Construction Equipment Swing Control Reducing Power Loss
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Solution Overview
Problem
In construction machinery, sudden swing operations lead to significant power loss due to the high rotational inertia of the top swing body, resulting in increased pressure and flux discharge from the hydraulic pump, which is not efficiently utilized by the swing motor, causing damage and inefficiency.
Innovation Solution
A swing control apparatus that includes a hydraulic pump, a pressure sensor, and a control unit that calculates and adjusts the pump command value based on the swing operation quantity and discharge pressure, using proportional and integral control to manage the discharge flux and pressure, thereby minimizing power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the swing operation quantity is increased to suddenly rotate the top swing body, then the swing speed increases, but the discharge pressure of the hydraulic pump exceeds the swing relief pressure causing power loss
Solution Approach 1:
The control unit preliminarily adjusts the pump command value based on the swing operation quantity before the swing motor can fully utilize the discharged flux. By anticipating the swing demand and gradually increasing the pump output, the system prevents sudden pressure spikes that would otherwise exceed the swing relief pressure and cause power loss through the relief valve.
Solution Approach 2:
The control unit continuously monitors the discharge pressure of the hydraulic pump and adjusts the pump command value in real-time based on feedback from the actual pressure conditions. When the discharge pressure approaches or exceeds the swing relief pressure, the control unit reduces the pump command value to maintain pressure within efficient operating limits, thereby minimizing power loss.
2Quantity of substance
If the discharge flux from the hydraulic pump is increased to match the swing operation quantity, then the swing motor receives sufficient flux, but the top swing body's rotational inertia prevents sudden speed increase causing pressure buildup
Solution Approach 1:
The system dynamically adjusts the pump command value based on the relationship between discharge flux and actual swing speed demand. Rather than maintaining a fixed flux-output relationship, the control unit continuously modifies the pump command to match the instantaneous requirements of the swing motor, accounting for the rotational inertia that prevents immediate speed response to flux changes.
3Productivity
If the pump command value is suddenly increased to provide maximum flux, then the swing operation responds quickly, but the discharge pressure exceeds the first reference pressure causing excessive power loss
Solution Approach 1:
The control unit changes the pump command value parameter in a controlled, gradual manner rather than making sudden jumps. By incrementally adjusting the pump command based on the swing operation quantity and current discharge pressure, the system achieves the necessary swing operation response while keeping the discharge pressure below the first reference pressure threshold, thereby minimizing power loss through the swing relief valve.
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 power loss by gradually increasing the discharge flux and pressure, minimizing the quantity of working oil drained through the swing relief valve, while maintaining the increasing rate of the swing speed, thus enhancing the efficiency of the swing motor operation.
Implementation Method 1
a hydraulic pump discharging working oil for driving a swing motor and controlling a discharge flux according to an input pump command value Vpump
Implementation Method 2
a pressure sensor sensing pressure of the working oil discharged from the hydraulic pump
Data Source
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AI summary
Disclosed is a swing control apparatus of construction machinery, including: a hydraulic pump 100 discharging working oil for driving a swing motor 120 and controlling a discharge flux according to an input pump command value Vpump; a pressure sensor 102 sensing pressure of the working oil discharged from the hydraulic pump 100; and a control unit 150 calculating the pump command value Vpump based on a swing operation quantity Vsw input from the swing operation unit 130 to output the calculated pump command value to the hydraulic pump 100, wherein when the input swing operation quantity Vsw is larger than a preset reference swing operation quantity Vswo and the discharge pressure Ppump of the hydraulic pump 100 detected by the pressure sensor 102 is lower than a first reference pressure Pswr1, the control unit 150 calculates a converted swing operation quantity Vsw' gradually increasing from the reference swing operation quantity Vswo to the input swing operation quantity Vsw and calculates the pump command value Vpump of the hydraulic pump 100 corresponding to the converted swing operation quantity Vsw'.