Non-circular cross-section profiled shell roll-draw forming process, device and design method thereof

Abstract

This application provides a process, apparatus, and design method for roll forming of non-circular cross-section irregular shells. The design method includes the following steps: A1, designing the three-dimensional shape of the punch based on the three-dimensional shape of the inner wall of the non-circular cross-section irregular shell; A2, determining the number of a set of cooperating forging rolls based on the three-dimensional shape of the outer wall of the non-circular cross-section irregular shell, wherein the number of forging rolls is greater than or equal to 2, and the axes of all forging rolls are coplanar; A3, designing the shape of the loading surface of each forging roll based on the three-dimensional shape of the outer wall of the non-circular cross-section irregular shell, wherein the intersection line of the loading surface and the contact plane constitutes the outer perimeter of the die orifice of the irregular shell forming apparatus, the intersection line of the outer wall of the punch and the contact plane constitutes the inner perimeter of the die orifice, and the contact plane is the plane formed by the intersection of the axes of all forging rolls. The technical solution of this application can effectively improve the roll forming quality of non-circular cross-section irregular shells.

Description

Technical Field

[0001] This application belongs to the field of materials processing technology, and further relates to metal material drawing forming technology, specifically providing a non-circular cross-section irregular shell roller drawing forming process, device and design method. Background Technology

[0002] Localized loading-continuous forming methods, such as drawing, refer to the processing method of drawing or stretching a blank under external force, forcing the blank of metal or other materials to undergo plastic deformation to obtain a shaped product. This is the mainstream technology for manufacturing large-sized shells with deep holes. Currently, conventional drawing forming methods are prone to cracking or breaking of components during the forming process due to fixed die openings and excessive longitudinal tensile stress in the wall. Therefore, they are only suitable for drawing forming of straight-walled shells with circular cross-sections.

[0003] In recent years, a process using roller dies for drawing and forming has emerged. Roller drawing and forming can change the sliding friction between the billet and the die into rolling friction by using a set of rollers, thereby significantly reducing the longitudinal tensile stress on the billet during deformation. Therefore, it is suitable for forming complex cross-sectional shapes and conical parts. For example, roller drawing can be used for forming irregular cross-section wires such as square cross-sections and polygonal cross-sections; processes such as "roll extrusion" can be used for forming large-sized circular cross-section conical / straight-walled shells.

[0004] However, the application of roll forming technology to the forming of non-circular cross-section irregular shells remains a gap. The challenges lie in the significant differences in deformation at different circumferential locations along the metal billet wall during roll forming, and the asynchronous flow along the generatrix in different areas of the metal billet, leading to defects such as tearing and flow line disorder during the forming process. Therefore, it is necessary to address the technical bottlenecks in the roll forming of non-circular cross-section irregular shells and improve existing equipment and processes. Summary of the Invention

[0005] To address the problems existing in the prior art, this application provides a non-circular cross-section irregular shell roll forming device and its design method, as well as a non-circular cross-section irregular shell roll forming process using the device, which can better realize the roll forming of irregular shells with non-circular cross-section and conical walls.

[0006] The first aspect of this application provides a design method for a non-circular cross-section irregular shell roll forming device, wherein the non-circular cross-section irregular shell roll forming device is used to form a shell-shaped blank into a non-circular cross-section irregular shell, including the following steps:

[0007] A1, Design the three-dimensional shape of the punch based on the three-dimensional shape of the inner wall of the non-circular cross-section irregular shell;

[0008] A2, based on the three-dimensional shape of the outer wall of the non-circular cross-section irregular shell, determine the number of a set of mutually cooperating forging rolls, wherein the number of forging rolls is greater than or equal to 2, and the axes of each forging roll are coplanar;

[0009] A3. Based on the three-dimensional shape of the outer wall of the non-circular cross-section irregular shell, the shape of the loading surface of each forging roll is designed. The intersection of the loading surface and the contact plane constitutes the outer perimeter of the die orifice of the non-circular cross-section irregular shell roll forming device. The intersection of the outer wall of the punch and the contact plane constitutes the inner perimeter of the die orifice. The contact plane is the plane formed by the intersection of the axes of each forging roll.

[0010] Preferably, the contact plane is perpendicular to the stretching direction of the non-circular cross-section irregular shell roller forming device.

[0011] Preferably, the inner circumference of the die opening and / or the outer circumference of the die opening change continuously with the movement of the punch and / or the rotation of each of the forging rolls.

