RU2375134C2 - Method of production of impact extrusion on tube-profile presses and device used for this - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: invention refers to metal forming and may be used during impact extrusion of tubular bodies of complex shape on tube-profile presses. Extrusion is performed by means of device containing container, matrix unit, extrusion stem and mandrel. Heated perform is provided to two-peace work cavity of device by mandrel installed on extrusion stem. Extrusion is done into space of work cavity restricted by mandrel. Impact extrusion is removed from container together with extrusion stem and mandrel. Mandrel is installed on extrusion stem with possibility of prompt dismantling and it has taper working surface. On this surface radial grease grooves are arranged in increments of 15-30 mm. Distance between grooves is 2-10 mm.

EFFECT: increase in efficiency of production and enhancement of durability of used production tooling.

3 cl, 5 dwg, 1 ex

Description

The invention relates to the processing of metals by pressure and can be used for stamping by extrusion of hollow products of complex configuration mainly on tube-shaped presses.

One of the most optimal schemes for metal forming is extrusion stamping, in which plastic deformation occurs under conditions of comprehensive non-uniform compression at high compressive stresses, which allows obtaining high degrees of deformation and stamping low-plastic alloys, which acquire high strength properties during processing.

A known method of manufacturing forgings by extrusion, including the sludge of the original billet, the formation of a semi-finished product by extruding the rod with the preliminary formation of the flange, the final stamping, while the semi-finished product is formed with the dimensions of the flange part in the plan in the range of 0.9-1.0 from the corresponding dimensions in the plan finally stamped forgings, and the final stamping is carried out with the displacement of metal in the groove at an angle of 5-85 ° to the vertical axis of the forgings (RF patent No. 2205722, publ. 10.06.2003, IPC B21K 1/00).

The disadvantage of this method is the low productivity due to the need for several transitions, low metal utilization.

Known stamp for closed die forging, containing in the upper part - the body, insert, punch and a self-locking clip suspended from the punch using rods, and in the lower part - the body, insert and ejector, the lower insert is made of prefabricated and consists of a fixed insert with a cone cavity, which is associated with the outer surface of the movable insert-clips with the inner cylindrical surface and the insert-bottom, the angle of their conjugation is greater than the angle of self-braking, in addition, on the inner surface of the movable insert ki-cage formed bead, to which a push-bottom (RF Patent № 2294812, publ. 10.03.2007, IPC B21J 13/02).

This invention coincides with the claimed that it allows the manufacture of stampings with minimal stamping slopes on the outer side surface, improving accuracy and ensuring the stability of the geometric dimensions of stampings, eliminating their jamming in the stamp.

The disadvantage of this device is the design complexity, the inability to manufacture stampings of complex configuration, the need for vertical hydraulic presses.

A known method of manufacturing hot extrusion stampings on presses with a moving container, including feeding the heated preform to the container, extruding the preform in the container with a press washer, pressing part of the preform into a die to form a constant-section stamping part and forming a thickening, the part of the matrix assembly is placed in the container which, before the thickening is formed, is moved relative to it, forming a cavity between the conjugate planes of the matrix unit and the container, in which then t thickening draft remainder of the blank by synchronous displacement press washer and the container (RF patent №2259897, published 10.09.2005 g.) - prototype.

This invention coincides with the claimed that it allows, with one installation of the workpiece, to produce complex internal and external stamping surfaces. The invention minimizes the specific efforts on the tool, high quality products, expanding the technological capabilities of hot die forging to increase the complexity of the shape of the outer contour and cavity and improve the service properties of parts using metals and alloys of increased strength. The technological capabilities of universal tube-type presses with a moving container are also greatly expanded.

The disadvantage of this method is that the tooling of the method is not optimized for the production of stampings such as bushings having a length to diameter ratio of more than 2 and stamping slopes close to the self-braking angle (this is especially critical for materials with a high coefficient of friction, for example, for titanium alloys), in this case, sticking and subsequent destruction of the tool is observed.

