Steering Bellows Leak Detection With External Sensor End Fitting
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Solution Overview
Problem
In autonomous vehicles with cable-driven steering systems, detecting leaks in steering bellows is difficult due to the lack of a direct mechanical link, leading to rapid deterioration of the steering system if not addressed promptly.
Innovation Solution
A steering bellows design incorporating a tubular end fitting with a radial outlet and an external fluid tightness sensor, allowing for quick and easy detection of leaks through sensors like gas concentration, liquid detection, pressure, or flow sensors, with easy mounting and maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a bellows is used in autonomous vehicles with cable-driven steering systems, then the steering system can be sealed to prevent water or moisture entry, but it becomes difficult to detect leaks in the bellows due to the lack of direct mechanical link
Solution Approach 1:
A sensor is introduced as an intermediary element within the bellows structure to detect leaks. The sensor acts as a mediator between the sealed bellows interior and the external monitoring system, enabling leak detection without compromising the sealing capability. The sensor can detect changes in pressure, temperature, or other parameters that indicate a leak, thus resolving the contradiction between maintaining a sealed system and enabling leak detection.
Solution Approach 2:
The traditional mechanical link between the steering wheel and steering system is replaced with a cable-driven system in autonomous vehicles. This substitution, while enabling automation, removes the direct mechanical feedback that would otherwise indicate bellows leaks. The invention compensates for this by introducing sensors that electronically detect leaks, replacing the mechanical indication method with an electronic sensing approach.
2Difficulty of detecting and measuring
If sensors are integrated inside the bellows sleeve, then leak detection capability is improved, but the sensor mounting and maintenance becomes complex and obstructs fluid flow
Solution Approach 1:
The sensor is nested within a tubular end fitting that is attached to the radial outlet of the bellows sleeve. This nested structure allows the sensor to be positioned close to the outlet for effective leak detection while being externally mounted, thus avoiding obstruction of fluid flow inside the sleeve. The end fitting acts as a protective housing for the sensor, making it accessible for maintenance without disassembling the entire bellows structure.
Solution Approach 2:
Instead of integrating the sensor in the radial direction within the sleeve (which would obstruct flow), the sensor is positioned in the axial direction at the end fitting. This dimensional change allows the sensor to detect leaks effectively while being located outside the fluid flow path, thus avoiding obstruction and simplifying mounting and maintenance.
3Reliability
If the radial outlet is closed by a sealing piece inside the sleeve, then fluid tightness is improved, but the sensor mounting becomes difficult and maintenance is complicated
Solution Approach 1:
The bellows structure is segmented into distinct functional parts: the sleeve for fluid containment, the radial outlet for sensor access, and the external end fitting for sensor housing. This segmentation allows the sensor to be mounted on the external end fitting rather than inside the sleeve, maintaining fluid tightness through the outlet while enabling easy sensor removal and replacement for maintenance without disassembling the entire bellows.
Solution Approach 2:
The tubular end fitting serves as an intermediary structure between the radial outlet and the sensor. It provides a mounting interface for the sensor while maintaining the sealing function of the outlet. The end fitting can be easily attached or detached, facilitating sensor maintenance without compromising the fluid tightness of the bellows system.
Data Source
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AI summary
A steering bellows (1) comprising a sleeve (2) delimited by a peripheral lateral wall (3), said sleeve (2) comprising, in succession in the axial direction, at least one first annular end, referred to as the large base (4), a part (5) which can be deformed in the direction of an elongation or shortening of said bellows (1) and which is formed of a succession of coaxial turns, a second annular end referred to as the small base (6), said sleeve (2) comprising a zone (7) of transition between the deformable part (5) and the large base (4) and having, in the transition zone (7), a radial outlet (8) provided in the peripheral lateral wall (3) of the sleeve (2). The radial outlet (8) is closed by a tubular endpiece (9) that is mounted on said radial outlet (8) and that has a first end (10) connected to the radial outlet (8) and an opposite closed end (11), this endpiece (9) extending outside the sleeve (2), this endpiece (9) internally delimiting a cavity (10) housing at least one fluid-tightness sensor (13) of said bellows.