Plastic corrugated pipe with an ultra-strong flared end and associated forming tool

Abstract

A plastic corrugated pipe with an ultra-strong flared end, comprising a main pipe and a flared pipe formed in one piece, the main pipe comprising an inner wall and an outer wall, and alternately arranged wave crests and wave troughs being provided on the outer wall, characterized in that: the expanded tube comprises a first main body expansion transition section, a short reinforcement section, a reinforcement transition section, a long reinforcement section and a second main body expansion transition section, which are connected to each other in sequence, wherein the first main body expansion transition section is connected at one end to the main pipe and at the other end to the short reinforcement section, wherein the long reinforcement section and the short reinforcement section are connected by the reinforcement transition section, wherein the long reinforcement section is connected at the other end to the second main body expansion transition section and the second main body expansion transition section is connected at the other end to the main pipe, wherein the first main body expansion transition section has a gradually increasing pipe inner diameter from the corrugation trough of the main pipe to the short reinforcement section, wherein the second main body expansion transition section has a gradually increasing pipe inner diameter from the corrugation trough of the main pipe to the long reinforcement section, wherein the reinforcement transition section has a gradually decreasing pipe inner diameter from the short reinforcement section to the long reinforcement section, wherein a first annular reinforcing rib is provided on each of the outer tube walls of the first main body expansion transition section, the reinforcement transition section and the second main body expansion transition section, wherein a second annular reinforcing rib and a third annular reinforcing rib, which are arranged at a distance from each other, are provided on the tube outer wall of the short reinforcing section, wherein a plurality of fourth annular reinforcing ribs and a plurality of fifth annular reinforcing ribs are provided on the tube outer wall of the long reinforcing section, wherein the fourth and fifth annular reinforcing ribs each have a trapezoidal cross-section, the fourth annular reinforcing ribs having a greater cross-sectional width than the fifth annular reinforcing ribs, and wherein a plurality of fifth annular reinforcing ribs are arranged between each two adjacent fourth annular reinforcing ribs.

Description

TECHNICAL FIELD

[0001] The present utility model relates to the technical field of plastic double-wall corrugated pipes, specifically a plastic corrugated pipe with an ultra-strong flared end and an associated forming tool. STATE OF THE ART

[0002] Double-wall plastic corrugated pipes are widely used in municipal sewage disposal, sewage drainage projects, agricultural irrigation and water diversion projects and other fields due to their advantages such as light weight, smooth inner wall, low flow resistance, high pressure capacity and corrosion resistance.

[0003] The traditional connection method for double-wall plastic corrugated pipes uses a flared end (also called a female end) and a male end that are inserted into a push-fit connection, with a sealing ring installed between them. After manufacturing a complete double-wall plastic corrugated pipe, which has a male end and a female end, a portion of the pipe must be cut off to form a male and female pipe, thus achieving the connection size required by the customer. Then, a portion of the male end is inserted into the female end to complete the installation.

[0004] Market studies show that the current state-of-the-art flared end (female end) has low strength and is easily deformed during storage and transportation due to the above connection method. Such deformation of the flared end impairs the sealing effect of the plug-in connection between the female and male ends and increases the risk of water leakage at the pipe joints.

[0005] To solve the problems of the current state of the art, namely the low strength of the female end of a double-wall corrugated pipe and the deformation of the female end when plugged into the male end of the double-wall corrugated pipe, a structural improvement of conventional double-wall plastic corrugated pipes is required. Accordingly, conventional molding modules cannot produce new types of plastic corrugated pipes, so traditional corrugated pipe molding modules must also be improved to form new types of double-wall plastic corrugated pipes. CONTENT OF THE PRESENT UTILITY MODEL

[0006] The present utility model is based on a first object of providing a plastic corrugated pipe with an ultra-strong flared end in order to solve the problem of the susceptibility to deformation of a flared end of a connected double-wall corrugated pipe during use.

[0007] Based on the same technical concept, the present utility model has a second object of providing a double-wall corrugated pipe forming tool used to produce a plastic corrugated pipe with an ultra-strong flared end.

