A method of assembling and welding a 3800 liter force type common base tank

Abstract

The application provides a 3800-lifting force type common base storage tank assembly and welding method, which comprises a circumferential shape dimension control method of binding support, the control method comprising installing the binding support in a bearing ring state, adding quadrant marks on a shell segment support ring and a transition ring, and assembling the transition ring with the marked mark line by taking one of the binding supports as a reference when the bearing ring is assembled, so as to meet the circumferential precision of the binding support and the rear end frame; and an axial shape dimension control method of the binding support, the control method comprising installing the binding support in a bearing ring state, and controlling the shrinkage of ring seam welding, so as to meet the axial spacing dimension precision between the bearing rings and between the bearing ring and the rear end frame. The application can realize horizontal assembly and welding of a Φ3800m super-long common base structure storage tank body, has low equipment investment cost, solves the problems of deformation and binding support precision coordination control of the super-long common base storage tank assembly and welding, and fills the technical blank of new storage tank product development.

Description

Technical Field

[0001] This application belongs to the field of rocket propellant tank welding technology, and particularly relates to a welding method for assembling a 3800-lift common-bottom propellant tank. Background Technology

[0002] To meet the development requirements of a certain aerospace model in my country, a Φ3800mm lifting common-bottom tank was designed. The tank consists of a short shell, a bottom, a front tank section, a common bottom, a rear tank section, and a load-bearing ring. The theoretical diameter of the tank is on the Φ3800mm level, and the tank length reaches 23000-26000mm. The front and rear bottoms and the common bottom are ellipsoidal, with the common bottom being a single-layer structure. Multiple binding supports are designed on the load-bearing ring for connection with the product's wings.

[0003] Compared to mature Φ3350mm rocket propellant tank products, this product not only has a diameter that changes from Φ3350mm to Φ3800mm, but also a length exceeding 23000mm. Furthermore, it features a double-chamber, common-bottom structure, making its structure more complex. Additionally, considering the installation requirements of the wing-mounted supports on the load-bearing ring structure, the control of the tank's welding dimensions is more stringent. Currently, there are no similar assembly, welding, and dimensional control technologies for propellant tanks in China, presenting challenges in coordinating welding deformation and the precision of the mounting supports for ultra-long common-bottom propellant tanks. Summary of the Invention

[0004] In view of this, this application aims to propose an assembly and welding method for a 3800-lift common-bottom tank to solve the problems of difficult coordination and control of welding deformation and binding support accuracy of ultra-long common-bottom tanks.

[0005] To achieve the above objectives, the technical solution of this application is implemented as follows:

[0006] This application provides a method for assembling and welding a 3800-liter common-bottom tank, wherein the common-bottom tank is assembled and welded from an oxygen tank and a methane tank, and multiple sets of load-bearing rings are provided at the cylindrical section of the methane tank. The method includes:

[0007] A method for controlling the circumferential shape and position dimensions of a binding support, the method comprising installing the binding support in the state of the load-bearing ring, adding quadrant markings on the shell section support ring and transition ring, and assembling the binding support with one of the binding supports as a reference and assembling it with the markings on the transition ring during the assembly of the load-bearing ring, so as to meet the circumferential accuracy of the binding support and the rear end frame.

[0008] A method for controlling the axial shape and position dimensions of a binding support, the method comprising installing the binding support in the state of the bearing ring, and controlling the shrinkage of the circumferential weld to meet the axial spacing dimensional accuracy between bearing rings and between the bearing ring and the rear end frame.

[0009] Furthermore, the method for controlling the circumferential shape and position dimensions of the binding support includes:

[0010] The first load-bearing ring is assembled and welded to the corresponding shell section support ring. A first binding support is provided on the first load-bearing ring. Quadrant lines are engraved on the shell section support ring. The first binding support is used as a reference and is aligned with the quadrant lines on the shell section support ring to ensure that the first binding support provided on the first load-bearing ring is in the circumferential position of the whole box.

[0011] Furthermore, it also includes:

[0012] The second load-bearing ring is assembled and welded to the corresponding shell segment support ring. The second load-bearing ring is provided with a second binding support. The second binding support is used as a reference and is aligned with the quadrant line on the shell segment support ring to ensure the circumferential relative position of the first binding support and the second binding support.

