Metal Pipe Fitting Taper Forming Method and Taper Forming Die

Abstract

The present invention belongs to the technical field of metal fitting forming, and discloses a metal pipe taper forming method and a taper forming die. This metal pipe taper forming method first mechanically roughens the outer wall of the metal pipe and performs a saponification treatment on it before taper forming. The mechanical roughening treatment can increase the roughness of the outer wall of the metal pipe, improve the adhesion of the outer wall of the metal pipe to the saponified powder, ensure that the saponified powder can smoothly adhere to the outer wall of the metal pipe, reduce the friction between the metal pipe and the die, improve the lubrication performance of the die of the metal pipe, ensure that the metal pipe will not adhere to the die during the subsequent taper forming process, and thus improve the forming effect of the metal pipe. The method is particularly suitable for the taper forming of metal pipes with strong corrosion resistance such as titanium alloys, improves the forming effect of the metal pipe, reduces the defect rate, and improves production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of metal parts forming, in particular to a taper forming method and a taper forming die for a metal pipe. Background Art

[0002] With the popularity of cycling and the changing riding environment, different cyclists have increasingly specialized demands for bicycles made of different materials. Titanium alloy frames have good elasticity and shock absorption properties, which can effectively absorb vibrations and impacts from the road, reducing the bumpy feeling during riding. They can find a perfect balance between comfort and performance on roads, mountains, gravel, and other roads, providing cyclists with a more comfortable riding experience. At the same time, titanium alloy is not easy to corrode and is resistant to extreme high temperatures. The fatigue strength of titanium alloy frames is 5 times higher than that of ordinary aluminum alloy frames. It will not cause metal fatigue due to stress, and its high strength will increase the service life of the bicycle. Therefore, more and more cyclists will choose bicycles with titanium alloy frames.

[0003] In order to meet the above needs, more and more manufacturers have begun to devote themselves to the manufacture of titanium alloy frames. However, due to the unique characteristics of titanium alloy pipes such as high strength, high hardness, low plasticity, high elastic modulus and high temperature sensitivity, these characteristics make it extremely difficult to process them, especially in the design of bicycles. Due to the difference in the outer diameters of the head tube and the seat tube, titanium alloy pipes usually have a tapered shape with a larger front and a smaller back. When this taper is applied to aluminum alloy pipes, a beveling machine is often used for processing. However, due to the high strength and high hardness of titanium alloy pipes, cracks generally occur during beveling, which leads to a low yield rate, which not only increases costs but also affects production efficiency.

[0004] Therefore, a metal pipe taper forming method and a taper forming die are needed to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a metal pipe taper forming method and a taper forming die, which can improve the yield rate of titanium alloy pipe taper forming process, reduce cracking, and improve product production efficiency.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A method for forming a metal pipe taper, the method comprising the following steps:

[0008] S10, mechanically roughening the outer wall of the metal pipe;

[0009] S20, performing saponification treatment on the metal pipe;

[0010] S30, using a taper forming die to process the taper of the metal pipe.

[0011] As an optional technical solution, mechanically roughening the outer wall of the metal pipe specifically includes: sandblasting the outer wall of the metal pipe using a sandblasting device.

[0012] As an optional technical solution, using a sandblasting device to sandblast the outer wall of the metal pipe specifically includes:

[0013] S11, placing sandblasting medium into the sandblasting device;

[0014] S12, placing the metal pipe into a sandblasting device;

[0015] S13, starting the sandblasting device, and then stopping after sandblasting the metal pipe for a first preset time.

[0016] As an optional technical solution, performing saponification treatment on the metal pipe specifically includes: placing the metal pipe in a holding container, placing the holding container in a saponification tank and soaking it for a second preset time before taking it out.

[0017] As an optional technical solution, the taper forming mold includes a mold body and a taper sleeve mold, the mold body is provided with a limiting cavity and a sliding cavity that are interconnected, the taper sleeve mold is provided with a taper hole, and the taper sleeve mold is slidably set in the sliding cavity under the drive of an external driving member; using the taper forming mold to process the taper of the metal pipe fitting specifically includes: positioning the end of the metal pipe fitting in the limiting cavity, and the taper sleeve mold slides along the sliding cavity toward the limiting cavity under the drive of an external driving member, so that the inner wall of the taper hole squeezes the part of the metal pipe fitting located in the sliding cavity until the taper sleeve mold reaches a preset position.

