Preparation method of composite pipe, composite pipe and processing device of composite pipe

Abstract

The invention provides a preparation method of a composite pipe, the composite pipe and a processing device of the composite pipe, relates to the technical field of composite pipes, and aims to solve the problem that in the prior art, a bimetal composite pipe only has compressive strength and cannot give consideration to vibration reduction and sound absorption performance, so that the application range of the bimetal composite pipe is small. The preparation method of the composite pipe comprises the steps that the metal pipe, the hollow balls and the metal base material are provided; the melting point of the metal tube and the melting point of the hollow ball are both larger than that of the metal base material. Melting the metal substrate to obtain a liquid metal substrate; the liquid metal base material and the hollow ball are injected into the rotating metal pipe through centrifugal casting, so that the liquid metal base material and the hollow ball are located on the inner wall of the metal pipe, and a composite structure with the hollow ball is obtained; and the composite structure with the hollow balls is cooled, so that the liquid metal base material is solidified, and the composite pipe with the hollow balls is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of composite pipes, and particularly to a preparation method of a composite pipe, a composite pipe, and a processing device for the composite pipe. Background Art

[0002] A bimetallic composite pipe is a pipe composed of two different metal materials through a special process. Bimetallic composite pipes are widely used in industrial fields such as oil fields, chemical industries, and power industries. With the continuous development of modern industries, especially in high-end equipment and extreme working condition environments, higher requirements are put forward for the performance of bimetallic composite pipes.

[0003] Currently, bimetallic composite pipes only have compressive strength, but the bimetallic composite pipes in the prior art cannot take into account the vibration damping and sound absorption performance, resulting in a small application range of bimetallic composite pipes. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of a composite pipe, a composite pipe, and a processing device for the composite pipe, which are used to take into account vibration damping and sound absorption and compressive strength, and expand the application range of the composite pipe.

[0005] To achieve the above purpose, the present invention provides the following technical solutions: In the first aspect, the present invention provides a preparation method of a composite pipe. The preparation method of the composite pipe includes: Providing a metal pipe, hollow spheres, and a metal substrate; the melting point of the metal pipe and the melting point of the hollow spheres are both greater than the melting point of the metal substrate; Melting the metal substrate to obtain a liquid metal substrate; Adopting centrifugal casting to inject the liquid metal substrate and the hollow spheres into the rotating metal pipe, so that the liquid metal substrate and the hollow spheres are located on the inner wall of the metal pipe and a composite structure with hollow spheres is obtained; Performing a cooling treatment on the composite structure with hollow spheres, so that the liquid metal substrate solidifies and a composite pipe with hollow spheres is obtained.

[0006] In the method for preparing the composite tube provided by the present invention, since the melting points of both the metal tube and the hollow spheres are higher than the melting point of the metal substrate, when the liquid metal substrate and the hollow spheres are injected into the rotating metal tube, neither the hollow spheres nor the metal tube will melt, ensuring the original forms of the hollow spheres and the metal tube. Further, the composite structure with hollow spheres is cooled to solidify the liquid metal substrate and obtain a composite tube with hollow spheres. Compared with the prior art method of directly mechanically bonding two metal tubes to form a composite tube, the composite tube prepared by the method provided by the present invention has a higher interfacial bonding strength, reduces or eliminates the probability of delamination failure of the composite tube, and extends the service life of the composite tube. Still further, since the above composite tube includes a metal tube and the solidified metal substrate, and since all solid metals have compressive strength, the composite tube has compressive strength. Since the composite tube includes hollow spheres, the hollow spheres can dissipate energy by virtue of their unique cavity structure, so the composite tube has excellent sound absorption and energy absorption functions. In summary, the composite tube prepared by the method provided by the present invention takes into account vibration and sound absorption and compressive strength, expanding the scope of application of the composite tube.

[0007] In one implementation, the liquid metal substrate and the hollow spheres form a metallurgical bond with the metal tube; and / or, the material of the metal tube is different from the material of the metal substrate; and / or, the material of the metal substrate is a light metal.

[0008] In one implementation, the density of the hollow spheres is greater than the density of the liquid metal substrate; in the composite tube, the hollow spheres are close to the inner wall of the metal tube.

[0009] In one implementation, before injecting the liquid metal substrate and the hollow spheres into the rotating metal tube by centrifugal casting, the method for preparing the composite tube further includes: Fixing the metal tube in a mold with a cavity and heating the metal tube to obtain a metal tube with a preset temperature; Driving the mold and the metal tube with the preset temperature to rotate; Wherein, the preset temperature is greater than or equal to 0.6Tm and less than or equal to 0.8Tm; Tm represents the melting point temperature of the metal tube.

[0010] In a second aspect, the present invention further provides a composite tube, which is prepared by the method for preparing the composite tube described in the above technical solution. The above composite tube includes: a metal tube and a lining tube. The lining tube is sleeved inside the metal tube, and the lining tube includes a metal substrate and hollow spheres.

[0011] In the composite pipe provided by the present invention, since the composite pipe includes a metal pipe and a metal substrate, and since all solid metals have compressive strength, the composite pipe has compressive strength. Further, since the composite pipe includes hollow spheres, and the hollow spheres can dissipate energy by virtue of their unique cavity structure, the composite pipe has excellent sound absorption and energy absorption functions. In summary, the composite pipe in the present invention takes into account both vibration reduction and sound absorption and compressive strength, expanding the scope of application of the composite pipe.

[0012] In a third aspect, the present invention also provides a processing device for a composite pipe, which is applied to the preparation method of some of the composite pipes described in the above technical solution. The processing device for the composite pipe includes: a mold, a base, a heating member, a clamping assembly, and a driving assembly. Along the axial direction of the mold, a cavity penetrating the mold is provided in the mold; the cavity is used to accommodate the metal pipe and / or the composite pipe. The base is used to carry the mold; the clamping assembly is arranged on the mold and is located in the cavity, and the clamping assembly is used to clamp and fix the metal pipe located in the cavity; the driving assembly is used to drive the mold to rotate.

[0013] The processing device for the composite pipe provided by the present invention has a simple structure and is easy to manufacture and use.

[0014] In one implementation, the processing device for the composite pipe further includes: a heating member, which is arranged on the mold.

