A steel belt reinforced spiral corrugated pipe and a production system and method thereof

Abstract

The application discloses a steel-belt-reinforced spiral corrugated pipe and a production system and a production method thereof, relates to the fields of corrugated pipe structures and production, and comprises an outer layer pipe and an inner layer pipe, wherein a spiral structure formed by winding a steel belt is arranged between the outer layer pipe and the inner layer pipe, the inner wall of the spiral structure is fixed with a plurality of steel strips, and the axial directions of all the steel strips cross the two ends of the spiral structure.

Description

Technical Field

[0001] This invention relates to the field of corrugated pipe structure and manufacturing, and in particular to a steel strip reinforced spiral corrugated pipe and its manufacturing system and method. Background Technology

[0002] Currently, spiral corrugated pipes with steel strip reinforcement have a structure in which an annular steel strip is attached to both the outer and inner layers of the pipe. The cross-sectional shape of the annular steel strip is approximately "Ω", with a circular protrusion in the middle and narrow flat structures on both sides. In the spiral corrugated pipe, there are gaps between adjacent annular steel strips. The structure of the spiral corrugated pipe is that there is a flat structure between adjacent spiral peaks. This flat structure is not supported by the steel strip structure, or the narrow flat edges of the steel strip cannot fully meet the dimensions of the flat structure. In other words, the flat structure is unsupported. Under long-term pressure, cracks are prone to appear at this location, resulting in a shorter pipe life. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned problems by providing a steel strip reinforced spiral corrugated pipe, its production system, and production method, which enables the flat structure between the spiral peaks to be supported, improving the pressure resistance at that location, reducing the possibility of cracks, and thus extending the service life of the pipe.

[0004] The technical solution adopted in this invention is as follows: a steel strip reinforced spiral corrugated pipe, comprising a polyethylene outer layer and a polyethylene inner layer, wherein the polyethylene outer layer and the polyethylene inner layer have a spiral structure formed by winding steel strip, and multiple steel strips are fixed to the inner wall of the spiral structure, and the axial direction of all steel strips spans both ends of the spiral structure.

[0005] Furthermore, the axis of the steel bar is parallel to the axis of the spiral structure.

[0006] Furthermore, all the steel bars are arranged circumferentially around the axis of the spiral structure.

[0007] A production system for spiral corrugated pipes, used to produce the steel strip reinforced spiral corrugated pipes, comprising at least a clamping assembly and an extrusion assembly arranged sequentially; wherein:

[0008] A support shaft is rotatably connected to the fixing component of the clamping assembly. The axis of rotation of the support shaft is its own axis, and the axis of rotation of the support shaft is collinear with the extrusion axis of the spiral bellows. The support shaft is connected to a drive device for driving the rotation of the support shaft through a mechanical transmission connection structure. Multiple support rods are provided on the support shaft, and the axes of the support rods are not parallel to the axis of the support shaft. A winding and welding robot is rotatably connected to each support rod. One end of the steel bar is used for welding to the steel strip under the action of the welding robot, and the other end of the steel bar is wound on the winding.

[0009] Furthermore, the rotational angular velocity of the support shaft is equal to the rotational angular velocity of the helical bellows.

[0010] Furthermore, the welding time of the welding robot is t, which satisfies:

[0011] 0 < t < w / v;

[0012] Where: w is the width of the narrow flat structure; v is the production speed of the spiral corrugated pipe.

[0013] Furthermore, the support rod is a telescopic rod, including a fixed section and a telescopic section, and is wound and installed on the fixed section or the telescopic section. The welding robot is installed on the telescopic section, and a locking mechanism is provided between the fixed section and the telescopic section.

[0014] Furthermore, the extrusion assembly includes at least an outer extrusion die and an inner extrusion die, both of which have a plastic inlet and an extrusion outlet, and a cavity is provided between the plastic inlet and the extrusion outlet and is connected to the plastic inlet.

[0015] Furthermore, an adhesive applicator is provided in the space between the welding robot and the inlet of the extrusion assembly;

[0016] Alternatively, the outer and inner extrusion molds are also equipped with glue inlets, which are connected to the cavity and located between the plastic inlet and the extrusion port.

