Automatic welding robot for large-diameter pipeline

Abstract

The invention belongs to the technical field of welding equipment, and particularly relates to a large-diameter pipeline automatic welding robot which comprises a box body and a controller installed on the outer side wall of the box body, and further comprises two semi-annular covers arranged on one side of the box body, the two semi-annular covers are in butt joint to form an annular structure, and the two semi-annular covers are provided with clamping sleeve assemblies and are fixed to the outer side of the butt joint position of the two plastic-coated steel pipes through the clamping sleeve assemblies; the pressure measuring unit is installed on the side wall of the semi-annular cover. The butt joint pressure of the large-diameter pipeline can be monitored in real time, the supporting pressure can be regulated and controlled, the welding quality is guaranteed, annular welding is achieved, the unstable condition of land is estimated, meanwhile, after welding, welding seams can be protected, welding seam leakage points can be detected, and defects and positions can be prompted in time; and the welding and assembling quality and stability of the large-diameter pipeline in the collapsible land are comprehensively guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of welding equipment, and in particular relates to an automatic welding robot for large-caliber pipelines. Background Art

[0002] With the improvement of quality requirements for welding products and the acceleration of product upgrades, traditional manual welding operations can no longer meet the automation and flexibility requirements of welding product manufacturing. The difficulty and high cost of hiring workers in the welding manufacturing industry and the actual need to improve product quality have made "replacing people with machines" an inevitable development strategy for the transformation and upgrading of the welding manufacturing industry.

[0003] At present, in the construction of water conservancy projects, the water pipelines generally used are large-diameter plastic-coated steel pipes. In order to improve the convenience of transportation, the large-diameter plastic-coated steel pipes are generally transported to the site, and then the large-diameter pipes are welded on site. During welding, special welding devices are required, such as a large-diameter pipe automatic welding robot disclosed in patent announcement number CN115555779A; Although the welding device disclosed in the above patent can perform automated welding on large-diameter pipes, when laying large-diameter plastic-coated steel pipes in collapsible loess sections, local land subsidence is more likely to occur due to the soft soil, which greatly reduces the foundation bearing capacity of one end of the pipe, thereby directly affecting the pipe and destroying the originally stable butt welding pressure environment at the butt welding position. Although the fixed frame at the welding end of the pipe has a certain locking and alignment capability, the fixed frame and the pipe are not integrally connected and there is a certain gap. Therefore, when the pipe bearing pressure changes due to land subsidence, this pressure may still act on the weld through the pipe, especially during the welding process, when the welding material masterbatch has not yet fully fused with the pipe, once the butt pressure is destroyed, the weld is prone to change, which ultimately leads to a significant reduction in welding quality. Summary of the invention

[0004] The purpose of the present invention is to provide a large-diameter pipeline automatic welding robot in view of the above problems.

[0005] To achieve the above object, the present invention adopts the following technical scheme: a large-caliber pipeline automatic welding robot, comprising a box body and a controller installed on the outer wall of the box body, wherein a hydraulic station is arranged inside the box body, and further comprising: Two semi-annular covers are arranged on one side of the box body, and the two semi-annular covers are butted together to form a ring structure. The two semi-annular covers are installed with a ferrule assembly and are fixed to the outside of the butt joint of the two plastic-coated steel pipes through the ferrule assembly; A pressure measuring unit is installed on the side wall of the semi-annular cover, and each pressure measuring end of the pressure measuring unit detects pressure through a ferrule assembly; An inner mounting seat is arranged on the inner side of the semi-annular cover, and the inner mounting seat is located on the inner side of the joint of the two plastic-coated steel pipes. A top pressure unit is installed on the side wall of the inner mounting seat, and the controller controls the hydraulic station and the top pressure unit to work according to the electrical signal output by the pressure measuring unit. A support rod is fixedly installed on the side wall of the inner mounting seat; The welding manipulator is arranged on the inner side of the semi-annular cover, and the ferrule assembly is equipped with a rotary drive mechanism, which drives the welding manipulator to move in an annular manner along the joint of the two plastic-coated steel pipes; The early warning unit is arranged on the inner side of the semi-annular cover, and the controller controls the early warning unit to work according to the electrical signal output by the pressure measuring unit.

[0006] Preferably, the ferrule assembly includes two left half rings and two right half rings, the two right half rings are butt-jointed and sleeved on the outside of the plastic-coated steel pipe on the same side, the two left half rings are fixedly connected to the inner wall of the semi-annular cover on the same side, and the two left half rings are butt-jointed and sleeved on the outside of the plastic-coated steel pipe on the same side, and the outer walls of the two right half rings and the outer walls of the two semi-annular covers are both equipped with locking assemblies.

