Blade profile of sheet-shaped axial flow fan formed by adopting squeezing, pulling and cutting process

Abstract

The invention discloses a fan blade of a sheet-shaped axial flow fan formed by adopting a squeezing, pulling and cutting process, wherein a blade is formed by arc wires and based on the same radius of curvature; the front edge and the rear edge of the blade can be cut; and the ratio L / R of the chord length l to the radius R of curvature at each radius part of the blade before cutting and after cutting ranges from 0.5 to 0.8. The blade profiled disclosed by the invention is an arc-shaped blade with equal thickness and formed by adopting a squeezing and pulling process; different cutting modes are adopted to meet pneumatic performance requirements of various blades with variable circular rector designs; the front edge of the blade can be cut, so efficient blades with lifted front, and wide outside and narrow inside, or narrow outside and wide inside, or equivalent-wide inside and outside can be conveniently manufactured together with different organizations of a central line; all the blades have low cost and few consumptive materials, achieve multiple purposes through one die, and overcome the shortcoming that the front edge of the existing wing cannot be cut.

Description

technical field [0001] The invention relates to an axial-flow fan blade, in particular to a thin-plate axial-flow fan blade shaped by an extrusion-drawing process, which belongs to the field of fluid engineering. Background technique [0002] At present, there are many fan production units that produce fan blades formed by extrusion and stretching. The front end is an airfoil type and the rear end is a thin plate type. Diameter fans meet the requirements of aerodynamic performance, and have been verified by practice to have good aerodynamic performance, and have been used by many cooling tower factories. So far, it is the ideal supporting fan for large cooling towers and has been confirmed by many companies. But for small and medium-sized cooling towers with small capacity (200m 3 / h capacity tower) blades manufactured by the above method, the manufacturing cost will be higher than the original thin-plate fan, especially under the premise of fierce competition in the cooli...

AI Technical Summary

Problems solved by technology

For the airfoil shape of the fan blades mentioned above, each specification cooling tower is designed separately and molded one by one. At each calculation radius, it is necessary to manufacture a sample with different curvature radii, chord lengths, and blade angles. Due to the large number of mold consumables and manufacturing costs are relatively high, and blade manufacturers are required to have a high level of technology, making it difficult to achieve low cost

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