[0017] A method for producing a spiral corrugated pipe, using the aforementioned spiral corrugated pipe production system to produce the steel strip reinforced spiral corrugated pipe, includes the following steps:

[0018] S1: The clamping assembly arranges the already formed steel strips to constrain the pitch and helix angle of the spiral structure formed by the steel strips;

[0019] S2: As the spiral bellows rotates and is extruded, the steel strip is released from the coil, while the welding robot welds the steel strip onto the narrow flat structure of the steel strip.

[0020] S3: In step S2, as the spiral corrugated pipe is rotated and extruded, the spiral structure formed by the steel strip rotates accordingly. The drive mechanism drives the support shaft to rotate synchronously with the spiral structure. Therefore, the axis of the steel strip remains parallel to the axis of the spiral structure formed by the steel strip, and multiple steel strips will not twist.

[0021] S4: The steel strip with welded steel bars enters the extrusion assembly. Under the action of the outer extrusion die, the outer layer is attached to the outer wall of the spiral structure, and the inner layer is attached to the inner wall of the spiral structure. Under the action of other components of the extrusion assembly, the final production of the spiral corrugated pipe is completed.

[0022] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0023] 1. This invention sets up steel bars that span both ends of the steel strip, so that there are steel bars between adjacent steel strip rings in the spiral structure. After the spiral corrugated pipe is formed, the flat structure can be supported by the steel bars, and the steel bars can be supported by the steel strip, so that the position has the ability to withstand pressure for a long time, reducing the possibility of cracks in the position and improving the service life of the pipe.

[0024] 2. This invention specifically improves its production system and production method, enabling the continuous production of spiral corrugated pipes with steel bars. Attached Figure Description

[0025] The present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0026] Figure 1 This is a schematic diagram of the structure of the spiral bellows disclosed in this invention;

[0027] Figure 2 This is a schematic diagram of a spiral structure with welded steel bars disclosed in this invention from two oblique sides.

[0028] Figure 3 This is a schematic diagram of the production system disclosed in this invention;

[0029] Figure 4 This is a schematic diagram of the circumferential arrangement of the support rods disclosed in this invention;

[0030] Figure 5 This is a schematic diagram of the axial arrangement of the support rod disclosed in this invention;

[0031] Figure 6 A schematic diagram showing the location of the glue inlet has been published.

[0032] The markings in the diagram are: 1-outer layer; 2-spiral structure; 21-steel strip; 22-narrow flat structure; 3-inner layer; 4-steel strip forming assembly; 5-feeding support assembly; 6-clamping assembly; 61-limiting block; 71-support frame; 72-drive device; 73-support shaft; 74-support rod; 75-welding robot; 76-winding; 77-mechanical transmission connection structure; 8-extrusion assembly; 81-cavity; 82-plastic inlet; 83-glue inlet; 84-extrusion port. Detailed Implementation

[0033] In the description of this specification, it should be noted that if terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," or "outer" appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, they are only for the convenience of describing this specification and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this specification.

[0034] Furthermore, the use of terms such as "horizontal" or "vertical" in this specification does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0035] In the description of this specification, it should also be noted that, unless otherwise expressly specified and limited, the terms “set up,” “install,” “connect,” and “link” should be interpreted broadly. For example, a link can be a fixed link, a detachable link, or an integral link; it can be a mechanical link or an electrical link; it can be a direct link or an indirect link through an intermediate medium; it can be a connection within two components.

[0036] Example 1

[0037] like Figures 1-2 As shown, a steel strip reinforced spiral corrugated pipe includes an outer layer 1 and an inner layer 3. The outer layer 1 and the inner layer 3 have a spiral structure 2 formed by winding steel strip. Multiple steel bars 21 are fixed to the inner wall of the spiral structure 2, and the axial direction of all steel bars 21 spans both ends of the spiral structure 2.

[0038] In fact, in this embodiment, the cross-sectional shape of the annular steel strip is approximately "Ω" shaped, and the spiral structure 2 is formed by winding a single steel strip, as shown below. Figure 2 As shown, there are multiple steel strip rings, and the steel strip 21 is actually fixed on the narrow flat structure 22 on each steel strip ring, that is, there is a steel strip 21 between adjacent steel strip rings; for the spiral corrugated pipe, after the spiral corrugated pipe is formed, the flat structure can be supported by the steel strip 21, and the steel strip 21 can be supported by the steel strip, so that the position has the ability to withstand pressure for a long time, reducing the possibility of cracks appearing at the position and improving the service life of the pipe.

