A welding device and method for large-section pipes for petrochemical use

Abstract

The present invention belongs to the field of pipeline welding technology, specifically a welding device and method for large-cross-section pipes used in the petrochemical industry. The device comprises a positioning platform mounted with a rotating travel mechanism, a centering support mechanism provided on the sidewall of the rotating travel mechanism, a groove grinding mechanism provided on the side of the rotating travel mechanism remote from the centering support mechanism, and a welding machine connected to the rear of the sidewall of the rotating travel mechanism near the groove grinding mechanism via a second support plate. The present invention can perform pre-weld cleaning on different grooves of different large-size pipes and can also clean the coating of multi-layer weld beads during welding to improve welding quality.

Description

Technical Field

[0001] The present invention belongs to the technical field of pipeline welding, and in particular relates to a pipeline welding device and a welding method for a petrochemical industry with a large cross-section. Background Art

[0002] Large-sized petrochemical pipelines are made by welding multiple pipe sections together during installation. The quality of welding has a significant impact on the operation of petrochemical pipelines.

[0003] First of all, before welding large-size pipes, the welding groove needs to be polished and cleaned to ensure the cleanliness of the weld and prevent the occurrence of weld defects.

[0004] Secondly, when welding large-scale pipes, multiple weld filler passes are required to improve weld quality and strength. During welding, a base weld is first performed, followed by multiple filler welds on top of the initial weld to improve weld quality. Before each weld, the coating of the previous weld must be knocked off to prevent slag inclusion defects in the current weld.

[0005] However, when welding large-sized pipes, welders cannot move along the pipe surface, and the pipes cannot be rotated during on-site welding, making the welding operation extremely difficult. At the same time, the paths for cleaning the grooves and the coating are far longer than those for ordinary pipes, greatly increasing the workload of welders. Summary of the Invention

[0006] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a welding device and a welding method for large-section pipes for petrochemical use, which at least partially solve the above problems.

[0007] In a first aspect, the present invention provides a large-section pipe welding device for petrochemical use, comprising a positioning platform, which plays a supporting and positioning role during on-site operations.

[0008] Furthermore, a circling walking mechanism is installed on the positioning platform, and a centering support mechanism is provided on the side wall of the circling walking mechanism. The circling walking mechanism can rotate relative to the centering support mechanism to achieve the effect of circumferential pipe welding.

[0009] Furthermore, a groove grinding mechanism is provided on a side of the orbiting walking mechanism away from the centering support mechanism.

[0010] Furthermore, the side wall of the circling walking mechanism is connected to a welding machine through a second support plate near the rear of the groove grinding mechanism, and the operating height and operating radius of the welding machine can be automatically adjusted; the centering support mechanism is fixed on the outer wall of the pipeline, and the pipeline supports the centering support mechanism, and the centering support mechanism can locate the center of the pipeline, so that the circling walking mechanism can drive the groove grinding mechanism and the welding machine to rotate around the center of the pipeline, and perform groove grinding, welding, skin removal and cover welding on the pipeline.

[0011] Furthermore, the circling walking mechanism includes a walking motor, a driving wheel and a driven wheel. The walking motor is arranged on the positioning platform, the driving wheel is arranged at the output end of the walking motor, and the driven wheel is engaged with the driving wheel.

[0012] Furthermore, in order to facilitate the positioning of the center of the pipeline for subsequent circumferential welding, the centering support mechanism includes a centering plate and a centering rod. The centering plate surrounds the outer wall of the pipeline, and the centering rod has multiple groups of threads passing through the centering plate. There are at least three groups of centering rods to locate the center of the pipeline.

[0013] Furthermore, the driven wheel rotates on the side wall of the centering disk.

[0014] Furthermore, the centering rods are provided with scales so that the screwing depth of each set of centering rods is the same, thereby positioning the center of the pipeline.

