Apparatus to transport and cool rolled products such as rods, wires, round pieces or similar

Information

  • Patent Grant
  • 6473991
  • Patent Number
    6,473,991
  • Date Filed
    Friday, March 2, 2001
    23 years ago
  • Date Issued
    Tuesday, November 5, 2002
    22 years ago
Abstract
Apparatus to transport and cool rolled products such as bars, round pieces, rods or similar, arrangable downstream of a coil-forming head, comprising a plurality of transport rollers, at least partly motorized and parallel to each other to define a substantially horizontal transport plane on which the rolled products arranged in coils are able to lie, ventilator in correspondence with the transport rollers to blow air towards the rolled products and a conveyor to convey more air towards the lateral edges of the coils than towards the central zone of the coils, the conveyor comprising a plurality of elements, arranged at intervals between the transport rollers. Each of the elements shaped to define transit channels having a first transverse section greater in correspondence with the ends of the transport rollers and a second transverse section less in correspondence with the median zone of the transport rollers.
Description




FIELD OF THE INVENTION




This invention concerns an apparatus to transport and cool rod, metal wires, steel round pieces or similar, in the segment between a coil-forming machine, arranged downstream of the last rolling stand of a rolling mill, and a collection device where the cooled product is wound into rolls or coils.




BACKGROUND OF THE INVENTION




In the field of hot rolling mills, the state of the art includes apparatus to convey and simultaneously cool rolled product, such as rods, wires, bars, round pieces or similar, between the outlet of the last rolling stand and the collection device. The rolled product, in fact, which at outlet from the last rolling stand has a temperature of between 750° C. and 1150° C., before being wound into rolls or coils is properly cooled, and possibly subjected to heat treatment, to give it the desired final structure and the desired mechanical properties.




This cooling is usually achieved by using air, which is blown onto the product passing through by blowers arranged below a horizontal conveyor with rollers.




The rolled product, downstream from the last rolling stand, passes into a coil-forming head.




Since the density of the coils is higher in the lateral zone of the conveyor than in the central zone, it is necessary to provide means which provide a substantially uniform cooling of the product.




The state of the art includes an apparatus wherein, between the blowers which blow the air and the conveyor rollers there are one or more horizontal plates with differentiated apertures, consisting of slits or holes, to direct a greater quantity of air in correspondence with the lateral zones of the conveyor.




This conventional apparatus has the disadvantage, however, that it is very bulky, complex and therefore costly, and it is not versatile, because once the holed plates have been sized, and located between the blowers and the rollers, they are difficult to modify or replace with others having a different configuration of the apertures. This disadvantage is not insignificant, if we think that it is essential to adapt the cooling methods according to the type of product treated and the final result to be obtained. It must not be forgotten that the cooling curve of the product, that is, the progressive lowering of the temperature, univocally causes the phase transformation, and consequently the final mechanical characteristics of the product.




Document JP-A-


59-113918


discloses a device to transport and cool rolled bars wound in coils, which comprises a plurality of conveyor rolls arranged with the axes of rotation parallel to each other. Each conveyor roll has a cylindrical central part, which has a set diameter and is able to contact the rolled stock to be conveyed, and two lateral parts with a smaller diameter than that of the central part. Between the rolls, brought into reciprocal proximity, passages are created for the cooling air, which is blown from below. The passages are narrower at the center and wider in correspondence with the lateral zones. The device has at least the following two disadvantages, however: the lateral ends of the conveyor rolls are weakened, since their diameter is reduced with respect to that of the central part; moreover, in correspondence with the lateral ends the coils tend to deform, because they have nothing to support them.




The present Applicant has devised, embodied and tested, with excellent results, the apparatus to transport and cool rolled products such as rods, wires, round pieces or similar according to the invention, to overcome these shortcomings of the state of the art.




SUMMARY OF THE INVENTION




The apparatus to transport and cool rolled products according to the invention is set forth and characterized in the main claim, while the dependent claims describe other innovative features of the invention.




