Spinning device and method for forming a thin-walled rotary body member

Abstract

The present application belongs to the technical field of manufacturing of rotary body components, and particularly relates to a spinning forming device and method for thin-walled rotary body components, which comprises a rotary table, an annular part clamp, a die and a spinning mechanism. The annular part clamp is used for clamping a cylindrical part. The upper surface of the die is a convex rotary curved surface, and the cylindrical part surrounds the outer periphery of the die. The spinning mechanism comprises a plurality of tool heads that can be adjusted in position in a three-dimensional coordinate system. The tool head comprises a spinning wheel that is in rolling contact with the cylindrical part, and is used for fitting the cylindrical part to the upper surface of the die. The device uses the cylindrical part as a spinning blank, and performs necking spinning to close the necking, thereby forming a large curved rotary body component. The necking spinning using the cylindrical part as the blank can avoid various local deformation defects and tooling precision problems caused by welding, and can also avoid stress concentration and performance inhomogeneity. The required equipment is simple, and additional process steps such as patch welding are not required, thereby improving the forming efficiency of the overall box bottom.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of manufacturing of rotary body components, and particularly relates to a spinning forming device and method for thin-walled rotary body components. BACKGROUND

[0002] The head of the fuel tank bottom is a standard rotary body component, and the spinning process is a metal forming process specially used for forming rotary body parts, which is used to manufacture complex-shaped parts such as conical bodies and curved generatrixes. This process is achieved by subjecting the metal sheet to the combined action of pressure and rotation before bending. This process can produce high-precision parts with good surface quality and has a wide range of applications in the energy, aerospace, automotive and other industries. In the field of aerospace, the spinning process is usually used to manufacture the shells of fuel tanks, such as liquid oxygen and liquid hydrogen, and engine components, as well as large antenna reflectors and other components. The fuel tank bottom needs to withstand the pressure load of the internal fuel tank bottom, the collision and vibration load during transportation, and the temperature changes during use. When designing and manufacturing the head of the fuel tank bottom, the above load conditions need to be fully considered, and the head of the fuel tank bottom needs to have sufficient rigidity and strength to reduce the impact of vibration and shock, and also needs to be subjected to necessary testing and evaluation to verify the load-bearing performance and durability of the head of the fuel tank bottom.

[0003] At present, the common forming methods for large thin-walled tank bottoms are: melon-seed deep drawing-welding type and sheet welding-spinning type. The melon-seed deep drawing-welding type first deep draws the rolled blank into a melon-seed shape, and then welds each melon-seed part into a whole tank bottom. The sheet welding-spinning type prepares multiple preformed blanks in advance. Since the existing technology cannot form a large blank at one time, it can only be prepared into a large blank by welding, and finally a large thin-walled tank bottom is formed by the head spinning method.

[0004] As is known, the welding site is locally expanded due to the instantaneous high temperature of welding, and the material structure changes. Moreover, the process needs to be operated multiple times, and the welding passes gradually increase with the increase of the diameter of the tank bottom. The unevenness of welding easily causes shape deviation and performance unevenness. Ultimately, it affects the assembly accuracy and performance unevenness of the workpiece, thereby affecting the service life of the part. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a spinning forming device and method for thin-walled rotary body components, which can avoid various local deformation defects and tooling precision problems caused by welding, and also can avoid stress concentration and performance unevenness.

[0006] The spinning forming device for thin-walled rotary body components provided by the present application comprises:

[0007] rotary table

[0008] annular part clamp arranged on the rotary table, the annular part clamp being used for clamping the cylindrical part

[0009] mold arranged on the annular part clamp, an upper surface of the mold being a convex rotary surface, and the cylindrical part surrounding an outer periphery of the mold

[0010] spinning mechanism, the spinning mechanism comprising a plurality of tool heads, the tool heads being capable of adjusting positions in a three-dimensional coordinate system, and the tool heads comprising spinning wheels, the spinning wheels being in rolling contact with the cylindrical part, and being used for fitting the cylindrical part to the upper surface of the mold

[0011] Optionally, the upper surface of the mold is an elliptic paraboloid or a spherical surface.

