Folding and shortening trailer

Abstract

The utility model relates to a folding and shortening trailer which comprises four telescopic stand columns arranged in a rectangular mode at intervals and at least two oppositely-arranged side face folding mechanisms, and the two ends of each side face folding mechanism are hinged to the two adjacent telescopic stand columns respectively. In the folding process of the folding and shortening trailer, the side face folding mechanisms drive the telescopic stand columns connected with the side face folding mechanisms to contract and shorten; in the unfolding process of the folding and shortening trailer, the side face folding mechanisms drive the telescopic stand columns connected with the side face folding mechanisms to extend; the height of the folding and shortening trailer in the folding state is smaller than that in the unfolding state. According to the folding trailer, the telescopic stand columns are arranged, in the folding or unfolding process of the trailer, the folding mechanism is used for driving the telescopic stand columns to be shortened or stretched, and therefore the space of a cloth bag installed on the tops of the telescopic stand columns is enlarged after the trailer is unfolded after the cloth bag is folded and shortened. Meanwhile, after the folding and shortening trailer is folded, the telescopic stand columns are shortened, the occupied space is small, and carrying and transportation are convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of folding trailers, in particular to a folding and height-reducing trailer. Background Art

[0002] In daily life and production, it is often necessary to carry luggage or items, etc. During the carrying process, trailer tools are often used. Due to the characteristics of being easy to push and time-saving and labor-saving, trailer tools are widely used when carrying things. In order to facilitate the storage of trailer tools, the trailer tools are designed into a foldable structure, which is very light. After folding, it can be placed in the vehicle and is convenient to carry.

[0003] However, for the existing folding trailers, when in the unfolded state, the volume is small and fewer items can be stored; while in the folded state, the volume is large and it occupies a large space. Especially when it is folded and stored in a place with limited space such as the trunk of a car, it is particularly inconvenient, seriously affecting the user experience.

[0004] For traditional folding trailers, due to the structural limitations of the folding mechanism itself, the height of the trailer after folding is significantly higher than that in the unfolded state, which results in a large occupied area when the trailer is stored. And if only considering reducing the occupied area when the trailer is stored, then the volume in the unfolded state of the trailer will inevitably be sacrificed. Thus, the volume in the unfolded state of the trailer and the occupied area when stored restrict each other, which is a difficult problem studied by those skilled in the art. Summary of the Utility Model

[0005] (1) Technical Problems to be Solved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the utility model provides a folding and height-reducing trailer, which solves the technical problems that the volume in the unfolded state of the folding trailer is small while the volume in the folded state is large.

[0007] (2) Technical Solutions

[0008] In order to achieve the above purpose, a folding and height-reducing trailer of the utility model includes four telescopic columns arranged at intervals in a rectangle and at least two side folding mechanisms arranged oppositely. The two ends of the side folding mechanism are respectively hinged to two adjacent telescopic columns.

[0009] During the folding process of the folding and height-reducing trailer, the side folding mechanism drives the telescopic column connected thereto to contract and become shorter; during the unfolding process of the folding and height-reducing trailer, the side folding mechanism drives the telescopic column connected thereto to extend; the height of the folding and height-reducing trailer in the folded state is less than that in the unfolded state.

[0010] Optionally, the telescopic column includes a lifting rod.

[0011] The top of the lifting rod is the top of the telescopic column, and linkage ends are provided at both ends of the side folding mechanism and are hinged to the lifting rod of the corresponding telescopic column.

[0012] During the folding process of the folding and height-reducing trailer, the length of the side folding mechanism becomes shorter, and the linkage end drives the lifting rod to move downward.

[0013] During the unfolding process of the folding and height-reducing trailer, the length of the side folding mechanism becomes longer, and the linkage end drives the lifting rod to move upward.

[0014] The height of the side folding mechanism after folding is lower than the height of the telescopic column.

[0015] Optionally, the telescopic column further includes a fixed vertical rod;

[0016] The lifting rod slides vertically relative to the fixed vertical rod;

[0017] Both ends of the side folding mechanism further include fixed ends, and the fixed ends are hinged to the fixed vertical rod of the corresponding telescopic column;

[0018] During the folding or unfolding process of the side folding mechanism, the fixed end rotates, and the linkage end drives the lifting rod to move along the fixed vertical rod.

[0019] Optionally, a linkage sliding sleeve is slidably arranged on the fixed vertical rod;

[0020] The lifting rod is connected to the linkage sliding sleeve, and the linkage end is hinged to the linkage sliding sleeve;

[0021] A top foot fixing member is arranged at the top of the fixed vertical rod, and the fixed end is hinged to the top foot fixing member;

[0022] During the folding process of the folding and height-reducing trailer, the linkage end hinged to the linkage sliding sleeve drives the lifting rod to move downward through the linkage sliding sleeve;

[0023] During the unfolding process of the folding and height-reducing trailer, the linkage end hinged to the linkage sliding sleeve drives the lifting rod to move upward through the linkage sliding sleeve.

[0024] Optionally, the lifting rod is located outside the fixed vertical rod, and the lifting rod is slidably connected to the top foot fixing member. During the up and down movement of the lifting rod, the top foot fixing member provides lateral limit to the lifting rod;

[0025] Alternatively, the fixed vertical rod is of a hollow structure, the lifting rod is slidably sleeved inside the fixed vertical rod, the linkage sliding sleeve is slidably sleeved outside the fixed vertical rod, a vertical strip-shaped hole is formed in the fixed vertical rod, the lifting rod is connected to the linkage sliding sleeve through a connecting member, and during the up and down movement of the lifting rod, the fixed vertical rod provides lateral limitation to the lifting rod.

[0026] Optionally, the folding and height-reducing trailer has four side folding mechanisms located at the front, rear, left, and right. The side folding mechanisms located on the left and right have Structure One or Structure Two, and the side folding mechanisms located at the front and rear have Structure One;

[0027] Structure One is as follows:

[0028] Structure One includes a plurality of sequentially hinged X-shaped rod groups, and each X-shaped rod group includes a first connecting rod and a second connecting rod hinged in the middle;

[0029] In the side folding mechanism, the first end of the first connecting rod of the X-shaped rod group at the head end forms the fixed end, and the first end of the second connecting rod forms the linkage end;

[0030] The first end of the first connecting rod of the X-shaped rod group at the tail end forms the fixed end, and the first end of the second connecting rod forms the linkage end;

[0031] In one X-shaped rod group, the first end of the first connecting rod and the first end of the second connecting rod are on the same side;

[0032] Structure Two is as follows:

[0033] Structure Two includes a first fork rod and a second fork rod at one end, a third fork rod and a fourth fork rod at the other end, and a T-shaped folding assembly in the middle;