[0018] As an optional technical solution, the tapered forming mold also includes a fixing structure, which includes a connected fixing seat and a fixing column, the fixing seat is arranged on the side of the mold body away from the tapered sleeve, and at least part of the fixing column is located in the limiting cavity; positioning the metal pipe in the limiting cavity specifically includes: extending the metal pipe into the limiting cavity through one end of the limiting cavity close to the tapered sleeve, sleeved the metal pipe on the outer periphery of the fixing column, and limiting the end of the metal pipe.

[0019] As an optional technical solution, the tapered forming mold further includes a limit block, which is arranged in the limit cavity; the tapered sleeve mold reaches the preset position specifically: the tapered sleeve mold abuts against the limit block under the drive of an external driving member.

[0020] The present invention also adopts the following technical solutions:

[0021] The taper forming die is suitable for the taper forming method of the metal pipe fitting as described above, and the taper forming die comprises:

[0022] A mold body, wherein the mold body is provided with a limiting cavity and a sliding cavity that are interconnected, the limiting cavity is used to limit the metal pipe, and the head end of the metal pipe is located in the sliding cavity;

[0023] A tapered sleeve die, driven by an external driving member, can be slidably disposed in the sliding cavity in a direction approaching or away from the limiting cavity, the tapered sleeve die is provided with a tapered hole, the tapered hole and the limiting cavity are coaxially arranged, and the inner wall of the tapered hole is used to extrude the metal pipe;

[0024] A fixing structure, comprising a fixing seat and a fixing column, wherein the fixing seat is arranged on the mold body and is located on the side of the limiting cavity away from the sliding cavity, the fixing column is connected to the fixing seat, and at least part of the fixing column is located in the limiting cavity.

[0025] As an optional technical solution, the tapered forming mold also includes a limiting structure, which includes a limiting groove and a limiting protrusion. The limiting groove is opened on the fixed column, and the limiting groove extends along the axial direction of the fixed column to the end face of the fixed column close to the sliding cavity. The limiting protrusion is protruded from the inner wall of the limiting cavity. The limiting protrusion and the limiting groove are arranged in combination, and the limiting protrusion is used to abut against the metal pipe fitting.

[0026] As an optional technical solution, the tapered forming mold further includes a guide post, which is arranged in the sliding cavity. A guide hole is provided on the tapered sleeve mold, and the guide post is slidably arranged in the guide hole.

[0027] Beneficial effects of the present invention:

[0028] The invention discloses a metal pipe taper forming method, which comprises the following steps: mechanically roughening the outer wall of the metal pipe; performing saponification on the metal pipe; and processing the taper of the metal pipe using a taper forming die. According to the metal pipe taper forming method, the outer wall of the metal pipe is first mechanically roughened and saponified before the metal pipe is taper-formed. The mechanical roughening can increase the roughness of the outer wall of the metal pipe, improve the adhesion of the outer wall of the metal pipe to the saponified powder, ensure that the saponified powder can smoothly adhere to the outer wall of the metal pipe, reduce the friction between the metal pipe and the die, improve the lubrication performance of the die of the metal pipe, ensure that the metal pipe will not adhere to the die during the subsequent taper forming process, and thus improve the forming effect of the metal pipe. The method is particularly suitable for the taper forming of metal pipes with strong corrosion resistance such as titanium alloys, improves the forming effect of the metal pipe, reduces the defective rate, and improves production efficiency.

[0029] The present invention also discloses a taper forming die, which is suitable for the above-mentioned metal pipe taper forming method. The taper forming die includes a die body, a taper sleeve and a fixed structure. The die body is provided with a limiting cavity and a sliding cavity that are interconnected. The limiting cavity is used to limit the end of the metal pipe. The head end of the metal pipe is located in the sliding cavity. The taper sleeve is slidably arranged in the sliding cavity. The taper sleeve is provided with a taper hole coaxially arranged with the limiting cavity. The inner wall of the taper hole is used to extrude the metal pipe. The fixed structure includes a fixed seat and a fixed column. The metal pipe can be sleeved on the outer periphery of the fixed column to limit the position. This taper forming die limits the end of the metal pipe by the limiting cavity of the die body and the fixed seat of the fixed structure, thereby ensuring the stability of the metal pipe during the taper forming process, thereby improving the forming effect. The taper forming is performed by extruding the metal pipe through the taper hole, which reduces the problem of easy cracking of titanium alloy pipe taper forming, thereby improving the yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 1 is a schematic structural diagram of a taper forming die according to an embodiment of the present invention;

