Device and method for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy

Abstract

The present invention relates to a device and a method for electromagnetically flaring a hole in a melon component made of a high-strength aluminum alloy, comprising a lower positioning base, a support frame, an upper positioning base, a base plate, and a melon component flaring tool, wherein the lower positioning base comprises a lower positioning column, a bushing a arranged in a mounting hole in the lower positioning column, and a lower positioning pin arranged in the bushing a, wherein the upper positioning base comprises an upper positioning column, a bushing b arranged in a mounting hole of the upper positioning column, and an upper positioning pin arranged in the bushing b, wherein the support frame, the lower positioning column, and the upper positioning column are provided on the base plate.The present invention utilizes the properties of electromagnetic forming, which significantly improves the plasticity of the aluminum alloy at high forming speeds. It enables the local flanging of holes in melon components. The device employs electromagnetic flanging technology to replace the conventional large hydraulic system for mold flanging, thus avoiding the use of large plates and hydraulic equipment weighing several tons. This simplifies the device, the process, and the dies, and improves the quality and efficiency of producing flared holes in melon components.

Description

Technical area

[0001] The present invention belongs to the field of equipment manufacturing and relates to an apparatus and a method for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy. State of the art

[0002] With the development of the aerospace industry, increasingly stringent requirements are being placed on the performance of launch vehicles, posing many new challenges for the manufacturing process. In a rocket fuel storage or tank, the elliptical box base consists of a circular ring, a bifurcated ring, and a top cover. The circular ring consists of eight welded melon-shell-like components, which are also referred to as melon structural parts, melon components, or melon flaps. The melon component is a large, thin-walled, and preferably elliptical-shaped component. To facilitate the connection of the pipe and the fuel tank by welding and to ensure the quality of the welding, it is necessary to create a flanged hole in the melon component.Melon components are large and complex, and the axial direction of the hole corresponds to the axial direction of the fuel tank. The conventional method of forming a hole in a melon component by flanging requires complicated tooling and is prone to defects such as wrinkles and cracks, and the production speed is low.

[0003] Chinese Utility Model CN207508048U discloses a convex mold with a normal or normally oriented hole in an elliptical melon component with a diameter of 3350 mm. A die is intended to mechanically form the normally oriented convex hole in the melon component. The mechanically created convex hole changes its convex shape several times during the forming process, which is inefficient and prone to cracking. On the other hand, the concave die according to the disclosed utility model is pulled vertically by a central screw, and the mechanical force acting on the convex hole is so large that it can easily become unstable. The positioning accuracy is not high enough when such a concave die is pulled only by a central screw.

[0004] Chinese Patent Application CN110899451A discloses a method and apparatus for forming a flange hole in the one-piece bottom of a launch vehicle's storage tank. Specifically, it discloses "a forming coil, a female or concave forming die, and a positioning device. The positioning device ensures that the flange hole formed in the one-piece bottom of the casing is correctly positioned, using electromagnetic pulse hole turning technology instead of the conventional steel die hole turning technology." The patent application's method for forming a flange hole is applied only to the one-piece bottom of the storage tank. The bottom of the storage tank is larger overall and occupies a large space. Because the one-piece bottom of the storage tank is composed of a symmetrical part, it is easier to position and install compared to a melon-shaped component.In addition, if a crack occurs in a convex hole in the one-piece bottom of the storage tank, the bottom cannot be replaced like a melon component, resulting in greater losses. For the further development of space travel, larger-diameter rockets are required, and with improvements in welding technology, storage tanks are primarily assembled from melon components.

