Pneumatic Tire Stone Ejection Projection Design
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Solution Overview
Problem
Existing pneumatic tire designs with triangular prism-shaped projections for stone sticking suppression face difficulties in ejecting small stones due to uneven deformation, leading to potential damage from stuck stones.
Innovation Solution
A pneumatic tire with a trapezoid-shaped stone-sticking prevention projection featuring a low-step and high-step portion, where the low-step portion includes inclined surfaces along the groove side surfaces, allowing for differential movement and ejection of small stones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a triangular prism-shaped projection is used, then the projection can prevent small stones from entering the groove, but the uneven deformation causes the projection to swing and small stones to remain stuck
Solution Approach 1:
The projection is divided into multiple segments: a first projection and a second projection with different cross-sectional shapes. The first projection has a triangular cross-section for preventing stone entry, while the second projection has a trapezoidal cross-section for enabling stone ejection through differential deformation. This segmentation allows each projection to specialize in one function, resolving the contradiction between stone prevention and stone ejection.
Solution Approach 2:
Different parts of the projection structure are given different geometric properties. The first projection maintains a triangular cross-section with higher rigidity for stable stone blocking, while the second projection uses a trapezoidal cross-section with asymmetric rigidity distribution (higher on one side, lower on the other) to enable controlled deformation and stone ejection. This local differentiation of geometric quality allows simultaneous optimization of both stone prevention and ejection functions.
2Strength
If the projection has high rigidity to maintain shape, then stone prevention is effective, but the projection cannot deform to eject stuck stones
Solution Approach 1:
The projection structure incorporates local quality variations through different cross-sectional geometries. The first projection uses a triangular cross-section providing high overall rigidity for stable stone blocking, while the second projection employs a trapezoidal cross-section with asymmetric leg lengths, creating localized rigidity differences that enable controlled deformation for stone ejection while maintaining sufficient structural strength.
Solution Approach 2:
The projection system is segmented into multiple independent projection elements with different rigidity characteristics. This allows the system to exhibit both high rigidity (when both projections are engaged) and controlled deformation (when the more compliant second projection deforms), resolving the contradiction between maintaining shape for prevention and deforming for ejection.
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
The design effectively reduces the likelihood of small stones getting stuck and enables rapid ejection, minimizing damage to the tire by adjusting the rigidity and deformation of the projection.
Implementation Method 1
the low-step portion includes a first-side inclined surface inclined along a first groove side surface of the groove in a depth direction of the groove and a second-side inclined surface inclined along a second groove side surface of the groove in the depth direction of the groove
Implementation Method 2
the rigidity on the top side in the triangle is lower than the rigidity on the bottom side of the triangle. Accordingly, in the case where small stones enter the groove and press the upper part of the projection, the deformation amount on the top side of this projection is relatively large
Data Source
AI summary
The present invention provides a pneumatic tire including: a groove formed in a tread, the groove having a groove bottom and groove side surfaces arising from the groove bottom; and a projection projecting from the groove bottom, wherein the projection includes a low-step portion located at a low position with reference to the groove bottom and a high-step portion located at a high position with reference to the groove bottom, the low-step portion has a first-side inclined surface inclined in a depth direction of the groove along a first groove side surface of the groove and a second-side inclined surface inclined in the depth direction of the groove along a second groove side surface of the groove, and the first-side inclined surface and the second-side inclined surface are inclined in different directions from each other.