[0015] In one implementation, the clamping assembly includes: A first clamping unit, which is sleeved in the mold, and the outer wall of the first clamping unit abuts against the inner wall of the mold; the first clamping unit is used to limit the axial movement of the metal pipe and / or the composite pipe; A second clamping unit, along the direction perpendicular to the axial direction of the mold, the first clamping unit and the second clamping unit are arranged oppositely; one end of the second clamping unit opposite to the first clamping unit moves in a direction close to or away from the first clamping unit to clamp and fix or release the metal pipe located in the cavity; Along the axial direction of the mold, the mold includes opposite first and second ends; two clamping assemblies are respectively located at the first end and the second end; The second clamping unit included in the clamping assembly close to the first end is detachably connected to the mold through a connecting assembly; The second clamping unit included in the clamping assembly close to the second end is fixedly connected to the inner wall of the mold.

[0016] In one implementation, the first clamping unit includes: An annular connecting member, which is sleeved in the mold, and the outer wall of the annular connecting member abuts against the inner wall of the mold; The annular limiting member is sleeved inside the annular connecting member; the thickness of the annular limiting member is greater than that of the annular connecting member, and the annular limiting member is used to limit the axial movement of the metal pipe and / or the composite pipe; the thickness direction of the annular limiting member and the thickness direction of the annular connecting member are both perpendicular to the axis of the mold; the width of the annular connecting member is greater than that of the annular limiting member, and the width direction of the annular connecting member and the width direction of the annular limiting member are both consistent with the axis of the mold; The second clamping unit includes: A driving member having a telescopic rod; A clamping member, the free end of the telescopic rod is connected to the clamping member; the driving member is used to drive the clamping member to approach or move away from the first clamping unit to clamp and fix or release the metal pipe; A groove is formed on the outer side wall of the first end of the mold; the connecting assembly includes: A bearing member having a bearing surface; A first connecting member is disposed on the bearing surface and is clamped with the groove; A second connecting member is disposed on the bearing surface and is spaced apart from the first connecting member; the width of the second connecting member is greater than that of the first connecting member; the width direction of the second connecting member and the width direction of the first connecting member are both perpendicular to the axis of the mold; the driving member is connected to the side surface of the second connecting member close to the first connecting member.

[0017] In one implementation, the processing device for the composite pipe further includes a telescopic blocking assembly; the telescopic blocking assembly includes a receiving member and a telescopic blocking member. The receiving member has a receiving space, and the receiving member is connected to the surface of the driving member facing away from the clamping member. Along the axis of the mold, the receiving member has an opposite open end and a closed end. The first end of the telescopic blocking member is connected to the side surface of the clamping member, and the second end of the telescopic blocking member passes through the open end and is connected to the closed end. When the driving member drives the clamping member to approach or move away from the first clamping unit, the telescopic blocking member extends or contracts. The telescopic blocking member located outside the receiving member is located between the second clamping unit and the metal substrate. Description of the Drawings

[0018] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 It is a cross-sectional view of the composite pipe in the embodiment of the present invention; Figure 2 It is a side view of the composite pipe in the embodiment of the present invention; Figure 3 It is a schematic structural diagram of the processing device for the composite pipe in the embodiment of the present invention; Figure 4 It is a cross-sectional view of the partial structure of the processing device for the composite pipe in the embodiment of the present invention before assembly; Figure 5 In the embodiment of the present invention Figure 4 is an enlarged schematic view of a partial structure; Figure 6 is a cross-sectional view of a partial structure of a processing device for a composite tube in the embodiment of the present invention; Figure 7 In the embodiment of the present invention Figure 6 is an enlarged schematic of a partial structure in Figure 1 ; Figure 8 In the embodiment of the present invention Figure 6 is an enlarged schematic of a partial structure in Figure 2 ; Figure 9 In the embodiment of the present invention Figure 8 is an enlarged schematic view of a partial structure; Figure 10 is a cross-sectional view of a partial structure when there is a composite tube in the processing device for a composite tube in the embodiment of the present invention; Figure 11 In the embodiment of the present invention Figure 10 is an enlarged schematic of a partial structure in Figure 1 ; Figure 12 In the embodiment of the present invention Figure 10 is an enlarged schematic of a partial structure in Figure 2 ; Figure 13 is a schematic structural view of a first clamping unit in the embodiment of the present invention; Figure 14 is a three-dimensional cross-sectional view of a connection component in the embodiment of the present invention.

[0019] Reference numerals: 1 - metal tube; 2 - inner lining tube, 20 - hollow ball, 21 - metal substrate; 3 - mold, 30 - cavity, 31 - groove; 4 - base, 40 - bearing seat, 41 - bracket, 42 - rotating member; 5 - heating member; 6 - clamping assembly, 60 - first clamping unit, 600 - annular connecting member, 601 - annular limiting member; 61 - second clamping unit, 610 - driving member, 6100 - telescopic rod, 611 - clamping member; 7 - driving assembly; 8 - connection component, 80 - bearing member, 81 - first connecting member, 82 - second connecting member; 90 - telescopic blocking assembly, 900 - receiving member, 901 - telescopic blocking member; 91 - casting ladle. Detailed implementation manners

[0020] For the convenience of clearly describing the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, terms such as "first" and "second" are used to distinguish identical or similar items with basically the same functions and roles. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and do not limit their sequence. Those skilled in the art can understand that terms such as "first" and "second" do not limit the quantity and execution order, and the terms "first" and "second" do not necessarily limit being different.

[0021] It should be noted that in the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present invention should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly, using words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0022] In the present invention, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of single item (item) or plural items (items). For example, at least one (item) of a, b or c can represent: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b and c, where a, b and c can be single or multiple.

[0023] To solve the above technical problems, the embodiments of the present invention provide a preparation method of a composite tube, a composite tube and a processing device of the composite tube.

[0024] In a first aspect, the present invention provides a preparation method of a composite tube. The preparation method of the composite tube includes: Step 101: Refer to Figure 1 and Figure 2 , and provide a metal tube 1, a hollow sphere 20 and a metal substrate 21; the melting points of both the metal tube 1 and the hollow sphere 20 are greater than the melting point of the metal substrate 21; As a possible implementation manner, the materials of the above metal tube 1 and the metal substrate 21 are different. At this time, the composite tube can have the characteristics of different metal materials, further expanding the application range of the composite tube.

[0025] As a possible implementation, the material of the above-mentioned metal tube 1 can be stainless steel, carbon steel or titanium alloy. There is no specific limitation on the material of the metal tube 1 here, as long as it can meet the actual needs. When the material of the metal tube 1 is stainless steel, the composite tube has excellent compressive strength.

[0026] The material of the above-mentioned metal substrate 21 is a light metal, which makes the composite tube have a light weight at this time. For example, the material of the metal substrate 21 can be aluminum, magnesium, etc., as long as it can meet the actual needs. When the material of the metal substrate 21 is aluminum, the composite tube has corrosion resistance and alkali resistance.