[0015] Furthermore, the groove grinding mechanism includes a grinding motor, a telescopic rod and a grinding disc. The grinding motor is fixed to the side wall of the driven wheel through a support plate. The telescopic rod is connected to the output end of the grinding motor through a gear set. The telescopic rod rotates with the grinding motor to grind the groove of the pipeline or grind the coating on the surface of the multi-layer weld. The telescopic rod can be telescopically fixed to adapt to the different outer diameters of the multi-layer weld. Multiple groups of grinding discs are hinged to the bottom end of the telescopic rod, and the grinding discs can grind grooves of different angles.

[0016] Furthermore, the gear set includes bevel gear 1 and bevel gear 2, wherein bevel gear 1 is arranged at the output end of the grinding motor, and bevel gear 2 is arranged at the top end of the telescopic rod, and bevel gear 1 and bevel gear 2 are meshed and connected.

[0017] Furthermore, a spring is connected between the grinding disc and the telescopic rod, and an array of beveled slots is provided at the bottom end of the telescopic rod. A positioning pin is provided in the beveled slot, and the grinding disc is hinged in the positioning pin. The grinding disc can be automatically pushed outward under the action of the spring, so that the grinding disc fits the groove, so as to grind grooves of different slopes and widths.

[0018] Furthermore, the driven wheel is composed of two symmetrical half gear rings.

[0019] Furthermore, the centering disk is composed of two symmetrical open disks, a boss is provided on the side of the open disk close to the driven wheel, the half gear ring is rotatably mounted on the boss, and a shoulder is provided on the outer side of the boss to prevent the half gear ring from falling off. The upper surface of the open disk is provided with an array of lifting holes, and the end of the open disk is provided with a connecting flange;

[0020] Furthermore, the symmetrical opening plates on both sides are fixed by connecting flanges, the centering rod is threadedly connected to the lifting hole, and a grooved pressure plate is provided at the bottom of the centering rod. By rotating the centering rod, the grooved pressure plate at the bottom of the centering rod is pressed tightly against the pipe, and the values ​​of the scales on each centering rod are kept consistent, thereby completing the positioning of the center of the pipe.

[0021] Furthermore, two groups of positioning grooves are provided on the front and rear of the half gear ring, and the support plate 1 and the support plate 2 are respectively provided in the two groups of positioning grooves.

[0022] In a second aspect, the present invention further provides a method for welding a large-section pipe for petrochemical use, comprising the following steps:

[0023] S1. Clamp two sets of symmetrical open discs onto the pipe and connect and secure them via connecting flanges.

[0024] S2. Twist the centering rod toward the center of the pipe to make it initially contact with the outer wall of the pipe;

[0025] S3. Adjust the centering rods in each direction one by one so that the scales on the centering rods in each direction are the same;

[0026] S4. Install the two sets of half gear rings on the boss, and then splice and fix the two sets of half gear rings;

[0027] S5. Install the groove grinding mechanism in the positioning groove of the driven wheel through the support plate 1, and install the welding machine in another positioning groove on the driven wheel through the support plate 2;

[0028] S6. Adjust the position of the travel motor and the driving wheel through the positioning table so that the driving wheel and the driven wheel are engaged;

[0029] S7. Adjust the length of the telescopic rod to make the grinding disc fit the groove;

[0030] S8, start the travel motor and the grinding motor, so that the groove grinding mechanism and the welding machine complete the first round of grinding and welding;

[0031] S9. Re-adjust the telescopic rod so that the grinding disc fits the first circle of weld to grind the coating. Repeat the above steps.

[0032] The beneficial effects achieved by the present invention using the above structure are as follows:

[0033] 1. The centering support mechanism, under the action of the centering plate and the centering rod, can center large-sized petrochemical pipelines with different diameters, so that the groove grinding mechanism and the welding machine can perform pre-weld grinding and welding operations;

[0034] 2. The groove grinding mechanism can adapt to grooves of different slopes and widths under the action of the grinding disc and spring, and the equipment has strong versatility;

[0035] 3. Under the action of the telescopic rod, the groove grinding mechanism can also be telescopically adjusted in the height direction to adapt to pipes of different diameters and realize the groove grinding of pipes of different diameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A side view of an embodiment of the present invention;

[0037] Figure 2 Schematic diagram of the structure of an embodiment of the present invention;

[0038] Figure 3 It is a partial cross-sectional view of the structural diagram of the groove grinding mechanism;

[0039] Figure 4 It is a structural diagram of the telescopic rod head;

[0040] Figure 5 for Figure 3 Enlarged view of part I;

[0041] Figure 6 The exploded diagram of the driven wheel and the centering support mechanism;

[0042] Figure 7 Schematic diagram of the structure of the open disk.

