Multi-layer trailer frame and multi-layer trailer

Abstract

The present invention discloses a multi-layer trailer frame and a multi-layer trailer, wherein the trailer frame includes a support frame and two storage parts; the support frame includes at least three uprights, the uprights are provided with fixed seats and sliding seats, and a scissor mechanism is pivoted between the fixed seats and sliding seats of two adjacent uprights on the same side; the first storage part includes two first storage racks, the outer sides of which are respectively pivoted to the two first uprights and the height of the pivoting position is located below the sliding seat, the inner sides are connected and the two first storage racks can at least rotate relative to each other; the second storage part includes two second storage racks, the outer sides of which are respectively able to rotate relative to the sliding seats of the two first uprights, the inner sides are connected and the two second storage racks can at least rotate relative to each other. It has the following advantages: it can realize a multi-layer structure with a simple structure; it can form a linkage to facilitate the opening and closing of the trailer frame; the height of the folded trailer frame is low, the occupied space is small, and the packaging, storage and transportation costs are low.

Description

Technical Field

[0001] The invention relates to a trailer, in particular to a multi-layer trailer frame and a multi-layer trailer. Background Art

[0002] The conventional trailer frame is a single-layer structure, such as US8011686B2 and CN117842156B. The single-layer trailer frame has a small storage volume, and there is a need for further improvement. In view of this deficiency, some people have proposed solutions, such as CN215883720U, which discloses a double-layer foldable trolley, including a foldable frame, the frame including four wheel assemblies, a front wall assembly, a rear wall assembly, two symmetrical side wall assemblies, a push handle assembly, an upper chassis assembly, and a lower chassis assembly. The front end and rear end of the lower chassis assembly are rotatably connected to the lower end of the front wall assembly and the lower end of the rear wall assembly, respectively, and the front end and rear end of the upper chassis assembly are rotatably connected to the middle end of the front wall assembly and the middle end of the rear wall assembly, respectively. The upper chassis assembly and the lower chassis assembly are connected in the middle of the same side by a connecting strip. Although it introduces the double-decker trailer structure, the cross tube, U-shaped cross bar and vertical bar constitute a connecting rod mechanism with a complex structure. In addition, the U-shaped cross bar rotates upward during the folding process, which makes the height of the folded trailer frame high, occupies a large space, and has high packaging, transportation and storage costs. Summary of the invention

[0003] The present invention provides a trailer frame with a multi-layer structure and a trailer with a multi-layer structure, which overcomes the shortcomings of wheels in the background technology.

[0004] One of the technical solutions adopted by the present invention to solve the technical problem is: a multi-layer trailer frame, comprising:

[0005] The support frame comprises N vertical frames arranged along the X direction, N≥3, the vertical frames comprise two vertical columns fixed at intervals in the Y direction, a fixed seat is fixed on the top of the vertical column, a sliding seat is slidably arranged on the vertical column, a scissor mechanism is pivotally connected between the fixed seat and the sliding seat of every two vertical frames adjacent to each other on the same side, and the N vertical frames move away from or approach along the X direction to open or close the trailer frame; among the support frames: the two vertical frames located on the outer side in the X direction are the first vertical frames, and the remaining vertical frames are the second vertical frames;

[0006] The first storage part includes two first storage racks, the outer sides of the two first storage racks are respectively pivotally connected to the two first vertical racks and the pivoting positions are located below the slide seat, the inner sides are connected and the two first storage racks can at least rotate relative to each other; and

[0007] The second storage part includes two second storage racks. The outer sides of the two second storage racks can rotate relative to the slide seats of the two first vertical racks respectively, and the inner sides are connected and the two second storage racks can at least rotate relative to each other.

[0008] In one embodiment: a first limiting mechanism is provided between two first racks, a second limiting mechanism is provided between two second racks, and the opened trailer rack: the two first racks pass through the maximum opening angle of the limit of the first limiting mechanism, and the two second racks pass through the maximum opening angle of the limit of the second limiting mechanism.

[0009] In one embodiment: the column of the second frame is a second column, and the second frame also includes a support rod fixed between the two second columns and located under the slide; the inner sides of the two first storage racks are pivotally connected together, and the first storage part of the opened trailer frame is supported on the support rod and the maximum opening angle of the two first storage racks is limited by supporting on the support rod.

