A press bending forming device and method thereof

Abstract

The application discloses a press bending forming device and a method thereof. The device comprises a concave die, a limiting device, a side flat die assembly, a convex die and a side die head assembly. The side flat die assembly comprises a first side flat die and a second side flat die. The first side flat die is slidably arranged in a first guide groove, and the second side flat die is slidably arranged in a second guide groove. The convex die is arranged above a first forming cavity. The side die head assembly comprises a first side die head and a second side die head. The first side die head is slidably arranged in the first guide groove, and the second side die head is slidably arranged in the second guide groove. The application can continuously complete the press bending forming process of a plate blank in the same device, and the plate blank does not need to be transferred between multiple sets of dies. The application avoids the complicated steps of repeatedly disassembling, repositioning and the like in the traditional process, realizes the continuous controllability of the overall forming process, significantly shortens the production period and improves the production efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of pipe forming, and in particular to a bending forming apparatus and method thereof. Background Technology

[0002] In the aerospace field, large-diameter, small-bending-radius thin-walled bends are core components of pressurization systems. Spacecraft interiors are densely packed with equipment, and bends, by changing the direction of the pipes and bypassing obstacles, enable efficient connections between different components, playing a crucial role in transporting fluids such as propellant and coolant. The large-diameter design effectively reduces fluid flow resistance, while the small relative bending radius (R / D; R is the bending radius; D is the pipe diameter) meets the flexible layout requirements within the compact space of aerospace equipment, and the thin-walled structure directly serves the goal of spacecraft lightweighting. However, traditional processes for manufacturing large-diameter, small-bending-radius thin-walled bends face multiple challenges: insufficient springback control leads to ellipticity and wall thickness issues; small-curvature bends are prone to external cracking or internal wrinkling; 1mm thin walls cannot withstand internal pressures exceeding 30MPa and are prone to instability; weld strength is limited, and residual stress and alternating loads after forming can easily trigger microcrack propagation. In contrast, pressure bending can form large-diameter thin-walled tubes with a relative bending radius of one. The principle is to use the upper die to provide concentrated pressure and the lower die to provide constraint support. The bottom of the upper die is an arc surface that matches the target curvature, and the top of the lower die has a positioning groove to fix the blank. Under the stable pressure of the hydraulic system, the tube reaches the yield strength and produces plastic bending deformation.

[0003] Traditional bending forming methods involve pre-bending the edges, pre-bending the bottom, pressing the top together, and then welding internally and externally. This is a common method for manufacturing large-diameter, small-bending-radius thin-walled tubes. However, current technology requires the slab to undergo multiple processing steps and be transferred to multiple sets of different molds for pre-bending, resulting in long production cycles, low processing efficiency, and high energy consumption, which does not meet the needs of green aviation development in the new era. In addition, the slab needs to be repeatedly positioned in different molds, which is greatly affected by the operator's skill level, leading to inconsistent finished product quality. Summary of the Invention

[0004] Therefore, it is necessary to provide a bending forming apparatus and method to solve at least one of the above-mentioned technical problems.

[0005] A bending forming apparatus, comprising: A die has a first forming cavity, a first guide groove, and a second guide groove. The first forming cavity extends along a first direction, and the first guide groove and the second guide groove both extend along a second direction, which is perpendicular to the first direction. The first guide groove and the second guide groove are respectively disposed on both sides of the first forming cavity, and the first guide groove and the second guide groove are both connected to the first forming cavity. The limiting device includes a first limiting component and a second limiting component. The first limiting component and the second limiting component are respectively disposed above the first guide groove and the second guide groove. The first limiting component and the second limiting component are disposed opposite to each other and are used to support the two ends of the slab respectively. A side mold assembly includes a first side mold and a second side mold, wherein the first side mold is slidably disposed in a first guide groove, and the second side mold is slidably disposed in the second guide groove, wherein the first side mold is configured to be flush with one side edge of the first molding cavity, and the second side mold is configured to be flush with the other side edge of the first molding cavity; A punch is disposed above the first forming cavity. The punch can be driven to move toward or away from the die so that the punch enters or exits the first forming cavity. The punch and the side flat die assembly cooperate to bend the blank to fit with the first forming cavity and form an intermediate part. The side die head assembly includes a first side die head and a second side die head. The first side die head is slidably disposed in the first guide groove, and the second side die head is slidably disposed in the second guide groove. The first side die head and the second side die head are used to bend the intermediate part to obtain a formed tube.

