SU637178A1 - Flanging method - Google Patents

Description

I

This invention relates to distal forming technology.

There is a known method of flanging sheet products, which consists in forming a hole in the flat or hollow product with sides of the nozzle type by means of a translational movement of the punch into the hole. the matrix on which the workpiece is placed l.

The disadvantages of this method are the need for a pre-bore in the blank, the limited height of the bead to be obtained, and the possibility of breaking the bead due to the presence of tensile stresses on the edges of the bead bore of the billet.

Closest to the present invention is a method of flanging holes in hollow blanks by moving a worn punch in the cutting direction, in which the billet is locally heated by friction of the punch about it 2j. When implementing this method in

Depending on the mechanical properties of the material, it is necessary to experimentally set the rotational speed of the punch, which is not achievable in all cases. The consequence of this is to obtain low-quality beads of products along their inner and end surfaces.

The purpose of the invention is to improve the quality of products and reduce the complexity of the process.

This is achieved by the fact that the billet is heated to a temperature below the hot deformation temperature of 150-2004: and the rotation of the punch during the screening process is carried out with the number of revolutions determined by the ratio of 1.74 LR (T1-Gg)

R-SozooiN

where a is the coefficient of thermal conductivity; D - diameter of flanged aperture;

TT is the temperature difference on the surfaces of the workpiece after the establishment of a stationary mode; Р - force of contact punch with preparation; jU is the coefficient of friction; H - the thickness of the workpiece. The method is carried out as follows. Sheet blank with closed contour stack on the matrix. The Vrashakshdays tool is brought to the workpiece before it touches its upper plane with a contact force not exceeding the force required to bend the plane of the workpiece in longitudinal section. At the point of contact, the temperature is created 150-2OO C below the forging and with the onset of stationary heat transfer in the cross section, the workpiece deforms, after the estimated time, with your own tool, which becomes (in this case) a point source of constant power. The calculated speed for steel workpieces with a thickness of 1-2 mm 350O r / min. The method allows high-quality beading of holes: without cracks and gaps along the perimeter of the edge, with a frequency of the inner surface not lower than the 8th class at one technological reception, with a bead height of at least three thicknesses without taking into account the thickness of the workpiece in flat or spatial sheet blanks, including closed loop. 7, 1 F o rm a l a o o b b tj t o n A method of flanging the joints, including heating and subsequent flanging with a rotating punch, is distinguished by the fact that, in order to improve the quality of the products and reduce the complexity of the process , the billet is heated to a temperature below the hot deformation temperature by 15 ° -200 ° C, and the rotation of the punch during the flanging is carried out with the speed determined by the ratio - (, 74АP (T, -T) p-cosoC H deL - coefficient of heat-free- diameter of flanged aperture; - 2 temperature difference on surface after establishing the stationary regime; P - force of contact of the punch with the workpiece; XJ - friction coefficient; H - thickness of the workpiece. Sources of information taken into account during the examination: 1.Mars M. E. Listova stamping, Mashchinostroenie, 1967, 266-269, Fig. 124. 2. US Patent No. 2991551, L. 72-87, 1961.