[0007] Preferably, the pressure measuring unit includes four electric push rods, and each electric push rod is fixedly inserted into the side wall of the semi-annular cover on the same side, and the four electric push rods are evenly distributed in a ring shape about the axis of the plastic-coated steel pipe. The telescopic ends of the four electric push rods are equipped with pressure detection probes, and the pressure measuring end of each pressure detection probe is against the outer wall of the right semi-ring on the same side, and each electric push rod and each pressure detection probe is electrically connected to the controller.

[0008] Preferably, the top pressure unit includes four hydraulic cylinders fixedly mounted on the outer wall of the inner mounting seat, and the telescopic ends of the four hydraulic cylinders are installed with arc-shaped pressure steel plates, the outer wall of each arc-shaped pressure steel plate is abutted against the inner wall of the joint of the two plastic-coated steel pipes, the oil inlet and outlet ends of each hydraulic cylinder are connected to the hydraulic station, and the controller controls the operation of the corresponding hydraulic cylinder and hydraulic station according to the electrical signal output by the pressure detection probe.

[0009] Preferably, the rotary drive mechanism comprises two groups of rotating semi-ring plates, and a plurality of connecting columns are fixedly provided between the two rotating semi-ring plates in the same group, the outer wall of each left semi-ring is provided with two annular slide rails, the inner wall of each rotating semi-ring plate is fixedly installed with a slider, and each rotating semi-ring plate is located on the left semi-ring and moves in an annular manner through the slider and the annular slide rail, a mounting plate is installed on the top of one of the rotating semi-ring plates, and the welding robot is installed on the side wall of the mounting plate, a motor drive assembly is installed on the side wall of one of the semi-ring covers, and a gear is installed on the output end of the motor drive assembly, the gear is meshed with the outer wall of the rotating semi-ring plate on the same side, and the motor drive assembly is electrically connected to the controller.

[0010] Preferably, the early warning unit includes a fixed plate fixedly mounted on the outer wall of one of the rotating semi-ring plates, and an air pump is fixedly mounted on the side wall of the fixed plate, the air outlet end of the air pump is fixedly connected to a hollow block, an air outlet pipe is fixedly plugged into the side wall of the hollow block, a gas flow meter is installed at the pipe end of the air outlet pipe, an air outlet normally closed solenoid valve is installed inside the air outlet pipe, an exhaust pipe is fixedly plugged into the side wall of the hollow block, and an exhaust normally open solenoid valve is installed inside the exhaust pipe, a jet head is installed at the pipe end of the exhaust pipe, the air outlet end of the jet head is directly opposite to the joint of two plastic-coated steel pipes, the suction end of the air pump is fixedly connected to an intake pipe, a protective component is installed on the intake pipe, the air pump and the gas flow meter are both electrically connected to a controller, and the controller controls the operation of the air outlet normally closed solenoid valve and the exhaust normally open solenoid valve according to the electrical signals output by each pressure detection probe.

[0011] Preferably, the protection component includes a pipe adapter installed on the side wall of the fixed plate, one end of the pipe adapter is fixedly connected to a nitrogen storage tank, and the other end of the pipe adapter is connected to an intake pipe, a normally open solenoid valve for separate suction is installed at a position below the pipe adapter inside the intake pipe, and a normally closed solenoid valve for suction is installed at one end of the pipe adapter connected to the intake pipe, and both the normally open solenoid valve for separate suction and the normally closed solenoid valve for suction are electrically connected to a controller.

[0012] Preferably, two support columns are fixedly mounted on the side wall of the inner mounting seat, and the rod ends of the two support columns are commonly fixedly connected to the same air suction pipe, a fan is installed inside the air suction pipe, and a nitrogen detector is fixedly mounted on one side of the pipe wall of the air suction pipe located at the air outlet end of the fan, and the nitrogen detector is electrically connected to the controller.

[0013] Compared with existing technologies, the advantages of a large-diameter pipeline automatic welding robot are: 1. Through the cooperation of the provided box, controller, hydraulic station, semi-annular cover, ferrule assembly, pressure measuring unit, inner mounting seat and top pressure unit, the misalignment pressure of the two butted large-diameter pipes is monitored in real time, and the supporting pressure on the inner wall of the large-diameter pipe is adjusted from the inside based on the monitoring result, so as to avoid as much as possible the instability of the collapsible land, which may cause excessive deviation in the butt welding of the two butted large-diameter pipes and affect the butt welding of the large-diameter pipes, thereby ensuring the welding quality. Through the cooperation of the provided rotating drive mechanism and the welding manipulator, the two butted large-diameter pipes can be annularly welded.

