RU2600594C2 - Method for making sleeve-shaped workpieces from bar - Google Patents

Abstract

FIELD: metal processing.

SUBSTANCE: invention relates to metal pressing and can be applied to production of shell body workpiece in shape of sleeve. In metal processing center, measured piece blank is separated from rod and center-drilling is formed on its end. Then workpiece is longitudinally oriented and fed into inductor for heating. Heated workpiece is thermostatically controlled for 3 to 10 minutes. Chamber of shell body is formed on workpiece by three-roll rolling on mandrel. Then, calibration of bottom and walls of workpiece is performed. For that, workpiece installed on mandrel is pushed into mold to rest against bottom of workpiece. Then workpiece installed on same mandrel is pressed for passage through row of precision rings. Rings are made with decreasing diameter and are fixed in bearing container equipped with axial extractor. Workpiece is pressed into device of stepped controlled cooling, wherein it is cooled down.

EFFECT: as result, automation is provided of workpiece making process of shell sleeves by combining operations, higher accuracy, and improving strength characteristics of workpieces.

1 cl, 3 dwg

Description

The invention relates to the field of metal forming, and more particularly to rolling billets of continuous cross-section with rolls located on the outer surface of the product and with axes not perpendicular to its axis, combined with piercing a blind hole through a central mandrel.

The level of this technical field characterizes the method described in the book B.A. Romantseva et al. “Production of hollow profiled blanks, M., NPO Inform Tei, 1992, p. 199, which, according to the technical nature and the number of matching features, is selected as the closest analogue to the proposed method.

According to a known method for the preparation of shell shells of the form of a glass receive according to the following flow chart:

- felling of bars on measured billets;

- running-in of the workpiece with centering in the helical rolling mill;

- firmware centered blanks in a glass with a bottom on a helical rolling mill;

- calibration of the bottom of the glass (prepress);

- broach the glass on the mandrel in the rolling mill;

- cooling the finished workpiece;

- control of geometric parameters and surface conditions.

This method is implemented in the manufacture of blanks for shells of artillery shells at the Sibselmash Production Association in Novosibirsk.

The disadvantage of this method is the high difference of the manufactured blanks due to the mechanical removal of the punch during the formation of the chamber of the central hole due to the non-perpendicularity of the end face of the chopped blanks along its longitudinal axis and different ductility of the metal, unevenly heated in cross section and volume, which limits the use of the method for the manufacture of critical products - shells of small-caliber shells.

When calibrating the bottom and walls of the glass, its internal profile is deformed, and subsequent uncontrolled cooling of the workpiece is accompanied by grain growth, which negatively affects the fragmentation of the projectile.

The technical problem to which the present invention is directed is to improve the quality and purpose of the formed steel shell shells using advanced technology.

The required technical result is achieved by the fact that the known method of manufacturing a glass-shaped shell shell from a bar stock containing operations of separating dimensional piece blanks, centering them at the end, induction heating before three-roll rolling on a mandrel forming a chamber, calibrating the bottom and wall of the blank with subsequent cooling, characterized in that the separation from the bar of piece measured billets with the formation on the end of the centering is carried out in the metalworking center, centering billets they are oriented longitudinally, the billets heated in the inductor before the chamber formation are thermostated for 3-10 minutes, the billets are calibrated by forcing through the die tool on the mandrel in one installation, sequentially through the matrix on the stop in the bottom and through a series of precision rings of decreasing diameter fixed in a carrying container equipped with a coaxial ejector into the device of controlled cooling stepwise, while the stepwise cooling of the shell shell blanks is carried out at a speed of 15 0-200 ° C / s to a temperature of 750-800 ° C, and then to room temperature in air.

Distinctive features of the proposed technical solution have provided complete automation of the manufacturing process of shell shell blanks by combining operations to increase dimensional and weight accuracy, strength characteristics of the workpiece metal.