[0043] Among them, 1. Positioning table, 2. Surrounding walking mechanism, 3. Centering support mechanism, 4. Bevel grinding mechanism, 5. Welding machine, 6. Travel motor, 7. Driving wheel, 8. Driven wheel, 9. Centering plate, 10. Centering rod, 11. Support plate 1, 12. Grinding motor, 13. Bevel gear 1, 14. Bevel gear 2, 15. Telescopic rod, 16. Grinding disc, 17. Spring, 18. Bevel notch, 19. Locating pin, 20. Half gear ring, 21. Open plate, 22. Positioning groove, 23. Slotted pressure plate, 24. Support plate 2, 25. Boss, 26. Lifting hole, 27. Connecting flange.

[0044] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention but do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0047] like Figure 1 As shown, the present invention provides a large-section pipe welding device for petrochemical use, comprising a positioning platform 1, which plays a supporting and positioning role during on-site operation.

[0048] A circling walking mechanism 2 is installed on the positioning platform 1, and a centering support mechanism 3 is provided on the side wall of the circling walking mechanism 2. The circling walking mechanism 2 can rotate relative to the centering support mechanism 3 to achieve the effect of circumferential pipe welding.

[0049] A groove grinding mechanism 4 is provided on a side of the orbiting walking mechanism 2 away from the centering support mechanism 3 .

[0050] The side wall of the circling walking mechanism 2 is connected to a welding machine 5 through a support plate 24 near the rear of the groove grinding mechanism 4. The operating height and operating radius of the welding machine 5 can be automatically adjusted; the centering support mechanism 3 is fixed on the outer wall of the pipeline, and the pipeline supports the centering support mechanism 3, and the centering support mechanism 3 can locate the center of the pipeline, so that the circling walking mechanism 2 can drive the groove grinding mechanism 4 and the welding machine 5 to rotate around the center of the pipeline to perform groove grinding, welding, descaling and cover welding on the pipeline.

[0051] like Figure 1 and Figure 2 As shown, the orbiting walking mechanism 2 includes a walking motor 6, a driving wheel 7 and a driven wheel 8. The walking motor 6 is arranged on the positioning platform 1, the driving wheel 7 is arranged at the output end of the walking motor 6, and the driven wheel 8 is engaged with the driving wheel 7.

[0052] In order to facilitate the positioning of the center of the pipeline for subsequent circumferential welding, the centering support mechanism 3 includes a centering disk 9 and a centering rod 10. The centering disk 9 surrounds the outer wall of the pipeline, and multiple groups of threads of the centering rod 10 pass through the centering disk 9. There are at least three groups of centering rods 10 to locate the center of the pipeline.

[0053] The driven wheel 8 rotates on the side wall of the centering disk 9.

[0054] The centering rods 10 are provided with scales so that the screwing depth of each group of centering rods 10 is the same, thereby positioning the center of the pipeline.

[0055] like Figure 3 As shown, the groove grinding mechanism 4 includes a grinding motor 12, a telescopic rod 15 and a grinding disc 16. The grinding motor 12 is fixed to the side wall of the driven wheel 8 through a support plate 11. The telescopic rod 15 is connected to the output end of the grinding motor 12 through a gear set. The telescopic rod 15 rotates with the grinding motor 12 to grind the groove of the pipeline or grind the coating on the surface of the multi-layer weld. The telescopic rod 15 can be telescopically fixed to adapt to the different outer diameters of the multi-layer weld. Multiple groups of grinding discs 16 are hinged to the bottom end of the telescopic rod 15, and the grinding discs 16 can grind grooves of different angles.

