Control Valve Load Sense Signal Shaping
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Solution Overview
Problem
Existing directional control valves in load sensing systems are sensitive to manufacturing tolerances and valve actuation speeds, leading to inconsistent load sense signals, which are difficult to compensate for, especially in the field.
Innovation Solution
A control valve with a load sense signal shaping device, including a check valve or metering orifice, that stabilizes and manipulates the load sense signal by metering the flow of pressurized fluid, allowing for adjustments such as spring rate, preload force, and poppet area gain to tailor the boost pressure profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If prior art attempts to provide a load sense boost signal are used, then a load sense signal can be provided, but the signal is sensitive to manufacturing tolerances and valve actuation speeds
Solution Approach 1:
A check valve is introduced as an intermediary component in the load sense signal path. The check valve allows fluid flow in one direction while blocking reverse flow, creating a mechanical intermediary that stabilizes the load sense signal by preventing pressure fluctuations caused by manufacturing tolerances and actuation speed variations.
Solution Approach 2:
The invention changes the physical parameters of the load sense signal path by introducing a check valve with specific flow characteristics. This modifies the pressure-flow relationship in the load sense line, making the signal less sensitive to variations in manufacturing tolerances and valve actuation speeds through altered fluid dynamics parameters.
2Reliability
If prior art attempts to provide a load sense boost signal are used, then a load sense signal can be provided, but the signal is sensitive to valve actuation speeds
Solution Approach 1:
The check valve serves as a mechanical intermediary that decouples the load sense signal from direct dependence on valve actuation speed. By providing a one-way flow path, it ensures consistent signal generation regardless of how quickly or slowly the valve spool moves, thereby reducing sensitivity to actuation speed variations.
Solution Approach 2:
The check valve provides beforehand cushioning by pre-establishing a controlled flow path for the load sense signal. This preemptive flow management cushions against variations in actuation speed, ensuring that the signal remains stable even when the valve spool moves at different speeds during operation.
3Reliability
If prior art attempts to provide a load sense boost signal are used, then a load sense signal can be provided, but such variations are difficult to compensate for especially in the field
Solution Approach 1:
The check valve acts as a robust mechanical intermediary that provides inherent signal stabilization without requiring complex adjustment mechanisms. This simple mechanical solution eliminates the need for field compensation of manufacturing tolerances, as the check valve's one-way flow characteristic naturally compensates for variations in a passive, maintenance-free manner.
Solution Approach 2:
The check valve provides self-service compensation for manufacturing tolerances and actuation speed variations. The component automatically adjusts the load sense signal based on its inherent check valve functionality, requiring no external adjustment or field compensation. The system self-regulates the signal stability through the check valve's natural flow control 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 solution reduces sensitivity to manufacturing tolerances and valve actuation speeds, enabling stable and customizable load sense signals, improving the smooth operation of hydraulic systems by providing a consistent and adjustable load sense boost.
Implementation Method 1
In one embodiment, the load sense signal shaping device includes a check valve which preferably is located in the valve member
Implementation Method 2
a movable poppet biased toward the valve seat by a spring member interposed between the poppet and an abutment on the valve body
Data Source
AI summary
A control valve comprises a valve body having a fluid inlet and at least one work fluid outlet for supplying pressurized fluid to the fluid operated device. A valve member is movable in the valve body in a first direction from a null position to a full flow or open position for supplying flow of pressurized fluid from a feed passage to a work fluid outlet. The valve member has a load sense signal shaping device that provides for initial flow from the feed passage to the work fluid outlet through a metering orifice during movement of the valve member from the null position to the full flow open position so as to shape an initial boost pressure signal.