Hydraulic Pump Flow Control for Single and Combined Actuator Operation
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Solution Overview
Problem
Existing hydraulic pump control systems face challenges in maintaining optimal driving speed for hydraulic actuators during both single and combined operations, leading to insufficient or excessive delivery flow rates, resulting in energy loss.
Innovation Solution
A construction machine equipped with a variable displacement hydraulic pump, flow control valves, operation devices, and a controller that computes and adjusts target displacement volumes to ensure suitable speeds for hydraulic actuators while minimizing delivery flow rate, by selecting either the sum total or maximum value of computed displacement volumes based on operation amounts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the maximum tilting amount is increased to ensure sufficient delivery flow rate during combined operation, then the delivery flow rate becomes excessive during single operation, but energy loss is enlarged
Solution Approach 1:
The patent applies dynamics by making the maximum tilting amount adjustable rather than fixed. The control unit dynamically changes the maximum tilting amount based on whether single operation or combined operation is detected, allowing the system to adapt to different operational requirements and avoid excessive energy loss during single operation while ensuring sufficient flow rate during combined operation
Solution Approach 2:
The patent changes the parameter of maximum tilting amount based on operational conditions. When combined operation is detected, the maximum tilting amount is increased to ensure sufficient delivery flow rate; when single operation is detected, it is reduced to minimize energy loss. This parameter adjustment resolves the contradiction between maintaining adequate flow rate and reducing energy waste
2Speed
If the maximum tilting amount is set for each hydraulic actuator individually, then optimum maximum driving speed is obtained during single operation, but delivery flow rate becomes insufficient during combined operation
Solution Approach 1:
The patent applies universality by making the maximum tilting amount a shared resource that serves multiple hydraulic actuators. Instead of each actuator having a fixed independent maximum tilting amount, the control unit manages a unified maximum tilting amount that can be dynamically adjusted to serve the combined needs of multiple actuators during combined operation
Solution Approach 2:
The system dynamically adjusts the maximum tilting amount based on the number of actuators operating simultaneously. During combined operation, the maximum tilting amount is increased to provide sufficient delivery flow rate to multiple actuators, while maintaining individual actuator speed requirements through coordinated control
3Quantity of substance
If the delivery flow rate is increased to meet the sum total of required flow rates for multiple hydraulic actuators during combined operation, then the delivery flow rate becomes excessive during single operation
Solution Approach 1:
The patent changes the delivery flow rate parameter dynamically based on operational mode. The control unit detects whether single or combined operation is occurring and adjusts the maximum tilting amount accordingly, which directly controls the delivery flow rate. This ensures the flow rate matches the actual demand, improving energy efficiency during single operation while meeting the sum total requirements during combined operation
Solution Approach 2:
The system uses feedback from the control unit that monitors operational conditions to adjust the maximum tilting amount. By detecting the operational mode (single or combined), the system provides feedback that triggers appropriate adjustments to the delivery flow rate, preventing excessive flow rate and energy waste during single operation
Data Source
AI summary
Provided is a construction machine capable of driving each hydraulic actuator at a suitable speed while suppressing delivery flow rate of a hydraulic pump, both at a single operation time of driving each hydraulic actuator respectively singularly and at a combined operation time of simultaneously driving a plurality of hydraulic actuators. A controller is configure to compute a first required pump flow rate for each of operation amounts of a plurality of operation devices, compute a second required pump flow rate greater than the first required pump flow rate for the same operation amount for each of the operation amounts of the plurality of operation devices, select as a final required pump flow rate either smaller one of a sum total value of the first required pump flow rates computed for the operation amounts of the plurality of operation devices and a maximum value of the second required pump flow rates computed for the operation amounts of the plurality of operation devices, and control a regulator in such a manner that the delivery flow rate of the hydraulic pump and the final required pump flow rate will be equal.