Shell shells, the blanks of which are made according to the proposed method, are characterized by improved performance indicators.

Separation of piece-length measured workpieces from the bar and the formation of centering by cutting at the end of the machining center is characterized by high dimensional and geometric accuracy, efficiently and compactly.

The longitudinal orientation of the piece blanks on the conveyor by the end centering back is necessary for the subsequent three-roll rolling on the mandrel, which is automatically based in the centering during axial feeding.

Exposure of billets heated in the inductor for a predetermined time in the thermostat ensures temperature equalization in the volume to distribute the loads on the press tool and the metal flow, which is gradientless, which is aimed at increasing the accuracy of the press operations and creating identical thermomechanical conditions for their flow.

The thermostating time of induction heated billets in the range of 3-10 minutes has been optimized experimentally to guarantee equalization of temperature over the cross section and length of the billet, without loss of ductility and strength required for volumetric deformation of the rolling on the mandrel, forming the shell chamber.

Conducting sequentially two operations of calibrating the bottom and the wall of the workpiece in an autonomous die tool, but when installed on the same mandrel, provided, by definition, a common dimensional base and, therefore, is aimed at improving the accuracy of products.

Squeezing the workpiece on the mandrel through the matrix to the technological stop made it possible to prepress the bottom of the workpiece, ensuring its perpendicularity to the longitudinal axis.

Successive pressing of the workpiece mounted on the mandrel through a series of tool rings, the diameter of which decreases stepwise to the size of the centering thickening of the projectile body, reduced the specific load on the stamping tool, ensuring the accuracy of the shape and size of the finished product.

The coaxial installation of the ejector with the container carrying the calibrating rings is designed to eject machined workpieces under the puller, directing the parts to the cooling device.

The workpiece cooling operation is carried out stepwise with a controlled temperature reduction by local shutter speed at transitions aimed at obtaining a fine-grained metal structure to increase the strength characteristics of shells, preventing deformation aging, which stabilizes the ammunition assignment during long-term storage.

Accelerated cooling of steel finished billets after hot volumetric deformation to a temperature of 750-800 ° C is necessary to reduce grain size and, as a result, the strength characteristics of steel.

The cooling of the workpieces in the second stage with air speed prevents the occurrence of thermal stresses in the metal. Therefore, each essential feature is necessary, and their combination is sufficient to achieve a novelty of quality that is not inherent in the signs of disunity, that is, the technical problem posed in the invention is not solved by the sum of the effects, but by a new super-effect of the sum of the attributes.

The essence of the proposed method is illustrated in the drawing, which shows:

in FIG. 1 is a flow diagram of a sequence of operations;

in FIG. 2 is a schematic plan of an automatic device according to the invention;

in FIG. 3 - calibration device blanks.

The proposed method for the automatic manufacture of bar stocks of cases of small-caliber shells in the form of a glass includes sequentially technological operations (Fig. 1):

I, a - centering of the end of the bar;

I, b - separation of measured piece blanks by means of a cutting tool 4;

II - longitudinal orientation of the centering blanks along the end profile;

III - heating blanks for volumetric deformation;

IV - thermostating of heated billets;

V - three-roll rolling of blanks on a central punch;

VI, c - calibration (pre-pressing) with a punch-mandrel 30 of the bottom of the workpiece at the stop 35;

VI, g - calibration of the wall of the workpiece mounted on the mandrel 30, in precision rings 36;

VII - step controlled cooling of the finished workpiece.

The described method is implemented in an automatic device (Fig. 2), which contains the processing equipment installed in the technological sequence connected by transporting and transmitting devices.

The rods are refilled to the machining center 1, on the support 2 of which a drill 3 of end facing (Fig. 1, a) and a cutting tool 4 are mounted for subsequent separation of the measured piece blank (Fig. 1, b).

The processing center 1 by means of a conveyor 5 is connected to a vibratory hopper loading device 6 (VBZU) equipped with a mechanism 7 for orienting along the profile of the end face of the workpiece.