[0014] 2. Through the set early warning unit, the instability of the land where the pipeline is being welded can be roughly estimated based on the pressure fluctuations detected by the pressure measuring unit, and when the land instability is large, the personnel can be reminded to reinforce the land to improve the stability of the pipeline after laying. Secondly, the early warning unit can blow away dust and other impurities at the joints of large-diameter pipelines before welding begins, reducing the impact of dust and other impurities on welding stability.

[0015] 3. Through the set protection components, the weld can be protected after welding is completed, and with the set support columns, suction pipes, fans and nitrogen detectors, the weld leaks can be detected, so as to promptly remind personnel of the defects and defect locations of the weld. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of a large-diameter pipeline automatic welding robot provided by the present invention; Figure 2 It is a schematic cross-sectional structure diagram of a large-caliber pipeline automatic welding robot provided by the present invention; Figure 3 It is a three-dimensional structural schematic diagram of a semi-circular cover of a large-caliber pipeline automatic welding robot provided by the present invention; Figure 4 It is a three-dimensional structural schematic diagram of an inner mounting seat of a large-caliber pipeline automatic welding robot provided by the present invention; Figure 5 It is a structural schematic diagram of a ferrule assembly of a large-caliber pipeline automatic welding robot provided by the present invention; Figure 6 The invention provides a large-caliber pipeline automatic welding robot. Figure 2 A magnified view of the structure of part A; Figure 7 It is a schematic diagram of the side view connection structure of a rotating half ring plate and a left half ring of a large-caliber pipeline automatic welding robot provided by the present invention; Figure 8 The invention provides a large-caliber pipeline automatic welding robot. Figure 2 A magnified view of the structure of part B.

[0017] In the figure: 1 box, 2 controller, 3 hydraulic station, 4 semi-ring cover, 5 ferrule assembly, 51 left semi-ring, 52 right semi-ring, 53 locking assembly, 6 pressure measuring unit, 61 electric push rod, 62 pressure detection probe, 7 inner mounting seat, 8 top pressure unit, 81 hydraulic cylinder, 82 arc-shaped pressing steel plate, 9 welding manipulator, 10 rotating drive mechanism, 101 rotating semi-ring plate, 102 connecting column, 103 annular slide rail, 104 slider, 105 mounting plate, 106 motor drive assembly, 107 gear wheel, 11 early warning unit, 110 fixed plate, 111 air pump, 112 hollow block, 113 outlet pipe, 114 gas flow meter, 115 outlet normally closed solenoid valve, 116 exhaust pipe, 117 exhaust normally open solenoid valve, 118 nozzle, 119 suction pipe, 12 protection component, 121 pipeline adapter, 122 nitrogen storage tank, 123 suction normally open solenoid valve, 124 suction normally closed solenoid valve, 13 support column, 14 suction pipe, 15 fan, 16 nitrogen detector, 17 support rod. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely 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.

[0019] like Figure 1-Figure 8 As shown, a large-diameter pipeline automated welding robot includes a box body 1 and a controller 2 installed on the outer wall of the box body 1. A hydraulic station 3 is arranged inside the box body 1, and also includes: two semi-annular covers 4, the two semi-annular covers 4 are arranged on one side of the box body 1, and the two semi-annular covers 4 are butt-jointed to form an annular structure, the two semi-annular covers 4 are installed with a ferrule assembly 5, and are fixed to the outside of the butt joint of two plastic-coated steel pipes through the ferrule assembly 5, the ferrule assembly 5 includes two left semi-rings 51 and two right semi-rings 52, the two right semi-rings 52 are butt-jointed on the outside of the plastic-coated steel pipe on the same side, the two left semi-rings 51 are fixedly connected to the inner wall of the semi-annular cover 4 on the same side, and the two left semi-rings 51 are butt-jointed on the outside of the plastic-coated steel pipe on the same side, the outer walls of the two right semi-rings 52 and the outer walls of the two semi-annular covers 4 are both installed with locking assemblies 53, and the locking assembly 53 includes components such as bolts, nuts, gaskets, and butt blocks.