[0013] Furthermore, it also includes:

[0014] The rear bottom assembly is welded together, and the shell section support ring is replaced with a transition ring. The assembly is performed with the position corresponding to the second binding support set on the rear end frame and the quadrant line marked by the transition ring to ensure the circumferential relative position of the rear end frame and the binding support.

[0015] Furthermore, the method for controlling the axial shape and position dimensions of the binding support includes:

[0016] Welding of the first support ring to the third methane cylinder section: Based on the theoretical distance between the first support ring and the rear end frame and the theoretical length of the storage tank, the distance between the end face of the third methane cylinder section and the front end frame is calculated. Combining the empirical value of welding shrinkage and the measured distance between the end face of the third methane cylinder section and the front end frame, the milling length of the third methane cylinder section is calculated.

[0017] The first methane cylinder section is milled before welding to ensure the relative position of the first load-bearing ring in the entire container.

[0018] Furthermore, it also includes:

[0019] Welding the second support ring to the fourth methane cylinder section: After the first support ring is welded, measure the distance between its end face and the front end frame, and assemble and weld the fourth methane cylinder section. After the fourth methane cylinder section is welded, calculate the milling length of the fourth methane cylinder section based on the theoretical length of the tank, the actual distance between the first support ring and the front end face, the measured length between the first support ring and the second support ring, the theoretical distance between the second support ring and the rear end frame, and the empirical value of welding shrinkage.

[0020] The end face of the fourth methane cylinder section is milled to ensure the relative position of the first and second load-bearing rings.

[0021] Furthermore, the sixth methane cylinder section is welded to the rear bottom assembly: After the second support ring is welded, the fifth methane cylinder section is assembled and welded. After the fifth methane cylinder section is welded, the milling amount of the sixth methane cylinder section is calculated based on the theoretical distance between the second support ring and the rear end frame, and the actual distance between the second support ring and the rear end frame. Then, the storage tank is sealed and welded.

[0022] Furthermore, it also includes:

[0023] The binding support and the load-bearing ring are pre-positioned by using positioning pins, and the binding support is enlarged towards the load-bearing ring so that the connecting holes of the load-bearing ring and the binding support are coaxial and correspond one-to-one.

[0024] Disassemble the binding support, tap the connecting hole on the load-bearing ring, and enlarge and ream the connecting hole on the binding support. Connect the binding support and the load-bearing ring with bolts.

[0025] Furthermore, the supporting structure on the shell section support ring is controlled simultaneously to ensure that the theoretical diameter of the support is consistent with the theoretical inner diameter of the cylinder section. The shell section support ring is set on the non-welded section of the cylinder section for support, ensuring the roundness and coaxiality of the cylinder section assembly.

[0026] Furthermore, multiple corresponding limiting devices are provided on the support tray of the shell section support ring, and the multiple limiting devices are used to limit the outer contour of the load-bearing ring to the theoretical circle position.

[0027] Compared with the prior art, the assembly and welding method for a 3800-liter common-bottom tank described in this application has the following advantages:

[0028] The assembly and welding method for a 3800-lift common-bottom tank described in this application enables the horizontal assembly and welding of the tank body of a new Φ3800m ultra-long common-bottom structure tank in my country. The equipment investment cost is low, and it solves the problem of welding deformation and precision coordination control of binding supports in ultra-long common-bottom tanks, filling the technological gap in the development of new tank products. Attached Figure Description

[0029] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0030] Figure 1 This is a schematic diagram of the circumferential weld of the oxygen tank section as described in an embodiment of this application;

[0031] Figure 2 This is a schematic diagram of the circumferential weld of the oxygen tank sealing seam as described in an embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the welding of the methane tank section as described in the embodiments of this application;

[0033] Figure 4 This is a schematic diagram of the circumferential weld of the methane box sealing seam as described in the embodiments of this application;

[0034] Figure 5 This is a schematic diagram of the straight welding expansion ring as described in the embodiments of this application;

[0035] Figure 6 This is a schematic diagram of the expansion ring for sealing circumferential welds as described in an embodiment of this application;

[0036] Figure 7 This is a schematic planar view of the shell segment support ring described in an embodiment of this application;

[0037] Figure 8 This is a schematic diagram of the installation and binding support of the load-bearing ring as described in the embodiments of this application. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0039] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" 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.

