CN221068120U - Folding trailer - Google Patents

Abstract

The utility model relates to a folding trailer which comprises a first folding mechanism, a second folding mechanism, a third folding mechanism, a fourth folding mechanism, a bottom bracing mechanism and four upright posts, wherein the bottom bracing mechanism is connected between the four upright posts. The first folding mechanism, the second folding mechanism, the third folding mechanism and the fourth folding mechanism are sequentially connected between two adjacent upright posts. The first folding mechanism and the second folding mechanism comprise a first fork tube assembly, a second fork tube assembly and a third fork tube assembly, wherein the first end of the first fork tube assembly is connected with one of two adjacent upright posts, and the first end of the second fork tube assembly is connected with the other of the two adjacent upright posts; one connecting pipe of the first fork pipe assembly and the second fork pipe assembly is connected in a rotating mode, and the other connecting pipe of the first fork pipe assembly and the second fork pipe assembly is connected through a third fork pipe assembly. The connecting pipes of the first folding mechanism and the second folding mechanism are denser, stress can be effectively dispersed, better bearing is achieved, and deformation is not easy to occur after stress.

Description

Folding trailer

Technical Field

The utility model relates to the technical field of folding trailers, in particular to a folding trailer.

Background

In daily life and production, luggage, articles and the like often need to be carried, and a trailer tool is often used in the carrying process. The trailer tool is widely applied when carrying things because of the characteristics of convenient pushing, time saving and labor saving. In order to facilitate the storage of the trailer tool, the trailer tool is designed into a foldable structure, so that the trailer tool is very light and convenient to carry, and can be placed on a vehicle or in a knapsack after being folded, and the trailer tool occupies small space. However, the existing folding trailer has a single side structure, weak bearing capacity and easy deformation after being stressed.

Disclosure of utility model

First, the technical problem to be solved

In view of the above-mentioned drawbacks and shortcomings of the prior art, the present utility model provides a folding trailer, which solves the technical problem that the side structure of the folding trailer is easy to deform after being stressed.

(II) technical scheme

In order to achieve the purpose, the folding trailer comprises a first folding mechanism, a second folding mechanism, a third folding mechanism, a fourth folding mechanism, a bottom support mechanism and four upright posts which are arranged at intervals in a rectangular shape, wherein the bottom support mechanism is connected between the four upright posts;

The first folding mechanism, the third folding mechanism, the second folding mechanism and the fourth folding mechanism are sequentially connected between two adjacent upright posts, and the height after folding is not higher than the height of the upright posts;

The first folding mechanism and the second folding mechanism comprise a first fork tube assembly, a second fork tube assembly and a third fork tube assembly, wherein the first end of the first fork tube assembly is connected with one of two adjacent upright posts, and the first end of the second fork tube assembly is connected with the other of the two adjacent upright posts; one connecting pipe of the first fork pipe assembly and the second fork pipe assembly is rotationally connected, and the other connecting pipe of the first fork pipe assembly and the second fork pipe assembly is connected through the third fork pipe assembly.

Optionally, the first fork tube assembly comprises a first connecting tube and a third connecting tube which are connected in a rotating way, and the second fork tube assembly comprises a second connecting tube and a fourth connecting tube which are connected in a rotating way;

The first ends of the first connecting pipe and the second connecting pipe are rotationally connected, the first ends of the third connecting pipe and the fourth connecting pipe are rotationally connected with the third fork pipe assembly, and the pipe bodies of the first connecting pipe and the second connecting pipe are rotationally connected with the third fork pipe assembly;

The second end of the first connecting pipe is rotationally connected with the upper end of one of the two adjacent upright posts, and the second end of the second connecting pipe is rotationally connected with the upper end of the other of the two adjacent upright posts;

The second end of the third connecting pipe is in sliding connection with one of the two adjacent upright posts, and the second end of the fourth connecting pipe is in sliding connection with the other of the two adjacent upright posts.

Optionally, the upper ends of four stand all are provided with the apex angle mounting, first connecting pipe with the second end of second connecting pipe respectively with correspond on the stand apex angle mounting rotates to be connected.

