US3552164A - Rolling mill - Google Patents

Abstract

A ROLLING UNIT IN A ROLLING MILL FOR ROLLING METAL STOCK COMPRISES THREE ROLLS SPACED AT ANGLES OF 120* ABOUT A ROLLING AXIS. THE PERIPHERAL OUTLINES OF THE ROLLERS DEFINE THE SHAPE OF THE CROSS-SECTION DESIRED FOR THE METAL STOCK. MEANS ARE PROVIDED FOR SIMULTANEOUSLY COOLING AND LUBRICATING WITH A FIRST FLUID AT ADJUSTABLE PRESSURE THE METAL STOCK AND THE STOCK-ENGAGING SURFACES OF THE ROLLS AND WITH A SECOND FLUID AT INDEPENDENTLY ADJUSTABLE PRESSURE THE GUIDE MEMBERS WHICH SERVE TO GUIDE THE METAL STOCK AND THE REMAINING PORTIONS OF THE ROLLS NOT COOLED BY THE FIRST FLUID.

Description

Jan- 5, 197 v PRIOPERZI I 3,552,164

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I. PROPERZI ROLLING MILL Jan. 5, 1971 I 5 Sheets-Sheet 5 Filed Feb 19, 1968 United States Patent O M 3,552,164 ROLLING MILL Ilario Properzi, Via Cosimo del Fante 10, Milan, Italy Filed Feb. 19, 1968, Ser. No. 706,378 Claims priority, application Italy, Mar. 29, 1967, 14,306/ 67 Int. Cl. B21b 45/02, 45/04, 27/10 US. Cl. 7245 6 Claims ABSTRACT OF THE DISCLOSURE A rolling unit in a rolling mill for rolling metal stock comprises three rolls spaced at angles of 120 about a rolling axis. The peripheral outlines of the rollers define the shape of the cross-section desired for the metal stock. Means are provided for simultaneously cooling and lubricating with a first fluid at adjustable pressure the metal stock and the stock-engaging surfaces of the rolls and with a second fluid at independently adjustable pressure the guide members which serve to guide the metal stock and the remaining portions of the rolls not cooled BACKGROUND OF THE INVENTION The present invention relates generally to rolling mills such as are employed for the rolling of metal stock into the shape of bars, wires or analogously configurated products.

More particularly, the present invention is concerned with an improved rolling unit for use in such rolling mills.

In my prior United States patent, No. 3,142,208, I have disclosed rolling mills of the type here in question. The construction disclosed there has proved highly satisfactory for the rolling of many different metals, including lead, zinc, aluminum and alloys of these metals. It can also be utilized for rolling steel and copper, but with respect to these last materials the performance of my earlier disclosed construction is not entirely satisfactory.

While the mill shown in US. Pat. No. 3,142,208 can be used to roll bars or rods of copper and steel, I have found that its performance is adversely influenced by the high temperatures at which these metals must be rolled. Copper, for instance, must be rolled at a temperature which is almost double that of aluminum. These high temperatures do not cause any severe diificulties in mills intended for rolling ingots of large cross-sections, but they do cause substantial difiiculties in mills intended for rolling stock of comparatively limited cross-section such as bars, wires and the like.

Because of the high temperatures involved in rolling copper and steel stock, it is desirable to cool the rolls of the rolling units. In the case of rolls operating on ingots of large cross-section, it is possible to accomplish the cooling by directing strong jets of water or other liquid coolants against the rolls and stock. However, the use of this cooling method in a rolling mill operating on stock of smaller cross-section as in the case of the present invention, will unsuitably reduce the temperature of the stock below the level required for proper rolling.

Many attempts have been made to overcome this disadvantage. In one construction cooling is provided by spraying powerful jets of water onto the rolls, and simultaneously a fluid under pressure, such as compressed air, which contains atomized oil is used to create a positive pressure within the gearbox and to provide a lubricating effect on the driving mechanism. This solution suffers, however, from two major disadvantages, namely, the difficulty of obtaining a tight seal for the gearbox so as to 3,552,164 Patented Jan. 5, 1971 exclude water from the driving mechanism, and the very poor cooling etfect obtainable from the compressed air stream enriched with the atomized oil.

Another known solution uses water nozzles arranged in a certain manner. However, to avoid Water from entering the housing of the driving mechanism, it is necessary to employ intricately shaped water guards which makes the construction cumbersome and subject to difiiculties. There is no suggestion, furthermore, that the coolant may be a cooling and lubricating liquid which is continuously passed over the rolls and the work piece.