[0006] Optionally, the first limiting component includes a first side mold limiting member and a first slab limiting member, the first side mold limiting member being disposed above the first guide groove, and the first slab limiting member being disposed on the top surface of the first side mold limiting member; the second limiting component includes a second side mold limiting member and a second slab limiting member, the second side mold limiting member being disposed above the second guide groove, and the second slab limiting member being disposed on the top surface of the second side mold limiting member.

[0007] Optionally, the first side mold limiting member is provided with a first limiting hole, which is disposed through the first side mold limiting member along the second direction. The first limiting hole is used to limit the first side flat mold and the first side mold head. The second side mold limiting member is provided with a second limiting hole, which is disposed through the second side mold limiting member along the second direction. The second limiting hole is used to limit the second side flat mold and the second side mold head.

[0008] Optionally, the first slab limiting member has a first limiting groove for limiting one end of the slab, and the second slab limiting member has a second limiting groove for limiting the other end of the slab.

[0009] Optionally, it may also include a side mold rod assembly, the side mold rod assembly including a first side mold rod and a second side mold rod, the first side mold rod being configured to connect to the first side mold head or the first side flat mold, and the second side mold rod being configured to connect to the second side mold head or the second side flat mold.

[0010] Optionally, it may also include a connecting component, which is detachably connected to the punch and is used to move the punch.

[0011] Optionally, the connecting assembly includes a first pad and two connecting plates, both of which are disposed on the bottom surface of the first pad and are respectively connected to both sides of the punch.

[0012] Optionally, a second pad is also included, on which the die is disposed. The second pad has two positioning grooves, which are located on both sides of the die. The connecting plate is inserted into the positioning groove to position the punch relative to the die.

[0013] A bending forming method, the method using the above-mentioned bending forming apparatus, the method comprising the following steps: Pre-bending preparation: Move the first side flat mold to one side edge of the first forming cavity, and make the side of the first side flat mold facing the second side flat mold flush with one side edge of the first forming cavity. Move the second side flat mold to the other side edge of the first forming cavity, and make the side of the second side flat mold facing the first side flat mold flush with the other side edge of the first forming cavity. Bending and forming of the slab: The two ends of the slab are placed on the first slab limiting member and the second slab limiting member, respectively. The punch moves toward the die to enter the first forming cavity and bend the slab to fit against the first forming cavity. After obtaining the intermediate part, the first side flat die and the second side flat die are respectively removed from the first guide groove and the second guide groove. Then, the first side die head and the second side die head enter the first guide groove and the second guide groove, respectively. The first side die head and the second side die head move along the first side die limiting member and the second side die limiting member, respectively, to bend the intermediate part toward the punch to form the formed tube. After obtaining the formed tube, the first side die head and the second side die head are removed, and the punch is driven to move away from the die. Then, the punch is removed and the formed tube is taken out.

[0014] Optionally, the following steps may be included before the pre-bending preparation step: An anti-slip agent is applied to the outer curved side of the punch and the inner wall of the first forming cavity, and a lubricant is applied to the inner curved side of the punch.

[0015] The bending forming apparatus provided in this application uses a limiting device to position the slab. The side-flat die assembly, die, and punch cooperate to pre-bend the slab to form an intermediate part. Subsequently, the side-die assembly bends both sides of the intermediate part to finally obtain a formed tube. Therefore, this application can continuously complete the bending forming process of the slab within the same apparatus, eliminating the need to transfer the slab between multiple sets of molds. This avoids the cumbersome steps of repeated disassembly and repositioning in traditional processes, achieving continuous and controllable overall forming process, significantly shortening the manufacturing cycle and improving production efficiency. Furthermore, by cooperating with the side-flat die assembly and die, this application provides lateral constraint on the edges of the slab during the pre-bending stage, restricting the free flow of slab material to both sides, effectively preventing material accumulation and wrinkling at the edge of the first forming cavity of the intermediate part. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the bending forming device in one embodiment; Figure 2 This is a schematic diagram of the side flat mold assembly in one embodiment; Figure 3 This is a schematic diagram of the structure when the side flat mold assembly and the limiting assembly are engaged in one embodiment; Figure 4 This is a schematic diagram of the structure of the die in one embodiment; Figure 5 This is a schematic diagram of the structure of the second limiting component in one embodiment; Figure 6 This is a schematic diagram of the side mold head assembly in one embodiment; Figure 7 This is a schematic diagram of the connecting rod and the flat key in one embodiment; Figure 8 This is a schematic diagram of the slab structure in one embodiment; Figure 9 This is a schematic diagram of the structure of the first slab limiting member in one embodiment; Figure 10 This is a schematic diagram of the limiting component and the slab in one embodiment; Figure 11 This is a schematic diagram of the bending forming of a slab in one embodiment. Figure 1 ; Figure 12 This is a schematic diagram of the bending forming of a slab in one embodiment. Figure 2 ; Figure 13 This is a schematic diagram of the bending forming of a slab in one embodiment. Figure 3 ; Figure 14 This is a schematic diagram of the bending forming of a slab in one embodiment. Figure 4 ; Figure 15 This is a schematic diagram of the structure of the formed tube in one embodiment.