VBZU 6 contains (Fig. 1) a peripheral spiral tray 8, at the output of which is mounted a hook, spring loaded 9 lever 10 of the secondary orientation mechanism 7.

Tray 8 VBZU 6 communicates with the conveyor 11, feeding the longitudinally oriented workpieces (centering back) to the inductor 12, where they are heated to the temperature of plastic deformation of the metal (950-1000 ° C).

The inductor 12 is connected by a conveyor 13 with a thermostat 14, where the workpieces are kept for a predetermined time.

The thermostat 14 is equipped with a pusher 15 of a single-piece transfer of billets in a three-roll mill 16 rolling.

The rolling mill 16 (Fig. 1) of the billet mounted by centering on a profiled punch 17 (mandrel), which is fixed by an abutment 18, contains three sloping rolls 19 inclined to the longitudinal axis that deform the outer surface of the workpiece, combined with the formation of a blind central hole by the punch 17 - shell body chambers.

On the rear side 20 of the mill 16 (Fig. 2), a conveyor 21 for feeding the blanks to the inclined tray 22 is installed.

In the tray 22, there is a pusher 23 mounted on the rod of the cylinder 24, which feeds the workpiece to the center line of the calibrating device 25, which carries a rotary tool plate 27 and a spindle 28 connected to the reverse drive 29 with longitudinal displacements on the power frame 26.

The lead screw 28 carries a central mandrel 30 for basing the workpiece with a cam, and it is connected to the drive 29 by means of its kinematically coupled nut 31 (Fig. 3), which carries the drive pulley 32.

An array 33 and a power container 34 are symmetrically mounted on the turntable 27.

The matrix is equipped with a removable adjustable focus 35, and a number of precision rings 36 are fixed in the container 34 (Fig. 1), the diameter of which is successively reduced to the size of the centering thickening of the shell of the projectile.

A transverse puller 37 of the drive cylinder 38 is adjacent to the container 34 (Fig. 3), and cylinders 39 and 40 are mounted on the frame 26, respectively, of the rotation of the plate 27 and the step feed of the ejector 41.

An axial ejector 41 is mounted on the rod 42 of the cylinder 40 and is located at the centering sleeve 43 fixed in the frame 26 at the center line of the calibration device 25.

The cylinder rod 39 by means of a crank 43 is connected with a rotary plate 27 for sequential positioning of the tool matrix and the container 34 on the center line (coaxial to the mandrel 30 on the lead screw 28).

A chute 44 for supplying the workpieces to the cooling device 45 (Fig. 2) is installed under the tool turntable 27, where they lower the temperature of their metal in steps, preventing grain growth in the structure and deformation aging during storage of products.

The proposed method is carried out in the following order of active actions for the formation of blanks shaped glass.

The source rods are strengthened in the machining center 1, where the central blind hole (centering of the end face) and the measured length are successively drilled, cutting off the centering piece blank from the rod (Fig. 1, a, b).

Cutting the workpiece by conveyor 5 is fed to the hopper VBZU 6, where they are longitudinally oriented on the spiral peripheral tray 8 and rise to the height of the feed to the inductor 12.

At the exit from VBZU 6, the workpieces interact with the secondary longitudinal orientation mechanism 7, the profile lever 10 (hook) of which is deflected by the monolithic end face of the workpiece. After the passage of the workpiece under the action of the spring 9, the lever 10 returns to its original position.

If the workpiece is located on the tray 8 with the centering forward, then its cavity is geometrically closed by the hook of the lever 10, deflecting the workpiece from the motion path: raises and turns (canting), spatially reorientes the blind end forward.

Next, the conveyor 11 feeds the workpiece into the inductor 12, where it is heated to a temperature of 950-1000 ° C for subsequent plastic volumetric deformation.

