Mandrel of pipe bending machine

Abstract

The utility model relates to the technical field of pipe bending processing, in particular to a pipe bending machine core rod, which is characterized in that a plurality of round supporting plates with the same size and shape are designed to form a core rod assembly, and a movable seam exists between every two adjacent round supporting plates, so that the round supporting plates form a deflectable chain type structure through the movable seams; the mandrel assembly can be dynamically attached to pipe walls with different curvatures in the bending process, effective support is provided for the inner wall of a pipeline, and therefore the problems of deformation, wrinkling and the like when the pipeline is bent can be effectively solved, the springback phenomenon is reduced, and the machining precision is improved. The connecting movable pieces are movably connected into the middle connecting pieces in a telescopic mode, so that the movable seams between the adjacent circular supporting plates are adjustable. Therefore, when the bending angle of the pipeline is large, the movable seam between the adjacent circular supporting plates can be enlarged, and the adaptability is improved. And when the bending angle of the pipeline is small, the movable seam between the adjacent round supporting plates can be reduced, and therefore the supporting effect is improved.

Description

Technical Field

[0001] This utility model relates to the field of pipe bending technology, and in particular to a pipe bending mandrel. Background Technology

[0002] In machining workshops, bending pipes is a common processing operation. Because pipes are hollow, if the bent section lacks internal support, the cross-section may become elliptical or flattened after compression, especially noticeable in thin-walled pipes or small-radius bends. Furthermore, the inner side of the bend forms dense wrinkles due to material shrinkage, which can extend into the non-bent area in severe cases. This also leads to uncontrolled springback and precision deviations. Using a mandrel as internal support can effectively improve these issues.

[0003] The mandrel in a pipe bending machine is a core component in the pipe bending process, primarily used to support the inner wall of the metal pipe to prevent deformation and wrinkling during bending. It adheres closely to the inner wall of the pipe during bending, maintaining its shape through mechanical force and preventing cross-sectional collapse or wrinkle formation. This ensures that parameters such as the bending radius and angle conform to the preset trajectory, reducing the impact of springback on processing accuracy. Compared to traditional anti-deformation methods such as sand filling, mandrel operation is more convenient and yields superior results.

[0004] Pipe bending mandrels are designed differently depending on the type and functional requirements, but most types of pipe bending mandrels contain multiple moving parts. This design optimizes the accuracy, efficiency and adaptability of the pipe bending process.

[0005] There needs to be a certain gap between the various moving parts in the mandrel of the pipe bending machine. This allows each moving part to adjust its angle independently to adapt to different bending angles. It ensures that the mandrel can fit against the inner wall of the pipe in real time under various bending operations, reducing collapse or wrinkles caused by insufficient support during the bending process.

[0006] The problem is that if the gaps between the moving parts are too small, the range of angles that each moving part can adjust independently is small, thus limiting the overall bending angle of the mandrel and reducing its adaptability. On the other hand, if the gaps between the moving parts are too large, the supporting area of ​​the moving parts on the inner wall of the pipe will be smaller during the bending process, resulting in poorer support for the fabric and a decrease in the effectiveness of improving problems such as deformation and wrinkling. Utility Model Content

[0007] In view of this, the purpose of this utility model is to propose a mandrel for a tube bending machine to solve the technical problems in the prior art.

[0008] To achieve the above objectives, this utility model provides a mandrel for a pipe bending machine, comprising a mandrel assembly for supporting the inner wall of a pipe and a connecting rod fixedly connected to the end of the mandrel assembly. The other end of the connecting rod is disposed on the output shaft of a driving device for driving the telescopic movement of the mandrel assembly. The mandrel assembly further includes:

[0009] Several circular support plates of the same size and shape, with movable gaps between adjacent circular support plates;

[0010] An intermediate connector is located at the center of the inner part of the circular support plate. The circular support plate is fixedly connected to the intermediate connector. Connecting movable parts are movably connected to the front and rear sides of the intermediate connector. The connecting movable parts are hinged to another connecting movable part in the adjacent circular support plate.

[0011] A fixing mechanism located within the intermediate connector is used to secure the movable connecting part, preventing it from moving.

[0012] Furthermore, the circular support plate has an inner annular groove that runs through the front and back at its center, and the intermediate connecting member is located at the center of the inner annular groove.

[0013] Furthermore, each of the four side walls of the intermediate connector is fixedly connected to a fixed post, and the circular support plate is fixedly connected to the fixed post.