[0012] Optionally, the annular part clamp and the mold are used for fastening the cylindrical part.

[0013] Optionally, a diameter of the mold close to the annular part clamp is not less than 3 m.

[0014] Optionally, the diameter of the mold close to the annular part clamp is 3-10 m.

[0015] Optionally, the tool heads further comprise lathes.

[0016] A spinning forming method of a thin-walled rotary body component, comprising the following steps:

[0017] The spinning forming device of the thin-walled rotary body component is used to fasten the cylindrical part through the annular part clamp and the mold, the annular part clamp surrounds the outer periphery of the mold, the track parameters of the spinning wheels are set, the rotary table and the spinning mechanism are started, and the cylindrical part is subjected to multi-pass initial necking spinning to form a tapered cylindrical part.

[0018] Then, the tapered cylindrical part is further spun and gradually fitted to the upper surface of the mold to form a rotary body rough product.

[0019] The rotary body rough product is removed for solid solution treatment, the microstructure performance of the workpiece is adjusted, and conditions are provided for subsequent mold fitting spinning.

[0020] The size and track parameters of the spinning wheels are replaced, the rotating speed of the rotary table is re-adjusted, the rotary body rough product is subjected to finishing spinning, the fitting precision, wall thickness distribution and surface quality of the spun rotary body meet the requirements, and the thin-walled rotary body component is obtained.

[0021] Optionally, the taper of the tapered cylindrical part is 25°-35°.

[0022] Optionally, the rotary body rough product is in a structure with both ends open or a structure with one end sealed.

[0023] Optionally, the spinning forming method of the thin-walled rotary body member further comprises: ring rolling the cylindrical blank to prepare the cylindrical member by ring rolling; and then heat treating to eliminate processing stress, improve ductility and processability of the cylindrical member, and facilitate subsequent spinning forming.

[0024] The beneficial effects of the present application are that the ring member clamp, the die and the cylindrical member fixed thereon are synchronously rotated by opening the rotary table, the spinning wheel on the spinning mechanism is rolled on the outer surface of the cylindrical member, and the cylindrical member is gradually creeped and gradually thinned to form a thin-walled rotary body member with a closed end, which can be a head of a fuel tank bottom. The spinning forming method using the cylindrical member as a blank can avoid various local deformation defects and tooling precision problems caused by welding, stress concentration and uneven performance, and facilitates subsequent tank bottom assembly. The required equipment is simple, and no additional welding process is required, which improves the forming efficiency of the tank bottom, and can achieve thinner wall thickness and lower weight, which is beneficial to the lightweight development of aerospace devices.

[0025] If the existing spinning device is used to process the thin-walled rotary body member, a circular plate is basically used as a blank, and the spinning is gradually transitioned from the middle to the edge, which is a process of expanding and thinning. The part close to the edge is excessively stretched, which may cause cracks and affect the structural strength of the product, and also limits the diameter of the thin-walled rotary body member, making it difficult to manufacture some large fuel tank bottom heads.

[0026] In addition, compared with directly melting and casting a large thin-walled rotary body member, the ring rolling of the cylindrical member can effectively eliminate internal microscopic defects to better realize the spinning of the cylindrical member, which not only enables the workpiece to obtain a high-hardness and high-smoothness surface, but also significantly improves the fatigue strength limit and torsional strength of the workpiece. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The structure schematic diagram of the spinning forming device provided by the embodiment of the present application is shown in the figure;

[0028] Figure 2 The rolling principle diagram of the ring rolling mill provided by the embodiment of the present application is shown in the figure;

[0029] Figure 3 The forming process diagram of the rotary body member provided by the embodiment of the present application is shown in the figure.

