Hydraulic Rate Control Self-Adjusting Valve
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hydraulic rate control piston-type devices fail to maintain a near constant piston rod velocity over a wide range of applied loads due to the need for high spring biasing, which increases the size and weight of the device and limits effective load compensation.
Innovation Solution
A compact hydraulic rate control device with a self-adjusting valve member that controls fluid flow through a series of variable and fixed orifices within the piston head, allowing for consistent fluid flow and piston travel velocity across varying loads by adjusting the flow area in response to pressure changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a spring-biased tapered pin valve element is used to control fluid flow rate, then the flow area varies in inverse proportion to the load applied, but the device size and weight increase due to high spring biasing requirements
Solution Approach 1:
The invention extracts the spring-biased tapered pin valve element from the system and replaces it with a self-adjusting valve member that responds directly to pressure differential. This eliminates the need for high spring biasing forces, thereby reducing device size and weight while maintaining the ability to control fluid flow rate in response to applied load.
Solution Approach 2:
The invention introduces a pressure-responsive self-adjusting valve member as an intermediary between the pressure differential and the fluid flow rate. This valve member directly translates pressure differential into flow rate control without requiring mechanical spring biasing, achieving load compensation with reduced device mass.
2Ease of operation
If a spring-biased tapered pin valve element is used to control fluid flow rate, then the flow area varies in inverse proportion to the load applied, but the device complexity increases due to high spring biasing requirements
Solution Approach 1:
The invention removes the complex spring-biased tapered pin valve mechanism and replaces it with a simpler pressure-responsive self-adjusting valve member. This simplifies the device structure while maintaining the functional capability to control fluid flow rate in response to load variations.
Solution Approach 2:
The self-adjusting valve member automatically responds to pressure differential changes without requiring external spring biasing or complex control mechanisms. The valve member self-regulates the fluid flow rate based on the applied load, reducing device complexity while maintaining operational effectiveness.
3Speed
If conventional hydraulic rate control devices are used, then the stowage bin opens slowly when empty, but opens faster when fully loaded, losing constant velocity control
Solution Approach 1:
The invention implements a feedback mechanism where the self-adjusting valve member continuously responds to pressure differential changes caused by varying applied loads. This feedback loop automatically adjusts the fluid flow rate to maintain substantially constant piston rod velocity across a wide range of applied loads, achieving both speed control and load adaptability.
Solution Approach 2:
The invention changes the operating parameter from fixed spring-biased flow control to pressure-differential-responsive flow control. The self-adjusting valve member dynamically adjusts the fluid flow rate based on instantaneous pressure differential, enabling constant velocity control across varying load conditions without requiring high spring biasing 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
The device achieves a substantially constant velocity characteristic over a wide range of applied loads, reducing size and weight while maintaining effective load compensation and fluid flow control.
Implementation Method 1
the self-adjusting valve member controls fluid flow through a series of variable and fixed orifices within the piston head, allowing for consistent fluid flow and piston travel velocity across varying loads by adjusting the flow area in response to pressure changes
Data Source
AI summary
A rate control device includes an outer cylinder defining an interior chamber having a longitudinal axis and containing a hydraulic fluid. A piston head mounted to a proximal end or a piston rod is slidably positionable within the interior chamber. A rate control valve is disposed within an interior cavity of the piston head coaxially with the longitudinal axis of the interior chamber of the cylinder. The rate control valve includes a variable flow rate orifice and a fixed flow rate orifice disposed in series relationship with respect to fluid flow through the rate control valve.