Annular weld joint welding method in support-free state and positioning device of annular weld joint welding method

Abstract

The invention belongs to the technical field of welding, and particularly discloses an annular weld joint welding method in a support-free state, which comprises the following steps of: S1, fixing a cylinder section weldment by using a positioning device; s2, welding a weld joint; a two-side multi-layer manual TIG welding process is adopted, and a segmented back-step welding mode is adopted for welding of a front bottom layer; a whole-circle constrained continuous welding process is adopted for the second layer of the front face and the back face bottom sealing. Assembly positioning welding spots and weld joints can be effectively reduced, welding deformation and welding stress are controlled, weld forming consistency and appearance quality are guaranteed, and therefore the welding quality of the circumferential weld is remarkably improved; the invention further discloses a positioning device used for clamping the barrel section weldment, the positions and the relative distance of the upper fixing ring and the lower fixing ring can be flexibly adjusted through the adjusting bolts, therefore, precise fixing of barrel sections of different sizes within a certain range is achieved, and the fixing problem caused by manufacturing errors of large-size barrel sections is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of welding, and relates to a ring weld welding method in a non-supporting state and a positioning device thereof. BACKGROUND

[0002] Welding technology plays an extremely important role in the field of aerospace. With the rapid development of aerospace technology, the manufacturing of rockets, satellites and other spacecraft puts forward extremely high requirements on the quality and performance of structural parts. Among them, product ring weld welding is one of the key processes in the manufacturing process of spacecraft, and is widely used in large components such as rocket fuel tanks and satellite frames. The aluminum alloy fuel tank ring weld usually has the characteristics of large diameter and long length, and needs to overcome a series of technical difficulties such as material deformation, welding defects, positioning difficulties, welding stress control and the like during the manufacturing process.

[0003] The rocket fuel tank and its accessories are the key load-bearing components of the equipment or device, and their structural strength and sealing performance directly determine the reliability and safety of the spacecraft. In other extreme environment applications such as nuclear power plants, the ring welds also play an important role, for example, the manufacturing of nuclear reactor pressure vessels requires extremely high weld quality to ensure long-term stable operation; the ring tunnel joint of the storage tank is the connection body of the oxidant and fuel isolation and transportation channel, and the weld quality requirement is more critical.

[0004] However, the current technology also has some shortcomings: due to the particularity of the cylinder structure and the complexity of the welding process, the actual operation causes the weld joint to be multiple due to the large number of positioning points, and the joint part is prone to crack defects, which reduces the strength of the weld joint. In actual operation, the problem of no constraint caused by product structure often occurs, which not only reduces the overall rigidity and stability of the cylinder, but also may cause deformation, leakage or even rupture of the equipment during operation. In the actual operation process, due to the limitation of product structure, it is not possible to directly use an automatic welding device to complete assembly and welding, and 4 people are required to work efficiently in the full-process assembly and welding process, which is low in work efficiency, and there are problems of poor weld width consistency and poor weld forming after welding.

[0005] Although various special fixtures are used to assist ring weld welding in the prior art, a support structure or a large number of positioning welds still need to be arranged inside the cylinder segment, and the quick and repeated clamping of multiple ring welds cannot be considered, and the weld deformation control and efficiency are difficult to balance. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a ring weld welding method in a non-supporting state and a positioning device thereof, which can fix different sizes of cylinder segments within a certain range, realize quick fixing and clamping of multiple welds on the same product, and improve the weld quality.

[0007] To achieve the above objectives, the present invention employs the following technical solutions: A method for welding annular seams without support includes the following steps: S1. Use a positioning device to fix the cylindrical section weldment. The positioning device applies radial clamping force to the outer wall of the cylindrical section to be welded by two sets of upper and lower cylindrical section fixing rings and their clamping bolts on the outer periphery of the cylindrical section. The cylindrical section is fixed in place before welding without any support structure inside the cylindrical section. S2. Welding seam: The two-sided multi-layer manual TIG welding process is adopted. The front root layer is welded by segmented step welding. The second layer on the front and the bottom sealing on the back are welded by a full-circle constrained continuous welding process.

[0008] More specifically, S1 also includes repeatedly clamping the positioning device onto the cylindrical weldment to achieve rapid fixing and welding of multiple circumferential welds.