[0010] In one embodiment, the inner sides of the two first racks are pivotally connected together, and at least one first rack has an inner side with an extension portion, and the extension portion of one first rack is supported on the other first rack to limit the maximum opening angle of the two adjacent first racks.

[0011] In one embodiment: the inner sides of the two first racks are pivotally connected together, and the inner sides of the two first racks have facing abutting surfaces, and the maximum opening angle of the two first racks is limited by the abutting surfaces of the two first racks facing each other.

[0012] In one embodiment, the column of the first stand is a first column, a pivot seat is fixedly arranged on the first column, two cantilevers are arranged on the outer sides of the two first storage racks, the cantilevers are provided with pivots, and the pivots are pivotally connected to the pivot seat.

[0013] In one embodiment: the column of the second frame is the second column, and the second frame also includes a positioning seat slidably connected to the second column and located between the fixed seat and the sliding seat; the outer sides of the two second racks are respectively rotatably connected to the sliding seats of the two first frames, and the inner sides are connected to the positioning seat, and the positioning seat of the opened trailer frame is supported on the sliding seat, and the maximum opening angle of the two second racks is limited by the positioning seat supporting the sliding seat.

[0014] In one embodiment, the positioning seat includes a sliding sleeve on the second column and a pivot seat fixed to the sliding sleeve, and pivot positions are respectively provided on both sides of the pivot seat. The inner sides of the two second racks can be rotatably connected to the pivot positions on both sides of the pivot seat.

[0015] In one embodiment, a cross bar is fixedly disposed between the pivotal seats of the two second columns of the second frame.

[0016] In one embodiment: the column of the second frame is the second column, and a second support rod is fixed between the slides of the two second columns; the outer sides of the two second storage racks are rotatably connected to the slides of the two first frames respectively, and the inner sides are pivotally connected together; the second storage part of the opened trailer frame is supported on the second support rod and the maximum opening angle of the two second storage racks is limited by supporting on the second support rod.

[0017] In one embodiment: the outer sides of the two second racks are rotatably connected to the slides of the two first vertical racks respectively, the inner sides of the two second racks are pivotally connected together, and at least one second rack has a second extension portion on the inner side, and the second extension portion of one second rack is supported on the other second rack to limit the maximum opening angle of the two adjacent second racks.

[0018] In one embodiment: the outer sides of the two second racks are rotatably connected to the slides of the two first vertical racks, the inner sides of the two second racks are pivotally connected together, and the inner sides of the two second racks have second top abutting surfaces facing each other, and the second top abutting surfaces of the two second racks are pressed against each other to limit the maximum opening angle of the two second racks.

[0019] In one embodiment, the column of the first stand is a first column, and the second rack has a crossbar on the outer side, and the two ends of the crossbar are respectively pivotally connected to the slide seats of the two first columns of the first stand.

[0020] In one embodiment: the column of the first frame is the first column, and the first column is also fixed with a second fixed seat located between the fixed seat and the sliding seat. A clamping fork frame is connected between the fixed seat and the second fixed seat of the two first columns, and the sliding seat of the first column of the opened trailer frame rests under the second fixed seat.

[0021] In one embodiment, the column of the first frame is a first column, and a cross bar located between a fixed seat and a sliding seat is fixed on the two first columns, and the sliding seat of the first column of the opened trailer frame rests under the cross bar.

[0022] In one embodiment, the support frame includes two first frames and one second frame; the N frames are separated or approached along the X direction, and the first storage rack and the second storage rack rotate downward or upward relative to the first frame to open or fold the trailer frame.

[0023] The second technical solution adopted by the present invention to solve its technical problem is: a multi-layer structure trailer, including a body cloth, a handle and the multi-layer structure trailer frame, the first vertical frame is provided with wheels, the handle is connected to a first vertical frame, and the body cloth is connected to the trailer frame.

[0024] In one embodiment, the upper peripheral edge of the vehicle body cloth is connected to the fixing seat and the vehicle body cloth is supported on the second storage portion.

[0025] In one embodiment: the column of the first stand is a first column, a cross bar is fixedly provided at the bottom ends of the two first columns, one end of the handle can be rotatably connected to the cross bar, and the above-mentioned wheels that can be installed and removed are provided under the first column.