[0031] Figure 2 is a cross-sectional view of a taper forming die according to an embodiment of the present invention;

[0032] Figure 3 yes Figure 2 A partial enlarged view of middle A;

[0033] Figure 4 Schematic diagram of the structure of the taper forming die (upper die hidden) according to an embodiment of the present invention;

[0034] Figure 5 is a cross-sectional view of a mold body according to an embodiment of the present invention;

[0035] Figure 6 2. It is a structural diagram of a tapered sleeve die and a connecting assembly according to an embodiment of the present invention;

[0036] Figure 7 is a cross-sectional view of a tapered sleeve die and a connecting assembly according to an embodiment of the present invention;

[0037] Figure 8 is a structural schematic diagram of a fixing structure according to an embodiment of the present invention;

[0038] Figure 9 It is a logic diagram of the metal pipe taper forming method according to an embodiment of the present invention.

[0039] In the picture:

[0040] 1. Taper forming die; 2. Metal pipe fittings;

[0041] 10. Mold body; 11. Limiting cavity; 12. Sliding cavity; 13. Upper mold; 131. Upper semicircular arc; 132. Upper groove; 14. Lower mold; 141. Lower semicircular arc; 142. Lower groove;

[0042] 20. Tapered sleeve die; 21. First taper die; 211. Tapered hole; 22. Second taper die; 221. Through hole;

[0043] 30. Fixing structure; 31. Fixing seat; 311. Main body; 312. Abutting plate; 32. Fixing column;

[0044] 41. Limiting groove; 42. Limiting protrusion;

[0045] 50. Connecting assembly; 51. Connecting seat; 52. Support rod. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0047] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0048] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0049] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0050] like Figures 1 to 8 As shown, a tapered forming mold 1 is provided in this embodiment, which includes a mold body 10, a tapered sleeve mold 20 and a fixed structure 30. The mold body 10 is provided with a limiting cavity 11 and a sliding cavity 12 that are interconnected. The limiting cavity 11 is used to limit the end of the metal pipe 2, and the head end of the metal pipe 2 is located in the sliding cavity 12. The tapered sleeve mold 20 can be slid in the sliding cavity 12 along the direction close to or away from the limiting cavity 11 under the drive of an external driving member. The tapered sleeve mold 20 is provided with a tapered hole 211. The tapered hole 211 and the limiting cavity 11 are coaxially arranged. The inner wall of the tapered hole 211 is used to extrude the metal pipe 2. The fixed structure 30 includes a fixed seat 31 and a fixed column 32. The fixed seat 31 is arranged on the mold body 10 and is located on the side of the limiting cavity 11 away from the sliding cavity 12. The fixed column 32 is connected to the fixed seat 31, and at least part of the fixed column 32 is located in the limiting cavity 11.

[0051] Specifically, in this embodiment, Figure 5As shown, the mold body 10 includes an upper mold 13 and a lower mold 14, which are movably connected. The upper mold 13 is provided with an upper semicircular arc 131, and the lower mold 14 is provided with a lower semicircular arc 141. The upper semicircular arc 131 and the lower semicircular arc 141 form a limiting cavity 11 with a circular cross-section. The upper mold 13 is provided with an upper groove 132, and the lower mold 14 is provided with a lower groove 142. The upper groove 132 and the lower groove 142 form a sliding cavity 12 with a rectangular cross-section. The limiting cavity 11 with a circular cross-section can be adapted to the shape of the metal pipe 2, can facilitate the centering of the metal pipe 2, and thus improve the forming effect of the metal pipe 2, and the sliding cavity 12 with a rectangular cross-section can improve the support and guiding effect of the tapered sleeve die 20, thereby ensuring the stability of the movement of the tapered sleeve die 20, and thus ensuring the forming effect of the metal pipe 2; The fixing seat 31 of the fixing structure 30 is fixedly connected to the lower mold 14, the fixing column 32 is cylindrical, and the fixing column 32 and the limiting cavity 11 are coaxially arranged, which can ensure that the metal pipe fitting 2 is sleeved on the fixing column 32 with a good centering effect, thereby ensuring the forming effect of the metal pipe fitting 2; a tapered hole 211 is provided on the tapered sleeve die 20. When the tapered sleeve die 20 moves in the direction close to the limiting cavity 11, the metal pipe fitting 2 will gradually enter the tapered hole 211, and the inner wall of the tapered hole 211 will squeeze the metal pipe fitting 2, thereby forming the metal pipe fitting 2 into a preset taper. The metal pipe fitting 2 is tapered in the direction of extrusion. Compared with the method of using a beveling machine for processing in the prior art, it is less likely to produce defects such as cracking, thereby effectively ensuring the forming effect of high-strength and high-hardness metal pipe fittings 2 such as titanium alloy pipe fittings.

