Roll crossing apparatus for cross-rolling mill

Abstract: Herein disclosed is a roll crossing apparatus for use in a cross-rolling mill of the type, in which upper and lower work rolls are caused to cross together with their respective backup rolls by moving upper and lower roll chocks in pass lines opposite to each other together with upper and lower cross heads interposed between the upper and lower chocks and the inner side face of a housing. The roll crossing apparatus comprises: upper and lower gradient portions (E) formed in opposite directions on the inner side faces formed on the upper cross head (1) and the lower cross head (2) and at the inner side faces of the housing (10); and wedges (3) interposed between the upper and lower cross heads (1, 2) and the inner side faces of the housing (10) and having upper and lower opposite slopes (F) made slidable on the gradient portions (E) of the upper and lower cross heads (1, 2). Thus, the upper and lower cross heads (1, 2) are moved in the opposite pass lines by moving the slopes (F) of the wedges (3) upward and downward.

Description: The present invention relates to a roll crossing apparatus for causing the upper and lower rolling rolls of a cross-rolling mill to cross each other in horizontal directions. Apparatuses according to the pre-characterising parts of claims 1 and 2 are known from JP-A-55-45583. Description of the Prior Art Fig. 8 is a side elevation showing an essential portion of a cross-rolling mill and exemplifying an apparatus of the prior art, and Fig. 9 is a perspective view showing the concept of a roll crossing apparatus of the mill of Fig. 8. As shown, shafts 35 are rotated, as better seen from Fig. 9, through individual bevel gears 34 by individual motors 51. Then, screw shafts 32 screwed in nuts 33 are rotated through individual worm reduction gears 31. Thus, an upper cross head 29 and a lower cross head 30 fitted in guides 36 are moved in opposite pass line directions. As these upper and lower cross heads 29 and 30 move, an upper work roll chock 25 and an upper backup roll chock 27, and a lower work roll chock 26 and a lower backup roll choke 28 rotate in opposite directions with respect to the central portions of upper and lower work rolls 21 and 22, as taken in the roll axis directions, to cause the upper work roll 21 and an upper backup roll 23, and the lower work roll 22 and a lower backup roll 24 to cross each other. In the rolling operation, a rolled sheet S has its shape adjusted by regulating the cross angle and by bending the upper and lower work rolls 21 and 22. The apparatus described above has the following drawbacks. (1) Since the upper and lower cross heads 29 and 30 having considerable lengths are individually supported at two points by the two screw shafts 32, they are large-sized to have their thicknesses increased in their pass line directions. This makes it necessary to widen the window (i.e., the spacing between the inner side faces) of a housing 20 or to deepen grooves which are formed in the inner side faces of the housing 20 to fit the upper and lower cross heads 29 and 30. As a result, the housing 20 has its strength and rigidity deteriorated to make it necessary to have its size further enlarged. (2) Since the load to be borne by the upper and lower cross heads 29 and 30 are applied directly to the screw shafts 32 and the nuts 33, these shafts 32 and nuts 33 have to be large-sized to enlarge the sizes of the roll crossing drive trains such as the worm reduction gears 31. (3) Each stand has to be equipped with as many as sixteen sets of screw shafts 32, nuts 33 and worm reduction gears 31 so that the whole apparatus grows accordingly complicated and expensive. (4) In case an existing parallel rolling mill is to be reformed into a cross-rolling mill having a high ability to control the sheet shapes, the housing 20 has to be remarkably worked. SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a roll crossing apparatus for a cross-rolling mill, which can be small-sized and manufactured at a reasonable cost. Another object of the present invention is to provide a roll crossing apparatus which can be easily reformed from that of an existing parallel rolling mill to that of the cross-rolling mill. In order to achieve the above-specified objects, the present invention has adopted the structures defined in claims 1 or 2. Moreover, the roll crossing apparatus having the structure described above may be disposed at only one of the working side and the drive side of the rolling mill, and the rolls may be supported at fixed points at the other side. Since the roll crossing apparatus is given the structures defined in claims 1 or 2, the upper and lower rolls are enabled to cross each other at a desired angle in the following manners (1) and (2). (1) When in the rolling operation of the rolling mill, the upper and lower rolls are caused to cross at a desired angle by moving the individual wedges upward or downward to have their