In my aforementioned US. Pat No. 3,142,208, I have provided a lubricating and cooling system for a rolling mill, comprising one lubricating circuit which provides lubrication and cooling of the parts which cooperate to carry and drive the rolls, and another independent cooling circuit which cools and lubricates the rolls and the stock. In this way small-diameter stock may be rolled without reducing the temperature of the stock below the level re quired for satisfactory rolling. This system has been proved satisfactory for a moderate output.

However, the production rate of rolling units has been markedly increased since I disclosed the construction in US. Pat. No. 3,142,208. Also, it is becoming evermore common to work metals having a high melting point. For all of these reasons the adherence of metallic residues on the surface of the rolls, which at moderate output speed was no particular problem, is now found to be a particularly objectionable shortcoming because it often requires shutting down of the rolling mill for cleaning and maintenance operations, besides providing rolled products whose surfaces are rough and irregular.

It is therefore a general object of the present invention to overcome the aforementioned disadvantages.

A more particular object of the invention is to provide an improved rolling unit of a rolling mill, wherein the stock, the guide members for the stock, and the rolls are all cooled to the respectively necessary extent without danger that the degree of cooling of one type of element might adverse influence another type of element which requires a different degree of cooling.

Another object of the invention is to provide such a rolling unit, and cooling and lubrication therefor, wherein the adherence of metallic residues on the surface of the rolls is avoided.

SUMMARY OF THE INVENTION I have found that these objects can be attained if the entire rolling surfaces o the rolls and of the supporting member or members are subjected to the cooling and lubricating action of a pressurized fluid.

In accordance with one feature of my invention I provide a rolling unit for rolling metal stock, comprising the combination of a plurality of rolls arranged for rotation about respective mutually inclined axes, the rolls each having a transverse plane normal to the respective axis and the transverse planes being inclined to one another and converging toward a common rolling axis along which the metal stock advances; mounting and drive means for maintaining and rotating the rolls; biasing means surrounding the rolls and the mounting and drive means, the biasing means including an inner biasing portion surrounding the common rolling axis, the rolls having peripheral portions projecting into the inner biasing portion and defining therewith a first fluid path, and the biasing means further including an outer biasing portion surrounding the remainder of said rolls and-the mounting and drive means and defining therewith a second fluid path; sealing means associated with each of the rolls and operative for sealing the first fluid path from the second fluid path; feed means operative for continuously circulating a pressurized cooling and lubricating fluid in the first path, and for continuously circulating a pressurized cooling and lubricating fluid in the second path; and regulating means operative for regulating the pressure of fluid in the first and second paths, respectively.

Thus, the rolling unit with a first circulation system for a pressurized cooling and lubricating fluid which constantly surrounds the surfaces of the rolling cylinders while the same act upon the metal stock, the surfaces of the entrance and exit guide members for the metal stock, and the surface of the metal stock itself, and with a second system for a second fluid which lubricates and cools the driving and supporting elements of the rolling unit. More particularly, the first circulation system for the cooling and lubricating liquid, which latter is usually an emulsion of oil in water serves to thoroughly surround the entire periphery of the rolls, of the guide members and of the metal stock from the entrance to the exit of the rolling unit with the cooling and lubricating fluid at a pressure which is adjustable independently of the pressure of fluid in the second system. It is an important consideration of the present invention that the pressure of this fluid serves to counteract adherence between the surfaces of the rolling cylinders and the surfaces of the hot stock which is worked by the rolling cylinders as well as adherence between the guide members and the metal stock. The independent adjustment of fluid pressure permits precise control of lubrication and cooling in dependence upon given local requirements.

My invention also affords protection to the stock against being contracted by the external air, in that the stock traverses the entire rolling mill completely immersed in the lubricating and cooling fluid.

Resort to my present invention also enhances the cooling effect of the liquid and serves to dissipate as much heat as possible from the rolling mill without, however, reducing the temperature of the metal stock to values so low as to impede the rolling operation.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments with reference to the accompanying draw- BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows in cross-section an embodiment of a rolling unit incorporating my invention;

FIG. 2 is a view similar to FIG. 1, and illustrates the circulation of fluids within the rolling unit shown in FIG. 1.

FIG. 3 is a view similar to FIG. 1 but illustrating another embodiment of a rolling unit incorporating my invention;

FIG. 4 is a view similar to FIG. 2, and illustrates the circulation of fluids within the rolling unit shown in FIG. 3; and

FIG. 5 is a longitudinal cross-section through a rolling mill comprising two rolling units which respectively correspond to those of FIGS. 1 and 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing firstly FIGS. 1 and 2, it will be seen that the rolling mill in its entirety is generally identified with reference numeral 1. In its basic features it corresponds to the unit disclosed in my US. Pat. No. 3,142,208, to which reference may be had.

