Thermal insulation composite pipe forming device

Abstract

The application discloses a heat-insulation composite pipe forming device, and relates to the technical field of pipe forming. The heat-insulation composite pipe forming device comprises an inner pipe extrusion die, a heat-insulation layer extrusion die, a blind hole forming mechanism and an outer skin extrusion die which are sequentially arranged. The inner pipe extrusion die is used for extruding an inner pipe. The heat-insulation layer extrusion die is used for extruding a heat-insulation layer and coating the heat-insulation layer on the outer surface of the inner pipe. The blind hole forming mechanism is used for punching an inner wall filling blind hole on the heat-insulation layer before the heat-insulation layer is shaped. The outer skin extrusion die is used for extruding an outer skin layer and coating the outer skin layer on the outer surface of the inner pipe and filling the filling blind hole. The heat-insulation composite pipe forming device is provided with the blind hole forming mechanism, so that the heat-insulation composite pipe formed by the heat-insulation composite pipe forming device can form the filling blind hole on the heat-insulation layer. The filling blind hole is filled with high-density polyethylene, so that the outer skin and the heat-insulation layer are prevented from being separated from each other due to the different thermal expansion rates of the outer skin and the heat-insulation layer.

Description

Technical Field

[0001] This invention relates to the field of pipe forming technology, specifically to a heat-insulating composite pipe forming device. Background Technology

[0002] Thermal insulation composite pipes typically consist of an inner pipe, a polyurethane insulation layer, and an outer skin. The outer skin is usually made of high-density polyethylene. Polyurethane insulation pipes are made by chemically reacting and foaming high-performance polyether polyol blends and polymethylene polyphenyl isocyanate. Polyurethane insulation pipes are used for insulation and cold insulation projects of various indoor and outdoor pipelines, centralized heating pipelines, central air conditioning pipelines, and industrial pipelines in chemical, pharmaceutical, and other industries. Since the invention of polyurethane synthetic materials, polyurethane foam insulation pipes have been rapidly developed as an excellent thermal insulation material, and their application range has become increasingly wide. Due to their simple construction, energy-saving, and corrosion-resistant effects, they are widely used in various heating, cooling, oil transportation, and steam transportation pipelines.

[0003] The inner pipe of the thermal insulation composite pipe is usually equipped with a mounting bracket between the inner pipe and the insulation layer. The purpose of the mounting bracket is to increase the connection strength between the inner pipe and the insulation layer. At the same time, because the pressure between the polyurethane insulation layer and the outer pipe is greater at the bracket, the connection strength between the outer pipe and the insulation layer is further increased.

[0004] However, the mounting bracket and the inner tube bracket are interference fit, so the mounting bracket is always installed manually on the inner tube. This means that if the bracket needs to be installed, it cannot be produced in a single step. This results in low production efficiency.

[0005] To improve the automation and production efficiency of thermal insulation composite pipes, a one-step molding method is currently commonly used. For example, utility model patent CN209534210U discloses a one-step molding equipment for polyolefin polyurethane thermal insulation composite pipes, in which the inner pipe, foamed insulation layer, and outer pipe are formed in one step. Another example is the molding device for polyurethane thermal insulation composite pipes disclosed in invention patent application CN113513638A, where the polyurethane insulation layer and outer pipe are formed in one step from the inner pipe outwards.

[0006] Therefore, in the current production of some thermal insulation composite pipes, the installation bracket is usually omitted, and the connection strength between the insulation layer and the inner pipe is improved by treating the outer wall of the inner pipe. However, the connection strength between the outer pipe and the insulation layer cannot be guaranteed.

[0007] However, thermal expansion and contraction are quite severe in the use of such pipes, but the thermal expansion rates of polyurethane and polyethylene differ significantly.

[0008] The thermal expansion coefficient of polyurethane used as the insulation layer is approximately 80 × 10⁻⁶. ⁻6 At ℃, the coefficient of thermal expansion of high-density polyethylene is approximately 150 × 10⁻⁶.⁻6 The temperature difference of / ℃ causes shear stress between the outer protective layer and the polyurethane insulation layer under temperature cycling after long-term use, resulting in delamination, which manifests as longitudinal or circumferential bulges. Existing molding devices cannot solve this problem. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a heat-insulating composite pipe forming device, which solves the problem in existing technologies where shear stress is generated between the outer protective layer and the polyurethane insulation layer under temperature difference cycling, leading to delamination and manifesting as longitudinal or circumferential bulging.

