Limiting structure and electric cart
By introducing a limit structure into the trolley pull rod assembly, the movable and static frictional force buffering and locking the pull rod assembly is solved, and the safety and reliability are improved.
Patent Information
- Application Number
- CN202421810082.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-29
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-07-29
AI Technical Summary
The friction resistance between the existing trolley pull rod assembly and the trolley frame is insufficient, resulting in greater inertia and impact force during rotation, which is easy to hit the operator and damage the components.
A limiting structure is designed, including a first limiting bracket and a tie rod assembly, which restricts the rotation of the tie rod assembly to a predetermined angle through the first mating surface, and uses the first and second mating surfaces to generate dynamic friction resistance and static friction forces, respectively, to buffer and lock the tie rod assembly to prevent it from falling with greater inertia and impact force.
It effectively reduces the impact force of the pull rod assembly when it falls, avoids damage to components, and improves the safety and reliability of the trolley.
Smart Images
Figure CN223072558U_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of electric carts, and particularly to a limiting structure and an electric cart. Background Art
[0002] In a handcart, it is usually necessary to push or pull the handcart to move through a pull rod assembly. To facilitate pushing and pulling the handcart, the connection between the pull rod assembly and the bottom of the handcart frame is usually designed as a rotatable structure. Currently, one end of the pull rod assembly of the handcart is rotatably connected to the bottom of the handcart frame through a pin shaft. The frictional resistance between the pull rod assembly and the rotating shaft is limited, resulting in a small resistance during the rotation of the pull rod assembly. When the other end of the pull rod assembly rotates and falls to the ground, the inertia and impact force are relatively large, which is likely to hit the operator, posing a safety hazard, and is also likely to cause damage to the push-pull rod and the components installed on the push-pull rod. Summary of the Utility Model
[0003] The present disclosure provides a limiting structure and an electric cart to at least solve the above problems in the prior art.
[0004] To achieve the above object, the present disclosure provides the following technical solution: A limiting structure, comprising:
[0005] A pull rod assembly, the pull rod assembly includes a first pull rod base provided at the bottom end, and the pull rod assembly is used to push or pull the handcart;
[0006] A first limiting bracket, the first limiting bracket is configured with a first axis and a first mating surface, and the first pull rod base is rotatably connected to the first limiting bracket with the first axis as the axis and along the first mating surface, and the first mating surface is used to lock the pull rod assembly rotated to a predetermined angle.
[0007] In an implementable embodiment, the first mating surface includes a first free surface, a first pre-tightening surface, and a first locking surface, and the first free surface, the first pre-tightening surface, and the first locking surface are circumferentially continuously arranged on the first limiting bracket with the first axis as the axis;
[0008] When the first pull rod base rotates to the first free surface, it rotates freely between the first pull rod base and the first free surface. When the first pull rod base rotates to the first pre-tightening surface, it rotates with damping between the first pull rod base and the first pre-tightening surface. When the first pull rod base rotates to the first locking surface, the first locking surface locks the first pull rod base.
[0009] In an implementable embodiment, the first free surface is an arc surface, the arc radius corresponding to the first free surface is not greater than the rotation radius of the outermost end of the first pull rod base, and the radian range corresponding to the first free surface is 5° - 15°.
[0010] In an implementable embodiment, the first pre-tightening surface is continuously disposed between the first free surface and the first locking surface, and the distance between the first pre-tightening surface and the first axis gradually increases in the direction from the end connected to the first free surface to the end connected to the first locking surface, and the angular range corresponding to the first pre-tightening surface is 10°-20°.
[0011] In an implementable embodiment, the pull rod assembly further includes:
[0012] A pull rod main body;
[0013] A first folding rod, which is disposed obliquely along the first axis on one side of the pull rod main body, one end of the first folding rod is rotatably connected to the pull rod main body, and the other end of the first folding rod is rotatably connected to the first pull rod base around a second axis;
[0014] A second folding rod, which is disposed obliquely along the first axis on the other side of the pull rod main body, and one end of the second folding rod is rotatably connected to the pull rod main body around a third axis;
[0015] A second pull rod base, the other end of the second folding rod is rotatably connected to the second pull rod base; wherein, the second axis is disposed on the first pull rod base, the third axis is disposed on the second pull rod base, and the second axis is perpendicular to the first axis and parallel to the third axis.
[0016] In an implementable embodiment, the limiting structure further includes a second limiting bracket, and the second limiting bracket has the same structure as the first limiting bracket.
