CN219821462U - Folding vehicle - Google Patents

Abstract

The utility model relates to the technical field of hand-pulled trolleys and discloses a folding trolley, which comprises four upright posts and wheels, wherein the four upright posts are vertically arranged, the projections of the four upright posts on a horizontal plane are sequentially positioned at four corners of a rectangle, the wheels are arranged at the lower ends of the upright posts, the two upright posts at the head part of the folding trolley and the two upright posts at the tail part of the folding trolley are connected through transverse frames, the two upright posts at the left end of the folding trolley and the two upright posts at the right end of the folding trolley are connected through longitudinal frames, the transverse frames and/or the longitudinal frames are the folding frames, and a first folding rod and a second folding rod at the two ends of the folding frames are pivoted with the upright posts. When the folding vehicle is in an unfolding state, the side face of the folding vehicle can be supported more comprehensively, so that the inner lining can be prevented from protruding outwards, and the folding vehicle is guaranteed to have good trafficability; in addition, the folding bicycle has smaller body shape in the folding state, and can keep the flatness of the top.

Description

Folding vehicle

Technical Field

The utility model relates to the technical field of hand-pulled trolleys, in particular to a folding assembly, a folding frame and a folding trolley.

Background

For portability, small vehicles for outdoor transportation of items are often designed in a collapsible structure that has a small body size in a collapsed state. At present, in the process that some foldable carts on the market are deformed from a storage state to an unfolding state, the problem that four side surfaces or bottom surfaces lack an effective supporting structure for supporting exists, so that the side parts of flexible liners protrude outwards after the carts are loaded with cargoes, and the carts are prevented from smoothly passing through a narrow road section, and the use experience of users is poor. For example, chinese patent application No. CN202120510352.7 discloses a foldable cart, in which the lower end of the frame moves upward integrally in the process of deforming from the storage state to the unfolded state, resulting in a lack of effective support for the lower half of the four sides of the foldable cart, and the loaded cargo easily protrudes the lower parts of the sides of the flexible liner, which not only affects the overall aesthetic appearance of the cart, but also reduces the trafficability of the cart when passing through a small road.

In addition, there are foldable carts that use other structures on the market, but these foldable carts after folding can appear folding the problem that the side lever of car frame and the connecting rod top between the side lever are uneven, and the concrete is high in the middle and low in the outside or high in the middle of the outside, and folding end effect and the convenient degree are not good enough when manual handling. For example, the utility model of EP11169940a is not convenient enough to carry by hand because the height of the outer vertical support bars after folding is higher than the height of the middle side bars connected to the vertical support bars.

Disclosure of Invention

The folding vehicle has smaller body shape in the folding state, can keep the flatness of the top, has better folding effect, and can comprehensively support the side surface of the folding vehicle in the unfolding state.

In order to achieve the above purpose, the present utility model provides the following technical solutions:

according to one aspect of the utility model, a folding assembly is provided, the folding assembly comprises a first folding rod and a second folding rod which are mutually intersected, a sliding sleeve and a stop block are arranged on the first folding rod, a first pivot is fixed on the second folding rod, the sliding sleeve can slide along the length direction of the first folding rod, the sliding sleeve is pivoted with the second folding rod through the first pivot, and the stop block is fixedly connected with the first folding rod.

In some embodiments, the first folding bar is equal in length to the second folding bar, and the stop is approximately the same distance from one end of the first folding bar as the first pivot axis.

Another aspect of the present utility model provides a folding leg comprising at least two folding assemblies as described above, said first folding bars being connected in series, said first folding bars being adjacent to each other being pivotally connected by a second pivot, said second folding bars being connected in series, said second folding bars being adjacent to each other being pivotally connected by a third pivot, said second pivot, said third pivot being in the same plane between two of said folding assemblies being adjacent to each other, said folding assemblies being adjacent to each other being symmetrical about said plane

In some embodiments, the number of folding assemblies is an even number.

The folding frame provided by the utility model can be folded, is convenient to store and has a simpler operation mode. In addition, the height of the folding frame can be kept constant in the folding process, which is beneficial to reducing the installation difficulty.

