EP0379937B1 - Horizontal extrusion press - Google Patents

Description

The invention relates to horizontal extrusion presses with axially displaceable pick-up holder and runner in the press frame between the lower, weight-absorbing and upper, holding-down guides. A prerequisite for trouble-free operation of such extrusion presses and for high dimensional accuracy, in particular also the wall thickness of hollow profiles over the entire length of the pressed product, is an aligned, central alignment of the transducer with the pressing tools, i.e. to the die and to the press ram or die ram as well as to the press mandrel during hollow extrusion, this alignment being maintained through the pressing process. A first alignment of the transducer to the pressing tools with the aid of suitable alignment aids is still common today. For alignment, the pick-up holder and the spar of the press are equipped with adjustable guide shoes. If the guides - as usual today - as x-guides, i.e. with guide surfaces aligned with the main axis of the press, thermal expansion in the guides can be compensated. In order to determine tilting of the transducer holder and to be able to counteract it, the arrangement of at least three sensors is known (DE-A-23 04 326), which are arranged on the end face of the transducer and distributed around its axis and the position of the end face relative to one perpendicular to Show axis of the reference plane.

According to the aforementioned prior art, angular deviations can be determined, but not transverse deviations between the transducer and the pressing tools, as can be caused, for example, by temperature differences on the receptacle holder. The requirement of being able to detect and correct transverse deviations between the transducer and the pressing tools was the aim of the solution according to DE-A-28 50 576 and DE-A-30 20 156, according to which a coherent beam of electromagnetic vibrations between one Transmitter and a receiver offset parallel to the press axis and by a second and possibly third receiver with a central one Beam passage openings extend, two of the receivers being connected at a distance to the transducer or transducer holder and the transmitter, and, if appropriate, the further receiver being connected to the components of the overall system which are to be brought into alignment and to be held. The pick-up holder of this press and also the running bar can be provided with adjustable guide shoes for the aligned alignment of the pick-up to the press ram and to the other press tools. This solution has not proven itself under operating conditions, since it has proven to be susceptible to faults and a hindrance and therefore does not justify the high construction costs.

The object to be achieved by the invention is accordingly to detect and, depending on the elements, correct angular and transverse deviations from the aligned position of the transducer with respect to the pressing tools with the rough conditions (high mechanical and thermal loads and heavy contamination) of the extrusion operation have grown. In extrusion presses of the type mentioned at the outset, the holding-down guide shoes of which are also flexibly connected to the transducer holder and the running beam by means of pressure elements and are held under positive pressure in a form-fitting manner on the upper guides, the object of the invention is achieved using sensors known per se in that According to the invention, the sensors designed as displacement sensors are arranged on the upper, holding-down guide shoes to the transducer holder and to the runner between the guide shoes and the transducer holder or runner carrying them, the distance between the guide shoes and the transducer holder or runner acting and indicating in the same direction as the pressure elements. The invention can be implemented with known, tried and tested elements, the sensors being able to be accommodated at a protected location without to occupy a special room that is therefore otherwise available. The sensors can be designed, for example, as inductive displacement transducers and arranged parallel to pressure elements which push the guide shoes off the arms of the pickup holder and the arms of the running bar for contact with the upper guides. Another possibility is to design the pressure elements acting on the guide shoes as piston-cylinder units, in which case the pistons form the travel sensors or are connected directly to them.

As changes in operating conditions, e.g. which does not suddenly set the temperature of the components, it is often sufficient to assign the measuring sensors to the measuring points on the control station of the press, which indicate any deviations that occur, so that the operating personnel can recognize the extent of the deviations and make the necessary corrections. In the context of the invention, however, it is also possible to provide the actuators of the guide shoes with a motor drive, for the control of which signals are connected to a control computer evaluating the measured values of the sensors.

Figur 1

zeigt eine liegende Strangpresse in einer Seitenansicht zu der die

Figur 2

einen Schnitt in Blickrichtung II-II und die

Figur 3

einen Schnitt in Blickrichtung III-III in größerem Maßstab zeigen.
Eine der unteren Führungen ist in

Figur 4

als vergrößerter Ausschnitt aus der Figur 2 dargestellt, zu dem die

Figur 5

einen Schnitt nach der Linie V-V zeigt, während die

Figur 6

einen entsprechenden Schnitt durch die obere Führung zeigt.

The drawings show an embodiment of the invention.