The apparatus according to the invention, which is able to be arranged downstream of a coil-forming head in a rolling mill, comprises transport rollers, at least some of which are motorized, arranged parallel so as to define a substantially horizontal transport plane on which the rolled product arranged in coils is able to lie, ventilation means being arranged in correspondence with the transport rollers to blow air towards the rolled product and conveyor means to convey a greater quantity of air towards the lateral edges of the coils than that conveyed towards the central zone of the coils.




One purpose of the invention is to achieve means to convey the air which allow to cool the rolled product homogeneously while it is being transported by the transport rollers and which are at the same time simple, reliable and easy to replace.




In accordance with this purpose, the means to convey the air comprise a plurality of elements arranged at intervals between the transport rollers and shaped so as to define transit channels, or outflow gaps, having at least a first transverse section which is greater in correspondence with the ends of the transport rollers and at least a second transverse section which is less in correspondence with the median zone of the transport rollers.




The intermediate elements preferably consist of rollers arranged slightly lower than the drawing rollers, so that they do not interfere with the rolled product above, so they are so-called “dummy rollers”.




While the general concept applies that the diameter of the intermediate rollers is variable, the shape of the latter can be chosen as desired, according to the characteristics of the product to be cooled, the density of the coils, the speed of transport of the product and any other parameter which might influence the cooling curve.




According to another characteristic feature, which adds to and integrates the advantages of the intermediate elements, in the median zone of the conveyor conduit of the ventilation means two switches are provided; the controlled inclination thereof allows to direct more or less air towards the ends of both the drawing and the intermediate rollers.











BRIEF DESCRIPTION OF THE DRAWINGS




These and other characteristics of the invention will be clear from the following description of some preferential forms of embodiment, given as a non-restrictive example, with reference to the attached drawings wherein:





FIG. 1

is a schematic side view of a transport and cooling apparatus according to the invention;





FIG. 2

is a view from above, partial and enlarged, of the apparatus in

FIG. 1

;





FIG. 3

is an enlarged detail of

FIG. 1

;





FIG. 4

is a transverse view, partial and schematic, of the apparatus shown in

FIG. 1

;





FIGS. 5



a


-


5




d


are schematic representations of a detail of the apparatus shown in

FIG. 1

, according to four forms of embodiment;





FIG. 6

is a graphic representation of the average speed of the air in the different zones of the apparatus shown in

FIG. 1

, compared with that of conventional apparatuses;





FIGS. 7



a


-


7




d


show the four embodiments of

FIGS. 5



a


-


5




d


in a variant.











DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS




With reference to

FIG. 1

, an apparatus


10


to transport and cool rolled products


11


, such as wires, round pieces, rods or similar, according to the invention, is arranged between a coil-forming head


12


, which is downstream of the last rolling stand


13


, and a collection device


15


of a conventional type.




The coil-forming head


12


is able to bend the rolled product


11


, emerging from the rolling stand


13


at a temperature of between about 750° C. and 1150°, to form a plurality of coils


16


(FIGS.


1


and


2


), continuous and substantially circular in shape, which are able to arrange themselves on a substantially horizontal plane, each one slightly off-set with respect to the adjacent coil.




The apparatus


10


comprises a plurality of transport rollers


20


mounted rotatable on a supporting structure


21


and arranged parallel to each other so as to define a substantially horizontal supporting plane, or transport belt, for the coils


16


. The transport belt has a width “l” (

FIG. 2

) a little more than the diameter “d” of the coils


16


and defines two lateral areas A


1


and A


2


between the coils


16


and the lateral sides of the structure


21


.




The zones A


1


and A


2


serve to prevent the coils


16


from jamming on the sides of the structure


21


.




At least some of the transport rollers


20


are motorized by motors and transmission organs of a conventional type, not shown in the drawings.




Under the transport rollers


20


a plurality of blowers


22


are arranged (FIGS.


1


and


3


), each of which is able to generate a flow of air, from the bottom upwards, able to hit the coils


16


passing on the transport rollers


20


above.




According to one characteristic of the invention, intermediate rollers


23


are arranged at intervals between the transport rollers


20


. The rollers


23


rest in a removable manner on corresponding V-shaped seatings


25


made on bars


26


which support the structure


21


.