[0030] In the figure: 11, rotary table; 12, ring member clamp; 13, die; 21, spinning wheel; 31, cylindrical member; 32, tapered cylindrical member; 33, rotary body rough product; 34, thin-walled rotary body member; 41, main roller; 42, core roller; 43, guide roller. DETAILED DESCRIPTION

[0031] As Figures 1-3 shown in the figure, the spinning forming device for the thin-walled rotary body component provided by the embodiment of the application comprises a rotary table 11, an annular piece clamp 12 arranged on the rotary table 11, a die 13 arranged on the annular piece clamp 12, and a spinning mechanism, the annular piece clamp 12 is used for clamping a cylindrical piece 31; the upper surface of the die 13 is a convex rotary curved surface, and the cylindrical piece 31 surrounds the outer periphery of the die 13; the spinning mechanism comprises a plurality of tool heads that can be adjusted in position in a three-dimensional coordinate system, and the tool head comprises a spinning wheel 21 that is in rolling contact with the cylindrical piece 31 and is used for fitting the cylindrical piece 31 to the upper surface of the die 13.

[0032] Compared with the prior art, the spinning forming device for the thin-walled rotary body component 34 provided by the application synchronously rotates the annular piece clamp 12, the die 13 and the cylindrical piece 31 fixed thereon by opening the rotary table 11, the spinning wheel 21 on the spinning mechanism rolls and presses on the outer surface of the cylindrical piece 31, cooperates with the die 13 to roll, makes the cylindrical piece 31 gradually creep, gradually thins, and gradually forms the thin-walled rotary body component 34 with a closed end, the thin-walled rotary body component 34 can be a head of a fuel tank bottom, and the diameter reduction and closing spinning with the cylindrical piece 31 as a blank can avoid various local deformation defects and tool precision problems caused by welding, can also avoid stress concentration and performance unevenness, is convenient for subsequent tank bottom assembly work, and the required equipment is simple, does not need to perform additional splicing and welding process steps, improves the forming efficiency of the whole tank bottom, and can realize thinner wall thickness and lower weight, which is beneficial to the lightweight development of aerospace devices.

[0033] If the existing spinning device is used to process the thin-walled rotary body component 34, basically, a circular plate is used as a blank, the spinning is performed from the middle to the edge, it is a process of diameter expansion and thickness reduction, cracks may occur due to excessive elongation of the part close to the edge, which affects the structural strength of the product, and also limits the diameter of the thin-walled rotary body component 34, and it is difficult to manufacture some large fuel tank bottom heads.

[0034] In addition, compared with directly melting and casting a large thin-walled rotary body component 34, the ring rolling cylindrical piece 31 can effectively eliminate internal microscopic defects and ensure that the elongation rate of the component is better to realize the closing spinning of the cylindrical piece 31, which can not only make the workpiece obtain a surface with high hardness and high smoothness, but also can significantly improve the fatigue strength limit and torsional strength of the workpiece.

[0035] It should be noted that the structure of the other half is omitted in the embodiment, and the dashed line therein is a symmetry line and also a rotation axis of the rotary table 11. Figure 1 The structure of the other half is omitted, and the dashed line therein is a symmetry line and also a rotation axis of the rotary table 11.

[0036] In the embodiment, the cylindrical piece 31 can be a straight cylinder or a tapered cylinder.

[0037] In the embodiment, the upper surface of the die 13 is an elliptic paraboloid or a spherical surface.

[0038] Specifically, the upper surface of the die 13 is a convex surface for the fitting of the cylindrical member 31, and includes a partial radial side surface, which gradually decreases in diameter from the radial side surface to the top. It is to be noted that the radial side surface of the die 13 close to the ring clamp 12 is a straight cylinder, which is convenient for later assembly.

[0039] Further, the upper surface and the lower surface of the die 13 are both elliptic paraboloids or spherical surfaces, like an inverted pot.

[0040] In the embodiment, the ring clamp 12 and the outer side of the die 13 are fastened together to hold the cylindrical member 31, so that the edge of the processed thin-walled rotary member 34 can be closely fitted with the die 13, and the later trimming operation can be reduced, and the edge of the thin-walled rotary member 34 can meet the design requirements.