Heated preforms are conveyed via conveyor 13 to a thermostat 14, which is held for 3-10 minutes, the time required to equalize the temperature in the metal volume.

From the thermostat 14, the workpieces, individually and with a given cycle, are pushed by the pusher 15 into the rolling mill 16, where the workpiece is installed by the end centering on the punch 17, between the three rolling rolls 19, forming a chamber of the shell body - a blind central hole. Then the formed workpiece is removed from the mandrel 17 on the conveyor 21, which feeds it into the tray 22 under the pusher 23 of the cylinder 24.

The pusher 23 on the cylinder rod 24 moves the workpiece to the center line of the calibration device 27, where the central punch 30 of the lead screw 28 is aligned with its blind hole and pushes the workpiece into the matrix 33 to the stop 35, on which the bottom is pressed, the longitudinal axis of the workpiece is pressed, i.e. its calibration in shape and size.

Next, the lead screw 28, reversible from the actuator 29, the punch 30 is removed from the workpiece, the emphasis 35 is removed, then the plate 27 is turned by a cylinder 39 by means of a crank 43, as a result of which a container 34 is mounted on the center line of the device 27.

The axial position of the container 34 is fixed by the ejector 41, which is aligned with the centering sleeve 43 of the frame 26, when measured by the cylinder 40.

Then, the blank is punch 30 is fed through the calibrating rings 36 of the container 34, as a result of sequential volumetric deformation, the wall of the blank chamber is fixed, which is fixed on the mandrel-plug 30. In this case, the diameter of the blank is calibrated in accordance with the size of the centering thickening of the shell of the shell.

When the lead screw 28 is reversed, the formed workpiece is fixed from longitudinal movement by the puller 37, and the mandrel punch 30 is removed from its chamber, and the free workpiece through the groove 44 enters the cooling device 45.

In the device 45, the workpiece is cooled stepwise according to the following mode: at a speed of 150-200 ° C / s to a temperature of 750-800 ° C, and then in air to ambient temperature.

As a result of controlled cooling in the workpiece metal, grain growth is excluded and the required strength characteristics of steel are ensured.

The proposed productive method for manufacturing geometrically accurate and high-quality workpieces for shells of small-caliber shells is recommended for practical use in an automatic mass production device.

A comparison of the proposed technical solution with the identified analogues of the prior art did not reveal an identical match of the totality of the essential features of the invention.

The proposed differences in the method for manufacturing glass-shaped blanks are not obvious to specialists in bulk deformation of metals and artillery ammunition, which do not directly follow from the statement of the technical problem.

Practical manufacturing of shell shell blanks from bar stock is possible with a modernized operating automatic device, including three-roll rolling with chamber piercing in centering piece blanks on an axial mandrel, subsequent combined calibration of forming surfaces and final step cooling, providing specified geometric dimensions and strength characteristics.

From the foregoing, we can conclude that the invention meets the conditions of patentability.

Claims (2)

1. A method of manufacturing a billet shell projection having a cup shape, comprising separating a piece piece from the rod, centering off at its end face, induction heating the billet, rolling it three-roll on a mandrel with forming a shell of the shell body and calibrating the bottom and wall of the billet with subsequent cooling, characterized in that the separation from the bar of the measured piece blanks and the formation of centering at its end are carried out in a metalworking center, the blank with centering is longitudinally oriented and fed to the inductor, the workpiece heated in the inductor before the chamber is formed, is thermostated for 3-10 minutes, while the bottom and walls are calibrated by sequentially pushing the workpiece mounted on the mandrel to the bottom and pushing the workpiece installed on the same mandrel, to pass through a series of precision rings, made with a decreasing diameter and fixed in a carrier container equipped with an axial ejector, into a controlled cooling device in which a step is carried out thawing the workpiece. 2. The method according to p. 1, characterized in that the stepwise cooling of the workpiece is carried out at a speed of 150-200 ° C / s to a temperature of 750-800 ° C, and then to room temperature in air.

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