Injection Molding Ejector Control for Mold Damage Prevention
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Solution Overview
Problem
Injection molding machines face issues with mold damage and magnetic clamping failures due to mismatched ejector rod configurations and incorrect setting of advancing stroke values, leading to potential mold separation and damage during mold changes.
Innovation Solution
An injection molding machine with first and second determining means to assess mold changes and stroke setting changes, using position detection to adjust the ejecting force and velocity to a protective level until the correct forward end position is confirmed, ensuring safe ejection and preventing mold damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the ejector rod configuration is changed to match different mold structures, then the adaptability of the injection molding machine is improved, but the risk of mold damage increases if the configuration does not match
Solution Approach 1:
The control unit receives feedback signals from detection units that monitor the actual position of the ejector rod distal end. This feedback mechanism allows the system to detect whether the ejector rod has reached the predetermined position, and to adjust or stop the ejection operation accordingly, preventing mold damage from mismatched configurations
Solution Approach 2:
A detection unit acts as an intermediary between the ejector rod and the control system. This intermediary detects the position of the ejector rod distal end and transmits information to the control unit, enabling safe operation with different mold configurations without direct mechanical contact that could cause damage
2Productivity
If the advancing stroke of the ejector rod is increased to ensure complete ejection, then the ejection effectiveness is improved, but the mold or ejector may be damaged if the stroke exceeds the permissible range
Solution Approach 1:
The control unit is pre-programmed with predetermined positions for the distal end of the ejector rod. Before executing the ejection stroke, the system references these predetermined positions to limit the maximum advancement, ensuring complete ejection while preventing excessive stroke that could cause damage
Solution Approach 2:
The detection unit continuously monitors the ejector rod position and provides feedback to the control unit. When the distal end reaches the predetermined position, the feedback signal triggers the control unit to stop further advancement, preventing damage from excessive stroke
3Ease of operation
If magnetic clamping is used to hold the mold on the movable platen, then the ease of operation is improved, but the mold may separate and fall if the ejection force exceeds the clamping force
Solution Approach 1:
The detection unit provides real-time feedback on ejector rod position to the control unit. This feedback mechanism ensures that the ejection force is applied only over the necessary distance, preventing excessive force that could overcome the magnetic clamping and cause mold separation
Solution Approach 2:
The patent replaces mechanical clamping systems with magnetic clamping to hold the mold on the movable platen. This substitution improves ease of operation for mold mounting and removal while the controlled ejection stroke prevents the magnetic clamping force from being exceeded
4Ease of operation
If the forward end position is set as the movement limit position, then the simplicity of operation is improved, but the ejection stroke may not be optimal for all molding operations
Solution Approach 1:
The system allows the predetermined position of the ejector rod distal end to be dynamically adjusted based on detection results. The control unit can modify the forward end position setting according to feedback from the detection unit, enabling optimization for different molding operations while maintaining ease of operation through automated 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
Enhances safety by maintaining a reduced ejecting force and velocity until the appropriate forward end position is set, preventing mold or ejector damage and ensuring the mold remains securely clamped during changes.
Implementation Method 1
injection molding machine having a device that clamps the mold on a surface of a movable platen magnetically
Data Source
AI summary
An injection molding machine that performs a safe ejecting action of a molded article until a setting state of an ejector rod and a set forward end position for an ejection stroke of a molded article ejector are suitable for a mold in use. A resistor R1 is set to ON when a mold is changed and a resistor R2 is set to ON when a set value of the forward end position of the ejection stroke is changed. When resistor R1 or resistor R2 is ON, ejection is performed with a reduced ejecting force and at a reduced ejecting velocity. When a detected position of the ejector rod reaches the set forward end position, resistors R1 and R2 are turned OFF and thereafter the ejection is performed with a normal ejecting force and a normal ejecting velocity, to thereby prevent damage to the mold or to the molded article ejector.