[0005] Currently, the forming of a hole in a melon component by flanging is mainly carried out using large hydraulic forming machines weighing several tons. This involves conventional pre-production of holes followed by multiple flanging steps, which requires a set of large forming tools with convex (male) and concave (female) dies. The current process is not only complicated, but also requires multiple sets of tools and dies, and the manufacturing cost is high. To prevent cracks, the product must be formed in multiple steps, and intermediate products must be polished, trimmed, and annealed. The manufacturing process is quite complicated, resulting in low productivity, high costs, and high labor intensity for workers.To meet the requirements for forming a hole in a melon component by flanging, all components must be formed in the annealed state to allow sufficient time for plastic deformation in the normally oriented hole area, also called the side hole area, which makes it impossible to optimize the entire process while the melon component is being assembled and tested on the hydraulic press and in further process steps, resulting in a lengthy, time-consuming and costly process. Content of the invention

[0006] The purpose of the present invention is to overcome the disadvantages of the prior art and to provide an apparatus and a method for producing and / or forming a hole or a side hole or an opening in a melon component or melon-skin-like component made of a high-strength aluminum alloy by electromagnetic flanging.

[0007] To achieve the above-mentioned objectives, the following technical solutions are disclosed within the scope of the present invention: A device for electromagnetically crimping a hole in a melon-shell-like component, or melon component for short, made of a high-strength aluminum alloy, comprising a lower positioning base, a support frame, an upper positioning base, a bottom plate, and a crimping tool for crimping the hole in the melon component. The lower positioning base comprises a lower positioning column, a bushing a arranged in a mounting hole in the lower positioning column, and a lower positioning pin arranged in the bushing a. The upper positioning base comprises an upper positioning column, a bushing b arranged in a mounting hole of the upper positioning column, and an upper positioning pin arranged in the bushing b. The support frame, the lower positioning column, and the upper positioning column are provided on the bottom plate.The flanging tool for flanging the hole in the melon component comprises an upper press seat, a press plate, lifting eyes, an upper flanging die, a concave forming die, a stand, an upper positioning base, a flanging positioning pin, a forming coil, a positioning pin for the upper press seat, and a press plate positioning pin. The concave forming die, the upper positioning base, and the stand are arranged on the base plate. The stand is arranged symmetrically on both sides of the concave forming die, and the upper flanging die is connected to the press plate. The forming coil is connected to an upper press seat. The upper press seat is connected to the press plate. The press plate is fixedly connected to the stand. The forming coil comprises a coil skeleton, a coil, and a conductor wire.The coil and the conductor wire are each connected to the coil frame, and the conductor wire is connected to a power supply. The electromagnetic force generated by the forming coil acts on the area where the melon component is to be formed, and the normally aligned initial hole in the melon component is formed into the desired flanged hole in the melon component under the electromagnetic force.

[0008] Preferably, the lower curved surface of the upper crimping die and the inner surface of the hole portion in the melon member are fitted to each other, and the upper surface of the concave forming die and the outer surface of the hole portion in the melon member are fitted to each other, and the axial direction of the hole of the concave forming die is in the same direction as that of the crimped hole in the melon member.

[0009] Preferably, the upper flanging die and the concave forming die are axially positioned by flanging positioning pins, and a die plate positioning pin is provided between the die plate and the column to ensure that the upper flanging die can be quickly and accurately mounted in place for subsequent forming operations.

[0010] Preferably, a positioning pin for the upper press seat is provided between the upper press seat and the press plate, which enables quick and precise positioning and assembly of the forming coil.

[0011] Preferably, the support point of the support frame can be an adjustable mechanism that can be adjusted in height and locked.

[0012] Preferably, the pressure plate and the base plate are provided with lifting eyes for lifting and mounting.

