RU2086333C1 - Method of making laminate sheet blank for drawing - Google Patents

Abstract

FIELD: sheet forming, namely manufacture of laminate blanks for drawing parts, mainly with damping properties in machine engineering. SUBSTANCE: method comprises steps of making shaped blank and joining its layers at blanking process due to formation of vertical burrs on separate portions of blank perimeter. Layers of blank in the form of two sheets or strips with synthetic film placed between them are loaded to blanking die set. Portions with vertical burr are arranged in zones of minimum displacement of blank flange at process of successive drawing. Length value of portion with vertical burr is selected equal to 5-7 thickness values of laminate blank. Said vertical burr is formed due to provision of increased gap between die and punch. EFFECT: enhanced efficiency. 3 cl, 3 dwg

Description

 The invention relates to sheet stamping and can be used in all engineering industries in order to obtain multilayer blanks for drawing parts, mainly with damping properties.

 Known methods for connecting sheet blanks and devices for their implementation / 1,2,3 /. When using these methods, the workpieces are superimposed one on top of another and, under the influence of the tool, are cut and bent.

 A disadvantage of the known methods is the need to use special devices and tools for connecting sheet blanks, as well as the fact that the incised and bent flange at the joints does not allow the use of the obtained two-layer blanks for subsequent drawing of parts.

 There is also a known method of manufacturing bimetallic hollow parts by obtaining a two-layer workpiece from layers having different ductility, and subsequent drawing with refinement, including fixing the workpiece layers before drawing in areas located in the directions along and across the direction of rolling the material of the less plastic layer by local incomplete shearing blanks / 4 /.

 The disadvantage of this method is the high complexity and high cost of obtaining a workpiece from a two-layer material.

 The purpose of the invention to reduce the complexity and cost of manufacturing multilayer blanks for drawing.

 This goal is achieved by the fact that in the method of manufacturing a multilayer sheet billet for drawing, including connecting its layers, according to the invention, the billet is made curly, and the layers are joined in the process of cutting the billet due to the formation of a vertical burr in separate sections of its perimeter, and the die is loaded blanks in the form of two sheets or strips. Layers of the workpiece in the form of two sheets or strips are loaded into a die cut with a synthetic film located between them.

 Sections with a vertical burr are located in areas with the smallest movement of the workpiece flange during subsequent drawing, and the length of the sections with a burr is chosen equal to 5-7 thicknesses of the multilayer workpiece.

 In FIG. 1 is a plan of the bottom of the die cutting stamp; figure 2 section aa figure 1; figure 3 section BB of figure 1.

 The method is carried out in a stamp containing a punch 1, a matrix 2, a clamp 3 (figure 3). The sheet blank contains the lower 4 and upper 5 layers and a synthetic film 6, a vertical burr 7 (figure 2).

 The method is as follows.

 In the punch die on the punch 1, the lower 4 and upper layers of the workpiece are loaded in the form of metal sheets or strips and a synthetic film 6 located between them, which acts as a damping material. During the slide of the press (not shown in the drawing), the layers are pressed down by the clamp 3, the punch 1 and the matrix 2. When cutting in separate sections of the workpiece perimeter, a vertical burr 7 is formed, fastening the lower 4 and upper 5 layers and the film 6 located between them. The vertical burr is located in areas with the smallest movement of the workpiece flange during subsequent extraction. The length of the section with a burr is chosen equal to 5-6 thicknesses of the multilayer workpiece. It was experimentally established that when the length of the section with the burr is not less than 5 thicknesses of the two-layer billet, reliable connection of the sheets is ensured. When the length of the section with the burr is not more than 7 thicknesses of the two-layer workpiece, these areas during the drawing process do not adversely affect the braking of the workpiece flange.

 The formation of a vertical burr 7 is ensured by increasing the gap 8 between the punch 1 and the matrix 2 in separate sections of the perimeter of the cut blank. In the gap between the punch and the matrix increased by 30–40, the metal of the workpiece does not cleave during cutting, but is deformed by separation. During deformation, the metal of the upper layer 5 and the synthetic film 6 are pulled onto the deformed metal of the lower layer 4, and when the metal ruptures, a burr 7 is formed, which securely fastens the preform layers.

 Boundaries of increased clearance from 30 to 40 give an optimal burr. With a smaller gap, metal is chipped and a reliable connection of the sheets is not ensured. When you increase over 40 of the gap 8, a large burr is formed, which worsens the conditions of the flow of metal into the opening of the matrix during the subsequent exhaust.

 Using the method of manufacturing a multilayer sheet billet for hoods will reduce the noise level of the car by obtaining parts with damping properties, reduce the cost of these parts by reducing the complexity and eliminating the use of expensive imported material.

Claims (3)

 1. A method of manufacturing a multilayer sheet billet for drawing, comprising connecting its layers, characterized in that the billet is made curly, the layers are joined in the process of cutting the workpiece by forming a vertical burr in separate sections of its perimeter, and the blank layers are loaded into the die cut in the form two sheets or strips.  2. The method according to claim 1, characterized in that the blanks are loaded with blanks in the form of two sheets or strips with a synthetic film located between them.  3. The method according to claim 1, characterized in that the sections with a vertical burr are located in areas with the smallest movement of the workpiece flange during subsequent drawing, and the length of the sections with a burr is chosen equal to 5-7 thicknesses of the multilayer workpiece.

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