A new type of elbow mandrel structure
By designing a novel bent tube mandrel structure that connects a series of universal core balls and bent tube core balls, the problem that existing mandrel structures cannot adapt to complex bending requirements is solved, and multi-angle and multi-length tube support and bending effects are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HAINING ZHENGXUAN AUTOMOBILE LIGHTWEIGHT PARTS CO LTD
- Filing Date
- 2025-06-09
- Publication Date
- 2026-05-29
AI Technical Summary
Existing mandrel structures cannot adapt to bending requirements of different lengths and angles, and traditional pin and single ball structures have great limitations and cannot meet complex bending requirements.
A novel bending mandrel structure was designed, which achieves bending support at multiple angles and lengths by connecting multiple universal mandrel balls and bending mandrel balls in series. The ball rotation connection is used to meet the support requirements of different pipe shapes.
It enables omnidirectional bending of metal pipes, provides excellent support, is suitable for various pipe shapes, and extends the service life of equipment.
Smart Images
Figure CN224294392U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of pipe bending fixture technology, specifically relating to a novel pipe bending mandrel structure. Background Technology
[0002] To achieve the desired bending radius, operators use pipe bending machines to bend metal pipes. The bent pipes are then used on the mechanical equipment that requires bending.
[0003] Currently, there are two structural operations for pipe bending: one is the mandrel-less pipe bending method, in which the metal pipe is placed directly on the pipe bending machine, and the clamping block and rotating block hold the bending part of the metal pipe and rotate it for bending; since there is no internal support for the metal pipe, this method is suitable for metal pipes with thin walls and large bending angles.
[0004] Another method is mandrel bending, where a mandrel is inserted into the bending section of the metal pipe. The bending machine's clamps and rotating blocks hold the bending section of the metal pipe and rotate it for bending. The mandrel provides support and controls the deformation of the metal pipe during the bending process.
[0005] However, the mandrels currently available on the market are pin structures, similar to plate chains, which can only be bent in two opposite directions; some mandrels are single sphere structures, which can only bend tubes with large included angles. The bending length of a single sphere structure is limited and cannot be used for the long bending arc sections of tubes. Summary of the Invention
[0006] In view of the shortcomings of the above-mentioned background technology, the purpose of this utility model is to provide a novel bending mandrel structure, in which the bending mandrel components can be connected in different numbers to meet the bending requirements of different lengths. At the same time, the use of spherical rotation connection can realize all-round angle bending.
[0007] To solve the above-mentioned technical problems, the purpose of this utility model is achieved as follows:
[0008] A novel mandrel structure for bending tubes includes a first connecting block, a mandrel connected to the tail end of the first connecting block, and a mandrel connected to the head end of the first connecting block.
[0009] The first end of the mandrel is connected to the first universal core ball, and the tail end of the first universal core ball is a sphere. The sphere is inserted into the mandrel and locked by the first locking block to limit its rotation. The outer surface of the first end of the first universal core ball is fitted with the first curved tube core ball, which fits against the inner wall of the curved tube. The cross-sectional shape of the first curved tube core ball is the same as the cross-sectional shape of the tube sleeve. The first end of the first universal core ball can be fitted with the sphere of the next first universal core ball.
[0010] Based on the above scheme and as a preferred embodiment of the above scheme: a first through hole is provided on the first connecting block, which penetrates the first and last surfaces, and an annular first stop protrudes from the inner wall of the first through hole;
[0011] The inner wall of the tail end of the first through hole is provided with internal thread, and the head end of the core rod is provided with external thread. The core rod is threadedly connected to the first connecting block.
[0012] Based on the above scheme and as a preferred embodiment of the above scheme: the tail end of the mandrel is cylindrical, and the end face of the tail end of the mandrel is concave to form the first threaded pit.
[0013] The tail end of the mandrel is inserted into the first through hole of the first connecting block, and the mandrel abuts against the first stop block; the center line of the first through hole coincides with the center line of the first threaded pit, and the fixing bolt passes through the first stop block and is screwed into the first threaded pit for fixation.
