Air cooler plug pipe box inner corner submerged arc welding method and auxiliary welding tooling

Abstract

The present application relates to the field of submerged-arc welding of the inner corner of a pipe box of a wire grommet, and discloses a submerged-arc welding method for the inner corner of a pipe box of a wire grommet of an air cooler and an auxiliary welding tool, wherein the welding method comprises the following steps: Step 1, preparation before submerged-arc welding of the pipe box of the wire grommet; Step 2, adaptive adjustment of the spacing of the auxiliary welding tool; Step 3, adjustment of the positions of the baffle and the conducting nozzle of the auxiliary welding tool; and Step 4, submerged-arc welding of the inner corner of the pipe box of the wire grommet; and the auxiliary welding tool comprises the pipe box of the wire grommet and the auxiliary welding tool, the pipe box of the wire grommet is in the shape of a hollow cuboid, the inner corners of the pipe box of the wire grommet are located at the four corners of the interior of the pipe box of the wire grommet, and the auxiliary welding tool moves slowly and uniformly along the inner corners of the pipe box of the wire grommet at the bottom of the two sides of the pipe box of the wire grommet. The present application has the beneficial effects of overcoming the problem of insufficient amount of welding flux buried on the inclined groove of the inner corner of the pipe box of the wire grommet and the problem of invalid welding of the flow to the area, and greatly improving the welding efficiency of the inner corner of the pipe box.

Description

Technical Field

[0001] This invention relates to the field of submerged arc welding technology for the inner corner of a plug box, and particularly to a submerged arc welding method and auxiliary welding fixture for the inner corner of an air cooler plug box. Background Technology

[0002] In submerged arc welding, a 30-50mm thick layer of granular flux covers the weld bevel of the workpiece. A continuously fed welding wire generates an arc between itself and the workpiece under the flux layer. The heat of the arc melts the welding wire, workpiece, and flux, forming a molten metal pool that isolates them from the air. As the welding machine moves forward automatically, the arc continuously melts the workpiece metal, welding wire, and flux in front of it, while the edge behind the molten pool cools and solidifies to form the weld. The molten slag subsequently solidifies to form a hard slag shell. Submerged arc welding is typically suitable for flat welding positions.

[0003] In the manufacturing of pressure equipment such as detachable heat exchangers and air-cooled heat exchangers, submerged arc welding is often used for the fillet welds inside pipe boxes. Submerged arc welding has long been the mainstream welding solution for the main welds of pipe boxes due to its advantages such as high deposition efficiency, excellent weld mechanical properties, smooth weld formation, and minimal manual intervention. However, specifically in the welding scenario of the inner corner of the plug-in pipe box, due to the complex structure of the pipe box cavity, the large differences in the size and specifications of individual parts, and the narrow internal welding operation space, the main technical problems of existing submerged arc welding are: 1. During the submerged arc welding process, because the welding bevel of the inner corner of the plug-in pipe box is inclined at 45°, it is difficult to achieve precise and stable control of the flux delivery point and the amount of filler material in the weld bead. This easily leads to flux deviation and a large amount flowing to the ineffective area outside the weld, resulting in insufficient flux coverage and inadequate arc protection at the effective welding position; 2. The adjustment stroke of the wire feed nozzle of the matching submerged arc welding equipment has inherent limitations, and the adjustable coverage range is limited, making it difficult to adapt to different pipe diameters and different corner positions, which can cause arc deviation and other issues. At the same time, under the combined effect of the above two types of technical problems, it is easy to cause various welding defects such as porosity, slag inclusion, and lack of fusion, which significantly reduces the reliability of the weld seal and the overall pressure bearing safety performance. It will also increase the time for non-destructive testing and rework, seriously restricting the improvement of welding efficiency. Based on the aforementioned technical problems existing in the prior art, the inventors developed a submerged arc welding method and auxiliary welding fixture for the inner corner of the air cooler plug box, which can effectively solve the technical problems existing in the prior art. Summary of the Invention

[0004] To address the problems in the prior art, this invention provides a submerged arc welding method and auxiliary welding fixture for the inner corners of the wire plug tube box in an air cooler. This invention utilizes the auxiliary welding fixture to slowly and uniformly move within the wire plug tube box, completing the submerged arc welding of both inner corners of the wire plug tube box in one operation. This achieves simultaneous submerged arc welding of both sides of the inner corners of the wire plug tube box, significantly improving the welding efficiency of the inner corners.

[0005] This invention provides an auxiliary welding fixture for submerged arc welding of the inner corners of an air cooler plug box. The fixture includes a plug box and an auxiliary welding tool. The plug box is a hollow cuboid, with its four inner corners forming the inner corners. The auxiliary welding tool includes a wire feed tube and a flux tube arranged horizontally and parallel to each other, forming one group of two groups symmetrically arranged. A width adjustment mechanism is fixedly positioned near the rear end of the two symmetrically arranged groups of wire feed tubes and flux tubes. This mechanism adjusts the spacing between the two groups and clamps them to form a single unit. Two clamping blocks are provided, symmetrically arranged. One clamping block is positioned above the left group of wire feed tubes and flux tubes, and the other is positioned above the right group. The upper part features a mounting base plate fixedly positioned below the clamping blocks, with each clamping block corresponding to a mounting base plate below it. The clamping blocks and mounting base plates engage in a tightening action to secure the wire feed tube and flux tube. Two conductive nozzles are provided, fixedly positioned at the front end of the angle adjustment mechanism. The angle adjustment mechanism is symmetrically arranged, with one fixed to the upper left rear position of the left mounting base plate and the other fixed to the upper right rear position of the right mounting base plate. The angle adjustment mechanism is used to fix the conductive nozzles and adjust their angles. Two flux boxes are symmetrically arranged, one fixed to the front right position of the left mounting base plate and the other fixed to the front left position of the right mounting base plate. The flux boxes are used to store flux. An adjustable baffle is positioned in front of the flux boxes. The baffle controls the flux flow direction and increases the flux coverage.