[0039] Example 2

[0040] Based on Example 1, further feasible implementation methods are proposed.

[0041] In one feasible implementation, the axis of the steel strip 21 can be parallel to or not parallel to the axis of the spiral structure 2, as long as it can span adjacent steel strip rings. Preferably, the axis of the steel strip 21 is parallel to the axis of the spiral structure 2. This facilitates production and saves steel strip 21 material. It also avoids the torsional force that causes the steel strip 21 to shift its position under external pressure (i.e., when the spiral corrugated pipe is subjected to radial pressure, if the axis of the steel strip 21 is not parallel to the axis of the spiral structure 2, the steel strip 21 will generate a torsional force relative to the spiral corrugated pipe, thereby causing the steel strip 21 to shift its position). This ensures the supporting capacity and stability of the steel strip 21.

[0042] One feasible implementation is that all steel bars 21 are arranged circumferentially around the axis of the spiral structure 2 to ensure uniform force distribution when under pressure.

[0043] Example 3

[0044] like Figures 3-6 As shown, a production system for spiral corrugated pipes, used to produce the steel strip reinforced spiral corrugated pipes, includes at least a clamping assembly 6 and an extrusion assembly 8 arranged sequentially; wherein:

[0045] The support shaft 73 is rotatably connected to the fixing member of the clamping assembly 6, such as by connecting the support frame 71 to the housing or base in the clamping assembly 6. That is, the support frame 71 is fixed on the housing or base in the clamping assembly 6, and the support shaft 73 is rotatably connected to the support frame 71. It should be noted that the support frame 71 should be installed in the gap space between adjacent steel belt rings to make way for the movement of the steel belt. Considering that the spiral structure 2 will be welded with steel strip 21 later, the support frame 71 is preferably installed at the entrance of the clamping assembly 6, and the support shaft 73 extends into the clamping assembly 6.

[0046] The rotation axis of the support shaft 73 is its own axis, and the rotation axis of the support shaft 73 is collinear with the extrusion axis of the spiral bellows; the support shaft 73 is mechanically connected to a drive device 72 for driving the support shaft 73 to rotate; a plurality of support rods 74 are provided on the support shaft 73, the axis of the support rods 74 is not parallel to the axis of the support shaft 73, preferably the axis of the support rods 74 is perpendicular to the axis of the support shaft 73; a winding coil 76 and a welding robot 75 are rotatably connected to each support rod 74, one end of the steel strip 21 is used to weld with the steel strip under the action of the welding robot 75, and the other end of the steel strip 21 is wound on the winding coil 76.

[0047] It should be noted that, since welding robots 75 and winding coils 76 need to be installed on multiple support rods 74, they will occupy some circumferential space. In the case that not all support rods 74 can be installed on the same cross section, and since each steel bar 21 requires a welding robot 75 for welding, and each welding robot 75 and the corresponding winding coil 76 require a support rod 74 to provide an installation position, under the condition that the more steel bars 21 there are, the stronger their ability to support the flat structure, multiple support rods 74 can be arranged circumferentially on different cross sections on the axis of the support shaft 73, and the support rods 74 arranged on different cross sections are staggered with each other.

[0048] As is well known, the extrusion production process of spiral corrugated pipes is spiral extrusion, which involves two simultaneous movements: the first is rotation around its own axis, and the second is translation along the axis. The purpose of the first movement is to ensure that the outer layer 1 and inner layer 3 extruded from the extrusion assembly 8 are circumferentially attached to the outer and inner walls of the spiral structure 2, respectively, to form a complete circumferential pipe wall. The second movement is for continuous production. Therefore, during the extrusion production of spiral corrugated pipes, the spiral structure 2, formed by winding steel strips, also experiences both of these movements simultaneously. The rotating support shaft 73 effectively solves the technical problem of how to weld on the moving spiral structure 2, as detailed below.