[0026] Compared with the background technology, this technical solution has the following advantages:

[0027] 1. Through the scissor mechanism, N vertical frames can be moved away from or close to each other in the X direction to expand and fold the trailer frame; the first storage part includes two first storage frames, the outer sides of which are respectively pivoted to the two first vertical frames, and the inner sides are connected and can rotate; the second storage part includes two second storage frames, the outer sides of which can be rotated relative to the slide seats of the two first vertical frames, and the inner sides are connected and can rotate. Then: firstly, a multi-layer structure can be realized with a simple structure; secondly, a linkage can be formed to facilitate the expansion and folding of the trailer frame; thirdly, the height of the folded trailer frame is low, the occupied space is small, and the packaging, storage and transportation costs are low.

[0028] 2. In the opened trailer frame: the two first storage racks are opened at the maximum angle defined by the first limiting mechanism, and the two second storage racks are opened at the maximum angle defined by the second limiting mechanism, thereby improving the stability of the trailer frame when it is unfolded.

[0029] 3. The inner sides of the two first racks are pivoted together, and the first rack of the opened trailer frame is supported on the support rod and the maximum opening angle of the two first racks is limited by supporting on the support rod, thereby improving the supported stability of the first rack and improving the strength of the second stand. The inner sides of the two second racks are pivoted together, and the second rack of the opened trailer frame is supported on the second support rod and the maximum opening angle of the two second racks is limited by supporting on the second support rod, thereby improving the supported stability of the second rack and improving the strength of the second stand.

[0030] 4. The maximum opening angle of two adjacent first racks is limited by supporting the extended portion of a first rack against another first rack, or the maximum opening angle of two adjacent second racks is limited by supporting the second extended portion of a second rack against another second rack. The structure is simple and the support is stable.

[0031] 5. The maximum opening angle of the two first racks is limited by the top abutting surfaces of the two first racks facing each other, or the maximum opening angle of the two second racks is limited by the second top abutting surfaces of the two second racks facing each other, and the structure is simple.

[0032] 6. A pivot seat is fixedly provided on the first column, a cantilever is provided on the other side of the first storage rack, the cantilever is provided with a pivot, and the pivot is pivotally connected to the pivot seat for easy assembly.

[0033] 7. The outer side of the second storage rack is rotatably connected to the sliding seat of the first vertical frame, and the inner side is connected to the positioning seat. The positioning seat of the opened trailer frame is supported on the sliding seat, and the maximum opening angle of the two second storage racks is limited by the positioning seat supported on the sliding seat. Therefore: first, it is convenient to assemble; second, the positioning seat can be supported by the sliding seat, and the second storage part can be supported by the positioning seat, and the support stability is high; third, the expansion and contraction of the scissor-type mechanism is linked with the expansion and contraction of the second storage part, which improves the linkage reliability and facilitates the expansion and contraction of the trailer frame.

[0034] 8. The positioning seat includes a sliding sleeve and a pivot seat. The two sides of the pivot seat are respectively provided with pivot positions. The inner sides of the two second storage racks can be rotatably connected to the pivot positions on both sides of the pivot seat, which is convenient for assembly.

[0035] 9. A cross bar is fixedly provided between the pivot seats of the two second columns of the second frame to improve the linkage reliability and the strength of the second frame.

[0036] 10. A cross bar is provided on the outer side of the second storage rack, and both ends of the cross bar are respectively pivotally connected to the sliding seats of the two first columns of the first vertical frame, so as to facilitate assembly and improve the strength of the first vertical frame.

[0037] 11. A clamping fork frame is connected between the fixed seat and the second fixed seat of the two first columns, and the sliding seat of the first column of the opened trailer frame rests under the second fixed seat, or, a cross bar located between the fixed seat and the sliding seat is fixed on the two first columns, and the sliding seat of the first column of the opened trailer frame rests under the cross bar, thereby improving the strength of the first frame and improving the stability of the opened trailer frame in the unfolded state. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0039] Figure 1 It is a three-dimensional schematic diagram of a trailer frame in an open state according to a specific implementation method.