[0006] The inner corner of the pipe box is provided with a welding bevel for welding to form a molten pool and a submerged arc weld.

[0007] The width adjustment mechanism includes an upper clamping block and a lower clamping block, both of which are cuboid in shape. The upper and lower clamping blocks are aligned vertically for use. The bottom of the upper clamping block and the upper part of the lower clamping block each have two corresponding clamping grooves. The clamping groove at the bottom of the upper clamping block is in contact with the upper surface of the wire feeding tube and the flux tube, respectively, while the clamping groove at the top of the lower clamping block is in contact with the lower surface of the wire feeding tube and the flux tube, respectively. A fixing block is located on the upper and lower clamping blocks. The fixing block is T-shaped. The upper, lower, and fixing blocks have symmetrical screw holes on their left and right sides, which pass through the bodies of the upper, lower, and fixing blocks. An adjusting screw hole is provided on the side of the front protrusion of the fixing block. The two ends of the adjusting screw are screwed into the adjusting screw hole, and a nut is fixedly installed in the middle of the adjusting screw. The adjusting screw can be tightened by using a wrench to achieve the fit between the adjusting screw and the adjusting screw hole.

[0008] The upper clamping block, lower clamping block, and fixing block are used to fix and clamp the wire feeding tube and flux tube by screws passing through the screw holes; one end of the adjusting screw has a left-hand thread and the other end has a right-hand thread.

[0009] The clamping block includes a clamping block body, which is rectangular in shape. A threaded hole is symmetrically opened on the upper part of the clamping block body. The clamping groove is a concave arc shape, and the clamping groove is symmetrically opened on the bottom of the clamping block body. The symmetrical clamping groove is attached to the upper part of the wire feeding tube and the flux tube.

[0010] The mounting base plate includes a rectangular base plate. A support block is fixedly installed at the rear edge of the base plate. The support block is also rectangular, and its rear, left, and right ends are flush with the rear, left, and right ends of the base plate, respectively. Support grooves are symmetrically provided on the upper part of the support block. The support grooves are concave arc-shaped, and their arc surfaces are in contact with the lower surfaces of the wire feeding tube and the flux tube, respectively.

[0011] The angle adjustment mechanism includes a fixed body, which is rectangular in shape. A conductive nozzle mounting hole is opened at the center of the front end of the fixed body, and a wire feeding tube mounting hole is opened at the center of the rear end of the fixed body. The conductive nozzle mounting hole and the wire feeding tube mounting hole are connected. A tightening screw is tightened and fixed in the middle of the upper part of the fixed body. Four to six tightening screws are arranged in the middle of the upper part of the fixed body. The tightening screws pass through the body of the fixed body and tighten against the upper surface of the conductive nozzle or the upper surface of the wire feeding tube.

[0012] The flux box includes a sheet metal bending box, which is a hollow square shape. A U-shaped hole is opened on the outside of the sheet metal bending box, which provides movable space for adjusting the angle of the conductive tip. A limiting block is fixedly installed at the bottom rear side of the sheet metal bending box. A limiting groove for limiting the flux tube is opened in the middle of the upper part of the limiting block. Fixing screw holes are opened on the limiting blocks on both sides of the limiting groove, and the fixing screw holes pass vertically upward through the upper rear side of the sheet metal bending box. Adjustment slots are symmetrically opened on the front side of the sheet metal bending box, and the adjustment slots penetrate through the body of the sheet metal bending box.

[0013] The baffle includes a baffle body, which is Z-shaped. The mounting holes are located on the rear side of the baffle body and are arranged symmetrically from top to bottom. The positions of the mounting holes and the adjustment slots are corresponding front to back. Screws pass through the mounting holes and the adjustment slots to fix the baffle body to the front side of the sheet metal bending box. A chamfer is formed on the outer front corner of the baffle body, and the chamfer is 15×45°.

[0014] This invention provides a submerged arc welding method for the inner corner of the plug tube box of an air cooler, mainly including the following steps:

[0015] Step 1: Preparations before submerged arc welding of the wire plug box: First, align the baffle of the auxiliary welding fixture with the front end face of the wire plug box. At this point, the mounting base plate of the auxiliary welding fixture should be in horizontal contact with the bottom inner wall of the wire plug box. Then, connect the wire feeding tube to the wire discharge end of the wire feeding mechanism. Use the wire feeding mechanism to feed the wire through the wire feeding tube and the conductive nozzle on the angle adjustment mechanism to the inner corner of the box. Simultaneously, fix the flux tube to the output end of the pneumatic conveying mechanism at the bottom of the flux cylinder. Also, fix the flux tube near the rear end surface to the mechanical displacement platform.

[0016] Step 2: Adaptive adjustment of the spacing of auxiliary welding fixtures: Based on the distance between the inner corners of the plug box, the operator uses a wrench to tighten the nut in the middle position of the adjusting screw of the width adjustment mechanism, causing the adjusting screw to rotate. With the adjusting screw having a left-hand thread at one end and a right-hand thread at the other end, and the engagement with the adjusting screw hole on the fixing block, the fixing blocks on the left and right sides will have linearly opposite displacements along the adjusting screw until the baffle contacts the inner walls on both sides of the plug box.

