Directional control valve
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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 fluid control at high pressures and flow rates.
Innovation Solution
A directional control valve with a pressure equalization circuit that applies equal pressure to both ends of the spool, allowing direct solenoid driving without increasing size, using a housing with a spool hole and solenoid driving sections to manage fluid flow and pressure effectively.
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 control capability is improved, but the device size, weight, and structural complexity increase
Solution Approach 1:
The patent extracts and removes the solenoid proportional pressure reducing valve from the system, replacing it with a direct-acting spool valve design. This eliminates the complex pressure reducing mechanism while maintaining high pressure and flow rate control through the spool's direct response to control signals.
Solution Approach 2:
Instead of using a complex pressure reducing valve to indirectly control the spool, the patent inverts the approach by having the solenoid directly actuate the spool. This direct-acting design simplifies the structure while achieving the same or better control performance for high pressure and flow rate applications.
2Power
If a solenoid proportional pressure reducing valve is used to generate pilot pressure, then the pressure and flow rate control capability is improved, but the fuel consumption increases due to standby pressure requirements
Solution Approach 1:
The patent removes the pilot pressure generation system entirely, eliminating the need for continuous standby pressure. The spool valve is directly actuated by the solenoid, which only consumes energy when actively changing the valve position, thereby significantly reducing fuel consumption.
Solution Approach 2:
The solenoid operates in a periodic, on-demand manner rather than continuously maintaining standby pressure. It activates only when control changes are needed, converting the continuous energy consumption of the pressure reducing valve into intermittent operation that reduces overall fuel consumption.
3Device complexity
If the solenoid directly drives the spool without a pressure reducing valve, then the device size is reduced and structure is simplified, but the spool becomes difficult to actuate at high pressure and flow rate
Solution Approach 1:
The patent applies local quality by creating a controlled low-pressure environment specifically at the spool actuation points. The pressure equalization circuit ensures that the spool ends are exposed to equalized pressure conditions, reducing the differential pressure resistance and enabling easy actuation even in high-pressure fluid systems.
Solution Approach 2:
The pressure equalization circuit acts as an intermediary mechanism between the high-pressure fluid and the spool actuation system. It mediates the pressure differential by equalizing pressures on both sides of the spool, thereby enabling the solenoid to easily move the spool without requiring excessive force.
4Device complexity
If the solenoid directly drives the spool without pressure equalization, then the device structure is simplified, but the spool operation becomes unstable at high pressure and flow rate
Solution Approach 1:
The pressure equalization circuit creates equipotential conditions by ensuring equal pressure on both ends of the spool. This eliminates pressure-induced instability and ensures that the spool operates smoothly and predictably, improving reliability without adding significant structural complexity.
Solution Approach 2:
The pressure equalization circuit preemptively counteracts the destabilizing effect of pressure differential by equalizing pressures before the spool actuation occurs. This preliminary action prevents instability from developing, ensuring reliable spool operation in high-pressure applications.
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 high-pressure and high-flow-rate fluid control without size increase, stabilizing spool operation and reducing fuel consumption by eliminating the need for a solenoid proportional pressure reducing valve.
Implementation Method 1
a pressure equalization circuit that equally applies a pressure to the first end portion and the second end portion of the spool
Implementation Method 2
a first solenoid driving section having a first needle that is coupled to or integrally formed with a first end portion of the spool and that drives the spool; and a second solenoid driving section having a second needle that is coupled to or integrally formed with a second end portion of the spool and that drives the spool
Data Source
AI summary
A directional control valve includes: a housing having a cylindrical spool hole communicating with an inlet port letting a fluid from an external supply source at a predetermined pressure and an outlet port flowing the fluid to a working cylinder; a spool movable in the spool hole axially and changing an amount of flow of the fluid; a first solenoid driving section having a first needle coupled to or integral with a first end portion of the spool and driving the spool; and a second solenoid driving section having a second needle coupled to or integral with a second end portion of the spool and driving the spool, the directional control valve including a pressure equalization circuit equally applying a pressure to the end portions.