Double-valve-needle structure for large-diameter electronic expansion valve

Abstract

The double-valve-needle structure comprises an outer valve needle and a nut, a first inner cavity is formed in the outer valve needle, a valve port cover is installed at the lower end of the outer valve needle, an open hole is formed in the bottom of the valve port cover, a side hole communicated with the open hole is formed in the outer side wall of the valve port cover, and the outer side wall of the valve port cover is provided with a second inner cavity. A nut is installed in the first inner cavity in a sliding mode, an inner valve element is installed at the lower end of the nut, a second inner cavity is formed in the lower portion of the inner valve element, an inner valve needle sliding up and down and a compression spring assisting in resetting of the inner valve needle are installed in the second inner cavity, and the open hole is blocked or opened by controlling axial movement of the inner valve needle. The flow regulating valve not only can regulate small flow, but also can regulate large flow, so that the flow regulating precision is greatly improved, and the adaptive capacity is stronger.

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