slopes sliding on the gradient portions of the upper and lower cross heads thereby to move both the upper and lower cross heads in the opposite pass line directions. Thanks to the adoption of the vertically integrated wedges, the upper and lower cross heads are moved in the opposite pass line directions, when in the rolling operation of the rolling mill, by moving the vertically integrated wedges upward or downward to have their slopes sliding on the upper and lower opposite gradient portions of the upper and lower cross heads. Thus, the upper and lower rolls are caused to cross each other at the desired angle. In the structure in which one of the drive side and the working side is supported at the fixed point, on the other hand, the upper and lower rolls are caused to cross on the roll end at the fixed support side. (2) When in the rolling operation of the rolling mill, the upper and lower rolls are caused to cross each other at a desired cross angle by moving the individual wedges upward and downward, while being guided by the guide blocks fixed on the outer side faces of the housing, to have their slopes sliding on the gradient portions of the upper and lower cross heads thereby to move the upper and lower cross heads in the opposite pass line directions thereby to rotate the upper and lower roll chokes in the opposite directions. Thanks to the adoption of the vertically integrated wedges, like the aforementioned case (1), the upper and lower cross heads are moved together in the opposite pass line directions as the result of the vertical movements of the integrated wedges. Moreover, the operations are similar to those of the foregoing case (1) if one of the drive side and the working side is supported at the fixed point. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side elevation showing an essential portion of a cross-rolling mill which is equipped with a roll crossing apparatus according to one embodiment of the present invention; Fig. 2 is a section taken along line II - II of Fig. 1; Fig. 3 is a side elevation showing an essential portion of a cross-rolling mill which is equipped with a roll crossing apparatus according to another embodiment of the present invention; Fig. 4 is a section taken along line IV - IV of Fig. 3; Fig. 5 is a side elevation similar to that of Fig. 3 but shows an essential portion of a cross-rolling mill which does not embody the invention, but illustrates how the work rolls only are caused to cross each other by wedges arranged on the outer sides of a housing; Fig. 6 is a section similar to that of Fig. 4 but shows the case, in which work rolls are moved only at a drive side D but supported at a fixed point at a working side W; Fig. 7 presents diagrams for expressing the displacements of the rolls in case the displacements of the roll ends are performed only at the drive side or the working side; Fig. 8 is a side elevation showing an essential portion of a cross-rolling mill and exemplifying an apparatus of the prior art; and Fig. 9 is a perspective view showing the concept of a roll crossing apparatus of the mill of Fig. 8. DESCRIPTION OF THE PREFERRED EMBODIMENTS In Figs. 1 and 2, reference numerals 1 and 2 designate upper and lower cross heads, respectively, which individually have their outer side faces formed with a number of steps of gradient portions E. These gradient portions E are vertically oppositely sloped at the upper and lower cross heads 1 and 2. These cross heads 1 and 2 slide on each other around a pass line. Moreover, the cross heads 1 and 2 further slide on the two side faces of an upper work roll chock 26 and an upper backup roll chock 27, and a lower word roll chock 26 and a lower backup roll chock 28, respectively, but are inhibited to move vertically by upper and lower guides 11 and 12. Numeral 3 designates vertically integrated wedges which have their slopes F sliding on the gradient portions E of the upper and lower cross heads 1 and 2. The wedges 3 are interposed between the inner side faces of a housing 10 and the upper and lower cross heads 1 and 2 and are guided by side guides 8. Moreover, the wedges 3 have their upper ends connected to the screw shafts 4 of worm reduction gears 6, which are screwed in nuts 5 buried in the housing 10. Numeral 7 designates a drive motor for the two worm reduction gears 6. Numerals 21, 22, 23, 24 designate an upper work roll, a lower work roll, an upper backup roll and a lower backup roll, respectively, which are supported like the prior art by the upper and lower work roll chocks 25 and 26 and the upper and lower backup roll chocks 27 and 28. The operations of the present apparatus will be described in the following. The individual screw shafts 4 are rotated through the corresponding worm reduction gears 6 by the motor 7. By these rotations, the wedges 3 at the entrance side A of a working side W and at the exit side B of a drive side D are moved downward, and the wedges 3 at the exit side B of the working side W and at