Electromagnetic Core Puller Actuation for Injection Molding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current injection molding technologies face challenges in achieving precise and fast core pull movements due to hydraulic or pneumatic drives, leading to process fluctuations and difficulties in achieving a media-tight seal and proper positioning of inserts, which can result in deformation or incomplete encapsulation of molded parts.
Innovation Solution
The use of an electromagnetic drive for core pulls allows for fast and precise movement, enabling short switching times and precise positioning of sensors close to the core puller, thereby ensuring timely removal and preventing deformation or incomplete encapsulation of inserts during the injection molding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If hydraulic or pneumatic drives are used for core pulls, then the core pulls can be actuated during injection molding, but the switching times are long and process fluctuations occur
Solution Approach 1:
The patent replaces hydraulic or pneumatic drives with an electromagnetic drive system for the core pull. This substitution enables much faster switching times (reducing from hundreds of milliseconds to milliseconds range) while providing precise control over the core pull movement, thereby improving both speed and positioning precision of inserts during injection molding.
2Loss of time
If sensors are positioned far in front of core pulls to account for long switching times, then the core pulls can be controlled, but process fluctuations lead to different core pull movements relative to melt front position
Solution Approach 1:
By replacing the slow hydraulic/pneumatic actuation with an electromagnetic drive, the patent dramatically reduces the switching time. This allows sensors to be positioned much closer to the core pulls (reducing the distance that was previously needed to compensate for delay), which in turn reduces process fluctuations and improves the consistency of core pull movement relative to the melt front position.
3Manufacturing precision
If core pulls are moved late to avoid premature movement, then inserts are not displaced, but the molding compound solidifies on the core pulls and cracks may form
Solution Approach 1:
The electromagnetic drive system enables precise temporal control of core pull movement with very fast response times. This allows the core pulls to be moved at the optimal moment - early enough to prevent molding compound solidification and crack formation, but with such precise control that premature movement and insert displacement are avoided. The fast switching capability provides the necessary temporal resolution to hit the narrow optimal window.
4Ease of operation
If hydraulic drives are used for core pulls, then the core pulls can be actuated, but media-tight seal achievement is problematic
Solution Approach 1:
The patent replaces hydraulic drives with an electromagnetic drive system that directly actuates the core pulls. This elimination of hydraulic media and transmission components removes the source of potential leaks and seal failures. The electromagnetic drive provides clean, direct actuation that maintains media-tight seals while still enabling core pull actuation during injection molding.
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 achieves precise and rapid core pull movements, ensuring a media-tight enclosure of inserts and effective venting, reducing the risk of deformation and improving the quality of injection-molded parts by allowing for shorter switching times and more accurate positioning of the core puller relative to the melt front.
Implementation Method 1
the core puller (9) is connected to an electromagnetic drive (15) in order to be able to move the core puller (9) out of the tool (1)
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to a device for injection molding a molded part (5) by means of a plastic molding compound, comprising a mold (1) connected to an injection molding machine, wherein the mold (1) comprises at least one core puller (9) and the at least one core puller (9) is connected to an electromagnetic drive (15), in order to be able to displace the at least one core puller (9) out of the cavity (3) in the mold (1) during the injection of the plastic molding compound into the cavity (3). The invention further relates to a method for injection molding a molded part (5) by means of a plastic molding compound in an injection molding machine, wherein a core puller (9) is first positioned in a region of a cavity (3) of a mold (1), the mold (1) is closed, and the plastic molding compound is injected into the cavity (3) in the mold (1). During the filling process, the core puller (9) is withdrawn from the cavity (3) in the mold (1) by means of an electromagnetic drive (15).