WO2000041843A1

WO2000041843A1 - Welding machine

Info

Publication number: WO2000041843A1
Application number: PCT/GB2000/000081
Authority: WO
Inventors: Leslie Ernest Power; Reginald Taylor; Michael Anthony Brennan
Original assignee: Meltax Gmbh,
Priority date: 1999-01-13
Filing date: 2000-01-13
Publication date: 2000-07-20
Also published as: AU1994100A

Abstract

An internal pipe welding machine including a pipeline wall engaging drive system having at least one track laying drive arrangement connected to a rear part of a chassis of the internal pipe welding machine for moving the internal pipe welding machine axially within a pipeline.

Description

WELDING MACHINE

The present invention relates to internal pipe welding machines.

Known internal pipe welding machines utilise a driven wheel system to advance the internal pipe welding machine along the pipeline. However under adverse conditions such as when the pipeline has been laid in an uphill direction, or where the internal surface of the pipeline is damp, as a result of condensation from ambient air, or where such dampness has frozen due to the ambient air temperature dropping below 0 degrees centigrade, slippage can occur between the wheel drive system and the pipeline. Where the wheel drive system is driven by air motors this can result in the air tanks mounted on the internal pipe welding machine being depleted when the machine is moving independently from any external compressed air source, making it difficult to subsequently move the machine.

Thus according to the present invention there is provided internal pipe welding machine including a pipeline wall engaging drive system having at least one track laying drive arrangement connected to a rear part of a chassis of the internal pipe welding machine for moving the internal pipe welding machine axially within the pipeline.

The invention will now be described by way of example only with reference to the accompanying drawings in which;

Figures 1-5 are successive composite cross-section views of an internal pipe welding machine according to the present invention; Figure 6 is an enlarged view of part of figure 4;

Figure 7 is a cross-section view taken along the mounting axle of track laying idle arrangement 612;

Figure 8 is a cross-section view taken along the rear idle sprocket axle 644 of track laying idle arrangement 612; and

Figure 9 is an isometric schematic view of a track laying drive arrangement 612

With reference to figures 1-5 there is shown an internal pipe welding machine 10 positioned within a pipeline 1. The pipeline 1 comprises a series of pipes each of which have been welded together to ensure a fluid tight pipeline.

The internal pipe welding machine 10 enables the joint 6 between the end 4 of pipeline 1 and end 5 of adjacent pipe 3 to be welded from the inside. Additionally the joint 6 can be welded from the outside by the use of a separate external pipe welding machine.

The internal pipe welding machine 10 comprises the following major components:-

a) Nose cone assembly 20 b) Thruster assembly 30 c) A plurality of arrester assemblies 40 d) A plurality of automatic welder assemblies 50 e) An articulated joint assembly 60 f) A drive assembly 70 g) An air receiver 80 h) A command rod coupling 85, and i) A chassis 11

The nose cone assembly 20 includes a manual welder 19 including a welding torch 21 along with a spool of welding wire 22. The nose cone assembly 20 includes a plate 23 to which the thruster assembly 30 is connected. The nose cone assembly also includes a plurality of circumferentially equispaced pivotal guide arms 24 (in this case six) which are also connected to the thruster assembly 30.

Thruster assembly 30 includes a plurality of circumferentially equispaced pipe engaging clamps 31, a pair of guide wheels 32 and a rotatable ring member 33.

Mounted on ring member 33 is a plurality (in this case six) of circumferentially equispaced automatic welder assemblies 50.

A plate 61 of articulated joint assembly 60 is attached to the back of the thruster assembly 40. Attached to plate 61 is a plurality (in this case three) of circumferentially equispaced arrester assemblies 40. Each arrester assembly 40 includes an extendable shaft 41 with a positioning abutment 42 at one end.

The articulated joint assembly 60 allows the front subframe 12 of chassis 11 to articulate relative to the rear subframe 13 of chassis 11 and includes an articulated joint 62 and a plurality (in this case two) of loading wheels 63.

A plate 71 of the drive assembly 70 is attached to the back of the articulated joint assembly 60.

Drive assembly 70 includes a plurality (in this case three) of circumferentially equispaced track laying arrangements 72. Drive assembly 70 also includes 2 batteries 73 and a tank 74 of inert welding shield gas. A plate 75 of the drive assembly 70 is connected to the air receiver assembly 80.

The air receiver assembly 80 includes an air receiver tank 81.

