LASER CONTROLLED INTERNAL WELDING MACHINE FOR A PIPELINE

Abstract

The present invention is directed to a system for welding together segments of a pipeline. The system includes an external alignment mechanism for externally supporting and manipulating the orientation of pipe segments in order to align relative segments. The system also includes an internal welding mechanism for applying a weld to an interior face joint of the two abutted pipe segments. The internal welding mechanism including a torch for applying a weld, a laser for tracking the weld profile and guiding an articulating head of the torch, and a camera for visually inspecting the weld after the weld is applied.

Description

FIELD OF THE INVENTION

The present invention is directed to a system for aligning and connecting two pipe segments together by welding.

BACKGROUND OF THE INVENTION

Conventional internal welders frequently include internal alignment mechanisms that expand radially outward to contact the interior of the pipe. Alignment of the two pipe segments is accomplished from inside when extension members of a central member contact the interior of the pipe relatively close to the pipe segment joint faces on either side of the joint as shown in U.S. Pat. Nos. 3,461,264; 3,009,048; 3,551,636; 3,612,808 and GB 1261814 (which is each incorporated herein by reference in its entirety). In order to weld the joint, the structure of the expander must allow sufficient space to accommodate a rotating torch. It would therefore be advantageous to provide internal alignment that allows sufficient space for a rotating or articulating torch or to align the pipe segments externally so as to eliminate the need for an internal expander which may create significant internal clutter.

In addition, the conventional process of internal welding usually involves internal or external alignment and an insertion of the internal welder so that torches align with the face joint. In this process it is sometimes difficult to assess the accuracy of positioning of the internal welder in general and the torch in particular. It is even more difficult to assess the accuracy of the position of the torch as the torch traverses the inside of the pipe along its orbital path during welding. It would therefore be advantageous to provide a system of tracking the structure of or positioning of pipe edges at the pipe interface in order to control the torch by use of the tracked condition of the interface. Specifically, it would be advantageous to first track a profile of the interface with a laser before sending a signal to an electronic controller to direct the position and orientation of the welding torch relative to the tracked pipe interface profile.

Furthermore, conventional pipeline welding systems that employ external alignment mechanisms typically support two segments on rollers and manipulate the position and orientation of the segments until alignment is satisfactory. Whether an alignment is satisfactory typically will depend, for example, on industry acceptable high-low gauges that are fairly accurate but are manually operated and positioned at discrete locations and not over the entire pipe interface. In any case, the profile or structure of the interface as observed from the inside of the pipe is not typically a consideration for quality of alignment. It would therefore be advantageous to provide an alignment system in which information about the interface profile as read by the laser is used as an input parameter during the external alignment process. Specifically, it would be advantageous to provide the information from the torch controlling laser to the controller which would utilize the information in controlling external alignment mechanisms.

Moreover, conventional pipeline systems for welding pipe segments will typically lack a capability to visually inspect the weld applied by the torch. It therefore would be advantageous to provide a camera that followed the torch weld application and a display for showing an image of the weld in order for an operator to visually inspect the quality of the weld.

Other advantages of the present disclosure will be apparent by review of this disclosure. Patentable advantages are not limited to those highlighted in this section.

SUMMARY OF THE INVENTION

The present invention system for aligning and welding together the faces of two pipe segments includes an external alignment mechanism and a welding mechanism. The external alignment mechanisms may be as sophisticated as the line up modules shown in the drawings or as simple as a tipton clamp as illustrated in U.S. Pat. No. 1,693,064. The mechanisms used may also be suitable for on or off shore pipeline construction. U.S. Pat. No. 1,693,064 is incorporated herein by reference in its entirety. Whatever mechanism is employed, the external alignment mechanism supports and adjustably positions each segment so that the segments are substantially collinear or axially aligned along their longitudinal axes.

The external alignment mechanism may support a pipe segment and may include powered features that allow the position and orientation of the pipe to be adjusted. Specifically, the external alignment mechanism may include rollers that allow the pipe to move longitudinally. The pipe may also be supported by rollers that allow the pipe to be rolled about the longitudinal axis and moved up and down. The position and orientation adjustments may be automatic as by motor power or hydraulic power controlled at an operator station or fed into a central controller that automatically controls an aligns the segments based on predetermined alignment parameters or feedback from an internal laser reading an interface or joint profile.

