SU605700A1 - Device for step-wise cutting - Google Patents

Description

(54) DEVICE FOR STEP CUTTING

The invention relates to a pressure treatment and can be used in sheet metal forging.

A device I is known for finishing cutting holes in sheet parts with separation of waste into parts containing a matrix and a movable punch with annular ribs located on the side surface along circumferential arcs and having cutting edges.

The known device is not adapted for step cutting of shaped contours in sheet parts.

Another device is known (2 | for stepped cutting of shaped contours, in sheet pieces, containing a matrix, a movable punch symmetrical in two mutually perpendicular longitudinal planes, and an abutment for limiting the movement of a part supplied parallel to one of the planes of symmetry of the punch, fixedly mounted in the hole of the die and entering when cutting into an axial hole made in the punch and have a shape corresponding to the shape of the cross section of the stop.

This device does not provide cutting with separation of the cut-out waste into parts that

impedes metal flow during cutting. This increases the specific forces on the punch and decreases its durability. In addition, the use of a punch of known design 5 with a feed t 0, 3N, where H is the thickness of the workpiece, is associated with the occurrence of significant recoil forces, causing the workpiece and the –punson to move each other. As a result, machining accuracy and cut quality are degraded.

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The purpose of the invention is to reduce the cutting effort and increase the quality of the cut.

Claims (1)

In order to achieve this goal, grooves open from its working 8 TORT, having a V-shaped cross-section, having a width in the feed direction equal to its spacing, and an angle equal to one quarter of the punch, are made on the side surface of the punch. located between the planes of symmetry 0, one face of the groove is perpendicular to the feed direction of the workpiece, and the part of the stop that is placed in the punch during cutting has a rhombus cross section, the large diagonal of which is located in proportion of the feed direction of the treated part. FIG. 1 shows the device described, longitudinal section; Fig. 2 shows the cutting part of the punch; FIGS. 3 and 4 are sections aa and bb of figs. 2; in fig. 5shema step cutting, realizable on the described device; in fig. b - diagram of the formation of recoil forces when cutting parts (cross section fng. 5); in fig. 7 is a schematic of the force distribution balancing the recoil of the tool and part. The device for step cutting includes a matrix 2 n Poins / sleep 3 fixed in the housing 1, symmetrical in two mutually perpendicular longitudinal planes and mounted on the stem 4 of the drive. The stop 5 for Restricting the movement of the workpiece is located in the hole of the die 2 and is fixed in the nut 6 so that it can move along the direction of movement of the punch to adjust for the thickness of the workpiece. which is located along the feed direction of the workpiece. The axial hole in the punch has a shape corresponding to the rhythmic shape of the cross section of the stop. On the side surface of the punch, parallel to the core, the grooves 8 and 9, open at its working end, have a V-shape in the transverse; The width of the grooves 8-n 9 in the feed direction is equal to its pitch t, and the angle between the edges, / 45-75 °. In each quarter of the punch, located between the planes of symmetry, one of the faces of the groove 8 is perpendicular to the feed direction of the workpiece. Punch 3 has front and rear oti.oui and sbz cutting angles, the magnitude of which is chosen depending on the physical and mechanical properties of the material of the part being cut, the speed parameters of the cutting process and the strength characteristics of the material of the punch. The acute angle of the rhombic hole in the punch is removed from the cutting edge at a distance of t - 0.2 mm. The punch has holes 10 for supplying coolant. The die hole for cutting soft steel and non-ferrous metals has a cylindrical shape, and for cutting high-strength and stainless steels - a shape corresponding to the shape of a punch, with a gap equal to 3-5 of the thickness of the part .. A cut is made in the stop, the upper edge 11 of which is located from mirrors of matrix 2 at a distance equal to H - (1.5-2.0 mm). The described device operates as follows. From the mechanical wire, the rod 4 with the punch 3 performs a reciprocating motion. At the initial moment of insertion of the punch into the part, die-cutting 12 of the segment shape is formed (see Fig. 5). The angle of the angle 90 eliminates the possibility of spinning the metal. The recess of a-yhope facilitates the free flow of metal in the direction of feed of the part, and the rhombic shape of the stop in the lateral direction. The cutting of the notches on the anvil is eliminated by moving it by the moving punch 3. After removing the punch from the die, the part is moved by the value of t and the punch performs the next working stroke. In this case, cutting-out 13 segment shapes and two cuttings are formed. During the subsequent movement of the punch, cuttings 15, 16, 17, etc. are formed. In the established cutting process, one central cutting is made and two more pairs located on both sides of the first one. Once in the matrix, they are removed with compressed air through a special window. The cutting is performed with abundant lubrication of the workpiece and the tool supplied from the holes of the punch and passing along the side flats on the upper part of the stop 5. With cuttings with a step t 0.3 N, a pressing force P occurs, pushing the workpiece and the workpiece out of place. However, the presence of grooves with an angle of 90 ° on the punch allows the force P arising on the front part of the side surface of the punch to close on the punch by the forces P / 2u of the grooves 8 inclined to the feed direction, thus preventing the punch from moving and details. In addition, the maximum recoil forces occur after some penetration of the punch into the workpiece, i.e., after the beginning of the shaping of the central die cut 12 of a trapezoidal shape. The described device allows to expand the range of thicknesses of the cut out parts by 30-40%, as well as provide cutting with a step of 0.1 N t.0.3 N, which is especially important for manual punching machines, the weight of which should be minimal. Claim I. Device for step cutting of shaped contours in sheet parts, containing a matrix, a movable punch symmetrical in two mutually perpendicular longitudinal planes, and an emphasis for limiting the movement of the part supplied parallel to one of the planes of symmetry of the punch fixed mounted in the hole matrix and entering with cutting into an axial bore made in the punch and having a shape corresponding to the shape of the cross section of the abutment, characterized in that, in order to reduce the cutting force of the cut quality and enhancement, on the lateral surface of the punch, parallel to the forming surface, grooves open at its working end, having a V-shaped cross section, width in the direction of the NIN feed, equal to its pitch, n angle between the faces, equal to 45-f-75 °, in each quarter of the punch located between the planes of symmetry one of the faces of the groove is perpendicular to the feed direction of the workpiece.