Solenoid Proportional Valve Dither Control for Hydraulic Fluid Temperature
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Solution Overview
Problem
Existing hydraulic systems face issues with solenoid proportional valves experiencing insufficient hysteresis reduction when dither amplitude is too small and vibration sound generation when it is too large, necessitating a balanced approach.
Innovation Solution
A controller adjusts the dither amplitude of the solenoid proportional valve based on the temperature of the hydraulic fluid, setting it to different values in distinct temperature ranges to optimize hysteresis reduction and minimize vibration sound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the dither amplitude is increased to reduce hysteresis of the solenoid proportional valve, then responsiveness is improved, but vibration sound is generated in the control valve
Solution Approach 1:
The patent applies dynamics by making the dither amplitude adjustable rather than fixed. The control unit dynamically changes the dither amplitude based on operating conditions (such as valve position, flow rate, or pressure) to optimize the balance between reducing hysteresis and minimizing vibration sound. This allows the system to adapt the dither characteristics to different operational states, improving responsiveness when needed while reducing vibration sound during other conditions.
Solution Approach 2:
The patent changes the parameter of dither amplitude based on different operating conditions. By monitoring parameters such as valve position, flow rate, or pressure, the control unit adjusts the dither amplitude to appropriate levels. For example, a larger dither amplitude may be applied when the valve is near extreme positions to ensure adequate hysteresis reduction, while a smaller amplitude is used during normal operation to minimize vibration sound.
2Object-generated harmful factors
If the dither amplitude is decreased to prevent vibration sound, then vibration sound is reduced, but hysteresis reduction effect becomes insufficient
Solution Approach 1:
The system dynamically adjusts the dither amplitude based on real-time operating conditions rather than using a fixed low amplitude. This ensures that when conditions require stronger hysteresis reduction (such as when the valve is near extreme positions or during high-flow conditions), the dither amplitude is increased accordingly, while maintaining low amplitude during normal conditions to prevent vibration sound.
Solution Approach 2:
The control unit changes the dither amplitude parameter according to monitored operating parameters such as valve position, flow rate, or pressure. This ensures that the dither amplitude is optimized for each operating condition, providing sufficient hysteresis reduction effect when needed while minimizing vibration sound during other conditions.
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 effectively reduces hysteresis and minimizes vibration sound in solenoid proportional valves by dynamically adjusting the dither amplitude according to fluid temperature, enhancing system responsiveness and operational stability.
Implementation Method 1
a dither amplitude is superimposed on the current that is supplied to the solenoid proportional valve to reduce hysteresis of the solenoid proportional valve
Implementation Method 2
reduce hysteresis of the solenoid proportional valve
Data Source
AI summary
A hydraulic system of a working machine includes a hydraulic actuator to be driven with a hydraulic fluid; a solenoid proportional valve to control the hydraulic actuator in accordance with a current that is supplied; and a controller to control the current that is supplied to the solenoid proportional valve. The controller changes a dither amplitude of the current that is supplied to the solenoid proportional valve in accordance with a temperature of the hydraulic fluid.