CN113623467B

CN113623467B - Directionally reinforced pipe and preparation method thereof

Info

Publication number: CN113623467B
Application number: CN202010376849.4A
Authority: CN
Inventors: 高彤; 张卫红; 宋龙龙; 邓可欣
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2020-05-07
Filing date: 2020-05-07
Publication date: 2022-11-04
Anticipated expiration: 2040-05-07
Also published as: CN113623467A

Abstract

The invention discloses a directionally reinforced pipe and a preparation method thereof, wherein the pipe comprises an inner pipe part, an outer pipe part and a transition connecting pipe part which are sleeved with each other, and the transition connecting pipe part is used for connecting the outer wall of the inner pipe part and the inner wall of the outer pipe part so as to reinforce the pipe in a set direction. Compared with the traditional isotropic pipe, the transitional connecting pipe part is arranged between the inner pipe part and the outer pipe part of the pipe provided by the invention, and the pipe can be reinforced in the set direction, so that the strength and rigidity of the pipe in the set direction can be higher than those in other directions, therefore, when the pipe is used in an occasion with higher strength and rigidity requirements in a single direction (main bearing direction), the waste of the strength and rigidity of the pipe in a non-main bearing direction can be avoided, and the light weight level of the product can be improved to a greater extent, so that the current light weight development requirement can be met.

Description

Directionally reinforced pipe and preparation method thereof

Technical Field

The invention relates to the technical field of pipe preparation, in particular to a directional reinforced pipe and a preparation method thereof.

Background

At present, most of radial performances of conventional pipes are isotropic, that is, the pipes have the same or basically the same characteristics of rigidity, strength and the like in the circumferential direction, but in some specific occasions, the pipes are often required to have higher rigidity and strength in a certain radial direction (main bearing direction), and at the moment, if the isotropic pipes are adopted, the waste of rigidity and strength in a non-main bearing direction is inevitably caused, and the lightweight design of products is not facilitated.

Therefore, how to provide a solution to overcome the above-mentioned drawbacks still remains a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide a directionally reinforced pipe and a preparation method thereof, wherein the pipe can be reinforced in a set direction so as to avoid waste of strength and rigidity of the pipe in a non-main bearing direction and facilitate lightweight design of products.

In order to solve the technical problem, the invention provides a directional reinforced pipe, which comprises an inner pipe part, an outer pipe part and a transitional connecting pipe part, wherein the inner pipe part, the outer pipe part and the transitional connecting pipe part are sleeved with each other, and the transitional connecting pipe part is used for connecting the outer wall of the inner pipe part and the inner wall of the outer pipe part so as to reinforce the pipe in a set direction.

Compared with the traditional isotropic pipe, the transitional connecting pipe part is arranged between the inner pipe part and the outer pipe part of the pipe provided by the invention, and the pipe can be reinforced in a set direction, so that the strength and rigidity of the pipe in the set direction can be higher than those of the pipe in other directions, therefore, when the pipe is used in an occasion with higher strength and rigidity requirements in a single direction (a main bearing direction), the waste of the strength and rigidity of the pipe in a non-main bearing direction can be avoided, and the lightweight level of a product can be improved to a greater extent, so that the development requirement of the current lightweight can be met.

Optionally, the transition connecting pipe portion comprises an oval pipe sleeved on the inner pipe portion; the inner walls of the two ends of the short axis of the elliptical tube are connected with the inner tube part, and the outer walls of the two ends of the long axis of the elliptical tube are connected with the outer tube part; or the inner wall of one end of the long shaft of the oval tube is connected with the inner tube part, and the outer wall of the other end of the long shaft of the oval tube is connected with the outer tube part.

Optionally, the transition connection pipe portion includes more than two oval pipes, each the oval pipe cup joints each other, and the inlayer the oval pipe overcoat in interior pipe portion, the transition connection pipe portion with inlayer the inner wall of oval pipe with interior pipe portion links to each other, and with outermost the outer wall of oval pipe with outer pipe portion links to each other, and adjacent two-layer the oval pipe links to each other.

Optionally, the major axes of the oval tubes are arranged in the same direction, the inner walls of the oval tubes at the innermost layer at two ends of the minor axis are connected with the inner tube part, and the outer walls of the oval tubes at the outermost layer at two ends of the major axis are connected with the outer tube part; in the two adjacent layers of the elliptical tubes, the inner walls of the two ends of the short shaft of the elliptical tube positioned on the outer layer are connected with the outer walls of the two ends of the short shaft of the elliptical tube positioned on the inner layer.