[0040] Figure 2 It is one of the three-dimensional schematic diagrams of the trailer frame during the folding process of the specific implementation method.

[0041] Figure 3 This is the second stereoscopic schematic diagram of the trailer frame during the folding process according to the specific implementation method.

[0042] Figure 4 It is a three-dimensional schematic diagram of a trailer frame in a folded state according to a specific implementation method.

[0043] Figure 5 It is a perspective exploded schematic diagram of a trailer frame according to a specific implementation method.

[0044] Figure 6 It is a schematic diagram of the principle of a trailer frame in an open state according to a specific implementation manner.

[0045] Figure 7 It is a schematic diagram of the principle of the trailer frame during the folding process of a specific implementation method.

[0046] Figure 8 It is a perspective schematic diagram of a trailer according to a specific embodiment.

[0047] Fig. 9 It is a partially exploded three-dimensional schematic diagram of a trailer frame according to a specific implementation method.

[0048] Fig.10 It is a three-dimensional schematic diagram of a handle of a trailer frame in a retracted state according to a specific implementation manner.

[0049] Fig.11 It is a three-dimensional schematic diagram of a handle of a trailer frame in a rotating state according to a specific implementation manner.

[0050] Fig.12 It is a three-dimensional schematic diagram of the trailer frame of the second specific embodiment in an open state.

[0051] Fig.13 It is a three-dimensional schematic diagram of the trailer frame of the second specific embodiment during the folding process.

[0052] Fig.14 yes Fig.13 An enlarged schematic diagram of point A.

[0053] Fig.15 It is a three-dimensional schematic diagram of the trailer frame of the third specific embodiment in an open state.

[0054] Fig.16 It is a three-dimensional schematic diagram of the trailer frame of the third specific embodiment during the folding process.

[0055] Description of labels:

[0056] A first stand 1, a first column 11, a fork frame 12, a third cross bar 13, and wheels 14;

[0057] The second stand 2, the second stand 21, the support rod 22;

[0058] The fixed seat 31, the sliding seat 32, the positioning seat 33, the sliding sleeve 331, the second pivot seat 332, the second cross bar 333, the first pivot seat 34, and the second fixed seat 35;

[0059] The first storage part 5, the first storage rack 51, and the cantilever 511;

[0060] The second storage portion 6, the second storage rack 61, and the first cross bar 611;

[0061] Vehicle body cloth 7, handle 8. DETAILED DESCRIPTION

[0062] Please refer to Figures 1 to 7 The multi-layer trailer frame includes a support frame, a first storage portion 5 and a second storage portion 6, and the second storage portion 6 and the first storage portion 5 are arranged up and down.

[0063] The support frame includes two first frames 1 and a second frame 2 located between the two first frames 1. The first frame 1, the second frame 2, and the other first frame 1 are arranged in parallel along the X direction. The first frame 1 includes two first columns 11 fixed at intervals in the Y direction, and the second frame 2 includes two second columns 21 fixed at intervals in the Y direction. In this specific embodiment, three frames are used as an example for explanation (two first frames and one second frame), but it is not limited to this. Multiple second frames can be set as needed (such as two second frames in the second specific embodiment). The tops of the first column 11 and the second column 21 are fixed with a fixed seat 31, and the first column 11 and the second column 21 are slidably provided with a slide seat 32. The fixed seat 31 and the slide seat 32 of the first column 11 are provided with two first pivot positions arranged at right angles, and the fixed seat 31 and the slide seat 32 of the second column 21 are provided with two first pivot positions arranged symmetrically on the left and right. The second column 21 is also slidably provided with a positioning seat 33 located between the fixed seat 31 and the sliding seat 32. The second stand 2 also includes a support rod 22 fixedly connected to the bottom ends of the two second columns 21 and located below the sliding seat 32.

[0064] A scissor mechanism 4 is pivotally connected between the first pivoting position of the fixed seat 31 of the first column 11 and the second column 21 on the same side and the first pivoting position of the slide 32, and the first frame 1 and the second frame 2 can move away from or approach each other along the X direction to open and close the trailer frame, and the positioning seat 33 of the second frame 2 of the trailer frame in the open state (opened trailer frame) is supported on the slide 32 to maintain the open state. The scissor mechanism 4 includes a scissor unit or a plurality of scissor units pivoted together in series (adjacent upper and lower ends are respectively pivoted together), and the scissor unit includes two connecting rods pivoted together in the middle.

