A welding device for large-diameter plastic-coated steel pipes

Abstract

The present invention belongs to the technical field of steel pipe welding, and in particular relates to a welding device for large-diameter plastic-coated steel pipes, comprising a base, a bracket, a first cylinder and a welding gun, wherein the bracket is fixedly arranged on the top of the base, the first cylinder is arranged on the bracket, and the welding gun is fixedly arranged on the movable end of the first cylinder. The device also comprises: two clamping mechanisms, respectively arranged between the top sides of the base and the top sides of the bracket, the two clamping mechanisms being capable of clamping and fixing two large-diameter plastic-coated steel pipes after docking; and a transverse moving mechanism, arranged on the top of the bracket. The present invention controls and coordinates the actions of various mechanisms through a PLC controller to ensure that welding, cooling, and smoke removal are carried out simultaneously, thereby improving welding efficiency and quality stability, solving the problems of insufficient heat input control, easy damage to the coating, and poor working environment of existing welding devices, and ensuring the corrosion resistance and service life of large-diameter plastic-coated steel pipes.

Description

Technical Field

[0001] The invention belongs to the technical field of steel pipe welding, and in particular relates to a welding device for large-diameter plastic-coated steel pipes. Background Art

[0002] Large-diameter plastic-coated steel pipes are widely used in infrastructure fields such as water conservancy and municipal administration because they combine the mechanical properties of steel and the anti-corrosion properties of plastic. Since the length of a single large-diameter plastic-coated steel pipe is usually 6-12 meters, and actual projects (such as municipal pipelines and long-distance pipelines) require continuous pipeline systems of hundreds to tens of kilometers, it is necessary to connect the segmented large-diameter plastic-coated steel pipes into a whole by welding. For example, announcement No. CN220073799U discloses a new type of plastic-coated steel pipe manufacturing device for manufacturing large-diameter anti-corrosion plastic-coated steel pipes.

[0003] However, the existing welding device can only complete the process of fusion welding, and has no integrated cooling module, and cannot effectively regulate the welding heat input. The thickness of the plastic coating layer is usually 0.3-1.5mm, and its heat resistance limit is relatively low (the softening point of polyethylene is about 120℃, and the short-term temperature resistance of epoxy resin is ≤180℃). The heat input of conventional welding devices is large, and the width of the heat-affected zone of the weld can reach 100-150mm, which causes the coating to carbonize, bulge and delaminate at high temperatures. After the plastic coating layer of the large-diameter plastic-coated steel pipe is damaged, the metal substrate will accelerate the corrosion rate under special geological conditions such as collapsible loess and saline soil, thereby affecting the service life of the large-diameter plastic-coated steel pipe.

[0004] To this end, a welding device for large-diameter plastic-coated steel pipes is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a welding device for large-diameter plastic-coated steel pipes in order to solve the above problems.

[0006] To achieve the above-mentioned object, the present invention adopts the following technical solutions: A welding device for large-diameter plastic-coated steel pipes, comprising a base, a bracket, a first cylinder and a welding gun, wherein the bracket is fixedly arranged on the top of the base, the first cylinder is arranged on the bracket, and the welding gun is fixedly arranged on the movable end of the first cylinder, and further comprising:

[0007] Two clamping mechanisms are respectively arranged between the top two sides of the base and the top two sides of the bracket, and the two clamping mechanisms can clamp and fix the two large-diameter plastic-coated steel pipes after docking;

[0008] A transverse movement mechanism is provided on the top of the bracket, and two suspension rods are symmetrically fixed to the bottom of the transverse movement mechanism, and the lower ends of the two suspension rods are fixed with a same suspension ring;

[0009] A rotating mechanism is provided on the lifting ring, the first cylinder is fixedly provided on the inner side wall of the rotating mechanism, two support rods are symmetrically fixed on the cylinder wall of the first cylinder, and the upper ends of the two support rods are respectively fixed with a first support plate and a second support plate;

[0010] A cooling mechanism is provided between the side wall of the first cylinder, the first support plate and the second support plate, and the cooling mechanism is located on both sides of the welding gun, and the cooling mechanism is used to cool the surfaces on both sides of the welding part of the large-diameter plastic-coated steel pipe;

[0011] a smoke removal mechanism fixedly disposed on the lower surface of the second support plate, with a detection end of the smoke removal mechanism extending to one side of the welding gun;

[0012] A blowing mechanism is provided on the side wall of the smoke removal mechanism, and the blowing end of the blowing mechanism extends to the welds of two large-diameter plastic-coated steel pipes;

[0013] A PLC controller is fixedly arranged on the side wall of the bracket, and the first cylinder, welding gun, clamping mechanism, lateral movement mechanism, rotating mechanism, cooling mechanism, smoke removal mechanism and blowing mechanism are all electrically connected to the PLC controller.

[0014] Preferably, the clamping mechanism includes an arc-shaped bracket fixedly provided on the top of the base, a second cylinder is fixedly provided on the top of the bracket, and an arc-shaped pressure plate is fixedly provided on the movable end of the second cylinder.