[0034] The first fork rod and the second fork rod are hinged in the middle, and the third fork rod and the fourth fork rod are hinged in the middle;

[0035] The first end of the first fork rod forms the fixed end, the first end of the second fork rod forms the linkage end, and the first end of the first fork rod and the first end of the second fork rod are on the same side;

[0036] The first end of the third fork rod forms the fixed end, the first end of the fourth fork rod forms the linkage end, and the first end of the third fork rod and the first end of the fourth fork rod are on the same side;

[0037] The T-shaped folding assembly includes a fifth fork rod, a sixth fork rod, and a seventh fork rod; among them,

[0038] The first end of the fifth fork rod is hinged to the second end of the second fork rod, and the first end of the sixth fork rod is hinged to the second end of the fourth fork rod;

[0039] The second end of the fifth fork rod and the second end of the sixth fork rod are hinged,

[0040] The hinged part of the fifth fork rod and the sixth fork rod is connected to the first end of the seventh fork rod, and the second ends of the first fork rod and the third fork rod are both hinged to the second end of the seventh fork rod;

[0041] In the first structure and the second structure: during the folding process of the folding and lowering trailer, the fixed end and the linkage end on the same side move away from each other; during the unfolding process of the folding and lowering trailer, the fixed end and the linkage end on the same side move closer to each other.

[0042] Optionally, the adjacent fixed ends of two adjacent side folding mechanisms are connected to the same top foot fixing member, and the adjacent linkage ends of two adjacent side folding mechanisms are connected to the same linkage sliding sleeve.

[0043] Optionally, the folding and lowering trailer further includes a bottom support mechanism, the bottom support mechanism is hinged between the four telescopic columns, and a set of relatively arranged side folding mechanisms are respectively connected to the bottom support mechanism through a first connection component and a second connection component; the bottom support mechanism can be folded and contracted to gather, and the height after folding is lower than the height of the telescopic columns;

[0044] The folding and lowering trailer further includes a handle mechanism, the handle mechanism includes a telescopic rod, a first cross bar and a second cross bar, the first ends of the first cross bar and the second cross bar are both hinged to the telescopic rod, and the second ends of the first cross bar and the second cross bar are respectively rotatably connected to the lower ends of two adjacent telescopic columns at a limited angle, the telescopic rod can be telescoped, and the height of the telescopic rod in the retracted state is lower than the height of the telescopic columns;

[0045] Rollers are provided at the lower ends of the four telescopic columns, and at least one pair of the rollers are universal wheels.

[0046] Optionally, the bottom support mechanism includes a first bottom connecting member and a second bottom connecting member, a third bottom connecting member is provided on the first connection component, and a fourth bottom connecting member is provided on the second connection component;

[0047] The first bottom connecting member is rotatably connected to the lower ends of two adjacent telescopic columns at a limited angle through a first bottom connecting rod;

[0048] The second bottom connecting member is rotatably connected to the lower ends of the other two adjacent telescopic columns at a limited angle through a second bottom connecting rod;

[0049] The first bottom connecting member is rotatably connected to the third bottom connecting member and the fourth bottom connecting member at a limited angle through a third bottom connecting rod;

[0050] The second bottom connecting member is rotatably connected to the third bottom connecting member and the fourth bottom connecting member at a limited angle through a fourth bottom connecting rod;

[0051] When the folding and height-reducing trailer is in a folded state, the heights of the first bottom connecting member and the second bottom connecting member are both lower than the height of the telescopic upright column.

[0052] (III) Advantageous Effects

[0053] During the folding process of the folding and height-reducing trailer, the side folding mechanism drives the telescopic upright column connected thereto to contract and become shorter. During the folding process, the telescopic upright column automatically contracts and becomes shorter. During the unfolding process of the folding and height-reducing trailer, the side folding mechanism drives the telescopic upright column connected thereto to extend, and during the unfolding process, the telescopic upright column automatically extends, with convenient operation and easy for users to use.

[0054] By providing a telescopic upright column to change the volume of the trailer when unfolded and the volume when folded, when unfolded, the telescopic upright column extends, increasing the height of the trailer after unfolding, and thus increasing the volume inside the trailer; when folded, the telescopic upright column contracts and becomes shorter, reducing the overall height of the folding and height-reducing trailer, and thus reducing the occupied space of the trailer, which is convenient for carrying and transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 is a perspective view of Structure 1 of the folding and height-reducing trailer of the present utility model;

[0056] Figure 2 is a perspective view of Structure 2 of the folding and height-reducing trailer of the present utility model;

[0057] Figure 3 is a connection diagram of the side folding mechanism in Embodiment 1 of the folding and height-reducing trailer of the present utility model;

[0058] Figure 4 is a structural diagram of the telescopic upright column in Embodiment 1 of the folding and height-reducing trailer of the present utility model;

[0059] Figure 5 is a structural diagram of the telescopic upright column in Embodiment 2 of the folding and height-reducing trailer of the present utility model;

[0060] Figure 6 is a side view of Embodiment 1 of the folding and height-reducing trailer of the present utility model;

[0061] Figure 7 is a side view of Embodiment 2 of the folding and height-reducing trailer of the present utility model;

[0062] Figure 8Front view of the first embodiment of the folding and height - reducing trailer of the present utility model;

[0063] Figure 9 Front view of the second embodiment of the folding and height - reducing trailer of the present utility model;

[0064] Figure 10 Side view of the second structure of the folding and height - reducing trailer of the present utility model;

[0065] Figure 11 Top view of the folding and height - reducing trailer of the present utility model;

[0066] Figure 12 Schematic diagram of the semi - folded state of the folding and height - reducing trailer of the present utility model;

[0067] Figure 13 Schematic diagram of the folded state of the folding and height - reducing trailer of the present utility model.