[0065] The first storage portion 5 includes two first storage racks 51, the outer sides of the two first storage racks 51 are respectively pivoted to the two first upright frames 1 and the pivoting position is located below the slide seat 32. The first storage portion 5 constitutes a lower storage layer. The inner sides of the two first storage racks 51 are rotatably connected together or connected together through a connecting seat (such as the inner sides of the two first storage racks are respectively connected to the two sides of the connecting seat). The first storage portion 51 of the trailer frame in the opened state is supported on the support rod 22. The first storage portion 5 is supported by the structure in which the inner sides of the two first storage racks 51 are connected together or / and supported on the support rod 22. The first storage racks are supported on the support rod 22 and the two first storage racks are also limited to be at the maximum opening angle. Other structures can also be used as needed. In the specific structure: a first pivot seat 34 is fixedly provided on the bottom of the two first columns 11 of the first stand 1, and the first pivot seat 34 is provided with a second pivot position. Two cantilevers 511 are provided on the other side of the two first storage racks 51, and the cantilever 511 is provided with a pivot, which is pivotally connected to the second pivot position of the first pivot seat 34.

[0066] The second storage portion 6 includes two second storage racks 61, the outer sides of the two second storage racks 61 can be rotatably connected to the slides 32 of the two first upright frames 1, and the inner sides of the two second storage racks 61 can be rotatably connected to the positioning seats 33 of the two second columns 21 of the second upright frame 2. The positioning seats 33 of the second upright frame 2 of the trailer frame in the open state are supported on the slide 32 to maintain the open state, and the second storage portion 6 is supported on the slide 32. The second storage portion 6 constitutes an upper storage layer, and the maximum opening angle of the two second storage racks is limited by the positioning seats 33 supporting the slide 32. In the specific structure: one side of the second storage rack 61 has a first cross bar 611, and the two ends of the first cross bar 611 are respectively pivoted to the sliding seats 32 of the two first columns 11 of the first frame 1; the positioning seat 33 includes a sliding sleeve 331 of the second column 21 and a second pivot seat 332 fixed to the sliding sleeve 331, and third pivot positions are respectively provided on both sides of the second pivot seat 332. A second cantilever is provided on the other side of the second storage rack 61, and the second cantilevers on the other sides of the two second storage racks 61 can be rotatably connected to the third pivot positions on both sides of the second pivot seat 332 to facilitate assembly and improve support strength. A second cross bar 333 is fixed between the second pivot seats 332 of the two second columns 21 of the second frame 2 to improve support strength and to improve the strength of the second frame.

[0067] In this embodiment: a second fixed seat 35 located between the fixed seat 31 and the sliding seat 32 is fixedly provided on the first column 11 of the first frame 1, and a fork clamp 12 is connected between the fixed seat 31 and the second fixed seat 35 of the two first columns 11, and the sliding seat 32 of the first column of the trailer frame in the open state rests against the second fixed seat 35 to enhance the strength of the first frame and improve the stability when it is in the open state.

[0068] Open the trailer frame: the first frame 1 and the second frame 2 move away from each other (pull apart in the length direction), the scissor mechanism 4 opens, the two first racks 51 of the first storage part 5 open (the first rack 51 rotates downward relative to the first frame), and the two second racks 61 of the second storage part 6 open, until the slide seat 32 of the first column 11 slides upward to the second fixed seat 35, the first storage part 5 is supported on the support rod 22, and the positioning seat 33 is supported on the slide seat 32 of the second column 21, so that the trailer frame is in an open state.

[0069] Folding the trailer frame: lift up the middle of the first storage part 5 and the second storage part 6 (the first storage frame 51 rotates upward relative to the first vertical frame), and under the linkage action of the scissor-type mechanisms 4 on both sides, the slide seat 32 slides downward, and the first vertical frame 1 and the second vertical frame 2 approach each other (the trailer frame is folded in the length direction) until the trailer frame is in a folded state.