[0012] Preferably, the design method of the non-circular cross-section irregular shell roll forming device further includes the following steps: determining the shape parameters of the shell blank based on the three-dimensional shape of the punch and the shape of the loading surface of each of the forging rolls.

[0013] Furthermore, the shape parameters of the shell-shaped blank include at least one of the following parameters: the outer wall shape, inner wall shape, wall thickness, and depth-to-diameter ratio of the shell-shaped blank.

[0014] Preferably, the design method of the non-circular cross-section irregular shell roll forming device further includes the following steps: optimizing the non-circular cross-section irregular shell roll forming device and / or the shell blank based on the longitudinal deformation of the shell blank during the forming process.

[0015] Furthermore, the non-circular cross-section irregular shell roll forming device and / or the shell-shaped blank are optimized, specifically: when the longitudinal deformation rate of any region of the shell-shaped blank is less than that of other regions, the outer perimeter of that region is reduced and / or the wall thickness of the shell-shaped blank in that region is increased; and when the longitudinal deformation rate of any region of the shell-shaped blank is greater than that of other regions, the outer perimeter of that region is expanded and / or the wall thickness of the shell-shaped blank in that region is decreased.

[0016] Preferably, the design method of the non-circular cross-section irregular shell roll forming device further includes the following steps: designing a rotational engagement unit, a reset unit, a fixing unit, a stamping unit, and a loading and unloading unit, wherein the rotational engagement unit is used to make each of the forging rolls rotate collaboratively; the reset unit is used to return the punch and each of the forging rolls to their initial positions; the fixing unit is used to support each of the forging rolls; the stamping unit is used to drive the punch to move along the drawing direction; and the loading and unloading unit is used to load the shell-shaped blank and unload the non-circular cross-section irregular shell.

[0017] The second aspect of this application provides a non-circular cross-section irregular shell roll forming device, including a punch, a set of cooperating forging rolls, a rotating cooperation unit, a reset unit, a fixing unit, a stamping unit, and an unloading unit, wherein the non-circular cross-section irregular shell roll forming device is designed and generated by the above-described design method for non-circular cross-section irregular shell roll forming device.

[0018] Preferably, the punch and each of the forging rolls are made of high-temperature resistant die steel.

[0019] Preferably, the materials of the shell-shaped blank and the non-circular cross-section irregular shell are at least one of metallic materials, alloy materials, and metal matrix composite materials.

[0020] A third aspect of this application provides a non-circular cross-section irregular shell roll forming process, which uses the aforementioned non-circular cross-section irregular shell roll forming device to form a shell-shaped blank into a non-circular cross-section irregular shell, including the following steps:

[0021] Step 1: Assemble the non-circular cross-section irregular shell roller die drawing forming device and place each part in its initial position;

[0022] Step 2: Preheat the punch and forging roll to 300-400°C, and spray a release agent on the working surfaces of the forging roll and punch.

[0023] Step 3: Preheat the shell-shaped blank to a temperature suitable for plastic processing, then transfer and nest it into the punch.

[0024] Step four: The punch moves the shell-shaped billet downwards. The outer wall of the shell-shaped billet rotates due to the friction generated by contact with the loading surface of the forging roll. The shell-shaped billet undergoes continuous local plastic deformation through the inner and outer circumferences at the die opening until it completely passes through the loading surface.

[0025] Preferably, the non-circular cross-section irregular shell roll forming process further includes the following steps:

[0026] Step 5: The punch drives the drawn non-circular cross-section irregular shell upward, and the unloading device is activated to separate the punch and the non-circular cross-section irregular shell. Then, the non-circular cross-section irregular shell is cooled under the required conditions according to the material characteristics.

[0027] Step six: Reset the cooperating forging rolls.

[0028] The non-circular cross-section irregular shell roll forming process, apparatus, and design method provided in the embodiments of this application have at least the following characteristics:

[0029] Beneficial effects:

[0030] This application designs a set of co-rotating forging rolls based on the inner and outer wall shapes of an irregularly shaped shell with a non-circular cross-section, in conjunction with a punch to achieve localized loading and continuous forming of the irregularly shaped shell. The number of forging rolls and the appropriate allocation of the loading area for each forging roll are determined based on the specific shape of the non-circular cross-section of the irregularly shaped shell.

[0031] Based on the outer wall morphology of the non-circular cross-section irregular shell, the shape and size of the loading surface of each forging roll are reasonably designed, and the forging roll is modified by diameter adjustment to achieve the drawing forming of the non-circular cross-section irregular shell with tapered wall.