The welding mechanism is preferably an internal welding machine that applies a weld (e.g., a gas metal arc weld “GMAW”) from inside the pipe segments to a face or edge joint of the segment and into a v-shaped opening formed by chamfered edges of the two pipe segments (other cross-sectional shapes other than a V may be used also). The welding mechanism includes a carriage capable of engaging the inner walls of the pipe to secure or lock itself within the pipe in a fixed position and a welding portion rotatably supported from the carriage within the pipe. Specifically, the internal welder is located within the aligned pipe and then positioned longitudinally so that a weld head or torch is in longitudinal proximity to the edge joint. The welding mechanism also includes a rotary mechanism for rotating the welding portion relative to the carriage. The weld head or torch is rotatably supported on the welding portion about the pipe longitudinal axis so that the torch may closely follow the entire interior joint interface in an orbital rotation. Specifically, during welding, the torch of the articulating head follows the edge joint around the entire interior circumference of the pipe applying weld material. In addition to circular rotation relative to the carriage, various control elements may move the weld head axially along the pipe relative to the carriage, radially toward and away from the joint, and pivotally about a point or axis (e.g., an axis parallel or perpendicular to pipe longitudinal axis A-A). A controller may direct the torches pivoting. These degrees of freedom of articulation allow the weld head to be very effective and efficient in filling in interface profiles optimally and where necessary.

The welding mechanism also includes a laser tracking mechanism that works in conjunction with the torch of the welding portion to sense interface joint profile or/and weld material profile to apply weld material to the edge joint in the appropriate location and amount. The laser mechanism surveys the weld and sends a signal to the controller of the articulating weld head to control movement of the head around the entire edge joint. Specifically, the torch follows the laser as the weld head control system continuously receives weld profile information from the edge joint. The information is then used to continuously adjust the torch to achieve the desired weld structure.

In addition to the laser tracking mechanism, the system may include a 2D camera for visual inspection of the weld. The 2D camera is mounted on the welding portion and follows the torch so that an operator can inspect the weld as soon as it is created by the torch. A visual signal is delivered to an external operator display. For example, the 2D camera may be a color camera and a change in coloration may indicate a weld defect to the operator. A perceived change in profile may also indicate a defect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a pipe welding system of the present invention showing two externally aligned pipe segments supported on alignment mechanisms.

FIG. 2 illustrates an enlarged external view of a pipe interface of two segments to be welded using the system of FIG. 1.

FIG. 3 illustrates the system of FIG. 1 showing a welding mechanism inserted into a segment according to FIG. 1.

FIG. 4 illustrates an enlarged view of a section of FIG. 3 showing the welding portion of the welding mechanism positioned for welding in a pipe segment according to FIG. 1.

FIG. 5 illustrates a cross-sectional view of FIG. 4 cut through B-B showing the arrangement of various weld portion elements.

FIGS. 6 and 7 illustrate side views of the welding mechanism of FIG. 1.

FIG. 8 illustrates a perspective view of the system of FIG. 1 in a configuration showing a first step of use in which a pipe segment is place on an external alignment mechanism.

FIG. 9 illustrates a perspective view the system of FIG. 1 in a configuration showing a step subsequent to FIG. 8 in which a welding mechanism is inserted into a pipe segment.

FIG. 10 illustrates a side view of the welding portion of the system of FIG. 1.

FIG. 11 illustrates an enlarged perspective view of a section of the welding portion of the system of FIG. 1.

FIG. 12 illustrates another enlarged perspective view of a section of the welding portion of the system of FIG. 1.

FIG. 13 illustrates an enlarged perspective view of the rotary mechanism of the system of FIG. 1.