[0014] Based on the above scheme and as a preferred embodiment of the above scheme: it further includes a sleeve; a second annular stop protruding from the tail end surface of the sleeve; the sleeve is inserted into the first through hole, the second stop and the first stop are stacked and attached, and the head end face of the sleeve is attached to the tail end face of the mandrel.
[0015] The fixing bolt passes through the sleeve and is threadedly connected to the mandrel for fixation, with the head of the fixing bolt touching the tail end of the sleeve.
[0016] Based on the above scheme and as a preferred embodiment of the above scheme: the first universal core ball includes two symmetrically assembled semi-universal core balls; the tail end of the semi-universal core ball is a hemisphere, the hemisphere extends to the front end to form an integral semi-cylinder, the outer surface of the semi-cylinder is recessed to form a first groove, the outer edge of the semi-cylinder protrudes to form a third stop, and the interior of the semi-cylinder is recessed to form a hemispherical pit.
[0017] The first curved tube core ball has a through first circular hole in the middle, and a fourth annular stop block protrudes from the inner wall of the tail end of the first circular hole.
[0018] The hemispherical pits of the first two hemispheres are joined together to wrap around the last two hemispheres for positioning; the first round hole of the first curved core ball is fitted into the semi-cylinder, and the snap ring is embedded in the first slot to clamp and fix the fourth stop block.
[0019] Based on the above scheme and as a preferred embodiment of the above scheme: the first edge of the mandrel is recessed to form a first pit, the bottom surface of the first pit is recessed to form a first arc-shaped pit, and the side surface of the first pit is recessed to form a second threaded pit.
[0020] The bottom surface of the first card block is recessed to form a second arc-shaped pit, and the first end face of the first card block is provided with a first countersunk hole.
[0021] The first and second arc-shaped recesses enclose the sphere of the first universal core ball, and the screw is inserted into the first countersunk hole and threadedly connected and fixed to the second threaded recess.
[0022] Based on the above scheme and as a preferred option: the first pit is a trapezoid with a larger inner diameter and a smaller outer diameter.
[0023] Based on the above scheme and as a preferred option, the tail end of the semi-universal core ball is recessed to form an oil storage pit.
[0024] The outstanding and beneficial technical effects of this utility model compared to the prior art are:
[0025] This utility model presents a novel bent tube mandrel structure, which, compared with the prior art,
[0026] The first connecting block connects the mandrel and the core rod, serving as an intermediate component. The first universal core ball is inserted into the core rod, and the first bent core ball is fitted onto the first universal core ball, serving as a support for the bent tube. The first connecting block is threadedly connected to the mandrel, and the first connecting block is threadedly connected to the core rod. Due to the series connection of the balls, the first and second first universal core balls form a universal shaft structure that can conform to the curvature inside the tube. As the equipment operates, the metal tube moves forward as a whole; the core shaft structure moves backward. The entire core rod and first bent core ball assembly provides support and shaping for the inner wall of the metal tube, ensuring that the metal tube does not dent during bending. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of the overall exploded structure of this utility model.
[0028] Figure 2 This is a schematic diagram of the overall structure of this utility model.
[0029] Figure 3 This is an assembly diagram of the present invention.
[0030] Figure 4 This is a schematic cross-sectional view of the overall structure of this utility model.
[0031] Reference numerals: First connecting block 1; First through hole 10; First stop block 11; Core rod 2; Core bar 3; First threaded recess 30; Fixing bolt 31; First recess 32; First arc-shaped recess 320; Second threaded recess 321; First universal core ball 4; Semi-universal core ball 40; Hemisphere 400; Semi-cylinder 401; First slot 402; Third stop block 403; Hemispherical recess 404; Oil reservoir 405; First bent tube core ball 5; First round hole 50; Fourth stop block 51; Snap ring 52; First snap block 6; Second arc-shaped recess 60; First countersunk hole 61; Sleeve 7; Second stop block 70; Detailed Implementation
[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments;
[0033] This embodiment provides a novel bending mandrel structure, including a first connecting block 1, a mandrel 2 connected to the tail end of the first connecting block 1, and a mandrel 3 connected to the head end of the first connecting block 1;
[0034] The first connecting block 1, the core rod 2, and the core bar 3 are all made of metal blocks. The core rod 2 is installed on the pipe bending equipment. The first connecting block 1 is connected to the front end of the core rod 2 as an intermediate part, and then connected to the core bar 3 to form a whole.
