Hydraulic Pump Segmentation for Simultaneous Excavator Actuation
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Solution Overview
Problem
The hydraulic driving system in existing construction machines, such as hydraulic excavators, faces challenges in supplying operating oil to actuators like the boom, arm, and bucket at a required flow rate when these are operated simultaneously with the turning operation, due to the blocking of pilot pressure to the control valves.
Innovation Solution
A liquid-pressure driving system is designed with multiple pumps and control valves that allow selective use of pumps to ensure operating oil is supplied to the boom, arm, and bucket actuators at a required flow rate, even during turning operations, through a command output device that manages the flow based on the operation of the bucket actuator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the control valves of the first control valve group other than the turning control valve are utilized as control valves that assist the control valves of the second and third control valve groups, then the operating oil can be supplied to the actuators when the amount of operating oil from the second and third control valve groups is inadequate, but when the turning operation is performed simultaneously with boom, arm, or bucket operation, the operating oil cannot be supplied to each actuator at a required flow rate
Solution Approach 1:
The patent divides the control valve groups into separate functional units: the first control valve group is dedicated to the turning operation, while the second and third control valve groups are dedicated to boom, arm, and bucket operations. This segmentation prevents the pilot pressure blocking issue that occurred in the prior art where control valves were shared across multiple functions, ensuring that each actuator receives the required flow rate independently without interference from turning operations.
2Reliability
If the pilot pressure input to the control valves of the first control valve group other than the turning control valve is blocked at the time of the turning operation, then the turning operation can be prioritized, but the operating oil cannot be supplied to the boom, arm, or bucket actuators at a required flow rate when operated simultaneously with turning
Solution Approach 1:
The patent separates the control valve groups so that the first control valve group handles turning operations exclusively, while the second and third control valve groups handle boom, arm, and bucket operations. This eliminates the need to block pilot pressure to one group to prioritize another, as each group operates independently with its own dedicated control valves, enabling simultaneous operations without flow rate restrictions.
Solution Approach 2:
The system is pre-configured with dedicated control valve groups for different functions, so that when simultaneous operations are required, the pilot pressure pathways are already separated and ready to operate independently. This preliminary structural arrangement prevents the need for dynamic blocking and ensures that all actuators can receive required flow rates simultaneously during turning operations.
3Device complexity
If a single hydraulic pump supplies operating oil to multiple actuators through shared control valves, then the system structure can be simplified, but the flow rate requirement for each actuator cannot be met when multiple actuators operate simultaneously with turning
Solution Approach 1:
The patent implements separate control valve groups for different hydraulic functions: the first control valve group for turning, the second for boom and arm operations, and the third for bucket operations. Although this increases structural complexity compared to a shared system, it ensures that each actuator receives the required flow rate independently, eliminating the flow distribution conflicts that occur in simplified shared systems during simultaneous operations.
Solution Approach 2:
Each control valve group is designed to handle specific functions universally: the second control valve group can supply operating oil to both boom and arm actuators, while the third control valve group supplies to the bucket actuator. This multi-functional design within dedicated groups allows flexible operation while maintaining independent flow rate control for each actuator during simultaneous operations with turning.
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 configuration ensures that each actuator receives the necessary flow rate of operating oil regardless of the turning operation, maintaining operational efficiency and consistency in the performance of the boom, arm, and bucket.
Implementation Method 1
first and second liquid-pressure pump each configured to supply a pressure liquid to a boom actuator through a boom control valve, to an arm actuator through an arm control valve, and to a bucket actuator through a first bucket control valve; a third liquid-pressure pump configured to supply the pressure liquid to the bucket actuator through a second bucket control valve and to a turning motor through a turning control valve
Data Source
AI summary
A hydraulic driving system includes first to third liquid-pressure pumps and control valves. The first boom control valve is connected to the first hydraulic pump, and the second arm control valve and the first bucket control valve are connected to the second liquid-pressure pump. Further, the turning control valve and the second bucket control valve are connected to the third hydraulic pump. When a pilot pressure XAk0 is output from a bucket operating device while a turning operation is performed, a command switching device outputs a pilot pressure XAk1 to the first bucket control valve. When the pilot pressure XAk0 is output from the bucket operating device while the turning operation is performed, the command switching device outputs a pilot pressure XAk2 to a second bucket control valve.