Thermoplastic Air Spring Piston Ring to Lock Bellows Beads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing air spring designs face issues with the bead of the rolling bellows slipping off the piston seat, particularly when made of thermoplastic material, and existing solutions require additional components, making mounting complex and costly.
Innovation Solution
An axially protruding, substantially cylindrical securing ring on the rolling piston is partially heated and deformed radially outward using a forming die to securely encase the bead of the rolling bellows, providing a stable and reliable anti-slip connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional retaining lugs, securing rings, or screw-fit covers are used to prevent slipping, then reliability against slipping is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent changes the physical state of the thermoplastic piston material through heating and cooling. The piston is heated to above its glass transition temperature to make it formable, then cooled to stabilize the deformed shape. This parameter change allows the piston itself to become the securing mechanism without additional components.
Solution Approach 2:
The piston serves multiple functions: it provides the securing action against the bellows bead while simultaneously being secured itself. The integrated design where the piston performs both securing and being secured eliminates the need for separate retaining components.
2Reliability
If additional securing components are added to prevent slipping, then reliability is improved, but ease of manufacture deteriorates
Solution Approach 1:
The patent merges the securing function with the piston structure itself. The piston is designed with an integrated geometry that directly engages the bellows bead, combining the piston and securing mechanism into a single component rather than separate parts.
Solution Approach 2:
The temporary modification of material properties through heating allows for simplified assembly. The heated piston can be easily deformed to secure the bellows, then cooled to lock in place, creating a simple two-step manufacturing process without complex mounting operations.
3Ease of manufacture
If the piston is made of thermoplastic material, then ease of manufacture is improved, but reliability against slipping deteriorates
Solution Approach 1:
The patent exploits the temperature-dependent properties of thermoplastic materials. Above the glass transition temperature, the material becomes soft and formable for easy manufacturing. Below this temperature, it becomes rigid and reliable for preventing slipping. The same material property change enables both ease of manufacture and reliability.
Solution Approach 2:
The patent utilizes the phase transition of the thermoplastic piston material at its glass transition temperature. The material transitions from a rigid state during normal operation to a soft, formable state during heating, allowing it to be deformed for securing purposes, then returns to rigid state upon cooling to prevent slipping.
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 ensures a simple, secure, and reliable connection between the rolling bellows and piston, enhancing the airtight seal and preventing slipping, even with thermoplastic materials, by creating a stable press fit and additional press fit with the support shoulder.
Implementation Method 1
at least partial heating of the axially protruding securing ring of the rolling piston to the plasticization temperature of the plastic material of the rolling piston
Implementation Method 2
insertion of a forming die in the securing ring of the seat of the rolling piston, wherein the forming die has at least one substantially conical region, the first small diameter of which fits in the seat of the rolling piston, and the second diameter of which is larger than the first diameter
Data Source
AI summary
The invention relates to an air spring having:a rolling bellows (1) with an opening which has a bead (2) reinforced by a core (3) anda rolling piston (4) with a seat (5) for the rolling bellows (1) and a support shoulder (7) for the rolling bellows (1),wherein when the rolling bellows (1) is in the mounted state, its end assigned to the rolling piston (4) is connected to the rolling piston (4) in an airtight manner by a clamping fit between the bead (2) and the seat (5) of the rolling piston (4), and the bead (2) of the rolling bellows (1) rests at least partly on the support shoulder (7), wherein the rolling piston (4) is made of a thermoplastic material. The object of the invention is to improve an air spring of the type outlined above such that the bellows (1) can very reliably and simply be prevented from slipping off the piston (4), in particular in view of the use of plastic as the piston material. This is achieved in that on the seat (5) for the rolling bellows (1), the rolling piston (4) has an axially protruding, substantially cylindrical securing ring (8), which protrudes axially beyond the bead (2) of the rolling bellows (1) after mounting of the rolling bellows (1) on the seat (5), can be plasticized by an at least partial heating process, and in the plasticized state can be deformed radially outwardly over the bead (2) of the rolling bellows (1) by a forming die (9, 10, 11) such that the bead (2) is at least partly surrounded by the deformed securing ring (8).