A method for manufacturing a manned spaceflight sealed cabin

Abstract

A manned spaceflight sealed cabin manufacturing method, comprising: using a spinning die to spin a blank to manufacture a shoulder structure (1-1), which is a circular truncated cone with a smooth convex top; welding three conical materials to form a circular truncated cone as a side wall conical section (1-3); welding the shoulder structure (1-1) and the side wall conical section (1-3) to connect to form a side wall structure (1); welding three conical materials to form an inverted circular truncated cone as a bottom conical section (2-1); processing a blank to manufacture a cylindrical bottom column section (2-3); welding the bottom conical section (2-1) and the bottom column section (2-3) to form a bottom structure (2); sequentially assembling the side wall structure (1), the bottom structure (2) and a spherical bottom structure (3) to obtain the sealed cabin; then milling the outer surface to form a grid cavity; and then performing overall heat treatment to remove stress. The present application is suitable for overall manufacturing of a large sealed cabin structure with integral stiffening and light weight, and can effectively improve the cabin bearing capacity and reduce the structure weight.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aerospace equipment manufacturing, in particular to a manned spaceflight sealed cabin manufacturing method. BACKGROUND

[0002] Manned spacecraft needs to enter the lunar orbit, and the launch and return mechanical environment is more harsh, so the new type of sealed cabin has more urgent demand for large bearing, light weight and high reliability. The new type of manned sealed cabin adopts an integrated wallboard configuration, which eliminates the traditional connecting frame, the cabin outside reinforcing rib is continuous, the number of passengers is twice that of Shenzhou spacecraft, and the weight is effectively reduced by more than 30% compared with the traditional cabin body, which brings great difficulty to manufacturing.

[0003] The existing Shenzhou spacecraft is of a skin + stringer configuration, and its manufacturing technical process mainly includes the following steps: firstly, the outer contour skin of the spacecraft is superplastic formed; secondly, flange end frames are welded at specified positions of the skin; thirdly, reinforcing stringers are spot welded inside the skin; and finally, the cabin body flange is milled to ensure the interface precision of the cabin section. The structure belongs to the early Apollo spacecraft configuration, and the limited internal space is not suitable for the new state requirements.

[0004] The existing space station is of a wallboard + connecting frame configuration, and its manufacturing technical process mainly includes the following steps: firstly, the grid wallboard is roll-bent; secondly, the grid wallboard is welded into a cylindrical piece; thirdly, the cylindrical assembly is mechanically processed at the places with interface precision; and finally, the cylindrical piece is ring seam welded with the connecting frame to form a sealed cabin. The reinforcing rib outside the cabin is discontinuous, the mechanical bearing capacity is poor, the weight cost of using the connecting frame is large, and the light weight requirement is not met. SUMMARY

[0005] The present application provides a manned spaceflight sealed cabin manufacturing method to solve the problems that in the overall manufacturing process of the sealed cabin structure, the welding product assembly quality, welding defect control and welding mechanical strength are strictly required and difficult to control; in the whole cabin state, the wallboard grid and other features are processed by chip removal, and due to the weak rigidity of the cabin structure, vibration is easy to occur during the processing process, so that the wall thickness precision and the roughness of the sealing surface are difficult to guarantee; the sealed cabin has undergone processes such as spinning forming, roll bending, large thickness welding and overall processing, and the stress evolution is complex, so the stress control is difficult.

[0006] The present application provides a manned spaceflight sealed cabin manufacturing method, which includes the following steps:

[0007] Step 1, spinning the blank according to the set trajectory to manufacture a shoulder structure by using a spinning die, wherein the shoulder structure is a circular truncated cone with a smooth convex top;

[0008] Step 2, roll-bending the fan-shaped unfolded surface material into a conical material, and then welding three conical materials to form a circular truncated cone as a side wall conical segment; the diameter of the circular surface at the bottom of the shoulder structure is the same as that of the circular surface at the top of the side wall conical segment.