[0027] As a possible implementation, step 102: Refer to Figure 1 and Figure 2 , after providing the metal tube 1, the hollow sphere 20 and the metal substrate 21, surface treatment is performed on the metal tube 1 and the hollow sphere 20 to remove the surface oxides and contaminants.

[0028] Exemplarily, a flap wheel and sandpaper are used to polish the inner surface of the metal tube 1 and the outer surface of the hollow sphere 20 respectively to remove the surface oxides and contaminants.

[0029] Step 103: Melt the metal substrate 21 to obtain a liquid metal substrate; Exemplarily, the metal substrate 21 is placed in a melting furnace and heated to a target temperature, which is higher than the melting point of the metal substrate 21, so that the metal substrate 21 is completely melted to obtain a liquid metal substrate. Further, after obtaining the liquid metal substrate, the liquid metal substrate is kept warm for a certain time to ensure that the liquid metal substrate has good fluidity and pouring effect. For example, the difference between the target temperature and the melting point of the metal substrate 21 is greater than or equal to 50 °C and less than or equal to 100 °C. For example, the difference can be 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 95 °C or 100 °C, etc.

[0030] Step 104: Refer to Figure 1 and Figure 2 , by using centrifugal casting, the liquid metal substrate and the hollow sphere 20 are injected into the rotating metal tube 1 so that the liquid metal substrate and the hollow sphere 20 are located on the inner wall of the metal tube 1 and a composite structure with the hollow sphere 20 is obtained; Exemplarily, start the drive motor, and the drive motor drives the metal tube 1 to rotate. Pour the liquid metal substrate in the melting furnace into the pouring ladle 91 to mix with the hollow spheres 20. Then, inject the liquid metal substrate and the hollow spheres 20 into the rotating metal tube 1 through the pouring channel. During the rotation of the metal tube 1, the liquid metal substrate and the hollow spheres 20 are evenly distributed on the inner wall of the metal tube 1 under the action of centrifugal force. As a possible implementation manner, the liquid metal substrate and the hollow spheres 20 form a metallurgical bond with the metal tube 1. At this time, compared with the prior art method of directly mechanically bonding two metal tubes 1 together to form a composite tube, the use of metallurgical bonding ensures that the composite tube has excellent performance, makes the interfacial bonding strength of the composite tube higher, reduces or eliminates the probability of delamination failure of the composite tube, and extends the service life of the composite tube.

[0031] The material of the hollow spheres 20 is not specifically limited herein, as long as it can meet the actual requirements. For example, the material of the hollow spheres 20 can be stainless steel, steel, etc.

[0032] As a possible implementation manner, the centrifugal force of the hollow spheres 20 is greater than that of the liquid metal substrate. At this time, the hollow spheres 20 are close to the inner wall of the metal tube 1, and there is no distribution of hollow spheres 20 at the position in the composite tube far from the metal tube 1. Based on this, it is possible to avoid the situation where the inner wall of the composite tube is uneven due to the distribution of the hollow spheres 20 on the inner wall of the composite tube, so that the inner wall surface of the composite tube is flat and the surface quality of the inner wall of the composite tube is ensured. Further, the later-solidified liquid metal substrate forms a complete layer, that is, the inner wall layer of the composite tube.

[0033] In some embodiments, the density of the hollow spheres 20 is greater than that of the liquid metal substrate.

[0034] Step 105: Refer to Figure 1 and Figure 2 , perform a temperature reduction treatment on the composite structure with the hollow spheres 20 to solidify the liquid metal substrate and obtain a composite tube with the hollow spheres 20. As for the way of temperature reduction, it can be set according to the actual situation and is not specifically limited herein.

[0035] As a possible implementation manner, after obtaining the composite tube with the hollow spheres 20, the preparation method of the composite tube further includes: After the temperature of the composite tube is reduced to the set temperature, stop the rotation of the composite tube, and then perform a cutting process on the composite tube to obtain a complete composite tube.

[0036] Exemplarily, after the composite tube is completely cooled, turn off the drive motor to stop rotating, and then cut off the clamping parts at both ends of the composite tube to obtain a complete composite tube.

[0037] As a possible implementation, before centrifugal casting is adopted to inject the liquid metal substrate and the hollow spheres 20 into the rotating metal tube 1, the method for preparing the composite tube further includes: Fix the metal tube 1 in the mold 3 having a cavity 30, and perform a heat treatment on the metal tube 1 to obtain a metal tube 1 having a preset temperature; Drive the mold 3 and the metal tube 1 having a preset temperature to rotate.

[0038] The above preset temperature can be determined according to the melting point of the metal tube 1 or other influencing factors. In some embodiments, the preset temperature is greater than or equal to 0.6Tm and less than or equal to 0.8Tm; Tm represents the melting point temperature of the metal tube 1; for example, the preset temperature can be 0.6Tm, 0.63Tm, 0.65Tm, 0.7Tm, 0.73Tm, 0.75Tm, 0.78Tm or 0.8Tm, etc.

[0039] If the temperature of the metal tube 1, which is the outer tube of the composite tube, is too low, when the liquid metal substrate is injected into the metal tube 1, the temperature of the liquid metal substrate will rapidly decrease, and it is not easy to achieve the diffusion of the liquid metal substrate. Therefore, before centrifugal casting, a heat treatment is performed on the metal tube 1. When the temperature of the metal tube 1 is the preset temperature, the mutual diffusion efficiency between metals is higher, which is convenient for the liquid metal substrate to combine with the solid metal tube.

[0040] It should be noted that there are various ways to heat the metal tube 1. For example, an induction heating coil is provided in the mold 3, and the metal tube 1 is heated by electromagnetic induction using the induction heating coil. Alternatively, the mold 3 and the metal tube 1 are placed in a heating chamber, and the mold 3 and the metal tube 1 are heated simultaneously.

[0041] Since the metal tube 1 is fixed in the mold 3 having a cavity 30, when the mold 3 and the metal tube 1 having a preset temperature are driven to rotate, the rotation speed of the mold 3 is equal to the rotation speed of the metal tube 1 having a preset temperature. In this case, during centrifugal casting, the liquid metal substrate and the hollow spheres 20 are evenly distributed, so that the diameters of all parts of the finally obtained composite tube are basically the same or completely the same, the inner wall surface of the composite tube is flat, and the inner wall surface quality of the composite tube is ensured.

