Mold Filling Sealing Ring Radial Expansion Dynamics
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Solution Overview
Problem
Existing devices for filling molds with foamable materials face issues with sealing ring wear due to frictional stress during the foaming process, leading to frequent interruptions and replacement, especially when exposed to steam or other heat applications.
Innovation Solution
A design where the sealing ring's radial thickness is less than the annular groove depth, with compressed air connected to the bottom of the groove, allowing the ring to radially expand and seal effectively without protruding, reducing friction and wear, and using multiple annular grooves for enhanced sealing and pressure distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sealing ring protrudes from the annular groove to ensure sealing contact, then sealing reliability is improved, but frictional wear increases and service life decreases
Solution Approach 1:
The sealing ring is designed to dynamically change its radial position based on working conditions. During foaming, compressed air pressure causes the sealing ring to radially expand and protrude from the annular groove, ensuring reliable sealing contact. During filling, the sealing ring retracts into the groove, minimizing friction. This dynamic adaptation resolves the contradiction between sealing reliability and service life.
Solution Approach 2:
The sealing ring's radial thickness is specifically designed to be less than the annular groove depth, creating a parameter relationship that enables controlled protrusion. The compressed air pressure parameter is utilized to trigger radial expansion, transforming the sealing ring from a static component to one that adaptively changes its sealing engagement based on operational phase.
2Reliability
If compressed air is continuously applied to the annular groove to maintain sealing, then sealing reliability is improved, but device complexity and air consumption increase
Solution Approach 1:
Compressed air is applied periodically rather than continuously - specifically during the foaming phase when sealing is critical. The closing working chamber serves as an intermittent compressed air source, pressurizing the annular groove only when needed. This periodic action maintains sealing reliability while avoiding unnecessary complexity and resource consumption during filling operations.
Solution Approach 2:
The closing working chamber serves dual functions: driving the closing rod and simultaneously providing compressed air to the annular groove for sealing. This self-service arrangement eliminates the need for separate control mechanisms, reducing device complexity while maintaining reliable sealing during foaming operations.
3Reliability
If the sealing ring is made thicker to improve sealing contact, then sealing reliability is improved, but frictional stress and wear increase
Solution Approach 1:
Rather than using a constantly thick sealing ring that would always contact the channel wall, the design uses a thinner ring that dynamically expands only when needed. The radial thickness being less than the groove depth enables this dynamic behavior, reducing friction during non-sealing phases while maintaining adequate sealing capability when pressurized.
Solution Approach 2:
Compressed air pressure is utilized to radially expand the sealing ring only during foaming operations. This pneumatic activation provides sufficient sealing contact quality temporarily without requiring a permanently thick sealing ring, thereby minimizing frictional stress and wear during filling and other non-sealing phases.
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 solution extends the sealing ring's lifespan by minimizing friction and wear, ensuring a reliable seal without premature degradation, and simplifies the construction by utilizing compressed air for dual functions, maintaining operational integrity during the foaming process.
Implementation Method 1
compressed air acts on the annular groove at the bottom of the annular groove. As a result, the sealing ring, which was previously located completely in the annular groove due to its radially inward bias, is radially expanded and pressed with its radially circumferential outer surface to form a seal against the inner wall of the filling channel
Implementation Method 2
the closing working chamber and the opening working chamber being pressurized alternately with compressed air to drive the movement of the drive piston
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a device for filling a mold with foamable material. It comprises a filling tube 2 arranged on the mold, which has at one end a filling channel 10 opening into the mold chamber, wherein the foamable material can be introduced into the mold chamber via the filling tube 2 and the filling channel 10.The sealing rod 16, projecting axially through the filling tube 2 and capable of being driven axially, has a sealing piston 18 at its end facing the mold, which can be inserted into the filling channel 10 to close it, and has a drive piston 11 at its end facing away from the mold, which is axially movable in a cylinder 3 and divides the cylinder interior into a closing chamber 12 and an opening chamber 13, wherein the closing chamber 12 and the opening chamber 13 can be alternately pressurized with compressed air to drive the drive piston 11. The sealing piston 18 has a radially circumferential annular groove 20 in its circumferential surface, in which an elastic sealing ring 21 is arranged, sealing an annular gap between the sealing piston 18 and the filling channel 10.