[0017] The present disclosure provides the following technical solution: an electric trolley, including the above-mentioned limiting structure, and the trolley is an electric trolley.
[0018] In the above-mentioned limiting structure, when the pull rod main body freely falls, it drives the first pull rod base to rotate around the first axis and along the first mating surface. When the pull rod assembly rotates to a predetermined angle, the first mating surface defines and locks the pull rod assembly to prevent the pull rod assembly from continuing to rotate, and avoids the pull rod assembly from falling to the ground with a large inertia and impact force, thereby avoiding damage to the pull rod assembly and the components installed on the pull rod assembly and improving the safety of the push-pull cart.
[0019] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present disclosure will become readily understood. In the drawings, several embodiments of the present disclosure are shown in an exemplary but not restrictive manner, where:
[0021] In the drawings, the same or corresponding reference numerals denote the same or corresponding parts.
[0022] Figure 1 A schematic structural diagram of the limiting structure in an embodiment of the present disclosure is shown;
[0023] Figure 2 Shows Figure 1 An enlarged view of the partial area A in
[0024] Figure 3 Shows Figure 1 A front view of the first limiting bracket in
[0025] Figure 4 Shows Figure 1 An enlarged view of the partial area B in
[0026] Figure 5 Shows Figure 1 A front view of the second limiting bracket in
[0027] Figure 6 A schematic structural diagram of an electric trolley in an embodiment of the present disclosure is shown.
[0028] Description of the reference numerals in the figure:
[0029] In the figure: 10, limiting structure; 11, pull rod assembly; 111, pull rod main body; 112, first pull rod base; 113, second pull rod base; 114, first folding rod; 115, second folding rod; 116, second axis; 117, third axis; 12, first limiting bracket; 121, first axis; 122, first mating surface; 1221, first free surface; 1222, first pre-tightening surface; 1223, first locking surface; 13, second limiting bracket; 131, fourth axis; 132, second mating surface; 1321, second free surface; 1322, second pre-tightening surface; 1323, second locking surface. Detailed implementation manners
[0030] To make the objectives, features, and advantages of the present disclosure more obvious and understandable, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present disclosure.
[0031] It should be understood that various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of this disclosure can be achieved, and no limitations are imposed herein.
[0032] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" can explicitly or implicitly include at least one such feature. In the description of this disclosure, "a plurality" means two or more, unless otherwise specifically defined.
[0033] The following will describe the embodiments of the present utility model in conjunction with the accompanying drawings.
[0034] Please refer to Figure 1 and Figure 2 , the present disclosure provides a limiting structure 10. The limiting structure 10 includes a pull rod assembly 11 and a first limiting bracket 12. The pull rod assembly 11 includes a pull rod main body 111 and a first pull rod base 112. One end of the pull rod main body 111 is connected to the first pull rod base 112. The pull rod assembly 11 is used to push or pull a trolley. The first limiting bracket 12 is configured with a first axis 121 and a first mating surface 122. The first pull rod base 112 is rotatably connected to the first limiting bracket 12 with the first axis 121 as the axis and along the first mating surface 122. The first mating surface 122 is used to lock the pull rod assembly 11 rotated to a predetermined angle.
[0035] In the above-mentioned limiting structure 10, when the pull rod assembly 11 accidentally falls under the action of gravity, the pull rod main body 111 drives the first pull rod base 112 to rotate with the first axis 121 as the axis and along the first mating surface 122. When the pull rod assembly 11 rotates to a predetermined angle, the first mating surface 122 defines and locks the pull rod assembly 11 to prevent the pull rod assembly 11 from continuing to rotate and avoid the pull rod assembly 11 falling to the ground with a large inertia and impact force, thereby avoiding damage to the pull rod assembly 11 and the components installed on the pull rod assembly 11 and improving the safety of the push-pull cart.
[0036] In this embodiment, the first limiting bracket 12 and the first pull rod base 112 are rotatably connected by a pin shaft.
[0037] Please refer to Figure 2In some embodiments, the first mating surface 122 includes a first free surface 1221, a first pre-tightening surface 1222 and a first locking surface 1223. The first free surface 1221, the first pre-tightening surface 1222 and the first locking surface 1223 are circumferentially and continuously arranged on the first limiting bracket 12 with the first axis 121 as the axis; when the first rod base 112 rotates to the first free surface 1221, the first rod base 112 and the first free surface 1221 rotate freely, that is, the friction force between the first rod base 112 and the first free surface 1221 is zero or the friction force is low. When the first rod base 112 rotates to the first pre-tightening surface 1222, the first rod base 112 and the first pre-tightening surface 1222 rotate with damping. When the first rod base 112 rotates to the first locking surface 1223, the first locking surface 1223 locks the first rod base 112.
