Push-bending device and method

Abstract

The application discloses a push-bending forming device and a method thereof. The device comprises a workbench, a die main body, a push-bending assembly and two support assemblies. One of the two support assemblies is located at one end of a forming cavity, and the other support assembly is located at the other end of the forming cavity. The support assembly comprises a fixed base, a moving base, a clamping assembly and a guide assembly. The clamping assembly is arranged on the moving base and is used for clamping and fixing a push head or a flexible top rod. The fixed base is fixedly arranged on the workbench. The guide assembly is connected between the fixed base and the moving base and is used for limiting the movement of the moving base along the feeding direction of a pipe blank. The device only needs to make the end faces of the push head and the push cylinder and the flexible top rod and the top cylinder parallel and fit, so that the assembly difficulty is greatly reduced, the transmission and accumulation of errors in the assembly are reduced, and the assembly precision is improved.

Description

Technical Field

[0001] This invention relates to the technical field of pipe bending forming, and particularly to a bending forming device and method. Background Technology

[0002] Aluminum alloy thin-walled tubes with small bending radius (usually referring to tubes with a wall thickness to outer diameter ratio of less than 0.05 and a bending radius to outer diameter ratio of less than 1.5) have advantages such as light weight, high strength, good corrosion resistance, and compact structure, and are widely used in pipeline systems in aviation, aerospace, and automotive fields.

[0003] Traditional push-bending forming devices require aligning the push cylinder and its flange with the central axis of the mold cavity, as well as the top cylinder and its flange, to achieve proper assembly positioning. During assembly, the positions of the push cylinder and top cylinder are first fixed. Then, the mold is moved so that both ends of the mold cavity align with the central axes of the push cylinder and top cylinder, respectively. The mold is then fixed, and the unfixed cylinder is moved to align with the central axis of the mold cavity. Finally, the push head and flexible ejector rod are fixed to the piston rods of the push cylinder and top cylinder, respectively, using flanges to complete the assembly. This assembly method involves complex fits between the push cylinder, ejector rod, mold cavity, push head, and flexible ejector rod, making it prone to error transmission. Furthermore, the accuracy of the fit depends entirely on visual observation, requiring a high level of operator skill and making assembly deviations highly likely. The push head or flexible ejector rod is prone to misalignment during experiments, potentially damaging the mold. Additionally, the high weight of the hydraulic cylinder and mold makes movement difficult, resulting in low assembly efficiency and significantly extending the experimental cycle. 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 device, comprising: Workbench; The mold body is set on the worktable, and the mold body has a forming cavity, in which the tube blank is placed; A push-bending assembly includes a push head, a flexible push rod, a push cylinder, and a top cylinder. The push head and the flexible push rod are both disposed within the forming cavity, and the push head and the flexible push rod respectively abut against both ends of the tube blank. The push cylinder is disposed at one end of the forming cavity and is configured to abut against the push head. The top cylinder is disposed at the other end of the forming cavity and is configured to abut against the flexible push rod. Two support assemblies, one of which is located at one end of the molding cavity and configured to clamp and fix the push head, and the other of which is located at the other end of the molding cavity and configured to clamp and fix the flexible push rod; The support assembly includes a fixed base, a movable base, a clamping assembly, and a guiding assembly. The clamping assembly is disposed on the movable base and is used to clamp and fix the pusher or the flexible push rod. The fixed base is fixedly disposed on the worktable. The guiding assembly is connected between the fixed base and the movable base and is used to restrict the movable base from moving along the feed direction of the tube blank.

[0006] Optionally, the guide assembly includes a telescopic rod and two ball joints, one end of which is connected to the fixed base via one of the ball joints, and the other end of which is connected to the movable base via the other ball joint.

[0007] Optionally, the movable base includes a movable part and a lifting part. The movable part is disposed at the bottom of the lifting part and can move along the worktable. The lifting part can rise and fall along its own axis.

[0008] Optionally, the support assembly further includes a connecting rod, one end of which is connected to the clamping assembly, and the other end of which is connected to the movable base.

[0009] Optionally, in each of the support components, there are two fixed bases, two guide components, two movable bases, and two connecting rods. The two connecting rods are respectively disposed at both ends of the clamping component. The two movable bases are respectively connected to the two connecting rods. One guide component is connected between one movable base and one fixed base, and the other guide component is connected between another movable base and another fixed base. The two fixed bases are arranged opposite to each other.

