MXPA97007340A - Pipe covered to form spirals for spiral forming machines, and the method reconditioner relat - Google Patents

Abstract

The present invention relates to a coated spiral forming tube (11), for a spiral forming head of spiral forming machines for metallic wire, comprising a plurality of wear-resistant inserts having an internal gap through which passes the metallic wire and an external surface that connects to the inner surface of the suction-forming tube (11), wherein the resistant inserts (10) are substantially all similar with a substantially annular shape with a longitudinal dimension ("1") which it engages with the minimum radius of curvature of the spiral-forming tube (11), and has at least partially convex rounded front faces (10a) and a traversed inner gap (12) comprising a first introduction segment (12a) for introducing the metallic cable and a second following segment (12b) which is substantially cylindrical

Description

TUBE COATED TO FORM SPIRALS FOR SPIRAL FORMING MACHINES, AND THE RELATIVE RECONDITIONER METHOD This invention relates to a coated tube for forming spirals for spiral forming machines, and to the relative method for reconditioning them, as stipulated in the respective main claims. The invention is applied in spiral forming machines, with a spiral forming head used in semi-finished products arriving from the hot rolling process, such as wire, rods, round pieces, or the like. The state of the art charges machines to obtain spirals from metallic wire of different diameters, comprising a rotary head forming spirals with a tube to form the spirals. In these machines, the semi-finished product arriving from the rolling line is introduced, by the appropriate feeding device, into the tube of the spiral forming head. The rotary movement of the spiral forming head, as the wire passes through it, whether this wire is smooth or has protuberances, subjects the spiral forming tube to high stresses that may compromise its structural integrity and / or the original geometric configuration. These tensions are added to the tangential thrusts of the metallic wire as it passes through, and cause friction conditions, and consequently, wear, on the inside of the tube, which are particularly serious. As the tube wears, the machine becomes unbalanced, and when the tube is replaced, the machine needs to be rebalanced. For this reason, the spiral-forming tube of the spiral-forming head is realized on the understanding that, under certain operating conditions, it is integrated and completely coated with auxiliary elements having high characteristics of wear resistance. This solution, although it ensures a longer duration of the spiral forming tube, and consequently, fewer interventions on it, also causes problems related to the high costs of procuring and reconditioning the tube, due to its more complex structure, and to the fact that can not be partially exchanged. The Patent of the United States of North America US-A-4, 074, 553 teaches the use of tubular inserts made of a wear-resistant material, which are inserted and fastened inside the spiral-forming tube. These tubular inserts have, on the external surface, butt flanges and self-centered flanges that allow them to be assembled reciprocatingly in order to define a transit channel for the metallic wire inside the spiral forming tube. The particular conformation of these wear-resistant inserts, which includes flanges and grooves on the external surface, as well as particular conformations of the front and rear ends to achieve a reciprocal connection, involve high production costs and assembly costs. Moreover, the longitudinal dimension of these inserts, since it must be such as to allow the aforementioned grooves and flanges, can not be less than certain values, which causes problems in the placement of the inserts themselves inside the spiral forming tube. . Moreover, the assembly of the inserts defines a channel of a segmented type that is not particularly suitable for the spiral development of the tube. Moreover, this solution causes considerable problems during the replacement of the inserts, since the spiral-forming tube must necessarily be dismantled, or even the tube and also the relative rotational support. In addition, the particular and specific shape of the inserts prevents them from being exchanged. Replacement or reconditioning operations, therefore, are costly, long, and laborious, and cause long interruptions to the cycle of spiral formation, and considerable costs. In addition, these operations must be performed by many workers, since the dismantling and assembly of the spiral forming tube is extremely complex. Accordingly, the present applicants have designed, tested, and incorporated this invention to overcome the drawbacks of the state of the art, and to achieve other advantages. This invention is stipulated and characterized in the respective main claims, while the dependent claims describe variants of the idea of the main mode. The purpose of the invention is to provide a coated tube to form spirals for spiral forming machines, which is simple, functional, and practical, which allows rapid reconditioning, and consequently, limited cycle deactivation times, and extremely low costs. A further purpose of the invention is to facilitate the operations of inserting / removing the liner, allowing this to be done by one worker only.