[0017] Step 3, Adjustment of the position of the baffle and conductive nozzle of the auxiliary welding fixture: 1. Under the condition that the baffle is in contact with the inner walls of both sides of the plug box in Step 2, make a fine adjustment to the position of the baffle: First, loosen the screws passing through the mounting thread hole and the adjustment groove, and move the baffle body outward along the adjustment groove until the upper end face of the outer chamfer of the baffle is in contact with the inner wall of the bottom left and right inner corners of the plug box, and the bottom end face of the baffle is in contact with the bottom of the plug box; at the same time, make the outer end face of the chamfer of the baffle correspond to the welding bevel of the inner corner of the box; 2. Adjustment of the position of the conductive nozzle: First, loosen all the tightening screws on the upper part of the fixing body of the angle adjustment mechanism, and the operator rotates the conductive nozzle so that the end of the conductive nozzle is aligned with the welding bevel of the inner corner of the box;

[0018] Step 4: Submerged arc welding of the inner corners of the plug box: First, start the wire feeding mechanism, mechanical displacement platform, and pneumatic conveying mechanism. The wire feeding mechanism feeds the wire to the inner corners of the plug box on both sides of the bottom through the wire feeding tube, angle adjustment mechanism, and contact nozzle. Simultaneously, the mechanical displacement platform slowly and uniformly moves the flux tube and mounting base plate towards the rear of the plug box. At the same time, the pneumatic conveying mechanism uniformly and constantly delivers the flux from the flux cylinder to the flux box through the inside of the flux tube. At this point, the flux exits from the sheet metal of the flux box... The flux flows from the bottom of the U-shaped hole in the bent box to the position of the baffle. At this time, under the synergistic effect of the slow and uniform movement of the flux box and the baffle, the baffle collects and gathers the flux particles towards the position of the conductive nozzle. Under the protection of the flux, the welding wire melts through the conductive nozzle by generating an arc. The chamfer of the baffle can avoid the weld and slag at the inner corner of the pipe box. When the left and right baffles move slowly and uniformly to the rear end of the wire plug pipe box, the left and right conductive nozzles, left and right flux boxes and left and right baffles are used to realize the one-time submerged arc welding operation of the inner corner of the pipe box on both sides of the wire plug pipe box.

[0019] In step three, the center of the conductive nozzle is aligned with the bottom of the inner corner bevel of the plug box on both sides.

[0020] The beneficial effects of this invention are as follows: 1. Through the coordinated operation of the flux box and the baffle, flux particles are continuously collected and gathered towards the contact tip position during the slow and uniform movement of the flux box and the baffle, overcoming the problem of insufficient flux coverage and flow to ineffective welding areas on the inclined bevel of the inner corner of the plug tube box. 2. Through the flexible adjustment of the contact tip angle by the angle adjustment mechanism and multi-point locking, the center of the contact tip is accurately aligned with the inner corner of the tube box, completely solving the problem of limited adjustment stroke of the wire feeding tip in traditional equipment and difficulty in adapting to the welding posture in narrow spaces, ensuring stable feeding of the welding wire into the root of the bevel, stable arc combustion, and improved welding quality. 3. Through the synchronous movement of the two sets of tooling symmetrically arranged on the left and right under the traction of the mechanical displacement platform, the submerged arc welding of the inner corners on both sides of the plug tube box is completed in one go, realizing the synchronous submerged arc welding of the inner corners of the plug tube box on both sides, which greatly improves the welding efficiency of the inner corners of the tube box. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the auxiliary welding fixture of the present invention;

[0023] Figure 3 For the present invention Figure 2 Schematic diagram of the width adjustment mechanism, angle adjustment mechanism, flux box and baffle;

[0024] Figure 4 This is a schematic diagram of the mounting base plate of the present invention;

[0025] Figure 5 This is a schematic diagram of the flux box and baffle of the present invention;

[0026] Markings in the diagram: 1. Plug box, 2. Inner corner of the box, 3. Auxiliary welding fixture, 31. Thread feed tube, 32. Flux tube, 33. Width adjustment mechanism, 331. Upper clamping block, 332. Lower clamping block, 333. Fixing block, 334. Clamping groove, 335. Screw hole, 336. Adjusting screw hole, 337. Adjusting screw rod, 338. Nut, 34. Clamping block, 341. Clamping block body, 342. Threaded hole one, 343. Clamping groove, 35. Mounting base plate, 351. Base plate, 35 2. Support block; 353. Support groove; 354. Thread 2; 36. Conductive nozzle; 37. Angle adjustment mechanism; 371. Fixing body; 372. Conductive nozzle mounting hole; 373. Wire feeding tube mounting hole; 374. Tightening screw; 38. Flux box; 381. Sheet metal bending box; 382. U-shaped hole; 383. Limiting block; 384. Fixing thread hole; 385. Limiting groove; 386. Adjustment groove; 39. Baffle; 391. Baffle body; 392. Mounting thread hole; 393. Chamfer. Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments. These embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0028] This invention provides a submerged arc welding method and auxiliary welding fixture for the inner corner of the plug tube box of an air cooler:

[0029] like Figure 1 and 2 As shown, the wire feeding tube 31 and the flux tube 32 are arranged horizontally and parallel to each other, and the wire feeding tube 31 and the flux tube 32 arranged horizontally and parallel to each other form a group. The two groups of wire feeding tubes 31 and flux tubes 32 are arranged symmetrically from left to right.

[0030] The aforementioned wire feeding tube 31, connected to the wire discharge end of the wire feeding mechanism, delivers the welding wire through the center of the conductive nozzle 36 to the welding position at the inner corner 2 of the tube box. On the one hand, it solves the problem of narrow welding operation space inside the wire plug tube box, making it impossible to feed the wire directly. On the other hand, it realizes remote and directional delivery of the welding wire, ensuring that the welding wire can be accurately aligned with the root position of the welding bevel.

[0031] The flux pipe 32, as described above, is connected to the output end of the pneumatic conveying mechanism at the bottom of the flux cylinder for conveying flux. Simultaneously, it is fixedly connected to the mechanical displacement platform, serving as the traction connection point for the entire tooling movement, thus achieving "dual-purpose use": on one hand, it serves as a channel for pneumatic flux conveying; on the other hand, it acts as a traction carrier for the overall tooling movement. This integrated design reduces the number of pipelines required inside the pipe box, adapting to the objective condition of a narrow pipe box cavity.