Like reference numerals have been used to identify like elements throughout this disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-3, the system for welding pipeline segments together is described as follows. FIG. 1 shows an external alignment mechanism 10A and 10B which is capable of supporting, positioning, and repositioning multiple lengths of pipeline. Each mechanism 10A and 10B may include supports (e.g., rollers) upon which a length of pipeline may be supported. A longitudinal roller 12 moveably supports pipeline segment 105 such that segment 105 may be repositioned along its longitudinal direction defined by arrow A. In addition, rotational rollers 14 are rotatable about an axis parallel to axis A-A of support segment 105 on either side of segment 105 enabling them to rotate or adjust the angular orientation of segment 105 about axis A-A. External alignment mechanism 10 is able to automatically manipulate multiple segments into various positions and orientations via motors, hydraulics, etc. For example the segments may be raised, lowered, rotated, tilted, pivoted, etc.

As shown in FIG. 1, external alignment mechanisms 10A and 10B support multiple segments 105, 110 and adjust their position and orientation until segments 105, 110 are both aligned such that their longitudinal axes A-A are collinear and one end of each of the segments 105, 110 abuts at interface edges. Specifically, FIG. 2 illustrates an enlarged view of detail 100 of FIG. 1 in which the edges form a pipe interface 120 (known as a “fit up” joint).

The pipeline aligning and welding system of the present invention applies a weld to the interior of the interface 120 from inside the fitted up segments 105, 110. To apply a weld to the interior of joint 120, an internal welding mechanism 300 is rolled into an end of one of the segments 105 as shown in FIG. 3. A second segment 110 is then placed on external alignment mechanism 10B and manipulated until both segments 105, 110 are satisfactorily aligned. An external force may then be applied to a reach rod 345 of the internal welding mechanism 300 or the mechanism may include automatic self propulsion means for adjusting its axial position within the aligned segments 105, 110.

As shown in FIGS. 4 -7, welding mechanism 300 includes a carriage 301 and a welding portion 302. Carriage 301 includes at least one alignment mechanism 340A, 340B which may expand radially to engage the interior surface of segments 105 or 110. This expansion and engagement both secures the axial/longitudinal position of welding mechanism 300 relative to segment 105, 110 and aligns or radially centers welding mechanism 300 within segments 105, 110. Carriage 301 also includes a body 311 on which rotating mechanism 335 is supported. Body 311 is comprised of multiple elongated structural support members that extend between alignment mechanism 340A and 340B. As discussed below welding portion 302 includes a similar corresponding structure 313.

Welding portion 302 is rotatably connected to carriage 301 and extends from an end of carriage 301. The relative rotation between carriage 301 and welding portion 302 is facilitated by a rotary mechanism 335. Rotary mechanism 335 is secured to carriage 301 and automatically (via a motor and gears) rotates welding portion 302 relative to carriage 301 about longitudinal axis A. Welding portion 302 may be cantilevered from carriage 301 or may be supported by an additional alignment mechanism 340C located so that torch 305 is positioned between alignment mechanisms 340B and 340C. When alignment mechanism 340C is provided, welding portion 302 is rotatable relative to and between both alignment mechanisms 340B and 340C when alignment mechanisms 340B and 340C expand to secure themselves to the interior of a segment. Furthermore, carriage 301 may include a reach rod 345 which can be structured as an elongated extension from carriage 301 which an operator may grasp to insert/push or retract/pull welding mechanism 300 to axially position it within a segment 105, 110.

FIG. 4 shows an enlarged view of section 200 of FIG. 3 in which only segment 105 is present and segment 110 is absent. As shown in FIG. 4, welding portion 302 includes a welding group 303 which comprises a torch 305, a laser sensor 310, and a color camera 320. Welding portion 302 further has a body 313 on which torch 305, laser sensor 310, and color camera 320 are supported. Laser 310 tracks an interior joint of segments 105, 110, and detects an interface profile to be used to position torch 305 in applying a weld to the joint interface. Body 313 extends between alignment mechanism 340B and 340C. Section 200 shows welding mechanism 300 located inside segment 105 with torch 305 generally pointed in a radially outward direction and positioned to apply a weld to face joint 120. FIG. 5 shows an embodiment of a general schematic cross-sectional view of welding mechanism 300 through section B-B which shows welding group 303 looking in the direction of insertion of welding mechanism 300. FIG. 5 also shows a direction D of rotation of welding group 303 when it is rotated by rotary mechanism 335. Therefore, a welding action on a particular point along weld joint 120 will first be acted on by laser sensor 310 followed by torch 305 and finally by 2D inspection camera 320.