[0014] Furthermore, the upper half of the circular support plate has a uniform thickness, while the lower half of the circular support plate becomes thinner towards the bottom.

[0015] Furthermore, the thickness of the uppermost part of the lower half of the circular support plate is the same as that of the upper half of the circular support plate, which is 2-3cm, and the thickness of the lowermost part of the lower half of the circular support plate is 1-2cm.

[0016] Furthermore, the number of the circular support plates is 10-15 pieces, and they are arranged in a segmented manner, with the central axes of all the circular support plates in the unbent state being collinear.

[0017] Furthermore, the fixing mechanism includes a pressure plate and a fixing screw. The pressure plate is movably connected within the intermediate connecting member, and its lower end presses against the connecting movable member. The fixing screw is threadedly connected to the circular support plate and the intermediate connecting member, and its lower end presses against the pressure plate.

[0018] Furthermore, a groove is provided on the side wall of the circular support plate, and the tool mating part at the outer end of the fixing screw is located in the groove, and the tool mating part is provided with a cross groove or an internal hexagonal groove.

[0019] The beneficial effects of this utility model are as follows: 1. By designing several circular support plates of the same size and shape to form a mandrel assembly, and there is a movable gap between adjacent circular support plates, the circular support plates form a deflectable chain structure through the movable gap, so that the mandrel assembly can dynamically fit the pipe wall with different curvatures during the bending process, and provide an effective support for the inner wall of the pipe. Therefore, it can effectively improve the problems of deformation and wrinkling when the pipe is bent, and reduce the springback phenomenon and improve the processing accuracy.

[0020] 2. The circular support plate has an internal intermediate connector, with movable connecting parts on its front and rear sides. Adjacent circular support plates are hinged together via their respective movable connecting parts, enabling rotation. The movable connecting parts are retractable within the intermediate connector, allowing for adjustment of the gap between adjacent circular support plates. Therefore, when the pipe bending angle is large, the gap between adjacent circular support plates can be widened to improve adaptability. Conversely, when the pipe bending angle is small, the gap can be narrowed to enhance support effectiveness.

[0021] 3. A fixing mechanism is also provided within the intermediate connector to fix the movable connecting part and prevent it from moving. This creates a rigid connection between the movable connecting part and the intermediate connector, ensuring the stability of the entire mandrel assembly.

[0022] 4. Because the upper part of the mandrel assembly extends and the lower part contracts during bending, the thickness of the upper half of the circular support plate is set to be uniform, and the thickness of the uppermost part of the lower half of the circular support plate is the same as that of the upper half, while the thickness of the lower half of the circular support plate decreases towards the bottom. This ensures effective support while maximizing the bending angle of the mandrel assembly, thereby accommodating a wider range of bending radii. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in this utility model 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 for this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the overall structure and principle of the device of this utility model.

[0025] Figure 2 This is a schematic diagram illustrating the structural principle of the circular support plate in the device of this utility model.

[0026] Figure 3 This is a schematic diagram of the internal structure of the intermediate connecting member in the device of this utility model.

[0027] Figure 4This is a schematic diagram of the structural principle of the fixing mechanism in the device of this utility model.

[0028] The diagram is marked as follows:

[0029] 101. Mandrel assembly; 102. Movable joint; 103. Connecting rod; 104. Circular support plate; 105. Intermediate connector; 106. Fixed column; 107. Inner annular groove; 108. Connecting movable part; 109. Pressure plate; 110. Fixed screw. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments.

[0031] It should be noted that, unless otherwise defined, the technical or scientific terms used in this utility model should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0032] The first aspect of this utility model is as follows: Figure 1 , Figure 2 and Figure 3 As shown, a certain gap is required between the various moving parts in the mandrel of the pipe bending machine. This allows each moving part to be independently adjusted to adapt to different bending angles, ensuring that the mandrel can conform to the inner wall of the pipe in real time under various bending operations, reducing collapse or wrinkling caused by insufficient support during bending. Therefore, this solution designs a mandrel assembly 101 to support the inner wall of the pipe. The mandrel assembly 101 is composed of several circular support plates 104 of the same size and shape, and there is a movable gap 102 between adjacent circular support plates 104.

[0033] The mandrel assembly 101 is fixedly connected to a connecting rod 103 at one end. The other end of the connecting rod 103 is located on the output shaft of the drive device and is used to drive the mandrel assembly 101 to move telescopically. When the pipe is bent, the mandrel assembly 101 can be driven to move to the bending part and play a supporting role.

