EP0822017B1 - Drive arrangement for a metal extrusion press - Google Patents

Abstract

The invention relates to a drive arrangement for a metal extrusion press with a piston-cylinder unit acting between a cylinder spar (21) and a counter spar (22) or a plurality of piston-cylinder units (24, 23) arranged in parallel, which the working stroke of the or the movable piston (24) or cylinder (s) (23) with respect to the tools (28, 27, 29) supported by the counter beam (22) or with auxiliary piston-cylinder units (34) for withdrawal and idle stroke. If such a metal extrusion press is to be driven at high speed in the retraction or idle stroke by means of the auxiliary piston-cylinder units (34) in order to shorten the idle times, large volume flows with high flow speeds have to be managed. To eliminate the disadvantages associated with this, it is proposed according to the invention to provide the piston (s) (24) with the piston rod (s) (25, 26) of the same diameter passing through the cylinder (23), the cylinder (23) against the piston rod on both sides (25, 26) to seal and to connect the two-sided cylinder sections (23a, 23b) of the same effective area by a short-circuit line (35) which can be closed by a switchable shut-off valve (36) for the working stroke. <IMAGE>

Description

Metal extrusion presses are mostly designed as frame presses and consist of a cylinder beam, a counter beam, these into a frame connecting tie rods (columns) and an in the frame of one running in the cylinder of the cylinder spar Piston movable barrel. In the direct pressing process a matrix and a sensor for one for pressing coming block supported on the counter beam, while the block Squeezing ram with the barrel moved by the piston becomes. In the indirect pressing process is on the counter beam Die stamp supported while the transducer with a Sealing disc receives a block to be pressed and is moved with the barrel by the piston. As a piston are usually provided plungers and there are Plunger piston-cylinder units acting between cylinder spar and barrel for retreat or in double acting Training for retreat and assigned to idle or rapid traverse. However, the use of differential pistons is also known (hydraulic presses and hydraulic fluid systems, volume 3, Fig. 57, pages 64 to 67, by Ernst Müller, Springer-Verlag Berlin / Göttingen / Heidelberg) saving Piston-cylinder units for withdrawal.

To achieve a high degree of utilization of the presses idle times are minimized. Idle and retreat should therefore be driven at the highest possible speed. Here are large volume flows between the master cylinder and Oil tank to cope with high flow speed, being turbulent flows and consequent air inclusions in the Oil and foam formation can occur to counter is that the oil lines as short as possible and the cross sections of the oil lines and the valves are kept large (low Δ p) and filters are also large. To the To be able to keep oil lines short are oil tank, drive and Control as close to the press cylinder as possible Metal extrusion arranged over the press cylinder, which is also has the advantage of taking up little space, but not always is desired.

Another possibility known from US-A-4 155 300 Coping with large volume flows with high Flow rate is the piston with the Piston rods passing through the master cylinder on both sides the same diameter and the two-sided Seal piston rods against the master cylinder so that There are partial cylinders of the same effective area on both sides, through a switchable shut-off valve to the working stroke lockable short-circuit line are connected to each other. About the connecting the cylinder spaces on both sides of the piston Short circuit is a quick transition of the oil from one to the other cylinder chamber with low flow resistance possible, with a corresponding dimensioning of the short-circuit line and arranged in this switchable check valve without Difficulty can be met. It should be the Flow velocity in the short-circuit line 8 m / sec and in the check valve do not exceed 12 m / sec.

Not necessarily with the size of the pressing force required division into two or more main pistons and cylinders and by the pistons being provided with piston rods, which replace the tie rods (columns) in the classic Frame design by connecting to the counter beam, one has one for the direct and for the indirect Press process suitable metal extrusion the structural effort the classic design reduced, as a result special spar and the overall length of the press could be reduced accordingly (hydraulic presses and hydraulic fluid systems, Volume 3, Fig. 83 and 84, pages 93 to 95, by Ernst Müller, Springer-Verlag Berlin / Göttingen / Heidelberg). The pistons of this press are trained as a differential plunger. However, it turns out that the formation of the pistons known from US-A-4 155 300 piston rods penetrating the cylinders on both sides of the same diameter for use with the Metal bar presses frameless design is particularly suitable since these, besides their own ability to cope with large Volume flows through the cylinders passing through on both sides Piston rods also have a stable guide in the cylinder spar its cylinders guaranteed.

