Variable Cross-Section Valve Control for Hydraulic Load Stability
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Solution Overview
Problem
Existing systems for controlling the movement of work implements on vehicles, such as wheel loaders and excavators, face inefficiencies due to highly variable gravity-driven loads, leading to increased parasitic power loss, wear, and reduced operator comfort, especially when dealing with heavy loads that require restrictive return valves, causing abrupt motion stops and potential loss of vehicle stability.
Innovation Solution
A method and system that utilize a hydraulic fluid pump with a controller and sensors to modulate fluid flow through hydraulic cylinders by adjusting the cross-section of valves, allowing for dynamic control of fluid flow based on operator commands, cylinder speed, and load signals, enabling efficient movement of work implements by optimizing valve positions for varying loads, thereby reducing power loss and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If restrictive return valves are used to control heavy loads, then control capability is improved, but parasitic power loss increases and motion becomes abrupt
Solution Approach 1:
The patent applies dynamics by making the valve cross-section adjustable rather than fixed. The controller dynamically modifies the cross-section of the at least one valve based on real-time feedback from cylinder position sensors and state observers, allowing the system to adapt valve opening to match actual load conditions and desired motion profiles, thereby reducing parasitic power loss while maintaining control capability.
Solution Approach 2:
The patent changes the parameter of valve cross-section from a fixed value to a variable parameter that can be continuously adjusted. By modifying the cross-section area of the valve based on control signals from the controller, the system optimizes fluid flow characteristics to reduce power loss while maintaining adequate control over heavy loads.
2Reliability
If restrictive return valves are used to control heavy loads, then control capability is improved, but wear on components increases
Solution Approach 1:
The dynamic adjustment of valve cross-section prevents excessive wear by avoiding consistently restrictive valve positions. The controller modulates the valve opening based on actual system state, reducing unnecessary friction and mechanical stress on valve components and hydraulic elements during normal operation while maintaining control authority when needed.
3Reliability
If restrictive return valves are used to control heavy loads, then control capability is improved, but operator comfort deteriorates due to abrupt motion stops
Solution Approach 1:
The system uses dynamic valve cross-section adjustment to create smooth, continuous motion profiles. The controller processes feedback from position sensors and state observers to gradually modulate the valve opening, eliminating abrupt motion stops and providing operators with comfortable, predictable control response while maintaining full control capability for heavy loads.
4Device complexity
If fixed valve cross-section is used, then system simplicity is maintained, but adaptability to varying loads deteriorates
Solution Approach 1:
The patent introduces dynamic adjustability of valve cross-section through electronic control, transforming a static mechanical system into an adaptive controlled system. The controller receives feedback from sensors and state observers, then modifies valve cross-section in real-time to adapt to varying load conditions, dramatically improving versatility while adding manageable complexity through electronic control architecture.
Solution Approach 2:
The system implements feedback control by using cylinder position sensors and state observers to continuously monitor system state, then feeding this information back to the controller which adjusts valve cross-section accordingly. This closed-loop feedback mechanism enables automatic adaptation to varying loads without requiring manual intervention or complex mechanical adjustments.
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 approach enhances the efficiency of work implement movement by minimizing power loss, reducing wear on vehicle components, and improving operator comfort by dynamically adjusting fluid flow according to load conditions, maintaining control and stability across different load weights.
Implementation Method 1
a hydraulic fluid pump for providing a fluid flow to the work implement... modulating fluid flow to a hydraulic cylinder through at least one valve... controllably modifying a cross-section of the at least one valve to modulate the fluid flow of the hydraulic cylinder
Data Source
AI summary
A system for controllably moving a work implement of a work vehicle having a hydraulic fluid pump for providing fluid to the work implement, the system comprising: at least one operator command tool to produce an operator command signal to move the implement of the work vehicle; at least one sensor to sense a cylinder speed signal indicative of a speed of a hydraulic cylinder coupled to the implement; at least one valve to modulate the fluid flow of the hydraulic cylinder; and a controller.