Electromagnetic composite spinning forming method for aluminum alloy shell

Abstract

The invention belongs to the technical field of equipment manufacturing, and relates to an electromagnetic composite spinning forming method for an aluminum alloy shell, which comprises the following steps: S1, assembling and installing an aluminum alloy pipe blank and a spinning core mold; s2, the aluminum alloy pipe blank is subjected to spinning forming and thinning machining; s3, reducing electromagnetic pulses are gradually applied to the outer surface of the spinning pipe fitting in the length direction through an electromagnetic pulse module; and S4, the pipe fitting is separated from the core mold through a material returning ring, and the size of the spinning blank is inspected. According to the method, after core mold shearing spinning forming is completed, electromagnetic pulse hole shrinkage force is gradually applied in the length direction in the core mold in the in-situ assembly state, so that a shell is completely attached to the core mold, residual stress is relaxed, dimensional deviation caused by random disturbance such as equipment precision, material uniformity and residual stress in spinning forming can be effectively restrained, and the yield of the shell is improved. And the precision of a spinning product is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of equipment manufacturing technology, and relates to an electromagnetic composite spinning forming method for an aluminum alloy shell. BACKGROUND

[0002] Aluminum alloy thin-walled shells are widely used in the manufacturing of high-precision parts in the fields of aerospace and the like. The material utilization rate is low through mechanical processing, and the metal flow line is damaged, so that the expected mechanical properties cannot be obtained. The spinning preparation of aluminum alloy thin-walled precision shells has the unique advantages of high material utilization rate and complete metal flow.

[0003] The spinning manufacturing precision of aluminum alloy thin-walled shells is comprehensively affected by equipment and process, and it is difficult to control the precision, or a high equipment and process cost needs to be paid to ensure the precision. In the industrial spinning production, the spinning forming precision of aluminum alloy thin-walled shells with an inner diameter range of 150-250 mm, a wall thickness range of 0.5-3 mm and a length range of 500-2500 mm can only reach the order of 0.1 mm.

[0004] In recent years, electromagnetic pulses have begun to be applied to the metal rolling industry. Electromagnetic pulse forming is a method of using pulse magnetic field force to process metal workpieces at high speed, and the necking and diameter-reducing forming of various pipes can be completed by relying on electromagnetic pulse forming alone. Electromagnetic pulses are also applied to the lap welding of metal material pipes, and through the necking deformation and high-speed collision with the internal base material and the interface combination, even the metallurgical combination can be realized. In addition, research shows that electromagnetic pulse forming can reduce residual stress through oscillation, and under the action of elastic waves and plastic waves, the micro-plastic size regulation of metal components can be realized.

[0005] The spinning forming precision of aluminum alloy thin-walled shells is affected by multiple factors such as equipment precision, core mold manufacturing precision, core mold-billet assembly precision, billet organization performance quality and process method, and the 0.1 mm order forming precision requires that the core mold-billet assembly gap be less than 0.15 mm, which is difficult to achieve in engineering and has a high cost. However, the existing electromagnetic pulse pipe forming technology can easily achieve the 0.01 mm order forming precision, but the coaxial positioning assembly of the coil and the die is difficult in the electromagnetic diameter-reducing forming process, and is not suitable for large-scale production. SUMMARY

[0006] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide an electromagnetic composite spinning forming method for an aluminum alloy thin-walled shell, which can solve the problems of high assembly difficulty and insufficient forming precision of the existing spinning forming technology.

[0007] In order to achieve the above purpose, the following technical scheme is adopted in the present application: An electromagnetic composite spinning forming method for an aluminum alloy shell, comprising the following steps: S1, assembling and installing an aluminum alloy tube blank and a spinning core mold; S2, spinning forming thinning processing of aluminum alloy pipe blank; S3, applying diameter-reducing electromagnetic pulse on the outer surface of the spinning pipe along the length direction by the electromagnetic pulse module; S4, taking out the pipe from the core mold by using the material return ring, and inspecting the size of the spinning blank.

[0008] Further, the inner diameter of the aluminum alloy thin-walled shell is 150-250 mm, the wall thickness is 0.5-3 mm, and the length is 500-2500 mm.

[0009] Further, in S1, the core mold is cleaned using glycerol before installation, and the surface quality of the core mold is checked to confirm that there is no defect such as scratch or scratch affecting product quality; after cleaning, the outer surface of the core mold is evenly coated with molybdenum disulfide grease.

[0010] Further, in S1, the diameter of the outer surface of the core mold is less than the inner diameter of the pipe blank, and the assembly gap is greater than 0.5 mm.

[0011] Further, in S2, the inner diameter of the blank after spinning forming is greater than the outer diameter of the core mold, and the gap is greater than 0.2 mm.