[0010] To achieve the above objectives, the present invention provides a heat-insulating composite pipe forming device, comprising an inner tube extrusion mold, an insulation layer extrusion mold, a blind hole forming mechanism, and an outer skin extrusion mold arranged sequentially.

[0011] The inner tube extrusion die is used to extrude the inner tube, the insulation layer extrusion die is used to extrude the insulation layer and cover the outer surface of the inner tube, and the outer skin extrusion die is used to extrude the outer skin and cover the outer surface of the inner tube, and fill the blind holes.

[0012] The blind hole forming mechanism includes:

[0013] The rotating belt has at least three sets, and the at least three sets are arranged in a circular matrix on the outside of the insulation layer;

[0014] The U-shaped platform is provided in multiple sets and is installed at equal intervals on each set of rotating belts;

[0015] A forming mold is located on the side of the U-shaped platform away from the center line of the rotary belt;

[0016] A pressure assembly is assembled on one side of the U-shaped platform near the centerline of the rotary belt.

[0017] The track platform is located in the centerline area of ​​the rotating belt and is used to apply force to the pressure component, so that the forming mold forms a filling blind hole on the insulation layer, and the filling blind hole is solidified during the rotation of the forming mold.

[0018] Further, the forming mold includes:

[0019] A carrier ring, which is slidably disposed on a U-shaped carrier platform;

[0020] The leaflet is hinged to one end of the carrier ring near the insulation layer. When the leaflet is not open, it forms a columnar structure and the inner wall of the leaflet has a slope.

[0021] The pressure assembly is used to first push the carrier ring and the leaflets to move vertically, and then push the slope to open the leaflets.

[0022] Furthermore, the pressure assembly includes a force-bearing rod, one end of which is fixed with a pressure plate, and a spring is provided between the pressure plate and the carrying ring. A pressure rod is fixed at one end of the force-bearing rod near the pressure plate, and the pressure rod extends into the carrying ring and is fixed with a sloped pressure plate.

[0023] The U-shaped platform is provided with a limiting protrusion on the side away from the rotating belt;

[0024] The other end of the force-bearing rod is equipped with a head, and a spring is provided between the head and the U-shaped platform.

[0025] Furthermore, the track platform, starting from the end closest to the insulation layer extrusion die, is provided with a primary inclined section, a primary parallel section, a secondary inclined section, a parallel shaping section, a primary upward inclined section, a secondary parallel section, and a secondary upward inclined section in sequence, which cooperate with the pressure assembly.

[0026] Furthermore, each set of rotating belts consists of two parallel rotating belts spaced apart, forming an unobstructed space between the two rotating belts. The U-shaped platform and the track platform are both located between the corresponding two rotating belts.

[0027] Furthermore, it also includes a frame located on both sides of the rotary belt and used to support the rotary belt, and the track platform is fixed on the frame;

[0028] The U-shaped platform is provided with side support rods on both sides, and the frame is provided with side support rails adapted to the side support rods.

[0029] Furthermore, a support frame, a drive mechanism, and an end frame are also provided. The support frame is located at both ends of the rotating belt and is located outside the insulation layer. The end frame is fixed to the end of the frame.

[0030] The drive mechanism includes: a sprocket fixed at one end of the central shaft of the pulley of the rotary belt, and another sprocket set at a position close to it. A worm gear is set on the coaxial sprocket, and a chain is set between the two sprockets. The rotation of the rotary belt is controlled by driving the worm gear to rotate.

[0031] The present invention has the following beneficial effects:

[0032] (1) The heat insulation composite pipe forming device is equipped with a blind hole forming mechanism, which enables the heat insulation composite pipe formed to form a filling blind hole on the insulation layer. The filling blind hole is filled with high-density polyethylene, and this part of high-density polyethylene is integrated with the high-density polyethylene of the outer skin. Thus, the filling blind hole restricts the outer skin from detaching from the insulation layer by restricting the high-density polyethylene from detaching from the insulation layer, thereby greatly reducing the situation of the outer skin and the insulation layer detaching from each other and bulging due to the difference in thermal expansion rates between the outer skin and the insulation layer, ensuring the tightness of the connection between the two, and thus avoiding the situation of a large amount of corrosive gas and liquid entering between the outer skin and the insulation layer, which would reduce the life of the pipe.

