US3899910A

US3899910A - Prestress type rolling mill

Info

Publication number: US3899910A
Application number: US474403A
Authority: US
Inventors: Keiichi Aramaki
Original assignee: Nippon Kokan Ltd
Current assignee: JFE Engineering Corp
Priority date: 1973-06-19
Filing date: 1974-05-30
Publication date: 1975-08-19
Anticipated expiration: 1992-08-19
Also published as: GB1434504A; JPS5310947B2; DE2429375A1; JPS5017357A

Abstract

A novel structure of a prestress type universal rolling mill suitable for rolling H-sections and others of various gages in which a roll stand housing is divided into upper and lower housings so that a bottom horizontal roll and a pair of vertical rolls may be readily mounted into the lower housing from above, the upper housing with a top horizontal roller mounted therein may be joined with the lower housing as such, and the upper and lower housings may be readily joined with a plurality of tension bars which utilize hydraulic pressure. The prestress type universal rolling mill structure of this invention is thus compact, rigid and light in weight and permits changing of the rolls in a short period of time with ease.

Description

United States Patent [191 Aramalti PRESTRESS TYPE ROLLING MILL [75] Inventor: Keiichi Aramaki, Fukuyama, Japan [73] Assignee: Nippon Kokan Kabushiki Kaisha,

Tokyo, Japan 22 Filed: May 30,1974

21 Appl.No.:474,403

4/1974 Svagr 72/238 X [4 1 Aug. 19, 1975 Primary ExaminerMilton S. Mehr Attorney, Agent, or Firm-Flynn & Frishauf [5 7 ABSTRACT A novel structure of a prestress type universal rolling mill suitable for rolling H-sections and others of various gages in which a roll stand housing is divided into upper and lower housings so that a bottom horizontal roll and a pair of vertical rolls may be readily mounted into the lower housing from above, the upper housing with a top horizontal roller mounted therein may be joined with the lower housing as such, and the upper and lower housings may be readily joined with a plurality of tension bars which utilize hydraulic pressure. The prestress type universal rolling mill structure of this invention is thus compact, rigid and light in weight and permits changing of the rolls in a short period of time with ease.

7 Claims, 2 Drawing Figures PATENTED mm 1915 saw 1 u; 2

FIG.|

PATENTEDAUG1 QIBYS sum 2 UF 2 PRESTRESS TYPE ROLLING MILL BACKGROUND OF THE INVENTION The present invention relates to rolling mills for rolling I-I-section steels, etc. of different gages, and more particularly it relates to a novel prestress type universal rolling mill structure which is compact and rigid and in which the rolls can be readily changed.

Generally, in a rolling plant where large section steels are rolled, it has been customary to roll on the same line a variety of section steel products of many different gages including standard section steels which are called as angle and channel steels, sheet piles and I-I-section steels, and therefore it has been necessary to facilitate the changing of the rolls in the rolling mills and minimize the time required for this operation. For this reason, many different types of rolling mills have been developed. For example, the roll changing methods whereby only the rolls are changed with the mill stands being fixedly arranged on the rolling line, are divided into two classes, the C hook method and the cross beam method. In the former, the rolls are lifted and removed by means of an overhead crane or the like employing a C hook. Thus, the roll-changing time is increased by the use of the crane and it is impossible to improve the rate of operation since no rolling operation takes place during the roll changing. The latter is a method employing cross beams connecting right and left housings so that the roll bearing chocks may be mounted at any given positions on the cross beams. When the rolls are to be changed, the cross beams are moved upward and/or downward so that the rolls are withdrawn transversely through the window of the housing utilizing the cross beams as guides. While this method has the advantage of changing the roll body length in accordance with the rolling gage to reduce the roll deflection and also reducing the weight of the rolls, it is disadvantageous in that much time is required for changing the rolls as with the former method and the roll changing time is made longer than that of the below-mentioned stand changing methods due to the fact that a zero adjustment between rolls, adjustments of mill auxiliary equipment, etc. must be effected after every roll changing operation.

