A process and apparatus for narrow gap arc welding of thick plate girth joints

Abstract

The application provides a thick plate ring joint narrow gap arc welding process, which comprises two groups of to-be-welded cylinders in butt joint, forms a narrow gap weld, and the narrow gap weld is in a ring state; a coordinate system is established with the center of the to-be-welded cylinder as an origin, the normal line of the cylinder as a Z-axis direction, an X-axis as a horizontal direction and a Y-axis as a vertical direction; a metal backing plate is arranged in the narrow gap weld, the metal backing plate is at an angle of 45 degrees with the normal line of the to-be-welded cylinder, and a triangular area is formed between the metal backing plate and the to-be-welded cylinder; a welding gun moves in the X-axis and Y-axis directions, completely fills the triangular area, completes initial weld filling, and the welding pool plane is parallel to the X-axis; the welding gun moves along the X-axis direction, meanwhile, a roller frame drives the to-be-welded cylinder to roll, the welding pool plane is always parallel to the X-axis, and the metal backing plate intersects with the welding pool plane at the welding end point and is perpendicular to the welding pool plane; the welding gun moves along the X-axis direction, meanwhile, the welding gun is lifted along the Y-axis direction.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and more specifically to a narrow-gap arc welding process and equipment for thick plate circumferential seams. Background Technology

[0002] Circumferential welding of thick-walled containers is an important application area of ​​narrow-gap welding. As is well known, narrow-gap welding is a highly efficient arc welding method for thick plate welding, and it is also effective for circumferential welding of thick-walled containers. However, the disadvantages of narrow-gap welding also exist in narrow-gap welding of thick-walled containers. The width of the narrow-gap bevel is usually 10-20mm. The welding methods currently used require a relatively complex welding torch structure and have high dimensional accuracy requirements for the workpiece bevel. Therefore, the narrow-gap welding method can only be used for welding some special products with precision machining of the bevel, such as the welding of thick-walled high-pressure vessels. There are also many thick-walled cylindrical products in steel structures, engineering machinery and other fields with large welding workloads, and conventional narrow-gap welding methods cannot be applied to the welding of such products. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a narrow gap arc welding process and equipment for thick plate circumferential seams, so as to overcome the above-mentioned defects in the existing technology.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A narrow-gap arc welding process for circumferential seams of thick plates, characterized by comprising the following steps:

[0006] Step 1: The two sets of cylinders to be welded are joined together to form a narrow gap weld. The narrow gap weld is in a ring shape. A coordinate system is established with the center of the cylinder to be welded as the origin, with the cylinder normal as the Z-axis, the X-axis as the horizontal direction, and the Y-axis as the vertical direction.

[0007] Step 2: A metal backing plate is placed in the narrow gap weld. The metal backing plate is at a 45° angle to the normal direction of the cylinder to be welded, and a triangular area is formed between the metal backing plate and the cylinder to be welded.

[0008] Step 3: The welding torch moves along the X and Y axes to completely fill the triangular area, completing the initial weld filling, and the weld pool plane is parallel to the X axis.

[0009] Step 4: The welding torch moves along the X-axis. At the same time, the roller frame drives the cylinder to be welded to roll. The plane of the weld pool is always parallel to the X-axis until the metal pad intersects with and is perpendicular to the plane of the weld pool at the end of the welding process.

[0010] Step 5: The welding torch moves along the X-axis while simultaneously being raised along the Y-axis.

[0011] Preferably, in step two, one end of the metal backing plate is aligned with the bottom of the narrow gap weld, and the other end of the metal backing plate is aligned with the surface of the cylinder to be welded.

[0012] Preferably, in step four, the rotational speed of the workpiece driven by the roller frame is matched with the welding current to achieve automatic tracking in the arc height direction.

[0013] Preferably, in step five, the movement path of the welding torch in the X-axis direction is from the metal pad to the surface of the cylinder to be welded.

[0014] Preferably, the workpiece to be processed is stopped rotating in step five.

[0015] Preferably, the welding torch includes a support and a welding torch. The support is provided with two sets of roller frames, which are arranged opposite each other on both sides of the welding torch. Each set of roller frames is provided with a pair of rollers, and a support groove for placing the workpiece to be processed is provided between the pairs of rollers. The support grooves on the two sets of roller frames are located on the same straight line.

[0016] Preferably, the roller pair includes a first roller and a second roller, both of which have a hinge shaft at their bottom. A first cylinder is provided between the two sets of hinge shafts, driving the two sets of hinge shafts to move so that the first roller and the second roller move closer or further apart. A support plate is provided at the bottom of the roller pair, and a second cylinder is provided at the bottom of the support plate, driving the support plate to move up and down. A sliding groove is provided on the frame, and the support plate and the hinge shaft are slidably disposed in the sliding groove, which is arranged along the length of the support groove.

