Small-diameter core rod structure for bent pipe and bent pipe forming device

Abstract

The utility model provides a small-diameter core rod structure for a bent pipe and a bent pipe forming device, and solves the technical problems that a core rod is short in service life and is difficult to adapt to a small-diameter bent pipe. The small-diameter core rod structure for the bent pipe comprises a core rod body, a connecting rod, a pin body and a ball head assembly, a mounting cavity is formed in one end of the core rod body, the connecting rod is located in the mounting cavity, and the pin body penetrates through the cavity wall of the mounting cavity and the connecting rod to fixedly connect the mounting cavity and the connecting rod; a limiting cavity is formed in the end of the connecting rod, the ball head assembly comprises a ball head part, and the ball head part is located in the limiting cavity and can rotate in the limiting cavity; a solid structure is reserved in the middle of the core rod body, the structural strength of the core rod body is guaranteed, and the service life of the core rod structure is prolonged; after the connecting rod and the ball head assembly are installed in a matched mode, the connecting rod is installed in the limiting cavity from one end in the installation cavity and then locked through the pin body. The structure deforms in the pipe body along with the pipe body, the ellipse and wrinkles of the pipe body are controlled and limited within a certain range, and the structure is suitable for accurate bending forming of small-pipe-diameter pipe bodies.

Description

Technical Field

[0001] This utility model relates to the field of precision pipe bending technology, and in particular to a small-diameter mandrel structure for pipe bending and a pipe bending forming device. Background Technology

[0002] In the precision bending of the tube, the mandrel plays an important internal supporting role, effectively reducing tube deformation and wrinkling. In actual use, the mandrel is fixed on the machine tool, and the tube is sleeved on the outside of the mandrel. As the machine tool bends the tube, the mandrel inside the tube provides support, preventing the tube from deforming and wrinkling.

[0003] Existing mandrel structures, such as Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of a mandrel in the prior art; it includes a screw 2, a mandrel body 1', a sleeve 3 and a ball head 4'. The screw 2 passes through the mandrel body 1' and is threadedly connected to the mandrel body 1' and the sleeve 3. The ball head 4 is located at one end of the sleeve 3 and is rotatable.

[0004] The applicant has found that the prior art has at least the following technical problems: In the above structure, on the one hand, the screw 2 needs to pass through the mandrel body 1' and be threaded to the sleeve 3. The mandrel body 1' needs to reserve a cavity for the screw to pass through, which reduces the strength of the mandrel body and results in a short service life. On the other hand, it is difficult to assemble and connect the screw with the mandrel body. The diameter of the mandrel body is difficult to be less than 7 mm, which makes it difficult to adapt to small-diameter bends. Utility Model Content

[0005] The purpose of this utility model is to provide a small-diameter mandrel structure and a pipe bending forming device for pipe bending, so as to solve the technical problems of short mandrel service life and difficulty in adapting to small-diameter pipe bending in the prior art; the various technical effects of the preferred technical solution among the many technical solutions provided by this utility model are described in detail below.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The small-diameter mandrel structure for pipe bending provided by this utility model includes a mandrel body, a connecting rod, a pin, and a ball joint assembly, wherein:

[0008] One end of the core rod body has a mounting cavity, the connecting rod is located in the mounting cavity, and the pin passes through the cavity wall of the mounting cavity and the connecting rod to fix the two together.

[0009] The end of the connecting rod has a limiting cavity, and the ball head assembly includes a ball head, which is located in the limiting cavity and can rotate within the limiting cavity.

[0010] Preferably, the end of the limiting cavity has an opening, and the limiting cavity is a spherical cavity that matches the outer contour of the ball head.

[0011] Preferably, the connecting rod includes a first semi-cylinder and a second semi-cylinder, wherein:

[0012] The first semi-cylinder is provided with a first positioning hole, and the end of the first semi-cylinder has a first hemispherical cavity;

[0013] The second semi-cylinder is provided with a second positioning hole, and the end of the second semi-cylinder has a second hemispherical cavity. The pin passes through the cavity wall of the mounting cavity, the first positioning hole and the second positioning hole to fix the first semi-cylinder and the second semi-cylinder in the mounting cavity, and the first hemispherical cavity and the second hemispherical cavity are spliced ​​together to form the limiting cavity.

[0014] Preferably, locking holes are provided on opposite sides of the core rod body. The locking holes penetrate the cavity wall of the mounting cavity and correspond one-to-one with the positions of the first positioning hole and the second positioning hole.

[0015] Preferably, the number of pins is one or at least two. When the number of pins is at least two, all the pins are arranged at intervals along the length of the connecting rod.