[0010] Optionally, the clamping assembly includes a first flange, a second flange, and a fastener. The first flange and the second flange are disposed opposite to each other and are fixedly connected by the fastener. The first flange and the second flange enclose a clamping hole, which is used to clamp and fix the pusher or the flexible push rod.

[0011] Optionally, the tube blank may also include a filling medium comprising two first medium segments having a first hardness and a second medium segment having a second hardness. The two first medium segments are respectively filled at both ends of the tube blank, and the second medium segment is filled in the middle portion of the tube blank and located between the two first medium segments. The first hardness is greater than the second hardness.

[0012] A push-bending forming method, using the above-mentioned push-bending forming device, the method includes the following steps: The pusher and the flexible push rod are placed inside the molding cavity; Place the two support components on the worktable, adjust the position and height of the movable base in each support component so that the clamping component clamps the push head and the flexible push rod respectively, then fix the fixed base in each support component on the worktable. After fixing the two fixed bases, retract the movable base and move the push head to the initial forming position. The second medium segment is filled into the middle part of the tube blank, and the two first medium segments are respectively filled into both ends of the tube blank. Then the tube blank is placed in the forming cavity. The push cylinder and the top cylinder are respectively attached to one end face of the push head and the flexible push rod, so that the piston rods of the push cylinder and the top cylinder are in parallel contact with the end faces of the push head and the flexible push rod, respectively. The push cylinder and the top cylinder are driven, the push head pushes the tube blank and the filling medium along the feed direction, and the flexible push rod applies a reverse force to expand the filling medium and provide support for the inner wall of the tube blank. During the forming process, the fixed base of each of the support components is fixedly set on the worktable, and the movable base and the clamping assembly move synchronously along the feed direction under the drive of the push head or the flexible push rod. After forming is completed, the push cylinder and the top cylinder are retracted, the clamping assembly is released, and the formed tube is taken out.

[0013] Optionally, in the filled state, the thickness of the first medium segment on the side close to the outer side of the tube blank bend is greater than the thickness of the first medium segment on the inner side of the tube blank bend, so that the support force provided by the first medium segment to the outer side of the tube blank bend is greater than the support force provided to the inner side of the tube blank bend.

[0014] Optionally, the pusher has a first inclined surface at one end near the tube blank, and one end of one of the first medium segments has a second inclined surface adapted to the first inclined surface to achieve complete contact between the pusher and the end face of the first medium segment. The flexible push rod has a third inclined surface at one end near the tube blank, and another end of the first medium segment has a fourth inclined surface adapted to the third inclined surface to achieve complete contact between the flexible push rod and the end face of the first medium segment.

[0015] This application employs two support components. The clamping components of these two components respectively clamp and fix the pusher head and the flexible ejector rod. A fixed base is fixed to the worktable. A guiding component restricts the movement of the base and clamping components to the direction of tube blank feed. This ensures that the pusher head or flexible ejector rod always moves along the tube blank feed direction during tube blank forming without deviation. Therefore, the push-bending forming device of this application does not require the pusher head and push cylinder to be coaxially aligned, nor does it require the flexible ejector rod and top cylinder to be coaxially aligned. Power transmission during the tube blank push-bending forming process is achieved simply by the push cylinder and pusher head abutting, and the top cylinder and flexible ejector rod abutting. Compared to the strict coaxiality requirements between the push cylinder and pusher head, and between the flexible ejector rod and top cylinder in traditional push-bending devices, the device of this application only requires parallel contact of the end faces, significantly reducing assembly difficulty, minimizing the transmission and accumulation of assembly errors, and improving assembly accuracy. Furthermore, since the pusher head and flexible ejector rod are not fixed to the push cylinder and top cylinder, they can be quickly detached after forming, resulting in faster and safer pressure relief. 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 overall structure of the bending forming device in one embodiment; Figure 2 This is a partial structural schematic diagram of the bending forming device in one embodiment; Figure 3 This is a schematic diagram of the support assembly of the bending device in one embodiment; Figure 4 This is a partial structural diagram of the support component in one embodiment; Figure 5 This is a schematic diagram of the workbench and lower pad in one embodiment; Figure 6 This is a schematic diagram of the pusher and flexible push rod in one embodiment; Figure 7 This is a schematic diagram of the push-bending forming process in one embodiment; Figure 8 This is a schematic diagram of the filling medium and tube blank in one embodiment; 1. Workbench; 11. Limiting block; 12. Groove; 2. Mold body; 21. Forming cavity; 211. Input section; 212. Bending section; 213. Output section; 22. Lower mold; 23. Lower pad; 3. Bending assembly; 31. Push head; 311. First inclined plane; 32. Flexible ejector rod; 321. Third inclined plane; 33. Push cylinder; 34. Top cylinder; 4. Support assembly; 41. Fixed base; 411. Fixed seat; 412. Magnetic seat; 42. Movable base; 421. Movable part; 422. Lifting part; 43. Clamping assembly; 431. First flange; 432. Second flange; 433. Fixing element; 44. Guide assembly; 441. Telescopic rod; 442. Ball joint; 443. Ball head; 444. Ball socket; 45. Connecting rod; 5. Filling medium; 51. First medium section; 52. Second medium section; 53. Second inclined surface; 54. Fourth inclined surface; 6. Tube blank.

