Horizontal assembling and welding method for circular seam of ultra-long cylinder section

Abstract

The invention provides an ultra-long cylinder section circular seam horizontal assembling and welding method which comprises the steps that a long cylinder section is hoisted into a horizontal tool, and the heading levelness of the long cylinder section and the coaxiality of the axis of the cylinder section and the axis of a supporting mechanism are controlled; the assembly roundness of the cylinder section is adjusted by controlling the supporting tension of the inner supporting tool and adopting an auxiliary local external pressure method; local misalignment existing after the cylinder section is assembled is eliminated in a local positioning welding and local correction mode, local gaps existing after the cylinder section is assembled are eliminated in an in-situ milling cylinder section end face and full-positioning gap welding mode, and milling comprises rough milling and finish milling. By means of the device, horizontal assembly and welding of circular seams of ultra-long cylinder section storage tanks of new-generation medium-sized carrier rockets can be achieved, the problem of deformation of thin-wall ultra-long weak-rigidity cylinder section products in horizontal assembly is solved, on the premise that the production cost of the products is reduced, the assembly and welding efficiency of the products is improved, and the production efficiency is improved. And an effective technical support is provided for a high-efficiency and batch rocket tank product production mode.

Description

Technical Field

[0001] The present application belongs to the technical field of rocket tank welding, and in particular relates to a horizontal assembly welding method for annular seams of ultra-long cylinder sections. Background Art

[0002] The mainstream foreign long-barreled rocket tanks, represented by the Vulcan and SLS rockets, all adopt the vertical assembly welding scheme, and the tank structure is generally thickened to improve the rigidity of the tank. However, the vertical assembly scheme brings higher requirements to the design and construction of the tank plant, greatly increases the cost of the plant, and brings many engineering operation risks to high-altitude operations. At the same time, the traditional "short-barreled" tank welding mode scheme and equipment do not meet the "long-barreled" tank assembly accuracy guarantee and welding process implementation, and there are obvious technical bottlenecks.

[0003] The existing long-tube tank body circumferential seam welding method has the following main disadvantages:

[0004] (1) The vertical assembly welding method requires the construction of a new high-rise factory building, which has high manufacturing costs;

[0005] (2) The equipment investment cost of the vertical assembly welding method is high, and a section lifting device is required to meet the vertical assembly requirements;

[0006] (3) The vertical assembly welding method limits the choice of welding process methods. Usually, stir friction welding or plasma arc welding is required to achieve the "horizontal welding" of the circumferential seam. The process method is complicated, the equipment upgrade cost is high, and the production efficiency is low;

[0007] In summary, the existing long-barrel vertical assembly welding method is costly and has low production efficiency, and is not suitable for high-efficiency, mass-produced rocket tank product production. Summary of the invention

[0008] In view of this, the present application aims to propose a horizontal assembly welding method for annular seams of ultra-long cylinder sections to solve at least one of the above problems.

[0009] To achieve the above purpose, the technical solution of this application is implemented as follows:

[0010] The present application provides a horizontal assembly welding method for an ultra-long cylinder section annular seam, comprising:

[0011] Hoist the long cylinder section into the horizontal fixture, and control the horizontality of the long cylinder section and the coaxiality between the axis of the cylinder section and the axis of the supporting mechanism;

[0012] By controlling the supporting tension of the inner support fixture and using the auxiliary local external pressure method, the roundness of the barrel section assembly is adjusted;

[0013] The local misalignment after the barrel section is assembled is eliminated by local positioning welding and local correction, and the local gap after the barrel section is assembled is eliminated by in-situ milling of the barrel section end face and full positioning gap welding, wherein milling includes rough milling and fine milling.

[0014] Furthermore, before the cylinder section is put on the rack, the front and rear end surfaces of the long cylinder section are processed by a horizontal lathe, and the middle position of the long cylinder section is fixed by means of a turning auxiliary tooling;

[0015] After the barrel section is put on the rack, the shell section support ring tooling is used to support one side of the barrel section to the theoretical roundness. By moving the tooling bed, the other side of the barrel section is aligned with the tooling bed headbox bottom assembly, and the welding end face is tightened using an internal support expansion ring so that the coaxiality of the front and rear ends of the tightened barrel section meets the established range.

[0016] Further, the welding spindle installed in the horizontal tooling includes an extension frame, an intermediate connecting section and a support shaft;

[0017] The extension frame is a squirrel cage structure, one end of which is connected to the flange of the bed end flower plate, and the other end is connected to the flange of the middle connecting section or to the support shaft, and the middle connecting section is a conical structure;

[0018] The support shaft is connected to the middle connecting section, or is directly connected to the extension frame.

