High-precision spinning forming process for ribbed barrel segments

Abstract

The present invention proposes a high-precision spinning forming process method for ribbed barrel segments, aiming to solve the problems of diameter expansion and uneven deformation in the traditional spinning process. The process includes double-sided turning of a prefabricated barrel blank to ensure the inclination, installing a spinning mold with a ribbed structure, heating the barrel blank, and then putting it on a mold with an inner cross groove to achieve an interference fit. Subsequently, a three-wheel spinning machine is started for spinning, and induction heating is used to improve the plasticity of the material so that the material flows into the cross groove of the mold. After the spinning is completed, the wheels are replaced with turning tools, the outer surface is turned, and finally the parts are removed. The present invention uses the difference in thermal expansion coefficient of the material and diameter compensation to control the inner diameter, and achieves uniform external dimensions through induction heating and in-situ turning processes. This process is suitable for materials such as aluminum alloy and high-strength steel, significantly improves the dimensional accuracy of the barrel segment, and provides technical support for the overall near-net forming of the barrel segment of aircraft such as tactical projectiles. This invention not only optimizes the spinning process, but also improves the quality and performance of the final product.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace ribbed thin-walled cylinder segment forming technology, and in particular to a high-precision spinning forming process method for ribbed cylinder segments. Background Art

[0002] The ribbed thin-walled barrel section is a typical missile compartment structure, widely used in aerospace applications. It is typically constructed of aluminum alloys, high-strength steel, and other materials. The cabin wall thickness varies depending on load distribution and equipment layout requirements, with the maximum thickness of the skin area typically not exceeding 3mm. Various stiffening ribs, such as longitudinal and circumferential ribs, are placed along the inner walls of the cabin to enhance overall structural strength and stability.

[0003] Traditional processing techniques primarily rely on casting and machining to produce thin-walled, ribbed cylinder sections. However, this approach suffers from high material removal and low processing efficiency, making it particularly challenging to process ribs within complex structures. Furthermore, the use of difficult-to-form materials makes traditional processing prone to deformation and cracking, further increasing both the difficulty and cost of fabrication.

[0004] To address these issues, the integral spinning process has gradually been introduced into the manufacturing of ribbed barrel segments. This process effectively reduces material waste, improves processing efficiency, and maintains good material properties during the forming process. However, the spinning of ribbed barrel segments still presents some technical challenges. For example, the expansion of the part diameter during the spinning process can lead to significant deviations in the overall dimensions of the formed part. In particular, for ribbed barrel segments measuring one meter in size, the dimensional deviation (the difference between the maximum and minimum diameters) after spinning can reach as much as 1-2 mm. Furthermore, the expansion of the ribs results in incomplete filling, resulting in variations in rib height, with the maximum deviation being around 1 mm. These deviations severely impact the dimensional accuracy and overall performance of the ribbed barrel segments.

[0005] After a novelty search, it was discovered that the invention patent (application number ZL202011112466.2) invented a laser-assisted shearing spinning device and forming method. This device and method are mainly used for the forming of small semi-cone angle parts of difficult-to-deform metals. The patent mainly uses laser assistance to realize the part forming process, and the laser action area is located on both sides of the spinning wheel. The patent adopts an induction heating process, which has relatively high heating uniformity and can reduce the expansion and deformation of the parts.

[0006] The invention patent (application number 202010219568.8) invented an integrated hot forming method for aluminum alloy plates with composite-solid solution quenching. This method uses a high-temperature solid solution stage to form the parts, followed by rapid quenching treatment and then aging. The heat treatment process after the parts are formed still cannot control deformation. Its working principle and method are fundamentally different from this patent.

[0007] The invention patent (application number 202111172468.5) invented a laser-assisted solid solution warm spinning method and a cylinder segment with cross ribs. This method adopts the method of solid solution first and then spinning, which effectively avoids the reduction in precision caused by heat treatment deformation. However, this patent is prone to dimensional deviations such as diameter expansion and uneven wall thickness. This patent uses interference fit + induction heating method to effectively avoid the above-mentioned problems that are prone to occur in the spinning process. At the same time, it adopts in-situ turning to further improve the quality of the parts after forming.

[0008] Therefore, in order to improve the dimensional accuracy and overall performance of the ribbed barrel segment, it is necessary to develop a new spinning process method to solve the problems existing in traditional processing technology and overall spinning process. Summary of the Invention

[0009] In view of the defects in the prior art, the purpose of the present invention is to provide a high-precision spinning forming process for ribbed barrel segments.