[0008] According to the present utility model, the first problem is solved by the following technical solution: A plastic corrugated pipe with an ultra-strong flared end comprises a main pipe and a flared pipe formed in one piece, wherein the main pipe comprises an inner wall and an outer wall and wave crests and wave troughs arranged alternately are provided on the outer wall, wherein the expanded tube comprises a first main body expansion transition section, a short reinforcement section, a reinforcement transition section, a long reinforcement section and a second main body expansion transition section, which are connected to each other in sequence, wherein the first main body expansion transition section is connected at one end to the main pipe and at the other end to the short reinforcement section, wherein the long reinforcement section and the short reinforcement section are connected by the reinforcement transition section, wherein the long reinforcement section is connected at the other end to the second main body expansion transition section and the second main body expansion transition section is connected at the other end to the main pipe, wherein the first main body expansion transition section has a gradually increasing pipe inner diameter from the corrugation trough of the main pipe to the short reinforcement section, wherein the second main body expansion transition section has a gradually increasing pipe inner diameter from the corrugation trough of the main pipe to the long reinforcement section, wherein the reinforcement transition section has a gradually decreasing pipe inner diameter from the short reinforcement section to the long reinforcement section, wherein a first annular reinforcing rib is provided on each of the outer tube walls of the first main body expansion transition section, the reinforcement transition section and the second main body expansion transition section, wherein a second annular reinforcing rib and a third annular reinforcing rib, which are arranged at a distance from each other, are provided on the tube outer wall of the short reinforcing section, wherein a plurality of fourth annular reinforcing ribs and a plurality of fifth annular reinforcing ribs are provided on the tube outer wall of the long reinforcing section, wherein the fourth and fifth annular reinforcing ribs each have a trapezoidal cross-section, wherein the fourth annular reinforcing ribs have a greater cross-sectional width than the fifth annular reinforcing ribs, and wherein a plurality of fifth annular reinforcing ribs are arranged between each two adjacent fourth annular reinforcing ribs.

[0009] Preferably, the first annular reinforcing rib has an arcuate cross-section.

[0010] Preferably, the second and third annular reinforcing ribs on the outer tube wall of the short reinforcing section each have a rectangular cross-section.

[0011] Preferably, the third annular reinforcing rib has a larger cross-sectional width than the second annular reinforcing rib, the second annular reinforcing rib serving for auxiliary cutting of the pipe.

[0012] Preferably, a demoulding slope is provided on the inner pipe wall of the long reinforcement section to facilitate demoulding.

[0013] Preferably, in use, a portion to be cut off is cut off, the portion to be cut off comprising, in sequence, a portion of the main pipe, the first main body expansion transition portion, and the second annular reinforcing rib.

[0014] Preferably, after the part to be cut off has been cut off, the expanded pipe forms a receiving end, while a part of the main pipe forms a spigot end, wherein the spigot end is inserted into the receiving end and a sealing ring is provided between the trough of the spigot end and the receiving end.

[0015] According to the present utility model, the second problem is solved by the following technical solution: A double-wall corrugated pipe forming tool used for producing the above plastic corrugated pipe with an ultra-strong flared end, the forming tool comprising a plurality of main module groups for forming the main pipe and a plurality of expansion module groups for forming the flared pipe; wherein a mold cavity of the single main module group comprises annular convex rings and annular concave rings arranged alternately, the annular convex rings forming the wave troughs of the main tube and the annular concave rings forming the wave crests of the main tube; wherein a mold cavity of the single expansion module group comprises a first transition section mold cavity for forming the first main body expansion transition section, a short reinforcement section mold cavity for forming the short reinforcement section, a reinforcement transition section mold cavity for forming the reinforcement transition section, a long reinforcement section mold cavity for forming the long reinforcement section, and a second transition section mold cavity for forming the second main body expansion transition section.

[0016] Preferably, it is provided that the first transition section mold cavity and the second transition section mold cavity are designed as first conical tube cavities, wherein in the single first conical tube cavity a plurality of arcuate inner concave rings are provided for shaping the respective first annular reinforcing rib, wherein the reinforcing transition section mold cavity is designed as a second conical tube cavity in which the arcuate inner concave rings are arranged for shaping the respective first annular reinforcing rib, wherein a first rectangular inner concave ring for forming the second annular reinforcing rib and a second rectangular inner concave ring for forming the third annular reinforcing rib are provided on the inner wall of the mold cavity of the short reinforcing section, wherein a first trapezoidal inner concave ring for forming the respective fourth annular reinforcing rib and a second trapezoidal inner concave ring for forming the respective fourth annular reinforcing rib are provided on the inner wall of the mold cavity long reinforcing section.