[0038] When the operator moves the tie rod assembly 11, the tie rod assembly 11 rotates from a vertical state along the first matching surface 122 with the first axis 121 as the axis, and the first tie rod base 112 of the tie rod assembly 11 rotates to the angle area of the first free surface 1221, so that the tie rod assembly 11 can adjust the angle within the angle area of the first free surface 1221, so that the operator can push or pull the trolley at a suitable angle. When the tie rod assembly 11 accidentally falls under the action of gravity, the tie rod assembly 11 quickly rotates from a vertical state along the first free surface 1221 with the first axis 121 as the axis to the first pre-tightening surface 1222, and friction resistance is generated between the first pre-tightening surface 1222 and the first tie rod base 112 to reduce the impact force when the tie rod assembly 11 falls. When the first tie rod base 112 slides from the first pre-tightening surface 1222 to the first locking surface 1223, the static friction force generated between the first locking surface 1223 and the first tie rod base 112 locks and fixes the first tie rod base 112.
[0039] In this way, the first mating surface 122 first buffers the tie rod assembly 11 through the dynamic friction resistance generated by the first pre-tightening surface 1222, and then locks and fixes the tie rod assembly 11 through the static friction force generated by the first locking surface 1223, so that the tie rod assembly 11 enters the first locking surface 1223 with a weaker impact force, which is beneficial to reduce the wear on the first locking surface 1223. At the same time, the first locking surface 1223 locks and fixes the tie rod assembly 11 to prevent the tie rod assembly 11 and the components installed on the tie rod assembly 11 from impacting the ground, thereby causing damage to the tie rod assembly 11 or the components installed on the tie rod assembly 11.
[0040] Please also read Figure 2 and Figure 3 Specifically, the angle of the first free surface 1221 is A1, and the angle of the first preload surface 1222 is B1. A1 and B1 satisfy the formula: A1+B1≤90°.
[0041] Please refer to Figure 2 and Figure 3 In this embodiment, the first free surface 1221 is an arc surface, and the arc radius corresponding to the first free surface 1221 is not greater than the rotation radius of the outermost end of the first tie rod base 112. Preferably, the radius of the first free surface 1221 is the same as the rotation radius of the first tie rod base 112, so that the first free surface 1221 can rotatably support the tie rod assembly 11, thereby reducing the wear of the pin shaft on the first limit bracket 12 by the tie rod assembly 11, and bearing a part of the gravity of the tie rod assembly 11 to reduce the pin shaft between the first tie rod base 112 and the first limit bracket 12, and the radian range of the arc corresponding to the first free surface 1221 is 5°-15°.
[0042] It can be understood that the outermost end of the first tie rod base 112 refers to the point, line, or surface on the first tie rod base 112 that is closest to the first axis 121.
[0043] In this way, when the angle of the first free surface 1221 is less than 5°, the angle of rotation of the tie rod assembly 11 along the first free surface 1221 is small, resulting in a small adjustment range of the tie rod assembly 11 and affecting the user's pushing and pulling experience; when the angle of the first free surface 1221 is greater than 15 degrees, the movement range of the tie rod assembly 11 when falling under the action of gravity is large, resulting in a large impact force when the push-pull assembly enters the first pre-tightening surface 1222, and a small angle reserved for the first pre-tightening surface 1222, thereby resulting in a large impact force when the tie rod assembly 11 enters the first locking surface 1223 and accelerating the wear of the first locking surface 1223; when the angle of the first free surface 1221 is between 5° and 15°, it can not only ensure that the tie rod assembly 11 has a large adjustment range, but also maintain the impact force of the tie rod assembly 11 entering the first locking surface 1223 within a stable range to reduce wear.
[0044] Please refer to Figure 2 and Figure 3 In this embodiment, the first pre-tightening surface 1222 is continuously provided between the first free surface 1221 and the first locking surface 1223, and the distance between the first pre-tightening surface 1222 and the first axis 121 gradually increases in the direction from the end connected to the first free surface 1221 to the end connected to the first locking surface 1223, and the angle range of the first pre-tightening surface 1222 is 10°-20°.