[0019] Furthermore, the extension frame is composed of a plurality of support tubes and support rings, and the plurality of support tubes are arranged in a spaced-apart manner to form a circular sleeve with a hollow structure inside, and the plurality of support rings are arranged in a spaced-apart manner on the plurality of support tubes, one end of the support tube is connected to the flange of the flower disc at the end of the bed, and the other end is connected to the flange of the middle connecting section or to the support shaft.

[0020] Furthermore, the extension frame, the middle connecting section and the supporting shaft are all made of aluminum alloy.

[0021] Furthermore, the support tension of the inner support tooling is controlled to pre-tighten the barrel section, so that the support block pad fits the inner side of the barrel section welding area, and the support tension is controlled to increase so that the diameter of the barrel section butt joint annular seam is equal to or slightly larger than the diameter in the natural state by 0-1mm;

[0022] The weld area is tightened by auxiliary external pressure chain.

[0023] Furthermore, the local misalignment and local gap positions are determined and marked, small beam positioning welding is performed on both sides of the misalignment, and then the local misalignment is eliminated by heating correction;

[0024] The whole circle small beam positioning welding is adopted, and the positioning welding shrinkage principle is utilized to fill the seams and eliminate local gaps.

[0025] Furthermore, a 3-5mm milling margin is reserved on the welding edge of the long cylinder section before being put on the rack. After the cylinder section is leveled on the rack, the margin is removed by rough milling;

[0026] By moving the bed mechanism, try to align the annular seam of the barrel section to check whether the assembly clearance meets the process requirements. If not, perform fine milling on the welding end face.

[0027] Compared with the prior art, the horizontal assembly welding method for annular seams of ultra-long cylinder sections described in this application has the following beneficial effects:

[0028] The present application describes a method for horizontal assembly and welding of annular seams of ultra-long barrel segments. The method can realize horizontal assembly and welding of annular seams of ultra-long barrel segment tanks of a new generation of medium-sized launch vehicles. The investment cost of plant and equipment is low, and the problem of horizontal assembly deformation of thin-walled, ultra-long, weakly rigid barrel segment products is solved. While reducing the production cost of products, the assembly and welding efficiency of products is also improved, providing effective technical support for a high-efficiency, mass-produced rocket tank product production model. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0030] Figure 1 This is a flow chart of a horizontal assembly welding method for an ultra-long cylinder section annular seam according to an embodiment of the present application;

[0031] Figure 2 This is a schematic diagram of a typical long tank structure described in an embodiment of the present application;

[0032] Figure 3 This is a schematic diagram of horizontal assembly of the long cylinder section described in the embodiment of the present application;

[0033] Figure 4 A schematic diagram of a method for eliminating gaps by positioning welding according to an embodiment of the present application;

[0034] Figure 5 This is a simulation diagram of the deformation of the conventional lengthened main shaft described in the embodiment of the present application;

[0035] Figure 6 This is a schematic diagram of the welding spindle structure described in an embodiment of the present application;

[0036] Figure 7 This is a simulation diagram of the welding spindle deformation described in an embodiment of the present application.

[0037] Description of reference numerals:

[0038] 1-Extension frame; 2-Middle connecting section; 3-Support shaft. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0040] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be the usual meanings understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0041] In order to meet the needs of future mass production of medium-sized launch vehicles, a "long cylinder section welding" tank manufacturing solution is proposed. By adopting "long cylinder section welding", the annular seam of the tank is reduced, which can effectively improve the production efficiency of the tank product, enhance the overall performance of the cylinder section, and save the tank processing cost.

[0042] Typical long cylinder tank structure Figure 2 As shown, the long-section tank structure has the characteristics of overlong sections and weak rigidity. The typical tank product has a diameter of 2.25m, and the tank body adopts a single-section or a few-section structure. The length of a single section is 6-8m, the welding thickness is 4-5mm, and the skin thickness is as low as less than 2mm. Compared with traditional tanks, the weakened structural rigidity makes the tank assembly and welding more difficult.

[0043] Explanation of professional terms:

[0044] Horizontal welding: The welding mode for vertical assembly welding of the annular seam of a long cylinder tank section is that the welding device is parallel to the horizontal line; the traditional horizontal welding adopts the flat welding mode, and the welding gun is perpendicular to the horizontal line.