[0017] By using the above technique, the present utility model achieves the following advantageous effects: In the plastic corrugated pipe with an ultra-strong flared end according to the present utility model, the first main body flare transition section is connected to the main pipe at one end and to the short reinforcement section at the other end. The long reinforcement section and the short reinforcement section are connected by the reinforcement transition section. The long reinforcement section is connected to the second main body flare transition section at the other end, and the second main body flare transition section is connected to the main pipe at the other end. The first main body flare transition section has a gradually increasing pipe inner diameter from the corrugation trough of the main pipe to the short reinforcement section. The second main body flare transition section has a gradually increasing pipe inner diameter from the corrugation trough of the main pipe to the long reinforcement section.The reinforcement transition section has a gradually decreasing inner diameter from the short reinforcement section to the long reinforcement section. This ensures gradual transitions in pipe diameter between the aforementioned pipe sections, preventing stress concentrations. This prevents cracking in the pipe and increases the overall strength of the pipe.

[0018] A first annular reinforcing rib is provided on each of the outer tube walls of the first main body expansion transition section, the reinforcement transition section, and the second main body expansion transition section. A second annular reinforcing rib and a third annular reinforcing rib, arranged at a distance from one another, are provided on the outer tube wall of the short reinforcement section. A plurality of fourth annular reinforcing ribs and a plurality of fifth annular reinforcing ribs are provided on the outer tube wall of the long reinforcement section. The fourth and fifth annular reinforcing ribs each have a trapezoidal cross-section. The fourth annular reinforcing ribs have a larger cross-sectional width than the fifth annular reinforcing ribs. A plurality of fifth annular reinforcing ribs are arranged between each two adjacent fourth annular reinforcing ribs.The respective reinforcing ribs are provided on the first main body expansion transition portion, the short reinforcing portion, the reinforcing transition portion, the long reinforcing portion, and the second main body expansion transition portion of the expanded tube, respectively, thereby increasing the structural strength of the expanded tube and preventing deformation of the expanded tube during plug-in connection.

[0019] The plastic corrugated pipe with an ultra-strong flared end produced by the double-wall corrugated pipe forming die according to the present utility model exhibits high overall structural strength. In particular, the structural strength of the flared pipe is improved, preventing deformation of the expanded pipe during use. This effectively solves the problem of low strength of the flared end and susceptibility to deformation during storage and transportation of conventional pipes. SHORT DESCRIPTION OF THE DRAWING

[0020] Showing Fig. 1 is a schematic structural view of a plastic corrugated pipe with an ultra-strong flared end according to the present utility model in a longitudinal section; Fig. 2 is a schematic structural view of the plastic corrugated pipe with an ultra-strong flared end according to the present utility model in use; Fig. 3 is a schematic structural view of a molding tool for the plastic corrugated pipe with an ultra-strong flared end according to the present utility model; Fig. 4 is a schematic structural view of a pair of opposing modules of the mold for the plastic corrugated pipe with an ultra-strong flared end according to the present utility model during closing; Fig. 5 an enlarged schematic structural view of the expansion module group according to Fig. 3; Reference symbol: 1 main pipe 101 Wellenberg 102 wave trough 2 flared pipe 201 first main body widening transition section 2011 first annular reinforcement rib 202 short reinforcement section 2021 second annular reinforcing rib 2022 third annular reinforcing rib 203 long reinforcement section 2030 Reinforcement transition section 2031 fourth annular reinforcing rib 2032 fifth annular reinforcing rib 204 second main body widening transition section; Q part to be cut off 3 sealing ring; A main module group; B Expansion module group 401 annular convex ring 402 annular concave ring 501 first transition section-mold cavity 5011 arcuate inner concave ring 502 mold cavity short reinforcement section 503 mold cavity long reinforcement section 504 second transition section-mold cavity 5021 first rectangular inner concave ring 5022 second inner rectangular concave ring 5030 Reinforcing transition section mold cavity 5031 first trapezoidal inner concave ring 5032 second trapezoidal inner concave ring 6 Vacuum suction channel 7 Connecting groove 8 Gas extraction groove DETAILED DESCRIPTION

[0021] The following detailed description of the technical solution of the present utility model is given with reference to the drawings and the concrete embodiments in order to better understand the output, the design and the effect of the present utility model, but this should not be understood as limiting the scope of the appended claims of the present utility model.

[0022] As in Fig. As shown in Figure 1, the plastic corrugated pipe with an ultra-strong flared end comprises a main pipe 1 and a flared pipe 2 formed as one piece. The main pipe 1 includes an inner wall and an outer wall, and the outer wall is provided with alternating wave crests 101 and wave troughs 102.

[0023] The expanded pipe 2 comprises a first main body expansion transition portion 201, a short reinforcement portion 202, a reinforcement transition portion, a long reinforcement portion 203, and a second main body expansion transition portion 204, which are connected to each other in sequence.