[0018] 1. Die cavity; 11. First forming cavity; 12. First guide groove; 13. Second guide groove; 14. Clearance groove; 2. Limiting device; 21. First limiting assembly; 211. First side mold limiting component; 212. First slab limiting component; 213. First limiting hole; 214. First limiting groove; 22. Second limiting assembly; 221. Second side mold limiting component; 222. Second slab limiting component; 223. Second limiting hole; 224. Second limiting groove; 3. Side flat mold assembly; 31. First side flat mold assembly; 32. Second side flat mold; 4. Punch; 5. Side mold head assembly; 51. First side mold head; 52. Second side mold head; 53. First cavity; 54. Second cavity; 6. Side mold rod assembly; 61. First side mold rod; 62. Second side mold rod; 7. Connecting assembly; 71. First pad; 72. Connecting plate; 73. Connecting rod; 74. Flat key; 75. Second pad; 76. Positioning groove; 8. Slab; 81. Intermediate part; 82. Forming tube; 83. Outer side of the bend; 84. Inner side of the bend.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0022] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the term "and / or" throughout the text includes three solutions; taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that simultaneously satisfies A and B. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] refer to Figures 1 to 14This application provides a bending forming apparatus, which includes a die 1, a limiting device 2, a side die assembly 3, a punch 4, and a side die head assembly 5. The die 1 has a first forming cavity 11, a first guide groove 12, and a second guide groove 13. The first forming cavity 11 extends along a first direction, and the first guide groove 12 and the second guide groove 13 both extend along a second direction, which is perpendicular to the first direction. The first guide groove 12 and the second guide groove 13 are respectively disposed on both sides of the first forming cavity 11. The guide grooves 13 are all connected to the first forming cavity 11; the limiting device 2 includes a first limiting component 21 and a second limiting component 22, which are respectively disposed above the first guide groove 12 and the second guide groove 13, and are arranged opposite to each other to support the two ends of the blank 8 respectively; the side flat mold assembly 3 includes a first side flat mold 31 and a second side flat mold 32, which are slidably disposed in the first guide groove 12 and the second side flat mold 32 are slidably disposed in the first guide groove 13. The second guide groove 13; the first side flat die 31 is configured to be flush with one side edge of the first forming cavity 11; the second side flat die 32 is configured to be flush with the other side edge of the first forming cavity 11; the punch 4 is disposed above the first forming cavity 11; the punch 4 can be driven to move towards or away from the die 1, so that the punch 4 enters or exits the first forming cavity 11; the punch 4 and the side flat die assembly 3 cooperate to bend the blank 8 to fit against the first forming cavity 11 and form the intermediate part 81; the side die head assembly 5 includes a first side die head 5 1. The first side mold 51 is slidably disposed in the first guide groove 12, and the second side mold 52 is slidably disposed in the second guide groove 13. The first side mold 51 and the second side mold 52 are used to bend the intermediate part 81 to obtain the formed tube 82. The first side mold 51 has a first cavity 53, and the second side mold 52 has a second cavity 54. The first cavity 53 and the second cavity 54 surround to form a second forming cavity. The second forming cavity and the first forming cavity 11 surround to form a forming cavity that matches the shape of the formed tube 82.

