EP0179330B1 - Rolling train for a superposed, continuously working casting installation for wire production - Google Patents

Description

The invention relates to a rolling mill for an upstream, continuously operating casting plant for wire production, with a plurality of horizontal / vertical rolling stands, which are driven together with mutually rigid speed ratios, and with several preceding this rolling stand group and with two following this rolling stand group horizontal - / Vertical roll stands, which are designed as Vario grates with individually variable roll speeds.

Casting and rolling systems, in particular for the production of copper or steel wire - consisting essentially of a continuously operating casting machine together with a cooling compensation section and a drive unit as well as a subsequent rolling mill - are usually equipped with a few independently variable individual stands to adapt to changing operating conditions and to avoid malfunctions, which are upstream or downstream of a multi-stand mill block with central drive.

The configuration of the last two roll stands as individual stands is particularly desirable because even small, unavoidable temperature differences in the strand lead to differences in the wire diameter and must therefore be compensated for with regard to the required dimensional tolerances. In addition, it must be ensured that the strand runs through two adjacent rolling stands, as far as possible without tensile and compressive stresses, in particular in the last rolling stands. The latter, in particular, leads to the strand jamming in front of the subsequent roll stand, forming a knot, and finally tearing off.

So far, the strand in the area of the last rolling stands has been monitored by means of a loop control, that is to say by means of photoelectric scanning of a loop, the height of which is kept within a predetermined fluctuation range by adjusting the speed of the rolling stands.

A rolling mill of the type mentioned at the beginning - described in the Krupp brochure "Approaches in the development of Krupp / Hazelett casting-rolling plant for the production of contirod" from 1982 (code: 291-1912 e 10582) - is in the direction of production seen, equipped with several (according to embodiment 3 in FIG. 4: at least three) Vario stands, a plurality of roll stands combined to form a rolling block and two downstream Vario stands.

A group drive for several roll stands of a rolling mill is already known from German patent specification 970 102. Starting from the basic speed of the group drive, the speed of each roll stand can be changed via an associated differential gear, which is equipped with a speed-adjustable power take-off acting on the total gear.

The disadvantage of the prior art is that the use of individual stands or the use of group stands equipped with differential gears and auxiliary drives is associated with a considerable outlay.

The invention has for its object to develop a rolling mill as part of a casting and rolling mill, which can be used with reasonable effort for casting and rolling machines of lower performance, allows adaptation to changing operating conditions and based on the statement whether the strand is under tension or pressure , reduces the risk of malfunctions and facilitates the manufacture of a perfect product.

The basic idea of the invention is to connect all the rolling stands of the rolling mill to a central drive, but at the same time to design the two first and last two rolling stands individually as variable speed stands; the entire rolling mill thus forms a rolling block with four Vario stands. In order to record the tensile stress in the rolling stock, the second and third vario stands (i.e. the second and second to last roll stands in the rolling direction) and the adjacent roll stand, which are pivotably arranged, and which accommodate the associated pair of rolls together with drive elements and which are each supported on two pressure transducers, which are effectively held in the roll stand in the rolling direction or in the counter-rolling direction. In the event of a tensile load, the two adjacent chocks move towards one another and stress the internal pressure transducers with respect to the strand section. The display of the pressure cells loaded in each case can thus be used as an output signal for a change in the roller speed of the relevant variator stands in order to set an unlatched state in the strand.

The variable-speed adjustment unit associated with each variometer frame can be mechanically, hydraulically or electrically effective. It is preferably designed (regardless of its other configuration) in such a way that it enables the speed of the Vario stand rollers to be changed continuously or rapidly.

A PIV transmission is particularly suitable as a speed-changing adjustment unit (claim 2). It is a form-fitting gear, which essentially consists of two pairs of conical disks with conical disks that can be moved against each other and a chain as a power transmission. Such gears are particularly suitable for small torques and high speeds and can therefore be used without additional gears, especially on the last two in the rolling direction Vario stands of the rolling mill are used.

In another embodiment of the subject matter of the invention, the vario stands are connected to the central drive via hydraulic adjustment gears, each consisting of a hydraulic pump with a downstream hydraulic motor. The hydraulic pump is driven at the primary speed of the central drive; the output speed of the adjustment gear can be changed continuously in a known manner.

