A fully automatic metal pipe bending machine

Abstract

This invention relates to a fully automatic metal pipe bending machine, belonging to the technical field of pipe bending equipment. The invention includes a frame and a mandrel assembly and a bending module mounted on the frame. The mandrel assembly includes a mandrel and a ball-end module connected to the end of the mandrel. The bending module includes a bending die. The ball-end module includes multiple ball-end units arranged around the central axis of the mandrel. These ball-end units are slidably mounted on the mandrel. The ball-end units can converge inwards to reduce the outer diameter of the ball-end module, and can also expand outwards to increase the outer diameter of the ball-end module, thus pressing the ball-end module firmly against the inner wall of the metal pipe. The ball-end module pressed against the inner wall of the metal pipe firmly compresses the metal pipe onto the bending die. The ball-end module of this invention can firmly press the inner wall of the metal pipe, preventing the metal pipe from collapsing or wrinkling during bending.

Description

Technical Field

[0001] This invention relates to the field of pipe bending equipment technology, and in particular to a fully automatic metal pipe bending machine. Background Technology

[0002] Metal pipes, as important structural components and fluid transport parts, are widely used in aerospace, automotive manufacturing, furniture and home appliances, and petrochemical industries. To meet complex spatial layouts and structural strength requirements, metal pipes often need to be bent. Metal pipe bending machines are the core equipment for this process; they use the coordinated movement of bending dies, clamping dies, and pressure dies to bend straight pipe blanks into pipes with specific angles and radii.

[0003] In bending processes involving thin-walled metal pipes or those with small bending radii, the pipe experiences tangential tensile stress on the outer side of the bending deformation zone and tangential compressive stress on the inner side. This complex stress state easily leads to cross-sectional distortion at the bend, especially on the inner wall, which is prone to instability and wrinkling under compressive stress. It can even cause excessive flattening of the bend cross-section, severely affecting the appearance quality, flow channel cross-sectional area, and pressure-bearing capacity of the pipe fittings.

[0004] To address the aforementioned issues, a common technological approach in the prior art is to introduce a mandrel. For example, the core technical solution of a pipe bending machine mandrel disclosed in patent publication number CN220658853U includes a mandrel body, a mandrel head positioned at the top of the mandrel body, and a support rod installed at the bottom of the mandrel body. The bottom of the mandrel body has an installation groove, and the top of the installation groove has a liquid storage tank. A guide hole is provided on one side of the installation groove, and a liquid guide pipe is installed inside the guide hole. One end of the liquid guide pipe is connected to the liquid storage tank. Several evenly distributed first overflow holes are provided around the circumference of the liquid storage tank.

[0005] When in use, the working part of the mandrel is inserted into the area of ​​the pipe that is about to undergo plastic deformation. The outer surface of the mandrel head abuts against the inner wall of the pipe to balance or counteract the pressure from the outer wall, thereby suppressing the elliptical deformation of the pipe cross section, preventing wrinkling of the inner wall, and ensuring the roundness and flatness of the bent part.

[0006] However, the mandrels commonly used in existing technologies have technical drawbacks in practical applications. Because the diameter of the mandrel head typically needs to be slightly smaller than the inner diameter of the tube for easy insertion and removal, an unavoidable gap exists between the outer wall of the mandrel head and the inner wall of the metal tube. Especially under conditions of concentrated bending stress and complex material flow, this gap prevents the mandrel from truly being "firmly supported" against the tube wall. When the external bending force exceeds the local stability limit of the tube, even with a mandrel present, the unsupported areas of the tube wall will still experience plastic instability, causing the metal tube to collapse or wrinkle. Furthermore, existing mandrels are generally only applicable to metal tubes of the same type, resulting in a narrow range of applications. Summary of the Invention

[0007] This invention provides a fully automatic metal pipe bending machine to solve the technical problem in the prior art where the mandrel in the metal pipe bending machine cannot truly tighten the metal pipe, causing the metal pipe to still be flattened and wrinkled during bending.

[0008] To solve the above problems, the present invention provides a fully automatic metal pipe bending machine with the following technical solution:

[0009] A fully automatic metal pipe bending machine includes a frame and a mandrel assembly and a bending module mounted on the frame. The mandrel assembly includes a mandrel and a ball head module connected to the end of the mandrel. The bending module includes a bending die. The ball head module includes multiple ball head units arranged around the central axis of the mandrel. The multiple ball head units are slidably mounted on the mandrel. The multiple ball head units can converge inward to reduce the outer diameter of the ball head module. The multiple ball head units can also expand outward to increase the outer diameter of the ball head module so that the ball head module is pressed tightly against the inner wall of the metal pipe. The ball head module pressed tightly against the inner wall of the metal pipe can press the metal pipe against the bending die.