The stand changing methods where the stand with rolls to be changed is removed from the rolling line and is replaced with a new stand preliminarily equipped with the necessary mill accessories including the new rolls. are divided into two classes, i.e., one in which the stand is removed by means of a crane and the other in which the stand is removed by means of an extracting device. In the former, an overhead crane or a specially designed gantry crane is employed whereby the stand with the rolls to be changed is lifted and removed from the line and a stand equipped with the new rolls is installed on the line. Thus, this method requires the use of a large capacity crane and it is not preferred for that reason. The latter method which employs an extracting device is designed so that the strand to be changed is withdrawn over the track crossing the rolling line at right angles and the new stand on the transverse track is inserted into the line by means of the extracting device. The roll changing time of this latter method isthe shortest among the previously described conventional roll changing methods.

There is a still further roll changing method which is called as an inner housing cartridge method and in which each individual stand has a housing divided into an outer housing and an inner cartridge so that the reaction force of the vertical rolls is borne by the inner housing and the vertical rolling reaction of the horizontal rolls is born by the outer housing, and the stand is fixedly held on the rolling line and only the inner housing with the rolls to be changed is removed. A disadvantage of this method is that due to the housing consisting of the outer housing and the inner cartridge, more clearance is produced as compared with the stand changing-type one piece rolling mills and the roll changing time is the same with that of the previously described roll changing methods. In addition to those described so far, there is a prestress type stand rolling mill in which the mill housing is divided into three portions which are connected together with tension bars having hydraulic nuts and a link type rolling mill employing an eccentric pin and links. While the former has the advantage of a simple and light construction and there is no possibility of producing any clearance due to the divided housing portions being connected together by means of the tension bar, there is a disadvantage that the intermediate housing must have a large dimension which necessarily makes the dimension of the entire rolling mill greater than that of the unitary construction rolling mills. There is a further disadvantage that since the housing is divided into three parts, the screw down mechanism for the top, vertical and bottom rolls must be separately installed in the respective housings and therefore the screw down motor. reduction gear, etc. must be provided for each housing portion, thus requiring the greatest possible care during the assembling of the stand not to give any blow to the motor and other parts.

SUMMARY OF THE INVENTION With a view to overcoming the foregoing difficulty of the conventional universal mills, it is the object of the present invention to provide a prestress type universal rolling mill in which the roll stand housing is divided into upper and lower housings to provide a rigid housing structure and thereby to ensure an improved dimensional accuracy of the rolled products.

The apparatus according to the present invention has among its advantages the fact that due to the roll stand housing divided into two parts, a bottom horizontal roll with its bearing chocks and a pair of vertical rolls with its chocks can be inserted into the lower housing from above, and the upper housing equipped with a top horizontal roll and its bearing chocks can be mounted in the lower housing, whereby both the horizontal rolls and the vertical rolls can be readily changed.

Another advantage of the apparatus of this invention is that the roll stand housing is divided only into two parts, and moreover the lower housing serves as the housing for the pair of vertical rolls as well as the bottom horizontal roll, whereby a rolling mill structure which is provided is compact and rigid and the weight of the stand is reduced to facilitate stand changing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a front view showing an embodiment of a prestress type universal rolling mill according to the present invention; and I i FIG. 2 is a side view of FIG. 1.

"The present-invention will now be described in greater detail with reference to the illustrated embodime'nt.

-ln FIGS. 1 and 2, the housing of a prestress type universal rolling mill is divided into two parts, i.e.. an

,-;upper housing 1 and a lower housing 2, and a bearing 1 chock ,4 equipped with its bearings is placed on each of the necksof a top horizontal roll 3 in the upper housing L A. wedge ,liner is mounted on the bearing chock 4 sothat the thickness of the wedge liners 5 is suitably selected to be fit for rolls of different diameters. A sliding I ,wedge 6 of the same taper as the wedge liner 5 is placed ,on the wedge liner 5 so that the sliding wedges 6 are horizontally slidable by means of worm gears 8 and a screw down motor 9 through bars 7. Consequently, the roll draft canbe set as desired and the rolling reaction of the top horizontal roll 3 is transmitted to the upper housing 1 through the bearing chocks 4, the wedge linersrS and the sliding wedges 6. Each of the bearing chocks 4 for the roll 3 is suspended by a roll balancing cylinder l1, and a roll horizontal position adjusting equipment isarranged on the' side opposite to the driving side.

