High-precision spinning forming process method for cylinder section with ribs

Abstract

The invention provides a high-precision spinning forming process method for a ribbed cylinder section, and aims to solve the problems of diameter expansion, unevenness in deformation and the like in the traditional spinning process. The process comprises the following steps: performing double-sided turning on a prefabricated cylinder blank to ensure the inclination, mounting a spinning mold with a rib structure, heating the cylinder blank, and sleeving the heated cylinder blank on a mold with an inner cross groove to realize interference fit. And then, a three-spinning-roller spinning machine is started for spinning, the plasticity of the material is improved through induction heating, and the material flows into a cross groove of the mold. And after spinning is completed, the spinning roller is replaced with a turning tool, the outer surface is turned, and finally the part is taken out. According to the method, the inner diameter is controlled through material thermal expansion coefficient difference and diameter compensation, and boundary dimension homogenization is achieved through the induction heating and in-situ turning technology. The process is suitable for materials such as aluminum alloy and high-strength steel, the size precision of the cylinder section is remarkably improved, and technical support is provided for overall near-net forming of aircraft cylinder sections such as tactical projectiles. The spinning process is optimized, and the quality and performance of a final product are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of forming processes for aerospace ribbed thin-walled barrel sections. Specifically, it relates to a high-precision spinning forming process method for ribbed barrel sections. Background Art

[0002] The ribbed thin-walled barrel section structure is a typical structure form of missile cabin sections, and cabin sections with this structure form have extensive applications in the aerospace field. Generally, they are made of aluminum alloy, high-strength steel, etc. The wall thickness of the cabin body is generally a ribbed structure according to the load distribution and the layout requirements of the equipment inside the cabin. Among them, the maximum wall thickness in the skin area generally does not exceed 3 mm, and various reinforcing ribs, such as longitudinal and circumferential reinforcing ribs, will be arranged on the inner wall of the cabin to enhance the strength and stability of the overall structure.

[0003] Traditional processing techniques mainly use the method of casting + machining to manufacture ribbed thin-walled barrel sections. However, this method has problems such as a large amount of material removal and low processing efficiency, especially the processing of internal ribs with complex structures is more difficult. In addition, due to the use of difficult-to-form materials, traditional processing techniques are prone to deformation and cracks during the processing, further increasing the processing difficulty and cost.

[0004] To solve the above problems, the integral spinning process has gradually been introduced into the manufacture of ribbed barrel sections. The integral spinning process can effectively reduce material waste, improve processing efficiency, and can maintain good material properties during the forming process. However, for the spinning forming of ribbed barrel sections, there are still some technical problems. For example, during the spinning process, due to the diameter expansion effect of the part, there are large deviations in the external dimensions of the formed part. Especially for ribbed barrel sections with a size of 1 meter, the size deviation (the difference between the maximum diameter and the minimum diameter) after spinning forming can reach up to 1 - 2 mm. At the same time, due to the diameter expansion phenomenon, the ribs are not fully filled, there are differences in the rib height, and the maximum deviation of the ribs is about 1 mm. These deviations seriously affect the dimensional accuracy and overall performance of the ribbed barrel sections.

[0005] After novelty search, it is found that the invention patent (application number ZL202011112466.2) invented a spinning device and forming method with laser-assisted shearing. This device and method are mainly aimed at the forming of parts with a small semi-cone angle of difficult-to-deform metals. This 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, while this patent uses an induction heating process, and its heat uniformity is relatively high, which can reduce the diameter expansion and uneven deformation of the part; The invention patent (application number: 202010219568.8) invented an integrated hot forming method for aluminum alloy plate composite solution treatment. This method forms parts during the high-temperature solution treatment stage, then conducts rapid quenching treatment, and then aging. However, the deformation during the heat treatment process after part forming still cannot be controlled, and its principle of action and method of action are fundamentally different from those of this patent.