The intermediate rollers


23


are arranged on a lower plane than the transport rollers


20


, so that they never come into contact with the product


11


which has to be transported and cooled.




The intermediate rollers


23


are shaped so as to define, together with the transport rollers


20


, transit channels or outflow gaps


27


(

FIGS. 5



a


-


5




d


) for the air arriving from the blowers


22


. To be more exact, the transverse section of the channels


27


is greater in correspondence with the ends of the transport rollers


20


and less in correspondence with the median zone of the latter. This is to convey a greater quantity of cooling air towards the lateral ends of the coils


16


, where there is a greater density, and to provide a substantially homogeneous cooling of the rolled product


11


.




To obtain this variation in section in the channels


27


, the intermediate rollers


23


can have any convenient shape; they may have a constant diameter D


1


in the median zone and a diameter D


2


, less than D


1


, in the peripheral zones, with a sudden change in diameter between the two zones (

FIG. 5



a


); a shape identical to the previous one but with a gradual connection zone between the median zone and the peripheral zone (

FIG. 5



b


); a barrel-type shape (

FIG. 5



c


); or a sinusoidal shape (

FIG. 5



d


). Obviously, the rollers


23


may have many other shapes, not shown here.




According to a variant, in order to optimize the feeding of air towards the zones where the coils


16


are most dense, and at the same time to prevent a large quantity of air from being conveyed to no purpose towards the zones A


1


and A


2


of the transport belt, the intermediate rollers


23


are appropriately shaped so that their ends


23




a


and


23




b


(

FIGS. 7



a


-


7




d


), near the structure


21


, have the same diameter D


1


which they have in their central zone. Advantageously the distance between the inner edges of the two ends


23




a


and


23




b


is the same as the diameter “d” of the coils


16


.




Advantageously the ratio between the diameter D


2


and the diameter D


1


is between 0.1 and 0.7.




Moreover, the ratio between the length of the median zone “m” (

FIGS. 5



a


and


7




a


) and the diameter “d” of the coils


16


, which in

FIG. 7



a


corresponds substantially to the distance between the inner edges of the two ends


23




a


and


23




b,


is advantageously between 0.5 and 0.9.




Each intermediate roller


23


, since it is resting on the corresponding V-shaped seatings


25


, can easily be removed and replaced, even by another roller of a different shape, so as to vary the section of the channels


27


.




Moreover, the intermediate rollers


23


can also be regulated in height, by means of any conventional device, not shown in the drawings, in order to adapt the apparatus


10


to the different conditions and materials rolled, without having to change the rollers


23


themselves.




According to a variant, not shown in the drawings, between two adjacent transport rollers


20


two or more intermediate rollers


23


may be arranged, so as to define channels


27


of different shapes.




According to another characteristic feature of the invention, two switches


29


and


30


are associated with each blower


22


(FIGS.


3


and


4


), and are arranged inside the conduit


31


to convey the air. The switches


29


and


30


are pinned on corresponding horizontal pins


32


and


33


and are connected by means of a pair of gears


35


and


36


, so that their rotations, both in a clock-wise and anti-clockwise direction, are synchronized. Each switch


30


is connected to an actuation mechanism


37


, comprising a fluido-dynamic piston


39


, which is able to regulate the simultaneous inclination of both switches


29


and


30


.




With each mechanism


37


it is thus possible to regulate the diversion, towards the ends of the rollers


20


and


23


, of the quantity of air which is thrust upwards by the corresponding blower


22


.




Practical tests have proved that with the apparatus


10


according to the invention, the average speed of the air in the different zones of the transport belt, from the centre towards the periphery of the rollers


20


, or towards the sides of the supporting structure


21


, has a development represented by a continuous line in the graph shown in

FIG. 6

, wherein the x-axis indicates the ratio between the value “X” measured from the center of the transport belt and the distance “X


1


” from the center of the transport belt to the periphery of the latter. As can be seen, the development of the average air speed, expressed in meters per second, has a peak precisely in correspondence with the zone where the coils


16


of the rolled product


11


have their greatest density, contrary to what happens in conventional devices, where the average air speed, in the corresponding zones of the transport belt, is substantially constant, as is clear from the line of dashes shown in FIG.