The utility model further provides a folding bicycle which comprises four upright posts and wheels, wherein the four upright posts are vertically arranged, the projections of the four upright posts on a horizontal plane are sequentially positioned at four corners of a rectangle, the wheels are arranged at the lower ends of the upright posts, the two upright posts at the head part of the folding bicycle and the two upright posts at the tail part of the folding bicycle are connected through transverse frames, the two upright posts at the left end of the folding bicycle and the two upright posts at the right end of the folding bicycle are connected through longitudinal frames, the transverse frames and/or the longitudinal frames are folding frames as described above, and the first folding rods and the second folding rods at the two ends of the folding frames are pivoted with the upright posts.

In some embodiments, the folding cart further comprises a center seat, a projection of the center seat on a horizontal plane is located at a geometric center of the rectangle, a diagonal rod is arranged between the center seat and the upright post, one end of the diagonal rod is pivoted with the center seat, the other end of the diagonal rod is pivoted with the lower end of the upright post, and the center seat can move up and down in a height range of the upright post.

In some embodiments, the longitudinal frame comprises four of the folding assemblies.

In some embodiments, the folding cart further comprises two cross bars, the two cross bars are respectively located at two sides of the center seat, one end of each cross bar is pivoted with the center seat, and the other end of each cross bar is pivoted with the middle lower end of the longitudinal frame.

In some embodiments, the folding cart further comprises a traction assembly coupled to adjacent two of the uprights.

In some embodiments, the traction assembly comprises:

a first pull rod;

the handle is connected with one end of the first pull rod;

the three connecting pieces are arranged on the first pull rod and can slide along the length direction of the first pull rod;

one end of the second pull rod is pivoted with the three connecting pieces through a fourth pivot;

the two second pull rods are pivoted with the second pull rods through fifth pivots, and the fifth pivots are parallel to the fourth pivots;

the two connecting pieces are fixedly connected with the two adjacent upright posts respectively, the adapter piece is pivoted with the connecting pieces through a sixth pivot, and the sixth pivot is perpendicular to the fourth pivot and parallel to the horizontal plane.

Compared with the prior art, the transverse frame and the longitudinal frame on the folding bicycle adopt novel folding frame structures, and when the folding bicycle is in an unfolding state, the folding frame enables the side face of the folding bicycle to be more comprehensively supported, so that the inner lining can be prevented from protruding outwards, and the folding bicycle is guaranteed to have better trafficability; in addition, this folding car has less size when folding state, can keep the planarization at top moreover, has better folding effect.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

It should be understood that the elements shown in the figures are for simplicity and clarity of illustration. In a commercially viable embodiment, there may be some elements that are useful or necessary but are well known in the art in order to reduce obstruction in the view.

Fig. 1 is a front view of a folding assembly of an embodiment of the present utility model.

Fig. 2 is a rear view of a folding assembly of an embodiment of the present utility model.

Fig. 3 is a right side view of a folding assembly of an embodiment of the present utility model.

Fig. 4 is a cross-sectional view taken along line A-A in fig. 3.

Fig. 5 is a schematic view of a folding assembly of an embodiment of the present utility model in single use, the folding assembly being fully unfolded.

Fig. 6 is another schematic view of a folding assembly of an embodiment of the present utility model in a folded condition when the folding assembly is in use alone.

Fig. 7 is a block diagram of a folding leg according to the present utility model, which has two folding assemblies.

Fig. 8 is a block diagram of another folding leg according to the present utility model, which has four folding assemblies.

Fig. 9 is a perspective view of a folding cart in accordance with an embodiment of the utility model.

Fig. 10 is a partially enlarged view at C in fig. 9.

Fig. 11 is a top view of a folding cart in accordance with an embodiment of the utility model.

Fig. 12 is a schematic view of a folding cart in a folded condition in accordance with an embodiment of the utility model.