the entrance side A of the drive side D are moved upward to bring their slopes F into sliding engagement with the gradient portions E of the upper and lower cross heads 1 and 2 so that these cross heads 1 and 2 are moved in the pass line directions opposed to each other. As a result of the movements of the upper and lower cross heads 1 and 2, the upper work roll chock 25 and the upper backup roll chock 27, and the lower work roll chock 26 and the lower backup roll chock 28 rotate the axially central portions of the upper and lower work rolls 21 and 22 in the opposite directions to cause the upper work roll 21 and the upper backup roll 23 to cross the lower work roll 22 and the lower backup roll 24. In the rolling operation, the shape of a rolled sheet S is adjusted by regulating that cross angle and by bending the upper and lower work rolls 21 and 22. Incidentally, a drive source to be used for lifting the wedges 3 may be exemplified by a hydraulic cylinder. According to the present embodiment, the loads to be borne by the upper and lower cross heads 1 and 2 are transmitted through the wedges 3 to the worm reduction gears 6 so that the worm reduction gears 6, the screw shafts 4 and the nuts 5 can be small-sized. In the present embodiment, moreover, the number of sets of the worm reduction gears 6 can be decreased to 4 for each stand. The roll crossing apparatus of the cross-rolling mill thus far described has the following effects because it is provided with the wedges having the slopes F and the upper and lower cross heads having the gradient portions E to come into engagement with the slopes F. (1) Since the loads to be borne by the upper and lower cross heads are dispersed and supported by the inner side faces of the housing through the wedges, the spacing between (i.e., the sum of the thicknesses of the upper and lower cross heads and the wedges in the pass line direction) the roll chocks and the inner side faces of the housing may be small to reduce the window width (i.e., the spacing between the two inner side faces) of the housing. As a result, the housing can have its upper cross beams thinned to have its size reduced. (2) Since the loads to be borne by the upper and lower cross heads are transmitted through the wedges to the drive line of the roll crossing apparatus, the drive line can have small-sized parts. (3) Since a set of upper and lower cross heads are formed with the gradient portions E whereas the vertically integral upper and lower wedges are formed with the opposite slopes F, the upper and lower rolls can be prevented from any operational displacement by moving the vertically integral wedges upward and downward together by a set of drive lines so that the setting accuracy of the roll crossing position can be stabilized and improved. Next, another embodiment will be described with reference to Figs. 3 and 4. Incidentally, the parts of Figs. 3 and 4 similar to those of Figs. 1 and 2 will be designated at identical reference numerals so as to simplify the description. In Figs. 3 and 4, reference numerals 1 and 2 designate upper and lower cross heads, respectively, which are individually formed on their outer side faces (i.e., the side faces opposed to the roll chocks) with a number of steps of gradient portions E. These gradient portions E are vertically opposite at the upper and lower cross heads 1 and 2. These upper and lower cross heads 1 and 2 can move in opposite pass line directions, respectively, at the upper and lower portions of guide blocks 13 which are fixed on the outer side faces of the entrance side A and the exit side B of the drive side D and the working side W of a housing 10. An upper work roll chock 25 and an upper backup roll chock 27, and a lower work roll chock 26 and a lower backup roll chock 28 to come into engagement with the upper and lower cross heads 1 and 2, respectively, are moved together with the upper and lower cross heads 1 and 2, respectively. Numeral 3 designates vertically integrated wedges, which have their slopes F formed to slide on the gradient portions E of the upper and lower cross heads 1 and 2. These wedges 3 are interposed between the upper and lower cross heads 1 and 2 and the guide blocks 13 and have their upper ends connected to screw jacks 14 which are fixed on the outer side faces of the drive side D and the working side W of the housing 10. These screw jacks 14 at the entrance side A and the exit side B are connected through a shaft 15. Moreover, the screw jack 14 at the entrance side A is connected to one motor 7 through upper and lower bevel gears 16b and 16c and a bevel gear 16a which is arranged midway of the two upper bevel gears 16b at the drive side D and the working side W, Numerals 21, 22, 23 and 14 designate an upper work roll, a lower work roll, an upper backup roll and a lower backup roll, respectively, which are supported by the upper and lower work roll chocks 25 and 26 and the upper and lower backup roll chocks 27 and 28, respectively. The