[0042] See Figure 1 and Figure 2, in the method for preparing the composite pipe provided by the embodiment of the present invention, since the melting points of both the metal pipe 1 and the hollow spheres 20 are higher than the melting point of the metal substrate 21, when the liquid metal substrate and the hollow spheres 20 are injected into the rotating metal pipe 1, neither the hollow spheres 20 nor the metal pipe 1 will melt, ensuring the original forms of the hollow spheres 20 and the metal pipe 1. Further, the composite structure with the hollow spheres 20 is cooled to solidify the liquid metal substrate and obtain a composite pipe with the hollow spheres 20. Compared with the prior art method of directly mechanically combining two metal pipes 1 to form a composite pipe, the composite pipe produced by the method provided by the embodiment of the present invention has a higher interfacial bonding strength, reduces or eliminates the probability of delamination failure of the composite pipe, and extends the service life of the composite pipe. Still further, since the above composite pipe includes the metal pipe 1 and the solidified metal substrate 21, and since all solid metals have compressive strength, the composite pipe has compressive strength. Especially when the metal pipe 1 is made of stainless steel or carbon steel and the material of the metal substrate 21 is a light metal, due to the advantages of high strength, good toughness, light weight, corrosion resistance, and alkali resistance of different solid metals. Therefore, the composite pipe produced by the method provided by the embodiment of the present invention also has the above advantages. Since the composite pipe includes the hollow spheres 20, the hollow spheres 20 can dissipate energy by virtue of their unique cavity 30 structure, so the composite pipe has excellent sound absorption and energy absorption effects. In summary, the composite pipe produced by the method provided by the embodiment of the present invention not only takes into account the comprehensive mechanical properties of vibration damping, sound absorption, high strength, and high toughness, but also can maintain excellent service performance in extreme environments such as high pressure, low temperature, high salt, and corrosion, expanding the application range of the composite pipe and enabling it to be used in engineering applications in a wide temperature range environment. In other words, the composite pipe produced by the method provided by the embodiment of the present invention combines vibration damping and sound absorption with excellent compressive and shear strength, corrosion resistance, and high stability. Based on this, under dynamic loads, the requirements for vibration attenuation can be met. In addition, the method provided by the embodiment of the present invention realizes the solid-liquid metallurgical bonding of different metal materials through centrifugal casting. Under the action of centrifugal force, the hollow spheres 20 are distributed near the inner wall of the metal pipe 1, ensuring the surface quality of the inner wall of the composite pipe and effectively solving the problems of poor performance and surface quality of the composite pipe.

[0043] In the second aspect, the embodiment of the present invention also provides a composite pipe, which is prepared by using the method for preparing the composite pipe described in the above technical solution. Refer to Figure 1 and Figure 2 , the above composite pipe includes: a metal pipe 1 and a lining pipe 2. The lining pipe 2 is sleeved inside the metal pipe 1, and the lining pipe 2 includes a metal substrate 21 and hollow spheres 20. It should be noted that the metal substrate 21 here is the liquid metal substrate cooled in the first aspect.

[0044] Refer to Figure 1 and Figure 2, in the composite tube provided by the embodiment of the present invention, since the composite tube includes a metal tube 1 and a metal substrate 21, and since all solid metals have compressive strength, the composite tube has compressive strength. Further, since the composite tube includes hollow spheres 20, and the unique cavity 30 structure of the hollow spheres 20 can dissipate energy, the composite tube has excellent sound absorption and energy absorption effects. In summary, the composite tube in the embodiment of the present invention takes into account both the vibration damping and sound absorption performance and the compressive and shear strength, expanding the scope of application of the composite tube.

[0045] As a possible implementation, refer to Figure 1 and Figure 2 , the metal tube 1 and the inner liner tube 2 are metallurgically bonded through the interface.

[0046] Compared with the method of directly mechanically bonding two metal tubes 1 together to form a composite tube in the prior art, the use of interface metallurgical bonding makes the interface bonding strength of the composite tube higher while ensuring excellent performance of the composite tube, reducing or eliminating the probability of delamination failure of the composite tube, and extending the service life of the composite tube.

[0047] Refer to Figure 1 and Figure 2 , as a possible implementation, the hollow spheres 20 are close to the inner wall of the metal tube 1, and there is no distribution of hollow spheres 20 at the position in the composite tube far from the metal tube 1. Based on this, it is possible to avoid the situation where the inner wall of the composite tube is uneven due to the distribution of the hollow spheres 20 on the inner wall of the composite tube, so that the inner wall surface of the composite tube is flat and the surface quality of the inner wall of the composite tube is ensured.

[0048] As a possible implementation, the material of the metal tube 1 is different from the material of the metal substrate 21. At this time, the composite tube can have the characteristics of different metal materials, further expanding the scope of application of the composite tube.

[0049] As a possible implementation, the material of the above metal tube 1 can be stainless steel, carbon steel or titanium alloy. The material of the metal tube 1 is not specifically limited here, as long as it can meet the actual needs. When the material of the metal tube 1 is stainless steel, the composite tube has excellent compressive strength.

[0050] The material of the above metal substrate 21 is a light metal, which makes the composite tube have a light weight at this time. For example, the material of the metal substrate 21 can be aluminum, magnesium, etc., as long as it can meet the actual needs. When the material of the metal substrate 21 is aluminum, the composite tube has corrosion resistance and alkali resistance to salt.

[0051] Combined with the foregoing description, when the metal tube 1 is made of stainless steel or carbon steel and the material of the metal substrate 21 is a light metal, since the dissimilar solid metals respectively have the advantages of high strength, good toughness, light weight, corrosion resistance and alkali resistance to salt. Further, since the composite tube includes the hollow balls 20, the hollow balls 20 can dissipate energy by virtue of their unique cavity 30 structure, so the composite tube has excellent sound absorption and energy absorption effects. In summary, the composite tube manufactured by the method provided by the embodiment of the present invention takes into account the performance of vibration reduction and sound absorption, light weight, high strength and high toughness, corrosion resistance and alkali resistance to salt, etc., and expands the scope of application of the composite tube.

[0052] In a third aspect, the present invention also provides a processing device for a composite tube, and the processing device for the composite tube is applied to the preparation method of the partial composite tube described in the first aspect. Refer to Figures 3 to 14 , the processing device for the composite tube includes: a mold 3, a base 4, a heating member 5, a clamping assembly 6 and a driving assembly 7. Along the axis A of the mold 3, the mold 3 has a cavity 30 penetrating through the mold 3; the cavity 30 is used to accommodate the metal tube 1 and / or the composite tube. The base 4 is used to carry the mold 3; the clamping assembly 6 is arranged on the mold 3 and is located in the cavity 30, and the clamping assembly 6 is used to clamp and fix the metal tube 1 located in the cavity 30; the driving assembly 7 is used to drive the mold 3 to rotate. The processing device for the composite tube provided by the embodiment of the present invention has a simple structure and is easy to manufacture and use.