Optionally, linkage sliding sleeves are slidably arranged on the four upright posts;

the second ends of the third connecting pipe and the fourth connecting pipe are respectively and rotatably connected with the corresponding linkage sliding sleeve on the upright post.

Optionally, the third fork tube assembly includes a fifth connecting tube and a sixth connecting tube;

The two ends of the fifth connecting pipe are respectively in one-to-one corresponding rotary connection with the first end of the third connecting pipe and the pipe body of the second connecting pipe;

and two ends of the sixth connecting pipe are respectively in one-to-one corresponding rotary connection with the first end of the fourth connecting pipe and the pipe body of the first connecting pipe.

Optionally, the third folding mechanism and the fourth folding mechanism each comprise a fourth fork tube assembly and a fifth fork tube assembly connected to each other;

the fourth fork tube assembly is connected with one of the two adjacent upright posts, and the fifth fork tube assembly is connected with the other of the two adjacent upright posts.

Optionally, the fourth fork tube assembly comprises a first bent tube and a second bent tube which are connected in a rotating way, and the fifth fork tube assembly comprises a first straight tube and a second straight tube which are connected in a rotating way;

the first bent pipe is rotationally connected with the first end of the first straight pipe, and the second bent pipe is rotationally connected with the first end of the second straight pipe;

The second end of the first bent pipe is rotationally connected with the upper end of the corresponding upright post, and the second end of the second bent pipe is rotationally connected with the corresponding linkage sliding sleeve on the upright post;

The second end of the first straight pipe is rotationally connected with the corresponding upper end of the upright post, and the second end of the second straight pipe is rotationally connected with the corresponding linkage sliding sleeve on the upright post.

Optionally, the bottom support mechanism comprises a bottom connecting piece and four bottom connecting pipes;

The first ends of the four bottom connecting pipes are rotationally connected with the bottom connecting piece at a limited angle, and the second ends of the four bottom connecting pipes are rotationally connected with the lower ends of the four upright posts at a limited angle in a one-to-one correspondence.

Optionally, the folding trailer further comprises a handle mechanism;

The handle mechanism comprises a telescopic rod, a first transverse pipe and a second transverse pipe, wherein the first ends of the first transverse pipe and the second transverse pipe are respectively and rotatably connected with the telescopic rod, and the second ends of the first transverse pipe and the second transverse pipe are respectively and rotatably connected with the lower ends of the two stand columns connected with the fourth folding mechanism in a one-to-one correspondence manner;

the height of the handle mechanism after folding and shrinking is not higher than that of the upright post.

Optionally, the lower ends of the four upright posts are all provided with rollers.

(III) beneficial effects

The third cross pipe assembly is arranged at the joint of the first cross pipe assembly and the second cross pipe assembly and used for filling the hollow area of the joint, so that the connecting pipes of the first folding mechanism and the second folding mechanism are denser, the stress of the first folding mechanism and the second folding mechanism can be effectively dispersed, the overall strength of the first folding mechanism and the second folding mechanism is improved, better bearing is realized, and the connecting pipes are not easy to deform after being stressed.

Drawings

FIG. 1 is a schematic view of a folded trailer of the present utility model in an unfolded state;

FIG. 2 is a perspective view of the folding trailer of the present utility model in an unfolded state;

FIG. 3 is a front view of the folding trailer of the present utility model in an unfolded state;

FIG. 4 is a left side view of the folding trailer of the present utility model in an unfolded state;

FIG. 5 is a top view of the folding trailer of the present utility model in an unfolded state;

FIG. 6 is a front view of the folding trailer of the present utility model in a folded condition;

Fig. 7 is a left side view of the folding trailer of the present utility model in a folded condition.

[ Reference numerals description ]

1: A column; 11: a first upright; 12: a second upright; 13: a third upright; 14: a fourth upright;

2: a bottom support mechanism; 21: a bottom connecting piece; 22: a bottom connecting pipe;

31: a first folding mechanism; 32: a second folding mechanism; 33: a third folding mechanism; 34: a fourth folding mechanism;

321: a first fork tube assembly; 322: a second fork tube assembly; 323: a third fork tube assembly; 324: a fourth fork tube assembly; 325: a fifth fork tube assembly;

3211: a first connecting pipe; 3212: a third connecting pipe; 3221: a second connecting pipe; 3222: a fourth connecting tube; 3231: a fifth connecting pipe; 3232: a sixth connecting tube;

3241: a first elbow; 3242: a second elbow; 3251: a first straight tube; 3252: a second straight tube;

4: a linkage sliding sleeve;

5: a vertex angle fixing piece;

6: a handle mechanism; 60: a telescopic rod; 61: a first cross tube; 62: a second cross tube;

7: and a roller.