[0040] Please see Figures 1 to 4 As shown, this embodiment provides a method for assembling and welding a 3800-liter common-bottom tank. The common-bottom tank is assembled and welded from an oxygen tank and a methane tank. Multiple sets of load-bearing rings are installed in the cylindrical section of the methane tank. Therefore, this embodiment adopts an integrated process flow for the horizontal assembly and welding of ultra-long tanks, as detailed below:

[0041] The front bottom assembly is mounted, and the first section of the oxygen tank is assembled and welded. The second, third, fourth, and fifth sections of the oxygen tank are then assembled and welded in sequence. The common bottom and methane tank section assemblies are mounted, the oxygen tank is sealed and welded, and the second and third sections of the methane tank are assembled and welded. The first load-bearing ring is assembled and welded, the fourth and second load-bearing rings are assembled and welded, the fifth and sixth sections of the methane tank are assembled and welded, and the rear bottom assembly is assembled. The distance from the binding support on the first and second load-bearing rings to the rear end frame is precisely measured, and the allowance is milled and the dimensions are remeasured. The methane tank is sealed and welded, and the tank is removed from the frame and precisely measured.

[0042] It should be noted that this embodiment only uses the first bearing ring, the second bearing ring, the first binding support, and the second binding support as examples for explanation and illustration, and does not specifically limit the number of the above components. Further details will not be provided here.

[0043] In response to the requirements of horizontal assembly welding for circumferential seam welding of ultra-long cylindrical box sections, tooling such as Φ3800mm box circumferential seam expansion rings, shell section support rings, and auxiliary trolleys is used to meet the assembly welding requirements of the box section. The specific details are described below.

[0044] 1. For the circumferential joints in the oxygen tank and methane tank sections, such as... Figure 5 As shown, this embodiment uses a straight welded inner support ring to expand the theoretical diameter Φ3790mm. A 1mm welding anti-deformation amount is preset on each side. It adopts a split support block mode, and each support block can provide a support force of not less than 300Kg, which meets the rigid support requirements of a 12mm-15mm thick box section.

[0045] 2. For the circumferential seams at the bottom / section of the oxygen and methane tanks, such as... Figure 6 As shown, this embodiment uses a conical welded inner support ring, and the pad surface can fit the gradually changing ellipsoidal surface of the bottom of the box / cylinder section circumferential seam to support a theoretical diameter of Φ3790mm. A 1mm welding anti-deformation amount is preset on one side. At the same time, a detachable support block mode is adopted, and a single support block can provide a support force of not less than 300Kg. After the box is sealed and welded, it can be disassembled and removed from the box.

[0046] 3. Regarding the assembly and welding process of the circumferential seam of the enclosure, such as... Figure 7 As shown, this embodiment uses a shell section support ring, which can be expanded to a theoretical diameter of Φ3789mm, consistent with the theoretical inner diameter of the cylinder section. It provides support in the non-welded section of the cylinder section to ensure the roundness and coaxiality of the cylinder section assembly. Pneumatic clamping is used to achieve quick clamping and disassembly.

[0047] Meanwhile, four limiting devices are designed at the support tray of the shell section support ring. The limiting devices are evenly installed at the support tray. When the load-bearing ring is assembled, the outer contour of the load-bearing ring is limited to the theoretical Φ3818mm circle position, thereby ensuring good coaxiality between the load-bearing ring assembly and the tooling datum.

[0048] It should be noted that the limiting device described in this embodiment is a limiting block, and the limiting block is fixed to the support tray by fixing bolts to effectively limit the outer contour of the load-bearing ring. This embodiment does not specifically limit the shape and structure of the limiting block. Any device that can achieve the limiting function is within the protection scope of this embodiment, and will not be described in detail further.