[0010] According to the present invention, a high-precision spinning forming process method for a ribbed barrel segment is provided, the method comprising the following steps:

[0011] Step S1: performing double-sided turning processing on the prefabricated tube blank to process the inclination angle and to form a boss structure for spinning positioning;

[0012] Step S2: Installing the ribbed structure spinning mold on the spinning machine;

[0013] Step S3: heating the tube blank to a preset temperature and keeping the temperature for a preset time, so that the tube blank expands due to the heat;

[0014] Step S4: The heated cylindrical blank is placed on the spinning die with the inner cross groove and cooled to room temperature, and an interference fit is generated between the die and the cylindrical blank by utilizing the principle of thermal expansion and contraction;

[0015] Step S5: starting the three-wheel spinning machine to perform spinning, and using the induction heating coil to perform auxiliary heating on the part during the spinning process, and the heating temperature is controlled at a preset temperature;

[0016] Step S6: After the spinning is completed, the spinning wheel is replaced with a turning tool, and the spun tube blank is turned to ensure that the outer diameter of the part is consistent with the design drawing requirements;

[0017] Step S7: Fix the outer side of the part with a clamp, remove it from the spinning tooling, and turn the internal ribs based on the outer diameter to ensure that the accuracy of the ribbed barrel section is within a preset range.

[0018] Preferably, in step S1, the roundness of the preformed tube blank is less than or equal to 0.5 mm, and the thermal expansion coefficient of the preformed tube blank is greater than 0.5 mm / 100°C; the wall thickness of the preformed tube blank is α mm, the height is γ mm, the outer diameters of the large and small ends of the preformed tube blank are D1 mm and D2 mm respectively, D1=D2+1 mm, and the inclination angle is θ°.

[0019] Preferably, in step S2, the thermal expansion coefficient of the spinning mold is smaller than that of the tube blank, and the diameter of the tube blank after thermal expansion is greater than D3mm; the outer diameter of the large end of the spinning mold is D3mm, and the outer diameter of the small end is D4mm.

[0020] Preferably, in step S3, the holding time is 60 minutes, and the diameter of the tube blank expanded by heat after heating is D1 / D2+3 mm.

[0021] Preferably, in step S4, the tube blank is placed on a spinning die with a 45° inner cross groove, and the principle of thermal expansion and contraction is utilized to produce an interference fit between the tube blank and the die after cooling; the outer diameter D3=D1+0.5mm of the spinning die near the large end of the tube section, and the inclination angle is θ° consistent with the tube blank; in the spinning forming step, a single-pass spinning process is adopted for spinning to ensure that the ribs in the tube section are fully filled and evenly distributed.

[0022] Preferably, in step S5, the feed rate of the rotating wheel is βmm / r; the induction heating coil is arranged outside the front end mold of the three rotating wheels to perform local induction heating on the undeformed area of ​​the barrel section during spinning, and the diameter expansion caused by spinning is 1mm.

[0023] Preferably, in step S6, the diameter of the part is expanded after spinning, and the size D of the part after spinning is 1终 =D 2终 The turning tool has an outer diameter of D1-0.2mm and a straight line trajectory. In-situ turning is used to ensure that the parts achieve the required shape and accuracy.

[0024] Preferably, after turning the outer surface, it is fixed with a clamp, and the mold is removed and then installed on a spinning machine. The inner surface turning tool is replaced and the internal ribs are turned.

[0025] Preferably, the ribbed structure of the spinning die includes longitudinal and / or circumferential reinforcement ribs to meet the requirements for barrel strength and rigidity in different application scenarios.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention uses the process of "utilizing expansion coefficient differences to achieve interference fit of the tube blank - induction heating-assisted spinning - in-situ turning" to effectively control the diameter expansion of the ribbed barrel segment during the spinning process. By compensating the diameter of the spinning tube blank, the dimensional accuracy of the product is significantly improved, achieving the goal of controlling the accuracy of the ribbed barrel segment to within 1 mm.

[0028] 2. The present invention uses induction heating technology to replace traditional flame heating. This not only makes the heated area, temperature and heating zone of the parts more uniform, but also has higher efficiency, faster temperature rise and more convenient temperature control compared to laser heating. This is conducive to the control of the evolution of the internal structure of the material, further improving the quality and performance of the product.

