Ultrasound Locking Thermoplastic Steering Box Plug
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for closing orifices in casings, such as those in power steering systems, face challenges in achieving quick, cost-effective, and precise assembly of plastic plugs on metal casings, with issues related to precise positioning, locking, and potential damage during adjustment or disassembly.
Innovation Solution
A closing method involving a screwing step followed by rotational locking, where a thermoplastic plug hub is screwed into the orifice and then heated to soften and deform, forming male members within a female cavity in the casing wall, providing axial retention and rotational blocking without obstructing axial translation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If glue is used to lock the plug in rotation, then the plug can be locked firmly, but the polymerization time delays assembly and prevents immediate quality checking
Solution Approach 1:
The patent replaces the chemical bonding mechanism (glue polymerization) with a mechanical interlocking mechanism. The plug features radial locking protrusions that engage with corresponding grooves in the casing wall, providing immediate mechanical locking without requiring chemical curing time. This substitution eliminates the waiting period while maintaining reliable locking.
Solution Approach 2:
The patent changes the physical state of the plug material from rigid to softened state during assembly. The thermoplastic material is heated to become soft and deformable, allowing the locking protrusions to be formed and engaged with the casing wall. After cooling, the material hardens to maintain the locked position, providing both ease of assembly and secure locking.
2Reliability
If the plug is screwed in and then locked by crimping, then the plug can be locked firmly, but the calibration position may be disrupted and damage may occur
Solution Approach 1:
The patent performs the calibration positioning action before the locking action. The plug is first screwed to the calibrated position where the functional clearance is correct, and only then are the locking protrusions formed to secure it in place. This sequence ensures that the calibration position is established before any locking mechanism is applied, preventing disruption of the precise positioning.
Solution Approach 2:
The patent applies different properties to different parts of the plug. The main body of the plug remains rigid to maintain calibration position, while localized portions (the locking protrusions) are softened and deformed to engage with the casing wall. This localized softening allows locking without affecting the overall structural integrity and calibration accuracy of the plug.
3Productivity
If the plug material is softened and deformed to lock, then quick assembly is achieved, but the plug must be firmly locked against shocks and vibrations
Solution Approach 1:
The patent utilizes phase transition of the thermoplastic material from solid to softened state and back to solid. During assembly, the material is heated to transition to a soft, deformable state for easy molding of locking protrusions. After engagement with the casing wall, cooling transitions the material back to a hard, stable state that can resist shocks and vibrations, thus achieving both quick assembly and reliable locking.
Solution Approach 2:
The patent changes the temperature parameter of the plug material during assembly. Heating increases the material's deformability for quick shaping of locking features, while subsequent cooling restores the material's rigidity to ensure stable locking under operational conditions. This parameter change enables both rapid assembly and secure locking.
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
This method allows for rapid, cost-effective, and precise assembly of plastic plugs on metal casings, maintaining functional clearances and preventing unintended axial position changes, thus ensuring reliable operation of power steering systems.
Implementation Method 1
a portion of the plug made of thermoplastic material is heated so as to soften said thermoplastic material
Implementation Method 2
the softened thermoplastic material is forced to penetrate, then to solidify, in a female cavity
Implementation Method 3
the softened thermoplastic material is forced to penetrate, then to solidify, in a female cavity hollowed out in the wall
Data Source
Figure 1~5
Figure 6~7
Figure 8~15
AI summary
The invention relates to a method that makes it possible to plug an orifice (1) of central axis (XX') pierced in a wall (2) of a box (3), using a plug (4) having a threaded hub (5) that is screwed into the orifice (1), said method comprising a rotation locking step (b) during which the rotation of the threaded hub (5) about the central axis (XX') is blocked by heating a portion of the plug (4) which is made of thermoplastic material so as to soften said thermoplastic material, then by forcing the softened thermoplastic material to penetrate into, and then solidify in, a female cavity (10) hollowed in the wall of the orifice so as to constitute a male member (11) which fits into said female cavity, the female cavity (10) being arranged in such a way that it forms, against the action of the male member (11), a guiding end stop which on the one hand prevents the male member (11), and therefore the hub (5), from rotating about the central axis (XX'), so as to oppose any rotary screwing/unscrewing of the plug (4) and which on the other hand maintains a degree of freedom in axial translation along said central axis (XX'), of said male member (11) within said female cavity (10), so as not to impede a sliding of the hub (5) and of its screw thread (5T) along the central axis (XX'), against the wall (2).