Detailed Description

The utility model will be better explained for understanding by referring to the following detailed description of the embodiments in conjunction with the accompanying drawings. Wherein references herein to "upper", "lower", "etc. are made with reference to the orientation of fig. 1.

While exemplary embodiments of the present utility model are shown in the drawings, it should be understood that the present utility model may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the utility model to those skilled in the art.

As shown in fig. 1 to 7, the present utility model provides a folding trailer, which includes a first folding mechanism 31, a second folding mechanism 32, a third folding mechanism 33, a fourth folding mechanism 34, a bottom support mechanism 2, and four upright posts 1 arranged at rectangular intervals, wherein the four upright posts 1 are a first upright post 11, a second upright post 12, a third upright post 13, and a fourth upright post 14, respectively. The first folding mechanism 31, the third folding mechanism 33, the second folding mechanism 32 and the fourth folding mechanism 34 are sequentially connected between two adjacent upright posts 1, namely, the first folding mechanism 31 is connected between the first upright post 11 and the second upright post 12, the third folding mechanism 31 is connected between the second upright post 12 and the third upright post 13, the second folding mechanism 32 is connected between the third upright post 13 and the fourth upright post 14, the fourth folding mechanism 34 is connected between the fourth upright post 14 and the first upright post 11 for forming a side wall structure, the bottom bracing mechanism 2 is connected between four upright posts 1 for forming a bottom surface supporting structure, and articles can be placed conveniently. The height of the folded first folding mechanism 31, the folded second folding mechanism 32, the folded third folding mechanism 33 and the folded fourth folding mechanism 34 is not higher than the height of the upright 1, so that the folding state of the folding trailer is guaranteed to be the same as the unfolding state, the folding volume is reduced, and the folding trailer is convenient for a user to store and carry. Further, the first folding mechanism 31 and the second folding mechanism 32 each include a first fork tube assembly 321, a second fork tube assembly 322, and a third fork tube assembly 323, where each of the first fork tube assembly 321, the second fork tube assembly 322, and the third fork tube assembly 323 is formed by two rotationally intersecting connecting tubes, a first end of the first fork tube assembly 321 is connected to one of the two adjacent columns 1, and a first end of the second fork tube assembly 322 is connected to the other of the two adjacent columns 1. The end of one of the connecting pipes of the first fork pipe assembly 321 and the second fork pipe assembly 322 is rotatably connected through a rotation shaft, and the other connecting pipe of the first fork pipe assembly 321 and the second fork pipe assembly 322 is connected through a third fork pipe assembly 323. The third cross pipe assembly is installed in the junction of first fork pipe assembly 321 and second fork pipe assembly 322 for fill the fretwork region of junction, make the connecting tube of first folding mechanism 31 and second folding mechanism 32 denser, can disperse the atress of first folding mechanism 31 and second folding mechanism 32 effectively, improve the bulk strength of first folding mechanism 31 and second folding mechanism 32, realize better bearing, be difficult for the deformation after the atress.

