Hydraulic Boom Control Using Attachment Weight for Stable Lowering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hydraulic excavator systems face instability in boom lowering speed control due to dynamic pressure fluctuations from varying working attachment weights, leading to poor operability.
Innovation Solution
A boom lowering control system that inputs working attachment weight information to a controller, using a map to estimate holding pressure and adjust the meter-out opening area of the control valve based on this estimation to maintain consistent discharge flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the discharge flow rate from the boom cylinder head side oil chamber is controlled by a control valve to maintain constant boom lowering speed, then the lowering speed can be regulated according to operating tool input, but the discharge flow rate varies with pressure changes caused by different working attachment weights, resulting in inaccurate lowering speed control
Solution Approach 1:
The control system detects the actual discharge flow rate and compares it with the target flow rate, then adjusts the control valve opening area based on this feedback to maintain accurate lowering speed control despite pressure variations from different attachment weights
Solution Approach 2:
The control valve opening area is dynamically adjusted based on real-time pressure conditions and flow rate feedback, allowing the system to adapt to varying attachment weights and maintain consistent lowering speed control accuracy
2Ease of operation
If dynamic pressure values from pressure sensors are used for control, then real-time pressure information is available, but the control becomes unstable and unpredictable due to unstable and unpredictable pressure values from varying usage status
Solution Approach 1:
A flow rate detection device serves as an intermediary to directly measure the discharge flow rate, providing stable and accurate flow information that mediates between the unstable pressure signals and the control valve, enabling stable control without being affected by pressure fluctuations
Solution Approach 2:
The control system replaces reliance on mechanical pressure sensor readings with direct flow rate detection, substituting the indirect pressure-based control approach with a direct flow measurement approach that provides more stable and predictable control signals
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
Stable boom lowering speed control is achieved, improving operability by ensuring the boom lowers at a consistent speed regardless of attachment changes.
Implementation Method 1
a pressure in the boom cylinder head side oil chamber is high. Therefore, a lowering speed of the boom is normally controlled by controlling a discharge flow rate from a boom cylinder head side oil chamber
Data Source
AI summary
In a working machine in which a replaceable working attachment is attached to a tip portion of a working arm including a boom, even when the working attachment is replaced, lowering the boom at a lowering speed corresponding to an operation amount of an operating tool is controlled in a stable state. A monitor device for inputting information relating to a weight of an attached working attachment to a controller is provided. A map indicating a relationship between the weight of the replaceable working attachment (8) and a holding pressure of a boom cylinder head side oil chamber is provided in a controller. A holding pressure estimated value corresponding to the weight of the attached working attachment is obtained, based on the map. A configuration is adopted so that an opening area of a contraction side discharge opening of a control valve is controlled based on the holding pressure estimated value.