[0010] By adopting the above technical solution, multiple ball-head units that can converge inward and expand outward are set at the end of the mandrel, allowing the ball-head module to flexibly adjust its outer diameter according to different pipe diameters, thus expanding the applicability of the equipment. Simultaneously, when the multiple ball-head units converge inward, the outer diameter of the ball-head module decreases, facilitating the insertion of the mandrel assembly into the metal tube. When the multiple ball-head units expand outward, the ball-head module is firmly supported against the inner wall of the metal tube. Compared to traditional mandrels where there is a large gap between the mandrel head and the inner wall of the metal tube, the ball-head module in this invention can better fit against the inner wall of the metal tube. This allows the inner side of the metal tube, where bending deformation is occurring, to be supported by the ball-head module and maintain a complete circular cross-section during bending. This avoids problems such as pipe wall instability, wrinkling, or collapse during bending, improving the quality of pipe bending.

[0011] Furthermore, the mandrel includes an inner shaft and an outer shaft. The outer shaft is slidably fitted on the outside of the inner shaft. The ball joint unit is radially slidably installed at the end of one of the inner shafts and the outer shaft. A push block is provided at the same end of the other inner shaft and the outer shaft. The push block is driven to cooperate with the ball joint unit. When the outer shaft and the inner shaft slide relative to each other axially, the ball joint unit is driven by the push block to slide radially along the mandrel.

[0012] By adopting the above technical solution, through the cooperation of the push block and the ball head unit, the axial movement of the push block is converted into the radial extension and retraction of the ball head unit when the inner shaft and the outer shaft slide relative to each other. The structure is compact and the transmission is reliable, making the tightening and retraction operation of the ball head module more stable and precise, and facilitating automated control.

[0013] Furthermore, the ball head unit is slidably mounted radially at the end of the inner shaft, and the push block is connected to the end of the outer shaft. Multiple ball head units enclose a conical inner cavity. The push block is inserted into the conical inner cavity and abuts against the cavity wall. When the push block slides relative to the inner shaft toward the small diameter end of the conical inner cavity with the outer shaft, it can drive each ball head unit to move outward so that the ball head module is tightly supported on the inner wall of the metal tube.

[0014] By adopting the above technical solution, the conical inner cavity in the ball head module and the inclined surface of the push block are matched to drive the radial expansion of the ball head unit when the outer shaft moves axially relative to the inner shaft. The structure is simple, the transmission is smooth, and the inner wall of the metal pipe is always tightly supported during the bending process.

[0015] Furthermore, the end of the inner shaft is provided with a mounting cavity, and a magnetic block is provided in the mounting cavity. A sliding rod is connected to the inner wall of the ball head unit. The sliding rod extends radially along the inner shaft and slides radially at the end of the inner shaft. The inner end of the sliding rod passes through the mounting cavity and is magnetic. The inner end of the sliding rod can be attracted to the magnetic block so that each ball head unit is reset to the state where the outer diameter of the ball head module is at its minimum.

[0016] By adopting the above technical solution, the ball head unit can be automatically reset by means of magnetic adsorption, which simplifies the reset mechanism. Compared with the method of setting a spring to reset the ball head unit, it avoids the failure problem caused by mechanical spring fatigue or jamming, improves the reliability and consistency of ball head unit shrinkage, and ensures that the ball head module can be restored to the minimum outer diameter before each tube insertion, which facilitates smooth insertion into metal tubes of different specifications.

[0017] Furthermore, the inner shaft is mounted on the frame to prevent rotation around its own axis, while the outer shaft is sleeved on the outside of the inner shaft to prevent rotation relative to the inner shaft.

[0018] By adopting the above technical solution and using anti-rotation installation, it is ensured that the inner shaft and outer shaft do not rotate relative to each other during relative sliding, so that the radial movement direction of the ball head unit is always consistent, avoiding misalignment or jamming of the ball head unit due to torsion, and improving the stability and lifespan of the mandrel assembly in long-term use.

[0019] Furthermore, the outer shaft includes a small-diameter shaft segment and a large-diameter shaft segment arranged sequentially along the back of the ball head module, and the junction of the small-diameter shaft segment and the large-diameter shaft segment forms a limiting step for axially limiting the metal tube.

[0020] By adopting the above technical solution, the limiting step can axially position the metal tube, prevent the metal tube from moving axially during the process of fitting the mandrel onto the outside or during bending, ensure accurate bending position, and improve the precision and consistency of pipe bending processing.