As shown in fig. 1 to 3, the first folding mechanism 31 and the second folding mechanism 32 are identical in structure and are disposed opposite to each other, and the structure and the mounting manner of the second folding mechanism 32 will be specifically described below. In the second folding mechanism 32, the first fork tube assembly 321 includes a first connecting tube 3211 and a third connecting tube 3212 that are rotatably connected by a rotation shaft, and the second fork tube assembly 322 includes a second connecting tube 3221 and a fourth connecting tube 3222 that are rotatably connected by a rotation shaft. The first end of the first connecting pipe 3211 is rotationally connected with the first end of the second connecting pipe 3221 through a rotating shaft, the first end of the third connecting pipe 3212 and the first end of the fourth connecting pipe 3222 are respectively rotationally connected with one ends of two connecting pipes of the third fork pipe assembly 323 in one-to-one correspondence, and pipe bodies of the first connecting pipe 3211 and the second connecting pipe 3221 are respectively rotationally connected with the other ends of two connecting pipes of the third fork pipe assembly 323 in one-to-one correspondence, so that a composite cross pipe structure similar to an love is formed. The second end of the first connecting pipe 3211 is rotatably connected with the upper end of one of the two adjacent columns 1, the second end of the second connecting pipe 3221 is rotatably connected with the upper end of the other of the two adjacent columns 1, the second end of the third connecting pipe 3212 is slidably connected with one of the two adjacent columns 1, and the second end of the fourth connecting pipe 3222 is slidably connected with the other of the two adjacent columns 1. In the structure shown in fig. 3, the second end of the first connecting pipe 3211 is rotatably connected to the upper end of the fourth upright 14, the second end of the second connecting pipe 3221 is rotatably connected to the upper end of the third upright 13, the second end of the third connecting pipe 3212 is slidably and rotatably connected to the fourth upright 14, and the second end of the fourth connecting pipe 3222 is slidably and rotatably connected to the third upright 13. Referring to fig. 6, in the process of folding and collapsing the folding trailer to the folded state, the third upright 13 and the fourth upright 14 are close to each other, the two fork tubes of the first fork tube assembly 321, the second fork tube assembly 322 and the third fork tube assembly 323 are all rotationally folded, and the first fork tube assembly 321, the second fork tube assembly 322 and the third fork tube assembly 323 are all collapsed, at this time, the third connecting tube 3212 and the fourth connecting tube 3222 are rotated upwards while the second ends of the third connecting tube 3212 and the fourth connecting tube 3222 slide downwards, so that the height of the folded first fork tube assembly 321, second fork tube assembly 322 and third fork tube assembly 323 is not higher than the height of the upright 1.

Further, as shown in fig. 3 and 4, the upper ends of the four upright posts 1 are respectively sleeved with a vertex angle fixing piece 5. Wherein, the second end of the first connecting tube 3211 is rotationally connected with the top corner fixing member 5 at the upper end of the fourth upright 14, and the second end of the second connecting tube 3221 is rotationally connected with the top corner fixing member 5 at the upper end of the third upright 13, so as to facilitate the disassembly and assembly of the first fork tube assembly 321 and the second fork tube assembly 322.

Further, as shown in fig. 3 and 4, four posts 1 are each slidably provided with a linkage sliding sleeve 4. The second end of the third connecting tube 3212 is rotationally connected with the linkage sliding sleeve 4 on the fourth upright 14, the second end of the fourth connecting tube 3222 is rotationally connected with the linkage sliding sleeve 4 on the third upright 13, and the linkage sliding sleeve 4 realizes sliding and rotation of the third connecting tube 3212 and the fourth connecting tube 3222. After the vertex angle fixing piece 5 is removed, the linkage sliding can slide out from the upper end of the upright post 1, so that the convenience of disassembly and assembly is further improved.

As shown in fig. 3, the third fork tube assembly 323 includes a fifth connecting tube 3231 and a sixth connecting tube 3232, the first end of the fifth connecting tube 3231 being rotatably connected to the first end of the third connecting tube 3212; the second end of the fifth connecting tube 3231 is rotatably connected to the body of the second connecting tube 3221 at a position on the body between the rotational connection point of the second connecting tube 3221 and the fourth connecting tube 3222 to the first end of the second connecting tube 3221, preferably at a center point of the body between the rotational connection point of the second connecting tube 3221 and the fourth connecting tube 3222 to the first end of the second connecting tube 3221. Likewise, a first end of the sixth connecting tube 3232 is rotatably connected to a first end of the fourth connecting tube 3222; the second end of the sixth connecting tube 3232 is rotatably connected to the body of the first connecting tube 3211 at a position on the body between the rotational connection point of the first connecting tube 3211 and the third connecting tube 3212 to the first end of the first connecting tube 3211, preferably at a central point of the body between the rotational connection point of the first connecting tube 3211 and the third connecting tube 3212 to the first end of the first connecting tube 3211.