The auxiliary piston-cylinder units required by the idle stroke and return stroke are in the previously known metal extrusion press frameless design between the counter beam and the cylinder beam arranged, which is a structural disadvantage, since the Working space is narrowed as a result. According to US-A-4 155 300 intended arrangement of the auxiliary drive between the spar and the press frame is not in the frameless design possible. The object of the invention is to remedy this disadvantage. This task is solved by the fact that at a Metal extrusion press by the preamble of the claim 1 outlined design the auxiliary piston-cylinder units for the idle stroke and retraction between the cylinder spar and one Supporting spar are arranged and acting at the same time from the Master cylinders projecting free ends of the piston rods connecting support bar to compensate for the piston rod expansion is movably supported in the direction of the press axis.

The state of the art is still to be found in US-A-3 818 801 refer, which already shows a support spar, which free The ends of piston rods do not connect as a counter bearing is provided for auxiliary piston-cylinder units.

In a further development of the invention, the support bar can furthermore a piston-cylinder unit bear in the press axis is arranged and the piston rod as a fin bumper for between the support beam and the master cylinder beam in the press axis insertable and through a central opening in the master cylinder spar press blocks to be brought into the transducer is formed.

Figur 1

ist eine Prinzipdarstellung einer erfindunsggemäßen Metallstrangpresse in rahmenloser Mehrzylinderbauart. Einzelheiten einer Metallstrangpresse des in Fig. 1 dargestellten Bauprinzips und eingerichtet zur Ausübung des direkten Preßverfahrens sind dargestellt in

Figur 2a

in einer Seitenansicht, in

Figur 2b

in einer Aufsicht, in

Figur 2c

in einer Stirnansicht, in

Figur 2d

in einem Schnitt nach der in Figur 2b eingetragenen Schnittlinie d-d und in

Figur 2e

in einem Schnitt nach der in Figur 2b eingetragenen Schnittlinie e-e. Während in Figur 2a die Situation vor Beginn des Preßvorgangs zeigt ist in

Figur 3

in einer Seitenansicht die gleiche Presse in der Situation zum Ende des Preßvorganges dargestellt.

Figur 4

zeigt eine Situation während des Ladens eines Preßblockes zu der in

Figur 5

eine Abwandlung gezeigt ist. Die gleiche Metallstrangpresse ist eingerichtet zur Ausübung des indirekten Preßverfahrens dargestellt in

Figur 6a

in einer Seitenansicht, in

Figur 6b

in einer Aufsicht, in

Figur 6c

in einer Stirnansicht, in

Figur 6d

in einem Schnitt nach der in Figur 6b eingetragenen Schnittlinie D-D und in

Figur 6e

in einem Schnitt nach der in Figur 6b eingetragenen Schnittlinie E-E. Figur 6a zeigt wiederum die Situation vor Beginn des Preßvorganges und die

Figur 7

die Situation zum Ende des Preßvorganges.

Figur 8

zeigt eine Situation während des Ladens eines Preßblockes im indirekten Preßverfahren.

Embodiments of the invention are shown in the drawings.

Figure 1

is a schematic diagram of a metal extrusion press according to the invention in a frameless multi-cylinder design. Details of a metal extrusion press of the construction principle shown in FIG. 1 and set up to carry out the direct pressing process are shown in

Figure 2a

in a side view, in

Figure 2b

in supervision, in

Figure 2c

in a front view, in

Figure 2d

in a section along the section line dd shown in FIG. 2b and in

Figure 2e

in a section along the section line ee entered in Figure 2b. 2a shows the situation before the start of the pressing process in

Figure 3

in a side view the same press shown in the situation at the end of the pressing process.

Figure 4

shows a situation during the loading of a press block to that in

Figure 5

a modification is shown. The same metal extrusion press is set up to carry out the indirect pressing process shown in

Figure 6a

in a side view, in

Figure 6b

in supervision, in

Figure 6c

in a front view, in

Figure 6d

in a section along the line DD shown in Figure 6b and in

Figure 6e

in a section along the section line EE shown in Figure 6b. Figure 6a again shows the situation before the start of the pressing process and the

Figure 7

the situation at the end of the pressing process.

Figure 8

shows a situation during the loading of a press block in the indirect pressing process.

