Abstract: In order to study the cause of the failure of the electronic expansion valve coil under low temperature conditions, this study analyzed the relationship among injection molding process, winding structure, environmental condition and insulation wall thickness of electronic expansion valve coil. Thermal expansion and contraction cause the insulation layer to crack, and condensed water enters the tiny cracks of the coil, which reduces the insulation performance of the coil and causes the coil to fail.

Key words: Electronic expansion valve coil, Low temperature failure, Insulation layer wall thickness, Winding deformation, Coil injection