[0009] Step 3, welding the shoulder structure and the sidewall cone segment to form the sidewall structure;

[0010] Step 4, bending the fan-shaped spread surface material into a conical material, and then welding the three conical materials to form an inverted circular table as a bottom cone segment; the top circular surface of the bottom cone segment has the same diameter as the bottom circular surface of the sidewall cone segment;

[0011] Step 5, milling the cylindrical part blank to form a cylindrical bottom column segment; the diameter of the cylinder of the bottom column segment is the same as the diameter of the bottom circular surface of the bottom cone segment;

[0012] Step 6, welding the bottom cone segment and the bottom column segment to form a bottom structure;

[0013] Step 7, spinning the blank according to a set trajectory by using a spinning die to manufacture a spherical bottom structure; the bottom structure is a downward convex spherical surface, and the diameter of the circular bottom surface of the spherical bottom structure is the same as the diameter of the cylinder of the bottom column segment;

[0014] Step 8, connecting the sidewall structure, the bottom structure, and the spherical bottom structure to obtain the sealed cabin;

[0015] Step 9, milling the outer surface of the sealed cabin to form a grid cavity;

[0016] Step 10, performing overall heat treatment on the sealed cabin to remove stress.

[0017] Further, the spinning die is used to spin the blank according to a set trajectory to manufacture the shoulder structure or the spherical bottom structure, and specifically:

[0018] The spinning die includes a core die, a first tail top, a second tail top, and a spinning wheel; the first tail top is in a disc configuration, and the second tail top is in a conical configuration;

[0019] The manufacturing process is as follows: heating the core die to 200℃±50℃, heating the blank to 200-300℃, then installing the heated blank on the core die, connecting the first tail top to the main shaft of the external processing machine tool and tightly pressing the workpiece, spinning the spinning wheel according to a set trajectory to make the plate blank tightly adhere to the front end of the die, tightly pressing the workpiece to the die-adhering part by using the second tail top, and spinning the spinning wheel according to a set trajectory in multiple passes until the blank completely adheres to the die.

[0020] Further, the surface roughness of the core die and the spinning wheel is better than 0.8 microns; the spinning core die and the blank are supplemented with heat on site during the spinning process to ensure that the temperature of the core die and the blank is within a specified range.

[0021] Further, the fan-shaped expanded surface material is roll-bent into a conical material, and then three pieces of the conical material are welded to form a circular truncated cone as the side wall conical segment or an inverted circular truncated cone as the bottom conical segment, specifically:

[0022] First, the wall plate is milled into a fan-shaped expanded surface material, and then the expanded surface material is roll-bent into a conical material using a plate rolling machine; the wall plate material is 5B70 aluminum alloy with a thickness of 70 mm, and the roll-bent part profile tolerance is less than 3 mm when the expanded surface material is roll-bent into a conical material using the plate rolling machine; the roll-bending process is adjusted gradually with a single adjustment amount of 5-10 mm;

[0023] Three pieces of the conical material are welded to form the side wall conical segment or the bottom conical segment.

[0024] Further, the three pieces of the conical material are welded to form the side wall conical segment or the bottom conical segment, specifically:

[0025] The vacuum electron beam welding method is adopted, the weld thickness is 60-70 mm, the electron beam focal length is 200-350 mm, the welding voltage is 60 KV, the welding current is 250-300 mA, and the welding speed is 200-300 mm / min.

[0026] Further, the top angle of the side wall conical segment is 18°, and the top angle of the bottom conical segment is 30°.

[0027] Further, the shoulder structure and the side wall conical segment are welded to form the side wall structure, or the bottom conical segment and the bottom column segment are welded to form the bottom structure, specifically:

[0028] The vacuum electron beam welding method is adopted, the welding thickness is 50-60 mm, the electron beam focal length is 200-350 mm, the welding voltage is 60 KV, the welding current is 200-250 mA, and the welding speed is 250-300 mm / min.

[0029] Further, in step 9, the outer surface of the sealed cabin is milled to form a grid cavity, specifically:

[0030] First, the outer surface of the sealed cabin is milled by a five-axis milling center to achieve a specified process allowance;

[0031] The inner part of the sealed cabin is supported by a flexible tooling, and then the sealed cabin is milled by a five-axis milling center to achieve a specified precision requirement;

[0032] Finally, the girth weld of the sealed cabin is milled by a five-axis milling center.

[0033] Further, the first round milling process has a process allowance of 5mm, the first round milling process uses a machine tool spindle speed of 10000-20000r / min, a cutting depth of 4mm, and a cutting width of 6mm.

