Folding and riding structure of folding trailer steering system

Abstract

This application discloses a folding and riding structure for a folding trailer steering system. The structure further includes a foldable chassis with a connecting device fixedly connected to one lower end, the connecting device including a chassis support seat, and directional wheels connected to the bottom of the chassis. The directional wheels are connected to a steering structure via a wheel directional swing arm, and the steering structure is foldable, and a directional rod assembly is further connected to the steering structure for controlling the movement of the steering structure. With the above design, a steering structure consisting of multiple steering arms is provided between the two directional wheels. The steering structure controls the steering of the directional wheels and can be switched between an unfolded state and a folded state to suit the folding of the foldable chassis, which is simple to control, convenient, and practical. Furthermore, by adopting this structure, the directional wheels can be changed to straight fork universal wheels, improving vehicle running stability and safety in use.

Description

[Technical Field]

[0001] The present invention relates to the trailer technology field, and more particularly to the folding and riding structure of a folding trailer steering system. [Background technology]

[0002] A folding trailer is a foldable, towable cargo carrier that is easy to use, can transport cargo, is convenient to store, and saves time and effort, so it is widely used in cargo transportation and is currently commonly used for outdoor activities and short-distance transportation.

[0003] Currently, conventional trailers, whether foldable or not, typically employ diagonal fork universal wheels to facilitate steering. Due to their structural design (the wheel axle and the rotating axis are not aligned vertically), diagonal fork universal wheels are more convenient and labor-saving to steer than conventional straight fork universal wheels (where the wheel axle and the rotating axis are aligned vertically), and they rotate according to the direction of force transmission. However, because they steer freely, they are more difficult to control than straight fork universal wheels. Diagonal fork universal wheels tend to rotate downward due to downward forces, especially when under load or on an uphill slope. The only way to prevent the trailer from deviating is to manually pull it in the opposite direction, which is inconvenient. Furthermore, trailers are typically used outdoors, and due to the free-moving characteristics of the diagonal fork universal wheels, they may steer spontaneously when pressed on uneven surfaces. At this time, increasing the forward force can steer the diagonal fork universal wheel in the correct direction, but because the diagonal fork universal wheel is tilted diagonally due to the pressure and there is also resistance due to the unevenness of the road surface, the applied force at this time becomes greater than the various resistances, which can significantly reduce the trailer's usability, especially when the load is heavy.

[0004] Therefore, there is a need to design a folding and riding structure for a folding trailer steering system to overcome one or more of the deficiencies of the prior art discussed above. Summary of the Invention [Means for solving the problem]

[0005] The technical solution adopted by the present invention to solve the above technical problems is as follows: A folding and riding structure of a folding trailer steering system further includes a foldable chassis, a directional wheel is connected to the bottom of the foldable chassis, the directional wheel is connected to a steering structure via a wheel directional swing arm, the steering structure is foldable, and a directional rod assembly is further connected to the steering structure for controlling the movement of the steering structure.

[0006] In one preferred embodiment, a connection device is provided on one side of the foldable frame, the connection device including a frame support seat, the directional wheel is connected to the frame support seat, and the end of the directional rod assembly is connected to the frame support seat.

[0007] In one preferred embodiment, the steering structure includes a directional guide rod and a steering arm, and a plurality of the steering arms are provided, and the plurality of steering arms are rotatably connected to each other, and the steering arms located at both ends are rotatably connected to the corresponding wheel direction swing arms, and one end of the directional guide rod is movably connected to the steering arm located in the middle, and the other end of the directional guide rod is connected to the directional rod assembly.

[0008] In one preferred embodiment, the pitch of the two wheel directional swing arms at the same end is smaller or larger than the pitch between the two wheel directional horizontal rotation axes at the same end.

[0009] In one preferred embodiment, the directional rod assembly includes a directional rod support arm and a directional rod, at least two directional rod support arms are provided, the directional rod is located between the two directional rod support arms and its bottom is rotatably connected to the directional rod support arms, the end of the directional rod support arm close to the directional rod is rotatably connected to the directional rod via a steering bearing, and the end of the directional rod support arm away from the directional rod is rotatably connected to the foldable frame.

[0010] In one preferred embodiment, the upper end of the foldable frame is connected to a seat plate through a seat plate support frame, and the seat plate is detachably mounted on the foldable frame.