[0045] Thus, when the angle of the first pre-tightening surface 1222 is less than 10 degrees, the buffering range of the first pre-tightening surface 1222 is small, resulting in poor buffering effect of the first pre-tightening surface 1222. When the angle of the first pre-tightening surface 1222 is greater than 20°, the angle range reserved for the first free surface 1221 and the first locking surface 1223 is small, making the angle adjustment range of the tie rod assembly 11 small, which affects the user experience. When the angle of the first pre-tightening surface 1222 is between 10° and 20°, it can not only ensure that the tie rod assembly 11 has a large adjustment range, but also ensure the buffering effect of the first pre-tightening surface 1222.
[0046] Please refer to Figure 1 , in some embodiments, the tie rod assembly 11 further includes a first folding rod 114, a second folding rod 115 and a second tie rod base 113. The first folding rod 114 is disposed obliquely along the first axis 121 on one side of the tie rod main body 111. One end of the first folding rod 114 is rotatably connected to the tie rod main body 111, and the other end of the first folding rod 114 is rotatably connected to the first tie rod base 112 around the second axis 116. The second folding rod 115 is disposed obliquely along the first axis 121 on the other side of the tie rod main body 111, and one end of the second folding rod 115 is rotatably connected to the tie rod main body 111 around the third axis 117. The other end of the second folding rod 115 is rotatably connected to the second tie rod base 113. The second axis 116 is disposed on the first tie rod base 112, the third axis 117 is disposed on the second tie rod base 113, and the second axis 116 is perpendicular to the first axis 121 and parallel to the third axis 117.
[0047] When folding the folding tie rod assembly 11, the other end of the first folding rod 114 rotates around the second axis 116. At the same time, the other end of the second folding rod 115 rotates around the third axis 117, so that the first folding rod 114 and the second folding rod 115 approach and fold each other, thereby realizing the rapid folding of the tie rod assembly 11.
[0048] It can be understood that in order to meet the market demand, existing trolleys usually need to be designed as foldable trolleys to facilitate reducing the occupied space of the trolley and facilitating the storage and transportation of the trolley. Therefore, in order to adapt to the foldable trolley, the tie rod assembly 11 needs to be designed as a foldable tie rod assembly 11.
[0049] Please refer to together Figure 1 and Figure 4, in some embodiments, the limiting structure 10 further includes a second limiting bracket 13, which has the same structure as the first limiting bracket 12. Further, the second limiting bracket 13 is configured with a fourth axis 131 and a second mating surface 132. The second drawbar base 113 is rotatably connected to the second limiting bracket 13 about the fourth axis 131 along the second mating surface 132. The second limiting bracket 13 is used to lock the drawbar assembly 11 rotated to a predetermined angle. Specifically, the first axis 121 and the fourth axis 131 are located on the same straight line.
[0050] In this way, when the drawbar assembly 11 falls freely, the drawbar body 111 drives the second drawbar base 113 to rotate about the first axis 121 and along the second mating surface 132. When the drawbar assembly 11 rotates to a predetermined angle, the second mating surface 132 defines and locks the drawbar assembly 11 to prevent the drawbar assembly 11 from continuing to rotate and to avoid the drawbar assembly 11 falling to the ground with a large inertia and impact force, thereby avoiding damage to the drawbar assembly 11 and the components installed on the drawbar assembly 11 and improving the safety of the trolley.
[0051] In this embodiment, the second limiting bracket 13 and the second drawbar base 113 are rotatably connected by a pin shaft.
[0052] Please refer to Figure 4 and Figure 5 , in some embodiments, the second mating surface 132 includes a second free surface 1321, a second pre-tightening surface 1322 and a second locking surface 1323. The second free surface 1321, the second pre-tightening surface 1322 and the second locking surface 1323 are circumferentially and continuously arranged on the second limiting bracket 13 about the fourth axis 131. When the second drawbar base 113 rotates to the second free surface 1321, the second drawbar base 113 and the second free surface 1321 rotate freely, that is, the friction force between the second drawbar base 113 and the second free surface 1321 is zero or relatively small. When the second drawbar base 113 rotates to the second pre-tightening surface 1322, the second drawbar base 113 rotates with damping between the second drawbar base 113 and the second pre-tightening surface 1322. When the second drawbar base 113 rotates to the second locking surface 1323, the second locking surface 1323 locks the second drawbar base 113.