[0013] The present invention also describes a method for electromagnetically flanging a hole or side hole in a melon-shell-like component, or melon component for short, made of a high-strength aluminum alloy, the method comprising the following steps: S1: Cutting in the area outside the theoretical edge line of the melon component with a five-axis laser cutting device to form machining allowances on all four sides or edges, inserting or cutting the upper positioning hole and the lower positioning hole in the upper allowance area and the lower allowance area of ​​the melon component by means of laser cutting, and inserting or cutting the normally aligned initial hole along the normal direction in the hole area; S2: Aligning and fitting the hole machining portion of the melon component between the upper flanging die and the concave forming die, wherein the hole is a normally aligned initial hole and the positioning block passes through the normally aligned initial hole, and rotating the positioning block handle to connect the threaded end of the positioning block handle to the bottom plate; S3: Matching the lower positioning hole in the melon component to the lower positioning pin of the lower positioning base, tightening the screws on both sides of the pressing plate and the stand to firmly press the melon component, unscrewing the positioning block handle to remove the positioning block, and inserting the upper positioning pin into the upper positioning base through the upper positioning hole in the melon component; S4: Installing a forming coil inside the upper flanging die and tightening the screws between the upper press seat and the press plate; S5: Connecting a conductor wire to a power supply, exciting and transforming the normally oriented initial hole into a crimped hole in the melon component under the action of the electromagnetic induction force, completing the electromagnetic crimping of the holes in the melon component made of a high-strength aluminum alloy.

[0014] Preferably, the inner surface of the melon component is an ellipsoidal surface formed by rotating an elliptical line 1a2+1b2=1 along the short axis b, wherein the inner diameter of the flanged hole in the melon component is D2 and the axis of the flanged hole in the melon component is parallel to the short axis b and at a distance d1.

[0015] Preferably, the upper positioning hole in the melon component is a normally aligned waist-shaped hole, the lower positioning hole is normally aligned to a round hole, and the upper positioning hole and the lower positioning hole are located on the center line of the melon component, and the normally aligned initial hole, the upper positioning hole, and the lower positioning hole are simultaneously machined or produced by five-axis laser cutting.

[0016] In electromagnetic forming, or flanging, the repulsive force of the blank caused by electromagnetic induction is used to cause plastic deformation of the blank away from the forming coil, thereby shaping the workpiece into a specific shape. In electromagnetic forming, or flanging, a magnetic field is used as a medium to exert electromagnetic force. Mechanical contact is avoided, thus eliminating friction, eliminating the need for lubricant, reducing the occurrence of defects and kickbacks, and improving quality.

[0017] The present invention utilizes the characteristics of electromagnetic forming to significantly improve the plasticity of aluminum alloy under high forming speeds and realizes the local flanging of a hole in a melon component. The device uses electromagnetic flanging technology to flanging a hole in a melon component instead of the conventional large hydraulic flanging system, thus avoiding the use of large and hydraulic equipment weighing several tons. This simplifies the device, process, and dies, and improves the quality and efficiency of manufacturing flanged holes in melon components.

[0018] The present invention brings the following advantages and effects: (1) The device for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy enables the machining of a hole in a melon component by electromagnetic forming, and the electromagnetic forming has the advantages of high efficiency, high quality, and high stability, and avoids defects such as cracks and insufficient dimensions of the conventionally formed holes; (2) the overall volume of the device is small, the components are easy to process and rework, and the disadvantages of large hydraulic forming devices on which large curved melon components depend for flanging the holes are avoided; (3) the device is designed to position the melon components in a simple, fast and accurate manner; (4) the process for electromagnetically flanging the holes in melon components made of high-strength aluminum alloy has a single process parameter, which is easy to control, and the surface quality of the flanged holes is good; (5) The machining process ensures low manufacturing costs, is simple and safe to handle, avoids mechanical contact, thus generating no friction and requiring no lubricant, making it an efficient and environmentally friendly machining and forming technology. Short descriptions of the drawings Fig. 1 Schematic representation of the device of the present invention; Fig. 2 Schematic representation of the device of the present invention in half-sectional view; Fig. 3 Schematic representation of the structure of the preformed coil of the present invention; Fig. 4 Schematic representation of the structure of the upper die of the present invention; Fig. 5 Schematic representation of the structure of a melon component with a flanged hole; Fig. 6 Schematic representation of the method for forming the hole in a melon component by flanging according to the present invention; Fig. 7 Schematic representation of the positioning of the melon component according to the present invention; Fig. 8 Schematic representation of the positioning and installation of the melon component according to the present invention; Fig. 9 Schematic representation of the assembled magnetic coil according to the present invention; Fig. 10 Schematic representation of a melon component with a crimped hole obtained by electromagnetic crimping according to the present invention. Concrete embodiments