[0034] The second round milling process uses a machine tool spindle speed of 15000-25000r / min, a cutting depth of 3mm, and a cutting width of 0.2mm.

[0035] The ring weld of the sealed cabin is milled, and the machine tool spindle speed is 10000-25000r / min, the cutting depth is 3mm, and the cutting width is 1mm.

[0036] Further, in step 10, the sealed cabin is subjected to overall heat treatment to remove stress, specifically:

[0037] After the first round milling of the outer surface of the sealed cabin reaches the specified process allowance, the sealed cabin is subjected to overall heat treatment to remove stress, the heat treatment temperature is 200-250 DEG C, the holding time is 3-4h, and the residual stress of the sealed cabin after stress removal is less than 80Mpa.

[0038] Compared with the prior art, the present application has the following advantages:

[0039] 1. The novel sealed cabin manufacturing method is suitable for overall manufacturing of the overall stiffened lightweight large sealed cabin structure, and can effectively improve the cabin body carrying capacity and reduce the structure weight.

[0040] 2. The present application realizes the first application of 5B70 aluminum alloy large thickness spinning technology in manned space sealed cabin, reduces the number of welds and end frames in the prior art, improves the product quality stability, and lays a foundation for subsequent reusable.

[0041] 3. The present application realizes the first application of vacuum electron beam welding in manned space sealed cabin structure, the welding energy concentration heat affected zone is small, and the welding quality is better than that of traditional welding.

[0042] 4. The whole cabin flexible overall machining technology can ensure stress release deformation and self-adaptive flexible adjustment when machining in the whole cabin state, and ensure the wall thickness precision ±0.1mm.

[0043] 5. The stress relief process can ensure that the overall stress distribution of the cabin body manufacturing is uniform, the maximum stress is less than 80Mpa, the risk of deformation or cracking caused by stress release during the service process of the sealed cabin can be reduced, and the reliability of the sealed cabin can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 It is a novel manned sealed cabin structure manufactured by the present application.

[0045] Figure 2is a manufacturing flowchart of the sealed cabin of the present application.

[0046] Figure 3 is a spinning forming diagram of the large-thickness wall plate of the present application.

[0047] Figure 4 is a spinning forming flowchart of the present application.

[0048] Figure 5 is a conical segment electron beam welding diagram of the present application.

[0049] Figure 6 is a cabin segment ring weld diagram of the present application.

[0050] Figure 7 is a cabin segment overall machining state diagram of the present application.

[0051] Figure 8 is a cabin segment overall state diagram of the present application. DETAILED DESCRIPTION

[0052] In the overall manufacturing process of the novel sealed cabin structure, for example, 5B70 high-strength aluminum alloy plate blanks of δ70×Φ3500mm (wall thickness 70mm, diameter 3500mm) are spun formed, the material flow state in the spinning process is complex due to the large wall thickness size, and it is difficult to ensure the structural size precision and mechanical properties; the 70mm large-thickness high-strength aluminum alloy material is vacuum electron beam welded, this welding technology is used for the first time on the manned space sealed cabin structure, and the welding product assembly quality, weld defect control and weld mechanical strength are strictly required, and it is difficult to control; the wall plate grid and other features are milled under the overall cabin state, and due to the weak rigidity of the cabin structure, vibration is easy to occur during the machining process, and it is difficult to ensure the wall thickness precision and the roughness of the sealing surface; the sealed cabin undergoes spinning forming, roll forming, large-thickness welding and overall machining processes, and the stress evolution is complex, and it is difficult to control the stress.

[0053] The sealed cabin comprises a side wall structure 1, a bottom structure 2 and a spherical bottom structure 3 connected from top to bottom. The side wall structure 1 comprises a shoulder structure 1-1 and a side wall conical segment 1-3, the shoulder structure 1-1 is a top smooth convex circular truncated cone, the side wall conical segment 1-3 is a circular truncated cone, and the diameter of the circular face at the bottom of the shoulder structure 1-1 is the same as the diameter of the circular face at the top of the side wall conical segment 1-3. The bottom structure 2 comprises a bottom conical segment 2-1 and a bottom column segment 2-3, the bottom conical segment 2-1 is an inverted circular truncated cone, that is, the diameter of the circular face at the top of the circular truncated cone is greater than the diameter of the circular face at the bottom, the diameter of the circular face at the top of the bottom conical segment 2-1 is the same as the diameter of the circular face at the bottom of the side wall conical segment 1-3, and the diameter of the circular column of the bottom column segment 2-3 is the same as the diameter of the circular face at the bottom of the bottom conical segment 2-1. The spherical bottom structure 3 is a downward convex spherical surface, and the diameter of the circular face of the spherical bottom is the same as the diameter of the circular column of the bottom column segment 2-3.

