What factors should be paid attention to in machining and blanking of spiral air duct

1、 For plate thickness, the dimension of ventilation pipe and pipe fittings shall be marked. The outer dimension of rectangular air duct shall be calculated, and the outer diameter of circular air duct shall be calculated. The thickness of thin steel plate, ship zinc steel plate or aluminum plate and stainless steel plate used for ventilation duct is generally within the range of 0.5-2 mm. However, for the thick wall duct and components with special requirements, the thickness of the plate wall is greater than 2 In other words, the diameter of circular air duct should be calculated according to the medium diameter (outer diameter minus wall thickness or inner diameter plus wall thickness). For rectangular air duct, the expansion should be calculated according to the outer dimension of air duct.

2、 The key link of unfolding blanking allowance is to reserve the bite margin and assembly flange allowance. When the sheet air duct, pipe fittings and components are unfolded and laid off, it is necessary to consider the connection mode of the thin plate and whether the interface of the air nozzle, pipe fittings and components is equipped with flange, so as to leave a certain amount of margin when unfolding and blanking.