[0021] Furthermore, a metal tube feeding conveyor is provided on the side of the frame. The mandrel assembly is located between the bending module and the metal tube feeding conveyor. The end of the mandrel without the ball head module is rotatably mounted on the frame around the horizontal axis. The mandrel can rotate to the end of the metal tube feeding conveyor where the ball head module is facing the metal tube feeding conveyor to receive the metal tube. It can also rotate the ball head module toward the bending module after the ball head module has tightened the metal tube to transfer the metal tube to the bending module.

[0022] By adopting the above technical solution, the mandrel has both receiving and transfer functions. Through rotation, it realizes the automatic picking up of pipes from the feeding conveyor line and the transfer to the pipe bending module, realizing the seamless connection between the feeding and bending processes, reducing manual intervention, and improving the working efficiency and automation level of the fully automatic pipe bending machine.

[0023] Furthermore, the frame is provided with a material discharge channel, which is located between the metal tube feeding conveyor line and the mandrel. The mandrel can drive the ball head module to rotate above the material discharge channel after the metal tube is bent, and keep the ball head module tilted downward so that the bent metal tube can fall into the material discharge channel after being released by the ball head module.

[0024] By adopting the above technical solution, the bent metal tube is moved to the top of the unloading channel by rotating the mandrel and tilted to release it, realizing automatic unloading. The tube falls into the unloading channel by gravity, without the need for additional power or manual handling, which simplifies the unloading mechanism and improves unloading efficiency and automation.

[0025] Furthermore, the frame is provided with a mounting base, the mandrel assembly is connected to the mounting base, and the mounting base can rotate about a horizontal axis perpendicular to the central axis of the mandrel.

[0026] Furthermore, the mounting base can slide back and forth between the metal tube feeding conveyor line and the bending module.

[0027] By adopting the above technical solution, the mounting base has both rotation and sliding functions, which allows the mandrel to move flexibly in space. It can accurately align with the feeding conveyor line to pick up the pipe, and can also stably transport the pipe to the bending module for processing. Finally, the finished product is transferred to the unloading chamber. At the same time, it also makes the equipment applicable to metal pipes of different lengths, improves the flexibility of the equipment in a limited space and the efficiency of process connection, and expands the scope of application of the equipment.

[0028] The beneficial effects of the fully automatic metal pipe bending machine provided by this invention are as follows: By setting a radially expandable ball head unit, it solves the problem of insufficient support caused by the gap between the traditional mandrel head and the pipe wall, which easily leads to pipe wall instability, wrinkling, or collapse. It also enables adaptive tightening of metal pipes of different diameters, expanding the product's applicability. Combined with the rotation and sliding functions of the mandrel assembly, the feeding, transfer, bending, and unloading processes are efficiently integrated, achieving fully automated operation and improving production efficiency and equipment space utilization. Attached Figure Description

[0029] Figure 1 A first-view perspective three-dimensional structural diagram of a fully automatic metal pipe bending machine provided for this invention;

[0030] Figure 2 A three-dimensional structural diagram of a fully automatic metal pipe bending machine from a second perspective, provided by the present invention;

[0031] Figure 3 A front view of a fully automatic metal pipe bending machine provided by the present invention;

[0032] Figure 4 A top view of a fully automatic metal pipe bending machine provided by the present invention;

[0033] Figure 5 A side view of a fully automatic metal pipe bending machine provided by the present invention;

[0034] Figure 6 A three-dimensional structural diagram of a mandrel assembly in a fully automatic metal pipe bending machine provided by the present invention;

[0035] Figure 7 A cross-sectional view of a mandrel assembly in a fully automatic metal pipe bending machine provided by the present invention;

[0036] Figure 8 This is a simplified schematic diagram illustrating the state of a fully automatic metal pipe bending machine during processing, as provided by the present invention.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Frame; 101. Material feeding channel; 102. Material storage chamber; 2. Drive motor one; 3. Guide rail; 4. Transmission screw; 5. Drive motor two; 6. Connecting seat one; 7. Connecting seat two; 8. Mounting seat; 9. Metal pipe; 10. Movable frame; 11. Bending die; 12. Clamping block; 13. Pressure block; 14. Drive cylinder two; 15. Drive cylinder three; 16. Mounting plate; 17. Drive cylinder four; 18. 19. Stop block; 20. Drive cylinder one; 21. Ball head unit; 22. Inner shaft; 23. Mounting cavity; 24. Outer shaft; 25. Small diameter shaft section; 26. Large diameter shaft section; 27. Limiting groove; 28. Limiting step; 29. ​​Push block; 20. Limiting block; 21. Magnetic block one; 22. Sliding rod; 23. Magnetic block two; 24. Guide shaft; 25. Intermediate shaft; 36. Elastic element; 37. Connecting plate. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art should understand that the embodiments described below are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0040] The following is one embodiment of a fully automatic metal pipe bending machine provided by the present invention:

[0041] like Figures 1-8 As shown, a fully automatic metal pipe bending machine includes a frame 1, a mandrel assembly, a pipe bending module, and a metal pipe feeding and conveying line.

