WO2009050559A1

WO2009050559A1 - Apparatus for reducing a weld bead

Info

Publication number: WO2009050559A1
Application number: PCT/IB2008/002724
Authority: WO
Inventors: Massimo Magnani
Original assignee: Imec Tubes S.P.A.
Priority date: 2007-10-16
Filing date: 2008-10-14
Publication date: 2009-04-23
Also published as: ITMO20070320A1

Abstract

An apparatus for reducing a weld bead (2) of a welded tube (3) comprises abutting means (38) that is insertable into said tube (3) for abutting on an internal wall (41) of said tube (3), supporting carriage means (4) for supporting said abutting means (38) and magnetic field generating means (24), mounted on said supporting carriage means (4), for generating a magnetic field acting on a portion (37) of said abutting means (38) so as to retain said portion (37), said generating means comprising permanent magnet means (24).

Description

Apparatus for reducing a weld bead

The invention relates to an apparatus for reducing a weld bead.

In particular, the invention relates to an apparatus for reducing a weld bead of a tube welded longitudinally in a continuous manner.

Apparatuses comprising a supporting carriage are known for reducing a weld bead of a tube welded longitudinally in a continuous manner, The supporting carriage is movable with a reciprocating motion parallelly to an advance direction of the welded tube.

The supporting carriage comprises a frame inside which electromagnets are mounted. The electromagnets are used for generating a magnetic field acting on an end portion of an abutting element so as to retain this end portion.

In other words, the magnetic field generated by the electromagnets fixes the supporting carriage with respect to the end portion.

The end portion, which is made of magnetisable material, is connected to an abutting portion of the abutting element.

The abutting portion, which is made of nonmagnetic material, is insertable, in use, into the welded tube for abutting on an internal wall of the welded tube, this internal wall comprising an internal surface of the weld bead.

Known apparatuses further comprise a first pressing roller and a second pressing roller cooperating with the abutting portion for reducing, by compression, the weld bead. In use, the abutting element is inserted into the welded tube so that the abutting portion is interposed between the first pressing roller and the second pressing roller.

A drawback of the known apparatuses is that the electromagnets generate a magnetic field that is very extended and of a high intensity that is such as to spread outside the frame of the supporting carriage. This may entail risks for the health of operators and malfunctions in the electromagnetic equipment such as, for example, computers and pacemakers respectively positioned near such an apparatus . A further drawback of the aforesaid apparatuses consists of the costs to be sustained to purchase the high-voltage power necessary for operating the electromagnets .

Another drawback consists of the need to provide cables of a large diameter for connecting the electromagnets to the electric supply network.

Further, such cables, which are particularly cumbersome and costly, are moved, in use, by the supporting carriage. This means that, in use, such cables may hit and injure the operators located near the cables . An object of the invention is to improve the apparatuses for reducing a weld bead, in particular, the apparatuses for reducing a weld bead of a tube welded longitudinally in a continuous manner. A further object is to make apparatuses for reducing a weld bead that are not dangerous for the health of operators and which do not cause malfunctions in electromagnetic equipment that is respectively positioned near such apparatuses. Another object is to produce apparatuses for reducing a weld bead that are cheaper and less cumbersome than known apparatuses .

According to the invention an apparatus is provided for reducing a weld bead of a welded tube, comprising abutting means that is insertable into said tube for abutting on an internal wall of said tube, supporting carriage means for supporting said abutting means and magnetic field generating means, mounted on said supporting carriage means, for generating a magnetic field acting on a portion of said abutting means so as to retain said portion, characterised in that said generating means comprises permanent magnet means . Owing to the invention it is possible to make an apparatus for reducing a weld bead that is not dangerous for the health of operators and does not cause malfunctions in electromagnetic equipment that is respectively positioned near the apparatus .

In fact, said magnetic field generated by said permanent magnet means is a magnetic field that is concentrated so as not to spread outside a frame of said supporting carriage means . Further, said permanent magnet means does not require electric current to operate and consequently does not need to be connected by connecting cables to an electric power supply network. This enables, on the one hand, the money that is necessary to purchase the electric current and the connecting cables to be saved and on the other hand makes the apparatxis according to the invention safer and less cumbersome than known apparatuses . The invention can be better understood and implemented with reference to the attached drawings that illustrate an embodiment thereof by way of non- limiting example, in which: Figure 1 is a partially sectioned schematic side view and with certain details removed in order better to highlight others, of an apparatus for reducing weld beads; Figure 2 is a schematic side view, with certain details removed in order better to highlight others, of permanent magnet means included in the apparatus in Figure 1 in a non- operating position; Figure 3 is a view like that of Figure 2 of the permanent magnet means in an operating position;

Figure 4 is a partially sectioned schematic front view and with certain details removed in order better to highlight others , of the permanent magnet means in Figure 2 in the non-operating position; Figure 5 is an enlarged detail of Figure 4; Figure 6 is a view like that of Figure 4 of the permanent magnet means in the operating position.