The invention can be implemented particularly well if the rolling stands - which have pivotably arranged chocks - are equipped with overhung rollers, the pitch of which can be changed via eccentric bushes held in the chocks (claim 4). A roll stand of this type is known, for example, from European Patent 0 042 879.

In the case of a rolling mill with several main drive shafts, the speed-changing adjusting units are preferably driven via the free ends of the main drive shafts and the rollers of the vario stands via hollow shafts which surround the main drive shaft in question coaxially with it (claim 5). The adjustment unit is thus connected on the drive side to the main drive shaft in question and on the drive side via the hollow shaft to the associated vario scaffold.

To monitor the string load with a suitable speed adjustment, the Vario stands are equipped with speed sensors (claim 6).

The invention is explained below with reference to the drawing.

• Fig. 1 als Schemabild den Aufbau einer Gießwalzanlage zur Herstellung von Kupferdraht, die mit der erfindungsgemäßen Walzstraße ausgestattet ist,
• Fig. 2 in schematischer Darstellung die gegenseitige Zuordnung der in Walzrichtung aufeinanderfolgenden Horizontal- und Vertikal-Walzgerüste mit mittig angeordnetem Zentralantrieb,
• Fig. 3 schematisch einen Schnitt durch das in Walzrichtung erste Horizontal-Walzgerüst, welches über ein Drehzahlerhöhungsgetriebe und ein PIV-Getriebe als Variogerüst an den Zentralantrieb der Walzstraße angeschlossen ist,
• Fig. 4 schematisch einen Schnitt durch das in Walzrichtung letzte Horizontal-Walzgerüst, welches über ein PIV-Getriebe als Variogerüst an den Zentralantrieb der Walzstraße angeschlossen ist,
• Fig. 5 schematisch einen Schnitt durch das letzte Horizontal-Walzgerüst, welches über ein Hydraulik-Verstellgetriebe mit Hydraulikpumpe und Hydraulikmotor als Variogerüst an den Zentralantrieb der Walzstraße angeschlossen ist,
• Fig. 6 schematisch einen Schnitt durch das letzte Horizontal-Walzgerüst, welches zur Überwachung der Strangbeanspruchung ein schwenkbares Einbaustück und zwei Druckmeßdosen aufweist,
• Fig. 7 als Schemabild das Zusammenwirken der letzten drei Walzgerüste zum Zwecke der Strangüberwachung und Drehzahlanpassung, und
• Fig. 8 stark schematisiert eine Walzstraße mit sechs Horizontal- und Vertikal-Walzgerüsten, die zum Teil als Variogerüste ausgebildet sind, und mit einem Zentralantrieb, der über einen vorgeschalteten Getriebekasten sämtliche Walzgerüste der Walzstraße antreibt.

Show it:

• 1 is a schematic diagram of the structure of a casting and rolling plant for the production of copper wire, which is equipped with the rolling mill according to the invention,
• 2 shows a schematic illustration of the mutual assignment of the horizontal and vertical roll stands successively in the rolling direction with a central drive arranged in the center,
• 3 schematically shows a section through the first horizontal rolling stand in the rolling direction, which is connected to the central drive of the rolling train via a speed-increasing gear and a PIV gear as a vario stand.
• 4 schematically shows a section through the last horizontal rolling stand in the rolling direction, which is connected to the central drive of the rolling train via a PIV gear as a vario stand,
• 5 schematically shows a section through the last horizontal rolling stand, which is connected to the central drive of the rolling train via a hydraulic adjusting gear with hydraulic pump and hydraulic motor as a vario stand.
• 6 schematically shows a section through the last horizontal rolling stand, which has a pivotable chock and two pressure transducers for monitoring the strand stress,
• Fig. 7 as a schematic image of the interaction of the last three roll stands for the purpose of strand monitoring and speed adjustment, and
• Fig. 8 is a highly schematic of a rolling mill with six horizontal and vertical rolling stands, some of which are designed as Vario stands, and with a central drive which drives all the rolling stands of the rolling mill via an upstream gear box.