[0034] The mandrel assembly 101 is composed of several circular support plates 104 of the same size and shape. The adjacent circular support plates 104 are rotatably connected, and there is a movable seam 102 between the adjacent circular support plates 104. This allows each circular support plate 104 to form a deflectable chain structure through the movable seam 102, so that the mandrel assembly 101 can dynamically conform to the pipe wall with different curvatures during the bending process, providing effective support to the inner wall of the pipe. Therefore, it can effectively improve the problems of deformation and wrinkling when the pipe is bent, reduce springback and improve processing accuracy.

[0035] Preferably, the upper half of the circular support plate 104 has a uniform thickness, while the lower half of the circular support plate 104 becomes thinner towards the bottom. The uppermost part of the lower half of the circular support plate 104 has the same thickness as the upper half, which is 2-3 cm, and the lowermost part of the lower half of the circular support plate 104 has a thickness of 1-2 cm.

[0036] Preferably, the number of circular support plates 104 is 10-15 pieces, and they are arranged in sections, with the central axes of all the circular support plates 104 collinear in the unbent state.

[0037] Because the upper end of the mandrel assembly 101 extends and the lower end contracts during bending, the upper half of the circular support plate 104 is made to have a uniform thickness, and the uppermost thickness of the lower half of the circular support plate 104 is the same as the upper half, while the thickness of the lower half of the circular support plate 104 decreases towards the bottom. This ensures effective support while maximizing the bending angle of the mandrel assembly 101, thereby accommodating a wider range of bending radii.

[0038] The first aspect of this utility model is as follows: Figure 1 , Figure 3 and Figure 4 As shown, if the gap between the moving parts is too small, the range of angles that each moving part can adjust independently is small, thus limiting the overall bending angle of the mandrel and reducing its adaptability. Conversely, if the gap between the moving parts is too large, the supporting area of ​​the moving parts on the inner wall of the pipe during the bending process will be reduced, resulting in poorer support and a decrease in the effectiveness of improving deformation and wrinkling. Therefore, this solution provides an intermediate connector 105 inside the circular support plate 104, and connecting movable parts 108 are movably connected to the front and rear sides of the intermediate connector 105. Adjacent circular support plates 104 are hinged through their respective two opposing connecting movable parts 108 to achieve a rotational relationship.

[0039] Additionally, a fixing mechanism is provided within the intermediate connector 105 to secure the movable connector 108, preventing it from moving. The fixing mechanism includes a pressure plate 109 and a fixing screw 110. The pressure plate 109 is movably connected within the intermediate connector 105, with its lower end pressing against the movable connector 108. The fixing screw 110 is threadedly connected to the circular support plate 104 and the intermediate connector 105, with its lower end pressing against the pressure plate 109.

[0040] In addition, the inner center of the circular support plate 104 is provided with an inner annular groove 107 that runs through the front and back, and the intermediate connector 105 is located at the center of the inner annular groove 107. The four side walls of the intermediate connector 105 are each fixedly connected to a fixing post 106, and the circular support plate 104 is fixedly connected to the fixing post 106.

[0041] The connecting movable member 108 is telescopically connected to the intermediate connecting member 105, which makes the movable gap 102 between adjacent circular support plates 104 adjustable. Therefore, when the pipe bending angle is large, the movable gap 102 between adjacent circular support plates 104 can be increased to improve adaptability. When the pipe bending angle is small, the movable gap 102 between adjacent circular support plates 104 can be decreased to improve the support effect.

[0042] Preferably, a groove is provided on the side wall of the circular support plate 104, and the tool mating part at the outer end of the fixing screw 110 is located in the groove, and the tool mating part is provided with a cross groove or an internal hexagonal groove.

[0043] A fixing mechanism is also provided within the intermediate connector 105 to fix the connecting movable member 108 and prevent it from moving. This makes the connecting movable member 108 and the intermediate connector 105 a rigid connection, ensuring the stability of the entire mandrel assembly 101.

[0044] In summary, this utility model uses several circular support plates 104 of the same size and shape to form a mandrel assembly 101, and there is a movable seam 102 between adjacent circular support plates 104, so that each circular support plate 104 forms a deflectable chain structure through the movable seam 102. This allows the mandrel assembly 101 to dynamically conform to the pipe wall with different curvatures during the bending process, providing effective support to the inner wall of the pipe. Therefore, it can effectively improve the problems of deformation and wrinkling when the pipe is bent, reduce springback and improve processing accuracy.