[0015] Preferably, the lateral movement mechanism includes two X-axis electric slide rails symmetrically fixed on the top of the bracket, a slider is provided between the two X-axis electric slide rails, and the bottom of the slider is fixedly connected to the upper ends of the two suspension rods.

[0016] Preferably, the rotating mechanism includes a motor fixedly mounted on the top of the lifting ring, a gear is fixedly mounted on the output shaft of the motor, the lifting ring is a hollow structure, and a gear ring is provided inside the lifting ring for rotation via a bearing, the gear ring is meshed with the gear, and the tail of the first cylinder is fixedly mounted on the top inner wall of the gear ring.

[0017] Preferably, the cooling mechanism includes a water supply tank fixedly arranged on the lower surface of the first support plate and a return water tank on the lower surface of the second support plate, and the movable end of the first cylinder is symmetrically provided with a first arc-shaped cooling plate and a second arc-shaped cooling plate, and the first arc-shaped cooling plate and the second arc-shaped cooling plate are both hollow structures, a water supply pipe is fixedly provided on the top of the first arc-shaped cooling plate, and the upper end of the water supply pipe is connected to the water supply pump inside the water supply tank, and an electromagnetic flow valve is provided on the pipe wall of the water supply pipe, a return water pipe is fixedly provided on the top of the second arc-shaped cooling plate, and the upper end of the return water pipe is fixedly connected to the side wall of the return water tank, and a connecting pipe is fixedly provided between the first arc-shaped cooling plate and the second arc-shaped cooling plate.

[0018] Preferably, two fixed blocks are symmetrically fixed on the movable end of the first cylinder, and two sliding rods are symmetrically slidably provided on the two fixed blocks. The lower ends of the sliding rods on the same side are fixedly connected to the first arc-shaped cooling plate and the second arc-shaped cooling plate respectively, and a spring is fixed between the upper end of the sliding rod on the same side and the fixed block.

[0019] Preferably, a cleaning brush is fixedly provided on one side of the first curved cooling plate, and the cleaning brush is located on one side of the first curved cooling plate and the second curved cooling plate, and close to between the first curved cooling plate and the second curved cooling plate.

[0020] Preferably, the smoke removal mechanism includes an air suction cylinder fixedly arranged on the lower surface of the second support plate, a suction fan is fixedly provided inside the air suction cylinder, a multi-layer filter is fixedly provided inside the air suction cylinder and above the suction fan, an air suction pipe is fixedly provided at the bottom of the air suction cylinder, and the end of the air suction pipe extends to one side of the welding gun, a fixing sleeve is threadedly provided at the end of the air suction pipe, and a temperature sensor is fixedly provided inside the fixing sleeve.

[0021] Preferably, the blowing mechanism includes a blowing pipe fixedly arranged on the side wall of the suction cylinder, the end of the blowing pipe extends to one side of the first arc-shaped cooling plate and the second arc-shaped cooling plate and is fixedly provided with a hollow blowing plate, the lower surface of the hollow blowing plate is provided with a plurality of evenly distributed blowing holes, and the pipe wall of the blowing pipe is provided with a refrigerator.

[0022] Compared with the existing technology, the beneficial effects of the present invention are:

[0023] 1. Through the set rotating mechanism and cooling mechanism, the rotating mechanism drives the gear to mesh with the gear ring through the motor, so that the welding gun can rotate 360° around the axis of the large-diameter plastic-coated steel pipe to complete the continuous welding of the annular weld; at the same time, the cooling mechanism can cool down both sides of the welding part, so that the temperature on both sides of the weld can quickly drop to the safety threshold of the coating, effectively avoiding defects such as carbonization and bulging of the plastic coating layer. Moreover, the cooling mechanism can also move synchronously around to achieve the coordinated operation of full-circumferential welding and dynamic cooling, thereby improving welding efficiency and quality.

[0024] 2. Through the smoke removal mechanism, the suction fan draws the welding smoke into the suction tube through the suction pipe. At the same time, the smoke passes through multiple layers of filter screens and undergoes three-stage purification, including primary glass fiber mesh, activated carbon adsorption layer, and HEPA high-efficiency filter layer, to effectively remove welding slag particles, VOCs and other harmful substances, thereby improving the working environment. At the same time, a temperature sensor is provided at the end of the suction pipe. The temperature sensor can detect the temperature of the smoke gas and dynamically and accurately adjust the opening and closing degree of the electromagnetic flow valve according to the temperature value, thereby realizing intelligent control of the cooling water volume.

