Stud Pin Recesses for Tire Retention

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Solution Overview

Problem

Studded snow tires experience frequent stud pin drop on concrete or asphalt road surfaces due to forces applied during driving, braking, or cornering, as the clawing force between the stud pin and road surface overcomes the retaining force in the tread rubber material.

Innovation Solution

A stud pin design with a tip end, buried base, and trunk portion, featuring recesses and projections on the outer peripheral surface, is embedded in the tread portion of the tire, where the buried base and trunk portion are secured by pressure from the side surfaces of the stud pin installation hole, enhancing retention within the tire.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the stud pin is tightly embedded in the tread portion to prevent pin drop, then the retention force is improved, but the complexity of the stud pin structure increases

Engineering Contradiction:
Improveretention forceVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The stud pin is divided into multiple functional segments: a tip end portion for road contact, a buried base for embedding in the tire, and a trunk portion connecting them. The buried base is further segmented into a bottom portion and side surfaces, each with specific geometric features (recesses and projections) that perform distinct functions. This segmentation allows each part to be optimized for its specific role while working together to solve the retention problem.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stud pin employs asymmetric geometry in several places: the bottom portion has a specific shape with recesses that create corresponding projections on the opposite side; the trunk portion has an asymmetric cross-section that interacts with the installation hole. These asymmetric features create mechanical interlocking that prevents rotation and enhances retention without requiring complex additional components.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If the stud pin is designed with complex geometric features to prevent rotation, then the pin drop resistance is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvepin drop resistanceVSAvoidgeometric feature precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The recesses and projections are pre-formed as integral features of the stud pin during manufacturing, rather than being created through post-assembly operations. The bottom portion is formed with recesses that automatically create corresponding projections on the opposite side, ensuring precise geometric relationships are established before the pin is installed in the tire. This preliminary formation of interlocking features simplifies the assembly process while maintaining high precision.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the stud pin has a larger buried base to improve retention, then the securing force is improved, but the volume of the stud pin increases

Engineering Contradiction:
Improvesecuring forceVSAvoidstud pin volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The buried base is designed with localized geometric features (recesses and projections) that concentrate the retention function in specific areas rather than uniformly distributing mass throughout the entire base. The recesses create mechanical interlocking zones that provide high securing force with minimal material, allowing the stud pin to achieve strong retention while maintaining a compact overall volume.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2933121B1Stud pin and pneumatic tire
Publication Date: 2019.06.19 THE YOKOHAMA RUBBER CO LTD
  • EP2933121B1 patent drawingFigure 1
  • EP2933121B1 patent drawingFigure 2
  • EP2933121B1 patent drawingFigure 3

AI summary

A stud pin configured to be installed in a stud pin installation hole in a tread portion of a pneumatic tire includes a tip end which makes contact with a road surface; and a buried base embedded in the tread portion; pressure from the side surface of the stud pin installation hole on the bottom portion and the trunk portion securing the stud pin. The buried base extends in one direction and includes a flanged trunk portion provided between the bottom portion and the tip portion. The bottom portion includes a plurality of first recesses formed on and along an outer peripheral surface thereof that is in contact with a side surface of the stud pin installation hole; and the trunk portion includes a plurality of second recesses formed on and along an outer peripheral surface thereof that is in contact with the side surface of the stud pin installation hole. The first recesses provided on the bottom portion and the second recesses provided on the trunk portion are provided at the same peripheral position as the outer peripheral surface of the buried base.