[0032] like Figure 2 As shown, the width adjustment mechanism 33 is fixedly installed near the rear end of two sets of wire feeding tubes 31 and flux tubes 32 arranged symmetrically on the left and right. The width adjustment mechanism 33 is used to adjust the distance between the two sets of wire feeding tubes 31 and flux tubes 32 and to fix and clamp the two sets of wire feeding tubes 31 and flux tubes 32 to form a whole.

[0033] The aforementioned width adjustment mechanism 33 utilizes the coordinated action of the upper clamping block 331, lower clamping block 332, fixing block 333, clamping groove 334, screw hole 335, adjusting screw hole 336, adjusting screw rod 337, and nut 338 to cause linearly opposite displacements of the fixing blocks 333 on both sides. This adjusts the distance between the two sets of wire feeding tubes and flux tubes, and clamps the two sets of tubes together. On one hand, it can adapt to wire plug boxes of different diameters and sizes, solving the problem of "large differences in single-piece size specifications" in the prior art. On the other hand, the left / right thread design allows for synchronous and equidistant movement on both sides, ensuring the welding fixture remains centered and symmetrical, improving welding accuracy. Furthermore, the clamping grooves of the upper and lower clamping blocks clamp the wire feeding tubes and flux tubes together to form an integral structure, enhancing the rigidity and stability of the fixture and preventing tube displacement during welding.

[0034] like Figure 2 , 3 As shown in Figure 4, there are two clamping blocks 34, which are arranged symmetrically from left to right. One clamping block 34 is located on the upper part of the left group of wire feeding tubes 31 and flux tubes 32, and the other is located on the upper part of the right group of wire feeding tubes 31 and flux tubes 32. The mounting base plate 35 is fixedly located on the lower part of the clamping block 34, and a mounting base plate 35 is correspondingly provided on the lower part of each clamping block 34. The clamping blocks 34 and the mounting base plate 35 are pressed together to fix and clamp the wire feeding tubes 31 and flux tubes 32.

[0035] The aforementioned clamping block 34, clamping block body 341, threaded hole 342, and clamping groove 343 are configured such that the clamping groove 343 at the bottom of the clamping block 34 cooperates with the mounting base plate 35 to fix and clamp the wire feeding tube 31 and the flux tube 32. The arc-shaped clamping groove 343 fits against the outer circle of the tube body to achieve surface contact rather than point contact, increasing the clamping area, preventing the tube body from rotating or shifting during movement, and improving the stability of wire feeding and flux feeding.

[0036] The above-mentioned installation base plate 35, base plate 351, support block 352, and support groove 353 are used to install the base plate 35 as a bearing platform. The bottom of the base plate 35 is in horizontal contact with the bottom inner wall of the plug box 1, and the upper part supports the wire feeding tube and flux tube through the support groove 353. At the same time, it provides an installation foundation for the angle adjustment mechanism 37 and flux box 38.

[0037] The aforementioned arrangement of the clamping block 34 and mounting base plate 35, on the one hand, constructs a three-dimensional clamping structure of "upper pressure and lower support". After the clamping block 34 and mounting base plate 35 are fastened by threaded connection, the support groove 353 and the clamping groove 343 together form an annular enclosing space that matches the outer circle of the tube, firmly locking the wire feeding tube 31 and the flux tube 32 in the predetermined position. On the other hand, it realizes the axial and radial limiting of the wire feeding tube 31 and the flux tube 32. After the clamping block 34 and the mounting base plate 35 cooperate to clamp the tube body, the radial (up and down, left and right) freedom of the tube body is restricted, and the tube body is only allowed to move along the axial trajectory set by the base plate 351 with the tooling as a whole.

[0038] like Figure 2 and 3 As shown, there are two conductive nozzles 36, which are fixedly mounted at the front end of the angle adjustment mechanism 37.

[0039] The conductive nozzle 36, fixedly mounted at the front end of the angle adjustment mechanism 37, delivers the welding wire to the welding bevel at the inner corner of the pipe box and acts as a conductive element to generate an electric arc in order to melt the welding wire. This ensures that the port of the conductive nozzle 36 is precisely aligned with the 45° inclined welding bevel, solving the problem in the prior art that "the adjustment stroke of the wire feed nozzle has inherent limitations, it is difficult to adapt to welding postures at different corner positions, and it causes arc deviation," thus ensuring stable arc combustion and weld formation quality.

[0040] like Figure 2 and 3 As shown, the angle adjustment mechanism 37 is arranged symmetrically on the left and right sides. One is fixed on the upper left rear position of the left mounting base plate 35, and the other is fixed on the upper right rear position of the right mounting base plate 35. The angle adjustment mechanism 37 is used to fix the conductive nozzle 36 and adjust the angle of the conductive nozzle 36.

[0041] The aforementioned angle adjustment mechanism 37 utilizes the cooperation between the fixing body 371, the conductive nozzle mounting hole 372, the wire feeding tube mounting hole 373, and the tightening screw 374. On one hand, by loosening the tightening screw 374 and rotating the conductive nozzle 36, the angle of the conductive nozzle 36 can be flexibly adjusted to ensure accurate wire feeding. On the other hand, 4-6 tightening screws 374 tighten from above to securely lock the conductive nozzle 36 and the wire feeding tube 31, preventing angle deviation due to vibration during welding.

[0042] like Figure 1 , 2 As shown in Figure 5, there are two flux boxes 38 arranged symmetrically on the left and right sides. One is fixedly set at the front right side of the left mounting base plate 35, and the other is fixedly set at the front left side of the right mounting base plate 35. The flux boxes 38 are used to store flux.