[0068]

Explanation of reference numerals

[0069] 1: Telescopic column; 11: First telescopic column; 12: Second telescopic column; 13: Third telescopic column; 14: Fourth telescopic column; 15: Linking sliding sleeve; 16: Foot fixing part; 17: Strip - shaped hole;

[0070] 111: First lifting rod; 112: First fixed vertical rod;

[0071] 121: Second lifting rod; 122: Second fixed vertical rod;

[0072] 131: Third lifting rod; 132: Third fixed vertical rod;

[0073] 141: Fourth lifting rod; 142: Fourth fixed vertical rod;

[0074] 2: Side - folding mechanism; 21: First folding mechanism; 22: Second folding mechanism; 23: Third folding mechanism; 24: Fourth folding mechanism;

[0075] 201: Linking end; 202: Fixed end;

[0076] 211: First X - shaped rod group; 212: Second X - shaped rod group; 213: Third X - shaped rod group; 214: Fourth X - shaped rod group; 215: Fifth X - shaped rod group;

[0077] 2111: First connecting rod; 2112: Second connecting rod;

[0078] 2121: Third connecting rod; 2122: Fourth connecting rod;

[0079] 231: First fork rod; 232: Second fork rod; 233: Third fork rod; 234: Fourth fork rod; 235: Fifth fork rod; 236: Sixth fork rod; 237: Seventh fork rod;

[0080] 25: First connection component; 26: Second connection component; 251: First suspension rod; 261: Second suspension rod;

[0081] 3: Bottom support mechanism; 31: First bottom connection part; 32: Second bottom connection part; 33: Third bottom connection part; 34: Fourth bottom connection part; 35: First bottom connecting rod; 36: Second bottom connecting rod; 37: Third bottom connecting rod; 38: Fourth bottom connecting rod;

[0082] 4: Handle mechanism; 41: Telescopic rod; 42: First cross bar; 43: Second cross bar;

[0083] 5: Roller. Detailed implementation manner

[0084] In order to better explain the present invention for easy understanding, the present invention will be described in detail below with reference to the accompanying drawings through specific implementation manners.

[0085] Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and the scope of the present invention can be fully conveyed to those skilled in the art.

[0086] As Figure 1 and Figure 2 shown, the present invention provides a folding and height-reducing trailer, and the height in the folded state is less than the height in the unfolded state.

[0087] As Figures 1 to 3As shown, the collapsible and height-reducing trailer includes four telescopic columns 1 arranged at rectangular intervals and at least two oppositely arranged side folding mechanisms 2. That is, the side folding mechanism 2 of the collapsible and height-reducing trailer has three forms: The first form is to arrange one side folding mechanism 2 on each of the left and right sides; the second form is to arrange one side folding mechanism 2 on each of the front and rear sides; the third form is to arrange one side folding mechanism 2 on each of the front, rear, left, and right sides. For the convenience of description, the side folding mechanism 2 on the left side is defined as the first folding mechanism 21, the side folding mechanism 2 on the right side is defined as the second folding mechanism 22, the side folding mechanism 2 on the front side is defined as the third folding mechanism 23, and the side folding mechanism 2 on the rear side is defined as the fourth folding mechanism 24; the first folding mechanism 21 and the second folding mechanism 22 are two opposite side folding mechanisms 2, and the third folding mechanism 23 and the fourth folding mechanism 24 are two opposite side folding mechanisms 2. The four telescopic columns 1 arranged at rectangular intervals are respectively the first telescopic column 11, the second telescopic column 12, the third telescopic column 13, and the fourth telescopic column 14. When the side folding mechanism 2 is in the first form, the first folding mechanism 21 is hinged between the first telescopic column 11 and the second telescopic column 12, and the second folding mechanism 22 is hinged between the third telescopic column 13 and the fourth telescopic column 14; when the side folding mechanism 2 is in the second form, the third folding mechanism 23 is hinged between the first telescopic column 11 and the fourth telescopic column 14, and the fourth folding mechanism 24 is hinged between the second telescopic column 12 and the third telescopic column 13; when the side folding mechanism 2 is in the third form, the connection methods of the four side folding mechanisms 2 include the connection methods in the first form and the second form.

[0088] As Figure 12 and Figure 13As shown in the figure, during the folding process of the folding and height-reducing trailer, the side folding mechanism 2 drives the telescopic upright column 1 connected thereto to contract and become shorter. That is, the first folding mechanism 21 and the third folding mechanism 23 drive the first telescopic upright column 11 to contract and become shorter and the top to become lower, the first folding mechanism 21 and the fourth folding mechanism 24 drive the second telescopic upright column 12 to contract and become shorter and the top to become lower, the second folding mechanism 22 and the third folding mechanism 23 drive the fourth telescopic upright column 14 to contract and become shorter and the top to become lower, and the second folding mechanism 22 and the fourth folding mechanism 24 drive the third telescopic upright column 13 to contract and become shorter and the top to become lower. During the folding process, the telescopic upright column 1 automatically contracts and becomes shorter, with convenient operation and easy for users to use. On the contrary, during the unfolding process of the folding and height-reducing trailer, the side folding mechanism 2 drives the telescopic upright column 1 connected thereto to extend and the top to become higher. That is, the first folding mechanism 21 and the third folding mechanism 23 drive the first telescopic upright column 11 to extend and the top to become higher, the first folding mechanism 21 and the fourth folding mechanism 24 drive the second telescopic upright column 12 to extend and the top to become higher, the second folding mechanism 22 and the third folding mechanism 23 drive the fourth telescopic upright column 14 to extend and the top to become higher, and the second folding mechanism 22 and the fourth folding mechanism 24 drive the third telescopic upright column 13 to extend and the top to become higher. During the unfolding process, the telescopic upright column 1 automatically extends and the top becomes higher, with convenient operation and easy for users to use. By setting the telescopic upright column 1, the volume of the trailer during unfolding and the volume during folding are changed. When unfolding, the telescopic upright column 1 extends and the top becomes higher, increasing the height of the trailer after unfolding, and thus increasing the internal volume of the trailer; when folding, the telescopic upright column 1 contracts and becomes shorter and the top becomes lower, reducing the overall height of the folding and height-reducing trailer, and thus reducing the occupied space of the trailer, which is convenient for carrying and transportation.

[0089] Further, as Figures 3 to 5 shown, the first telescopic upright column 11 includes a first lifting rod 111, the second telescopic upright column 12 includes a second lifting rod 121, the third telescopic upright column 13 includes a third lifting rod 131, and the fourth telescopic upright column 14 includes a fourth lifting rod 141. The tops of each lifting rod are respectively the tops of each telescopic upright column 1. Refer to Figure 4, at both ends of the first folding mechanism 21, there are linkage ends 201 hinged to the first lifting rod 111 and the second lifting rod 121. At both ends of the second folding mechanism 22, there are linkage ends 201 hinged to the third lifting rod 131 and the fourth lifting rod 141. At both ends of the third folding mechanism 23, there are linkage ends 201 hinged to the first lifting rod 111 and the fourth lifting rod 141. At both ends of the fourth folding mechanism 24, there are linkage ends 201 hinged to the second lifting rod 121 and the third lifting rod 131. During the folding process of the folding and height-reducing trailer, the lateral length of each side folding mechanism 2 becomes shorter. The linkage ends 201 at both ends of each side folding mechanism 2 drive the corresponding lifting rods to automatically move downward, and each telescopic column 1 automatically shrinks and becomes shorter. During the unfolding process of the folding and height-reducing trailer, the lateral length of each side folding mechanism 2 becomes longer. The linkage ends 201 at both ends of each side folding mechanism 2 drive the corresponding lifting rods to automatically move upward, and each telescopic column 1 automatically extends and the top becomes higher. Moreover, the height of each side folding mechanism 2 after folding is lower than the height of the telescopic column 1 after it shrinks and the top becomes shorter.

