Hydraulic Switch Valve Pilot Pressure Staging for Smooth Speed Changes
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Solution Overview
Problem
Existing hydraulic systems for work machines face challenges in efficiently managing pilot pressure to switch hydraulic switch valves quickly and smoothly, leading to inefficiencies in speed changes and potential shocks during operation.
Innovation Solution
The hydraulic system incorporates a hydraulic pump to supply a pilot fluid and a hydraulic switch valve that switches based on pilot pressure. It includes a direction switch valve to apply a first pilot pressure and a pressure applying device to apply a second pilot pressure, which is lower than the first, to facilitate smooth and rapid switching of the hydraulic switch valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a single pilot pressure is used to switch the hydraulic switch valve, then the valve can be switched to a switching position, but the switching speed is insufficient and shocks occur during operation
Solution Approach 1:
The system applies a second pilot pressure (lower than the first) in advance through the pressure applying device before the main switching action occurs. This preliminary pressure preparation enables the hydraulic switch valve to switch more quickly and smoothly from one position to another, reducing switching time and minimizing shocks during the transition.
Solution Approach 2:
The system uses two different pilot pressure levels (first pilot pressure and second pilot pressure that is lower) to control the hydraulic switch valve. By changing the pressure parameter during the switching process, the valve can transition more efficiently between positions, improving switching speed while reducing harmful shocks.
2Loss of time
If pilot pressure is applied quickly to switch the valve, then switching is rapid, but shocks and instability occur during the switching process
Solution Approach 1:
The pressure applying device prepares the second pilot pressure in advance, creating a controlled pressure environment before the main switching action. This preliminary preparation reduces the abruptness of pressure changes, allowing quick switching while maintaining system stability and reducing shocks.
Solution Approach 2:
The system uses the second pilot pressure as a cushioning mechanism that prepares the hydraulic switch valve for the upcoming switching action. This beforehand cushioning reduces the impact and instability during switching, enabling rapid transitions while maintaining system stability.
3Device complexity
If only a direction switch valve is used to apply pilot pressure, then the system structure is simpler, but the switching performance is insufficient
Solution Approach 1:
The pressure applying device is integrated into the existing hydraulic system structure, working in conjunction with the direction switch valve. This multi-functional arrangement uses the same pilot fluid supply system to provide both directional control and pressure modulation, achieving improved switching performance without significantly increasing system complexity.
Solution Approach 2:
The second pilot pressure acts as an intermediary element between the pilot fluid supply and the hydraulic switch valve. This intermediate pressure level facilitates smoother and faster switching by preparing the valve for the main pressure change, improving productivity while maintaining a relatively simple system structure.
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 configuration enables quick and efficient switching of the hydraulic switch valve, improving the speed change process and reducing shocks during operation, thereby enhancing the overall performance and reliability of the hydraulic system.
Implementation Method 1
a hydraulic pump to supply a pilot fluid
Implementation Method 2
a direction switch valve to apply a first pilot pressure to the hydraulic switch valve
Implementation Method 3
a pressure applying device to apply a second pilot pressure to the hydraulic switch valve. The second pilot pressure is lower than the first pilot pressure
Data Source
AI summary
A hydraulic system for a work machine includes a hydraulic pump to supply a pilot fluid, and a hydraulic switch valve to be switched to a plurality of switching positions based on a pilot pressure. The pilot pressure is a pressure of the pilot fluid supplied from the hydraulic pump. The hydraulic system includes a direction switch valve to apply a first pilot pressure to the hydraulic switch valve to switch the hydraulic switch valve into one of the plurality of switching positions. The hydraulic system includes a pressure applying device to apply a second pilot pressure to the hydraulic switch valve. The second pilot pressure is lower than the first pilot pressure.