[0043] The flux box 38, as described above, includes a sheet metal bending housing 381, a U-shaped hole 382, ​​a limiting block 383, a fixing screw hole 384, a limiting groove 385, and an adjustment groove 386. The sheet metal bending housing 381 serves two purposes: firstly, it temporarily stores the flux; secondly, it guides the flux to flow evenly and stably to the welding area. The U-shaped hole 382 provides adjustable space for the angle of the conductive nozzle 36, preventing structural interference between the conductive nozzle 36 and the sheet metal bending housing 381, thus achieving functional compatibility between flux delivery and conductive nozzle angle adjustment. The limiting groove 385 fixes and restricts the position of the flux tube 32, ensuring stable connection of the flux delivery channel. By adjusting the setting of the groove 386, an installation and adjustment channel is provided for the fine adjustment of the front and rear position of the baffle 39. This allows for the fine adjustment of the distance between the baffle 39 and the inner walls on both sides of the plug box 1, thereby enabling the outer end face of the baffle 39 to fit against the inner walls on both sides of the plug box 1 (the fitting distance is limited to the baffle 39 being able to move slowly and uniformly along the inner walls on both sides of the plug box 1).

[0044] like Figure 1 , 2 As shown in Figures 3 and 5, the baffle 39 is adjustablely positioned at the front of the flux box 38. The baffle 39 is used to control the flux flow direction and increase the flux embedment amount. The baffle 39 includes a baffle body 391, which is Z-shaped. The mounting screw holes 392 are located at the rear of the baffle body 391 and are arranged symmetrically from top to bottom. The positions of the mounting screw holes 392 and the adjustment grooves 386 are corresponding to each other. Screws pass through the mounting screw holes 392 and the adjustment grooves 386 to fix the baffle body 391 to the front of the sheet metal bending box 381. A chamfer 393 is formed on the outer corner of the front side of the baffle body 391, and the chamfer 393 is 15×45°.

[0045] By setting the baffle 39 as described above, during the slow and uniform movement of the baffle 39, the baffle 39 collects and gathers the scattered flux toward the weld seam at the inner corner 2 of the pipe box, which solves the core problems in the background technology of "flux deviation, large amount of flow to the ineffective area outside the weld seam, and insufficient flux burial thickness at the effective welding position", and improves the amount of flux burial at the inner corner 2 of the pipe box.

[0046] The structure of the baffle body 391 is set to Z-shape. On the one hand, this allows the baffle body 391 to adapt to the installation position on the front side of the sheet metal bending box 381, enabling the baffle body 391 to be adjusted in the left and right directions on the front side of the sheet metal bending box 381. On the other hand, it forms an effective flux interception surface, improving the collection and aggregation effect of flux particles.

[0047] The aforementioned design involves creating a chamfer 393 at the outer bottom corner of the baffle body 391. This chamfer design serves two purposes: firstly, it allows the outer front corner of the baffle 39 to avoid the welds and slag already formed at the inner corner 2 of the pipe box, preventing interference from the baffle 39 and ensuring the continuity of the welding process and the integrity of the weld surface. Secondly, it allows adjustment of the flux embedding amount at the welds at the inner corner 2 of the split pipe box.

[0048] By adjusting the groove 386 and the mounting threaded hole 392, and by loosening or tightening the screws, the lateral position of the fine-tuning baffle can be moved along the adjusting groove 386, so that the baffle precisely fits the inner walls of both sides of the threaded plug box 1.

[0049] like Figure 1-5 As shown, before submerged arc welding is performed on the inner corner of the air cooler plug box, the conductive nozzle 36 is connected to the positive terminal of the power supply, and the body of the plug box 1 is connected to the negative terminal of the power supply.

[0050] The welding wire conveying mechanism, pneumatic conveying mechanism, and mechanical displacement platform described in this invention are entirely within the scope of existing technology. The specific structure and working principle of the welding wire conveying mechanism, pneumatic conveying mechanism, and mechanical displacement platform are fully known to those skilled in the art. Therefore, there is no need to elaborate on the structure and working principle of the welding wire conveying mechanism, pneumatic conveying mechanism, and mechanical displacement platform.

[0051] like Figure 1-5 As shown, the present invention uses two sets of wire feeding tubes 31 / flux tubes 32 arranged symmetrically on the left and right, equipped with symmetrical conductive nozzles 36, flux boxes 38 and baffles 39. Under the traction of a mechanical displacement platform, the whole system moves synchronously, forming a double-sided synchronous submerged arc welding system for the weld seam of the inner corner 2 of the wire plug tube box 1. This system achieves one-time synchronous submerged arc welding of the inner corners of both sides of the wire plug tube box 1. Compared with the single-sided sequential welding method, it significantly improves the welding efficiency. At the same time, due to the symmetrical welding heat input on both sides, it reduces the dimensional deviation and residual thermal stress caused by uneven thermal deformation of the wire plug tube box.

[0052] Example 1, such as Figure 1-5 As shown, a submerged arc welding method for the inner corner of the air cooler plug box mainly includes the following steps:

[0053] Step 1: Preparations before submerged arc welding of the plug tube box: First, align the baffle 39 of the auxiliary welding fixture 3 with the front end face of the plug tube box 1. At this time, the mounting base plate 35 of the auxiliary welding fixture 3 is in horizontal contact with the bottom inner wall of the plug tube box 1. Then, connect the wire feeding tube 31 to the wire discharge end of the wire feeding mechanism. Use the wire feeding mechanism to feed the wire through the wire feeding tube 31 and the conductive nozzle 36 on the angle adjustment mechanism 37 to the inner corner 2 of the tube box. At the same time, fix the flux tube 32 to the output end of the pneumatic conveying mechanism at the bottom of the flux cylinder. Also, fix the flux tube 32 near the rear end surface to the mechanical displacement platform.