[0035] The first end of the core rod 3 is connected to the first universal core ball 4. The tail end of the first universal core ball 4 is a ball. The ball is inserted into the core rod 3 and locked by the first locking block 6 to limit its rotation. The ball of the first universal core ball 4 is inserted into the core rod 3 to achieve universal angle rotation. The rotation can achieve uniform force on the contact surface and increase the service life.
[0036] The first universal core ball 4 has a first bent tube core ball 5 sleeved on the outer surface of its head end. The first bent tube core ball 5 fits against the inner wall of the bent tube, and the cross-sectional shape of the first bent tube core ball 5 is the same as the cross-sectional shape of the tube sleeve.
[0037] The first curved core ball 5 is fitted onto the first universal core ball 4, allowing for disassembly, assembly, and replacement. The outer contour of the first curved core ball 5 is selected according to the shape of different pipe materials; for example, for round pipes, the cross-section of the first curved core ball 5 is circular, and for square pipes, the cross-section is rectangular. It fits snugly against the inner wall of the pipe, providing better support. The structure of the first curved core ball 5 is not limited to existing rectangular pipes; it can be applied to irregularly shaped pipes such as round, square, and elliptical pipes. It only requires that the mandrel 3 and the first curved core ball 5 be made to match the cross-sectional shape of the pipe. Any pipe shape without a negative angle bend is acceptable.
[0038] The first end of the first universal joint 4 of the previous one can be fitted onto the body of the second first universal joint 4. The first universal joint 4 of the previous and subsequent ones are connected in a detachable structure, which is suitable for different length requirements of the bending parts on metal pipes, making it more practical.
[0039] As described above, in the specific usage process, the first connecting block 1 is connected to the front end of the core rod 2 of the pipe bending device; Figure 2 The structure illustrates a shape for a rectangular tube. The mandrel 3 is placed inside the tube to be bent. As the tube is bent, the first universal core ball 4 and the first bent tube core ball 5 rotate. At the same time, the first bent tube core ball 5 provides support inside the tube, ensuring that the tube does not concave during the bending process.
[0040] Furthermore, the first connecting block 1 has a first through hole 10 that extends through the front and rear surfaces, and the inner wall of the first through hole 10 has a protruding annular first stop block 11; the first stop block 11 separates the first through hole 10 from front to back.
[0041] The inner wall of the tail end of the first through hole 10 is provided with internal thread, and the head end of the core rod 2 is provided with external thread. The core rod 2 is threadedly connected to the first connecting block 1.
[0042] As described above, the first connecting block 1 and the core rod 2 are connected by a thread, allowing for disassembly and replacement.
[0043] In another embodiment, the core rod 2 is welded to the first connecting block 1.
[0044] Furthermore, the tail end of the mandrel 3 is cylindrical, and the end face of the tail end of the mandrel 3 is concave to form the first threaded pit 30.
[0045] The tail end of the core rod 3 is inserted into the first through hole 10 of the first connecting block 1, and the core rod 3 abuts against the first stop block 11;
[0046] The core rod 3 is inserted and sleeved with the first connecting block 1;
[0047] The center line of the first through hole 10 coincides with the center line of the first threaded pit 30, and the fixing bolt 31 passes through the first stop 11 and is screwed into the first threaded pit 30 for fixation.
[0048] As described above, the first connecting block 1 and the core rod 3 are connected and fixed by fixing bolts 31; they can be disassembled and replaced; the length of the core rod 3 is suitable for the length of the metal pipe.