[0011] In one preferred embodiment, the directional rod is connected to the steering bearing, and the directional rod is further provided with a folding structure for bending the directional rod in a predetermined direction, and a pull rod switching sleeve is slidably provided on the directional rod for limiting the folding of the directional rod.

[0012] In one preferred embodiment, a pedal is further rotatably connected to the end of the foldable frame where the directional rod assembly is provided.

[0013] In one preferred embodiment, both ends of the steering arm located in the middle are provided so as to be horizontally rotatable around a center.

[0014] In one preferred embodiment, the end of the foldable chassis connected to the directional wheel is provided with a limiting structure for limiting the maximum rotation angle of the directional wheel.

[0015] In one preferred embodiment, each of the two directional wheels connected to the steering structure is provided with a wheel rotation limiting structure that engages with each other and limits the rotation of the directional wheels after the foldable chassis is folded.

[0016] In one preferred embodiment, the wheel restraint structure includes a pin sleeve and a pin, the pin sleeve being provided on one of the direction wheels and the pin being provided on the other direction wheel, and the pin sleeve facing the pin.

[0017] In one preferred embodiment, one end of the pin sleeve is flared. [Effects of the Invention]

[0018] The beneficial effects of the present invention are as follows: a steering structure consisting of multiple steering arms is provided between the two directional wheels, and the steering structure controls the steering of the directional wheels and can switch between an unfolded state and a folded state to suit the folding of the foldable chassis, which is simple to control, convenient, and practical; and by adopting this structure, the directional wheels can be changed into straight fork universal wheels, which improves the running stability of the vehicle, has high usage safety, is easier to steer, has a reasonable design, a simple structure, and low cost. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is a structural diagram of the present invention. [Figure 2] 1 is a structural diagram of a steering structure and a directional rod assembly according to the present invention; [Figure 3] FIG. 3 is a schematic diagram of the folded state of FIG. 2. [Figure 4] FIG. 3 is a schematic diagram of the steering state of FIG. 2. [Figure 5] 1 is a schematic diagram of the bending of the directional rod of the present invention; [Figure 6] FIG. 2 is a schematic diagram of Ackermann steering according to the present invention. [Figure 7] 1 is a cross-sectional view of a wheel rotation limiting structure according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0020] In order to make the above-mentioned objects, features, and advantages of the present invention more clearly comprehensible, specific embodiments of the present invention will be described in detail below in conjunction with the drawings. In the following description, many specific details will be described in order to fully understand the present invention. However, the present invention is not limited to the specific embodiments disclosed below, because the present invention can be embodied in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the scope of the present invention.

[0021] In describing the embodiments of the present invention, it should be understood that the terms "connect" and "attach" should be interpreted broadly unless otherwise clearly specified or limited. For example, "connect" may be a detachable connection, a non-detachable connection, a direct connection, or an indirect connection via an intermediate medium. Furthermore, "communication" may be a direct connection or an indirect connection via an intermediate medium. Here, "fixed" refers to a connection such that the relative positional relationship between the two components remains unchanged after the connection. Directional terms used in the embodiments of the present invention, such as "inner," "outer," "top," and "bottom," merely refer to the directions in the drawings. Therefore, the directional terms used are intended to better and more clearly describe and understand the embodiments of the present invention, and do not suggest or imply that the indicated devices or elements require a specific direction, a specific orientation, or operation, and therefore should not be interpreted as a limitation on the embodiments of the present invention.

[0022] In the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying the relative importance or number of technical features being indicated. Thus, a feature qualified by "first" or "second" may explicitly or implicitly include one or more of that feature.

[0023] In the embodiments of this utility model, "and / or" is used to simply describe the relationship between related objects and indicates that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the text generally indicates that the related objects before and after it are in an "or" relationship.

[0024] In this specification, a description with reference to "one embodiment" or "some embodiments" means that one or more embodiments of the present invention include the particular feature, structure, or characteristic described in connection with that embodiment. Thus, the appearance of phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in still other embodiments" in various places in this specification does not necessarily refer to the same embodiment, but rather means "one or more, but not all, embodiments." Unless otherwise specifically emphasized, the terms "including," "including," "comprises," "comprises," and variations thereof mean "including, but not limited to." Therefore, the present specification is not limited by the specific embodiments disclosed below.