Optionally, the major axes of the oval tubes are arranged in the same direction, the inner wall of one end of the major axis of the oval tube in the innermost layer is connected with the inner tube part, the outer wall of one end of the major axis of the oval tube in the outermost layer is connected with the outer tube part, and the ends of the major axes of the oval tubes in two adjacent layers are connected.

Optionally, the major axes of two adjacent layers of the elliptical tubes are perpendicular to each other, the inner wall of the innermost layer of the elliptical tubes at two ends of the minor axis is connected with the inner tube part, and the outer wall of the outermost layer of the elliptical tubes at two ends of the major axis is connected with the outer tube part; and in the two adjacent layers of the elliptical tubes, the inner walls at the two ends of the short axis of the elliptical tube positioned at the outer layer are connected with the outer walls at the two ends of the long axis of the elliptical tube positioned at the inner layer.

Optionally, the transition connection pipe portion comprises a transition pipe and more than two elliptical pipes, each elliptical pipe is sleeved with the other elliptical pipe, the innermost elliptical pipe is connected with the inner pipe portion through inner walls at two ends of a short shaft of the innermost elliptical pipe, the outermost elliptical pipe is connected with the outer pipe portion through outer walls at two ends of a long shaft of the outermost elliptical pipe, and the adjacent two elliptical pipes are connected through the transition pipe.

Optionally, a gap between the inner pipe portion and the transition connecting pipe portion and/or a gap between the outer pipe portion and the transition connecting pipe portion and/or a gap in the transition connecting pipe portion is provided with a filling material.

The invention also provides a processing method of the directionally reinforced pipe, which is suitable for the directionally reinforced pipe and comprises the following steps: s1, configuring an internal mold; s2, winding the prepreg around the inner die to form the inner tube part; s3, configuring a transition die on the outer side of the inner pipe part according to the cross-sectional shape of the transition connecting pipe part, and winding the prepreg around the transition die to form the transition connecting pipe part; s4, configuring an outer die on the outer side of the transitional connecting pipe part; step S5, winding the prepreg around the outer die to form the outer tube part; when the transition connecting pipe part comprises a plurality of sleeved branch pipes, the transition die comprises a plurality of branch dies, each branch die is configured for multiple times, and the prepreg is sequentially wound around each branch die to form each branch pipe of the transition connecting pipe part.

Alternatively, in each of the step S2, the step S3, and the step S5, the prepreg is wound without being cut.

Drawings

FIG. 1 is a cross-sectional view of a first embodiment of a directionally reinforced pipe provided by the present invention;

FIG. 2 is a cross-sectional view of a second embodiment of a directionally reinforced tubing provided in accordance with the present invention;

FIG. 3 is a cross-sectional view of a third embodiment of a directionally reinforced tubing provided in accordance with the present invention;

FIG. 4 is a cross-sectional view of a fourth embodiment of a directionally reinforced tubing provided in accordance with the present invention;

FIG. 5 is a cross-sectional view of a fifth embodiment of a directionally reinforced pipe provided by the present invention;

FIG. 6 is a cross-sectional view of a sixth embodiment of a directionally reinforced pipe provided by the present invention;

FIG. 7 is a cross-sectional view of a seventh embodiment of the directionally reinforced tubing provided in the present invention;

FIG. 8 is a cross-sectional view of an eighth embodiment of a directionally reinforced tubing provided in the present invention;

FIG. 9 is a flow chart of a method of making a directionally reinforced pipe provided by the present invention.

The reference numbers in fig. 1-9 are illustrated as follows:

1 an inner tube part;

2 an outer tube part;

3, transition connecting pipe parts, 31 elliptical pipes and 32 transition pipes;

an internal mold A, a transition mold B, a mold B1 split mold and an external mold C.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Example one

Referring to fig. 1-8, fig. 1 is a cross-sectional view of a first embodiment of a directionally reinforced pipe provided by the present invention, fig. 2 is a cross-sectional view of a second embodiment of a directionally reinforced pipe provided by the present invention, fig. 3 is a cross-sectional view of a third embodiment of a directionally reinforced pipe provided by the present invention, fig. 4 is a cross-sectional view of a fourth embodiment of a directionally reinforced pipe provided by the present invention, fig. 5 is a cross-sectional view of a fifth embodiment of a directionally reinforced pipe provided by the present invention, fig. 6 is a cross-sectional view of a sixth embodiment of a directionally reinforced pipe provided by the present invention, fig. 7 is a cross-sectional view of a seventh embodiment of a directionally reinforced pipe provided by the present invention, and fig. 8 is a cross-sectional view of an eighth embodiment of a directionally reinforced pipe provided by the present invention.

