A method for manufacturing a coaxial tube

Abstract

This invention discloses a method for manufacturing a coaxial tube, comprising the following specific steps: Step 1) Positioning one end of the coaxial tube using a positioning die mechanism; Step 2) Moving a pre-flaring die mechanism to one end of the coaxial tube and pre-flaring the end of the coaxial tube using the pre-flaring die mechanism; Step 3) Moving a flaring and de-ribbing die mechanism to one end of the coaxial tube and flaring and de-ribbing the end of the coaxial tube using the flaring and de-ribbing die mechanism; Step 4) Moving a punching die mechanism to one end of the coaxial tube and punching the flared end of the coaxial tube using the punching die mechanism; Step 5) Moving a necking die mechanism to one end of the coaxial tube and necking the flared end using the necking die mechanism. This invention can simultaneously complete the flaring, de-ribbing, punching, necking, and shaping processes of the coaxial tube, reducing the number of workpiece loading and unloading operations and improving processing efficiency.

Description

Technical Field

[0001] This invention relates to the field of coaxial tube processing technology, and in particular to a method for manufacturing a coaxial tube. Background Technology

[0002] An existing coaxial tube has ribs on its inner wall, the ribs being arranged along the axial direction of the coaxial tube and protruding from the inner wall of the coaxial tube.

[0003] The traditional coaxial tube processing method follows these steps: ribbing – deburring – cleaning – flaring – drilling – deburring – cleaning – necking. Ribbing involves using a lathe to remove the ribs from the inner wall of the coaxial tube end, resulting in a smooth inner wall without protruding ribs. Flaring involves using a flaring die to flare the end of the coaxial tube, creating a flared end. Drilling involves drilling the required hole in the flared end. Narrowing involves using a necking die to narrow the end of the coaxial tube, resulting in the desired necked structure.

[0004] Traditional coaxial tube processing technology has the following drawbacks: The machining and drilling steps generate a large amount of debris and burrs at the machining locations. Therefore, deburring and cleaning are required after the machining and drilling steps, resulting in numerous processes and increasing the complexity of the entire process. Secondly, in the traditional processing method, each machining step needs to be carried out on a separate processing machine. Each separate processing requires loading and unloading, which greatly increases the workload, the time consumed in machining a coaxial tube, and the processing efficiency is low. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art and provide a method for manufacturing a coaxial tube.

[0006] The objective of this invention is achieved through the following technical solution: a method for manufacturing a coaxial tube, comprising the following specific steps:

[0007] Step 1) Position one end of the coaxial tube using the positioning die mechanism, and then clamp the coaxial tube with the clamping die.

[0008] Step 2) The pre-flaring die mechanism is moved to one end of the coaxial tube and the end of the coaxial tube is pre-flared by the pre-flaring die mechanism;

[0009] Step 3) The flaring and deribbing die mechanism is moved to one end of the coaxial tube and the flaring and deribbing die mechanism is used to flare and deribble the end of the coaxial tube to form a flared end.

[0010] Step 4) The punching die mechanism moves to one end of the coaxial tube and punches the flared end of the coaxial tube.

[0011] Step 5) The necking die mechanism moves to one end of the coaxial tube and performs necking processing on the flared end of the coaxial tube.

[0012] Preferably, in step 1), the positioning punch mechanism includes a positioning punch seat connected to the first driving mechanism. The positioning punch seat is provided with a positioning rod, and one end of the positioning rod is provided with a positioning end face. When positioning the coaxial tube, the positioning punch seat moves to the set position under the drive of the first driving mechanism, and one end of the coaxial tube contacts the positioning end face on the positioning rod and moves to the clamping position under the push of the positioning rod.

[0013] Preferably, in step 2), the pre-flaring die mechanism includes a first flaring punch seat, a first flaring punch core, and a first flaring punch sleeve. The first flaring punch seat is connected to a second driving mechanism. One end of the first flaring punch core is connected to the first flaring punch seat, and the other end of the first flaring punch core is provided with a first expansion portion. The first flaring punch sleeve is fitted onto the first flaring punch core and can slide along the first flaring punch core. A first spring is provided between the first flaring punch sleeve and the first flaring punch seat. The first flaring punch core is provided with a spring for pressing the first flaring punch sleeve. The first limiting shoulder of the line limit; when the coaxial tube is pre-flared, the first flaring punch is aligned with one end of the coaxial tube, and the first flaring punch and the first flaring sleeve are driven to move towards the coaxial tube by the second driving mechanism; the first flaring sleeve stops after it contacts the side of the die, at which time the first flaring sleeve is sleeved on the outside of the coaxial tube; the first flaring punch continues to move and extends into the coaxial tube, and the end of the coaxial tube is expanded under the action of the first expansion part; then the first flaring punch and the first flaring sleeve return to the initial position.

