A multiwall corrugated pipe and a method for producing the same

Abstract

The application discloses a multi-wall corrugated pipe and belongs to the field of corrugated pipes, and solves the problem that the bending moment and axial pressure are affected when the existing corrugated pipe improves the compression resistance. The multi-wall corrugated pipe comprises an inner corrugated pipe and an outer corrugated pipe, the outer corrugated pipe is wrapped around the periphery of the inner corrugated pipe, the inner corrugated pipe and the outer corrugated pipe each comprise a plurality of interval arranged corrugated convex pipes and corrugated groove pipes, each corrugated groove pipe of the outer corrugated pipe is matched with and fixedly connected with each corrugated convex pipe of the inner corrugated pipe, and a first reinforcing assembly is arranged in a sealing cavity. The inner side of each corrugated convex pipe of the inner corrugated pipe is provided with a second reinforcing assembly. The multi-wall corrugated pipe effectively improves the compression resistance of the multi-wall corrugated pipe, facilitates the bending installation of the corrugated pipe, and prolongs the service life of the corrugated pipe. The application further discloses a production method of the multi-wall corrugated pipe. The production method can realize the processing of the multi-wall corrugated pipe.

Description

Technical Field

[0001] This invention relates to the field of corrugated pipes, and more specifically, to a multi-walled corrugated pipe and a method for producing the same. Background Technology

[0002] A bellows is a tubular elastic sensing element made of foldable corrugated sheets connected along the folding and stretching direction. It is a cylindrical, thin-walled, corrugated shell with multiple transverse corrugations, possessing elasticity and capable of displacement under pressure, axial force, lateral force, or bending moment. Traditional bellows have a relatively simple structure, generally a single-layer wall structure. However, as bellows are increasingly used in different fields, the requirements for their compressive strength have also gradually increased. Therefore, multi-wall bellows have emerged, i.e., bellows with multiple layers of walls, such as the double-wall bellows corresponding to patent number CN202221993689.9. There are also bellows that add pressure-resistant beams within the multi-wall bellows, such as the bellows corresponding to patent number CN202120944689.9. The compressive strength of the bellows is further improved through axially and circumferentially arranged columnar and annular pressure-resistant beams.

[0003] In the existing corrugated pipes mentioned above, the inner layer is generally a straight pipe or a columnar pressure-resistant beam. While this can improve compressive strength, it increases the bending moment during actual use, making it difficult to bend and install, especially for large-diameter corrugated pipes. Bending them during installation is laborious and carries the risk of breakage. Therefore, existing high-compression-strength corrugated pipes still require further improvement. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the above-mentioned shortcomings of the prior art. The purpose of the present invention is to provide a multi-wall corrugated pipe that effectively improves the compressive strength of the multi-wall corrugated pipe, facilitates the bending and installation of the corrugated pipe, and extends the service life of the corrugated pipe.

[0005] The second objective of this invention is to provide a method for producing multi-walled corrugated pipes, which can realize the processing of multi-walled corrugated pipes.

[0006] To achieve the aforementioned objective, the present invention provides a multi-walled corrugated pipe, comprising an inner corrugated pipe and an outer corrugated pipe, wherein the outer corrugated pipe wraps around the outer corrugated pipe. Both the inner and outer corrugated pipes include multiple spaced-apart corrugated protrusions and corrugated grooves. Adjacent corrugated protrusions and corrugated grooves are connected by connecting pipes. Each corrugated protrusion of the outer corrugated pipe corresponds to each corrugated groove of the inner corrugated pipe in position. Each corrugated groove of the outer corrugated pipe is fitted and fixedly connected to each corrugated protrusion of the inner corrugated pipe. A sealed cavity is formed between each corrugated protrusion of the outer corrugated pipe and each corrugated groove of the inner corrugated pipe. A first reinforcing component is provided within the sealed cavity, and a second reinforcing component is provided on the inner side of each corrugated protrusion of the inner corrugated pipe.