[0025] 3. Through the provided blowing mechanism, the high-temperature gas purified by the smoke removal mechanism is cooled to room temperature by the refrigerator, and then blown to the weld through the uniform blowing holes of the hollow blowing plate. While avoiding damage to the coating by sudden cooling, it accelerates the cooling of the weld, achieving the dual effects of smoke purification and weld cooling, and improving the environmental protection and safety of the welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a stereoscopic diagram from the first perspective of a welding device for large-diameter plastic-coated steel pipes provided by the present invention;

[0027] Figure 2 This is a perspective view from a second perspective of a welding device for large-diameter plastic-coated steel pipes provided by the present invention;

[0028] Figure 3 This is a three-dimensional diagram of the connection between the lateral movement mechanism, the hanger rod and the hanger ring of a welding device for large-diameter plastic-coated steel pipes provided by the present invention;

[0029] Figure 4 This is a perspective view of one side of a lifting ring of a welding device for large-diameter plastic-coated steel pipes provided by the present invention;

[0030] Figure 5 This is a three-dimensional view of the other side of the lifting ring of a welding device for large-diameter plastic-coated steel pipes provided by the present invention;

[0031] Figure 6 This is a cutaway perspective view of a lifting ring of a welding device for large-diameter plastic-coated steel pipes provided by the present invention;

[0032] Figure 7This is a three-dimensional diagram of the structures on both sides of the first cylinder and welding gun of a welding device for large-diameter plastic-coated steel pipes provided by the present invention;

[0033] Figure 8 This is a three-dimensional diagram of a fume removal mechanism and a blower mechanism of a welding device for large-diameter plastic-coated steel pipes provided by the present invention;

[0034] Figure 9 This is a partial three-dimensional view of the end face of the suction pipe of a welding device for large-diameter plastic-coated steel pipes provided by the present invention.

[0035] In the figure: 1 base, 2 bracket, 3 first cylinder, 4 welding gun, 5 clamping mechanism, 51 arc bracket, 52 second cylinder, 53 arc pressure plate, 6 horizontal movement mechanism, 61 X-axis electric slide rail, 62 slider, 7 suspension rod, 8 lifting ring, 9 rotating mechanism, 91 motor, 92 gear, 93 ring gear, 10 support rod, 11 first support plate, 12 second support plate, 13 cooling mechanism, 131 water supply tank, 132 return water tank, 133 first arc cooling plate, 134 second Curved cooling plate, 135 water supply pipe, 136 electromagnetic flow valve, 137 return pipe, 138 connecting pipe, 14 smoke removal mechanism, 141 suction tube, 142 suction fan, 143 multi-layer filter, 144 suction pipe, 145 fixing sleeve, 146 temperature sensor, 15 blower mechanism, 151 blowing pipe, 152 hollow blowing plate, 153 blowing hole, 154 refrigerator, 16 PLC controller, 17 fixing block, 18 sliding rod, 19 spring, 20 cleaning brush. DETAILED DESCRIPTION

[0036] 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.

[0037] like Figures 1-9 As shown, a welding device for large-diameter plastic-coated steel pipes includes a base 1, a bracket 2, a first cylinder 3 and a welding gun 4. The bracket 2 is fixedly arranged on the top of the base 1, the first cylinder 3 is arranged on the bracket 2, and the welding gun 4 is fixedly arranged at the moving end of the first cylinder 3. It also includes:

[0038] Two clamping mechanisms 5 are respectively arranged between the top two sides of the base 1 and the top two sides of the bracket 2. The two clamping mechanisms 5 can clamp and fix the two large-diameter plastic-coated steel pipes after docking. The clamping mechanism 5 includes an arc-shaped bracket 51 fixedly arranged on the top of the base 1, and a second cylinder 52 is fixedly provided on the top of the bracket 2. The movable end of the second cylinder 52 is fixedly provided with an arc-shaped pressure plate 53. The two large-diameter plastic-coated steel pipes to be welded are placed steadily into the interior of the two arc-shaped brackets 51, and the second cylinder 52 is controlled to start the extension movement, driving the corresponding arc-shaped pressure plate 53 to move downward steadily. The inner surface of the arc-shaped pressure plate 53 perfectly fits the top contour of the large-diameter plastic-coated steel pipe and completes a firm clamping.

[0039] The transverse moving mechanism 6 is arranged at the top of the bracket 2. Two suspension rods 7 are symmetrically fixed at the bottom of the transverse moving mechanism 6. The lower ends of the two suspension rods 7 are fixed with the same suspension ring 8. The transverse moving mechanism 6 includes two X-axis electric slide rails 61 symmetrically fixed at the top of the bracket 2. A slider 62 is provided between the two X-axis electric slide rails 61. The bottom of the slider 62 is fixedly connected to the upper ends of the two suspension rods 7. When the two X-axis electric slide rails 61 are started, the slider 62 slides smoothly along the transverse track, driving the suspension rod 7 and the suspension ring 8 at the bottom of the slider 62 to move synchronously.