[0017] Preferably, the slide includes a first slide, a second slide, and a third slide. Slider blocks are respectively provided in the first slide and the second slide. The two sets of hinge shafts are respectively hinged to the two sets of sliders. The support plate is provided in the third slide and is fixedly connected to both sets of sliders.

[0018] Preferably, a second cylinder is provided at the bottom of the support plate, and the second cylinder drives the support to move up and down.

[0019] Preferably, the roller frame is provided with several sets of roller pairs, all of which are located on the same straight line. The roller frame is provided with two sets of rotating shafts, which are respectively located on the first roller and the second roller. Electromagnets are provided at both ends of the rotating shafts.

[0020] The beneficial effects of this invention are as follows: Welding using this process achieves efficient and rapid welding in the welding of thick-walled high-pressure vessels. While ensuring welding accuracy, it places lower demands on the welding torch and offers faster welding speeds, meeting the needs of steel structures, engineering machinery, and other thick-walled cylindrical products with high welding workloads. The roller frame ensures alignment of the two sets of workpieces during welding, preventing misalignment that could affect welding accuracy and results. The first cylinder drives the adjustment of the mounting positions of the first and second rollers. Simultaneously, the support plate, first roller, and second roller provide clamping for the workpieces. Furthermore, the sliding plate further clamps the two sets of workpieces, reducing the gap between them and improving welding accuracy. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the initial welding position filling process of the present invention;

[0022] Figure 2 This is a schematic diagram showing the completion position of the initial welding position filling process according to the present invention;

[0023] Figure 3 This is a schematic diagram of the circumferential weld filling process of the present invention;

[0024] Figure 4 This is a schematic diagram of the end point of circumferential weld filling according to the present invention;

[0025] Figure 5 This is a structural diagram of the support structure of the present invention;

[0026] Figure 6 This is a structural diagram of the roller frame of the present invention;

[0027] Figure 7 This is a diagram of the roller structure of the present invention;

[0028] Figure 8 This is a diagram of the slide structure of the present invention.

[0029] Figure 9 This is an overall structural diagram of the present invention.

[0030] Reference numerals: 1. Bracket; 2. Welding torch; 3. Roller frame; 4. Roller pair; 41. Support groove; 42. First roller; 43. Second roller; 44. Hinge shaft; 45. First cylinder; 46. Rotating shaft; 5. Support plate; 61. First slide groove; 62. Second slide groove; 63. Third slide groove; 64. Slider; 65. Slide plate. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings:

[0035] like Figure 1-5 As shown, in step one, two sets of cylinders to be welded are joined together to form a narrow gap weld. The narrow gap weld is in a ring shape. A coordinate system is established with the center of the cylinder to be welded as the origin, with the cylinder normal as the Z-axis, the X-axis as the horizontal direction, and the Y-axis as the vertical direction.

[0036] Step 2: A metal backing plate is placed inside the narrow gap weld. One end of the metal backing plate is aligned with the bottom of the narrow gap weld, and the other end of the metal backing plate is aligned with the surface of the cylinder to be welded. The metal backing plate and the normal direction of the cylinder to be welded form a 45° angle. The metal backing plate and the cylinder to be welded form a triangular area, and the triangular area is initially filled with weld.

[0037] Step 3: The welding torch 2 moves along the X and Y axes to completely fill the triangular area, completing the initial weld filling. The weld pool plane is parallel to the X axis, meaning the plane after welding is parallel to the plane containing the X axis, ensuring that the triangular area is completely filled.

[0038] Step 4: The welding torch 2 moves along the X-axis, while the roller frame 3 drives the cylinder to be welded to roll. The weld pool plane is always parallel to the X-axis until the metal backing plate intersects and is perpendicular to the weld pool plane at the welding endpoint. At the same time, the roller frame 3 drives the rotation speed of the workpiece to match the welding current, realizing automatic tracking in the arc height direction. This ensures that the rotation speed of the workpiece on the roller frame 3 matches the welding speed, ensuring complete welding during the rotation of the workpiece. The welding process at this time is similar to vertical gas-electric welding because there is sufficient welding heat input to ensure reliable fusion of the sidewalls. When the position of the metal backing plate at the welding starting point reaches the vertical position, the workpiece rotation stops.

[0039] Step 5: Welding torch 2 moves along the X-axis and simultaneously rises along the Y-axis to complete the remaining welding and fill, achieving complete weld filling.