[0041] The specific structure of the ring clamp 12 is as follows: a small step is processed at the lower end of the workpiece (the cylindrical member 31), a press ring is processed on the ring clamp 12, and the step of the workpiece is pressed by fastening the screw. The lower part of the die 13 has a flange, and the fastening screw fixes the ring clamp 12 on the flange of the lower edge of the die 13, so that the die 13, the workpiece and the ring clamp 12 are fastened together. The clamping jaw 14 only needs to be tightened on the die 13 to complete the required tooling.

[0042] In the embodiment, the diameter of the die 13 close to the ring clamp 12 is not less than 3m, that is, the diameter of the radial side surface of the die 13 is not less than 3m, and thus the inner diameter of the edge of the thin-walled rotary member 34 processed by the spinning forming device is not less than 3m, which is suitable for manufacturing large thin-walled rotary members 34 with a closed end, such as the end cover of the liquid oxygen and liquid hydrogen fuel tank of a spacecraft.

[0043] Preferably, the diameter of the die 13 close to the ring clamp 12 is 3-10m, so that the currently suitable materials can be used to manufacture most of the end covers of the fuel tank.

[0044] When the diameter of the required fuel tank bottom head is too large, reaching dozens of meters or even larger, the material directly changes from the cylindrical part 31 to the head part (the head of the fuel tank bottom), and the thinning rate of the material is larger. Limited by the properties of the current material, folding and cracking are easily generated. Therefore, a spinning forming device with a mold 13 with a required diameter can be used to manufacture an open-end rotary body member, and then another spinning forming device with a specific suitable mold 13 is selected according to the size of the necking part of the rotary body member to spin the remaining part with another cylindrical part 31. After edge cutting and trimming, the two parts are connected by welding to form the required fuel tank bottom head.

[0045] In the embodiment, the tool head further includes a turning tool. Specifically, the spinning wheel 21 on the spinning mechanism can be replaced by a turning tool to process and finish the local position of the workpiece (thin-walled rotary body member 34), realize spinning and turning on the same device, avoid the error generated by secondary clamping, complete multi-process processing at the same time of clamping, and ensure the machining accuracy of the tank bottom.

[0046] In the embodiment, the spinning mechanism includes a three-axis truss and a plurality of mechanical hands arranged on the three-axis truss, which are not shown in the figure. The tool head can be replaceably mounted on the mechanical hand. In this way, the tool head can be adjusted in three-dimensional coordinates.

[0047] In the embodiment, please refer to Figure 2 Sometimes the specifications of the cylindrical part 31 do not meet the requirements of direct spinning processing, and need to be reshaped and expanded in diameter. Therefore, a ring rolling mill needs to be used. The ring rolling mill can be a spinning forming device matched component. The ring rolling mill includes a main roller 41, a core roller 42, and two symmetrically arranged guide rollers 43. The main roller 41 rotates while moving in the direction of the line connecting the center of the main roller 41 and the core roller 42, i.e. the pressing motion. The roll gap between the two rollers determines the wall thickness of the ring. When the main roller 41 approaches the core roller 42 at an appropriate speed, the rolling force is generated on the ring between the two rollers, and the ring rotates. When the rolling force meets the piercing condition of the ring, the ring extends in the tangent direction of the contact point between the main roller 41 and the core roller 42, so that the diameter of the ring increases. The left and right guide rollers 43 function to keep the rolling process stable and the roundness of the ring.

[0048] In a specific embodiment, taking a 10m diameter integral tank composed of two curved surface rotary bodies as an example: the first step is to form the lower 1.5m part of the integral tank bottom, and the second step is to form the middle 1.5m part of the integral tank. The curved surface rotary body of the lower 1.5m part and the curved surface rotary body of the middle 1.5m part are welded to form an integral tank bottom with a height of 3mm and an opening diameter of 3.8m.