[0053] Refer to Figures 3 to 14 , since the clamping assembly 6 is used to clamp and fix the metal tube 1 located in the cavity 30, when the driving assembly 7 drives the mold 3 to rotate and then drives the metal tube 1 located in the mold 3 to rotate, the rotation speed of the mold 3 is equal to the rotation speed of the metal tube 1. In this case, during centrifugal casting, the liquid metal substrate and the hollow balls 20 are evenly distributed, so that the diameters of all parts of the finally obtained composite tube are basically the same or completely the same, the inner wall surface of the composite tube is flat, and the inner wall surface quality of the composite tube is ensured.

[0054] As a possible implementation manner, refer to Figure 5 and Figure 7 , the clamping assembly 6 includes: a first clamping unit 60 and a second clamping unit 61.

[0055] Refer to Figure 5 , Figure 7 , Figure 8 , Figure 11 and Figure 12 , the first clamping unit 60 is sleeved in the mold 3, the first clamping unit 60 is located in the cavity 30, and the outer wall of the first clamping unit 60 abuts against the inner wall of the mold 3; the first clamping unit 60 is used to limit the axial movement of the metal tube 1 and / or the composite tube.

[0056] Refer to Figures 7 to 12, along the direction B perpendicular to the axial direction A of the die 3, the first clamping unit 60 and the second clamping unit 61 are arranged opposite to each other. One end of the second clamping unit 61 opposite to the first clamping unit 60 moves in a direction close to or away from the first clamping unit 60 to clamp and fix or release the metal tube 1 located in the cavity 30. At this time, the above-mentioned second clamping unit 61 can be used to limit the radial movement of the metal tube 1. Further, the above-mentioned clamping assembly 6 can be applicable to metal tubes 1 with different thickness specifications, and thus is applicable to manufacturing composite tubes with different thickness specifications.

[0057] See Figures 6 to 8 , along the axial direction A of the die 3, the die 3 includes opposite first and second ends; two clamping assemblies 6 are respectively located at the first and second ends. Among them, the second clamping unit 61 included in the clamping assembly 6 close to the first end is detachably connected to the die 3 through the connecting assembly 8; the second clamping unit 61 included in the clamping assembly 6 close to the second end is fixedly connected to the inner wall of the die 3.

[0058] See Figures 4 to 12 , exemplarily, when the first end of the die 3 is the inlet end of the metal tube 1, in the actual use process, first detach the connecting assembly 8 from the die 3. Since the second clamping unit 61 included in the clamping assembly 6 close to the first end is detachably connected to the die 3 through the connecting assembly 8, when the connecting assembly 8 is detached, the second clamping unit 61 included in the clamping assembly 6 close to the first end also moves out of the cavity 30 of the die 3, leaving space for the metal tube 1 to enter the cavity 30 of the die 3. Since the second clamping unit 61 included in the clamping assembly 6 close to the second end is fixedly connected to the inner wall of the die 3, the first clamping unit 60 and the second clamping unit 61 included in the clamping assembly 6 close to the second end are fixed in the cavity 30. Then, after the metal tube 1 enters the cavity 30 through the first end of the die 3, make the clamping assembly 6 close to the second end clamp and fix one end of the metal tube 1. Then, install the assembled connecting assembly 8 and the clamping assembly 6 close to the first end on the die 3, and make the clamping assembly 6 close to the first end clamp and fix the other end of the metal tube 1.

[0059] See Figure 7 , Figure 8 and Figure 13, in an alternative manner, the first clamping unit 60 includes: an annular connecting member 600 and an annular limiting member 601. The annular connecting member 600 is sleeved inside the mold 3, and the outer wall of the annular connecting member 600 abuts against the inner wall of the mold 3. The annular limiting member 601 is sleeved inside the annular connecting member 600; the thickness D1 of the annular limiting member 601 is greater than the thickness D2 of the annular connecting member 600, and the annular limiting member 601 is used to limit the axial movement of the metal tube 1 and / or the composite tube; the thickness direction of the annular limiting member 601 and the thickness direction of the annular connecting member 600 are both perpendicular to the axis A of the mold 3. The width W1 of the annular connecting member 600 is greater than the width W2 of the annular limiting member 601, and the width direction of the annular connecting member 600 and the width direction of the annular limiting member 601 are both consistent with the axis A of the mold 3.

[0060] See Figures 10 to 13 , in actual use, the end of the metal tube 1 abuts against the annular limiting member 601, and a part of the outer wall of the metal tube 1 abuts against the inner wall of the annular connecting member 600. It should be noted that the above-mentioned annular connecting member 600 and annular limiting member 601 can be integrally formed or assembled separately. As for the materials and dimensions of the annular connecting member 600 and the annular limiting member 601, they can be set according to the actual situation. The shapes of the annular connecting member 600 and the annular limiting member 601 are set according to the shape of the metal tube 1 and the shape of the inner wall of the mold 3. For example, the cross-sections of the annular connecting member 600, the annular limiting member 601, the metal tube 1, and the mold 3 are all circular. It should be noted that the above-mentioned annulus is not limited to a circular annulus and can also be a square annulus, a pentagonal annulus, or other special-shaped annuli.

[0061] See Figures 7 to 13 , in the case of adopting the above technical solution, since the thickness of the annular limiting member 601 is greater than the thickness of the annular connecting member 600, when the metal tube 1 is located between two annular limiting members 601 distributed along the axis of the mold 3, the metal tube 1 is limited between the two annular limiting members 601, that is, the axial movement of the metal tube 1 is limited. Further, since the annular connecting member 600 has a certain thickness and the width of the annular connecting member 600 is greater than the width of the annular limiting member 601, the annular connecting member 600 separates the metal tube 1 from the inner wall of the mold 3. At this time, the outer wall of the metal tube 1 is exposed to the air in the cavity 30 of the mold 3. During the subsequent rotation of the metal tube 1, the air in the cavity 30 of the mold 3 is also in rotation, and the air flow rate is large. Especially when it is necessary to cool and solidify the liquid metal substrate after casting, there is air with a relatively large flow rate in the rotating mold 3, and at this time, the cooling efficiency of the liquid metal substrate can be accelerated, thereby improving the preparation efficiency of the composite tube.

[0062] See Figure 7 and Figure 8, in an alternative manner, the second clamping unit 61 includes: a driving member 610 and a clamping member 611. The driving member 610 has a telescopic rod 6100, and the free end of the telescopic rod 6100 is connected to the clamping member 611; the driving member 610 is used to drive the telescopic rod 6100 to move, and the telescopic rod 6100 drives the clamping member 611 to approach or move away from the first clamping unit 60 to clamp and fix or release the metal tube 1.