[0018] 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

[0019] 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.

[0020] 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.

[0021] 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.

[0022] refer to Figures 1 to 8This application provides a push-bending forming device, which includes a worktable 1, a mold body 2, a push-bending assembly 3, and two support assemblies 4. The mold body 2 is disposed on the worktable 1 and has a forming cavity 21, in which a tube blank 6 is disposed. The push-bending assembly 3 includes a push head 31, a flexible push rod 32, a push cylinder 33, and a top cylinder 34. The push head 31 and the flexible push rod 32 are both disposed in the forming cavity 21 and abut against both ends of the tube blank 6, respectively. The push cylinder 33 is disposed at one end of the forming cavity 21 and is configured to abut against the push head 31 to push the tube blank 6 to move along the forming cavity 21. The top cylinder 34 is disposed at the other end of the forming cavity 21. The top cylinder 34 is configured to abut against the flexible push rod 32; one of the support components 4 is located at one end of the forming cavity 21 and is configured to clamp and fix the push head 31, and the other support component 4 is located at the other end of the forming cavity 21 and is configured to clamp and fix the flexible push rod 32. The support component 4 includes a fixed base 41, a movable base 42, a clamping component 43 and a guide component 44. The clamping component 43 is disposed on the movable base 42 and is used to clamp and fix the push head 31. The fixed base 41 is fixedly disposed on the worktable 1. The guide component 44 is connected between the fixed base 41 and the movable base 42 and is used to restrict the movable base 42 from moving along the feed direction of the tube blank 6.

[0023] This application provides two support components 4, with clamping components 43 of the two support components 4 clamping and fixing the push head 31 and the flexible push rod 32 respectively. The fixed base 41 is fixed to the worktable 1. The guide component 44 restricts the movement of the moving base 42 and the clamping component 43 to only move along the feed direction of the tube blank 6, thereby ensuring that the push head 31 or the flexible push rod 32 always moves along the feed direction of the tube blank 6 during the tube blank 6 forming process and will not deviate. Therefore, the push bending forming device of this application does not require the push head 31 and the push cylinder 33 to be coaxially arranged, or the flexible push rod 32 and the top cylinder 34 to be coaxially arranged. The power transmission during the push bending forming process of the tube blank 6 can be realized simply by the push cylinder 33 and the push head 31 abutting, and the top cylinder 34 and the flexible push rod 32 abutting. Compared to the strict coaxiality requirements between the push cylinder 33 and push head 31, and between the flexible push rod 32 and the top cylinder 34 in traditional push bending devices, the device of this application only requires parallel contact of the end faces, which greatly reduces the assembly difficulty, reduces the transmission and accumulation of errors during assembly, and improves assembly accuracy. In addition, since the push head 31 and the flexible push rod 32 are not fixed to the push cylinder 33 and the top cylinder 34, they can be quickly detached after forming, resulting in faster and safer pressure relief.