[0049] The curved surface rotary body forming idea of the lower 1.5m part of the integral tank bottom is as follows:

[0050] 1. Using 2219 aluminum alloy material, first ring rolling a cylindrical blank with an inner diameter of φ9980mm, a thickness of 70-80mm, and a height of 800mm;

[0051] 2. Machining the cylindrical blank to an inner diameter of φ10000mm and an outer diameter of φ10060mm, and adding a step of 80mm high and 5mm protruding at the bottom;

[0052] 3. Spinning the straight cylinder blank to a conical cylinder with a 25°-35° taper on the corresponding conical cylinder die with film bonding;

[0053] 4. Annealing the conical cylinder to eliminate work hardening and improve the machinability of the workpiece;

[0054] 5. Replacing the conical cylinder die with a whole box bottom head-shaped die for reducing diameter and film bonding spinning to form a large curved surface body member;

[0055] 6. Solid solution of the whole box bottom;

[0056] 7. Accurate shaping of the whole box bottom to form a final wall thickness of 6mm. The upper aperture of the curved surface body of the lower 1.5m of the whole box bottom is <φ7000mm, and the lower aperture is φ10000mm; the curved surface body of the middle 1.5m of the whole box bottom is shaped in the same way as the lower 1.5m of the curved surface body, and the upper aperture is <φ3800mm after final shaping.

[0057] A spinning forming method of a thin-walled rotary body member, comprising the following steps:

[0058] Using the spinning forming device of the thin-walled rotary body member, first fasten the cylindrical blank 31 through the ring blank clamp 12 and the die 13, the ring blank clamp 12 is around the outer periphery of the die 13, set the track parameters of the spinning wheel 21, open the rotary table 11 and the spinning mechanism, and perform multi-pass initial necking spinning on the cylindrical blank 31 to form a conical cylinder 32;

[0059] Then, further spin the conical cylinder 32 and gradually adhere to the upper surface of the die 13 to form a rotary body rough product 33;

[0060] Remove the rotary body rough product 33 for solid solution treatment to adjust the organizational performance of the workpiece and provide conditions for subsequent film bonding spinning;

[0061] Replace the size and track parameters of the spinning wheel 21 and re-adjust the speed of the rotary table 11 to perform shaping spinning on the rotary body rough product 33, and the spinning rotary body obtained has the required bonding accuracy, wall thickness distribution and surface quality, and the thin-walled rotary body member 34 is obtained.

[0062] By adopting the cylindrical part 31 as the spinning blank, through the reducing spinning, the port of the cylindrical part 31 is closed, and finally a large-sized rotary body component, such as the end cover of the fuel tank of the spacecraft, is formed. Compared with the prior art, the reducing closing spinning of the cylindrical part 31 as the blank can avoid various local deformation defects and tooling precision problems caused by welding, can also avoid stress concentration and performance inhomogeneity, the required equipment is simple, no additional welding process steps are required, and the forming efficiency of the overall tank bottom is improved. At the same time, thinner wall thickness and lower weight can be achieved, which is beneficial to the lightweight development of aerospace devices.

[0063] In the embodiment, the taper of the tapered cylinder part 32 is 25°-35°, preferably, the taper of the tapered cylinder part 32 is 30°.

[0064] For large-sized overall tank bottom spinning, the required workpiece height is 1000mm or more, the blank height of general ring rolling is about 800mm, and workpieces exceeding 800mm need to be lengthened by spinning extrusion. If a large-sized rotary body workpiece of 800mm or more is directly subjected to reducing film-coating spinning, obvious closing instability phenomenon occurs at the upper part of the workpiece. If the straight cylinder is first spun to a tapered cylinder with a taper of 25°-35°, the tapered cylinder workpiece can be lengthened by spinning extrusion to the required height, the reducing amount of the subsequent closing film-coating spinning process can be reduced, and the end face closing instability phenomenon of the upper part of the workpiece can be effectively avoided.

[0065] In the embodiment, the rotary body rough product 33 has a structure with both ends open or a structure with one end closed, which can be determined according to the material and the specification of the thin-walled rotary body component 34. In most cases, the rotary body rough product 33 has a structure with both ends open, and the upper end opening is formed by reducing.