[0049] Furthermore, it also includes a sleeve 7; a second annular stop 70 protrudes from the tail end surface of the sleeve 7; the sleeve 7 is a cylindrical metal part, and the second stop 70 is protruding and integrally formed.
[0050] The sleeve 7 is inserted into the first through hole 10, the second stop 70 is stacked and attached to the first stop 11, and the first end face of the sleeve 7 is attached to the tail end face of the core rod 3.
[0051] The sleeve 7 fills the first through hole 10 and serves as the carrier of the fixing bolt 31, protecting the fixing bolt 31 and preventing it from being quickly damaged by repeated bending, thus increasing its service life.
[0052] The fixing bolt 31 passes through the sleeve 7 and is threadedly connected to the core rod 3 for fixation. The head of the fixing bolt 31 is in contact with the tail end of the sleeve 7.
[0053] As described above, a second stop 70 is fitted onto the first stop 11, and then the fixing bolt 31 is threaded through and connected to the core rod 3.
[0054] Furthermore, the first universal core ball 4 includes two symmetrically assembled semi-universal core balls 40; the tail end of the semi-universal core ball 40 is a hemisphere 400, the hemisphere 400 extends to the front end to form an integral semi-cylinder 401, the outer surface of the semi-cylinder 401 is recessed to form a first groove 402, the outer edge of the semi-cylinder 401 protrudes to form a third stop 403, and the interior of the semi-cylinder is recessed to form a hemispherical pit 404.
[0055] The first universal core ball 4 is made up of two half universal core balls 40 spliced together in order to allow the next first universal core ball 4 to be inserted, while the "sphere" can rotate freely in all directions;
[0056] The first curved tube core ball 5 has a through first circular hole 50 in the middle, and an annular fourth stop 51 protrudes from the inner wall of the tail end of the first circular hole 50.
[0057] The hemispherical pits 404 of the first two semi-universal core balls 40 are joined together to wrap around the last two hemispheres 400 for positioning; the first round hole 50 of the first curved core ball 5 is inserted into the semi-cylinder 401, and the snap ring 52 is embedded in the first slot 402 to clamp and fix the fourth stop block 51.
[0058] As described above, the hemispherical pits 404 on the upper semi-cylinders of the first two hemispheres 40 can hold the latter two hemispheres 400 in place. Then, the first curved core ball 5 is inserted. The shape of the first curved core ball 5 matches the shape of the metal tube and is secured with a retaining spring 52 to prevent it from coming off. The number and length of the first universal core balls 4 are corresponding to the curvature requirements of the curved section.
[0059] In another embodiment, the first curved tube core ball 5 component changes shape according to the shape of the tube to be processed. It only shows 2 sets in series under normal circumstances, but can be expanded to 3 sets or more, customized according to its own needs.
[0060] Furthermore, the first edge of the mandrel 3 is recessed to form a first pit 32, the bottom surface of the first pit 32 is recessed to form a first arc-shaped pit 320, and the side surface of the first pit 32 is recessed to form a second threaded pit 321.
[0061] The bottom surface of the first locking block 6 is recessed to form a second arc-shaped pit 60, and the first end face of the first locking block 6 is provided with a first countersunk hole 61.
[0062] The first arc-shaped recess 320 and the second arc-shaped recess 60 enclose the sphere of the first universal core ball 4, and the screw is inserted into the first countersunk hole 61 and threadedly connected and fixed to the second threaded recess 321.
[0063] As described above, the first universal core ball 4 is inserted into the core rod 3 and wrapped with the first locking block 6, so that it can be both fixed and rotated, achieving two goals at once.
[0064] Furthermore, the first pit 32 is a trapezoid with a larger inner diameter and a smaller outer diameter.
[0065] As mentioned above, the first locking block 6 also has one side longer than the other, making it difficult to detach from the core rod 3.
[0066] Furthermore, the middle of the tail end of the semi-universal core ball 40 is recessed to form an oil storage pit 405.
[0067] As mentioned above, the lubricating oil is stored in the oil reservoir 405 to increase smooth rotation.
