SU841713A1 - Die for drawing stepped parts - Google Patents

Description

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The invention relates to sheet punching and relates to the design of a die for stretching stepped parts using an elastic medium.

Known shtamp for extracting stepped parts from sheet blanks, containing a matrix in the form of a housing with an elastic working medium, a movable ring clamp and a hydraulic cylinder, the stem of which carries the central and annular outer punches. The stamp provides stretching first of a greater degree, and then less 1.. However, when drawing a smaller step, the conditions for the flow of material are unfavorable, since the material for shaping must overhang from the flange, having undergone two bends at a small radius. In addition, since there must be a flange deformation on this junction, it is necessary to prevent the corrugation on the flange by increasing the pressure in the forming unit. For these reasons, the technological capabilities of this stamp are also extremely limited due to the ruptures of the workpiece at the second transition (with a lower stage of stretching).

The purpose of the invention is to improve the quality of the parts produced by creating an axial support when drawing a stage of smaller diameter.

This goal is achieved by improving the flow conditions of the material of the billet to the central punch when stretching a step of smaller diameter due to axial overpressure. For this, the stamp is provided with an annular container with an elastic medium fixed on the external punch, and the clamp is made in the form of a sleeve with a flange, the cylindrical part of which has a diameter corresponding to the diameter of the working cavity of the container, and is provided with an annular insert installed on the inner surface with the possibility of axial movement.

FIG. 1 shows the proposed chip in the initial position; in fig. 2 - the same, at the time of drawing out a step of a larger diameter; in fig. 3 - the same at the moment of stretching a step of smaller diameter.

The stamp contains a matrix 1 with a hydroelastic medium 2, a hydraulic cylinder 3, an annular punch 5 and a container 6 with an elastic medium 7 are fixed on the piston 4, and a punch 8 with a limiting flange 9 and a return spring 10 is placed in the hole of the piston 4 the shape of the sleeve 11 with a flange. An annular insert 12 is installed on the side of the inner surface of the sleeve with the possibility of relative axial movement. When the presser is lowered, its cylindrical part enters the container 6.

When the matrix 1 is lowered with the working medium 2 acting on the workpiece 13, the pressure is lowered down until the end of its cylindrical part comes into contact with the elastic medium 7 of the container 6. The pressure in the container 6 rises, as a result of which the ring 12 moves upwards by axially pressing the workpiece The ring punch 5 moves downward, thereby increasing the pressure in the hydraulic cylinder and causing the punch 8 to move upward.

The pressing force is determined by the pressure of the medium in the matrix housing and the ratio of the areas of the working and supporting parts of the sleeve 11 and the ring 12.

Claims (1)

Invention Formula A stamp for extracting stepped parts containing a matrix with a working medium, a pressure and a hydraulic cylinder, on the piston of which there are central and ring punches, characterized in that, in order to improve the quality of the parts obtained by creating an axial back-up when extracting a step of smaller diameter, it is equipped an annular container with an elastic medium fixed on the external punch and the clamp is made in the form of a sleeve with cement, the cylindrical part of which has a diameter corresponding to the diameter of the working cavity of the container and is equipped with an annular insert installed on the side of the inner surface with the possibility of relative axial movement. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 592485, cl. B 21 D 22/12, 08/06/76.