EP0043025B1 - Indirect metal extrusion press and apparatus for removing "frozen" billets - Google Patents

Abstract

Metal billets trapped in the billet container of an indirect extrusion press are removed by indirect extrusion in the reverse direction until the billet size is reduced sufficiently for the residue to be expelled bodily from the container. The stem used to support the container-closing plug constitutes, or is replaced by a stem for effecting the reverse indirect extrusion.

Description

The invention relates to an indirect metal extrusion press, which consists of a press frame, which is formed from a cylinder spar supporting the main press cylinder, a counter spar and tie rods connecting the cylinder spar and the counter spar. Furthermore, the indirect metal extrusion press consists of a hollow punch supported on the counter spar, which in turn supports the die, a axially displaceable, axially displaceable pick-up holder carrying the pick-up and a moving die moved by the main plunger, carrying a locking punch with a locking disk. As far as pipes or hollow profiles are to be produced, the presses are additionally provided with a punch which can be displaced through the then punched-through sealing punch into the die by pistons in cylinders.

Since there are no relative movements between the press block and the transducer walls in indirect extrusion, the force required by these indirect metal extrusion presses is lower. As a result, relatively long metal blocks can be used. This makes it difficult or even impossible to remove blocks "frozen" in the bore of the transducer, since the installed pressing force is not sufficient to expel the relatively long press blocks against the large wall friction of the press blocks in the transducer bore.

The term "frozen" blocks are to be understood as blocks which, due to malfunctions, no longer have the temperature sufficient for pressing with high degrees of deformation, can no longer or should not be brought to a sufficient temperature in the press, or for other reasons, for example Breakage of the die, can not be pressed further.

It is already known (DE-C-570 750) in a metal extrusion press with two coaxially arranged pressing dies, with which the direct and indirect pressing process can be carried out, for removing cooled blocks from the bore of the transducer to remove the hollow punch located on the counter beam . In its place, a sleeve or sleeve for receiving the cooled block (see FIGS. 3 and 4) is brought into the press axis, which supports the sensor against the counter beam. However, depending on the length of the block and the corresponding friction, the pressing of a longer, cooled, entire block, which is used, in particular in the indirect pressing method, may exceed the required pressing force.

The aim of the invention is to improve the indirect metal extrusion press with its devices in order to make it possible to remove "frozen" blocks from the bore of the receiver with certainty.

This aim is achieved according to the invention in the presses of the type described at the outset in that the closure stamp can be exchanged for a hollow stamp or a profile stamp which only partially fills the available cross section, with a circumscribing circle of the diameter of the closure stamp and with profile cutouts which are open to the outside, or a hollow stamp or a A sealing disc is also assigned to the profile stamp of the corresponding design, and that the locking disc can be removed from a block "frozen" in the sensor, whereupon the frozen block is pressed indirectly against the hollow stamp or profile stamp provided with an attached or molded auxiliary die against the actual pressing direction.

It is known (DE-C-480 957) to pull the mandrel together with a closure plate g which closes the pick-up bore g by means of spring-mounted pull-out claws h in a tubular extrusion press using the indirect pressing method to accelerate the pressing process after the pressing operation from the bore of the pick-up for quick removal of the remnant.

Furthermore, it is known from DE-B-1 452 320 to arrange a holder movable transversely to the press axis in an indirect metal extrusion press for the production of tubes on the press beam, on which a closure piece and a compression die formed longer than the closure piece in the pressing direction is attached.

The compression die compresses the block to be pressed, before a perforated mandrel, which is guided and centered through the closure piece, punctures the block before being pressed out, as a result of which the block rises backwards.

However, these publications relate only to partial features of the present invention and cannot give the person skilled in the art any indication of the overall feature of the invention.

If a block freezes, the sealing disc used is usually clamped in the sensor bore and can therefore only be removed with considerable force. In order to make this possible without additional devices, according to a further feature of the invention, for expanding the sealing disk, it can be connected in a tensile manner to the sealing punch or hollow or profile punch.

