Electric-operated valve
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Solution Overview
Problem
Existing electric-operated valves in refrigeration cycles exhibit significant variation in minimum throttle flow rates due to component and assembly accuracy tolerances, leading to inconsistent fluid flow rates when the same number of pulses is input to the stepping motor.
Innovation Solution
The electric-operated valve design includes a valve body with a valve port and seat, a stepping motor, and a valve member with a seating, intermediate, and tip portion, where the intermediate portion's outer diameter is larger at one end than the tip portion, and the rotor's stopper mechanism restricts rotation in one direction, ensuring a minimum throttle passage distance that is greater than or equal to the moving distance corresponding to D + 1 pulses, thereby reducing the tolerance range of the valve opening pulse number.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the valve member is designed with a tapered seating portion and tip portion, then the valve can achieve proper sealing contact with the valve seat, but the minimum throttle flow rate varies significantly due to component and assembly accuracy tolerances
Solution Approach 1:
The patent changes the geometric parameters of the valve member by adding an intermediate portion with a specific outer diameter between the seating portion and tip portion. This intermediate portion creates a controlled minimum throttle passage that compensates for variations in seating contact, thereby stabilizing the minimum throttle flow rate across different manufacturing tolerances
Solution Approach 2:
The intermediate portion acts as an intermediary element between the seating portion and tip portion. It provides a controlled flow passage that mediates the flow characteristics, ensuring consistent minimum throttle flow rate regardless of variations in the sealing contact between the valve member and valve seat
2Manufacturing precision
If the number of pulses input to the stepping motor is increased to ensure the valve member reaches the valve opening position, then the valve can overcome tolerance variations, but the initialization time and energy consumption increase
Solution Approach 1:
The valve member is preliminarily positioned by the stopper mechanism at a reference position that corresponds to a specific rotor position. This preliminary positioning ensures that when pulses are input during initialization, the valve member reaches the correct valve opening position more quickly and accurately, reducing both initialization time and pulse requirements
3Ease of manufacture
If the valve member structure is simplified to reduce manufacturing complexity, then production cost decreases, but the ability to maintain consistent minimum throttle flow rate across production batches deteriorates
Solution Approach 1:
The valve member is segmented into three distinct portions: a seating portion for sealing contact, an intermediate portion for controlling minimum throttle flow, and a tip portion for final flow regulation. This segmentation allows each portion to be optimized for its specific function while maintaining overall manufacturing simplicity and consistency
Data Source
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AI summary
In an electric-operated valve (1), when a rotor (41) is at a reference position, a valve member (30) is in contact with a valve seat (18). When the rotor is at a valve opening position where the valve member separates from the valve seat, a minimum throttle passage (38) is formed between a lower end (36b) of the intermediate portion (36) and an orifice portion (17a). D represents a tolerance range of the number of pulses input to a stepping motor (66) while the rotor rotates from the reference position to the valve opening position, and a distance between the lower end of the intermediate portion and an upper end (17a1) of the orifice portion when the valve member is in contact with the valve seat is greater than or equal to a moving distance of the valve member corresponding to D + 1 pulses.