[0032] To address the issue of uneven longitudinal flow of billet during the roll forming process of non-circular cross-section irregular shells, the shape parameters of the roll forming device and the pre-made shell-shaped billet are optimized to achieve active control of local plastic deformation of the billet during the forming process, thereby realizing near-uniform flow along the generatrix direction at different circumferential positions of the non-circular cross-section irregular shell. Attached Figure Description

[0033] Figure 1a A three-dimensional view of a non-circular cross-section irregular shell;

[0034] Figure 1b for Figure 1a A top view of the non-circular cross-section irregular shell shown;

[0035] Figure 1c for Figure 1a The AA-direction sectional view of the non-circular cross-section irregular shell is shown.

[0036] Figure 2 This is an assembly schematic diagram of the non-circular cross-section irregular shell roll forming apparatus according to an embodiment of this application;

[0037] Figure 3 This is a flowchart illustrating the design method of a non-circular cross-section irregular shell roller die drawing forming apparatus according to an embodiment of this application;

[0038] Figure 4aThis is a schematic diagram of slicing a non-circular cross-section irregular shell according to an embodiment of this application;

[0039] Figure 4b For based on Figure 4a A schematic diagram of the inner wall of multiple non-circular cross-section irregular shells obtained by slicing;

[0040] Figure 5 A top view of a set of cooperating forging rolls according to an embodiment of this application;

[0041] Figure 6a A perspective view of a variable diameter forging roll according to an embodiment of this application;

[0042] Figure 6b for Figure 6a The forging roll shown is a front view.

[0043] Figure 6c for Figure 6a The side view of the forging roll shown;

[0044] Figure 7 This is a schematic diagram illustrating the formation of a die opening through an inner perimeter line and an outer perimeter line according to an embodiment of this application;

[0045] Figure 8 This is a schematic diagram showing the continuous change of the die opening size during the drawing process according to an embodiment of this application;

[0046] Figure 9 This is a schematic diagram illustrating the optimization of a non-circular cross-section irregular shell roll forming apparatus and / or shell-shaped blank according to an embodiment of this application. Detailed Implementation

[0047] The present application will now be further described based on preferred embodiments and with reference to the accompanying drawings.

[0048] In the description of the embodiments of this application, it should be noted that if terms such as "upper," "lower," "inner," or "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In the description of this application, in order to distinguish different units, terms such as "first" and "second" are used in this specification, but these are not limited by the manufacturing order, nor should they be construed as indicating or implying relative importance. Their names may differ in the detailed description and claims of this application.

[0049] The vocabulary used in this specification is for illustrative purposes and is not intended to limit the scope of this application. It should also be noted that, unless otherwise expressly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection via an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of these terms in this application.

[0050] In addition, for ease of understanding, the various components on the drawings have been enlarged or reduced in the accompanying drawings, but this is not intended to limit the scope of protection of this application.

[0051] Figures 1a to 1c A perspective view, a top view, and a side sectional view of a non-circular cross-section irregular shell 600 are shown respectively. The non-circular cross-section irregular shell 600 has a non-circular cross-section and is made of various metal materials such as steel, titanium alloy, aluminum alloy, tantalum alloy, and tungsten alloy, or metal matrix composite materials based on the above-mentioned materials.

[0052] The non-circular cross-section irregular shell 600 is relatively large, and as... Figures 1a to 1c As shown, the non-circular cross-section irregular shell 600 has a deep blind hole 610, its shell wall 630 is a cone shape with a larger top and a smaller bottom along the longitudinal direction, its shell wall extends from top to bottom to form generatrices, and the horizontal cross-section 620 of the shell wall 630 is a non-circular irregular polygon.

[0053] It is quite difficult to perform the drawing and forming of the above-mentioned non-circular cross-section irregular shell 600 using the currently conventional roller die drawing and forming process, because:

[0054] In conventional roll forming processes, the forging rolls used are suitable for drawing circular cross-section shells, whose shell walls are regularly circular along the circumference, resulting in relatively uniform stress distribution throughout the process. However, in the non-circular cross-section irregular shell 600 shown in Figure 1, the deformation varies significantly at different circumferential locations (such as multiple corner locations) of the shell wall 630 during the drawing process. Therefore, during the drawing process, asynchronous flow (deformation) of different parts of the metal billet along the generatrix direction can easily occur, leading to defects such as billet tearing and flow line disorder during the drawing process. Consequently, the performance and quality of the final non-circular cross-section irregular shell 600 are reduced.

