Excavator Hydraulic Flow Control for Stable Swing and Arm Motion
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Solution Overview
Problem
Existing shovels destabilize arm motion during complex operations involving swing and arm closing when the bucket is not in contact with the excavation object, leading to insufficient pressing force from the swing hydraulic motor.
Innovation Solution
A shovel design incorporating a control device that adjusts the opening area of a control valve based on work details, using sensors and actuators to stabilize motion during complex operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the flow rate of hydraulic oil to the arm cylinder is reduced to increase swing hydraulic motor flow rate, then the pressing force from the swing hydraulic motor is improved, but the motion stability of the arm is worsened
Solution Approach 1:
The patent applies dynamics by making the control valve opening area variable rather than fixed. The control device dynamically adjusts the opening area of the control valve in the second conduit based on detected work conditions (such as whether the bucket is contacting the excavation object). This allows the system to optimize hydraulic oil distribution in real-time, increasing flow to the swing hydraulic motor when needed while maintaining sufficient flow to the arm cylinder for stability, thereby resolving the contradiction between pressing force and motion stability.
2Power
If hydraulic oil is supplied preferentially to the swing hydraulic motor, then the pressing force is improved, but the arm motion becomes unstable when the bucket is not contacting the excavation object
Solution Approach 1:
The patent implements feedback control by using sensors to detect work conditions (such as bucket contact status with the excavation object) and feeding this information back to the control device. The control device then adjusts the control valve opening area accordingly. When the bucket is not contacting the excavation object, the system maintains larger opening area to ensure stable arm motion; when contact is detected, it reduces the opening area to prioritize swing hydraulic motor flow rate and pressing force, thus resolving the contradiction between pressing force and operation reliability.
3Speed
If the control valve opening area is reduced to stabilize swing operation, then the swing performance is improved, but the arm cylinder receives insufficient hydraulic oil flow
Solution Approach 1:
The patent applies dynamics by making the control valve opening area variable rather than fixed. The control device dynamically adjusts the opening area of the control valve in the second conduit based on detected work conditions (such as whether the bucket is contacting the excavation object). This allows the system to optimize hydraulic oil distribution in real-time, increasing flow to the swing hydraulic motor when needed while maintaining sufficient flow to the arm cylinder for stability, thereby resolving the contradiction between pressing force and motion stability.
Data Source
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AI summary
A shovel (100) according to an embodiment of the present invention includes a left main pump (14L), an arm cylinder (8), a swing hydraulic motor (2A), a directional control valve (173) corresponding to the swing hydraulic motor (2A), a directional control valve (176L) corresponding to the arm cylinder (8), a left center bypass conduit (40L) connecting the left main pump (14L) and the directional control valve (173), a control valve (177) installed in a left parallel conduit (42L) connecting the left center bypass conduit (40L) and the directional control valve (176L), and a controller (30) configured to control the opening area of the control valve (177) according to information on work details.