[0042] like Figure 1 , Figure 2 As shown, the frame 1 is arranged on a horizontal ground. The bottom of the frame 1 is provided with a material storage cavity 102, and the frame 1 is also provided with a vertically penetrating material drop channel 101 that communicates with the material storage cavity 102.

[0043] For ease of description, the length direction of frame 1 in the figure is defined as the left-right direction, and the width direction is defined as the front-back direction.

[0044] On the frame 1, there is a left-right extending guide rail 3 on each side of the front and rear of the material feeding channel 101. On the frame 1, in front of the guide rail 3 located on the rear side, there is a left-right extending transmission screw 4. On the left side of the transmission screw 4, there is a drive motor 2. The drive motor 2 is fixedly installed on the frame 1. The transmission screw 4 is connected to the drive motor 2.

[0045] Mounting assemblies are slidably mounted on two guide rails 3. The mounting assemblies include a first connecting seat 6, a second connecting seat 7, a connecting shaft assembly, and a mounting seat 8.

[0046] Connecting seat 1 (6) and connecting seat 2 (7) are slidably mounted on two guide rails 3 on the front and rear sides of the material discharge channel 101, respectively, in the left and right directions. Connecting seat 2 (7) has a transmission cavity inside, and a drive motor 2 (5) is fixedly mounted on connecting seat 2 (7). The power output end of drive motor 2 (5) passes through the transmission cavity. Connecting seat 2 (7) is screwed into the transmission screw 4. When drive motor 1 (2) drives the transmission screw 4 to rotate, it can drive connecting seat 2 (7) to slide in the left and right directions, thereby driving the mounting seat assembly to move in the left and right directions.

[0047] The connecting shaft assembly is rotatably connected between connecting seat 1 (6) and connecting seat 2 (7), such as... Figure 2 As shown, the connecting shaft assembly includes a connecting plate 31, an intermediate shaft 29, and a guide shaft 28.

[0048] There are two connecting plates 31, which are arranged at intervals and are both located between connecting seat 1 6 and connecting seat 2 7.

[0049] The intermediate shaft 29 extends forward and backward and is connected to two connecting plates 31. The front end of the intermediate shaft 29 passes through the connecting plate 31 located on the front side and is rotatably mounted on the connecting seat 6. The rear end of the intermediate shaft 29 passes through the connecting plate 31 located on the rear side and passes through the transmission cavity on the connecting seat 7. The rear end of the intermediate shaft 29 is connected to the power output end of the drive motor 5 located in the transmission cavity.

[0050] There are two guide shafts 28. Both guide shafts 28 extend in the front-back direction and are fixedly connected between the two connecting plates 31. The two guide shafts 28 are respectively located on the left and right sides of the intermediate shaft 29.

[0051] The connecting shaft assembly is an integral structure formed by an intermediate shaft 29, two guide shafts 28 and two connecting plates 31. The front and rear ends of the intermediate shaft 29 are respectively rotatably mounted on connecting seat 6 and connecting seat 7. When the intermediate shaft 29 rotates, it will drive the entire connecting shaft assembly to rotate.

[0052] Mounting base 8 is slidably fitted onto the outside of intermediate shaft 29 and two guide shafts 28 in the front-to-back direction. Mounting base 8 and the connecting shaft assembly are relatively anti-rotating. An elastic element 30 capable of extending and retracting in the front-to-back direction is connected between mounting base 8 and connecting plate 31 located at the rear. The elastic element 30 applies a forward elastic force to mounting base 8 and is a spring sleeved on the outside of intermediate shaft 29. A drive cylinder 19 is also fixedly mounted on mounting base 8, and drive cylinder 19 has a drive output end capable of extending and retracting left and right.

[0053] The aforementioned drive motor 25 can drive the connecting shaft assembly to rotate around the central axis of the intermediate shaft 29, thereby causing the mounting base 8 to rotate around the central axis of the intermediate shaft 29.

