Integral drawing technique of draught fan volute

The invention relates to an overall deep drawing technology of a scroll casing of a blower, including the following steps: a steel plate for deep drawing is cut into sheets with a required size; the sheet is pressed and deep drawn to a required height; a workpiece is trimmed to a set height by a punching machine, the trimmed workpiece is cut into the left and right parts of the scroll casing at one time by the punching machine; the cut left and right workpieces of the scroll casing are punched with mounting holes by the punching machine, and after being provided with the mounting holes, the left and right parts of the scroll casing are connected together by spot welding; after process molding, the scroll casing is treated with deburring, polishing, washing, examining and warehousing. The scroll casing produced by the overall deep drawing technology of the scroll casing has stable size, can lower welding difficulty, overcome the defects caused by separate machining such as excessive working procedures, complex technique, long working hours, and the like, and avoid the quality problems which are likely to occur in separate machining process such as size over-tolerance, and the like, thus improving the appearance quality and prolonging the service life of the scroll casing; therefore, the scroll casing can achieve better price advantage and higher economic benefits in market competition.