[0024] For details, please refer to Figure 7The forming cavity 21 has an input section 211, a bending section 212, and an output section 213. The input section 211 and the output section 213 are respectively connected and disposed at both ends of the bending section 212. The tube blank 6 can be driven to enter the bending section 212 through the input section 211 and then move to the output section 213. The pusher 31 can enter the forming cavity 21 through the input section 211 and push the tube blank 6 to move along the forming cavity 21. The flexible push rod 32 is disposed in the output section 213. The guide component 44 of the support component 4 for clamping and fixing the pusher 31 is used to limit the axial movement of the moving base 42 along the input section 211. The guide component 44 of the support component 4 for clamping and fixing the flexible push rod 32 is used to limit the axial movement of the moving base 42 along the output section 213.

[0025] For details, please refer to Figure 2 The mold body 2 includes a lower mold 22 and a lower backing plate 23, which are fixedly connected by bolts. Furthermore, the mold body 2 also includes an upper mold, which is connected to the lower mold 22 to form a molding cavity 21.

[0026] refer to Figure 5 The bending forming device also includes a limiting block 11. The worktable 1 and the lower pad 23 are both provided with grooves 12. The limiting block 11 is set in the groove 12 to realize the positioning of the lower pad 23 and the worktable 1.

[0027] Specifically, the groove 12 is rectangular in shape, and the four sides of the groove 12 are parallel to the four sides of the worktable 1, ensuring that the end face of the mold body 2 is parallel to the end face of the piston rod of the push cylinder 33 and the top cylinder 34, respectively.

[0028] Specifically, both push cylinder 33 and top cylinder 34 are hydraulic cylinders.

[0029] For details, please refer to Figure 4 The fixed base 41 includes a fixed base 411 and a magnetic base 412. The fixed base 411 and the magnetic base 412 are connected by bolts, and the fixed base 411 is fixed to the worktable 1 by the magnetic base 412. Furthermore, the worktable 1 is made of metal and can be attracted by the magnetic base 412.

[0030] refer to Figure 3 and Figure 4 The guide assembly 44 includes a telescopic rod 441 and two ball joints 442. One end of the telescopic rod 441 is connected to the fixed base 41 through one of the ball joints 442, and the other end is connected to the movable base 42 through the other ball joint 442.

[0031] Specifically, the spherical connector 442 includes a ball head 443 and a ball socket 444. The ball head 443 is disposed in the ball socket 444, and the ball socket 444 is rotatable relative to the ball head 443. The ball head 443 is fixedly disposed on the top of the fixed base 41 or the movable base 42, and the ball socket 444 is disposed at one end of the telescopic rod 441.

[0032] refer to Figure 4 The movable base 42 includes a movable part 421 and a lifting part 422. The movable part 421 is disposed at the bottom of the lifting part 422. The movable part 421 can move along the worktable 1, and the lifting part 422 can rise and fall along its own axis.

[0033] Specifically, the moving part 421 includes two wheels, which are respectively disposed on both sides of the lifting part 422. The lifting part 422 is a hydraulic cylinder. Through the connection of the ball joint 442, the telescopic rod 441 can maintain the connection between the fixed base 41 and the lifting part 422 of the moving base 42 while the fixed base 41 remains at a constant height, and the lifting part 422 of the moving base 42 moves up and down along its own axis. Under the traction of the telescopic rod 441, the flange can be moved along the feed direction of the tube blank 6, and the height of the flange can be adjusted by adjusting the height of the moving base 42.

[0034] refer to Figure 3 The support assembly 4 also includes a connecting rod 45, one end of which is fixedly connected to the clamping assembly 43, and the other end of which is fixedly connected to the movable base 42. By providing the connecting rod 45, the clamping assembly 43 can extend to the location of the pusher 31 or the flexible ejector 32 for clamping, while the movable base 42 can be flexibly arranged in the lateral space of the molding cavity 21, avoiding interference with the pusher cylinder 33, the ejector cylinder 34, or the mold body 2.

[0035] refer to Figures 1 to 4 Each support component 4 has two fixed bases 41, two guide components 44, two movable bases 42, and two connecting rods 45. The two connecting rods 45 are respectively disposed at both ends of the clamping component 43. The two movable bases 42 are respectively connected to the two connecting rods 45. One guide component 44 is connected between one movable base 42 and one fixed base 41, and the other guide component 44 is connected between another movable base 42 and another fixed base 41. The two fixed bases 41 are arranged opposite to each other.

