Hydraulic Speed-Up Valve Control for Precise Excavator Locus Tracking
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Solution Overview
Problem
Construction machines experience deviations from target loci during excavation due to changes in excavation load, leading to reduced finishing precision and increased operational inefficiencies, as existing locus controllers fail to effectively manage hydraulic fluid diversion and pressure balances between boom and arm cylinders.
Innovation Solution
A construction machine configuration that includes a first and second hydraulic actuator, directional control valves, and an excavation load sensor, with a speed-up control section that adjusts the driving amount of the directional control valves based on the pressure difference between the boom and arm cylinder hydraulic chambers, ensuring precise hydraulic fluid diversion and maintaining speed balance between actuators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the excavation load increases, then the excavation force improves, but the tip end of the front work device deviates from the target locus due to changes in diversion amount
Solution Approach 1:
The control device monitors the actual speeds of the boom and arm cylinders, compares them with target speeds, and adjusts the opening degrees of the diversion valves in real-time based on speed deviations and excavation load conditions to maintain precise locus control
Solution Approach 2:
The opening degrees of the diversion valves are dynamically adjusted based on real-time detection of excavation load and cylinder speeds, allowing the system to adapt to changing load conditions while maintaining speed balance and precision
2Speed
If the opening degree of directional control valve for arm is set lower to maintain speed balance under light load, then the speed balance improves, but the system cannot adapt when excavation load increases
Solution Approach 1:
The system dynamically adjusts valve opening degrees based on detected excavation load and actual cylinder speeds, transitioning from static pre-set openings to real-time adaptive control that maintains speed balance across varying load conditions
Solution Approach 2:
Speed sensors monitor actual cylinder speeds and feed this information back to the control device, which adjusts diversion valve openings accordingly to maintain speed balance under varying load conditions
3Manufacturing precision
If the locus controller adjusts opening degrees of directional control valves to maintain convergence, then the convergence control improves, but the tip end deviates when excavation load increases due to diversion amount changes
Solution Approach 1:
The control device uses feedback from speed sensors and load detection to continuously adjust diversion valve openings, maintaining both precision convergence and operational efficiency under varying excavation loads
Solution Approach 2:
The control device proactively adjusts diversion valve openings based on detected load changes before significant speed imbalances occur, preventing deviations rather than merely correcting them
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 effectively suppresses deviations from the target locus and prevents relief-caused losses, ensuring predetermined finishing precision even under increased excavation loads by dynamically controlling the hydraulic fluid diversion and pressure balance between the boom and arm cylinders.
Implementation Method 1
a hydraulic pump device (2) including first and second hydraulic pumps (21, 22)... a first directional control valve (23) provided in a first pump line (L1) that is a delivery hydraulic line of the first hydraulic pump (21) and controlling a flow rate and a direction of a hydraulic fluid supplied to the first hydraulic actuator (5)... a second directional control valve (25) provided in the second pump line (L2) and controlling a flow rate and a direction of a hydraulic fluid supplied to the second hydraulic actuator (6)
Implementation Method 2
an excavation load sensor that detects an excavation load imposed on the work implement (15)... a first speed-up control section that drives the first speed-up directional control valve (24)... configured to control a driving amount of the first speed-up directional control valve (24) in response to the excavation load detected by the excavation load sensor
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a construction machine that can attain predetermined finishing precision while avoiding a relief-caused loss even if an excavation load increases in leveling work, slope face shaping work, or the like. The construction machine includes: a work implement driven by a first hydraulic actuator and a second hydraulic actuator; a first directional control valve controlling a flow rate and a direction of a hydraulic fluid supplied to the first hydraulic actuator; a first speed-up directional control valve provided in a second pump line and controlling a flow rate and a direction of a hydraulic fluid supplied to the first hydraulic actuator; and a second directional control valve controlling a flow rate and a direction of a hydraulic fluid supplied to the second hydraulic actuator. The construction machine includes: an excavation load sensor that detects an excavation load imposed on the work implement; and a first speed-up control section that drives the first speed-up directional control valve, and the first speed-up control section is configured to control a driving amount of the first speed-up directional control valve in response to the excavation load.