Forming method and extrusion die for harmonica-shaped tube of heat exchanger

Abstract

The invention discloses a forming method and an extrusion die for a harmonica-shaped tube of a heat exchanger. Firstly, a bent arc-shaped harmonica-shaped tube profile is extruded, and then a linear harmonica-shaped tube profile is extruded; the extrusion die comprises a straightening plate arranged at one side of a lower die, and the straightening plate straightens and deforms the arc harmonica-shaped tube profile into the linear harmonica-shaped tube profile; the curvature radius Ra of a central layer of the bent arc-shaped harmonica-shaped tube profile and the length L of the initial section of the linear harmonica-shaped tube profile meet the equation that Ra=(0.525-0.55) L; due to the adoption of a production mode of firstly extruding into the arc harmonica-shaped tube and then deforming into the linear harmonica-shaped tube by the straightening plate, die cores are positioned on the circumference with the same diameter, the pressure difference of an extrusion cylinder in the radial direction is eliminated, the strength and the rigidity of the die are greatly improved, the service life of the die is obviously prolonged, the machining period of the die is shortened, the cost is reduced, meanwhile, extrusion forming is stable, metal flow is uniform, and the production efficiency is remarkably improved.

Description

technical field [0001] The invention relates to the field of technology and molds for extruding harmonica tube profiles, in particular to a forming method for heat exchanger harmonica tubes and an extrusion mold thereof. Background technique [0002] The heat exchanger harmonica tube (referred to as the harmonica tube, the same below) is named for its end face shape similar to a harmonica. It is an aluminum alloy profile necessary for heat exchange systems such as automobiles and home air conditioners. During use, the harmonica tube can be filled with cooling Medium, used as a fluid conduit for heat exchange systems. [0003] With the continuous development of the automobile industry and the continuous improvement of people's home conditions, the production and ownership of cars and home air conditioners are also increasing year by year, especially in the secondary market for car maintenance, the demand for harmonica tubes is huge; and in order to improve The thermal conduc...

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Problems solved by technology

[0004] The harmonica pipe has thin walls and many holes, and it is difficult to form during extrusion production. The key is that the hot extrusion dies used for extrusion have a high scrap rate, which makes the molds used for hot extrusion of high-quality and large-scale wide harmonica pipes in China almost They are all purchased from abroad, and most of the hot extrusion dies for harmonica tubes used in heat exchangers in China are limited to dies with less than 12 holes. Some porous and small ribs can especially be used to produce large-scale wide-width thin-walled harmonicas on continuous extrusion machines. Tube molds are almost less

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