[0024] The first main body expansion transition section 201 is connected at one end to the main pipe 1 (the main pipe on the left side of Fig. 1) and at the other end connected to the short reinforcement section 202. The long reinforcement section 203 and the short reinforcement section 202 are connected by the reinforcement transition section 2030. The long reinforcement section 203 is connected at the other end to the second main body widening transition section 204, and the second main body widening transition section 204 is connected at the other end to the main pipe 1 (the main pipe on the right side of Fig. 1) connected.

[0025] The first main body expansion transition section 201 has a gradually increasing pipe inner diameter from the corrugation trough 102 of the main pipe 1 to the short reinforcement section 202. The second main body expansion transition section 204 has a gradually increasing pipe inner diameter from the corrugation trough 102 of the main pipe 1 to the long reinforcement section 203. The reinforcement transition section 2030 has a gradually decreasing pipe inner diameter from the short reinforcement section 202 to the long reinforcement section 203.

[0026] A first annular reinforcing rib 2011 is provided on each of the outer tube walls of the first main body expansion transition section 201, the reinforcement transition section 2030, and the second main body expansion transition section 204. A second annular reinforcing rib 2021 and a third annular reinforcing rib 2022 are provided on the outer tube wall of the short reinforcement section 202, arranged at a distance from each other. A plurality of fourth annular reinforcing ribs 2031 and a plurality of fifth annular reinforcing ribs 2032 are provided on the outer tube wall of the long reinforcement section 203. The fourth annular reinforcing ribs 2031 and the fifth annular reinforcing ribs 2032 each have a trapezoidal cross-section. The fourth annular reinforcing ribs 2031 have a larger cross-sectional width than the fifth annular reinforcing ribs 2032.A plurality of fifth annular reinforcing ribs 2032 are arranged between each two adjacent fourth annular reinforcing ribs 2031.

[0027] In some embodiments, the first annular reinforcing rib 2011 preferably has an arcuate cross-section. In contrast to flared ends in conventional double-wall corrugated pipes, this design is characterized by an increased width and thickness of the first annular reinforcing rib 2011, which results in greater strength.

[0028] In some embodiments, the second annular reinforcing rib 2021 and the third annular reinforcing rib 2022 on the outer tube wall of the short reinforcing section 202 each have a rectangular cross-section. The third annular reinforcing rib 2022 has a larger cross-sectional width than the second annular reinforcing rib 2021. The second annular reinforcing rib 2021 serves to assist in cutting the tube, thus enabling a cleaner and more aesthetically pleasing tube cut. The provision of the third annular reinforcing rib 2022 not only increases the strength of the flared end and prevents its deformation, but also prevents deformation and cracking during the plug-in connection.

[0029] Preferably, a demoulding slope is provided on the inner tube wall of the long reinforcement section 203 to facilitate demoulding.

[0030] In the present utility model, the fourth annular reinforcing ribs 2031 and the fifth annular reinforcing ribs 2032 on the outer tube wall of the long reinforcing portion 203 have different cross-sectional widths. These two types of annular reinforcing ribs with different trapezoidal cross-sections are arranged according to a specific rule. Fig. 1, three fifth annular reinforcing ribs 2032 are arranged between two adjacent fourth annular reinforcing ribs 2031 in one section of the long reinforcing section 203. Six fifth annular reinforcing ribs 2032 are arranged between two adjacent fourth annular reinforcing ribs 2031 in another section. Seven fifth annular reinforcing ribs 2032 are arranged between two adjacent fourth annular reinforcing ribs 2031 in a further section. This means that several fourth annular reinforcing ribs 2031 with smaller cross-sectional widths are arranged between the fourth annular reinforcing ribs 2031 with a larger cross-sectional width. This arrangement increases strength, reduces shrinkage of the inner wall, and ensures high strength of the expanded pipe 2 when two pipes are plugged together without compromising the sealing effect.This significantly improves the overall strength of the flared end of the pipe.

[0031] Experimental comparisons show that this design has higher strength than variants with only fifth annular reinforcing ribs 2032 or only fourth annular reinforcing ribs 2031.

[0032] When used, a part is cut off. As can be seen from Fig. 2, the cut-off part Q includes, in order, a part of the main pipe 1, the first main body expansion transition portion 201, and the second annular reinforcing rib 2021. After the cut-off part is cut, the expanded pipe 2 forms a female end, while a part of the main pipe 1 forms a male end. The male end is inserted into the female end, and a sealing ring 3 is provided between the corrugation trough 102 of the male end and the female end. The sealing by the sealing ring 3 prevents any leakage or leakage.