[0053] Under the operation of the operator, the drawbar assembly 11 rotates about the fourth axis 131 from the vertical state along the second mating surface 132, and the second drawbar base 113 of the drawbar assembly 11 rotates to the angular region of the second free surface 1321, so that the drawbar assembly 11 can adjust the angle within the angular region of the second free surface 1321, facilitating the operator to push or pull the trolley at a suitable angle. When the drawbar assembly 11 accidentally drops under the action of gravity, the drawbar assembly 11 quickly rotates from the vertical state about the fourth axis 131 along the second free surface 1321 to the second pre-tightening surface 1322. A frictional resistance is generated between the second pre-tightening surface 1322 and the second drawbar base 113 to reduce the impact force when the drawbar assembly 11 descends. When the second drawbar base 113 slides from the second pre-tightening surface 1322 to the second locking surface 1323, the static frictional force generated between the second locking surface 1323 and the second drawbar base 113 locks and fixes the second drawbar base 113;
[0054] In this way, the second mating surface 132 first buffers the drawbar assembly 11 through the dynamic frictional resistance generated by the second pre-tightening surface 1322, and then locks and fixes the drawbar assembly 11 through the static frictional force generated by the second locking surface 1323, enabling the drawbar assembly 11 to enter the second locking surface 1323 with a weaker impact force, which is beneficial to reducing the wear of the second locking surface 1323. At the same time, the second locking surface 1323 locks and fixes the drawbar assembly 11 to prevent the drawbar assembly 11 and the components installed on the drawbar assembly 11 from impacting the ground, resulting in damage to the drawbar assembly 11 or the components installed on the drawbar assembly 11.
[0055] Please refer to Figure 4 and Figure 5 Specifically, the angle of the second free surface 1321 is A2, and the angle of the second pre-tightening surface 1322 is B2. Among them, A2 and B2 satisfy the formula: A2 + B2 ≤ 90°.
[0056] Please refer to Figure 4 and Figure 5 In this embodiment, the second free surface 1321 is an arc surface, and the radius of the second free surface 1321 is not greater than the rotation radius of the second drawbar base 113. Preferably, the radius of the second free surface 1321 is the same as the rotation radius of the second drawbar base 113, so that the second free surface 1321 can rotationally support the drawbar assembly 11, thereby reducing the wear of the drawbar assembly 11 on the pin shaft of the second limiting bracket 13, and the angular range of the second free surface 1321 is 5° - 15°.
[0057] In this way, when the angle of the second free surface 1321 is less than 5°, the angle at which the rod assembly 11 rotates along the second free surface 1321 is smaller, resulting in a smaller adjustment range of the rod assembly 11, affecting the user's push-pull experience; when the angle of the second free surface 1321 is greater than 15 degrees, the range of motion of the rod assembly 11 when falling under gravity is larger, resulting in a larger impact force of the rod assembly 11 entering the second pre-tightening surface 1322, and a smaller angle reserved for the second pre-tightening surface 1322, thereby resulting in a larger impact force of the rod assembly 11 entering the second locking surface 1323 and accelerating the wear of the second locking surface 1323; when the angle of the second free surface 1321 is between 5° and 15°, it can not only ensure that the rod assembly 11 has a larger adjustment range, but also maintain the impact force of the rod assembly 11 entering the second locking surface 1323 in a stable range to reduce wear.
[0058] Please also read Figure 4 and Figure 5 In this embodiment, the second pre-tightening surface 1322 is continuously arranged between the second free surface 1321 and the second locking surface 1323, and the distance between the second pre-tightening surface 1322 and the fourth axis 131 gradually increases from one end connected to the second free surface 1321 toward one end connected to the second locking surface 1323, and the angle range of the second pre-tightening surface 1322 is 10°-20°.
[0059] In this way, when the angle of the second pre-tensioning surface 1322 is less than 10 degrees, the buffering range of the second pre-tensioning surface 1322 is smaller, resulting in poor buffering effect of the second pre-tensioning surface 1322. When the angle of the second pre-tensioning surface 1322 is greater than 20°, the angle range reserved for the second free surface 1321 and the second locking surface 1323 is smaller, which makes the angle adjustment range of the pull rod assembly 11 smaller, affecting the user experience. When the angle of the second pre-tensioning surface 1322 is between 10° and 20°, it can ensure that the pull rod assembly 11 has a larger adjustment range and the buffering effect of the second pre-tensioning surface 1322.
