For the treatment of plate thickness, the dimension of ventilation pipes and pipe fittings shall be marked. For rectangular air pipes, the outer dimension shall be calculated, and for circular air pipes, the outer diameter dimension shall be calculated. The ventilation pipes of the air duct production line are made of sheet steel, zinc steel plate or aluminum plate, stainless steel plate, and the thickness is generally within 0.5-2 mm.
The expansion of the air duct production line has little impact on the size, so it can be ignored in the process of setting out. However, for thick wall ducts and components with special requirements, when the thickness of the plate wall is greater than 2 mm, the influence of the thickness of the plate wall must be considered. That is to say, for the unfolding and blanking of circular air duct, the diameter shall be calculated according to the middle diameter (the outer diameter minus the wall thickness or the inner diameter plus the wall thickness). For the rectangular air duct, the unfolding shall still be calculated according to the outer dimension of the air duct.
The key link of the air duct production line
is to reserve the undercut allowance and assembly flange allowance. When carrying out unfolding and blanking of thin plate air ducts, fittings and components, it is necessary to consider whether the connection mode of thin plate and the interface of air nozzles, fittings and components are equipped with flanges, so as to leave a certain margin when unfolding and blanking.