[0040] The rotating mechanism 9 is arranged on the hanging ring 8, and the first cylinder 3 is fixedly arranged on the inner wall of the rotating mechanism 9. The rotating mechanism 9 includes a motor 91 fixedly arranged on the top of the hanging ring 8. The output shaft of the motor 91 is fixedly provided with a gear 92. The hanging ring 8 is a hollow structure, and the interior of the hanging ring 8 is provided with a ring gear 93 that rotates through a bearing. The ring gear 93 is meshed with the gear 92. The tail of the first cylinder 3 is fixedly provided on the top inner wall of the ring gear 93. When the motor 91 is running, it can drive the gear 92 to rotate, and the gear 92 can drive the ring gear 93 to rotate, so that the ring gear 93 rotates inside the hanging ring 8. Since the first cylinder 3 is fixedly connected to the inner wall of the ring gear 93, it can drive the welding gun 4 to rotate 360° around the axis of the large-diameter plastic-coated steel pipe; two support rods 10 are symmetrically fixed on the barrel wall of the first cylinder 3, and the upper ends of the two support rods 10 are respectively fixed with a first support plate 11 and a second support plate 12.

[0041] The cooling mechanism 13 is arranged between the side wall of the first cylinder 3, the first support plate 11 and the second support plate 12, and the cooling mechanism 13 is located on both sides of the welding gun 4. The cooling mechanism 13 is used to cool the surfaces on both sides of the welding portion of the large-diameter plastic-coated steel pipe. The cooling mechanism 13 includes a water supply tank 131 fixedly arranged on the lower surface of the first support plate 11 and a return water tank 132 on the lower surface of the second support plate 12. The moving end of the first cylinder 3 is symmetrically provided with a first arc-shaped cooling plate 133 and a second arc-shaped cooling plate 134. The moving end of the first cylinder 3 is symmetrically fixed with two fixed blocks 17, and the two fixed blocks 17 are symmetrically slidably provided with two The sliding rod 18, the lower end of the sliding rod 18 on the same side is fixedly connected to the first curved cooling plate 133 and the second curved cooling plate 134 respectively, and a spring 19 is fixed between the upper end of the sliding rod 18 on the same side and the fixed block 17. The first curved cooling plate 133 and the second curved cooling plate 134 can move up and down inside the fixed block 17 through the sliding rod 18, and the upper end of the sliding rod 18 is provided with a spring 19, which can make the first curved cooling plate 133 and the second curved cooling plate 134 have the function of elastic expansion and contraction; the first curved cooling plate 133 and the second curved cooling plate 134 are both hollow structures, and the top of the first curved cooling plate 133 is fixed. A water supply pipe 135 is provided, and the upper end of the water supply pipe 135 is connected to the water supply pump inside the water supply tank 131. The wall of the water supply pipe 135 is provided with an electromagnetic flow valve 136. A return pipe 137 is fixedly provided on the top of the second curved cooling plate 134, and the upper end of the return pipe 137 is fixedly connected to the side wall of the return water tank 132. A connecting pipe 138 is fixedly provided between the first curved cooling plate 133 and the second curved cooling plate 134. The water supply pump inside the water supply tank 131 is running (an elastic piston plate is provided inside the water supply tank 131. During the 360° rotation of the water supply tank 131, in order to ensure that the water supply tank 131 can continue to be supplied with water, the water supply pump 135 is connected to the water supply tank 131. The elastic piston plate can continuously press the cooling water into the position of the water supply pump. For example, when the water supply box 131 rotates to the lowest position, the water supply pump may be at the top position. The cooling water flows downward due to gravity. The elastic piston plate pushes the cooling water into the position of the water supply pump through elastic force. The cooling water can be drawn into the water supply pipe 135 and transported to the interior of the first curved cooling plate 133 through the water supply pipe 135. Since the first curved cooling plate 133 and the second curved cooling plate 134 are connected through the connecting pipe 138, the cooling water fills the internal flow channels of the first curved cooling plate 133 and the second curved cooling plate 134.A cleaning brush 20 is fixed to one side of the first curved cooling plate 133. The cleaning brush 20 is located on one side of the first curved cooling plate 133 and the second curved cooling plate 134, and is located between the first curved cooling plate 133 and the second curved cooling plate 134. The rotation of the first curved cooling plate 133 and the second curved cooling plate 134 drives the cleaning brush 20 to rotate together. Since the cleaning brush 20 is aligned with the joint of the large-diameter plastic-coated steel pipe, the cleaning brush 20 can clean the joint of the large-diameter plastic-coated steel pipe, preventing impurities from adhering and affecting the welding quality.

[0042] The smoke removal mechanism 14 is fixedly arranged on the lower surface of the second support plate 12, and the detection end of the smoke removal mechanism 14 extends to one side of the welding gun 4. The smoke removal mechanism 14 includes a suction cylinder 141 fixedly arranged on the lower surface of the second support plate 12, a suction fan 142 is fixedly arranged inside the suction cylinder 141, and a multi-layer filter 143 is fixedly arranged inside the suction cylinder 141 and above the suction fan 142. A suction pipe 144 is fixedly arranged at the bottom of the suction cylinder 141, and the end of the suction pipe 144 extends to one side of the welding gun 4. The end of the suction pipe 144 is threadedly provided with a fixing sleeve 145, and A temperature sensor 146 is fixedly provided inside the fixed sleeve 145. The suction fan 142 runs to quickly draw out the air in the suction cylinder 141 and the suction pipe 144, so that a negative pressure environment is formed inside the suction pipe 144. The smoke and harmful gases generated during the welding process can be quickly sucked into the suction cylinder 141 and filtered through the multi-layer filter mesh 143 inside the suction cylinder 141. When the smoke gas is about to enter the suction pipe 144, it will first flow through the inside of the fixed sleeve 145. A temperature sensor 146 is installed inside the fixed sleeve 145 to detect the temperature of the smoke gas.