[0066] In the embodiment, the spinning forming method of the thin-walled rotary body component 34 further includes: ring rolling and breaking down the cylindrical blank, and preparing the cylindrical part 31 by the ring rolling method; and then heat treatment is performed to eliminate processing stress, improve the ductility and processability of the cylindrical part 31, and facilitate the subsequent spinning forming. In this way, the ring rolling of the cylindrical part 31 can effectively eliminate internal microscopic defects to ensure better elongation of the component, realize the closing spinning of the cylindrical part 31, and also prepare the cylindrical part 31 meeting the specification.

[0067] It should be understood by those skilled in the art that the above discussion of any embodiment is only exemplary and is not intended to limit the scope of protection of the present application to these examples; under the idea of the present application, the above embodiments or technical features in different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of one or more embodiments of the present application as described above. In order to be brief, they are not provided in detail.

[0068] It is intended that the embodiments of the application herein described be interpreted to cover all such modifications, alterations, and equivalents as fall within the true spirit and scope of the application. Accordingly, what is desired to be secured by Letters Patent is the subject matter as follows:

Claims

1. A method of spinning forming a thin-walled revolutional member, characterized by, A spinning forming device for implementing the spinning forming method; The spinning forming device comprises: a rotary table (11); a ring-shaped part clamp (12) disposed on the rotary table (11) and used for clamping a cylindrical part (31); a die (13) disposed on the ring-shaped part clamp (12), the upper surface of the die (13) being a convex rotary curved surface, and the cylindrical part (31) surrounding the outer periphery of the die (13); and a spinning mechanism comprising a plurality of tool heads adjustable in position in a three-dimensional coordinate system, the tool heads comprising spinning wheels (21) in rolling contact with the cylindrical part (31) and used for fitting the cylindrical part (31) to the upper surface of the die (13). The spinning forming method comprises the following steps: first, the cylindrical part (31) is fastened by the ring-shaped part clamp (12) and the die (13), the ring-shaped part clamp (12) surrounds the outer periphery of the die (13), the trajectory parameters of the spinning wheels (21) are set, the rotary table (11) and the spinning mechanism are started, and the cylindrical part (31) is subjected to multi-pass initial closing spinning to form a tapered cylindrical part (32); then, the tapered cylindrical part (32) is further spun and gradually fitted to the upper surface of the die (13) to form a rotary body rough product (33); the rotary body rough product (33) is removed for solid solution treatment to adjust the organizational properties of the workpiece and provide conditions for subsequent die fitting spinning; the size and trajectory parameters of the spinning wheels (21) are changed, the rotational speed of the rotary table (11) is adjusted, and the rotary body rough product (33) is subjected to finishing spinning to obtain a spun rotary body with required fitting precision, wall thickness distribution, and surface quality.

2. The spinning forming method of a thin-walled revolution body member according to claim 1, characterized by The upper surface of the die (13) is an elliptical parabolic surface or a spherical surface.

3. The spinning forming method of a thin-walled revolution body member according to Claim 1, characterized by The ring-shaped part clamp (12) and the die (13) are fastened to the cylindrical part (31) on the outer side.

4. The spinning forming method of a thin-walled revolution body member according to Claim 1, characterized by The diameter of the die (13) near the ring-shaped part clamp (12) is not less than 3 m.

5. The spinning forming method of a thin-walled revolution body member according to Claim 1, characterized by The diameter of the die (13) near the ring-shaped part clamp (12) is 3-10 m.

6. The spinning forming method of a thin-walled revolution body member according to Claim 1, characterized by The tool head further comprises a turning tool.

7. The spinning forming method of a thin-walled revolution body member according to Claim 1, characterized by The taper of the tapered cylindrical part (32) is 25°-35°.

8. The spinning forming method of a thin-walled revolution body member according to Claim 1, characterized by The rotary body rough product (33) has a structure with both ends open or a structure with one end sealed.

9. The spinning forming method of a thin-walled revolution body member according to Claim 1, characterized by Further comprising: a ring rolling opening process is performed on a cylindrical blank to prepare the cylindrical part (31) by ring rolling; and then heat treatment is performed to eliminate processing stress, improve the ductility and processability of the cylindrical part (31), and facilitate subsequent spinning forming.

Images