[0016] Preferably, the ball head assembly further includes a limiting block and an insertion portion, wherein:

[0017] The insertion part and the ball head are integrally formed. A snap-fit ​​groove is formed in the limiting block. The insertion part is located in the snap-fit ​​groove and is fixedly connected by a pin.

[0018] The limiting block is located outside the core rod body and is used to abut against the inner wall of the tube.

[0019] Preferably, the ball head assembly further includes a limiting block, which is integrally formed with the ball head and is located outside the mandrel body to abut against the inner wall of the tube.

[0020] Preferably, a keyway is provided on the outer wall of the mandrel body.

[0021] Preferably, a fixing cavity is provided at the end of the mandrel body opposite to the mounting cavity for locking onto the machine tool.

[0022] This utility model also provides a pipe bending forming device, including a machine tool and the above-mentioned small-diameter mandrel structure for bending pipes. The mandrel body is fixed on the machine tool, and the mandrel body and the ball head assembly are used to insert into the pipe body to be processed.

[0023] The small-diameter mandrel structure and bending forming device for pipe bending provided by this utility model have the following advantages compared with the prior art: the connecting rod is located in the mounting cavity at one end of the mandrel body, wrapping around the ball head, eliminating the need for screws; the connecting rod does not need to pass through the entire mandrel body; the middle of the mandrel body retains a solid structure, ensuring the structural strength of the mandrel body and improving the service life of the mandrel structure; after the connecting rod and the ball head assembly are installed together, they are inserted into the limiting cavity from one end of the mounting cavity and then locked by the pin, making assembly simple and convenient. This structure deforms with the pipe body inside, controlling the ellipticity and wrinkling of the pipe body within a certain range. The structure is compact, requires no screws, is particularly suitable for precise bending and forming of small-diameter pipes, and has high structural strength. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of 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 some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a mandrel in the existing technology.

[0026] Figure 2 This is a schematic diagram of the overall structure of a small-diameter mandrel structure for bending pipes;

[0027] Figure 3 This is a cross-sectional structural schematic diagram of the first embodiment of the small-diameter mandrel structure for bending pipes;

[0028] Figure 4 This is a cross-sectional structural schematic diagram of the second embodiment of the small-diameter mandrel structure for bending pipes;

[0029] Figure 5 This is a schematic diagram of the connection between the connecting rod, pin, and ball joint assembly.

[0030] Figure 6 This is a schematic diagram of the structure of the first half-cylinder, the pin, and the ball head assembly.

[0031] In the figure: 1. Core rod body; 101. Keyway; 102. Locking hole; 2. Connecting rod; 201. Limiting cavity; 202. Opening; 21. First semi-cylinder; 211. First hemispherical cavity; 22. Second semi-cylinder; 23. First positioning hole; 24. Second positioning hole; 3. Pin; 4. Ball head; 5. Limiting block; 6. Pin rod; 7. Fixing cavity; 8. Insertion part. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0033] In the description of this utility model, it should be understood that the terms "center," "length," "width," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and "side," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0034] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] This invention provides a small-diameter mandrel structure for bending pipes. This structure deforms inside the pipe body, controlling the ellipticity and wrinkling of the pipe within a certain range. It has a compact structure, requires no screws, and is particularly suitable for the precise bending and forming of small-diameter pipes, while also exhibiting high structural strength.

[0036] The following is combined Figures 2-6 The technical solution provided by this utility model will be described in more detail.

[0037] Example 1:

[0038] See Figures 2-6As shown, the small-diameter mandrel structure for bending pipes provided by this utility model includes a mandrel body 1, a connecting rod 2, a pin 3, and a ball head assembly. The mandrel body 1 has a mounting cavity at one end, the connecting rod 2 is located in the mounting cavity, and the pin 3 passes through the cavity wall of the mounting cavity and the connecting rod 2 to fix the two together. The end of the connecting rod 2 has a limiting cavity 201, and the ball head assembly includes a ball head 4, which is located in the limiting cavity 201 and can rotate within the limiting cavity 201.

[0039] In this embodiment, a small-diameter mandrel structure is used for bending pipes. The connecting rod 2 is located in the mounting cavity at one end of the mandrel body 1 and wraps around the ball head 4. No screws are required. The connecting rod 2 does not need to pass through the entire mandrel body 1. The middle part of the mandrel body 1 retains a solid structure, which ensures the structural strength of the mandrel body 1 and improves the service life of the mandrel structure.

[0040] After the connecting rod 2 is installed in conjunction with the ball head assembly, it is inserted into the limiting cavity 201 from one end of the mounting cavity and then locked by the pin 3. The assembly is simple and convenient.