[0049] The drive device 72 outputs rotational motion to the input end of the mechanical transmission connection structure 77. After being decelerated by the mechanical transmission connection structure 77, the motion is output from the output end of the mechanical transmission connection structure 77 and acts on the support shaft 73, which rotates around its own axis. The drive device 72 is fixed to the fixing part of the clamping assembly 6, such as the support frame 71. A servo motor can be selected so that the output speed can be controlled by the built-in program, which is convenient for adapting to different processes. The mechanical transmission connection structure 77 can be a gear reducer, and its housing can be fixed to the support frame 71. The rotation of the support shaft 73 drives the support rod 74 to rotate, and the rotation of the support rod 74 drives the winding coil 76 and the welding robot 75 to rotate. The welding robot 75 welds the steel strip 21 onto the narrow flat structure 22 of the steel strip, realizing the connection between the steel strip and the steel strip 21. The rotation of the support shaft 73 weakens or even eliminates the difference in circumferential motion between the spiral structure 2 and the welding robot 75. The axial movement of the spiral structure 2 pulls out the steel strip 21 wound on the winding coil 76.

[0050] It should be noted that, in this embodiment, the clamping assembly 6 is used to arrange the bent steel strip, constrain the steel strip, and limit the pitch and helix angle of the spiral structure 2 formed by the steel strip winding; the structure of the clamping assembly 6 is consistent with the clamping mechanism in the extrusion assembly 8, both having multiple sets of limiting groups, each set of limiting groups is arranged along the circumference of the spiral structure 2, and the limiting groups cooperate to limit the helix angle of the spiral structure 2; the limiting group has multiple limiting blocks 61 arranged along the axial direction of the spiral structure 2, and the limiting blocks 61 limit the pitch of the spiral structure 2.

[0051] In this embodiment, the welding robot 75, which actually welds the steel strip and steel bar 21, is located inside the clamping assembly 6 or between the clamping assembly 6 and the extrusion assembly 8. This allows the welding process to be completed after the steel strip is arranged and before the inner layer 3 and outer layer 1 are applied. On the one hand, the steel bar 21 can be used to stabilize the helix angle and pitch of the spiral structure 2, ensuring that they do not change after leaving the clamping assembly 6, thus ensuring that the parameters of the spiral corrugated pipe are consistent after the inner layer 3 and outer layer 1 are applied. On the other hand, the welding process occurs after the steel strip is arranged in the clamping assembly 6, which can ensure the stability of the welding position and ensure the effective implementation of the welding process.

[0052] In this embodiment, the production system also has other structures, such as the steel strip forming assembly 4 and the feeding support assembly 5, etc., wherein:

[0053] The steel strip forming assembly 4, consisting of a forming machine and a bending machine, is used to form and bend the steel strip; it is located at the very upstream of the entire production system.

[0054] The feeding support assembly 5, used to collect and store the formed and bent steel strip, is located between the steel strip forming mechanism and the clamping assembly 6;

[0055] The extrusion assembly 8 is used to extrude the inner layer 3 on the inside of the spiral structure 2 and the outer layer 1 on the outside of the steel strip, and to compact the inner layer 3 and the outer layer 1 onto the spiral structure 2.

[0056] The structure of the aforementioned mechanism is known to those skilled in the art, and will not be described in detail here.

[0057] Example 4

[0058] Based on Example 3, further feasible implementation methods are proposed.

[0059] In one feasible implementation, in order to ensure that the axis of the steel bar 21 is collinear with the axis of the spiral structure 2 and to avoid the phenomenon of the steel bar 21 winding around during long-term operation of the entire production system, the rotational angular velocity of the support shaft 73 is equal to the rotational angular velocity of the spiral bellows, so that the support shaft 73 rotates synchronously with the spiral structure 2, that is, the welding robot 75 actually has no relative motion with the spiral structure 2 in the axial direction.

[0060] In one feasible implementation, the welding time of the welding robot 75 is t, which satisfies:

[0061] 0 < t < w / v; where: w is the width of the narrow flat structure 22; v is the axial production speed of the spiral corrugated pipe. This constraint ensures that when the welding robot 75 welds the steel strip 21 to the steel strip, the welding length does not exceed the width of the narrow flat structure 22.

[0062] Of course, the welding interval T can be equal to l / v; where: l is the pitch of the spiral structure 2; v is the extrusion speed of the spiral bellows, so as to ensure that each welding can fall on the narrow flat structure 22 of the steel strip.

