RU2364458C2 - Method of fabricating curved items from bar - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to metal pressure working technologies and is intended for implementation in metallurgy. Primarily one performs mandrel bending of two loops on the blank end sections by way of having the bar rolled with rollers moving along curvilinear trajectories. Subsequently the blank is bent in the same direction to produce a third loop. Two blanks in two positions are bent simultaneously. In the first and the second positions accordingly the two primary loops and the third loops are produced. During the interval between two successive bending operations the blank with two loops becomes shifted from Position 1 to Position 2 along the mandrels which process is accompanied by simultaneous relocation of the finished item.

EFFECT: provision for high endurance of stamp.

5 cl, 6 dwg, 1 ex

Description

The invention relates to the processing of metals by pressure and is intended for use in the metallurgical industry in the production of parts from bars such as rail fasteners.

A known method of manufacturing curved parts from a bar / 1 / having three loops, carried out in a stamp by initial bending on the mandrels of two loops at the end sections of the workpiece by rolling a couple of rollers across the bar and then bending the rest of the workpiece. These signs coincide with the essential features of the claimed invention. The bending of the loops is carried out at the same position with the release of the originally curved loops from contact with the mandrels. Subsequent bending of the middle part of the workpiece is carried out in the opposite direction to the initial bending.

The disadvantage of this method is the impossibility of obtaining in one stamp parts having loops at the ends of the workpiece and a large loop in its middle part.

A known method of manufacturing curved parts from a bar / 2 / having three loops, carried out in a stamp by initial bending on the mandrels of two loops at the end sections of the workpiece and subsequent bending of the rest of the workpiece. These signs coincide with the essential features of the claimed invention. The bending of the loops is carried out at the same position with the release of the originally curved loops from contact with the mandrels. Subsequent bending of the middle part of the workpiece is carried out in the opposite direction to the initial bending.

The disadvantage of this method is the impossibility of obtaining in one stamp parts having loops at the ends of the workpiece and a large loop in its middle part, due to an unacceptable scheme for performing technological transitions in bending.

Closest to the technical nature of the claimed is a method of manufacturing curved parts from a bar / 3 / having three loops, carried out in a stamp by initial bending on the mandrels of two loops at the ends of the workpiece by rolling a pair of rollers moving along curved paths along the bar, and subsequent bending the rest of the workpiece in the same direction until the formation of the third loop. These signs coincide with the essential features of the claimed invention. The bending of the loops is carried out at the same position with the release of the originally curved loops from contact with the mandrels.

The disadvantage of this method is the insufficiently reliable operation of the stamp of complex design due to the need to perform two operations of bending the workpiece at one position and the periodic failure of the torsion spring, which must be triggered after the initial bending to translate the bending rollers into the fixation position of the workpiece, and due to the insufficient durability of the bushings and copiers.

The basis of the invention is the task in a method of manufacturing curved parts from a bar by rational execution of bending operations in two positions to ensure reliable operation of the stamp and high durability of its parts.

To solve this problem, a method of manufacturing curved parts from a bar having three loops is carried out in a stamp by initial bending on the mandrels of two loops at the end sections of the workpiece by rolling in a bar a pair of rollers moving along curved paths, and then bending the rest of the workpiece in the same direction to the formation of the third loop. In contrast to the prototype, two blanks are bending simultaneously at two positions, two loops are bent at the first position, and a third loop at the second position, and in the time interval between bends, the workpiece with two loops is shifted from the first to the second position along the mandrels while moving the finished part . Removing the finished part is carried out by pressing the initially curved billet. Before the initial bending, the die is cut in a die of measured length. At the end of bending, the first end is stamped with the front end of the next workpiece. A part having three loops is transferred to the third position of the stamp, where it is bent in another plane.

The foregoing features of the claimed invention provide a technical result, which consists in ensuring reliable operation of the stamp and high durability of its parts.

A causal relationship between the totality of the essential features of the claimed invention and the achieved technical result is as follows.

Keeping bending of two workpieces simultaneously at two positions of the die, namely bending at the first position of two loops of the first workpiece, and at the second position of the third loop of the second workpiece, makes it possible to simplify the design of the stamp, to eliminate the axial movement of the mandrels to release the originally curved loops from contact with these mandrels , eliminate the translation of the bending rollers in the fixation position of the workpiece and, thus, increase the reliability of the stamp and the durability of its parts.

The shift of the workpiece with two loops in the time interval between bending from the first to the second position along the mandrels with the simultaneous movement of the finished part allows bending at the same time at two positions of the stamp.

Removing the finished part by pressing the initially curved billet makes it possible to combine the mechanized execution of auxiliary operations and simplify the design of the stamp.

Cutting a workpiece of measured length before the initial bending in a stamp allows you to automate the manufacturing process of parts on a single press and increase productivity.