[0029] 3. The process route adopted by the present invention is particularly suitable for various forming materials such as aluminum alloy and high-strength steel. Spinning and turning are synchronized on one device, avoiding dimensional accuracy deviation caused by mold loading and unloading, and effectively improving the applicability and flexibility of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0031] Figure 1 It is a schematic diagram of the induction heating forming process of the ribbed tube segment of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0033] Example 1:

[0034] Reference Figure 1 According to the present invention, a high-precision spinning forming process method for a ribbed barrel segment is provided, the method comprising the following steps:

[0035] Step S1: The prefabricated tube blank is double-sided turned to machine the inclination angle and to machine a boss structure for spinning positioning; the roundness of the prefabricated tube blank is less than or equal to 0.5 mm, and the thermal expansion coefficient of the prefabricated tube blank is greater than 0.5 mm / 100 ° C; the wall thickness of the prefabricated tube blank is α mm, the height is γ mm, the outer diameters of the large and small ends of the prefabricated tube blank are D1 mm and D2 mm respectively, D1=D2+1 mm, and the inclination angle is θ°.

[0036] Step S2: Install the ribbed structure spinning mold on the spinning machine; the thermal expansion coefficient of the spinning mold is smaller than the thermal expansion coefficient of the tube blank, and the diameter of the tube blank after thermal expansion is greater than D3mm; the outer diameter of the large end of the spinning mold is D3mm, and the outer diameter of the small end is D4mm.

[0037] Step S3: The tube blank is heated to a preset temperature and kept at this temperature for a preset time, so that the tube blank expands due to the heat; the heating temperature is T1 = 500°C - 680°C, and the temperature is kept at this temperature for 60 minutes. After heating, the diameter of the tube blank expanded by heat is D1 / D2 + 3mm.

[0038] Step S4: The heated tube blank is put on the spinning die with an inner cross groove and cooled to room temperature, and an interference fit is generated between the die and the tube blank by utilizing the principle of thermal expansion and contraction; the tube blank is put on the spinning die with a 45° inner cross groove, and an interference fit is generated between the tube blank and the die after cooling by utilizing the principle of thermal expansion and contraction; the outer diameter D3=D1+0.5mm of the spinning die near the large end of the barrel section, and the inclination angle is θ° consistent with the tube blank; in the spinning forming step, a single-pass spinning process is adopted for spinning to ensure that the ribs in the barrel section are fully filled and evenly distributed.

[0039] Step S5: Start the three-wheel spinning machine to perform spinning. During the spinning process, the induction heating coil is used to assist in local heating of the part, and the heating temperature is controlled at a preset temperature. The feed rate of the spinning wheel is βmm / r, and the heating temperature is 400℃~500℃. The induction heating coil is arranged on the outside of the mold at the front end of the three spinning wheels to perform local induction heating on the undeformed area of ​​the barrel section during spinning. The heating temperature T3 is controlled within the range of ±3℃, and the diameter expansion caused by spinning is 1mm.

[0040] Step S6: After the spinning is completed, the spinning wheel is replaced with a turning tool, and the spun tube blank is turned to ensure that the outer diameter of the part is consistent with the design drawing requirements; the diameter of the part is expanded after spinning, and the size of the part after spinning D 1终 =D 2终 The turning tool has an outer diameter of D1-0.2mm and a straight line trajectory. In-situ turning is used to ensure that the parts achieve the required shape and accuracy.

[0041] Step S7: The part is secured on the outside with a clamp and removed from the spinning tooling. Using the outer diameter as a reference, internal ribs are turned to achieve precision control of the ribbed barrel section within a preset range. After turning the outer surface, the part is secured with a clamp, the mold is removed, and then installed on the spinning machine. The inner surface turning tool is replaced and the internal ribs are turned. The ribbed structure of the spinning mold includes longitudinal and / or circumferential reinforcement to meet the strength and stiffness requirements of the barrel section in different application scenarios.