[0024] The bending forming apparatus provided in this application uses a limiting device 2 to position the blank 8. The side flat die assembly 3, the concave die 1, and the convex die 4 cooperate to pre-bend the blank 8 to form an intermediate part 81. Subsequently, the side die head assembly 5 bends both sides of the intermediate part 81 to finally obtain the formed tube 82. Therefore, this application can continuously complete the bending forming process of the blank 8 in the same apparatus without transferring the blank 8 between multiple sets of molds. This avoids the cumbersome steps of repeated disassembly and repositioning in traditional processes, realizes continuous and controllable overall forming process, significantly shortens the manufacturing cycle, and improves production efficiency. In addition, this application uses the cooperation of the side flat die assembly 3 and the concave die 1 to provide lateral constraints on the edge of the blank 8 during the pre-bending stage, restricting the free flow of the blank 8 material to both sides, which can effectively prevent the material of the intermediate part 81 located at the edge of the first forming cavity 11 from accumulating and wrinkling.

[0025] Specifically, after the first side die 51 and the second side die 52 complete the lateral extrusion, the intermediate part 81 is pressed into a formed tube 82 that fits the contour of the punch 4. At this time, the formed tube 82 is still fitted onto the punch 4. After driving the first side die 51 and the second side die 52 to retract, the punch 4 is driven to exit the forming cavity, and the formed tube 82 can be removed from the punch 4. Finally, the joint of the removed formed tube 82 is welded internally and externally to obtain the required large-diameter, small-bending-radius thin-walled bent tube.

[0026] Specifically, the shape of the first forming cavity 11 matches the outer contour 83 of the desired bent pipe and is used to form the outer arc surface of the bent pipe. The shape of the second forming cavity matches the inner contour 84 of the desired bent pipe and is used to form the inner arc surface of the bent pipe. When the first side mold head 51 and the second side mold head 52 approach each other to the mold closing position, the first cavity 53 and the second cavity 54 merge relative to each other and jointly enclose to form the second forming cavity. When the second forming cavity and the first forming cavity 11 are closed vertically, they together enclose to form a forming cavity that matches the complete contour of the desired bent pipe.

[0027] In this embodiment, the first direction is the width direction of the die 1, and the second direction is the length direction of the die 1.

[0028] Specifically, the first side mold head 51 and the second side mold head 52 have the same structure, and the first side flat mold 31 and the second side flat mold 32 have the same structure.

[0029] refer to Figures 1 to 3The first limiting component 21 includes a first side mold limiting member 211 and a first blank limiting member 212. The first side mold limiting member 211 is fixedly disposed above the first guide groove 12, and the first blank limiting member 212 is fixedly disposed on the top surface of the first side mold limiting member 211 by bolts. The second limiting component 22 includes a second side mold limiting member 221 and a second blank limiting member 222. The second side mold limiting member 221 is fixedly disposed above the second guide groove 13, and the second blank limiting member 222 is fixedly disposed on the top surface of the second side mold limiting member 221 by bolts, so as to ensure that the blank does not slip during the pressing and forming process, thereby affecting the forming quality.

[0030] Specifically, the first side mold limiting member 211 is provided with a first limiting hole 213. The first limiting hole 213 is provided through the first side mold limiting member 211 along the second direction. The shape formed by the first limiting hole 213 and the first guide groove 12 is matched with the first side mold head 51 and the first side flat mold 31 respectively, so as to limit the first side flat mold 31 and the first side mold head 51. The second side mold limiting member 221 is provided with a second limiting hole 223. The second limiting hole 223 is provided through the second side mold limiting member 221 along the second direction. The shape formed by the second limiting hole 223 and the second guide groove 13 is matched with the second side flat mold 32 and the second side mold head 52 respectively, so as to limit the second side flat mold 32 and the second side mold head 52, thereby ensuring that the first side mold head and the second side mold head do not tilt upwards when they converge toward the inner side of the bending of the punch.

[0031] Furthermore, the first guide groove 12 and the second guide groove 13 have the same shape, both being arc-shaped grooves, to facilitate the sliding of the side mold head assembly 5 and the side flat mold assembly 3.

[0032] refer to Figure 3 The first slab limiting member 212 has a first limiting groove 214, and the second slab limiting member 222 has a second limiting groove 224.

[0033] Specifically, the first slab limiting member 212 has a first opening, the shape of which matches the shape of one end of the slab 8. The first opening and the top surface of the first side mold limiting member 211 enclose each other to form a first limiting groove 214 to support and limit one end of the slab 8. The second slab limiting member 222 has a second opening, the shape of which matches the shape of one end of the slab 8. The second opening and the top surface of the second side mold limiting member 221 enclose each other to form a second limiting groove 224 to support and limit the other end of the slab 8.