[0054] Step 2: Adaptive adjustment of the spacing of auxiliary welding fixtures: Based on the distance between the inner corners 2 of the plug box 1, the operator uses a wrench to tighten the nut 338 in the middle position of the adjusting screw 337 of the width adjustment mechanism 33, so that the adjusting screw 337 rotates. With the adjusting screw 337 having a left-hand thread at one end and a right-hand thread at the other end, and under the meshing action of the adjusting screw hole 336 on the fixing block 333, the fixing blocks 333 on the left and right sides will have linearly opposite displacements along the adjusting screw 337 until the baffle 39 contacts the inner walls on both sides of the plug box 1.

[0055] Step 3: Adjustment of the position of the baffle and conductive nozzle of the auxiliary welding fixture: 1. Under the condition that the baffle 39 is in contact with the inner walls on both sides of the plug box 1 in Step 2, make a fine adjustment to the position of the baffle 39: First, loosen the screws passing through the mounting thread hole 392 and the adjustment groove 386, and move the baffle body 391 outward along the adjustment groove 386 until the upper outer end face of the chamfer 393 of the baffle 39 is in contact with the inner wall of the bottom left and right inner corners 2 of the plug box 1, and the baffle... 39's bottom end face fits into the bottom of the plug box 1; at the same time, the outer end face of the chamfer 393 of the baffle 39 corresponds to the welding bevel of the inner corner 2 of the box; 2. Adjustment of the position of the conductive nozzle: First, loosen all the tightening screws 374 on the upper part of the fixing body 371 of the angle adjustment mechanism 37. The operator rotates the conductive nozzle 36 so that the port of the conductive nozzle 36 is aligned with the welding bevel of the inner corner 2 of the box, and the center of the conductive nozzle 36 is aligned with the center of the inner corner 2 of the two sides of the plug box 1 at 45°.

[0056] Step 4: Submerged arc welding of the inner corners of the plug box: First, start the wire feeding mechanism, mechanical displacement platform, and pneumatic conveying mechanism. The wire feeding mechanism feeds the wire to the inner corners 2 on both sides of the bottom of the plug box 1 via the wire feeding tube 31, angle adjustment mechanism 37, and contact nozzle 36. Simultaneously, the mechanical displacement platform slowly and uniformly moves the flux tube 32 and mounting base plate 35 towards the rear of the plug box 1. At the same time, the pneumatic conveying mechanism uniformly and constantly delivers the flux from the flux cylinder through the inside of the flux tube 32 to the flux box 38. At this time, the flux flows from the sheet metal bending box 381 of the flux box 38. The flux flows to the bottom of the U-shaped hole 382 and reaches the position of the baffle 39. At this time, under the synergistic effect of the slow and uniform movement of the flux box 38 and the baffle 39, the baffle 39 collects and gathers the flux particles towards the position of the conductive nozzle 36. Under the protection of the flux, the welding wire generates an arc through the conductive nozzle 36 to melt the welding wire. The chamfer 393 of the baffle 39 can avoid the weld and slag at the inner corner of the pipe box. When the left and right baffles 39 move slowly and uniformly to the rear end position of the wire plug pipe box 1, the left and right conductive nozzles 36, the left and right flux boxes 38 and the left and right baffles 39 are used to realize the one-time submerged arc welding operation of the inner corners 2 of the pipe box on both sides of the wire plug pipe box 1.

[0057] Example 2, as follows Figure 1-5 As shown, a submerged arc welding method for the inner corner of the air cooler plug box mainly includes the following steps:

[0058] Step 1: Preparations before submerged arc welding of the plug tube box: First, align the baffle 39 of the auxiliary welding fixture 3 with the front end face of the plug tube box 1. At this time, the mounting base plate 35 of the auxiliary welding fixture 3 is in horizontal contact with the bottom inner wall of the plug tube box 1. Then, connect the wire feeding tube 31 to the wire discharge end of the wire feeding mechanism. Use the wire feeding mechanism to feed the wire through the wire feeding tube 31 and the conductive nozzle 36 on the angle adjustment mechanism 37 to the inner corner 2 of the tube box. At the same time, fix the flux tube 32 to the output end of the pneumatic conveying mechanism at the bottom of the flux cylinder.

[0059] Step 2: Adaptive adjustment of the spacing of auxiliary welding fixtures: Based on the distance between the inner corners 2 of the plug box 1, the operator uses a wrench to tighten the nut 338 in the middle position of the adjusting screw 337 of the width adjustment mechanism 33, so that the adjusting screw 337 rotates. With the adjusting screw 337 having a left-hand thread at one end and a right-hand thread at the other end, and under the meshing action of the adjusting screw hole 336 on the fixing block 333, the fixing blocks 333 on the left and right sides will have linearly opposite displacements along the adjusting screw 337 until the baffle 39 contacts the inner walls on both sides of the plug box 1.

[0060] Step 3: Adjustment of the position of the baffle and conductive nozzle of the auxiliary welding fixture: 1. Under the condition that the baffle 39 is in contact with the inner walls on both sides of the plug box 1 in Step 2, make a fine adjustment to the position of the baffle 39: First, loosen the screws passing through the mounting thread hole 392 and the adjustment groove 386, and move the baffle body 391 outward along the adjustment groove 386 until the upper outer end face of the chamfer 393 of the baffle 39 is in contact with the inner wall of the bottom left and right inner corners 2 of the plug box 1, and the baffle... 39's bottom end face fits into the bottom of the plug box 1; at the same time, the outer end face of the chamfer 393 of the baffle 39 corresponds to the welding bevel of the inner corner 2 of the box; 2. Adjustment of the position of the conductive nozzle: First, loosen all the tightening screws 374 on the upper part of the fixing body 371 of the angle adjustment mechanism 37. The operator rotates the conductive nozzle 36 so that the port of the conductive nozzle 36 is aligned with the welding bevel of the inner corner 2 of the box, and the center of the conductive nozzle 36 is aligned with the center of the inner corner 2 of the two sides of the plug box 1 at 45°.