[0090] Furthermore, as Figures 3 to 5 shown, the first telescopic column 11 further includes a first fixed vertical rod 112. The second telescopic column 12 further includes a second fixed vertical rod 122. The third telescopic column 13 further includes a third fixed vertical rod 132. The fourth telescopic column 14 further includes a fourth fixed vertical rod 142. The first lifting rod 111 slides vertically relative to the first fixed vertical rod 112. The second lifting rod 121 slides vertically relative to the second fixed vertical rod 122. The third lifting rod 131 slides vertically relative to the third fixed vertical rod 132. The fourth lifting rod 141 slides vertically relative to the fourth fixed vertical rod 142. At both ends of the first folding mechanism 21, there are fixed ends 202 hinged to the first fixed vertical rod 112 and the second fixed vertical rod 122. At both ends of the second folding mechanism 22, there are fixed ends 202 hinged to the third fixed vertical rod 132 and the fourth fixed vertical rod 142. At both ends of the third folding mechanism 23, there are fixed ends 202 hinged to the first fixed vertical rod 112 and the fourth fixed vertical rod 142. At both ends of the fourth folding mechanism 24, there are fixed ends 202 hinged to the second fixed vertical rod 122 and the third fixed vertical rod 132. During the folding or unfolding process of each side folding mechanism 2, each fixed end 202 rotates around the hinge axis hinged to the corresponding fixed vertical rod respectively, and the fixed end 202 does not move up and down, while each linkage end 201 drives the corresponding lifting rods hinged to it to move in the length direction of the fixed vertical rod, that is, in the vertical direction.

[0091] Specifically, as Figures 3 to 5As shown in the figure, linkage sliding sleeves 15 are slidably arranged on the first fixed vertical rod 112, the second fixed vertical rod 122, the third fixed vertical rod 132, and the fourth fixed vertical rod 142. The first lifting rod 111, the second lifting rod 121, the third lifting rod 131, and the fourth lifting rod 141 are respectively connected to the linkage sliding sleeves 15 on the first fixed vertical rod 112, the second fixed vertical rod 122, the third fixed vertical rod 132, and the fourth fixed vertical rod 142 in a one-to-one correspondence. The linkage ends 201 at both ends of the first folding mechanism 21 are respectively hinged to the linkage sliding sleeves 15 on the first fixed vertical rod 112 and the second fixed vertical rod 122. The linkage ends 201 at both ends of the second folding mechanism 22 are respectively hinged to the linkage sliding sleeves 15 on the third fixed vertical rod 132 and the fourth fixed vertical rod 142. The linkage ends 201 at both ends of the third folding mechanism 23 are respectively hinged to the linkage sliding sleeves 15 on the first fixed vertical rod 112 and the fourth fixed vertical rod 142. The linkage ends 201 at both ends of the fourth folding mechanism 24 are respectively hinged to the linkage sliding sleeves 15 on the second fixed vertical rod 122 and the third fixed vertical rod 132. Top foot fixing parts 16 are arranged at the tops of the first fixed vertical rod 112, the second fixed vertical rod 122, the third fixed vertical rod 132, and the fourth fixed vertical rod 142. The fixed ends 202 at both ends of the first folding mechanism 21 are respectively hinged to the top foot fixing parts 16 on the first fixed vertical rod 112 and the second fixed vertical rod 122. The fixed ends 202 at both ends of the second folding mechanism 22 are respectively hinged to the top foot fixing parts 16 on the third fixed vertical rod 132 and the fourth fixed vertical rod 142. The fixed ends 202 at both ends of the third folding mechanism 23 are respectively hinged to the top foot fixing parts 16 on the first fixed vertical rod 112 and the fourth fixed vertical rod 142. The fixed ends 202 at both ends of the fourth folding mechanism 24 are respectively hinged to the top foot fixing parts 16 on the second fixed vertical rod 122 and the third fixed vertical rod 132. During the folding process of the folding and lowering trailer, the linkage end 201 hinged to the linkage sliding sleeve 15 drives the lifting rod to move downward through the linkage sliding sleeve 15. During the unfolding process of the folding and lowering trailer, the linkage end 201 hinged to the linkage sliding sleeve 15 drives the lifting rod to move upward through the linkage sliding sleeve 15.

[0092] The structures of the first telescopic upright column 11, the second telescopic upright column 12, the third telescopic upright column 13, and the fourth telescopic upright column 14 include the following two embodiments:

[0093] Embodiment 1, see Figure 5, taking the first telescopic column 11 as an example for illustration, the first lifting rod 111 is located outside the first fixed vertical rod 112. The top foot fixing member 16 on the first fixed vertical rod 112 is provided with a through hole whose central axis is parallel to the central axis of the first fixed vertical rod 112. The first lifting rod 111 is sleeved in the through hole so that the first lifting rod 111 is slidably connected to the top foot fixing member 16 on the first fixed vertical rod 112. During the up and down movement of the first lifting rod 111, the top foot fixing member 16 on the first fixed vertical rod 112 constitutes a lateral limit for the first lifting rod 111, making the first lifting rod 111 can only move in the direction of the central axis of the through hole. The second telescopic column 12, the third telescopic column 13, and the fourth telescopic column 14 all have the same structure as the first telescopic column 11, which will not be elaborated here;

[0094] Embodiment 2, see Figure 4 , taking the first telescopic column 11 as an example for illustration, the first fixed vertical rod 112 is of a hollow structure. The first lifting rod 111 is slidably sleeved inside the first fixed vertical rod 112. The linkage sliding sleeve 15 on the first fixed vertical rod 112 is slidably sleeved outside the first fixed vertical rod 112. A vertical strip-shaped hole 17 is provided on the first fixed vertical rod 112. The first lifting rod 111 is connected to the linkage sliding sleeve 15 on the first fixed vertical rod 112 through a connecting member. The connecting member includes rivets, bolts, etc., as long as it can detachably connect the first lifting rod 111 to the linkage sliding sleeve 15 on the first fixed vertical rod 112 through the strip-shaped hole 17, which will not be limited here. During the up and down movement of the first lifting rod 111, the first fixed vertical rod 112 constitutes a lateral limit for the first lifting rod 111, making the first lifting rod 111 can only move in the direction of the central axis of the first fixed vertical rod 112. The second telescopic column 12, the third telescopic column 13, and the fourth telescopic column 14 all have the same structure as the first telescopic column 11, which will not be elaborated here.