[0020] The pressure measuring unit 6 is installed on the side wall of the semi-annular cover 4, and each pressure measuring end of the pressure measuring unit 6 detects pressure through the ferrule assembly 5. The pressure measuring unit 6 includes four electric push rods 61, and each electric push rod 61 is fixedly inserted in the side wall of the semi-annular cover 4 on the same side. The four electric push rods 61 are evenly distributed in a ring shape about the axis of the plastic-coated steel pipe. The telescopic ends of the four electric push rods 61 are installed with pressure detection probes 62, and the pressure measuring ends of each pressure detection probe 62 are against the outer wall of the right semi-ring 52 on the same side. Each electric push rod 61 and each pressure detection probe 62 are electrically connected to the controller 2. The pressure detection probe 62 can detect the pressure value and output an electrical signal to the controller 2 when the pressure exceeds or falls below the threshold.

[0021] The inner mounting seat 7 is arranged on the inner side of the semi-annular cover 4, and the inner mounting seat 7 is located on the inner side of the joint of the two plastic-coated steel pipes. A top pressure unit 8 is installed on the side wall of the inner mounting seat 7, and the controller 2 controls the hydraulic station 3 and the top pressure unit 8 to work according to the electrical signal output by the pressure measuring unit 6. A support rod 17 is fixedly installed on the side wall of the inner mounting seat 7. The top pressure unit 8 includes four hydraulic cylinders 81 fixedly installed on the outer side wall of the inner mounting seat 7, and the telescopic ends of the four hydraulic cylinders 81 are all installed with arc-shaped pressure steel plates 82. The outer side walls of each arc-shaped pressure steel plate 82 are all against the inner wall of the joint of the two plastic-coated steel pipes. The oil inlet and oil outlet ends of each hydraulic cylinder 81 are connected to the hydraulic station 3. The controller 2 controls the corresponding hydraulic cylinder 81 and the hydraulic station 3 to work according to the electrical signal output by the pressure detection probe 62.

[0022] The welding manipulator 9 is arranged on the inner side of the semi-annular cover 4, and the ferrule assembly 5 is installed with a rotating drive mechanism 10, which drives the welding manipulator 9 to move in a circular manner along the joint of the two plastic-coated steel pipes. The rotating drive mechanism 10 includes two groups of rotating semi-annular plates 101, and a plurality of connecting columns 102 are fixedly arranged between the two rotating semi-annular plates 101 in the same group. The outer wall of each left semi-ring 51 is provided with two annular slide rails 103, and the inner wall of each rotating semi-annular plate 101 is fixedly installed with a slider 104, and each rotating semi-annular plate 101 is connected by a sliding block. Block 104 and annular slide rail 103 are located on the left half ring 51 and move in a circle. A mounting plate 105 is installed on the top of one of the rotating half ring plates 101, and the welding robot 9 is installed on the side wall of the mounting plate 105. A motor drive assembly 106 is installed on the side wall of one of the semi-annular covers 4, and a gear 107 is installed on the output end of the motor drive assembly 106. The gear 107 is meshed with the outer side wall of the rotating half ring plate 101 on the same side. The motor drive assembly 106 is electrically connected to the controller 2, and the motor drive assembly 106 includes components such as a motor, an output shaft, and bearings.

[0023] The early warning unit 11 is arranged on the inner side of the semi-annular cover 4, and the controller 2 controls the early warning unit 11 to work according to the electrical signal output by the pressure measuring unit 6. The early warning unit 11 includes a fixed plate 110 fixedly installed on the outer side wall of one of the rotating semi-annular plates 101, and an air pump 111 is fixedly installed on the side wall of the fixed plate 110, and the air outlet end of the air pump 111 is fixedly connected to a hollow block 112, and an air outlet pipe 113 is fixedly plugged into the side wall of the hollow block 112, and a gas flow meter 114 is installed at the pipe end of the air outlet pipe 113, and an air outlet normally closed solenoid valve 115 is installed inside the air outlet pipe 113, and an exhaust pipe 116 is fixedly plugged into the side wall of the hollow block 112, and the exhaust pipe 116 is fixedly plugged into the side wall of the hollow block 112. An exhaust normally open solenoid valve 117 is installed inside the air pipe 116, and a nozzle 118 is installed at the end of the exhaust pipe 116. The air outlet end of the nozzle 118 is opposite to the joint of the two plastic-coated steel pipes. The suction end of the air pump 111 is fixedly connected to the suction pipe 119, and the suction pipe 119 is installed with a protective component 12. The air pump 111 and the gas flow meter 114 are both electrically connected to the controller 2. The controller 2 controls the operation of the outlet normally closed solenoid valve 115 and the exhaust normally open solenoid valve 117 according to the electrical signals output by each pressure detection probe 62. The gas flow meter 114 can detect the gas flow passing through and transmit the gas flow value to the controller 2.