[0042] Example 2:

[0043] The present invention relates to a high-precision spinning forming process method for a ribbed barrel segment. The process is aimed at controlling the shape and precision of a barrel segment of a storage tank with a grid convex rib structure. The specific steps are as follows: 1) first, a prefabricated barrel blank is subjected to double-sided turning processing, and a boss structure is processed. The barrel blank has a diameter of D1mm and D2mm; 2) a spinning die with a ribbed structure is installed on a spinning machine, and the outer diameter of the spinning die is D3mm; 3) the barrel blank is heated at a temperature of 500°C to 680°C (depending on the material) and kept warm for 60 minutes. After heating, the diameter of the part expands by D1 / D2+3mm due to heat; 4) the barrel blank is then quickly put on a spinning die with a 45° inner cross groove, and an interference fit is generated between the barrel blank and the die by utilizing the principle of thermal expansion and contraction; 5) a three-wheel spinning machine is started for spinning forming. During the spinning process, an induction heating coil is used to perform auxiliary heating on a part of the part. The heating temperature is 400°C to 500°C (depending on the material) so that the material flows into the cross groove of the die; 6) the size of the part after spinning is D 1终 =D 2终 The turning tool cuts the outer diameter to D1-0.2mm, using a straight trajectory. In-situ turning ensures the part achieves the desired shape and precision. This invention utilizes differences in material thermal expansion coefficients to control the inner diameter of the ribbed barrel segment. Simultaneously, by establishing a process combining induction heating and in-situ turning, it achieves uniform control of the overall external dimensions, providing technical support for the near-net-shape forming of barrel segments for aircraft, such as tactical projectiles.

[0044] The process route of the present invention utilizes the difference in thermal expansion coefficients between the mold and the tube blank, and uses thermal expansion and contraction to achieve an interference fit between the tube blank and the outer diameter of the mold, thereby effectively improving the filling effect of the part ribs during the spinning process. By compensating the diameters of the large and small ends of the part, the dimensional deviation caused by the expansion phenomenon is effectively reduced. At the same time, in conjunction with the subsequent turning process, the dimensional accuracy of the product is further improved. After actual measurement, the part accuracy is better than 1mm, the rib deviation is about 0.5mm, and the arc and straightness are better than the existing indicators. The use of induction heating technology, compared with traditional flame heating methods, the heated area, heated temperature and heated area of ​​the parts are more uniform. At the same time, compared with laser heating, induction heating is more efficient, heats up more quickly, and temperature control is convenient. At the same time, the heated area is more uniform, which is conducive to the control of the evolution of the internal structure of the material. The use of in-situ turning technology can be combined with the specific material to formulate a detailed process route, which is not affected by the disassembly of the tooling, and effectively improves the scope of application of the process.

[0045] See Figure 1 , is a flow chart of the spinning forming process of the ribbed barrel segment, which includes the following steps:

[0046] Step S1: Perform double-sided turning on the prefabricated tube blank to form a boss structure; the roundness of the prefabricated tube blank is less than or equal to 0.5mm, and the thermal expansion coefficient of the prefabricated tube blank is greater than 0.5mm / 100℃; the wall thickness of the prefabricated tube blank is αmm, the height is γmm, the outer diameters of the large and small ends of the prefabricated tube blank are D1mm and D2mm respectively, D1=D2+1mm, and the inclination angle is θ°.

[0047] Step S2: Installing a spinning die with a ribbed structure on a spinning machine, wherein the outer diameter of the spinning die is D3 and the outer diameter of the small end is D4 mm; the thermal expansion coefficient of the spinning die is smaller than the thermal expansion coefficient of the tube blank.

[0048] Step S3: The tube blank is heated to a preset temperature and kept at the preset temperature for a preset time to allow the tube blank to expand due to the heat. The heating temperature is T1 = 500°C to 680°C (depending on the material), and the temperature is kept for 60 minutes. After heating, the diameter of the tube blank expanded by heat is D1 / D2 + 3mm.

[0049] Step S4: The heated tube blank is placed on a spinning die with an inner cross groove, and an interference fit is created using the principle of thermal expansion and contraction. The tube blank is placed on a spinning die with a 45° inner cross groove, and an interference fit is created between the tube blank and the die using the principle of thermal expansion and contraction. The outer diameter of the spinning die near the large end of the barrel section is D3 = D1 + 0.5 mm, and the inclination angle is θ°, consistent with the tube blank. In the spinning forming step, a single-pass spinning process is used to ensure that the ribs in the barrel section are fully filled and evenly distributed. The ribbed structure of the spinning die includes longitudinal and / or circumferential reinforcement ribs to meet the strength and stiffness requirements of the barrel section in different application scenarios.

[0050] Step S5: Start the three-wheel spinning machine to perform spinning. During the spinning process, the induction heating coil is used to assist in local heating of the part, and the heating temperature is controlled at a preset temperature. The feed rate of the spinning wheel is βmm / r. The induction heating coil is arranged on the outside of the mold at the front end of the three spinning wheels to perform local induction heating on the undeformed area of ​​the barrel section during spinning. The heating temperature T3 is controlled within the range of ±3°C, and the diameter expansion caused by spinning is 1mm.