[0055] Therefore, it is necessary to optimize the design of the roll forming device to obtain an improved roll forming device for non-circular cross-section irregular shells. Using the improved device to roll form the non-circular cross-section irregular shell 600 can ensure that all parts of the blank undergo continuous and uniform deformation during the forming process. This ensures that the final non-circular cross-section irregular shell 600 is free from defects such as cracks and disordered flow lines, effectively improving the performance of the non-circular cross-section irregular shell 600.

[0056] Figure 2 A schematic diagram of the assembly of the non-circular cross-section irregular shell roll forming apparatus is shown in some preferred embodiments. Figure 2 As shown, the non-circular cross-section irregular shell roll forming device includes a punch 100, a set of cooperating forging rolls (including a first forging roll 210, a second forging roll 220, a third forging roll 230 and a fourth forging roll 240), a rotational cooperating unit, a reset unit 400, and a fixing unit.

[0057] Furthermore, in Figure 2 In the illustrated embodiment, the first forging roll 210, the second forging roll 220, the third forging roll 230, and the fourth forging roll 240 rotate around their respective axes 211, 221, 231, and 241, respectively. The four axes 211, 221, 231, and 241 are coplanar, and the plane formed by their intersection constitutes the contact plane T of the non-circular cross-section irregular shell roll forming device.

[0058] Furthermore, in Figure 2 In the embodiment shown, the rotational engagement unit includes bevel gears 300 disposed at both ends of the rotating shaft of each forging roll. The bevel gears 300 mesh with each other to enable the first forging roll 210, the second forging roll 220, the third forging roll 230 and the fourth forging roll 240 to rotate in coordination with each other.

[0059] Furthermore, the fixing unit fixes the rotation shaft of each forging roll with bearings to ensure the support rigidity of each forging roll during rotation.

[0060] Furthermore, such as Figure 2 As shown, the reset unit 400 includes a rack 410 and a gear 420 that cooperate with each other. The gear 420 is coaxially fixedly connected to the rotation shaft of the first forging roll 210. The rack 410 moves radially under the control of the cylinder, thereby driving the gear 420 and the first forging roll 210 to rotate, so as to reset each forging roll in a coordinated manner before each forming.

[0061] Furthermore, the non-circular cross-section irregular shell roll forming device also includes a stamping unit and a loading and unloading unit (not shown in the figure). Specifically, the stamping unit can be a hydraulic device or other equipment that provides loading force to the punch 100; the loading and unloading unit can be composed of mutually cooperating robotic arms, clamps, limit modules, and other equipment well known to those skilled in the art, and is powered by pneumatic or hydraulic equipment to realize the loading action of the shell blank 500 and the unloading action of the non-circular cross-section irregular shell 600.

[0062] See Figure 2 As shown, during the roll forming process of the non-circular cross-section irregular shell roll forming device for forming shell blank 500, the punch 100, driven by the stamping unit, is embedded into the shell blank 500 and drives the shell blank 500 to bite into each forging roll along the forming direction (as shown by the black arrow in the figure). Then, the friction between the shell blank 500 and the punch 100 and each forging roll is used to drive the forging roll to rotate passively. Under the combined action of the loading surface of the punch 100 and each forging roll, the shell blank 500 undergoes local plastic deformation. During the deformation process, its sidewalls thin along the wall thickness direction and elongate along the generatrix direction, thereby completing the entire forming process and obtaining a non-circular cross-section irregular shell 600.

[0063] In the embodiments of this application, the punch 100 and each forging roll are made of high-temperature resistant die steel. The shell-shaped blank 500 and the non-circular cross-section irregular shell 600 can be made of metal materials such as steel, or alloy materials such as titanium alloy, aluminum alloy, tantalum alloy, tungsten alloy, etc., or metal matrix composite materials with the above materials as the matrix.

[0064] Figure 2 This is merely a illustrative description of the non-circular cross-section irregular shell roll forming apparatus provided in some embodiments of this application. It should be understood that in specific implementations, the design of the non-circular cross-section irregular shell roll forming apparatus can be adapted according to the specific shape of the non-circular cross-section irregular shell to be manufactured and the material properties of the blank used. The design method of the non-circular cross-section irregular shell roll forming apparatus provided in this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0065] Figure 3 A flowchart illustrating a design method for a non-circular cross-section irregular shell roll forming apparatus according to some embodiments of this application is shown. This method is used to design a non-circular cross-section irregular shell roll forming apparatus, such as... Figure 3 As shown, this design method includes the following steps:

[0066] A1, Design the three-dimensional shape of the punch based on the three-dimensional shape of the inner wall of the non-circular cross-section irregular shell;

[0067] A2, based on the three-dimensional shape of the outer wall of the non-circular cross-section irregular shell, determine the number of a set of mutually cooperating forging rolls, wherein the number of forging rolls is greater than or equal to 2, and the axes of each forging roll are coplanar;

[0068] A3. Based on the three-dimensional shape of the outer wall of the non-circular cross-section irregular shell, the shape of the loading surface of each forging roll is designed. The intersection of the loading surface and the contact plane constitutes the outer perimeter of the die orifice of the non-circular cross-section irregular shell roll forming device. The intersection of the outer wall of the punch and the contact plane constitutes the inner perimeter of the die orifice. The contact plane is the plane formed by the intersection of the axes of each forging roll.