The problem to which the invention is directed is the manufacture of extrusion stampings with stamping slopes less than the self-braking angle with a length to internal stamping diameter of more than 2, improving accuracy and ensuring the stability of the geometric dimensions of stampings, eliminating their jamming in the stamp, increasing maintainability and tool life .

The technical result achieved by the implementation of the invention is as follows:

- saving stamped metal by improving the accuracy of forming surfaces of stampings;

- improving the productivity of the stamping process by eliminating the time to extract stuck stampings and ease of extraction;

- increasing the durability and maintainability of the tool due to the optimal organization of the lubrication scheme of the pressing process and the rapid replacement of failed parts of the tool;

- increasing the capabilities of universal press equipment, in particular tube-profile presses.

The specified technical result is achieved by the fact that in the method of manufacturing hollow forgings by hot extrusion on tube-shaped presses in a device containing a matrix unit, a stamp and a needle including feeding a heated workpiece, extruding it with a stamp and removing the stamping, the heated workpiece is fed into a releasable working the cavity of the device formed by preliminary rigid connection of the container with the matrix unit mounted on a press stamp with a needle having profile grooves filled with lubricant Squeezing the workpiece is carried out in the working space of the cavity defined by needle punching and extraction from the container after manufacture of the container together with the exhaust punching, press stamp and needle.

The specified technical result is achieved by the fact that in the device for manufacturing hollow forgings by hot extrusion on tube-shaped presses containing a matrix unit, a container that can be moved, a stamp and a needle, the container is equipped with liners installed in it, and the matrix unit is equipped with a detachable matrix sleeve, having the possibility of axial movement limited by the keyways made in it, the aforementioned inserts and the matrix sleeve are made with the possibility of formation when the matrices are joined th node and demountable container working chamber, and a needle mounted on a ram, with quick release and formed with a conical working surface on which a step has 15-30 mm radial oil grooves, the distance between the grooves 2-10 mm.

It is advisable that the lubrication grooves are formed by the front and rear along the working movement of the stamp with conical surfaces that are inclined to the surface of the needle at angles of 0 ° 30'-1 ° 30 'and 2 ° -5 ° 30', respectively.

The invention is illustrated by drawings, where in Fig.1 shows a typical part 1 made in accordance with the claimed invention, in Fig.2 - the beginning of the extrusion process, in Fig.3 - the end of the process, Fig.4 - diagram of the extraction of the finished product, Fig .5 - the needle.

The method is as follows.

Before extrusion begins, the movable container 2 is rigidly attached to the matrix unit 3, while the matrix unit contacts the container insert 4 on a conical surface, a working cavity is formed, limited by the end insert 5 on the container side, and the matrix guide 6 and the detachable matrix sleeve on the matrix side, 7 is cut along the axis into two elements in which keyways 8 are made, allowing them to move relative to the keys 9. Before pressing, the press stamp 10 with the installed needle 11 is relegated and the dimensions of the container, the workpiece 12 is installed on the needle, pre-lubricating grooves of the needle 13 are filled with grease. By moving the press stamp, the workpiece 12 on the needle is transported into the working cavity all the way into the matrix sleeve 7. Then, the working stroke is set to the press stamp and the workpiece is extruded into the working cavity, at the same time, conical surfaces begin to form. Next, the metal flows into the outer protrusions (flanges).

After the extrusion of the stamping, the container 2 and the stamp 10 with the needle are retracted, and the needle 11 is removed. On the matrix board 14, the matrix unit is replaced with a receiving unit 15 with a pin 16 mounted thereon. Then, stamping is pushed by a press stamp onto the pin.

During the extraction of the needle, the matrix sleeve 7, due to friction forces, moves along the axis within the length of the keyway along the conical surface of the guide 6, its detachable elements move in the radial direction, forming the space above the outer surface of the stamping necessary for its extraction.

The lubrication grooves on the surface of the needle have a dual purpose:

- thanks to a specially selected profile they ensure the supply of lubricant between the needle and the product both during extrusion and during the extraction of the needle, which allows to drastically reduce the angle of self-braking, and the lubricant reserve located in the grooves guarantees the stability of the process;

- during extrusion due to narrow bands on the working surface in contact with the extruded metal, the proliferation of adhesion spots between the needle and the stamping is limited. This allows high-quality molding of the inner surface of the product during extrusion and guarantees free extraction of the tool (needle).