The frameless metal extruder shown in Figure 1 has a cylinder beam 21 and a counter beam 22. In the in Cylinder spar supported in the direction of the press axis 21 are two master cylinders 23 diametrically in the schematic diagram at the same distance from the press axis or at more than two Master cylinders in an even distribution concentric to the Press axis arranged. Those guided in the master cylinders 23 Pistons 24 are provided on both sides with piston rods 25 and 26, of which the piston rods 25 are arranged with the stationary Counter beam 22 are connected. The master cylinders 23 are from Cylinder bottoms or covers opposite the piston rods 25 and Sealed 26 of the same diameter, so that there is on both sides the piston 24 cylinder spaces 23a and 23b the same effective area surrender. By acting on the pistons 24 in the cylinder chambers 23a, the cylinder beam 21 is placed on the stationary counter beam 22 too moved. With one carried by the cylinder spar 21 Press ram 27 is made from a transducer 28 through a die 29 a block pressed into a strand. The die 29 supports down on the counter beam 22 for further support of auxiliary piston-cylinder units 30 serves the piston rods 30a are connected to the block sensor 28. The auxiliary piston-cylinder units 30 serve to press the block sensor 28 to the die 29 when pressing a block, for setting down of the block pickup 28 from the die 29 when the Press remnants and, if appropriately dimensioned, also for further Moving the block receiver 28.

The displacement of the cylinder spar 21 to the working stroke takes place corresponding to the pressing of a block relative to the strand slowly by acting on the pistons 24 from the cylinder spaces 23a via the pressure oil supply lines 31 while that from the Cylinder spaces 23b displaced oil discharged via lines 32 is in an oil tank 33. For a quick retreat or a Feed in rapid traverse of the cylinder spar 21 are Auxiliary piston-cylinder units 34 provided the double acting and can be acted upon accordingly. With the fast Retraction movement or the feed movement in rapid traverse of the Cylinder bars 21 are large amounts of oil from the cylinders 23 too oust what in a volume exchange between the Cylinder chambers 23a and 23b of the cylinders 23 are used for this purpose are connected via short-circuit lines 35, in which switchable check valves (unlockable check valves) 36 are located. The short-circuit lines 35 and the valves 36 have Cross-sectional dimensions based on the rapid volume exchange allow between the cylinder spaces 23a and 23b. For support the auxiliary piston-cylinder units 34 is a support bar 37 provided with the piston rods 26 supported by it connected is. The support bar 37 is in the direction of the press axis movable to compensate for the expansion of the piston rods 25/26 supported.

The structural details of that in Figure 1 in principle Metal extrusion press shown are in Figures 2 to 5 Setting up the press for the direct pressing process and the Figures 6 to 8 when setting up the press for the indirect Pressing process shown, referring to the description of the press based on the principle representation when using the same Reference number is referenced. With these The press with four main cylinders is an exemplary embodiment 23 provided in a cylinder spar 21. As especially from the Figures 2a and 6a can be seen, the master cylinder 23 on both ends with guide bushings 38 and sealing rings 39 for the same diameter piston rods 25 and 26th provided, according to the given distance of Guide bushings 38 stable at the ends of the master cylinder 23 Guides of the pistons 24 with their piston rods 25 and 26 result, which are therefore suitable the tie rods (columns) of to replace the classic frame design of the presses.

For the operation of the press in the direct pressing process (Fig. 2 to 5) the cylinder spar 21 is transverse with one in guides 40 to the press axis displaceable slide 41 provided by a piston-cylinder unit 42 is actuated. The slider 41 carries the press ram 27 and is offset in the sliding direction provided with a through hole 43 for stamp receiving, which alternately introduced with the press ram 27 in the press axis can be, so that through this through hole 43 a press block can be loaded, as shown in Figures 4 and 5. The counter beam 22 is provided with a die changing device 44 provided, which is displaceable transversely to the press axis and with Recordings 45 is provided for replaceable dies 29. During the pressing of a block, the pickup 28 of the piston-cylinder units 30 firmly against the die 29 pressed. After the pressing process, the pickup 28 of the piston-cylinder units 30 as far from the die 29 removed that between transducer 28 and die 29 a separation of the press residue is possible, as shown in Figure 4.

In Figure 4 is also the loading one for pressing shown pending block, which simultaneously with the Removal of the press residue takes place. For this purpose, the slide 41 placed in the position in which the through hole 43 is located in the press axis. With a not shown Lifting device is a bridge piece 46 between the transducers 28 and the through hole 43 introduced in the slide 41. A block to be pressed is in a block transport 47 the space between the cylinder spar 21 and the support spar 37 to placed in the press axis. One as a bumper trained piston rod 48 of a piston-cylinder unit 49, which is attached to the support beam 37 in the press axis the press block to be loaded through an opening 50 in the cylinder spar 21 and through the through hole 43 in the slide 41 via the Bridge piece 46 in the bore of the transducer 28. After Withdrawal of the piston rod 48, lowering the bridge piece 46 and moving the ram 27 back into the Press axis can start the next pressing process (in figure 2a shown starting position). The movements are controlled so that they overlap as much as possible.