[0060] The working principle of the above-mentioned limiting structure 10 is roughly as follows:
[0061] When the operator moves the rod assembly 11, the rod body 111 drives the first folding rod 114 and the second folding rod 115 to rotate synchronously around the first axis 121 or the fourth axis 131 (the first axis 121 and the fourth axis 131 are collinear), the first rod base 112 rotates to the area of the first free surface 1221, and the second rod base 113 rotates to the area of the second free surface 1321, so as to adjust the push-pull angle of the rod assembly 11;
[0062] When the drawbar assembly 11 accidentally drops under the action of gravity, the drawbar body 111 drives the first folding rod 114 and the second folding rod 115 to rotate synchronously, so that the first drawbar base 112 rotates to the first pre-tightening surface 1222 with a large impact force, and the second drawbar base 113 rotates to the second pre-tightening surface 1322 with a large impact force. Dynamic frictions are generated on both the first pre-tightening surface 1222 and the second pre-tightening surface 1322 to buffer the impact force of the drawbar assembly 11, so that the first drawbar base 112 enters the first locking surface 1223 with a weaker impact force, and the first drawbar base 112 is locked and fixed by the locking surface. It also enables the second drawbar base 113 that moves synchronously to enter the second locking surface 1323 with a weaker impact force, and the second drawbar base 113 is locked and fixed by the second locking surface 1323;
[0063] In this way, the drawbar assembly 11 is locked and limited simultaneously by the first mating surface 122 of the first limiting bracket 12 and the second mating surface 132 of the second limiting bracket 13, so as to improve the locking effect on the drawbar assembly 11.
[0064] Please refer to Figure 6 , the present disclosure embodiment also provides an electric trolley, the electric trolley includes the above-mentioned limiting structure 10, and the trolley is an electric trolley.
[0065] In this embodiment, the energy storage device of the electric trolley is installed on the drawbar body 111.
[0066] As mentioned above, the above is only the specific implementation manner of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present disclosure can easily think of changes or substitutions, which should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.
Claims
1. A limit structure, characterized in that, Comprising: A drawbar assembly, the drawbar assembly including a first drawbar base provided at the bottom end, and the drawbar assembly being used to push or pull a trolley; A first limiting bracket, the first limiting bracket being configured with a first axis and a first mating surface, and the first drawbar base being rotatably connected to the first limiting bracket with the first axis as the axis and along the first mating surface, and the first mating surface being used to lock the drawbar assembly rotated to a predetermined angle.
2. The limiting structure according to claim 1, wherein The first mating surface includes a first free surface, a first pre-tightening surface and a first locking surface, and the first free surface, the first pre-tightening surface and the first locking surface are circumferentially continuously arranged on the first limiting bracket with the first axis as the axis; When the first drawbar base rotates to the first free surface, it rotates freely between the first drawbar base and the first free surface. When the first drawbar base rotates to the first pre-tightening surface, it rotates with damping between the first drawbar base and the first pre-tightening surface. When the first drawbar base rotates to the first locking surface, the first locking surface locks the first drawbar base.
3. The limit structure according to claim 2, wherein The first free surface is an arc surface, the arc radius corresponding to the first free surface is not greater than the rotation radius of the outermost end of the first drawbar base, and the radian range corresponding to the first free surface is 5° - 15°.
4. The limiting structure according to claim 2, wherein The first pre-tightening surface is continuously arranged between the first free surface and the first locking surface, and the distance between the first pre-tightening surface and the first axis gradually increases in the direction from the end connected to the first free surface to the end connected to the first locking surface, and the angle range corresponding to the first pre-tightening surface is 10° - 20°.
5. The limit structure according to claim 1, wherein, The drawbar assembly further includes: A drawbar main body; A first folding rod, which is inclined along the first axis direction and arranged on one side of the drawbar main body, the One end of the first folding rod is rotatably connected to the drawbar main body, and the other end of the first folding rod is rotatably connected to the first drawbar base around a second axis; A second folding rod, which is inclined along the first axis direction and arranged on the other side of the drawbar main body, and one end of the second folding rod is rotatably connected to the drawbar main body around a third axis; A second drawbar base, and the other end of the second folding rod is rotatably connected to the second drawbar base; wherein, The second axis is configured on the first drawbar base, the third axis is configured on the second drawbar base, and the second axis is perpendicular to the first axis and parallel to the third axis.
6. The limiting structure according to claim 5, wherein The limiting structure further includes a second limiting bracket, and the second limiting bracket has the same structure as the first limiting bracket.
7. An electric trolley, characterized in that, Including the limiting structure according to any one of claims 1 - 6, and the trolley is an electric trolley.