As shown in fig. 2 and 4, the third folding mechanism 33 and the fourth folding mechanism 34 each include a fourth fork tube assembly 324 and a fifth fork tube assembly 325 that are connected to each other. Referring to fig. 4, the third folding mechanism 33 and the fourth folding mechanism 34 are identical in structure and disposed opposite to each other, and the structure and the mounting manner of the fourth folding mechanism 34 will be specifically described below. In the fourth folding mechanism 34, the fourth fork tube assembly 324 is connected to the first upright 11 and the fifth fork tube assembly 325 is connected to the fourth upright 14. Specifically, the fourth fork tube assembly 324 includes a first elbow 3241 and a second elbow 3242 rotatably coupled, and the fifth fork tube assembly 325 includes a first straight tube 3251 and a second straight tube 3252 rotatably coupled. The first bent pipe 3241 is rotatably connected to the first end of the first straight pipe 3251, and the second bent pipe 3242 is rotatably connected to the first end of the second straight pipe 3252. The second end of the first bent pipe 3241 is rotationally connected with the vertex angle fixing piece 5 at the upper end of the first upright 11, and the second end of the second bent pipe 3242 is rotationally connected with the linkage sliding sleeve 4 on the first upright 11. The second end of the first straight pipe 3251 is rotatably connected with the top angle fixing piece 5 at the upper end of the fourth upright 14, and the second end of the second straight pipe 3252 is rotatably connected with the linkage sliding sleeve 4 on the fourth upright 14. Referring to fig. 7, during the folding of the folding trailer to a folded state, the first upright 11 and the fourth upright 14 are close to each other, the fourth fork tube assembly 324 and the fifth fork tube assembly 325 are rotated and folded, the fourth fork tube assembly 324 and the fifth fork tube assembly 325 are both retracted, at this time, the second bent tube 3242 and the second straight tube 3252 are both rotated upward, and the second ends of the second bent tube 3242 and the second straight tube 3252 are both slid downward, so that the folded height of the fourth fork tube assembly 324 and the fifth fork tube assembly 325 is not higher than the height of the upright 1.

As shown in fig. 1 and 5, the base support mechanism 2 includes a base link 21 and four base links 22. The bottom connecting piece 21 is symmetrically provided with four mounting grooves, the bottoms of the mounting grooves are horizontally arranged and are downward in opening when the folding trailer is in an unfolded state, and the first end of the bottom connecting pipe 22 is positioned in the mounting grooves and is rotationally connected with the inner walls of the mounting grooves. When the bottom connecting pipe 22 rotates from the inclined state when in the folded state to the state that the pipe wall is abutted against the bottom of the mounting groove compared with the bottom connecting piece 21, the bottom connecting pipe 22 cannot continue to rotate due to the limitation of the mounting groove, so that the horizontal state is maintained, and effective supporting force is provided for the bottom of the trailer. The second end of the bottom connecting tube 22 is also rotatably connected with the lower end of the upright 1 at a limited angle, and the structure is similar to that of the first end, except that the notch is upward, and the lower end of the upright 1 is provided with a connecting mounting groove with the notch upward, so that the bottom connecting tube 22 is limited to rotate downward to a horizontal state only from an inclined state when in a folded state compared with the mounting groove of the lower end of the upright 1. During folding of the trailer, the bottom links 21 are driven to move upwards, the four bottom links 22 are rotated from a horizontal state when unfolded to an inclined state, and the four bottom links 22 are gathered with each other.