[0063] Exemplarily, the above clamping member 611 can be a clamping plate, and the material of the clamping plate can be set according to the actual situation. The above driving member 610 can be a hydraulic driving member or a pneumatic driving member, etc., and the driving source of the corresponding driving member 610 can be a hydraulic cylinder or a pneumatic cylinder, and the telescopic rod 6100 can be a piston rod.

[0064] See Figure 4 , Figure 5 , Figure 7 and Figure 14 , in an alternative manner, a groove 31 is formed on the outer side wall of the first end of the mold 3. The connecting assembly 8 includes: a carrier 80, a first connecting member 81 and a second connecting member 82. The carrier 80 has a bearing surface; the first connecting member 81 is disposed on the bearing surface, and the first connecting member 81 is used for snap-fitting with the groove 31. The second connecting member 82 is disposed on the bearing surface. Along the axial direction A of the mold 3, the second connecting member 82 is located on one side of the first connecting member 81, and the second connecting member 82 is spaced apart from the first connecting member 81; the width W3 of the second connecting member 82 is greater than the width W4 of the first connecting member 81. Such a setting can reserve space for the subsequent installation of the second clamping unit 61 and prevent the first connecting member 81 from interfering with the normal operation of the second clamping unit 61. The width direction of the second connecting member 82 and the width direction of the first connecting member 81 are both perpendicular to the axial direction A of the mold 3; the driving member 610 is connected to the side surface of the second connecting member 82 that is close to the first connecting member 81. Exemplarily, the side surface of the driving member 610 is connected to the side surface of the second connecting member 82 that is close to the first connecting member 81 and faces the cavity 30.

[0065] It should be noted that the above carrier 80, first connecting member 81 and second connecting member 82 can be integrally formed or assembled separately. The shapes and sizes of the carrier 80, first connecting member 81 and second connecting member 82 can be set according to the actual situation. For example, the carrier 80 can be an annular carrier or a semi-annular carrier. The first connecting member 81 is an annular first connecting member or a semi-annular first connecting member. The second connecting member 82 is an annular second connecting member or a semi-annular second connecting member. It should be noted that the term "annular" throughout the text can refer to a circular ring, a square ring, a pentagonal ring or other special-shaped rings. Further, the thickness of the second connecting member 82 is greater than the thickness of the first connecting member 81, and the thickness direction of the second connecting member 82 and the thickness direction of the first connecting member 81 are both consistent with the axial direction of the mold 3.

[0066] See Figures 7 to 12 , as a possible implementation, the processing device for the composite tube further includes: a telescopic blocking component 90. The telescopic blocking component 90 includes: a receiving member 900 and a telescopic blocking member 901. The receiving member 900 has a receiving space, and the receiving member 900 is connected to the side of the driving member 610 that is away from the clamping member 611. Along the axial direction A of the mold 3, the receiving member 900 has an opposite open end and a closed end. For example, as Figure 9 shown, the outer wall of the above-mentioned receiving member 900 is fixedly connected to the side of the driving member 610 that is away from the clamping member 611, and the open end of the receiving member 900 faces the inside of the cavity 30 of the mold 3.

[0067] See Figures 7 to 12 , the first end of the telescopic blocking member 901 is connected to the side surface of the clamping member 611, and the second end of the telescopic blocking member 901 passes through the open end and is connected to the closed end. When the driving member 610 drives the clamping member 611 to approach or move away from the first clamping unit 60, the telescopic blocking member 901 extends or contracts. The telescopic blocking member 901 located outside the receiving member 900 is located between the second clamping unit 61 and the metal substrate 21. Specifically, the telescopic blocking member 901 located outside the receiving member 900 is located between the second clamping unit 61 and the inner liner tube 2.

[0068] See Figure 11 and Figure 12 , in the case of adopting the above technical solution, when injecting the liquid metal substrate and the hollow balls 20 into the outer tube, the telescopic blocking component 90 is used to block the second clamping unit 61 from the flowing liquid metal substrate and the hollow balls 20, so as to prevent the second clamping unit 61 from being damaged by the flowing liquid metal substrate and the hollow balls 20. Specifically, the metal tube 1, the first clamping unit 60, the telescopic blocking component 90 and the inner wall of the mold 3 enclose the second clamping unit 61, preventing the second clamping unit 61 from being contacted by the flowing liquid metal substrate and the hollow balls 20.

[0069] See Figure 7 and Figure 9, Exemplarily, before the driving member 610 drives the clamping member 611 close to the first clamping unit 60, the telescopic blocking member 901 is in a contracted state. When the driving member 610 drives the clamping member 611 close to the first clamping unit 60, the telescopic blocking member 901 gradually extends so that the overall size of the telescopic blocking member 901 becomes larger to protect the second clamping unit 61. When the driving member 610 drives the clamping member 611 away from the first clamping unit 60, the telescopic blocking member 901 gradually contracts to restore to its original state. It should be noted that whether the telescopic blocking member 901 extends or contracts, the length of the telescopic blocking member 901 on the side of the second clamping unit 61 after the change is always equal to the height of the second clamping unit 61 after the change, and the height direction of the second clamping unit 61 is consistent with the telescopic direction of the telescopic rod 6100.

[0070] In some embodiments, when the telescopic blocking member 901 is an L-shaped baffle structure, the L-shaped baffle structure and the clamping member 611 perform telescopic movements synchronously. Among them, in the initial state, the L-shaped baffle structure is a stacked baffle, and when the stacked baffle gradually unfolds, the total length of the L-shaped baffle structure gradually becomes longer.

[0071] For example, when the telescopic rod 6100 drives the clamping member 611 close to the first clamping unit 60, the height of the second clamping unit 61 becomes higher. If the length of the baffle included in the telescopic blocking member 901 outside the receiving member 900 (that is, the telescopic blocking member 901 originally on the side of the second clamping unit 61) after being fully unfolded is equal to the height of the second clamping unit 61 after the change, the telescopic blocking member 901 inside the receiving member 900 may not unfold or unfold less.

[0072] If the length of the baffle included in the telescopic blocking member 901 outside the receiving member 900 after being fully unfolded is less than the height of the second clamping unit 61 after the change, the telescopic blocking member 901 inside the receiving member 900 unfolds to compensate for the telescopic blocking member 901 originally on the side of the second clamping unit 61, so that the length of the telescopic blocking member 901 on the side of the second clamping unit 61 after the increase is equal to the height of the second clamping unit 61 after the change.