[0045] An intermediate connector 105 is provided inside the circular support plate 104, and connecting movable members 108 are movably connected to the front and rear sides of the intermediate connector 105. Adjacent circular support plates 104 are hinged together by their respective two connecting movable members 108, thus achieving a rotational relationship. The connecting movable members 108 are telescopically connected within the intermediate connector 105, making the gap 102 between adjacent circular support plates 104 adjustable. Therefore, when the pipe bending angle is large, the gap 102 between adjacent circular support plates 104 can be widened to improve adaptability. When the pipe bending angle is small, the gap 102 between adjacent circular support plates 104 can be narrowed to improve the support effect. Furthermore, a fixing mechanism is provided within the intermediate connector 105 to fix the connecting movable members 108, preventing them from moving. This creates a rigid connection between the connecting movable members 108 and the intermediate connector 105, ensuring the stability of the entire mandrel assembly 101.

[0046] Because the upper end of the mandrel assembly 101 extends and the lower end contracts during bending, the upper half of the circular support plate 104 is made to have a uniform thickness, and the uppermost thickness of the lower half of the circular support plate 104 is the same as the upper half, while the thickness of the lower half of the circular support plate 104 decreases towards the bottom. This ensures effective support while maximizing the bending angle of the mandrel assembly 101, thereby accommodating a wider range of bending radii.

[0047] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention includes the claims being limited to these examples; within the framework of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in the details for the sake of brevity.

[0048] This utility model is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A mandrel for a pipe bending machine, comprising a mandrel assembly (101) for supporting the inner wall of a pipe and a connecting rod (103) fixedly connected to the end of the mandrel assembly (101), wherein the other end of the connecting rod (103) is disposed on the output shaft of a driving device for driving the telescopic movement of the mandrel assembly (101), characterized in that, The mandrel assembly (101) further includes: Several circular support plates (104) of the same size and shape, and there is a movable gap (102) between adjacent circular support plates (104); An intermediate connector (105) is located at the center of the inner part of the circular support plate (104). The circular support plate (104) is fixedly connected to the intermediate connector (105). Connecting movable parts (108) are movably connected to the front and rear sides of the intermediate connector (105). The connecting movable parts (108) are hinged to another connecting movable part (108) in the adjacent circular support plate (104). A fixing mechanism is provided in the intermediate connector (105) to fix the connecting movable part (108) so that it cannot move.

2. The mandrel for a pipe bending machine according to claim 1, characterized in that, The circular support plate (104) has an inner annular groove (107) that runs through the front and back at its center, and the intermediate connector (105) is located at the center of the inner annular groove (107).

3. A pipe bending mandrel according to claim 1 or 2, characterized in that, The intermediate connector (105) has a fixed column (106) fixedly connected to each of its four side walls (upper, lower, left, and right), and the circular support plate (104) is fixedly connected to the fixed column (106).

4. A pipe bending mandrel according to claim 1, characterized in that, The upper half of the circular support plate (104) has a uniform thickness, while the lower half of the circular support plate (104) becomes thinner towards the bottom.

5. A pipe bending mandrel according to claim 4, characterized in that, The thickness of the uppermost part of the lower half of the circular support plate (104) is the same as that of the upper half of the circular support plate (104), which is 2-3cm, and the thickness of the lowermost part of the lower half of the circular support plate (104) is 1-2cm.

6. A pipe bending mandrel according to claim 1, characterized in that, The number of the circular support plates (104) is 10-15 pieces, and they are arranged in a segmented manner. The central axes of all the circular support plates (104) in the unbent state are collinear.

7. A pipe bending mandrel according to claim 1, characterized in that, The fixing mechanism includes a pressure plate (109) and a fixing screw (110). The pressure plate (109) is movably connected in the intermediate connecting member (105), and its lower end presses on the connecting movable member (108). The fixing screw (110) is threadedly connected to the circular support plate (104) and the intermediate connecting member (105), and the lower end of the fixing screw (110) presses on the pressure plate (109).

8. A pipe bending mandrel according to claim 7, characterized in that, The circular support plate (104) has a groove on its side wall, and the tool mating part at the outer end of the fixing screw (110) is located in the groove, and the tool mating part is provided with a cross groove or an internal hexagonal groove.

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