[0033] The plastic corrugated pipe with an ultra-strong flared end according to the present utility model is characterized by the high strength of its flared end. After the push-in connection is made, the flared end exhibits a low tendency to deform. This ensures that the sealing effect of the push-in connection is not compromised and that no water leakage occurs at the pipe connection.

[0034] As in Fig. As shown in Figures 3 to 5, a double-wall corrugated pipe forming die is used to manufacture the above-described plastic corrugated pipe with an ultra-strong flared end. The forming die includes multiple main module groups A for forming the main pipe 1 and multiple expansion module groups B for forming the flared pipe 2. A mold cavity of each main module group A includes annular convex rings 401 and annular concave rings 402 arranged alternately. The annular convex rings 401 form the wave troughs 102 of the main pipe 1, and the annular concave rings 402 form the wave crests 101 of the main pipe 1.

[0035] A mold cavity of the single expansion module group B includes a first transition portion mold cavity 501 for forming the first main body expansion transition portion 201, a short reinforcement portion mold cavity 502 for forming the short reinforcement portion 202, a reinforcement transition portion mold cavity 5030 for forming the reinforcement transition portion 2030, a long reinforcement portion mold cavity 503 for forming the long reinforcement portion 203, and a second transition portion mold cavity 504 for forming the second main body expansion transition portion 204.

[0036] The first transition section mold cavity 501 and the second transition section mold cavity 504 are formed as first conical tube cavities. A plurality of arcuate inner concave rings 5011 are provided in the single first conical tube cavity for forming the respective first annular reinforcing rib 2011.

[0037] The reinforcing transition portion molding cavity 5030 is formed as a second conical tube cavity in which the arcuate inner concave rings 5011 are arranged to form the respective first annular reinforcing rib 2011.

[0038] On the inner wall of the mold cavity of the short reinforcing portion 502, a first rectangular inner concave ring 5021 for forming the second annular reinforcing rib 2021 and a second rectangular inner concave ring 5022 for forming the third annular reinforcing rib 2022 are provided.

[0039] On the inner wall of the mold cavity long reinforcing portion 503, a first trapezoidal inner concave ring 5031 for forming the respective fourth annular reinforcing rib 2031 and a second trapezoidal inner concave ring 5032 for forming the respective fourth annular reinforcing rib 2031 are provided.

[0040] As in Fig. 4 and Fig.As shown in Figure 5, the internal cavity formed by closing two opposing modules during the molding process forms the internal cavity of the mold for molding the plastic corrugated pipe with an ultra-strong flared end. A plurality of gas exhaust grooves 8 and vacuum suction channels 6 are provided in the internal cavity of each of the modules. The gas exhaust grooves 8 and the vacuum suction channels 6 are connected to each other by a connecting groove 7. The mold cavity of a molding module communicates with the vacuum suction channels 6, which in turn are connected to an external vacuum pump. When molding the plastic corrugated pipe with an ultra-strong flared end, the mold cavity must be vacuum-suctioned so that the pipe blank of the outer wall of the plastic corrugated pipe with an ultra-strong flared end adheres to the inner wall of the mold cavity by suction, thus forming a corrugated shape.

[0041] During operation, the forming modules operate sequentially in a cycle along a closed circular path, continuously producing plastic corrugated pipes with ultra-strong flared ends.

[0042] The plastic corrugated pipe with an ultra-strong flared end, molded and manufactured using the mold for forming plastic corrugated pipes with ultra-strong flared ends according to the present utility model, significantly increases the strength of the expanded pipe. Furthermore, it features a simple structure and easy assembly. The mold can be installed on standard double-wall corrugated pipe production lines without the need to replace other components.

[0043] The present utility model is not limited to the embodiments described above. All improvements based on the concept, principles, structure, or methods of the present utility model are within the scope of protection of the present utility model.