[0069] Step A1 is used to design and generate the three-dimensional shape of the punch 100. Specifically, in the embodiments of this application, step A1 can be implemented using various existing three-dimensional modeling methods. For example, after completing the design of the three-dimensional digital model of the non-circular cross-section irregular shell 600, the three-dimensional digital model of the punch 100 can be generated through Boolean operations; alternatively, the solid of the non-circular cross-section irregular shell 600 can be three-dimensionally scanned to obtain the three-dimensional point cloud set of its inner wall, and then the three-dimensional digital model of the inner wall can be generated through surface modeling, and the three-dimensional shape of the punch 100 can be determined based on the three-dimensional shape of the inner wall. Another example is that the non-circular cross-section irregular shell 600 can first be sliced ​​along the drawing direction (e.g., ...). Figure 4a As shown), to obtain two-dimensional slices b~h of the inner wall of multiple non-circular cross-section irregular shells 600 (as shown). Figure 4b As shown in the figure, the three-dimensional shape of punch 100 can be obtained by using the above multiple two-dimensional slices and surface fitting technology.

[0070] In addition, in some specific embodiments, a circular contact portion that contacts the stamping unit can be further provided at the upper end of the punch 100 to achieve good contact between the punch 100 and the stamping unit.

[0071] Steps A2 and A3 are used to design a set of cooperating forging rolls. Each forging roll is used to apply pressure to different parts of the outer wall of the shell blank 500. Together with the punch 100, the shell blank 500 is squeezed to make it extend and thin in the circumferential direction of the cross section. As the forging rolls rotate and the punch 100 presses down, the shell blank 500 flows in the generatrix direction.

[0072] like Figure 1bAs shown, since the non-circular cross-section irregular shell 600 has a non-circular cross-section, the stress situation of the shell blank 500 at different positions along the circumferential direction of the cross-section (especially at the position where the corner appears) is significantly more complex than that of the shell with a circular cross-section during the drawing process. Therefore, in the embodiment of this application, the number of forging rolls is first determined by step A2 to optimize different loading areas. Then, by step A3, the shape of the loading surface of each forging roll is determined based on the three-dimensional shape of the outer wall of the non-circular cross-section irregular shell 600.

[0073] Specifically, Figure 5 A top view of a set of cooperating forging rolls is shown in some embodiments. Figure 5 The process includes four forging rolls (first forging roll 210, second forging roll 220, third forging roll 230, and fourth forging roll 240), which divide the outer wall of the shell-shaped blank 500 into four loading areas. In other embodiments of this application, those skilled in the art can determine the number of cooperating forging rolls and the specific division scheme of the loading areas on the outer wall of the shell-shaped blank 500 according to the specific shape and size of the non-circular cross-section irregular shell to be drawn.

[0074] Meanwhile, as mentioned above, the axes 211, 221, 231, and 241 of each forging roll are coplanar, and the plane formed by their intersection constitutes the contact plane T of the non-circular cross-section irregular shell roll forming device. The inner and outer walls of the shell blank 500 come into contact with the punch 100 and each forging roll on this plane. Obviously, in the preferred real-time example, the drawing direction should be perpendicular to the contact plane T so that the axis of rotation of each forging roll is perpendicular to the direction of movement of the punch 100, thereby ensuring the smooth rotation of each forging roll.

[0075] Figures 6a to 6c It shows Figure 5 Schematic diagrams of the first forging roll 210 from various angles, as shown below. Figure 6a As shown in Figure c, the first forging roll 210 has a continuous loading surface 212, which is oriented according to the rotation direction ( Figure 6c (As indicated by the black arrow in the middle) It has a starting point 212A and an ending point 212B. Obviously, the three-dimensional shape of this loading surface should be determined based on the three-dimensional shape of the outer wall of the non-circular cross-section irregular shell 600. Specifically, it can be similar to the design process of the punch 100. By combining the shapes of multiple slices of the outer wall of the non-circular cross-section irregular shell 600 with the relative positions of each forging roll and the non-circular cross-section irregular shell 600, the above-mentioned multiple slices are divided. The lines obtained after division are then rotated and translated in three dimensions according to the rotation direction of the corresponding forging roll. Finally, the loading surface of the forging roll is formed by a spatial surface fitting operation.