[0052] Specifically, in this embodiment, the lower mold 14 is fixedly arranged above the machine, and a lifting mechanism is provided on the top of the machine. The lifting mechanism is fixedly connected to the upper mold 13, and can drive the upper mold 13 to move in the direction close to or away from the lower mold 14, thereby realizing the opening and closing of the mold body 10. A side push pressure cylinder is provided on the side of the machine, and the telescopic rod of the side push pressure cylinder is connected to the tapered sleeve mold 20. When the telescopic rod is extended and retracted, it can drive the tapered sleeve mold 20 to move in the direction close to or away from the limit cavity 11, thereby being able to perform tapered forming on the metal pipe fitting 2, and can be normally withdrawn from the mold after forming, ensuring that the metal pipe fitting 2 is normally taken out after forming.

[0053] Specifically, in this embodiment, the fixing seat 31 is tightened to the lower mold 14 by bolts. In other embodiments, it can also be connected to the lower mold 14 by welding or other methods, which will not be described in detail here.

[0054] Specifically, in this embodiment, the fixing base 31 includes a body 311 and an abutment plate 312. The abutment plate 312 is connected to the body 311 and is used to abut the mold body 10. The body 311 is provided with a connection hole, and the fixing column 32 has a connecting threaded hole along its own axis. A connecting bolt passes through the connecting hole and is threadedly connected to the connecting threaded hole to detachably connect the fixing column 32 and the body 311. The abutment plate 312 abuts the lower mold 14. The arrangement of the abutment plate 312 creates a gap between the upper mold 13 and the body 311, which can prevent interference between the upper mold 13 and the body 311 during the lifting process, thereby effectively reducing noise during operation and improving the comfort of the working environment. The fixing column 32 and the body 311 are connected by a connecting bolt, which can facilitate replacement of the fixing column 32 if it is damaged, thereby reducing raw material costs.

[0055] Specifically, in this embodiment, a first through hole and a second through hole are respectively provided on the main body 311 and the abutment plate 312, and the first through hole and the second through hole are connected. A threaded hole is provided on the lower mold 14, and the bolt passes through the first through hole and the second through hole and is threadedly connected to the threaded hole to connect the fixing seat 31 to the lower mold 14. This connection method not only has good reliability, but also can be easily disassembled and assembled, thereby improving the convenience of use.

[0056] In another embodiment, the main body 311 and the abutting plate 312 are connected by welding, and the abutting plate 312 and the lower mold 14 are also connected by welding, which will not be described in detail here.

[0057] Specifically, in this embodiment, Figure 6 and Figure 7 As shown, the tapered die includes a first tapered die 21 and a second tapered die 22. The first tapered die 21 is provided with the aforementioned tapered hole 211, and the second tapered die 22 is provided with a through hole 221. The tapered hole 211 and the through hole 221 are coaxially arranged. The first tapered die 21 and the second tapered die 22 are connected by bolts. The tapered hole 211 is used to extrude the metal pipe 2, and the through hole 221 is used to pass the metal pipe 2.