Since a large number of sealing disks is required, it is advantageous to provide connecting means which require little processing effort, particularly on the sealing disks. A weakening of the sealing disks by the connecting means must also be avoided. For this reason, according to another feature, the Invention, the closure disc and the closure stamp, hollow stamp or profile stamp at the ends facing each other by annular rear turns formed bundles and can be connected by a counterbond in the rear turns, divided and connectable by a collar ring. By pulling back the sealing stamp, hollow stamp or profile stamp with the sealing disc connected to it, the latter is separated from the "frozen" block.

In a further development of the invention, the "frozen" block is pressed continuously or in a multiple offset stroke, and separated extruded strand sections are separated into chargeable scrap pieces until the block remnant can be pressed out, for which purpose, as is known per se, a bushing between the barrel spar and the receiver of a slightly larger inner diameter than the bore of the transducer for receiving the block residue.

If the closure disk and the closure, hollow or profile stamp have ends formed by back turns at their mutually facing ends and can be connected by a clamp, then the method of operation according to a further feature of the invention is to be supplemented in such a way that the pickup holder and the spar when pressed in driven a relative position and held in this by known couplings between the transducer holder and the spar, so that in the event of a block freezing, the locking disc with collar and backward rotation protrudes from the transducer.

• Fig. 1 in schematischer Darstellung eine Indirekt-Metallstrangpresse zur Herstellung von Hohlprofilen.

The drawings show exemplary embodiments of the invention. It shows

• Fig. 1 shows a schematic representation of an indirect metal extrusion press for the production of hollow profiles.

• Fig. 2a bis 2e unter Einsatz eines Hohlstempels und den
• Fig. 3a bis 3g unter Einsatz eines Profilstempels, während den
• Fig. 4a bis 4c das anschließende Entfernen des Blockrestes zu entnehmen ist.
• Fig. 5 zeigt als Einzelheit den Profilstempel und die Schelle zum Verbinden der Verschlußscheibe mit dem Profilstempel
• Fig. 6 zeigt den Profilstempel im Schnitt nach der in Fig. 5 angezeigten Schnittlinie VI-VI
• Fig. 7 zeigt einen Schnitt nach der in Fig. 5 angezeigten Schnittlinie VII-VII und
• Fig. zeigt einen Schnitt nach der in Fig. 7 angezeigten Schnittlinie VIII-VIII.

The mode of operation of this indirect metal extrusion press when removing a "frozen" block can be seen in the cut-out representations in different operating positions, namely

• 2a to 2e using a hollow punch and
• 3a to 3g using a profile stamp, during the
• 4a to 4c the subsequent removal of the block residue can be seen.
• Fig. 5 shows as a detail the profile stamp and the clamp for connecting the sealing disc with the profile stamp
• Fig. 6 shows the profile stamp in section along the section line VI-VI shown in Fig. 5
• Fig. 7 shows a section along the section line VII-VII and shown in Fig. 5
• Fig. Shows a section along the section line VIII-VIII shown in Fig. 7.

The indirect metal extrusion press shown in Fig. 1 consists of the press frame, which is formed from a cylinder beam 1, a counter beam 2 and tie rods 3 connecting them. The cylinder spar 1 carries the main press cylinder 4, in which the plunger 5 sits as the main press piston. The plunger 5 is connected via a frame 6 to the running beam 7, which is guided axially movably in the press frame along the tie rods 3. The plunger 5 feeds the spar 7, while for the retraction piston rods 8 are connected to the spar 7 via the frame 6 and are seated with their pistons 9 in the retracting cylinders 10, which are carried by the cylinder spar 1 like the master cylinder 4.

Also axially movable in the press frame along the tie rods 3 is a pickup holder 11, for the displacement of which pistons 12 are provided which are connected to the pickup holder 11 via piston rods 13 and are seated in cylinders 14 which are also carried by the cylinder spar 1. With 15 clamping connections are designated, which sit in the spar 7 and encompass the piston rods 13, through which the spar 7 can be firmly connected to the piston rods 13 so that the spar 7 can be firmly connected to both the pickup holder 11 and the piston 12 .

