An automatic welding fixture for the circumferential seam of a pressure tank body

Abstract

This invention discloses an automatic welding fixture for circumferential seams of pressure tank bodies, relating to the field of circumferential seam welding. It includes a burner module and an adjusting rod for hinged connection between two adjacent burner modules. The adjusting rod is equipped with a hinge seat, and a baffle is fixedly installed on the hinge seat. The fixture also includes at least one drainage port on the baffle and a drainage plate assembly disposed within the drainage port. This automatic welding fixture for circumferential seams of pressure tank bodies, through the telescopic movement of a single hydraulic rod, combined with the sliding guide of an L-shaped groove and a protrusion, and the meshing transmission of a rack and a drive gear, can sequentially drive a first drainage plate and a second drainage plate to form three airflow channels. The first channel focuses on smooth smoke exhaust, avoiding smoke accumulation in the initial welding stage; the second channel focuses on reflecting the heat from the burner upwards to the tank body for efficient preheating; and the third channel, in conjunction with a negative pressure suction port, can forcibly extract and collect the explosive, high-flow-rate smoke generated.

Description

Technical Field

[0001] This invention relates to the field of circumferential welding technology, and more specifically to an automatic welding fixture for circumferential seams of pressure tank bodies. Background Technology

[0002] In the field of pressure vessel manufacturing, circumferential welding of the pressure vessel body is a key process to ensure the strength and sealing of the vessel. Currently, automated welding equipment is widely used in this process, among which flame preheating devices are common auxiliary equipment used to preheat the weld area before welding to reduce welding stress and prevent cracking.

[0003] A preheating and hydrogen removal device for the circumferential weld seam of a thick-walled pressure vessel, disclosed in Chinese Patent Publication No. CN211889553U, includes a base plate. Supporting guide rollers are fixedly connected to the four corners of the upper part of the base plate. A tank body is placed on top of the four supporting guide rollers. Two parallel columns are positioned at the middle of the upper part of the base plate. A second base plate is fixedly connected to the lower end of each column, and an arc-shaped gas pipe is fixedly connected to the upper end of each column. This prior art uses two insulated covers to enclose the preheated circumferential weld seam on the tank body, but the inner wall of the insulated covers does not adhere to the outer wall of the tank body to avoid friction. This method avoids the problem of a sudden temperature drop in the circumferential weld seam under low-temperature conditions, which would lead to a long preheating time. By using an insulation layer and a heat-reflective layer, the heat preheated at the circumferential weld seam is kept constantly warm and reflected back to the circumferential weld seam, significantly shortening the preheating time of the rotating tank body.

[0004] However, the inner wall of the insulation cover maintains a certain gap with the outer wall of the tank to avoid friction. This gap becomes a flow channel for high-temperature flue gas during preheating. Because the insulation cover has an arc-shaped semi-enclosed structure, the high-temperature flue gas generated by combustion of the gas in the arc-shaped gas pipe cannot be discharged in time and is forced to continuously circulate along the outer circumference of the tank inside the insulation cover. This flue gas retention exposes the circumferential seam area of ​​the tank to continuous scouring by high-temperature flue gas. Due to the influence of the tank's rotation direction and the geometry of the insulation cover on the flue gas flow path, the heating intensity at different points along the circumference of the tank varies significantly, resulting in uneven preheating temperature distribution. Summary of the Invention

[0005] The purpose of this invention is to provide an automatic welding fixture for the circumferential seam of a pressure tank body to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an automatic welding fixture for the circumferential seam of a pressure tank body, comprising a flame burner module and an adjusting rod for hinged connection of two adjacent flame burner modules, wherein the adjusting rod is provided with a hinge seat and a baffle is fixedly installed on the hinge seat, and further comprising: At least one drainage port is provided on the baffle; An upper slope and a lower slope are fixedly installed inside the drainage port and arranged symmetrically. The drainage plate assembly disposed within the drainage port includes: Rotate the first drainage plate located inside the drainage port; The second drainage plate, which is installed inside the drainage port, is rotated. In the initial state, the first drainage plate and the second drainage plate are detachably coupled to form an integral plate surface. A protrusion fixedly mounted on the first drainage plate; A drive assembly disposed on the inner wall of the baffle, the drive assembly comprising: Hydraulic rod; An L-shaped groove is fixedly installed at the end of the hydraulic rod, the protrusion is slidably connected in the L-shaped groove, and the L-shaped groove has a horizontal section and a vertical section; A rack fixedly mounted at the end of the hydraulic rod; and, A drive gear that is slidably mounted on the end of the second diverter plate via a spline and can mesh with a rack; Negative pressure suction port located on the baffle; The extension and retraction of the hydraulic rod, through the cooperation of the L-shaped groove and the protrusion, and the cooperation of the rack and the drive gear, drives the first diversion plate and the second diversion plate to sequentially form a first channel pointing towards the tank, a second channel pointing towards the bottom of the fire nozzle, and a third channel with a V-shaped cross section.