[0025] As shown in Figures 1 to 5, the present invention provides a folding and riding structure for a folding trailer steering system, which further includes a foldable frame 10 with directional wheels 12 connected to the bottom, the directional wheels 12 being connected to a steering structure 14 via a wheel directional swing arm 121, the steering structure 14 being foldable, and a directional rod assembly 13 being further connected to the steering structure 14 for controlling the movement of the steering structure 14.

[0026] Specifically, the foldable vehicle frame 10 is a convergent body, which protrudes upward in the middle and is folded and converged toward the center from four directions, i.e., front, rear, left and right, and the convergent body occupies less space after being folded than other types of foldable vehicle frames 10. The foldable frame 10 is provided with four connecting devices 11 surrounded by a rectangle, each connecting device 11 including a frame support seat 111 for connection to the frame, each with a directional wheel 12 below the frame support seat 111, a wheel directional swing arm 121 at one end at the top of the directional wheel 12, a steering structure 14 for controlling the rotation of the directional wheel 12 connected between the two wheel directional swing arms 121, a directional rod assembly 13 further connected to the steering structure 14, which can rotate horizontally relative to the foldable frame 10 and is used to control the movement of the steering structure 14, during rotation movement, it swings the steering structure 14 left and right, and the steering structure 14 rotates the directional wheel 12 left and right, thereby controlling the rotation of the directional wheel 12.

[0027] However, since the directional wheels 12 are connected via the steering structure 14 and are driven to rotate by the steering structure 14, they may also be straight fork universal wheels, which are more stable during driving than diagonal fork universal wheels and cannot rotate freely but can only rotate when subjected to a force in a specific direction, thereby improving safety in use and also making steering of straight fork universal wheels easier under heavy loads. The front directional wheels 12 can rotate horizontally, while the rear directional wheels 12 are fixed and cannot rotate horizontally.

[0028] Furthermore, the steering structure 14 includes a directional guide rod 141 and a steering arm 142, and a plurality of the steering arms 142 are provided, and the plurality of steering arms 142 are connected to each other so as to be rotatable in sequence, and one end of the directional guide rod 141 is movably connected to the steering arm 142 located in the middle, and the other end of the directional guide rod 141 is connected to the directional rod assembly 13, Specifically, the steering structure 14 includes a directional guide rod 141 and a plurality of steering arms 142, which are rotatably connected to each other and can rotate and fold with respect to each other, suitable for folding the foldable chassis 10. One end of the directional guide rod 141 is rotatably connected to the steering arm 142 located in the middle, and the other end of the directional guide rod 141 is fixedly connected to the directional rod assembly 13. When the directional rod assembly 13 rotates, it swings the directional guide rod 141, which swings to move the steering arm 142 left and right, thereby rotating the directional wheel 12 connected to the steering arm 142 left and right, thereby realizing steering control. There are preferably five steering arms 142, with the two steering arms 142 at both ends having the same length, and the two steering arms 142 connected to both ends having the same length, thereby forming a shape similar to the letter "π" when folded.

[0029] However, the rotation center of the direction guide rod 141 and the rotation center of the direction wheel 12 are located on the same straight line. This structure eliminates the need to provide a chute on the direction guide rod 141. Otherwise, the movement trajectory of the direction guide rod 141 is arc-shaped and the steering arm 142 moves linearly, so a chute needs to be provided on the direction guide rod 141 to prevent it from becoming unable to rotate due to a collision of the movements.

[0030] Furthermore, the pitch of the two wheel direction swing arms 121 at the same end is smaller or larger than the pitch between the horizontal rotation axes of the two direction wheels 12 at the same end.

[0031] Specifically, as shown in Figure 6, in order to prevent tire wear caused by the two directional wheels 12 having the same angle when turning, the connection points between the leftmost steering arm 142 and the rightmost steering arm 142 and the corresponding wheel direction swing arm 121 are located on a straight line from the horizontal rotation axis center of the front two directional wheels 12 to the center of the spacing between the rear two directional wheels 12. As a result, when the front two directional wheels 12 turn, the extension line of the vertical rotation axis of the directional wheels 12 and the extension line of the vertical rotation axis of the rear end directional wheel 12 intersect at one point, thereby realizing the Ackermann steering principle and reducing tire wear when turning.

[0032] However, in the structure shown in Figure 6, the pitch of the two wheel direction swing arms 121 is smaller than the pitch between the two directional wheel horizontal rotation axes at the same end. In this configuration, 100% Ackermann steering effect can be achieved, and the most ideal effect can be obtained. Even if the pitch of the two wheel direction swing arms 121 is larger than the pitch between the two directional wheel horizontal rotation axes at the same end, the Ackermann steering effect can be similarly achieved, but in this configuration, the most ideal effect cannot be obtained.

