Magnetic Ejector Rods for Injection Molding Die Exchange
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Solution Overview
Problem
The existing ejector devices in injection molding machines require significant time and cost to exchange ejector pins due to complex and labor-intensive processes, especially when switching between different die configurations, which can lead to operational burdens and potential damage to the ejector plate.
Innovation Solution
The implementation of a magnetic rod fixing system that allows for the detachable and removable attachment of ejector rods to the ejector plate using magnetic forces, simplifying the process of exchanging ejector rods by allowing for easy installation and removal based on the new die configuration without the need to replace entire rods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ejector pins are made as single continuous integral type pins with base end portions fixed to the ejector plate, then the structural strength and reliability are improved, but the burden and time required for exchanging ejector pins become heavy and great
Solution Approach 1:
The ejector pin is divided into two separate parts: a base end side ejector pin fixed to the ejector plate and a tip end side ejector pin that passes through the die. This segmentation allows the tip end side pin to be exchanged independently without removing the base end side pin, significantly reducing exchange time and burden while maintaining the structural integrity of the fixed portion.
Solution Approach 2:
The tip end side ejector pin is extracted as a separate removable component from the overall ejector pin assembly. This extracted portion can be easily removed and replaced from the die side without affecting the base end portion fixed to the ejector plate, solving the contradiction between structural strength and exchange efficiency.
2Ease of manufacture
If ejector pins are made as single continuous integral type pins, then the manufacturing simplicity is improved, but the cost and burden of exchanging them become great
Solution Approach 1:
The ejector pin system is segmented into a permanent base end portion and removable tip end portions. The base end side ejector pin remains as a simple integral structure easy to manufacture, while the tip end side ejector pins can be exchanged to adapt to different die configurations, achieving both manufacturing simplicity and exchange flexibility.
Solution Approach 2:
The base end side ejector pin serves as a universal fixed component that supports multiple different tip end side ejector pins. This multi-functionality allows the same base structure to work with various pin configurations depending on the die being used, improving adaptability without complicating the manufacturing of the base portion.
3Reliability
If the tip end side ejector pin is allowed to shift in directions orthogonal to the axis to prevent operational faults due to thermal expansion, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The tip end side ejector pin is designed with dynamic freedom to shift in directions orthogonal to its axis within the die cavity. This dynamic capability allows the pin to accommodate thermal expansion and positioning variations without requiring complex mechanical constraints, improving reliability while maintaining relatively simple construction.
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 solution significantly reduces the burden and cost of exchanging ejector rods by enabling simple and efficient installation and removal of necessary rods, minimizing operational faults and reducing the load on the ejector drive mechanism.
Implementation Method 1
a plurality of magnetic rod fixing means that generate magnetism for removably fixing some or all of the ejector rods to the ejector plate
Data Source
AI summary
A burden of exchanging ejector rods is reduced in an injection molding machine when exchanging rods during exchange of a die. A plurality of rod insertion holes are formed so as to pierce through a movable platen. A plurality of ejector rods are inserted into rod insertion holes so as to slide freely therein. An ejector plate is disposed at the rear side of the movable platen. In a plurality of the ejector rods, a plurality of base rods are inserted into rod insertion holes so as to slide freely therein. Their base end portions are fixed to the ejector plate. Detachable rods are removably stuck with magnetism to the base rods by first and second magnets.