The reference numerals are explained as follows:

in the figure: 1. a first folding bar; 2. a second folding bar; 3. a sliding sleeve; 4. a stop block; 5. a first pivot; 6. a first object; 7. a second object; 8. a second pivot; 9. a third pivot; 10. a column; 1001. a rod body; 1002. an upper connecting seat; 1003. a lower connecting seat; 11. a wheel; 12. a cross frame; 13. a longitudinal frame; 14. a center seat; 15. a diagonal rod; 16. a cross bar; 17. a first pull rod; 18. a handle; 19. a triple piece; 20. a second pull rod; 21. an adapter; 22. a connecting piece; 23. a fourth pivot; 24. a fifth pivot; 25. and a sixth pivot.

Detailed Description

Various aspects of the utility model are described in further detail below.

Unless defined or otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition, any method and materials similar or equivalent to those described can be used in the method of the present utility model.

The terms are described below.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The article "a" or "an" as used herein may also include plural referents unless the context clearly dictates otherwise. Further, as used in the specification, the terms "comprises" and/or "comprising," and/or "including," are intended to specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. And terms such as "above," "below," "upper" and "lower" are used to indicate relative positional relationships between elements or structures, rather than absolute positions.

Other advantages and effects of the present disclosure will become readily apparent to those skilled in the art from the following disclosure, which describes embodiments of the present disclosure by way of specific examples. It will be apparent that the described embodiments are merely some, but not all embodiments of the present disclosure. The disclosure may be embodied or practiced in other different specific embodiments, and details within the subject specification may be modified or changed from various points of view and applications without departing from the spirit of the disclosure. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict. All other embodiments, which can be made by one of ordinary skill in the art without inventive effort, based on the embodiments in this disclosure are intended to be within the scope of this disclosure.

It is noted that various aspects of the embodiments are described below within the scope of the following claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the present disclosure, one skilled in the art will appreciate that one aspect described herein may be implemented independently of any other aspect, and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method practiced using any number of the aspects set forth herein. In addition, such apparatus may be implemented and/or such methods practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.

It should also be noted that the illustrations provided in the following embodiments merely illustrate the basic concepts of the disclosure by way of illustration, and only the components related to the disclosure are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.

In addition, in the following description, specific details are provided in order to provide a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects may be practiced without these specific details.

Referring to fig. 1 to 4, the present utility model provides a folding assembly, which comprises a first folding rod 1 and a second folding rod 2 which are intersected with each other, wherein a sliding sleeve 3 and a stop block 4 are arranged on the first folding rod 1, a first pivot 5 is fixed on the second folding rod 2, the sliding sleeve 3 can slide along the length direction of the first folding rod 1, the sliding sleeve 3 is pivoted with the second folding rod 2 through the first pivot 5, the sliding sleeve 3 can rotate around the axis of the first pivot 5, the stop block 4 is fixedly connected with the first folding rod 1, and the stop block 4 is used for limiting.

In some embodiments, the first folding bar 1 is equal in length to the second folding bar 2, and the distance between the stop 4 and one end of the first folding bar 1 is approximately equal to the distance between the first pivot 5 and one end of the second folding bar 2.

The folding component can be used singly or in combination of a plurality of folding components.

Fig. 5 and 6 are schematic diagrams of the folding assembly when used singly, the left end of the first folding bar 1 and the left end of the second folding bar 2 are pivoted with the first object 6, the right end of the first folding bar 1 and the right end of the second folding bar 2 are movably connected with the second object 7, and the right end of the first folding bar 1 and the right end of the second folding bar 2 can slide on the second object 7; the folding subassembly is folding in-process, and sliding sleeve 3 slides relative first folding pole 1, and sliding sleeve 3 rotates relative second folding pole 2, and the distance between the left end of first folding pole 1 and the left end of second folding pole 2 is invariable, and the distance between the right-hand member of first folding pole 1 and the right-hand member of second folding pole 2 changes.

As shown in fig. 5, in this figure, the sliding sleeve 3 is in contact with the stopper 4, the stopper 4 prevents the sliding sleeve from continuing to slide toward the right end of the first folding bar 1, and the left end of the first folding bar 1 is aligned with the left end of the second folding bar 2, and the right end of the first folding bar 1 is aligned with the right end of the second folding bar 2. The folding assembly is shown in fig. 5 in a fully unfolded state, with the largest distance between the first object 6 and the second object 7.

