CN107477266B

CN107477266B - Double-wall corrugated pipe

Info

Publication number: CN107477266B
Application number: CN201710817856.1A
Authority: CN
Inventors: 范卫华; 黄宝元; 冯济斌
Original assignee: Zhejiang Weixing New Building Materials Co Ltd
Current assignee: Zhejiang Weixing New Building Materials Co Ltd
Priority date: 2017-09-12
Filing date: 2017-09-12
Publication date: 2020-03-06
Anticipated expiration: 2037-09-12
Also published as: CN107477266A

Abstract

The present invention provides a double-walled corrugated pipe comprising: the outer wall is in a cylindrical shape, annular first convex portions and annular first concave portions are formed in the length direction of the outer wall in an alternating mode, the inner wall is in a straight cylindrical shape, the inner wall is sleeved in the outer wall and connected with the first concave portions, first cavities are formed between the first convex portions, the outer wall is made of HDPE, and the inner wall is made of LDPE. According to the double-wall corrugated pipe provided by the invention, the outer wall is of a corrugated structure, HDPE is used as a raw material, the ring rigidity of the outer wall is ensured, and LDPE is used as a raw material in the inner layer, so that the bending rigidity is reduced.

Description

Double-wall corrugated pipe

Technical Field

The invention relates to the technical field of pipelines, in particular to a double-wall corrugated pipe which is applied to same-layer drainage and assembly type building drainage.

Background

Double-walled corrugated pipes are used mainly for: urban drainage, sewage discharge engineering, drainage engineering, farmland irrigation, sand control engineering, low-pressure water supply system, municipal drainage, sewage pipeline reconstruction, buried sheaths of wires and cables and the like. The existing double-wall corrugated pipeline is of a structure with smooth inner wall and corrugated outer wall, and the wave trough section of the outer wall and the inner wall are adhered into a whole through high-temperature extrusion. The outer wall is of an annular corrugated structure, so that the annular rigidity of the pipe is greatly enhanced, and the resistance of the pipeline to soil load is enhanced. The corrugated pipe with the same ring stiffness can save 50-70% of materials compared with a solid-wall pipe.

The corrugated pipe can be divided into a UPVC double-wall corrugated pipe and a HDPE (High Density Polyethylene) double-wall corrugated pipe according to the material. The UPVC double-wall corrugated pipe, also called PVC-U double-wall corrugated pipe, is produced by processing polyvinyl chloride as main raw material. HDPE double-wall corrugated pipe, also called polyethylene double-wall corrugated pipe, is produced by processing high density polyethylene as raw material. The same material is used, and the mechanical strength is higher.

The existing double-wall corrugated pipeline has strong structural rigidity, poor toughness and no bending, is one pipe with the length of several meters or more than ten meters, and has high transportation and connection cost and great construction difficulty; in addition, for the drainage pipeline of the building, the number of pipes is large, and the procedures of cutting, positioning, calculating connection and the like are required, so that the drainage pipeline is complicated; there are also some phenomena where the sanitary ware cannot be positioned accurately. .

Disclosure of Invention

The invention aims to provide a double-wall corrugated pipe, which reduces the bending rigidity, thereby reducing the construction difficulty and the construction cost and shortening the construction period.

In order to solve the above technical problems, the present invention provides a double-wall corrugated pipe, comprising: outer wall and inner wall, the outer wall is the tube-shape, along the length direction of outer wall forms first convex part of cyclic annular and first concave part in turn, the inner wall is straight tube-shape, the cover is located in the outer wall, with first concave part is connected, with form first cavity between the first convex part, the inner wall material is LDPE (Low-Density Polyethylene).

Further, the outer wall material is HDPE.

Further, the first concave part is cylindrical, annular second convex parts and second concave parts are alternately formed along the length direction of the outer wall, the inner wall is connected with the second concave parts, and a second cavity is formed between the inner wall and the second convex parts.

Further, the second convex portion is convex outward in a circular arc shape, and the second concave portion is concave inward in a circular arc shape.

Further, the first concave portion includes one second convex portion and two second concave portions on both sides thereof.

Further, at least one groove is arranged on the first concave part.

Further, the groove is arc-shaped.

Further, the wall thickness of the outer wall is 0.05-0.14 times of the nominal diameter of the double-wall corrugated pipe, the distance between every two adjacent first convex parts is 0.5-1.4 times of the wall thickness of the outer wall, and the length of the first convex parts in the length direction of the outer wall is 0.2-0.7 times of the distance between the first convex parts.

Further, the wall thickness of the outer wall is 0.07-0.1 times of the nominal diameter of the double-wall corrugated pipe, the distance between every two adjacent first convex parts is 0.7-1 times of the wall thickness of the outer wall, and the length of the first convex parts in the length direction of the outer wall is 0.3-0.5 times of the distance between the first convex parts.