With reference to Figures 1 to 6 there is shown an apparatus 1 for reducing a weld bead 2 of a tube 3 welded longitudinally in a continuous manner.

The apparatus 1 comprises a first supporting carriage 4. The first supporting carriage 4 is movable with a reciprocating motion parallelly to a substantially horizontal advance direction A of the tube 3. In particular, the first supporting carriage 4 is movable between a first position Zl and a second position, which is not shown, the second position being positioned downstream of the first position Zl along the advance direction A. In use, the first supporting carriage 4 is moved according to a first direction Fl, which has the same direction of an advance sense F of the welded tube 3 along the advance direction A, from the first position Zl to the second position, whilst it is moved along a second direction F2 , opposite the advance sense F, from the second position- to the first position Zl.

The first supporting carriage 4 comprises a frame 5.

The frame 5 is mounted on sliding blocks 6 that are slidable along guides 7.

The guides 7 are fixed to a base 8 that is movable by moving means 9, for example comprising a pneumatic actuator, transversely with respect to the advance direction A. To the frame 5 there is fixed a guiding element 10, arranged, in use, for acting as a guide for the tube 3. The guiding element 10 substantially has the shape of a hollow cylinder and extends substantially parallelly to the advance direction A.

In particular, the guiding element 10 is fixed to a first wall 11 and to a second wall 12 of the frame 4, the first wall 11 being opposite the second wall 12 and being positioned upstream of the second wall 12 along the advance direction A. Further, the guiding element 10 defines for the tube 3, respectively in the first wall 11 and in the second wall 12, an inlet 13 into the first supporting carriage 4 and an outlet 14 from the first supporting carriage 4. The guiding element 10 is further made of nonmagnetic material, for example bronze.

The apparatus 1 further comprises permanent magnet means 24 for generating, as will be better disclosed below, a concentrated magnetic field. The permanent magnet means 24 is positioned inside the frame 5 and outside the guiding element 10.

The permanent magnet means 24 is driven by driving means 25 towards and away from the guiding element 10, between a non- operating position Rl (Figures 2 and 4) , in which the permanent magnet means 24 is at a certain distance from the guiding element 10, and an operating position R2 (Figures 3 and 6) , in which the permanent magnet means 24 abuts on a peripheral surface 50 of the guiding element 10. In other words, the driving means 25 enables a distance between the permanent magnet means 24 and the guiding element 10 to be adjusted, the guiding element 10 being available in different internal and external diameters in function of a diameter of the tube 3. The permanent magnet means 24 extends substantially parallelly to the advance direction A.

In particular, the permanent magnet means 24 has a substantially prismatic shape.

In an embodiment of the invention which is not shown, the permanent magnet means 24 has a substantially cylindrical shape .

The permanent magnet means 24 comprises a first permanent magnet 15, a second permanent magnet 16 and a third permanent magnet 17. The first permanent magnet 15, the second permanent magnet 16 and the third permanent magnet 17 are oriented so as to repel one another . In other words, the first permanent magnet 15, the second permanent magnet 16 and the third permanent magnet 17 comprise respectively a first portion 21, a second portion 22 and a third portion 23, having the same polarity, extending substantially parallelly to the advance direction A and facing the guiding element 10.

The first permanent magnet 15, the second permanent magnet 16 and the third permanent magnet 17 are mutually angularly spaced apart by an angle substantially equal to 120°. The first permanent magnet 15, the second permanent magnet 16 and the third permanent magnet 17 substantially have the same length.

Further, the first permanent magnet 15, the second permanent magnet 16 and the third permanent magnet 17 comprise respectively a first end wall 34, a second end wall 35 and a third end wall, which is not shown, that are substantially contained on a plane substantially perpendicular to the advance direction A. In an embodiment of the invention, which is not shown, the permanent magnet means 24 comprises one or two permanent magnets, which are suitably angularly spaced.