[0073] When the telescopic rod 6100 drives the clamping member 611 away from the first clamping unit 60, the height of the second clamping unit 61 becomes smaller, and the baffle included in the telescopic blocking member 901 returns to its original overlapping or folded state so that the length of the telescopic blocking member 901 on the side of the second clamping unit 61 is equal to the height of the second clamping unit 61 after the change.

[0074] In some embodiments, see Figure 9 , the above-mentioned telescopic blocking member 901 is an L-shaped telescopic blocking member. The material of the telescopic blocking member 901 can be flexible steel, carbon fiber fabric, etc.

[0075] As a possible implementation, refer to Figures 3 to 14 The processing device for the composite tube further includes: a heating member 5 disposed on the mold 3. At this time, the processing device for the composite tube is applied to the preparation method of all the composite tubes described in the first aspect.

[0076] In an alternative embodiment, the above-mentioned heating member 5 can be disposed on the outer wall of the mold 3, or on the inner wall of the mold 3, or between the outer wall and the inner wall of the mold 3 (i.e., embedded in the solid part of the mold 3). The setting position of the heating member 5 can be selected according to the actual situation and will not be specifically limited herein. Refer to Figure 5 and Figure 11 In the embodiment of the present invention, the heating member 5 is disposed between the outer wall and the inner wall of the mold 3 and close to the cavity 30, which is convenient for better heating the metal tube 1 and improves the heating efficiency.

[0077] In some embodiments, the above-mentioned heating member 5 can be an induction heating coil.

[0078] As a possible implementation, refer to Figure 3 The processing device for the composite tube further includes: a casting ladle 91 having a casting channel. The casting ladle 91 is used to melt the solid metal base material 21 and hold and accommodate the liquid metal base material and the hollow spheres 20. During actual use, the liquid metal base material and the hollow spheres 20 are injected into the rotating metal tube 1 through the casting channel.

[0079] As a possible implementation, refer to Figure 3 The above-mentioned base 4 includes: a bearing seat 40, a bracket 41 and a rotating member 42. Four brackets 41 are spaced apart on the bearing seat 40, and four rotating members 42 are correspondingly disposed on the four brackets 41, and the rotating member 42 rotates relative to the bracket 41. The specific connection manner between the rotating member 42 and the bracket 41 will not be specifically limited herein. The mold 3 is rotatably disposed between the four rotating members 42, and the driving assembly 7 is power-connected to one of the rotating members 42. The driving assembly 7 is used to drive the rotating member 42 to rotate, thereby driving the mold 3 to rotate, and the other three rotating members 42 are driven members that rotate as the mold 3 rotates. Exemplarily, the driving assembly 7 can be a driving motor, and the rotating member 42 can be a rotating wheel.

[0080] The following describes the specific process of preparing the composite tube using the processing device for the composite tube by taking a possible implementation as an example. It should be understood that the following description is only for understanding and not for specific limitation.

[0081] Step 101: Refer to Figures 1 to 14 Provide the metal tube 1, the hollow spheres 20 and the metal base material 21; Among them, the metal tube 1 is: a 304 stainless steel seamless tube with an outer diameter of 200 mm, a wall thickness of 5 mm, and a length of 500 mm. The hollow sphere 20 is: a 304 stainless steel hollow sphere with an outer diameter of 4 mm and a wall thickness of 0.5 mm. The number of hollow spheres 20 is 100. 6061 aluminum alloy is selected as the metal substrate 21. Specifically, the metal substrate 21 is: an aluminum ingot with a volume of 2824 of the aluminum ingot.

[0082] Step 102: Refer to Figures 1 to 14 , and perform surface treatment on the metal tube 1 and the hollow sphere 20 to remove the surface oxides and contaminants.

[0083] Exemplarily, use a flap wheel and sandpaper to polish the inner surface of the 304 stainless steel seamless tube and the outer surface of the stainless steel hollow sphere respectively to remove the surface oxides and contaminants.

[0084] Step 103: Refer to Figures 1 to 14 , install the processed 304 stainless steel seamless tube between two first clamping units 60, and then start the second clamping unit 61 to fix the 304 stainless steel seamless tube in the mold 3; place the processed 304 stainless steel hollow sphere in the casting ladle 91.

[0085] Refer to Figures 1 to 14 , specifically, when the first end of the mold 3 is the inlet end of the metal tube 1, in actual use, first disassemble the connection component 8 from the mold 3. Since the second clamping unit 61 included in the clamping component 6 near the first end is detachably connected to the mold 3 through the connection component 8, when the connection component 8 is disassembled, the second clamping unit 61 included in the clamping component 6 near the first end also moves out of the cavity 30 of the mold 3, leaving space for the metal tube 1 to enter the cavity 30 of the mold 3. Since the second clamping unit 61 included in the clamping component 6 near the second end is fixedly connected to the inner wall of the mold 3, the first clamping unit 60 and the second clamping unit 61 included in the clamping component 6 near the second end remain stationary in the cavity 30. Then, after the metal tube 1 enters the cavity 30 through the first end of the mold 3, the driving member 610 drives the clamping member 611 to approach the first clamping unit 60, so that the clamping component 6 near the second end clamps and fixes one end of the metal tube 1. Then, install the assembled connection component 8 and the clamping component 6 near the first end on the mold 3, and use the driving member 610 to drive the clamping member 611 to approach the first clamping unit 60, so that the clamping component 6 near the first end clamps and fixes the other end of the metal tube 1.

[0086] Step 104: Place the aluminum ingot with a volume of 2824 in the melting furnace and heat it to 750 °C to completely melt it and keep it warm for 20 min to ensure good fluidity and pouring effect.

[0087] Step 105: Start the induction heating coil installed inside the mold 3 to perform electromagnetic induction heating on the 304 stainless steel seamless pipe, and heat the 304 stainless steel seamless pipe to 800 °C.

[0088] Step 106: Start the drive motor, and drive the mold 3 and the 304 stainless steel seamless pipe to rotate through the base 4. Pour the molten aluminum liquid in the melting furnace into the casting ladle 91 to mix with the 304 stainless steel hollow balls. Then, inject the molten aluminum liquid and the 304 stainless steel hollow balls into the rotating 304 stainless steel seamless pipe through the casting channel. During the rotation of the 304 stainless steel seamless pipe, the molten aluminum liquid and the 304 stainless steel hollow balls are evenly distributed on the inner wall of the 304 stainless steel seamless pipe under the action of centrifugal force, and form a metallurgical bond with the 304 stainless steel seamless pipe. Among them, the 304 stainless steel hollow balls are close to the inner wall of the 304 stainless steel seamless pipe, and there is no distribution of hollow balls 20 at the position far from the 304 stainless steel seamless pipe in the composite pipe.