[0024] The protection component 12 includes a pipe adapter 121 installed on the side wall of the fixed plate 110, one end of the pipe adapter 121 is fixedly connected to a nitrogen storage tank 122, and the other end of the pipe adapter 121 is connected to the intake pipe 119, a normally open solenoid valve 123 for suction is installed in the interior of the intake pipe 119 below the pipe adapter 121, and a normally closed solenoid valve 124 for suction is installed at one end of the pipe adapter 121 connected to the intake pipe 119, and both the normally open solenoid valve 123 for suction and the normally closed solenoid valve 124 for suction are electrically connected to the controller 2.

[0025] Two support columns 13 are fixedly installed on the side wall of the inner mounting seat 7, and the rod ends of the two support columns 13 are fixedly connected to the same suction pipe 14, a fan 15 is installed inside the suction pipe 14, and a nitrogen detector 16 is fixedly installed on the pipe wall of the suction pipe 14 at one side of the air outlet end of the fan 15, and the nitrogen detector 16 is electrically connected to the controller 2. When the nitrogen detector 16 detects nitrogen, the nitrogen molecules undergo an oxidation-reduction reaction under the action of a specific electrolyte and an electrode material, and generate a current signal related to the nitrogen concentration. This is an existing mature technology, so it will not be elaborated here.