[0049] In response to the unique characteristics of the product structure and usage requirements, this embodiment designs a method for controlling the consistency of shape and dimension of an ultra-long common-bottom tank with a load-bearing ring structure, including:

[0050] 1. Method for ensuring dimensional accuracy of single-bearing-ring state binding support

[0051] During the machining of the load-bearing ring, based on the overall design and the assembly position of the binding support, and in conjunction with the connecting hole positions of the binding support, a precision five-axis CNC machining machine is used to pre-fabricate the pilot holes for the binding support connecting bolts in the load-bearing ring state (part state). The pilot holes (0.5mm smaller than the tapping pilot hole diameter) are then pre-fabricated on the binding support in the part state according to the dimensional requirements of the design drawings. The connecting hole diameters are consistent with the bore diameter of the load-bearing ring. During the machining of the load-bearing ring and binding support connecting bolt holes, the machining accuracy of the connecting hole positions is strictly controlled.

[0052] After the load-bearing ring and the binding support are machined separately, the binding support and the load-bearing ring are pre-positioned using locating pins. A drill is then used to enlarge the hole from the binding support towards the load-bearing ring (to the diameter of the tapped hole), ensuring that the connecting holes of the load-bearing ring and the binding support are coaxial and correspond one-to-one. Subsequently, the binding support is disassembled, the bolt connecting holes on the load-bearing ring are tapped, and the bolt connecting holes on the binding support are enlarged and reamed to the design requirements. Finally, bolts are used to connect the binding support and the load-bearing ring.

[0053] 2. Accuracy Control Method for Welding and Assembly Process of Load-Bearing Ring

[0054] By effectively controlling the welding process of the storage tank, the assembly accuracy of the binding supports can be guaranteed in the overall tank state. By adding marking lines to the transition ring and shell section support ring (located at the non-welded end of the cylinder section), assembly is performed using the first and second binding supports as references. The circumferential accuracy of the binding supports is ensured by the accuracy of the equipment and tooling, while the axial position of the binding supports is ensured by the shrinkage during the welding process. The following sections will discuss the control schemes for the circumferential and axial assembly accuracy of the binding supports.

[0055] A. Circumferential position accuracy control

[0056] Install the binding support in the bearing ring state (see schematic diagram of bearing ring and binding support structure as shown in Figure 1). Figure 8 As shown), quadrant markings are added to the shell section support ring and transition ring. During the assembly of the load-bearing ring, one of the binding supports is used as a reference, and the assembly is performed with the markings on the transition ring to ensure the circumferential accuracy requirements of the binding support and the rear end frame, as detailed below:

[0057] (1) Assembly and welding of the first load-bearing ring and the shell section support ring: The shell section support ring is positioned and connected to the equipment through the positioning pin holes to ensure the relative position of the equipment and the shell section support ring. Position lines are marked at the corresponding positions on the shell section support ring. Taking the first binding support as a reference, the assembly is aligned with the position lines on the shell section support ring to ensure the circumferential position of the binding support on the first load-bearing ring in the whole box. According to past experience, the assembly accuracy of a single position line can be guaranteed to be ±0.5mm;

[0058] (2) Assembly and welding of the second bearing ring and the shell section support ring: After the first bearing ring is welded, the fourth methane cylinder section is assembled and welded normally. When assembling and welding the second bearing ring, it is assembled with the second binding support as the reference and the upper quadrant line of the shell section support ring to ensure the circumferential position of the binding support on the second bearing ring. Assembling with the upper quadrant line of the same shell section support ring as the reference ensures the circumferential relative position of the binding support on the first bearing ring and the second bearing ring. According to past experience, the assembly accuracy of a single quadrant line can be guaranteed to be ±0.5mm;

[0059] (3) Rear bottom assembly welding: After the second load-bearing ring is welded, the fifth methane cylinder section is assembled and welded normally. The shell section support ring is replaced with a rear transition ring, which is positioned and connected to the equipment using the same positioning pin hole to ensure the relative position of the rear transition ring and the equipment. The position line corresponding to the binding support is marked on the transition ring. When assembling and welding the rear bottom assembly, the assembly is performed with the position corresponding to the second binding support on the rear end frame and the position line marked on the transition ring to ensure the circumferential relative position of the rear end frame and the binding support (with one or two). Based on past experience, the assembly accuracy of a single position line can be guaranteed to be ±0.5mm;

[0060] Considering extreme assembly conditions, the limit error for the circumferential position of the load-bearing ring is ±1.5mm. When assembling the second load-bearing ring and the rear bottom assembly, adaptive adjustments can be made based on the assembly status of the previous section to ensure circumferential assembly accuracy.