[0076] In some specific embodiments, such as Figure 1cAs shown, the shell wall of the non-circular cross-section irregular shell 600 that needs to be drawn has a conical shape that is larger at the top and smaller at the bottom. Obviously, in this case, the distance between the loading surface 212 of the forging roll 210 and the axis will change continuously. For example, Figure 6c After the forging roll 210 is cut in the II direction, the distances from the starting point 212A and the ending point 212B on its cutting surface to the axis are ra and rb, respectively, and ra > rb. As the forging roll rotates, its loading surface gradually expands.

[0077] Figure 7 This diagram illustrates a specific die opening of a non-circular cross-section irregular shell roll forming apparatus in some embodiments, such as... Figure 7 As shown, the die opening is formed by an outer circumferential line 20 and an inner circumferential line 10. The outer circumferential line 20 is formed by the intersection of the loading surfaces of each forging roll and the contact plane T, while the inner circumferential line 10 is formed by the intersection of the outer wall of the punch 100 and the contact plane T. Clearly, depending on the number of forging rolls and the specific shape of the loading surfaces, the outer circumferential line 20 can be composed of multiple curves. Furthermore, to accommodate excess material generated by the plastic deformation of various parts of the billet during the drawing process, such as… Figure 7 As shown, there is a spacing L between each forging roll, and triangular grooves are provided to accommodate the excess material extruded.

[0078] The die opening represents the intersection line on the contact plane T where the punch 100 and each forging roll contact the shell-shaped blank 500 respectively. Clearly, when drawing and forming a non-circular cross-section irregular shell 600 with tapered walls, the inner circumference line 10 and / or the outer circumference line 20 move with the punch 100 (along...). Figure 8 The drawing direction (indicated by the black arrow in the middle) and / or the rotation of each forging roll continuously change, causing the die orifice shape to be as follows: Figure 8 The changes shown are continuous.

[0079] In some preferred embodiments of this application, the design method of the non-circular cross-section irregular shell roll forming device further includes the following steps: determining the shape parameters of the shell blank 500 based on the three-dimensional shape of the punch 100 and the shape of the loading surface of each forging roll. The shape parameters of the shell blank 500 include at least one of the following parameters: outer wall shape, inner wall shape, wall thickness, and depth-to-diameter ratio. By pre-processing the shell blank 500 with through holes or blind holes of a small depth-to-diameter ratio through processes such as extrusion, cutting, and punching according to the shape of the punch 100 and each forging roll, the uniformity of plastic deformation of various parts of the blank during the drawing process can be significantly improved, effectively enhancing the performance and product quality of the formed non-circular cross-section irregular shell 600.

[0080] In some preferred embodiments of this application, the design method of the non-circular cross-section irregular shell roll forming device further includes the following steps: optimizing the non-circular cross-section irregular shell roll forming device and / or the shell blank 500 based on the longitudinal deformation of the shell blank 500 during the forming process.

[0081] Specifically, the above optimization steps are as follows: when the longitudinal deformation rate of any region of the shell blank 500 is less than that of other regions, the outer perimeter 20 of that region is reduced and / or the wall thickness of the shell blank 500 in that region is increased; and when the longitudinal deformation rate of any region of the shell blank 500 is greater than that of other regions, the outer perimeter 20 of that region is expanded and / or the wall thickness of the shell blank 500 in that region is decreased.

[0082] Figure 9 The diagram illustrates the principle of optimizing a non-circular cross-section irregular shell roll forming device and / or shell blank 500 in some preferred embodiments of this application. The upper part of the diagram represents the unoptimized case, and the lower part represents the optimized case.

[0083] like Figure 9 As shown in the upper part, although the punch and each forging roll of the non-circular cross-section irregular shell roll forming device are determined based on the shape of the inner and outer walls of the non-circular cross-section irregular shell, so that the shape of the inner and outer circumference lines is consistent with the intersection line of the inner and outer walls of the non-circular cross-section irregular shell on the contact plane, in the actual drawing forming process, because the billet needs to be extended along the non-circular circumference and flow along the generatrix, the plastic deformation of the billet is not uniform in different areas. Especially in the bending area (such as the junction of area B and area C), there may be a large difference in the flow velocity of the billet along the generatrix at different positions, which makes the billet easy to tear, break, or form disordered flow lines after drawing in this area.

