Direct-Acting Directional Valve With Pressure-Equalized Spool
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Solution Overview
Problem
The pilot type selector valve with a solenoid proportional pressure reducing valve is large, heavy, and complex, leading to high fuel consumption due to the need for standby pressure, and direct driving configurations result in unstable spool actuation at high pressures and flow rates.
Innovation Solution
A directional control valve with a direct acting selector valve, where the solenoid driving section directly moves the spool, and a pressure equalization circuit is used to stabilize spool operation by equally applying pressure to both ends of the spool, eliminating the need for a solenoid proportional pressure reducing valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a solenoid proportional pressure reducing valve is used to control high pressure and flow rate fluid, then the pressure and flow rate of the fluid can be set high, but the valve becomes larger in size, larger in weight, and has a more complicated structure
Solution Approach 1:
The patent extracts and removes the solenoid proportional pressure reducing valve from the system, replacing it with a direct-acting solenoid valve. This eliminates the intermediate pressure reducing stage while maintaining the ability to control high pressure and flow rate fluid directly through the spool mechanism, thereby simplifying the overall structure.
Solution Approach 2:
The patent segments the control function by separating the solenoid driving section from the pressure reducing function. The solenoid directly actuates the spool to control fluid flow without requiring a separate pressure reducing valve, achieving functional integration that reduces structural complexity.
2Power
If a solenoid proportional pressure reducing valve is used to generate pilot pressure, then the pressure and flow rate of the fluid can be controlled, but the fuel consumption increases due to the need for standby pressure
Solution Approach 1:
The patent implements periodic action by enabling the solenoid valve to operate only when fluid control is actually needed, rather than maintaining continuous standby pressure. The solenoid can be activated on-demand to open or close flow paths, eliminating the energy waste associated with maintaining constant pilot pressure in a pressure reducing valve system.
Solution Approach 2:
By removing the pressure reducing valve that requires continuous pilot pressure generation, the system eliminates the source of standby pressure consumption. The direct-acting solenoid valve controls fluid flow without requiring a separate pressure generation system, thereby reducing energy consumption.
3Device complexity
If the solenoid driving section directly drives the spool, then the size and weight are reduced and structure is simplified, but the spool becomes difficult to actuate at high pressure and flow rate, resulting in unstable fluid control
Solution Approach 1:
The patent applies preliminary action by designing the spool with pre-optimized geometric features including tapered sections and specifically positioned flow holes. These design elements create favorable pressure distribution and reduce friction forces before the spool actuation begins, enabling reliable movement even at high operating pressures without requiring complex assistance mechanisms.
Solution Approach 2:
The patent implements local quality by creating non-uniform pressure distribution through strategically placed flow holes in the spool body. The spool has different hole configurations in different sections, allowing high pressure fluid to act on specific areas to generate forces that assist spool movement in critical regions, thereby improving actuation reliability at high pressures.
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 allows for high pressure and flow rate settings without increasing the valve's size, ensuring stable fluid control and reducing fuel consumption by eliminating standby pressure, while maintaining a small and simplified structure.
Implementation Method 1
a first solenoid driving section that drives a first end portion of the spool in a first direction along a first central axis of the spool
Implementation Method 2
a pressure equalization circuit that communicates a discharge side of the spool with a supply side of the spool
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A directional control valve (1) includes: a housing (10) having a cylindrical spool hole (20) communicating with an inlet port (16) letting a fluid from an external supply source (2) at a predetermined pressure and an outlet port (18A, 18B) flowing the fluid to a working cylinder (4); a spool (22) movable in the spool hole (20) axially and changing an amount of flow of the fluid; a first solenoid driving section (30A) having a first needle (22A) coupled to or integral with a first end portion (22a) of the spool (22) and driving the spool (22); and a second solenoid driving section (30B) having a second needle (22B) coupled to or integral with a second end portion (22b) of the spool (22) and driving the spool (22), the directional control valve (1) including a pressure equalization circuit equally applying a pressure to the end portions (22a, 22b).