[0007] Furthermore, the first reinforcing component includes a support ring and a top ring, which are connected by a plurality of evenly arranged top rods. The support ring is sleeved on the outer wall of the corrugated groove tube corresponding to the inner corrugated tube, and the inner wall of the support ring is in contact with the outer wall of the corrugated groove tube corresponding to the inner corrugated tube. The top ring is embedded in the corrugated protrusion tube corresponding to the outer corrugated tube.

[0008] Furthermore, the top ring has a rectangular cross-section, and the support ring has a circular cross-section.

[0009] Furthermore, the second reinforcing component includes an inner ring and an outer ring, which are connected by a plurality of evenly arranged support columns. The outer ring is embedded in the corrugated protrusion tube corresponding to the inner corrugated tube, and the inner wall surface of the inner ring is flush with the inner wall surface of the corrugated groove tube corresponding to the inner corrugated tube.

[0010] Furthermore, the outer ring has a rectangular cross-section, and the inner ring has a circular cross-section.

[0011] Furthermore, the length of the corrugated protrusion corresponding to the outer corrugated pipe is the same as the length of the corrugated groove corresponding to the inner corrugated pipe. Correspondingly, the length of the corrugated groove corresponding to the outer corrugated pipe is the same as the length of the corrugated protrusion corresponding to the inner corrugated pipe, and the wall thickness of the outer corrugated pipe is the same as the wall thickness of the inner corrugated pipe.

[0012] Furthermore, the maximum width of the first reinforcing component is less than the length of the corrugated protrusion corresponding to the outer corrugated pipe, and the maximum width of the second reinforcing component is less than the length of the corrugated protrusion corresponding to the inner corrugated pipe.

[0013] Furthermore, a reinforcing structure is provided at the joint between each corrugated groove tube corresponding to the outer corrugated tube and each corrugated protrusion tube corresponding to the inner corrugated tube. The reinforcing structure includes multiple protruding locking teeth, and the multiple locking teeth are embedded in the corrugated groove tube corresponding to the outer corrugated tube.

[0014] To achieve the second objective mentioned above, the present invention provides a method for producing multi-wall corrugated pipes, the method comprising the following steps:

[0015] Step 1: Evenly embed multiple second reinforcing components into the sand core to obtain a sand mold. Then install the sand mold in the lower mold. Next, close the upper mold and the lower mold to form a mold with an inner corrugated tube forming cavity. Finally, inject molten raw material into the inner corrugated tube forming cavity in the mold. After cooling, mold opening, and crushing of the sand mold, an inner corrugated tube with second reinforcing components is obtained.

[0016] Step 2: Insert multiple first reinforcing components into the corresponding corrugated grooves of the inner corrugated tube;

[0017] Step 3: Extrusion molding to produce a cylindrical tube with an inner diameter larger than the maximum outer diameter of the first reinforcing component;

[0018] Step 4: Place the cylindrical tube around the outer perimeter of the inner corrugated tube, then squeeze the outer wall of the cylindrical tube so that the inner wall of the cylindrical tube fits into the first reinforcing component. Finally, squeeze out the corrugated groove tubes corresponding to the outer corrugated tubes one by one at intervals, so that the corrugated groove tubes corresponding to the outer corrugated tubes fit into the corrugated protrusion tubes corresponding to the inner corrugated tubes, thus obtaining a multi-walled corrugated tube.

[0019] As a further improvement, in step 4, the cylindrical tube is first heated to a soft state before being extruded. 。

[0020] Beneficial effects

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. The multi-walled corrugated pipe of the present invention adopts an outer corrugated pipe and an inner corrugated pipe structure with the same shape, and a first reinforcing component is added between the outer corrugated pipe and the inner corrugated pipe, and a second reinforcing component is added inside the inner corrugated pipe. This effectively improves the compressive strength of the multi-walled corrugated pipe. Furthermore, the first reinforcing component and the second reinforcing component are independently radially supported on the corrugated pipe and are unrestrained in the axial direction. This can satisfy the high compressive strength of the corrugated pipe without affecting the bending moment and axial pressure of the corrugated pipe, which facilitates the bending and installation of the corrugated pipe and extends the service life of the corrugated pipe. It is particularly suitable for large-diameter corrugated pipes.