As shown in fig. 1-4, the folding trailer further includes a handle mechanism 6, specifically, referring to fig. 4, the handle mechanism 6 includes a telescopic rod 60, a first transverse tube 61, and a second transverse tube 62, and first ends of the first transverse tube 61 and the second transverse tube 62 are rotatably connected to a connecting member mounted on the telescopic rod 60. Specifically, a rod body of the telescopic rod 60 is connected with a limiting member, a first end of the first transverse tube 61 is rotationally connected with a first side of the limiting member, a first end of the second transverse tube 62 is rotationally connected with a second side of the limiting member, the first side of the limiting member is opposite to the first upright 11, and the second side of the limiting member is opposite to the fourth upright 14. The first transverse tube 61 and the second transverse tube 62 are limited by the stopper, and the first transverse tube 61 and the second transverse tube 62 can only rotate downward around the stopper from an inclined state in the folded state to a nearly horizontal state and then cannot continue to rotate, or rotate upward around the stopper from an inclined state in the unfolded state to a nearly vertical state, see fig. 4 and 7. When folding, after the first transverse tube 61 and the second transverse tube 62 rotate, the telescopic rod 60 moves downwards, so that the height of the telescopic rod 60 is reduced, and meanwhile, the height of the telescopic rod 60 is further reduced through the shrinkage of the telescopic rod 60, so that the height of the handle mechanism 6 after folding and shrinkage is not higher than that of the upright post 1. The second ends of the first transverse pipe 61 and the second transverse pipe 62 are respectively in one-to-one corresponding rotation connection with the connecting pieces which are arranged at the lower ends of the first upright post 11 and the fourth upright post 14 in a rotating mode, the rotating shafts of the connecting pieces are perpendicular to the rotating shafts of the first cross rod and the second cross rod, when the connecting pieces rotate, the free ends of the telescopic rods 60 move away from or close to the trailer, and when the free ends of the telescopic rods 60 move away from the trailer, certain included angles exist between the telescopic rods 60 and the planes where the first upright post 11 and the fourth upright post 14 are located, so that the telescopic rods are convenient for a user to drag. A pull ring is attached to a second end of telescoping rod 60 to further facilitate the towing of the trailer by the user. The lower extreme of arbitrary 1 stand all is provided with gyro wheel 7, and preferably, wherein, the gyro wheel 7 that the lower extreme of first stand 11 and fourth stand 14 set up is the universal wheel, further makes things convenient for the user to drag the trailer.

In the description of the present utility model, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium; may be a communication between two elements or an interaction between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present utility model, unless expressly stated or limited otherwise, a first feature is "on" or "under" a second feature, which may be in direct contact with the first and second features, or in indirect contact with the first and second features via an intervening medium. Moreover, a first feature "above," "over" and "on" a second feature may be a first feature directly above or obliquely above the second feature, or simply indicate that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is level lower than the second feature.

In the description of the present specification, the terms "one embodiment," "some embodiments," "examples," "particular examples," or "some examples," etc., refer to particular features, structures, materials, or characteristics described in connection with the embodiment or example as being included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While embodiments of the present utility model have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the utility model, and that alterations, modifications, substitutions and variations may be made in the above embodiments by those skilled in the art within the scope of the utility model.

Claims (9)

1. The folding trailer is characterized by comprising a first folding mechanism (31), a second folding mechanism (32), a third folding mechanism (33), a fourth folding mechanism (34), a bottom support mechanism (2) and four upright posts (1) which are arranged at intervals in a rectangular shape, wherein the bottom support mechanism (2) is connected between the four upright posts (1);

The first folding mechanism (31), the third folding mechanism (33), the second folding mechanism (32) and the fourth folding mechanism (34) are sequentially connected between two adjacent upright posts (1), and the height after folding is not higher than the height of the upright posts (1);

The first folding mechanism (31) and the second folding mechanism (32) comprise a first fork tube assembly (321), a second fork tube assembly (322) and a third fork tube assembly (323), wherein a first end of the first fork tube assembly (321) is connected with one of two adjacent upright posts (1), and a first end of the second fork tube assembly (322) is connected with the other of the two adjacent upright posts (1); one connecting pipe of the first fork pipe assembly (321) and the second fork pipe assembly (322) is rotationally connected, and the other connecting pipe of the first fork pipe assembly (321) and the second fork pipe assembly (322) is connected through the third fork pipe assembly (323);

The first fork tube assembly (321) comprises a first connecting tube (3211) and a third connecting tube (3212) which are connected in a rotating way, and the second fork tube assembly (322) comprises a second connecting tube (3221) and a fourth connecting tube (3222) which are connected in a rotating way;

The first ends of the first connecting pipe (3211) and the second connecting pipe (3221) are rotationally connected, the first ends of the third connecting pipe (3212) and the fourth connecting pipe (3222) are rotationally connected with the third fork pipe assembly (323), and the pipe bodies of the first connecting pipe (3211) and the second connecting pipe (3221) are rotationally connected with the third fork pipe assembly (323);

The second end of the first connecting pipe (3211) is rotationally connected with the upper end of one of the two adjacent upright posts (1), and the second end of the second connecting pipe (3221) is rotationally connected with the upper end of the other of the two adjacent upright posts (1);

The second end of the third connecting pipe (3212) is in sliding connection with one of the two adjacent upright posts (1), and the second end of the fourth connecting pipe (3222) is in sliding connection with the other of the two adjacent upright posts (1).