FIGS. 10-12 illustrate multiple perspectives of the welding portion 302. FIG. 10 shows a wire delivery system 322. Wire delivery system 322 includes a wire spool storage 323, an optional wire straightener 325, and a wire feed mechanism 330 which is automatically controlled to deliver the appropriate amount of wire to torch 305. As rotary mechanism 335 rotates welding portion 302, wire is fed to the torch 305 by wire delivery mechanism 322.

As mentioned above, torch 305 may be positioned and oriented in multiple ways by multiple mechanisms. Torch 305 is supported on a manipulator. The manipulator includes a radial positioner, an axial positioner and a pivoter. Specifically, a radial positioner 307 (e.g., a rack and pinion) on which torch 305 is supported is capable of moving the torch radially toward and away from the interior surface of segments 105, 110. In other words, towards and away from the interface of segments 105, 110 to be welded. In addition, an axial positioner 309 (e.g., a rack and pinion) may move torch 305 axially within segments 105, 110. The manipulator also includes a pivoter 308 that allows the torch to pivot (e.g., about an axis parallel to segment longitudinal axis A-A). Pivotal movement by pivoter 308 may be powered by a motor and gears 306. For example, the motor may be a stepper motor.

The torch manipulator may compound the manipulative movements of the above mentioned elements by dependently supporting the elements. For example, body 313 may support the axial positioner which in turn supports the radial positioner which in turn supports the pivoter which in turn supports the torch. Similarly, the axial positioner may be supported by the radial positioner. Furthermore, any order of support may be employed.

The elements of the manipulator are controlled by a controller which receives as input, a series of signals including a signal from laser 310 and then processes the information before transmitting a signal to at least radial positioner 307, axial positioner 309, pivoter 308, and wire delivery system 322. Torch 305 is then repositioned and reoriented continuously according to predetermined parameters of the controller based on signals from profile reading laser 310.

The operation of the present invention internal welding system will now be described. FIGS. 1, 8 and 9 illustrate the process of positioning and welding segments 105 and 110 together. In operation, one or more of the following lettered steps may be executed so that: a) a pipe segment 105 is placed on alignment device/pipe stand 10A; b) internal welding machine 300 is then inserted into pipe segment 105; c) a second pipe segment 110 is then aligned with pipe segment 105 and welding mechanism 300 is pulled forward by reach rod 345 or automatically driven so that torch 305 generally lines up with faces joint 120 of pipe segments 105, 110; d) alignment mechanisms 340A, 340B (and if necessary 340C) are then engaged to secure welding mechanism 300 within pipe segments 105, 110; e) in one embodiment (optional), rotary mechanism 335 rotates weld head 305 to perform an initial scan of interface joint 120 of pipe segments 105, 110 by laser sensor device 310 to ensure optimal fit up; f) if required, steps (c), (d) and (e) may be repeated, i.e. pipe segments 105, 110 are realigned/rotated and rescanned by laser 310, to improve “fit up”; g) optionally, internal alignment mechanism 340C on the rear of the welding mechanism 300 is engaged to hold the axial position of welding mechanism 300 with respect to both pipe sections 105, 110; h) with welding mechanism 300 secure in pipe segments 105 and 110, the root weld (first weld) cycle begins so that laser 310 scans pipe interface 120, torch 305 follows laser 310, and the output from laser 310 is used to control the position of articulated torch 305, where the position and orientation of torch 305 with respect to the interface 120 is controlled so as to produce the best quality weld; i) in addition to a signal from laser 310, thru the arc current monitoring can also be used in directing the torch position; j) after the completion of a 360° weld, weld head 305 is rotated back to an original position; k) the profile (using laser 310) and the visual inspections (with 2D color camera 320) are performed either in the previous step (j) or on a separate inspection run; 1) after inspection, aligning mechanism 340A-C are released and welding mechanism 300 is pulled or driven forward towards the open end of welded pipe 105, 110 and with the nose of welding mechanism 300 exposed, like (b), pipe segment 110 is placed on external alignment mechanism 10B and advanced to the next joint; m) steps (c) to (1) are then repeated for the entire production run.