operations of the present apparatus will be described in the following. The upper and lower cross heads 1 and 2 are moved in the opposite pass line directions by rotating the individual screw jacks 14 by the motor 7 through the individual bevel gears 16a, 16b and 16c to move the wedges at the entrance side A of the working side W and at the exit side B of the drive side downward and the wedges 3 at the exit side B of the working side W and at the entrance side A of the drive side D upward thereby to have their slopes F sliding on the gradient portions E of the upper and lower cross heads 1 and 2. As a result of the movements of those upper and lower cross heads 1 and 2, the upper work roll chock 25 and the upper backup roll chock 27, and the lower work roll chock 26 and the lower backup roll chock 28 are rotated in the opposite directions on the axial center portions of the upper and lower work rolls 21 and 22. Thus, the upper work roll 21 and the upper backup roll 23, and the lower work roll 22 and the lower backup roll 24 are caused to cross at a desired cross angle ϑ from the center C of the rolling mill thereby to roll a sheet S. In the rolling operations, the widthwise shape of the rolled sheet S is adjusted by regulating that cross angle ϑ and by bending the upper and lower work rolls 21 and 22. Incidentally, the drive source to be used for moving the wedges 3 upward and downward may be exemplified by a hydraulic cylinder. The present embodiment adopts a pair cross-rolling mill, in which the upper work roll 21 and the upper backup roll 23, and the lower work roll 22 and the lower backup roll 24 are paired and rotated to cross. However, the present invention can also be applied to a work roll crossing mill, in which only the upper and lower work rolls 21 and 22 are made to cross, as shown in Fig. 5. According to the embodiment showing in Figs. 3 to 5, the bevel gear 16a is arranged between the two bevel gears 16b at the drive side D and the working side W on the top surface of the housing 10 and is connected through a not-shown shaft to the single motor 7. This roll crossing apparatus is operated by the single motor 7 so that the motor 7 can be easily controlled. At the same time, the upper and lower cross heads 1 and 2 at the drive side D and the working side W can be moved in complete synchronism so that the upper and lower work rolls and backup rolls 21, 22, 23 and 24 are enabled to cross smoothly and accurately. Moreover, the following effects can be achieved by the roll crossing apparatus of the cross-rolling mill according to the embodiment shown in Figs. 3 to 5. (1) Since the wedges are moved upward and downward to move the upper and lower cross heads in the opposite pass line directions thereby to cause the upper and lower work rolls to cross each other, the loads to be borne by the upper and lower cross heads are vertically dispersed and supported through the wedges by the guide blocks so that these guide blocks can be small-sized. (2) Since the upper and lower wedges are integrally moved upward and downward, the upper and lower can be moved in complete synchronism so that the upper and lower rolls can accurately cross each other. (3) Since the wedges and the guide blocks for guiding the upper and lower cross heads are mounted on the outer side faces of the housing, the existing parallel rolling mill can be easily reformed into the cross-rolling mill which has a high ability of controlling the shape of the rolled sheet. Incidentally, in the embodiments thus far described, the individual rolls are moved at both the drive side D and the working side W in the opposite directions of the entrance side A and the exit side B of the rolled sheet S. As shown in Fig. 6, however, the work rolls 21 and 22 may be moved only at the drive side D in the opposite directions of the entrance side A and the exit side B but may be supported at fixed points at the working side W. This structure is illustrated in Fig. 7. In Fig. 7, diagram (a) illustrates the situation of the displacements of the rolls of the roll crossing apparatus which is constructed to have its rolls moved at both the drive side D and the working side W, diagram (b) illustrates the displacements of the rolls, in a solid line, in case the rolls are moved only at the working side W and supported at the fixed points at the drive side D, and in a broken line in the opposite case. In the embodiments thus far described, moreover, the wedges 3 are disposed according to the present invention at both the entrance side A and the exit side B of the rolled sheet. However, the present invention covers the modification, in which the wedges 3 are disposed only at the entrance side A or the exit side B while leaving the other side as in the conventional arrangement shown in Figs. 8 and 9, or supported and held by a hydraulic cylinder. This modification may take place in case the present invention is applied to a portion in case the existing facilities are to be renovated.