[0033] Further, the directional rod assembly 13 includes a directional rod support arm 131 and a directional rod 132, at least two directional rod support arms 131 are provided, the directional rod 132 is located between the two directional rod support arms 131, and its bottom is rotatably connected to the directional rod support arm 131, the end of the directional rod support arm 131 close to the directional rod 132 is rotatably connected to the directional rod 132 via a steering bearing 133, and the end of the directional rod support arm 131 away from the directional rod 132 is rotatably connected to the foldable frame 10.

[0034] Specifically, the directional rod assembly 13 includes two directional rod support arms 131, one end of which is rotatably connected to the frame support seat 111 and is rotatable in the longitudinal direction relative to the frame support seat 111, and the two directional rod support arms 131 are arranged opposite each other. The directional rod 132 is arranged between the two directional rod support arms 131 and is connected to the directional rod support arm 131 via a steering bearing 133, thereby allowing the directional rod support arm 131 to rotate relative to the directional rod 132. When the foldable chassis 10 needs to be folded, the directional rod 132 is first pulled to change the directional rod support arms 131 from horizontal to inclined at a certain angle. At this time, when the foldable chassis 10 is folded and the foldable chassis 10 is converged, the pitch on both sides narrows, pressing the directional rod support arms 131. The directional rod support arms 131 are lifted under pressure, changing from inclined to vertical, and simultaneously lifting the directional rod 132. The lifting of the directional rod 132 synchronously raises the steering structure 14 via the directional guide rod 141, completing the folding of the foldable chassis 10. When the foldable chassis 10 is in the unfolded state, the two directional rod support arms 131 are pulled by the foldable chassis 10 to maintain a horizontal state, preventing the directional rod 132 from moving up and down during use.

[0035] However, a horizontally extending boss (not shown) is provided on each bottom side of the end of the two directional rod support arms 131 that is farther from the directional rod 132. When the two directional rod support arms 131 are in a horizontal position, this boss comes into contact with the connecting seat of the foldable vehicle frame 10 and abuts against the connecting seat, preventing the directional rod support arms 131 from sinking and also sharing the force acting on the connecting portion between the directional rod support arms 131 and the steering bearing 133.

[0036] Furthermore, in this embodiment, the upper end of the foldable vehicle frame 10 is connected to a seat plate 15 via a seat plate support frame 151, and the seat plate 15 is detachably installed on the foldable vehicle frame 10. Specifically, the seat plate 15 is detachably installed on the foldable vehicle frame 10, and can be removed when the seat plate 15 is not needed, to prevent it from affecting the loading of luggage or the folding of the foldable vehicle frame 10.

[0037] Furthermore, the directional rod 132 is connected to the steering bearing 133, and the directional rod 132 is further provided with a folding structure for bending the directional rod 132 in a predetermined direction, and a pull rod switching sleeve 134 for limiting the folding of the directional rod 132 is slidably provided on the directional rod 132.

[0038] Specifically, the directional rod 132 is inserted into the steering bearing 133 and is horizontally rotatable relative to the steering bearing 133, swinging the directional guide rod 141 left and right. A folding structure is provided on the portion of the directional rod 132 above the steering bearing 133. This folding structure allows the directional rod 132 to rotate vertically relative to the steering bearing 133, forming an inclined shape and making it easy to pull. A pull rod switching sleeve 134 is further fitted onto the directional rod 132 to limit the rotation of the directional rod 132 in the vertical direction. When the pull rod switching sleeve 134 covers the folding structure, the directional rod 132 is restricted by the pull rod switching sleeve 134 and cannot rotate vertically via the folding structure. When it is necessary to rotate the directional rod 132 vertically, the pull rod switching sleeve 134 can be moved out of the range of the folding structure.

[0039] However, the connection point between the steering bearing 133 and the directional rod support arm 131 is at the bottom, and this configuration can to some extent limit the steering bearing 133 from tilting when the two directional rod support arms 131 are folded, causing the directional rod 132 to tilt.

