Excavator Arm Valve Circuit for Oil Recycling and Meter-Out Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydraulic excavator drive systems face challenges in recycling hydraulic oil during arm crowding and performing independent meter-out control during arm pushing, requiring a low-cost simple circuit with a small number of components.
Innovation Solution
The system includes an arm cylinder, an arm control valve, and an arm switching valve that can switch between neutral, recycling, and meter-out control positions, incorporating a check valve to allow hydraulic oil recycling at arm crowding and independent meter-out control at arm pushing, using a low-cost simple circuit with a small number of components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a recycling line with a recycling valve and switching valve is added to enable hydraulic oil recycling at arm crowding, then hydraulic oil recycling is achieved, but the circuit complexity and number of components increase
Solution Approach 1:
The patent merges the recycling valve and switching valve into a single integrated arm switching valve with three positions (neutral, recycling, and meter-out control). This consolidation reduces the number of separate components while maintaining the functionality of both recycling and meter-out control operations.
Solution Approach 2:
The arm switching valve is designed as a multi-functional component that can perform three different functions: blocking all lines in neutral position, enabling hydraulic oil recycling in recycling position, and providing independent meter-out control in meter-out control position. This single valve replaces what would traditionally require multiple separate valves.
2Ease of operation
If independent meter-out control is implemented at arm pushing, then independent control capability is achieved, but the number of components and circuit complexity increase
Solution Approach 1:
The patent combines the meter-out control function with the recycling function in a single arm switching valve. The valve integrates multiple control capabilities (neutral blocking, recycling, and meter-out control) into one component, reducing the total number of valves needed in the system.
Solution Approach 2:
The arm switching valve is designed with three distinct positions that can be dynamically switched between based on operational requirements. This dynamic switching capability allows the system to adapt between different control modes (recycling vs. independent meter-out control) using a single versatile component.
3Device complexity
If a single-rod hydraulic cylinder is used with head-side line and rod-side line connected to control valve, then the hydraulic system can be simplified, but independent meter-out control and recycling cannot be achieved simultaneously
Solution Approach 1:
The patent segments the control functions by introducing an additional arm switching valve that specifically manages the rod-side line independently. This segmentation allows the head-side line to be controlled by the arm control valve while the rod-side line can be independently controlled for recycling or meter-out operations, achieving both simplification and versatility.
Solution Approach 2:
The arm switching valve acts as an intermediary component between the rod-side line and both the head-side line and tank. It mediates the hydraulic flow to enable either recycling (by connecting rod-side to head-side) or independent meter-out control (by connecting rod-side to tank), providing flexible control without complicating the overall system architecture.
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
Enables hydraulic oil recycling at arm crowding and independent meter-out control at arm pushing with a low-cost simple circuit, utilizing only the arm switching valve with a check valve, effectively managing pressure differences between supply lines.
Implementation Method 1
The arm switching valve incorporates therein a check valve that allows a flow from the rod-side line toward the head-side line when the arm switching valve is in the recycling position
Implementation Method 2
an arm switching valve connected to the arm pushing supply line by a rod-side line, connected to the arm crowding supply line by a head-side line, and connected to the tank by a second tank line
Data Source
AI summary
A hydraulic excavator drive system (1) includes an arm control valve (31) and an arm switching valve (41). The arm switching valve (41) is connected to an arm pushing supply line (34) by a rod-side line (42) and to an arm crowding supply line (35) by a head-side line (43). The arm switching valve (41) is switched between a neutral position, a recycling position in which the arm switching valve (41) allows the rod-side line (42) to communicate with the head-side line (43) and a second tank line (44), and a meter-out control position in which the arm switching valve (41) allows the head-side line (43) to communicate with the tank line (44). The arm switching valve (41) incorporates therein a check valve (45) that allows a flow from the rod-side line (42) toward the head-side line (43) when the arm switching valve (41) is in the recycling position.