[0014] Preferably, in step 3), the flaring and de-ribbing die mechanism includes a second flaring punch seat, a second flaring punch core, and a second flaring punch sleeve. The second flaring punch seat is connected to a third driving mechanism. One end of the second flaring punch core is connected to the second flaring punch seat, and the other end of the second flaring punch core is provided with a second expansion portion, the maximum diameter of which is greater than the maximum diameter of the first expansion portion. The second flaring punch sleeve is fitted onto the second flaring punch core and can slide along the second flaring punch core. A second spring is provided between the second flaring punch sleeve and the second flaring punch seat. The second flaring punch core is provided with a second spring for limiting the position of the second flaring punch sleeve. Limiting shoulder; When performing flaring and deribbing on the coaxial tube, the second flaring punch is aligned with one end of the coaxial tube, and the second flaring punch and the second flaring sleeve are driven to move towards the coaxial tube by the third drive mechanism; the second flaring sleeve stops after it contacts the side of the die, at which point the second flaring sleeve is fitted on the outside of the coaxial tube; the second flaring punch continues to move and extends into the coaxial tube, and under the action of the second expansion part, the end of the coaxial tube is expanded a second time to form a flared end, and the ribs on the inner wall of the coaxial tube are eliminated by the expansion and pressure of the second expansion head; then the second flaring punch and the second flaring sleeve retract to the initial position.

[0015] Preferably, in step 4), the punching die mechanism includes a punching base, a sliding base, and a connecting sleeve. The punching base is connected to a fourth driving device, and the connecting sleeve is fixed on the sliding base. The punching base has a guide groove, and the connecting sleeve is slidably connected in the guide groove. A third spring is provided between the connecting sleeve and the inner wall of the guide groove. The punching base has a follower block, and the sliding base has a sliding groove, in which a slider is slidably connected. The follower block has a connecting tenon at one end near the slider, and the slider has a tenon groove corresponding to the sliding connecting tenon. The connecting tenon is slidably connected in the tenon groove. The connecting sleeve has a mandrel, and the sliding base has a positioning sleeve located outside the mandrel. An annular positioning space is formed between the positioning sleeve and the mandrel. The slider has a punch. The mandrel has a clearance hole corresponding to the punch, and the positioning sleeve has a through hole through which the punch can pass.

[0016] Preferably, in step 4), when punching the coaxial tube, the flared end of the coaxial tube is aligned with the mandrel on the punching die mechanism. Then, the punching base and the slide base move along the direction of the coaxial tube under the drive of the fourth drive device. During the movement, the flared end of the coaxial tube extends into the positioning space between the positioning sleeve and the mandrel. Subsequently, the slide base contacts the outside of the clamping die, and the slide base stops moving. The punching base continues to move forward under the drive of the fourth drive device, and drives the follower block to move. As the follower block moves, the slider drives the punch to move towards the coaxial tube under the action of the follower block. The punching of the coaxial tube is completed by the movement of the punch. After punching is completed, the punching base is reset under the drive of the fourth drive device.

[0017] Preferably, in step 5), the necking die mechanism includes a necking punch seat connected to a fifth driving device; the necking punch seat has a necking cavity; during the necking process, the flared end of the coaxial tube faces the necking cavity, and the necking punch seat moves toward the end of the coaxial tube under the drive of the fifth driving device, the flared end of the coaxial tube extends into the necking cavity and is tightly attached to the inner wall of the necking cavity, and the end of the coaxial tube forms a necking structure under the action of the necking cavity; then the necking punch seat is reset under the action of the fifth driving device.

[0018] Preferably, after step 5) is completed, the end of the coaxial tube is shaped by a forming die mechanism.