[0040] The welding process using this technology achieves efficient and rapid welding in the welding of some thick-walled high-pressure vessels. At the same time, while ensuring welding accuracy, it has lower requirements for the welding torch 2 and faster welding speed, which can meet the needs of steel structures, engineering machinery and other thick-walled cylindrical products with large welding workloads.

[0041] like Figure 5-8 As shown, a narrow-gap arc welding device for circumferential seams of thick plates is used for the above-mentioned process. The device includes a support 1 and a welding torch 2. The support 1 holds two sets of workpieces to be processed, fixing them while simultaneously connecting them. The welding torch 2 performs narrow-gap welding on the two sets of workpieces. Two sets of roller frames 3 are mounted on the support 1, positioned opposite each other on both sides of the welding torch 2. These roller frames 3 hold the two sets of workpieces, respectively, achieving both positioning and... The roller frame 3 drives the two sets of workpieces to rotate synchronously during the welding process, ensuring the smooth progress of the welding process. Each set of roller frames 3 is equipped with a pair of rollers 4, and a placement groove for placing the workpieces is set between the roller pairs 4. The placement groove is used to position and install the workpieces. At the same time, the placement grooves on the two sets of roller frames 3 are on the same straight line, ensuring that the two sets of workpieces are aligned during the welding process, avoiding misalignment of the two sets of workpieces during the welding process, which would affect the welding accuracy and welding effect.

[0042] The roller pair 4 includes a first roller 42 and a second roller 43. The first roller 42 and the second roller 43 support the workpiece to be processed while simultaneously rotating the workpiece on the first roller 42 and the second roller 43. The rotation speed of the first roller 42 and the second roller 43 matches the current of the welding torch 2, ensuring that the rotation speed of the workpiece matches the welding speed during welding, resulting in more uniform welding. Hinges 44 are respectively provided at the bottom of the first roller 42 and the second roller 43. These hinges 44 allow adjustment of the mounting angle of the first roller 42 and the second roller 43, enabling them to move closer or further apart. A first cylinder 45 is provided between the two sets of hinges 44. The first cylinder 45 drives both sets of hinges 44 to move simultaneously, causing the first roller 42 and the second roller 43 to move closer or further apart, thus opening and closing the placement slot. A support plate 5 is provided at the bottom of the roller pair 4. The bottom of the support plate 5 is equipped with an elastic element. Before welding, the first cylinder 45 drives the two sets of hinge rods to rotate, separating the first roller 42 and the second roller 43. The workpiece to be processed is then placed on the support plate 5. The plate moves downward under the action of the elastic element, while simultaneously driving the first roller 42 and the second roller 43 to press against the upper surface of the workpiece under the action of the first cylinder 45. The first roller 42, the second roller 43, and the support plate 5 are used to achieve a fixed connection of the workpiece on the roller frame 3. The frame is equipped with a sliding groove, in which the support plate 5 and the hinge shaft 44 are slidably disposed. The sliding groove is arranged along the length of the support groove 41. When the workpieces to be processed are fixedly connected on the roller frame 3, the support plate 5 and the hinge shaft 44 are driven to move in the sliding groove, that is, the support plate 5 and the hinge shaft 44 move towards the side where the welding gun 2 is located, so as to realize the two sets of workpieces to be processed are close to or far away, and to realize the clamping of the two sets of workpieces to be processed, so as to avoid the gap between the two sets of workpieces to be processed during the welding of the metal backing plate, which would affect the welding effect.

[0043] The slide includes a first slide 61, a second slide 62, and a third slide 63. The third slide 63 is disposed within the first slide 61 and the second slide 62, and sliders 64 are respectively disposed within them. Two sets of hinge shafts 44 are respectively hinged to the two sets of sliders 64. Using the sliders 64, it is ensured that while the hinge shafts 44 slide within the first slide 61 and the second slide 62, the hinge shafts 44 can rotate relative to the first slide 61 and the second slide 62, ensuring the normal use of the hinge shafts 44. At the same time, a slide plate 65 is disposed at the bottom of the support plate 5. The slide plate 65 is disposed within the third slide 63 and is fixedly connected to the two sets of sliders 64. A motor is disposed on the slide plate 65. The motor drives the slide plate 65 to move within the third slide 63, thereby driving the sliders 64 within the first slide 61 and the second slide 62 to move, thus pushing the workpiece to be processed toward the side where the welding gun 2 is located.