Branding the front end of the next workpiece at the end of bending in the first position makes it possible to increase the productivity of manufacturing parts.

Transferring a part having three loops to the third position of the stamp, where it is bent in another plane, allows expanding the technological capabilities of manufacturing spatial details in one stamp.

The invention is illustrated by drawings, which depict:

figure 1 is an example of a manufactured three-loop parts, curved in two planes;

figure 2 is a side view of figure 1;

figure 3 - arrangement of parts of the bending tool at the 1st position of the stamp before starting bending;

figure 4 is a diagram of the bending of small loops of the part at the 1st position (section along BB in Fig.6);

figure 5 - diagram of the bending of the third loop at the 2nd position of the stamp (section along BB in Fig.6);

Fig.6 is a section along aa in Fig.4.

The manufacture of curved parts from a bar having three loops, two small 1 and one large 2, is carried out in a stamp by initial bending on the mandrels of 4 end sections 3 of the workpiece to form two loops 1. The initial bending is carried out at the first position 5 of the stamp by rolling a pair of bending rolls across the bar rollers 6 moving along curved paths 7 formed by the surfaces of the copier 8. A variant of curved paths can be circles with centers located inside two loops, for example, at centers of cylindrical surfaces Tei mandrels 4. To compensate for the springing hinges curved rollers 1 6 folded end portions at an angle greater than 180 °. The rollers 6 can rotate on the axes 9 and rotate around the mandrels 4 using the earrings 10. The earrings 10 are mounted with the possibility of rotation on the axes 11, mounted on the movable plate 12 of the stamp. Subsequent bending of the rest of the workpiece in the same direction until the formation of the third loop 2 is carried out at the second position 13 of the stamp. To do this, in the time interval between bending the workpiece with two loops is shifted from the first to the second position of the stamp along the mandrels 4. At the end of its movement, the workpiece comes out of contact with the mandrels 4, but is located on the mandrels 14. The rollers 15 located on the axes 16, using the earrings 17, rotating on the axes 18, bend the workpiece around the mandrels 14 by an angle greater than 90 °, and thus compensate for the spring loop 2 after removing the load bending. The rollers 15 are guided by the surfaces 19 of the copier 20 placed on the fixed plate 21 in the second position. Simultaneously with the shift of the initially curved workpiece from the mandrels 14 in the second position, the finished part moves through the cutout in the copier 20 by pressing this workpiece on it. The movement of the workpiece produce pushers 22 located in the grooves 23 and synchronously associated with the progress of the slider press.

The bending blank can be chopped in the same stamp from the bar, which is set above the mandrels 4 and 14 through the cutout in the stand 24 until it stops 25. The cutting is carried out with a knife 26, which is mounted on the bending tool 27, which interacts with the bar at the initial moment of bending. The other end of the rod is bent by a symmetrically arranged bending tool 28, made without a knife. At the end of bending in the first position, it is possible to brand the front end of the next workpiece on the stand 24 using a punch 29.

If for parts with three loops, the loops are not in the same plane, but have a spatial shape, the curved flat workpiece is not removed, but transferred to the third position of the stamp, where it is bent in another plane.

Example. On a press with a force of 1000 kN from a bar with a diameter of 17 mm, the rail fastening terminals are bent simultaneously in two positions. In the first position, two loops are bent at the ends of the workpiece, and in the second position, the third loop. At the end of the return stroke of the press, the pushers associated with the slider move the first workpiece to the second position, and the finished part is removed by pressing the first workpiece.

Information sources

1. USSR patent No. 1817723, cl. B21D 35/00, 22/02. Bull. No. 19, 1993.

2. Patent of Russia No. 2157291, cl. B21D 53/36, 7/06, 35/00. Bull. No. 28, 2000.

3. Patent of Russia No. 2233205, cl. B21D 7/06, 22/02. Bull. No. 21, 2004.

Claims (5)

1. A method of manufacturing curved parts having three loops from a bar in a stamp, comprising initial bending on the mandrels of two loops at the end sections of the bar stock by rolling in a pair of rollers moving along curved paths, and subsequent bending of the rest of the workpieces in the same direction to form a third loops, characterized in that they simultaneously bend two blanks in two positions, on the first of which two loops on the first blank are bent, and on the second - the third loop on the second blank, and in The time interval between bends the workpiece with two loops is shifted from the first to the second position along the mandrels while moving the part with three loops. 2. The method according to claim 1, characterized in that the removal of the part with three loops is carried out by pressing the initially curved blank with two loops. 3. The method according to claim 1, characterized in that before the initial bending in the stamp, a bar is cut into blanks of measured length. 4. The method according to claim 1, characterized in that at the end of bending at the first position, the front end of the next workpiece is branded. 5. The method according to claim 1, characterized in that the part having three loops is passed to the third position of the stamp for bending it in another plane.

Images