In a further embodiment of the invention, which is not shown, the permanent magnet means 24 comprises more than three permanent magnets, which are suitably angularly spaced.

The aforesaid driving means 25 comprises first driving means 18, second driving means 19 and third driving means 20 for respectively driving the first permanent magnet 15, the second permanent magnet 16 and the third permanent magnet 17 towards and away from the guiding element 10.

In particular, the first driving means 18 comprises a first actuator 28 and a second actuator 29.

The first actuator 28 and the second actuator 29 are positioned, alongside one another, along a direction substantially parallel to the advance direction A and are fixed to a top wall 26 of the frame 5. The second driving means 19 comprises a third actuator 30 and a fourth actuator 31.

The third actuator 30 and the fourth actuator 31 are positioned, alongside one another, along a direction substantially parallel to the advance direction A and are fixed to a base wall 32 of the frame 5, the base wall 32 being opposite the top wall 26.

The third driving means 20 comprises a fifth actuator, which is not shown, and a sixth actuator 33. The fifth actuator and the sixth actuator 33 are positioned, alongside one another, along a direction substantially parallel to the advance direction A and are fixed to the base wall 32, the fifth actuator and the sixth actuator 33 respectively facing the third actuator 30 and the fourth actuator 31.

In use, when the permanent magnet means 24 is positioned, and maintained, by the driving means 25 in the operating position R2 , the permanent magnet means 24 generates a concentrated magnetic field having an intensity that is such as to act on, and retain, an end portion 37 of an abutting element 38.

In other words, in the operating position R2 , the intensity of the magnetic field generated by the permanent magnet means 24 near the end portion 37 is such as to fix the first supporting carriage 4 relatively to the end portion 37.

On the other hand, when the permanent magnet means 24 is positioned by the driving means 25 in the non-operating position Rl the aforesaid magnetic field has an intensity that is not sufficient for retaining the end portion 37. In other words, in the non-operating position Rl, the intensity of the magnetic field generated by the permanent magnet means 24 near the end portion 37 is not sufficient to fix the first supporting carriage 4 relatively to the end portion 37, the end portion 37 thus being movable with respect to the first supporting carriage 4. The end portion 37 has a substantially cylindrical shape and is made of magnetisable material .

The end portion 37 is furthermore connected, by an extended element 39, or rod, to an abutting portion 40 of the abutting element 38.

The abutting portion 40 has a substantially cylindrical shape and is made of nonmagnetic material.

The abutting portion 40, in use, is insertable into the tube 3 to abut on an internal wall 41 of the tube 3, this internal wall 41 comprising an internal surface 42 of the weld bead 2.

The apparatus 1 further comprises a first pressing roller 43 and a second pressing roller 44 cooperating with the abutting portion 40 for reducing, by compression, the weld bead 2.

The first pressing roller 43 and the¹ second pressing roller 44 are rotatable respectively around a first rotation axis Xl and. a second rotation axis X2, the first rotation axis Xl and the second rotation axis X2 ^" being substantially horizontal and perpendicular with respect to the advance . direction A of the tube 3.

The . first pressing roller 43 is operationally positioned above, and faces, the second pressing roller- 44, between .the first pressing roller 43 and the second pressing roller 44 there being interposed, in use, the tube 3.

The first pressing roller 43 is movable along an operating direction B, substantially vertical and perpendicular to the advance direction A, towards and away from the second pressing roller 44, between a work position W, in which the first pressing roller 43 abuts on a first portion 45, comprising an external surface 47 of the weld bead 2 of an external wall 46 of the tube 3, and a rest position, which is not shown, in which the first pressing roller 43 is raised with respect to the tube 3. The second pressing roller 44, in use, acts as a rest for the welded tube 3 and abuts on a second portion 48 of the external wall 46 opposite the first portion 45. The first pressing roller 43 and the second pressing roller 44 are supported by a second supporting carriage 49 that is movable with a reciprocating motion parallelly to the advance direction A.

In particular, the second supporting carriage 49 is movable between a further first position Z2 and a further second position, which is not shown, the further second position being positioned upstream of the further first position Z2 along the advance direction A.

In use, the second supporting carriage 49 is moved according to a third direction F3 , opposite the advance sense F, from the further first position Z2 to the further second position, whilst the second supporting carriage 49 is moved according to a fourth direction F4, which has the same direction of the advance sense F, from the further second position to the further first position Z2. Further, in use, the abutting element 38 is inserted into the welded tube 3 so that the abutting portion 40 is interposed between the first pressing roller 43 and the second pressing roller 44. Still, in use, the end portion 37 is retained by, and fixed relatively to, the first supporting carriage 4 by the magnetic field generated by the permanent magnet means 24 positioned in the operating position R2.