[0054] like Figure 6 , Figure 7 As shown, the mandrel assembly includes a mandrel and a ball head module. The mandrel includes an inner shaft 21 and an outer shaft 22. The left end of the inner shaft 21 is fixedly mounted on the mounting base 8, and the right end of the inner shaft 21 is provided with a mounting cavity 211. A cylindrical magnetic block 25 is fixedly mounted in the center of the mounting cavity 211. A ring of limiting blocks 24 is also provided on the outer side wall of the inner shaft 21, evenly arranged around the central axis of the inner shaft 21. The limiting blocks 24 are located on the left side of the mounting cavity 211.

[0055] The outer shaft 22 is slidably fitted onto the outside of the inner shaft 21. The outer shaft 22 includes a large-diameter shaft section 222 and a small-diameter shaft section 221 connected sequentially from left to right. The left end of the large-diameter shaft section 222 is connected to the drive output end of the aforementioned drive cylinder 19. A limiting step 224 is formed at the connection position between the large-diameter shaft section 222 and the small-diameter shaft section 221. The limiting step 224 is used to axially limit the metal tube 9 fitted onto the outside of the outer shaft 22. A limiting groove 223 is provided on the side wall of the small-diameter shaft section 221, which is evenly distributed around the central axis of the small-diameter shaft section 221. The limiting groove 223 extends in the left and right direction, and the aforementioned limiting blocks 24 are respectively inserted into the limiting grooves 223. A push block 23 is connected to the right end of the small-diameter shaft section 221, which is evenly distributed around the central axis of the small-diameter shaft section 221. The multiple push blocks 23 form a hemispherical pushing structure.

[0056] The ball head module is connected to the right end of the inner shaft 21. The ball head module includes multiple ball head units 20, which are evenly distributed around the central axis of the inner shaft 21. The multiple ball head units 20 enclose a conical inner cavity, with the smaller diameter end of the conical inner cavity facing to the right. The aforementioned push blocks 23 are inserted into the conical inner cavity. A sliding rod 26 extending radially along the inner shaft 21 is connected to the inner wall of the ball head unit 20. The sliding rod 26 slides along the inner shaft 21 radially, and its inner end passes through the mounting cavity 211 on the inner shaft 21. A magnetic block 27 is connected to the inner end of the sliding rod 26.

[0057] Magnetic block 27 can be attracted to magnetic block 25 to keep each ball head unit 20 in the position closest to the central axis of the inner shaft 21, thus keeping the outer diameter of the ball head module in a minimum state. The drive cylinder 19 can drive the outer shaft 22 to slide to the right relative to the inner shaft 21, and the push block 23 pushes each ball head unit 20 through the cavity wall of the conical inner cavity, so that each ball head unit 20 moves away from the central axis of the inner shaft 21 at the same time, thereby increasing the outer diameter of the ball head module and supporting it tightly against the inner wall of the metal tube 9.

[0058] like Figures 1-5 As shown, the pipe bending module includes a bending die 11, a movable frame 10, a pressure block 13, and a stop block 18. The structure of the pipe bending module is described below in its position before it starts working.

[0059] The bending die 11 is located on the right side of the frame 1. The bending die 11 has an arc-shaped forming groove with a semi-circular cross-section. The central axis of the forming groove extends vertically, and the arc-shaped opening faces directly to the right. The bending die 11 is rotatably mounted on the frame 1 around the central axis of the forming groove.

[0060] A clamping block 12 is provided at the front entrance of the forming groove on the bending die 11. A straight groove with a semi-circular cross-section is provided on the front side of the clamping block 12. The opening of the straight groove faces forward and is tangent to the entrance end of the forming groove.

[0061] The movable frame 10 is located on the right side of the frame 1, and the rear end of the movable frame 10 is rotatably mounted on the frame 1 about the central axis of the bending mold 11.

[0062] The pressure block 13 is positioned directly opposite the clamping block 12 on the front side of the clamping block 12. A second straight groove with a semi-circular cross-section is located on the rear side of the pressure block 13, with its opening opposite to that of the first straight groove. The pressure block 13 is guided and slidably mounted on the movable frame 10 in the front-back direction. The movable frame 10 is also equipped with a second drive cylinder 14, which has a drive output end capable of extending and retracting forward and backward. The pressure block 13 is connected to the drive output end of the second drive cylinder 14, enabling the second drive cylinder 14 to drive the pressure block 13 to move backward, bringing the pressure block 13 and the clamping block 12 closer together to clamp the metal tube 9.

[0063] The stop block 18 is elongated and located to the left of the pressure block 13 and in front of the bending die 11. A straight groove 3 is provided on the rear side of the stop block 18. The cross-section of the straight groove 3 is semi-circular and the opening faces backward. The straight groove 3 is positioned directly in front of the horizontally arranged mandrel.