[0061] B. Axial position accuracy control

[0062] The binding supports are installed in the bearing ring section state. By controlling the shrinkage of the circumferential weld, the axial spacing accuracy between the first bearing ring and the second bearing ring, and between the first bearing ring and the rear end frame, is ensured, as follows:

[0063] (1) Welding of the first support ring to the third methane cylinder section: Based on the theoretical distance L1 between the first support ring and the rear frame and the theoretical length L2 of the storage tank, the distance L3 between the end face of the third methane cylinder section and the front frame is calculated. Combining the empirical value Δh of the welding shrinkage and the measured distance L3′ between the end face of the third methane cylinder section and the front frame, the milling length L3 of the third methane cylinder section is obtained. 铣 .

[0064] L3 铣 =L3′-L3+Δh=L3′-(L2-L1)+Δh

[0065] Before welding, the first methane cylinder section is milled to ensure the relative position of the first load-bearing ring in the whole box. According to past welding experience, the fluctuation of welding shrinkage is within ±1mm, thereby ensuring the distance between the first load-bearing ring and the rear frame.

[0066] (2) Welding of the second support ring to the fourth methane cylinder section: After the first support ring is welded, the distance from its end face to the front end frame is measured, and then the assembly and welding of the fourth methane cylinder section is carried out normally. After the fourth methane cylinder section is welded, the milling length L4 of the fourth methane cylinder section is calculated based on the theoretical length L2 of the tank, the actual distance L4 between the first support ring and the front end face, the measured length L5 between the first and second support rings, the theoretical distance L6 between the second support ring and the rear end frame, and the empirical value Δh of welding shrinkage. 铣 .

[0067] L4 铣 = (L2-L4-L6)-L5+Δh

[0068] The end face of the fourth methane cylinder section is milled to ensure the relative position of the first and second support rings. Based on a welding shrinkage fluctuation range of ±1mm, the axial position of the two support rings can be guaranteed within ±1mm.

[0069] (3) Welding of the sixth methane cylinder section to the rear bottom assembly: After the welding of the second support ring 2 is completed, the assembly and welding of the fifth methane cylinder section is carried out normally. After the welding of the fifth methane cylinder section is completed, based on the theoretical distance L6 between the second support ring and the rear end frame, and the actual distance L6′ between the second support ring and the rear end frame, and prioritizing the axial position of the binding support, the milling amount L6 of the sixth methane cylinder section is calculated. 铣 The concentrated force storage tank was sealed by welding.

[0070] L6 铣 =(L6′-L6)+Δh

[0071] Based on experience, the welding shrinkage of a single circumferential seam fluctuates within ±1mm. Before welding the first and second support rings, the second methane cylinder section is milled according to the theoretical length. Therefore, the relative position of the two support rings needs to be guaranteed by a circumferential seam, and its axial relative position accuracy can be guaranteed to be ±1mm. The distance between the support ring and the rear end frame needs to be guaranteed by the sealing circumferential seam. Therefore, the axial position of a single support ring and the rear end frame can be guaranteed to be ±1mm, and the axial position of the two support rings and the rear end frame can be guaranteed to be ±2mm.

[0072] This method enables the horizontal assembly and welding of my country's new Φ3800m ultra-long common-bottom structure storage tank, with low equipment investment costs. It solves the problems of deformation during assembly and welding of ultra-long common-bottom storage tanks and the coordination and control of the accuracy of binding supports, filling the technological gap in the development of new storage tank products.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

[0074] The embodiments of this 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 this application should be included within the protection scope of this application.

