Tire Interlayer Rubber Modulus Control for Layer Separation
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Solution Overview
Problem
The integration of a spiral cord layer and an auxiliary belt layer in tires leads to strain generation and potential separation issues due to the continuous nature of the reinforcing cords, which is not a problem in intersecting belt layers, causing failure in the tire.
Innovation Solution
By defining a modulus of the rubber between the spiral cord layer and the auxiliary belt layer to a prescribed value, specifically having a 100% modulus of the interlayer rubber between 20 to 95% of the coating rubber of the auxiliary belt layer, and controlling the inclination angle of the reinforcing cords, the tire suppresses the occurrence of separation between the layers.
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 strain generation occurs between layers causing separation and failure
Solution Approach 1:
The invention changes the physical parameter of the rubber material by controlling its 100% modulus to be within a specific range (20-95% of the coating rubber's modulus). This parameter adjustment allows the interlayer rubber to deform appropriately under stress, preventing strain accumulation and layer separation while maintaining the simplified spiral cord layer structure.
Solution Approach 2:
The invention applies different material properties to different locations: the interlayer rubber at the ends of the spiral cord layer has a specifically controlled 100% modulus that differs from the coating rubber. This local quality differentiation addresses the strain concentration issue at the layer ends without compromising the overall structural simplicity.
2Reliability
If the 100% modulus of interlayer rubber is made lower than coating rubber, then layer separation is suppressed, but manufacturing precision requirements increase
Solution Approach 1:
The invention defines a specific parameter range for the 100% modulus of interlayer rubber (20-95% of coating rubber's modulus) that balances reliability improvement with manufacturing feasibility. This parameter specification provides clear manufacturing targets while achieving the goal of preventing layer separation.
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 effectively inhibits the separation between the spiral cord layer and the auxiliary belt layer, enhancing tire durability by reducing strains and preventing layer separation.
Implementation Method 1
a 100% modulus of at least a rubber other than a coating rubber of the auxiliary belt layer among rubbers interposed between the spiral cord layer and the auxiliary belt layer is lower than a 100% modulus of the coating rubber of the auxiliary belt layer
Data Source
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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. At least at ends in a tire width direction of a region where the spiral cord layer and the auxiliary belt layer are laminated, a 100% modulus of at least a rubber other than a coating rubber of the auxiliary belt layer among rubbers interposed between the spiral cord layer and the auxiliary belt layer is lower than a 100% modulus of the coating rubber of the auxiliary belt layer.