Guide device for rolling long metal products

Abstract

Guide device for rolling long metal products, comprising at least a pair of guide rolls coplanar with each other and rotatable round axes of rotation inclined with respect to a rolling axis, a support body on which the guide rolls are mounted and configured to keep the guide rolls constantly in contact with the long metal products, and a support structure configured to support the support body and to which the latter is attached. At least the support structure is made of one or more non-ferrous metal materials with a specific weight less than half the average weight of steel and with heat conductivity equal to or greater than double the average heat conductivity of steel.

Claims

1. Guide device for rolling long metal products, comprising at least a pair of guide rolls coplanar with each other and rotatable round axes of rotation inclined with respect to a rolling axis, a support body on which said guide rolls are mounted and configured to keep said guide rolls constantly in contact with said long metal products, said guide rolls are rotatable independent of said support body, and a support structure configured to support said support body and to which the latter is attached, wherein the support structure and the support body are made of one or more non-ferrous metal materials with a specific weight less than half the average weight of steel and with heat conductivity equal to or greater than double the average heat conductivity of steel, wherein the support body includes a pair of rotatable support levers, one support lever for each guide roll, and wherein an elastic return member is mounted to the support body, connected to each rotatable support lever of the pair of rotatable support levers, and directed substantially perpendicular to the pair of rotatable support levers to allow for rotation of the pair of rotatable support levers, such that the pair of rotatable support levers stretch toward a pre-set inactive position of the guide rolls.

2. Guide device as in claim 1, wherein said one or more non-ferrous metal materials have a specific weight equal to or less than 3 g/cm.sup.3.

3. Guide device as in claim 1, wherein said one or more non-ferrous metal materials have a heat conductivity higher than 140 W/m K.

4. Guide device as in claim 1, wherein said one or more metal materials of which at least the support structure is made are chosen from a group comprising light metal alloys with an aluminum or magnesium base and containing at least two elements of either aluminum, magnesium, titanium, copper, zinc or silicon.

5. Guide device as in claim 1, wherein said one or more metal materials have a mechanical resistance to traction higher than at least 300 MPa.

6. Guide device as in claim 1 wherein the support structure and the support body are both made of the same non-ferrous metal material.

7. Guide device as in claim 1, wherein the support structure is made of a first non-ferrous metal material, and the support body is made of a second non-ferrous metal material, said first non-ferrous metal material having a mechanical resistance higher than that of the second non-ferrous metal material, and said second non-ferrous metal material having a heat conductivity higher than that of the first non-ferrous metal material.

8. Guide device as in claim 1 any claim hereinbefore, wherein said support structure is made of an aluminum-magnesium-silicon alloy 6082 and/or an aluminum-zinc alloy 7075.

9. Guide device as in claim 1, wherein the support body is made of an aluminum-magnesium-silicon alloy 6082 and/or an aluminum-zinc alloy 7075.

10. Guide device as in claim 1, wherein the support body is attached to the support structure by pivoting elements round which each of the support levers is configured to rotate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other characteristics of the present invention will become apparent from the following description of a form of embodiment, given as a non-restrictive example with reference to the attached FIG. 1, which shows a three-dimensional view of a guide device for rolling long metal products made according to the present invention.

DETAILED DESCRIPTION OF SOME FORMS OF EMBODIMENT

(2) We shall now refer in detail to the various forms of embodiment of the present invention, of which one or more examples are shown in the attached drawing. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, the characteristics shown or described insomuch as they are part of one form of embodiment can be adopted on, or in association with, other forms of embodiment to produce another form of embodiment. It is understood that the present invention shall include all such modifications and variants.

(3) The attached FIG. 1 is used to describe forms of embodiment of a guide device 10 usable in rolling long metal products, such as for example thin bars, ribbed bars, rod, wire or other similar products.

(4) In the present description, for clarity and simplicity of exposition, we shall refer by way of example to a bar 11 which is rolled in rolling stands, not shown in the drawings, along a rolling axis Z.

(5) With reference to FIG. 1, in possible forms of embodiment, the guide device 10 includes a pair of guide rolls 12, coplanar with respect to each other and mounted idle on respective axes of rotation X1, X2.

(6) The axes of rotation X1, X2 of the guide rolls 12 are parallel to each other and are positioned on opposite sides of the rolling axis Z, with respect to which they are inclined, orthogonal for example.

(7) In some forms of embodiment, the guide device 10 can also include two or more support levers 14, on each of which one of the guide rolls 12 is mounted.

(8) The support levers 14 in their entirety define a support body 13 configured to support the guide rolls 12.

(9) It is understood that such forms of embodiment are described hereafter merely by way of example of possible solutions of the support body 13 and are not intended to limit the latter to the specific configuration. Indeed, it is not excluded that the support body 13 can be made according to other configurations, while keeping the same function of supporting the guide rolls 12. For example, it can be provided that the support body 13 is made in a single piece, conformed as a fork and suitably shaped, and that it includes, instead of the support levers 14, two arms on which the guide rolls 12 are mounted.

(10) The support body 13 can be configured to keep the guide rolls 12 constantly in contact with the bar 11 during rolling.

(11) For example, the positioning of the support levers 14 can be chosen so that the interaxis of the guide rolls 12 is such as to distance the external surface of the guide rolls 12 by an amount equal to or a little less than the transverse size of the bar 11.

(12) In this way, the guide rolls 12 are both constantly in contact with the bar 11 that passes between them, but without exerting any further rolling on the bar 11 itself. The passage of the bar 11 between the guide rolls 12 confers on them, by friction on their external surface, the rotatory motion around the respective axes of rotation X1 and X2.