[0019] Preferably, the forming die mechanism includes a forming punch seat, a forming punch sleeve, and a forming punch core. The forming punch seat is connected to a sixth driving device. One end of the forming punch core is fixedly connected to the forming punch seat, and the other end of the forming punch core is provided with a forming head. The forming punch sleeve is fitted onto the forming punch core and can slide along the forming punch core. A forming cavity is provided inside the forming punch sleeve, and a third spring is provided between the forming punch sleeve and the forming punch seat. When forming the end of the coaxial tube, the forming die mechanism moves to one end of the coaxial tube, at which time the coaxial tube... The end of the tube faces the forming punch, and the forming punch and forming sleeve move toward the coaxial tube under the drive of the sixth drive device. During the movement, the coaxial tube first extends into the forming cavity on the forming sleeve. When the forming sleeve contacts the outside of the clamping die, the forming sleeve stops moving, while the forming punch continues to move forward. The forming head on the forming punch inserts into the end of the coaxial tube to form and correct the opening at the end of the coaxial tube. After forming, the forming punch and forming sleeve are reset under the action of the sixth drive device.

[0020] The beneficial effects of this invention are as follows: This invention can simultaneously complete the flaring, debonding, punching, necking, and shaping processes of a coaxial tube. During processing, each processing step is completed through the interposition and movement of the pre-flaring die mechanism, the flaring and debonding die mechanism, the punching die mechanism, the necking die mechanism, and the shaping die mechanism. The entire processing process only requires one positioning and clamping of the coaxial tube, greatly reducing the number of workpiece loading and unloading operations, saving a significant amount of intermediate time, and greatly improving processing efficiency. This invention adopts an expansion and pressure debonding method. Through the squeezing and expansion action of the first and second expansion parts on the inner wall of the coaxial tube, the ribs are eliminated. Compared with the traditional turning debonding method, this invention does not generate burrs and chips during processing, thus eliminating the need for deburring and cleaning steps, reducing the overall process steps, and improving overall processing efficiency. Furthermore, this invention uses a punching processing method, where each punching produces only one piece of punching chips, while the traditional drilling processing method produces a large amount of drill chips. Therefore, this hole processing method in this invention eliminates the need for subsequent cleaning steps, further improving overall processing efficiency. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the processing flow of the present invention.

[0022] Figure 2 This is a schematic diagram of the positioning die mechanism positioning the coaxial tube.

[0023] Figure 3 This is a flowchart illustrating the pre-expansion process of a pre-expansion die mechanism for pre-expansion of a coaxial tube.

[0024] Figure 4 A schematic diagram of the process for flaring and deribbing a coaxial tube using a flaring and deribbing die mechanism.

[0025] Figure 5 This is a schematic diagram of the punching die mechanism.

[0026] Figure 6 This is a schematic diagram of the follower block and slider.

[0027] Figure 7 This is a schematic diagram of the process of punching holes in a coaxial tube using a punching die mechanism.

[0028] Figure 8 A schematic diagram of the process for the necking die mechanism to perform necking processing on a coaxial tube.

[0029] Figure 9 A schematic diagram of the process for shaping the ends of a coaxial tube using a forming die mechanism.

[0030] In the diagram: 1. Coaxial tube; 5. Clamping die; 6. Positioning punch; 7. Fixing sleeve; 8. Positioning rod; 10. First flaring punch; 11. First spring; 12. First flaring sleeve; 13. First flaring core; 14. First expansion part; 15. First limiting shoulder; 16. Second flaring punch; 17. Second spring; 18. Second flaring core; 19. Second flaring sleeve; 20. Second expansion part; 21. Second limiting shoulder. 25. Punch base, 26. Slide base, 27. Follower block, 28. Slider, 29. Punch, 30. Slide, 31. Connecting sleeve, 32. Core rod, 33. Clearance hole, 34. Guide groove, 35. Third spring, 36. Positioning sleeve, 37. Connecting tenon, 38. Tenon oblique groove, 40. Reduction punch base, 41. Reduction cavity, 45. Shaping punch base, 46. Shaping punch sleeve, 47. Shaping punch core, 48. Third spring. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0032] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0033] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0034] like Figures 1 to 9 As shown, a method for manufacturing a coaxial tube includes the following specific steps:

[0035] Step 1) Position one end of the coaxial tube 1 using the positioning die mechanism, and then clamp the coaxial tube 1 with the clamping die 5.