The casting and rolling system for the production of copper wire shown by way of example in FIG. 1 has the following main components: an intermediate container 1 for receiving liquid copper, which is connected to a casting machine 3 via a feed channel 2, a cooling section 4 with a drive unit 5 for the further transport of the Casting leaving strand 6 and a subsequent rolling mill 7.

As seen in the casting and rolling direction (arrow 8), this consists of twelve roll stands, namely the horizontal roll stands H1, H3, H5, H7, H9 and H11 as well as the vertical roll stands V2, V4, V6, V8, V10 and V12 ; a vertical roll stand is followed by a vertical roll stand.

The rolling mill 7 is combined to form a rolling block by means of a central drive 9 which is arranged in the center and is common to all the rolling stands. The central drive is located between the vertical mill stand V6 and the subsequent horizontal mill stand H7.

The central drive 9 designed as a DC motor drives a downstream branching gear 10 via its shaft 9a to drive four main drive shafts 11 to 14 rotating at different speeds (FIG. 2). The main drive shafts 11 and 12, to which the horizontal roll stands H1, H3 and H5 and the vertical roll stands V2, V4 and V6 are assigned, have a lower speed than the main drive shafts 13 and 14 with the horizontal roll stands H7, H9 and H11 or V8, V10 and V12.

Apart from the first and last horizontal and vertical roll stands H1, V2 and H11, V12 in the rolling direction (arrow 8), all of the roll stands are, in a known manner, rigidly driven by bevel gear 15 with the associated main drive shaft 11, 12, 13 and 14 connected: Their speed therefore depends invariably on the speed of shaft 9a.

In contrast, the first and second as well as the penultimate and last roll stand are driven by the respective main drive shaft 11 to 14 with the interposition of a speed-changing adjusting unit 16, 17, 18 and 19. The adjustment unit is like this designed that the speed of the roll stands in question - which are accordingly referred to as Vario stands - can be changed continuously regardless of the speed of the main drive shaft.

All variometer stands H1, V2, H11, V12 have speed sensors 20. The second and penultimate Vario stand V2 and H11 as well as the adjacent roll stand H3 and V10 are each equipped with pressure cells 21 L, 21 R arranged in pairs, the task and mode of operation of which will be described later.

In the variator stand H1 shown in FIG. 3, an independent change in the speed of the rollers 22 is made possible by interposing a PIV transmission 23, which in a known manner consists of two conical disk pairs 24, 25 with a chain 26 as a transmission element. The translation between the input shaft 27 and the output shaft 28 can be changed smoothly and continuously by moving the conical disks of each conical disk pair relative to one another.

The main shaft 11 assigned to the variometer stand H1 is connected via a coupling 29 to the sun gear 30a of a planetary gear 30, which drives the input shaft 27 at an increased speed via a ring gear 30b, the sun gear 30a and a web 30c. The output shaft 28 moves via a clutch 31, a spur gear 32a, b and a hollow shaft 32c, a bevel gear 33a, b, a further spur gear 34a, b two ring gears 35a, b which are in engagement with one another via their external toothing; The spur gears 36 of the drive shafts 37 for the two interacting rollers 22 are driven in a known manner via their internal toothing.

The mutual distance between the overhung rollers 22 can be changed continuously by rotating two eccentric bushes 38, in which the drive shafts 37 are mounted and which in turn are supported in a chock 39. This is movably connected via a pivot axis 40 and a guide pin 41 to the stationary stand 42 of the variometer stand H1.

Since PIV transmissions only transmit high power at relatively high speeds, the Vario stands H1 and V2 - to which the slow-running main drive shafts 11 and 12 are assigned - must be equipped in the manner mentioned with an additional transmission to increase the input speed in the PIV transmission .

The main drive shaft 11 is passed coaxially through the hollow shaft 32c, which carries the spur gear 32b and the bevel gear 33a.

Due to the higher speed of the main drive shafts 13 and 14 for the rear rolling stands in the rolling direction (cf. FIG. 2), the associated drive arrangement can be of simpler design than the one just described.