[0058] Further, if Figure 2 and Figure 4As shown, the tapered forming mold 1 also includes a limiting structure, which includes a limiting groove 41 and a limiting protrusion 42. The limiting groove 41 is opened in the fixed column 32, and the limiting groove 41 extends along the axial direction of the fixed column 32 to the end face of the fixed column 32 close to the sliding cavity 12. The limiting protrusion 42 is protruded from the inner wall of the limiting cavity 11. The limiting protrusion 42 and the limiting groove 41 are arranged in coordination, and the limiting protrusion 42 is used to abut against the metal pipe 2. Specifically, in this embodiment, the limiting groove 41 extends along the axial direction of the fixing column 32, and the above-mentioned limiting groove 41 is provided on the partial structure of the fixing column 32 along the length direction, and the limiting groove 41 extends along the axial direction of the fixing column 32 to the end face of the fixing column 32 close to the sliding cavity 12, and the limiting protrusion 42 is convexly provided on the inner wall of the limiting cavity 11, and after the fixing column 32 is extended into the limiting cavity 11, the limiting protrusion 42 is located at the end of the limiting groove 41 away from the sliding cavity 12. This arrangement can facilitate the fixing column 32 to extend into the limiting cavity 11, and avoid the limiting protrusion 42 affecting the fixing column 32 Normal installation; the limiting protrusion 42 and the bottom of the limiting groove 41 are set at intervals, and during the taper forming process of the metal pipe 2, the limiting protrusion 42 can abut against the metal pipe 2. When the metal pipe 2 is subjected to pressure, the end of the metal pipe 2 will be deformed, causing part of the structure of the metal pipe 2 to enter the gap between the limiting protrusion 42 and the limiting groove 41, and then clamping the metal pipe 2, thereby avoiding affecting the demolding of the taper sleeve 20, improving the operating efficiency during the taper forming process, and the deformed part can be removed by machining after the taper forming is completed.

[0059] Specifically, in this embodiment, Figure 2 and Figure 3 As shown, the limiting structure includes a limiting groove 41 and a limiting protrusion 42. In other embodiments, the limiting structure may include multiple limiting grooves 41 and multiple limiting protrusions 42. The multiple limiting grooves 41 are arranged at circumferential intervals along the fixed column 32, and the multiple limiting protrusions 42 are arranged at circumferential intervals along the inner wall of the limiting cavity 11. The multiple limiting protrusions 42 and the multiple limiting grooves 41 are arranged in a one-to-one correspondence, which can clamp the metal pipe 2 after the metal pipe 2 is tapered and formed, thereby facilitating the demolding of the tapered sleeve 20 and improving the efficiency of the tapered forming of the metal pipe 2.

[0060] Furthermore, the taper forming die 1 further includes a guide post disposed in the sliding cavity 12. The taper sleeve die 20 is provided with a guide hole, in which the guide post is slidably disposed. Specifically, in this embodiment, the guide post is slidably disposed in the guide hole. During the movement of the taper sleeve die 20, the guide post can effectively guide the taper sleeve die 20, thereby ensuring that the taper hole 211 of the taper sleeve die 20 can be well aligned with the metal pipe 2, thereby improving the taper forming effect of the metal pipe 2 and improving the yield rate.

[0061] Specifically, in this embodiment, Figure 2 and Figure 4 As shown, the tapered forming mold 1 also includes a connecting assembly 50, which includes a connecting seat 51 and a support rod 52. The support rod 52 is arranged on the connecting seat 51. The support rod 52 is used to connect to the tapered sleeve 20, and there are multiple support rods 52. The multiple support rods 52 are respectively arranged on the periphery of the tapered hole 211 to improve the stability of the tapered sleeve 20 during movement. The connecting seat 51 is used to connect the telescopic rod of the side push pressure cylinder to ensure the normal movement of the tapered sleeve 20.

[0062] Specifically, in this embodiment, the tapered forming module also includes a limit block, which is arranged in the sliding cavity 12. The limit block is used to abut against the tapered sleeve die 20. When the tapered sleeve die 20 and the limit block abut against each other, it means that the tapered forming process has been completed. The tapered sleeve die 20 can be withdrawn from the mold under the drive of the side push pressure cylinder, and then the formed metal pipe 2 can be taken out. This arrangement can avoid the tapered sleeve die 20 from colliding with the mold body 10, thereby improving safety during use.

[0063] like Figure 9 As shown, this embodiment also provides a method for taper forming of a metal pipe 2, which is used to taper form a metal pipe 2 with high hardness and high strength. The method for taper forming of a metal pipe 2 includes the following steps.