[0006] The invention patent (application number: 202111172468.5) invented a laser-assisted solution temperature spinning forming method and a component with cross ribs. This method uses the way of solution treatment first and then spinning, effectively avoiding the reduction of precision caused by heat treatment deformation. However, this patent is prone to dimensional deviations such as diameter expansion and uneven wall thickness. For the above problems that are likely to occur during the spinning process in this patent, the method of interference fit + induction heating is adopted, effectively avoiding the occurrence of this problem. At the same time, the in-situ turning method is used to further improve the quality of the part after forming.

[0007] Therefore, in order to improve the dimensional accuracy and overall performance of the component with ribs, it is necessary to develop a new spinning forming process method to solve the problems existing in the traditional processing technology and the overall spinning technology. Summary of the Invention

[0008] Aiming at the defects in the prior art, the purpose of the present invention is to provide a high-precision spinning forming process method for a component with ribs.

[0009] According to a high-precision spinning forming process method for a component with ribs provided by the present invention, the method includes the following steps: Step S1: Perform double-sided turning on the prefabricated tube blank, process the inclination angle, and process a boss structure for spinning positioning; Step S2: Install the spinning die with rib structure on the spinning machine tool; Step S3: Heat-treat the tube blank, heat it to a preset temperature and keep it warm for a preset time to make the tube blank expand due to heat; Step S4: Put the heated tube blank on the spinning die with internal cross grooves and cool it to room temperature. Due to the principle of thermal expansion and contraction, an interference fit is generated between the die and the tube blank; Step S5: Start the three-spin-wheel spinning machine for spinning forming. During the spinning process, use the induction heating coil to assist in heating the local part of the part, and control the heating temperature at the preset temperature; Step S6: After spinning is completed, replace the spin wheel with a turning tool and turn the spun tube blank to ensure that the outer diameter of the part is consistent with the requirements of the design drawing; Step S7: Fix the outside of the part with a hoop, take it out from the spinning tooling, and turn the internal ribs with the outer diameter as the reference to control the accuracy of the component with ribs within the preset range.

[0010] Preferably, in the step S1, 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 part are D1 mm and D2 mm respectively, D1 = D2 + 1 mm, and the inclination angle is θ°.

[0011] Preferably, in the step S2, the thermal expansion coefficient of the spinning die is less than that of the tube blank, and the diameter of the tube blank after thermal expansion is greater than D3 mm; the outer diameter of the large end of the spinning die is D3 mm, and the outer diameter of the small end is D4 mm.

[0012] Preferably, in the step S3, the heat preservation time is 60 min, and the diameter of the tube blank after heating and thermal expansion is D1 / D2 + 3 mm.

[0013] Preferably, in the step S4, the tube blank is sleeved on the spinning die with 45° internal cross grooves, and using the principle of thermal expansion and contraction, an interference fit is generated 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 = D1 + 0.5 mm, and the inclination angle θ° is the same as that of the tube blank; in the spinning forming step, a single-pass spinning process is used for spinning to ensure the full filling and uniform distribution of the internal ribs in the tube section.

[0014] Preferably, in the step S5, the feed rate of the spinning wheel is β mm / r; the induction heating coil is arranged outside the die at the front end of the three spinning wheels to locally inductively heat the undeformed area of the tube section during spinning, and the diameter expansion amount generated by spinning is 1 mm.

[0015] Preferably, in the step S6, the part after spinning generates diameter expansion, and the size D of the part after spinning 1终 =D 2终 , the outer diameter turned by the turning tool is D1 - 0.2 mm, and the trajectory is a straight line. In-situ turning is used to ensure that the part reaches the required shape and accuracy.

[0016] Preferably, after turning the outer surface, it is fixed with a hoop, and the die is disassembled, then installed on the spinning machine, the internal surface turning tool is replaced, and the internal ribs are turned.

