Pneumatic Tire Block Edge Deformation Control

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Solution Overview

Problem

Conventional pneumatic tires experience upward deformation of block edges on dry roads due to friction, leading to inadequate braking performance and increased rolling resistance.

Innovation Solution

The tire design incorporates shallower circumferential grooves and ribs that compress block edges, reducing deformation and enhancing braking performance, while the angle of lug grooves is set between 45° to 70° to minimize orthogonal forces, thereby suppressing upward deformation and reducing rolling resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If deep circumferential main grooves are used to ensure braking performance on wet roads, then water evacuation capability is improved, but block edges become more prone to upward deformation on dry roads

Engineering Contradiction:
Improvebraking performance on wet roadVSAvoidblock edge deformation
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The circumferential groove is segmented into two parts: a deep main groove for water evacuation and a shallower fine groove adjacent to it. The fine groove has a width of 1-3mm and depth of 2-5mm, creating a rib structure that stabilizes block edges while the main groove maintains wet road braking performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the circumferential groove have different depths and widths. The main groove is deep for water evacuation, while the fine groove is shallower to provide edge stabilization. This local differentiation allows each region to perform its specific function optimally.

Inventive Principle:
Principle #3Local quality

2Force

If high friction force is applied to blocks during braking on dry roads, then braking performance is improved, but edge portions of blocks deform upward due to friction

Engineering Contradiction:
Improvebraking forceVSAvoidblock edge shape
Core Design Contradiction:
ForceVSShape

Solution Approach 1:

The rib structure created by the fine groove is positioned adjacent to block edges before braking occurs. This pre-positioned structural support counteracts the upward deformation force that will be generated during high-friction braking, preventing shape change before it occurs.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The rib formed between the main groove and fine groove acts as an intermediary structural element. It mediates between the braking force applied to the block and the block edge, distributing stresses and preventing direct upward deformation of the edge portion.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If blocks are allowed to deform in the tire widthwise direction during cornering, then flexibility is improved, but heat generation due to inner friction increases rolling resistance

Engineering Contradiction:
Improvetire flexibility during corneringVSAvoidrolling resistance
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The rib structure is pre-formed adjacent to block edges before the tire encounters cornering forces. This preliminary structural arrangement guides block deformation along controlled paths, preventing uncontrolled widthwise movement that would generate excessive internal friction and heat.

Inventive Principle:
Principle #10Preliminary action

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

This design ensures superior braking performance on both wet and dry roads and decreases rolling resistance, contributing to lower fuel consumption by minimizing heat generation and deformation.

Implementation Method 1

these ribs work to suppress deformation of the blocks

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

edge portions of the blocks on the lug groove side are deformed upward or toward the radially inner direction

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 3

edges of the lug grooves on the trailing side the blocks effectively work in a low μ road such as a wet road surface

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

edge portions of the blocks on the lug groove side are deformed upward due to frictions between the edge portions and the road surface

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 5

heat generation due to inner friction of rubber constituting the blocks

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 6

heat generation due to inner friction of rubber constituting the blocks is reduced

Methodology Applied
Scientific EffectHeat generation: Heating

Data Source

PatentEP2213482B1Pneumatic tire
Publication Date: 2013.02.27 BRIDGESTONE CORP
  • EP2213482B1 patent drawingFigure 1(A)~1(B)
  • EP2213482B1 patent drawingFigure 2~3

AI summary

The present invention provides a pneumatic tire capable of ensuring good braking performance by making an edge effect be fully demonstrated by suppressing upward deformation of edge portions of a block. A block row constituted of plural shoulder blocks 24 is provided on the outer side in the tire widthwise direction of the center rib 16, with a circumferential fine groove 18 diposed therebetween. A block row constituted of plural shoulder blocks 32 is provided on the outer side in the tire widthwise direction of the center rib 26, with a circumferential shallow groove 28 disposed therebetween. In a case where edge portions of the blocks on the lug groove side are deformed upwardly due to frictions between the edge portions and a road surface when a relatively high force is inputted or on a dry road surface, the center rib 16 adjacent to the center blocks 24 and the shoulder rib 26 adjacent to the shoulder blocks 32 work to suppress deformation of the center blocks 24 and deformation of the shoulder blocks 32, respectively. As a result, upward deformation of the edge portions on the lug groove side, of each block, is suppressed, whereby sufficient braking performance can be demonstrated when a relatively high force is inputted or on a dry road.