For example, the main drive shaft 13 - which coaxially penetrates a hollow shaft 43c - is connected via the coupling 29 directly to an input shaft 27 of the PIV transmission 23 for the variator stand H11 (last horizontal rolling stand of the rolling mill) (cf. FIG. 4). The output shaft 28 drives the rollers 22 via the clutch 31, a neutral spur gear 43a, b, a further clutch 44 and a bevel gear 45a, b in the manner already described (cf. FIG. 3); the design of the drive elements between the bevel gear 45b and the rollers 22 is therefore not shown.

The speed-changing adjustment unit 16 to 19 (cf. FIG. 2) can also consist of a hydraulic adjustment gear which connects to the main drive shaft in question, for example the main drive shaft 13 shown in FIG. 5.

Via a volume-variable hydraulic pump 46 with a pressure line 47, this drives a speed-adjustable hydraulic motor 48, the drive shaft 49 of which is drivingly connected to the spur gear 34a, b already described. The parts 46 and 48 are additionally connected to one another via an unpressurized return line 50.

The hydraulic adjustment gear can, depending on the requirements, also be designed in such a way that only the hydraulic pump 46 or the hydraulic motor 48 can be adjusted for the purpose of changing the speed.

The speed adjustment of the rollers 22 of the variometer stands H1, V2, H11 and V12 can also be brought about with other speed-changing adjustment units. In particular, it is possible to connect the Vario scaffolding to the associated main drive shaft 11 to 14 via a slip-controlled magnetic powder coupling.

For the purpose of determining whether the strand 6 (cf. FIG. 1) is subjected to tension or pressure, with the possibility of a suitable speed adjustment, the horizontal rolling stand H3 and the last vario stand (or last horizontal shown in FIG. 6) are - Roll stand) H11 - as well as the vertical roll stands V2 and V10 - each equipped with two pressure transducers 21 L and 21 R, on whose sensors 21 the chock 39 (which receives the eccentric bushes 38 and roller drive shafts 37) in the counter-rolling direction or in the rolling direction supports. Each load cell is attached via a mounting plate 51 and a base 52 in a recess 42a in the roller stand 42.

The vertical rolling stands V2 and V10 differ from the illustrated embodiment only in that the pivot axis 40, the chock 39 and the guide pin 41 are not horizontal but vertical.

The suspension of the chocks 39 should in any case - for example by using bearings with as little friction as possible - be such that the pivoting movement in the counter-rolling direction or in the rolling direction is opposed as little resistance as possible.

For example, if the one coming from the left Strand (arrow 8 in Fig. 1) pushes the chock 39 to the right, the pressure cell 21 R will produce an output signal in this regard. The same applies with regard to the load cell 21 L, provided that the chock is pivoted to the left with respect to the roller stand 42 under the tensile action from the strand.

The method which can be carried out with the invention and which can be used to monitor the strand stress in the last three or first three roll stands and by adjusting the speed of the associated Vario stands H11, V12 or H1, V2 is explained in detail below with reference to FIG. 7:

If the roll speed of the last roll stand V12 is too high with respect to the penultimate roll stand H11, the strand section located therebetween is subjected to tensile stress with the risk of tearing. The chock 39 of the roll stand H11 is supported on the pressure cell 21 R, which indicates the tensile stress of the strand section. The tensile stress can be reduced by lowering the roller speed of the V12 stand: The load cell 21 R of the H11 stand then shows smaller load values.

If the roll stand V12 has a roll speed that is too low with respect to the previous roll stand, the associated strand section is subject to a compressive stress with the risk of jamming and knot formation. The load cell 21 L of the roll stand H11 shows increased values. These can be influenced by the fact that the roller speed of the last roll stand V12 is increased by engaging in the associated adjustment unit (cf. FIGS. 3 to 5).

By suitably adjusting the roller speed of the V12 stand with respect to the previous H11 stand, it can thus be ensured that the associated strand section runs through without stress; This state can be recognized from the fact that both pressure transducers 21 L and 21 R of the penultimate mill stand H11 indicate normal values.

The setting of a state in which the strand section between the roll stands V10 and H11 passes through without stress could in principle be brought about in a corresponding manner, as has just been described for the last two roll stands. The Vario stand H11 (like the last Vario stand V12 before) is to be regarded as the last rolling stand on which the required speed adjustment is carried out; the status of the continuous strand section is displayed via the pressure transducers 21 and 21 R of the roll stand V10.