An additional purpose is to obtain a wear-resistant coating composed of inserts of a single type, of a small size and of a simple shape, and therefore, economical to obtain and adaptable to the spiral-shaped development of the spiral-forming tube. It is also a purpose of the invention to be able to rotate the inserts randomly, and obtain a restoration of the transit channel without replacing the inserts themselves for a number of times, including more than 10 restorations. The wear-resistant inserts forming the coating of the tube according to the invention are substantially composed of an annular element of an external diameter which is coupled with the inner diameter of the spiral-forming tube into which the inserts are to be inserted, and a reduced internal diameter that matches the diameter of the metal wire. The internal hollow of the wear-resistant inserts has a first connection or introduction portion, and a second substantially cylindrical portion. The internal surface of these wear resistant inserts is substantially cylindrical, which gives an extremely simple production process, and makes insertion / removal very easy. Moreover, the reduced longitudinal dimension of the wear-resistant inserts, which varies from 20 to 40 millimeters, conveniently 30 millimeters, gives them characteristics that make them extremely adaptable for the development in spiral form of the spiral forming tube. These characteristics of adaptability are increased by the substantially spherical or curved conformation of the front faces of the inserts, which allow them to be configured in a continuous contact, even in the arched portions of the spiral forming tube. According to the invention, the inlet mouth of the spiral-forming tube communicates with the inlet towards the internal recess of the first wear-resistant insert. According to the invention, the wear-resistant inserts are inserted into and extracted from the spiral-forming tube by means of a flexible cable element or a similar or comparable element. This cable element has, in correspondence with at least one of its ends, an element for temporarily limiting the inserts. According to the invention, in order to restore the transit channel without replacing the inserts, the inserts are removed by means of the flexible cable element, they are rotated randomly around the flexible cable element, and then, they are reinserted; in this way, the preferential channel that had been created is removed, and the transit channel is restored to optimum conditions. In one embodiment of the invention, in correspondence with a first end, the cable has a limiting element of the tube that can be dissociated from the cable itself, and which cooperates with the insert front face, while, in correspondence with the second end, The cable has a limiting element of the type that comes into contact with the internal hollow of the inserts. The coating is introduced, in one embodiment of the invention, by progressively threading a desired number of inserts onto the cable, as they are limited, at the first end of the cable, and consequently, can not be unscrewed from the aforementioned limiting element. The second end of the cable is then introduced from the exit mouth of the spiral forming tube, until it leaves the entrance mouth of the same tube. When all the inserts are located inside the spiral forming tube, the limiting element of the dissociable type of the cable is removed, and the cable itself is unscrewed from the spiral forming tube. Subsequently, in correspondence with the outlet mouth of the spiral forming tube, a fastening element is inserted for the inserts, which, consequently, are clamped between the fastening element and the stop element associated with the inlet mouth of the coil. spiral forming tube. The inserts are removed from the spiral forming tube, inserting the first end of the cable into the inlet mouth, until it leaves the exit mouth of the spiral forming tube. When pulling the first end of the cable, the limiting element of the second end comes into contact with the internal recess of the first insert; this first insert, limited to the cable, is therefore dragged together with all the others towards the outer part of the spiral forming tube. The attached figures are given as a non-restrictive example, and show a preferred embodiment of the invention as follows: Figure 1 shows a front view of a spiral-forming tube with a coating that can be replaced by means of the method in accordance with invention. Figure 2 shows the "A-A" section of Figure 1, as the wear-resistant inserts are inserted. Figure 2a shows the "A-A" section of the Figure 1, when the inserts have been fully inserted. Figure 3 shows the view from "B" of Figure 2a. Figure 4 shows a partially sectioned view from above of the spiral forming tube of Figure 1. Figure 5 shows the enlarged view of detail "X" of Figure 4, when the wear resistant inserts have been fully inserted. Figure 5a shows detail "X" of Figure 4, when the inserts are being extracted. Figure 6a shows the first form of insert mode. Figure 6b shows a variant of Figure 6a.

