Tire Spiral Cord Layer Separation Prevention
Solution Overview
Problem
The integration of a spiral cord layer and an auxiliary belt layer in tires leads to strain generation and separation issues due to the continuous nature of the reinforcing cords, which is not present in intersecting belt layers, causing potential failure.
Innovation Solution
Defining a spiral cord layer and an auxiliary belt layer with prescribed cord inclination directions, where the auxiliary belt layer's inclination direction matches or differs from the spiral cord layer's when the angle is between 54.7° and 90° or 0° and 54.7° respectively, to minimize interlayer strain and separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a spiral cord layer with continuous reinforcing cords is used, then the tire structure is simplified and manufacturing is easier, but interlayer strain and separation occur between the spiral cord layer and auxiliary belt layer
Solution Approach 1:
The patent changes the cord inclination angle parameter of the auxiliary belt layer to be equal to or greater than the cord inclination angle of the spiral cord layer. This parameter adjustment prevents the auxiliary belt layer from experiencing tensile stress during tire deformation, thereby eliminating interlayer strain and separation while maintaining the simplified spiral cord layer structure
Solution Approach 2:
Instead of trying to modify the spiral cord layer structure to prevent separation, the patent inverts the approach by adjusting the auxiliary belt layer's cord inclination angle to match or exceed the spiral cord layer's angle. This ensures that the auxiliary belt layer does not experience tensile stress, thereby preventing separation without compromising the simplified structure
2Reliability
If the auxiliary belt layer cord inclination angle is less than the spiral cord layer cord inclination angle, then the auxiliary belt layer experiences tensile stress during tire deformation, but increasing the angle may affect other tire performance parameters
Solution Approach 1:
The patent establishes a specific parameter relationship where the auxiliary belt layer cord inclination angle is equal to or greater than the spiral cord layer cord inclination angle. This parameter setting ensures that the auxiliary belt layer does not experience tensile stress during tire deformation, preventing separation while maintaining tire performance
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Provided is a technology for suppressing, in a tire including a spiral cord layer and an auxiliary belt layer, the occurrence of separation between the spiral cord layer and the auxiliary belt layer. The tire includes: a carcass 14 toroidally extending between a pair of bead portions 13; a spiral cord layer 1 arranged on an outer side in a tire radial direction of a crown portion of the carcass 14 and in which an upper layer 1A and a lower layer 1B are formed by spirally winding a reinforcing cord; and an auxiliary belt layer 17 arranged on the outer side in the tire radial direction of the spiral cord layer 1. An inclination direction of belt cords of the auxiliary belt layer and an inclination direction of the reinforcing cord of the upper layer of the spiral cord layer are the same when an angle α of the belt cords of the auxiliary belt layer with respect to the tire circumferential direction is 54.7° < α < 90°, and these inclination directions are different when the angle α of the belt cords of the auxiliary belt layer with respect to the tire circumferential direction is 0° < α < 54.7°.