RU2352429C1 - Method of rifled barrel producing - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: it is produced blank in the form of tube with along the full length hole. Then by several stages from this blank it is received barrel forging with rifle and chamber. At that at first by means of radial clamping on mandrel it is produced forging with rifle on deforming part. For this blank hole in the form of tube is implemented of diameter, exceeding barrel blank diameter rifle for groove value, necessary for installation in specified hole of mandrel for rifle forming. At the following stage it is implemented preliminary mechanical operation by cutting of internal and external surfaces of forging in area of chamber. Then area of chamber is subject to radial clamping.

EFFECT: metal consumption reduction.

2 cl, 4 dwg

Description

The invention relates to the processing of metals by pressure and can be used in the manufacture of rifled stepped trunks.

A known method of manufacturing a barrel (see patent RU 2156670, IPC B21D 51/16, 22/00, 41/00, publ. 09/27/2000), including the manufacture of the original billet pipe blanks with the lead-in, deformable and drive part in in the form of a large and small cylinders, while the small cylinder of the lead part is made with a diameter equal to or greater than the final outer diameter of the breech barrel part, and the large cylinder of the lead part is kept with the diameter of the initial workpiece, the radial compression of the semi-finished product and its final machining with removal the length of the lead-in only.

The described method has the following disadvantages.

1. Due to the preservation of the large cylinder of the lead part with the diameter of the initial billet (without machining), the length of the under-lead of the lead part increases, because defects on the initial billet (ovality, nicks, pitting, possibly traces of corrosion, etc.) are retained on the raw diameter and it is not practical to radially compress it. The presence of at least one of the above defects on the pipe billet limits the possibility of using the method, because in the process of radial compression, part of the defects are forged, part is copied to the inner surface. The thickness thickness from defects on the outer surface leads to rapid wear of an expensive tool (mandrel and strikers). For the same reason, it is impossible to produce a semi-finished barrel with a chamber from such a tube blank.

2. In the manufacture of forgings with a chamber, the removal of at least a small cylinder of the lead part of the billet pipe is inevitable.

A known method of manufacturing a rifled barrel of a 6P6M machine gun (see OST B3-6011-85, p. 59, 60, 62), adopted as a prototype. The method includes manufacturing a billet-pipe from the initial billet with a lead-in, deformable, and driving parts, the diameter of the billet-pipe opening being greater than the maximum diameter of the chamber along the entire length of the billet-pipe, manufacturing in one operation the radial compression of the barrel forgings with rifling and chamber and the final mechanical processing.

The prototype has the following disadvantages.

1. The method is economically feasible in the manufacture of short trunks, in which the difference between the maximum internal diameter of the chamber and the diameter along the fields of the threaded part is insignificant (for trunks of small calibers). In the manufacture of trunks of large-caliber products (12.7; 14.5; 23; 30 mm), the method is impractical to use due to the large length of the initial workpiece and the significant difference between the maximum diameter of the chamber and the diameter of the threaded part in the fields, because to implement the method, it is necessary to obtain a hole diameter in the billet pipe that is larger than the maximum diameter of the chamber along the entire length of the billet pipe, which leads to significant labor and material costs.

2. When forging the barrel bore and the chamber in one radial crimping operation, a difficult to manufacture and expensive mandrel is used with its insignificant resistance.

3. When implementing the method, the bullet chamber entrance is formed with an allowance for final processing.

The invention solves the problem of manufacturing a large-caliber rifled barrel with a chamber by the method of radial compression.

The technical result obtained by the implementation of the invention is to reduce the consumption of material in the manufacture of radial compression forgings of large-caliber trunks with a chamber.

The specified technical result is achieved by the fact that in the method of manufacturing a threaded barrel, including the manufacture of a billet-pipe from the initial billet with a lead-in, deformable, and lead parts, radial compression of the forgings of the barrel with rifling and a chamber and final machining, the new is that the billet- the pipe is made with a hole along the entire length with a diameter greater than the diameter of the forgings along the cuts by the amount of the required clearance, with which a mandrel is formed in the hole for forming I rifling during radial compression, and the forging with rifling and the chamber is made in several stages, at the same time, the forging with rifling on the deformable part is first made by radial pressing, then preliminary machining is performed by cutting the inner and outer surfaces of the forgings in the chamber area, and then the chamber area subjected to radial compression, while the forging and mandrel are fixed from rotation and axial movement along the rifling and the pool entrance of the chamber.

The method is illustrated by drawings, where figure 1 shows the workpiece pipe; figure 2 - forging with a threaded channel; figure 3 - forging after machining by cutting in place of the chamber; figure 4 - forging with a mandrel after radial compression of the chamber.

The method is implemented as follows.

A drawing of the forging of the barrel with a chamber and rifling in the channel is being developed. From the condition of equality of volumes and the permissible degree of deformation, develop:

- drawing forgings for the operation of radial compression of the chamber;

- drawing forgings of the barrel with a threaded channel;

- drawing of the workpiece pipe;

- determine the diameter and length of the original workpiece.

From the initial billet by machining, a billet-pipe 1 with a lead-in, deformable, and lead-in parts with a pipe hole diameter d _o greater than the diameter of the grooves d _{n of the} forging 2 by the size of the required clearance S, with which the mandrel 3 is installed in the hole to form grooves, is obtained. At the first stage of radial crimping on a radial crimping machine, a forging 2 is made with a threaded channel on the deformable part with a field diameter d _p and a groove diameter d _n . The inner surface of the forgings 2 from the side of the lead part is processed by cutting at the calculated length with the formation of the preliminary surfaces of the chamber, namely the bullet entrance and the hole with a diameter D _o greater than the maximum diameter of the chamber D _max . The outer surface of the forging part of the forgings 2 is processed from the beginning of the bullet entry to the side of the lead-in and the lead parts, while the section from the beginning of the bullet entrance to the lead-in side is grinded into a diameter smaller than the diameter of the breech of the forging after radial compression of the chamber, and the section from the beginning of the bullet entrance the side of the ends of the lead part of the forging 2 is grinded into dimensions, based on the equality of volumes before and after compression and the permissible degree of deformation. Next, forgings 2 are installed in the lead center, fixing forgings of the forgings with the mating surfaces of the guide part of the mandrel 4. Fasten the forgings 2 between the leash and retaining centers of the radial crimping machine, send mandrel 4 to the forging inlet of the forging and radially compress the forgings in the chamber area, remove the mandrel 4 from the chamber, unfasten the obtained forging 5, remove it from the radial crimping machine and produce the final machining of the threaded barrel.

Claims (2)

1. A method of manufacturing a threaded barrel, including the manufacture of a workpiece in the form of a pipe with a lead-in, deformable, and lead parts, manufacture of a radial compression of the forgings of the barrel with rifling and a chamber using a mandrel for forming rifling and final machining, characterized in that the workpiece in the form the pipes are made with a hole along the entire length, having a diameter exceeding the diameter of the forging of the barrel by rifling by the amount of clearance required to install a mandrel for the rifling of the grooves during radial compression, and the forging of the barrel with rifling and the chamber is made in several stages, while first the radial pressing is made of the forging of the barrel with rifling on the deformable part of the pipe, then preliminary machining is performed by cutting the inner and outer surfaces of the forging of the barrel in the chamber area, and then the area of the chamber forgings of the barrel is subjected to radial compression. 2. The method according to claim 1, characterized in that at the stage of radial compression of the area of the chamber forging the barrel using a mandrel, and the forging of the barrel and the mandrel is fixed from rotation and axial movement along the rifling of the barrel and the pool entrance of the chamber.

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