[0064] The stop block 18 is mounted on the frame 1 and is movable in both left-right and front-back directions. The specific connection method of the stop block 18 on the frame 1 is as follows: a third drive cylinder 15 is mounted on the frame 1. The third drive cylinder 15 has a drive output end capable of moving back and forth. A mounting plate 16 is connected to the drive output end of the third drive cylinder 15. The stop block 18 is guided and slidably mounted on the mounting plate 16 in the left-right direction. A fourth drive cylinder 17 is mounted on the mounting plate 16. The fourth drive cylinder 17 has a drive output end capable of moving left and right. The stop block 18 is connected to the drive output end of the fourth drive cylinder 17. With the above structure, the stop block 18 can move back and forth under the drive of the third drive cylinder 15 and move left and right under the drive of the fourth drive cylinder 17.

[0065] like Figure 8As shown, when the bending module is in use, the second drive cylinder 14 drives the pressure block 13 to move backward, clamping the metal tube 9 between the pressure block 13 and the clamping block 12. The fourth drive cylinder 17 is activated, causing the stop block 18 to push the metal tube 9, which is fitted on the outside of the mandrel, to press it against the bending mold 11. The ball head module then presses the metal tube 9 against the forming groove on the bending mold 11 from the inside of the metal tube 9. The movable frame 10 is driven to rotate around the vertical central axis of the bending die 11. The movable frame 10 drives the pressure block 13 to rotate. Since the pressure block 13 presses and fixes the metal tube 9 onto the clamping block 12, and the clamping block 12 is fixed onto the bending die 11, the pressure block 13 and the clamping block 12 will rotate together with the bending die 11. The pressure block 13 and the clamping block 12 will rotate with the metal tube 9. Since the ball head module presses the metal tube 9 onto the bending die 11, when the pressure block 13 and the clamping block 12 rotate with the metal tube 9, the metal tube 9 will bend around the forming groove in the bending die 11, thereby realizing the bending of the metal tube 9.

[0066] The metal tube feeding conveyor line is located on the left side of the frame 1. This line transports metal tubes 9 from left to right. The mounting base 8 rotates the mandrel assembly so that the ball head module faces due left, aligning it with the metal tube 9 transported by the conveyor line, thus allowing it to be inserted into the metal tube 9. The metal tube feeding conveyor line is a belt conveyor, not shown in the figure.

[0067] Mounting base 8 can also drive the mandrel assembly to rotate so that the ball head module is above the material discharge channel 101 and remains tilted downwards, so as to discharge the processed metal tube 9.

[0068] The outer side of the ball head unit 20 is coated with lubricating oil. When the ball head unit 20 is pressed against the inner wall of the metal tube 9, the pressing force prevents the metal tube 9 from sliding relative to the ball head module when no external force is applied. This allows the mandrel assembly to drive the metal tube 9 to swing between the metal tube feeding conveyor line and the bending module. When the metal tube 9 is bent, it can slide relative to the ball head module when it is subjected to the pulling force of the rotating pressure block 13 and clamping block 12 in the bending module, thus allowing it to be bent smoothly.

[0069] The above-mentioned pipe bending module is existing technology, and its structure will not be described in detail here.

[0070] In use, the second drive motor 5 first drives the mounting base 8 to rotate. The mounting base 8 then rotates the mandrel assembly to the left side of the mounting base 8, with the ball head module facing directly to the left. At this time, each magnetic block 2 is attracted to the first magnetic block, and the ball head module is in its smallest outer diameter state, facing the metal tube feeding conveyor line. As the metal tube 9 on the metal tube feeding conveyor line moves to the right, the ball head module automatically inserts into the metal tube 9. When the metal tube 9 is blocked by the limiting step 224 on the outer shaft 22, the first drive cylinder 19 is activated, causing the outer shaft 22 to slide to the right relative to the inner shaft 21. The push block 23 pushes each ball head unit 20 to move outward synchronously, and each ball head unit 20 is supported tightly against the inner wall of the metal tube 9, achieving temporary relative fixation between the mandrel assembly and the metal tube 9.

[0071] Drive motor 2 drives mounting base 8 to rotate 180 degrees clockwise. The mandrel assembly, carrying the metal tube 9, flips to the right side of mounting base 8 and remains horizontal. Drive motor 1 drives transmission screw 4 to rotate, adjusting the left and right position of mounting base 8 and positioning the metal tube 9 in a suitable position so that the ball head module abuts against the bending die 11 through the wall of the metal tube 9. Drive cylinder 3 is activated, causing stop block 18 to push the metal tube 9 backward, pressing the metal tube 9 onto the bending die 11. Start the second drive cylinder 14 to make the pressure block 13 cooperate with the clamping block 12 to clamp the end of the metal tube 9. Then drive the movable frame 10 to rotate around the rotation center. The pressure block 13 rotates with the movable frame 10. Since the pressure block 13 and the clamping block 12 clamp the end of the metal tube 9, the pressure block 13 will drive the bending die 11 and the metal tube 9 to rotate. Since the metal tube 9 is pressed on the bending die 11 by the ball head module, the metal tube 9 will bend and deform around the arc-shaped forming groove on the bending die 11 when it rotates, thereby realizing the bending process of the metal tube 9.