[0023] 2. The multi-wall corrugated pipe production method of the present invention uses a sand casting method with a mold to cast the inner corrugated pipe, which facilitates the installation of the second reinforcing component inside the inner corrugated pipe. The outer corrugated pipe is pressed around the inner corrugated pipe by extrusion molding of a cylindrical tube and is fitted into the first reinforcing component, which facilitates the installation of the first reinforcing component. This method uses a combination of casting and extrusion molding to produce multi-wall corrugated pipes, ensuring the compressive strength and service life of the product, and achieving the purpose of extending the service life of multi-wall corrugated pipes. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the front cross-sectional structure of the present invention;

[0025] Figure 2 for Figure 1 Enlarged structural diagram at point A;

[0026] Figure 3 This is an enlarged side view of the first reinforcing component in this invention;

[0027] Figure 4 This is an enlarged side view of the second reinforcing component in this invention.

[0028] Wherein: 1-corrugated protruding tube, 2-corrugated grooved tube, 3-connecting tube, 4-sealed cavity, 5-first reinforcing component, 6-second reinforcing component, 7-tooth, 51-support ring, 52-top ring, 53-top rod, 61-inner ring, 62-outer ring, 63-support column, a-inner corrugated tube, b-outer corrugated tube. Detailed Implementation

[0029] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0030] See Figure 1-4A multi-walled corrugated pipe includes an inner corrugated pipe a and an outer corrugated pipe b. The inner corrugated pipe a and the outer corrugated pipe b have the same shape, but the diameter of the outer corrugated pipe b is larger than the diameter of the inner corrugated pipe a. The outer corrugated pipe b surrounds the inner corrugated pipe a. Both the inner corrugated pipe a and the outer corrugated pipe b include multiple spaced-apart corrugated protrusions 1 and corrugated grooves 2. Both the corrugated protrusions 1 and corrugated grooves 2 are cylindrical tubes. Adjacent corrugated protrusions 1 and corrugated grooves 2 are connected by connecting pipes 3, forming the inner corrugated pipe a and the outer corrugated pipe b, respectively. Each corrugated protrusion 1 corresponding to the outer corrugated pipe b corresponds to each corrugated groove 2 corresponding to the inner corrugated pipe a, and each corrugated groove 2 corresponding to the outer corrugated pipe b corresponds to the inner corrugated pipe a. The grooved tube 2 is fitted and fixedly connected to each corrugated protrusion tube 1 corresponding to the inner corrugated tube a, that is, the crest of the inner corrugated tube a corresponds to the trough of the outer corrugated tube b, and the trough of the inner corrugated tube a corresponds to the crest of the outer corrugated tube b. This does not affect the bending or axial extension of the multi-wall corrugated tube. A sealed cavity 4 is formed between each corrugated protrusion tube 1 corresponding to the outer corrugated tube b and each corrugated groove tube 2 corresponding to the inner corrugated tube a, which reduces material usage, facilitates the installation of reinforcing components, and effectively improves the compressive strength of the multi-wall corrugated tube. A first reinforcing component 5 is provided in the sealed cavity 4, and a second reinforcing component 6 is provided on the inner side of each corrugated protrusion tube 1 corresponding to the inner corrugated tube a, further improving the compressive strength of the multi-wall corrugated tube.

[0031] Preferably, the first reinforcing component 5 includes a support ring 51 and a top ring 52, wherein the support ring 51 and the top ring 52 are connected by a plurality of evenly arranged top rods 53, the support ring 51 is sleeved on the outer wall of the corrugated groove tube 2 corresponding to the inner corrugated tube a, and the inner wall of the support ring 51 is in contact with the outer wall of the corrugated groove tube 2 corresponding to the inner corrugated tube a, and the top ring 52 is embedded in the corrugated protrusion tube 1 corresponding to the outer corrugated tube b to prevent the first reinforcing component 5 from loosening.