As shown in fig. 1-8, the present invention provides a directional reinforced pipe, which comprises an inner pipe portion 1, an outer pipe portion 2 and a transition connecting pipe portion 3, wherein the inner pipe portion 1, the outer pipe portion 2 and the transition connecting pipe portion 3 are sleeved with each other, and the transition connecting pipe portion 3 is used for connecting the outer wall of the inner pipe portion 1 and the inner wall of the outer pipe portion 2 to reinforce the pipe in a set direction.

Compared with the traditional isotropic pipe, the transitional connecting pipe part 3 is arranged between the inner pipe part 1 and the outer pipe part 2 of the pipe, the pipe can be reinforced in the set direction, so that the strength and rigidity of the pipe in the set direction can be higher than those of the pipe in other directions, and thus, when the pipe is used in occasions with higher strength and rigidity requirements in a single direction (main bearing direction), the waste of the strength and rigidity of the pipe in a non-main bearing direction can be avoided, and the light weight level of the product can be improved to a greater extent, so that the development requirement of light weight at present can be met.

Here, the embodiment of the present invention does not limit what kind of the above-mentioned occasion with large requirements for unidirectional strength and stiffness specifically means, in other words, the embodiment of the present invention does not limit the application scenario of the above-mentioned pipe; for example, for the wing main beam of the unmanned aerial vehicle, the bending resistance requirement of the wing main beam in the direction perpendicular to the airfoil surface is higher than that of the wing main beam along the course, and for the application scene, the directional reinforced pipe provided by the invention can well meet the bending resistance requirement of the wing main beam in the direction perpendicular to the airfoil surface, and the weight of the main beam can be greatly reduced to meet the design requirement of light weight, so that the method has positive significance for reducing load, prolonging endurance and the like.

The set direction may be a single direction or a plurality of directions, and in the case of a plurality of directions, the set direction may be determined in accordance with an actual application scenario, by reinforcing the entire area formed by combining the plurality of directions, or by reinforcing a plurality of mutually independent directions.

The following embodiments of the present invention will describe the structure of the directionally reinforced pipe provided by the present invention with reference to several specific embodiments, wherein the reinforced position of the pipe can refer to the pipe wall pointed by the arrow in the drawings.

As shown in fig. 1, the transitional coupling pipe portion 3 may include only one oval pipe 31, the oval pipe 31 may be sleeved on the inner pipe portion 1, the oval pipe 31 may be connected to the inner pipe portion 1 by inner walls at both ends of a minor axis thereof and connected to the outer pipe portion 2 by outer walls at both ends of a major axis thereof, and in this case, a pipe wall of the oval pipe 31 in a major axis direction may be reinforced.

Referring to fig. 2, and fig. 2 is a modification of fig. 1, the elliptical tube 31 may have an inner wall at one end of its major axis connected to the inner tube portion 1 and an outer wall at the other end of its major axis connected to the outer tube portion 2, and at this time, the tube wall at one side of the tube may be reinforced.

Except for the scheme that only one elliptical tube 31 exists, the transition connecting tube portion 3 can also adopt the scheme that comprises more than two elliptical tubes 31, at the moment, the elliptical tubes 31 can be mutually sleeved, the innermost elliptical tube 31 can be sleeved on the inner tube portion 1, the transition connecting tube portion 3 can be connected with the inner tube portion 1 through the inner wall of the innermost elliptical tube 31 and connected with the outer tube portion 2 through the outer wall of the outermost elliptical tube 31, and the two adjacent elliptical tubes 31 can be connected. Compare in an oval pipe 31's scheme, a plurality of oval pipe 31's scheme is more applicable to the situation that the pipe wall is relatively thick, because the pipe wall is thick, carries out progressively stack through a plurality of oval pipe 31 of size crescent, can improve the local anti unstability performance of tubular product, simultaneously, also can guarantee the reinforcing effect to tubular product.

In one embodiment, as shown in fig. 3, the major axes of the respective oval tubes 31 may be arranged in the same direction, the innermost oval tube 31 may be connected to the inner tube portion 1 with the inner walls at both ends of the minor axis thereof, and the outermost oval tube 31 may be connected to the outer tube portion 2 with the outer walls at both ends of the major axis thereof; in the two adjacent layers of the elliptical tubes 31, the inner walls at the two ends of the short axis of the elliptical tube 31 positioned at the outer layer can be connected with the outer walls at the two ends of the short axis of the elliptical tube 31 positioned at the inner layer, and at this time, the reinforcing positions of the tube are still the two side walls in the direction of the long axis of the elliptical tube 31.