[0036] The positioning punch mechanism includes a positioning punch 6 connected to the first drive mechanism. The positioning punch 6 has a fixed sleeve 7, and the fixed sleeve 7 has a positioning rod 8. One end of the positioning rod 8 has a positioning end face. The first drive device drives the positioning punch to move linearly. The first drive device can be a cylinder, hydraulic cylinder, or electric actuator, etc. When positioning the coaxial tube 1, the positioning punch 6 moves to the set position under the drive of the first drive mechanism. One end of the coaxial tube 1 contacts the positioning end face on the positioning rod and moves to the clamping position under the push of the positioning rod 8. Then, the clamping die 5 finally clamps the coaxial tube 1.

[0037] After clamping the coaxial tube 1 with the clamping mold 5, the coaxial tube 1 is firmly clamped and cannot move. The positioning and clamping of the coaxial tube 1 in step 1) determines the clamping position of the coaxial tube, providing a basis for subsequent precise processing.

[0038] Step 2) The pre-flaring die mechanism is moved to one end of the coaxial tube 1 and the end of the coaxial tube 1 is pre-flared by the pre-flaring die mechanism.

[0039] The pre-flaring die mechanism includes a first flaring punch seat 10, a first flaring punch core 13, and a first flaring punch sleeve 12. The first flaring punch seat 10 is connected to a second drive mechanism. One end of the first flaring punch core 13 is connected to the first flaring punch seat 10, and the other end of the first flaring punch core 13 is provided with a first expansion portion 14. The first expansion portion 14 is a spherical expansion portion, and the maximum diameter of the first expansion portion 14 is larger than the inner diameter of the coaxial tube 1. The first flaring punch sleeve 12 is fitted on the first flaring punch core 13 and can slide along the first flaring punch core 13. The inner diameter is larger than the outer diameter of the coaxial tube 1; a first spring 11 is provided between the first flaring punch 12 and the first flaring punch seat 10, and a first limiting shoulder 15 is provided on the first flaring punch core 13 for limiting the first flaring punch 12; the function of the second driving device is to drive the first flaring punch seat 10 to move linearly, and the first driving device can be a cylinder, hydraulic cylinder or electric push rod, etc.; before pre-flaring processing, the first flaring punch 12 is in the forward extension position under the action of the first spring 11, and at this time the front end of the first flaring punch 12 extends out of the front end of the first flaring punch core 13. When pre-flaring the coaxial tube 1, the first flaring punch 13 is aligned with one end of the coaxial tube 1, and the first flaring punch 13 and the first flaring sleeve 12 are driven to move toward the coaxial tube 1 by the second drive mechanism; the first flaring sleeve 12 stops after it contacts the side of the die 5, at which point the first flaring sleeve 12 is fitted on the outside of the coaxial tube 1; the first flaring punch 13 continues to move and extends into the coaxial tube 1, and the end of the coaxial tube is expanded under the action of the first expansion part 14; then the first flaring punch and the first flaring sleeve retract to the initial position.

[0040] After the coaxial tube 1 undergoes pre-expansion processing, the end of the coaxial tube 1 is expanded once, thus initially forming a flared structure at the end of the coaxial tube 1; at the same time, the compression of the inner wall of the coaxial tube 1 by the first expansion part 14 eliminates the rib structure on the inner wall of the end of the coaxial tube 1 to a certain extent, making the inner wall of the end of the coaxial tube smoother than before.

[0041] Step 3) The flaring and deribbing die mechanism is moved to one end of the coaxial tube 1 and the flaring and deribbing die mechanism is used to flare and deribble the end of the coaxial tube 1 to form a flared end.