[0007] Preferably, the coupling structure of the first drainage plate and the second drainage plate includes: A long slot is formed at the first end of the first drainage plate; A pin that slides radially on the second drain plate, and a first spring for forcing the pin to extend; In the coupled state, the surfaces of the first and second drainage plates form a stepped structure in the thickness direction.

[0008] Preferably, a detection unit is also provided at the top of the baffle. The detection unit is used to detect the flue gas velocity and control the extension and retraction distance of the hydraulic rod through a control template based on the detection result.

[0009] Preferably, the system also includes an arc plate hinged to the baffle, the arc plate having a bulging end facing the centerline of the tank and used for sensing the flue gas velocity.

[0010] Preferably, the baffle is also provided with multiple vents whose ends are connected to the uphill section.

[0011] Preferably, the pin has inclined surfaces at both ends, and a pin that cooperates with the inclined surfaces is fixedly provided on the back side of the drive gear. It also includes a trigger tube that is slidably sleeved outside the negative pressure suction port, and the end face of the trigger tube is driven to abut against the drive gear.

[0012] Preferably, the side wall of the baffle is provided with a negative pressure cavity, a movable plate for adjusting its capacity is slidably disposed in the negative pressure cavity, and a drive motor for driving the movable plate is fixedly disposed in the baffle.

[0013] Preferably, the movable plate is fixedly connected to the trigger tube so that the trigger tube communicates with the negative pressure chamber.

[0014] Preferably, the end of the negative pressure suction port is closed, and its side wall has a side opening.

[0015] Preferably, the flame grid module has two states, including a first state in which the flame temperature gradually increases along the rotation direction of the tank during the initial stage of welding, and a second state in which the flame temperature tends to be uniform.

[0016] The automatic welding fixture for the circumferential seam of a pressure tank provided by the present invention has the following beneficial effects: 1. This patent utilizes the telescopic movement of a single hydraulic rod, combined with the sliding guide of the L-shaped groove and the protrusion, as well as the meshing transmission of the rack and drive gear, to sequentially drive the first and second guide plates to form three airflow channels. The first channel focuses on smooth smoke exhaust, avoiding smoke accumulation in the early stages of welding; it also focuses on guiding the smoke downwards towards the flame burner nozzle, preventing high-temperature smoke from backflowing into the flame burner nozzle. The third channel, combined with the negative pressure suction port, can forcibly suck and collect the explosively generated large flow of smoke. 2. This patent utilizes a stepped structure where the surfaces of the first and second guide plates are not completely coplanar in the thickness direction, but rather have a predetermined height difference. When high-temperature flue gas flows along the upper surface of the guide plates, a localized low-pressure backflow vortex is generated at this step. This vortex peels away the boundary layer between the mainstream flue gas and the plate surface, effectively reducing frictional resistance, enhancing heat exchange between the flue gas and the plate surface, and facilitating the recovery of some waste heat. 3. This patent uses the negative pressure suction point formed by the vent to actively suck away the flue gas before it reaches the end of the burner, thereby cutting off the propagation path of the wall-adhering flow. This causes the flue gas concentration and flow rate around the end module to drop sharply, and the nozzle is no longer subjected to continuous scouring by high-temperature flue gas. This significantly reduces the risk of overheating and carbon buildup rate of the nozzle at that location, and extends the service life of the burner. 4. This patent increases the volume of the negative pressure chamber and reduces the pressure inside the chamber by adjusting the displacement of the movable plate. This creates a suction effect at the V-shaped channel. When the flue gas velocity increases explosively, the flue gas is forcibly collected with a large suction volume, which significantly improves the safety and stability of the welding process. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present invention; Figure 2 This is a schematic diagram of the hinge seat structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the baffle structure provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the drainage plate assembly structure provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the first state of the diversion plate assembly provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the second state of the diversion plate assembly provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the third state of the diversion plate assembly provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the L-shaped slide and hydraulic rod structure provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the default state of the arc plate structure provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the deflection state of the arc plate structure provided in an embodiment of the present invention; Figure 11 This is a schematic diagram showing the positions of the drive gear and trigger tube provided in an embodiment of the present invention; Figure 12 This is a front sectional view of the baffle provided in an embodiment of the present invention; Figure 13 Provided for embodiments of the present invention Figure 12 Enlarged schematic diagram of structure A in the middle.