[0019] To clarify the purpose, technical solutions, and advantages of the invention, the invention will be described in more detail below with reference to the accompanying drawings and exemplary embodiments. It should be understood that the specific embodiments described herein are used only to explain the present invention and are not intended to limit the present invention. Example:

[0020] An apparatus for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy comprises a lower positioning base 1, a support frame 2, an upper positioning base 9, a bottom plate 17, and a melon component flanging tool. The lower positioning base 11 comprises a lower positioning column 1-1, a bushing a 1-2, and a lower positioning pin 1-3. The upper positioning base 9 comprises a bushing b 9-2, an upper positioning column 9-3, and an upper positioning pin 9-1. The support frame 2, the lower positioning column 1-1, and the upper positioning column 9-3 are fixed to the bottom plate 17 by screws. The melon component flanging tool comprises an upper press seat 3, a press plate 4, lifting eyes 5, an upper flanging mold 6, a concave forming die 7, a stand 8, an upper positioning base 9, a flanging positioning pin 10, a forming coil 11,a positioning pin for the upper press seat 13 and a press plate positioning pin 14, wherein the concave forming die 7 is screwed to the base plate 17, the upper flanging die 6 is screwed to the press plate 4, and the stand 8 is screwed to the base plate 17, wherein the stand 8 is arranged symmetrically on both sides of the concave forming die 7, the upper flanging die 6 and the concave forming die 7 are clamped on the two sides of the normally aligned starting hole 12-e of the melon component 12, the forming coil 11 is connected to the upper press seat 3 by screws, the upper press seat 3 is connected to the press plate 4 by screws, the press plate 4 is connected to the stand 8 by screws, and the clamping of the melon component 12 is achieved by clamping between the upper flanging die 6 and the concave forming die 7 by Tightening the screws between the press plate 4 and the stand 8, whereby the formed coil 11 is a coil skeleton 11-1,a coil 11-2 and a conductor wire 11-3, the conductor wire 11-3 is connected to a power supply, and the electromagnetic force generated by the forming coil 11 acts on the area of ​​the melon component 12 to be formed, and the normally aligned initial hole 12-e of the melon component 12 is bent, folded, or folded under the force to form the desired flanged, folded, or folded hole in the melon component 12-a.

[0021] The lower curved surface of the upper crimping die 6 and the inner surface of the hole portion of the melon member 12 are fitted to each other, the upper surface of the concave forming die 7 and the outer surface of the hole portion of the melon member 12 are fitted to each other, and the axial direction of the hole of the concave forming die 7 is in the same direction as that of the crimped hole 12-a in the melon member 12.

[0022] The upper flanging die 6 and the concave forming die 7 are first installed with two flanging positioning pins 10 for axial positioning, and the press plate 4 and the two uprights 8 are each equipped with a press plate positioning pin 14 to ensure that the upper flanging die 6 can be quickly and accurately installed in place for subsequent forming operations.

[0023] A positioning pin for the upper press seat 13 is provided between the upper press seat 3 and the press plate 4, which enables quick and precise positioning and assembly of the forming coil.

[0024] The support frame 2 is a welded part for supporting the outside of the melon component 12, wherein the two support points of the support frame 2 are highly adjustable and lockable.

[0025] A lifting eye 5 is attached to all four corners of the top of the press plate 4 and the base plate 17 to facilitate lifting and assembly.

