Pipe fitting free-bending forming device capable of integrated variable-axis machining

Abstract

Disclosed in the present invention is a pipe fitting free-bending forming device capable of integrated variable-axis machining. A base moving module is used for providing a bending die with translational degrees of freedom in the X direction and the Y direction. A precision adjustment module comprises two state switching modules and two auxiliary adjustment modules, wherein changing the positions of rotary motors in the state switching modules and of passive shafts in the auxiliary adjustment modules can realize switching of the bending die among follow-up, semi-active and active states, so as to adjust the number of machining axes of the device. A fixed guide module is located at the rear side of a bending machining module, the fixed guide module always remaining stationary during machining. An arc surface at the front end of a guide mechanism is in contact with guide tail fins of the bending machining module, so as to control the machining orientation of the bending die in the follow-up and semi-active states. The device achieves integrated multi-axis machining of pipe fitting free bending devices, and can expand the application range of the complete device while improving the quality and efficiency of pipe bending machining.

Description

An integrated variable-axis machining device for free bending and forming of pipe fittings Technical Field

[0001] This invention relates to a device for free bending and forming of metal tubes, and more particularly to a device for free bending and forming of tubes with integrated variable shaft processing. Background Technology

[0002] Metal bends are key components for fuel delivery and cooling in high-end manufacturing products such as aerospace, automotive, and shipbuilding. Free bending forming devices for pipes offer high processing flexibility, enabling the one-time bending forming of spatially complex bend configurations.

[0003] In traditional free bending forming devices for pipe fittings, the number of motion axes is fixed after manufacturing and assembly. Common free bending devices for pipe fittings can be divided into three-axis, four-axis, and five-axis types. Higher axis count devices cannot achieve free bending processing with lower axis counts due to structural limitations. Increasing the number of axes can improve the processing accuracy of the free bending device, but it also reduces the overall stability of the device and increases processing costs due to the addition of an extra motor. Free bending devices with a fixed number of axes can only meet the free bending processing needs within a certain range. Under conditions of constantly changing processing requirements, it is difficult to balance bending accuracy and stability, easily leading to problems such as insufficient processing precision.

[0004] In order to expand the application scope of the free bending device for pipe fittings and to achieve a dynamic balance between the processing accuracy and stability of the free bending device, there is a need for a multi-axis integrated free bending forming device for pipe fittings that can adjust the number of processing axes as needed. Summary of the Invention

[0005] To address the problems in the background art, this invention provides an integrated variable axis processing tube free bending forming device. By changing the position of the rotary motor, the passive shaft, and the number of guide tail wings in the precision adjustment module, the number of processing axes can be switched. Different numbers of processing axes can be selected when facing tube bending with different forming requirements, thereby improving the processing efficiency and final forming quality of the tube bending.

[0006] The technical solution adopted in this invention is as follows: 1. A basic moving module for an integrated variable-axis processing tube free bending forming device, used to adjust the translational degrees of freedom of the X and Y axes of the device; a precision adjustment module fixedly connected to the basic moving module, used to switch the processing state of the bending processing module, thereby adjusting the number of processing axes of the device; a fixed guide module, used to guide the straight tube blank; and a bending processing module installed in the precision adjustment module, used to process the straight tube blank and complete the free bending forming of the straight tube blank.

[0007] The basic movement module includes an X-axis linear translation module and a Y-axis linear translation module. The Y-axis linear translation module is fixedly connected to the X-axis linear translation module, and the Y-axis linear translation module is fixedly connected to the precision adjustment module.

[0008] The precision adjustment module includes a main mounting module, two state switching modules, and two auxiliary adjustment modules. The main mounting module includes a main support plate, cross roller bearings, a bending die mounting base, and a drive shaft. The main support plate of the main mounting module is fixedly connected to the base moving module. The bending processing module is set inside the bending die mounting base, whose four sides are sequentially designated as RX side, RY side, A side, and B side. The RY side of the bending die mounting base is mounted on the main support plate via cross roller bearings. The two state switching modules are designated as the RX axis state switching module and the RY axis state switching module, respectively. The state switching module is installed on the RX side of the bending die mounting base, and the RY axis state switching module is installed on the RY side of the bending die mounting base. Two auxiliary adjustment modules are respectively set on the A and B sides of the bending die mounting base, and the passive shaft of each auxiliary adjustment module is connected to the bending processing module. A drive shaft is also fixedly installed on the RY side of the bending die mounting base. A cross roller bearing, the RY side plate of the bending die mounting base, the drive shaft and the bending processing module are arranged sequentially along the axial direction of the output shaft of the RY axis state switching module. The position where the output shaft of the RY axis state switching module is fixedly connected to the drive shaft 42 is marked as position 3.

[0009] The state switching module includes a rotary motor, a rotary motor mounting component, and an axial position control module. The rotary motor mounting component is installed on the corresponding side of the bending die mounting base through the axial position control module. The rotary motor is fixedly installed in the rotary motor mounting component. The axial position control module is used to adjust the axial displacement of the rotary motor, so that the connection state of the output shaft of the rotary motor is switched, thereby switching the processing state of the bending processing module.

[0010] The axial position control module includes a second slide rail, a second slider, a drive gear, a linear rack, and a gear motor. The linear rack is fixedly connected to the bending die mounting base, the gear motor is fixedly connected to the rotary motor mounting component, the output shaft of the gear motor is coaxially fixedly connected to the drive gear, and the drive gear meshes with the linear rack to form a gear rack pair. The second slide rail is fixedly connected to the bending die mounting base, and the second slider is slidably mounted in the second slide rail. The gear motor drives the rotary motor mounting component to slide axially along the output shaft of the rotary motor through the gear rack pair, while the second slider slides axially along the output shaft of the rotary motor in the second slide rail.