[0070] In another embodiment: please refer to Figures 8 to 11The multi-layer trailer comprises a body cloth 7, a handle 8 and the above-mentioned trailer frame. The upper edge of the body cloth 7 is connected to the fixed seat 31 and the bottom surface is supported on the second storage part 6. If the body cloth 7 is a container formed by four surrounding surfaces and a bottom surface, the upper part of the surrounding surface (the upper edge) is fixedly connected to the fixed seat 31, and the bottom surface is supported on the second storage part 6. The bottom ends of the two first columns 11 of the first frame 1 are fixedly provided with a third crossbar 13, and the first pivot seat 34 is located on the third crossbar 13. One end of the handle 8 can be rotatably connected to the third crossbar 13, and the handle can be a telescopic structure. The wheels 14 can be detachably connected to the bottom of the first column 11.

[0071] The second specific implementation mode is different from the previous specific implementation mode in that: Figure 12 to Figure 14 The supporting method of the second storage part 6 is different, specifically: the inner sides of the two second storage racks 61 are pivotally connected together, the inner side of one second storage rack 61 has a second extension portion 612, and the other second storage rack 61 is fixedly provided with a limit seat, and the limit seat is provided with an upward supporting groove 613. When the second extension portion 612 is supported in the supporting groove 613 of the other second storage rack 61, the maximum opening angle of the two second storage racks is limited to support the second storage part 6 in an open state.

[0072] The third specific implementation mode is different from the second specific implementation mode in that: Fig.15 , Fig.16 The support frame includes four frames, including two first frames 1 and two second frames 2 located between the first frames 1, a scissor mechanism 4 is connected between the slide seats and fixed seats of adjacent first frames and second frames, and a scissor mechanism 4 is connected between the slide seats and fixed seats of two adjacent second frames.

[0073] The above description is only a preferred embodiment of the present invention, and therefore cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the patent scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. Multi-layer trailer frame, characterized by: include: The support frame comprises N vertical frames arranged along the X direction, N≥3, the vertical frames comprise two vertical columns fixed at intervals in the Y direction, a fixed seat is fixed on the top of the vertical column, a sliding seat is slidably arranged on the vertical column, a scissor mechanism is pivotally connected between the fixed seat and the sliding seat of every two vertical frames adjacent to each other on the same side, and the N vertical frames move away from or approach along the X direction to open or close the trailer frame; among the support frames: the two vertical frames located on the outer side in the X direction are the first vertical frames, and the remaining vertical frames are the second vertical frames; The first storage part includes two first storage racks, the outer sides of the two first storage racks are respectively pivotally connected to the two first vertical racks and the pivoting positions are located below the slide seat, the inner sides are connected and the two first storage racks can at least rotate relative to each other; and The second storage part includes two second storage racks. The outer sides of the two second storage racks can rotate relative to the slide seats of the two first vertical racks respectively, and the inner sides are connected and the two second storage racks can at least rotate relative to each other.

2. The multi-layer trailer frame according to claim 1, characterized in that: A first limiting mechanism is provided between the two first racks, a second limiting mechanism is provided between the two second racks, and the opened trailer frame has: the two first racks pass through the maximum opening angle of the limiting position of the first limiting mechanism, and the two second racks pass through the maximum opening angle of the limiting position of the second limiting mechanism.

3. The multi-layer trailer frame according to claim 1, characterized in that: The column of the second frame is the second column, and the second frame also includes a support rod fixed between the two second columns and located under the slide; the inner sides of the two first storage racks are pivotally connected together, and the first storage part of the opened trailer frame is supported on the support rod and the maximum opening angle of the two first storage racks is limited by supporting on the support rod.

4. The multi-layer trailer frame according to claim 1, characterized in that: The inner sides of the two first racks are pivotally connected together, and at least one first rack has an inner side with an extension portion, and the extension portion of one first rack is supported on another first rack to limit the maximum opening angle of two adjacent first racks.

5. The multi-layer trailer frame according to claim 1, characterized in that: The inner sides of the two first racks are pivotally connected together, and the inner sides of the two first racks have facing abutting surfaces, and the maximum opening angle of the two first racks is limited by the abutting surfaces of the two first racks facing each other.