In one embodiment, a signal from laser sensor 310 is sent to an electronic controller of external alignment mechanism 10 to automatically reposition one or both of segments 105, 110 for a more desirable face joint 120 arrangement. Furthermore, the foregoing steps may be executed in the stated order. However, variations in the order are also contemplated.

In another embodiment, instead of stopping after the first 360° weld, the rotation is continued to lay another weld pass, the laser could be used to inspect & track simultaneously while the trailing 2D color camera continues inspection after the second weld.

In still another embodiment, instead of welding a complete 360° weld, the weld is performed in two 180° halves with the same start position. This implementation would require either multiple laser sensors for tracking or a mechanism to physically oscillate the laser and/or the torch in order to maintain the tracking sensor's lead position in both directions of rotation (i.e., rotate the torch and laser so that they switch positions).

While the present invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. It is to be understood that terms such as “top”, “bottom”, “front”, “rear”, “side”, “height”, “length”, “width”, “upper”, “lower”, “interior”, “exterior”, and the like as may be used herein, merely describe points of reference and do not limit the present invention to any particular orientation or configuration.

Claims

1. A system for aligning and welding together two segments of a pipe: a welding mechanism for applying a weld to a face joint of the two segments, the welding mechanism including an articulating torch, a laser sensor for reading a profile of the face joint, and an electronic controller for receiving information signals from the laser sensor to control the position and/or orientation of the torch;an alignment mechanism for manipulating the orientation of the longitudinal axis of at least one of the segments relative to the other; andwherein the welding mechanism further includes a carriage for securing a position of the welding mechanism in the pipe and a welding portion capable of rotating relative to the supporting portion within the pipe; andwherein the torch and the laser sensor are rotatably supported by the welding portion such that during welding, the torch follows the laser sensor along the face joint.

2. The system of claim 1 wherein, the weld mechanism further includes a camera for optically sensing a joint face.

3. The system of claim 1 wherein, the articulating movement of a torch head on the torch may include one of radial translation movement toward and away from the face joint, translation movement in a direction of the longitudinal axis of the segments, pivotal movement relative to the weld mechanism about an axis that is parallel to the pipe segment longitudinal axis and pivotal movement relative to the weld head about an axis that is perpendicular to the pipe segment longitudinal axis.

4. The system of claim 1 wherein, the alignment mechanism manipulates the orientation of the at least one segment by contact with an exterior of the at least one segment.

5. The system of claim 1, wherein the electronic controller receives a signal from the laser sensor to direct the alignment mechanism to adjust the relative positions of the pipe segments based on predetermined alignment parameters.

6. The system of claim 1 wherein, the weld mechanism rotates within and relative to an interior of a face joint of two segments so that the torch follows the laser sensor, the laser sensor providing continuous face joint profile data to the electronic controller which in turn continuously directs the positioning of the torch.

7. The system of claim 2 wherein, the camera follows the torch along a weld joint path, the camera sending a signal to an operation station display to allow an operator to inspect an image of a portion of the weld.

8. A method of aligning and welding together two segments of a pipe comprising the steps of: placing a first pipe segment on an alignment device;inserting an internal welding machine having a laser and a weld torch into the first pipe segment;generally aligning a second pipe segment with the first pipe segment and internal welding machine;griping an external portion of the first and second pipe segments to adjusting an axial position of the internal welding machine so as to generally line up with a face joint of the first and second pipe segments;adjusting a relative alignment of the first and second pipe segments via the alignment device based on a signal from the internal welder;beginning a root weld cycle in which the laser scans the face joint, the torch follows the laser, and the output from the laser is used to control the position of articulated torch, where the position and orientation of the torch with respect to the face joint is controlled to produce a quality weld;determining a face joint profile from the laser;releasing the alignment device and removing internal welding machine from an open pipe segment end; andrepositioning a next sequential pipe segment on the external alignment mechanism in preparation for welding of a next joint.

9. The method of claim 8, further comprising the steps of providing a rotary mechanism on which the laser and torch rotate to perform an initial scan of the face joint by laser sensor; and; generating a signal from the rotating laser to direct alignment of the first and pipe second by the alignment device before welding begins.