[0019] Explanation of reference numerals in the attached figures: 1. Baffle; 2. Drainage port; 3. Upper slope; 4. Lower slope; 5. First drainage plate; 6. Second drainage plate; 7. Protrusion; 8. Hydraulic rod; 9. L-shaped groove; 10. Rack; 11. Drive gear; 12. Negative pressure suction port; 13. Long groove; 14. Pin; 15. First spring; 16. Detection unit; 17. Arc plate; 18. Expanded end; 19. Vent; 20. Pin; 21. Third spring; 22. Trigger tube; 23. Negative pressure chamber; 24. Movable plate; 25. Drive motor; 26. Side opening; 27. Assembly plate; 28. Second spring; 30. Fire vent module; 40. Hinge seat; 50. Extension; 60. Elastic bladder. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0021] like Figure 1-13 As shown, an automatic welding fixture for the circumferential seam of a pressure tank includes a flame burner module 30 and an adjusting rod for hinged connection of two adjacent flame burner modules 30. The adjusting rod is provided with a hinge seat 40, and a baffle 1 is fixedly installed on the hinge seat 40. The fixture also includes: At least one drainage port 2 is provided on the baffle 1; The upper slope 3 and the lower slope 4 are fixedly installed inside the drainage port 2 and are arranged symmetrically. The drainage plate assembly disposed within the drainage port 2 includes: Rotate the first drainage plate 5 located inside the drainage port 2; Rotate the second drainage plate 6 located inside the drainage port 2. In the initial state, the first drainage plate 5 and the second drainage plate 6 are detachably coupled to form an integral plate surface. A protrusion 7 is fixedly installed on the first drainage plate 5; A drive assembly is disposed on the inner wall of baffle 1. The drive assembly includes: Hydraulic rod 8; An L-shaped groove 9 is fixedly installed at the end of the hydraulic rod 8, and a protrusion 7 is slidably connected in the L-shaped groove 9. The L-shaped groove 9 has a horizontal section and a vertical section. A rack 10 fixedly mounted at the end of the hydraulic rod 8; and, A drive gear 11 is slidably disposed at the end of the second diversion plate 6 via a spline and can mesh with the rack 10; Negative pressure suction port 12 is provided on baffle 1; The extension and retraction of the hydraulic rod 8, through the cooperation of the L-shaped slide groove 9 and the protrusion 7, and the cooperation of the rack 10 and the drive gear 11, drives the first diversion plate 5 and the second diversion plate 6 to form a first channel pointing towards the tank, a second channel pointing towards the bottom of the fire nozzle, and a third channel with a V-shaped cross section.

[0022] Specifically, the flame grid module 30 has two states, including a first state in which the flame temperature along the rotation direction of the tank increases in a gradient during the initial stage of welding, and a second state in which the flame temperature tends to be uniform.

[0023] like Figures 1 to 3 As shown, the tooling includes multiple fire-discharge modules 30 arranged in an arc along the circumferential seam of the pressure tank body. The baffle 1 is made of high-temperature resistant stainless steel plate, such as 310S, and is elongated in shape, with its length direction aligned with the axial direction of the fire-discharge module 30. The drain port 2 is a rectangular through hole penetrating the wall thickness of the baffle 1, preferably 2-4 in number, and evenly distributed along the length direction of the baffle 1. Each upper slope 3 and lower slope 4 is a heat-resistant cast steel part with a wedge-shaped or arc-shaped cross-section. It also includes assembly plates 21 rotatably mounted on the two side walls of the drain port 2 via a heat-resistant rotating shaft. The two assembly plates 21 are parallel and opposite to each other, and the assembly plates 21 are fixedly connected to the first drain plate 5.