[0026] The operating principle of the present invention is now described as follows: the large-diameter plastic-coated steel pipe to be welded is hoisted into a pre-dug pipeline pit, and the pipeline is aligned with the corresponding plastic-coated steel pipe (in order to facilitate welding, a welding pit needs to be dug in advance at the butt joint of the two plastic-coated steel pipes, and the notch of the welding pit needs to be larger than the length of the semi-annular cover 4), and then the left semi-ring 51 and the right semi-ring 52 and the semi-annular cover 4 are butt-sleeved on the outside of the butt joint of the two plastic-coated steel pipes, and the two semi-annular covers 4 are locked and fixed together by the locking assembly 53, and the two right semi-rings 5 2 are locked and fixed together (the locking assembly 53 includes bolts, nuts, washers, docking blocks and other components), and then the inner mounting seat 7 is inserted into the inner side of the large-diameter plastic-coated steel pipe to be welded by lifting the support rod 17, so that the inner mounting seat 7 is at the docking position of the two large-diameter plastic-coated steel pipes, and then the oil inlet and outlet ends of each hydraulic cylinder 81 are connected to the oil delivery end and oil return end of the hydraulic station 3, and the connection circuits between the hydraulic cylinder 81, the electric push rod 61, the air pump 111, the welding manipulator 9 and other components and the controller 2 are connected, and then the controller 2 is started; After the controller 2 is started, it will control the telescopic ends of the four electric push rods 61 to extend synchronously, so that each pressure detection probe 62 is against the right half ring 52. After the electric push rods 61 work for 5 seconds, the controller 2 controls the four electric push rods 61 to stop working. At this time, the pressure detection probe 62 can apply a clamping force to the right half ring 52 (the pressure measuring end of the pressure detection probe 62 is provided with an arc block for increasing the contact area between the pressure measuring end and the right half ring 52). Subsequently, the controller 2 controls the hydraulic station 3 to deliver hydraulic oil to the oil inlet ends of the four hydraulic cylinders 81, so that the telescopic ends of the four hydraulic cylinders 81 extend, and then the four arc-shaped pressing steel plates 82 can be driven to move toward the inner wall of the plastic-coated steel pipe and press against each other. Under the pressure output by the four hydraulic cylinders 81, the four arc-shaped pressing steel plates 82 will support the inner wall of the plastic-coated steel pipe. After the hydraulic cylinder 81 works for 7 seconds, the controller 2 controls the hydraulic station 3 to suspend the oil supply to each hydraulic cylinder 81. Subsequently, the controller 2 controls the air pump 111 to start working. At this time, the air suction end of the air pump 111 draws in external air through the air suction pipe 119 (in order to prevent dust in the external air from adhering to the joint of the two large-diameter plastic-coated steel pipes, a filter can be installed at the air suction pipe 119), and the air flow is ejected through the nozzle 118 through the hollow block 112 and the exhaust pipe 116. At the same time, the controller 2 controls the motor drive assembly 106 to work, and the motor drive assembly 106 drives the gear 107 to rotate, and the gear 107 meshes with the side wall of the rotating semi-ring plate 101 on the same side. The gear 107 can drive the rotating semi-ring plate 101 on the same side to rotate. Since the rotating semi-ring plates 101 on both sides are fixed by the connecting column 102, each rotating semi-ring plate 101 will rotate synchronously along the annular slide rail 103 through the slider 104. At this time, the air pump 111 starts to move in an annular manner synchronously through the fixed plate 110. Therefore, the airflow delivered by the air pump 111 will move along the joint of the two large-diameter plastic-coated steel pipes, so as to blow away the dust and other impurities that may exist at the joint of the plastic-coated steel pipes, thereby reducing the influence of dust and other impurities on the subsequent welding strength. When the motor drive assembly 106 drives the air pump 111 to rotate 360°, the controller 2 controls the motor drive assembly 106 to rotate in the opposite direction, so that the air pump 111 rotates 360° and resets (an angle encoder is provided at the output shaft of the motor drive assembly 106, and the controller 2 controls the driving angle of the motor drive assembly 106 according to the electrical signal output by the angle encoder). Subsequently, the controller 2 controls the motor drive assembly 106 to rotate forward again, and starts the welding manipulator 9 at the same time. During the rotation of the rotating semi-ring plate 101, the welding end of the welding manipulator 9 can butt-weld the two plastic-coated steel pipes until the welding manipulator 9 also rotates 360°, and then the controller 2 controls the welding manipulator 9 to stop working. During the welding process, if the soil in a local position of the pipeline sinks due to its collapsible property, taking the land sinking phenomenon at one end away from the joint of the two plastic-coated steel pipes as an example, due to the land sinking, the end of the plastic-coated steel pipe away from the joint will drop synchronously with the land sinking. Therefore, the end of the plastic-coated steel pipe away from the joint will apply an upward pulling force to the joint end. If the pipe end of the plastic-coated steel pipe joint with a semi-annular cover 4 installed is subjected to upward pressure, the electric push rod 61 on the lower side of the semi-annular cover 4 will synchronously increase the pressure on the pressure detection probe 62 on the same side. At this time, the strength of the electrical signal output by the lower pressure detection probe 62 to the controller 2 exceeds the threshold value, and then the control The controller 2 will immediately control the hydraulic station 3 to resume work, and control the hydraulic station 3 to deliver hydraulic oil to the lower hydraulic cylinder 81. Therefore, the pressure applied