In a first working step, in which the weld bead 2 is reduced, the permanent magnet means 24 is in the operating position R2, the first pressing roller 43 is positioned in the work position W, the abutting portion 40 is inserted into the welded tube 3 , and the second supporting carriage 49 is moved from the further first position Z2 to the further second position. In this first working step, moreover, the abutting portion 40 is maintained by the first pressing roller 43 and the second pressing roller 44 abutting on the internal wall 41 of the welded tube 3.

In this manner, the welded tube 3 moves by friction the abutting portion 40 along the advance direction A according to the advance sense F.

Moreover, in the first working step, the end portion 37, which is stiffly connected to the abutting portion 40 by the rod 39 and fixed relatively to the first supporting carriage 4 by the magnetic field generated by the permanent magnet means 24, moves the first supporting carriage 4 from the first position Zl to the second position.

In this manner, in the first working step, the first supporting carriage 4 is moved by the end portion 37 along the advance direction A according to the first direction Fl which has the same direction of the advance sense F, whilst the second supporting carriage 49 is moved by other moving means that is not shown along the advance direction A according to the third direction F3 opposite the advance sense F. In other words, in the first working step, the first supporting carriage 4 and the second supporting carriage 49 are moved towards one another .

In a second working step, in which the welded tube 3 moves along the advance direction A with the advance sense F without the weld bead 2 being reduced, the first pressing roller 43 is positioned in the rest position, the abutting portion 40 is inserted into the welded tube 3, the second supporting carriage 49 is moved from the further second position to the further first position Z2 and the first supporting carriage 4 is moved, by suitable further moving means, which are not shown, from the second position to the first position Zl.

In this second working step, the abutting portion 40 does not abut on and is at a certain distance from the internal wall 41 of the welded tube 3 and the end portion 37, fixed relatively to the supporting carriage 4 by the aforesaid magnetic field, is moved by the first supporting carriage 4 along the advance direction A according to this second direction F2.

In this manner, in the second working step, the first supporting carriage 4 is moved along the advance direction A according to this second direction F2, whilst the second supporting carriage 49 is moved along the advance direction

A according to the fourth direction F4.

In other words, in the second working step the first supporting carriage 4 and the second supporting carriage 49 are moved away from one another.

It should be noted that the aforesaid apparatus 1 can also be used for reducing a weld bead made for welding two metal pieces having any shape . It should be noted how the apparatus 1 is not dangerous for the health of operators placed near said apparatus 1 and does not cause malfunctions in electromagnetic equipment placed near said apparatus 1.

In fact, the magnetic field generated by the permanent magnet means 24 is a concentrated magnetic field such as not to spread outside the frame 5 of the first supporting carriage 4.

Further, the permanent magnet means 24 does not need electric current to operate and consequently does not need to be connected by connecting cables to an electric power supply network.

On the one hand, this enables the money that is necessary to purchase the electric current and the connecting cables to be saved and on the other hand makes the apparatus 1 safer and less cumbersome than the apparatuses disclosed in the prior art .

Claims

1. Apparatus for reducing a weld bead (2) of a welded tube

(3), comprising abutting means (38) that is insertable into said tube (3) for abutting on an internal wall (41) of said tube (3) , supporting carriage means (4) for supporting said abutting means (38) and magnetic field generating means (24) , mounted on said supporting carriage means (4) , for generating a magnetic field acting on a portion (37) of said abutting means (38) so as to retain said portion (37) , characterised in that said generating means comprises permanent magnet means (24) .

2. Apparatus according to claim 1, wherein said permanent magnet means (24) is movable towards and away from said portion (37) , between an operating position (R2) , in which said permanent magnet means (24) retains said portion (37) , and a non-operating position (Rl) in which said permanent magnet means (24) does not retain said portion (37) .

3. Apparatus according to claim 1, or 2, wherein said permanent magnet means (24) extends substantially parallelly to an advance direction (A) of said tube (3) .

4. Apparatus according to any preceding claim, wherein said permanent magnet means (24) has a substantially prismatic shape.

5. Apparatus according to any one of -claims 1 to 3 , wherein said permanent magnet means (24) has a substantially cylindrical shape.