6


.




In fact, in the apparatus


10


according to the invention, it is the outflow area between the drawing roller


20


and the intermediate roller


23


which distributes the air between the edge and center of the transport belt. The shape of the intermediate roller


23


serves to manage the speed profile on the width “l” of the belt, even if the air speed ratio at the edge and center is the same.




It is obvious that modifications and additions may be made to the apparatus


10


as described heretofore, but these shall remain within the field and scope of the invention. For example, the intermediate rollers


23


could be replaced by elements having a non-cylindrical shape, such as plates with a variable section or otherwise.




It is also obvious that, although the invention has been described with reference to a specific example, a skilled person shall certainly be able to achieve many other equivalent forms thereof, but these shall all come within the field and scope of the invention.



Claims
  • 1. Apparatus to transport and cool rolled products (11) able to be arranged downstream of a coil-forming head (12), comprising:a plurality of transport rollers (20), at least partly motorized and arranged parallel to each other so as to define a substantially horizontal transport plane on which said rolled products (11) arranged in coils (16) are able to lie, ventilation means (22) arranged in correspondence with said transport rollers (20) to blow air towards said rolled products (11) and conveyor means to convey towards the lateral edges of said coils (16) a greater quantity of air than that conveyed towards the central zone of said coils (16), wherein said conveyor means comprise a plurality of elements (23) arranged at intervals between said transport rollers (20), each of said elements (23) being shaped so as to define transit channels (27) and the quantity of air permitted to pass to pass though said transit chanels (27), said transit channels (27) having at least a first transverse section which is greater in correspondence with the ends of said transport rollers (20) and at least a second transverse section which is less in correspondence with the median zone of said transport rollers (20).
  • 2. Apparatus as in claim 1, wherein said elements consist of variable section plates.
  • 3. Apparatus as in claim 1, wherein said ventilation means comprise a plurality of blowers (22), wherein with each of said blowers (22) is associated at least a switch (30) arranged inside an air conveyor conduit (31), located between the corresponding blower (22) and said transport rollers (20) and able to divert the air blown by the blower (22) towards said first greater transverse section.
  • 4. Apparatus as in claim 3, wherein said switch (30) is connected with an actuation mechanism (37) able to regulate the inclination thereof.
  • 5. Apparatus as in claim 4, wherein two switches (29, 30) are associated with each of said blowers (22).
  • 6. Apparatus as in claim 3, wherein two switches (29, 30) are associated with each of said blowers (22).
  • 7. Apparatus as in claim 3, wherein two switches (29, 30) are associated with each of said blowers (22).
  • 8. Apparatus as in claim 3, wherein the cooled rolled products are selected from the group consisting of bars, round pieces and rods.
  • 9. Apparatus of claim 1, wherein said intermediate rollers (23) are arranged on a lower plane than said transport rollers (20), such that said intermediate rollers (23) do not contact said products (11).
  • 10. Apparatus as in claim 1, wherein said elements comprise variable section plates.
  • 11. Apparatus of claim 1, wherein said transit channels (27) are not all of the same shape.
  • 12. Apparatus to transport and cool rolled products (11) able to be arranged downstream of a coil-forming head (12), comprising:a plurality of transport rollers (20), at least partly motorized and arranged parallel to each other so as to define a substantially horizontal transport plane on which said rolled products (11) arranged in coils (16) are able to lie, ventilation means (22) arranged in correspondence with said transport rollers (20) to blow air towards said rolled products (11) and conveyor means to convey towards the lateral edges of said coils (16) a greater quantity of air than that conveyed towards the central zone of said coils (16), wherein said conveyor means comprise a plurality of elements (23) arranged at intervals between said transport rollers (20), each of said elements (23) being shaped so as to define transit channels (27) having at least a first transverse section which is greater in correspondence with the ends of said transport rollers (20) and at least a second transverse section which is less in correspondence with the median zone of said transport rollers (20) and said elements consist of intermediate rollers (23) with a variable diameter.