[0042] The overall structure of the flaring and de-ribbing die mechanism is similar to that of the pre-flaring die mechanism. The flaring and de-ribbing die mechanism includes a second flaring punch seat 16, a second flaring punch core 18, and a second flaring punch sleeve 19. The second flaring punch seat 16 is connected to a third driving mechanism. One end of the second flaring punch core 18 is connected to the second flaring punch seat 16, and the other end of the second flaring punch core 18 is provided with a second expansion portion 20. The maximum diameter of the second expansion portion 20 is larger than the maximum diameter of the first expansion portion 14. The second flaring punch sleeve 19 is fitted onto the second flaring punch core 18, and the second flaring punch sleeve 19 can move along the first... A flaring punch 18 slides, a second spring 17 is provided between the second flaring punch sleeve 19 and the second flaring punch base 16, and a second limiting shoulder 21 is provided on the second flaring punch 18 to limit the second flaring punch sleeve 19; the function of the third driving device is to drive the second flaring punch base 16 to move linearly, and the third driving device can be a cylinder, hydraulic cylinder or electric push rod, etc.; before flaring is performed, the second flaring punch sleeve 18 is in the forward extension position under the action of the second spring 17, at which time the front end of the second flaring punch sleeve 19 extends out of the front end of the second flaring punch 18. When the coaxial tube 1 is flared and deribbed, the second flaring punch 18 is aligned with one end of the coaxial tube 1, and the second flaring punch 18 and the second flaring punch sleeve 19 are driven to move toward the coaxial tube 1 by the third drive mechanism; the second flaring punch sleeve 19 stops after it contacts the side of the die 5, at which point the second flaring punch sleeve 19 is fitted on the outside of the coaxial tube 1; the second flaring punch 18 continues to move and extends into the coaxial tube 1, and under the action of the second expansion part 20, the end of the coaxial tube 1 is expanded a second time to form a flared end, and the ribs on the inner wall of the coaxial tube 1 are eliminated by the expansion and pressure action of the second expansion head; then the second flaring punch and the second flaring punch sleeve retract to the initial position.

[0043] After the coaxial tube 1 undergoes flaring and debonding, the end of the tube expands twice, forming a flaring end. Simultaneously, the second expansion section 20 further compresses the inner wall of the coaxial tube 1 end, completely eliminating the rib structure and making the inner wall smooth and flat. This invention employs debonding through flaring. The compression and expansion of the first and second expansion sections on the inner wall of the coaxial tube eliminates the ribs. Compared to traditional turning debonding methods, this invention does not generate burrs or debris during processing, thus eliminating the need for deburring and cleaning steps, reducing the overall process steps, and improving overall processing efficiency.

[0044] Step 4) The punching die mechanism moves to one end of the coaxial tube 1 and punches the flared end of the coaxial tube.

[0045] The punching die mechanism includes a punching base 25, a slide base 26, and a connecting sleeve 31. The punching base 25 is connected to a fourth driving device, and the connecting sleeve 31 is fixed on the slide base 26. The punching base 25 is provided with a guide groove 34, and the connecting sleeve 31 is slidably connected in the guide groove 34. A third spring 35 is provided between the connecting sleeve 31 and the inner wall of the guide groove 34. The punching base 25 is provided with a follower block 27, and the slide base 26 is provided with a slide groove 30. A slider 28 is slidably connected in the slide groove 30. The slider 28 moves along... The sliding direction of the slide groove 30 is perpendicular to the sliding direction of the connecting sleeve 31 along the guide groove 34; the follower block 27 is provided with a connecting tenon 37 at one end near the slider 28, and the slider 28 is provided with a tenon groove 38 corresponding to the sliding connecting tenon, and the connecting tenon 37 is slidably connected in the tenon groove 38; the follower block 27 moves laterally, and the lateral movement of the follower block 27 drives the slider 28 to move vertically in the slide groove 30; the connecting sleeve is provided with a core rod 32, and the outer diameter of the core rod 32 matches the inner diameter of the flared end of the coaxial tube 1. A positioning sleeve 36 is provided on the slide base 26. The positioning sleeve 36 is annular and located outside the mandrel 32. An annular positioning space is formed between the positioning sleeve 36 and the mandrel 32, which allows the flared end of the coaxial tube 1 to be inserted. A punch 29 is provided on the slider 28, and the arrangement direction of the punch 29 is consistent with the sliding direction of the slider 28. The mandrel 32 is provided with a clearance hole 33 corresponding to the punch 29, and the positioning sleeve 36 is provided with a through hole through which the punch 29 can pass. The function of the fourth driving device is to drive the punching seat 25 to move linearly. The fourth driving device can be a cylinder, hydraulic cylinder, or electric actuator, etc.