In another embodiment, the major axes of the oval tubes 31 may be arranged in the same direction, the inner wall of one end of the major axis of the innermost oval tube 31 is connected to the inner tube 1, the outer wall of one end of the major axis of the outermost oval tube 31 is connected to the outer tube 2, and the ends of the major axes of the two adjacent oval tubes 31 may be connected.

Such an embodiment may again include the following two cases: first, as shown in fig. 4, the elliptical tubes 31 are connected to the inner tube portion 1 at the same end (lower end in the drawing) of the major axis, the other ends (upper end in the drawing) of the major axis of the elliptical tubes 31 are not connected to each other, and the outer wall of the other end (upper end in the drawing) of the major axis of the outermost elliptical tube 31 may be connected to the outer tube portion 2; second, the oval tubes 31 may be connected to the inner and outer tubes or tube portions at both ends of the major axis thereof, respectively, and taking the case of the two oval tubes 31 shown in fig. 5 as an example, the innermost oval tube 31 may be connected to the inner tube portion 1 at the lower end of the major axis thereof and to the outermost oval tube 31 at the upper end of the major axis thereof, and the outermost oval tube 31 may be connected to the outer tube portion 2 at the lower end of the major axis thereof.

In another embodiment, the major axes of two adjacent layers of the oval tubes 31 may be perpendicular to each other, the innermost layer of the oval tubes 31 may be connected to the inner tube part 1 with the inner walls at both ends of the minor axis thereof, and the outermost layer of the oval tubes 31 may be connected to the outer tube part 2 with the outer walls at both ends of the major axis thereof; in the two adjacent layers of the oval tubes 31, the oval tube 31 positioned at the outer layer can be connected with the inner wall at the two ends of the short axis and the outer wall at the two ends of the long axis of the oval tube 31 positioned at the inner layer. With this embodiment, the main reinforcing positions of the pipe are two side walls in the long axis direction of the outermost oval tube 31.

Further, as shown in fig. 7 and 8, the transition connecting pipe portion 3 may further include a transition pipe 32 and two or more elliptical pipes 31, the elliptical pipes 31 may be sleeved with each other, the innermost elliptical pipe 31 may be connected to the inner pipe portion 1, the outermost elliptical pipe 31 may be connected to the outer pipe portion 2, the transition pipe 32 may be disposed between two adjacent elliptical pipes 31, and each two adjacent elliptical pipes 31 are connected to the transition pipe 32 therebetween. With the structure, through the arrangement of the transition pipe 32, the pipe wall between the inner pipe part 1 and the outer pipe part 2 is actually designed in a layered manner, and then the elliptical pipes 31 are respectively arranged in the layers between the transition pipe 32 and the inner pipe part 1 and between the transition pipe 32 and the outer pipe part 2 (if a plurality of sleeved transition pipes 32 exist, the layers can also comprise the space between two adjacent transition pipes 32) for reinforcement.

In the above solution including the transition pipe 32, the connection structure of the elliptical pipe 31 and the transition pipe 32, the inner pipe portion 1, and the outer pipe portion 2 may be designed by referring to the foregoing description in which only the portion of the elliptical pipe 31 exists, and a repetitive description will not be made herein.

It should be noted that the above description of the structural form of the transition connecting pipe portion 3 is only an exemplary illustration of the embodiment of the present invention, and cannot be taken as a limitation of the implementation range of the directionally reinforced pipe provided by the present invention, and in practical applications, the structural form of the transition connecting pipe portion 3 may be varied as long as it is ensured that there is a connection between the pipes (if a plurality of pipes are included) of the transition connecting pipe portion 3, and that there is also a connection between the transition connecting pipe portion 3 and the inner pipe portion 1 and the outer pipe portion 2, and that the strength and rigidity of the pipe in the set direction can be reinforced.

In the embodiment of the present invention, the cross-sectional shapes of the inner tube portion 1, the outer tube portion 2, and the transition tube 32 are not limited, and in the embodiment of the drawings, the cross-sectional shapes of the inner tube portion 1, the outer tube portion 2, and the transition tube 32 are all circular, and may be square or other shapes in practice; in the above-described embodiments, the elliptical tube 31 as the core member of the transition connecting tube portion 3 is actually only a specific example that can produce the directional reinforcing effect, and other reinforcing tube structures similar to the elliptical tube 31 structure, such as a tube having a cross-sectional shape of a waist circle, a strip, a drum, or the like, may be employed.