The lubricating grooves of the needle 13 are made in increments of 15-30 mm with a distance between the grooves of 2-10 mm. The most favorable lubrication conditions are created when the geometric profile of the lubrication groove is formed by two conical surfaces, while the front surface is tilted relative to the needle surface at an angle of 0 ° 30'-1 ° 30 'and the rear at an angle of 2 ° -5 ° 30 '. These values are selected empirically. Lubrication grooves are located on the conical working surface.

An example of a specific implementation.

We produce hollow stamping of variable cross-section (both diameter and wall thickness varies) with a flange of titanium alloy Ti 6A1 4V on a tube-profile press with a force of 3150 tons. A pipe segment is used as a workpiece

⌀ 203 × 41 × 3 85 mm.

Before stamping begins, the container is fed to the matrix unit and rigidly attached by the force of the pressure cylinders. The billet is heated to a temperature of 960 ° C and put on a needle outside the press line, then, together with the needle, it is fed to the axis of the press. Pre-lubricating grooves of the needle are filled with grease of the following composition: cylinder oil 52 (GOST 6411) - 4 parts + pencil graphite (GOST 4404) - 1 part. The needle mounted on the press washer is connected to the press stamp, then the needle together with the workpiece is fed into the container, a working force is applied, in which the workpiece is pressed into a conical split metric sleeve, a flange is extruded at the end of the stroke of the press stamp. Then the container, together with the press washer, needle and stamp, is removed from the metric assembly, while the detachable sleeve is removed at a certain distance (keyway length) from the conical matrix sleeve until a gap is formed, while the radial loads on the outer surface of the stamping are removed. The stamping and detachable sleeve are removed from the matrix assembly, then the press washer and needle are removed from the stamping by the course of the press stamp. The container is fed to the matrix node. A quick-release needle with a press washer is removed from the press stamp and removed from the press axis of the press. On the matrix board, a receiving unit is fed to the pressing axis, then hollow stamping is pushed out by the course of the press stamp from the container onto the receiving pin.

It turns out hollow stamping with a length of 368 mm, with a small end diameter of конца 176 mm and a wall thickness of 33 mm, a large cone diameter of ⌀ 202 mm and a wall thickness of 36 mm and a flange diameter of ⌀ 232 mm and a wall thickness of 51 mm.

This invention allows us to expand the technological capabilities of standard tube-type presses and to produce on them by extrusion by pressing high-precision products of complex geometric shapes with minimal tolerances and inlets (stamping biases), including from hardly deformable alloys.

Claims (3)

1. A method of manufacturing hollow forgings by hot extrusion on tube-shaped presses in a device containing a container, a matrix unit, a stamp and a needle, including feeding a heated workpiece, extruding it with a stamp and removing the stamping, characterized in that the heated workpiece is fed into a releasable working the cavity of the device formed by preliminary rigid connection of the container with the matrix unit mounted on the press stamp with a needle having profile grooves filled with grease, extruding woks are carried out into the space of the working cavity bounded by the needle, and the stamping is removed from the container after they are removed together with the stamp and the needle, which is carried out after extrusion. 2. A device for the manufacture of hollow stampings by hot extrusion on tube-type presses, comprising a matrix unit, a container that can be moved, a stamp and a needle, characterized in that the container is equipped with liners installed in it, and the matrix unit is a detachable matrix sleeve that has the ability axial movement limited by key grooves made therein, said liners and matrix sleeve are made with the possibility of formation when docked matrix unit and container detachable p bochey cavity and the needle is mounted on the slide with the possibility of quick release and formed with a conical working surface on which a step has 15-30 mm radial oil grooves, the distance between which is 2-10 mm. 3. The device according to claim 2, characterized in that the lubricating grooves are formed by two conical surfaces, wherein said conical surfaces, which are the front and rear along the working movement of the press stamp, are inclined to the surface of the needle by an angle of 0 ° 30 ′, respectively -1 ° 30 'and 2 ° -5 ° 30'.

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