[0046] When punching the coaxial tube 1, the punching die mechanism moves to one end of the coaxial tube. At this time, the flared end of the coaxial tube 1 is aligned with the mandrel 32 on the punching die mechanism. Then, the punching base 25 and the slide base 26 move along the direction of the coaxial tube 1 under the drive of the fourth drive device. During the movement, the flared end of the coaxial tube 1 extends into the positioning space between the positioning sleeve and the mandrel. Subsequently, the slide base 26 contacts the outside of the clamping die 5 and stops moving. The punching base 25 continues to move forward under the drive of the fourth drive device, and drives the follower block 27 to move. As the follower block 27 moves, the slider 28 drives the punch 29 to move towards the coaxial tube 1 under the action of the follower block 27. The punching of the coaxial tube 1 is completed by the movement of the punch 29. After punching is completed, the punching base is reset under the drive of the fourth drive device.

[0047] This invention uses a punching method to process holes. Each punching operation produces only one piece of slag, while traditional drilling methods produce a large amount of drill slag. Therefore, this hole processing method eliminates the need for subsequent cleaning steps, thereby reducing the overall processing steps and improving overall processing efficiency.

[0048] Step 5) The necking die mechanism moves to one end of the coaxial tube 1 and performs necking processing on the flared end of the coaxial tube 1 through the necking die mechanism.

[0049] The necking die mechanism includes a necking punch seat 40, which is connected to a fifth driving device. The necking punch seat 40 is provided with a necking cavity 41. The function of the fifth driving device is to drive the necking punch seat 40 to move linearly. The fifth driving device can be a cylinder, hydraulic cylinder, or electric actuator, etc. During the necking process, the necking die mechanism moves to one end of the coaxial tube 1. At this time, the flared end of the coaxial tube 1 is facing the necking cavity 41. The necking punch seat 40 moves towards the end of the coaxial tube 1 under the drive of the fifth driving device. The flared end of the coaxial tube 1 extends into the necking cavity 41 and is tightly attached to the inner wall of the necking cavity 41. Under the action of the necking cavity 41, the end of the coaxial tube 1 forms a necking structure. Then, the necking punch seat 40 is reset under the action of the fifth driving device.

[0050] Step 6) The forming die mechanism moves to one end of the coaxial tube and performs forming processing on the end of the coaxial tube 1 through the forming die mechanism.

[0051] The forming die mechanism includes a forming punch base 45, a forming punch sleeve 46, and a forming punch core 47. The forming punch base 45 is connected to a sixth driving device. One end of the forming punch core 47 is fixedly connected to the forming punch base 45, and the other end of the forming punch core 47 is provided with a forming head. The forming punch sleeve 46 is fitted onto the forming punch core 47 and can slide along the forming punch core 47. The forming punch sleeve 46 has a forming cavity inside, and a third spring 48 is provided between the forming punch sleeve and the forming punch base. The function of the sixth driving device is to drive the forming punch base 45 to move linearly. The sixth driving device can be a cylinder, a hydraulic cylinder, or an electric actuator, etc. When performing forming processing on the end of the coaxial tube 1... The forming die mechanism moves to one end of the coaxial tube 1, at which point the end of the coaxial tube 1 is directly opposite the forming core 47. The forming core 47 and the forming sleeve 46 move toward the coaxial tube 1 under the drive of the sixth drive device. During the movement, the coaxial tube 1 first extends into the forming cavity on the forming sleeve. When the forming sleeve 46 contacts the outer side of the clamping die 5, the forming sleeve 46 stops moving, while the forming core 47 continues to move forward. The forming head on the forming core 47 is inserted into the end of the coaxial tube to form and correct the opening at the end of the coaxial tube. After the forming is completed, the forming core 47 and the forming sleeve 46 are reset under the action of the sixth drive device.

[0052] In this invention, the pre-flaring die mechanism, the flaring and deribbing die mechanism, the punching die mechanism, the necking die mechanism, and the shaping die mechanism are all mounted on a moving mechanism. The moving mechanism can be an electric linear guide. The pre-flaring die mechanism, the flaring and deribbing die mechanism, the punching die mechanism, the necking die mechanism, and the shaping die mechanism are moved and repositioned under the drive of the electric linear guide, thereby realizing the various processing steps of the pipe fitting.