The bilateral positions of the upper and lower housings 1 and 2 are determined by a side tapered guide surface 12, and the upper and lower housings l and 2 forming a contact surface 14 are joined together by four tension'bars l3.' The horizontal force caused by top horizontal roll 3 mounted therein and the

vertical rolls

18 and 19 and then by disengaging a bottom horizontal roll spindle coupling, the bottom horizontal roll 28 can be picked out upwardly and withdrawn from the roll stand. Each of the tension bars 13 joining the upper and lower housings 1 and 2 together, is secured at its lower end by a cotter 34 attached to the lower housing 2 and is provided with a hydraulic pressure nut 35 at its the rolling torque of the top horizontal roll 3 is transmitted to the upper housing 1 from the side faces of the bearing chocks 4 through an upper housing window surface 15 and it is also transmitted to the lower housing 2 through the guide surface 12 and to the founda- 7 tion through a sole plate 16. The lowermost end face 17 of the upper housing 1 serves as an upper guide face for the respective chocks 20 of vertical rolls l8 and 19 so that the upward movement of the chocks 20 is regulated by joining the upper housing 1 with the lower housing 2, whereas the chocks 20 can be picked out upwardlyas desired by removing the upper housing 1 first. ,7

The vertical rolls l8 and 19 are provided with bearings on the inside thereof and they are respectively mounted on a stationary shaft installed in the chock 20. Consequently, the rolling reaction of the vertical rolls l8 and 19 is borne by the

vertical rolls

18 and 19, the bearings, the stationary shafts, the chocks 20, wedge liners 22, sliding wedges 21 and a yoke constituting part of the lower housing 2. The thickness of the wedge liners 22 is suitably selected in accordance with the gage of a section to be rolled, the roll diameter, etc. and they are provided at the rear of the respective chocks 20. The screwdown or adjustment of the vertical rolls l8 and 1 9 is effected by vertically moving the sliding wedges 21 by means of worm gears 24, a chain 25 and a motor 26 through rods 23. The chock 20 is pulled outward by a roll balancing cylinder 27 so that no space is produced between the sliding wedge 21 and the wedge liner 22. 7 1 7 On the other hand, the bottomhorizontal roll 28 in the lower housing 2.is provided, similarly with the top horizontal roll 3, with bearing chocks 29, wedge liners 30, sliding wedges 31, bars 32, worm gears 33, etc., and by lifting and picking out the upper housing 1 with the upper end. When the hydraulic pressure is applied to the hydraulic pressure nuts 35 so that the upper and lower housings l and 2 are held together closely, nuts 36 are turned and pressed against contact surfaces 37 and then the hydraulic pressure is removed.

In the illustrated embodiment, in addition to the construction described above, wheels 38 are provided at the lower part of the roll stand to support the entire weight of the mill, and a pair of liftingrails 39 are arranged below the wheels 38 so that the stand can be moved freely by an extracting device. In other words, a stand clamp 41 mounted on a hydraulic cylinder unit is retracted and then the rails 39 are raised to separate the stand from the sole plate 16, whereby the stand is withdrawn by the extracting device and replaced with a stand equipped with the new rolls. The stand with the new rolls is transferred onto the rails 39 so that when the new stand is positioned in place, the rails 39 are lowered and the stand thus engaged with the sole plate 16 is secured in position by the stand clamp 41.