  • 13. Apparatus as in claim 12, wherein said intermediate rollers (23) have a greater diameter (D1) in correspondence with a lower median zone and a smaller diameter (D2) in correspondence with their ends.
  • 14. Apparatus as in claim 13, wherein said intermediate rollers (23) are barrel-shaped.
  • 15. Apparatus as in claim 13, wherein said intermediate rollers (23) are sinusoidal in shape.
  • 16. Apparatus of claim 13, wherein a ratio between said median zone, corresponding substantially to the width of said intermediate rollers (23), and the diameter of said coils (16) is between 0.5 and 0.9.
  • 17. Apparatus of claim 13, wherein a ratio between said smaller diameter (D2) and said greater diameter (D1) is between 0.1 and 0.7.
  • 18. Apparatus as in claim 2, wherein said intermediate rollers (23) have their ends resting in a removable fashion on V-shaped seatings (25) made on a supporting structure (21).
  • 19. Apparatus as in claim 12, wherein said intermediate rollers (23) are associated with lifting means able to regulate their position in height with respect to said transport rollers (20).
  • 20. Apparatus as in claim 12, wherein said intermediate rollers (23) are shaped so that their ends (23a, 23b), outside the bulk of said coils (16), have substantially the same diameter (D1) as said median zone.
  • 21. Apparatus as in claim 12, wherein two or more intermediate rollers (23) are arranged between two adjacent transport rollers (20).
  • 22. Apparatus of claim 12, wherein said intermediate rollers (23) are arranged on a lower plane than said transport rollers (20), such that said elements (23) do not contact said products (11).
  • 23. Apparatus of claim 12, wherein said transit channels (27) are not all of the same shape.
  • 24. Apparatus to transport and cool rolled products (11) able to be arranged downstream of a coil-forming head (12), comprising:a plurality of transport rollers (20), at least partly motorized and arranged parallel to each other so as to define a substantially horizontal transport plane on which said rolled products (11) arranged in coils (16) are able to lie, ventilation means (22) arranged in correspondence with said transport rollers (20) to blow air towards said rolled products (11) and conveyor means to convey towards the lateral edges of said coils (16) a greater quantity of air than that conveyed towards the central zone of said coils (16), wherein said conveyor means comprise a plurality of elements (23) arranged at intervals between said transport rollers (20), each of said elements (23) being shaped so as to define transit channels (27) having at least a first transverse section which is greater in correspondence with the ends of said transport rollers (20) and at least a second transverse section which is less in correspondence with the median zone of said transport rollers (20), wherein said ventilation means comprise a plurality of blowers (22), wherein with each of said blowers (22) is associated at least a switch (30) arranged inside an air conveyor conduit (31), located between the corresponding blower (22) and said transport rollers (20) and able to divert the air blown by the blower (22) towards said first greater transverse section, wherein two switches (29, 30) are associated with each of said blowers (22), and wherein said two switches (29, 30) are connected with each other by means of a pair of gears (35, 36) so that their inclinations are synchronized.
  • 25. Apparatus of claim 24, wherein said intermediate rollers (23) are arranged on a lower plane than said transport rollers (20), such that said intermediate rollers (23) do not contact said products (11).
  • 26. Apparatus of claim 24, wherein said transit channels (27) are not all of the same shape.
Priority Claims (1)
Number Date Country Kind
UD00A0047 Mar 2000 IT
US Referenced Citations (10)
Number Name Date Kind
3390871 McLean et al. Jul 1968 A
3832788 Kato et al. Sep 1974 A
3940967 Vitelli Mar 1976 A
4054276 Wilson Oct 1977 A
4084797 Karlberger Apr 1978 A
4468262 Kaneda et al. Aug 1984 A
4580353 Jalil et al. Apr 1986 A
4843734 Varwig Jul 1989 A
5079937 Scholer Jan 1992 A
5871596 Kiefer Feb 1999 A
Foreign Referenced Citations (3)
Number Date Country
77182 Oct 1970 DD
0060227 Sep 1982 EP
59113918 Jun 1984 JP