When monitoring the strand section between the roll stands V10 and H11, however, it must be taken into account that every speed adjustment on the roll stand H11 changes the previously set, stress-free state of the strand section between the roll stands H11 and V12. So that the working conditions between the last two roll stands - regardless of a speed adjustment of the penultimate H11 mill stand with regard to the third last mill stand V10 - remain unchanged, every change in the roll speed of the H11 mill stand must be carried out simultaneously and in the same ratio on the last V12 stand.

Since the last-mentioned speed adjustment on the last roll stand V12 cannot be carried out by hand, one measure of the method is to equip the two last (or first two) roll stands in question with speed sensors 20 and the measurement signals obtained by means of these with an electronic control unit to process, which comprises a computer and a comparison unit.

in das folgende Verhältnis E um:

The computer calculates the change in speed of the H11 variator

into the following ratio E um:

ermittelt. Zur Drehzahlanpassung werden diesem Wert entsprechende Stellsignale an die Schalteinheit des Variogerüsts V12 übermittelt.The output signal of the speed sensor 20 on the roll stand V12 corresponding to n (12) beforehand is also input into the computer, which has the value

determined. To adjust the speed, corresponding control signals are transmitted to the switching unit of the V12 scaffolding.

ermittelt, zeigt an, wann der Differenzwert Null erreicht und die Drehzahlanpassung am Variogerüst V12 abgeschlossen ist.The comparison unit already mentioned, which continuously adjusts the difference value during the adjustment of the roller speed of the V12 stand

determined, indicates when the differential value reaches zero and the speed adjustment on the V12 scaffolding has been completed.

The procedure basically consists of first adjusting the operating state between the roll stands H11 and V12 by adjusting the speed of the last V12 stand, then adjusting the operating state between the H11 and V12 stands by adjusting the speed of the H11 and V12 and the third last roll stand V10 and taking into account the speed change on the H11 stand to maintain the already set operating state between the last two roll stands in the same ratio to make a speed adjustment on the last roll stand V12.

The described method can be carried out accordingly on the first three roll stands H1, V2 and H3, the speed adjustment between H1 and V2 using the variometer stand H1 and the speed adjustment between V2 and H3 is effected via the V2 scaffolding.

The front roll stands H1 and V2 in question are also equipped with speed sensors 20, the measurement signals of which are processed in the manner already described in an electronic control unit with a computer and a comparison unit. The operating state initially set between the two vario stands H1 and V2 is maintained even after a speed adjustment between the vario stand V2 and the subsequent rolling stand H3 in that the roller speed of the first vario stand H1 is influenced simultaneously and in the same ratio with the speed change on the second vario stand V2 .

The invention is not limited to rolling trains with main drive shafts; Rather, it can also be used when all the rolling stands are driven by a central drive via a gear box.

In the embodiment according to FIG. 8, the central drive 9 with the shaft 9a is connected upstream of a gear box 53, from which the horizontal and vertical roll stands h1, v2, h3, v4, h5 and v6, which follow one another in the rolling direction (arrow 8), are theirs Receive drive energy. The first two and last two roll stands h1, v2 and h5, v6 are designed as vario stands with individually variable speed; the roll speed of the middle roll stands h3 and v4 depends invariably on the speed of the shaft 9a of the central drive 9.

With regard to their basic function and equipment, the roll stands h1, v2, h5 and v6 correspond to the previously described vario-stands H1, V2, H11 and V12, the middle roll stands h3, v4 correspond to the roll stands H3 and V10 (cf. Fig. 2).

The shaft 9a is connected via spur gears 54a, b or 55a, b, c in terms of drive to a roller drive shaft 56 or 57 of the roll stands h3 and v4. The roller drive shafts 56 and 57, in turn, drive a hollow shaft 60 or 61 via spur gears 58a, b or 59a, b and from there a further hollow shaft 64 or 65 via spur gears 62a, b or 63a, b.