As shown in fig. 6, the sliding sleeve 3 is separated from the stop block 4 in this figure, the left end of the first folding rod 1 is aligned with the left end of the second folding rod 2, the right end of the first folding rod 1 is aligned with the right end of the second folding rod 2, and the folding assembly is in a folded state. In fig. 6, the distance between the first object 6 and the second object 7 becomes smaller than in fig. 5.

Referring to fig. 8 and 9, the present utility model also provides a folding leg, which is also an embodiment of a plurality of folding assemblies when used in combination. The folding frame comprises at least two folding assemblies as described above, wherein the first folding bars 1 in the folding frame are sequentially connected, the first folding bars 1 adjacent to each other are pivoted through the second pivot shafts 8, the second folding bars 2 in the folding frame are sequentially connected, the second folding bars 2 adjacent to each other are pivoted through the third pivot shafts 9, the second pivot shafts 8 and the third pivot shafts 9 between the two folding assemblies adjacent to each other are positioned in the same plane B, and the folding assemblies adjacent to each other are symmetrical about the plane B.

The folding leg of fig. 7 comprises two of the aforementioned folding assemblies, the folding leg of fig. 8 comprises four of the aforementioned folding assemblies, and in other embodiments the number of folding assemblies in the folding leg may be three or more. In fig. 7, two first folding bars 1 are V-shaped after being connected, and two second folding bars 2 are inverted V-shaped after being connected. In fig. 8, four first folding bars 1 are connected to form a W shape, and four second folding bars 2 are connected to form an inverted W shape.

In a preferred embodiment, the number of folding assemblies is an even number. When the quantity of folding subassembly is even number, the first folding pole 1 at folding frame both ends, second folding pole 2 all can with stand 10 pin joint, and this kind of connected mode is more simple and convenient, is favorable to reducing the assembly degree of difficulty of folding frame.

The folding frame provided by the utility model can be folded, is convenient to store and has a simpler operation mode. In addition, the height of the folding frame can be kept constant in the folding process, which is beneficial to reducing the installation difficulty.

Referring to fig. 9 to 12, the utility model further provides a folding cart, which comprises four upright posts 10 and wheels 11, wherein the four upright posts 10 are vertically arranged, the projections of the four upright posts 10 on a horizontal plane are sequentially positioned at four corners of a rectangle, the wheels 11 are arranged at the lower ends of the upright posts 10, the two upright posts 10 at the head part of the folding cart and the two upright posts 10 at the tail part of the folding cart are connected through transverse frames 12, the two upright posts 10 at the left end of the folding cart and the two upright posts 10 at the right end of the folding cart are connected through longitudinal frames 13, the transverse frames 12 and/or the longitudinal frames 13 are the folding frames, and the first folding rods 1 and the second folding rods 2 at the two ends of the folding frames are pivoted with the upright posts 10.

In use, the folding cart is fitted with a liner (not shown) for holding articles in the space defined by the cross frame 12 and the vertical frame 13. The inner lining can be made of flexible materials which do not affect the folding of the folding cart, and the folding cart can be folded without dismantling the inner lining. The inner liner can also be made of rigid materials, and the inner liner is required to be detachably connected with the transverse frames 12 and the longitudinal frames 13, so that the folding vehicle can be folded after the inner liner is detached from the folding vehicle.

In a preferred embodiment, the folding cart further includes a center seat 14, a projection of the center seat 14 on a horizontal plane is located at a geometric center of the rectangle, an inclined rod 15 is disposed between the center seat 14 and the upright 10, one end of the inclined rod 15 is pivoted to the center seat 14, the other end of the inclined rod 15 is pivoted to a lower end of the upright 10, and the center seat 14 can move up and down within a height range of the upright 10. Referring to fig. 9 and 11, when the folding wagon is in the unfolded state, the four diagonal rods 15 are all parallel and coplanar with the horizontal plane, with the central seat 14 in the lowest position flush with the lower end of the upright 10. Referring to fig. 12, when the folding cart is in a folded state, the four diagonal rods 15 are all inclined, and the center seat 14 is at the highest position flush with the upper end of the upright 10. The carrying capacity of the folding cart can be improved by providing the diagonal rods 15 at the bottom of the folding cart while preventing the middle of the liner from sagging downward.

