Tube Fitting Regulating Structure for Over-Tightening Prevention
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Solution Overview
Problem
Existing tube fittings in semiconductor processing systems face issues with the union nut advancing beyond the proper squeezing position, leading to distorted components and compromised seal performance due to excessive pressure, which can result in damage and defective manufacturing.
Innovation Solution
The tube fitting design incorporates multiple regulating portions that intersect the axial direction of the union nut, preventing it from advancing beyond the proper squeezing position by applying torque that alerts the user to stop screwing, thus maintaining the seal integrity and preventing distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the union nut is made to contact a single regulating portion, then the torque sharply rises to alert the worker, but the regulating portion can be distorted by excessive pressure allowing the union nut to advance beyond the proper squeezing position
Solution Approach 1:
The regulating portion is divided into multiple segments (first regulating portion and second regulating portion) arranged at different radial positions. Each segment independently contacts the union nut at different stages of tightening, distributing the load and preventing distortion of any single segment while providing staged torque feedback to the worker.
2Ease of operation
If the union nut is allowed to advance freely along the external thread, then the squeezing position can be adjusted, but the union nut may advance beyond the proper squeezing position causing distortion and damage
Solution Approach 1:
The first and second regulating portions are positioned to contact the union nut before it can advance beyond the proper squeezing position. These regulating portions create preliminary resistance that prevents the harmful action of over-tightening while still allowing free adjustment up to the correct position.
3Device complexity
If the regulating portion is made of plastic material like other components, then it integrates with the fitting body, but it cannot withstand excessive pressure without distortion
Solution Approach 1:
The regulating function is segmented into multiple portions at different radial positions rather than relying on a single robust structure. This segmentation allows each portion to be made of plastic material integrated with the fitting body while collectively providing sufficient pressure resistance through distributed contact points.
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
The design effectively prevents the union nut from over-tightening, ensuring reliable sealing and preventing damage to the fitting body, thereby maintaining high seal performance and preventing twist-off risks.
Implementation Method 1
transmits to a hand of a worker both torque sharply raised by the contact with the first regulating portion and torque sharply raised by the contact with the second regulating portion
Data Source
AI summary
A fitting body includes a tubular end whose outer periphery has an external thread and whose inner periphery has an annular groove or protrusion. A sleeve connects a tube to the tubular end of the fitting body. A union nut includes a first axial end that receives the tube therein and a second axial end to be screwed onto the external thread of the fitting body. The fitting body includes first and second regulating portions extending in directions that intersect an axial direction of the fitting body to contact the union nut being screwed onto the external thread and then sharply raise torque to be transmitted through the union nut to a hand of a worker. When being screwed onto the external thread, the union nut contacts the first regulating portion and subsequently the second regulating portion.