[0011] In the RY axis state switching module, the rotary motor mounting component is also provided with a limit post. When the output shaft of the rotary motor in the RY axis state switching module is fixedly connected to the bending mold support or guide block in the bending processing module, the limit post is locked in the RY limit hole on the drive shaft.

[0012] The auxiliary adjustment module includes a cylinder and a passive shaft. The output shaft of the cylinder is fixedly connected to the passive shaft, and the passive shaft is connected to the bending processing module.

[0013] The bending processing module includes a bending die, a bending die support, a guide block, a limiting block, and a compression spring. The bending die support is installed within the bending die mounting base of the precision adjustment module, and the bending die is rotatably mounted within the bending die support. Both ends of the bending die have inward-facing grooves, and the middle of the bending die has an axial hole. The straight tube blank is placed in the hole in the middle of the bending die, and the inner wall of the hole in the middle of the bending die is arc-shaped and serves as the working surface of the straight tube blank. Axial guide grooves are opened on the RX and RY sides of the bending die, and a corresponding guide block is installed in each guide groove. One end of the guide groove is open. A limit block is installed at the end face of the bending die at the opening of the groove. Corresponding compression springs are installed in the guide grooves at both ends of the guide blocks on the RX and RY sides. Corresponding countersunk holes are opened on the A and B sides of the bending die. The output shaft of the state switching module / passive shaft of the auxiliary adjustment module cooperates with the bending die support. The position where the output shaft of the state switching module / passive shaft of the auxiliary adjustment module cooperates with the bending die support is marked as position 1. Or the output shaft of the state switching module / passive shaft of the auxiliary adjustment module cooperates with the bending die. The position where the output shaft / passive shaft of the state switching module cooperates with the bending die is marked as position 2.

[0014] The bending processing module also includes a guide tail fin, which is fixedly installed at the input end of the bending die.

[0015] II. A processing method for free bending and forming of pipe fittings. The processing method uses the aforementioned integrated variable axis processing device for free bending and forming of pipe fittings. The processing method includes the following steps: When performing three-axis processing of a straight pipe blank, a guide tail wing is installed in the device, the fixed guide module is in close contact with the guide tail wing, and the output shafts of the RX axis state switching module and the RY axis state switching module, as well as the passive shafts of the auxiliary adjustment modules on the A side and the B side, are all located at position 1, so that the bending die is in a follow-up state, completing the three-axis processing of the straight pipe blank; When performing four-axis processing of a straight pipe blank, a guide tail wing is installed in the device, the fixed guide module is in close contact with the guide tail wing, the output shaft of the RX axis state switching module or the output shaft of the RY axis state switching module is in position 2, the output shaft of the RY axis state switching module or the RX axis state switching module is in position 1, and the passive shafts of the auxiliary adjustment modules on the A side and the B side are all located at position 1, so that the bending die is in a semi-active state, completing the four-axis processing of the straight pipe blank; When performing five-axis machining of a straight tube blank, the output axis of the RX axis state switching module is in position 1, the output axis of the RY axis state switching module is in position 3, and the passive axes of the auxiliary adjustment modules on sides A and B are both in position 2, so that the bending die is in an active state and the five-axis machining of the straight tube blank is completed.

[0016] The beneficial effects of the present invention are as follows: (1) The present invention can switch between different processing axes by adjusting the position of the rotary motor and the passive shaft. When facing pipes with different forming requirements, different numbers of axes are used for processing. While improving the efficiency of pipe bending and forming quality, it can also improve the overall applicability of the equipment.

[0017] (2) The axis switching method of the present invention is simple and efficient. Operators can quickly switch between different configurations such as three-axis, four-axis, and five-axis, reducing the time and difficulty of complex adjustments, further improving processing flexibility, and shortening the production cycle. The initial position of the bending die can be adjusted by the guide tail wing on the rear side of the bending die.

[0018] (3) This invention integrates the advantages of various free bending forming devices. The overall design of the device is compact, ensuring full utilization of the bending processing space and reducing the possibility of interference between the forming pipe section and various molds. Attached Figure Description

[0019] Figure 1 is a schematic diagram of the overall device of the present invention.

[0020] Figure 2 is a schematic diagram of the basic moving module; where (a) is a three-dimensional axonometric view of the basic moving module and (b) is an exploded view of the basic moving module.

[0021] Figure 3 is a schematic diagram of the precision adjustment module.

[0022] Figure 4 is an exploded view of the state switching module.

[0023] Figure 5 is a schematic diagram of the auxiliary adjustment module.

[0024] Figure 6 is an exploded view of the main installation module.

[0025] Figure 7 is a schematic diagram of the drive shaft; where (a) is the front view of the drive shaft and (b) is the side view of the drive shaft.

[0026] Figure 8 is a schematic diagram of the bending processing module; where (a) is schematic diagram one of the bending processing module and (b) is schematic diagram two of the bending processing module.

[0027] Figure 9 is a schematic diagram of the bending mold support.

[0028] Figure 10 is a schematic diagram of a bending mold with all kinds of parts assembled.

[0029] Figure 11 is a schematic diagram of a bending die; where (a) is schematic diagram one of the bending die, (b) is schematic diagram two of the bending die, and (c) is schematic diagram three of the bending die.

[0030] Figure 12 is a schematic diagram of the limiting block; where (a) is schematic diagram one of the limiting block and (b) is schematic diagram two of the limiting block.

[0031] Figure 13 is a schematic diagram of the guide block; where (a) is schematic diagram one of the guide block, (b) is schematic diagram two of the guide block, and (c) is schematic diagram three of the guide block.