[0024] Furthermore, in the initial stage of welding, such as when starting circumferential tack welding or root pass welding of the pressure tank body, the flame plate module 30 is in the first state. At this time, along the direction of rotation of the pressure tank body, i.e., the welding travel direction, the flame temperature of the flame plate module 30 increases in a stepwise manner. The flame plate nozzle located upstream that passes a certain point on the tank body has a lower temperature, while the flame plate nozzle located downstream that passes that point has a higher temperature. This gradient heating method allows the temperature of the tank body metal to gradually increase before entering the welding zone, avoiding welding deformation caused by sudden and violent thermal expansion. Preferably, the welding torch of the welding device is fixedly installed at the end of the flame plate module 30 along the rotation direction, so that the tank body enters the welding zone precisely after undergoing complete gradient preheating.

[0025] When the pressure tank rotates one revolution, completing the initial preheating or entering the overall preheating stage before the formal welding filler weld or cap weld, the flame grid module 30 switches to the second state. In this state, through control components such as the gas proportional valve, the flame temperature of all flame grid nozzles is adjusted to a uniform and stable high temperature value, such as 350±10℃. This state is used to uniformly and fully preheat the entire circumferential seam to ensure consistent molten pool fluidity, uniform weld structure, and stress relief during subsequent welding processes.

[0026] In the initial state (i.e., when the fire-grate module 30 is in the first state, welding has not yet started or the amount of smoke is small in the early stage of welding), the piston rod of the hydraulic rod 8 extends the longest distance and is in position A. Figure 8As shown in Figure a. At this time, the protrusion 7 is located at the far end of the horizontal section of the L-shaped slide 9, closest to the body of the hydraulic rod 8. In this position, the protrusion 7 drives the entire assembly plate 21 to deflect through the L-shaped slide 9, causing the coupled first guide plate 5 and second guide plate 6 to tilt towards the pressure tank cylinder. A second channel is formed between the end of the first guide plate 5 and the lower slope 4, pointing downwards towards the flame nozzle. This channel can guide the high-temperature fumes generated by welding to the lower part of the flame module 30, heating the area that has not entered the preheating flame, thereby achieving directional guidance of high-temperature airflow and realizing basic smoke exhaust function. At this time, the negative pressure suction port 12 is closed or inactive.

[0027] When preheating of the cylinder is required, hydraulic rod 8 retracts to position B. During this process, protrusion 7 slides along the horizontal section of L-shaped groove 9 towards hydraulic rod 8 to position B, until it reaches the intersection of the horizontal and vertical sections, as shown below. Figure 8 As shown in Figure b, because the protrusion 7 is limited by the right-angle structure at the intersection and cannot continue to move horizontally, the entire coupled guide plate assembly is lifted and deflected, causing the head end of the first guide plate 5 to tightly abut against the upper slope 3. At this time, the coupling plate surface and the upper slope 3 cooperate to form a second channel pointing downwards from the flame bar nozzle. This channel guides some of the heat generated by the flame bar downwards from the flame bar nozzle, preventing high-temperature flue gas from backflowing into the flame bar nozzle and exposing the nozzle to an overheated environment for a long time. At the same time, it guides some of the flue gas downwards to prevent it from interfering with the weld pool. During this process, the drive gear 11 begins to rotate under the drive of the rack 10, but because the second guide plate 6 is still coupled to the first guide plate 5, its rotation is constrained, and the drive gear 11 only idles on the spline or produces a small displacement.

[0028] When the flue gas volume increases sharply, hydraulic rod 8 further retracts to position C, such as Figure 8 As shown in Figure c, at this time, the vertical section of the L-shaped chute 9 moves backward relative to the protrusion 7. Since the vertical section no longer exerts a lateral thrust on the protrusion 7, the first guide plate 5 remains stationary under the action of its rotating shaft friction and airflow pressure, and its head end still abuts against the upper slope 3. At the same time, the rack 10 continues to retract with the end of the hydraulic rod 8, driving the drive gear 11 meshing with it to rotate significantly. The drive gear 11 forces the second guide plate 6 to deflect downward independently through the spline. This causes the end of the second guide plate 6 to move away from the first guide plate 5, and together with the upper slope 3, forms a third channel with a V-shaped cross-section. At this time, the negative pressure suction port 12 is exactly located at the bottom end of the V-shaped channel. Activating the negative pressure suction port 12 will generate a strong negative pressure in the V-shaped channel, efficiently sucking in the welding fumes and concentrating them for discharge.