[0017] Preferably, the ribbed structure of the spinning die includes longitudinal and / or circumferential stiffeners to meet the requirements for the strength and stiffness of the tube section in different application scenarios.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. Through the process route of "using the difference in expansion coefficients to achieve interference fit of tube blanks - induction heating assisted spinning forming - in-situ turning", the present invention effectively controls the diameter expansion phenomenon of the ribbed cylinder section during the spinning forming process. Through the diameter compensation of the spun cylinder blank, the dimensional accuracy of the product is significantly improved, achieving the goal of controlling the accuracy of the ribbed cylinder section within 1 mm. 2. The present invention uses induction heating technology to replace the traditional flame heating method. This not only makes the heated area, heated temperature, and heating region of the part more uniform, but also, compared with laser heating, the induction heating efficiency is faster, the temperature rise is more rapid, and the temperature control is more convenient. This is conducive to controlling the evolution of the internal structure of the material and further improving the quality and performance of the product. 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 deviations caused by mold loading and unloading, and effectively improving the application range and flexibility of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, objectives, and advantages of the present invention will become more apparent: Figure 1 It is a schematic diagram of the induction heating forming process of the ribbed cylinder section of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those of ordinary skill in the art can make several changes and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0021] Example 1: Refer to Figure 1 , according to a high-precision spinning forming process method for a ribbed cylinder section provided by the present invention, the method includes the following steps: Step S1: Perform double-sided turning on the prefabricated tube blank, process the inclination angle, and process 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 part are D1 mm and D2 mm respectively, D1 = D2 + 1 mm, and the inclination angle is θ °.

[0022] Step S2: Install the ribbed structure spinning die on the spinning machine tool; the thermal expansion coefficient of the spinning die is less than that of the cylinder blank, and the diameter of the cylinder blank after thermal expansion is greater than D3 mm; the outer diameter of the large end of the spinning die is D3 mm, and the outer diameter of the small end is D4 mm.

[0023] Step S3: Heat-treat the cylinder blank, heat it to a preset temperature and keep it warm for a preset time to make the cylinder blank expand by heating; the heating temperature is T1 = 500°C - 680°C, keep it warm for 60 min, and the diameter of the cylinder blank after heating and expansion is D1 / D2 + 3 mm.

[0024] Step S4: Put the heated cylinder blank on the spinning die with internal cross grooves and cool it to room temperature. An interference fit is generated between the die and the cylinder blank using the principle of thermal expansion and contraction; put the cylinder blank on the spinning die with 45° internal cross grooves, and using the principle of thermal expansion and contraction, an interference fit is generated between the cylinder blank and the die after cooling; the outer diameter D3 of the spinning die near the large end of the cylinder section is D1 + 0.5 mm, and the inclination angle is θ° which is the same as that of the tube blank; in the spinning forming step, a single-pass spinning process is used for spinning to ensure the full filling and uniform distribution of the internal ribs in the cylinder section.

[0025] Step S5: Start the three-roller spinning machine for spinning forming. During the spinning process, use an induction heating coil to assist in heating a local part of the part, and control the heating temperature at the preset temperature; the feed rate of the roller is β mm / r, and the heating temperature is 400°C - 500°C; the induction heating coil is arranged outside the die at the front end of the three rollers to perform local induction heating on the undeformed area of the cylinder section during spinning, and the heating temperature T3 is controlled within the range of ±3°C, and the diameter expansion amount generated by spinning is 1 mm.

[0026] Step S6: After spinning is completed, replace the roller with a turning tool and turn the spun tube blank to ensure that the outer diameter of the part is consistent with the requirements of the design drawing; the part expands in diameter after spinning, and the size D of the part after spinning 1终 =D 2终 , the turning tool turns the outer diameter to D1 - 0.2 mm, and the trajectory is a straight line. In-situ turning is used to ensure that the part reaches the required shape and accuracy.

[0027] Step S7: Fix the outside of the part with a hoop, take it out of the spinning tooling, take the outer diameter as the reference, turn the internal ribs to control the accuracy of the ribbed cylinder section within the preset range. After turning the outer surface, fix it with a hoop, then disassemble the die, and then install it on the spinning machine, replace the turning tool for the inner surface, and turn the internal ribs. The ribbed structure of the spinning die includes longitudinal and / or circumferential stiffeners to meet the requirements of the strength and stiffness of the cylinder section in different application scenarios.

