SU871937A1 - Method of producting tubular neck on the tubular work end - Google Patents

Description

(54) METHOD OF OBTAINING THE INTERNAL MOUTH AT THE END OF A TUBULAR PREPARATION

one

The present invention relates to the field of metal forming, namely, seaming methods.

A known method of producing an internal neck at the end of a toothed billet by molding a transition section at the heated end of the billet and pushing it into the billet 1.

The disadvantage of this method is the complexity of the technology for producing such openings.

The aim of the invention is to simplify the manufacturing technology.

This goal is achieved due to the fact that according to the method of obtaining the internal neck at the end of the tubular billet by molding. at the heated end of the workpiece of the transition section and forcing it into the workpiece, the transition section is formed in the form of a cylinder, the outer diameter of which is equal to the sum of the internal diameter of the neck and the four radii of free bending of the metal in the deformation zone.

In order to obtain a stepped neck, the transition section is molded as a stepped cylinder, and then each step is subsequently pushed inside the workpiece.

In addition, the deformation zone is heated during the process of forcing the neck inside the billet, and the area adjacent to it is cooled.

FIG. 1 shows the original blank; in fig. 2-4 are the steps of forming the transition section; in fig. 5-7 - stages of forcing the transition section into the neck; in fig. 8 - finished product;

10 in FIG. 9 - step transition area on the workpiece; in fig. 10 and 11 are the steps of forcing the transition step portion into the workpiece; in fig. 12 - finished product.

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Example. A tubular workpiece 1 with a heated to forging temperature end is associated with a rotational movement around its own axis, for example, in a lathe chuck, with a rotational speed of 400-800 rev / min. Then a friction tool 2

20 form (roll in) outer cylindrical surface with a flat bottom with diameter DB d + MRu .7

where d. - the diameter of the mandrel, equal to the internal diameter of the neck; RU- bending radius.

After that, the tool is retracted to its original position.

To obtain at the end of the tube, the inner neck from the outer to the flat bottom is exposed to a cylindrical free-rotating mandrel 3 moved in the axial direction. At the same time provide local heating of the source of plastic deformation, for example, single-turn inductor 4 to forging temperature. The metal of the pipe in the center of plastic deformation deforms along the radius of free bending of RU. In this case, the magnitude of the free bending radius will be constant and stably maintained for the entire length of the deformation of the transitional cylindrical section.

To shape the neck of the stepped shape 5, the outer cylindrical surface of the stepped shape with a flat bottom is formed at the end of the tubular billet. The diameter of each step of the cylindrical surface is determined by the formula, then at the same time, heating the deformation zone with an annular inductor and the impact of a stepped mandrel on a flat bottom of a cylindrical surface with a smaller diameter, each step is inverted in a sequence, the neck is turned.

The local heating of the zone of plastic deformation, determined by the radius of free bending, is caused by a factor in the loss of stability of the transition section or section of the latter’s mating with the workpiece body.

In this connection, it is necessary to increase the axial stability of the workpiece and to ensure that all operations can be performed from one installation of the workpiece in the spindle of the rolling machine.

To this end, the transition section is intensively cooled (for example, with a stream of water, steam, compressed air, etc.), and the area of free bending is heated (for example, with a single-turn inductor) to a temperature that significantly reduces the resistance to plastic deformation.

Example. It is necessary to obtain from a pipe with a diameter of 108 mm and a wall thickness of 4 mm a blank for a roller of a conveyor belt of a no-insert structure, on both ends of which it is necessary to make cylindrical necks (glasses) located inside the roller body, the inside diameter of the neck 40 mm, length 40 mm. The neck is matched to the body of the blank by the end walls. Throats are designed for mounting bearing units.

For this, the tubular billet clamped in the spindle of the rolling-in machine with one end heated to a temperature of 1000 ° C causes rotational motion around its own axis with a rotational speed of 375 rpm. Then a transverse movement of the friction tool at the end of the tubular billet forms the transition section in the form of an outer cylindrical surface.

with a flat bottom, with an outer diameter D 70 mm and a length of 35 mm.

By its base, the outer surface is connected to the body of the workpiece by a conical transition section with an angle of i-75 °.

After the formation of the outer neck is completed, the friction tool is retracted to its original position. Then, with a single-turn inductor, we heat up to 1200 ° C a zone of plastic deformation, determined by the value of the bending radius Ra 7.5 mm. At the same time, we press the mouth of the free-rotating mandrel b with a diameter of 40 mm, which is moved in the axial direction at a speed of 8. mm / sec. Synchronous axial displacement of the deformation zone displacing

inductor.

Under the action of applied forces, the metal of the outer surface (neck) in the center of plastic deformation is deformed with a bend, thereby forming the internal neck in the body of the workpiece. The conical surface is then reformed into a flat one with the same mandrel by means of a small amount of sediment.

When forming the internal neck at the other end of the workpiece, after reinstallation, the same sequence of operations is carried out.

during the forming of the neck length of 120 mm and the diameter of the mandrel oL 40 mm

the free bending section is heated to a forging temperature of 1000 ° C, and the transition section is cooled with water to 300-400 ° C.

The use of this method in the production of a flawless design of belt conveyor rollers saves metal by 1.2-1.3 times due to the replacement of cast inserts with one-piece stamped ones and reduces the labor intensity of the manufacture of rollers by 2 times.

Claims (3)

1. A method for producing an internal neck at the end of a tubular billet by molding on the heated end of a billet the transition section and forcing it into the workpiece, characterized in that, in order to simplify the manufacturing technology, the transition section is formed in the form of a cylinder, the outer diameter of which is equal to the sum of the internal diameter of the neck and four radii of free bending of the metal in the deformation zone. 2. A method according to claim 1, characterized in that, in order to obtain an internal neck step-shaped, the transition section is formed in the form of a stepped cylinder, and then successively pushing each step inside the workpiece. 3. The method according to paragraphs. I and 2, characterized in that the deformation zone is heated during the process of forcing the throat inside the billet, and the adjacent portion is cooled. Sources of information taken into account in the examination 1. USSR author's certificate in application No. 2644207, cl. B 21 D 51/10, 1978. yt./ needles