SU1669615A2 - Sheet blank for drawing cylindrical part with two longitudinal grooves - Google Patents

Abstract

The invention relates to the processing of metals by pressure and can be used in instrument making, mechanical engineering, the radio industry and other areas of the national economy. The purpose of the invention is to improve the quality of the grooves in the manufacture of parts with a height greater than its diameter. The angle between the radii passing through the junction points of the central and concave portions of the larger side is equal to the angle between the radii passing through the intersection points of the circumference of the neutral layer of the finished part with the walls of its groove. The radius of rounding of the corners of the workpiece is equal to the angle of conjugation of the open end of the finished part with the walls of its grooves. The larger side of the workpiece has straight lines in parallel to the longitudinal axis of symmetry, bounded on one side by the corners of the workpiece, and at a distance of 0.60 to 0.68 of the diameter of the conventional round workpiece from the transverse axis of symmetry, the concave parts. The device allows to obtain cylindrical parts with longitudinal grooves of the same width along the entire height of the groove, which improves the quality of the finished product, reduces the percentage of defective products, thereby reducing metal consumption and labor costs for manufacturing. 2 Il.

Description

The invention relates to the processing of metals by pressure, namely to sheet blanks for drawing cylindrical parts with grooves, and can be used, for example, to make filling cups and other products in instrument making, mechanical engineering, radio industry and other areas of the national economy.

The aim of the invention is to improve the quality of the grooves in the manufacture of parts with a height greater than its diameter.

FIG. 1 shows a sheet blank for drawing a cylindrical part; Fig. 2,3 is a cylindrical part with

grooves, obtained by drawing from the workpiece.

Sheet blank has the shape of a quadrangle with rounded corners with a rounding radius RI equal to the radius RI of the open end of the finished part with the walls of its grooves.

The smaller side H of the billet is equal to the diameter of the conventional round billet DI, necessary for stretching a hollow semi-finished product with a diameter D and a height h, and can be determined by the formula

Di VD2 + 4DhT,

where DI is the diameter of the round billet required for drawing a hollow semi-finished product with a diameter D and height h;

oh oh oh

SP

Yu

D is the diameter of the hollow semi-finished product; h - the height of the hollow semi-finished product.

The smaller side H of the Workpiece has the shape of an arc of a circle of radius R2 equal to

DI is the sum of half the diameter of the conditional

round billet required for the extrusion of a hollow semi-finished product with a diameter equal to the diameter of the grit part O and the double height of the groove of the finished part 2hi, with the center lying on the longitudinal axis

symmetry of the workpiece, i.e. R2 - “- + 2hi.

The larger side of the workpiece is less than twice the height of the groove of the glass, i.e. equals H + 2hi. The larger side of the workpiece has concave sections symmetrically located with respect to the axis of symmetry of the workpiece, made along the radius R, the value of which is proportional to the width of the groove of the finished part, and adjoining arcs and circumference with a radius equal to the radius of the circular

blanks.

The angle a between the radii passing through the interface points of the central (convex) and concave portions of the larger side is equal to the angle between the radii passing through the intersection points of the circumference of the neutral layer of the finished part with the walls of its groove.

The concave portions R of the larger side of the workpiece, at a distance from the transverse axis of symmetry equal to (0.60-0.68) DI, become straight, parallel to the longitudinal axis of symmetry of the workpiece, forming rounded corners with the smaller side of the workpiece

Extraction of parts from the workpiece is carried out as follows.

During the convolution of the workpiece, the drawing is actually carried out to a height h less than the total height h + hi of the finished part, and the hi section passes only the bending cycle, the smaller sides of the workpiece form the open end of the finished part, the concave and straight sections of the larger side - the groove walls and the circumference arc of the larger side is the bottom of the groove.

The radii of the rounds of the workpiece during the drawing process remain almost unchanged and form rounded edges of the grooves.

When stretching to a height h. under the influence of radial tensile and tangential compressive stresses, a part of the metal volume of the nominal workpiece Di is displaced

in the peripheral radial direction. On the section of arcs of circles Di of the larger side forming the bottom of the groove, the volume of metal moving along arrow A goes to

increase in height h details.

The metal displaced in the direction B increases the thickness of the sheet preparation near the diameter DI to the size of the size of the one-sided gap between

punch and die.

The volume of metal displaced in the direction B goes to fill the concavity of the section R of the contour of the workpiece and convert the radius R to a straight line section forming the wall of the groove of the part. Displacement and redistribution of the volume of a metal displaced under the action of radial tensile and tangential compressive stresses when stretched to a height of N higher, occurs in the 2H (1.20-1.36) - Di section.

The rest, more distant from the center of the sheet blanks arriving at the small side of it, the displaced metal (due to its limited volume) comes from and, therefore, the displacement and redistribution of the displaced metal in the rest of the total length H + 2hi of the billet is not observed, therefore, straight sections of the contour of the workpiece, starting at a distance of (0.60-0.68) DI from the transverse axis and extended to the corners of the workpiece, remain unchanged.

In the described blank, the contour of the large side, adjacent to the small side, has a rectilinear shape; therefore, the part, pulled out of the proposed blank, has a groove of the same width, without deviations,

The search for the shape and dimensions of the workpiece, corresponding to the purpose of the invention and necessary to stretch a part of a given size, was carried out by experimentally determining the shape and size of the workpiece for a large number of parts with different geometrical

dimensions, followed by analysis of the varying dimensions of the part on the shape and dimensions of the corresponding blank.

The cylindrical parts obtained from the proposed billet had a diameter of mm, height (h + gm) 6-14 mm, material grade steel 10 KP-OM with a thickness of 0.25-0.45 mm and brass L 62 with a thickness of 0.3-0.4 mm

The use of the proposed blank allows to obtain cylindrical parts with two longitudinal grooves of the same width along the entire height of the groove, which improves the quality of the finished product, reduces the percentage of defective products, thereby reducing metal consumption and labor costs for manufacturing. All this reduces the cost of the finished product.

Of the blanks corresponding to the proposed technical solution, cartridges for electric bulbs for the lighting of the console were made in an experimental order, the quality of which confirmed the effectiveness of the proposed technical solution.

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Claims (1)

Claims of the Invention Sheet blank for drawing a cylindrical part with two longitudinal grooves according to ed. No. 1569057, characterized in that, in order to improve the quality of the grooves in the manufacture of a part with a height greater than its diameter, it is provided with straight sections lying on its large sides and connecting the concave sections with the angles of the workpiece. the billet to the points of intersection of the concave sections with straight lines is 0.6-0.68 of the diameter of the conventional round billet. Hj - (0.60-0.68) -V, figure 1 Fi.Z FIG 2