Excavator Hydraulic Circuit Floating Function Control
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Solution Overview
Problem
Existing hydraulic circuits for construction machines with floating functions cannot effectively inactivate the floating function during boom-up or jack-up operations, and fail to efficiently manage hydraulic energy usage during leveling and grading work.
Innovation Solution
A hydraulic circuit with a control system that includes pressure sensors and electronic proportional control valves to manage the flow of hydraulic fluid between pumps, a boom driving control valve, and a boom confluence control valve, allowing for selective supply of hydraulic fluid to the boom cylinder based on pressure conditions, enabling the floating function to be activated during boom-down and inactivated during boom-up, thus optimizing energy use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the floating function is always active to allow boom descent by self-weight, then energy is saved during leveling work, but the jack-up operation cannot be performed when hydraulic fluid is needed in the small chamber
Solution Approach 1:
The system dynamically switches between floating mode and forced descent mode based on operational requirements. The control valve shifts between positions to either connect the small chamber to the tank (floating mode for energy saving) or supply hydraulic fluid to the small chamber (jack-up mode for operational flexibility), allowing the system to adapt to different work conditions
Solution Approach 2:
The system uses pressure sensors to detect pressure values in real-time and feeds this information back to the control unit. Based on the feedback from pressure sensors detecting pressure in the small chamber and pilot pressure, the control unit automatically determines whether to activate floating mode or jack-up mode, enabling automatic adaptation to operational needs
2Adaptability or versatility
If hydraulic fluid is supplied to the small chamber during boom descent, then jack-up operation is enabled, but hydraulic energy is wasted that could be used for other actuators
Solution Approach 1:
The control system dynamically adjusts hydraulic fluid supply based on detected pressure conditions. When pressure in the small chamber is insufficient for jack-up, hydraulic fluid is supplied. When pressure is sufficient, the system switches to floating mode to conserve energy for other actuators, optimizing energy utilization while maintaining jack-up capability when needed
3Device complexity
If a simple floating control is used, then the circuit is simple, but it cannot automatically switch between floating mode and jack-up mode based on operational needs
Solution Approach 1:
Pressure sensors continuously monitor pressure in the small chamber and pilot pressure, providing feedback to the control unit. The control unit automatically processes this feedback information and switches between floating mode and jack-up mode without manual intervention, achieving automatic mode switching while maintaining reasonable circuit complexity through standardized sensor and control components
Solution Approach 2:
The patent replaces manual mechanical control with an automated control system using pressure sensors, control units, and solenoid valves. This substitution enables automatic mode switching based on pressure feedback, reducing the need for complex manual valve operations while achieving intelligent automation of the hydraulic circuit
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 allows for efficient hydraulic energy management by supplying hydraulic fluid to other actuators during boom descent, saving energy and improving workability during leveling and grading tasks, while enabling selective hydraulic fluid supply to the boom cylinder for jack-up operations.
Implementation Method 1
a pressure sensor configured to detect a pressure value in the small chamber of the boom cylinder; a pilot pressure sensor configured to detect a pilot pressure value
Implementation Method 2
hydraulic fluid discharged from a hydraulic pump can be used for a hydraulic actuator other than a boom cylinder, thereby saving the hydraulic energy
Implementation Method 3
a control valve configured to be shifted in response to a pressure detection value of the pressure sensor and a pilot pressure detection value of the pilot pressure sensor
Data Source
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AI summary
Disclosed are a hydraulic circuit for using a hydraulic fluid in a hydraulic pump in another hydraulic actuator, during levelling and grading work by means of an excavator, and a method for controlling a floating function. A hydraulic circuit for construction machinery having a floating function, according to the present invention, is provided with: two or more hydraulic pumps; a hydraulic cylinder connected to the hydraulic pumps; a boom driving control valve provided on the flow path between the hydraulic pump on one side and the hydraulic cylinder; a boom confluence control valve provided on the flow path between the hydraulic pump on the other side and the hydraulic cylinder; an operating lever; a first sensor for measuring the hydraulic fluid pressure of a large chamber of the hydraulic cylinder; a second sensor for measuring the boom lowering pilot pressure applied to one end of the boom driving control valve; a control valve provided on the flow path between the operating lever and the other ends of the boom driving control valve and the boom confluence control valve.