Pneumatic Tire Chafer Design for Construction Vehicle Separation
Solution Overview
Problem
Construction vehicle tires experience separation at the steel chafer end portion due to overload, which existing technologies have not adequately addressed.
Innovation Solution
A pneumatic tire design featuring a steel chafer with an outer end portion height between 0.5 to 0.7 times the rim flange height, paired with sub-chafers made of organic fiber and a shock-absorbing rubber layer, to suppress separation at the outer end portions of all chafers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a steel chafer with outer end portion height of 0.5 to 0.7 times rim flange height is used, then separation at steel chafer end portion is suppressed, but the structure becomes more complex requiring additional sub-chafers and shock absorbing rubber
Solution Approach 1:
The chafer structure is segmented into multiple functional layers: steel chafer for primary reinforcement, organic fiber sub-chafers for secondary support, and shock absorbing rubber for impact mitigation. This segmentation allows each layer to address specific aspects of separation resistance, collectively solving the reliability problem while distributing the complexity across specialized components rather than requiring a single complex structure
Solution Approach 2:
The invention employs composite material construction by combining steel cords in the steel chafer with organic fiber cords in the sub-chafers, and integrating these with rubber materials. This composite approach leverages the high strength of steel, the flexibility and energy absorption of organic fibers, and the shock-absorbing properties of rubber, achieving superior separation resistance through material synergy rather than structural complexity alone
2Reliability
If sub-chafers made of organic fiber are added between steel chafer and rim fitting surface, then separation at outer end portions of all chafers is suppressed, but manufacturing complexity increases
Solution Approach 1:
The invention specifies precise parameter ranges for the sub-chafers, including cord diameter (0.6 to 1.8 mm), inclination angle (5 to 15 degrees relative to bead core), and disposal density (10 to 40 pieces per 5 cm). These controlled parameters standardize the manufacturing process, making the addition of sub-chafers a routine operation with defined specifications rather than a complex custom fabrication task
Solution Approach 2:
The sub-chafers act as an intermediary layer between the steel chafer and the rim fitting surface, providing a transition zone that distributes stresses and prevents direct contact between the rigid steel chafer and the rim. This intermediary function simplifies the overall design by creating a buffer zone that naturally mitigates separation forces without requiring complex attachment mechanisms
Data Source
AI summary
A pneumatic tire includes: a carcass layer wrapping a bead core and a bead filler and being turned back; a steel chafer formed by steel cords and disposed between the carcass layer and a rim fitting surface; and sub-chafers between the steel chafer and the rim fitting surface and made of organic fiber. The steel chafer includes an outer end portion outward of the bead filler in a tire lateral direction. The outer end portion has a height from 0.5 times to 0.7 times a height of a rim flange. The sub-chafers each include an outer end portion outward of the bead filler in the tire lateral direction. The outer end portion has a height from 0.7 times to 0.9 times a height of a rim flange. The carcass layer has a turned up height from 2.5 times to 4.5 times a height of a rim flange.