Further, the wall thickness of the outer wall is 0.09 times of the nominal diameter of the double-wall corrugated pipe, the distance between every two adjacent first convex parts is 0.9 times of the wall thickness of the outer wall, and the length of each first convex part in the length direction of the outer wall is 0.4 times of the distance between every two adjacent first convex parts.

According to the double-wall corrugated pipe provided by the invention, the outer wall is of a corrugated structure, HDPE is used as a raw material, the ring rigidity of the outer wall is ensured, and LDPE is used as a raw material for the inner layer, so that the bending rigidity is reduced, and the double-wall corrugated pipe is convenient to bend. For drainage of the same floor and drainage of an assembly type building, the double-wall corrugated pipe provided by the invention can be bent at will, pipe fittings such as elbows and the like are saved, for example, only one centralized drainage fitting is needed in a toilet, other pipe fittings are not needed, and the construction time is greatly saved; the double-wall corrugated pipe can be bent at will, and the positioning accuracy of sanitary ware and the like is greatly improved.

Drawings

FIG. 1 is a schematic structural view of a double-walled corrugated pipe of the present invention;

FIG. 2 is an enlarged view of detail A of FIG. 1;

FIG. 3 is a first alternative embodiment of a first recess in a double-walled bellows of the present invention;

FIG. 4 is a second alternative embodiment of the first recess in the double-walled bellows of the present invention;

FIG. 5 is a third alternative embodiment of the first recess in the double-walled bellows of the present invention;

fig. 6 is a structural diagram of the double-wall corrugated pipe in a bending state according to the invention.

In the figure, 1, an inner wall, 2, a first convex part, 3, a first concave part, 31, a groove, 32, a second convex part, 33, a second concave part, 34, a second cavity and 4, a first cavity.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

A double-walled corrugated pipe, as shown in fig. 1 and 2, comprising: the outer wall is cylindrical, annular first convex parts 2 and annular first concave parts 3 are formed alternately along the length direction of the outer wall, the inner wall 1 is in a straight cylindrical shape and is sleeved in the outer wall and connected with the first concave parts 3, first cavities 4 are formed between the first convex parts 2, the outer wall is made of HDPE, and the inner wall 1 is made of LDPE.

The material of the inner wall 1 is LDPE, and the flexible material is convenient to bend. The outer wall is made of HDPE, and the excellent mechanical property of the HDPE is utilized to provide ring rigidity. In addition, as shown in fig. 6, the outer wall has a corrugated structure, the outer part is bent, the corrugations are widened and bent, the inner part is bent, the corrugations are compressed, the corrugations are tightly connected, and the corrugations are not deformed except the bent parts. Meanwhile, the inner wall 1 of the bending part is smoothly transited without abnormal deformation.

The production method comprises the following steps: the double-wall corrugated pipe adopts two single-screw extruders to plasticize and extrude materials, the materials are extruded by a composite machine head to form two layers of concentric blank pipes with uniform wall thickness, the two layers of concentric blank pipes enter a forming cavity combined with a module in a forming machine, the outer layer is vacuumized between the outer layer and the module to enable the outer layer to be tightly attached to the module, meanwhile, compressed air is filled between the inner layer and the outer layer to enable the inner layer and the outer layer at the wave crest to be separated, and the inner layer and the outer layer at the wave trough are pressed under the action of a sizing core rod column module, so that the double-.

In this embodiment, the outer wall is the ripple structure and uses HDPE as former material, has guaranteed the ring rigidity of outer wall, and the inlayer uses LDPE as former material, has reduced bending stiffness.

In an alternative embodiment of this embodiment, as shown in fig. 5, the first concave portion 3 is cylindrical, and annular second convex portions 32 and second concave portions 33 are alternately formed along the longitudinal direction of the outer wall, and the inner wall 1 is connected to the second concave portions 33 to form second cavities 34 with the second convex portions 32. In the present embodiment, the second convex portion 32 and the second concave portion 33 may have a trapezoidal shape, an arc shape, or another shape, and preferably, the shape is an arc shape. As shown in fig. 5, the second convex portion 32 is convex outward in a circular arc shape, and the second concave portion 33 is concave inward in a circular arc shape. In the present embodiment, the first concave portion 3 also uses a corrugated structure, which enhances the radial rigidity of the first concave portion on the one hand, and further reduces the bending rigidity of the double-wall corrugated pipe on the other hand.

In an alternative embodiment of this embodiment, the first concave part 3 includes one second convex part 32 and two second concave parts 33 located at two sides thereof.

