Hydraulic Pilot Control Oscillation Damping
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Solution Overview
Problem
Existing hydraulic pilot control units for mobile vehicles suffer from oscillatory movements caused by vehicle vibrations and abrupt mechanism releases, leading to uncontrolled operations and safety issues, with prior solutions either providing insufficient damping or increasing operational force.
Innovation Solution
A hydraulic pilot control unit with an oscillation damping system featuring a casing with two chambers, where the upper chamber is connected to the discharge line through a strategically placed discharge hole, allowing hydraulic oil to fill completely and purge air bubbles, and utilizing coaxial springs to manage damping resistance during actuation and return strokes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a damping system is added to prevent oscillatory movements, then oscillation damping is improved, but device complexity increases
Solution Approach 1:
The damping function is merged with the existing upper chamber and discharge hole structure. The upper chamber serves dual purposes: as a hydraulic chamber and as a damping chamber. The discharge hole strategically positioned in the upper chamber creates a flow restriction that provides damping during the return stroke without requiring separate damping components.
Solution Approach 2:
The upper chamber is designed to perform multiple functions: it serves as the hydraulic chamber for normal operation and simultaneously as the damping chamber for oscillation control. This multi-functionality eliminates the need for dedicated damping components while achieving the desired oscillation damping effect.
2Stability of the object's composition
If damping resistance is increased to reduce oscillations, then oscillation damping is improved, but operational force increases
Solution Approach 1:
The damping resistance is made dynamic rather than constant. During the actuation stroke, the poppet encounters minimal resistance as hydraulic oil is pushed toward the discharge hole. During the return stroke, the strategically positioned discharge hole creates controlled flow restriction that provides damping. This dynamic resistance profile achieves oscillation damping without significantly increasing operational force.
Solution Approach 2:
The damping effect is applied periodically during the return stroke rather than continuously. The discharge hole is positioned to create flow restriction only when the poppet is moving upward, providing damping during the return stroke while minimizing impact on the actuation stroke. This periodic application of damping reduces oscillations without substantially increasing operational force.
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
Effectively dampens oscillatory motions without increasing operational force, ensuring safe and controlled vehicle operations while reducing material and fabrication costs compared to prior art solutions.
Implementation Method 1
During such return stroke, the poppet 7 slides within the upper chamber 6 experiencing a resistance against its movement, thereby producing a damping effect; such resistance is due to the fact that the hydraulic oil is forced to move from the upper to the lower part of the upper chamber 6 through the clearance between the external diameter of the poppet 7 and the internal diameter of the upper chamber 6.
Implementation Method 2
a pressure spring 2 that transmits the pressing force applied from the poppet 7 to the spool 8
Data Source
Figure 1
Figure 2
Figure 3a
AI summary
The present invention relates to the field of units for hydraulic pilot control of directional-control valves used in the fabrication of mobile vehicles and particularly relates to a hydraulic pilot control with an oscillation damping system. Connections are provided among the chambers (6,9) in the pilot control unit (1) to provide a damping effect in the actuation stroke, thereby preventing any oscillation: the provision of such connections among the chambers has the function of preventing air stagnation; this arrangement prevents any undamped behavior due to incomplete filling upon installation or to air transported in the hydraulic fluid.