[0044] A second cylinder is installed at the bottom of the support plate 5. The second cylinder drives the support to move up and down. After the two sets of workpieces are pressed together and the welding in steps two and three is completed, and after ensuring that the two sets of workpieces will not separate, the first cylinder 45 drives the two sets of hinge rods to rotate, so that the first roller 42 and the second roller 43 are disengaged from the workpieces. At the same time, the second cylinder drives the support plate 5 to move upward and drives the workpieces to move upward. When the workpieces move to a certain height, the first cylinder 45 drives the first roller 42 and the second roller 43 to press against the lower surface of the workpieces, so that the workpieces are placed on the first roller 42 and the second roller 43, ensuring that the workpieces on the first roller 42 and the second roller 43 can rotate on the roller pair 4. During the movement of the workpieces, the welding torch 2 moves with the workpieces.

[0045] The roller frame 3 is equipped with several sets of roller pairs 4, all located on the same straight line and equidistant from each other. For longer workpieces, multiple sets of roller pairs 4 can provide support, preventing the workpiece from becoming too heavy and unstable on the roller frame 3 due to excessive weight. Two sets of rotating shafts 46 are also provided on the roller frame 3, respectively mounted on the first roller 42 and the second roller 43. During use, the two sets of rotating shafts 46 drive the first roller 42 and the second roller 43 to rotate. Simultaneously, the rotating shafts 46... 6. The rotating shafts 46, which are equipped with electromagnets at both ends and are located on the same straight line, are connected end to end. That is, the rotating shafts 46 on the two adjacent sets of roller pairs 4 are connected. During use, the status of the workpiece to be processed on the roller pair 4 is detected, and the on and off status of the electromagnets is controlled to realize the connection between the two adjacent sets of rotating shafts 46. The rotating shafts 46 on the roller pair 4 that are in contact with the workpiece to be processed are connected, and the rotating shafts 46 that are not in contact with the workpiece to be processed are separated. While ensuring that the workpiece to be processed is installed stably and rotates, the unused roller pair 4 does not rotate, avoiding the roller pair 4 from spinning idly and causing waste of resources. At the same time, impurities and other things rotate inside the roller pair 4, causing wear on the roller pair 4.

[0046] Working principle: During use, the first cylinder 45 drives the first roller 42 and the second roller 43 to move, causing the placement groove to open and placing the workpiece into the placement groove. The support plate 5 moves downward under the action of the elastic element. At the same time, the first cylinder 45 drives the first roller 42 and the second roller 43 to move towards the side where the workpiece is located and press against the upper surface of the workpiece. The first roller 42, the second roller 43, and the support plate 5 are used to clamp the workpiece. Meanwhile, the sliding plate 65 moves within the groove. The sliding mechanism clamps the two sets of workpieces and completes the welding in steps one, two, and three. Then, the first cylinder 45 releases the workpieces, and the second cylinder drives the support plate 5 to move upward above the first roller 42 and the second roller 43. After that, the first roller 42 and the second roller 43 are driven to be below the workpieces, and the support plate 5 is driven to reset. This allows the workpieces to press against the first roller 42 and the second roller 43 and rotate with the first roller 42 and the second roller 43, thus completing the welding.

[0047] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A narrow-gap arc welding process for circumferential seams of thick plates, characterized in that, Includes the following steps: Step 1: The two sets of cylinders to be welded are joined together to form a narrow gap weld. The narrow gap weld is in a ring shape. A coordinate system is established with the center of the cylinder to be welded as the origin, with the cylinder normal as the Z-axis, the X-axis as the horizontal direction, and the Y-axis as the vertical direction. Step 2: A metal backing plate is placed in the narrow gap weld. The metal backing plate is at a 45° angle to the normal direction of the cylinder to be welded, and a triangular area is formed between the metal backing plate and the cylinder to be welded. Step 3: The welding torch (2) moves along the X-axis and Y-axis to completely fill the triangular area, completing the initial weld filling, and the weld pool plane is parallel to the X-axis. Step 4: The welding torch (2) moves along the X-axis. At the same time, the roller frame (3) drives the cylinder to be welded to roll. The welding pool plane is always parallel to the X-axis until the metal pad intersects and is perpendicular to the welding pool plane at the welding endpoint. Step 5: The welding torch (2) moves along the X-axis and is simultaneously lifted along the Y-axis. In step 5, the movement path of the welding torch (2) in the X-axis direction is from the metal pad to the surface of the cylinder to be welded. In step 5, the workpiece to be processed stops rotating.

2. The narrow-gap arc welding process for thick plate circumferential seams according to claim 1, characterized in that, In step two, one end of the metal backing plate is aligned with the bottom of the narrow gap weld, and the other end of the metal backing plate is aligned with the surface of the cylinder to be welded.

3. The narrow-gap arc welding process for thick plate circumferential seams according to claim 1, characterized in that, In step four, the roller frame (3) drives the rotation speed of the workpiece to be processed to match the welding current, thereby achieving automatic tracking in the arc height direction.

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