At the front of the nose cone assembly 20 there is positioned a command rod rear coupling 85 which is releasably connected to a command rod 86. Command rod 86 is of a length such that it projects beyond the end of pipe 3 and includes at that end a command rod control panel (not shown) which can be used to control various functions of the machine and a command rod front coupling (not shown) which releasably connects the command rod to a supply of services eg. compressed air, battery charging current and welding current generators. Control signals pass down the command rod, to the machine, along with service supplies such as compressed air, welding current, and welding shield gas.

Once the internal pipe welding machine has completed a weld sequence, continued operation of the machine is as follow: -

1) An operator standing at the open end of the pipeline, ie. at the open end of the pipe that has newly been welded into place, adjacent the command rod control panel disconnects the command rod front coupling from the services and then operates the panel so as to retract the clamps and then start the air motors which in turn drive each track drive 72 so as to advance the machine along the pipeline 1 with the front subframe 12 being carried on guide wheels 32. The air motors are supplied by pressurised air from the air receiver tank 81.

The machine is advanced, pushing the control rod before it, the control rod being fed into the next pipe to be welded which has previously been located proximate the end of the pipeline. A wall proximity sensor (not shown) moulded on the machine engages the inner wall of the pipe. When the nose cone assembly 20 projects from the open end of the pipeline 1 to such an extent that the proximity sensor no longer engages the wall, the machine is automatically stopped.

2) The operator further advances the machine by operating a machine control panel (not shown), situated within the nose cone assembly and accessable to the operator, such that the automatic welder assemblies 50 project beyond the open end of the pipeline.

3) The extendable shaft 41 of each arrester assembly 40 is then extended and rotated such that the positioning abutment 42 is axially aligned with a weld plane of the welder assemblies 50 and radially aligned with the end of the pipeline.

4) The operator then reverses the machine until the positioning abutments 42 contact the pipeline and prevent further rearward movement of the machine. At this position the weld plane of the automatic welder assemblies are now aligned with the end of the pipeline (see fig 1).

5) The rearmost pipe-engaging clamps 31A are then deployed to clamp the machine securely relative to the pipeline.

6) Each positioning abutment 42 is then rotated about the axis of the extendable shaft 41, and the extendable shaft is then withdrawn such that each positioning abutment lies between two adjacent rear pipe-engaging clamps 31 A, clear of the path of the automatic welder assemblies (see below).

7) The section of pipe is then moved such that its end to be welded abuts the end 4 of the pipeline.

8) The operator then deploys the front pipe-engaging clamps 3 IB by using the command rod control panel.

9) At some convenient time following stage 1) above of the operation of the machine, and prior to welding (see below) the control rod front coupling is reconnected to the supply of services and the air receiver tank 81 can be re-pressurized if necessary.

10) Welding of the joint 6 between the pipe 3 pipeline 1 then occurs in two stages:

Firstly the automatic welder assemblies positioned at 12 o'clock, 2 o'clock and 4 o'clock (when viewing from the front of the machine) weld the joint 6 whilst the ring member 33 rotates clockwise by approximately 60 degrees ^"to weld one half of the joint 6. It should be noted that the automatic welder assemblies originally positioned at 6 o'clock, 8 o'clock and 10 o'clock are now positioned at 8 o'clock, 10 o'clock and 12 o'clock respectively. These latter automatic welder assemblies are then operated whilst the ring member is rotated sixty degrees anti-clockwise to weld the remaining half of the joint 6.

11) The operator then unclamps the front and rear pipe-engaging clamps via the command rod control panel and the machine can be advanced further along the pipeline to the next weld position.

With reference to figures 4 and 6-9 there is shown a pipe wall engaging drive system 610 comprising two track laying drive arrangements 611 positioned at the 4 o'clock and 8 o'clock positions when viewing the internal pipe welding machine from the front, and a track laying idle arrangement 612 positioned at the 12 o'clock position.

An actuating arrangement 614 allows the tracks of the drive arrangement and idle arrangement to move between a pipeline engaged position, shown at El of figure 4 and a pipeline disengaged position shown chain dotted at E2 of figure 4.

The actuating arrangement includes a double acting pneumatic actuator 620, having a body mounted on the rear subframe 13 and a ram 621 slidable relative to the body. The ram moves within tube 622 also mounted on the rear subframe 13 at a right-hand end when viewing figure 4; tube 622 includes two diametrically posed slots 623 and 624 (see figure 6). Slidable on tube 622 is a collar 625. A pin 626 is positioned within slots 623 and 624 and is secured in holes in ram 621 and also in holes in collar 625.