[0053] This invention can simultaneously complete the flaring, debonding, punching, necking, and shaping processes of coaxial tubes. During processing, each processing step is completed through the interlocking movement of the pre-flaring die mechanism, the flaring and debonding die mechanism, the punching die mechanism, the necking die mechanism, and the shaping die mechanism. The entire processing process only requires one positioning and clamping of the coaxial tube, greatly reducing the number of workpiece loading and unloading operations, saving a significant amount of intermediate time, and greatly improving processing efficiency. This invention uses an expansion-pressure debonding method, where the first and second expansion parts squeeze and expand the inner wall of the coaxial tube to eliminate the ribs. Compared with the traditional turning debonding method, this invention does not generate burrs and chips during processing, thus eliminating the need for deburring and cleaning steps, reducing the overall process steps, and improving overall processing efficiency. Furthermore, this invention uses a punching method, where each punching produces only one piece of punching debris, while traditional drilling methods produce a large amount of drill debris. Therefore, this hole processing method eliminates the need for subsequent cleaning steps, further improving overall processing efficiency.

[0054] This invention is not limited to the preferred embodiments described above. Anyone can derive other products in various forms under the guidance of this invention. However, regardless of any changes in shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A method for manufacturing a coaxial tube, characterized in that, The specific steps include the following: Step 1) Position one end of the coaxial tube using the positioning die mechanism, and then clamp the coaxial tube with the clamping die. Step 2) The pre-flaring die mechanism is moved to one end of the coaxial tube and the end of the coaxial tube is pre-flared by the pre-flaring die mechanism; Step 3) The flaring and deribbing die mechanism is moved to one end of the coaxial tube. The flaring and deribbing die mechanism performs flaring and deribbing processing on the end of the coaxial tube. Through the expansion and pressure action, the ribs on the inner wall of the coaxial tube are eliminated, and a flared end is formed at the end of the coaxial tube. Step 4) The punching die mechanism moves to one end of the coaxial tube and punches the flared end of the coaxial tube. Step 5) The necking die mechanism moves to one end of the coaxial tube and performs necking processing on the flared end of the coaxial tube.

2. The method for manufacturing a coaxial tube according to claim 1, characterized in that, In step 1), the positioning punch mechanism includes a positioning punch seat connected to the first driving mechanism. The positioning punch seat is provided with a positioning rod, and one end of the positioning rod is provided with a positioning end face. When positioning the coaxial tube, the positioning punch seat moves to the set position under the drive of the first driving mechanism, and one end of the coaxial tube contacts the positioning end face on the positioning rod and moves to the clamping position under the push of the positioning rod.

3. The method for manufacturing a coaxial tube according to claim 1, characterized in that, In step 2), the pre-flaring die mechanism includes a first flaring punch seat, a first flaring punch core, and a first flaring punch sleeve. The first flaring punch seat is connected to the second driving mechanism. One end of the first flaring punch core is connected to the first flaring punch seat, and the other end of the first flaring punch core is provided with a first expansion portion. The first flaring punch sleeve is fitted onto the first flaring punch core and can slide along the first flaring punch core. A first spring is provided between the first flaring punch sleeve and the first flaring punch seat. The first flaring punch core is provided with a limiting device for the first flaring punch sleeve. The first limiting shoulder; when pre-flaring the coaxial tube, the first flaring punch is aligned with one end of the coaxial tube, and the first flaring punch and the first flaring sleeve are driven to move toward the coaxial tube by the second driving mechanism; the first flaring sleeve stops after it contacts the side of the die, at which time the first flaring sleeve is sleeved on the outside of the coaxial tube; the first flaring punch continues to move and extends into the coaxial tube, and the end of the coaxial tube is expanded under the action of the first expansion part; then the first flaring punch and the first flaring sleeve return to the initial position.

4. The method for manufacturing a coaxial tube according to claim 1, characterized in that, In step 3), the flaring and de-ribbing die mechanism includes a second flaring punch seat, a second flaring punch core, and a second flaring punch sleeve. The second flaring punch seat is connected to a third driving mechanism. One end of the second flaring punch core is connected to the second flaring punch seat, and the other end of the second flaring punch core is provided with a second expansion portion, the maximum diameter of which is greater than the maximum diameter of the first expansion portion. The second flaring punch sleeve is fitted onto the second flaring punch core and can slide along the second flaring punch core. A second spring is provided between the second flaring punch sleeve and the second flaring punch seat. The second flaring punch core is provided with a second limiting shaft for limiting the second flaring punch sleeve. Shoulder; When performing flaring and deribbing on the coaxial tube, the second flaring punch is aligned with one end of the coaxial tube, and the second flaring punch and the second flaring sleeve are driven to move towards the coaxial tube by the third drive mechanism; the second flaring sleeve stops after it contacts the side of the die, at which point the second flaring sleeve is fitted on the outside of the coaxial tube; the second flaring punch continues to move and extends into the coaxial tube, and under the action of the second expansion part, the end of the coaxial tube is expanded a second time to form a flared end, and the ribs on the inner wall of the coaxial tube are eliminated by the expansion and pressure of the second expansion head; then the second flaring punch and the second flaring sleeve return to the initial position.