(13) The passage of the bar 11 through the guide rolls 12 generally occurs, using recently developed process and equipment technologies, at high speeds, in the order of 100 m/s, even up to 150 m/s, and with temperatures normally between about 800 C. and 1,100 C.

(14) In some forms of embodiment, to resist the high stresses to which it is subjected, each guide roll 12 can be made, at least in its external part, of a ceramic material, for example containing carbides, nitrides, carbonitrides, or hard oxides.

(15) In possible solutions, the external part can be defined by a ring integrated with a central core, made of a tougher material, for example steel or an aluminum alloy.

(16) The guide device 10 can also include a support structure 15, to which the support body 13 is attached, configured to support the support body 13 and defining to a large extent the overall external bulk of the guide device.

(17) The support structure 15 also has the function of allowing the assembly of the guide device 10 to the bearing components of the rolling line in the desired position along the rolling axis Z.

(18) In some forms of embodiment, the support body 13 can be made of steel, stainless steel for example.

(19) The support structure 15 is made of one or more non-ferrous metal materials with a specific weight lower than half the average weight of steel, preferably equal to or less than 3 g/cm.sup.3, and with heat conductivity equal to or higher than double the average of steel, preferably higher than 140 W/mK.

(20) Among the non-ferrous metal materials used to make the support structure 15 light metal alloys can be included for example, with an aluminum or magnesium base and containing at least two elements of either aluminum, magnesium, titanium, copper, zinc or silicon.

(21) Possible solutions provide to use an aluminum alloy from the 6000 series, that is, belonging to the aluminum-magnesium-silicon alloys, denominated 6082, also known by the trade name Anticorodal 100.

(22) This alloy has a specific weight of about 2.7 g/cm.sup.3, that is, about a third of the average weight of stainless steels, a heat conductivity of about 165 W/mK, that is, from about 6 to about 15 times higher than the average of stainless steels, and a typical resistance to traction of about 300 MPa.

(23) Alternative solutions can provide that the support structure 15 is made of an aluminum alloy of the 7000 series, that is, belonging to the aluminum-zinc alloys, denominated 7075, also known by the trade name Ergal 55.

(24) This alloy has a specific weight of about 2.8 g/cm.sup.3, that is, about a third of the average weight of stainless steels, a heat conductivity of about 155 W/mK, that is, from about 5 to about 10 times higher than the average of stainless steels, and a typical resistance to traction of about 500 MPa.

(25) In some forms of embodiment, the support structure 15 is made using both the above-mentioned aluminum alloys.

(26) In variant solutions, it can be provided that the support body 13 is made with one or both the aluminum alloys 6082 and 7075.

(27) When it is not made of steel, the support body 13 can be made of the same non-ferrous material as the support structure 15.

(28) It can also be provided that the support structure 15 is made of a first non-ferrous material, for example aluminum alloy 7075, and the support body 13 made of a second non-ferrous material, for example aluminum alloy 6082, or vice versa.

(29) It is clear from the above that, using a light non-ferrous alloy, for example with an aluminum base, the weight of the support structure 15, and possibly the support body 13, can advantageously be limited. The reduction in weight of these components of the guide device 10, which can even reach two thirds of the weight that, given the same sizes, they would have if they were made of steel, allows an overall reduction in weight of the guide device 10 of more than 30%, even up to 40% and more.

(30) This allows to keep the overall weight of the guide device 10, in preferential solutions, below 20 kg, which, according to some norms, constitutes a maximum weight limit that is allowed to be maneuvered manually by an operator without the assistance of mechanical lifting and movement means or arms, such as hoists, cranes, gantries or other similar machinery.

(31) The heat conductivity of the non-ferrous material cited above, in particular of the aluminum alloys, is such that the cooling of the support structure 15, and possibly also the support body 13, occurs at a considerably higher speed than that which said components would have if they were made of steel.

(32) As a consequence, this allows a considerably quicker cooling of the device guide 10, and therefore allows an operator to intervene, if necessary, on the guide device 10 itself, for example to replace it, or to disassemble it for maintenance, to intervene more rapidly and just before the suspension of rolling.

(33) Moreover, the use of the aluminum alloys cited above instead of stainless steel allows to reduce production costs and times of the support structure 15, and possibly also the support body 13, since these alloys allow to adopt less complex and less costly workings with respect to those needed for stainless steel.

(34) In some forms of embodiment, described by way of example with reference to the attached drawing, the support body 13 can be attached to the support structure 15 by means of pivoting elements 16 around which each of the support levers 14 is configured to rotate.

(35) This rotation can be intended to allow the movement of the guide rolls 12 reciprocally further away or nearer, in order to compensate possible irregularities or discontinuities in the size of the bar 11.

(36) FIG. 1 is used to describe forms of embodiment of the guide device 10 in which an elastic return member, for example a pre-compressed spring 17, is provided to allow the rotation of the support levers 14 and, at the same time, to make them stretch toward a pre-set inactive position in which the guide rolls 12 are at a desired reciprocal distance.

(37) It is clear that modifications and/or additions of parts may be made to the guide device 10 for rolling long metal products as described heretofore, without departing from the field and scope of the present invention.

(38) For example, in possible forms of embodiment, the guide device 10 can include one or more pairs of guide rolls 12, mounted on two or more corresponding support bodies 13 attached to the support structure 15 one after the other along the rolling axis Z.

(39) It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of guide device, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.