[0043] The blowing mechanism 15 is arranged on the side wall of the smoke removal mechanism 14, and the blowing end of the blowing mechanism 15 extends to the welds of the two large-diameter plastic-coated steel pipes. The blowing mechanism 15 includes a blowing pipe 151 fixedly arranged on the side wall of the suction cylinder 141. The end of the blowing pipe 151 extends to one side of the first curved cooling plate 133 and the second curved cooling plate 134 and is fixed with a hollow blowing plate 152. The lower surface of the hollow blowing plate 152 is provided with a plurality of evenly distributed blowing holes 153. The pipe wall of the blowing pipe 151 is provided with a refrigerator 154. The purified gas flows through the interior of the blowing pipe 151. When passing through the interior of the blowing pipe 151, the high-temperature gas is quickly cooled to normal temperature by the provided refrigerator 154. Subsequently, the normal-temperature gas is introduced into the interior of the hollow blowing plate 152 and is evenly blown to the weld area after the large-diameter plastic-coated steel pipe is welded through the multiple blowing holes 153 on the hollow blowing plate 152.

[0044] The PLC controller 16 is fixedly mounted on the side wall of the bracket 2 , and the first cylinder 3 , the welding gun 4 , the clamping mechanism 5 , the lateral movement mechanism 6 , the rotating mechanism 9 , the cooling mechanism 13 , the smoke removal mechanism 14 and the blower mechanism 15 are all electrically connected to the PLC controller 16 .

[0045] The operating principle of the present invention is described as follows: before carrying out the welding operation of large-diameter plastic-coated steel pipes, the staff operates the crane and slowly and steadily places the two large-diameter plastic-coated steel pipes to be welded into the two arc-shaped brackets 51 in turn. During the process of hoisting and placing, the other two staff members assist in pushing the two large-diameter plastic-coated steel pipes with their hands, so that the ends of the two large-diameter plastic-coated steel pipes pass through the inside of the lifting ring 8, and gradually adjust the position until the ends of the two large-diameter plastic-coated steel pipes form a docking state, preparing for subsequent surrounding welding. After the two large-diameter plastic-coated steel pipes are completely placed in the arc-shaped bracket 51, the staff operates the PLC The controller 16 sends a command to the two second cylinders 52. The two second cylinders 52 that receive the command start to extend, driving the corresponding arc-shaped pressure plates 53 to move downward smoothly. The inner surface of the arc-shaped pressure plates 53 perfectly matches the top contour of the large-diameter plastic-coated steel pipe. As the second cylinders 52 continue to push outward, the two arc-shaped pressure plates 53 respectively fit tightly against the tops of the two large-diameter plastic-coated steel pipes, apply pressure from above, and form an upper and lower clamping force with the arc-shaped support 51 below, completing the stable and reliable clamping and fixing of the large-diameter plastic-coated steel pipe, preventing displacement, shaking, etc. during the subsequent welding process, and ensuring the smooth progress of the subsequent welding work.

[0046] After completing the clamping and fixing of the large-diameter plastic-coated steel pipes, the staff again gave instructions to the equipment through the PLC controller 16, and started the two X-axis electric slides 61 and the first cylinder 3 in order. As the X-axis electric slide 61 started to operate, the slider 62 slid smoothly along the horizontal track, driving the hanger 7 and the hanging ring 8 at the bottom of the slider 62 to move synchronously. Immediately afterwards, the first cylinder 3 received the instruction, and the internal piston rod was quickly extended, pushing the lower end of the welding gun 4 to slowly move downward in the vertical direction and approach the docking position of the two large-diameter plastic-coated steel pipes. In the process of the welding gun 4 descending, the first curved cooling plate 133 and the second curved cooling plate 134 arranged on both sides of the first cylinder 3 also descended synchronously, and the first curved cooling plate 133 and the second curved cooling plate 134 were in contact with the outer walls of the two large-diameter plastic-coated steel pipes. Fitting, when the first curved cooling plate 133 and the second curved cooling plate 134 come into contact with the surface of the large-diameter plastic-coated steel pipe, they will be subjected to the reaction force of the large-diameter plastic-coated steel pipe, which will push the sliding rod 18 connected thereto upward, and the upward movement of the sliding rod 18 will stretch the spring 19 installed at its upper end, and the elastic restoring force of the spring 19 will press the first curved cooling plate 133 and the second curved cooling plate 134 against the surface of the large-diameter plastic-coated steel pipe, giving the first curved cooling plate 133 and the second curved cooling plate 134 the characteristics of elastic expansion and contraction, which can ensure that the first curved cooling plate 133 and the second curved cooling plate 134 are tightly fitted with the large-diameter plastic-coated steel pipe, and avoid damaging the plastic coating due to excessive contact force, making full preparations for subsequent cooling work, and also enabling the welding gun 4 to be accurately aligned with the butt joint of the two large-diameter plastic-coated steel pipes;