In order to facilitate the installation of the transverse frame 12 and the longitudinal frame 13, the upright post 10 comprises a rod body 1001, an upper connecting seat 1002 and a lower connecting seat 1003, the upper connecting seat 1002 and the lower connecting seat 1003 are fixedly connected with the upper end and the lower end of the rod body 1001 respectively, the folding rod is pivoted with the corresponding connecting body, and one end of the inclined rod 15 far away from the center seat 14 is pivoted with the lower connecting seat 1003.

In some embodiments, the longitudinal frame 13 includes four folding assemblies. The folding cart further comprises two cross bars 16, wherein the two cross bars 16 are respectively positioned at two sides of the center seat 14, one end of each cross bar 16 is pivoted with the center seat 14, and the other end of each cross bar 16 is pivoted with the middle lower end of the longitudinal frame 13. Referring to fig. 9, when the folding wagon is in the unfolded state, both diagonal rods 15 are parallel to the horizontal plane and coplanar with the diagonal rods 15. Referring to fig. 12, when the folding cart is in the folded state, both diagonal rods 15 become in the tilted state. The bearing capacity of the folding cart can be further improved by additionally arranging the cross bar 16 at the bottom of the folding cart, and the middle part of the lining is prevented from sinking downwards; in addition, the cross bar 16 can also improve the stability of the longitudinal frames 13 when the folding cart is in the unfolded state, so that the two longitudinal frames 13 are kept parallel.

In some embodiments, the folding cart further comprises a traction assembly connected to two adjacent uprights 10. When a user uses the folding bicycle, the folding bicycle can be pulled to move by pulling the traction assembly, so that the folding bicycle is more convenient to use.

Referring to fig. 9, in some embodiments, the traction assembly includes:

a first pull rod 17;

a handle 18, the handle 18 being connected to the upper end of the first pull rod 17;

a triple 19, the triple 19 is provided on the first pull rod 17 and can slide along the length direction of the first pull rod 17;

one end of the second pull rod 20 is pivoted with the three connecting pieces 19 through a fourth pivot 23, and the two second pull rods 20 are respectively positioned at the left side and the right side of the three connecting pieces 19;

the two connecting pieces 21 are arranged at one ends of the two second pull rods 20 far away from the three connecting pieces 19, the connecting pieces 21 are pivoted with the second pull rods 20 through fifth pivot shafts 24, and the fifth pivot shafts 24 are parallel to fourth pivot shafts 23;

two connecting elements 22 fixedly connected to the two uprights 10 of the tail (i.e. the rear end as shown in fig. 9), respectively, said adaptor 21 being pivoted to the connecting elements 22 by a sixth pivot 25, said sixth pivot 25 being perpendicular to the fourth pivot 23 and parallel to the horizontal plane.

As shown in fig. 9, when the folding cart is in the unfolded state, the first pull rod 17 can be adjusted to the vertical position, and the three connecting pieces 19 are positioned at the lower end of the first pull rod 17, and the first pull rod 17 and the two second pull rods 20 form a Y shape; further, the handle 18, the first link 17, the triple 19, the second link 20 and the rotating member are rotatable together about the sixth pivot 25, thereby putting the first link 17 in an inclined state to facilitate pulling of the folding cart. As shown in fig. 12, when the folding wagon is in the folded state, the triple 19 is located at the upper end of the first tie rod 17, so that the handle 18 and the first tie rod 17 are retracted to the lower position of the upright 10.

The novel folding frame structure is adopted by the transverse frame 12 and the longitudinal frame 13 on the folding bicycle, and when the folding bicycle is in an unfolding state, the folding frame enables the side face of the folding bicycle to be supported more comprehensively, so that the inner lining can be prevented from protruding outwards, and the folding bicycle is guaranteed to have better trafficability. In addition, the folding bicycle has smaller body shape in the folding state, and the upper ends of the transverse frame 12, the longitudinal frame 13 and the upright post 10 are positioned in the same plane, so that the flatness of the top can be kept, and the folding bicycle has better folding effect. The traction assembly used on the folding vehicle is ingenious in structural design, can be folded along with the folding vehicle, is simple and convenient to fold, and can adjust an included angle with the ground, so that the traction assembly is convenient to use.