Figure 1

shows a lying extruder in a side view of the

Figure 2

a section in viewing direction II-II and the

Figure 3

show a section in the direction III-III on a larger scale.
One of the lower guides is in

Figure 4

shown as an enlarged detail from Figure 2, to which the

Figure 5

shows a section along the line VV, while the

Figure 6

shows a corresponding section through the upper guide.

The lying extrusion press shown as an exemplary embodiment consists of a press frame 1 on which a cylinder spar 2 and a counter spar 3 rest, which are connected to one another by prestressed anchors 4. The anchors 4 are made of tension members, consisting of a plurality of sheet metal plates 5, which bear on the outside of the cylinder spar 2 and the counter beam 3 with hammer heads 6, and of the sheet metal plates 5, formed on the inside of the cylinder beam 2 and on the counter beam 3, that is to say rectangular pressure pieces 7 located between them . Wedge strips 8 and slideways 9, which form lower and upper guides 10 and 11, which form planes aligned with the press axis 12, are placed on the pressure pieces 7. Along the guides 10 and 11 are axially displaceably a pick-up holder 13 and a spar 14, piston and cylinder units 15 being provided for moving the pick-up holder 13 above and below and connected to the pick-up holder 13 by means of piston rods 16, while the spool 14 of a plunger arranged in cylinder 17 in the pressing direction and by return pistons arranged in cylinders 18 arranged on both sides of cylinder 17, which are connected with their piston rods 19 to the barrel member 14. The pick-up holder 13 carries a pick-up 20 and the running bar 14 a press ram 21. A die is supported on the counter bar 3 by a die holder 22.

The embodiment is a direct extrusion press. It goes without saying that the invention also relates to indirect extrusion presses in which the die is supported by a die stamp. Likewise, the invention relates to direct or indirect hollow extrusion presses in which a mandrel forming the extrusion cavity is arranged in the press die 21 or in the take-up plug which takes the place of a press die and is displaceable in a bore of the press die 21 or the closure piece.

As shown in FIGS. 2 and 3, but in particular the detail in FIG. 4 and FIGS. 5 and 6, the pick-up holder 13 is provided with arms 23 and the walking bar 14 with arms 24, which carry lower guide shoes 25 and upper guide shoes 26 with which they rest on the lower guides 10 or the upper guides 11. To align the transducer 20 to the tools and the tools (press ram 21 and die in the tool holder 22) with respect to one another, the lower guide shoes 25 are connected to the arms 23 of the transducer holder 13 and the arms 24 of the spar 14 by actuators. In the exemplary embodiment, threaded spindles 27 are provided as actuators, which are rotatable in threaded bores 28 located perpendicular to the guides 10 in the end pieces 23a to the lower arms 23 and 24a to the lower arms 24. At their ends facing the guide shoes 25, the threaded spindles 27 are provided with end pins 27a, with which they are rotatably seated in bores 29 of the guide shoes 25. Anchor bolts 30 are screwed into the guide shoes 25 and penetrate the hollow drilled threaded spindles 27, nuts 31 at the ends of the anchor bolts 30 securing the cohesion of the guide shoes 25 with the threaded spindles 27. With 32 rotation locks are designated, which an unwanted rotation of the threaded spindles 27 after Prevent setting. The upper guide shoes 26, which have the task of holding down the pickup holder 13 or the spar 14 and thus securing their position, are resiliently connected to the arms 23 of the pickup holder 13 or the arms 24 of the spool 14. For this purpose, plate spring assemblies 33 are arranged between the guide shoes 26 and the threaded spindles 34. Like the threaded spindles 27, these threaded spindles 34 are also rotatable in threaded bores 35 in the end pieces 23a of the upper arms 23 and 24a of the upper arms 24. The threaded spindles 34 are set in such a way that the plate spring assemblies 33 have a sufficient contact pressure of the guide shoes 26 on the upper guides 11 maintained. Nuts 37 placed on the anchor bolts 36 to the guide shoes 26 leave sufficient play so that the guide shoes 26 can always hold against the guides 11.

Tilting, asymmetrical thermal expansion and the like disturbances lead to a change in the distance between the end pieces 23a and 24a of the upper arms 23 and 24 of the pick-up holder 13 and the runner 14 to the upper guides 11 and under the force of the plate spring assemblies 33, the guide shoes settle 26 correspondingly from the end pieces 23a of the upper arms 23 and the end pieces 24a of the upper arms 24. The end pieces 23a and 24a of the upper arms 23 and 24 are therefore provided with sensors 38. These sensors 38 are inserted in bores 39 which are arranged axially parallel to the threaded bores 35 for receiving the threaded spindles 34. Nuts 38a fix the sensors 38 in the holes 39. In the sensors 38 are axially movable probes 40 which follow the guide shoes 26 under spring pressure and inductively detect their changes in position. Lines 41 connect the sensors 38 to their associated indicators on the press control station.