The spiral-forming tube 11 according to the invention includes inside it, wear-resistant inserts 10 of an annular shape defining an internal hollow 12; this hollow 12 comprises, in this case, a first introduction segment 12a, which is configured as a truncated cone, and a second substantially cylindrical segment 12b, with a section substantially coinciding with the minor section of the first segment 12a. The external diameter "D" of the wear-resistant insert 10 is slightly smaller than the internal diameter of the spiral-forming tube 11; while the internal diameter "d" of the cylindrical segment 12b of the internal hollow 12, is correlated in its size with the diameter of the metallic wire. The insert 10 has rounded front faces 10a convex outwards, to better adapt to the geometry of the spiral forming tube 11. In the embodiment shown in Figure 6a, the rounded shape extends over the entire surface of the front face 10a of the insert wear resistant 10. In the variant shown in Figure 6b, the rounded shape extends only over at least part of the outer circumference of the recess 12, so that a better connection between the adjacent wear resistant inserts 10 is given. The longitudinal dimension "L" of the wear-resistant inserts is between 20 and 40 millimeters, conveniently with a nominal value of approximately 30 millimeters. In this case, the spiral-forming tube 11 is solidly associated, in correspondence with its inlet mouth 11, with an insert 16 with an internal channel 17 configured as a truncated cone, whose smaller section substantially coincides with the larger section of the latter. hollow 12 of inserts 10. Replacement of wear-resistant inserts is made by means of a flexible metal cable 13, which has elements for limiting the wear-resistant inserts 10 at its two ends 13a, 13b. In correspondence with a first end 13a, the cable 13 has, in this case, the limiting element 14 of the removable type, in this case composed of a nut 114 associated with a thread made on this first end 13a. In correspondence with the first end 13b, the cable has the limiting element 15, which cooperates with the truncated cone segment 12a of the recess 12, in this case composed of a contrasting cone 115 which is of such size that it passes through the element 16, but not through the cylindrical segment 12b of the gap 12. The wear-resistant inserts 10 are inserted into the spiral-forming tube 11 of the spiral-forming head by screwing, by means of the cable 13, a certain number of wear-resistant inserts 10, suitable for covering the entire length of the spiral-forming tube 11, by mounting the cable 13 to the nut 114, on its first end 13a, which abuts the outer part of the last wear-resistant insert 110b. The second end 13b of the cable 13 is then inserted into the spiral forming tube 11 from its outlet mouth 11b, until it comes out of its inlet mouthla. The cable 13 is then pulled, thereby causing the wear-resistant inserts 10 to be drawn into the spiral-forming tube 11, until the first wear-resistant insert 110a is brought to the stop position against the element of the spiral. introduction 16. The nut 114 of the first end of the cable 13a is then unscrewed, thereby allowing the cable 13 to be withdrawn from the inlet mouth of the spiral-forming tube 11. Subsequently, the elements 18 for holding the inserts resistant to the 10, are associated with the outlet mouth 11b of the spiral forming tube 11; in this case, these elements 18 are composed of a fork 18 inserted in the coupling holes 19 made on the spiral forming tube 11, and which include their own fastening elements. The wear-resistant inserts 10 are extracted from the spiral-forming tube 11, by inserting the first end 13a of the cable 13, now dissociated from the nut 114, in the inlet mouthla, until it leaves the outlet mouth 11b. The subsequent pull of the cable 13 causes the contrasting cone 115 to come into contact with the truncated cone segment 12a of the recess 12 of the first wear-resistant insert 110a. This contrasting cone 115, as it can not pass through the recess 12, causes the wear-resistant inserts 10 to be pushed towards the outlet mouth 11b, and consequently, allows them to be extracted from the spiral-forming tube 11.

Claims (13)