In order to be able to also press hollow profiles with the press, a piercing mandrel is required, which is fastened to a piercing mandrel traverse 16. The piercing mandrel traverse 16 is guided so as to be axially movable in windows 17 which are incorporated into the frame 6 connecting the running beam 7 to the plunger 5. The plunger 5 is hollow and open to the punch mandrel 16 so that it forms a cylinder for a plunger 18 which can advance the punch mandrel 16. For the retraction of the mandrel traverse 16, this is connected to cylinders 19, in which plungers 20 are seated, which are supported on the runner 7. By means of clamping connections 22 in the mandrel cross member 16 and clamping connections 23 in the cylinder spar 1 and tie rods 24, the piercing mandrel cross member 16 can be fixed in the press frame.

For pressing a metal block 25, it is inserted into the sensor 26 carried by the sensor holder 11. A die stamp 28 fastened to the counter beam 2 in the stamp holder 27 supports a die 29. After a closure stamp 31 fastened to the barrel member 7 in the die holder 30 with the support closure piece 32 supported by it has advanced with the barrel member 7 against the block 25 and the block 25 as far as the die 29 has moved and - if a hollow profile is to be pressed - after the mandrel 34 fastened in the mandrel holder 33 to the mandrel cross member 16 has penetrated the metal block 25 until the mandrel tip is in the opening of the die 29, the clamp connection 15 is closed, so that the pick-up holder 11 with transducer 26 is connected to the walking beam 7. The transducer 26 with the receptacle that closes it to one side Merverschloßstück 32 and the locking die 31 now move together under the force of the plunger 5 and the piston 12 to the transducer displacement over the die punch 28, whereby the metal block 25 is squeezed indirectly to the strand which is through the hollow die punch 28 and the passage 35 in the counter beam 2 exits. So far, the construction and operation of the press correspond to the known state of the art.

If a block is now "frozen", if the block can no longer be pressed with a normally high degree of deformation from the beginning or shortly after it has been pressed on, the block must be removed from the transducer. A corresponding initial situation is given in FIGS. 2a and 3a if it is assumed that the block 25 located in the transducer 26 after pressing (FIG. 2a) or after compression from the beginning (FIG. 3a) using the maximum Do not squeeze the pressing force with the normal degree of deformation.

As shown in FIGS. 2b and 3b, the locking stamp 31 is first moved back into its starting position. In the example according to FIGS. 2a to 2e, the pickup closure piece 32a is then removed, which can be done with simple tools or special pulling devices if the pickup closure piece 32a is provided with corresponding catches or threads for connection to the puller. It is also possible to connect the pick-up closure piece 32a and the closure punch 31 to one another by means of a threaded bolt, and thus to have the pick-up closure piece 32a pulled out from the closure punch 31. Then the sealing stamp 31 is also removed.

As FIG. 2c shows, a hollow punch 36 is inserted in the barrel 7 in exchange for the closing punch 31 and supports an auxiliary die 37. The auxiliary die 37 has a die opening which is substantially larger than the main die 29.

If the barrel member 7 with the hollow punch 36 and the auxiliary die 37 seated thereon is moved against the block 25 by acting on the main piston 5, the metal die 25 is pressed out indirectly by the auxiliary die 37, contrary to the actual pressing direction, the extruded die Scrap strand 38 runs into the bore of the hollow punch 36, as shown in FIG. 2d.

As soon as the scrap strand 38 has reached a length of somewhat less than the depth of the bore in the hollow punch 36, the barrel member 7 is moved back into the starting position with the hollow punch 36 into the position shown in FIG. 2e. By means of the saw with the two saw blades 39 and 40, which can be moved transversely to the press axis on a support (not shown), a section 38a of the scrap strand 38 is separated and brought out, so that the section 38b of the scrap strand 38 can also be brought out. In one or more repetitions of this pressing process, the metal block 25 can be deformed to the necessary extent into scrap strand pieces 38a, b, etc. of a chargeable length, since, according to the opening of the auxiliary die 37, a shaping ratio to be overcome by the existing pressing force is maintained.