[0033] (2) The heat insulation composite pipe forming device, by setting a rotating belt, a forming mold located on the rotating belt and a track platform set on the rotating path, can enable the forming mold to form blind holes, shape and demold continuously, thereby achieving efficient and continuous operation.

[0034] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0035] Figure 1 This is a cross-sectional view of the end face of the thermal insulation composite pipe of the present invention;

[0036] Figure 2 This is an axial cross-sectional view of the thermal insulation composite pipe of the present invention;

[0037] Figure 3 This is a schematic diagram of the thermal insulation composite pipe forming device of the present invention;

[0038] Figure 4 This is a schematic diagram of the blind hole forming mechanism of the thermal insulation composite pipe forming device of the present invention.

[0039] Figure 5 This is a schematic diagram of a single rotating belt assembled on a support in the heat-insulating composite pipe forming device of the present invention;

[0040] Figure 6 For the present invention Figure 5 Enlarged view of area A;

[0041] Figure 7 This is a driving diagram of the rotary belt of the present invention;

[0042] Figure 8 This is a first-view view of the pressure assembly, forming mold, and U-shaped platform in this invention;

[0043] Figure 9 This is a second-view view of the pressure assembly, forming mold, and U-shaped platform in this invention;

[0044] Figure 10 For the present invention Figure 9 Exploded view;

[0045] Figure 11 This is a diagram showing the leaflets of the present invention open.

[0046] Figure 12 This is a cross-sectional view of the U-shaped platform of the present invention.

[0047] In the diagram, 100 is the inner tube; 200 is the insulation layer; 300 is the outer skin; 400 is the blind hole filling part; 1 is the bracket; 2 is the ring frame; 3 is the blind hole forming mechanism; 41 is the large gear ring; 42 is the bevel gear ring; 43 is the motor; 44 is the chain; 45 is the sprocket; 46 is the worm; 47 is the bevel gear; 48 is the worm wheel; 5 is the rotary belt; 6 is the pressure assembly; 61 is the force-bearing rod; 62 is the first spring; 63 is the first pressure plate; 64 is the second spring; 65 is the pressure rod; 66 is the slope pressure plate; 67 is the head; 7 is the forming mold; 71 is the... 72. Carrier ring; 73. Leaflet; 8. Slope; 9. Side support track; 10. Inner tube extrusion die; 11. Outer skin extrusion die; 12. End frame; 13. Skeleton; 14. Track platform; 15. Parallel shaping section; 16. Primary tilting section; 17. Primary parallel section; 18. Secondary tilting section; 19. Primary upward tilting section; 10. Secondary parallel section; 11. Secondary upward tilting section; 12. Insulation layer extrusion die; 13. U-shaped carrier platform; 14. Limiting protrusion; 15. Side support rod; 16. Grinding mechanism. Detailed Implementation

[0048] The following is based on Figures 1-12 This invention describes a heat-insulating composite pipe forming device provided by an embodiment of the present invention.

[0049] The present invention provides a heat-insulating composite pipe, comprising an inner pipe 100, an insulation layer 200 and an outer skin 300 arranged sequentially from the inside to the outside. The outer surface of the insulation layer 200 is provided with filling blind holes 400. The outer skin 300 can not only cover the insulation layer 200 but also fill the filling blind holes 400.

[0050] Preferably, the inner tube 100 is made of polypropylene or polyethylene by extrusion molding, the insulation layer 200 is made of polyurethane by extrusion molding, and the outer skin 300 is made of high-density polyethylene by extrusion molding.

[0051] Specifically, when the polyurethane is freshly extruded and not yet cured, a filling blind hole 400 is opened on its surface, and after curing, high-density polyethylene is extruded on its outer surface. This high-density polyethylene can serve as an outer skin 300 and can fill the filling blind hole 400.

[0052] Because the blind hole 400 of this thermal insulation composite pipe also contains high-density polyethylene, and this high-density polyethylene is integrated with the high-density polyethylene of the outer skin 300, the blind hole 400 restricts the outer skin 300 from detaching from the insulation layer 200 by limiting the high-density polyethylene from detaching from the insulation layer 200. This avoids the outer skin 300 from detaching from the insulation layer 200 due to the difference in thermal expansion rates, ensuring a tight connection between the two. This also prevents the entry of a large amount of corrosive gas or liquid between the outer skin 300 and the insulation layer 200, which could reduce the pipe's lifespan.