Further, the gap between the inner pipe portion 1 and the transition connecting pipe portion 3 and/or the gap between the outer pipe portion 2 and the transition connecting pipe portion 3 and/or the gap in the transition connecting pipe portion 3 (when a plurality of pipes exist in the gap in the transition connecting pipe portion 3), may be provided with a filling material, which may be a rigid foam, a space net frame formed by 3D printing, or the like, to fill the gap, and further, the local buckling resistance of the pipe may be improved.

The directional reinforced pipe can be formed by winding the prepreg in a non-breaking mode at one time, so that the formed pipe has higher integration degree, the number of parts of a structural system can be reduced, the manufacturing period can be greatly shortened, and the manufacturing cost is reduced.

Example two

Referring to fig. 9, fig. 9 is a flow chart of a method for manufacturing a directionally reinforced pipe according to the present invention.

As shown in fig. 9, the present invention also provides a method for processing a directionally reinforced pipe, which is applied to the directionally reinforced pipe according to the first embodiment of the present invention, and the method for processing the directionally reinforced pipe includes:

s1, configuring an internal mold A;

the inner die A is a detachable die, the outer surface of the inner die A can be coated with a release agent, and the cross-sectional shape of the inner die A can be set according to the cross-sectional shape requirement of the inner tube part 1.

S2, winding the inner die A by using a prepreg to form an inner tube part 1;

the prepreg may be a carbon fiber prepreg, and multiple layers of prepregs may be wound on the outer side of the inner mold a to form the inner pipe portion 1 with a set thickness, where the specific value of the set thickness is not limited herein, and in practical applications, a person skilled in the art may set the thickness according to actual requirements.

Step S3, configuring a transition mold B on the outer side of the inner pipe part 1 according to the cross-sectional shape of the transition connecting pipe part 3, and winding the transition mold B by using prepreg to form the transition connecting pipe part 3;

the transitional mold B may be a removable mold, in which case its outer surface may be coated with a release agent, or a non-removable mold, in which case the transitional mold B may exist as a filling material.

With reference to fig. 3, the transition connecting pipe portion 3 may actually include a plurality of sleeved branch pipes, and in this case, each branch pipe is formed separately, accordingly, the transition mold B may also include a plurality of branch molds B1, and in particular, during production, an inner-layer branch mold B1 may be disposed on the outer side of the inner pipe portion 1, and a prepreg may be wound around the inner-layer branch mold B1 to form an inner-layer oval pipe 31, and then an outer-layer branch mold B1 may be disposed on the outer side of the inner-layer oval pipe 31, and a prepreg may be wound around the outer-layer branch mold B1 to form an outer-layer oval pipe 31. The thickness of the partial pipes involved in the transition joint pipe section 3 is not limited here either.

S4, arranging an outer die C on the outer side of the transition connecting pipe part 3;

likewise, the outer mold C may be a removable mold, in which case its outer surface may be coated with a release agent, or a non-removable mold, in which case the outer mold C may be present as a filler material.

And S5, winding the prepreg around the outer die C to form the outer pipe part 2, and curing the composite material pipe by using resin to obtain a final pipe, wherein the specific curing mode can be thermosetting and the like.

By adopting the method, the directional reinforced pipe according to the first embodiment can be formed, and the technical effect of the directional reinforced pipe can be referred to the first embodiment, and will not be described repeatedly.

In the step S2, the step S3 and the step S5, the prepreg can be wound in a non-breaking mode, so that the directionally reinforced pipe provided by the invention is formed by one-time winding, the integration degree is higher, the number of parts of a structural system can be reduced, the manufacturing period can be greatly shortened, and the manufacturing cost is reduced.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be considered as the protection scope of the present invention.

Claims

1. A method for processing a directionally reinforced bearing pipe, wherein the bearing pipe comprises an inner pipe part (1), an outer pipe part (2) and a transition connecting pipe part (3) which are sleeved with each other, the transition connecting pipe part (3) is used for connecting the outer wall of the inner pipe part (1) and the inner wall of the outer pipe part (2) so as to reinforce the bearing pipe in a set direction, and the processing method comprises the following steps:

s1, configuring an internal mold (A);

s2, winding the inner die (A) by using a prepreg to form the inner pipe part (1);

s3, arranging a transition die (B) on the outer side of the inner pipe part (1) according to the cross-sectional shape of the transition connecting pipe part (3), and winding the prepreg around the transition die (B) to form the transition connecting pipe part (3);

s4, arranging an outer die (C) on the outer side of the transitional connecting pipe part (3);

a step S5 of winding the prepreg around the outer mold (C) to form the outer tube part (2);

when the transition connecting pipe part (3) comprises a plurality of sleeved branch pipes, the transition die (B) comprises a plurality of branch dies (B1), each branch die (B1) is configured for multiple times, and the prepreg is sequentially wound around each branch die (B1) to form each branch pipe of the transition connecting pipe part (3).

