Pneumatic Tire Tread Sipes With Harmonic Waves Against Stone Trapping
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Solution Overview
Problem
Pneumatic vehicle tires with incisions in the tread face a significant risk of stone trapping when driving on roads with grit, leading to irregular wear, impaired drainage, and vibrations due to stones getting stuck in the cuts, which compromises tire performance and safety.
Innovation Solution
The design features central incision sections that run in the form of a harmonic wave with an offset between the wave center line and the incision base line, reducing the ability of incisions to open and trap stones, with straight sections of 0.5 mm to 0.9 mm length, and an offset of 100% to 300% of the amplitude, minimizing the risk of stone trapping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If incisions are provided in the tread to improve grip on wet surfaces, snow, and ice, then grip performance is improved, but the risk of stone trapping increases
Solution Approach 1:
The incision features a wave-shaped central section with curved geometry instead of straight lines. This curvature causes stones to roll off the incision edges rather than becoming trapped, while the wave shape maintains effective cut edges for grip performance on snow and ice.
Solution Approach 2:
The incision design combines straight edge sections with a wave-shaped central section, creating an asymmetric profile. The straight edges provide stable anchoring while the wave center creates rolling motion for stone ejection, resolving the contradiction between grip effectiveness and stone trapping prevention.
2Ease of operation
If wave-shaped cuts are used to reduce transverse stiffness and improve handling, then handling characteristics are improved, but the complexity of incision geometry increases
Solution Approach 1:
The incision is divided into three distinct segments: straight edge sections and a wave-shaped central section. This segmentation allows each part to fulfill its specific function while maintaining overall manufacturability through standardized molding processes for winter tires.
Data Source
Figure 1~1a
Figure 2~3
AI summary
The invention relates to a pneumatic tyre for a vehicle having a tread with profile positives (1, 1', 1") with cuts (3, 3', 3"), which run in plan view parallel to one another and at an angle to the axial direction of 0° to 50°, a width (b1) from 0.4 mm to 0.8 mm, a central cut section (3a) running in plan view in the form of a harmonic wave with a wave centre line (Iw) corresponding to the propagation direction of the wave and two edge cut sections (3b), the course of which defines a cut base line (IEB) running parallel to the wave centre line (Iw), wherein the wave centre line (Iw) of the central cut portion (3a) runs parallel and offset to the cut base line (IEB) of the cut (3) and the offset (a1) is 75% - 400% of the amplitude (A) of the harmonic wave of the central cut portion (3a).