[0047] After the position of the welding gun 4 is accurately aligned, the staff will start the welding gun 4, the water supply pump inside the water supply tank 131 and the motor 91 synchronously through the PLC controller 16, triggering the welding and cooling collaborative operation process. The welding gun 4 adopts the metallurgical electrode gas shielded welding process, and the continuous solid welding wire is fed into the welding area through the wire feeding mechanism. When the welding wire contacts the butt joint of the large-diameter plastic-coated steel pipe, an arc is formed between the end of the welding wire and the butt joint under the action of the high current provided by the welding power supply. The high temperature of the arc causes the welding wire and the butt joint to melt rapidly, realizing the metallurgical bonding of the two large-diameter plastic-coated steel pipes. At the same time, the water supply pump inside the water supply tank 131 draws cooling water into the water supply tank. The water pipe 135 is transported to the interior of the first curved cooling plate 133 through the water supply pipe 135. Since the first curved cooling plate 133 and the second curved cooling plate 134 are connected through the connecting pipe 138, the cooling water is evenly filled in the internal flow channels of the first curved cooling plate 133 and the second curved cooling plate 134 under the action of pressure. The first curved cooling plate 133 and the second curved cooling plate 134 are made of a high thermal conductivity aluminum alloy substrate. The curved inner wall thereof is precisely fitted with the outer wall of the large-diameter plastic-coated steel pipe, which can quickly take away the heat from the welding area. After absorbing the heat, the cooling water increases in temperature and is discharged into the return water tank 132 through the return pipe 137, forming a closed-loop circulation cooling system.

[0048] When the motor 91 is running, it can drive the gear 92 to rotate, and the gear 92 is engaged with the ring gear 93 inside the hanging ring 8, so that the ring gear 93 rotates inside the hanging ring 8. Since the first cylinder 3 is fixedly connected to the inner wall of the ring gear 93, it can drive the welding gun 4 to rotate 360° around the axis of the large-diameter plastic-coated steel pipe. During this process, the welding gun 4 moves at a uniform speed along the butt joint annular seam of the large-diameter plastic-coated steel pipe to form a continuous and uniform annular weld. The first arc-shaped cooling plate 133 and the second arc-shaped cooling plate 134 on both sides rotate synchronously with the first cylinder 3, and always maintain contact with the two side surfaces of the welding area of the large-diameter plastic-coated steel pipe to form dynamic tracking cooling. Since the surfaces of the first arc-shaped cooling plate 133 and the second arc-shaped cooling plate 134 are both provided with a low friction coefficient PTF E coating (friction coefficient <0.1), and elastic loading is achieved through elastic connection, so that the first curved cooling plate 133 and the second curved cooling plate 134 can ensure good cooling effect during sliding while avoiding scratching the surface coating layer of the large-diameter plastic-coated steel pipe. This design controls the width of the heat-affected zone within 50mm (the traditional process is 100-150mm), so that the temperature on both sides of the weld is quickly reduced to below the safety threshold of the coating (<180°C), effectively avoiding defects such as carbonization and bulging of the plastic coating layer. The entire welding process is precisely synchronized by the PLC controller 16 to synchronize the actions of various actuators. The welding speed is stable at 300-500mm / min, and the annular weld is formed in one step, significantly improving the welding quality and production efficiency of large-diameter plastic-coated steel pipes.

[0049] When the welding operation is in progress, the worker starts the suction fan 142 through the PLC controller 16. The suction fan 142 quickly draws out the air in the suction cylinder 141 and the suction pipe 144 with strong suction force, so that a negative pressure environment is formed inside the suction pipe 144. Since the port of the suction pipe 144 is arranged on one side of the welding gun 4, the smoke and harmful gases generated during the welding process are quickly sucked into the suction cylinder 141 and filtered through the multi-layer filter 143 inside the suction cylinder 141. The first layer of the multi-layer filter 143 is a primary filter layer, which adopts a glass fiber mesh with increasing density gradient. It can intercept welding slag particles and metal oxides with a particle size greater than 5 microns. The middle layer is an activated carbon adsorption layer, which is pressed from high-iodine coconut shell activated carbon. Its developed pore structure and large specific surface area can effectively adsorb volatile organic compounds (VOCs) such as formaldehyde and styrene, as well as acidic gases in welding fumes. The innermost layer is a HEPA high-efficiency filter layer, which uses ultra-fine glass fiber filter paper treated with electrostatic electret technology to capture fine particles larger than 0.3 microns. Through the synergistic effect of these three layers of filters, harmful substances in the smoke are intercepted layer by layer, and the purified gas enters the subsequent treatment process.