[0053] Preferably, the outer diameter of the filling blind hole 400 is 1.1-1.3 times the thickness of the outer skin 300 to prevent the high-density polyethylene inside the filling blind hole 400 from breaking off from the outer skin 300.

[0054] Optionally, the filling blind hole 400 of the pipe can be a blind hole with different diameters at the inner and outer ends. In this embodiment, the filling blind hole 400 is frustum-shaped, with the larger diameter end of the frustum-shaped hole being the inner end and the smaller diameter end being the outer end. This method can further limit the detachment of high-density polyethylene in the filling blind hole 400.

[0055] The present invention also provides a heat-insulating composite pipe forming device.

[0056] Please refer to Figure 3 The heat-insulating composite pipe forming device includes an inner tube extrusion mold 9, an insulation layer extrusion mold 14, a blind hole forming mechanism 3, and an outer skin extrusion mold 10 arranged in sequence. The inner tube extrusion mold 9 is used to extrude the inner tube 100. The insulation layer extrusion mold 14 is used to extrude the insulation layer 200 and cover it on the outer surface of the inner tube 100. The blind hole forming mechanism 3 is used to punch inner wall filling blind holes 400 on the insulation layer 200 before it is shaped. The outer skin extrusion mold 10 is used to extrude an outer skin 300 layer and cover it on the outer surface of the inner tube 100, and fill the blind holes 400.

[0057] Figure 3 In the figure, the inner tube extrusion die 9 is assembled on the extruder. The polyurethane foam machine and the outer skin 300 extruder are not shown in the figure. Both are well-known technologies and will not be described in detail here.

[0058] Combination Figure 4 - Figure 7 As shown, the blind hole forming mechanism 3 mentioned above includes a rotary belt 5, a U-shaped platform 15, a forming mold 7, a pressure assembly 6, and a track platform 13.

[0059] The aforementioned rotating belt 5 is provided with at least three sets, and the at least three sets are arranged in a circular matrix outside the insulation layer 200, as in this embodiment. Figure 4 As shown, ten sets of rotating belts 5 are preferably provided, with two rotating belts 5 in each set. The two rotating belts 5 are arranged parallel to each other and spaced apart, with unobstructed space between the two rotating belts 5. (Refer to...) Figure 6 and Figure 7 To better understand, the two rotating belts 5 each have their own independent pulleys, and a U-shaped platform 15 is fixed between the two rotating belts 5. The closed end of the U-shaped platform 15 is close to the inner side of the rotating belt 5, and the open end of the U-shaped platform 15 is close to the outer side of the U-shaped platform 15. Multiple sets of U-shaped platforms 15 are provided and are fixed at equal intervals on each set of rotating belts 5, so that when the rotating belts 5 rotate, they can drive the U-shaped platforms 15 to rotate. In this embodiment, the rotating belt 5 is a V-belt or a belt.

[0060] The forming mold 7 is located on the side of the U-shaped platform 15 away from the center line of the rotating belt 5. The pressure component 6 is assembled on the side of the U-shaped platform 15 close to the center line of the rotating belt 5. The track platform 13 is located in the center line area of ​​the rotating belt 5. When the rotating belt 5 drives the U-shaped platform 15 to rotate, the forming mold 7 and the pressure component 6 on it rotate synchronously. When the forming mold 7 rotates to the position opposite to the insulation layer 200, the track platform 13 can apply force to the pressure component 6, so that the forming mold 7 forms a filling blind hole 400 on the insulation layer 200. During the rotation of the forming mold 7, the filling blind hole 400 is solidified and formed, and after the filling blind hole 400 is solidified, the forming mold 7 is removed from the filling blind hole 400.

[0061] Combination Figures 8-12 As shown, specifically, the forming mold 7 mentioned above includes a carrier ring 71, which is slidably disposed on a U-shaped platform 15. A leaf 72 is hinged to the carrier ring 71 near the opening end of the U-shaped platform 15. A slope 73 is provided on the inner wall of the leaf 72. The slope 73 can be an inclined surface or an arc surface. When the forming mold 7 rotates to face the insulation layer 200, the pressure component 6 first pushes the carrier ring 71 and the leaf 72 to move vertically, so that the entire leaf 72 opens a cylindrical hole in the insulation layer 200 in a closed posture. Then, the pressure component 6 pushes the slope 73 to open the leaf 72, and the opening can form a frustum-shaped blind hole in the cylinder.

