Valve Needle and Electronic Expansion Valve Having Valve Needle
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Solution Overview
Problem
The flow rate of refrigerant in electronic expansion valves cannot be accurately controlled due to assembly errors, leading to either excessive or insufficient refrigerant flow, which affects the performance of air conditioning systems.
Innovation Solution
A valve needle design with a blocking segment and two opening segments of varying cross-sectional areas, where the first opening segment maintains a constant cross-sectional area and the second opening segment adjusts the flow rate, ensuring stability even with assembly errors, and includes conical and cylindrical segments to manage flow characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the diameter of the opening segment of the valve needle gradually decreases towards the head, then the flow rate can be adjusted, but assembly errors cause unstable valve opening and inaccurate flow rate control
Solution Approach 1:
The valve needle is divided into three distinct segments: a blocking segment, a first opening segment with constant cross-sectional area, and a second opening segment with gradually decreasing cross-sectional area. This segmentation allows the first opening segment to provide stable flow control unaffected by assembly errors, while the second opening segment enables flow rate adjustment.
Solution Approach 2:
Different segments of the valve needle are designed with different cross-sectional area characteristics. The first opening segment maintains a constant cross-sectional area to ensure stability, while the second opening segment has a gradually decreasing cross-sectional area to enable flow rate adjustment. This local differentiation resolves the contradiction between stability and adjustability.
2Reliability
If the electronic expansion valve remains a small opening to prevent refrigerant accumulation, then refrigerant circulation is maintained, but assembly errors cause the flow rate to be too fast or too slow
Solution Approach 1:
The segmentation of the valve needle allows the first opening segment to provide a stable baseline flow control that is insensitive to assembly errors, ensuring reliable refrigerant circulation while maintaining accurate flow rate control through the second opening segment.
Data Source
AI summary
Disclosed are a valve needle and an electronic expansion valve having the valve needle. The valve needle is provided with a connecting end and a blocking end that are arranged opposite to each other; the blocking end includes a blocking segment, a first opening segment, and a second opening segment that are sequentially connected in an axial direction; the blocking segment cooperates with a valve port to block the valve port; a cross sectional area of the blocking segment close to the connecting end is greater than a cross sectional area of the blocking segment distant from the connecting end; a cross sectional area of the second opening segment close to the connecting end is greater than a cross sectional area of the second opening segment distant from the connecting end; and a cross sectional area of the first opening segment remains unchanged.