In an alternative embodiment of this embodiment, as shown in fig. 3 and 4, at least one groove 31 is further provided on the first concave portion 3. The groove 31 is annular in shape on the first recess 3. The groove 31 may be provided outside or inside the first recess 3. A plurality of grooves 31 may be provided, both on the outside and on the inside, staggered in the direction of the length of the double-walled bellows between each other. The purpose of the grooves 31 is to further reduce the mechanical strength of the first recesses 3, thereby reducing the bending stiffness of the double-walled bellows. The cross-sectional shape of the groove 31 is not limited, and may be rectangular, polygonal, or circular, and preferably, the cross-sectional shape of the groove 31 is circular. The arc shape can not cause stress concentration in the bending process to cause fracture.

In an alternative embodiment of this embodiment, as shown in fig. 1, the wall thickness h of the outer wall is 0.05 to 0.14 times the nominal diameter dn of the double-wall corrugated pipe, a distance k1 between two adjacent first protrusions 2 is 0.5 to 1.4 times the wall thickness h of the outer wall, and a length k2 of the first protrusion 2 in the length direction of the outer wall is 0.2 to 0.7 times the first protrusion distance k 1. Preferably, the wall thickness h of the outer wall is 0.07 to 0.1 times of the nominal diameter dn of the double-wall corrugated pipe, the distance k1 between two adjacent first protrusions 2 is 0.7 to 1 times of the wall thickness h of the outer wall, and the length k2 of each first protrusion 2 in the length direction of the outer wall is 0.3 to 0.5 times of the distance k1 between the first protrusions 2. Preferably, the outer wall thickness h is 0.09 times of the nominal diameter dn of the double-wall corrugated pipe, the distance k1 between two adjacent first protrusions 2 is 0.9 times of the outer wall thickness h, and the length k2 of the first protrusion 2 in the length direction of the outer wall is 0.4 times of the distance k1 between the first protrusions 2.

According to the double-wall corrugated pipe provided by the invention, the outer wall is of a corrugated structure, HDPE is used as a raw material, the ring rigidity of the outer wall is ensured, and LDPE is used as a raw material in the inner layer, so that the bending rigidity is reduced.

The scope of the invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.

Claims

1. A double-walled corrugated pipe, comprising: the outer wall is cylindrical, annular first convex parts and annular first concave parts are formed along the length direction of the outer wall in an alternating mode, the inner wall is straight cylindrical and is sleeved in the outer wall and connected with the first concave parts, first cavities are formed between the outer wall and the first convex parts, the inner wall is made of LDPE, the first concave parts are cylindrical, annular second convex parts and annular second concave parts are formed along the length direction of the outer wall in an alternating mode, the inner wall is connected with the second concave parts, second cavities are formed between the inner wall and the second convex parts, during production, two single-screw extruders are used for plasticizing and extruding materials, the materials are extruded through a composite machine head to form two layers of concentric blank pipes with uniform wall thickness, the blank pipes enter a forming cavity formed by combining the composite machine head with a module, vacuum is pumped between the outer layer and the module, the outer layer is enabled to be attached to the module in a clinging mode, and compressed air is filled between the inner layer, separating the inner layer and the outer layer at the wave crest, and pressing the inner layer and the outer layer at the wave trough under the action of the sizing mandril row module, wherein the outer layer forms the outer wall, and the inner layer forms the inner wall.

2. The double-walled bellows of claim 1, wherein the outer wall material is HDPE.

3. The double-walled bellows of claim 1, wherein the second convex portion is arcuate convex to the exterior and the second concave portion is arcuate concave to the interior.

4. The double-walled bellows of claim 1, wherein the first recess comprises: one second convex portion and two second concave portions on both sides thereof.

5. The double-walled bellows of claim 1, wherein the first recess is further provided with at least one groove thereon.

6. The double-walled bellows of claim 5, wherein the groove is radiused.

7. The double-wall corrugated pipe according to any one of claims 1 to 6, wherein the wall thickness of the outer wall is 0.05 to 0.14 times the nominal diameter of the double-wall corrugated pipe, the distance between two adjacent first protrusions is 0.5 to 1.4 times the wall thickness of the outer wall, and the length of the first protrusions in the length direction of the outer wall is 0.2 to 0.7 times the distance between the first protrusions.

8. The double-walled corrugated pipe according to claim 7, wherein the outer wall has a wall thickness of 0.07 to 0.1 times a nominal diameter of the double-walled corrugated pipe, a distance between two adjacent first protrusions is 0.7 to 1 times the wall thickness of the outer wall, and a length of the first protrusions in a length direction of the outer wall is 0.3 to 0.5 times the distance between the first protrusions.

9. The double-walled bellows of claim 8, wherein the outer wall has a wall thickness of 0.09 times a nominal diameter of the double-walled bellows, a distance between two adjacent first protrusions is 0.9 times the wall thickness of the outer wall, and a length of the first protrusions in a length direction of the outer wall is 0.4 times the distance between the first protrusions.