[0032] Figure 14 is a schematic diagram of the shaft system of the bending processing module and the precision adjustment module in the RX-A direction.

[0033] Figure 15 is a structural schematic diagram of the fixed guide module; where (a) is an overall schematic diagram of the fixed guide module, (b) is a schematic diagram of the guide mechanism (I), (c) is a schematic diagram of the guide mechanism (II), and (d) is a schematic diagram of the guide mechanism fixing component.

[0034] Figure 16 is a schematic diagram of the state switching module, auxiliary adjustment module and guide tail fin when the bending die is in the follow-up state; where (a) is a cross-sectional view of the state switching module and auxiliary adjustment module when the bending die is in the follow-up state; (b) is a cross-sectional view of the state switching module and auxiliary adjustment module when the bending die is in the follow-up state; and (c) is an axonometric view of the state switching module and auxiliary adjustment module when the bending die is in the follow-up state.

[0035] Figure 17 is a schematic diagram of the state switching module, auxiliary adjustment module and guide tail fin when the bending die is in a semi-active state; where (a) is a cross-sectional view of the state switching module and auxiliary adjustment module when the bending die is in a semi-active state; (b) is a cross-sectional view of the state switching module and auxiliary adjustment module when the bending die is in a semi-active state; and (c) is an axonometric view of the state switching module and auxiliary adjustment module when the bending die is in a semi-active state.

[0036] Figure 18 is a schematic diagram of the state switching module, auxiliary adjustment module and guide tail fin when the bending die is in the active state; where (a) is a cross-sectional view of the state switching module and auxiliary adjustment module when the bending die is in the active state; and (b) is an axonometric view of the state switching module and auxiliary adjustment module when the bending die is in the active state.

[0037] Figure 19 is a cross-sectional view of the overall structure of the present invention.

[0038] Figure 20 is a schematic diagram of the processing of the device proposed in this invention in a follow-up state.

[0039] In the diagram: 1. Basic moving module, 2. Precision adjustment module, 3. Fixed guide module, 4. Bending processing module, 5. Straight tube blank, 6. Y-axis motor, 7. Motor mounting base, 8. Vertical secondary support plate, 9. X-axis motor, 10. Support beam, 11. Motor mounting plate, 12. First slider, 13. First slide rail, 14. Horizontal support plate, 15. Ball screw, 16. Vertical primary support plate, 17. Tail end bearing seat, 18. Nut fixing seat, 19. Screw nut, 20. Front end bearing seat, 21. First key, 22. Coupling, 23. Main body mounting module, 24. State switching module, 25. Auxiliary adjustment module, 26. Slide rail mounting component, 27. 28. Second slide rail; 29. ​​Second slider; 30. Rotary motor; 31. Second key; 32. Drive gear; 33. Linear rack; 34. Rack mount; 35. Rotary motor mount; 36. Gear motor; 37. Gear motor mount; 38. Passive shaft; 39. Cylinder; 40. Main support plate; 41. Cross roller bearing; 42. Bending die mounting base; 43. Drive shaft; 44. Thrust bearing; 45. Flange bearing; 46. Bending die support; 47. Bending die; 48. Guide tail wing; 49. Guide block; 50. Compression spring; 51. Limit block; 52. Third key; 53. Guide mechanism; 54. Guide mechanism fixing part; 55. Limit post. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation examples.

[0041] As shown in Figures 1 and 19, the integrated variable-axis processing tube bending forming device proposed in this invention includes: a basic moving module 1, used to adjust the translational degrees of freedom of the device's X and Y axes, providing the device with motion degrees of freedom in the X and Y directions; a precision adjustment module 2 fixedly connected to the basic moving module 1, used to switch the processing state of the bending processing module 4, specifically by changing the position of the rotary motor 29 in the state switching module 24 and the passive shaft 37 in the auxiliary adjustment module 25 to switch the bending mold 46 between three states: follow-up, semi-active, and active, thereby adjusting the number of processing axes of the device; the precision adjustment module 2 is connected in series with the basic moving module 1, and the number of processing axes of the device can be switched by changing the position of the two rotary motors 29 and the two passive shafts 37 in the precision adjustment module 2.

[0042] The fixed guide module 3 is used to guide the straight tube blank 5. Located behind the bending module 4, the fixed guide module 3 forms a physical constraint with the guide tail wing 47 behind the bending module 4 to control the spatial attitude of the bending die 46 in both servo and semi-active states. The fixed guide module 3 serves two purposes: first, to adjust the attitude of the bending die 46 (i.e., its rotation around the RX and RY axes) in both servo and semi-active states; and second, to guide the straight tube blank 5, preventing instability or deformation of the unprocessed section of the straight tube blank 5 (i.e., the section behind the bending module that contacts the fixed guide module).

[0043] The bending module 4, installed in the middle of the precision adjustment module 2, is used to process the straight tube blank 5, completing the free bending forming of the straight tube blank 5. The bending module 4 is in direct contact with the straight tube blank 5 to apply the forming load required for bending the tube.

[0044] As shown in Figure 2(a) and Figure 2(b), the basic moving module 1 includes an X-axis linear translation module and a Y-axis linear translation module. The Y-axis linear translation module is fixedly connected to the X-axis linear translation module, and the Y-axis linear translation module is fixedly connected to the precision adjustment module 2.