Each of the three rolling cylinders 9, and 11 is provided with a pair of ring-shaped gaskets or packings 50 and 51 at both axial sides and these gaskets or packings are so dimensioned as to be positioned radially inward from the outer periphery of respective rolls 9, 10 and 11.

4 The gaskets 50 and 51 cooperate with the main housing 3 and the auxiliary housing 2, 4, 14, 15 to seal the inner chamber 7 from the outer chamber 8 so that oil or other liquid can flow through the former without escaping therefrom to the latter.

The flow path for the liquid which lubricates and cools the rolls 9, 10 and 11 is shown by solid-line arrows in FIG. 2, and the spaces filled with such liquid are indicated by the small circles in that figure. It will be seen that the liquid enters the rolling unit through an opening 19 at the top of the housing and flows over the peripheral portion of the roll 10 toward the rolling axis 6 along which the stock 106 moves. The liquid, or the oil as it will hereafter be called for simplicity, then divides into two streams with one flowing over the peripheral portion of the roll 9 and out the opening 20. The other stream flows over the peripheral portion of the roll 11 and out the opening 20' The rate at which the oil issues from the outlets 20 and 20 can be controlled by the valves 53 and 54 associated with the respective outlets, and thus the pressure of the oil within the housing can be varied simply by adjusting the rate at which it issues from the respective outlets. Both the valves 53 and 54 may be of any conventional type well known in the art.

The driving mechanism for the rolls 9, 10 and 11 is lubricated and cooled by liquid, usually oil, which flows through the outer chamber 8. The pressure and flow path of this oil is indicated by dotted areas and dashed-line arrows in FIG. 2. This second stream of oil enters at a pair of openings 29 and 30 provided in the top of the housing and fills the spaces around the drive shaft 12 which drives the rolls 9, 10 and 11, and around the gears and bearings associated with this shaft 12. The shafts 21 and 22, on which the rolls 9 and 11 are mounted for rotation, are hollow at their centers so that the oil of this second stream flow through these shafts to reach the outlet openings 31 and 32. The oil also fills the spaces around the gears and bearings associated with the shafts 21 and 22 as is evident from FIG. 2.

The respective bearings, gears, connecting means and other elements of the unit which do not constitute the invention are identified with reference numerals 5, 13, 16, 17, 23, 24, 25, 26, 27 and 28 and are not believed to require discussion as they correspond to similar elements in my US. Pat. No. 3,142,208.

It may be seen from the drawing that the path which is provided for the oil through the inner chamber 7 permits a free flow of cooling liquid than the path which is provided for the liquid which serves to lubricate the driving mechanism. Thus, the liquid flowing through the inner chamber 7 is capable of dissipating more heat than would otherwise be the case.

Referring now to FIGS. 3 and 4, the rolling unit shown therein is similar to that of FIGS. 1 and 2, except that the drive shaft 12A is located below the rolling axis. In FIGS. 3 and 4, the same reference characters as in FIGS. 1 and 2 have been used for corresponding parts, with the addition of the suflix A. A detailed description of the construction shown in FIGS. 3 and 4 is therefore not necessary.

Owing to the different positioning of the drive shaft 12A the lubricating and cooling liquid moves in FIGS. 3 and 4 in paths different from those of FIGS. 1 and 2. As shown in FIG. 4 by the dotted areas and dashed-line arrows, the liquid enters via the input duct 61 and fills the spaces around the shafts 21A and 22A, then flows through the hollow centers of these shafts so as to surround the drive shaft 12A, and is finally discharged to the exterior by means of the passages 64 and 65 which communicate with the outlet duct 66.

The second stream of cooling and lubricating liquid, as shown by small circles and solid-line arrows, enters in two streams through the inlet ducts 62 and 63, fiows over the peripheral portions of the rolls 9A and 11A, and then around the rolling axis 6A and the stock 106A to be rolled. Thereupon, the two streams are united and form a single stream that flows around the roll 10A and issues through the outlet port 67, whose rate of throughput is controlled by the valve 68 of conventional design. This valve 68 can also be replaced by a calibrated hole if desired.

In FIG. 5 I have illustrated a rolling mill comprising two rolling units 1 and 1A of which one is of the type disclosed in FIG. 1, while the other is of the type disclosed in FIG. 3. The metal stock to be rolled, in form of elongated bars, ingots or the like, is indicated with reference numerals 106 and 106A, respectively, in accordance with the identical reference numerals used in FIGS. 1 and 3.