[0036] Specifically, the two fixed bases 41, the two guide components 44, and the two movable bases 42 are all symmetrically arranged on the worktable 1 about the axis of the pusher 31.

[0037] refer to Figure 3The clamping assembly 43 includes a first flange 431, a second flange 432, and a fastener 433. The first flange 431 and the second flange 432 are arranged opposite to each other and are fixedly connected by the fastener 433. The first flange 431 and the second flange 432 enclose each other to form a clamping hole, which is used to clamp and fix the push head 31 or the flexible push rod 32.

[0038] Specifically, the inner wall of the clamping hole has a stepped surface, which is used to cooperate with the corresponding step or flange on the push head 31 or the flexible push rod 32 to limit the push head 31 or the flexible push rod 32 in the axial direction.

[0039] refer to Figures 6 to 8 The bending forming device also includes a filling medium 5, which is disposed inside the tube blank 6. The pusher 31 is configured to abut against one end of the tube blank 6 and drive the tube blank 6 to move along the forming cavity 21. One end of the flexible push rod 32 is configured to extend into the other end of the tube blank 6 to squeeze the filling medium 5, so that the filling medium 5 expands and supports the inner wall of the tube blank 6.

[0040] Specifically, the filling medium 5 includes two first medium segments 51 and a second medium segment 52. The two first medium segments 51 are respectively disposed at both ends of the tube blank 6, and the second medium segment 52 is disposed in the middle part of the tube blank 6 and located between the two first medium segments 51. The first medium segment 51 has a first hardness, and the second medium segment 52 has a second hardness, and the first hardness is greater than the second hardness.

[0041] In this embodiment, both the first medium segment 51 and the second medium segment 52 are polyurethane rubber. The first medium segment 51 has a Shore hardness of 90A and a cross-sectional shape of a right trapezoid. The filling method is that the thicker side of the rubber is close to the outer side of the bend of the tube blank 6, and the thinner side of the rubber is close to the inner side of the bend of the tube blank 6. The second medium segment 52 includes multiple cylindrical rubbers with a Shore hardness of 80A and a thickness of 12mm.

[0042] Existing push-bending forming devices use polyurethane rubber as the filling medium 5 during the forming process. The thrust of the pusher 31 causes the tube blank 6 and the polyurethane rubber to feed. Under the interaction of the thrust of the pusher 31 and the flexible push rod 32, the polyurethane rubber is squeezed and expanded, providing support for the tube wall and reducing defects such as instability, wrinkling, and cross-sectional distortion during the forming process. Traditional push-bending processes generally use rubber blocks of the same thickness and hardness as the filling medium 5. However, due to the different stress and deformation degrees of different parts of the tube blank 6, different rubbers with different properties are often required at different positions such as the front and rear ends and the middle, the inner and outer sides of the tube blank 6. If only uniform filling is performed, defects are easily generated during the forming process. If the filling rubber has high hardness, the rubber in the middle of the bend section needs greater internal pressure to expand and provide support, but the large internal pressure can easily damage the various push-bending components. If the filling rubber has low hardness, although the rubber in the middle position is easy to expand, the front and rear ends of the tube blank 6 are subjected to greater stress and deformation. If the rubber is too soft, it is difficult to provide support, and the front and rear ends of the tube blank 6 are prone to collapse. If the rubber thickness is large, during bending, large gaps will form between the rubber sections at the bends with greater deformation, making it unable to support the tube blank 6 and prone to wrinkling. If thin rubber is used, the thinner rubber is more easily damaged when directly subjected to a large pushing force, making it difficult to provide adequate support. Since the outer side of the tube blank 6 contains significantly more material than the inner side during the forming process, the outer side of the tube blank 6 requires more filling medium 5 than the inner side to ensure that the inner side is not difficult to expand due to excessive rubber while the outer side is adequately supported.