[0061] Step 4: Submerged arc welding of the inner corners of the plug box: First, start the wire feeding mechanism and the pneumatic feeding mechanism. The wire feeding mechanism feeds the wire to the inner corners 2 on both sides of the bottom of the plug box 1 through the wire feeding tube 31, the angle adjustment mechanism 37, and the contact nozzle 36. At the same time, the operator holds the flux tube 32 and drags the flux tube 32 and the mounting base plate 35 slowly and evenly towards the rear of the plug box 1. Simultaneously, the pneumatic feeding mechanism evenly and constantly delivers the flux in the flux cylinder through the inside of the flux tube 32 to the flux box 38. At this time, the flux flows from the sheet metal bending box 381 of the welding box 38. The flux flows to the bottom of the U-shaped hole 382 and reaches the position of the baffle 39. At this time, under the synergistic effect of the slow and uniform movement of the flux box 38 and the baffle 39, the baffle 39 collects and gathers the flux particles towards the position of the conductive nozzle 36. Under the protection of the flux, the welding wire generates an arc through the conductive nozzle 36 to melt the welding wire. The chamfer 393 of the baffle 39 can avoid the weld and slag at the inner corner of the pipe box. When the left and right baffles 39 move slowly and uniformly to the rear end position of the wire plug pipe box 1, the left and right conductive nozzles 36, the left and right flux boxes 38 and the left and right baffles 39 are used to realize the one-time submerged arc welding operation of the inner corners 2 of the pipe box on both sides of the wire plug pipe box 1.

[0062] Various modifications to the above embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be adapted to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A submerged arc welding method for the inner corner of an air cooler plug box, characterized in that: Step 1: Preparations before submerged arc welding of the wire plug box: First, align the baffle of the auxiliary welding fixture with the front end face of the wire plug box. At this point, the mounting base plate of the auxiliary welding fixture should be in horizontal contact with the bottom inner wall of the wire plug box. Then, connect the wire feeding tube to the wire discharge end of the wire feeding mechanism. Use the wire feeding mechanism to feed the wire through the wire feeding tube and the conductive nozzle on the angle adjustment mechanism to the inner corner of the box. Simultaneously, fix the flux tube to the output end of the pneumatic conveying mechanism at the bottom of the flux cylinder. Also, fix the flux tube near the rear end surface to the mechanical displacement platform. Step 2: Adaptive adjustment of the spacing of auxiliary welding fixtures: Based on the distance between the inner corners of the plug box, the operator uses a wrench to tighten the nut in the middle position of the adjusting screw of the width adjustment mechanism, causing the adjusting screw to rotate. With the adjusting screw having a left-hand thread at one end and a right-hand thread at the other end, and the engagement with the adjusting screw hole on the fixing block, the fixing blocks on the left and right sides will have linearly opposite displacements along the adjusting screw until the baffle contacts the inner walls on both sides of the plug box. Step 3, Adjustment of the position of the baffle and conductive nozzle of the auxiliary welding fixture:

1. Under the condition that the baffle is in contact with the inner walls of both sides of the plug box in Step 2, make a fine adjustment to the position of the baffle: First, loosen the screws passing through the mounting thread hole and the adjustment groove, and move the baffle body outward along the adjustment groove until the upper end face of the outer chamfer of the baffle is in contact with the inner wall of the bottom left and right inner corners of the plug box, and the bottom end face of the baffle is in contact with the bottom of the plug box; at the same time, make the outer end face of the chamfer of the baffle correspond to the welding bevel of the inner corner of the box; 2. Adjustment of the position of the conductive nozzle: First, loosen all the tightening screws on the upper part of the fixing body of the angle adjustment mechanism, and the operator rotates the conductive nozzle so that the end of the conductive nozzle is aligned with the welding bevel of the inner corner of the box; Step 4: Submerged arc welding of the inner corners of the plug box: First, start the wire feeding mechanism, mechanical displacement platform, and pneumatic conveying mechanism. The wire feeding mechanism feeds the wire to the inner corners of the plug box on both sides of the bottom through the wire feeding tube, angle adjustment mechanism, and contact nozzle. Simultaneously, the mechanical displacement platform slowly and uniformly moves the flux tube and mounting base plate towards the rear of the plug box. At the same time, the pneumatic conveying mechanism uniformly and constantly delivers the flux from the flux cylinder to the flux box through the inside of the flux tube. At this point, the flux exits from the sheet metal of the flux box... The flux flows from the bottom of the U-shaped hole in the bent box to the position of the baffle. At this time, under the synergistic effect of the slow and uniform movement of the flux box and the baffle, the baffle collects and gathers the flux particles towards the position of the conductive nozzle. Under the protection of the flux, the welding wire melts through the conductive nozzle by generating an arc. The chamfer of the baffle can avoid the weld and slag at the inner corner of the pipe box. When the left and right baffles move slowly and uniformly to the rear end of the wire plug pipe box, the left and right conductive nozzles, left and right flux boxes and left and right baffles are used to realize the one-time submerged arc welding operation of the inner corner of the pipe box on both sides of the wire plug pipe box.

2. The submerged arc welding method for the inner corner of the air cooler plug box according to claim 1, characterized in that: In step three, the center of the conductive nozzle is aligned with the bottom of the inner corner bevel of the plug box on both sides.