[0029] In the above technology, through the telescopic movement of a single hydraulic rod 8, combined with the sliding guidance of the L-shaped slide groove 9 and the protrusion 7, and the meshing transmission of the rack 10 and the drive gear 11, the first guide plate 5 and the second guide plate 6 can be driven in sequence to form three airflow channels. The first channel focuses on smooth smoke exhaust to avoid smoke accumulation in the early stage of welding; the second channel focuses on guiding the smoke downwards to the flame nozzle to avoid high-temperature smoke backflowing the flame nozzle; the third channel, combined with the negative pressure suction port 12, can forcefully suck and collect the explosively generated large flow of smoke.

[0030] As a further embodiment of the present invention, the coupling structure of the first drainage plate 5 and the second drainage plate 6 includes: A long groove 13 is formed at the head end of the first diversion plate 5; A pin 14 is slidably disposed on the second drain plate 6 in the radial direction, and a first spring 15 is used to force the pin 14 to extend; In the coupled state, the surfaces of the first drainage plate 5 and the second drainage plate 6 form a stepped structure in the thickness direction.

[0031] Specifically, the long slot 13 is axially formed at the first end of the first guide plate 5 (the end closest to the rotating shaft), and the root of the pin 14 is connected to the first spring 15. In the initial state, i.e., when the hydraulic rod 8 is in the first position A, the pin 14 is inserted into the long slot 13 of the first guide plate 5, rigidly locking the two into a single plate surface. This single plate surface can rotate synchronously around the rotating shaft of the assembly plate 21. In particular, when the first guide plate 5 and the second guide plate 6 are in this coupled state, their plate surfaces are not completely coplanar in the thickness direction, but have a preset height difference, thus forming a stepped structure. When guiding the flow, this stepped structure will generate micro-vortices at the edges of the steps through which the airflow passes, such as... Figure 5 As shown, this effectively delays boundary layer separation and reduces flow resistance.

[0032] When high-temperature flue gas flows along the upper surface of the guide plate, a localized low-pressure backflow vortex is generated at the stepped section. This vortex strips away the boundary layer between the mainstream flue gas and the plate surface, effectively reducing frictional resistance. Compared to a completely coplanar flat plate, this stepped structure reduces the frictional resistance of the flue gas flow while enhancing heat exchange between the flue gas and the plate surface, which is beneficial for recovering some waste heat.

[0033] As a further embodiment of the present invention, a detection unit 16 is provided at the top of the baffle 1. The detection unit 16 is used to detect the flue gas velocity and control the extension and retraction distance of the hydraulic rod 8 through a control template based on the detection result.

[0034] Specifically, an electric telescopic rod is installed on the side of the baffle 1, and an extension part 50 is fixedly provided at the extended end of the electric telescopic rod. An elastic bladder 60 is fixedly wrapped between the extension part 50 and the baffle 1. The adaptive adjustment of tanks with different diameters is achieved through the cooperation of the extension part 50 and the elastic bladder 60. The detection unit 16 is located on the extension part 50. The detection unit 16 is preferably a micro differential pressure sensor or a thermal mass flow sensor, used to detect the flow rate or dynamic pressure of the flue gas in real time. The detection unit 16 is electrically connected to a control module such as a PLC or a microcontroller.

[0035] The control module has preset flue gas flow thresholds corresponding to the three workstations A, B, and C. Its operating logic is as follows: When the detected flue gas velocity is lower than the first threshold (e.g., <2m / s, corresponding to the initial stage of welding or small-scale welding), the control template issues a command to keep or move the hydraulic rod 8 to position A, and use the first channel for natural smoke exhaust.

[0036] When the flue gas velocity is between the first and second thresholds (e.g., 2-5 m / s, corresponding to the preheating or filling stage), the control template commands hydraulic rod 8 to switch to station B and use the second channel for preheating and guiding.

[0037] When the flue gas velocity exceeds the second threshold (e.g., >5m / s, corresponding to large-scale welding or cover welding), the control template commands the hydraulic rod 8 to switch to position C and open the negative pressure suction port 12, using the third channel for forced smoke collection.

[0038] As a further embodiment of the present invention, it also includes an arc plate 17 hinged to the baffle 1, the arc plate 17 having a bulging end 18 facing the centerline of the tank and used for sensing the flue gas velocity.