[0032] Preferably, the second reinforcing component 6 includes an inner ring 61 and an outer ring 62, wherein the inner ring 61 and the outer ring 62 are connected by a plurality of evenly arranged support columns 63, the outer ring 62 is embedded in the corrugated protrusion 1 corresponding to the inner corrugated pipe a to prevent the second reinforcing component 6 from loosening, and the inner wall surface of the inner ring 61 is flush with the inner wall surface of the corrugated groove 2 corresponding to the inner corrugated pipe a to ensure that the diameter of the inner cavity of the corrugated pipe is sufficient so that fluid or other items can pass through smoothly.

[0033] The multi-walled corrugated pipe of the present invention adopts an outer corrugated pipe b and an inner corrugated pipe a structure with the same shape. A first reinforcing component 5 is added between the outer corrugated pipe b and the inner corrugated pipe a, and a second reinforcing component 6 is added inside the inner corrugated pipe a. This effectively improves the compressive strength of the multi-walled corrugated pipe. Furthermore, the first reinforcing component 5 and the second reinforcing component 6 are both independently radially supported on the corrugated pipe, with no axial constraint. This satisfies the high compressive strength of the corrugated pipe without affecting the bending moment and axial pressure of the corrugated pipe, facilitating the bending and installation of the corrugated pipe and extending its service life. It is particularly suitable for large-diameter corrugated pipes.

[0034] Preferably, the top ring 52 has a rectangular cross-section, increasing the contact area between the top ring 52 and the outer corrugated pipe b, thus improving the stability of the first reinforcing component 5. The support ring 51 has a circular cross-section, and by using the circular support ring 51 to contact the inner corrugated pipe a, the first reinforcing component 5 can swing relative to the inner corrugated pipe a when the corrugated pipe is bent, which further facilitates the bending of the corrugated pipe. Furthermore, the first reinforcing component 5 can be composed of two symmetrical semicircular rings, which facilitates the first reinforcing component 5 to be fitted onto the outer wall of the corrugated groove tube 2 of the inner corrugated pipe a.

[0035] Preferably, the outer ring 62 has a rectangular cross-section, which increases the contact area between the top ring 62 and the inner bellows a, thereby improving the stability of the second reinforcing component 6. The inner ring 61 has a circular cross-section, which reduces the resistance to fluids or other items inside the bellows by contacting the circular inner ring 61, thus facilitating their passage.

[0036] Preferably, the length of the corrugated protrusion 1 corresponding to the outer corrugated pipe b is the same as the length of the corrugated groove 2 corresponding to the inner corrugated pipe a. Correspondingly, the length of the corrugated groove 2 corresponding to the outer corrugated pipe b is the same as the length of the corrugated protrusion 1 corresponding to the inner corrugated pipe a. The wall thickness of the outer corrugated pipe b is the same as the wall thickness of the inner corrugated pipe a, thereby reducing the influence of the inner and outer corrugated pipe structure on the bending moment and axial extension of the corrugated pipe.

[0037] Preferably, the maximum width of the first reinforcing component 5 is less than the length of the corrugated protrusion 1 corresponding to the outer corrugated pipe b, that is, the width of the top ring 52 of the first reinforcing component 5 is less than the length of the corrugated protrusion 1, and the maximum width of the second reinforcing component 6 is less than the length of the corrugated protrusion 1 corresponding to the inner corrugated pipe a, that is, the width of the outer ring of the second reinforcing component 6 is less than the length of the corrugated protrusion 1. While meeting the compressive strength requirements, it provides as much space as possible for the axial expansion and contraction of the corrugated pipe, ensuring the axial ductility of the corrugated pipe.

[0038] Preferably, a reinforcing structure is provided at the joint between each corrugated groove tube 2 corresponding to the outer corrugated tube b and each corrugated protrusion tube 1 corresponding to the inner corrugated tube a. The reinforcing structure includes multiple protruding locking teeth 7, which are embedded in the corrugated groove tube 2 corresponding to the outer corrugated tube b, effectively preventing the problem of axial displacement of the outer corrugated tube b relative to the inner corrugated tube a, and further improving the structural strength of the multi-wall corrugated tube.