[0064] S10, performing mechanical roughening treatment on the outer wall of the metal pipe 2.

[0065] Specifically, in this embodiment, taking the metal pipe fitting 2 to be processed as a taper made of titanium alloy as an example, due to the large friction coefficient between the titanium alloy and the mold, in the process of using the tapered sleeve die 20 to taper the titanium alloy pipe fitting, the titanium alloy pipe fitting and the inner wall of the tapered sleeve die 20 are prone to mold sticking, resulting in poor surface quality or poor dimensional accuracy of the formed titanium alloy workpiece. However, due to the strong corrosion resistance of titanium alloy itself, the outer wall of the metal pipe fitting 2 is mechanically roughened. Compared with the method of using acidic liquid or alkaline liquid to react with the metal pipe fitting 2 to increase the roughness of its outer surface in the prior art, the mechanical roughening treatment method can not only overcome the corrosion resistance problem of the titanium alloy pipe fitting, but also reduce the adverse effects of chemical substances on the metal pipe fitting 2, and has high work efficiency.

[0066] Furthermore, mechanical roughening treatment of the outer wall of the metal pipe 2 specifically includes the following steps.

[0067] S11. Put sandblasting medium into the sandblasting device.

[0068] Specifically, in this embodiment, the sandblasting medium is 80# brown corundum, and its particle size range is 0.18mm to 0.25mm. 80# brown corundum has high hardness and strong grinding force. Its hardness reaches Mohs 9, which can significantly improve the efficiency and quality of sandblasting. It is environmentally friendly and safe, and has good economy and durability. It can be used repeatedly to reduce production costs.

[0069] S12, placing the metal pipe 2 into the sandblasting device.

[0070] Specifically, in this embodiment, when the metal pipe 2 is placed in the sandblasting device, a clamp needs to be provided on the inner wall of the metal pipe 2 to ensure that the outer wall of the metal pipe 2 can be sandblasted, thereby ensuring the sandblasting effect of the outer wall of the metal pipe 2, and making the sandblasting as uniform as possible, thereby improving the forming effect of the workpiece.

[0071] S13, starting the sandblasting device, and then stopping after sandblasting the metal pipe 2 for a first preset time.

[0072] Specifically, in this embodiment, the first preset time is in the range of 30s-50s, such as 32s, 35s, 40s, or 50s, and is not limited thereto. In actual use, the first preset time can be specifically set according to the diameter of the metal pipe 2, but it should be ensured that the sandblasting device remains in a stable working state for at least 30s to ensure the surface sandblasting quality of the metal pipe 2.

[0073] S20, performing saponification treatment on the metal pipe 2.

[0074] Specifically, in this embodiment, after the metal pipe 2 is mechanically roughened, it is necessary to perform saponification on the metal pipe 2. After the saponification, a layer of saponified powder will adhere to the outer wall of the metal pipe 2. The saponified powder can improve the lubrication of the metal pipe 2, thereby reducing the friction between the metal pipe 2 and the inner wall of the tapered sleeve die 20, thereby avoiding the sticking phenomenon between the metal pipe 2 and the tapered sleeve die 20, and avoiding the difficulty of demolding the tapered sleeve die 20, thereby ensuring the forming effect and forming efficiency of the metal pipe 2.

[0075] Furthermore, performing saponification treatment on the metal pipe 2 specifically includes: placing the metal pipe 2 in a receiving container, placing the receiving container in a saponification tank and soaking it for a second preset time, and then taking it out.

[0076] Specifically, in this embodiment, the holding container includes a tray and a bracket, the floors of the bracket and the tray are parallel and spaced apart, a limiting hole is opened on the bracket, the metal pipe 2 is inserted into the limiting hole, and the holding container with the metal pipe 2 is placed in the saponification pool and soaked for a second preset time and then taken out. The second preset time can meet the requirement of the saponification powder adhering to the outer wall of the metal pipe 2, thereby improving the tapered forming effect of the metal pipe 2.

[0077] Specifically, in this embodiment, the value range of the second preset time is 10min-15min, such as 11min, 12min or 13min, etc., which is not limited here. In actual use, the saponified powder attached to the surface of the metal pipe 2 should be able to play a good lubricating role. The second preset time can be specifically set according to actual use and is not limited here.