5. The method for manufacturing a coaxial tube according to claim 1, characterized in that, In step 4), the punching die mechanism includes a punching base, a slide base, and a connecting sleeve. The punching base is connected to a fourth driving device, and the connecting sleeve is fixed on the slide base. The punching base has a guide groove, and the connecting sleeve is slidably connected in the guide groove. A third spring is provided between the connecting sleeve and the inner wall of the guide groove. The punching base has a follower block, and the slide base has a slide groove, in which a slider is slidably connected. The follower block has a connecting tenon near the slider, and the slider has a tenon groove corresponding to the sliding connecting tenon. The connecting tenon is slidably connected in the tenon groove. The connecting sleeve has a mandrel, and the slide base has a positioning sleeve located outside the mandrel. An annular positioning space is formed between the positioning sleeve and the mandrel. The slider has a punch. The mandrel has a clearance hole corresponding to the punch, and the positioning sleeve has a through hole through which the punch can pass.

6. The method for manufacturing a coaxial tube according to claim 5, characterized in that, In step 4), when punching the coaxial tube, the flared end of the coaxial tube is aligned with the mandrel on the punching die mechanism. Then, the punching base and the slide base move along the direction of the coaxial tube under the drive of the fourth drive device. During the movement, the flared end of the coaxial tube extends into the positioning space between the positioning sleeve and the mandrel. Subsequently, the slide base contacts the outside of the clamping die, and the slide base stops moving. The punching base continues to move forward under the drive of the fourth drive device, and drives the follower block to move. As the follower block moves, the slider drives the punch to move towards the coaxial tube under the action of the follower block. The punching of the coaxial tube is completed by the movement of the punch. After punching is completed, the punching base is reset under the drive of the fourth drive device.

7. The method for manufacturing a coaxial tube according to claim 1, characterized in that, In step 5), the necking die mechanism includes a necking punch seat connected to a fifth driving device; the necking punch seat is provided with a necking cavity; during the necking process, the flared end of the coaxial tube faces the necking cavity, and the necking punch seat moves toward the end of the coaxial tube under the drive of the fifth driving device, the flared end of the coaxial tube extends into the necking cavity and is tightly attached to the inner wall of the necking cavity, and the end of the coaxial tube forms a necking structure under the action of the necking cavity; then the necking punch seat is reset under the action of the fifth driving device.

8. A method for manufacturing a coaxial tube according to claim 1, characterized in that, After step 5) is completed, the end of the coaxial tube is shaped by the forming die mechanism.

9. A method for manufacturing a coaxial tube according to claim 8, characterized in that, The forming die mechanism includes a forming punch base, a forming punch sleeve, and a forming punch core. The forming punch base is connected to a sixth driving device. One end of the forming punch core is fixedly connected to the forming punch base, and the other end of the forming punch core is provided with a forming head. The forming punch sleeve is fitted on the forming punch core and can slide along the forming punch core. The forming sleeve has a forming cavity, and a third spring is provided between the forming sleeve and the forming punch seat. When the end of the coaxial tube is being formed, the forming die mechanism moves to one end of the coaxial tube. At this time, the end of the coaxial tube is facing the forming punch core. The forming punch core and the forming sleeve move towards the coaxial tube under the drive of the sixth driving device. During the movement, the coaxial tube first extends into the forming cavity on the forming sleeve. When the forming punch contacts the outer side of the die, the forming punch stops moving, while the forming core continues to move forward. The forming head on the forming core is inserted into the end of the coaxial tube to form and correct the opening at the end of the coaxial tube. After the shaping is completed, the shaping punch and the shaping sleeve are reset under the action of the sixth drive device.

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