Electronic expansion valve

Abstract

The invention relates to an electronic expansion valve (1) which comprises a valve part (10) used for adjusting fluid flow. The valve part (10) comprises a valve body (12), a valve seat (18) arranged in the valve body, a valve needle (24) capable of opening and closing the valve seat, an actuating mechanism driving the valve needle to move axially, as well as a drive mechanism for providing power for the actuating mechanism, wherein the actuating mechanism comprises a spindle (50) capable of moving axially. The electronic expansion valve further comprises an electromagnetic maintaining mechanism (60) used for maintaining the spindle, and the structure includes that when the electromagnetic maintaining mechanism is powered up, the spindle is maintained in a first axial position, and in the first axial position, the valve needle can adjust opening of the valve seat, when the electromagnetic maintaining mechanism is powered off, the spindle is released to a second axial position, and in the second axial position, the valve needle closes the valve seat. According to the invention, when a system is powered off, the electronica expansion valve can be automatically closed.

Description

technical field [0001] The invention relates to an electronic expansion valve. Background technique [0002] The electronic expansion valve is an important part in the refrigeration / heating system, mainly used to regulate the flow of refrigerant fluid. A traditional electronic expansion valve generally includes a driving mechanism (stepping motor), an actuator (threaded screw mechanism), a throttling mechanism (needle and valve seat) and related auxiliary mechanisms. [0003] However, after the traditional electronic expansion valve is powered off, the electronic expansion valve cannot be automatically closed because the threaded screw mechanism loses its driving force. Therefore, in order to safely cut off the flow path, an independent electromagnetic switch valve (usually a normally closed valve, which opens when power is turned on and closes when power is off) is usually connected in series upstream or downstream of the electronic expansion valve. In this way, when the ...

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Problems solved by technology

[0004] However, adopting the above structure, on the one hand, the overall cost of the system is increased due to the addition of an independent electromagnetic switch valve, and on the other hand, in order to connect the electromagnetic switch valve in series, two brazing points will be added in the pipeline (that is, The inlet and outlet of the electromagnetic switch valve), which not only increases the assembly cost of the system but also increases the risk of system leakage

[0005] Another way to realize the automatic shutdown of the electronic expansion valve after power failure is to provide backup power for the electronic expansion valve, such as adding a supercapacitor for storing electric energy or installing a backup battery in the control board of the electronic expansion valve, but this method Also increases the cost of the electronic expansion valve and requires a more complex controller

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