Hydraulic Shovel Actuator Control Using Meter-In and Meter-Out Valves
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Solution Overview
Problem
Existing shovels have limited flexibility in controlling the movement of hydraulic actuators due to the fixed correspondence between spool displacement and oil passage opening areas in spool valves.
Innovation Solution
A shovel equipped with multiple hydraulic actuators, pressure sensors, meter-in and meter-out valves, and a controller that calculates required flow rates based on movement commands and output characteristics, allowing for more flexible control of hydraulic actuator movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a spool valve is used to control hydraulic actuators, then the opening areas of oil passages can be controlled, but the flexibility in controlling hydraulic actuator movements is limited due to fixed correspondence between spool displacement and opening areas
Solution Approach 1:
The control system is segmented into multiple independent components: a controller that calculates required flow rates, separate meter-in valves for controlling hydraulic oil supply, and meter-out valves for controlling hydraulic oil return. This segmentation allows each component to be optimized independently and provides greater flexibility in controlling hydraulic actuator movements compared to a single spool valve system.
Solution Approach 2:
The system transitions from the static, fixed correspondence of spool displacement to opening areas to a dynamic control system where the controller continuously calculates required flow rates based on movement commands and output characteristics, and adjusts valve openings in real-time. This enables adaptive control that responds to changing operational requirements.
2Measurement precision
If multiple valves and sensors are introduced for flexible control, then control precision is improved, but device complexity increases
Solution Approach 1:
Pressure sensors are installed in each hydraulic actuator to detect hydraulic oil pressure. The detected pressure information is fed back to the controller, which uses it to calculate the required flow rate and determine appropriate valve openings. This feedback mechanism enables precise control by continuously monitoring and adjusting based on actual system state.
Solution Approach 2:
The mechanical spool valve system is replaced with an electro-hydraulic control system where the controller electronically calculates required flow rates and actuates the meter-in and meter-out valves through electrical signals. This substitution provides more precise and flexible control while reducing the mechanical complexity of the valve body itself.
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 enables more precise and flexible control of hydraulic actuator movements, improving the operational capabilities of the shovel while reducing energy consumption.
Implementation Method 1
a pressure sensor configured to detect a pressure of hydraulic oil in each of the hydraulic actuators
Implementation Method 2
a meter-in valve in correspondence with each of the hydraulic actuators
Implementation Method 3
a meter-out valve in correspondence with each of the hydraulic actuators
Data Source
AI summary
A shovel includes a plurality of hydraulic actuators each configured to move in response to a movement command; a pressure sensor configured to detect a pressure of hydraulic oil in each of the hydraulic actuators; a meter-in valve in correspondence with each of the hydraulic actuators; a meter-out valve in correspondence with each of the hydraulic actuators; and a controller having a plurality of output characteristics set for each of the hydraulic actuators. The controller is configured to calculate a required flow rate corresponding to the movement command, based on an output characteristic corresponding to the movement command from among the plurality of output characteristics.