Ball Plunger Retaining Unit for Compact Two-Stage Ejection
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Solution Overview
Problem
Conventional two-stage ejection mechanisms in injection molding dies require two ejector plates, making it difficult to reduce the size of the mechanism, and existing retaining mechanisms lack simplicity in assembly and versatility.
Innovation Solution
A retaining unit with a recess for a pressing element that allows adjustable pressing force and detachable assembly, using a ball plunger to connect the ejector pin with the ejector plate, enabling compact and versatile ejection mechanisms with a single ejector plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a conventional two-stage ejection mechanism with two ejector plates is used, then the ejection function is achieved, but the size of the mechanism cannot be reduced
Solution Approach 1:
The patent merges the functions of two ejector plates into a single ejector plate by using a detachable ejection mechanism where the first ejection mechanism can be attached to and detached from the second ejection mechanism on the same plate, eliminating the need for a second ejector plate while maintaining two-stage ejection capability
Solution Approach 2:
The ejection mechanism is segmented into detachable components where the first ejection mechanism can be independently attached or detached from the second ejection mechanism, allowing flexible configuration and reducing the overall structure to a single ejector plate
2Adaptability or versatility
If a magnetic force-based retaining mechanism is used, then the structure is simplified, but the magnetic force cannot be changed and requires preparation for respective dies
Solution Approach 1:
The patent replaces the fixed magnetic force mechanism with a mechanical pressing element whose pressing force can be adjusted by changing parameters such as spring pre-load or pressing element configuration, allowing the same mechanism to adapt to different dies without reparation work
Solution Approach 2:
The retaining mechanism is designed with an adjustable pressing element that can accommodate different retention requirements across various dies, making it a universal mechanism that does not require die-specific preparation while maintaining adaptability
3Adaptability or versatility
If a retaining mechanism with fixed pressing force is used, then the structure is simple, but it lacks versatility for different dies
Solution Approach 1:
The retaining mechanism incorporates a dynamic pressing element with adjustable pressing force, transforming a static fixed-force mechanism into a dynamic adjustable one, enabling versatility for different dies while adding controlled complexity only where needed for adjustment
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 retaining unit facilitates easy assembly and high usability, allowing for compact and versatile ejection mechanisms in molding die assemblies, enabling efficient two-stage ejection without the need for multiple ejector plates, while maintaining independent movement of the ejector pin and plate.
Implementation Method 1
a ball plunger (pressing element) which presses the ejector pin
Data Source
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AI summary
Provided is a retaining unit that can be easily assembled with a die and has high versatility. Further, provided are a retaining unit that can be compactly assembled with a die, an ejection mechanism of a molding die assembly including the retaining unit, a fixed-side die, a movable-side die, a molding die assembly, and a molded article. The retaining unit includes a movable ejector pin 10, a ring-shaped member 11 used while being fixed in an unmovable state, and a ball plunger 12 attached to the ring-shaped member 11, and configured to press the ejector pin 10 and engage the ejector pin 10 with the ring-shaped member 11, wherein, when a force at a predetermined level or higher is applied in the movement direction of the ejector pin 10, the engagement with the ring-shaped member 11 is released so that the ejector pin 10 is allowed to move, and the ball plunger 12 is assembled with the ring-shaped member 11 so as to be unitized together.