[0045] Cylinder section butt joint ring seam: The tank contains multiple cylinder sections, and the structural form of the welds between the cylinder sections is butt joint, and the welds are the cylinder section butt joint ring seams.

[0046] Misalignment: The misalignment between the two butt edges of the weld after assembly is completed.

[0047] Welding spindle: core equipment for long cylinder section annular seam welding, used to support the welding inner support ring.

[0048] The present application adopts TIG welding technology, aiming to realize the welding production of the annular seam of the butt joint of the super-long cylinder section tank in the horizontal mode. The embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0049] See also Figure 1 As shown, this embodiment provides a horizontal assembly welding method for annular seams of ultra-long cylinder sections, which specifically includes the following steps:

[0050] Step S101, hoisting the long cylinder section into the horizontal fixture, and controlling the horizontality of the long cylinder section and the coaxiality between the axis of the cylinder section and the axis of the supporting mechanism.

[0051] Specifically, in this embodiment, a quick assembly and alignment method for the long tube section is set as follows:

[0052] After the long cylinder section is hoisted to the horizontal box circumferential seam welding equipment, it is necessary to ensure the horizontality of the cylinder section and the coaxiality of the cylinder section axis and the axis of the support mechanism. The quick method to ensure the horizontality of the cylinder section heading is:

[0053] A. Figure 3 As shown in the figure, the front and rear end surfaces of the long tube section are processed by horizontal lathe before being put on the rack to ensure that the parallelism of the front and rear end surfaces is no more than 1.5mm and the coaxiality is no more than 0.5mm;

[0054] B. Use special turning auxiliary tooling to fix the middle position of the long tube section to avoid local plastic deformation during the turning process;

[0055] C. After the barrel section is put on the rack, the tooling guarantee method is adopted. The shell section support ring tooling is used to support one side of the barrel section to the theoretical roundness, and the coaxiality with the tail plate is guaranteed to be no more than 1mm; by moving the bed, the other side of the barrel section (welding end face) is aligned with the headstock bottom assembly, and the welding end face is tightened with the inner support ring. After tightening, the coaxiality of the barrel section heading to the front and rear ends is ≤2mm;

[0056] D. Place a rail trailer under the long tube section to provide auxiliary support for the long tube section and prevent the product from deforming and sagging.

[0057] Step S102, adjusting the assembly roundness of the barrel section by controlling the support tension of the inner support tooling and using an auxiliary local external pressure method.

[0058] Specifically, in this embodiment, the thickness of the circumferential seam welding area of ​​the super-long cylinder section box is between 4-5 mm, the cylinder section itself has weak rigidity, and the welding area has weak deformation resistance. In order to achieve automatic TIG welding, the assembly misalignment must be no more than 0.5 mm and the assembly gap must be no more than 0.3 mm.

[0059] Adjust the assembly misalignment to control the assembly roundness of the barrel section: first use a smaller horizontal support force on the welding inner support fixture to ensure that the support block pad fits the inner side of the barrel section welding area; then add force to support the support block to ensure that the barrel section is subject to sufficient support tension. At this time, the diameter of the barrel section butt joint is equal to or slightly larger than the diameter in the natural state by 0-1mm; then tighten the weld area through an auxiliary external pressure chain.

[0060] Step S103, eliminating local misalignment after barrel section assembly by local positioning welding and local correction, and eliminating local gaps after barrel section assembly by in-situ milling of barrel section end faces and full positioning gap welding, wherein milling includes rough milling and fine milling.

[0061] Specifically, in this embodiment, the assembly gap is adjusted by reserving a 3-5mm milling margin on the welding edge of the long cylinder section before being put on the frame. After the cylinder section is leveled on the frame, the margin is first milled off using the rough milling mode. By moving the bed mechanism, the annular seam of the cylinder section is tried to be aligned to check whether the assembly gap meets the 0.3mm process requirement. If not, the welding end face is finely milled. After fine milling, the assembly gap can be further reduced.

[0062] Positioning welding plus local correction method: such as Figure 3 As shown, considering the engineering working conditions, this embodiment proposes a positioning welding plus local correction method to eliminate the local misalignment and gaps after assembly. First, determine the location of the local misalignment and gap and make a mark; perform small beam positioning welding on both sides of the misalignment, and then use heating correction to eliminate the local misalignment; for the local gap, use the full circle small beam positioning welding method, and use the positioning welding shrinkage principle to play the role of filling the gap and eliminating the gap, usually closing the arc at the maximum gap.