It will be noted that the rolling units 1 and 1A are arranged side-by-side and that the metal stock, which moves towards the right in FIG. 5, enters the rolling unit 1 through the inlet duct 69 thereof. It passes through the 'unit 1, leaving the same through the outlet duct 70, and

enters the unit 1A through the inlet duct 71 from which it advances to the outlet duct 72 of the unit 1A. The reason why the stock has been identified with reference numeral 106 in the unit 1, and with reference numeral 106A in the unit 1A, has already been discussed.

FIG. 5 clearly indicates that the stock 106/106A is immersed in cooling and lubricating liquid during its entire passage through the rolling mill, that is from the time it enters the inlet duct 69 of unit 1 until it leaves the unit 1A through the outlet duct 72 thereof. This is possible because some of the cooling and lubricating liquid entering the units 1 and 1A through the liquid- inlet passages 19 and 61, respectively, will be discharged from the inlet and outlet ducts 6972, as shown in FIG. 5. To make this possible at the juxtaposed ducts 70 and 71, these are slightly spaced so that some of the liquid can issue from the gap therebetween. The purpose of this constant immersion of the stock is to protect the same from contact with the ambient atmosphere, and at the gap between the ducts 70 and 71 such protection is assumeddespite the presence of the gapby the fact that the stream of liquid will issue in opposite directions from the ducts 70 and 71, impacting one another with gap and providing a constant protective mantle for the stock passing through this gap.

As FIG. 5 shows, the internal cross-section of the inlet ducts 69 and 71 is convergent in direction of movement of the stock 106/106A to provide for enhanced guidance of the stock into the interior of the respective rolling unit. At the same time the fact that the cross-section diverges in outward direction provides for less restricted flow of liquid and enhances the sealing action against the intrusion of ambient atmosphere. It is primarily for this latter reason that the inner cross-section of the outlet ducts 70 and 72 diverges in direction of movement of the stocks 106/106A.

While FIG. 5 shows a rolling mill which includes two of the rolling units herein discussed, it will be evident that such a mill may include any desired number of such rolling units, and that the arrangement and selection of the particular type of unit or units employed is formed only by the requirements which one made in a specific application.

It will be understood that each of the elements described above, or two or more together, may also find'a useful application in other types of devices differing from the types described above.

While the invention has been illustrated and described as embodied in a rolling unit for rolling metal stock, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can be applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed 05 new and desired to be secured by Letters Patent is set forth in the appended claims.

I claim:

1. A rolling unit for rolling metal stock, comprising the combination of a plurality of rolls arranged for rotation about respective mutually inclined axes, said rolls each having a transverse plane normal to the respective axis and said transverse planes being inclined to one another and converging towards a common rolling axis along which the metal stock advances; mounting and drive means for mounting and rotating said rolls; housing means surrounding said rolls and said mounting and drive means, said housing means including an inner housing portion surrounding said common rolling axis, said rolls having peripheral portions projecting into said inner housing portion and defining therewith a first fluid path, and said housing means further including an outer housing portion surrounding the remainder of said rolls and said mounting and drive means and defining therewith a second fluid path; sealing means associated with each of said rolls and operative for sealing said first fluid path from said second fluid path; feed means operative for continuously circulating a pressurized cooling and lubricating fluid in said first path in contact with said peripheral portions of said rolls, and for continuously circulating a pressurized cooling and lubricating fluid in said second path in con tact with said remainder of said rolls; and regulating means operative for independently regulating the pressure of fluid in said first and second paths, respectively.

2. A rolling unit as defined in claim 1, wherein said regulating means comprises valve means installed in the respective paths and operative for regulating the pressure of fluid in one path independent of the pressure of fluid in the other path.

3. A rolling unit as defined in claim 2, said fluid paths each having a fluid outlet portion and said valve means being installed in such fluid outlet portion of the respective fluid path.

4. A rolling unit as defined in claim 3, wherein said valve means comprises a pair of throttle valves each associated with one of said fluid paths.

5. A rolling unit as defined in claim 2, wherein said rolling unit has an inlet and an outlet for the metal stock; and further comprising means provided at said inlet and said outlet and operative for preventing contact of the ambient air with the metal stock passing through said rolling unit.

6. A rolling unit as defined in claim 1, wherein said sealing means comprises a pair of sealing gaskets associated with each of said rolls and being in sealing engagement with the same and with said inner housing portion for fluid tightly sealing said first fluid path from said second fluid path.

References Cited UNITED STATES PATENTS 1,896,674 2/1933 Longwell 72-4l 2,101,959 12/1937 Shulz 72-45 2,203,751 6/ 1940 Simons 7245 2,679,816 6/ 1954 Moore 7245 3,142,208 7/1964 Properzi 72-41 CHARLES W. LANHAM, Primary Examiner E. M. COMBS, Assistant Examiner US. Cl. X.R. 72-20l, 236

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