6. Apparatus according to any preceding claim, wherein said permanent magnet means (24) comprises permanent magnets (15, 16, 17) oriented so as to repel one another .

7. Apparatus according to claim 6, wherein said permanent magnets (15, 16, 17) are mutually angularly spaced apart .

8. Apparatus according to claim 6, or 7, wherein said permanent magnets (15, 16, 17) substantially have the same length.

9. Apparatus according to any one of claims 6 to 8, wherein said permanent magnets (15, 16, 17) comprise respective end walls (34, 35) contained on a plane that is transverse to said advance direction (A) .

10. Apparatus according to any one of claims 6 to 9, wherein said permanent magnets (15, 16, 17) comprise a first permanent magnet (15) , a second permanent magnet (16) and a third permanent magnet (17) .

11. Apparatus according to claim 10, wherein said first permanent magnet (15) , said second permanent magnet

(16) and said third permanent magnet (17) are mutually angularly spaced apart by an angle substantially equal to 120°.

12. Apparatus according to any preceding claim, wherein said portion (37) is an end portion of said abutting means (38) .

13. Apparatus according to any preceding claim, wherein said portion (37) is made of magnetisable material.

14. Apparatus according to any one of claims 3 to 13, as claims 4, 5, 6, 12 and 13 are appended to claim 3, wherein said portion (37) extends substantially parallelly to said advance direction (A) .

15. Apparatus according to any preceding claim, wherein said portion (37) has a substantially cylindrical shape .

16. Apparatus according to any one of claims 2 to 15, and comprising driving means (25) for moving said permanent magnet means (24) between said operating position (R2) and said non-operating position (Rl) .

17. Apparatus according to claim 16, as claim 16 is appended to claim 10, wherein said driving means (25) comprises first driving means (18) , second driving means (19) and third driving means (20) for driving respectively said first permanent magnet (15) , said second permanent magnet (16) and said third permanent magnet (17) .

18. Apparatus according to claim 17, wherein said first s driving means (18) , said second driving means (19) and said third driving means (20) each comprise a pair of actuators (28, 29; 30, 31; 33) .

19. Apparatus according to claim 17, or 18, wherein said first driving means (18) , said second driving meanso (19) and said third driving means (20) are fixed to walls (26, 32) of said supporting carriage means (4) .

20. Apparatus according to any preceding claim, wherein said supporting carriage means (4) comprises a guiding element (10) arranged for acting as a guide for saids tube (3) .

21. Apparatus according to claim 20, as claim 20 is appended to claim 2, wherein said supporting element (10) comprises a peripheral surface (50) arranged for being contacted by said permanent magnet means (24)0 positioned in said operating position (R2) .

22. Apparatus according to claim 20,' or 21, as claim 20 is appended to claim 3, wherein said guiding element (10) extends substantially parallelly to said advance direction (A) . 5

23. Apparatus according to any one of claims 20 to 22, wherein said guiding element (10) has a substantially tubular shape .

24. Apparatus according to any one of claims 20 to 23, wherein said guiding element (10) is made of0 nonmagnetic material .

25. Apparatus according to any one of claims 20 to 24, wherein said guiding element (10) defines for said tube

(3) an inlet (13) into, and an outlet (14) from, said supporting carriage means (4) .

26. Apparatus according to any one of claims 3 to 25 , wherein said supporting carriage means (4) is movable substantially parallelly to said advance direction (A) .

27. Apparatus according to any preceding claim, wherein said abutting means (38) comprises an abutting portion

(40) for abutting on said internal wall (41) .

28. Apparatus according to claim 27, wherein said abutting portion (40) extends substantially parallelly to said advance direction (A) . o

29. Apparatus according to claim 27, or 28, wherein said abutting portion (40) has a substantially cylindrical shape .

30. Apparatus according to any one of claims 27 to 29, wherein said abutting portion (40) is made ofs nonmagnetic material .

31. Apparatus according to any one of claims 27 to 30, wherein said abutting means (38) comprises a connecting element (39) for connecting said portion (37) to said abutting portion (40) . 0 32. Apparatus according to claim 31, as claim 27 is appended to claim 3, wherein said connecting element

(39) extends substantially parallelly to said advance direction (A) .

33. Apparatus according to any preceding claim, ands comprising pressing roller means (43, 44) for abutting on an external wall (46) of said welded tube (3) and for cooperating with said abutting means (38) for reducing by compression said weld bead (2) .