[0078] S30, using the taper forming die 1 to process the taper of the metal pipe 2.

[0079] The taper forming die 1 includes a die body 10 and a taper sleeve die 20. The die body 10 is provided with a mutually connected limiting cavity 11 and a sliding cavity 12. The taper sleeve die 20 is provided with a taper hole 211. The taper sleeve die 20 is driven by an external driving member and slides in the sliding cavity 12. Based on the above taper forming die 1, the taper forming die 1 specifically includes the following steps to process the metal pipe 2 with the taper forming die 1.

[0080] Specifically, in this embodiment, since the mold body 10 includes an upper mold 13 and a lower mold 14, before limiting the metal pipe 2, it is necessary to first start the lifting mechanism so that the lifting mechanism drives the upper mold 13 to rise, and then position the end of the metal pipe 2 in the limiting cavity 11, and then start the lifting mechanism so that the lifting mechanism drives the upper mold 13 to return. Then, the tapered sleeve 20 is driven by an external driving member to slide along the sliding cavity 12 toward the limiting cavity 11, so that the inner wall of the tapered hole 211 squeezes the part of the metal pipe 2 located in the sliding cavity 12 until the tapered sleeve 20 reaches the preset position.

[0081] Specifically, in this embodiment, after the metal pipe 2 is positioned, the side push pressure cylinder is started, and the telescopic rod of the side push pressure cylinder drives the tapered sleeve die 20 to move in the direction close to the limiting cavity 11, and the metal pipe 2 enters the tapered hole 211 of the tapered sleeve die 20. As the tapered sleeve die 20 moves, the inner wall of the tapered hole 211 squeezes the metal pipe 2 until the tapered sleeve die 20 moves to the preset position, completing the taper forming of the metal pipe 2. Then, the tapered sleeve die 20 is driven by the side push pressure cylinder to return to the initial position, and then the lifting mechanism is started to lift the upper die 13, and the taper-formed metal pipe 2 is taken out. If necessary, the taper forming of the next metal pipe 2 is carried out. This taper forming method has a good forming effect, can avoid cracking of the metal pipe 2, and can also have high work efficiency.

[0082] Furthermore, the taper forming die 1 further includes a fixing structure 30, which includes a fixed seat 31 and a fixed column 32 connected thereto. The fixed seat 31 is disposed on a side of the die body 10 away from the taper sleeve 20, and at least a portion of the fixed column 32 is located within the limiting cavity 11. Based on the above-described taper forming die 1, positioning the metal pipe 2 within the limiting cavity 11 specifically includes the following.

[0083] The metal pipe 2 is inserted into the limiting cavity 11 through one end of the limiting cavity 11 close to the tapered sleeve die 20 , and the metal pipe 2 is sleeved on the outer periphery of the fixing column 32 , and the end of the metal pipe 2 is limited.

[0084] Specifically, in this embodiment, since part of the fixing column 32 of the fixing structure 30 is located in the limiting cavity 11, the end of the metal pipe 2 is sleeved on the periphery of the fixing column 32, which can provide certain support and limitation for the metal pipe 2, thereby effectively improving the tapered forming effect of the metal pipe 2.

[0085] Furthermore, the taper forming mold 1 further includes a limit block disposed in the limit cavity 11. Based on the above taper forming mold 1, the taper sleeve mold 20 reaches the preset position when the taper sleeve mold 20 abuts against the limit block under the drive of an external driving member.

[0086] Specifically, in this embodiment, the side push pressure cylinder pushes the tapered sleeve die 20 to move until the tapered sleeve die 20 abuts against the limit block. This setting can increase the consistency of the product after tapered forming, thereby improving the product yield.

[0087] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for forming a metal pipe taper, characterized in that: The metal pipe taper forming method comprises the following steps: S10, performing mechanical roughening treatment on the outer wall of the metal pipe (2); S20, performing saponification treatment on the metal pipe (2); S30, using a taper forming die to process the taper of the metal pipe (2); The taper forming die comprises a die body (10) and a taper sleeve die (20), wherein the die body (10) is provided with a limiting cavity (11) and a sliding cavity (12) that are interconnected, and the taper sleeve die (20) is provided with a taper hole (211). The taper sleeve die (20) is slidably arranged in the sliding cavity (12) under the drive of an external driving member. Processing the taper of the metal pipe (2) using the taper forming die specifically includes: The end of the metal pipe (2) is positioned in the limiting cavity (11), and the tapered sleeve die (20) is driven by an external driving member to slide along the sliding cavity (12) in a direction close to the limiting cavity (11), so that the inner wall of the tapered hole (211) squeezes the portion of the metal pipe (2) located in the sliding cavity (12) until the tapered sleeve die (20) reaches a preset position.