2. A method of processing a directionally reinforced load bearing tube as claimed in claim 1, wherein said prepreg is wound without being cut in each of said steps S2, S3 and S5.

3. An oriented reinforced bearing pipe, characterized in that the bearing pipe comprises an inner pipe part (1), an outer pipe part (2) and a transition connecting pipe part (3) which are sleeved with each other, the transition connecting pipe part (3) is used for connecting the outer wall of the inner pipe part (1) and the inner wall of the outer pipe part (2) so as to reinforce the bearing pipe in a set direction, and the bearing pipe is prepared by the processing method of the oriented reinforced bearing pipe according to claim 1 or 2.

4. Directionally reinforced load carrying tube according to claim 3, characterized in that said transitional coupling tube section (3) comprises an oval tube (31), said oval tube (31) being externally fitted over said inner tube section (1);

the inner walls of the two ends of the short axis of the elliptical tube (31) are connected with the inner tube part (1), and the outer walls of the two ends of the long axis of the elliptical tube are connected with the outer tube part (2); or the inner wall of one end of the long shaft of the oval tube (31) is connected with the inner tube part (1), and the outer wall of the other end of the long shaft of the oval tube is connected with the outer tube part (2).

5. Directionally reinforced load carrying tube according to claim 3, characterized in that said transitional connecting tube portion (3) comprises more than two oval tubes (31), each of said oval tubes (31) being sleeved on each other, the innermost oval tube (31) being sleeved on the inner tube portion (1), said transitional connecting tube portion (3) being connected to the inner tube portion (1) with the inner wall of the innermost oval tube (31) and to the outer tube portion (2) with the outer wall of the outermost oval tube (31), and two adjacent layers of said oval tubes (31) being connected.

6. The directionally reinforced load bearing tube as claimed in claim 5, wherein the major axes of the oval tubes (31) are oriented in the same direction, the innermost oval tube (31) is connected to the inner tube portion (1) at the inner wall at both ends of its minor axis, and the outermost oval tube (31) is connected to the outer tube portion (2) at the outer wall at both ends of its major axis;

in the two adjacent layers of the elliptical tubes (31), the elliptical tube (31) positioned at the outer layer is connected with the outer walls at the two ends of the short axis of the elliptical tube (31) positioned at the inner layer through the inner walls at the two ends of the short axis.

7. Directionally reinforced load carrying tube according to claim 5, wherein the major axes of the oval tubes (31) are arranged in the same direction, the inner wall of one end of the major axis of the oval tube (31) at the innermost layer is connected to the inner tube portion (1), the outer wall of one end of the major axis of the oval tube (31) at the outermost layer is connected to the outer tube portion (2), and the ends of the major axes of the oval tubes (31) at two adjacent layers are connected.

8. Directionally reinforced load carrying tube according to claim 5, wherein the long axes of two adjacent layers of said oval tubes (31) are perpendicular to each other, the inner wall of the oval tube (31) at the innermost layer is connected to said inner tube portion (1) at both ends of its short axis, and the outer wall of the oval tube (31) at the outermost layer is connected to said outer tube portion (2) at both ends of its long axis;

in the two adjacent layers of the elliptical tubes (31), the inner walls at the two ends of the short axis of the elliptical tube (31) positioned at the outer layer are connected with the outer walls at the two ends of the long axis of the elliptical tube (31) positioned at the inner layer.

9. The directionally reinforced load-bearing pipe as claimed in claim 3, wherein said transition connecting pipe portion (3) comprises a transition pipe (32) and more than two oval pipes (31), each oval pipe (31) is sleeved with each other, and two adjacent layers of oval pipes (31) are connected through said transition pipe (32).

10. Directionally reinforced load-bearing pipe according to any of claims 3 to 9, characterized in that the gap between the inner pipe section (1) and the transition pipe section (3) and/or the gap between the outer pipe section (2) and the transition pipe section (3) and/or the gap inside the transition pipe section (3) is provided with a filling material.