Pneumatic-Hydraulic Valve Stem Geometry for Accurate Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pneumatic-hydraulic control valves have complex structures and suffer from inaccurate movement and insufficient sealing due to the long stroke of the metal wire and the reliance on spring return force, which can lead to elastic fatigue and decreased closing force.
Innovation Solution
A pneumatic-hydraulic type control valve with a simplified structure featuring a valve stem with different diameter stressed portions and a cable system that allows direct axial movement, ensuring accurate operation and enhanced sealing by utilizing a cable to pull the valve stem open, eliminating the need for a return spring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a metal wire is used to operate the lifting valve through a complex routing system with idler wheels, then the valve can be actuated, but the structure becomes complex and the wire stroke becomes long causing inaccurate movement
Solution Approach 1:
The patent extracts and eliminates the idler wheel and complex wire routing from the system. Instead of routing the control wire through multiple guides and wheels, the control rod is directly connected to the lifting valve, simplifying the structure while maintaining actuation functionality.
Solution Approach 2:
The patent introduces a new intermediary mechanism - a control rod with a head that directly engages the lifting valve. This replaces the metal wire intermediary system, providing more accurate and direct force transmission from the brake lever to the valve.
2Ease of operation
If a metal wire with long stroke is used to open the lifting valve, then the valve can be actuated, but movement accuracy deteriorates
Solution Approach 1:
The patent removes the long-stroke metal wire routing system and replaces it with a short-stroke control rod that directly connects the brake lever mechanism to the lifting valve, eliminating the accuracy problems associated with long wire strokes.
Solution Approach 2:
The patent replaces the flexible metal wire mechanical transmission system with a rigid control rod mechanical system, which provides more precise and accurate force transmission with minimal stroke.
3Ease of operation
If a spring is used to provide closing force for the lifting valve, then the valve can be closed automatically, but elastic fatigue occurs causing insufficient sealing
Solution Approach 1:
The patent makes the lifting valve self-closing through its own weight and gravitational force. The valve is designed to automatically return to the closed position when the control force is released, eliminating the need for external spring assistance while maintaining reliable sealing.
Solution Approach 2:
The patent completely removes the spring component from the valve assembly, eliminating the source of elastic fatigue while maintaining the automatic closing function through alternative means (valve weight and gravity).
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
The solution provides improved sealing and accuracy by ensuring the fluid closing force exceeds the opening force, reducing the stroke length and simplifying the structure, thereby maintaining effective valve operation without the need for a return spring.
Implementation Method 1
the first oil guiding hole of the valve base and the second oil guiding hole of the valve base are not obstructed by the flange of the stem body so as to communicate with each other
Implementation Method 2
utilizes the difference in the outer diameter between the first stressed portion and the second stressed portion to enable the fluid closing force to be slightly greater than the fluid opening force
Data Source
AI summary
A pneumatic-hydraulic type control valve includes a cable attached to a fixed base, a valve base disposed in the fixed base, and a valve stem disposed in the valve base and driven by the cable to be opened. First and second oil guiding holes of the valve base communicate with each other when the valve stem is opened, and the first and second oil guiding holes of the valve base do not communicate with each other when the valve stem is closed. Further, the valve stem has a first stressed portion for bearing a fluid closing force and a second stressed portion for bearing a fluid opening force. The outer diameter of the first stressed portion is larger than that of the second stressed portion. Thus, the present invention achieves effects of simplifying structure and accurate actuation without affecting the sealing effect.