[0043] This application effectively solves the problem that traditional uniform filling cannot adapt to the differentiated stress requirements of different parts of the tube blank 6 by using differentiated filling medium 5 inside the tube blank 6. By filling the two ends of the tube blank 6 with a first medium section 51 with higher hardness, strong support can be provided for the end areas of the tube blank 6 with large stress and deformation, preventing the ends of the tube blank 6 from collapsing. The middle part of the tube blank 6 is filled with a second medium section 52 with lower hardness, so that the rubber in the middle part can expand and play a supporting role under lower internal pressure, avoiding damage to the bending components due to excessive internal pressure. At the same time, the first medium section 51 adopts a right-angled trapezoidal structure with a thicker outer side and a thinner inner side, so that the outer side of the tube blank 6 receives more filling medium 5 than the inner side, which is adapted to the deformation characteristics of the outer side of the tube blank 6 having more material than the inner side, ensuring that the outer side is fully supported while the inner side is not difficult to expand due to excessive filling. The second medium section 52 adopts a cylindrical structure, which can uniformly fill the middle bending section 212 during the bending process, avoiding wrinkling caused by the inability to support the tube blank 6 due to excessive gaps in the rubber parts. Therefore, through the above-mentioned synergistic cooperation, this application jointly suppresses the common defects of front end collapse and wrinkling of the bending section 212 in push bending forming, and significantly improves the forming quality.

[0044] This application also provides a bending method using the above-described bending forming apparatus, the method comprising the following steps: S1. Install the limiting block 11 in the groove 12 of the workbench 1, and then position the lower pad 23 by the cooperation of the groove 12 on the lower pad 23 and the limiting block 11. Position the lower mold 22 by aligning the threaded hole on the lower pad 23 with the countersunk threaded hole on the lower mold 22, and connect and fix the lower mold 22 and the lower pad 23 with bolts. S2. Select a flexible push rod 32 that matches the inner diameter of the tube blank 6. Use a wire cutting machine to cut off a portion of one end of the flexible push rod 32 at an angle of α, so that the end face of the flexible push rod 32 away from the push cylinder 34 is completely in contact with the end face of the first medium section 51. Select a push head 31 that matches the inner diameter of the tube blank 6. Use a wire cutting machine to cut off a portion of one end of the push head 31 at an angle of β, so that the end face of the push head 31 away from the push cylinder 33 is completely in contact with the end face of the other first medium section 51.

[0045] Specifically, the pusher 31 includes a first section and a second section. The first section is located at the front end of the tube blank 6 and occupies one-third of the total length of the pusher 31. The outer diameter of the first section matches the inner diameter of the tube blank 6, and is used to conform to the inner wall of the tube blank 6 and push the tube blank 6 forward during forming. The second section occupies two-thirds of the total length of the pusher 31. The outer diameter of the second section is 2-4 mm smaller than that of the first section, so that the second section is suspended and does not directly contact the forming cavity 21. This reduces the friction area between the pusher 31 and the forming cavity 21, reduces the movement resistance, and protects the forming cavity 21 and the pusher 31 themselves from being scratched.

[0046] S3. Place the pusher 31 and the flexible push rod 32 into the molding cavity 21. At this time, the axis of the pusher 31 coincides with the central axis of the input section 211 of the molding cavity 21, and the axis of the flexible push rod 32 coincides with the central axis of the output section 213 of the molding cavity 21, thus completing the positioning of the pusher 31 and the flexible push rod 32. Place the two support components 4 on the worktable 1, adjust the position and height of the movable base 42 in each support component 4 so that the clamping component 43 clamps the push head 31 and the flexible push rod 32 respectively, then turn on the magnetic base 412 to fix the fixed base 41 in each support component 4 on the worktable 1. After fixing the two fixed bases 41, retract the movable base 42 and move the push head 31 to the initial forming position. The second medium segment 52 is filled into the middle part of the tube blank 6, and the two first medium segments 51 are filled into the two ends of the tube blank 6 respectively. Then the tube blank 6 is placed in the forming cavity 21. At this time, the pusher 31 and the flexible push rod 32 are in the initial position. After the mold body 2 is closed, the push cylinder 33 and the top cylinder 34 are respectively attached to one end face of the push head 31 and the flexible push rod 32, so that the piston rods of the push cylinder 33 and the top cylinder 34 are in parallel contact with the end faces of the push head 31 and the flexible push rod 32, respectively, driving the push cylinder 33 and the top cylinder 34. The push head 31 pushes the tube blank 6 and the filling medium 5 along the feed direction, and the flexible push rod 32 applies a reverse force, causing the filling medium 5 to expand and provide support for the inner wall of the tube blank 6. During the forming process, the fixed base 41 of each support component 4 is fixedly set on the worktable 1, and the moving base 42 and the clamping component 43 move synchronously along the feed direction under the drive of the push head 31 or the flexible push rod 32. After forming is completed, push cylinder 33 and top cylinder 34 are returned to their initial positions, clamping assembly 43 is released, mold is opened and the formed tube is taken out, the filling medium 5 inside the tube is removed, and the excess part of the tube is cut off.