[0028] Example 2: The present invention relates to a high-precision spinning forming process method for a ribbed cylinder section. Aiming at the shape and precision control of a storage tank cylinder section with a grid rib structure, the specific steps are as follows: 1) First, perform double-sided turning on the prefabricated cylinder blank and machine a boss structure. The diameters of the cylinder blank are D1 mm and D2 mm; 2) Install a ribbed structure spinning die on the spinning machine tool. The outer diameter of the spinning die is D3 mm; 3) Heat-treat the cylinder blank. The heating temperature is 500°C to 680°C (depending on different materials), and keep it warm for 60 minutes. After heating, the diameter of the part expands due to heat to D1 / D2 + 3 mm; 4) Then quickly put the cylinder blank on the spinning die with 45° internal cross grooves, and utilize the principle of thermal expansion and contraction to produce an interference fit between the cylinder blank and the die; 5) Start the three-spin-wheel spinning machine to perform spinning forming. During the spinning process, use an induction heating coil to assist in heating a part of the part. The heating temperature is 400°C to 500°C (depending on different materials) to enable the material to flow into the cross grooves of the die; 6) After spinning, the size D 1终 = D 2终 , the outer diameter of the turning with a turning tool is D1 - 0.2 mm, and the trajectory is a straight line. In-situ turning is carried out to ensure that the part reaches the required shape and precision. The present invention utilizes the difference in the coefficient of thermal expansion of materials to control the inner diameter of the ribbed cylinder section. At the same time, by establishing a process route of induction heating + in-situ turning, the uniform control of the overall external dimensions is realized, providing technical support for the overall near-net forming of cylinder sections of aircraft such as tactical projectiles.

[0029] The process route of the present invention adopts the characteristic of the difference in the coefficient of thermal expansion between the die and the cylinder blank, and utilizes thermal expansion and contraction to achieve an interference fit between the outer diameters of the cylinder blank and the die, thereby effectively improving the filling effect of the ribs of the part during the spinning forming process. Through the diameter compensation of the large and small ends of the part, the dimensional deviation caused by the diameter expansion phenomenon is effectively reduced. At the same time, in cooperation with the subsequent turning process, the dimensional precision of the product is further improved. After actual measurement, the precision of the part is better than 1 mm, the deviation of the ribs is about 0.5 mm, and the circularity and straightness are better than the existing indexes. The induction heating technology is adopted. Compared with the traditional flame heating method, the heated area, heated temperature and heating area of the part are more uniform. At the same time, compared with laser heating, the induction heating efficiency is faster, the temperature rises more rapidly, the temperature control is convenient, and the heated area is more uniform, which is beneficial to the control of the evolution of the internal structure of the material. The in-situ turning technology can formulate a refined process route according to the specific material, is not affected by the disassembly of the tooling, and effectively improves the applicable range of the process.

[0030] Please refer to Figure 1 , which is a flow chart of the spinning forming process method for a ribbed cylinder section, including the following steps: Step S1: Perform double-sided turning on the prefabricated cylinder blank to machine out a boss structure; the roundness of the prefabricated cylinder blank is less than or equal to 0.5 mm, and the thermal expansion coefficient of the prefabricated cylinder blank is greater than 0.5 mm / 100°C; the wall thickness of the prefabricated cylinder blank is α mm, the height is γ mm, the outer diameters of the large and small ends of the prefabricated cylinder blank part are D1 mm and D2 mm respectively, D1 = D2 + 1 mm, and the inclination angle is θ°.

[0031] Step S2: Install the ribbed structure spinning die on the spinning machine tool. 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 less than that of the cylinder blank.

[0032] Step S3: Heat-treat the cylinder blank, heat it to a preset temperature and keep it warm for a preset time to make the cylinder blank expand due to heat; the heating temperature is T1 = 500°C - 680°C (depending on different materials), keep it warm for 60 min, and the diameter of the cylinder blank after heating and expansion is D1 / D2 + 3 mm.