[0072] After the metal tube 9 is processed, the pressure block 13 and the stop block 18 release the metal tube 9. Under the action of the elastic element 30, the mounting seat 8 moves forward a distance to reset, driving the metal tube 9 forward a distance so that the metal tube 9 is disengaged from the forming groove on the bending die 11. The drive motor 5 is started again, driving the mounting seat 8 to rotate counterclockwise. The mandrel assembly brings the bent metal tube 9 to the top of the discharge channel 101, and the mandrel is kept in a downward tilted state. The drive cylinder 19 is started to release the ball head module from the metal tube 9. The processed metal tube 9 falls into the discharge channel 101 under its own weight and is collected in the storage chamber 102.

[0073] The ball-head module of this invention can be firmly supported on the inner wall of the metal tube 9, providing more robust and stable support during bending. This effectively prevents the metal tube 9 from being crushed or wrinkled during bending, resulting in better forming quality. Furthermore, this invention can also support and fix various types of metal tubes 9, broadening its applicability.

[0074] In this embodiment, the ball head unit 20 is installed at the end of the inner shaft 21, and the same end of the outer shaft 22 is connected to a push block 23 for pushing the ball head unit 20. In other embodiments, the ball head unit 20 is connected to the end of the outer shaft 22, and the push block 23 is connected to the end of the inner shaft 21. In this case, the outer shaft 22 is fixed on the mounting base 8, and the ball head unit 20 is pushed outward by driving the inner shaft 21 to slide relative to the outer shaft 22.

[0075] In this embodiment, a magnetic block 25 is provided in the mounting cavity 211 at the end of the inner shaft 21. A sliding rod 26 is connected to the inner wall of the ball head unit 20. A magnetic block 27 is connected to the inner end of the sliding rod 26. The magnetic block 25 attracts the magnetic block 27 and drives the ball head unit 20 to move inward, thereby realizing the reset of the ball head unit 20. In other embodiments, the ball head unit 20 is connected to the inner shaft 21 by a spring that can extend and retract radially along the inner shaft 21. When the spring resets, the ball head unit 20 converges inward, thereby realizing the reset of the ball head unit 20. At this time, since the spring will deform after long-term use, the spring needs to be replaced periodically.

[0076] In this embodiment, the outer shaft 22 includes a large-diameter shaft segment 222 and a small-diameter shaft segment 221. A limiting step 224 for axially limiting the metal tube 9 is formed at the junction of the large-diameter shaft segment 222 and the small-diameter shaft segment 221. In other embodiments, the outer shaft 22 is a smooth straight rod of equal diameter. In this case, the position of the metal tube 9 on the outer shaft 22 is adjusted by manually adjusting the relative position of the metal tube 9 and the outer shaft 22.

[0077] In this embodiment, the frame 1 is provided with a material discharge channel 101. After the metal tube 9 is bent and formed, the mandrel assembly directly brings the bent metal tube 9 to the top of the material discharge channel 101 to achieve material discharge. In other embodiments, the frame 1 is not provided with a material discharge channel 101. After the metal tube 9 is processed, the bent metal tube 9 is manually removed.

