Construction Machinery Hydraulic Control with Variable Orifice
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In construction machinery, existing electro-hydraulic main control valves with fixed orifice structures lead to inefficient flow distribution and decreased controllability, especially under heavy loads, resulting in reduced fuel efficiency and work efficiency.
Innovation Solution
A control system for construction machinery that includes a first hydraulic pump, actuators, control valves, spool displacement adjusting valves, and a control valve control portion using an electro-proportional pressure reducing valve (EPPRV) to dynamically adjust the spool displacement and pilot signal pressure, allowing for customizable manipulation signal ratios and improved horsepower distribution between hydraulic pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed orifice structure is used in the hydraulic line, then the flow distribution between actuators is adjusted, but inefficient flow distribution and deterioration in controllability occur due to the fixed orifice area
Solution Approach 1:
The patent replaces the fixed orifice structure with a variable orifice structure that can dynamically adjust its opening area based on operating conditions. The control valve control portion varies the orifice area ratio between parallel lines to optimize flow distribution for different work conditions, resolving the contradiction between fixed flow adjustment and adaptive efficiency.
Solution Approach 2:
The system changes the orifice area parameter dynamically based on manipulation signals and work conditions. By varying the orifice area ratio in response to operator input and system state, the patent achieves both good controllability and efficient flow distribution under different conditions.
2Force
If a relatively great load is exerted on the actuator, then the actuator can perform heavy work, but fuel efficiency decreases due to pressure loss
Solution Approach 1:
The patent dynamically adjusts the orifice area ratio based on load conditions and manipulation signals. When heavy loads are present, the system optimizes the orifice opening to minimize pressure loss while maintaining sufficient flow, thereby improving fuel efficiency without sacrificing load capacity.
3Power
If the horsepower distribution control of the hydraulic pumps is performed, then the power distribution is optimized, but a balance in flow distribution between actuators is further required for work efficiency
Solution Approach 1:
The patent applies different orifice area ratios to different parallel lines based on the specific actuator requirements and work conditions. This localized adjustment of flow characteristics complements the overall horsepower distribution control, ensuring both power optimization and flow balance for improved work efficiency.
4Speed
If the spool displacement of the control valve is increased, then the actuator speed is improved, but the flow distribution balance between parallel lines deteriorates
Solution Approach 1:
The patent dynamically adjusts the orifice area ratio in response to spool displacement and manipulation signals. When spool displacement increases to improve actuator speed, the system compensates by adjusting the orifice opening to maintain flow distribution balance between parallel lines.
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 solution enhances fuel efficiency, controllability, and work efficiency by adjusting the orifice area ratio and spool displacement to match user conditions, ensuring optimal speed balance between actuators, thereby improving user convenience and work efficiency.
Implementation Method 1
first and second spool displacement adjusting valves configured to supply a pilot signal pressure to spools of the first and second control valves in proportion to an inputted control signal
Implementation Method 2
first and second actuators connected to the first hydraulic pump through first and second parallel lines respectively and operable by a working oil discharged from the first hydraulic pump
Data Source
AI summary
A control system for construction machinery, includes a hydraulic pump, first and second actuators connected to the hydraulic pump through first and second parallel lines respectively, first and second control valves installed in the first and second parallel lines respectively and configured to control operations of the first and second actuators, first and second spool displacement adjusting valves configured to control displacement amounts of the spools of the first and second control valves, and a control valve control portion configured to output the control signal, and configured to limit a maximum allowable value of the manipulation signal for the first actuator to a value selected by the operator and limit a spool displacement amount of the second control valve according to the limited manipulation signal for the first actuator when the manipulation signal for a multiple operation of the first and second actuators is received.