[0009] A positioning device is applied to a method for welding annular welds in an unsupported state, specifically comprising: The cylindrical segment fixing ring is divided into upper and lower groups, which respectively fix the upper and lower welded cylindrical segments; each group of cylindrical segment fixing rings consists of 2 fixing rings; The clamping bolts are set on the cylinder section fixing ring to apply radial clamping force to the outer wall of the cylinder section to be welded. Adjusting bolts are installed at both ends of the fixing rings to connect the two fixing rings; The connecting bolts are located in the middle section of the fixing ring and connect the upper and lower sets of cylindrical fixing rings.

[0010] Specifically, the upper and lower sets of cylinder segment fixing rings are each equipped with 12 sets of clamping bolts, which are evenly distributed on the cylinder segment fixing rings. Each fixing ring has 6 bolt holes for assembling clamping bolts.

[0011] Specifically, a gasket is also provided between the cylinder segment fixing ring and the welded cylinder segment.

[0012] Specifically, the upper and lower sets of cylinder section fixing rings are arranged concentrically on the axis of the cylinder sections to be welded together by the connecting bolts.

[0013] The present invention has the following advantages: (1) The present invention ensures the accurate positioning of the cylinder section before welding by using the cooperation of the upper and lower sets of fixing rings and applying radial force to the cylinder section, thus avoiding the welding quality problems caused by misalignment in the traditional technology.

[0014] (2) The fixing device designed in this invention can flexibly adjust the position and relative distance of the upper and lower fixing rings by adjusting the bolts, thereby achieving precise fixing of cylinder sections of different sizes within a certain range, solving the fixing problem caused by manufacturing errors of large-size cylinder sections.

[0015] (3) The present invention can quickly fix and clamp multiple welds on the same product, avoiding the problem of repositioning and assembling each circumferential weld after welding in the traditional technology, and greatly improving production efficiency.

[0016] (4) The present invention specifies a front-side rooting segmented back-step welding process, a front-side second layer welding process, and a back-side sealing welding process with a full circle of constrained continuous welding. The small current parameter can effectively reduce the number of assembly positioning welding points, reduce weld joints, control welding deformation, ensure weld formation consistency and appearance quality, and effectively improve weld quality. Attached Figure Description

[0017] Fig. 1 This is a schematic diagram of the positioning device of the present invention; Fig. 2 This is a schematic diagram showing the connection state of the upper and lower cylinder sections of the present invention; Fig. 3 This is a schematic diagram of the welding state of the present invention; In the diagram, 1-Cylinder section fixing ring; 2-Clamping bolt; 3-Washer ring; 4-Cylinder section; 5-Adjusting bolt; 6-Connecting bolt; 7-Weld. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] like Figs. 1-2 As shown, the present invention provides a positioning device for welding cylindrical products, fixing two upper and lower cylindrical segments to be welded. The specific device includes: The cylindrical section fixing ring is divided into upper and lower groups, which respectively fix the upper and lower cylindrical sections to be welded. Each group of cylindrical section fixing rings consists of two semi-circular fixing rings. Each fixing ring is equipped with a clamping bolt, an adjusting bolt, and a connecting bolt. The clamping bolts are located on the circumference of the fixing ring, and each fixing ring has six bolt holes for assembling the clamping bolts. The inner end of the clamping bolt faces the outer wall of the cylindrical section, applying radial clamping force to the outer wall of the cylindrical section to be welded. The adjusting bolts are located at both ends of the fixing rings, connecting the two fixing rings to form a circle. The assembly consists of an annular cylindrical section fixing ring; connecting bolts, located in the middle of the fixing ring, connect the upper and lower sets of cylindrical section fixing rings, assembling the weld seam between the upper and lower cylindrical sections to be welded; the upper and lower sets of cylindrical section fixing rings are concentrically positioned along the axis of the cylindrical sections to be welded, connected by the connecting bolts, with the weld seam located between the two sets of cylindrical section fixing rings. Before each assembly, the position between the two sets of fixing rings and the weld seam can be adjusted using the connecting bolts, ensuring the concentricity of the upper and lower sets of cylindrical section fixing rings and thus preventing deviation in the relative position of the two cylindrical sections to be welded. A washer ring is also provided between the cylindrical section fixing ring and the cylindrical section to be welded to prevent the root of the clamping bolt from damaging the outer wall of the cylindrical section during force application.