3. A submerged arc welding auxiliary welding fixture for the inner corner of the air cooler plug box, characterized in that: The system includes a plug box and auxiliary welding fixtures. The plug box is a hollow cuboid with its four corners forming the inner corners. The auxiliary welding fixtures include a wire feed tube and a flux tube, which are arranged horizontally and parallel to each other, forming one group. The two groups of wire feed tubes and flux tubes are arranged symmetrically from left to right. A width adjustment mechanism is fixedly positioned near the rear end of the two symmetrically arranged groups of wire feed tubes and flux tubes. This mechanism is used to adjust the spacing between the two groups of wire feed tubes and flux tubes and to clamp them together to form a single unit. Two clamping blocks are provided, arranged symmetrically from left to right. One clamping block is positioned above the left group of wire feed tubes and flux tubes, and the other is positioned above the right group of wire feed tubes and flux tubes. A mounting base plate is fixedly positioned on top of the clamping blocks. At the bottom, each clamping block has a corresponding mounting base plate. The clamping blocks and mounting base plates clamp together to fix and press the wire feed tube and flux tube. There are two conductive nozzles, which are fixed at the front end of the angle adjustment mechanism. The angle adjustment mechanism is symmetrically arranged, one fixed at the upper left rear position of the left mounting base plate and the other fixed at the upper right rear position of the right mounting base plate. The angle adjustment mechanism is used to fix the conductive nozzle and adjust its angle. There are two flux boxes symmetrically arranged, one fixed at the front right position of the left mounting base plate and the other fixed at the front left position of the right mounting base plate. The flux boxes are used to store flux. A baffle is adjustable and located at the front of the flux box. The baffle is used to control the flux flow direction and increase the flux coverage.

4. The submerged arc welding auxiliary welding fixture for the inner corner of the air cooler plug box according to claim 3, characterized in that: The width adjustment mechanism includes an upper clamping block and a lower clamping block, both of which are cuboid in shape. The upper and lower clamping blocks are aligned vertically for use. The bottom of the upper clamping block and the upper part of the lower clamping block each have two corresponding clamping grooves. The clamping groove at the bottom of the upper clamping block is in contact with the upper surface of the wire feeding tube and the flux tube, respectively, while the clamping groove at the top of the lower clamping block is in contact with the lower surface of the wire feeding tube and the flux tube, respectively. A fixing block is located on the upper and lower clamping blocks. The fixing block is T-shaped. The upper, lower, and fixing blocks have symmetrical screw holes on their left and right sides, which pass through the bodies of the upper, lower, and fixing blocks. An adjusting screw hole is provided on the side of the front protrusion of the fixing block. The two ends of the adjusting screw are screwed into the adjusting screw hole, and a nut is fixedly installed in the middle of the adjusting screw. The adjusting screw can be tightened by using a wrench to achieve the fit between the adjusting screw and the adjusting screw hole.

5. The submerged arc welding auxiliary welding fixture for the inner corner of the air cooler plug box according to claim 4, characterized in that: The upper clamping block, lower clamping block, and fixing block are used to fix and clamp the wire feeding tube and flux tube by screws passing through the screw holes; one end of the adjusting screw has a left-hand thread and the other end has a right-hand thread.

6. The submerged arc welding auxiliary welding fixture for the inner corner of the air cooler plug box according to claim 3, characterized in that: The clamping block includes a clamping block body, which is rectangular in shape. A threaded hole is symmetrically opened on the upper part of the clamping block body. The clamping groove is a concave arc shape, and the clamping groove is symmetrically opened on the bottom of the clamping block body. The symmetrical clamping groove is attached to the upper part of the wire feeding tube and the flux tube.

7. The submerged arc welding auxiliary welding fixture for the inner corner of the air cooler plug box according to claim 3, characterized in that: The mounting base plate includes a rectangular base plate. A support block is fixedly installed at the rear edge of the base plate. The support block is also rectangular, and its rear, left, and right ends are flush with the rear, left, and right ends of the base plate, respectively. Support grooves are symmetrically provided on the upper part of the support block. The support grooves are concave arc-shaped, and their arc surfaces are in contact with the lower surfaces of the wire feeding tube and the flux tube, respectively.

8. The submerged arc welding auxiliary welding fixture for the inner corner of the air cooler plug box according to claim 3, characterized in that: The angle adjustment mechanism includes a fixed body, which is rectangular in shape. A conductive nozzle mounting hole is opened at the center of the front end of the fixed body, and a wire feeding tube mounting hole is opened at the center of the rear end of the fixed body. The conductive nozzle mounting hole and the wire feeding tube mounting hole are connected. A tightening screw is tightened and fixed in the middle of the upper part of the fixed body. Four to six tightening screws are arranged in the middle of the upper part of the fixed body. The tightening screws pass through the body of the fixed body and tighten against the upper surface of the conductive nozzle or the upper surface of the wire feeding tube.

9. The submerged arc welding auxiliary welding fixture for the inner corner of the air cooler plug box according to claim 3, characterized in that: The flux box includes a sheet metal bending box, which is a hollow square shape. A U-shaped hole is opened on the outside of the sheet metal bending box, which provides movable space for adjusting the angle of the conductive tip. A limiting block is fixedly installed at the bottom rear side of the sheet metal bending box. A limiting groove for limiting the flux tube is opened in the middle of the upper part of the limiting block. Fixing screw holes are opened on the limiting blocks on both sides of the limiting groove, and the fixing screw holes pass vertically upward through the upper rear side of the sheet metal bending box. Adjustment slots are symmetrically opened on the front side of the sheet metal bending box, and the adjustment slots penetrate through the body of the sheet metal bending box.

10. The submerged arc welding auxiliary welding fixture for the inner corner of the air cooler plug box according to claim 3, characterized in that: The baffle includes a baffle body, which is Z-shaped. The mounting holes are located on the rear side of the baffle body and are arranged symmetrically from top to bottom. The positions of the mounting holes and the adjustment slots are corresponding front to back. Screws pass through the mounting holes and the adjustment slots to fix the baffle body to the front side of the sheet metal bending box. A chamfer is formed on the outer front corner of the baffle body, and the chamfer is 15×45°.

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