[0063] The above steps utilize a two-step milling method, under the frame and on the frame, to ensure the parallelism of the barrel section before welding; utilize special tooling to control the deformation of the long barrel section during the flipping process, thereby ensuring the horizontality of the long barrel section after being put on the frame, and the coaxiality of the barrel section axis and the axis of the supporting mechanism; develop a method for controlling the misalignment and gap of the docking, by using the support force to pre-tighten to the formal tightening method, and assisting the local external pressure method to adjust the assembly roundness, and eliminate the misalignment through local positioning welding and correction methods; eliminate local gaps through in-situ milling of the barrel section end face and full positioning filling welding.

[0064] It should be noted that the horizontal welding tooling, flip auxiliary tooling, internal support tooling, auxiliary external pressure chain and other equipment used in this embodiment are all existing common equipment. This embodiment has not improved them and will not be described in detail here.

[0065] In some embodiments, the welding spindle installed in the horizontal tooling includes an extension frame 1, an intermediate connecting section 2 and a support shaft 3, and the extension frame 1, the intermediate connecting section 2 and the support shaft 3 are all made of aluminum alloy;

[0066] The extension frame 1 has a squirrel cage structure. The extension frame 1 is composed of multiple support tubes and support rings. The multiple support tubes are arranged in a spaced manner to form a circular sleeve with a hollow structure inside. The multiple support rings are arranged in a spaced manner on the multiple support tubes. One end of the support tube is flange-connected to the flower disc at the end of the bed, and the other end is flange-connected to the middle connecting section 2 or connected to the support shaft 3. The middle connecting section 2 has a conical structure.

[0067] Specifically, in this embodiment, in order to realize the circumferential seam welding of the long cylinder section, the equipment difficulty lies in realizing the accessible and lightweight design of the long main shaft.

[0068] 1) Demand Analysis:

[0069] The main shaft length is modified according to the product size, increasing 3000-4500mm on the traditional basis, increasing the stretching length of the bed tail accordingly, lengthening the coarse cross-section length of the main shaft, and shortening the thin cross-section length.

[0070] 2) Stress analysis after the traditional spindle is extended

[0071] like Figure 5 As shown in the figure, the force analysis of the traditional spindle after extension shows that the end load is 1t, the equivalent stress is 50.9MPa, and the flexural deformation is 8.29mm. The force analysis of the modified spindle shows that the end load is 1t, the equivalent stress is 47MPa, which is not much changed, and the flexural deformation is 22.3mm, which is about 3 times that of the normal spindle. Under this deformation condition, the spindle head is seriously lowered and can no longer meet the normal use function of the welding support ring.

[0072] The welding spindle of this embodiment adopts a squirrel cage structure. Figure 6 As shown in the figure, the design scheme divides the welding spindle into three parts, and the specific structure is as follows:

[0073] The first part is a squirrel cage extension frame 1, which is connected to the flower plate at the end of the bed on the right side. The diameter of the connecting flange is 1200mm, which is smaller than the inner diameter of the Φ2250 shell support of 1444mm. At the same time, according to the groove structure of the flower plate, 8 φ80×5 supporting steel pipes are evenly distributed, and 8 M20 bolts are connected at the corresponding radial positions; the inner hole of the connecting flange is 600mm, which is larger than the main shaft diameter of 360mm, allowing the main shaft to move inside without interference;

[0074] The second part is a middle cone section, one side of which is connected to the left flange of the squirrel cage extension frame 1, and the other side is connected to the support shaft 3;

[0075] Among them, according to the difference of the inner hole of the inner support, there are currently two types of support shafts 3, one with a diameter of 180 mm and the other with a diameter of 150 mm, to meet the requirements of different manhole flange diameters.

[0076] The length of the squirrel cage extension frame 1 is designed to be shorter than the current maximum length of the main shaft (4500mm), and the length of the cone section and the support shaft 3 is designed to be between 1200-1500mm. The support shaft 3 can be installed on the cone section or on the squirrel cage extension frame 1, ensuring that the internal support mechanism can work within the range of 7000mm.

[0077] The overall quality of the welding spindle is controlled within 1 t, and the flexural deformation is doubled compared to the current situation. Taking into account the auxiliary role of the barrel support trolley and the headstock support, as well as the improvement of the overall rigidity after the inner support is rounded, and there is no retraction action similar to the spindle, the welding spindle described in this embodiment is feasible.