6. The multi-layer trailer frame according to claim 3, 4 or 5, characterized in that: The column of the first stand is the first column, a pivot seat is fixedly arranged on the first column, two cantilevers are arranged on the outer sides of the two first storage racks, the cantilevers are provided with pivots, and the pivots are pivotally connected to the pivot seat.

7. The multi-layer trailer frame according to claim 1, characterized in that: The column of the second frame is the second column, and the second frame also includes a positioning seat slidably connected to the second column and located between the fixed seat and the sliding seat; the outer sides of the two second racks are respectively rotatably connected to the sliding seats of the two first frames, and the inner sides are connected to the positioning seat, and the positioning seat of the opened trailer frame is supported on the sliding seat, and the maximum opening angle of the two second racks is limited by the positioning seat supporting the sliding seat.

8. The multi-layered trailer frame according to claim 7, characterized in that: The positioning seat includes a sliding sleeve on the second column and a pivot seat fixed to the sliding sleeve. Pivot positions are respectively arranged on both sides of the pivot seat. The inner sides of the two second racks can be rotatably connected to the pivot positions on both sides of the pivot seat.

9. The multi-layered trailer frame according to claim 7, characterized in that: A cross bar is fixedly arranged between the pivot seats of the two second upright posts of the second upright frame.

10. The multi-layer trailer frame according to claim 1, characterized in that: The column of the second frame is the second column, and a second support rod is fixed between the slide seats of the two second columns; the outer sides of the two second storage racks are rotatably connected to the slide seats of the two first frames respectively, and the inner sides are pivotally connected together; the second storage part of the opened trailer frame is supported on the second support rod and the maximum opening angle of the two second storage racks is limited by supporting on the second support rod.

11. The multi-layer trailer frame according to claim 1, characterized in that: The outer sides of the two second racks are rotatably connected to the slide seats of the two first vertical racks respectively, and the inner sides of the two second racks are pivotally connected together. At least one of the second racks has a second extension portion on the inner side, and the second extension portion of one second rack is supported on the other second rack to limit the maximum opening angle of the two adjacent second racks.

12. The multi-layer trailer frame according to claim 1, characterized in that: The outer sides of the two second racks are rotatably connected to the slide seats of the two first vertical racks respectively, and the inner sides of the two second racks are pivotally connected together. The inner sides of the two second racks have second top abutting surfaces facing each other, and the second top abutting surfaces of the two second racks are pressed against each other to limit the maximum opening angle of the two second racks.

13. The multi-layered trailer frame according to any one of claims 7 to 12, characterized in that: The first upright column is a first upright column, and the second storage rack is provided with a cross bar on the outer side, and the two ends of the cross bar are respectively pivotally connected to the slide seats of the two first upright columns of the first upright frame.

14. The multi-layer trailer frame according to claim 1, characterized in that: The column of the first frame is the first column, and the first column is also fixed with a second fixed seat located between the fixed seat and the sliding seat. A clamping fork frame is connected between the fixed seats and the second fixed seats of the two first columns, and the sliding seat of the first column of the opened trailer frame rests under the second fixed seat.

15. The multi-layer trailer frame according to claim 1, characterized in that: The columns of the first frame are first columns, and a cross bar located between a fixed seat and a sliding seat is fixed on the two first columns, and the sliding seat of the first column of the opened trailer frame rests under the cross bar.

16. The multi-layer trailer frame according to claim 1, characterized in that: The support frame includes two first frames and one second frame; the N frames move away from or approach each other along the X direction, and the first storage rack and the second storage rack rotate downward or upward relative to the first frame to open or fold the trailer frame.

17. Multi-layer trailer, characterized by: It comprises a vehicle body cloth, a handle and a multi-layered trailer frame according to claim 1, wherein wheels are arranged under the first vertical frame, the handle is connected to a first vertical frame, and the vehicle body cloth is connected to the trailer frame.

18. The multi-story trailer according to claim 17, characterized in that: The upper peripheral edge of the vehicle body cloth is connected to the fixing seat and the vehicle body cloth is supported on the second storage portion.

19. The multi-story trailer according to claim 17, characterized in that: The column of the first frame is the first column, a cross bar is fixedly arranged at the bottom ends of the two first columns, one end of the handle can be rotatably connected to the cross bar, and the above-mentioned wheels that can be assembled and disassembled are arranged under the first column.

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