Injection-Molded Valve Core Fixing for Quiet Sealed Assemblies
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Solution Overview
Problem
Electromagnetically switchable valves face issues with the metallic core bursting the plastic sleeve due to dimensional inaccuracies and generating noise from relative movement, requiring precise manufacturing tolerances and corrosion protection.
Innovation Solution
The shut-off body is injected directly against the metallic core during the injection molding process, securing it in place and forming a sealing mechanism, eliminating the need for precise core placement and surface treatment, while ensuring an airtight and noise-free assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the metallic core is pressed into the plastic sleeve body, then the core is secured in position, but the plastic sleeve may burst open due to dimensional inaccuracies
Solution Approach 1:
The core is positioned in the sleeve body before the final injection molding step, allowing the core to be secured in advance while the injection process provides the securing force without requiring a separate press-fit operation that could damage the sleeve
2Ease of manufacture
If the core is inserted with loose tolerances, then manufacturing is easier, but the core moves relative to the sleeve causing noise
Solution Approach 1:
The injection molding process changes the physical state of the plastic material from liquid to solid, transforming it from a formable state during insertion to a rigid securing state after curing, thereby securing the core with loose tolerances without relative movement during operation
3Ease of manufacture
If the core is loosely inserted in the sleeve, then assembly is easier, but corrosion occurs due to contact with rinsing media
Solution Approach 1:
The plastic sleeve body acts as a protective shell that completely encloses the metallic core, isolating it from corrosive rinsing media while allowing easy assembly through the injection molding process that forms the sleeve around the core
4Ease of manufacture
If ventilation openings are provided in the sleeve body, then air can escape during shut-off body assembly, but the core is exposed to corrosive media
Solution Approach 1:
The core is positioned in the sleeve body with ventilation openings before injection molding, allowing air escape during shut-off body assembly, and the subsequent injection process seals these openings while maintaining core position, thereby achieving both assembly ease and corrosion protection
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 prevents sleeve damage, reduces noise, and eliminates corrosion risks, allowing for more relaxed manufacturing tolerances and quieter, more reliable operation of water-bearing household appliances like dishwashers.
Implementation Method 1
the shut-off body is then injected into an axial opening of the sleeve body in an injection molding process in such a way that it secures the core located in the sleeve body in its position relative to the sleeve body
Implementation Method 2
it is no longer necessary for the core to be pressed into a sleeve body, so that the risk of damage to the sleeve body is avoided. Nevertheless, the fact that plastic of the shut-off body is injected directly against the core during assembly means that it is held immovably in relation to the sleeve body
Implementation Method 3
The metallic core can therefore be accommodated in the sleeve body in an airtight manner in the finished valve, so that the risk of corrosion is avoided
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A valve is manufactured in such a way that at least one shut-off body (2) can be moved by a movable actuating body (4) enclosing a metallic core (3), the metallic core (3) being introduced into a sleeve body (6) containing plastic and the shut-off body (2) and/or the sleeve body (6) is injected directly against the metallic core (3), at least in some areas, thereby immovably securing it in its position in the sleeve body (6).