Load-Sensing Pump-Valve Coordination for Stable Hydraulic Flow Matching
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Solution Overview
Problem
Conventional load sensing hydraulic systems face issues with energy inefficiency due to overflow matching, pressure impact, and response delays, which affect system stability and energy utilization.
Innovation Solution
A flow self-compensating load sensing pump/valve coordinated electro-hydraulic system that includes an electronically controlled variable pump, flow control valves, pressure sensors, and a control system to precisely match hydraulic pump displacement with actuator flow demand, using a shuttle valve and bypass throttle valve to manage pressure and flow, reducing pressure margin and oscillation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional load sensing system uses preset pressure margin with long hydraulic pipe and complex shuttle valve network, then system flow supply and demand balance is achieved, but response delay and oscillation occur, reducing system stability
Solution Approach 1:
The patent replaces the conventional hydro-mechanical feedback control system with an electro-hydraulic coordinated control system. The electronic control joystick and control system generate control signals for the variable pump, eliminating the need for long hydraulic pipes and complex shuttle valve networks. This substitution of mechanical feedback with electronic control reduces response delay and improves system stability.
Solution Approach 2:
The patent introduces a bypass control valve as an intermediary component to manage pressure margin dynamically. Instead of using a fixed pressure margin through complex valve networks, the bypass control valve provides a direct pressure relief path that responds quickly to load changes, eliminating oscillation and improving stability without response delay.
2Use of energy by moving object
If electro-hydraulic flow matching system uses pump-valve synchronization control, then pump lagging valve control is eliminated, but pressure impact and energy losses occur due to overflow matching, reducing energy utilization efficiency
Solution Approach 1:
The patent implements dynamic pressure margin control through the bypass control valve, which adjusts system pressure based on actual load demands in real-time. Instead of fixed overflow matching, the system dynamically balances pump output with actuator demand, preventing unnecessary overflow and the associated energy losses while maintaining high energy utilization efficiency.
Solution Approach 2:
The patent changes the pressure margin parameter from a fixed preset value to a dynamically adjustable parameter controlled by the bypass control valve. This allows the system to optimize pressure levels according to actual operating conditions, eliminating energy losses from excessive pressure and overflow matching while maintaining efficient energy utilization.
3Reliability
If conventional load sensing system uses conservative pressure margin set value (2.0 MPa to 2.8 MPa) to consider local pressure losses, then flow supply and demand balance is maintained, but energy utilization efficiency is seriously affected
Solution Approach 1:
The patent implements a feedback control mechanism where the bypass control valve continuously monitors system pressure and load demands, adjusting the pressure margin dynamically. This feedback system maintains reliable flow supply and demand balance while optimizing energy utilization by avoiding excessive conservative pressure margins, allowing the system to adapt pressure levels to actual operating 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
This solution improves energy efficiency, reduces pressure surges and oscillations, and enhances control performance by accurately matching pump displacement with actuator flow, minimizing energy losses and improving system stability.
Implementation Method 1
an oil outlet of the bypass control valve is connected to an oil inlet of the bypass throttle valve... the control system generates a control signal of the electronically controlled variable pump by receiving a control signal of the electronic control joystick and pressure signals of the first pressure sensor and the second pressure sensor
Implementation Method 2
the shuttle valve is configured to screen out a maximum load pressure of the hydraulic actuator, an oil outlet of the shuttle valve is connected to a right spring chamber of the bypass control valve
Implementation Method 3
an oil outlet of the bypass control valve is connected to an oil inlet of the bypass throttle valve, an oil outlet of the bypass throttle valve is connected to the oil tank
Implementation Method 4
the oil inlet and the oil outlet of the bypass throttle valve are correspondingly provided with the first pressure sensor and the second pressure sensor
Data Source
AI summary
The disclosure provides a flow self-compensating load sensing pump/valve coordinated electro-hydraulic system, including a prime mover, an electronically controlled variable pump, a flow control valve, a hydraulic actuator, a shuttle valve, an electronic control joystick, a bypass control valve, two pressure sensors, a bypass throttle valve, and a control system, where an oil outlet of the shuttle valve is connected to a right spring chamber of the bypass control valve, a left chamber and an oil inlet of the bypass control valve are connected to an oil outlet of the electronically controlled variable pump, an oil inlet and an oil outlet of the bypass throttle valve are connected to an oil outlet of the bypass control valve and an oil tank, two ends of the oil inlet and the oil outlet of the bypass throttle valve are provided with the first pressure sensor and the second pressure sensor, respectively.