Í3 CLAIMS

1. A coated spiral forming tube (11) for a spiral forming head of spiral forming machines for metallic wire, which comprises a plurality of wear-resistant inserts having an internal gap through which the metallic wire passes, and a external surface that connects to the inner surface of the spiral-forming tube (11), the tube being characterized in that the wear-resistant inserts (10) are substantially all similar, with a substantially annular conformation, with a longitudinal dimension ("1") which engages with the minimum radius of curvature of the spiral-forming tube (11), rounded front faces (10a) at least partially convex, and a traversed internal gap (12) comprising a first introduction segment (12a) for introducing the metallic wire, and a second second segment (12b), substantially cylindrical. A spiral forming tube as in claim 1, wherein there is a shaped inlet mouth (lia), with an insert (16) defining an abutment element, for the first wear-resistant insert (110a) . 3. A spiral forming tube as in claim 1 or 2, wherein the wear-resistant insert (10) has a longitudinal dimension ("1") of between 20 and 40 millimeters. 4. A spiral forming tube as in any of the preceding claims, wherein the wear-resistant insert (10) has a longitudinal dimension ("1") of about 30 millimeters. 5. A spiral forming tube as in any of the claims, wherein the introduction segment (12a) of the recess (12) in the wear-resistant insert (10) is configured as a truncated cone. 6. A spiral forming tube as in any of the preceding claims, wherein the wear-resistant insert (10) has its external surface that connects to the inner surface of the tube (11) of a cylindrical shape that engages with the inner diameter of the spiral forming tube (11). A spiral forming tube as in any of the preceding claims, wherein the wear-resistant insert (10) has its front face (10a) at least partially rounded. 8. A spiral forming tube as in any of the preceding claims, wherein the entrance diameter of the introduction segment (12a) of the wear-resistant insert (10), has a dimension coordinated with the exit dimension of the through hole of the introduction element (16). 9. A spiral forming tube as in any of the preceding claims, wherein the outlet mouth (11b) cooperates with the fastening element (18) of the last wear-resistant insert (110b). A spiral-forming tube as in claim 9, wherein the fastening element is a fork element (118) cooperating with the insert holes (19) in the spiral-forming tube (11), also including a Clamping element for the fork element (118). A method for reconditioning a spiral forming tube (11) of a spiral forming head, in spiral forming machines for metallic wire, including the tube (11) therein, a plurality of wear resistant inserts defining a inner hollow through which passes the metallic wire, the inserts including an external surface that connects to the inner surface of the spiral forming tube (11), the method being characterized in that the wear-resistant inserts (10) are inserted / they extract from the spiral forming tube (11), by means of a flexible cable element (13) including, at least at one end (13b), at least one temporary limiting element (15) in contact with the internal hollow (12) ), and / or with the front wall of the wear-resistant inserts (10), the cable element being (13), with the wear-resistant inserts (10) threaded from a mouth (11a, 11b) of the spiral-forming tube (11), until the first wear-resistant insert (110a) is brought to a stop against a stop element cooperating with the other mouth (11a, 11b), and then the last wear-resistant loop is clamped with a clamping element, the removal of the wear-resistant inserts (10) of the spiral-forming tube being achieved ( 11), after the fastening element has been released, by introducing the cable element (13) from the other mouth (11b, lia) of the tube (11), until the temporary limiting element (15) is brought into contact with, and then held against, the internal hollow (12) and / or the front wall of the first wear-resistant insert. (110a), and therefore, the entire assembly of wear-resistant inserts is removed (10) 1

2. A method as in claim 11, wherein the introduction of the cable element (13) with the wear-resistant inserts (10), is achieved from the outlet mouth (11b) of the tube (11), until the The first wear-resistant insert (110a) is brought to an abutment position against an introduction element (16) associated with the inlet mouth (Ia) of the tube (11), while the removal of the wear-resistant inserts (11) is carried out. ) is achieved by introducing the cable element (13) from the inlet mouth (lia) of the tube (11), until the temporary limiting element (15) comes into contact with the internal recess (12) of the first insert wear resistant (110a). 1

3. A method as in claim 11 or 12, wherein the wear-resistant inserts (10) are removed by means of the cable element (13), are rotated randomly on the cable element (13), and re-insert and hold. SUMMARY A tube coated to form coils (11) of a spiral forming head, for spiral forming machines for metallic wire, which comprises a plurality of anti-wear inserts that include an internal gap for the passage of the metallic wire, and a surface external connecting to the inner surface of the spiral forming tube (11), the wear-resistant inserts (10) being substantially all similar, with a substantially annular conformation and a longitudinal dimension ("1") that engages with the radius minimum curvature of the spiral-forming tube (11), rounded front faces (10a) at least partially convex, and an internal gap (12) comprising a first segment (12a) for introducing the metallic wire, and a second segment (12b) ) substantially cylindrical next to the first. A method for reconditioning a spiral forming tube (11) of the spiral forming head of spiral forming machine for metallic wire, including the tube (11) therein, a plurality of wear resistant inserts defining an internal hollow for the case of the metallic wire, and including an external surface that connects to the inner surface of the spiral wrapping tube (11), inserting / removing the wear-resistant inserts (10) of the spiral-forming tube (11) by means of a flexible cable element (13) including, at least at one of its ends (13b), a limiting element at least temporarily (15) in contact with the internal hollow (12) and / or the front wall of the resistant inserts to wear (10), the cable element (13) being threaded with the wear-resistant inserts (10) from a mouth (11a) of the spiral-forming tube (11), to bring the first wear-resistant insert. (110a) to a stop position, a stop element cooperating with the other mouth (11b, lia), and thereby holding the last wear-resistant insert with the fastener, the wear-resistant inserts being removed (10a). ) of the spiral forming tube (11) by releasing the clamping element, and then by introducing the cable element (13) from the other mouth (11a, 11b) of the tube (11), until the limiting element temporary (15) comes into contact and then is held against the internal hollow (12) and / or the front wall of the first wear-resistant insert (110a), thereby removing the entire assembly of wear-resistant inserts (10).* * * * *