[0045] The X-axis linear translation module includes an X-axis motor 9, a first slider 12, a first slide rail 13, a transverse support plate 14, a first lead screw nut, and a ball screw 15. The first slide rail 13 and the X-axis motor 9 are bolted together in a transverse arrangement in the transverse support plate 14. Four first sliders 12 are slidably mounted in the first slide rail 13. The ball screw 15 is also mounted in the transverse support plate 14 through a bearing mounting seat. The first lead screw nut is sleeved in the ball screw 15. The axis of the ball screw 15 is denoted as the X-axis, and the track direction of the first slide rail 13 is parallel to the axis of the ball screw 15. One end of the ball screw 15 is coaxially fixed to the output shaft of the X-axis motor 9. The vertical primary support plate 16 of the Y-axis linear translation module is fixedly connected to the first slider 12 and the first nut fixing seat. The rotation of the X-axis motor 9 drives the ball screw 15 to rotate, thereby driving the Y-axis linear translation module to move on the X-axis.

[0046] The Y-axis linear translation module includes a Y-axis motor 6, a motor mounting base 7, a vertical secondary support plate 8, a support beam 10, a motor mounting plate 11, a vertical primary support plate 16, a tail bearing seat 17, a nut fixing seat 18, a Y-axis lead screw, a Y-axis guide rail, a lead screw nut 19, a front bearing seat 20, and a coupling 22. The Y-axis motor 6 is fixedly mounted in the vertical primary support plate 16 via the motor mounting base 7. The two ends of the Y-axis lead screw are mounted on the vertical primary support plate 16 via the tail bearing seat 17 and the front bearing seat 20. In the support plate 16, a vertically arranged Y-axis guide rail and a Y-axis lead screw are installed in the vertical primary support plate 16. Four Y-axis sliders are slidably installed in the Y-axis guide rail. The lead screw nut 19 is sleeved in the Y-axis lead screw. The vertical secondary support plate 8 is fixedly connected to the lead screw nut 19 through the nut fixing seat 18. The axial direction of the Y-axis lead screw is denoted as the Y-axis, and the track direction of the Y-axis guide rail is set parallel to the axial direction of the Y-axis lead screw. The output shaft of the Y-axis motor 6 is coaxially fixedly connected to the Y-axis lead screw through the first key 21 and the coupling 22. The support beam 10 is fixedly connected to the vertical secondary support plate 8, and the precision adjustment module 2 is fixedly connected to the vertical secondary support plate 8 and the support beam 10. The rotation of the Y-axis motor 6 drives the Y-axis lead screw to rotate, causing the lead screw nut 19 to move on the Y-axis, thereby driving the precision adjustment module 2 to move on the Y-axis.

[0047] As shown in Figures 3, 6, and 14, the precision adjustment module 2 includes a main mounting module 23, two state switching modules 24, and two auxiliary adjustment modules 25. The main mounting module 23 includes a main support plate 39, cross roller bearings 40, a bending die mounting base 41, and a drive shaft 42. The main support plate 39 of the main mounting module 23 is fixedly connected to the vertical secondary support plate 8 of the foundation moving module 1. The bending die support 45 of the bending processing module 4 is set inside the bending die mounting base 41. The bending die support 45 is connected to the state switching module 24 and the auxiliary adjustment module 25. The adjustment module 25 is connected to the bending die mounting base 41. The four sides of the bending die mounting base 41 are denoted as the RX side, RY side, A side, and B side, respectively. The RY side of the bending die mounting base 41 is mounted on the main support plate 39 through a cross roller bearing 40. The inner and outer rings of the cross roller bearing 40 can rotate relative to each other. The outer ring of the cross roller bearing 40 is connected to the main support plate 39, and the inner ring is connected to the RY side of the bending die mounting base 41, thereby giving the bending die mounting base 41 a degree of rotational freedom relative to the main support plate 39. The two state switching modules 24 are denoted as the RX axis state switching module and the RY axis state switching module, respectively. The output axis of the RX axis state switching module is parallel to the X-axis of the basic moving module 1, and the output axis of the RY axis state switching module is parallel to the Y-axis of the basic moving module 1. The RX axis state switching module is installed on the RX side of the bending die mounting base 41, and the RY axis state switching module is installed on the RY side of the bending die mounting base 41. The two auxiliary adjustment modules 25 are respectively located on the A side and B side of the bending die mounting base 41, and the passive axis 37 of each auxiliary adjustment module 25 is connected to the guide block 48 of the bending processing module 4 or the bending die support 45. The RX side of the bending die mounting base 41 and the A side of the bending die support 45 are connected by corresponding thrust bearings 43. The passive axis of the auxiliary adjustment module 25 on the A side is connected to the bending die mounting base 41 through a flange bearing 44. The purpose of setting the thrust bearing 43 and the flange bearing 44 is to eliminate friction caused by relative rotation between different components. In this embodiment, the B side of the bending die mounting base 41 is open, and the auxiliary adjustment module 25 at the B side is directly connected to the bending processing module 4. A drive shaft 42 is also fixedly installed at the RY side of the bending die mounting base 41. The cross roller bearing 40, the RY side plate of the bending die mounting base 41, the drive shaft 42 and the bending processing module 4 are arranged sequentially along the axial direction of the output shaft of the RY axis state switching module (i.e., the output shaft of the rotary motor 29). The position where the output shaft of the RY axis state switching module is fixedly connected to the drive shaft 42 is marked as position 3.