[0034] Specifically, the first side mold limiting member 211 and the second side mold limiting member 221 have the same shape and size; the first slab limiting member 212 and the second slab limiting member 222 have the same shape and size.

[0035] refer to Figure 1and Figure 3 The device of this application also includes a side mold rod assembly 6, which includes a first side mold rod 61 and a second side mold rod 62. One end of the first side mold rod 61 is configured to connect to a first side mold head 51 or a first side flat mold 31, and the other end is used to connect to a side cylinder to drive the first side mold rod 61 to move along the first guide groove 12. The second side mold rod 62 is configured to connect to a second side mold head 52 or a second side flat mold 32, and the other end is used to connect to another side cylinder to drive the second side mold rod 62 to move along the second guide groove 13.

[0036] Specifically, the first side mold rod 61 is detachably connected to the first side mold head 51 and the first side flat mold 31, respectively, and the second side mold rod 62 is detachably connected to the second side mold head 52 and the second side flat mold 32, respectively. During pre-bending of the slab 8, the first side mold rod 61 is connected to the first side flat mold 31, and the second side mold rod 62 is connected to the second side flat mold 32 to push the first side flat mold 31 and the second side flat mold 32 to move. After pre-bending is completed, the first side mold rod 61 is separated from the first side flat mold 31, and the second side mold rod 62 is separated from the second side flat mold 32. Then, the first side mold rod 61 is connected to the first side mold head 51, and the second side mold rod 62 is connected to the second side mold head 52.

[0037] refer to Figure 1 The device of this application also includes a connecting component 7, which is detachably connected to the punch 4. The connecting component 7 is used to connect to the main cylinder to drive the punch 4 to move.

[0038] refer to Figure 1 The connecting assembly 7 includes a first pad 71 and two connecting plates 72. The punch 4 is located below the first pad 71. Both connecting plates 72 are disposed on the bottom surface of the first pad 71. The top surface of the first pad 71 is used for connection to the main cylinder. The main cylinder is used to drive the first pad 71 to move up and down in the vertical direction, thereby driving the punch 4 to move up and down. The two connecting plates 72 are respectively connected to the two sides of the punch 4.

[0039] Specifically, the connecting assembly 7 also includes two connecting rods 73. One end of one connecting rod 73 is fixedly connected to one of the connecting plates 72, and the other end is fixedly inserted into one side of the punch 4. One end of the other connecting rod 73 is fixedly connected to one end of the other connecting plate 72, and the other end is fixedly inserted into the other side of the punch 4.

[0040] Furthermore, the connecting assembly 7 also includes two flat keys 74, which are respectively disposed between the connecting rod 73 and the punch 4 to limit the relative rotation between the connecting rod 73 and the punch 4.

[0041] Specifically, the first molding cavity 11 has clearance grooves 14 at both ends to avoid the connecting rod 73.

[0042] refer to Figure 1The device of this application also includes a second pad 75, and the die 1 is fixedly disposed on the second pad 75. The second pad 75 has a positioning groove 76. There are two positioning grooves 76, which are located on both sides of the die 1. The connecting plate 72 is used to insert into the positioning groove 76 to realize the positioning of the punch 4 relative to the die 1, so that the punch 4 is aligned with the first forming cavity 11 to press the blank 8 to fit against the first forming cavity 11.

[0043] This application also provides a bending forming method, which uses the above-mentioned bending forming apparatus, and the method includes the following steps: S1, blanking of slab 8 The area dimensions of the blank slab 8 can be determined using SolidWorks by unfolding the tube of diameter D to be formed along the midpoint of the inner side 84 of the bend, as shown below. Figure 8 As shown.

[0044] S2. Dimensional design and installation of the first slab limiting member 212 and the second slab limiting member 222 The first blank limiting member 212 and the second blank limiting member 222 need to restrict the movement of the blank 8 in the plane during the forming process, but excessive movement will seriously affect the forming quality. The dimensional parameters of the first blank limiting member 212 and the second blank limiting member 222 can be calculated by the following formula: (1.1) (1.2) (1.3) (1.4) (1.5) Where L is the distance between the first side mold limiting member 211 and the second side mold limiting member 221, L1 is the total length of the blank 8, D is the diameter of the required forming tube 82, R is the rounded corner of the first side mold limiting member 211 (to prevent the surface of the sheet metal from being scratched during forming), H is the width of the first side mold limiting member 211, H1 is the width of the blank 8 at a distance of D / 2+R from the center, and H2 is the width of both sides of the blank 8, as shown in the figure. Figure 9 and Figure 10 As shown.