[0062] Specifically, the pressure assembly 6 includes a force-bearing rod 61, which is slidably disposed on the U-shaped platform 15 along the length of the U-shaped platform 15. One end of the force-bearing rod 61 located inside the U-shaped platform 15 is fixed with a pressure plate 63, and the other end of the force-bearing rod 61 is fixed with a head 67. A spring 62 is provided between the head 67 and the U-shaped platform 15, and a spring 64 is provided between the pressure plate 63 and the carrier ring 71. A pressure rod 65 is fixed at the end of the force-bearing rod 61 near the pressure plate 63. The pressure rod 65 extends into the carrier ring 71 and is fixed with a slope pressure plate 66. A limiting protrusion 151 is provided on the side of the U-shaped platform 15 away from the rotating belt 5.

[0063] In this embodiment, when the head 67 is subjected to pressure, it can push the force rod 61, which in turn pushes the pressure plate 63, the spring 64, and the entire forming mold 7 to gradually approach the insulation layer 200, thereby opening a cylindrical blind hole until the carrier ring 71 is blocked by the limiting protrusion 151. At this time, the carrier ring 71 no longer moves, and the pressure plate 63 begins to compress the spring 64. Thus, the pressure plate 63 continuously drives the pressure rod 65 to push the slope pressure plate 66, that is, the slope pressure plate 66 can push the leaf 72 to open.

[0064] Specifically, in order to enable the track platform 13 to apply pressure to the head 67 in stages, depressurize it, and reset it, the track platform 13 is provided with a primary tilting part 132, a primary parallel part 133, a secondary tilting part 134, a parallel shaping part 131, a primary upward tilting part 135, a secondary parallel part 136, and a secondary upward tilting part 137 in sequence from the end near the insulation layer extrusion mold 14, which cooperate with the pressure component 6.

[0065] In this embodiment, when the forming mold 7 is not opposite to the insulation layer 200, that is, when the forming mold 7 is located on the outer layer of the rotating belt 5, the forming mold 7 is in the state of being retracted into the U-shaped carrier 15. The forming mold 7 gradually rotates to the side opposite to the insulation layer 200 in this state, and the forming mold 7 does not contact the insulation layer 200. As the rotating belt 5 continues to rotate, the pressure component 6 reaches the first tilting part 132. The first tilting part 132 applies the first thrust to the head 67, so that the force rod 61 can push the pressure plate 63, the spring 64 and the entire forming mold 7 to gradually approach the insulation layer 200. At this time, a cylindrical blind hole is opened on the insulation layer 200, and the carrier ring 71 is limited by the limiting protrusion 151. Then the head 67 reaches the first parallel part. At point 133, the cylinder blind hole remains intact. Then, the head 67 reaches the secondary inclined section 134. At this point, the carrier ring 71 stops moving, and the pressure plate 63 begins to compress the spring 64. This causes the pressure plate 63 to continuously drive the pressure rod 65 to push the slope pressure plate 66, which in turn pushes the leaflet 72 to open. The opening of the leaflet 72 transforms the cylindrical blind hole into a frustum-shaped blind hole. Subsequently, the head 67 reaches the area of ​​the parallel shaping section 131. This area is longer than the other areas, enabling the shaping of the frustum-shaped blind hole. After shaping, the head 67 sequentially reaches the first upward inclined section 135, the second parallel section 136, and the second upward inclined section 137, achieving the step-by-step and stable extraction of the forming mold 7 from the frustum-shaped blind hole.

[0066] In this embodiment, during the working process, when the forming mold 7 comes into contact with the insulation layer 200, that is, when the head 67 of the forming mold 7 comes into contact with the track platform 13, the two maintain synchronous and equal speed movement, that is, the two maintain a relatively stationary state in the extrusion direction.

[0067] Combination Figures 5-7 As shown, the heat-insulating composite pipe forming device provided in this embodiment of the invention also includes a frame 12. The frame 12 is located on both sides of the rotating belt 5 and is used to support the rotating belt 5. Specifically, the roller shaft of the end roller of the rotating belt 5 is rotatably mounted on the frame 12, and the track platform 13 is also fixed on the frame 12. Side support rods 152 are provided on both sides of the U-shaped platform 15, and the frame 12 is provided with side support tracks 8 that are adapted to the side support rods 152, so as to maintain the height stability of the U-shaped platform 15.