by the lower hydraulic cylinder 81 to the lower side will increase, thereby offsetting the pressure change caused by land subsidence, ensuring the stability of the docking position, and avoiding the influence of pressure change on the normal butt welding and the strength of the unfused weld at the docking position. It is suitable for large-diameter pipeline welding work on collapsible land. When the pressure detected by each pressure detection probe 62 recovers the threshold, the controller 2 controls the hydraulic station 3 to suspend work, so that the hydraulic cylinder 81 maintains the current pressure until the pressure detection probe 62 detects that the pressure exceeds the threshold again. Secondly, after the strength of the electrical signal output by the pressure detection probe 62 to the controller 2 exceeds the threshold, the controller 2 will control the normally closed solenoid valve 115 for air outlet and the normally open solenoid valve 117 for exhaust to open. At this time, the air delivered by the air pump 111 will enter the air outlet pipe 113 through the hollow block 112 and be discharged through the gas flow meter 114. When the pressure fluctuates frequently, it means that the stability of the land where the plastic-coated steel pipe is laid is not good. When the pressure fluctuates frequently, the controller 2 controls the amount of gas discharged from the gas flow meter 114 to increase. Therefore, the stability of the land can be judged by the gas flow measured by the gas flow meter 114. When the stability of the land is not good, the land should be reinforced in time after the subsequent pipeline welding contact to maintain the stability after the pipeline is laid. Finally, when the welding is completed, that is, after the controller 2 controls the welding manipulator 9 to stop working, the controller 2 controls the oil inside each hydraulic cylinder 81 to flow back to the hydraulic station 3, so that each arc-shaped pressing steel plate 82 is separated from the plastic-coated steel pipe, and at the same time, the controller 2 controls the motor drive assembly 106 to rotate in the opposite direction again, so that the air pump 111 starts to rotate. At the same time, the controller 2 controls the normally open solenoid valve 123 for separation and the normally closed solenoid valve 124 for suction to be energized and work. At this time, the nitrogen stored in the nitrogen storage tank 122 will escape, and the air pump 111 will extract the nitrogen and spray the nitrogen through the hollow block 112, the exhaust pipe 116 and the nozzle 118. The sprayed nitrogen moves along the weld after welding is completed. Nitrogen can be used to cool the weld, and oxygen in the air can be prevented from contacting the high-temperature weld metal, avoiding oxidation reaction of the weld during the cooling process, thereby improving the cooling quality of the weld, and the controller 2 synchronously controls the fan 15 and the nitrogen detector 16 to work, and the fan 15 can The air around the joint is adsorbed and the airflow passes through the nitrogen detector 16. If there is a welding leak in the weld, under the action of the negative pressure suction on the inner side of the plastic-coated steel pipe and the airflow pressure delivered by the external air pump 111, part of the nitrogen will enter the inner side of the plastic-coated steel pipe through the leak and flow through the nitrogen detector 16. The nitrogen concentration detected by the nitrogen detector 16 will increase and output an electrical signal to the controller 2. At this time, the controller 2 will send an early warning message to the staff, thereby reminding the staff that there is a leak in the weld. At the same time, the controller 2 controls the motor drive component 106 to suspend work (during the welding process, the controller 2 starts the nitrogen detector 16 and detects the nitrogen concentration in the current air, and calibrates it to zero with the current nitrogen concentration in the air to ensure the accuracy of the nitrogen concentration detection when detecting the weld leak and avoid false alarms. After each welding, it is necessary to replenish nitrogen into the nitrogen storage tank 122 through an external nitrogen storage device). At this point, the butt welding of a single large-diameter plastic-coated steel pipe is completed.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A large-diameter pipeline automatic welding robot, comprising a box (1) and a controller (2) installed on the outer wall of the box (1), wherein a hydraulic station (3) is arranged inside the box (1), characterized in that: Also includes: Two semi-annular covers (4) are arranged on one side of the box body (1), and the two semi-annular covers (4) are butted together to form an annular structure. The two semi-annular covers (4) are installed with a clamping sleeve assembly (5) and are fixed to the outside of the butt joint of the two plastic-coated steel pipes through the clamping sleeve assembly (5); A pressure measuring unit (6) is mounted on the side wall of the semi-annular cover (4), and each pressure measuring end of the pressure measuring unit (6) detects pressure through a ferrule assembly (5); An inner mounting seat (7) is arranged on the inner side of the semi-annular cover (4), and the inner mounting seat (7) is located on the inner side of the joint between the two plastic-coated steel pipes. A top pressure unit (8) is installed on the side wall of the inner mounting seat (7), and the controller (2) controls the hydraulic station (3) and the top pressure unit (8) to work according to the electrical signal output by the pressure measuring unit (6). A support rod (17) is fixedly installed on the side wall of the inner mounting seat (7); A welding manipulator (9) is arranged on the inner side of the semi-annular cover (4), and the ferrule assembly (5) is provided with a rotary drive mechanism (10), wherein the rotary drive mechanism (10) drives the welding manipulator (9) to move in a circular manner along the joint of the two plastic-coated steel pipes; The early warning unit (11) is arranged on the inner side of the semi-annular cover (4), and the controller (2) controls the early warning unit (11) to operate according to the electrical signal output by the pressure measuring unit (6).