[0048] The state switching module 24 includes a rotary motor 29, a rotary motor mounting component 34, and two sets of axial position control modules. The rotary motor mounting component 34 is mounted on the corresponding side of the bending die mounting base 41 via the axial position control modules. The rotary motor 29 is fixedly mounted in the rotary motor mounting component 34. The axial position control modules are used to adjust the axial displacement of the rotary motor 29, thereby switching the connection state of the output shaft of the rotary motor 29. Specifically, they switch the connection state of the output shaft of the rotary motor 29 with different components (guide block 48, bending die support 45, or drive shaft 42) via the third key 51, thus switching the processing state of the bending processing module 4. The two axial position control modules of the state switching module 24 can be arranged in two ways: diagonally opposite sides or parallel on the same side. In the diagonally opposite side arrangement, the gear motors 35 of the two sets of axial position control modules are on opposite sides of the rotary motor mounting component 34. In the parallel on the same side arrangement, the gear motors 35 of the two sets of axial position control modules are on the same side of the rotary motor mounting component 34. The state switching module 24 on the RX axis side of the main mounting module 23 is diagonally opposite side. The state switching module 24 on the RY axis side is arranged in parallel on the same side, that is, the gear motors 35 of the two sets of axial position control modules are on the same side of the rotary motor mounting 34 and the line connecting the two drive gears 31 is a parallel line to that side of the rotary motor mounting 34.

[0049] As shown in Figure 4, the axial position control module includes a slide rail mounting component 26, a second slide rail 27, a second slider 28, a second key 30, a drive gear 31, a linear rack 32, a gear motor mounting component 36, a rack mounting component 33, and a gear motor 35. The linear rack 32 is fixedly connected to the bending die mounting base 41 via the rack mounting component 33. The gear motor 35 is fixedly connected to the rotary motor mounting component 34 via the gear motor mounting component 36. The output shaft of the gear motor 35 is coaxially fixedly connected to the drive gear 31 via the second key 30. The drive gear 31 meshes with the linear rack 32 to form a gear rack pair. The second slide rail 27 is connected to the slide rail mounting component 38 via the second key 30. The mounting component 26 is fixedly connected to the bending die mounting base 41. The second slider 28 is slidably mounted in the second slide rail 27. The arrangement direction of the linear rack 32 is parallel to the sliding direction of the second slider 28. The axial direction of the output shaft of the gear motor 35 is arranged perpendicular to the axial direction of the output shaft of the rotary motor 29. The gear motor 35 drives the rotary motor mounting component 34 to slide along the axial direction of the output shaft of the rotary motor 29 through the gear and rack pair. At the same time, the second slider 28 slides along the axial direction of the output shaft of the rotary motor 29 in the second slide rail 27. The second slide rail 27 and the second slider 28 are used to ensure the stability of the movement of the rotary motor mounting component 34.

[0050] As shown in Figures 6, 7(a) and 7(b), in the RY axis state switching module, the rotary motor mounting component 34 is also provided with two limiting posts 54. When the output shaft of the rotary motor 29 in the RY axis state switching module is fixedly connected to the bending die support component 45 or guide block 48 in the bending processing module 4 through the third key 51, the two limiting posts 54 are locked in the RY limiting holes on the drive shaft 42 to limit the rotational freedom of the bending die mounting base 41 in the RY direction, and to prevent the bending die mounting base 41 from rotating around the RY axis when the bending die 46 is in the follow-up and semi-active state.

[0051] As shown in Figure 5, the auxiliary adjustment module 25 includes cylinders 38 and a passive shaft 37. The output shafts of two cylinders 38 arranged symmetrically along the axis of the passive shaft 37 are fixedly connected to the passive shaft 37. The passive shaft 37 is connected to the bending mold support 45 or guide block 48 of the bending processing module 4 through the extension and retraction control of the cylinders 38. The positions of the passive shaft 37 on side A and side B are determined by the number of shafts during the processing.

[0052] As shown in Figures 8(a), 8(b), 9, 10, 11(a), 11(b), and 11(c), the bending processing module 4 includes a bending die 46, a bending die support 45, a guide block 48, a limiting block 50, and a compression spring 49. The bending die mounting base 41 of the precision adjustment module 2 is provided with a bending die support 45, and the bending die 46 is rotatably installed in the bending die support 45. The bending die 46 and the bending die support 45 are joined together by a spherical fit. Both ends of the bending die 46 are provided with inward grooves (i.e., inward inclined surfaces as shown in Figure 11), and the middle of the bending die 46 is provided with an axial hole. The straight tube blank 5 is placed in the hole in the middle of the bending die 46. Since both ends of the bending die 46 are provided with inward grooves, the inner sidewall of the hole is arc-shaped. The inner wall of the hole in the middle of the bending die 46 is arc-shaped and serves as the working surface of the straight tube blank 5. The front end of the straight tube blank 5 is set in the hole in the middle of the bending die 46 and contacts the working surface. Axial guide grooves are provided on the RX and RY sides of the bending die 46. Each guide groove is equipped with a corresponding guide block 48. The structure of the guide block 48 is shown in Figure 13(a), Figure 13(b), and Figure 13(c). The slope of the guide groove along the axial direction is arc-shaped. The guide blocks 48 in the guide groove are used to connect the output shafts of the two state switching modules 24 and the passive shafts of the two auxiliary adjustment modules 25, respectively. One end of the guide groove is open. A limit block 50 is installed at the end face (i.e., the input end) of the bending die 46 at the opening of each guide groove to limit the guide block 48 and the compression spring 49. The structure of the limit block 50 is shown in Figure 12(a) and Figure 12(b). Corresponding compression springs 49 are installed in the guide grooves at both ends of the guide blocks 48 on the RX and RY sides to prevent the guide blocks 48 from moving when no force is applied. The bending die support 45 has keyway holes on the RX and RY sides, and through holes on the A and B sides. A keyway hole is provided in the guide block 48; corresponding countersunk holes are provided on the A and B sides of the bending die 46 for embedding the passive shaft 37 of the auxiliary adjustment module 25; the output shaft of the state switching module 24 / passive shaft 37 of the auxiliary adjustment module 25 mates with the corresponding hole of the bending die support 45, so that the output shaft and passive shaft 37 of the state switching module 24 mate with the bending die support 45. The position where the output shaft of the state switching module 24 / passive shaft 37 of the auxiliary adjustment module 25 mates with the bending die support 45 is recorded as position 1; or the output shaft of the state switching module 24 / passive shaft 37 of the auxiliary adjustment module 25 mates with the bending die 46, wherein the output shaft of the state switching module 24 mates with the guide block 48 of the bending die 46, and the passive shaft 37 of the auxiliary adjustment module 25 mates with the countersunk hole on the side of the bending die 46. The position where the output shaft / passive shaft 37 mates with the bending die 46 is recorded as position 2. In the case where the output shaft of the RY axis state switching module only mates with the drive shaft 42, this position is recorded as position 3.The output axis of the RY axis state switching module is set to position 1, 2, or 3, meaning the key on the output axis only engages with one keyway. The output axis of the RX axis state switching module is set to position 1 or 2.

