Motor-Positioned Poppet Valve for Precise Low-Flow Control
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Solution Overview
Problem
Poppet-type flow control valves face challenges in precise control of low flow rates due to pressure fluctuations in the control chamber, making precise positioning of the valve body difficult.
Innovation Solution
Incorporating an electric motor with a position detector and linear motion conversion mechanism for feedback control, along with a back pressure chamber and communication passage to equalize fluid pressures, allowing for precise positioning of the valve body and reducing the necessary thrust of the motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If flow rate control of the low flow rate region is performed by controlling the pressure in the control chamber, then the flow rate between ports is controlled, but precise flow rate control is difficult since the pressure in the control chamber easily changes due to slight flow rate variations
Solution Approach 1:
The patent replaces the conventional pressure-based control chamber mechanism with an electric motor-driven positioning system. The electric motor directly positions the valve body relative to the valve seat, eliminating the need for pressure control in the low flow rate region. This substitution of mechanical positioning for pressure control achieves precise flow rate control without the sensitivity issues of pressure fluctuations.
2Ease of operation
If a pilot valve body and solenoid actuator are used to control the pilot passage opening, then the valve body can be spaced apart from the valve seat, but the configuration becomes complex and precise positioning is difficult
Solution Approach 1:
The patent extracts and removes the complex pilot valve mechanism, solenoid actuator, and control chamber from the system. Instead, it uses a simplified electric motor-driven positioning system that directly controls the valve body position. This extraction of unnecessary components significantly reduces device complexity while maintaining or improving positioning precision.
Solution Approach 2:
The patent replaces the mechanical pilot valve and solenoid actuator system with an electric motor-driven positioning system. This substitution eliminates the complex feedback loop involving control chamber pressure and pilot passage opening, providing more direct and precise control over valve body position.
3Measurement precision
If the valve body is positioned by controlling the control chamber pressure, then flow rate control is achieved, but high precision positioning requires complex control mechanisms
Solution Approach 1:
The patent replaces the pressure-based control mechanism with a direct electric motor-driven positioning system. The electric motor, controlled by a controller based on position feedback, directly positions the valve body relative to the valve seat. This substitution provides high precision positioning with a simpler control mechanism, as it eliminates the intermediate pressure control step and its associated complexity.
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-precision positioning of the valve body relative to the valve seat, reduces electric power consumption by utilizing fluid pressure to maintain the valve-closed state, and simplifies the valve configuration.
Implementation Method 1
a linear motion conversion mechanism configured to convert a rotation amount of an output shaft of the electric motor into a linear motion displacement of the movable member in the advancing and retracting direction
Implementation Method 2
a communication passage through which the inlet passage and the back pressure chamber communicate with each other, the communication passage being configured to equalize a fluid pressure in the inlet passage and a fluid pressure in the back pressure chamber to each other
Data Source
AI summary
A poppet-type flow control valve includes: a valve housing including an inlet passage, an outlet passage, a valve chamber provided between the inlet passage and the outlet passage, and a valve seat provided in the valve chamber; a valve body accommodated in the valve housing and configured to advance and retract relative to the valve seat; a piston configured to move integrally with the valve body in an advancing and retracting direction, in which the valve body advances and retracts; a movable member movable in the advancing and retracting direction, in which the valve body advances and retracts, the movable member being configured to move integrally with the valve body at least when the movable member moves in a retracting direction of the advancing and retracting direction; an electric motor; a position detector configured to detect a rotational angle of an output shaft of the electric motor; a linear motion conversion mechanism configured to convert a rotation amount of the output shaft of the electric motor into a linear motion displacement of the piston in the advancing and retracting direction; and a controller configured to perform feedback control of the electric motor, such that the rotational angle of the output shaft, which is detected by the position detector, is adjusted to a rotational angle corresponding to a predetermined target distance between the valve seat and the valve body.