Claims: A cross-rolling mill comprising a roll crossing apparatus, said cross-rolling mill being of the type, in which upper and lower work rolls (21,22,23,24) are caused to cross together with their respective backup rolls by moving upper and lower cross heads (1,2) interposed between upper and lower roll chocks (25,26,27,28) and the inner side face of a housing (10) in pass lines opposite to each other, whereby wedges (3) are provided liftably up and down between said upper and lower cross heads (1,2) and the inner side faces of said housing (10), said roll crossing apparatus characterised by: the upper and lower cross heads (1,2) having cylindrical faces formed at those side faces thereof which face the sides of said upper and lower roll chocks (25,26,27,28) and each having a plurality of steps of gradient portions formed at those side faces thereof which face the inner side faces of said housing (10), such that the gradient angles are opposite in the upper and lower portions thereof; cylindrical liners provided on the roll chocks (25,26,27,28) in sliding contact with the cylindrical faces formed at the side faces of said upper and lower cross heads (1,2) on the sides of the roll chocks (25,26,27,28); said wedges (3) having complementary gradient portions formed on their faces opposed to said plurality of steps of the gradient portions of said upper and lower cross heads (1,2); and guide means (11,12) provided between the roll chocks (25,26,27,28) and the housing (10) with each of said wedges (3) held therebetween. A cross-rolling mill comprising a roll crossing apparatus, said cross-rolling mill being of the type, in which upper and lower work rolls (21,22,23,24,) are caused to cross by moving upper and lower cross heads (1,2) interposed betweeen upper and lower roll chocks (25,26,27,28) and the inner side face of a housing (10) in pass lines opposite to each other whereby wedges (3) are provided liftably up and down between said upper and lower cross-heads (1,2) and the inner side faces of said housing (10) said, roll crossing apparatus characterised by: the upper and lower work rolls (21-24) being caused to cross together with their respective backup rolls; the upper and lower cross heads (1,2) provided movably in pass lines on the outer side faces of the housing (10) on a drive side or working side, having cylindrical faces formed at those side faces thereof facing the sides of said upper and lower roll chocks (25,26,27,28) and each having a plurality of steps of gradient portions formed at those side faces thereof on the opposite sides thereto, such that the gradient angles are opposite in the upper and lower portions thereof; cylindrical liners provided on the roll chocks (25,26,27,28) in sliding contact with the cylindrical faces formed at the side faces of said upper and lower cross heads (1,2) on the side of the roll chocks (25,26,27,28); said wedges having complementary gradient portions formed on their faces opposed to said plurality of steps of the gradient portions of said upper and lower cross heads (1,2); and guide blocks (13) fixed on the housing (10) such as to guide said upper and lower cross heads (1,2) and wedges (3) on the outer side faces of the housing (10). A cross-rolling mill according to claim 1 or 2, in which said plurality of steps of the gradient portions formed on the upper and lower cross heads (1,2) and wedges (3) are provided such as to be arranged, on the working side, only on the side of the upper rolls and, on the drive side, only the side of the lower rolls, and vice versa. A cross-rolling mill according to claim 1, 2 or 3 in which associated work roll chocks (25,26) and backup roll chocks (27,28) are made movable in pass lines by means of a common wedge (3).

Inventors: HIURA TADASHI C O HIROSHIMA MA, HORIE KAZUHIKO C O HIROSHIMA M, KOUJIN HISAYOSHI C O HIROSHIMA, MATSUDA YUTAKA C O HIROSHIMA M, MITO YOSHIKI C O HIROSHIMA MAC, HIURA, TADASHI, C/O HIROSHIMA MACHINERY WORKS, HORIE, KAZUHIKO, C/O HIROSHIMA MACHINERY WORKS, KOUJIN, HISAYOSHI, C/O HIROSHIMA MACHINERY WORKS, MATSUDA, YUTAKA, C/O HIROSHIMA MACHINERY WORKS, MITO, YOSHIKI, C/O HIROSHIMA MACHINERY WORKS
Applicants: MITSUBISHI HEAVY IND LTD, MITSUBISHI JUKOGYO KABUSHIKI KAISHA
Application year: 1992
Main classification: B21B13
IPC codes: B21B13, B21B31