In the example according to FIGS. 3a to 3g, the closure stamp 31 is exchanged for a profile stamp 41, as can be seen from FIGS. 3b and 3c. Then the profile stamp 41 is moved up to the locking disc 32b, as shown in FIG. 3d, and the locking disc 32b and the profile stamp 41 are connected by a clamp 43 consisting of two halves and held together by a coupling ring 42, as is shown in FIG 5, 7 and 8 is explained in more detail. With the Laufhom 7 of the pistons 9 via the tie rods 8 and the frame 6 of the profile die 41 and the closure disk 32b is pulled out of the bore of the transducer 26 into the position shown in FIG. 3e, whereupon the clamp 42 is released and the shutter 32b can be removed.

The profile die 41 is now pressed against the block 25 in the receiver 26 by acting on the main press piston 5, which acts on the barrel 7 via the frame 6. Via the three profile recesses 44 (see FIG. 6) of the profile die 41, the block is pressed indirectly against the actual pressing direction into three scrap strands 45, which first run through the profile recesses 44 and then are diverted outside the transducer 26 and into pieces of chargeable length be split as shown in Fig. 3f. The profile recesses 44 are dimensioned in cross-section so that the pressing of the block 25 via the profile die 41 takes place with a considerably smaller deformation ratio than the die 29 would require during normal pressing, so that the pressing force for the pressing with the profile die 41 is still sufficient . When the block 25 is pressed to a sufficient extent, the crossbar 7 is moved back with the profile stamp 41 into the position shown in FIG. 3g.

The block 25 is pressed to the necessary or sufficient extent when its rest can be moved in the transducer 26 with the available pressing force. The hollow punch 36 (in the case of the embodiment according to FIGS. 2a to 2e) or the profile punch 41 (in the case of the embodiment according to FIGS. 3a to 3g) is then exchanged for a bushing 46, the inside diameter of which is somewhat larger than the inside diameter of the transducer 26 (see Fig.4a). By acting on the main plunger 5, the bushing 46 is pressed against the transducer 26 via the frame 6 and the barrel 7. At the same time, the pistons 12 can also be acted upon to support the displacement of the sensor. The will oppose the rest of the block 25 supporting the die stamp 28 is pressed out of the transducer 26 and enters the bore of the bushing 46, as in FIG. 4b. The rest of the block 25 is fixed in the socket 46 by means of clamping screws 47, so that when the barrel 7 is withdrawn from the socket 46, the rest of the block 25 and a possibly pressed strand 48 including the die 29 are taken along (see FIG. 4c). If a pressed strand 48 is present, it can be cut off at 49 and 50 and applied. The rest of the block 25 is brought out with the bush 46.

5 to 8 show details of the exemplary embodiment according to FIGS. 3a to 3g on a larger scale.

The profile stamp 41 is detachably fastened with its foot 51 by the stamp holder 52 in the running beam 7. At its front part, which enters the transducer 26, the profile punch 41 is reduced to a diameter which is slightly smaller than the bore of the transducer 26 and is further provided with profile recesses 44. The profile die 41 and the closure disk 32b are turned at their mutually facing ends in such a way that the profile die 41 has an annular groove 53 behind a collar 54 and the closure disk 32b has an annular groove 55 behind a collar 56. By a clamp 43 formed from two halves 43a and 43b, which engages with its collar 57 in the annular groove 53 on the profile die 41 and with its collar 58 in the annular groove 55 on the closure disk 32b, and the two halves 43a and 43b thereof by means of a coupling ring 42 are held together, the closure disk 32b can be connected to the profile stamp 41 in a tensile manner. Half 43a of clamp 43 is part of a C-shaped hook 59 which is attached to a crane with a shackle 60. Half 43b of clamp 43 is pivotally connected to half 43a or C-shaped hook 59 via hinge 61. In an eye 62 on the C-shaped hook 59, a bolt 63 is inserted, on which a sleeve 64 is displaceable, which carries the coupling ring 42 which holds the halves 43a and 43b of the clamp 43 together via the hanger 65. By moving the sleeve 64 on the bolt 63, the coupling ring 42 can move from the position shown in FIG. 5 with the hanger 65 to the position also shown in FIG. 5 without the hanger 65, in which the coupling ring 42 the two halves 43a and 43b of the clamp 43 is brought. In order to make it possible to apply the clamp 43 to the closure disk 32b, the coupling 15 between the piston rods 13 connected to the pickup holder 11 and the running bar 7 when pressing (upsetting and possibly punching the press block 25) is to be closed such that the annular groove 55 and the collar 56 on the closure disk 32b remain outside the transducer 26.

