Plastic Screw Connection With Integrated Locking Against Loosening
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Solution Overview
Problem
Existing screw connections require high tightening torque for sealing and are prone to unintentional loosening due to material relaxation, with complex manufacturing processes and material deformation issues, leading to potential breakage and inefficiencies.
Innovation Solution
A screw connection design featuring a monolithically integrated locking element and contour that engages positively to prevent rotation against the assembly direction, allowing for lower tightening torque while ensuring sealing and preventing loosening, with optional elastic elements for deformation compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high tightening torque is applied to ensure sealing and prevent loosening, then sealing reliability is improved, but the risk of screw component breakage increases due to weak points like sealing grooves
Solution Approach 1:
The patent segments the functions of sealing and anti-loosening into two independent mechanisms: a sealing groove for sealing and a locking element with locking contour for preventing loosening. This allows each function to be optimized independently, so that high torque is not needed for sealing, thus preventing breakage at weak points.
Solution Approach 2:
The locking element acts as an intermediary mechanism that prevents loosening through positive engagement with the locking contour, independent of the tightening torque. This mediator allows the connection to maintain its position without relying on high friction forces that could cause breakage.
2Strength
If the cross-section of the screw component is enlarged to increase resistance to torque, then strength is improved, but the size of the screw component increases
Solution Approach 1:
The patent separates the anti-loosening function from the main screw body by introducing a distinct locking element. This segmentation allows the screw component to maintain its original size while gaining enhanced torque resistance through the locking mechanism, rather than enlarging the entire component.
Solution Approach 2:
The locking element provides localized reinforcement at the critical anti-loosening function without requiring a general enlargement of the screw component. The local quality enhancement is achieved through the locking element's engagement with the locking contour, providing torque resistance only where needed.
3Strength
If multiple sprues are used in injection molding to achieve high strength, then screw part strength is improved, but material loss increases
Solution Approach 1:
The patent changes the manufacturing parameter from using multiple sprues to using a single sprue with optimized injection molding parameters. The locking element is integrated into the screw part design, allowing it to be molded with the base body using the same sprue, thus reducing material loss while maintaining strength.
4Reliability
If the locking element and locking contour are designed for positive engagement to prevent rotation, then anti-loosening capability is improved, but the complexity of the screw connection increases
Solution Approach 1:
The patent merges the locking element with the screw part base body through monolithic formation, and integrates the locking contour with the mating connector. This combining of functions into existing components avoids adding separate complex anti-loosening devices, thus maintaining simplicity while achieving reliable anti-loosening capability.
Data Source
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AI summary
The present invention relates to a screw connection (1) comprising a screw part (2) with an annular cross-section, in particular a hollow screw or a nut, which has a hollow cylindrical base body injection-molded from a plasticized polymeric mass. The base body has at least one internal channel (4) for arranging and/or passing through a piping system element and an internal thread and/or an external thread (6) for screwing onto a mating connector (8), wherein the screw part (2) can be screwed onto the mating connector (8) when rotated in an assembly direction (R) in an assembly direction (M).At least one locking element is monolithically integrally formed on the screw part (2), and a locking contour is formed in and against the assembly direction (R) as well as in the assembly direction (M) in an end position of the screw part (2) on the mating connector (8) and at least in the end position a rotation of the screw part (2) against the assembly direction (R) is blocked by a positive engagement of the locking element in the locking contour.