Solenoid Flow Control Valve With Pilot Bypass Pressure Release
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solenoid flow control valves struggle to quickly stop the flow of hydraulic liquid from the inlet port to the outlet port when switching from excitation to non-excitation state due to the restrictive discharge flow rate through the fixed restrictor.
Innovation Solution
Incorporating a bypass passage that allows the pilot pressure chamber to communicate with the outlet port, bypassing the fixed restrictor, and utilizing a pilot spool that opens the bypass passage when the solenoid is in a non-excitation state to increase the discharge flow rate and quickly lower the internal pressure of the pilot pressure chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a fixed restrictor is used on the outlet passage to control the discharge flow rate, then the flow rate can be regulated, but the response speed when stopping flow becomes slow
Solution Approach 1:
The outlet passage is segmented into two separate passages: a normal outlet passage with a fixed restrictor for flow control, and a bypass passage without a restrictor for rapid pressure equalization. This segmentation allows the system to achieve both flow regulation and fast response by selecting different pathways based on operational requirements
Solution Approach 2:
A bypass passage is introduced as an intermediary pathway that connects the pilot pressure chamber to the outlet port, providing an alternative route that bypasses the fixed restrictor. This intermediary structure enables rapid pressure equalization when needed, while the normal outlet passage maintains flow control capability
2Productivity
If the pilot pressure chamber is always connected to the outlet port via the outlet passage with fixed restrictor, then flow control is maintained, but the internal pressure cannot be quickly lowered when switching to non-excitation state
Solution Approach 1:
The system transitions from a static connection to a dynamic, state-dependent connection. When the solenoid valve is in the non-excitation state, the bypass passage dynamically opens to provide a low-resistance path for rapid pressure equalization. When excited, the bypass passage closes and normal flow control through the fixed restrictor is maintained
Solution Approach 2:
The bypass passage is pre-configured and ready to open immediately when the solenoid valve switches to the non-excitation state, providing a pre-established pathway for rapid pressure equalization without requiring gradual opening or complex control sequences
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
Enables rapid stopping of the hydraulic liquid flow from the inlet port to the outlet port by increasing the discharge flow rate through the bypass passage, improving the responsiveness of the hydraulic cylinder when switching from excitation to non-excitation states.
Implementation Method 1
a solenoid (3)
Implementation Method 2
a pilot spool (44) that closes the inlet passage (5) and opens the bypass passage (8) when the solenoid (3) is in a non-excitation state, and opens the inlet passage (5), generates a pilot pressure in the pilot pressure chamber (4), and closes the bypass passage (8) when the solenoid (3) is in an excitation state
Implementation Method 3
a main spool (24) that controls a flow rate from the inlet port (1) to the outlet port (2) in accordance with the pilot pressure in the pilot pressure chamber (4)
Implementation Method 4
a fixed restrictor (7) provided on the outlet passage (6)... Since the discharge flow rate is restricted by the fixed restrictor (7)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A solenoid flow control valve includes: an inlet passage that allows an inlet port to communicate with a pilot pressure chamber; an outlet passage that allows the pilot pressure chamber to communicate with an outlet port; a fixed restrictor provided on the outlet passage; a pilot spool that closes the inlet passage when a solenoid is in a non-excitation state, whereas when the solenoid is in an excitation state, opens the inlet passage at an opening degree corresponding to an input current value to generate a pilot pressure corresponding to the input current value in the pilot pressure chamber, the pilot spool opening a bypass passage when the input current value is less than a predetermined value and closing the bypass passage when the input current value is greater than or equal to the predetermined value; and a main spool that controls a flow rate from the inlet port to the outlet port in accordance with the pilot pressure in the pilot pressure chamber.