[0095] Embodiment 3, a long groove is provided on the side wall of the fixed vertical rod. The long groove is a guide rail groove. A strip-shaped protrusion matching the shape of the long groove is provided on the lifting rod. The strip-shaped protrusion is slidably sleeved in the long groove on the fixed vertical rod. The linkage sliding sleeve (15) is slidably sleeved outside the fixed vertical rod. The lifting rod is connected to the linkage sliding sleeve (15). At this time, the through hole on the top foot fixing member 16 is also provided with a groove for the strip-shaped protrusion to pass through. The lifting rod is slidably sleeved in the through hole on the top foot fixing member 16. During the up and down movement of the lifting rod, the long groove on the fixed vertical rod and the top foot fixing member 16 constitute a lateral limit for the lifting rod.

[0096] The structure of the side folding mechanism 2 located on the left and right sides can be Structure 1 or Structure 2, and the structure of the side folding mechanism 2 located on the front and rear sides is Structure 1, specifically as follows:

[0097] Structure 1:

[0098] AsFigures 4 to 9 As shown, the side folding mechanism 2 in Structure 1 includes a plurality of sequentially hinged X-shaped rod groups. The X-shaped rod group includes a first link 2111 and a second link 2112 that are hinged in the middle. The hinge point is not limited to the center points of the first link 2111 and the second link 2112, and the hinge point can be offset from the center point according to actual requirements. On the first folding mechanism 21, the second folding mechanism 22, the third folding mechanism 23, and the fourth folding mechanism 24, the first end of the first link 2111 in the X-shaped rod group at the head end constitutes a fixed end 202, and the first end of the second link 2112 in the X-shaped rod group at the head end constitutes a linkage end 201. The first end of the first link 2111 in the X-shaped rod group at the tail end constitutes a fixed end 202, and the first end of the second link 2112 in the X-shaped rod group at the tail end constitutes a linkage end 201. Moreover, in an X-shaped rod group, the first ends of the first link 2111 and the second link 2112 are on the same side. And, the adjacent fixed ends 202 of two adjacent side folding mechanisms 2 are connected to the same top foot fixing member 16, and the adjacent linkage ends 201 of two adjacent side folding mechanisms 2 are connected to the same linkage sliding sleeve 15.

[0099] In the preferred embodiment, both the first folding mechanism 21 and the second folding mechanism 22 include three sequentially hinged X-shaped rod groups, namely the first X-shaped rod group 211, the second X-shaped rod group 212, and the third X-shaped rod group 213. Among them, the first X-shaped rod group 211 is the X-shaped rod group at the head end, the third X-shaped rod group 213 is the X-shaped rod group at the tail end, and the second X-shaped rod group 212 is located between the first X-shaped rod group 211 and the third X-shaped rod group 213. The second X-shaped rod group 212 includes a third link 2121 and a fourth link 2122 whose rod bodies are hinged to each other. The first ends of the first links 2111 of the first X-shaped rod group 211 and the third X-shaped rod group 213 both constitute fixed ends 202, and the first ends of the second links 2112 of the first X-shaped rod group 211 and the third X-shaped rod group 213 both constitute linkage ends 201. The structures of the first folding mechanism 21 and the second folding mechanism 22 are the same and symmetric in position. Taking the illustration of the first folding mechanism 21 as an example for specific description, see Figure 6 and Figure 7, in the first folding mechanism 21, the first end of the first link 2111 of the first X-shaped link group 211 is hinged to the foot fixing member 16 on the first fixed vertical rod 112, and the first end of the second link 2112 of the first X-shaped link group 211 is hinged to the linkage sliding sleeve 15 on the first fixed vertical rod 112; the first end of the first link 2111 of the third X-shaped link group 213 is hinged to the foot fixing member 16 on the second fixed vertical rod 122, and the first end of the second link 2112 of the third X-shaped link group 213 is hinged to the linkage sliding sleeve 15 on the second fixed vertical rod 122; the second end of the first link 2111 of the first X-shaped link group 211 is hinged to the first end of the fourth link 2122, the second end of the second link 2112 of the first X-shaped link group 211 is hinged to the first end of the third link 2121, the second end of the first link 2111 of the third X-shaped link group 213 is hinged to the second end of the third link 2121, and the second end of the second link 2112 of the third X-shaped link group 213 is hinged to the second end of the fourth link 2122. In the second folding mechanism, the first end of the first link of the first X-shaped link group is hinged to the foot fixing member on the fourth fixed vertical rod, and the first end of the second link of the first X-shaped link group is hinged to the linkage sliding sleeve on the fourth fixed vertical rod; the first end of the first link of the third X-shaped link group is hinged to the foot fixing member on the third fixed vertical rod, and the first end of the second link of the third X-shaped link group is hinged to the linkage sliding sleeve on the third fixed vertical rod; the second end of the first link of the first X-shaped link group is hinged to the first end of the fourth link, the second end of the second link of the first X-shaped link group is hinged to the first end of the third link, the second end of the first link of the third X-shaped link group is hinged to the second end of the third link, and the second end of the second link of the third X-shaped link group is hinged to the second end of the fourth link.

[0100] In the preferred embodiment, both the third folding mechanism 23 and the fourth folding mechanism 24 include two X-shaped link groups, namely the fourth X-shaped link group 214 and the fifth X-shaped link group 215. The fourth X-shaped link group 214 is the X-shaped link group at the head end, and the fifth X-shaped link group 215 is the X-shaped link group at the tail end. The first ends of the first links 2111 of the fourth X-shaped link group 214 and the fifth X-shaped link group 215 both form the fixed ends 202, and the first ends of the second links 2112 of the fourth X-shaped link group 214 and the fifth X-shaped link group 215 both form the linkage ends 201. The structures of the third folding mechanism 23 and the fourth folding mechanism 24 are the same and symmetric in position. Taking the illustration of the third folding mechanism 23 as an example for specific description, see Figure 8 and Figure 9, in the third folding mechanism 23, the first end of the first link 2111 of the fourth X-shaped link group 214 is hinged to the top foot fixing member 16 on the fourth fixed vertical rod 142, and the first end of the second link 2112 of the fourth X-shaped link group 214 is hinged to the linkage sliding sleeve 15 on the fourth fixed vertical rod 142; the first end of the first link 2111 of the fifth X-shaped link group 215 is hinged to the top foot fixing member 16 on the first fixed vertical rod 112, and the first end of the second link 2112 of the fifth X-shaped link group 215 is hinged to the linkage sliding sleeve 15 on the first fixed vertical rod 112; the second end of the first link 2111 of the fourth X-shaped link group 214 is hinged to the second end of the first link 2111 of the fifth X-shaped link group 215, and the second end of the second link 2112 of the fourth X-shaped link group 214 is hinged to the second end of the second link 2112 of the fifth X-shaped link group 215. In the fourth folding mechanism, the first end of the first link of the fourth X-shaped link group is hinged to the top foot fixing member on the third fixed vertical rod, and the first end of the second link of the fourth X-shaped link group is hinged to the linkage sliding sleeve on the third fixed vertical rod; the first end of the first link of the fifth X-shaped link group is hinged to the top foot fixing member on the second fixed vertical rod, and the first end of the second link of the fifth X-shaped link group is hinged to the linkage sliding sleeve on the second fixed vertical rod; the second end of the first link of the fourth X-shaped link group is hinged to the second end of the first link of the fifth X-shaped link group, and the second end of the second link of the fourth X-shaped link group is hinged to the second end of the second link of the fifth X-shaped link group.