[0045] S3, Pre-bending preparation refer to Figure 11 Move the first side flat mold 31 to one side edge of the first molding cavity 11, and make the side of the first side flat mold 31 facing the second side flat mold 32 flush with one side edge of the first molding cavity 11. Move the second side flat mold 32 to the other side edge of the first molding cavity 11, and make the side of the second side flat mold 32 facing the first side flat mold 31 flush with the other side edge of the first molding cavity 11.

[0046] Specifically, the side of the first flat mold 31 facing the second flat mold 32 is a plane, and the side of the second flat mold 32 facing the first flat mold 31 is a plane.

[0047] S4, lubrication and anti-slip During the forming process of the slab 8, in order to avoid the material flowing violently on the outer side of the bend 83, resulting in severe thinning and cracking, it is necessary to apply anti-slip agent to the outer side of the bend 83 of the punch 4 and the inner wall of the first forming cavity 11 of the die 1 to increase the coefficient of friction; while on the inner side of the bend 84, the material is prone to accumulate and wrinkle, so it is necessary to apply lubricant to the inner side of the bend 84 of the punch 4 to reduce the coefficient of friction.

[0048] S5, bending forming of slab 8 refer to Figure 12-14 The two ends of the blank 8 are placed on the first blank limiting member 212 and the second blank limiting member 222 respectively. The punch 4 is driven downward by the main cylinder so that the punch 4 enters the first forming cavity 11 and bends the blank 8 to fit with the first forming cavity 11. After obtaining the intermediate part 81, the first side flat die 31 and the second side flat die 32 are respectively removed from the first guide groove 12 and the second guide groove 13. Then, the first side die head 51 and the second side die head 52 enter the first guide groove 12 and the second guide groove 13 respectively. The first side die head 51 and the second side die head 52 move along the first limiting hole 213 of the first side die limiting member 211 and the second limiting hole 223 of the second side die limiting member 221 respectively to bend the intermediate part 81 toward the punch 4 to form the formed tube 82. After obtaining the formed tube 82, the first side die head 51 and the second side die head 52 are removed, the punch 4 is driven upward, and then the punch 4 is removed and the formed tube 82 is taken out.

[0049] Specifically, after the bending forming is completed, the main cylinder is first lifted upwards, the connecting rod 73 is removed, the punch 4 is removed, and the forming tube 82 is taken out from the punch 4 along the bending radius direction. The forming tube 82 is as follows: Figure 15 As shown, D is the diameter of the formed tube, and R1 is the bending radius.

[0050] This application proposes a method for bending multiple curvatures in a single device using one main cylinder and two side cylinders, manufacturing a thin-walled bent tube with a large diameter and small bending radius from a slab 8. Preliminary pre-bending using the side flat die assembly 3 and the concave die 1 effectively prevents material accumulation and wrinkling at the edge of the first forming cavity 11. Simultaneously, the anti-slip design on the outer bending side 83 and the lubrication design on the inner bending side 84 of the punch 4 effectively improves the quality of the formed tube 82. Furthermore, the segmented die design not only reduces the difficulty of die manufacturing and shortens the die manufacturing cycle, but also makes it easier to remove the formed tube 82 from the punch 4, greatly improving production efficiency. The forming process of this application is simple to operate; manufacturing can begin simply by placing the cut slab 8 in the first slab limiting member 212 and the second slab limiting member 222, reducing labor costs and requiring less skill from the operator. After adjusting the parameters, the forming quality is stable and well-affected by the operator's skill level. The forming speed is fast and the efficiency is high.