[0039] Specifically, the arc plate 17 is hinged to the top of the baffle 1, i.e., the extension 50, via a thin-plate hinge (preferably a G-type hinge). The arc plate 17 and the extension 50 are connected by a second spring 28. The elastic force of the second spring 28 keeps the arc plate 17 pressed tightly against the extension 30. The arc surface of the bulging end 18 of the arc plate 17 faces the centerline of the pressure tank, i.e., directly towards the main flow direction of the flue gas. Within the normal flue gas velocity range, the impact force of the flue gas on the bulging end 18 is small and insufficient to overcome the frictional resistance or the preset small elastic force at the hinge, allowing the arc plate 17 to maintain its initial angle. When the flue gas velocity increases abnormally, such as a sudden change in welding parameters causing an explosive generation of flue gas, the airflow impact force on the bulging end 18 increases significantly, forcing the arc plate 17 to deflect around the hinge center. The bottom plane of the arc plate 17 gradually extends across the airflow channel as it deflects, creating a throttling effect on the flue gas and automatically reducing the flue gas velocity. This mechanical structure provides overcurrent protection without the need for external sensors and power sources. It has a fast response speed, extremely high reliability, and can effectively prevent high-temperature flue gas from excessively washing over subsequent equipment or carrying away too much heat.

[0040] As a further embodiment of the present invention, the baffle 1 is also provided with a plurality of vents 19 whose ends are connected to the uphill section 3.

[0041] Specifically, the vent 19 is disposed inside the elastic bladder 60, with its inlet located on the top surface of the extension 50 and close to the flame nozzle, and its outlet located on the inclined surface of the upper slope 3. The outlet position of the vent 19 is specially designed so that when the diversion plate assembly is in the third position (i.e., forming a V-shaped channel), the outlet is located in the negative pressure zone of the V-shaped channel. Through the suction generated by the negative pressure suction port 12, high-temperature flue gas can be actively drawn into the V-shaped channel through the vent 19. Since the inlet of the vent 19 is close to the smoke source, the suction resistance is small.

[0042] When the fire grate module 30 is in the first position (position A, normal smoke exhaust), the high-temperature fumes generated by welding will form a stable wall-attached flow along the baffle 1, the guide plate, and the outer wall of the cylinder. This wall-attached flow is beneficial in the early stage of preheating, as it can transfer heat to the unheated area. When the fumes flow through each module in sequence along the arrangement direction of the fire grate module 30 (i.e., along the circumference or axial direction of the cylinder), the modules closer to the end (i.e., the position of the welding torch or the arc end of the fire grate) are subjected to more severe fumes scouring. The fire grate nozzles of the end module E are exposed to this high-temperature, high-speed fumes backflow for a long time, which will cause the metal materials to creep in an environment that is continuously higher than the design temperature, significantly shortening their service life. In addition, carbon particles in the high-temperature fumes will deposit at the nozzle outlet, gradually clogging the nozzle orifice and causing abnormal flame shape. At the same time, the high-speed fumes will have a shearing effect on the flame root, which may cause welding defects.

[0043] This patent utilizes the negative pressure suction point formed by the vent 19 to actively suck away the smoke before it reaches the end of the burner, thereby cutting off the propagation path of the wall-mounted flow. This causes the smoke concentration and flow rate around the end module to drop sharply, and the nozzle is no longer subjected to continuous scouring by high-temperature smoke.

[0044] Furthermore, the elastic bladder 60 has the characteristic that its volume can expand and contract with changes in internal air pressure, and it is preferably made of high-temperature resistant elastic materials such as silicone rubber or fluororubber. The vent 19 serves as a channel through the elastic bladder 60 and normally maintains a set size; when the amount of welding fumes suddenly increases, causing the air pressure near the baffle 1 to rise, the elastic bladder 60 expands outward under the action of internal pressure, and the flow cross-section of the vent 19 increases accordingly, automatically increasing the suction volume to match the increased smoke exhaust demand; when the amount of fumes decreases, the elastic bladder 60 contracts, and the suction volume decreases accordingly.

[0045] As a further embodiment of the present invention, the two ends of the pin 14 are provided with inclined surfaces, and the back side of the drive gear 11 is fixedly provided with a pin 20 that cooperates with the inclined surfaces. It also includes a trigger tube 22 that is slidably sleeved outside the negative pressure suction port 12, and the end face of the trigger tube 22 abuts against the drive gear 11.