[0053] When the bending die 46 is in the follow-up and semi-active states, the bending processing module 4 also includes guide tail wings 47. Multiple guide tail wings 47 are fixedly installed at intervals along the circumference of the input end of the bending die 46 by limiting blocks 50. The output end of the guide mechanism 52 of the fixed guide module 3 is located inside the guide tail wings 47, and the guide tail wings 47 are always in contact with the output end of the guide mechanism 52 during movement. The output end (i.e., the front end) of the guide mechanism 52 has an arc-shaped structure, which is used to physically contact the guide tail wings 47 to control the spatial attitude of the bending die 46 in the follow-up and semi-active states. The guide mechanism 52 is installed on the guide mechanism fixing part 53 through six threaded holes on the rear side and bolts. During the bending process of the pipe, the guide mechanism 52 always remains stationary. When the bending die 46 is in the follow-up state, four guide tail wings are required; when the bending die 46 is in the semi-active state, two guide tail wings are required; when the bending die 46 is in the active state, guide tail wings 47 are not required, that is, the guide tail wings 47 can be freely detached. The bending die 46 has three motion states: follower, semi-active, and active. In the follower state, the bending die 46 has relative rotational degrees of freedom in the RX, RY, and RZ directions due to the spherical fit. These three degrees of freedom are passively controlled by the physical contact between the guide tail wing 47 and the guide mechanism 52 during processing. The X and Y degrees of freedom of the bending die 46 are actively controlled by the X-axis motor 9 and Y-axis motor 6 of the basic moving module 1. In the semi-active state, the RX (or RY) degree of freedom of the bending die 46 is actively controlled by the rotary motor 29 corresponding to the RX (or RY) state switching module, the RZ degree of freedom is restricted by the motor shaft of the rotary motor 29, and the remaining RY (or RX) degree of freedom is still passively controlled by the guide tail wing 47. In the active state, all four degrees of freedom of the bending die 46—X, Y, RX, and RY—are actively controlled, and the RZ degree of freedom is constrained.

[0054] During the processing, the number of processing axes can be selected independently according to the forming requirements, dynamically balancing the accuracy and stability of pipe bending and expanding the applicability of the device.

[0055] As shown in Figures 15(a), 15(b), 15(c) and 15(d), the fixed guide module 3 includes a guide mechanism 52 and a guide mechanism fixing member 53. The guide mechanism 52 is fixedly installed on the guide mechanism fixing member 53. The straight tube blank 5 is set in the middle of the guide mechanism fixing member 53 and the guide mechanism 52. The straight tube blank 5 passes through one end of the guide mechanism 52 and enters the bending die 46 of the bending processing module 4.

[0056] This invention also proposes a processing method for free bending and forming of pipe fittings. The processing method adopts an integrated variable axis processing device for free bending and forming of pipe fittings. The processing process is shown in Figure 20. The processing method includes the following steps: When performing triaxial processing of straight pipe blank 5, a guide tail wing 47 is installed in the device. The guide mechanism 52 of the fixed guide module 3 is in close contact with the guide tail wing 47. The output shafts of the control RX axis state switching module and the RY axis state switching module, as well as the passive shafts of the auxiliary adjustment modules 25 on the A side and the B side, are all located at position 1, that is, they are all fixedly connected to the panel corresponding to the bending die support 45. The limiting post 54 cooperates with the RY limiting hole of the driving shaft 42, as shown in Figures 16(a), 16(b), and 16(c), so that the bending die 46 is in a follow-up state. The bending die 46 and the bending die support 45 have RX and RY axes. The relative rotational degrees of freedom in the Y, R, and Z directions are achieved during the bending process. The X-axis motor 9 and Y-axis motor 6 of the basic moving module 1 actively control the movement of the bending processing module 4 in the X and Y directions. The rotary motors 29 on the RX and RY axes remain stationary. The constraints of the output shafts of the two rotary motors 29 and the two passive shafts 37 allow the bending mold support 45 to move together with the main mounting module 23 in the X and Y directions without rotating. The relative rotation of the bending mold 46 is adaptively adjusted through the contact between the guide tail wing 47 and the guide mechanism 52 during the processing, thus completing the triaxial processing of the straight tube blank 5. When performing four-axis machining of the straight tube blank 5, guide tail wing 47 is installed in the device. The guide mechanism 52 of the fixed guide module 3 is in close contact with the guide tail wing 47. The output shaft of the RX axis state switching module or the output shaft of the RY axis state switching module is in position 2, that is, the output shaft is fixedly connected to the guide block 48 corresponding to the bending die 46. The output shaft of the RY axis state switching module or the RX axis state switching module is in position 1, and the passive shafts of the auxiliary adjustment modules 25 on the A and B sides are both in position 1, so that the bending die 46 is in a semi-active state, completing the four-axis machining of the straight tube blank 5. Either the rotary motor 29 on the RX axis side or the RY axis side can be selected to be in position 2. If the rotary motor 29 on the RY axis side is in position 2 and the rotary motor 29 on the RX axis side is in position 1, then the rotational freedom of the bending die 46 in the RY direction is controlled by the rotary motor 29 on the RY axis side, and the rotational freedom in the RZ direction is restricted by the output shaft of the rotary motor 29 on the RY axis side. The line connecting the two guide tail wings is parallel to the RY-B axis system. If the RX axis rotary motor 29 is in position 2 and the RY axis rotary motor 29 is in position 1, then the RX direction rotational degree of freedom of the bending mold 46 is controlled by the RX axis rotary motor 29, and the RZ direction rotational degree of freedom is restricted by the output shaft of the RX axis rotary motor 29, as shown in Figure 17(a), Figure 17(b) and Figure 17(c). The line connecting the two remaining guide tail wings 47 is parallel to the RX-A axis.When the third key 51 on the output shaft of the RX-axis rotary motor 29 engages with the keyway of the guide block 48, the rotation of the motor shaft of the RX-axis rotary motor 29 can drive the guide block 48 and the bending die 46 assembled with the guide block 48 to rotate in the RX direction. At the same time, when the basic moving module 1 controls the bending processing module 4 to move in the X direction, the contact force between the guide tail 47 and the guide mechanism 52 will drive the guide block 48, which engages with the third key 51 on the RX-axis rotary motor 29, to slide in the guide groove to achieve the passive movement of the bending die 46 in the RY direction. The presence of the compression spring 49 ensures that the guide block 48 will only move when it is subjected to the contact force between the guide tail 47 and the guide mechanism 52, thereby ensuring the determinism and stability of the overall movement of the device.