[0054] The shoulder structure 1-1 and the side wall cone segment 1-3 are connected by vacuum electron beam welding to form a side wall structure 1. The bottom cone segment 2-1 and the bottom column segment 2-3 are connected by vacuum electron beam welding to form a bottom structure 2. The side wall structure 1, the bottom structure 2 and the spherical bottom structure 3 are sequentially connected by vacuum electron beam welding to obtain the sealed cabin. The outer surface of the sealed cabin is milled to form a grid cavity. The sealed cabin is subjected to overall heat treatment to remove stress.

[0055] The present application provides a manned space sealing cabin manufacturing method, comprising:

[0056] Step 1, using a spinning die to spin the blank according to the set trajectory to manufacture the shoulder structure 1-1, the shoulder structure 1-1 is a top smooth convex circular truncated cone;

[0057] Step 2, the fan-shaped expanded surface material is roll-bent into a conical material, and then three conical materials are connected by vacuum electron beam welding to form a circular truncated cone as a side wall cone segment 1-3; the diameter of the circular face at the bottom of the shoulder structure 1-1 is the same as that of the circular face at the top of the side wall cone segment 1-3;

[0058] Step 3, the shoulder structure 1-1 and the side wall cone segment 1-3 are connected by vacuum electron beam welding to form a side wall structure 1;

[0059] Step 4, the fan-shaped expanded surface material is roll-bent into a conical material, and then three conical materials are connected by vacuum electron beam welding to form an inverted circular truncated cone as a bottom cone segment 2-1; the diameter of the circular face at the top of the bottom cone segment 2-1 is the same as that of the circular face at the bottom of the side wall cone segment 1-3;

[0060] Step 5, a cylindrical blank is milled to manufacture a cylindrical bottom column segment 2-3; the diameter of the cylinder of the bottom column segment 2-3 is the same as that of the circular face at the bottom of the bottom cone segment 2-1;

[0061] Step 6, the bottom cone segment 2-1 and the bottom column segment 2-3 are connected by vacuum electron beam welding to form a bottom structure 2,

[0062] Step 7, using a spinning die to spin the blank according to the set trajectory to manufacture a spherical bottom structure 3; the bottom structure is a downward convex spherical surface, and the diameter of the circular bottom surface of the spherical bottom structure 3 is the same as that of the cylinder of the bottom column segment 2-3;

[0063] Step 8, the side wall structure 1, the bottom structure 2 and the spherical bottom structure 3 are connected by screwing to obtain the sealed cabin;

[0064] Step 9, the outer surface of the sealed cabin is milled to form a grid cavity;

[0065] Step 10, the sealed cabin is subjected to overall heat treatment to remove stress.

[0066] The method embodied in one embodiment is as follows:

[0067] The structure of the manned sealed cabin is shown in Figure 1 The sealed cabin structure is composed of a side wall structure 1, a bottom structure 2 and a spherical bottom structure 3 which are screwed together. The overall size of the cabin is Φ3400mm x 2850mm (diameter 3400mm, height 2850mm), and a large number of grid-shaped lightening structures are distributed on the outside of the cabin body. The thickness of the grid bottom skin is 1.5±0.1mm, the width of the grid rib is 4mm, and the maximum grid rib height is 60mm.

[0068] Figure 2 The sealed cabin manufacturing process is shown in the figure. The overall process route of the sealed cabin manufacturing method is to manufacture the cabin body in blocks and then connect them to form a whole. The side wall structure 1 is divided into a shoulder structure 1-1 and a side wall cone segment 1-3, which are connected by vacuum electron beam welding. The thickness of the electron beam ring weld 1-2 is 50-60mm. The bottom structure 2 is divided into a bottom cone segment 2-1 and a bottom column segment 2-3, which are connected by vacuum electron beam welding. The thickness of the electron beam weld 2-2 is 50-60mm. The spherical bottom structure is not segmented and is directly manufactured.

