Two-Stage Variable Flow Poppet Valve for Low-Force Opening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluid dispensing systems require significant user force to open the valve due to upstream fluid pressure, and they typically offer only binary flow rates, lacking control over fluid flow rates.
Innovation Solution
A variable flow valve design featuring an outer valve plug, bushing, inner valve plug, and cap, allowing for movement between fully closed, partially open, and fully open positions, with a first stage spring having a lower spring rate than the second stage spring to facilitate controlled fluid flow and reduce actuation force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the valve is designed to resist upstream fluid pressure to prevent leakage, then sealing reliability is improved, but the force required to actuate the valve increases
Solution Approach 1:
The valve is divided into two independent stages: an inner valve plug with a first stage seat, and an outer valve plug with a second stage seat. Each stage can be actuated independently, allowing the user to open one stage while keeping the other closed. This segmentation enables progressive opening where the inner stage opens first at lower force requirements, then the outer stage opens subsequently, thereby reducing the peak actuation force while maintaining reliable sealing at each stage.
2Device complexity
If the valve provides binary flow rates (fully open or fully closed), then the valve structure is simple, but control precision over fluid flow is lost
Solution Approach 1:
The valve transitions from a static binary state to a dynamic multi-state system. The two-stage design allows the valve to exist in multiple states: both stages closed (fully closed), inner stage open while outer stage closed (partially open/intermediate flow), both stages open (fully open). This dynamic capability enables intermediate flow rates between the minimum and maximum flow rates, providing continuous flow control while maintaining relatively simple valve structure through the use of two basic plug-and-seat configurations.
3Device complexity
If a single-stage valve design is used, then the device complexity is low, but the ability to provide variable flow rates is limited
Solution Approach 1:
The valve is divided into two independent stages: an inner valve plug with a first stage seat, and an outer valve plug with a second stage seat. Each stage can be actuated independently, allowing the user to open one stage while keeping the other closed. This segmentation enables progressive opening where the inner stage opens first at lower force requirements, then the outer stage opens subsequently, thereby reducing the peak actuation force while maintaining reliable sealing at each stage.
4Reliability
If the spring rate is increased to improve valve closure reliability, then sealing is improved, but the force required to actuate the valve increases
Solution Approach 1:
The valve is divided into two independent stages: an inner valve plug with a first stage seat, and an outer valve plug with a second stage seat. Each stage can be actuated independently, allowing the user to open one stage while keeping the other closed. This segmentation enables progressive opening where the inner stage opens first at lower force requirements, then the outer stage opens subsequently, thereby reducing the peak actuation force while maintaining reliable sealing at each stage.
Solution Approach 2:
Different spring rates are used for the two stages: the first stage spring has a lower spring rate while the second stage spring has a higher spring rate. This parameter differentiation allows the inner valve plug to open at lower actuation forces, while the outer valve plug requires higher forces for reliable closure. By matching spring rates to the specific requirements of each stage, the system achieves reliable sealing without excessively high actuation forces.
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
Enables precise control over fluid flow rates, reducing the force required to open the valve and providing non-binary flow options, enhancing user control and reducing material waste.
Implementation Method 1
a first stage spring disposed within the bushing and around the shaft and extending between the upstream end of the bushing and the cap
Implementation Method 2
a second stage spring disposed within the upstream fluid chamber and configured to bias the outer valve plug towards the outer valve seat
Implementation Method 3
The fluid upstream of the valve is pressurized, and that fluid pressure drives the fluid downstream past the valve when the valve is in the open position. The upstream fluid pressure resists movement of the valve from the closed position to the open position
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
A variable flow poppet valve includes a first stage, a second stage, a bushing disposed in the second stage, and a cap configured to actuate the valve open. The first stage includes an inner valve plug having a head with a first tapered portion and a shaft extending downstream from the head, and a first stage spring disposed within the bushing and extending around the shaft. The shaft is attached to the cap to allow the cap to actuate the inner valve plug to the open position. The second stage includes an outer valve plug having an upstream portion and a second tapered portion extending downstream from the upstream portion. The bushing includes a shoulder, and the cap is configured to engage the shoulder to actuate the outer valve plug to the open position.