[0068] In the description of this utility model, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0069] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In this utility model, unless otherwise expressly specified and limited, the terms "installation," "setting," "connection," "fixing," and "screw-on," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection.
[0070] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of protection of the present utility model. Therefore, all equivalent changes made to the structure, shape, and principle of the present utility model should be covered within the scope of protection of the present utility model.
Claims
1. A novel bent tube mandrel structure, characterized in that: It includes a first connecting block, a tail end connecting core rod of the first connecting block, and a head end connecting core bar of the first connecting block; The first end of the mandrel is connected to the first universal core ball, and the tail end of the first universal core ball is a sphere. The sphere is inserted into the mandrel and locked by the first locking block to limit its rotation. The outer surface of the first end of the first universal core ball is fitted with the first curved tube core ball, which fits against the inner wall of the curved tube. The cross-sectional shape of the first curved tube core ball is the same as the cross-sectional shape of the tube sleeve. The first end of the first universal core ball can be fitted with the sphere of the next first universal core ball.
2. The novel bent mandrel structure according to claim 1, characterized in that: The first connecting block has a first through hole that extends through the first and last surfaces, and the inner wall of the first through hole has a protruding annular first stop. The inner wall of the tail end of the first through hole is provided with internal thread, and the head end of the core rod is provided with external thread. The core rod is threadedly connected to the first connecting block.
3. The novel bent mandrel structure according to claim 2, characterized in that: The tail end of the mandrel is cylindrical, and the end face of the tail end of the mandrel is concave to form the first threaded pit. The tail end of the mandrel is inserted into the first through hole of the first connecting block, and the mandrel abuts against the first stop block; the center line of the first through hole coincides with the center line of the first threaded pit, and the fixing bolt passes through the first stop block and is screwed into the first threaded pit for fixation.
4. The novel bent mandrel structure according to claim 3, characterized in that: It also includes a sleeve; a second annular stop protruding from the tail end surface of the sleeve; the sleeve is inserted into the first through hole, the second stop is stacked and attached to the first stop, and the head end face of the sleeve is attached to the tail end face of the mandrel. The fixing bolt passes through the sleeve and is threadedly connected to the mandrel for fixation, with the head of the fixing bolt touching the tail end of the sleeve.
5. The novel bent mandrel structure according to claim 1, characterized in that: The first universal core ball includes two symmetrically assembled semi-universal core balls; the tail end of the semi-universal core ball is a hemisphere, the hemisphere extends to the front end to form an integral semi-cylinder, the outer surface of the semi-cylinder is recessed to form a first groove, the outer edge of the semi-cylinder protrudes to form a third stop, and the interior of the semi-cylinder is recessed to form a hemispherical pit. The first curved tube core ball has a through first circular hole in the middle, and a fourth annular stop block protrudes from the inner wall of the tail end of the first circular hole. The hemispherical pits of the first two hemispheres are joined together to wrap around the last two hemispheres for positioning; the first round hole of the first curved core ball is fitted into the semi-cylinder, and the snap ring is embedded in the first slot to clamp and fix the fourth stop block.
6. The novel bent mandrel structure according to claim 5, characterized in that: The first pit is formed by the indentation at the leading edge of the mandrel; the bottom surface of the first pit is formed by the indentation of the first arc-shaped pit; the side surface of the first pit is formed by the indentation of the second threaded pit. The bottom surface of the first card block is recessed to form a second arc-shaped pit, and the first end face of the first card block is provided with a first countersunk hole. The first and second arc-shaped recesses enclose the sphere of the first universal core ball, and the screw is inserted into the first countersunk hole and threadedly connected and fixed to the second threaded recess.
7. The novel bent mandrel structure according to claim 6, characterized in that: The first indentation is a trapezoid with a larger inner diameter and a smaller outer diameter.
8. The novel bent mandrel structure according to claim 5, characterized in that: The middle of the tail end of the semi-universal core ball is concave to form an oil storage pit.