2. The large-diameter pipeline automatic welding robot according to claim 1, characterized in that: The ferrule assembly (5) comprises two left half rings (51) and two right half rings (52), the two right half rings (52) being butt-jointed and sleeved on the outside of the plastic-coated steel pipe on the same side, the two left half rings (51) being fixedly connected to the inner wall of the semi-annular cover (4) on the same side, and the two left half rings (51) being butt-jointed and sleeved on the outside of the plastic-coated steel pipe on the same side, and the outer side walls of the two right half rings (52) and the outer side walls of the two semi-annular covers (4) are both installed with locking assemblies (53).

3. The large-diameter pipeline automatic welding robot according to claim 2 is characterized in that: The pressure measuring unit (6) includes four electric push rods (61), and each electric push rod (61) is fixedly inserted into the side wall of the semi-annular cover (4) on the same side, and the four electric push rods (61) are evenly distributed in a ring shape about the axis of the plastic-coated steel pipe. The telescopic ends of the four electric push rods (61) are installed with pressure detection probes (62), and the pressure measuring ends of each pressure detection probe (62) are against the outer wall of the right semi-ring (52) on the same side. Each electric push rod (61) and each pressure detection probe (62) are electrically connected to the controller (2).

4. The large-diameter pipeline automatic welding robot according to claim 3 is characterized in that: The top pressure unit (8) includes four hydraulic cylinders (81) fixedly mounted on the outer side wall of the inner mounting seat (7), and the telescopic ends of the four hydraulic cylinders (81) are all mounted with arc-shaped pressure steel plates (82), the outer side walls of each arc-shaped pressure steel plate (82) are abutted against the inner walls of the joints of the two plastic-coated steel pipes, the oil inlet and outlet ends of each hydraulic cylinder (81) are connected to the hydraulic station (3), and the controller (2) controls the corresponding hydraulic cylinder (81) and the hydraulic station (3) to work according to the electrical signal output by the pressure detection probe (62).

5. The large-diameter pipeline automatic welding robot according to claim 3 is characterized in that: The rotary drive mechanism (10) comprises two groups of rotary semi-ring plates (101), and a plurality of connecting columns (102) are fixedly arranged between the two rotary semi-ring plates (101) in the same group. The outer wall of each left semi-ring (51) is provided with two annular slide rails (103), and the inner wall of each rotary semi-ring plate (101) is fixedly mounted with a slider (104), and each rotary semi-ring plate (101) is located on the left semi-ring (51) via the slider (104) and the annular slide rail (103) to move in an annular manner. A mounting plate (105) is installed on the top of one of the rotating semi-ring plates (101), and the welding robot (9) is installed on the side wall of the mounting plate (105); a motor drive assembly (106) is installed on the side wall of one of the semi-ring covers (4), and a gear (107) is installed on the output end of the motor drive assembly (106), the gear (107) is meshed with the outer side wall of the rotating semi-ring plate (101) on the same side, and the motor drive assembly (106) is electrically connected to the controller (2).

6. The large-diameter pipeline automatic welding robot according to claim 5, characterized in that: The early warning unit (11) comprises a fixed plate (110) fixedly mounted on the outer side wall of one of the rotating semi-ring plates (101), and an air pump (111) is fixedly mounted on the side wall of the fixed plate (110), an air outlet end of the air pump (111) is fixedly connected to a hollow block (112), an air outlet pipe (113) is fixedly plugged into the side wall of the hollow block (112), a gas flow meter (114) is mounted on the end of the air outlet pipe (113), an air outlet normally closed solenoid valve (115) is mounted inside the air outlet pipe (113), an exhaust pipe (116) is fixedly plugged into the side wall of the hollow block (112), and the exhaust pipe (11 6) is installed with an exhaust normally open solenoid valve (117), the end of the exhaust pipe (116) is installed with a nozzle (118), the outlet end of the nozzle (118) is directly opposite to the joint of the two plastic-coated steel pipes, the suction end of the air pump (111) is fixedly connected with an intake pipe (119), and the intake pipe (119) is installed with a protective component (12), the air pump (111) and the gas flow meter (114) are both electrically connected to the controller (2), and the controller (2) controls the operation of the outlet normally closed solenoid valve (115) and the exhaust normally open solenoid valve (117) according to the electrical signals output by each pressure detection probe (62).

7. The large-diameter pipeline automatic welding robot according to claim 6, characterized in that: The protection component (12) comprises a pipe adapter (121) mounted on the side wall of the fixed plate (110); one end of the pipe adapter (121) is fixedly connected to a nitrogen storage tank (122), and the other end of the pipe adapter (121) is connected to an air intake pipe (119); a normally open electromagnetic valve (123) for separate suction is installed at a position below the pipe adapter (121) inside the air intake pipe (119); and a normally closed electromagnetic valve (124) for suction is installed at one end of the pipe adapter (121) connected to the air intake pipe (119); the normally open electromagnetic valve (123) for separate suction and the normally closed electromagnetic valve (124) for suction are both electrically connected to the controller (2).

8. The large-diameter pipeline automatic welding robot according to claim 7, characterized in that: Two support columns (13) are fixedly mounted on the side wall of the inner mounting seat (7), and the rod ends of the two support columns (13) are fixedly connected to the same air suction pipe (14), a fan (15) is installed inside the air suction pipe (14), and a nitrogen detector (16) is fixedly mounted on the pipe wall of the air suction pipe (14) at one side of the air outlet end of the fan (15), and the nitrogen detector (16) is electrically connected to the controller (2).

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