[0050] The purified gas flows through the interior of the blowing pipe 151, and then through the interior of the blowing pipe 151, through the provided refrigerator 154. The refrigerator 154 uses the compressor refrigeration principle to quickly cool the high-temperature gas to room temperature. Subsequently, the room-temperature gas is introduced into the interior of the hollow blowing plate 152, and is evenly blown to the weld area of the large-diameter plastic-coated steel pipe after welding through the multiple blowing holes 153 on the hollow blowing plate 152. This design not only achieves the harmless treatment of welding fumes, but also cleverly uses gas to cool the weld. While ensuring a clean working environment, it accelerates the cooling of the weld, comprehensively improving welding quality and work safety (room-temperature gas can effectively take away the residual heat of the weld and avoid damage to the coating due to sudden cooling, meeting the needs of cooling and coating protection);

[0051] During the synchronous operation of welding, cooling and smoke removal, when the smoke gas is about to enter the suction pipe 144, it will first flow through the inside of the fixed sleeve 145. A temperature sensor 146 is installed inside the fixed sleeve 145, which can detect the temperature of the smoke gas and quickly feed back the detected temperature value to the PLC controller 16. After receiving the temperature value, the PLC controller 16 will immediately start the internal preset intelligent control algorithm. The algorithm will dynamically and accurately adjust the opening and closing degree of the electromagnetic flow valve 136 according to the feedback temperature value, thereby realizing intelligent control of the cooling water amount. When the temperature of the smoke gas generated during the welding process is high, it indicates that the temperature of the current welding area is high. At this time, the temperature value detected by the temperature sensor 146 is large. Based on this, the PLC controller 16 will control the opening degree of the electromagnetic flow valve 136 to increase accordingly. As the opening degree of the electromagnetic flow valve 136 increases, more cooling water will quickly enter the inside of the first curved cooling plate 133 and the second curved cooling plate 134, and the cooling water flow The increase in the amount significantly improves the heat exchange efficiency of the first curved cooling plate 133 and the second curved cooling plate 134, thereby being able to more efficiently take away the large amount of heat generated in the welding area, effectively reducing the temperature of the welding part, inhibiting the further expansion of the heat-affected zone, and providing reliable protection for the plastic coating layer. On the contrary, when the smoke gas temperature is low, it means that the welding temperature is low. At this time, the temperature value detected by the temperature sensor 146 is small, and the PLC controller 16 will control the opening degree of the electromagnetic flow valve 136 to decrease accordingly, and control the amount of cooling water entering the first curved cooling plate 133 and the second curved cooling plate 134 to be appropriately reduced, thereby reducing the efficiency of heat exchange. This dynamic adjustment mechanism not only ensures the cooling effect during high-temperature welding, but also avoids the negative effects that may be caused by excessive cooling during low-temperature welding, such as coating shrinkage and cracking. At the same time, it also has adaptive adjustment capabilities, which can quickly respond and adjust the cooling water volume according to the real-time changes in temperature during the welding process, thereby saving water resources to the greatest extent.

[0052] After the welding is completed and the cooling is finished, the staff operates the PLC controller 16 to release the fixation of the large-diameter plastic-coated steel pipe, and then controls the crane to place the welded large-diameter plastic-coated steel pipe at the predetermined point, making full preparations for the subsequent large-diameter plastic-coated steel pipe laying, connection and other construction links.