[0101] Structure Two:

[0102] Such as Figure 10As shown in the figure, the side folding mechanism 2 in Structure II adopts a first folding mechanism 21 and a second folding mechanism 22, including a first fork rod 231 and a second fork rod 232 at one end, a third fork rod 233 and a fourth fork rod 234 at the other end, and a T-shaped folding assembly in the middle; the first fork rod 231 and the second fork rod 232 are hinged in the middle, the third fork rod 233 and the fourth fork rod 234 are hinged in the middle, and the hinge points are not limited to the center points of the two fork rods, and the hinge points can be offset from the center points according to actual requirements. The first end of the first fork rod 231 constitutes a fixed end 202, the first end of the second fork rod 232 constitutes a linkage end 201, and the first ends of the first fork rod 231 and the second fork rod 232 are on the same side. The first end of the third fork rod 233 constitutes a fixed end 202, the first end of the fourth fork rod 234 constitutes a linkage end 201, and the first ends of the third fork rod 233 and the fourth fork rod 234 are on the same side. The T-shaped folding assembly includes a fifth fork rod 235, a sixth fork rod 236, and a seventh fork rod 237; wherein, the first end of the fifth fork rod 235 is hinged to the second end of the second fork rod 232, the first end of the sixth fork rod 236 is hinged to the second end of the fourth fork rod 234, the second ends of the fifth fork rod 235 and the sixth fork rod 236 are hinged, and the hinge joint of the fifth fork rod 235 and the sixth fork rod 236 is connected to the first end of the seventh fork rod 237, and the second ends of the first fork rod 231 and the third fork rod 233 are both hinged to the second end of the seventh fork rod 237. Similarly, the structures of the first folding mechanism 21 and the second folding mechanism 22 are the same and symmetrically located. Taking the illustration of the first folding mechanism 21 as an example for specific description, see Figure 10 , in the first folding mechanism 21, the first end of the first fork rod 231 is hinged to the top foot fixing member 16 on the first fixed vertical rod 112, the first end of the second fork rod 232 is hinged to the linkage sliding sleeve 15 on the first fixed vertical rod 112, the first end of the third fork rod 233 is hinged to the top foot fixing member 16 on the second fixed vertical rod 122, and the first end of the fourth fork rod 234 is hinged to the linkage sliding sleeve 15 on the second fixed vertical rod 122. In the second folding mechanism 22, the first end of the first fork rod 231 is hinged to the top foot fixing member 16 on the fourth fixed vertical rod 142, the first end of the second fork rod 232 is hinged to the linkage sliding sleeve 15 on the fourth fixed vertical rod 142, the first end of the third fork rod 233 is hinged to the top foot fixing member 16 on the third fixed vertical rod 132, and the first end of the fourth fork rod 234 is hinged to the linkage sliding sleeve 15 on the third fixed vertical rod 132. In Structure I and Structure II, during the folding process of the folding and lowering trailer, the fixed end 202 and the linkage end 201 on the same side move away from each other, and the linkage end 201 drives the lifting rod to descend. During the unfolding process of the folding and lowering trailer, the fixed end 202 and the linkage end 201 on the same side move closer to each other, and the linkage end 201 drives the lifting rod to ascend.

[0103] As Figure 11As shown in the figure, the folding and height-reducing trailer further includes a bottom support mechanism 3, which is hinged between four telescopic columns 1. The first folding mechanism 21 and the second folding mechanism 22 are respectively connected to the bottom support mechanism 3 through a first connection assembly 25 and a second connection assembly 26. The bottom support mechanism 3 can be folded, contracted and gathered, and the height after folding is lower than the height of the telescopic columns 1. Further, the bottom support mechanism 3 includes a first bottom connecting member 31 and a second bottom connecting member 32. A third bottom connecting member 33 is arranged on the first connection assembly 25, and a fourth bottom connecting member 34 is arranged on the second connection assembly 26. The first bottom connecting member 31 is rotatably connected to the lower ends of the first telescopic column 11 and the fourth telescopic column 14 at a limited angle through a first bottom connecting rod 35. The second bottom connecting member 32 is rotatably connected to the lower ends of the second telescopic column 12 and the third telescopic column 13 at a limited angle through a second bottom connecting rod 36. The first bottom connecting member 31 is rotatably connected to the third bottom connecting member 33 and the fourth bottom connecting member 34 at a limited angle through a third bottom connecting rod 37. The second bottom connecting member 32 is rotatably connected to the third bottom connecting member 33 and the fourth bottom connecting member 34 at a limited angle through a fourth bottom connecting rod 38. In the folded state of the folding and height-reducing trailer, the heights of the first bottom connecting member 31 and the second bottom connecting member 32 are both lower than the height of the telescopic columns 1.