[0046] Specifically, when the hydraulic rod 8 switches from the second station to the third station, the trigger tube 22 is driven to slide axially first. A third spring 21 is provided between the drive gear 11 and the second guide plate 6 to keep the drive gear 11 extending a fixed distance. The end face of the trigger tube 22 pushes forward against the drive gear 11, forcing the drive gear 11 to overcome the elasticity of the third spring 21 and move axially along the spline. The pin 20 fixed on the back side of the drive gear 11 then moves closer to the pin 14, and the end of the pin 20 first contacts the inclined surface at the end of the pin 14. As the trigger tube 22 continues to push, the pin 20, through the engagement of the inclined surface, radially pushes the pin 14 back from its extended position, overcoming the elasticity of the first spring 15, so that the pin 14 completely exits from the long groove 13 of the first guide plate 5, realizing the forced separation of the first guide plate 5 and the second guide plate 6. After the separation is completed, the hydraulic rod 8 continues to retract, the rack 10 meshes with the drive gear 11 and drives it to rotate, causing the second guide plate 6 to deflect independently.

[0047] As a further embodiment of the present invention, a negative pressure cavity 23 is provided on the side wall of the baffle 1, a movable plate 24 for adjusting its capacity is slidably disposed in the negative pressure cavity 23, and a drive motor 25 for driving the movable plate 24 is fixedly disposed in the baffle 1.

[0048] Specifically, the movable plate 24 is fixedly connected to the trigger tube 22 so that the trigger tube 22 communicates with the negative pressure chamber 23. The end of the negative pressure suction port 12 is closed, and its side wall has a side opening 26. The negative pressure chamber 23 is a sealed space, and its side wall is formed by the movable plate 24. The movable plate 24 and the side wall of the baffle 1 are slidably sealed by a sealing ring (e.g., Figure 12 (As shown). By driving the movable plate 24 to reciprocate linearly within the negative pressure chamber 23, the internal volume of the negative pressure chamber 23 can be directly changed. When the movable plate 24 moves towards the inlet 2 (increasing the volume), the pressure inside the chamber drops instantaneously, generating a momentary additional suction peak, matching the instantaneous peak when the flue gas flow suddenly bursts. Subsequently, an external negative pressure source replenishes the gas, and the pressure gradually returns to the set value, avoiding abnormal suction on other burner nozzles. The negative pressure chamber 23 is connected to an externally installed negative pressure pump. The drive motor 25 is preferably a servo motor or a stepper motor. The output shaft of the drive motor 25 is connected to the movable plate 24 via a lead screw or gear rack mechanism, so that the sliding of the trigger tube 22 is completely synchronized with the movement of the movable plate 24. The trigger tube 22 itself is hollow, and its inner cavity is connected to the negative pressure chamber 23 through a channel inside the movable plate 24 or directly through a pipe. Therefore, when the drive motor 25 drives the movable plate 24 to move, the trigger tube 22 also moves accordingly.

[0049] The end of the negative pressure suction port 12 (i.e., the end facing the inside of the baffle 1) is closed, preventing fluid from entering or exiting. The openings are simply one or more side openings 26 formed on its sidewall. This structure works in conjunction with the trigger tube 22: initially, the trigger tube 22 is fitted over the negative pressure suction port 12, its smooth inner wall completely covering and sealing the side openings 26, keeping the negative pressure suction port 12 closed and preventing any suction. When negative pressure suction is required, the trigger tube 22 is driven to slide axially, changing the relative position between the trigger tube 22 and the negative pressure suction port 12, so that the side openings 26 are no longer covered by the inner wall of the trigger tube 22, thus opening the airflow channel. When suction is required (e.g., switching to position C), the drive motor 25 drives the movable plate 24 to move towards the drainage port 2. The movable plate 24, through a fixed connection, drives the trigger tube 22 to slide axially synchronously, gradually exposing the side openings 26 within the inner cavity of the trigger tube 22. The exposed area of ​​the side opening 26 is proportional to the displacement of the trigger tube 22—the greater the displacement, the larger the exposed opening area. Specifically, when the trigger tube 22 is displaced to its limit, it presses against the drive gear 11 and the rack 10 to fully mesh. At this point, the exposed area of ​​the side opening 26 is at its maximum, corresponding to the maximum required suction volume. After the suction peak, the trigger tube 22 can be slightly retracted to adjust the exposed area of ​​the side opening while maintaining the meshing of the gear 11 and the rack 10, thereby regulating the suction volume.