[0084] The above problems arise because of the special cross-sectional shape of the non-circular cross-section irregular shell. Therefore, it is necessary to optimize the different deformation conditions of each part of the shell blank 500 during the drawing process.

[0085] Specifically, the drawing process of the shell-shaped billet 500 can be simulated using existing simulation software to obtain the flow velocity (or longitudinal deformation velocity) of each part along the generatrix. If the longitudinal deformation velocity of a certain region of the shell-shaped billet 500 is less than that of other regions, it can be calculated as follows: Figure 9As shown in the lower part, the outer perimeter of this region is narrowed so that the loading surface of the redesigned forging roll is closer to the punch 100 in this region, thereby increasing the deformation of the shell blank 500 in this region and accelerating its flow rate in this region. Alternatively, the wall thickness of the shell blank 500 in this region can be increased to obtain an optimized shell blank 500, which can also accelerate the flow rate of the shell blank 500 in this region.

[0086] If the longitudinal deformation rate of a certain region of the shell-shaped billet 500 is greater than that of other regions, the outer perimeter of that region can be widened so that the loading surface of the redesigned forging roll is further away from the punch 100 in that region, thereby reducing the deformation of the shell-shaped billet 500 in that region and slowing down its flow rate. Alternatively, the wall thickness of the shell-shaped billet 500 in that region can be reduced to obtain an optimized shell-shaped billet 500, which also slows down the flow rate of the shell-shaped billet 500 in that region.

[0087] In some preferred embodiments of this application, the design method of the non-circular cross-section irregular shell roller die drawing forming device further includes the following steps: designing a rotational mating unit, a reset unit, a fixing unit, a stamping unit, and a loading and unloading unit. The functions of each of the above units have been described in detail in the description of the non-circular cross-section irregular shell roller die drawing forming device, and the specific implementation steps of its design are known to those skilled in the art, and will not be repeated here.

[0088] The embodiments of this application also provide a non-circular cross-section irregular shell roll forming process using the above-described non-circular cross-section irregular shell roll forming apparatus. Specifically, the process includes the following steps:

[0089] Step 1: Assemble the non-circular cross-section irregular shell roller die drawing forming device and place each part in its initial position;

[0090] Step 2: Preheat the punch and forging roll to 300-400°C, and spray a release agent on the working surfaces of the forging roll and punch.

[0091] Step 3: Preheat the shell-shaped blank to a temperature suitable for plastic processing, then transfer and nest it into the punch.

[0092] Step four: The punch moves the shell-shaped billet downwards. The outer wall of the shell-shaped billet rotates due to the friction generated by contact with the loading surface of the forging roll. The shell-shaped billet undergoes continuous local plastic deformation through the inner and outer circumferences at the die opening until it completely passes through the loading surface.

[0093] In some preferred embodiments, the process further includes the following steps:

[0094] Step 5: The punch drives the drawn non-circular cross-section irregular shell upward, and the unloading device is activated to separate the punch and the non-circular cross-section irregular shell. Then, the non-circular cross-section irregular shell is cooled under the required conditions according to the material characteristics.

[0095] Step six: Reset the cooperating forging rolls.

[0096] The specific embodiments of this application have been described in detail above. For those skilled in the art, several improvements and modifications can be made to this application without departing from the principle of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A design method for a non-circular cross-section irregular shell roll forming device, wherein the non-circular cross-section irregular shell roll forming device is used to draw and form a shell-shaped blank into a non-circular cross-section irregular shell, characterized in that, Includes the following steps: A1, Design the three-dimensional shape of the punch based on the three-dimensional shape of the inner wall of the non-circular cross-section irregular shell; A2, based on the three-dimensional shape of the outer wall of the non-circular cross-section irregular shell, determine the number of a set of mutually cooperating forging rolls, wherein the number of forging rolls is greater than or equal to 2, and the axes of each forging roll are coplanar; A 3, based on the three-dimensional shape of the outer wall of the non-circular cross-section irregular shell, the shape of the loading surface of each forging roll is designed. The intersection of the loading surface and the contact plane constitutes the outer perimeter of the die orifice of the non-circular cross-section irregular shell roller die drawing forming device. The intersection of the outer wall of the punch and the contact plane constitutes the inner perimeter of the die orifice. The contact plane is the plane formed by the intersection of the axes of each forging roll. The loading surface of at least one of the forging rolls varies continuously relative to its axis, and the inner circumference of the die and / or the outer circumference of the die continuously change with the movement of the punch and / or the rotation of each of the forging rolls. Each of the forging rolls rotates in coordination with the others through a rotating mating unit.