[0104] Specifically, the first connection assembly 25 and the second connection assembly 26 can be suspension rods or flexible members. When the number of X-shaped rod groups of the first folding mechanism 21 and the second folding mechanism 22 is odd, both the first connection assembly 25 and the second connection assembly 26 are suspension rods; when the number of X-shaped rod groups of the first folding mechanism 21 and the second folding mechanism 22 is even, both the first connection assembly 25 and the second connection assembly 26 are flexible members, such as steel wires. One end of the first connection assembly 25 and the second connection assembly 26 are respectively connected to the first folding mechanism 21 and the second folding mechanism 22, and the other ends are respectively connected to the third bottom connecting member 33 and the fourth bottom connecting member 34. Taking Structure One as an example, and the first folding mechanism 21 and the second folding mechanism 22 include three X-shaped rod groups for illustration, see Figures 4 to 7 , the first connection assembly 25 is a first suspension rod 251, the second connection assembly 26 is a second suspension rod 261, both the third bottom connecting member 33 and the fourth bottom connecting member 34 are suspension rod joints, and the suspension rod joints are slidably connected to the first suspension rod 251 and the second suspension rod 261. Installation grooves corresponding to the third bottom connecting rod 37 and the fourth bottom connecting rod 38 are arranged on the suspension rod joints. At this time, the notch of the installation groove faces upward, restricting the third bottom connecting rod 37 and the fourth bottom connecting rod 38 to only rotate from the inclined state in the folded state to the horizontal state. Limit joints for restricting the suspension rod joints are arranged at the ends of the first suspension rod 251 and the second suspension rod 261. When the suspension rod joint moves along the first suspension rod 251 or the second suspension rod 261 to the limit joint, the displacement of the suspension rod joint is restricted and cannot break away from the corresponding suspension rod. See Figure 11, both the first bottom connecting member 31 and the second bottom connecting member 32 are symmetrically provided with four mounting grooves. Two first bottom connecting rods 35 and two third bottom connecting rods 37 are respectively rotatably connected to the inner walls of the four mounting grooves on the first bottom connecting member 31 in a one-to-one correspondence. Two second bottom connecting rods 36 and two fourth bottom connecting rods 38 are respectively rotatably connected to the inner walls of the four mounting grooves on the second bottom connecting member 32 in a one-to-one correspondence. When the trailer is in the unfolded state, the bottom of the mounting groove is horizontally arranged and the opening is downward. Two first bottom connecting rods 35 and two third bottom connecting rods 37 are respectively located in the corresponding mounting grooves on the first bottom connecting member 31. Two second bottom connecting rods 36 and two fourth bottom connecting rods 38 are respectively located in the corresponding mounting grooves on the second bottom connecting member 32. When each bottom connecting rod rotates from the inclined state in the folded state to abut against the bottom of the mounting groove with the pipe wall with respect to the first bottom connecting member 31 and the second bottom connecting member 32, each connecting rod is restricted by the mounting groove and cannot continue to rotate, thereby maintaining a horizontal state and providing an effective supporting force for the bottom of the trailer. The lower ends of the first telescopic column 11, the second telescopic column 12, the third telescopic column 13 and the fourth telescopic column 14 are all horizontally provided with mounting grooves with upward openings. Two first bottom connecting rods 35 are respectively hinged to the mounting grooves at the lower ends of the first telescopic column 11 and the fourth telescopic column 14. Two second bottom connecting rods 36 are respectively hinged to the mounting grooves at the lower ends of the second telescopic column 12 and the third telescopic column 13. The mounting grooves restrict the first bottom connecting rod 35 and the second bottom connecting rod 36 to only rotate from the inclined state in the folded state to the horizontal state. When the first folding mechanism 21 and the second folding mechanism 22 are of structure two, in the first folding mechanism 21, the second ends of the first fork rod 231 and the third fork rod 233 are both hinged to the second end of the seventh fork rod 237. The second end of the seventh fork rod 237 is slidably connected to the third bottom connecting member 33. In the second folding mechanism 22, the second ends of the first fork rod 231 and the third fork rod 233 are both hinged to the second end of the seventh fork rod 237. The second end of the seventh fork rod 237 is slidably connected to the fourth bottom connecting member 34.

[0105] As Figure 1 , Figure 2 , Figure 8 , Figure 9 shown, the folding and height-reducing trailer further includes a handle mechanism 4. The handle mechanism 4 includes a telescopic rod 41, a first cross bar 42 and a second cross bar 43. The first ends of the first cross bar 42 and the second cross bar 43 are both hinged to the telescopic rod 41. The second ends of the first cross bar 42 and the second cross bar 43 are respectively rotatably connected to the lower ends of the first telescopic column 11 and the second telescopic column 12 at a limited angle. The telescopic rod 41 can be telescoped, and the height of the telescopic rod 41 in the retracted state is lower than the height of the telescopic column 1. The lower ends of the four telescopic columns 1 are all provided with rollers 5. At least one pair of the rollers 5 is a universal wheel, which is convenient for the user to control the traveling direction of the trailer.

[0106] Preferably, the tops of the four telescopic columns 1 are respectively used for corresponding connection with the four corners of the cloth bag of the folding and height-reducing trailer. During the folding or unfolding process of the trailer, the folding mechanism drives the lifting rod to rise or become shorter, which makes the space of the cloth bag installed on the top of the telescopic column 1 larger after the folding and height-reducing trailer is unfolded.

[0107] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0108] In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium; it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0109] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0110] In the description of this specification, the description of terms such as "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0111] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model.

Claims

1. A foldable trailer, characterized in that: The foldable and short trailer comprises four telescopic columns (1) arranged at intervals in a rectangular shape and at least two side folding mechanisms (2) arranged opposite to each other, wherein two ends of the side folding mechanisms (2) are respectively hinged to two adjacent telescopic columns (1); During the folding process of the foldable and shortened trailer, the side folding mechanism (2) drives the telescopic column (1) connected thereto to contract and shorten; during the unfolding process of the foldable and shortened trailer, the side folding mechanism (2) drives the telescopic column (1) connected thereto to extend; the height of the foldable and shortened trailer in the folded state is less than the height in the unfolded state.

2. The foldable and low-profile trailer according to claim 1, characterized in that: The telescopic column (1) comprises a lifting rod; The top of the lifting rod is the top of the telescopic column (1), and both ends of the side folding mechanism (2) are provided with linkage ends (201) hinged to the lifting rod corresponding to the telescopic column (1); During the folding process of the foldable and shortened trailer, the length of the side folding mechanism (2) becomes shorter, and the linkage end (201) drives the lifting rod to move downward; During the unfolding process of the foldable and shortened trailer, the length of the side folding mechanism (2) increases, and the linkage end (201) drives the lifting rod to move upward; The height of the side folding mechanism (2) after folding is lower than the height of the telescopic column (1).

3. The foldable and low-profile trailer according to claim 2, characterized in that: The telescopic column (1) also includes a fixed vertical rod; The lifting rod slides vertically relative to the fixed vertical rod; Both ends of the side folding mechanism (2) further include a fixed end (202), and the fixed end (202) is hinged to the fixed vertical rod of the corresponding telescopic column (1); During the folding or unfolding process of the side folding mechanism (2), the fixed end (202) rotates, and the linkage end (201) drives the lifting rod to move along the fixed vertical rod.

4. The foldable and low-profile trailer according to claim 3, characterized in that: A linkage sliding sleeve (15) is slidably arranged on the fixed vertical rod; The lifting rod is connected to the linkage sleeve (15), and the linkage end (201) is hinged to the linkage sleeve (15); A top foot fixing piece (16) is provided at the top of the fixed vertical rod, and the fixed end (202) is hingedly connected to the top foot fixing piece (16); During the folding process of the foldable and shortened trailer, the linkage end (201) hinged to the linkage sliding sleeve (15) drives the lifting rod to move downward through the linkage sliding sleeve (15); During the unfolding process of the foldable and shortened trailer, the linkage end (201) hinged to the linkage sliding sleeve (15) drives the lifting rod to move upwards via the linkage sliding sleeve (15).