[0041] This structure deforms within the tube, controlling the tube's ellipticity and wrinkling within a certain range. It is compact, screwless, and the outer diameter D of the mandrel body 1 is smaller than the outer diameter D1 of mandrels in existing technologies, making it particularly suitable for precise bending and forming of small-diameter tubes, while also providing high structural strength.

[0042] As an optional implementation, see Figure 4 As shown, the end of the limiting cavity 201 has an opening 202, and the limiting cavity 201 is a spherical cavity that matches the outer contour of the ball head 4.

[0043] The structure of the opening 202 facilitates the insertion of the ball head 4 into the limiting cavity 201 from the opening 202, which is convenient for assembly.

[0044] As an optional implementation, see Figure 5 and Figure 6 As shown, the connecting rod 2 includes a first semi-cylinder 21 and a second semi-cylinder 22, wherein: the first semi-cylinder 21 is provided with a first positioning hole 23, and the end of the first semi-cylinder 21 has a first hemispherical cavity 211; the second semi-cylinder 22 is provided with a second positioning hole 24, and the end of the second semi-cylinder 22 has a second hemispherical cavity; the pin 3 passes through the cavity wall of the mounting cavity, the first positioning hole 23 and the second positioning hole 24 to fix the first semi-cylinder 21 and the second semi-cylinder 22 in the mounting cavity, and the first hemispherical cavity 211 and the second hemispherical cavity are spliced ​​together to form a limiting cavity 201.

[0045] See Figure 2 As shown, locking holes 102 are provided on opposite sides of the core rod body 1. The locking holes 102 penetrate the cavity wall of the mounting cavity and correspond one-to-one with the positions of the first positioning hole 23 and the second positioning hole 24.

[0046] The connecting rod 2 is formed by the pin 3 passing through the first half-pillar 21 and the second half-pillar 22 and connecting the two. During assembly, the ball head 4 is first inserted into the first hemispherical cavity 211, and then the first half-pillar 21 and the second half-pillar 22 are spliced ​​together. The spliced ​​connecting rod 2 is inserted into the mounting cavity of the connecting rod 2. The pin 3 passes through the locking hole 102, the corresponding first positioning hole 23 and the second positioning hole 24 to lock the core rod body 1 and the connecting rod 2. The first half-pillar 21 and the second half-pillar 22 are prevented from separating by the pin 3 and the side of the mounting cavity.

[0047] As an optional implementation, the number of pins 3 is one or at least two, see [link to previous implementation]. Figure 1 As shown, when the number of pins 3 is at least two, all pins 3 are arranged at intervals along the length of the connecting rod 2, thereby ensuring the stability of the connection structure.

[0048] As an optional implementation, see Figure 2 As shown, the ball head assembly also includes a limiting block 5 and an insertion part 8, wherein: the insertion part 8 and the ball head 4 are integrally formed; the limiting block 5 has a snap-fit ​​groove, the insertion part 8 is located in the snap-fit ​​groove, and is fixedly connected by a pin 6; the limiting block 5 is located outside the mandrel body 1 and is used to abut against the inner wall of the tube. The limiting block 5 has an arc-shaped surface for abutting against the inner wall of the tube.

[0049] The aforementioned limiting block 5 and insertion part 8 are detachable, facilitating the disassembly and replacement of the structure.

[0050] As an optional implementation, see Figure 1 As shown, a keyway 101 is provided on the outer wall of the mandrel body 1 to facilitate the use of auxiliary equipment such as wrenches to turn the mandrel body 1.

[0051] As an optional implementation, see Figure 3 As shown, a fixing cavity 7 is provided at the end of the mandrel body 1 that is away from the mounting cavity, for locking onto the machine tool.

[0052] The fixed cavity 7 can be an internally threaded cavity for threaded connection with the machine tool. The mandrel body 1 can be fixed on the machine tool by the above structure, and the tube is sleeved on the outside of the mandrel. As the machine tool bends the tube, the mandrel body 1 is located inside the tube and plays a supporting role, which can prevent the tube from becoming elliptical and wrinkled.

[0053] In this embodiment, the mandrel structure connects the mandrel body 1 and the connecting rod 2 via a pin 3, and the ball head 4 and the limiting block 5 via a pin 6. The ball head 4 moves freely within the limiting cavity 201 of the connecting rod 2, allowing the structure to deform with the tube body inside, and controlling the ellipticity and wrinkling of the tube body within a certain range. Due to its compact structure and the absence of screws, it is particularly suitable for precise bending and forming of small-diameter tubes. It solves the problems of difficult machining of small parts and short service life associated with conventional methods, such as… Figure 2 As shown.

