Injection Valve Pin and Throat Control for Pressure Spike Reduction
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Solution Overview
Problem
Injection molding systems with fluid distribution valve systems face challenges in achieving quick movement responses due to the long physical distance between valve system communication ports and actuators, leading to delayed fluid movement and pressure spikes.
Innovation Solution
An injection molding apparatus with a valve pin driven by an actuator, where the valve pin extends through a fluid flow channel with a throat configuration and a bulbous portion, allowing for restricted and unrestricted flow control, and is driven by a spool mechanism powered by solenoids, enabling precise control over injection fluid flow to manage pressure differences and prevent spikes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If actuators are mounted at an extended distance away from the heated manifold chamber to protect valve integrity, then the reliability of the valve system is improved, but the speed of actuator response is worsened due to long fluid transmission distance
Solution Approach 1:
The system is divided into two separate modules: a heated manifold chamber containing the valve system and a separate actuator mounting location. This segmentation allows the valve system to be protected from heat while actuators can be positioned optimally for response speed, resolving the contradiction between reliability and speed.
Solution Approach 2:
A fluid communication system with optimized pathways acts as an intermediary between the valve system and actuators. The intermediary fluid transmission path minimizes delay while allowing physical separation for thermal protection, balancing reliability and response speed requirements.
2Manufacturing precision
If the valve pin extends through a long channel length, then the control precision over injection fluid flow is improved, but the time delay in fluid response is worsened
Solution Approach 1:
The channel geometry is optimized with local quality variations - specific sections have different diameters, smooth transitions, and polished surfaces to minimize flow resistance and delay. This allows precise flow control through extended channels while reducing time delay effects.
Solution Approach 2:
The valve pin incorporates dynamic positioning capabilities with variable speed actuation. The system can adjust the rate of valve pin movement based on process requirements, optimizing both control precision and response time by matching actuation speed to fluid dynamics characteristics.
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 apparatus achieves faster and more precise control over injection fluid flow, reducing pressure differences and eliminating spikes, thereby improving the quality of molded parts and reducing tensile forces on the valve pin.
Implementation Method 1
the spool being mechanically driven by first and second actuators or solenoids (70a, 70b) that each separately engage the spool at opposing axial ends
Implementation Method 2
the valve pin being drivable by the actuator axially upstream and downstream through the fluid flow channel
Data Source
AI summary
An injection molding apparatus including:a valve pin driven by an actuator, the valve pin extending axially through at least a portion of the channel length of the fluid flow channel, the fluid flow channel and the valve pin being configured or adapted such that the valve pin is movable axially upstream and downstream between an upstream position where the downstream flow of the injection fluid is restricted by a bulbous protrusion (B) of the pin being axially aligned (AL) with the throat (T) of the channel, an intermediate position where downstream flow of injection fluid is unrestricted (WG) and a fully downstream position where downstream flow of injection fluid is stopped at both the gate and at the throat.