Claims

1. A method of assembling and welding a 3800 liter force style common base tank, characterized by, The common base tank is assembled and welded by an oxygen tank and a methane tank, a plurality of groups of force rings are arranged at the barrel section of the methane tank, and the method comprises the following steps: The control method comprises installing the binding support in the force ring state, increasing quadrant marks on the shell segment support ring and the transition ring, and assembling the binding support with the marked line on the transition ring when the force ring is assembled, so as to meet the circumferential accuracy of the binding support and the rear end frame. The control method comprises installing the binding support in the force ring state, controlling the shrinkage of the ring seam welding, so as to meet the axial spacing size accuracy between the force rings and between the force ring and the rear end frame. The axial shape size control method of the binding support comprises: welding the first force ring and the third methane cylinder section; calculating the distance L3 between the end face of the third methane cylinder section and the front end frame according to the theoretical distance L1 between the first force ring and the rear end frame and the theoretical length L2 of the storage box, and combining the empirical value Δh of the welding shrinkage and the measured distance L3' between the end face of the third methane cylinder section and the front end frame to calculate the milling length L3 of the third methane cylinder section 铣 , and the specific formula is: L3milling=L3'-L3+Δh=L3'- (L2-L1) +Δh; The first methane barrel section is milled before welding, so as to ensure the relative position of the first force ring in the whole tank. Further comprising: The second force ring is welded with the fourth methane cylinder section: after the first force ring is welded, the distance between the end face and the front end frame is measured, the fourth methane cylinder section is assembled and welded, and after the fourth methane cylinder section is welded, the milling length L4 of the fourth methane cylinder section is calculated according to the theoretical length L2 of the storage tank, the actual distance L4 between the first force ring and the front end face, the measured length L5 between the first force ring and the second force ring, the theoretical distance L6 between the second force ring and the rear end frame, and the welding shrinkage empirical value Δh. 铣 The specific formula is: L4milling= (L2-L4-L6) -L5+Δh; The end face of the fourth methane barrel section is milled, so as to ensure the relative position of the first force ring and the second force ring. Further comprising: Sixth methane cylinder segment and rear bottom assembly welding: after the second force ring welding is completed, the fifth methane cylinder segment is assembled and welded, and after the fifth methane cylinder segment is welded, the actual distance L6' between the second force ring and the rear end frame is calculated according to the theoretical distance L6 between the second force ring and the rear end frame, and the milling amount L6 of the sixth methane cylinder segment is obtained 铣 , and then the storage box is welded and sealed. The specific formula is: L6milling= (L6'-L6) +Δh.

2. The method of claim 1, wherein, The circumferential shape and size control method of the binding support comprises: The first force ring is assembled and welded with the corresponding shell segment support ring, the first binding support is arranged on the first force ring, and the quadrant line is drawn on the shell segment support ring, so that the first binding support arranged on the first force ring is aligned and assembled with the quadrant line on the shell segment support ring, so that the first binding support arranged on the first force ring is aligned and assembled with the quadrant line on the shell segment support ring.

3. The method of claim 2, wherein, Further comprising: The second force ring is assembled and welded with the corresponding shell segment support ring, the second binding support is arranged on the second force ring, and the second binding support is aligned and assembled with the quadrant line on the shell segment support ring, so as to ensure the circumferential relative position of the first binding support and the second binding support.

4. The method of claim 3, wherein, Further comprising: The rear end frame is assembled and welded with the rear end frame, the shell segment support ring is replaced with the transition ring, and the position corresponding to the second binding support arranged on the rear end frame is assembled with the quadrant line drawn on the transition ring, so as to ensure the circumferential relative position of the rear end frame and the binding support.

5. The method of claim 1, wherein, Further comprising: The binding support is positioned with the force ring in advance by the positioning pin, the binding support is expanded to the force ring, so that the connection holes of the force ring and the binding support are coaxial and one-to-one corresponding; The binding support is disassembled, the connection holes on the force ring are tapped, and the connection holes on the binding support are expanded and reamed, and the binding support and the force ring are connected by bolts.

6. The method of claim 1, wherein: Meanwhile, the support structure on the shell segment support ring is controlled, so that the theoretical diameter of the support structure is consistent with the theoretical inner type surface diameter of the barrel section, the shell segment support ring is arranged on the non-welding section of the barrel section for support, and the barrel section assembly roundness and coaxiality are ensured.

7. The method of claim 1, wherein: A plurality of limiting devices corresponding to the shell segment support ring are arranged on the support tray, and the plurality of limiting devices are used for limiting the outer contour of the force ring to the theoretical circle position.

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