[0020] Example 1 A method for welding annular seams without support includes the following steps: S1. Use a positioning device to fix the cylindrical section weldment; butt the two cylindrical sections to be welded to form an annular weld; install the upper and lower sets of cylindrical section fixing rings of the positioning device on the outer circumference of the cylindrical sections on both sides of the annular weld; adjust the relative position between the two cylindrical section fixing rings in each set by adjusting the bolts, and tighten the clamping bolts; place a washer ring between the cylindrical section fixing ring and the outer wall of the cylindrical section, so that the clamping bolt applies radial clamping force to the outer wall of the cylindrical section, thereby limiting and fixing the cylindrical section before welding; connect the upper and lower sets of cylindrical section fixing rings into one piece by connecting bolts; adjust the connecting bolts to ensure that the upper and lower sets of cylindrical section fixing rings are concentric with the axis of the cylindrical section, and adjust the relative position between the upper and lower sets of cylindrical section fixing rings and the annular weld.

[0021] S2, Welded seam; such as Fig. 3 As shown, a two-sided, multi-layer manual TIG welding process is adopted; the front bottom layer welding adopts a segmented back-step welding method, which can reduce the number of positioning points and segments compared with welding without positioning devices; the front second layer and the back bottom sealing adopt a full-circle constrained continuous welding process, which can be achieved by using a positioner structure to achieve constrained continuous welding of the entire weld seam, thereby reducing welding deformation and ensuring weld seam formation consistency and appearance quality.

[0022] Welding process parameters are selected according to a pre-established process parameter library. The welding current in the process parameter library is appropriately reduced compared to the welding current of multi-segment, multi-point positioning welding process without positioning device, so as to reduce heat input during welding, reduce welding deformation and welding stress, and improve the welding quality of circumferential weld.

[0023] Example 2 A highly reliable welding method for circumferential welds in unsupported conditions with multiple weld seams is provided. The positioning device is repeatedly clamped onto the cylindrical weldment section to achieve rapid and fixed welding of multiple circumferential weld seams. The clamping steps and welding method are the same as in Example 1. This avoids the problem of needing to reposition and reassemble each circumferential weld after welding in traditional technologies, significantly improving production efficiency.

[0024] It should be noted that the foregoing embodiments are described as combinations of a series of steps for the sake of brevity. However, those skilled in the art should understand that this application is not strictly limited by the order of the steps, and some steps may be performed in different orders or simultaneously depending on the actual situation. Furthermore, the embodiments described in the specification are all preferred solutions, and not all operations involved are necessary for this application.

[0025] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A method of welding a circular weld in an unsupported condition, characterized in that, The method comprises the following steps: S1, fixing the cylinder segment weldment using a positioning device, which exerts radial clamping force on the outer wall of the weldment to be welded by arranging two sets of cylinder segment fixing rings and compression bolts thereon, and limiting and fixing the cylinder segment before welding without supporting structure inside the cylinder segment; S2, welding the weld; using two-sided multi-layer manual TIG welding process, the front bottom layer welding uses segmented backstep welding method; the second layer on the front and the back sealing bottom use whole-circle constrained continuous welding process.

2. A method of welding a circular weld in an unsupported condition according to claim 1, wherein S1 further comprises repeatedly clamping the positioning device on the cylinder segment weldment to realize rapid fixing and welding of multiple annular welds.

3. A positioning device, characterized in that The positioning device is applied to the annular weld welding method without support as claimed in any one of claims 1-2, and specifically comprises: cylinder segment fixing rings, which are divided into two sets of upper and lower fixing rings and fix the upper and lower weld cylinder segments, respectively; each set of cylinder segment fixing rings is composed of two fixing rings; compression bolts arranged on the cylinder segment fixing rings to exert radial clamping force on the outer wall of the weldment to be welded; adjusting bolts arranged at both ends of the fixing ring to connect the two fixing rings; connecting bolts arranged at the middle segment of the fixing ring to connect the two sets of upper and lower cylinder segment fixing rings.

4. A positioning device according to claim 3, characterized in that Each of the two sets of cylinder segment fixing rings is provided with 12 groups of compression bolts, which are evenly distributed on the cylinder segment fixing ring, and each fixing ring is provided with six bolt holes for assembling the compression bolts.

5. A positioning device according to claim 3, wherein A gasket ring is further arranged between the cylinder segment fixing ring and the weld cylinder segment.

6. A positioning device according to claim 3, wherein The two sets of cylinder segment fixing rings are concentrically arranged relative to the axis of the weld cylinder segment through the connecting bolts.

Images