Civil Engineering Tyre Crown Reinforcement for Impact Resistance
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Solution Overview
Problem
Heavy vehicle radial tires face challenges in impact resistance and fatigue cracking due to aggressive road conditions, which current reinforcement structures and tread patterns are insufficient to address effectively.
Innovation Solution
The tire design incorporates a crown reinforcement structure with a protective layer of elastic metal cables, a working reinforcement of non-elastic metal layers, and an additional reinforcement layer positioned between the carcass and working reinforcement, featuring a tread pattern with deep circumferential grooves and numerous oblique or transverse grooves to enhance shock resistance and bending rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the crown reinforcement uses non-elastic metal reinforcements with small angles to the circumferential direction, then the tire gains rigidity and strength to withstand rolling stresses, but the tire becomes more susceptible to impact shocks and fatigue cracking from aggressive road conditions
Solution Approach 1:
The crown reinforcement combines two types of metal reinforcements with different elastic properties: non-elastic metal reinforcements (angles ≤60°) provide rigidity for rolling stresses, while elastic metal reinforcements (angles ≥10°) provide flexibility to absorb impact shocks. This composite reinforcement structure resolves the contradiction by integrating materials with complementary mechanical properties.
Solution Approach 2:
The patent applies different reinforcement characteristics to different regions and layers of the crown reinforcement. The non-elastic reinforcements are positioned to handle primary rolling loads, while elastic reinforcements are positioned to specifically address impact zones. This local differentiation of material properties optimizes both strength and reliability in their respective functional zones.
2Reliability
If the tread pattern includes deep circumferential grooves and numerous oblique or transverse grooves, then the tire improves shock resistance and bending rigidity, but the structural complexity of the reinforcement system increases
Solution Approach 1:
The crown reinforcement is divided into distinct segments: at least two working layers with non-elastic reinforcements, at least one protective layer with elastic reinforcements, and an additional reinforcement layer. This segmentation allows each layer to perform its specific function (rolling stress resistance, impact absorption, or enhanced rigidity) without requiring the entire structure to be overly complex.
Solution Approach 2:
The patent optimizes specific parameters to balance performance and complexity: the additional reinforcement layer's axial width is limited to at most 0.9 times the smallest axial width of the working layers, and its reinforcement angle is constrained to at most 25°. These parameter controls prevent excessive complexity while achieving the desired shock resistance and bending rigidity.
3Stability of the object's composition
If the additional reinforcement layer has limited axial width (at most 0.9 times the working layers), then the tire maintains better flexibility and reduces thermal stress, but the coverage area for protecting against aggressive road conditions decreases
Solution Approach 1:
The patent sets the axial width of the additional reinforcement layer to at most 0.9 times the smallest axial width of the working layers, creating an optimized balance. This parameter control ensures the additional layer provides sufficient protective coverage while maintaining flexibility and preventing excessive thermal stress accumulation that would occur with a wider, more extensive reinforcement layer.
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 configuration reduces thermal stress, increases shock resistance, and improves the tire's ability to withstand aggressive road conditions without compromising mechanical linkages, thereby reducing the risk of material tearing and fatigue cracking.
Implementation Method 1
a protective layer comprising elastic metal reinforcements forming, with the circumferential direction, an angle at least equal to 10°
Implementation Method 2
a working reinforcement comprising at least two working layers respectively having an axial width and comprising reinforcements of non-elastic metals
Data Source
Figure 1~2
AI summary
Tyre (1) for a heavy vehicle of civil engineering type comprising a crown part extended on either side by sidewalls (3), the sidewalls and the beads, this crown part comprising a tread (2) and a crown reinforcement, the latter being situated radially between the tread (2) and a carcass reinforcement (4), the crown reinforcement comprising a protective reinforcement (6), a working reinforcement (5) and an additional reinforcement (7), the protective reinforcement (6) comprising at least one protective layer (61, 62) comprising elastic metallic reinforcers which, with the circumferential direction, form an angle at least equal to 10°, the working reinforcement (5) comprising at least two working layers (51, 52) comprising metal reinforcers which are crossed from one working layer to the next and, with the circumferential direction, form an angle at most equal to 60°, the additional reinforcement (7), centred axially on the equatorial mid plane of the tyre, comprising at least one layer (71, 72) having an axial width at most equal to 0.9 times the shortest of the axial widths of the at least two working layers (51, 52) and comprising metal reinforcers which, with the circumferential direction, form an angle at most equal to 25°, the tread (2) being provided with a tread block pattern that comprises at least two circumferentially oriented grooves (10), this tyre being such that the mean axial distance between the two grooves (10) closest to the equatorial mid plane is greater than the maximum axial width of the additional reinforcement (7) measured between the ends of the layers of this additional reinforcement that are axially furthest from the equatorial mid plane.