5. The foldable and low-profile trailer according to claim 4, characterized in that: The lifting rod is located outside the fixed vertical rod, and the lifting rod is slidably connected to the top foot fixing member (16). When the lifting rod moves up and down, the top foot fixing member (16) forms a lateral limit for the lifting rod; Alternatively, the fixed vertical rod is a hollow structure, the lifting rod is slidably sleeved inside the fixed vertical rod, the linkage sleeve (15) is slidably sleeved outside the fixed vertical rod, a vertical strip hole (17) is opened on the fixed vertical rod, the lifting rod is connected to the linkage sleeve (15) via a connecting piece, and when the lifting rod moves up and down, the fixed vertical rod constitutes a lateral limit for the lifting rod.

6. The foldable and low-profile trailer according to claim 4, characterized in that: The lifting rod is partially slidably sleeved inside the fixed vertical rod, and the linkage sleeve (15) is slidably sleeved outside the fixed vertical rod. The lifting rod is connected to the linkage sleeve (15). During the process of the lifting rod moving up and down, the fixed vertical rod forms a lateral limit for the lifting rod.

7. The foldable and low-profile trailer according to any one of claims 3 to 6, characterized in that: The foldable and short trailer has four side folding mechanisms (2) located at the front, rear, left and right, the side folding mechanisms (2) located at the left and right are structured as structure one or structure two, and the side folding mechanisms (2) located at the front and rear are structured as structure one; The structure 1 is: The structure 1 comprises a plurality of X-shaped rod groups hinged in sequence, wherein the X-shaped rod group comprises a first connecting rod (2111) and a second connecting rod (2112) hinged in the middle; In the side folding mechanism (2), the first end of the first connecting rod (2111) of the X-shaped rod group located at the head end constitutes the fixed end (202), and the first end of the second connecting rod (2112) constitutes the linkage end (201); The first end of the first connecting rod (2111) of the X-shaped rod group located at the tail end constitutes the fixed end (202), and the first end of the second connecting rod (2112) constitutes the linkage end (201); In one of the X-shaped rod groups, the first end of the first connecting rod (2111) and the first end of the second connecting rod (2112) are located on the same side; The second structure is: The second structure comprises a first fork rod (231) and a second fork rod (232) located at one end, a third fork rod (233) and a fourth fork rod (234) located at the other end, and a T-shaped folding assembly located in the middle; The first fork rod (231) and the second fork rod (232) are hinged at the middle, and the third fork rod (233) and the fourth fork rod (234) are hinged at the middle; The first end of the first fork rod (231) constitutes the fixed end (202), the first end of the second fork rod (232) constitutes the linkage end (201), and the first end of the first fork rod (231) and the first end of the second fork rod (232) are on the same side; The first end of the third fork rod (233) constitutes the fixed end (202), the first end of the fourth fork rod (234) constitutes the linkage end (201), and the first end of the third fork rod (233) and the first end of the fourth fork rod (234) are on the same side; The T-shaped folding assembly includes a fifth fork rod (235), a sixth fork rod (236) and a seventh fork rod (237); wherein, The first end of the fifth fork rod (235) is hinged to the second end of the second fork rod (232), and the first end of the sixth fork rod (236) is hinged to the second end of the fourth fork rod (234); The second end of the fifth fork rod (235) and the second end of the sixth fork rod (236) are hingedly connected, The hinged joint of the fifth fork rod (235) and the sixth fork rod (236) is connected to the first end of the seventh fork rod (237), and the second ends of the first fork rod (231) and the third fork rod (233) are both hinged to the second end of the seventh fork rod (237); In the first and second structures: during the folding process of the foldable and shortened trailer, the fixed end (202) and the linkage end (201) located on the same side move away from each other; during the unfolding process of the foldable and shortened trailer, the fixed end (202) and the linkage end (201) located on the same side move closer to each other.

8. The foldable and low-profile trailer according to claim 7, characterized in that: The adjacent fixed ends (202) of two adjacent side folding mechanisms (2) are connected to the same top foot fixing member (16), and the adjacent linkage ends (201) of two adjacent side folding mechanisms (2) are connected to the same linkage sliding sleeve (15).

9. The foldable and low-profile trailer according to claim 1, characterized in that: The foldable and short trailer further comprises a bottom support mechanism (3), the bottom support mechanism (3) being hinged between the four telescopic columns (1), and a group of oppositely arranged side folding mechanisms (2) being connected to the bottom support mechanism (3) via a first connecting assembly (25) and a second connecting assembly (26); the bottom support mechanism (3) can be folded, contracted and gathered, and the height after folding is lower than the height of the telescopic columns (1); The foldable and shortened trailer further comprises a handle mechanism (4), the handle mechanism (4) comprising a telescopic rod (41), a first cross rod (42) and a second cross rod (43), the first ends of the first cross rod (42) and the second cross rod (43) are both hinged to the telescopic rod (41), the second ends of the first cross rod (42) and the second cross rod (43) are respectively connected to the lower ends of two adjacent telescopic columns (1) in a one-to-one correspondence and are rotatably connected at a limited angle, the telescopic rod (41) is telescopic, and the height of the telescopic rod (41) in a retracted state is lower than the height of the telescopic column (1); Rollers (5) are arranged at the lower ends of the four telescopic columns (1), and at least one pair of the rollers (5) is a universal wheel.

10. The foldable and low-profile trailer according to claim 9, characterized in that: The bottom support mechanism (3) comprises a first bottom connecting member (31) and a second bottom connecting member (32); the first connecting component (25) is provided with a third bottom connecting member (33); and the second connecting component (26) is provided with a fourth bottom connecting member (34); The first bottom connecting member (31) is connected to the lower ends of two adjacent telescopic columns (1) by rotating at a limited angle through a first bottom connecting rod (35); The second bottom connecting member (32) is connected to the lower ends of the other two adjacent telescopic columns (1) by a second bottom connecting rod (36) so as to be rotatable at a limited angle; The first bottom connecting member (31) is connected to the third bottom connecting member (33) and the fourth bottom connecting member (34) by a third bottom connecting rod (37) to rotate at a limited angle; The second bottom connecting member (32) is connected to the third bottom connecting member (33) and the fourth bottom connecting member (34) by a fourth bottom connecting rod (38) so as to be rotatable at a limited angle; When the foldable and shortened trailer is in a folded state, the heights of the first bottom connecting member (31) and the second bottom connecting member (32) are both lower than the height of the telescopic column (1).

Images