[0012] Further, in S2, the wall thickness of the pipe blank after thinning processing is less than 2 mm.

[0013] Further, in S3, after spinning forming, the tail top of the spinning machine is removed, the electromagnetic pulse module is sleeved into the core mold, the electromagnetic pulse is applied on the outer surface of the spinning pipe by the electromagnetic pulse module, the electromagnetic pulse is applied along the length direction of the pipe, the center of the diameter-reducing force of the electromagnetic pulse is coincided with the center axis of the pipe, the application sequence starts from the assembly end of the shell close to the core mold and ends at the other end of the core mold.

[0014] Further, the electromagnetic pulse is configured by the electromagnetic coil module to produce diameter-reducing deformation of the blank; the electromagnetic coil module includes a copper coil, and the coil is insulated and glued, and after gluing, the central axis of the coil is processed into a cylinder, and is assembled to a steel clamp; a clamping structure is prepared on the steel clamp support for fixing and positioning with the spinning machine.

[0015] Further, the inner diameter of the electromagnetic coil module is greater than the outer diameter of the pipe blank after spinning forming of the pipe blank, and the gap is 3 mm.

[0016] The present application has the following advantages: (1) The present application is prepared by spinning process through the core mold and spinning wheel to reduce the thickness, and the core mold and the tube blank are naturally positioned with high precision after spinning forming, and the micro-plastic electromagnetic necking deformation is realized by electromagnetic pulse in this state, which can significantly improve the forming precision of the spinning product, and can expand the initial assembly gap window, allowing the tube blank to expand during spinning, thereby significantly improving the forming precision of the spinning product and reducing the difficulty of high-precision spinning.

[0017] (2) After the core mold shearing spinning forming is completed, the electromagnetic pulse necking force is applied in the length direction in the in-situ assembly state of the core mold, so that the shell is completely attached to the core mold, and the residual stress is relaxed.

[0018] (3) The present application can effectively suppress the size deviation caused by random disturbance such as equipment precision, material uniformity, residual stress, etc. during spinning forming, and improve the precision of the spinning product. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a schematic diagram of the spinning-electromagnetic implementation process of the present application; Figure 2 is a schematic diagram of the spinning implementation process of the present application; Figure 3 is a schematic diagram of the electromagnetic pulse module of the present application; 1-spinning core mold connecting flange; 2-electromagnetic pulse module; 3-spinning wheel seat; 4-aluminum alloy cylinder blank; 5-core mold; 6-spinning machine tail top; 7-spinning machine bed; 3-1-copper coil; 3-2-insulating glue layer; 3-3-steel hoop support. DETAILED DESCRIPTION

[0020] The present application will be described in detail below with reference to the accompanying drawings.

[0021] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0022] The present application provides an electromagnetic composite spinning forming method for an aluminum alloy shell, comprising the following steps: S1, assembly and installation of aluminum alloy tube blank and spinning core mold; the core mold is cleaned with glycerol, and the surface quality of the core mold is checked to confirm that there are no defects such as scratches and scratches that affect product quality; molybdenum disulfide grease is applied to the outer circular surface of the core mold, and it is confirmed that the application is uniform; the aluminum alloy tube blank is assembled and installed on the spinning core mold, the outer circular surface diameter of the core mold is slightly smaller than the inner circular diameter of the tube blank, and the assembly gap is kept above 0.5 mm; S2, aluminum alloy tube blank spinning forming thinning process; the aluminum alloy tube blank spinning forming equal thickness thinning is carried out, the inner diameter of the blank after spinning forming should be slightly larger than the outer diameter of the core mold, but the gap amount of more than 0.2 mm should be reserved; the aluminum alloy tube blank spinning forming equal thickness thinning is carried out on the CZ-450 horizontal spinning machine, the spinning forming process parameters are determined according to the initial wall thickness and the final product wall thickness, and the final product wall thickness should be less than 2 mm.

[0023] S3, the electromagnetic pulse module is used to apply the diameter-reducing electromagnetic pulse to the outer surface of the spinning tube along the length direction; after spinning forming, the tail top of the spinning machine is removed, and the electromagnetic pulse module is sleeved into the core mold; the electromagnetic pulse module is used to apply the electromagnetic pulse to the outer surface of the spinning tube, and the electromagnetic pulse is applied along the length direction of the tube, and the central axis of the electromagnetic pulse module is kept coincident with the central axis of the tube (core mold).

[0024] The application sequence starts from the shell close to the core mold assembly end to the distance tail top end S4, the tube is taken out of the core mold by using the material return ring, and the spinning blank size is inspected.

