Excavator Hydraulic Pump Priority Control for Boom and Stick
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Solution Overview
Problem
Conventional hydraulic control systems for working machines like hydraulic excavators face inefficiencies in operability and working efficiency due to pre-set priority settings for pressure oil supply from hydraulic pumps, which may not be suitable for all tasks and can vary based on operator desired working speed, leading to suboptimal performance even when the same hydraulic actuators are operated together.
Innovation Solution
A hydraulic control system with first and second hydraulic pumps, multiple hydraulic actuators, and flow rate control valves, where the control system electronically manages the flow rates and allows arbitrary change in the working order of these valves based on operator input, enabling flexible priority settings for pressure oil supply from either pump, especially for boom, stick, and swiveling motors, and includes a mode selection mechanism to optimize operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pre-set priority settings for pressure oil supply are used, then system simplicity is maintained, but operability and working efficiency are degraded for specific tasks
Solution Approach 1:
The patent implements dynamic priority assignment where the main pump designation changes automatically based on real-time operational conditions. When a hydraulic actuator requests oil supply, the system dynamically determines which pump should serve as main pump, rather than using fixed pre-set priorities. This dynamic adaptation improves operability for different tasks without requiring complex manual reconfiguration.
Solution Approach 2:
The control system automatically manages pump priority assignment without operator intervention. The ECU monitors hydraulic actuator operations and autonomously determines optimal main pump selection, allowing the system to self-adjust to different working conditions. This maintains simplicity from the operator's perspective while achieving task-optimized performance.
2Productivity
If fixed main pump assignment is used, then system complexity is reduced, but working efficiency is degraded when multiple actuators operate simultaneously
Solution Approach 1:
The patent replaces mechanical priority-setting mechanisms with electronic control. Instead of using complex mechanical valve arrangements or physical pump configurations to establish priority, the system uses an ECU to electronically manage flow rate control valves. This substitution enables flexible, software-based priority assignment that improves working efficiency without proportionally increasing mechanical complexity.
Solution Approach 2:
The system changes the operational parameters of flow rate control valves based on real-time conditions. When determining which pump serves as main pump, the ECU adjusts the opening degrees of relevant flow rate control valves to optimize oil supply distribution. This parameter-based control enables efficient adaptation to different operational scenarios.
3Adaptability or versatility
If auxiliary valves are installed for priority control, then flow rate priority can be adjusted, but device complexity and cost increase
Solution Approach 1:
The existing flow rate control valves serve multiple functions: they control both the magnitude of oil flow and the priority of pump supply through electronic modulation. Instead of requiring separate auxiliary valves for priority control, the system makes the existing valves multi-functional by enabling the ECU to adjust their opening degrees dynamically. This universality achieves priority adjustment flexibility without adding valve components.
Solution Approach 2:
The ECU acts as an intermediary that manages priority control through electronic signals rather than direct mechanical valve manipulation. Instead of installing complex mechanical priority-control valves, the system uses the ECU to send control signals to existing flow rate control valves, mediating the priority assignment through electronic control. This approach achieves adaptability while avoiding additional mechanical complexity.
Data Source
AI summary
To enable to arbitrarily change a hydraulic pump which supplies pressure oil to a hydraulic actuator at first in a hydraulic control system equipped with the hydraulic actuator using both first and second hydraulic pumps as a pressure oil source. An operation means is installed which can arbitrarily change working order of the first flow rate control valves for boom and stick for controlling the supply flow rate from first hydraulic pump to boom cylinder and stick cylinder and second flow rate control valves for boom and stick for controlling the supply flow rate from second hydraulic pump to boom cylinder and stick cylinder.