[0039] A method for producing multi-wall corrugated pipes includes the following steps:

[0040] Step 1: Multiple second reinforcing components 6 are evenly embedded in the sand core to obtain a sand mold. Specifically, the second reinforcing components are fitted onto a cylindrical sand core, and then the sand core is used to cover the second reinforcing components 6 to form a corrugated protruding sand core corresponding to the corrugated tube. This results in a sand mold corresponding to the inner wall of the inner corrugated tube. The sand mold is then installed in the lower mold, and the upper mold and lower mold are closed to form a mold with an inner corrugated tube forming cavity. Finally, molten raw material is injected into the inner corrugated tube forming cavity in the mold. After cooling, mold opening, and crushing of the sand mold, an inner corrugated tube a with the second reinforcing components 5 is obtained.

[0041] Step 2: Insert multiple first reinforcing components 5 into the corrugated groove tube 2 corresponding to the inner corrugated tube a respectively. Specifically, first insert the two semi-circular rings corresponding to the second reinforcing component 5 into the corrugated groove tube 2 corresponding to the inner corrugated tube a, and then weld them together to form a complete first reinforcing component 5.

[0042] Step 3: Extrusion molding of a cylindrical tube with an inner diameter larger than the maximum outer diameter of the first reinforcing component 5. Specifically, the cylindrical tube is extruded using a pipe extrusion molding machine.

[0043] Step 4: Place the cylindrical tube around the inner corrugated tube a, and then squeeze the outer wall of the cylindrical tube so that the inner wall of the cylindrical tube fits into the first reinforcing component 5. Specifically, the cylindrical tube is positioned on the worktable using a positioning fixture installed on the inner wall of the cylindrical tube, and then the roller is used to roll around the outer wall of the cylindrical tube. Finally, the corrugated groove tubes 2 corresponding to the outer corrugated tube b are squeezed out one by one at intervals, so that the corrugated groove tubes 2 corresponding to the outer corrugated tube b are in contact with the corrugated protrusion tubes 1 corresponding to the inner corrugated tube a. Specifically, the outer wall of the cylindrical tube is squeezed using a roller adapted to the corrugated groove tube 2, thus obtaining a multi-wall corrugated tube.

[0044] Preferably, in step 4, the cylindrical tube is first heated to a soft state before being squeezed. Specifically, the cylindrical tube is positioned and installed in a heating box, and the heating box is heated to soften the cylindrical tube, making it easier to squeeze and the reinforcing structure is also easier to be inserted into the outer corrugated tube b.

[0045] The multi-wall corrugated pipe production method of the present invention uses a sand casting method with a mold to cast the inner corrugated pipe, which facilitates the installation of the second reinforcing component 6 inside the inner corrugated pipe a. The outer corrugated pipe b is pressed around the inner corrugated pipe a by extrusion molding of a cylindrical tube and is fitted into the first reinforcing component 5, which facilitates the installation of the first reinforcing component 5. This method uses a combination of casting and extrusion molding to produce multi-wall corrugated pipes, ensuring the compressive strength and service life of the product, and achieving the goal of extending the service life of multi-wall corrugated pipes.