While a special auxiliary die 37 is placed on the hollow punch 36 in the embodiment according to FIGS. 2a to 2e, in the embodiment according to FIGS. 3a to 3g the profile punch 41 is made of one material or is provided with an end face support made of one material, that the use of a special matrix can be omitted.

It is also possible to dispense with a special locking punch 31 if the hollow punch 36 or the profile punch 41 are dimensioned and designed such that they can support the locking disk 32a or 32b directly during the pressing.

Claims (5)

1. An indirect metal extrusion press consisting of a press frame which is formed from a cylinder crosshead (1) bearing the main press cylinder (4), a counter cross-head (2) and tie rods (3) connecting the cylinder cross-head (1) and the counter cross-head (2); a hollow ram (28) supported on the counter cross-head (2), and supporting the die (29), a billet container holder (11) which is guided and is axially displaceable in the press frame and supports the billet container (26), and a moving cross-head (7) which is moved by the main press piston (5) and supports a closure ram (31) having a closure disc (32a, 32b), characterised in that the closure ram (31) can be exchanged for a hollow ram (36) or a profiled ram (41) which only partly fills the available cross-section, has a circumscribing circle with the diameter of the closure ram (31), and has outwardly open profile segments (44), or a closure disc (32a, 32b) is associated with a hollow ram (36) or a profiled ram (41) of corresponding construction, and in that the closure disc (32a, 32b) can be removed from a billet (25) which is »frozen« into the billet container (26) whereupon the frozen-in billet (25) is indirectly in the opposite direction to the normal extrusion direction, towards the hollow ram (36) or profiled ram (41) which is provided with an auxiliary die (37) mounted or integrally formed thereon.

2. An indirect metal extrusion press according to claim 1, characterised in that for removing the closure disc (32a, 32b) the latter can be connected in a traction-resistant manner to the closure ram (31) or the hollow or profiled ram (36, 41

3. An indirect metal extrusion press according to claim 2, characterised in that the closure disc (32b) and the closure ram (31), hollow ram (36) or profiled ram (41) have at the ends facing each other, shoulders (54, 56) formed by annular reliefs (53, 55) and can be connected by means of a clamping collar (43) which engages in the reliefs (53, 55) by means of counter-shoulders (57, 58), is split and can be locked by means of a screw collar ring (42).

4. An indirect metal extrusion press according to one of the preceding claims 1 to 3, characterised in that the extrusion of the »frozen-in« billet (25), continuously or in a repeatedly interrupted stroke, and the separation of the extruded extrusions (38, 45) into scrap pieces of chargeable size is effected until it is possible to force out the billet residue (25), for which purpose, as is known per se, al sleeve (46) of somewhat greater inner diameter than the bore of the billet container (26) is inserted between the moving crosshead (7) and the billet container (26) in order to receive the billet residue (25).

5. An indirect metal extrusion press according to claims 1 to 4 or to one of them, characterised in that the billet container holder (11) and the moving cross-head (7), during pressing, are moved into and are held by known couplings (15) between the billet container holder (11) and the moving cross-head (7) in a relative position such that should a billet (25) become frozen-in, the closure disc (32b) with the shoulder (56) and the relief (55) protrudes from the billet container (26).

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