[0053] 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 principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A welding device for large-diameter plastic-coated steel pipes, comprising a base (1), a bracket (2), a first cylinder (3) and a welding gun (4), wherein the bracket (2) is fixedly arranged on the top of the base (1), the first cylinder (3) is arranged on the bracket (2), and the welding gun (4) is fixedly arranged on the moving end of the first cylinder (3), characterized in that: Also includes: Two clamping mechanisms (5) are respectively arranged between the top sides of the base (1) and the top sides of the bracket (2), and the two clamping mechanisms (5) can clamp and fix the two large-diameter plastic-coated steel pipes after docking; A transverse moving mechanism (6) is provided on the top of the bracket (2); two suspension rods (7) are symmetrically fixed to the bottom of the transverse moving mechanism (6); and a same suspension ring (8) is fixed to the lower ends of the two suspension rods (7); A rotating mechanism (9) is provided on the lifting ring (8); the first cylinder (3) is fixedly provided on the inner wall of the rotating mechanism (9); two support rods (10) are symmetrically fixedly provided on the cylinder wall of the first cylinder (3); and a first support plate (11) and a second support plate (12) are fixedly provided on the upper ends of the two support rods (10); A cooling mechanism (13) is provided between the side wall of the first cylinder (3), the first support plate (11) and the second support plate (12), and the cooling mechanism (13) is located on both sides of the welding gun (4). The cooling mechanism (13) is used to cool the surfaces on both sides of the welding portion of the large-diameter plastic-coated steel pipe. The cooling mechanism (13) includes a water supply tank (131) fixedly provided on the lower surface of the first support plate (11) and a return water tank (132) provided on the lower surface of the second support plate (12). The movable end of the first cylinder (3) is symmetrically provided with a first arc-shaped cooling plate (133) and a second arc-shaped cooling plate (134). The first arc-shaped cooling plate (133) and the second arc-shaped cooling plate (134) are both hollow structures. A water supply pipe (135) is fixedly provided on the top of the first arc-shaped cooling plate (133), and the upper end of the water supply pipe (135) is connected to the upper end of the water supply pipe (135). The water supply pump inside the water supply tank (131) is connected, the wall of the water supply pipe (135) is provided with an electromagnetic flow valve (136), the top of the second arc-shaped cooling plate (134) is fixedly provided with a return pipe (137), and the upper end of the return pipe (137) is fixedly connected to the side wall of the return water tank (132), a connecting pipe (138) is fixedly provided between the first arc-shaped cooling plate (133) and the second arc-shaped cooling plate (134), the movable end of the first cylinder (3) is symmetrically fixed with two fixed blocks (17), and two sliding rods (18) are symmetrically slidably provided on the two fixed blocks (17), the lower ends of the sliding rods (18) on the same side are respectively fixedly connected to the first arc-shaped cooling plate (133) and the second arc-shaped cooling plate (134), and a spring (19) is fixedly provided between the upper end of the sliding rod (18) on the same side and the fixed block (17); a smoke removal mechanism (14) fixedly arranged on the lower surface of the second support plate (12), and a detection end of the smoke removal mechanism (14) extending to one side of the welding gun (4); the smoke removal mechanism (14) comprising a suction cylinder (141) fixedly arranged on the lower surface of the second support plate (12); a suction fan (142) fixedly arranged inside the suction cylinder (141); a multi-layer filter (143) fixedly arranged inside the suction cylinder (141) and above the suction fan (142); a suction pipe (144) fixedly arranged at the bottom of the suction cylinder (141); a terminal end of the suction pipe (144) extending to one side of the welding gun (4); a fixed sleeve (145) threadedly provided at the terminal end of the suction pipe (144); and a temperature sensor (146) fixedly provided inside the fixed sleeve (145); A blower mechanism (15) is provided on the side wall of the smoke removal mechanism (14), and the blowing end of the blower mechanism (15) extends to the weld seam of two large-diameter plastic-coated steel pipes, the blower mechanism (15) includes a blower pipe (151) fixedly provided on the side wall of the suction cylinder (141), the end of the blower pipe (151) extends to one side of the first curved cooling plate (133) and the second curved cooling plate (134) and is fixedly provided with a hollow blower plate (152), the lower surface of the hollow blower plate (152) is provided with a plurality of evenly distributed blower holes (153), and the pipe wall of the blower pipe (151) is provided with a cooler (154); A PLC controller (16) is fixedly mounted on a side wall of the bracket (2); the first cylinder (3), the welding gun (4), the clamping mechanism (5), the lateral movement mechanism (6), the rotating mechanism (9), the cooling mechanism (13), the smoke removal mechanism (14) and the blower mechanism (15) are all electrically connected to the PLC controller (16).

2. A welding device for large-diameter plastic-coated steel pipes according to claim 1, characterized in that: The clamping mechanism (5) comprises an arc-shaped bracket (51) fixedly arranged on the top of the base (1), a second cylinder (52) is fixedly arranged on the top of the bracket (2), and an arc-shaped pressing plate (53) is fixedly arranged on the movable end of the second cylinder (52).

3. A welding device for large-diameter plastic-coated steel pipes according to claim 1, characterized in that: The lateral movement mechanism (6) comprises two X-axis electric slide rails (61) symmetrically fixedly arranged on the top of the bracket (2), a slider (62) is arranged between the two X-axis electric slide rails (61), and the bottom of the slider (62) is fixedly connected to the upper ends of the two suspension rods (7).

4. A welding device for large diameter plastic coated steel pipes according to claim 1, characterized in that: The rotating mechanism (9) includes a motor (91) fixedly arranged on the top of the hanging ring (8), the output shaft of the motor (91) is fixedly provided with a gear (92), the hanging ring (8) is a hollow structure, and a gear ring (93) is provided inside the hanging ring (8) for rotation through a bearing, the gear ring (93) is meshed with the gear (92), and the tail of the first cylinder (3) is fixedly provided on the top inner wall of the gear ring (93).

5. The welding device for large-diameter plastic-coated steel pipe according to claim 1, characterized in that: A cleaning brush (20) is fixedly provided on one side of the first curved cooling plate (133), and the cleaning brush (20) is located on one side of the first curved cooling plate (133) and the second curved cooling plate (134), and is close to between the first curved cooling plate (133) and the second curved cooling plate (134).

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