Actuation of the pneumatic actuator 620 between an extended and a retracted position causes the collar (also known as a actuator member) to move between a disengaged and engage position respectively ie. a position where the drive and idle arrangements are disengaged and engaged respectively with the pipeline.

The actuating arrangement includes three linkage arrangements 615, one being associated with the track laying idle arrangement and the other two being associated, one with each track laying drive arrangement. The linkage arrangements 615 are substantially similar thus only one will be described in detail as follows :-

Each linkage arrangement 615 comprises two opposite handed sets of linkage components 616 and 617 mounted one on either side of track 618.

The set of linkage components 616 includes a first pivot lug 630A secured to rear subframe 13. First link 632A is pivotally mounted via a first pivot 631 A to first pivot lug 630A. First link 632A is also pivotally mounted to axle 633 via a second pivot 634A. A second link 635A is pivotally mounted at a third pivot 636A to axle 633 and also at a fourth pivot 637A to a fourth pivot lug 638A secured to collar 625; components 630B, 63 IB, 632B, 634B, 635B, 636B, 637B, and 638B of the second set of linkage components 617 are equivalent to their correspondingly numbered components in the set of linkage components 616.

First pivot 631 therefore comprises the combination of first pivot 631 A and 63 IB. First link 632, second link 635, second pivot 634, third pivot 636 and fourth pivot 637 similarly comprise the combination of their two component parts.

In this case the second pivot 634 and the third pivot 636 have coincident axes but this need not necessarily be the case in further embodiments.

The track laying drive arrangement or track laying idle arrangement is mounted on mounting axle 633 (see below).

Extending the ram causes the collar to move axially towards the right when viewing figure 4 such that the fourth pivot 637 moves away from the first pivot 631 and the second 634 and third 636 pivots move radially in board along with the axle 633. This causes the track laying drive arrangement or track laying idle arrangement as appropriate to disengage the pipeline wall. Retraction of the ram 621 causes the fourth pivot 637 to move towards the first pivot 631 thus re-engaging the drive arrangement or idle arrangement as appropriate with the pipeline wall.

The idle arrangement 612 includes a side plate 641 secured to a bearing housing 642, the bearing housing houses a self aligning rotating element bearing 643 having an outer bearing race with a spherical surface thus allowing the bearing housing 641 to yaw and roll relative to the bearing 643. An inner race of the bearing is secured rotationally fast to axle 633. Thus in addition to the roll and yaw movements just described, the track laying idle arrangement can also pitch relative to the axle 633 by virtue of the rotating elements within the bearing 643.

A similar arrangement allows each track laying drive arrangement to pitch, roll, and yaw relative to their respective mounting axles.

A second side plate 640 is secured in spaced apart relationship to side plate 641 by spacers (not shown).

Rear idle sprocket axle 644 (see figure 8) is mounted in self-aligning bearings 645 and 646 secured to side plates 641 and 640 respectively. Sprocket 645 is secured rotationally fast to sprocket mount 646 which in turn is secured rotationally fast to rear sprocket axle 644. A similar arrangement (not shown) secures a front idle sprocket to side plates 641 and 640 but additionally allows movement of the front idle sprocket axle toward and away from the rear idle sprocket axle to tension the track 618.

Each tracking laying drive arrangement (see figure 9) includes side plates 650 and 651, mounting axle 652, front axle 653, front sprocket 654, track 655, rear axle 656 and rear sprocket 657 equivalent to those components on the track laying idle arrangement. The track laying drive arrangement 611 further includes a front sprocket air actuated motor 658 connected to the front axle via front gear box 659, rear air actuated motor 660 connected to the rear axle 656 via rear gear box 661, and brake rear disc 662 also connected to rear axle 656. Brake calliper 663 is mounted via mounting arrangement 664 onto side plate 651. By operating the actuating arrangement the two track laying drive arrangements and the track laying idle arrangement can be forced into engagement with the pipeline wall to provide for increased friction between the tracks of the drive arrangements to enable the internal pipe welding machine to move along the pipeline under adverse conditions eg. up gradients, or when the pipeline wall is damp. The idle arrangement does not provide any drive but does allow the track laying drive arrangement to be loaded against the pipeline wall.

The reduction ratio in gear box 661 is different to that in gear box 659 thus when motor 660 is driving. rear axle 656 (and motor 658 is idling) the internal pipe welding machine progresses at a first speed which is different from when motor 658 is driving front axle 653 (and motor 660 is idling). Thus it is possible to provide an internal pipe welding machine that can travel along a pipeline at two different speeds.

