjacent blocks in the tread design.

Innovation Solution

A tread design featuring transversal sipes with a profile that allows for controlled embedding and opening, with a decreasing width from the outer ends to the center, ensuring adequate mutual constraint for stability and traction while minimizing friction and wear by obstructing further opening with block contact, thereby enhancing kilometric yield and reducing noise and vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If transversal sipes are designed with embedding portions to improve traction and lateral stability, then traction capability and lateral stability are improved, but wear and noise increase due to excessive friction between adjacent blocks

Engineering Contradiction:

Improvetraction capabilityVSAvoidwear

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The sipe profile varies locally along its length, with embedding portions at specific locations and non-embedding portions at others. This local differentiation allows the sipe to provide traction enhancement where needed while reducing friction and wear in other areas, resolving the contradiction between reliability and substance loss.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The transversal sipe is segmented into multiple functional zones along its length, including embedding portions for traction and non-embedding portions for wear reduction. This segmentation allows different sections to perform different functions, simultaneously achieving improved traction and reduced wear.

Inventive Principle:

Principle #1Segmentation

2Stability of the object's composition

If transversal sipes are designed with embedding portions to improve lateral stability, then lateral stability is improved, but noise and vibrations increase due to excessive friction between adjacent blocks

Engineering Contradiction:

Improvelateral stabilityVSAvoidnoise

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The sipe profile varies locally along its length, with embedding portions at specific locations and non-embedding portions at others. This local differentiation allows the sipe to provide traction enhancement where needed while reducing friction and wear in other areas, resolving the contradiction between reliability and substance loss.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The transversal sipe is segmented into multiple functional zones along its length, including embedding portions for traction and non-embedding portions for wear reduction. This segmentation allows different sections to perform different functions, simultaneously achieving improved traction and reduced wear.

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If transversal sipes have uniform width to simplify manufacturing, then ease of manufacture is improved, but traction and stability performance decrease due to inadequate block constraint

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidtraction capability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The sipe profile varies locally along its length, with embedding portions at specific locations and non-embedding portions at others. This local differentiation allows the sipe to provide traction enhancement where needed while reducing friction and wear in other areas, resolving the contradiction between reliability and substance loss.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The sipe profile is designed to be dynamic rather than static, with varying width along its length to create different functional zones. This dynamic profile allows the sipe to adapt its constraint function along its length, providing strong constraint where needed and reduced friction elsewhere, thereby improving traction capability while maintaining manufacturing feasibility.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS8616253B2Tyre for vehicle wheels

Publication Date: 2013.12.31 PIRELLI TYRE SPA

AI summary

A tire for vehicle wheels, in particular for heavy load vehicle wheels, has a tread band including an annular central portion astride an equatorial plane and two annular shoulder portions arranged on axially opposite sides with respect to the annular central portion. The annular central portion is separated from a respective annular shoulder portion by a respective circumferential groove. The annular central portion includes a plurality of blocks arranged along at least one circumferential row between two circumferential grooves and at least one transversal sipe arranged between two circumferentially consecutive blocks. The transversal sipe has a main surface oriented in a substantially radial direction and provided with at least one deformation defining, in the adjacent blocks, respective portions of mutual constraint. The deformation has an overall decreasing width from an axial end of the sipe to a central zone thereof and has a radial extension smaller than that of the aforementioned main surface.