[0069] The shoulder structure 1-1 and the spherical bottom structure 3 are manufactured by spinning process. The shoulder structure 1-1 and the spherical bottom structure 3 are first spun into a blank and then machined as a whole. The spinning forming is shown in Figure 3 The spinning die is composed of a core die 8, a first tail top 7, a second tail top 5 and a spinning wheel 10. The first tail top 7 and the second tail top 5 are made of 45 steel. The first tail top 7 is in the form of a disc, which is used to connect the main shaft 9 of the machine tool to the spinning blank, and to apply the main shaft clamping force to the spinning part, thereby increasing the stability of the spinning process. The second tail top 5 is in the form of a cone, which is used to press the corner area of the shoulder structure or the spherical bottom structure after spinning, to prevent deformation of the shoulder structure or the spherical bottom structure caused by subsequent spinning of the cone segment. The core die 8 and the spinning wheel 10 are made of hot work die steel, with a surface roughness better than 0.8 microns. The spinning process is as follows: the spinning core die 8 is heated to 200℃±50℃, the spinning blank 6 (δ70xΦ3500) is heated to 200-300℃, then the heated blank 6 is installed on the core die 8 with bolts, the machine tool main shaft is connected to the first tail top 7 and clamps the workpiece, the spinning wheel 10 is spun according to the set trajectory to make the plate blank tightly adhere to the front end of the die, the second tail top 5 clamps the workpiece to adhere to the die, and the spinning wheel 10 is spun in multiple passes according to the set trajectory 4 until it is completely adhered to the die. The spinning process requires a flame gun to provide on-site temperature compensation for the spinning core die 8 and the blank 6. A thermocouple and an infrared temperature detector are used for temperature detection to ensure that the temperature is within the specified range. Figure 4This is a flowchart of the roll forming process of this invention. After the slab is cut and formed, it is rolled and rolled into a whole. After the spinning is completed, photogrammetry is used to check the spinning accuracy of the product. Ultrasonic testing is used to check for defects inside the slab. Samples are taken from the spinning process allowance for mechanical and microstructure testing to check the internal quality of the product. If the test is qualified, it is used as a finished product. If the test is unqualified, it is compared with the model and iterated. The process parameters of the test roll are adjusted before the roll is processed again, or the model size is adjusted and the simulation is verified. After the simulation is qualified, the slab is cut and processed again.

[0070] The side wall conical section 1-3 and the bottom conical section 2-1 are each formed by rolling three thick plates into conical sections and then welding them together. Figure 5 As shown, the 70mm thick 5B70 wall panel is first milled into a fan-shaped unfolded material, and then rolled into a cone shape using a four-roll plate bending machine. The profile of the rolled part is <3mm. During the rolling process, the rolling pressure needs to be adjusted gradually, with a single adjustment of 5-10mm, until the final product profile meets the usage requirements. Among them, the side wall cone section structure 1-3 is formed by cutting at an 18° cone, and the bottom cone section 2-1 is formed by cutting at a 30° cone.

[0071] Large thickness electron beam welding, such as Figure 5 As shown, the electron beam longitudinal welds are shown in Figures 11 and 12, with a weld thickness of 60-70 mm. During the assembly of the conical wall panels 1-3-1, 1-3-2, and 1-3-3, the assembly gap at weld positions 11 and 12 is <0.2 mm. The welding parameters for the longitudinal welds are: electron beam focal length 200-350 mm, welding voltage 60 KV, welding current 250-300 mA, and welding speed 200-300 mm / min. Under these parameters, the longitudinal welds meet the Class I weld requirements of GJB1718A standard. The electron beam circumferential weld is shown in Figure 11. Figure 6 As shown in marking 1-2, the welding thickness is 50-60mm. When assembling the shoulder structure 1-1 and the side wall conical structure 1-3, the assembly gap at weld position 1-2 is <0.3mm. The welding parameters for the circumferential weld are: electron beam focal length 200-350mm, welding voltage 60KV, welding current 200-250mA, and welding speed 250-300mm / min. Under these parameters, the circumferential weld meets the requirements of Class I weld in GJB1718A standard.