By actuating brake calliper 663 to brake the disc 662 the internal pipe welding machine can be braked through the pipe wall engaging drive system ie. through track 655.

In further embodiments the disc 662 and calliper 663 can be mounted on any of the front or rear sprocket axles of any of the track laying drive arrangements or the track laying idle arrangements.

Calliper 663 includes disengaging pistons which are biased towards the disc 622 by a braking spring. The callipers operate such that supply of compressed air forces the pistons away from the brake disc 662 to release the brake. This arrangement is therefore a fail-safe arrangement wherein loss of air pressure causes the brake to be applied.

It should be noted that such a braking system uses less air than heretofore known arrangements which act by forcing brake shoes into direct engagement with the inner wall of the pipeline.

It should also be noted that by providing an internal pipeline welding machine which can move at two different speeds the consumption of air is minimised when compared to heretofore known internal pipeline welding machines.

Claims

1. An internal pipe welding machine including a pipeline wall engaging drive system having at least one track laying drive arrangement connected to a rear part of a chassis of the internal pipe welding machine for moving the internal pipe welding machine axially within a pipeline.

2. An internal pipe welding machine as defined in claim 1 in which the track laying drive arrangement includes a rear sprocket driven by a rear motor to move the internal pipe welding machine within the pipeline.

3. An internal pipe welding machine as defined in claim 1 or 2 in which the track laying drive arrangement has a front sprocket driven by a front motor to move the internal pipe welding machine within the pipeline.

4. An internal pipe welding machine as defined in claim 2 or 3 in which the front or rear sprocket is driven from the respective motor via a respective gear box.

5. An internal pipe welding machine as defined in claim 3 or 4 when dependent on claim 2 in which the rear motor produces a track speed different from that produced by the front motor to enable the internal pipe welding machine to travel at two different speeds within the pipeline.

6. An internal pipe welding machine as defined in claim 5 in which the two different track speeds are produced as a result of the front and rear gear boxes having different reduction ratios.

7. An internal pipe welding machine as defined in any previous claim in which the pipeline wall engaging drive system further includes a track laying idle arrangement for loading the track laying drive arrangement against the pipeline wall.

8. An internal pipe welding machine as defined in any previous claim in which the tracking laying drive or idle arrangement is rotatable in at least one of a pitch, roll or yaw direction relative to the said rear part of the chassis.

9. An internal pipe welding machine as defined in any proceeding claim in which the track laying drive or idle arrangement is mounted at a position between the front and rear sprockets.

10. An internal pipeline welding machine as defined in claim 9 in which the track laying drive or idle arrangement is mounted via a circle bearing.

11. An internal pipe welding machine as defined in any proceeding claim in which the front or rear sprockets of the track laying drive arrangement or idle arrangement are braked.

12. An internal pipe welding machine including track laying drive arrangements as defined in any proceeding claim and one track laying idle arrangement as defined in any one of claims 7-11.

13. An internal pipe welding machine as defined in any proceeding claim in which the pipeline wall engaging drive system is actuable by an actuating arrangement between a pipeline engaged position and a pipeline disengaged position.

14. An internal pipe welding machine as defined in claim 13 including a first link pivoted at one end by a first pivot to the rear part of the chassis, and being pivoted at a second end by a second pivot to a track laying drive arrangement, and a second link pivoted at one end by a third pivot to the track laying drive arrangement and pivoted at a second end by a fourth pivot to an actuator member, the forth pivot being moveable towards and away from the first pivot to engage and disengage the pipeline wall engaging drive system.

15. An internal pipe welding machine as defined in claim 14 in which the second and third pivots have coincident axes.

16. An internal pipe welding machine as defined in claim 14 or 15 in which at least one of the first or second or third or fourth pivots is in the form of a pair of pivots.

17. An internal pipe welding machine as defined in any one of claims 14-15 in which at least one of the first or second links is in the form of a pair of links.

18. An internal pipe welding as defined any one of claims 14-16 in which the actuator member moves axially relative to the pipeline axis.

19. An internal pipe welding machine as defined in any one of claims 14-17 in which the actuator member is moved by an actuator.

20. An internal pipe welding machine as defined in any one of claims 14-18 in which the actuator member is a collar slidable on a shaft.

21. An internal pipe welding machine as defined in anyone of claims 14-19 in which there are a plurality of track laying drive arrangements.

22. An internal pipe welding machine as defined in claim 20 including a track laying idle arrangement for loading the drive arrangement against a pipeline wall.

23. An internal pipe welding machine as defined in claim 20 or 21 in which the actuator member is common to all track laying drive and idle arrangements