[0089] Step 107: After casting, turn off the induction heating coil, ensure that the mold 3 continues to rotate, and the inner layer of metal aluminum gradually cools and solidifies to form a stable composite pipe. After the composite pipe is completely cooled, turn off the drive motor to stop rotating, turn off the second clamping unit 61, and take out the composite pipe from the mold 3. Then cut the clamped parts at both ends of the composite pipe to obtain a complete 304 stainless steel / 6061 aluminum alloy bimetallic hollow ball composite pipe.

[0090] Although the present invention has been described in connection with specific features and their embodiments, it is obvious that various modifications and combinations can be made without departing from the spirit and scope of the present invention. Accordingly, this specification and the drawings are merely exemplary illustrations of the present invention defined by the appended claims, and are considered to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A method for preparing a composite pipe, characterized in that, Comprising: Providing a metal tube, a hollow sphere, and a metal substrate; the melting point of the metal tube and the melting point of the hollow sphere are both greater than the melting point of the metal substrate; Melting the metal substrate to obtain a liquid metal substrate; Using centrifugal casting to inject the liquid metal substrate and the hollow sphere into the rotating metal tube, so that the liquid metal substrate and the hollow sphere are located on the inner wall of the metal tube and a composite structure with hollow spheres is obtained; Performing a cooling treatment on the composite structure with hollow spheres, so that the liquid metal substrate solidifies and a composite tube with hollow spheres is obtained.

2. The preparation method of the composite pipe according to claim 1, characterized in that, The liquid metal substrate and the hollow sphere form a metallurgical bond with the metal tube; And / or, the material of the metal tube is different from the material of the metal substrate; And / or, the material of the metal substrate is a light metal.

3. The manufacturing method of the composite tube according to claim 1, characterized in that, The density of the hollow sphere is greater than the density of the liquid metal substrate; in the composite tube, the hollow sphere is close to the inner wall of the metal tube.

4. The preparation method of the composite pipe according to claim 1, characterized in that, Before using centrifugal casting to inject the liquid metal substrate and the hollow sphere into the rotating metal tube, the preparation method of the composite tube further includes: Fixing the metal tube in a mold with a cavity and performing a heat treatment on the metal tube to obtain a metal tube with a preset temperature; Driving the mold and the metal tube with the preset temperature to rotate; Wherein, the preset temperature is greater than or equal to 0.6Tm and less than or equal to 0.8Tm; Tm represents the melting point temperature of the metal tube.

5. A composite pipe, characterized in that, Prepared by using the preparation method of the composite tube according to any one of claims 1 to 4; the composite tube includes: A metal tube; A lining tube sleeved inside the metal tube; the lining tube includes a metal substrate and hollow spheres.

6. A processing device for a composite pipe, characterized in that, Applied to the preparation method of the composite tube according to any one of claims 1 to 3; the processing device of the composite tube includes: A mold, along the axis of the mold, the mold has a cavity penetrating through the mold; the cavity is used to accommodate the metal tube and / or the composite tube; A base for carrying the mold; a clamping assembly disposed on the mold and located inside the cavity; the clamping assembly is used to clamp and fix the metal tube located inside the cavity; A driving assembly for driving the mold to rotate.

7. The processing device for the composite pipe according to claim 6, characterized in that, The processing device of the composite tube further includes: A heating element disposed on the mold.

8. The processing device for the composite pipe according to claim 6, characterized in that, The clamping assembly includes: A first clamping unit sleeved inside the mold, the outer wall of the first clamping unit abuts against the inner wall of the mold; the first clamping unit is used to limit the axial movement of the metal tube and / or the composite tube; A second clamping unit, along the direction perpendicular to the axis of the mold, the first clamping unit and the second clamping unit are oppositely arranged; one end of the second clamping unit opposite to the first clamping unit moves in a direction close to or away from the first clamping unit to clamp and fix or release the metal tube located inside the cavity; Along the axis of the mold, the mold includes opposite first and second ends; two clamping assemblies are respectively located at the first and second ends; The second clamping unit included in the clamping assembly close to the first end is detachably connected to the mold through a connecting assembly; The second clamping unit included in the clamping assembly near the second end is fixedly connected to the inner wall of the mold.

9. The processing device for the composite pipe according to claim 8, characterized in that, The first clamping unit includes: An annular connecting piece sleeved inside the mold, and the outer wall of the annular connecting piece abuts against the inner wall of the mold; An annular limiting piece sleeved inside the annular connecting piece; the thickness of the annular limiting piece is greater than the thickness of the annular connecting piece, and the annular limiting piece is used to limit the axial movement of the metal pipe and / or the composite pipe; the thickness direction of the annular limiting piece and the thickness direction of the annular connecting piece are both perpendicular to the axis of the mold; the width of the annular connecting piece is greater than the width of the annular limiting piece, and the width direction of the annular connecting piece and the width direction of the annular limiting piece are both consistent with the axis of the mold; The second clamping unit includes: A driving piece having a telescopic rod; A clamping piece, and the free end of the telescopic rod is connected to the clamping piece; the driving piece is used to drive the clamping piece to approach or move away from the first clamping unit to clamp and fix or release the metal pipe; A groove is formed on the outer side wall of the first end of the mold; the connecting assembly includes: A bearing piece having a bearing surface; A first connecting piece disposed on the bearing surface and clamped with the groove; A second connecting piece disposed on the bearing surface and spaced from the first connecting piece; the width of the second connecting piece is greater than the width of the first connecting piece; the width direction of the second connecting piece and the width direction of the first connecting piece are both perpendicular to the axis of the mold; the driving piece is connected to the side surface of the second connecting piece close to the first connecting piece.

10. The processing device for the composite pipe according to claim 9, characterized in that, The processing device for the composite pipe further includes: a telescopic blocking assembly; The telescopic blocking assembly includes: A receiving piece having a receiving space; the receiving piece is connected to the surface of the driving piece facing away from the clamping piece; along the axis of the mold, the receiving piece has an opposite open end and a closed end; A telescopic blocking piece, the first end of the telescopic blocking piece is connected to the side surface of the clamping piece, and the second end of the telescopic blocking piece passes through the open end and is connected to the closed end; when the driving piece drives the clamping piece to approach or move away from the first clamping unit, the telescopic blocking piece extends or contracts; the telescopic blocking piece located outside the receiving piece is located between the second clamping unit and the metal substrate.

Images