[0072] See section processing Figure 7 As shown, a large five-axis high-speed milling machining center is used for roughing and finishing. Roughing allows for a 5mm machining allowance; internal support fixtures are not required during roughing. The machine spindle speed for roughing is 10000-20000 rpm, with a depth of cut of 4mm and a width of 6mm. Finishing uses a motor spindle speed of 15000-25000 rpm, a depth of cut of 3mm and a width of 0.2mm, with internal flexible support fixtures. The wall thickness accuracy after machining can be guaranteed to be ±0.1mm. For machining of the entire compartment circumferential weld, see [link to details].Figure 8 The machining motor spindle speed is 10000-25000r / min, the cutting depth is 3mm, and the cutting width is 1mm.

[0073] In the case that 5mm process allowance is reserved in rough milling processing, integral heat treatment stress relief work is carried out, the stress relief temperature is 200-250 DEG C, the holding time is 3-4 hours, and the residual stress of the workpiece after stress relief is less than 80Mpa.

[0074] The similar process is adopted to complete the manufacturing of the bottom structure 2 and the spherical bottom 3. The bottom structure 2 is divided into a bottom cone segment 2-1 and a bottom column segment 2-3. The manufacturing process of the bottom cone segment 2-1 is consistent with the manufacturing process of the side wall cone segment 1-3, the cone segment wall plate is first formed by roll bending, then the cone segment is welded by using electron beam longitudinal welding, the process requirements of roll bending processing and electron beam longitudinal welding are the same as those of the side wall cone segment structure 1-3, and finally the bottom cone segment 2-1 is subjected to milling processing; the bottom column segment 2-3 is subjected to milling processing by using a cylindrical blank, and the milling processing is completed; the bottom cone segment 2-1 and the bottom column segment 2-3 are welded by using electron beam longitudinal welding, and finally the bottom structure 2 is subjected to milling at the welding joint according to method 6. The spherical bottom structure 3 is subjected to spinning forming of a blank, and then is subjected to milling processing. The milling processing is completed according to the processing requirements of the outer surface of the sealed cabin.

[0075] The contents not described in detail in the specification of the present application belong to the common knowledge of the person skilled in the art.

Claims

1. A method of manufacturing a manned space capsule, characterized by, The application relates to a method for manufacturing a sealed cabin. Step 1: a spinning die is used to spin a blank according to a set track to manufacture a shoulder structure (1-1), the shoulder structure (1-1) is a circular truncated cone with a smooth top; the spinning die comprises a core die (8), a first-stage tail top (7), a second-stage tail top (5) and a spinning wheel (10); the first-stage tail top (7) is in a disc configuration, and the second-stage tail top (5) is in a conical configuration; Step 2: fan-shaped unfolded surface materials are roll-bent into conical materials, and then three conical materials are welded to form a circular truncated cone as a sidewall conical segment (1-3); the diameter of the circular surface at the bottom of the shoulder structure (1-1) is the same as that of the circular surface at the top of the sidewall conical segment (1-3); Step 3: the shoulder structure (1-1) and the sidewall conical segment (1-3) are welded to form a sidewall structure (1); Step 4: fan-shaped unfolded surface materials are roll-bent into conical materials, and then three conical materials are welded to form an inverted circular truncated cone as a bottom conical segment (2-1); the diameter of the circular surface at the top of the bottom conical segment (2-1) is the same as that of the circular surface at the bottom of the sidewall conical segment (1-3); Step 5: a cylindrical bottom column segment (2-3) is manufactured by milling a cylindrical blank; the diameter of the cylinder of the bottom column segment (2-3) is the same as that of the circular surface at the bottom of the bottom conical segment (2-1); Step 6: the bottom conical segment (2-1) and the bottom column segment (2-3) are welded to form a bottom structure (2); Step 7: a ball bottom structure (3) is manufactured by spinning a blank according to a set track by using a spinning die; the bottom structure is a downward protruding spherical surface, and the diameter of the circular bottom surface of the ball bottom structure (3) is the same as that of the cylinder of the bottom column segment (2-3); Step 8: the sidewall structure (1), the bottom structure (2) and the ball bottom structure (3) are connected to obtain the sealed cabin; Step 9: a grid cavity is formed on the outer surface of the sealed cabin by milling, and the sealed cabin is subjected to overall heat treatment to remove stress; specifically, first, the outer surface of the sealed cabin is subjected to first-round milling to reach a specified process allowance; after the outer surface of the sealed cabin is subjected to first-round milling to reach the specified process allowance, the sealed cabin is subjected to overall heat treatment to remove stress, the heat treatment temperature is 200-250 DEG C, the holding time is 3-4 h, and the residual stress of the sealed cabin after the stress removal is less than 80 Mpa; the sealed cabin is supported by a flexible tooling inside, and then the sealed cabin is subjected to second-round milling to reach a specified precision requirement; finally, the girth weld of the sealed cabin is milled; In steps 2 and 4, fan-shaped unfolded surface materials are roll-bent into conical materials, and then three conical materials are welded to form a circular truncated cone as a sidewall conical segment (1-3) or an inverted circular truncated cone as a bottom conical segment (2-1), and the specific process is as follows: Firstly, the wallboard is milled into a fan-shaped spread material, and then the spread material is rolled into a conical material by using a plate rolling machine; the wallboard material is 5B70 aluminum alloy with a thickness of 70 mm, and the rolling piece profile tolerance is less than 3 mm when the spread material is rolled into a conical material by using the plate rolling machine; the rolling down amount is adjusted gradually during the rolling process, and the single adjustment amount is 5-10 mm; three conical materials are welded to form the side wall conical section (1-3) or the bottom conical section (2-1).