It will thus be seen from the foregoing description that inthe apparatus of this invention, the roll'stand housing is divided into upper and lower housings which are in turn joined together with four tension bars each provided with a hydraulic pressure unit at the upper end thereof and therefore the upper and lower housings can be separated from each other with extreme case. After removing the hydraulicpressure units, the upper housing with the top horizontal roll can be lifted upward along the tension bars by utilizing hangers 10, and

moreover by virtue of the fact that the 'lower end face 'of the upper housing provides an upper guide face for vertical roll chocks,'the removal of the upper housing permits the lifting of the vertical roll chocks with extreme ease. Further, there is an advantage that since the screw down device is of the wedge type, the rolling mill is made rigid andcon'sequently the length of the yoke stretch is reduced, makin'gthe rolling mill small and compact. However, the use of a screw down device of any known typed oes not have any detrimental effect on the essential qualities of the present invention. Since rollchanging is effected in such a manner that the rolls are lowered into place from above, the roll changing time can be reduced considerably, and moreover the width of the housing window can be made smaller than the roll diameter, thus making the entire rolling mill dently of thescrew down devices Furthermore, since the tension bars areused to join the upper and lower housings together, if a material is jammed between the rolls during rolling, it can be very easily released by loosening the hydraulic pressure nuts and therefore there is no need to install a roll releasing device, a breaker block or the like as in the conventional rolling mills. Furthermore, roll changing can be effected with a specially designed crane which raises and lowers rolls from above, and therefore there is no need to provide any extracting device to transversely withdraw the rolls as in the conventional rolling mills.

It should be appreciated from the foregoing that the present invention is extremely useful industrially, since it provides a prestress type universal rolling mill which is extremely compact and light in construction as a whole and in which all the accessory equipment including the sole plate, rail lifting equipment, stand extracting equipment and transverse extracting equipment are all made small and light in weight.

What is claimed is:

l. A prestress type universal rolling mill, comprising:

a lower housing;

a bottom horizontal roll mounted to said lower housing;

an upper housing removably coupled to said lower housing;

a top horizontal roll mounted to said upper housing;

a pair of vertical rolls directly supported on said lower housing and being removably mounted to said lower housing, said vertical rolls being removable by lifting thereof substantially in the vertical direction when said upper and lower housings are separated; and

mounting and joining means including generally vertically oriented side tapered guide surface means on said upper and lower housing for removably mounting and joining said upper housing to said lower housing, whereby a horizontal force exerted on said top horizontal roll is transmitted from said upper housing through said side tapered guide surface means and is borne by said lower housing.

2. A rolling mill structure as set forth in claim I wherein said side tapered guide surface means includes mating side tapered guide surfaces on said upper and lower housings; said mounting and joining means further including substantially horizontally oriented mating contact surfaces on said upper and lower housings.

3. A rolling mill structure as set forth in claim 2 wherein said mounting and joining means further comprises a plurality of tension bars further joining said upper and lower housings together.

4. A rolling mill structure as set forth in claim 3, wherein said mounting and joining means further comprises hydraulic pressure units coupled to the upper ends of respective tension bars for providing tension.

5. A rolling mill structure as set forth in claim 1, wherein the lower end surface of said upper housing comprises a removably guide face for the chocks of said vertical rolls, whereby when said upper housing is removed from said lower housing, the vertical rolls are free to be lifted vertically out from said lower housing.

6. A rolling mill structure as set forth in claim 1, wherein a material passing window is formed at least in said lower housing.

7. A rolling mill structure as set forth in claim 1 wherein said lower housing comprises respective screw down means coupled to said bottom horizontal roll and 1 to said vertical rolls.

Claims

1. A prestress type universal rolling mill, comprising: a lower housing; a bottom horizontal roll mounted to said lower housing; an upper housing rEmovably coupled to said lower housing; a top horizontal roll mounted to said upper housing; a pair of vertical rolls directly supported on said lower housing and being removably mounted to said lower housing, said vertical rolls being removable by lifting thereof substantially in the vertical direction when said upper and lower housings are separated; and mounting and joining means including generally vertically oriented side tapered guide surface means on said upper and lower housing for removably mounting and joining said upper housing to said lower housing, whereby a horizontal force exerted on said top horizontal roll is transmitted from said upper housing through said side tapered guide surface means and is borne by said lower housing.

2. A rolling mill structure as set forth in claim 1 wherein said side tapered guide surface means includes mating side tapered guide surfaces on said upper and lower housings; said mounting and joining means further including substantially horizontally oriented mating contact surfaces on said upper and lower housings.

7. A rolling mill structure as set forth in claim 1 wherein said lower housing comprises respective screw down means coupled to said bottom horizontal roll and to said vertical rolls.