[0054] Example 2:

[0055] The difference between this embodiment and Embodiment 1 is as follows: See Figure 3 As shown, the ball head assembly also includes a limiting block 5. The limiting block 5 and the ball head 4 are integrally formed. The limiting block 5 is located outside the mandrel body 1 and is used to abut against the inner wall of the tube.

[0056] In the above structure, the limiting block 5 and the ball head 4 are integrally formed, eliminating the need for additional connecting structures and improving structural stability. In this embodiment, during installation, the ball head assembly can first insert the ball head 4 into the first hemispherical cavity 211, then splice the first semi-cylinder 21 and the second semi-cylinder 22, and insert the spliced ​​connecting rod 2 into the mounting cavity of the connecting rod 2. The pin 3 passes through the locking hole 102, the corresponding first positioning hole 23, and the second positioning hole 24 to lock the core rod body 1 and the connecting rod 2.

[0057] Example 3:

[0058] This embodiment provides a pipe bending forming device, including a machine tool and the above-mentioned small-diameter mandrel structure for pipe bending. The mandrel body 1 is fixed on the machine tool, and the mandrel body 1 and the ball head assembly are used to insert into the pipe to be processed.

[0059] Because of the aforementioned mandrel structure, this pipe bending forming device is more suitable for bending small-diameter pipes.

[0060] The specific features, structures, or characteristics described in this specification may be combined in any suitable manner in one or more embodiments or examples.

[0061] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0062] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A small-diameter mandrel structure for bending pipes, characterized in that, Includes the mandrel body, connecting rod, pin, and ball joint assembly, wherein: One end of the core rod body has a mounting cavity, the connecting rod is located in the mounting cavity, and the pin passes through the cavity wall of the mounting cavity and the connecting rod to fix the two together. The end of the connecting rod has a limiting cavity, and the ball head assembly includes a ball head, which is located in the limiting cavity and can rotate within the limiting cavity.

2. The small-diameter mandrel structure for bending pipes according to claim 1, characterized in that, The end of the limiting cavity has an opening, and the limiting cavity is a spherical cavity that matches the outer contour of the ball head.

3. The small-diameter mandrel structure for bending pipes according to claim 1, characterized in that, The connecting rod includes a first half-cylinder and a second half-cylinder, wherein: The first semi-cylinder is provided with a first positioning hole, and the end of the first semi-cylinder has a first hemispherical cavity; The second semi-cylinder is provided with a second positioning hole, and the end of the second semi-cylinder has a second hemispherical cavity. The pin passes through the cavity wall of the mounting cavity, the first positioning hole and the second positioning hole to fix the first semi-cylinder and the second semi-cylinder in the mounting cavity, and the first hemispherical cavity and the second hemispherical cavity are spliced ​​together to form the limiting cavity.

4. The small-diameter mandrel structure for bending pipes according to claim 3, characterized in that, Locking holes are provided on opposite sides of the core rod body. The locking holes penetrate the cavity wall of the mounting cavity and correspond one-to-one with the positions of the first positioning hole and the second positioning hole.

5. The small-diameter mandrel structure for bending pipes according to claim 1, characterized in that, The number of pins is one or at least two. When the number of pins is at least two, all the pins are arranged at intervals along the length of the connecting rod.

6. The small-diameter mandrel structure for bending pipes according to claim 1, characterized in that, The ball head assembly further includes a limiting block and an insertion part, wherein: The insertion part and the ball head are integrally formed. A snap-fit ​​groove is formed in the limiting block. The insertion part is located in the snap-fit ​​groove and is fixedly connected by a pin. The limiting block is located outside the core rod body and is used to abut against the inner wall of the tube.

7. The small-diameter mandrel structure for bending pipes according to claim 1, characterized in that, The ball head assembly also includes a limiting block, which is integrally formed with the ball head. The limiting block is located outside the mandrel body and is used to abut against the inner wall of the tube.

8. The small-diameter mandrel structure for bending pipes according to claim 1, characterized in that, A keyway groove is provided on the outer wall of the mandrel body.

9. The small-diameter mandrel structure for bending pipes according to claim 1, characterized in that, The mandrel body has a fixing cavity at one end opposite to the mounting cavity for locking onto the machine tool.

10. A pipe bending forming device, characterized in that, The device includes a machine tool and a small-diameter mandrel structure for bending pipes as described in any one of claims 1-9, wherein the mandrel body is fixed to the machine tool, and the mandrel body and the ball head assembly are used for insertion into the pipe body to be processed.

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