2. The method of claim 1, wherein, The shoulder structure (1-1) or the ball bottom structure (3) is manufactured by spinning the blank according to the set trajectory by using a spinning die, and specifically, The core mold (8) is heated to 200℃±50℃, the blank (6) is heated to 200-300℃, then the heated blank (6) is installed on the core mold (8), the external machining machine tool spindle (9) is connected to the first tail top (7) and tightly presses the workpiece, the spinning wheel (10) is used to spin according to the set trajectory to make the plate blank tightly adhere to the front end of the mold, the second tail top (5) is used to tightly press the workpiece to adhere to the mold part, and the spinning wheel (10) is used to spin according to the set trajectory (4) for multiple passes until it completely adheres to the mold.

3. The method of claim 2, wherein, The surface roughness of the core mold (8) and the spinning wheel (10) is better than 0.8 microns; the spinning core mold (8) and the blank (6) are heated in place during the spinning process to ensure that the temperature of the core mold (8) and the blank (6) is within the specified range.

4. The method of claim 1, wherein, The three conical materials are welded to form the side wall conical section (1-3) or the bottom conical section (2-1), and specifically, The vacuum electron beam welding method is adopted, the weld thickness is 60-70 mm, the electron beam focal length is 200-350 mm, the welding voltage is 60 KV, the welding current is 250-300 mA, and the welding speed is 200-300 mm / min.

5. The method of claim 1, wherein, The conical top angle of the side wall conical section (1-3) is 18°, and the conical top angle of the bottom conical section (2-1) is 30°.

6. The method of claim 1, wherein, The shoulder structure (1-1) and the side wall conical section (1-3) are welded to form the side wall structure (1), or the bottom conical section (2-1) and the bottom column section (2-3) are welded to form the bottom structure (2), and specifically, The vacuum electron beam welding method is adopted, the weld thickness is 50-60 mm, the electron beam focal length is 200-350 mm, the welding voltage is 60 KV, the welding current is 200-250 mA, and the welding speed is 250-300 mm / min.

7. The method of claim 1, wherein, In step 9, the outer surface of the sealed cabin is milled to form a grid cavity, and specifically, A five-axis milling center is used to mill the sealed cabin for the first round of milling, the second round of milling, and the girth weld milling.

8. The method of claim 1, wherein, The first round of milling has a process allowance of 5 mm, and the first round of milling uses a machine tool spindle speed of 10,000-20,000 r / min, a cutting depth of 4 mm, and a cutting width of 6 mm; The second round of milling has a machine tool spindle speed of 15,000-25,000 r / min, a cutting depth of 3 mm, and a cutting width of 0.2 mm; The girth weld of the sealed cabin is milled with a machine tool spindle speed of 10,000-25,000 r / min, a cutting depth of 3 mm, and a cutting width of 1 mm.

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