[0040] Furthermore, in this embodiment, a pedal 16 is further rotatably connected to the end of the foldable frame 10 where the directional rod assembly 13 is provided, Specifically, in order to improve the riding comfort of the user, the frame support seat 111 is provided with a limiting engagement groove 112, within which the pedal 16 is rotatably connected, and the pedal 16 can be folded to a horizontal position when in use, thereby making it convenient for the user to place their feet on the pedal 16 when riding. When not in use, the pedal 16 is rotatably folded into the foldable frame 10, and two pedals 1 are provided, one on each side.

[0041] Furthermore, in this embodiment, both ends of the steering arm 142 located in the middle are provided so as to be horizontally rotatable around the center.

[0042] Specifically, the steering arm 142 located in the center is arranged so that both ends can rotate horizontally along the center, preventing a situation in which the directional rod 132 cannot rotate smoothly due to a collision of motion while rotating. Furthermore, this structure can reliably prevent a situation in which, under the Ackermann steering principle, when the two directional wheels 12 turn, the steering angles of the directional wheels 12 are different, causing interference between the steering arm 142 and the directional guide rod 141, preventing the Ackermann steering effect from being exerted normally.

[0043] Furthermore, the end of the foldable frame 10 connected to the directional wheel 12 is provided with a limiting structure for limiting the maximum rotation angle of the directional wheel 12 .

[0044] Specifically, in order to prevent the two directional wheels 12 from being driven by the steering arm 142 and rotating to the maximum angle, and then being unable to return smoothly, a limiting structure (not shown) is further provided on the bottom surface of the frame support seat 111 or the directional wheels 12, and this limiting structure is used in cooperation with the steering arm 142 or the wheel directional swing arm 121 to limit further rotation of the directional wheels 12 after they have rotated to a certain angle, thereby preventing the directional wheels 12 from being unable to return due to a rotation angle that is too large.

[0045] Furthermore, in this embodiment, each of the two directional wheels 12 connected to the steering structure 14 is provided with a wheel rotation limiting structure 17 that engages with each other and limits the rotation of the directional wheels 12 after the foldable chassis 10 is folded.

[0046] Specifically, after the folding vehicle body 10 is folded, the directional wheels 12 are not restricted and will rotate when movement occurs. At this time, the steering structure 14 restricts excessive rotation of the directional wheels 12 to some extent, but cannot completely restrict it. When the directional wheels 12 rotate, they cause the steering structure 14 to move, and this movement occurs after folding, which is likely to damage the steering structure 14. To prevent this, as shown in FIG. 7 , each of the two directional wheels 12 connected to the steering structure 14 is provided with a wheel rotation restricting structure 17 that engages with each other. This wheel rotation restricting structure 17 engages when the two directional wheels 12 approach each other, restricting the free rotation of the directional wheels 12 after folding, thereby protecting the steering structure 14 from damage.

[0047] Furthermore, the wheel restraint structure 17 includes a pin sleeve 171 and a pin 172, the pin sleeve 171 being provided on one of the directional wheels 12, the pin 172 being provided on the other directional wheel 12, and the pin sleeve 171 facing the pin 172.

[0048] Specifically, the pin sleeve 171 is fixed to one of the directional wheels 12 or is arranged so that its rotation is limited, and the pin 172 is fixed to the other directional wheel 12 or is arranged so that its rotation is limited. After the two directional wheels 12 are brought close to each other, the pin 172 is inserted into the pin sleeve 171, thereby restricting the rotation of the two directional wheels 12 through the cooperation of the pin sleeve 171 and the pin 172. The folded body is tied with a strap, and the pin sleeve 171 and the pin 172 on the directional wheels are tightly inserted and secured by the strap, thereby preventing separation. The cooperation of the pin sleeve 171 and the pin 172 can also achieve the purpose of towing, improving convenience.

[0049] Furthermore, one end of the pin sleeve 171 is horn-shaped.

[0050] Specifically, the end of the pin sleeve 171 facing the pin 172 is horn-shaped to improve the smoothness of engagement between the pin sleeve 171 and the pin 172. The horn design improves the ease of inserting the pin 172 into the pin sleeve 171.

[0051] As described above, in the present invention, a steering structure 14 consisting of a plurality of steering arms 142 is provided between the two directional wheels 12. The steering structure 14 controls the steering of the directional wheels 12 and can switch between an unfolded state and a folded state to suit the folding of the foldable chassis 10. The control is simple, convenient and practical. Furthermore, by adopting this structure, the directional wheels 12 can be changed into straight fork universal wheels, which improves the stability of vehicle driving, has high usage safety, is easier to steer, has a reasonable design, a simple structure and low cost.