[0051] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A bending forming device, characterized in that, include: A die has a first forming cavity, a first guide groove, and a second guide groove. The first forming cavity extends along a first direction, and the first guide groove and the second guide groove both extend along a second direction, which is perpendicular to the first direction. The first guide groove and the second guide groove are respectively disposed on both sides of the first forming cavity, and the first guide groove and the second guide groove are both connected to the first forming cavity. The limiting device includes a first limiting component and a second limiting component. The first limiting component and the second limiting component are respectively disposed above the first guide groove and the second guide groove. The first limiting component and the second limiting component are disposed opposite to each other and are used to support the two ends of the slab respectively. A side mold assembly includes a first side mold and a second side mold, wherein the first side mold is slidably disposed in a first guide groove, and the second side mold is slidably disposed in the second guide groove, wherein the first side mold is configured to be flush with one side edge of the first molding cavity, and the second side mold is configured to be flush with the other side edge of the first molding cavity; A punch is disposed above the first forming cavity. The punch can be driven to move toward or away from the die so that the punch enters or exits the first forming cavity. The punch and the side flat die assembly cooperate to bend the blank to fit with the first forming cavity and form an intermediate part. The side die head assembly includes a first side die head and a second side die head. The first side die head is slidably disposed in the first guide groove, and the second side die head is slidably disposed in the second guide groove. The first side die head and the second side die head are used to bend the intermediate part to obtain a formed tube.

2. The bending forming device according to claim 1, characterized in that, The first limiting component includes a first side mold limiting member and a first slab limiting member. The first side mold limiting member is disposed above the first guide groove, and the first slab limiting member is disposed on the top surface of the first side mold limiting member. The second limiting component includes a second side mold limiting member and a second slab limiting member. The second side mold limiting member is disposed above the second guide groove, and the second slab limiting member is disposed on the top surface of the second side mold limiting member.

3. The bending forming device according to claim 2, characterized in that, The first side mold limiting member has a first limiting hole, which is provided through the first side mold limiting member along the second direction. The first limiting hole is used to limit the first side flat mold and the first side mold head. The second side mold limiting member has a second limiting hole, which is provided through the second side mold limiting member along the second direction. The second limiting hole is used to limit the second side flat mold and the second side mold head.

4. The bending forming apparatus according to claim 2, characterized in that, The first slab limiting member has a first limiting groove, which is used to limit one end of the slab. The second slab limiting member has a second limiting groove, which is used to limit the other end of the slab.

5. The bending forming apparatus according to claim 1, characterized in that, It also includes a side mold rod assembly, which includes a first side mold rod and a second side mold rod, wherein the first side mold rod is configured to connect to the first side mold head or the first side flat mold, and the second side mold rod is configured to connect to the second side mold head or the second side flat mold.

6. The bending forming apparatus according to claim 1, characterized in that, It also includes a connecting component, which is detachably connected to the punch and is used to move the punch.

7. The bending forming apparatus according to claim 6, characterized in that, The connecting assembly includes a first pad and two connecting plates. The two connecting plates are disposed on the bottom surface of the first pad and are respectively connected to both sides of the punch.

8. The bending forming apparatus according to claim 7, characterized in that, It also includes a second pad, on which the die is disposed. The second pad has two positioning grooves, which are located on both sides of the die. The connecting plate is inserted into the positioning groove to position the punch relative to the die.

9. A bending forming method, said method using the bending forming apparatus as described in any one of claims 1-8, characterized in that, The method includes: Pre-bending preparation: Move the first side flat mold to one side edge of the first forming cavity, and make the side of the first side flat mold facing the second side flat mold flush with one side edge of the first forming cavity. Move the second side flat mold to the other side edge of the first forming cavity, and make the side of the second side flat mold facing the first side flat mold flush with the other side edge of the first forming cavity. Bending and forming of the slab: The two ends of the slab are placed on the first slab limiting member and the second slab limiting member, respectively. The punch moves toward the die to enter the first forming cavity and bend the slab to fit against the first forming cavity. After obtaining the intermediate part, the first side flat die and the second side flat die are respectively removed from the first guide groove and the second guide groove. Then, the first side die head and the second side die head enter the first guide groove and the second guide groove, respectively. The first side die head and the second side die head move along the first side die limiting member and the second side die limiting member, respectively, to bend the intermediate part toward the punch to form the formed tube. After obtaining the formed tube, the first side die head and the second side die head are removed, and the punch is driven to move away from the die. Then, the punch is removed and the formed tube is taken out.

10. A bending forming method according to claim 9, characterized in that, The pre-bending preparation step is preceded by the following steps: An anti-slip agent is applied to the outer curved side of the punch and the inner wall of the first forming cavity, and a lubricant is applied to the inner curved side of the punch.

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