Another way of loading one for crimping Figure 5 shows the next block, saving one the liftable and lowerable bridge piece is the transducer 28 of the Piston-cylinder unit 30 displaceable up to the slide 41 after the ram 27 from the slide 41 so far has been moved laterally so that it is outside the driving range of the transducer 28 and the through hole 43 in the slide 41st lies in the press axis. The block transport 47 in the space between cylinder spar 21 and support spar 37 in the Press axis introduced by the block Push-in / piston rod 48 of the piston-cylinder unit 49 through the opening 50 in the cylinder spar 21 and the through hole 43 pushed into the bore of the transducer 28 in the slide 41.

For the operation of the press in the indirect pressing process (Fig. 6 to 8) is a slide in the guide 40 on the cylinder spar 21 51 slidable transversely to the press axis, the one Locking disk 52 and a through hole 53 are provided is. When a block is pressed, the cylinder spar 21 presses via the closure disk 52 the pickup 28 in the direction of the counter beam 22 to. On the counter beam 21 is against Die changing device for the direct pressing of exchanged Supported slide 54, which is transverse to the in a guide 55 Press axis is displaceable and carries a die 56, onto which the transducer 28 is pushed, the block is pressed from the transducer 28 to the strand. At the end of Pressing the position shown in Fig. 7 is reached. The cylinder spar 21 is then retracted so that the shutter 52 releases from the pickup 28 so that the Slider 54 can be moved so far that the Through hole 53 is located in the press axis. The Following cylinder spar 21 is the pickup 28 in the Starting position (see Fig. 8) retracted. One of those Block transport 47 in the space between the cylinder spar 21 and the support beam 37 and the press block brought into the press axis is from the push-in / piston rod 48 of the piston-cylinder unit 49 through the opening 50 in the cylinder cross member 21 and the Return bore 53 in the slide 51 in the bore of the transducer 28 pushed so that the press for a subsequent pressing operation is ready. It goes without saying that in the process Intermediate operations such as the removal of the transducer by one clearing die 57 which can be exchanged for the die die 56 and the separation of a press remnant while moving the transducer 28 can be inserted. The die stamp 56 and the Broach 57 are attached to the slide 51 and alternately displaceable in the press axis, whereby the punches 56 and 57, respectively, removed from the press axis is outside the driving range of the pickup 28.

Claims (2)

1. A horizontal metal extrusion press, which is designed for the direct or the indirect pressing process and which is provided with two or more cylinders (23) arranged concentrically to the axis of the press with uniform distribution and combined in a main cylinder cross-head (21) and with main pistons (24) moved therein with piston rods (25, 26) of equal diameter passing through the cylinders (23) at both ends, wherein the piston rods (25) are connected to a counter cross-head (22) anchored in a stationary manner, the counter cross-head (22) supports one of the pressing tools, a receiver (28) with a die (26) in the direct pressing method, or a die ram (56) in the indirect pressing method respectively, and the main cylinder cross-head (21) displaceable towards the counter cross-head (22) in the direction of the axis of the press supports the other of the pressing tools, a press ram (27) in the direct pressing method, or a receiver (28) with a closure disc (52) in the indirect pressing method respectively, and further piston-cylinder units (34) are provided for the idling stroke and the return stroke of the main cylinder cross-head (21), characterized in that the auxiliary piston-cylinder units (34) for the idle stroke and return stroke of the main cylinder cross-head (21) are arranged so as to act between the said main cylinder cross-head (21) and a support cross-head (37), and the support cross-head (21) [sic - recte (37)] connecting at the same time the free ends of the piston rods (26) projecting out of the main cylinders (21) [sic - recte (23)] is supported so as to be movable in the direction of the axis of the press in order to compensate the extension of the piston rods (25,26).
2. A metal extrusion press according to Claim 1, characterized in that the support cross-head (37) carries a piston-cylinder unit (49) which is situated in the axis of the press and the piston rod of which is constructed as a drive-in rod (48) for dummy blocks to be inserted in the axis of the press between the support cross-head (37) and the main cylinder cross-head (21) and to be moved into the receiver (28) through a central opening (50) in the main cylinder cross-head (21).

Images