METHOD FOR MANUFACTURING AXISYMMETRIC SHELLS WITH INTERNAL RIFFLES Russian patent published in 2021 - IPC B21D22/00 

FIELD: mechanical engineering.

SUBSTANCE: invention relates to a method for manufacturing axisymmetric shells with internal riffles. The expected result is achieved by a method that includes blank and pressure processing with the formation of spiral corrugations of the opposite direction on the inner surface of the workpiece in two operations, first with a punch equipped with forming protrusions of the right, then of the left direction, when the punch and the workpiece are moved together through a matrix with a calibration hole of a larger, then smaller diameter. At the same time, the pipe is cut into cut-to-length sections, mechanical processing is performed with the formation of a ledge on the inner surface of the workpiece and phosphating. Then, the workpiece is installed in the device until the punch stops at the ledge of the workpiece and the riffles are formed in one or more transitions at each operation of pressure processing by means of a punch and a matrix. Moreover, the forming protrusions of the punch are made of a trapezoidal profile with anterior and posterior conical sections with an angle of 25-35°, conjugated with a cylindrical section with a length of 0.1-0.7 mm. The working surface of the matrix is made of a trapezoidal profile with anterior and posterior conical sections with an angle of 5-15°, conjugated along a radius of 0.5-2 mm with a cylindrical section, 2-7 mm long. An antifriction fluorine-containing coating is applied to the working surfaces of the punch and matrix, and during the formation of riffles, a fluorine-containing lubricant emulsion based on perfluoropolyether acid and industrial oil is applied to the working surfaces of the punch and matrix and to the outer surface of the workpiece.

EFFECT: increase in the accuracy and quality of the parts obtained, as well as an increase in manufacturing productivity and the metal utilization factor.

5 cl, 4 dwg, 2 ex