[0033] Step S4: Put the heated cylinder blank on the spinning die with internal cross grooves, and use the principle of thermal expansion and contraction to produce an interference fit; put the cylinder blank on the spinning die with 45° internal cross grooves, and use the principle of thermal expansion and contraction to make an interference fit between the cylinder blank and the die; the outer diameter D3 of the spinning die near the large end of the cylinder section is D1 + 0.5 mm, and the inclination angle is θ°, which is the same as that of the tube blank. In the spinning forming step, a single-pass spinning process is used for spinning to ensure the full filling and uniform distribution of the internal ribs in the cylinder section. The ribbed structure of the spinning die includes longitudinal and / or circumferential reinforcing ribs to meet the requirements for the strength and stiffness of the cylinder section in different application scenarios.

[0034] Step S5: Start the three-roller spinning machine for spinning forming. During the spinning process, use an induction heating coil to perform auxiliary heating on the local part of the part, and control the heating temperature at the preset temperature; the feed rate of the roller is β mm / r; the induction heating coil is arranged outside the die at the front end of the three rollers to perform local induction heating on the undeformed area of the cylinder section during spinning, and the heating temperature T3 is controlled within the range of ±3°C, and the diameter expansion amount generated by spinning is 1 mm. Step S6: The part after spinning generates diameter expansion, and the size D of the part after spinning 1终 =D 2终 , the turning tool turns the outer diameter to D1 - 0.2 mm, and the trajectory is a straight line. In-situ turning is used to ensure that the part reaches the required shape and accuracy.

[0035] Step S7: Fix the outside of the part with a hoop, take it out of the spinning tooling, and turn the internal ribs with the outer diameter as the reference to control the accuracy of the ribbed cylinder section within the preset range.

[0036] Those skilled in the art know that in addition to implementing the system and its various devices, modules, and units provided by the present invention in the form of pure computer-readable program code, the method steps can be logically programmed to enable the system and its various devices, modules, and units provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers, etc., to achieve the same functions. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a kind of hardware component, and the devices, modules, and units included therein for implementing various functions can also be regarded as the structures within the hardware component; the devices, modules, and units for implementing various functions can also be regarded as either software modules for implementing the method or structures within the hardware component.

[0037] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

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, processing the inclination angle, and processing 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 tube blank is placed on the spinning die with inner cross grooves, 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; Step S5: starting the three-wheel spinning machine to perform spinning, and using the induction heating coil to perform auxiliary heating on the parts 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, take it out from the spinning tooling, and turn the internal ribs based on the outer diameter to achieve the precision control of the ribbed barrel section within a preset range; In the step S1, the roundness of the prefabricated tube is less than or equal to 0.5 mm, and the thermal expansion coefficient of the prefabricated tube is greater than 0.5 mm / 100°C; the wall thickness of the prefabricated tube is α mm, the height is γ mm, the outer diameters of the large and small ends of the prefabricated 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 βmm / 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 1mm; 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 reinforcing ribs to meet the requirements for barrel strength and rigidity in different application scenarios.

2. The high-precision spinning forming process of a ribbed barrel segment according to claim 1 is characterized in that: 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.

3. The high-precision spinning forming process of a ribbed barrel segment according to claim 1 is characterized in that: In step S3, the heat preservation time is 60 minutes, and the diameter of the tube blank expanded by heat after heating is D1 / D2+3mm.

4. The high-precision spinning forming process of a ribbed barrel segment according to claim 1 is characterized in that: In the step S4, the tube blank is put on a spinning die with a 45° inner cross groove, and the principle of thermal expansion and contraction is used to generate an interference fit between the tube blank and the die after cooling; the outer diameter D3=D1+0.5mm of the spinning die close to 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 used for spinning to ensure sufficient filling and uniform distribution of the ribs in the tube section.

5. The high-precision spinning forming process of a ribbed barrel segment 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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