Claims

1. A fully automatic metal pipe bending machine, comprising a frame (1) and a mandrel assembly and a pipe bending module mounted on the frame (1), the mandrel assembly comprising a mandrel and a ball head module connected to the end of the mandrel, the pipe bending module comprising a bending die (11), characterized in that, The ball head module includes multiple ball head units (20) arranged around the central axis of the mandrel. The multiple ball head units (20) are all slidably mounted on the mandrel. The multiple ball head units (20) can converge inward to reduce the outer diameter of the ball head module. The multiple ball head units (20) can also expand outward to increase the outer diameter of the ball head module so that the ball head module is supported on the inner wall of the metal tube (9). The ball head module supported on the inner wall of the metal tube can press the metal tube onto the bending die (11). A metal tube feeding conveyor is provided on the side of the frame (1). The mandrel assembly is located between the bending module and the metal tube feeding conveyor. The end of the mandrel without the ball head module is rotated around the horizontal axis and installed on the frame (1). The mandrel can rotate to the end of the conveyor where the ball head module is facing the metal tube feeding conveyor to receive the metal tube (9). It can also drive the ball head module to rotate toward the bending module after the ball head module supports the metal tube (9) to transfer the metal tube (9) to the bending module. The frame (1) is provided with a material drop channel (101). The material drop channel (101) is located between the metal tube feeding conveyor line and the mandrel. The mandrel can drive the ball head module to rotate above the material drop channel (101) after the metal tube (9) is bent, and keep the ball head module tilted downward so that the bent metal tube (9) can fall into the material drop channel (101) after being released by the ball head module. The frame (1) is provided with a mounting base (8), and the mandrel assembly is connected to the mounting base (8). The mounting base (8) can rotate around a horizontal axis perpendicular to the central axis of the mandrel. As the mounting base (8) rotates, the mounting base (8) drives the mandrel assembly to rotate to the left side of the mounting base (8) with the ball head module facing directly to the left. At this time, the ball head module is in the state of minimum outer diameter, and the ball head module is facing the metal tube feeding conveyor line. As the metal tube (9) on the metal tube feeding conveyor line moves to the right, the ball head module automatically inserts into the metal tube (9). After multiple ball head units (20) expand outward to make the ball head module support the inner wall of the metal tube (9), the mounting base (8) rotates 180 degrees clockwise, and the mandrel assembly drives the metal tube (9) to flip to the correct position. On the right side of the mounting base (8) and kept horizontal, the metal tube (9) is adjusted to a suitable position by adjusting the left and right positions of the mounting base (8), so that the ball head module abuts against the bending die (11) through the tube wall of the metal tube (9). Under the action of the bending module, the metal tube (9) is bent. After the metal tube (9) is processed, the mounting base (8) is rotated counterclockwise, and the mandrel assembly brings the bent metal tube (9) to the top of the dropping channel (101). The ball head module releases the metal tube (9), and the processed metal tube (9) falls into the dropping channel (101) under its own weight.

2. A fully automatic pipe bending machine according to claim 1, characterized in that The spindle includes an inner shaft (21) and an outer shaft (22). The outer shaft (22) is slidably fitted on the outside of the inner shaft (21). The ball head unit (20) is slidably installed at the end of one of the inner shaft (21) and the outer shaft (22). The other end of the inner shaft (21) and the outer shaft (22) is provided with a push block (23). The push block (23) is driven to cooperate with the ball head unit (20). When the outer shaft (22) and the inner shaft (21) slide relative to each other in the axial direction, the ball head unit (20) is driven by the push block (23) and slides radially along the spindle.

3. A fully automatic pipe bending machine according to claim 2, characterized in that The ball head unit (20) is slidably installed at the end of the inner shaft (21) in the radial direction. The push block (23) is connected to the end of the outer shaft (22). Multiple ball head units (20) surround a conical inner cavity. The push block (23) is inserted into the conical inner cavity and abuts against the cavity wall. When the push block (23) slides relative to the inner shaft (21) toward the small diameter end of the conical inner cavity with the outer shaft (22), it can drive each ball head unit (20) to move outward so that the ball head module is supported on the inner wall of the metal tube (9).

4. A fully automatic pipe bending machine according to claim 3, characterized in that The inner shaft (21) has a mounting cavity (211) at its end. A magnetic block is provided in the mounting cavity (211). A sliding rod (26) is connected to the inner wall of the ball head unit (20). The sliding rod (26) extends radially along the inner shaft (21) and slides radially at the end of the inner shaft (21). The inner end of the sliding rod (26) passes through the mounting cavity (211) and is magnetic. The inner end of the sliding rod (26) can be attracted to the magnetic block so that each ball head unit (20) is reset to the state where the outer diameter of the ball head module is the smallest.

5. The fully automatic metal pipe bending machine according to claim 4, characterized in that, The inner shaft (21) is mounted on the frame (1) to prevent rotation around its own axis, and the outer shaft (22) is sleeved on the outside of the inner shaft (21) to prevent rotation relative to the inner shaft (21).

6. A fully automatic metal pipe bending machine according to any one of claims 1-5, characterized in that, The outer shaft (22) includes a small diameter shaft section (221) and a large diameter shaft section (222) arranged sequentially along the back ball head module. The connection between the small diameter shaft section (221) and the large diameter shaft section (222) forms a limiting step (224) for axially limiting the metal tube (9).

7. The fully automatic pipe bending machine according to claim 1, wherein The mounting base (8) can slide back and forth between the metal pipe feeding conveyor line and the bending module.

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