2. A folding trailer as claimed in claim 1, characterised in that the upper ends of the four uprights (1) are each provided with a top corner securing member (5), the second ends of the first connecting tube (3211) and the second connecting tube (3221) being respectively in rotational connection with the corresponding top corner securing members (5) on the uprights (1).

3. A folding trailer as claimed in claim 1, characterised in that four of said uprights (1) are each provided with a sliding linkage sleeve (4) slidingly disposed thereon;

The second ends of the third connecting pipe (3212) and the fourth connecting pipe (3222) are respectively connected with the corresponding linkage sliding sleeve (4) on the upright post (1) in a rotating mode.

4. A folding trailer according to claim 3, wherein the third fork tube assembly (323) comprises a fifth connecting tube (3231) and a sixth connecting tube (3232);

Two ends of the fifth connecting pipe (3231) are respectively in one-to-one corresponding rotary connection with the first end of the third connecting pipe (3212) and the pipe body of the second connecting pipe (3221);

The two ends of the sixth connecting pipe (3232) are respectively in one-to-one corresponding rotary connection with the first end of the fourth connecting pipe (3222) and the pipe body of the first connecting pipe (3211).

5. A folding trailer as claimed in claim 3, characterised in that the third folding mechanism (33) and the fourth folding mechanism (34) each comprise a fourth fork tube assembly (324) and a fifth fork tube assembly (325) connected to each other;

the fourth fork tube assembly (324) is connected with one of the two adjacent upright posts (1), and the fifth fork tube assembly (325) is connected with the other of the two adjacent upright posts (1).

6. The folding trailer of claim 5, wherein the fourth fork tube assembly (324) includes a first elbow (3241) and a second elbow (3242) rotatably connected, and the fifth fork tube assembly (325) includes a first straight tube (3251) and a second straight tube (3252) rotatably connected;

The first bent pipe (3241) is rotationally connected with the first end of the first straight pipe (3251), and the second bent pipe (3242) is rotationally connected with the first end of the second straight pipe (3252);

The second end of the first bent pipe (3241) is rotationally connected with the upper end of the corresponding upright post (1), and the second end of the second bent pipe (3242) is rotationally connected with the linkage sliding sleeve (4) on the corresponding upright post (1);

The second end of the first straight pipe (3251) is rotationally connected with the upper end of the corresponding upright post (1), and the second end of the second straight pipe (3252) is rotationally connected with the corresponding linkage sliding sleeve (4) on the upright post (1).

7. A folding trailer as claimed in claim 1, characterised in that the bottom stay mechanism (2) comprises a bottom connection (21) and four bottom connection pipes (22);

The first ends of the four bottom connecting pipes (22) are rotationally connected with the bottom connecting piece (21) at a limited angle, and the second ends of the four bottom connecting pipes (22) are rotationally connected with the lower ends of the four upright posts (1) at a limited angle in a one-to-one correspondence mode.

8. A folding trailer as claimed in claim 1, characterised in that the folding trailer further comprises a handle mechanism (6);

The handle mechanism (6) comprises a telescopic rod (60), a first transverse tube (61) and a second transverse tube (62), wherein the first ends of the first transverse tube (61) and the second transverse tube (62) are respectively and rotatably connected with the telescopic rod (60), and the second ends of the first transverse tube (61) and the second transverse tube (62) are respectively and rotatably connected with the lower ends of the two upright posts (1) connected with the fourth folding mechanism (34) in a one-to-one correspondence manner;

The height of the handle mechanism (6) after folding and shrinking is not higher than the height of the upright post (1).

9. A folding trailer as claimed in claim 1, characterised in that the lower ends of the four uprights (1) are each provided with rollers (7).