Needle Valve Nozzle Flow Control to Prevent Explosive Discharge
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Solution Overview
Problem
In injection molding of flat and/or elongated parts, it is challenging to fill the cavity completely without causing inhomogeneities due to temperature reduction and resulting flow lines from multiple feed orifices, which can lead to visible weak points and require finishing treatments.
Innovation Solution
An injection molding system with multiple actuator systems and electronically controlled flow control valves that manage the opening and closing of needle valve nozzles based on pressure line sensors to prevent explosive discharge and ensure precise control of the injection process, using sensors to detect flow rates and pressures for real-time adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple feed orifices are used to fill the cavity completely, then the filling completeness is improved, but flow lines and inhomogeneities arise due to melt temperature reduction and pressure loss
Solution Approach 1:
The patent applies preliminary action by opening nozzles in a predetermined sequence before the melt reaches subsequent feed orifices. The control system activates nozzles one after another based on programmed timing, ensuring that when melt arrives at a feed orifice, the nozzle is already open and ready, preventing explosive discharge and flow line formation while maintaining complete cavity filling
2Manufacturing precision
If nozzles are opened at different times to prevent flow lines, then surface quality is improved, but explosive discharge occurs when later nozzles open due to full pressure melt
Solution Approach 1:
The patent implements feedback control by using sensors (pressure sensors, flow sensors, or optical sensors) to detect the actual state of melt flow and pressure in real-time. The control system continuously monitors these parameters and adjusts the nozzle opening timing and duration accordingly, preventing explosive discharge by closing nozzles when melt arrival is detected while maintaining surface quality through precise timing control
3Manufacturing precision
If precise control of nozzle opening timing is implemented, then flow front markings are prevented, but device complexity increases due to multiple actuators and control systems
Solution Approach 1:
The patent applies universality by using a single centralized control system that manages multiple nozzles through a unified control architecture. The control unit (PLC or microcontroller) serves all nozzles with standardized actuator interfaces, allowing precise individual control of each nozzle while maintaining overall system simplicity through modular design and standardized components
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 prevents explosive discharge and flow front markings, ensuring consistent quality and reducing the need for finishing treatments by controlling the timing and pressure of nozzle openings, thereby improving the homogeneity of molded parts.
Implementation Method 1
at least two pressure line connectors to drive a piston to open or close a molding nozzle
Implementation Method 2
A flow control valve (20) is provided in the pressure line (L3) having an impact on the speed of a movement of the piston
Implementation Method 3
At least one sensor for detecting a flow rate or a pressure in the pressure line
Data Source
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AI summary
Injection molding system comprising at least one first actuator-system (D1,D2,D3), the first actuator system comprising : - a least one piston drive (10) having at least two pressure line connectors (CP2, CP3) to drive a piston to open or close a molding nozzle, - pressure lines (L1, L2) connectable to a change over valve (V) having a pressure line connector (P) and tank line connector (T) and at least two change over pressure line connectors, wherein the first change over valve pressure line connector (CV1) is connectable to a first pressure line (L1) and the second change over valve pressure line connector (CV2) is connectable to a second pressure line (L2), wherein the second pressure line (L2) is connected to the second pressure line connector (CP2) of the piston drive (10), - an electronically adjustable flow control valve (20) having a first pressure line connector and a second pressure line connector, wherein the first pressure line connector of the adjustable flow control valve being connected to the first pressure line (L1) to allowing a connection to the first pressure line connector (CV1) of the change over valve (V), and the second pressure line connector is connected to a third pressure line (L3) which establishes a connection to the second pressure line connector (CP3) of the piston drive (10), - at least one electronic flow sensor for (P1, P2, P3) sensing flow rate in the first, second and/or third pressure lines (L1, L2, L3), - a controller connected to the adjustable flow control valve and to the at least one sensor, configured to electronically adjust the flow control valve, depending on information of the at least one sensor, controlling thereby the timing and the speed of the movement of the piston and the molding nozzle.