[0026] The inner surface of the melon component 12 is preferably an ellipsoidal surface formed by rotating an elliptical line 1a2+1b2=1 along the short axis b, wherein the inner diameter of the flanged hole 12-a in the melon component is D2 and the axis of the flanged hole 12-a in the melon component is parallel to the short axis b and at a distance d1, wherein a method for electromagnetically flanging the side holes or holes in the melon component made of a high-strength aluminum alloy comprises the following steps: S1: Cutting in the area outside the theoretical edge line 12-f of the melon component with a five-axis laser cutting device to form machining allowances on all four sides or edges, machining or inserting the upper positioning hole 12-b and the lower positioning hole 12-c into the upper and lower allowance areas of the melon component by means of laser cutting, and cutting or inserting the normally oriented initial hole 12-e along the normal direction in the hole area for subsequent electromagnetic flanging; S2: Aligning and fitting the hole machining portion of the melon component 12 between the upper flanging die 6 and the concave forming die 7, wherein the holes are normally aligned starting holes 12-e and the positioning block 16 passes through the normally aligned starting holes 12-e, and rotating the positioning block handle 15 to screw the end of the positioning block handle 15 to the bottom plate 17; S3: Matching the lower positioning hole 12-c of the melon member 12 to the lower positioning pin 1-3 of the lower positioning base 1, tightening the screws on both sides of the pressing plate 4 and the stand 8 to firmly press the melon member 12, later unscrewing the positioning block handle 15 to remove the positioning block 16, and inserting the upper positioning pin 9-1 into the upper positioning base through the upper positioning hole 12-b of the melon member 12; S4: Mounting the forming coil 11 inside the upper flanging die 6 and tightening the screws between the upper press seat 3 and the press plate 4; S5: Connecting the lead wire 11-3 to a power supply, energizing and transferring a normally aligned initial hole 12-e into a crimped hole in the melon member 12-a under the action of the electromagnetic induction force, completing the electromagnetic crimping of the hole in the melon member made of a high-strength aluminum alloy.

[0027] The upper positioning hole 12-b of the melon member 12 is a normally aligned waist-shaped hole, the lower positioning hole 12-c is normal to a round hole, and the upper positioning hole and the lower positioning hole are located on the center line of the melon member 12, and the normally aligned initial hole 12-e, the upper positioning hole 12-b, and the lower positioning hole 12-c are simultaneously generated or machined by five-axis laser cutting.

[0028] The present invention is not limited to the specific embodiments mentioned above. The present invention covers any novel feature or combination disclosed in the present description, as well as the steps of any novel method or process or combination disclosed. List of reference symbols: 1 lower positioning base 2 support frames 3 upper press seat 4 Press plate 5 lifting eye 6 upper flanging form 7 concave forming die 8 stands 9 upper positioning base 10 flaring positioning pin 11 Form coil; 12 melon component; 13 Positioning pin for the upper press seat; 14 press plate positioning pin; 15 Positioning block handle 16 Positioning block 17 base plate; 1-1 lower positioning column 1-2 socket a; 1-3 lower positioning pin 9-1 upper positioning pin 9-2 socket b; 9-3 upper positioning column 11-1 Coil skeleton 11-2 Coil 11-3 Conductor wire 12-a flanged hole in the melon component 12-b upper positioning hole 12-c lower positioning hole 12-e normally aligned starting hole 12-f theoretical edge line of the melon component. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 110899451A

[0004]