[0025] Example 1: In this embodiment, the tube blank material is 5A03, the tube blank inner diameter is Φ265.8 mm, the wall thickness is 2.7 mm, the length is 800 mm, and the wall thickness size of the part after spinning is 0.9 mm. The core mold material is steel 9SiCr, the outer circular surface diameter is Φ264.5 mm, and the length is 1500 mm. The spinning implementation process assembly schematic diagram is shown in Figure 1 .

[0026] S1, the core mold is cleaned by using glycerol, and the surface quality of the core mold is checked to confirm that the surface is free of defects such as scratches and scratches affecting product quality. The molybdenum disulfide grease is applied to the outer circular surface of the core mold, and the uniformity of the application is confirmed.

[0027] S2, the aluminum alloy tube blank is assembled and installed to the spinning core mold; S3, according to the process state and part precision requirement, the total thinning rate of the material is 66.7%. The first pass thinning rate is 35%, the rotating speed of the core mold is 100 r / min, and the feeding speed is 180 mm / min; the second pass thinning rate is 30%, the rotating speed of the core mold is 120 r / min, and the feeding speed is 192 mm / min; the third pass thinning rate is 26%, the rotating speed of the core mold is 90 r / min, and the feeding speed is 108 mm / min.

[0028] After spinning forming, the outer diameter and thickness of the tube blank are checked in the core mold assembly state, a total of 5 measurement sections are taken in the length direction, and the number of thickness measurement points of each section is more than 3. The test results are as follows: the outer diameter of the tube blank is Φ267.3, and the wall thickness of the part is 0.8 mm detected by using the ultrasonic thickness gauge.

[0029] S4, remove the spinning machine tail top, move the spinning wheel frame, put the electromagnetic pulse module into the core mold, position it at the right end of the spinning wheel frame, see the action schematic diagram Figure 2 .

[0030] S5, the electromagnetic pulse module is used to spin the pipe, and electromagnetic pulses are applied in cycles of 100 mm, see Figure 3 The voltage of the electromagnetic pulse generator used is set to 12 kV, and the peak current is displayed as 243-257 kA.

[0031] S6, use the material return ring to complete demolding.

[0032] The present application is not limited to the foregoing specific embodiments. The present application extends to any novel one, or any new combination, of the characteristics disclosed in this specification, as well as to any novel method or process steps disclosed, or any new combination thereof.

Claims

1. A method for electromagnetic composite spinning forming of an aluminum alloy shell, characterized in that, Includes the following steps: S1. Assembly and installation of aluminum alloy tube blank and spinning mandrel; S2, Aluminum alloy tube blank spinning and thinning process; S3. Electromagnetic pulses for diameter reduction are applied sequentially along the length of the outer surface of the spun tube by an electromagnetic pulse module. S4. Use the ejector ring to remove the pipe fitting from the mandrel and inspect the dimensions of the spun blank.

2. The electromagnetic composite spinning forming method for an aluminum alloy shell according to claim 1, characterized in that, The aluminum alloy thin-walled shell has an inner diameter of 150-250 mm, a wall thickness of 0.5-3 mm, and a length of 500-2500 mm.

3. The electromagnetic composite spinning forming method for an aluminum alloy shell according to claim 1, characterized in that, S1 includes cleaning the mandrel with glycerol before installation; and uniformly applying molybdenum disulfide grease to the outer surface of the mandrel after cleaning.

4. The electromagnetic composite spinning forming method for an aluminum alloy shell according to claim 1, characterized in that, In S1, the outer diameter of the core mold is smaller than the inner diameter of the tube blank, and the assembly gap is 0.5 mm or more.

5. The electromagnetic composite spinning forming method for an aluminum alloy shell according to claim 1, characterized in that, In S2, after spinning, the inner diameter of the blank is larger than the outer diameter of the mandrel, and the gap is greater than 0.2 mm.

6. The electromagnetic composite spinning forming method for an aluminum alloy shell according to claim 1, characterized in that, In S2, the wall thickness of the tube blank after thinning is less than 2 mm.

7. The electromagnetic composite spinning forming method for an aluminum alloy shell according to claim 1, characterized in that, In S3, the electromagnetic pulse is applied along the length of the pipe, keeping the center of the electromagnetic pulse shrinkage force coincide with the central axis of the pipe. The application sequence starts from the end of the shell near the core mold assembly end and ends at the other end of the core mold.

8. The electromagnetic composite spinning forming method for an aluminum alloy shell according to claim 1, characterized in that, The electromagnetic pulse module is composed of copper coils and insulating materials. After being glued together, it is machined into a cylindrical shape with the central axis of the coil as the center axis, and then assembled onto a steel clamp.

9. The electromagnetic composite spinning forming method for an aluminum alloy shell according to claim 8, characterized in that, The inner diameter of the electromagnetic coil module is larger than the outer diameter of the tube blank after spinning, and the gap is 3 mm.

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