[0063] In one feasible implementation, the support rod 74 is a telescopic rod, including a fixed section and a telescopic section. One end of the telescopic section is slidably connected to the fixed section. The winding 76 is installed on the fixed section or the telescopic section. The welding robot 75 is installed on the telescopic section. A locking mechanism is provided between the fixed section and the telescopic section to facilitate the production of spiral corrugated pipes with different inner diameter specifications.

[0064] It should be noted that the locking mechanism for telescopic poles is a common mechanism in the field, such as locking by bolts passing through both the fixed section and the telescopic section, or locking by using clamps, etc. The specific structure of the locking mechanism is selected according to the actual situation. Those skilled in the art know that locking mechanisms can lock telescopic poles, and will not be described in detail here.

[0065] As can be seen from the description of Example 3, in one feasible implementation, the extrusion assembly 8 is capable of extruding the inner layer 3 and the outer layer 1. Thus, the extrusion assembly 8 includes at least an outer layer 1 extrusion die and an inner layer 3 extrusion die. Both the outer layer 1 extrusion die and the inner layer 3 extrusion die have a plastic inlet 82 and an extrusion port 84. A cavity 81 is provided between the plastic inlet 82 and the extrusion port 84 and is connected to it. Of course, the extrusion assembly 8 also has a pressing mechanism and a cooling and curing mechanism. These structures and mechanisms are commonly used in this industry and will not be described in detail here.

[0066] Furthermore, in order to ensure the stability of the inner layer 3 and the outer layer 1 on the spiral structure 2, it is usually necessary to apply an adhesive layer to the inner and outer sides of the spiral structure 2. For existing spiral corrugated pipes, the adhesive layer is pre-applied before the steel strip is formed or after bending. However, since the present invention involves welding the steel strip 21 onto the steel strip, pre-applying the adhesive layer is no longer applicable, as the presence of the adhesive layer will affect the welding quality. Therefore, the position of the adhesive layer needs to be changed, that is, the adhesive layer application process needs to be adjusted. The adjustment measures have at least the following two implementation methods.

[0067] In the first embodiment, a glue-applying device is provided in the space between the welding robot 75 and the entrance of the extrusion assembly 8. The glue-applying device can be the glue-applying device currently used in the production of spiral corrugated pipes, so as to achieve the application of glue layer.

[0068] In the second embodiment, the outer layer 1 extrusion mold and the inner layer 3 extrusion mold are also provided with glue inlet 83. Glue inlet 83 is connected to cavity 81 and is located between plastic inlet 82 and extrusion port 84. The glue layer is applied by coating the inner layer 3 and the spiral structure 2 on the bonding surface and the outer layer 1 and the spiral structure 2 on the bonding surface.

[0069] It should be noted that, for the first embodiment, since the steel strip 21 is a strip structure and the axis of the steel strip 21 is parallel to the axis of the spiral structure 2, it is difficult and incomplete to apply an adhesive layer to the spiral structure 2 on which the steel strip 21 is welded. Therefore, the second embodiment is preferred.

[0070] Example 5

[0071] A method for producing a spiral corrugated pipe, using the spiral corrugated pipe production system described in Examples 3-4, to produce the steel strip reinforced spiral corrugated pipe described in Examples 1-2, includes the following steps:

[0072] S1: The clamping assembly arranges 6 pairs of pre-formed steel strips to constrain the pitch and helix angle of the spiral structure 2 formed by the steel strips;

[0073] S2: As the spiral bellows rotates and is extruded, the steel strip 21 is released from the winding 76, while the welding robot 75 welds the steel strip 21 onto the narrow flat structure 22 of the steel strip.

[0074] S3: In step S2, as the spiral bellows is rotated and extruded, the spiral structure 2 formed by the steel strip rotates accordingly. The drive mechanism drives the support shaft 73 to rotate synchronously with the spiral structure 2. Therefore, the axis of the steel strip 21 remains parallel to the axis of the spiral structure 2 formed by the steel strip, and the multiple steel strips 21 will not twist.

[0075] S4: The steel strip with welded steel strip 21 enters the extrusion assembly 8. Under the action of the outer layer 1 extrusion die, the outer layer 1 is attached to the outer wall of the spiral structure 2, and the inner layer 3 is attached to the inner wall of the spiral structure 2. Under the action of other components of the extrusion assembly 8, the final production of the spiral corrugated pipe is completed.