[0050] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. An automatic welding fixture for the circumferential seam of a pressure tank body, comprising a flame burner module (30) and an adjusting rod for hinged connection of two adjacent flame burner modules (30), wherein the adjusting rod is provided with a hinge seat (40), and a baffle (1) is fixedly installed on the hinge seat (40), characterized in that, Also includes: At least one drainage port (2) is provided on the baffle (1); The upper slope (3) and lower slope (4) are fixedly installed in the drainage port (2) and arranged symmetrically. The drainage plate assembly disposed within the drainage port (2) includes: Rotate the first drainage plate (5) located inside the drainage port (2); Rotate the second drainage plate (6) located inside the drainage port (2). In the initial state, the first drainage plate (5) and the second drainage plate (6) are detachably coupled to form an integral plate surface. The protrusion (7) is fixedly installed on the first drainage plate (5); A driving assembly disposed on the inner wall of the baffle (1), the driving assembly comprising: Hydraulic rod (8); An L-shaped groove (9) is fixedly installed at the end of the hydraulic rod (8), the protrusion (7) is slidably connected in the L-shaped groove (9), and the L-shaped groove (9) has a horizontal section and a vertical section; A rack (10) fixedly mounted at the end of the hydraulic rod (8); and, A drive gear (11) that is slidably disposed at the end of the second diverter plate (6) and can mesh with the rack (10). Negative pressure suction port (12) is opened on the baffle (1); The extension and retraction of the hydraulic rod (8) is achieved through the cooperation of the L-shaped groove (9) and the protrusion (7), and the cooperation of the rack (10) and the drive gear (11), which drives the first diversion plate (5) and the second diversion plate (6) to form a first channel pointing to the tank, a second channel pointing to the bottom of the fire nozzle, and a third channel with a V-shaped cross section.

2. The automatic welding fixture for the circumferential seam of a pressure tank body according to claim 1, characterized in that, The coupling structure of the first drainage plate (5) and the second drainage plate (6) includes: A long groove (13) is opened at the head end of the first diversion plate (5); A pin (14) is slidably disposed on the second drain plate (6) in the radial direction, and a first spring (15) is used to force the pin (14) to extend. In the coupled state, the first drainage plate (5) and the second drainage plate (6) form a stepped structure in the thickness direction.

3. The automatic welding fixture for the circumferential seam of a pressure tank body according to claim 1, characterized in that, It also includes a detection unit (16) set at the top of the baffle (1), the detection unit (16) is used to detect the flue gas velocity, and control the extension distance of the hydraulic rod (8) through a control template based on the detection result.

4. The automatic welding fixture for the circumferential seam of a pressure tank body according to claim 1, characterized in that, It also includes an arc plate (17) hinged to the baffle (1), the arc plate (17) having a bulging end (18) facing the centerline of the tank and used to sense the flue gas velocity.

5. The automatic welding fixture for the circumferential seam of a pressure tank body according to claim 4, characterized in that, The baffle (1) is also provided with multiple vents (19) whose ends are connected to the uphill section (3).

6. The automatic welding fixture for the circumferential seam of a pressure tank body according to claim 1, characterized in that, The pin (14) has inclined surfaces at both ends, and the drive gear (11) has a pin (20) fixedly provided on the back side to cooperate with the inclined surfaces. It also includes a trigger tube (22) that is slidably sleeved outside the negative pressure suction port (12), and the end face of the trigger tube (22) is driven to abut against the drive gear (11).

7. The automatic welding fixture for the circumferential seam of a pressure tank body according to claim 6, characterized in that, The side wall of the baffle (1) is provided with a negative pressure chamber (23), and a movable plate (24) for adjusting its capacity is slidably provided in the negative pressure chamber (23), and a drive motor (25) for driving the movable plate (24) is fixedly provided in the baffle (1).

8. The automatic welding fixture for the circumferential seam of a pressure tank body according to claim 7, characterized in that, The movable plate (24) is fixedly connected to the trigger tube (22) so that the trigger tube (22) is connected to the negative pressure chamber (23).

9. The automatic welding fixture for the circumferential seam of a pressure tank body according to claim 1, characterized in that, The end of the negative pressure suction port (12) is closed, and its side wall has a side opening (26).

10. The automatic welding fixture for the circumferential seam of a pressure tank body according to claim 1, characterized in that, The flame grid module (30) has two states, including a first state in which the flame temperature along the rotation direction of the tank increases in a gradient during the initial stage of welding, and a second state in which the flame temperature tends to be uniform.

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