[0052] The invention is not limited to what has been described in the specification and examples, and since additional advantages and modifications may readily occur to those skilled in the art, it is not intended to be limited to the specific details, representative apparatus, and illustrated examples described herein without departing from the spirit and scope of the general concept as defined in the appended claims and equivalents. [Explanation of symbols]

[0053] 10. Foldable car frame 11. Connection device 111, Car frame support seat 112, limit engagement groove 12. Directional wheel 121. Wheel direction swing arm 13. Directional rod assembly 131, directional rod support arm 132 - Directional rod 133. Steering bearing 134, pull rod switching sleeve 14. Steering structure 141, directional guide rod 142. Steering arm 15. Seat board 151, seat support frame 16. Pedals 17. Wheel rotation limiting structure 171. Pin sleeve 172, pin.

Claims

1. A folding and riding structure of a folding trailer steering system, comprising: The folding and riding structure of the foldable trailer steering system further includes a foldable frame which is a convergent frame, wherein a directional wheel is connected to the bottom of the foldable frame, and the directional wheel is connected to a steering structure via a wheel directional swing arm, and the steering structure is foldably provided, and a directional rod assembly is further connected to the steering structure for controlling the movement of the steering structure.

2. 2. The folding and riding structure of the folding trailer steering system according to claim 1, wherein a connecting device is provided on one side of the foldable frame, the connecting device including a frame support seat, the directional wheel is connected to the frame support seat, and an end of the directional rod assembly is connected to the frame support seat.

3. 2. The folding and riding structure of a folding trailer steering system according to claim 1, wherein the steering structure includes a directional guide rod and a steering arm, a plurality of the steering arms are provided, the plurality of steering arms are rotatably connected to each other, the steering arms located at both ends are rotatably connected to the corresponding wheel directional swing arms, one end of the directional guide rod is movably connected to the steering arm located in the middle, and the other end of the directional guide rod is connected to the directional rod assembly.

4. The folding and riding structure of the folding trailer steering system according to claim 3, characterized in that the pitch of the two wheel direction swing arms at the same end is smaller or larger than the pitch between the two directional wheel horizontal rotation axes at the same end.

5. 4. The folding and riding structure of the folding trailer steering system according to claim 3, wherein the directional rod assembly includes a directional rod support arm and a directional rod, at least two directional rod support arms are provided, the directional rod is located between the two directional rod support arms and its bottom is rotatably connected to the directional rod support arms, the end of the directional rod support arm close to the directional rod is rotatably connected to the directional rod via a steering bearing, and the end of the directional rod support arm remote from the directional rod is rotatably connected to the foldable vehicle frame.

6. 2. The folding and riding structure of the folding trailer steering system according to claim 1, wherein the upper end of the foldable frame is connected to a seat plate through a seat plate support frame, and the seat plate is detachably mounted on the foldable frame.

7. 6. The folding and riding structure of a folding trailer steering system according to claim 5, wherein the directional rod is connected to the steering bearing, the directional rod is further provided with a folding structure for bending the directional rod in a predetermined direction, and the directional rod is slidably provided with a pull rod switching sleeve for limiting the folding of the directional rod.

8. 2. The folding and riding structure of the folding trailer steering system according to claim 1, wherein a pedal is further rotatably connected to the end of the foldable frame where the directional rod assembly is provided.

9. 4. The folding and riding structure of the folding trailer steering system according to claim 3, wherein both ends of the steering arm located in the middle are provided so as to be horizontally rotatable around a center.

10. The folding and riding structure of the folding trailer steering system according to claim 1, characterized in that the end of the foldable frame connected to the directional wheel is provided with a limiting structure for limiting the maximum rotation angle of the directional wheel.

11. Each of the two directional wheels connected to the steering structure has:

2. The folding and riding structure of the folding trailer steering system according to claim 1, wherein a wheel rotation limiting structure is provided to limit the rotation of the directional wheels after the foldable frame is folded, the wheel rotation limiting structure being engaged with each other.

12. The wheel restraint structure includes a pin sleeve and a pin, 12. The folding and riding structure of a folding trailer steering system according to claim 11, wherein the pin sleeve is provided on one of the directional wheels, the pin is provided on the other directional wheel, and the pin sleeve faces the pin.

13. 13. The folding and riding structure of a folding trailer steering system according to claim 12, wherein one end of the pin sleeve is horn-shaped.

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