[0068] Preferably, the various frames 12 are reinforced with a ring frame 2.

[0069] In addition, in order to achieve synchronous rotation of each rotary belt 5, a bracket 1, a drive mechanism and an end frame 11 are also provided.

[0070] The bracket 1 is located at both ends of the rotating belt 5 and is located outside the insulation layer 200, without contacting the insulation layer 200. The end bracket 11 is fixed to the end of the frame 12. The driving mechanism includes: a sprocket 45 fixed at one end of the pulley shaft of the rotating belt 5, and another sprocket 45 set at a position close to it. A worm gear 48 is set on the sprocket 45 on the same axis. A chain 44 is set between the two sprockets 45. The rotation of the rotating belt 5 is controlled by driving the worm gear 48 to rotate.

[0071] Specifically, a large gear ring 41 is mounted on the bracket 1, with corresponding small gears on both sides below the large gear ring 41, and a corresponding motor 43. When the motor 43 rotates, it can drive the large gear ring 41 to rotate. A bevel gear ring 42 is fixedly mounted on the side of the large gear ring 41 near the rotating belt 5. A bevel gear 47 meshes with the worm gear 48 on the bevel gear ring 42. The bevel gear 47 is equipped with a coaxial worm 46, which can mesh with the worm gear 48 to drive the worm gear 48. The bevel gear 47 and the worm 46 are coaxially connected and rotate synchronously, and both the bevel gear 47 and the worm 46 are rotatably mounted on the bracket 1.

[0072] like Figure 1 As shown, preferably, a corresponding polishing mechanism 16 should also be provided between the insulation layer extrusion mold 14 and the outer skin extrusion mold 10. The addition of the polishing mechanism 16 can ensure that the insulation layer 200 is flat after the blind hole is opened. The polishing mechanism 16 is preferably also equipped with a negative pressure dust suction structure to suck away the polyurethane debris generated after polishing.

[0073] In use, the inner tube extrusion die 9 first extrudes the inner tube 100, and after cooling and shaping, it enters the insulation layer extrusion die 14. The insulation layer extrusion die 14 extrudes the polyurethane and coats it on the inner tube 100 to form the insulation layer 200. Before the insulation layer 200 is shaped, it enters the blind hole forming mechanism 3. The following describes how the blind hole forming mechanism 3 forms a hole in the insulation layer 200: When the rotary belt 5 rotates, it drives the U-shaped platform 15 to rotate. When the forming mold 7 is not opposite the insulation layer 200, that is, when the forming mold 7 is located on the outer layer of the rotary belt 5, the forming mold 7 is in the state of being retracted into the U-shaped platform 15. The forming mold 7 gradually rotates to the side opposite the insulation layer 200 in this state, and the forming mold 7 does not contact the insulation layer 200. As the rotary belt 5 continues to rotate, the pressure component 6 reaches the first tilting part 132. The first tilting part 132 applies the first thrust to the head 67, so that the force rod 61 can push the pressure plate 63, the spring 64, and the entire forming mold 7 to gradually approach the insulation layer 200. At this time, a cylindrical blind hole is formed in the insulation layer 200, and the carrier ring 71 is limited by the protrusion 1. 51. Then, the head 67 reaches the first parallel section 133, where it is in a state of maintaining the cylindrical blind hole. Then, the head 67 reaches the second inclined section 134, where the carrier ring 71 no longer moves. The pressure plate 1 63 begins to compress the spring 2 64, so the pressure plate 1 63 continuously drives the pressure rod 65 to push the slope pressure plate 66. That is, the slope pressure plate 66 can push the leaf 72 to open. The opening of the leaf 72 can form the cylindrical blind hole into a frustum-shaped blind hole. Then, the head 67 reaches the area of ​​the parallel shaping section 131. The length of this area is relatively long compared to the other areas, which can realize the shaping of the frustum-shaped blind hole. After the shaping is completed, the head 67 sequentially reaches the first upward inclined section 135, the second parallel section 136, and the second upward inclined section 137, realizing the purpose of step-by-step and stable extraction of the forming mold 7 from the frustum-shaped blind hole.