[0047] Specifically, in the filled state, the thickness of the first medium segment 51 on the side close to the outer side of the bend of the tube blank 6 is greater than the thickness of the first medium segment 51 on the inner side of the bend of the tube blank 6, so that the supporting force provided by the first medium segment 51 to the outer side of the bend of the tube blank 6 is greater than the supporting force provided to the inner side of the bend of the tube blank 6.

[0048] Specifically, the pusher 31 has a first inclined surface 311 at one end near the tube blank 6, and one end of one of the first medium sections 51 has a second inclined surface 53 that matches the first inclined surface 311 to achieve complete fit between the end faces of the pusher 31 and the first medium section 51. The flexible push rod 32 has a third inclined surface 321 at one end near the tube blank 6, and one end of the other first medium section 51 has a fourth inclined surface 54 that matches the third inclined surface 321 to achieve complete fit between the end faces of the flexible push rod 32 and the first medium section 51.

[0049] In summary, this application simplifies the assembly process of the push-bending forming device. It simplifies the coordination between the push cylinder 33, top cylinder 34, forming cavity 21, flange, push head 31, and flexible push rod 32, reducing the transmission and accumulation of positioning errors and improving assembly accuracy. The piston rods of the push cylinder 33 and top cylinder 34 do not need to be coaxial with the push head 31 and flexible push rod 32; only parallel end faces are required. Therefore, when the piston rod is in complete contact with the end face of the pusher head 31 or the flexible ejector rod 32, when changing the mold body 2 of different sizes, there is no need to adjust the position of the pusher cylinder 33 and the ejector cylinder 34. The pusher head 31 and the flexible ejector rod 32 only need to be re-clamped and positioned by the support assembly 4 to adapt to the molding cavity 21 of the new mold body 2. When changing the ejector cylinder 34 and pusher cylinder 33 with different center heights, there is no need to disassemble the mold body 2 or add or remove the lower pad 23. The adaptation can be completed simply by adjusting the height of the moving base 42, significantly improving assembly efficiency and device versatility. During cylinder retraction, since the pusher head 31 and the flexible ejector rod 32 are not directly fixed to the pusher cylinder 33 and the ejector cylinder 34, they can quickly detach from the piston rod, resulting in faster and safer pressure reduction.

[0050] Furthermore, the pusher head 31 and flexible push rod 32 of this application increase the contact area with the first medium section 51, which enables the rubber to be subjected to more uniform force during the molding process and reduces the risk of the tube blank 6 becoming unstable due to uneven force causing the rubber to tilt. At the same time, the rear end of the pusher head 31 is suspended, which reduces the contact area between the pusher head 31 and the molding cavity 21 and reduces the damage to the pusher head 31 and the mold body 2 caused by friction during the molding process.

[0051] The present invention employs a method of using a differentiated filling medium 5, which uses filling medium 5 of different thicknesses, hardnesses and shapes in the middle part and the front and rear ends of the tube blank 6 to meet the condition that the outer side of the tube blank 6 is required to have more rubber than the inner side of the bend, thus solving the problem that the front and rear ends of the tube blank 6 are prone to collapse and the middle bending section 212 is prone to wrinkling.

