Cross Joint Failure Detection for Reliable Steering Systems
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Summary
Problems
In vehicle steering systems, it is difficult to identify which component fails first, such as the cross joint and intermediate shaft, due to variations in strength, making it challenging to allow the vehicle to continue running with minimal functions after a failure occurs.
Innovation solutions
A weakened portion is formed in the joint spider of the cross joint, which can break first, allowing the vehicle to continue running for a period and facilitating easy detection of the failure, by creating a cutout or constricted area on the shaft portion, and optionally applying a quenching treatment to ensure reliable breakage and notification.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If components are made with uniform strength, then manufacturing is easier, but failure portion cannot be identified in advance
Why choose this principle:
The patent applies local quality by creating a weakened portion with different strength characteristics than the rest of the component. The weakened portion has reduced cross-sectional area or material density at specific locations, making it the predetermined failure point while the rest of the component maintains full strength for normal operation.
Principle concept:
If a weakened portion is formed in the joint spider, then the failure portion can be identified in advance, but the manufacturing complexity increases
Why choose this principle:
The patent applies preliminary action by pre-forming the weakened portion during the manufacturing process itself, rather than adding complexity through separate assembly steps. The weakened portion is integrated into the joint spider manufacturing, making the identification of failure portions predictable without significantly increasing overall device complexity.
Application Domain
Data Source
AI summary:
A weakened portion is formed in the joint spider of the cross joint, which can break first, allowing the vehicle to continue running for a period and facilitating easy detection of the failure, by creating a cutout or constricted area on the shaft portion, and optionally applying a quenching treatment to ensure reliable breakage and notification.
Abstract
In a steering system that includes: an intermediate shaft on a steering wheel side; a pinion shaft on a steered wheel side; and a cross joint by which the intermediate shaft and the pinion shaft are rotatably connected to each other on a plane intersecting with each of the shafts, and that steers steered wheels by transmitting steering torque of a steering wheel from the intermediate shaft to the pinion shaft, a weakened portion is formed in a joint spider of the cross joint. The weakened portion can be identified in advance as a portion that breaks first. This makes it possible to realize a failure mode in which a vehicle is able to run by itself for a certain period of time after a failure.