[0056] The gear set includes a bevel gear 13 and a bevel gear 2 14 . The bevel gear 13 is arranged at the output end of the grinding motor 12 , and the bevel gear 2 14 is arranged at the top end of the telescopic rod 15 . The bevel gear 13 and the bevel gear 2 14 are meshed and connected.

[0057] like Figure 4 and Figure 5 As shown, a spring 17 is connected between the grinding disc 16 and the telescopic rod 15, and an array of oblique slots 18 are provided at the bottom end of the telescopic rod 15. A positioning pin 19 is provided in the oblique slot 18, and the grinding disc 16 is hinged in the positioning pin 19. The grinding disc 16 can be automatically pushed outward under the action of the spring 17, so that the grinding disc 16 fits the groove, so as to grind grooves of different slopes and widths.

[0058] like Figure 6 and Figure 7 As shown, the driven wheel 8 is composed of two mutually symmetrical half gear rings 20 spliced ​​together.

[0059] The centering plate 9 is composed of two symmetrical open plates 21. A boss 25 is provided on the side of the open plate 21 close to the driven wheel 8. The half ring gear 20 is rotatably mounted on the boss 25. A shoulder (not shown in the drawings) is provided on the outer side of the boss 25 to prevent the half ring gear 20 from falling off. The open plate 21 is provided with an array of lifting holes 26. The end of the open plate 21 is provided with a connecting flange 27.

[0060] The symmetrical opening disks 21 on both sides are fixed by connecting flanges 27. The centering rod 10 is threadedly connected to the lifting hole 26. A grooved pressure plate 23 is provided at the bottom of the centering rod 10. By rotating the centering rod 10, the grooved pressure plate 23 at the bottom of the centering rod 10 is pressed tightly against the pipe, and the values ​​of the scales on each centering rod 10 are kept consistent, thereby completing the positioning of the center of the pipe.

[0061] Two groups of positioning grooves 22 are provided on the front and rear sides of the half gear ring 20 , and the support plate 1 11 and the support plate 2 24 are respectively provided in the two groups of positioning grooves 22 .

[0062] The specific working principle is as follows:

[0063] The two halves of the open disc 21 are buckled onto the pipe, and then the two clip discs are fixedly connected via the connecting flange 27 . At this time, the open end of the clip disc faces downward, and the upper end is in contact with the pipe wall.

[0064] According to the known diameter of the pipeline, screw the centering rod 10 so that the grooved pressure plate 23 at the end of the centering rod 10 fits on the pipeline. It is important to adjust the screwing depth of the centering rod 10 in each direction so that the scale of the centering rod 10 in each direction is the same and its scale value is adapted to the pipeline diameter.

[0065] The two sets of half gear rings 20 are clamped on the boss 25 of the open disk 21. The two sets of half gear rings 20 are spliced ​​and fixed to form a driven wheel 8 by bolts, so that it can rotate around the boss 25 as a whole. When the driven wheel 8 rotates, the position will be limited by the shoulder on the boss 25 to prevent the driven wheel 8 from falling off.

[0066] Install the support plate 11 in the positioning groove 22 of the driven wheel 8, install the support plate 24 in another positioning groove 22 on the driven wheel 8, and then fix the various components of the groove grinding mechanism 4 one by one on the support plate 11, and at the same time fix the welding machine 5 on the support plate 2 24.

[0067] Then adjust the telescopic length of the telescopic rod 15 so that the grinding disc 16 at the bottom of the telescopic rod 15 is adapted to the height of the groove to be welded. The grinding disc 16 always keeps in contact with the groove under the elastic force of the spring 17. Then adjust the horizontal position and working height of the welding machine 5 so that the welding position is adapted to the groove position.

[0068] Adjust the position of the positioning platform 1 and make the driving wheel 7 and the driven wheel 8 on the travel motor 6 engage with each other.

[0069] After the adjustment is completed, the travel motor 6 and the grinding motor 12 are started. The grinding motor 12 drives the grinding disc 16 at the bottom of the telescopic rod 15 to rotate through the gear set. The grinding disc 16 grinds the groove surface during circulation to remove impurities such as oil, oxide scale, etc. at the groove, thereby reducing the risk of welding abnormalities.