[0052] 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: Workbench; The mold body is set on the worktable, and the mold body has a forming cavity, in which the tube blank is placed; A push-bending assembly includes a push head, a flexible push rod, a push cylinder, and a top cylinder. The push head and the flexible push rod are both disposed within the forming cavity, and the push head and the flexible push rod respectively abut against both ends of the tube blank. The push cylinder is disposed at one end of the forming cavity and is configured to abut against the push head. The top cylinder is disposed at the other end of the forming cavity and is configured to abut against the flexible push rod. Two support assemblies, one of which is located at one end of the molding cavity and configured to clamp and fix the push head, and the other of which is located at the other end of the molding cavity and configured to clamp and fix the flexible push rod; The support assembly includes a fixed base, a movable base, a clamping assembly, and a guiding assembly. The clamping assembly is disposed on the movable base and is used to clamp and fix the pusher or the flexible push rod. The fixed base is fixedly disposed on the worktable. The guiding assembly is connected between the fixed base and the movable base and is used to restrict the movable base from moving along the feed direction of the tube blank. The guide assembly includes a telescopic rod and two spherical connectors. One end of the telescopic rod is rotatably connected to the fixed base through one of the spherical connectors, and the other end is rotatably connected to the movable base through the other spherical connector. In each of the support components, there are two fixed bases, two guide components, and two movable bases. The two movable bases are respectively disposed at both ends of the clamping component. One guide component is connected between one movable base and one fixed base, and the other guide component is connected between another movable base and another fixed base. The two fixed bases are disposed opposite to each other.

2. The bending forming device according to claim 1, characterized in that, The movable base includes a movable part and a lifting part. The movable part is disposed at the bottom of the lifting part. The movable part can move along the worktable, and the lifting part can rise and fall along its own axis.

3. The bending forming device according to claim 1, characterized in that, The support assembly further includes a connecting rod, one end of which is connected to the clamping assembly, and the other end of which is connected to the movable base.

4. The bending forming device according to claim 3, characterized in that, In each of the support components, there are two connecting rods, which are respectively disposed at both ends of the clamping component, and the two movable bases are respectively connected to the two connecting rods.

5. The push-bending forming device according to claim 1, characterized in that, The clamping assembly includes a first flange, a second flange, and a fastener. The first flange and the second flange are arranged opposite to each other and are fixedly connected by the fastener. The first flange and the second flange enclose a clamping hole, which is used to clamp and fix the push head or the flexible push rod.

6. The bending forming device according to claim 1, characterized in that, It also includes a filling medium, which comprises two first medium segments having a first hardness and a second medium segment having a second hardness. The two first medium segments are respectively filled at both ends of the tube blank, and the second medium segment is filled in the middle part of the tube blank and located between the two first medium segments. The first hardness is greater than the second hardness.

7. A push-bending forming method, using the push-bending forming apparatus according to claim 6, characterized in that, The method includes: The pusher and the flexible push rod are placed inside the molding cavity; Place the two support components on the worktable, adjust the position and height of the movable base in each support component so that the clamping component clamps the push head and the flexible push rod respectively, then fix the fixed base in each support component on the worktable. After fixing the two fixed bases, retract the movable base and move the push head to the initial forming position. The second medium segment is filled into the middle part of the tube blank, and the two first medium segments are respectively filled into the two ends of the tube blank. Then the tube blank is placed in the forming cavity. The push cylinder and the top cylinder are respectively attached to one end face of the push head and the flexible push rod, so that the piston rods of the push cylinder and the top cylinder are in parallel contact with the end faces of the push head and the flexible push rod, respectively. The push cylinder and the top cylinder are driven, the push head pushes the tube blank and the filling medium along the feed direction, and the flexible push rod applies a reverse force to expand the filling medium and provide support for the inner wall of the tube blank. During the forming process, the fixed base of each of the support components is fixedly set on the worktable, and the movable base and the clamping assembly move synchronously along the feed direction under the drive of the push head or the flexible push rod. After forming is completed, the push cylinder and the top cylinder are retracted, the clamping assembly is released, and the formed tube is taken out.

8. The push-bending forming method according to claim 7, characterized in that, In the filled state, the thickness of the first medium segment close to the outer side of the tube blank bend is greater than the thickness of the first medium segment close to the inner side of the tube blank bend, so that the support force provided by the first medium segment to the outer side of the tube blank bend is greater than the support force provided to the inner side of the tube blank bend.

9. The push-bending forming method according to claim 8, characterized in that, The pusher has a first inclined surface at one end near the tube blank, and one end of one of the first medium segments has a second inclined surface adapted to the first inclined surface to achieve complete contact between the pusher and the end face of the first medium segment. The flexible push rod has a third inclined surface at one end near the tube blank, and another end of the first medium segment has a fourth inclined surface adapted to the third inclined surface to achieve complete contact between the flexible push rod and the end face of the first medium segment.

Images