[0076] It should be noted that before step S1, the steel strip can be formed by the steel strip forming assembly 4, that is, firstly, it is gradually pressed into an "Ω" shape by the forming machine, and then the steel strip is bent by the bending machine; then the formed steel strip is stored in the feeding support assembly 5; the clamping assembly 6 is installed at the discharge end of the feeding support assembly 5 to arrange the formed steel strip.

[0077] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A production system for a spiral corrugated pipe, used to produce a steel strip reinforced spiral corrugated pipe, the steel strip reinforced spiral corrugated pipe comprising an outer layer (1) pipe and an inner layer (3) pipe, wherein the outer layer (1) pipe and the inner layer (3) pipe have a spiral structure (2) formed by winding steel strip, the inner wall of the spiral structure (2) having a plurality of steel bars (21) fixed thereon, and the axial direction of all the steel bars (21) spanning both ends of the spiral structure (2); characterized in that: It includes at least a clamping assembly (6) and an extrusion assembly (8) arranged sequentially; wherein: A support shaft (73) is rotatably connected to the fixing member of the clamping assembly (6). The rotation axis of the support shaft (73) is its own axis, and the rotation axis of the support shaft (73) is collinear with the extrusion axis of the spiral bellows. The support shaft (73) is connected to a drive device (72) for driving the support shaft (73) to rotate via a mechanical transmission connection structure (77). Multiple support rods (74) are provided on the support shaft (73). The axis of the support rods (74) is not parallel to the axis of the support shaft (73). A winding (76) and a welding robot (75) are rotatably connected to each support rod (74). One end of the steel bar (21) is used to weld with the steel strip under the action of the welding robot (75), and the other end of the steel bar (21) is wound on the winding (76).

2. The production system according to claim 1, characterized in that: The rotational angular velocity of the support shaft (73) is equal to the rotational angular velocity of the helical bellows.

3. The production system according to claim 1, characterized in that: The welding time of the welding robot (75) is t, which satisfies: 0 < t < w / v; Where: w is the width of the narrow flat structure (22); v is the extrusion speed of the spiral corrugated pipe.

4. The production system according to claim 1, characterized in that: The support rod (74) is a telescopic rod, including a fixed section and a telescopic section. The winding (76) is installed on the fixed section or the telescopic section, and the welding robot (75) is installed on the telescopic section. A locking mechanism is provided between the fixed section and the telescopic section.

5. The production system according to claim 1, characterized in that: The extrusion assembly (8) includes at least an outer layer (1) extrusion die and an inner layer (3) extrusion die. Both the outer layer (1) extrusion die and the inner layer (3) extrusion die have a plastic inlet (82) and an extrusion port (84). A cavity (81) is provided between the plastic inlet (82) and the extrusion port (84) and is connected through the cavity (81).

6. The production system according to claim 5, characterized in that: A glue applicator is provided in the space between the welding robot (75) and the entrance of the extrusion assembly (8); Alternatively, the outer layer (1) extrusion mold and the inner layer (3) extrusion mold are also provided with glue inlet (83), which is connected to the cavity (81) and is located between the plastic inlet (82) and the extrusion port (84).

7. A method for producing a spiral corrugated pipe, using the spiral corrugated pipe production system according to any one of claims 1-6, to produce a steel strip reinforced spiral corrugated pipe, characterized in that: Includes the following steps: S1: The clamping assembly (6) arranges the already formed steel strips to constrain the pitch and helix angle of the spiral structure (2) formed by the steel strips; S2: As the spiral bellows is rotated and extruded, the steel strip (21) is released from the winding (76), while the welding robot (75) welds the steel strip (21) onto the narrow flat structure (22) of the steel strip. S3: In step S2, as the spiral bellows is rotated and extruded, the spiral structure (2) formed by the steel strip rotates accordingly. The drive mechanism drives the support shaft (73) to rotate synchronously with the spiral structure (2). Therefore, the axis of the steel strip (21) remains parallel to the axis of the spiral structure (2) formed by the steel strip, and the multiple steel strips (21) will not twist. S4: The steel strip with welded steel strip (21) enters the extrusion assembly (8), and under the action of the outer layer (1) extrusion die, the outer layer (1) is attached to the outer wall of the spiral structure (2), the inner layer (3) is attached to the inner wall of the spiral structure (2), and the final production of the spiral corrugated pipe is completed under the action of other components of the extrusion assembly (8).

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