Hydraulic Spool Valve Internal Passages for Higher Actuator Flow
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Solution Overview
Problem
Existing valve devices have limitations in increasing the flow rate of working fluid from supply ports to actuators due to the upper limit on the opening area of notches on the spool, which restricts the flow rate of hydraulic oil to actuators.
Innovation Solution
A valve device with a spool that includes multiple supply passages and a land portion, allowing communication between supply ports and an outflow passage in opposite directions based on the spool's axial movement, and a compensator spool to manage load sensing and fluid flow resistance, enhancing fluid flow control and cancellation of opposing fluid forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the opening area of the notch is increased to increase the flow rate of working fluid, then the flow rate increases, but the notch is provided on an outer peripheral surface of the spool and an upper limit of the opening area is determined by an outer diameter of the spool, making it difficult to further increase the flow rate
Solution Approach 1:
The invention transitions from a two-dimensional notch opening on the outer peripheral surface to a three-dimensional internal passage structure. By forming supply passages inside the spool body rather than relying on surface notches, the effective flow area is no longer constrained by the spool's outer diameter, enabling significantly increased flow rates while maintaining the same spool dimensions.
Solution Approach 2:
The invention divides the single supply passage into multiple supply passages (first supply passage, second supply passage, third supply passage) within the spool. This segmentation allows each passage to be optimized for flow control while collectively providing a larger total opening area that exceeds what a single external notch could achieve, thereby increasing the overall flow rate of working fluid to the actuator.
2Productivity
If multiple supply passages are provided to increase flow rate, then the flow rate increases, but the spool structure becomes more complex
Solution Approach 1:
The spool is designed to perform multiple functions simultaneously: it acts as a blocking element, a flow guide, and a flow resistance provider all within a single component. The first, second, and third supply passages are integrated into the spool body, allowing one component to control flow from multiple supply ports to the actuator while providing adjustable resistance, thereby managing complexity through functional integration rather than adding separate components.
Solution Approach 2:
The multiple supply passages are nested within the spool body, with each passage routed through the internal structure of the spool. This nesting approach allows complex flow paths to be contained within a single component rather than requiring multiple external parts, reducing overall system complexity while achieving the desired multi-path flow capability for increased flow rate.
Data Source
AI summary
A valve device includes: a main spool including supply passages and a supply-side land portion; and a valve block including an outflow passage, in which the supply passage allows a supply port to communicate with the outflow passage in a process of the main spool moving from a neutral position toward one stroke end in an axial direction, and the supply passage allows a supply port to communicate with the outflow passage in a process of the main spool moving from the neutral position toward the other stroke end in the axial direction, and the supply passage allows the supply port to communicate with the outflow passage in the process of the main spool moving toward the one stroke end and allows the supply port to communicate with the outflow passage in the process of the main spool moving toward the other stroke end.