In addition - as shown in Figure 5 - 14 on the end pieces 23a of the arms 23 of the transducer holder 13 and correspondingly on the end pieces 24a of the arms 24 of the spar 14 14 sensors 42 can be provided with feelers 43 which 44 the distance of the pressure pin Measure and display end pieces 23a and 24a and thus the position of the transducer holder 13 and the running bar 14 relative to the lower guides 10. The end pieces 23a and 24a are for receiving the measuring sensors 42 with stylus pins 43 and pressure bolts 44 provided with stepped bores 45, in the sections of smaller diameter, the pressure bolts 44 are guided, while the sections of larger diameter are closed by covers 46, which support the sensors 42 and support compression springs 47, which hold the pressure bolts 44 in contact with the lower guides 10 .

With their display of the initial position of the pickup holder 13 and the running bar 14 to the lower guides 10 and the changes in these initial positions, for example due to wear on the guide shoes 25, the sensors 42 provide additional information for assessing the measurement results on the sensors 38, which is why the sensors 42 also display measured values are assigned to the press on the control station and are supplied to the control computer as inputs when controlling the actuators.

FIGS. 5 and 6 show the end pieces 23a of the arms 23 of the pick-up holder 13. The running bar 14, which already has a guide in the cylinder 17 via the plunger connected to it, is therefore provided with only one guide shoe in each end piece 24a of the arms 24, which can be arranged in the middle of the end pieces 24a.

A modification of the exemplary embodiment shown is shown in dotted lines for one of the actuators in FIG. For motor rotation of the threaded spindle 27, the worm wheel 48 of a worm gear 49 is connected to it in a rotationally fixed but axially movable manner. The adjustment thus takes place via the motor 50 and the worm 51 in the worm gear 49 fastened to the end piece 23a. The motors 50 can be controlled manually from the control station or by control signals from a control computer evaluating the measured values of the sensors.

Claims (6)

1. Horizontal extrusion presses with a receiver holder (13) and a moving crosshead (14) displaceable axially in the press frame between lower guides (9) absorbing the weight and upper retaining guides (10), in which

   a) the receiver holder (13) and the moving crosshead (14) are provided with adjustable guide shoes (25) for bringing a receiver (20) and a press die (21) into alignment with the other press tools,

   b) retaining guide shoes (26) are provided which are connected flexibly to the receiver holder (13) and the moving crosshead (14) by pressure elements and which are held under the pressure force so that they rest against the upper guides (10) in a positive-locking manner,

   c) measuring sensors for detecting and indicating the position of the receiver axis relative to the press axis are provided between the receiver holder (13) or moving crosshead (14) and the press frame (1),

   characterised in that
   measuring sensors (38) formed as displacement pick-ups are arranged on the upper retaining guide shoes (26) for the receiver holder (13) and the moving crosshead (14), between these guide shoes (26) and the receiver holder (13) or moving crosshead (14) carrying them, these measuring sensors (38) measuring and indicating the distance from the guide shoes (26) to the receiver holder (13) or moving crosshead (14), and acting in the same direction as the pressure elements (33).
2. An extrusion press according to Claim 1,
   characterised in that
   the measuring sensors (38) are arranged in the receiver holder (13) or moving crosshead (14) adjacent to and parallel to the pressure elements (33), and their feeler pins (40) point towards the guide shoes (26).
3. An extrusion press according to Claim 1,
   characterised in that
   piston-cylinder units, whose pistons form displacement pick-ups of measuring sensors or are connected to the latter, are provided as pressure elements.
4. An extrusion press according to any one of the preceding Claims 1 to 3,
   characterised in that
   additional measuring sensors (42) are arranged on the receiver holder (13) and on the moving crosshead (14) for the lower guides (10).
5. An extrusion press according to any one of the preceding Claims 1 to 4,
   characterised in that
   the measuring sensors (38) and where appropriate the additional measuring sensors (42) are allocated data indicators on the control stand of the press.
6. An extrusion press according to any one of the preceding Claims 1 to 5,
   characterised in that
   the positioning elements (27) of the lower guide shoes (25) are provided with motor-operated drives (50), which are controlled by switching signals from a control computer which evaluates the data from the measuring sensors (38) and where appropriate from the additional measuring sensors (42).

Images