Each hollow shaft is connected to the input shaft 27 of a speed-changing adjusting unit 16, 17, 18 and 19, respectively, via an additional gear (which is designated 66 for the sake of simplicity), the output shaft 28 of the rollers 22 of the relevant variator stand h1, v2 having an infinitely variable speed , h5 or v6 rotated. The roller drive shaft 67, 68, 69 and 70 coupled to the output shaft 28 is passed through the hollow shaft 64, 60, 61 and 65 in question.

The previously mentioned PIV gears (cf. FIGS. 3 and 4) are particularly suitable as speed-changing adjustment units.

The advantage achieved by the invention is that even in the area of the first roll stands (H1, V2 and H3 or h1, v2 and h3), despite the large strand cross sections present (which preclude the use of loop control with optical observation), an operating state can be set in which the strand sections between the relevant roll stands are not subject to any stress.

Since the rolling mill only has a common central drive, the adjustment between casting machine and rolling mill required for casting rolling can be carried out by engaging in a single drive, although - although some rolling stands (H1, V2, H11, V12 or h1, v2, h5, v6 ) are designed as Vario stands with individually variable roll speeds - the roll speeds of all roll stands of the rolling mill are changed together.

In the case of casting rolling, the deformation conditions cannot be kept constant to the desired extent because the strand temperature fluctuates to an unavoidable extent. The rolling mill can therefore be adapted to the fluctuations in question via the front of the Vario stands. By suitably setting the operating conditions in the last rolling stands, tight tolerances can be maintained during the manufacture of the wire rod, and that for any wire diameter.

The proposed solution is also interesting from an economic point of view because instead of several individual drives and additional devices, only one central drive is used.

Claims (6)

1. A rolling train for a superposed continuously working casting installation for wire production, having a number of horizontal/vertical roll stands driven jointly with fixed speed ratios in relation to one another, said group of roll stands being preceded by several and followed by two horizontal/vertical roll stands constructed in the form of variable speed roll stands each having individually variable roll speeds, characterized in that four roll stands (H1, V2; H11, V12) taking the form of variable speed roll stands are each connected via their own speed adjusting units (16, 17; 18, 19) to a centrally disposed central drive (9) for all the roll stands (H1, V2, H3, V4, H5, V6, H7, V8, H9, V10, H11 and V12); to determine the tensile stressing in the rolling stock the second and third variable speed roll stands (V2; H11) and each adjacent roll stand (H3; V10) have pivotably disposed built-in members (39) which adjustably receive the associated pair of rolls (22) together with driving elements and each bear against two compression measuring gauges (21L, 21R) retained in the roll housing (42) and operative in the rolling direction (arrow 8) and the direction opposite to rolling repectively; and the roll speed of the variable speed roll stands (H1, V2; H11, V12) can be adjusted via the adjusting units (16, 17; 18, 19) operable in dependence on the output signal of the compression measuring gauges (21 L, 21 R).

2. A rolling train according to claim 1, characterized in that each of the variable speed roll stands (H1, V2; H11, V12) is connected to the central drive (9) via a PIV (pitch infinitely variable) transmission (23).

3. A rolling train according to any one of claims 1 and 2, characterized in that the variable speed roll stands (H1, V2; H11, V12) are connected to the central drive (9) via hydraulic adjusting transmissions each comprising a hydraulic pump (46) with a connected hydraulic motor (48).

4. A rolling train according to any one of the claims 1 and 3, characterized in that the roll stands (V2, H3, V10, H11) equipped with built-in members (39) have rolls (22) mounted overhung, whose adjustment can be altered via eccentric bushings (38) retained in the built-in members.

5. A rolling train having a number of main driving shafts according to any one of the claims 1 to 4, characterized in that the adjusting units (16, 17; 18, 19) are driven via the free shaft ends of the main driving shafts (12, 13; 14, 15) and the rolls (22) of the variable speed roll stands (H1, V2; H11, V12) via hollow shafts (32c; 43c), which enclose the main driving shaft (11; 13) in question and are disposed coaxially thereof.

6. A rolling train according to one of the claims 1 to 5, characterized in that the variable speed roll stands (H1, V2; H11, V12) are equipped with tachometers (20).

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