[0070] The travel motor 6 drives the driven wheel 8 to rotate through the driving wheel 7, and the driven wheel 8 drives the groove grinding mechanism 4 and the welding machine 5 to rotate along the pipeline welding groove in a circular manner. The groove grinding mechanism 4 grinds the groove in the front, and the welding machine 5 welds the groove that has just been ground in the rear.

[0071] After the first weld is completed, cool it for a certain period of time according to the welding requirements, and at the same time adjust the telescopic rod 15 upward so that the grinding disc 16 is adapted to the height of the first weld so as to clean the coating of the first weld when capping and prevent slag inclusion during the next welding.

[0072] Repeat the above steps for subsequent multiple welding passes.

[0073] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0074] While the embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions, and alterations can be made to the embodiments without departing from the principles and spirit of the invention.

[0075] The present invention and its embodiments are described above. Such description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the present invention, without inventive design, a structure and embodiment similar to the technical solution should fall within the scope of protection of the present invention.

Claims

1. A large cross-section pipe welding device for petrochemical use, characterized in that: include: Positioning stage (1); A circling walking mechanism (2), the circling walking mechanism (2) is arranged on a positioning platform (1), the circling walking mechanism (2) comprises a walking motor (6), a driving wheel (7) and a driven wheel (8), the walking motor (6) is arranged on the positioning platform (1), the driving wheel (7) is arranged at the output end of the walking motor (6), and the driven wheel (8) is meshed with the driving wheel (7); A centering support mechanism (3), the centering support mechanism (3) is arranged on the side wall of the surrounding walking mechanism (2), the centering support mechanism (3) comprises a centering disc (9) and a centering rod (10), the centering disc (9) surrounds the outer wall of the pipe, and the centering rod (10) has multiple groups of threads penetrating the centering disc (9); A groove grinding mechanism (4), wherein the groove grinding mechanism (4) is arranged on a side of the surrounding walking mechanism (2) away from the centering support mechanism (3); A welding machine (5), the welding machine (5) is connected to the side wall of the surrounding walking mechanism (2) near the rear of the groove grinding mechanism (4) through the second support plate (24), the groove grinding mechanism (4) includes a grinding motor (12), a telescopic rod (15) and a grinding disc (16), the grinding motor (12) is fixed to the side wall of the driven wheel (8) through the first support plate (11), the telescopic rod (15) is connected to the output end of the grinding motor (12) through a gear set, and the grinding disc (16) is hinged to the bottom end of the telescopic rod (15); The driven wheel (8) rotates on the side wall of the centering disk (9); The centering rod (10) is provided with a scale; The gear set includes a bevel gear 1 (13) and a bevel gear 2 (14), wherein the bevel gear 1 (13) is provided at the output end of the grinding motor (12), and the bevel gear 2 (14) is provided at the top end of the telescopic rod (15), and the bevel gear 1 (13) and the bevel gear 2 (14) are meshed and connected; A spring (17) is connected between the grinding disc (16) and the telescopic rod (15); an array of oblique slots (18) are provided at the bottom end of the telescopic rod (15); a positioning pin (19) is provided in the oblique slot (18); and multiple groups of the grinding discs (16) are hinged to the positioning pins (19); The driven wheel (8) is composed of two mutually symmetrical half gear rings (20) spliced ​​together; The centering disk (9) is composed of two symmetrical open disks (21) spliced ​​together, and a boss (25) is provided on one side of the open disk (21) close to the driven wheel (8), and the half gear ring (20) is rotatably arranged on the boss (25). The open disk (21) is provided with an array of lifting holes (26), and the end of the open disk (21) is provided with a connecting flange (27). The symmetrical open disks (21) on both sides are fixed by the connecting flange (27); The centering rod (10) is threadedly connected to the lifting hole (26), and a grooved pressure plate (23) is provided at the bottom of the centering rod (10); Two groups of positioning grooves (22) are provided on the front and rear of the half gear ring (20), and the support plate 1 (11) and the support plate 2 (24) are respectively provided in the two groups of positioning grooves (22).

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