[0057] When performing five-axis machining of the straight tube blank 5, the output shaft of the RX axis state switching module is in position 1, meaning the output shaft engages with the bending die support 45. The output shaft of the RY axis state switching module is in position 3, and the passive axes of the auxiliary adjustment modules 25 on sides A and B are both in position 2. The limiting post 54 no longer engages with the RY limiting hole of the driving shaft 42, as shown in Figures 18(a) and 18(b). The passive axes 37 on sides A and B fix the bending die 46 and the bending die support 45 together, preventing any relative movement between them. The RY axis rotary motor 29 controls the bending die mounting base 41 and the bending processing module 4 to rotate in the RY direction, while the RX axis rotary motor 29 controls the bending processing module 4 to rotate in the RX direction, putting the bending die 46 in an active state and completing the five-axis machining of the straight tube blank 5.

[0058] Therefore, the states of the bending die 46—follow-up, semi-active, and active—represent the three-axis, four-axis, and five-axis machining capabilities of the free bending forming device for pipe fittings, respectively. A low-axis free bending device offers higher processing stability and reliability, while a high-axis free bending device can perform additional rotational compensation to improve the forming accuracy of the bent pipe. This device integrates multiple processing axis counts, allowing users to autonomously select the processing axis count according to forming requirements, thus improving bending processing efficiency while expanding the device's applicability.

[0059] Finally, it should be noted that the above embodiments and descriptions are only used to illustrate the technical solutions of the present invention and not to limit it. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the disclosure of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the protection scope of the claims of the present invention.

Claims

1. A tube bending and forming device for integrated variable shaft machining, characterized in that, include: The basic movement module (1) is used to adjust the translational degrees of freedom of the X and Y axes of the device; The precision adjustment module (2) is fixedly connected to the basic moving module (1). The precision adjustment module (2) is used to switch the processing state of the bending processing module (4) to adjust the number of processing axes of the device. Fixed guide module (3) is used to guide the straight tube blank (5); The bending processing module (4) installed in the precision adjustment module (2) is used to process the straight tube blank (5) and complete the free bending forming of the straight tube blank (5).

2. The tube bending and forming device for integrated variable shaft machining according to claim 1, characterized in that, The basic moving module (1) includes an X-axis linear translation module and a Y-axis linear translation module. The Y-axis linear translation module is fixedly connected to the X-axis linear translation module, and the Y-axis linear translation module is fixedly connected to the precision adjustment module (2).

3. The tube bending and forming device for integrated variable shaft machining according to claim 1, characterized in that, The precision adjustment module (2) includes a main mounting module (23), two state switching modules (24), and two auxiliary adjustment modules (25). The main mounting module (23) includes a main support plate (39), a cross roller bearing (40), a bending die mounting base (41), and a drive shaft (42). The main support plate (39) of the main mounting module (23) is fixedly connected to the basic moving module (1). The bending processing module (4) is set inside the bending die mounting base (41). The four sides of the bending die mounting base (41) are denoted as RX side, RY side, A side, and B side, respectively. The RY side of the bending die mounting base (41) is mounted on the main support plate (39) through the cross roller bearing (40). The two state switching modules (24) are denoted as the RX axis state switching module and the R axis state switching module, respectively. The Y-axis state switching module and the RX-axis state switching module are installed on the RX side of the bending die mounting base (41), and the RY-axis state switching module is installed on the RY side of the bending die mounting base (41). Two auxiliary adjustment modules (25) are respectively set on the A side and the B side of the bending die mounting base (41), and the passive shaft (37) of each auxiliary adjustment module (25) is connected to the bending processing module (4). A drive shaft (42) is also fixedly installed on the RY side of the bending die mounting base (41). A cross roller bearing (40), the RY side plate of the bending die mounting base (41), the drive shaft (42) and the bending processing module (4) are arranged sequentially along the axial direction of the output shaft of the RY-axis state switching module. The position where the output shaft of the RY-axis state switching module is fixedly connected to the drive shaft 42 is marked as position 3.