Examples of embodiments of the utility model herein are intended to provide a general understanding of various embodiments and not a complete description of all elements and features of devices and systems that may use the techniques of the utility model. Many other embodiments will be apparent to, or can be derived from, the teaching herein, such that structural and logical substitutions and changes can be made without departing from the scope of the disclosure. The figures are also representational and are not drawn to scale. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.

The corresponding structures, materials, acts, and equivalents of all means or function plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the various embodiments has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the utility model. The embodiments were chosen and described in order to best explain the principles of the utility model and the practical application, and to enable others of ordinary skill in the art to understand the utility model for various embodiments and with various modifications as are suited to the particular use contemplated.

The purpose of the Abstract is to enable the reader to quickly ascertain the nature of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Furthermore, in the foregoing detailed description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single embodiment. Thus, the claims are hereby incorporated into the specification, with each claim standing on its own as a separate claimed subject matter.

The foregoing is merely illustrative of the present utility model, and the present utility model is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims (3)

1. The folding bicycle comprises four upright posts and wheels, wherein the four upright posts are vertically arranged, projections of the four upright posts on a horizontal plane are sequentially positioned at four corners of a rectangle, the wheels are arranged at the lower ends of the upright posts, the two upright posts at the head part of the folding bicycle and the two upright posts at the tail part of the folding bicycle are connected through transverse frames, and the two upright posts at the left end of the folding bicycle and the two upright posts at the right end of the folding bicycle are connected through longitudinal frames;

the transverse frames and/or the longitudinal frames are folding frames, the folding frames comprise at least two folding assemblies, the number of the folding assemblies is even, and the longitudinal frames comprise four folding assemblies;

the folding assembly comprises a first folding rod and a second folding rod which are mutually intersected, a sliding sleeve and a stop block are arranged on the first folding rod, a first pivot is fixed on the second folding rod, the sliding sleeve can slide along the length direction of the first folding rod, the sliding sleeve is pivoted with the second folding rod through the first pivot, and the stop block is fixedly connected with the first folding rod;

the first folding rods are sequentially connected, the first folding rods adjacent to each other are pivoted through second pivot shafts, the second folding rods adjacent to each other are sequentially connected, the second folding rods adjacent to each other are pivoted through third pivot shafts, the second pivot shafts and the third pivot shafts between the two folding assemblies adjacent to each other are positioned in the same plane, and the folding assemblies adjacent to each other are symmetrical about the plane;

the first folding rod and the second folding rod at the two ends of the folding frame are pivoted with the upright post; the method is characterized in that:

the projection of the central seat on the horizontal plane is positioned at the geometric center of the rectangle, a diagonal rod is arranged between the central seat and the upright post, one end of the diagonal rod is pivoted with the central seat, the other end of the diagonal rod is pivoted with the lower end of the upright post, and the central seat can move up and down in the height range of the upright post;

the two cross bars are respectively positioned at two sides of the center seat, one end of each cross bar is pivoted with the center seat, and the other end of each cross bar is pivoted with the middle lower end of the longitudinal frame.

2. The folding cart of claim 1, wherein: the traction assembly is connected with two adjacent upright posts.

3. The folding cart of claim 2 wherein said traction assembly comprises:

a first pull rod;

the handle is connected with one end of the first pull rod;

the three connecting pieces are arranged on the first pull rod and can slide along the length direction of the first pull rod;

one end of the second pull rod is pivoted with the three connecting pieces through a fourth pivot;

the two second pull rods are pivoted with the second pull rods through fifth pivots, and the fifth pivots are parallel to the fourth pivots;

the two connecting pieces are fixedly connected with the two adjacent upright posts respectively, the adapter piece is pivoted with the connecting pieces through a sixth pivot, and the sixth pivot is perpendicular to the fourth pivot and parallel to the horizontal plane.