[0051] Step S6: The diameter of the part is expanded after spinning, and the size of the part after spinning is D 1终 =D 2终 The turning tool has an outer diameter of D1-0.2mm and a straight line trajectory. In-situ turning is used to ensure that the parts achieve the required shape and accuracy.

[0052] Step S7: Fix the outer side of the part with a clamp, remove it from the spinning tooling, and turn the internal ribs based on the outer diameter to ensure that the accuracy of the ribbed barrel section is within a preset range.

[0053] Those skilled in the art will appreciate that, in addition to implementing the system and its various devices, modules, and units provided by the present invention in purely computer-readable program code, it is entirely possible to implement the same functions of the system and its various devices, modules, and units provided by the present invention in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; the devices, modules, and units for implementing various functions can also be considered as both software modules implementing the method and structures within the hardware component.

[0054] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A high-precision spinning forming process for a ribbed barrel segment, characterized in that: The method comprises the following steps: Step S1: performing double-sided turning processing on the prefabricated tube blank to process the inclination angle and to form a boss structure for spinning positioning; Step S2: Installing the ribbed structure spinning mold on the spinning machine; Step S3: heating the tube blank to a preset temperature and keeping the temperature for a preset time, so that the tube blank expands due to the heat; Step S4: The heated cylindrical blank is placed on the spinning die with the inner cross groove and cooled to room temperature, and an interference fit is generated between the die and the cylindrical blank by utilizing the principle of thermal expansion and contraction; Step S5: starting the three-wheel spinning machine to perform spinning, and using the induction heating coil to perform auxiliary heating on the part during the spinning process, and the heating temperature is controlled at a preset temperature; Step S6: After the spinning is completed, the spinning wheel is replaced with a turning tool, and the spun tube blank is turned to ensure that the outer diameter of the part is consistent with the design drawing requirements; Step S7: Fix the outer side of the part with a clamp, remove it from the spinning die, and turn the internal ribs based on the outer diameter to ensure that the accuracy of the ribbed barrel section is within a preset range; In step S1, the roundness of the preformed tube is less than or equal to 0.5 mm, and the thermal expansion coefficient of the preformed tube is greater than 0.5 mm / 100° C.; the wall thickness of the preformed tube is α mm, the height is γ mm, the outer diameters of the large and small ends of the preformed tube are D1 mm and D2 mm respectively, D1=D2+1 mm, and the inclination angle is θ°; In step S5, the feed rate of the spinning wheel is β mm / r; the induction heating coil is arranged outside the front end mold of the three spinning wheels to perform local induction heating on the undeformed area of ​​the barrel section during spinning, and the diameter expansion caused by spinning is 1 mm; After turning the outer surface, fix it with a clamp, remove the mold, and then install it on the spinning machine. Replace the inner surface turning tool and turn the internal ribs. The ribbed structure of the spinning die includes longitudinal and / or circumferential reinforcement ribs to meet the requirements for barrel strength and rigidity in different application scenarios.

2. The high-precision spinning forming process for ribbed barrel segments according to claim 1 is characterized in that: In step S2, the thermal expansion coefficient of the spinning mold is smaller than the thermal expansion coefficient of the tube blank, and the diameter of the tube blank after thermal expansion is greater than D3mm; the outer diameter of the large end of the spinning mold is D3mm, and the outer diameter of the small end is D4mm.

3. The high-precision spinning forming process for ribbed barrel segments according to claim 1 is characterized in that: In step S3, the holding time is 60 minutes.

4. The high-precision spinning forming process for ribbed barrel segments according to claim 1 is characterized in that: In step S4, the tube blank is placed on a spinning die with a 45° inner cross groove, and the principle of thermal expansion and contraction is utilized to produce an interference fit between the tube blank and the die after cooling; the outer diameter D3 of the spinning die near the large end of the tube section is D1+0.5 mm, and the inclination angle is θ° consistent with the tube blank; in the spinning forming step, a single-pass spinning process is used for spinning to ensure that the ribs in the tube section are fully filled and evenly distributed.

5. The high-precision spinning forming process for ribbed barrel segments according to claim 1 is characterized in that: In step S6, the diameter of the part is expanded after spinning, and the size of the part after spinning is D 1终 =D 2终 The turning tool has an outer diameter of D1-0.2mm and a straight line trajectory. In-situ turning is used to ensure that the parts achieve the required shape and accuracy.

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