2. The metal pipe taper forming method according to claim 1, characterized in that: The mechanical roughening treatment of the outer wall of the metal pipe (2) specifically includes: The outer wall of the metal pipe (2) is sandblasted using a sandblasting device.

3. The method for forming a metal pipe taper according to claim 2, wherein: The method of sandblasting the outer wall of the metal pipe (2) using a sandblasting device specifically includes: S11, placing sandblasting medium into the sandblasting device; S12, placing the metal pipe (2) into a sandblasting device; S13, starting the sandblasting device, sandblasting the metal pipe (2) for a first preset time, and then stopping.

4. The method for forming a metal pipe taper according to claim 1, wherein: The saponification treatment of the metal pipe (2) specifically includes: The metal pipe (2) is placed in a holding container, and the holding container is placed in a saponification tank and soaked for a second preset time before being taken out.

5. The method for forming a metal pipe taper according to claim 1, wherein: The tapered forming die further comprises a fixing structure (30), the fixing structure (30) comprising a fixing seat (31) and a fixing column (32) connected to each other, the fixing seat (31) being arranged on a side of the die body (10) away from the tapered sleeve die (20), and at least a portion of the fixing column (32) being located in the limiting cavity (11); Positioning the metal pipe (2) in the limiting cavity (11) specifically includes: The metal pipe (2) is extended into the limiting cavity (11) through one end of the limiting cavity (11) close to the tapered sleeve die (20), the metal pipe (2) is sleeved on the outer periphery of the fixed column (32), and the end of the metal pipe (2) is limited.

6. The method for forming a metal pipe taper according to claim 1, wherein: The taper forming die further comprises a limit block, which is arranged in the limit cavity (11); the taper sleeve die (20) reaches a preset position specifically as follows: The tapered sleeve die (20) is driven by an external driving member and abuts against the limit block.

7. A taper forming die, suitable for the taper forming method for a metal pipe according to any one of claims 1 to 6, characterized in that: The taper forming die comprises: A mold body (10), wherein the mold body (10) is provided with a limiting cavity (11) and a sliding cavity (12) that are communicated with each other, the limiting cavity (11) is used to limit the metal pipe (2), and the head end of the metal pipe (2) is located in the sliding cavity (12); A tapered sleeve die (20), driven by an external driving member, can be slidably disposed in the sliding cavity (12) in a direction approaching or moving away from the limiting cavity (11), the tapered sleeve die (20) is provided with a tapered hole (211), the tapered hole (211) and the limiting cavity (11) are coaxially disposed, and the inner wall of the tapered hole (211) is used for extruding the metal pipe (2); A fixing structure (30), the fixing structure (30) comprising a fixing seat (31) and a fixing column (32), the fixing seat (31) being arranged on the mold body (10) and being located on a side of the limiting cavity (11) away from the sliding cavity (12), the fixing column (32) being connected to the fixing seat (31), and at least a portion of the fixing column (32) being located in the limiting cavity (11).

8. The taper forming die according to claim 7, characterized in that: The tapered forming die also includes a limiting structure, which includes a limiting groove (41) and a limiting protrusion (42). The limiting groove (41) is opened on the fixed column (32), and the limiting groove (41) extends along the axial direction of the fixed column (32) to the end face of the fixed column (32) close to the sliding cavity (12). The limiting protrusion (42) is protruded from the inner wall of the limiting cavity (11). The limiting protrusion (42) and the limiting groove (41) are arranged in a coordinated manner, and the limiting protrusion (42) is used to abut against the metal pipe (2).

9. The taper forming die according to claim 7, characterized in that: The taper forming die further comprises a guide post, which is arranged in the sliding cavity (12). A guide hole is provided on the taper sleeve die (20), and the guide post is slidably arranged in the guide hole.

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