Claims

[1] A plastic corrugated pipe with an ultra-strong flared end, comprising a main pipe and a flared pipe formed in one piece, the main pipe comprising an inner wall and an outer wall, and the outer wall having alternately arranged wave crests and wave troughs, characterized by , that: the expanded tube comprises a first main body expansion transition section, a short reinforcement section, a reinforcement transition section, a long reinforcement section and a second main body expansion transition section, which are connected to each other in sequence, wherein the first main body expansion transition section is connected at one end to the main pipe and at the other end to the short reinforcement section, wherein the long reinforcement section and the short reinforcement section are connected by the reinforcement transition section, wherein the long reinforcement section is connected at the other end to the second main body expansion transition section and the second main body expansion transition section is connected at the other end to the main pipe, wherein the first main body expansion transition section has a gradually increasing pipe inner diameter from the corrugation trough of the main pipe to the short reinforcement section, wherein the second main body expansion transition section has a gradually increasing pipe inner diameter from the corrugation trough of the main pipe to the long reinforcement section, wherein the reinforcement transition section has a gradually decreasing pipe inner diameter from the short reinforcement section to the long reinforcement section, wherein a first annular reinforcing rib is provided on each of the outer tube walls of the first main body expansion transition section, the reinforcement transition section and the second main body expansion transition section, wherein a second annular reinforcing rib and a third annular reinforcing rib, which are arranged at a distance from each other, are provided on the tube outer wall of the short reinforcing section, wherein a plurality of fourth annular reinforcing ribs and a plurality of fifth annular reinforcing ribs are provided on the tube outer wall of the long reinforcing section, wherein the fourth and fifth annular reinforcing ribs each have a trapezoidal cross-section, the fourth annular reinforcing ribs having a greater cross-sectional width than the fifth annular reinforcing ribs, and wherein a plurality of fifth annular reinforcing ribs are arranged between each two adjacent fourth annular reinforcing ribs. [2] Plastic corrugated pipe with an ultra-strong flared end according to claim 1, characterized by that the first annular reinforcing rib has an arcuate cross-section. [3] Plastic corrugated pipe with an ultra-strong flared end according to claim 2, characterized by that the second and third annular reinforcing ribs on the outer tube wall of the short reinforcing section each have a rectangular cross-section. [4] Plastic corrugated pipe with an ultra-strong flared end according to claim 3, characterized bythat the third annular reinforcing rib has a larger cross-sectional width than the second annular reinforcing rib, wherein the second annular reinforcing rib serves for auxiliary cutting of the pipe. [5] Plastic corrugated pipe with an ultra-strong flared end according to claim 4, characterized by that a demoulding slope is provided on the inner pipe wall of the long reinforcement section to facilitate demoulding. [6] Plastic corrugated pipe with an ultra-strong flared end according to claim 1, characterized by that in use, a part to be cut off is cut off, the part to be cut off comprising in sequence a part of the main pipe, the first main body expansion transition section and the second annular reinforcing rib. [7] Plastic corrugated pipe with an ultra-strong flared end according to claim 6, characterized bythat after cutting off the part to be cut off, the expanded pipe forms a receiving end, while a part of the main pipe forms a spigot end, the spigot end being inserted into the receiving end and a sealing ring being provided between the trough of the spigot end and the receiving end. [8] Double-wall corrugated pipe forming tool, characterized by that it is used for producing the plastic corrugated pipe with an ultra-strong flared end according to claim 5, wherein the forming tool comprises a plurality of main module groups for forming the main pipe and a plurality of expansion module groups for forming the flared pipe; wherein a mold cavity of the single main module group comprises annular convex rings and annular concave rings arranged alternately, the annular convex rings forming the wave troughs of the main tube and the annular concave rings forming the wave crests of the main tube; wherein a mold cavity of the single expansion module group comprises a first transition section mold cavity for forming the first main body expansion transition section, a short reinforcement section mold cavity for forming the short reinforcement section, a reinforcement transition section mold cavity for forming the reinforcement transition section, a long reinforcement section mold cavity for forming the long reinforcement section, and a second transition section mold cavity for forming the second main body expansion transition section. [9] Double-wall corrugated pipe forming tool according to claim 8, characterized bythat the first transition section mold cavity and the second transition section mold cavity are designed as first conical tube cavities, wherein in the single first conical tube cavity a plurality of arcuate inner concave rings are provided for shaping the respective first annular reinforcing rib, wherein the reinforcing transition section mold cavity is designed as a second conical tube cavity in which the arcuate inner concave rings are arranged for shaping the respective first annular reinforcing rib, wherein a first rectangular inner concave ring for forming the second annular reinforcing rib and a second rectangular inner concave ring for forming the third annular reinforcing rib are provided on the inner wall of the mold cavity of the short reinforcing section, wherein a first trapezoidal inner concave ring for forming the respective fourth annular reinforcing rib and a second trapezoidal inner concave ring for forming the respective fourth annular reinforcing rib are provided on the inner wall of the mold cavity long reinforcing section.

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