Hydraulic Cylinder Stem Holding Valve With Staged Throttle Unblocking
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Solution Overview
Problem
Conventional hydraulic valves used for securing hydraulically lifted loads are prone to failure due to contamination, vibrations, pressure and temperature fluctuations, and wear, leading to leakage and loss of function.
Innovation Solution
The secondary check valve is designed with a first and second throttle mechanism upstream and downstream of the seal, respectively, with tightly controlled throttle gaps to minimize fluid flow during opening and closing, preventing seal damage and wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hydraulic valves are used for securing hydraulically lifted loads, then the device can perform basic valve functions, but the valves are prone to failure due to contamination, vibrations, pressure and temperature fluctuations, and wear, leading to leakage and loss of function
Solution Approach 1:
The valve is divided into two separate check valves arranged in series: a primary check valve and a secondary check valve. Each valve has its own sealing mechanism, allowing the system to maintain functionality even if one valve degrades or fails due to wear or contamination
Solution Approach 2:
The secondary check valve acts as a backup protection mechanism that is already in place before failure occurs. It provides preemptive protection against load dumping in case the primary valve fails due to harmful factors like contamination or wear
2Productivity
If the secondary check valve is opened quickly to reduce load, then the load can be reduced faster, but decompression flow occurs which causes wear and displacement of the elastomeric seal, leading to loss of function
Solution Approach 1:
The control shaft is designed to automatically perform preliminary actions by moving through intermediate positions that gradually open the valve. This staged opening process prevents sudden decompression flows that would damage the seal, while still achieving the desired load reduction
Solution Approach 2:
The valve opening process is made dynamic and adaptive through the control shaft's ability to move through multiple positions (closing position, intermediate positions, opening position). The valve responds dynamically to pressure conditions, opening gradually rather than abruptly, which protects the seal while maintaining productivity
3Speed
If the secondary check valve closes quickly, then the valve response time is reduced, but the seal may be damaged by dynamic pressure flow, leading to wear and displacement
Solution Approach 1:
The control shaft performs preliminary action by closing the second throttle before the seal contacts the valve seat. This sequence prevents high-velocity fluid flow from directly impacting the seal during closure, reducing wear and displacement risks while maintaining fast response times
Solution Approach 2:
The control shaft rushes through the intermediate closing position quickly to minimize the time the seal is exposed to potential damage, then completes the closure by closing the second throttle. This allows fast valve response while protecting the seal from prolonged exposure to harmful dynamic pressure flows
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 design significantly enhances operational reliability by preventing decompression flows and seal damage, ensuring the hydraulic cylinder shaft is held securely in position over a longer period.
Implementation Method 1
which in the secondary valve body closing position of the secondary valve body bears tightly against a, preferably circular, contact surface of the secondary valve seat of the hydraulic block, so that the secondary check valve is closed against a flow of the drive fluid
Implementation Method 2
the secondary valve body is provided with a spring-elastic compressible, preferably annular, in particular circular, for example torus-shaped, seal, preferably made of an elastomer
Implementation Method 3
The secondary check valve is designed with a first and second throttle mechanism upstream and downstream of the seal, respectively, with tightly controlled throttle gaps to minimize fluid flow during opening and closing
Implementation Method 4
preventing decompression flows and seal damage
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention relates to a device for holding a stem of a hydraulic cylinder in position, comprising a hydraulic block having a primary check valve (22) and a secondary check valve (23) connected in series, the latter comprising a secondary control stem (43), which is provided with a secondary valve body (52) and a seal. A first throttle (82.1) is formed upstream of the seal, and a second throttle (82.2) is formed downstream of the seal. The throttles (82.1, 82.2) are closed in a secondary control stem closed position, in which the secondary check valve (23) is blocked tight by means of the seal, wherein said throttles each have a very small throttle closing gap of preferably no more than 0.1 mm. Proceeding therefrom, the secondary control stem (43) can be transferred in an axial direction into an intermediate position (90.1) in which the throttles are still closed, that is, have a very small closing gap, but in which the secondary valve body (52) and the seal thereof is lifted from a secondary valve seat. Proceeding therefrom, the secondary control stem (43) can be moved further into an opening position in which the throttles are open, that is, each have a throttle opening gap which is much larger than the throttle closing gap, and in which the secondary valve body (52) and the seal thereof is lifted from the secondary valve seat. The invention also relates to a method for unblocking and blocking the secondary check valve (23) of the device.