Claims

[1] Device for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy, characterized bythat it comprises a lower positioning base, a support frame, an upper positioning base, a bottom plate, and a flanging tool for flanging the hole in the melon component, wherein the lower positioning base comprises a lower positioning column, a bushing a arranged in a mounting hole in the lower positioning column, and a lower positioning pin arranged in the bushing a, wherein the upper positioning base comprises an upper positioning column, a bushing b arranged in a mounting hole of the upper positioning column, and an upper positioning pin arranged in the bushing b, wherein the support frame, the lower positioning column, and the upper positioning column are provided on the bottom plate, wherein the flanging tool for flanging the hole in the melon component comprises an upper press seat, a press plate, lifting eyes, an upper flanging mold, a concave forming die, a stand, an upper positioning base,a flanging positioning pin, a forming coil, a positioning pin for the upper press seat, and a press plate positioning pin, wherein the concave forming die, the upper positioning base, and the stand are arranged on the base plate, the stand is arranged symmetrically on both sides of the concave forming die, and the upper flanging die is connected to the press plate, wherein the forming coil is connected to an upper press seat, wherein the upper press seat is connected to the press plate, which is fixedly connected to the stand, wherein the forming coil comprises a coil skeleton, a coil, and a conductor wire, wherein the coil and the conductor wire are connected to the coil skeleton, and the conductor wire is connected to a power supply. [2] Apparatus for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy according to claim 1, characterized bythat the lower curved surface of the upper crimping die and the inner surface of the hole portion of the melon component are fitted to each other; the upper surface of the concave forming die and the outer surface of the hole portion in the melon component are fitted to each other, and the axial direction of the hole of the concave forming die is in the same direction as the axial direction of the crimped hole in the melon component. [3] Apparatus for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy according to claim 1, characterized by that the upper flanging die and the concave forming die are axially positioned by flanging positioning pins and a press plate positioning pin is provided between the press plate and the stand. [4] Apparatus for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy according to claim 1, characterized bythat a positioning pin for the upper press seat is provided between the upper press seat and the press plate. [5] Apparatus for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy according to claim 1, characterized by that the support point of the support frame is an adjustable mechanism that can be adjusted in height and locked. [6] Apparatus for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy according to claim 1, characterized by that the press plate and the base plate are provided with lifting eyes. [7] A method for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy according to any one of claims 1 to 6, the method comprising the following steps: S1: Cutting in the area outside the theoretical edge line of the melon flap with a five-axis laser cutting device to form machining allowances on all four sides, inserting the upper positioning hole and the lower positioning hole into the upper allowance area and the lower allowance area of ​​the melon component by means of laser cutting, and cutting the normally aligned initial holes along the normal direction in the hole area; S2: Aligning and attaching the hole machining area of ​​the melon component between the upper flanging die and the concave forming die, wherein the hole is a normally aligned initial hole, the positioning block passes through the normally aligned initial hole, and rotating the positioning block handle to connect the threaded end of the positioning block handle to the base plate; S3: Match the lower positioning hole of the melon component to the lower positioning pin of the lower positioning base, tighten the screws on both sides of the pressing plate and the stand to press the melon component firmly, unscrew the positioning block handle to remove the positioning block, and insert the upper positioning pin into the upper positioning base through the upper positioning hole of the melon component; S4: Installing a forming coil inside the upper flanging die and tightening the screws between the upper press seat and the press plate; S5: Connecting a conductor wire to a power supply, exciting and transforming a normally oriented initial hole into a crimped hole in the melon component under the action of the electromagnetic induction force, completing the electromagnetic crimping of the hole in the melon component made of a high-strength aluminum alloy. [8] A method for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy according to claim 7, characterized by , the inner surface of the melon component is an ellipsoidal surface obtained by rotating an elliptic line 1a2+1b2=1 along the short axis b, wherein the inner diameter of the flanged hole in the melon component is D2 and the axis of the flanged hole in the melon component is parallel to the short axis b and at a distance d1. [9] A method for electromagnetically flanging a hole in a melon component made of a high-strength aluminum alloy according to claim 7, characterized bythat the upper positioning hole of the melon component is a normally aligned waist-shaped hole, the upper positioning hole and the lower positioning hole are normally aligned to form a round hole, and the upper positioning hole and the lower positioning hole are located on the center line of the melon component, and the normally aligned initial hole, the upper positioning hole and the lower positioning hole are processed simultaneously by five-axis laser cutting.

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