4. The tube bending and forming device for integrated variable shaft machining according to claim 3, characterized in that, The state switching module (24) includes a rotary motor (29), a rotary motor mounting component (34), and an axial position control module. The rotary motor mounting component (34) is installed on the corresponding side of the bending mold mounting base (41) through the axial position control module. The rotary motor (29) is fixedly installed in the rotary motor mounting component (34). The axial position control module is used to adjust the axial displacement of the rotary motor (29) so that the connection state of the output shaft of the rotary motor (29) is switched, thereby switching the processing state of the bending processing module (4).

5. The tube bending and forming device for integrated variable shaft machining according to claim 4, characterized in that, The axial position control module includes a second slide rail (27), a second slider (28), a drive gear (31), a linear rack (32), and a gear motor (35); the linear rack (32) is fixedly connected to the bending mold mounting base (41), the gear motor (35) is fixedly connected to the rotary motor mounting component (34), the output shaft of the gear motor (35) is coaxially fixedly connected to the drive gear (31), and the drive gear (31) meshes with the linear rack (32) to form a gear rack pair; the second slide rail (27) is fixedly connected to the bending mold mounting base (41), and the second slider (28) is slidably installed in the second slide rail (27); the gear motor (35) drives the rotary motor mounting component (34) to slide along the axial direction of the output shaft of the rotary motor (29) through the gear rack pair, while the second slider (28) slides along the axial direction of the output shaft of the rotary motor (29) in the second slide rail (27).

6. The tube bending and forming device for integrated variable shaft machining according to claim 3, characterized in that, In the RY axis state switching module, the rotary motor mounting component (34) is also provided with a limit post (54). When the output shaft of the rotary motor (29) in the RY axis state switching module is fixedly connected to the bending mold support component (45) or guide block (48) in the bending processing module (4), the limit post (54) is locked in the RY limit hole on the drive shaft (42).

7. The tube bending and forming device for integrated variable shaft machining according to claim 3, characterized in that, The auxiliary adjustment module (25) includes a cylinder (38) and a passive shaft (37). The output shaft of the cylinder (38) is fixedly connected to the passive shaft (37), and the passive shaft (37) is connected to the bending processing module (4).

8. The tube bending and forming device for integrated variable shaft machining according to claim 1, characterized in that, The bending processing module (4) includes a bending die (46), a bending die support (45), a guide block (48), a limiting block (50), and a compression spring (49); the bending die mounting base (41) of the precision adjustment module (2) is provided with a bending die support (45), and the bending die (46) is rotatably installed in the bending die support (45); both ends of the bending die (46) are provided with inward grooves and the middle of the bending die (46) is provided with an axial hole, and the straight tube blank (5) is placed in the hole in the middle of the bending die (46). The inner sidewall of the hole in the middle of the bending die (46) is arc-shaped and serves as the working surface of the straight tube blank (5); axial guide grooves are opened on the RX side and RY side of the bending die (46), and a corresponding guide block (48) is installed in each guide groove. One end of the guide groove is open. A limit block (50) is installed at the end face of the bending die (46) at the opening. Corresponding compression springs (49) are installed in the guide grooves at both ends of the guide blocks (48) on the RX and RY sides respectively. Corresponding countersunk holes are opened on the A and B sides of the bending die (46). The passive shaft (37) of the output shaft of the state switching module (24) / the passive shaft of the auxiliary adjustment module (25) cooperates with the bending die support (45). The position where the passive shaft (37) of the output shaft of the state switching module (24) / the passive shaft of the auxiliary adjustment module (25) cooperates with the bending die support (45) is recorded as position 1. Or the passive shaft (37) of the output shaft of the state switching module (24) / the passive shaft of the auxiliary adjustment module (25) cooperates with the bending die (46). The position where the passive shaft (37) of the output shaft of the state switching module (24) / the passive shaft of the auxiliary adjustment module (25) cooperates with the bending die (46) is recorded as position 2.

9. The tube bending and forming device for integrated variable shaft machining according to claim 8, characterized in that, The bending processing module (4) also includes a guide tail wing (47), which is fixedly installed at the input end of the bending die (46).

10. A processing method for freely bending and forming pipe fittings, characterized in that, The processing method employs the integrated variable shaft processing tube free bending forming device as described in claim 8, and the processing method includes the following steps: When performing triaxial machining of the straight tube blank (5), a guide tail wing (47) and a limiting block (50) are installed in the device. The fixed guide module (3) is in close contact with the guide tail wing (47). The output shafts of the control RX axis state switching module and the RY axis state switching module, as well as the passive shafts of the auxiliary adjustment modules (25) on the A side and the B side, are all located at position 1, so that the bending die (46) is in a follow-up state, and the triaxial machining of the straight tube blank (5) is completed. When performing four-axis machining of the straight tube blank (5), a guide tail wing (47) and a limiting block (50) are installed in the device. The fixed guide module (3) is in close contact with the guide tail wing (47). The output shaft of the RX axis state switching module or the output shaft of the RY axis state switching module is controlled to be in position 2, the output shaft of the RY axis state switching module or the RX axis state switching module is in position 1, and the passive shafts of the auxiliary adjustment modules (25) on the A side and the B side are all in position 1, so that the bending die (46) is in a semi-active state, and the four-axis machining of the straight tube blank (5) is completed. When performing five-axis machining of the straight tube blank (5), the output shaft of the control RX axis state switching module is in position 1, the output shaft of the control RY axis state switching module is in position 3, and the passive axes of the auxiliary adjustment modules (25) on the A side and the B side are both in position 2, so that the bending die (46) is in the active state, and the five-axis machining of the straight tube blank (5) is completed.

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