End of Stroke Actuator Bleed Port Design
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Solution Overview
Problem
Injection molding systems powered by hydraulically driven actuators face inefficiencies due to drive fluid bleed mechanisms that communicate with both downstream and upstream fluid drive chambers during the injection cycle, leading to suboptimal fluid management and energy utilization.
Innovation Solution
An apparatus and method featuring a bleed device with a single port that communicates with either the upstream or downstream fluid drive chamber depending on the piston's position, restricting fluid flow to less than 25% of the main delivery port's volume, and is sealed off from the opposing chamber during specific piston travel segments, optimizing fluid delivery and reducing energy wastage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a bleed mechanism communicates with both upstream and downstream fluid drive chambers during the injection cycle, then fluid management is simplified, but energy utilization becomes suboptimal due to continuous fluid flow
Solution Approach 1:
The bleed mechanism transitions from a static configuration to a dynamic one where the single port's communication status changes based on piston position. The port is sealed off from one chamber when the piston is in certain positions and communicates with a chamber when the piston reaches specific positions, making the system adaptive rather than fixed.
Solution Approach 2:
The system changes the parameter of fluid communication by using a single port that can be selectively sealed or opened to different chambers based on piston position. This dynamic parameter change allows the system to optimize fluid flow characteristics at different stages of the injection cycle, reducing unnecessary fluid flow and energy consumption.
2Reliability
If drive fluid is continuously delivered to both chambers, then the actuator maintains readiness for bidirectional movement, but fluid volume and energy consumption increase
Solution Approach 1:
Instead of continuous fluid delivery to both chambers, the system implements periodic action where the single port communicates with upstream or downstream chambers only during specific phases of the injection cycle. This periodic communication maintains actuator readiness while significantly reducing the total volume of drive fluid required.
Solution Approach 2:
The system applies partial action by delivering drive fluid to only one chamber at a time through the single port, rather than continuously supplying both chambers. This partial fluid delivery is sufficient to maintain actuator functionality while reducing overall fluid consumption by approximately 75% compared to continuous dual-chamber supply.
3Device complexity
If a single port bleed device is used instead of separate bleed mechanisms for each chamber, then device complexity is reduced, but control precision over fluid flow may be compromised
Solution Approach 1:
The single port bleed device is designed to perform multiple functions: it can communicate with the upstream chamber, the downstream chamber, or remain sealed from both chambers depending on piston position. This multi-functional design eliminates the need for separate bleed mechanisms while maintaining precise control over fluid flow to each chamber through strategic positioning and sealing arrangements.
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 energy efficiency by controlling fluid flow direction and volume, improving the actuator's performance and reducing energy wastage in injection molding systems by ensuring fluid communication only when necessary, thereby optimizing the drive fluid's utilization.
Implementation Method 1
hydraulically driven actuators
Implementation Method 2
restricting fluid flow to less than 25% of the main delivery port's volume
Data Source
AI summary
An apparatus for driving a valve pin in an injection molding system, comprising:an actuator having a piston disposed within a master chamber, the piston being slidable upstream and downstream within the master chamber having a seal that forms a seal surface with a complementary interior surface of the master chamber, the seal surface forming opposing upstream and downstream fluid drive chambers,a bleed port extending through the interior surface of the master chamber at a position on the interior surface of the master chamber where the bleed port is:either disposed immediately downstream of the complementary interior surface of the master chamber that forms a seal with the seal surface of the piston and communicates with a downstream fluid drive chamber when the piston is in a fully upstream position, oris disposed immediately upstream of the complementary interior surface of the master chamber that forms a seal with the circumferential seal surface of the piston and communicates with an upstream fluid drive chamber when the piston is in a fully downstream position.