2. The design method of the non-circular cross-section irregular shell roller die drawing forming device according to claim 1, characterized in that: The contact plane is perpendicular to the stretching direction of the non-circular cross-section irregular shell roller forming device.

3. The design method of the non-circular cross-section irregular shell roller die drawing forming device according to claim 1, characterized in that, It also includes the following steps: The shape parameters of the shell-shaped billet are determined based on the three-dimensional shape of the punch and the shape of the loading surface of each of the forging rolls.

4. The design method of the non-circular cross-section irregular shell roller die drawing forming device according to claim 3, characterized in that, The shape parameters of the shell-shaped blank include at least one of the following parameters: The outer wall shape, inner wall shape, wall thickness, and depth-to-diameter ratio of the shell-shaped billet.

5. The design method of the non-circular cross-section irregular shell roller die drawing forming device according to claim 1, characterized in that, It also includes the following steps: The non-circular cross-section irregular shell roll forming device and / or the shell blank are optimized based on the longitudinal deformation of the shell blank during the drawing process.

6. The design method of the non-circular cross-section irregular shell roller die drawing forming device according to claim 5, characterized in that, The optimization of the non-circular cross-section irregular shell roll forming device and / or the shell-shaped blank is as follows: When the longitudinal deformation rate of any region of the shell-shaped blank is less than that of other regions, the outer perimeter of that region is reduced and / or the wall thickness of the shell-shaped blank in that region is increased. as well as, When the longitudinal deformation rate of any region of the shell-shaped blank is greater than that of other regions, the outer perimeter of that region is enlarged and / or the wall thickness of the shell-shaped blank in that region is reduced.

7. The design method of the non-circular cross-section irregular shell roller die drawing forming device according to claim 1, characterized in that, It also includes the following steps: The design includes a rotation and mating unit, a reset unit, a fixing unit, a stamping unit, and a loading and unloading unit. The rotational engagement unit is used to make each of the forging rolls rotate in a coordinated manner; The reset unit is used to return the punch and each of the forging rolls to their initial positions. The fixing unit is used to support each of the forging rolls; The stamping unit is used to drive the punch to move along the drawing direction; The loading and unloading unit is used to load the shell-shaped blank and unload the non-circular cross-section irregular shell.

8. A non-circular cross-section irregular shell roll forming device, comprising a punch, a set of cooperating forging rolls, a rotating cooperating unit, a resetting unit, a fixing unit, a stamping unit, and a loading and unloading unit, characterized in that: The non-circular cross-section irregular shell roller mold drawing forming device is designed and generated by the design method of the non-circular cross-section irregular shell roller mold drawing forming device as described in any one of claims 1 to 7.

9. The non-circular cross-section irregular shell roller forming device according to claim 8, characterized in that: The punch and each of the forging rolls are made of high-temperature resistant die steel.

10. The non-circular cross-section irregular shell roller forming device according to claim 8, characterized in that: The materials of the shell-shaped blank and the non-circular cross-section irregular shell are at least one of the following: metallic materials, alloy materials, and metal matrix composite materials.

11. A non-circular cross-section irregular shell roll forming process, comprising using the non-circular cross-section irregular shell roll forming device as described in claim 8, to roll form a shell-shaped blank into a non-circular cross-section irregular shell, characterized in that, Includes the following steps: Step 1: Assemble the non-circular cross-section irregular shell roller die drawing forming device and place each part in its initial position; Step 2: Preheat the punch and forging roll to 300~400°C, and spray the release agent on the working surfaces of the forging roll and punch; Step 3: Preheat the shell-shaped blank to a temperature suitable for plastic processing, then transfer and nest it into the punch. Step four: The punch moves the shell-shaped billet downwards. The outer wall of the shell-shaped billet rotates due to the friction generated by contact with the loading surface of the forging roll. The shell-shaped billet undergoes continuous local plastic deformation through the inner and outer circumferences at the die opening until it completely passes through the loading surface.

12. The non-circular cross-section irregular shell roll forming process according to claim 11, characterized in that, It also includes the following steps: Step 5: The punch drives the drawn non-circular cross-section irregular shell upward, and the unloading device is activated to separate the punch and the non-circular cross-section irregular shell. Then, the non-circular cross-section irregular shell is cooled under the required conditions according to the material characteristics. Step six: Reset the cooperating forging rolls.

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