[0046] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention, and these will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A multi-walled corrugated pipe, characterized in that, The system includes an inner corrugated pipe (a) and an outer corrugated pipe (b), with the outer corrugated pipe (b) wrapping around the inner corrugated pipe (a). Both the inner corrugated pipe (a) and the outer corrugated pipe (b) include multiple spaced corrugated protrusions (1) and corrugated grooves (2). Adjacent corrugated protrusions (1) and corrugated grooves (2) are connected by connecting pipes (3). Each corrugated protrusion (1) of the outer corrugated pipe (b) corresponds to each corrugated groove (2) of the inner corrugated pipe (a), and each corrugated groove (2) of the outer corrugated pipe (b) is fitted and fixedly connected to each corrugated protrusion (1) of the inner corrugated pipe (a). A sealed cavity (4) is formed between each corrugated protrusion (1) corresponding to the outer corrugated pipe (b) and each corrugated groove (2) corresponding to the inner corrugated pipe (a). A first reinforcing component (5) is provided in the sealed cavity (4). A second reinforcing component (6) is provided on the inner side of each corrugated protrusion (1) corresponding to the inner corrugated pipe (a). The first reinforcing component (5) includes a support ring (51) and a top ring (52). The support ring (51) and the top ring (52) are connected by a plurality of evenly arranged top rods (53). The support ring (51) is sleeved on the outer wall of the corrugated groove (2) corresponding to the inner corrugated pipe (a), and the inner wall of the support ring (51) is flush with the inner corrugated pipe. The outer wall of the corrugated groove tube (2) corresponding to the corrugated tube (a) is fitted together. The top ring (52) is embedded in the corrugated protrusion tube (1) corresponding to the outer corrugated tube (b). The cross-section of the top ring (52) is rectangular, and the cross-section of the support ring (51) is circular. The second reinforcing component (6) includes an inner ring (61) and an outer ring (62). The inner ring (61) and the outer ring (62) are connected by a plurality of evenly arranged support columns (63). The outer ring (62) is embedded in the corrugated protrusion tube (1) corresponding to the inner corrugated tube (a). The inner wall surface of the inner ring (61) is flush with the inner wall surface of the corrugated groove tube (2) corresponding to the inner corrugated tube (a). The horizontal cross-section of the outer ring (62) is... The cross-section is rectangular, the cross-section of the inner ring (61) is circular, the length of the corrugated protrusion (1) corresponding to the outer corrugated pipe (b) is the same as the length of the corrugated groove (2) corresponding to the inner corrugated pipe (a), and correspondingly, the length of the corrugated groove (2) corresponding to the outer corrugated pipe (b) is the same as the length of the corrugated protrusion (1) corresponding to the inner corrugated pipe (a), the wall thickness of the outer corrugated pipe (b) is the same as the wall thickness of the inner corrugated pipe (a), the maximum width of the first reinforcing component (5) is less than the length of the corrugated protrusion (1) corresponding to the outer corrugated pipe (b), and the maximum width of the second reinforcing component (6) is less than the length of the corrugated protrusion (1) corresponding to the inner corrugated pipe (a).

2. A multi-walled corrugated pipe according to claim 1, characterized in that, The joint between each corrugated groove tube (2) corresponding to the outer corrugated tube (b) and each corrugated protrusion tube (1) corresponding to the inner corrugated tube (a) is provided with a reinforcement structure. The reinforcement structure includes multiple protruding locking teeth (7), and the multiple locking teeth (7) are embedded in the corrugated groove tube (2) corresponding to the outer corrugated tube (b).

3. A method for producing the multi-walled corrugated pipe according to claim 2, characterized in that, Includes the following steps: Step 1: Multiple second reinforcing components (6) are evenly embedded in the sand core to obtain a sand mold. Then, the sand mold is installed in the lower mold. The upper mold and the lower mold are then closed to form a mold with an inner corrugated tube forming cavity. Finally, molten raw material is injected into the inner corrugated tube forming cavity in the mold. After cooling, mold opening, and crushing of the sand mold, an inner corrugated tube (a) with the second reinforcing components (6) is obtained. Step 2: Insert multiple first reinforcing components (5) into the corrugated groove tubes (2) corresponding to the inner corrugated tubes (a); Step 3: Extrusion molding to produce a cylindrical tube with an inner diameter larger than the maximum outer diameter of the first reinforcing component (5); Step 4: Place the cylindrical tube around the inner corrugated tube (a), then squeeze the outer wall of the cylindrical tube so that the inner wall of the cylindrical tube fits into the first reinforcing component (5). Finally, squeeze out the corrugated groove tube (2) corresponding to the outer corrugated tube (b) one by one at intervals, so that the corrugated groove tube (2) corresponding to the outer corrugated tube (b) fits into the corrugated protrusion tube (1) corresponding to the inner corrugated tube (a), and a multi-wall corrugated tube can be obtained.

4. The method for producing a multi-walled corrugated pipe according to claim 3, characterized in that, In step 4, the cylindrical tube is first heated to a soft state before being extruded.

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