[0078] In terms of material selection, the main shaft is designed with aluminum alloy material. The cylinder wall thickness is 20mm, and the overall weight is reduced to 850kg. When loading the same boundary conditions, it can be seen that the equivalent stress is 39.1Mpa and the maximum deformation is 6mm, which occurs at the end of the thin shaft. Figure 7 As shown in the figure, it can be seen from the analysis that this solution can not only significantly reduce the weight of the tooling, but also effectively improve the overall rigidity and strength of the tooling to meet the product process requirements.

[0079] The welding spindle equipment described in this embodiment can realize the circumferential seam welding internal support of the 7000mm long cylinder section. It adopts a lightweight alloy structure, and the total weight of the equipment is reduced to 850Kg, achieving the lightweight goal. Under the condition of bearing the weight of the product and tooling, the disturbance is no more than 6mm, meeting the welding process requirements.

[0080] The welding method described in this embodiment can realize the horizontal assembly and welding of the annular seams of the super-long barrel section tank of a new generation of medium-sized carrier rockets. The investment cost of plant and equipment is low, and the problem of horizontal assembly deformation of thin-walled, super-long, weakly rigid barrel section products is solved. While reducing the production cost of products, the product assembly and welding efficiency is also improved, providing effective technical support for the high-efficiency and mass-produced rocket tank product production model.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

[0082] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims

1. A horizontal assembly welding method for annular seams of super-long cylinder sections, characterized in that: include: Hoist the long cylinder section into the horizontal fixture, and control the horizontality of the long cylinder section and the coaxiality between the axis of the cylinder section and the axis of the supporting mechanism; By controlling the support tension of the inner support fixture and using the auxiliary local external pressure method to adjust the assembly roundness of the barrel section; The local misalignment after the barrel section is assembled is eliminated by local positioning welding and local correction, and the local gap after the barrel section is assembled is eliminated by in-situ milling of the barrel section end face and full positioning gap welding, wherein milling includes rough milling and fine milling.

2. The method according to claim 1, characterized in that: Before the cylinder section is put on the rack, the front and rear end surfaces of the long cylinder section are processed by a horizontal lathe, and the middle position of the long cylinder section is fixed with the help of a turning auxiliary tooling; After the barrel section is put on the rack, the shell section support ring tooling is used to support one side of the barrel section to the theoretical roundness. By moving the tooling bed, the other side of the barrel section is aligned with the tooling bed headbox bottom assembly, and the welding end face is tightened using an internal support expansion ring so that the coaxiality of the front and rear ends of the tightened barrel section meets the established range.

3. The method according to claim 2, characterized in that: in, The welding spindle installed in the horizontal tooling includes an extension frame, an intermediate connecting section and a supporting shaft; The extension frame is a squirrel cage structure, one end of which is connected to the flange of the bed end flower plate, and the other end is connected to the flange of the middle connecting section or to the support shaft, and the middle connecting section is a conical structure; The support shaft is connected to the middle connecting section, or is directly connected to the extension frame.

4. The method according to claim 3, characterized in that: The extension frame is composed of multiple support tubes and support rings. The multiple support tubes are arranged in a spaced manner to form a circular sleeve with a hollow structure inside. The multiple support rings are arranged in a spaced manner on the multiple support tubes. One end of the support tube is connected to the flange of the flower disc at the end of the bed, and the other end is connected to the flange of the middle connecting section or to the support shaft.

5. The method according to claim 3, characterized in that: The extension frame, the middle connecting section and the supporting shaft are all made of aluminum alloy.

6. The method according to claim 1, characterized in that: Control the support tension of the inner support fixture to pre-tighten the barrel section so that the support block pad fits the inner side of the barrel section welding area, and control and increase the support tension so that the diameter of the barrel section butt joint annular seam is equal to or slightly larger than the diameter in the natural state by 0-1mm; The weld area is tightened by auxiliary external pressure chain.

7. The method according to claim 1, characterized in that: Determine the local misalignment and local gap positions and mark them, perform small beam positioning welding on both sides of the misalignment, and then eliminate the local misalignment by heating correction; The whole circle small beam positioning welding is adopted, and the positioning welding shrinkage principle is utilized to fill the seams and eliminate local gaps.

8. The method according to claim 1, characterized in that: Before putting on the rack, reserve 3-5mm milling margin on the welding edge of the long cylinder section. After the cylinder section is leveled on the rack, the margin is removed by rough milling. By moving the bed mechanism, try to align the annular seam of the barrel section to check whether the assembly clearance meets the process requirements. If not, perform fine milling on the welding end face.

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