[0074] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A heat-insulating composite pipe forming device, characterized in that, It includes an inner tube extrusion die (9), an insulation layer extrusion die (14), a blind hole forming mechanism (3), and an outer skin extrusion die (10) arranged in sequence. The inner tube extrusion die (9) is used to extrude the inner tube (100), the insulation layer extrusion die (14) is used to extrude the insulation layer (200) and cover the outer surface of the inner tube (100), and the outer skin extrusion die (10) is used to extrude the outer skin (300) and cover the outer surface of the insulation layer (200), and fill the blind holes (400) on the outer surface of the insulation layer (200). The blind hole forming mechanism (3) includes: Rotary belt (5), the rotary belt (5) is provided with at least three sets, and the at least three sets are arranged in a circular matrix outside the insulation layer (200); U-shaped platform (15), the U-shaped platform (15) is provided in multiple sets and is installed at equal intervals on each set of rotating belts (5); Forming mold (7), the forming mold (7) is located on the side of the U-shaped platform (15) away from the center line of the rotating belt (5); Pressure assembly (6), which is assembled on one side of the U-shaped platform (15) near the centerline of the rotary belt (5); The track platform (13) is located in the center line area of ​​the rotating belt (5) and is used to apply force to the pressure component (6) so that the forming mold (7) forms a filling blind hole (400) on the insulation layer (200) and the filling blind hole (400) is solidified during the rotation of the forming mold (7).

2. The heat-insulating composite pipe forming device according to claim 1, characterized in that, The forming mold (7) includes: A carrier ring (71) is slidably disposed on a U-shaped platform (15); Leaflet (72), the leaflet (72) is hinged to one end of the carrier ring (71) near the insulation layer (200), the leaflet (72) forms a columnar structure when it is not open, and the inner wall of the leaflet (72) has a slope (73). The pressure assembly (6) is used to first push the carrier ring (71) and the leaflet (72) to move vertically, and then push the slope (73) to open the leaflet (72).

3. The heat-insulating composite pipe forming device according to claim 2, characterized in that, The pressure assembly (6) includes a force rod (61), one end of which is fixed with a pressure plate (63), and a spring (64) is provided between the pressure plate (63) and the carrier ring (71). A pressure rod (65) is fixed at one end of the force rod (61) near the pressure plate (63), and the pressure rod (65) extends into the carrier ring (71) and is fixed with a slope pressure plate (66). The U-shaped platform (15) has a limiting protrusion (151) on the side away from the rotating belt (5). The other end of the force-bearing rod (61) is equipped with a head (67), and a spring (62) is provided between the head (67) and the U-shaped platform (15).

4. A heat-insulating composite pipe forming device according to claim 2 or 3, characterized in that, The track platform (13) is provided with a primary tilting part (132), a primary parallel part (133), a secondary tilting part (134), a parallel shaping part (131), a primary upward tilting part (135), a secondary parallel part (136), and a secondary upward tilting part (137) that cooperate with the pressure assembly (6) starting from the end near the extrusion die (14) of the insulation layer (200).

5. The heat-insulating composite pipe forming device according to claim 1, characterized in that, Each set of rotating belts (5) is arranged in parallel and at intervals, forming an unobstructed space between the two rotating belts (5). The U-shaped platform (15) and the track platform (13) are located between the corresponding two rotating belts (5).

6. The heat-insulating composite pipe forming device according to claim 1, characterized in that, It also includes a frame (12), which is located on both sides of the rotating belt (5) and is used to support the rotating belt (5), and the track platform (13) is fixed on the frame (12); The U-shaped platform (15) is provided with side support rods (152) on both sides, and the frame (12) is provided with side support rails (8) adapted to the side support rods (152).

7. The heat-insulating composite pipe forming device according to claim 6, characterized in that, A bracket (1), a drive mechanism, and an end frame (11) are also provided. The bracket (1) is located at both ends of the rotating belt (5) and is located outside the insulation layer (200). The end frame (11) is fixed to the end of the frame (12). The drive mechanism includes: a sprocket (45) fixed at one end of the pulley shaft of the rotary belt (5), and another sprocket (45) set at a position close to it. A worm gear (48) is set on the sprocket (45) on the same axis. A chain (44) is set between the two sprockets (45). The rotation of the rotary belt (5) is controlled by driving the worm gear (48) to rotate.

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