Frame and scooter
By using a truss structure and adjustable overlap design, the problems of modularity and insufficient rigidity of scooter frames have been solved, achieving lightweighting and versatility, and improving vehicle handling stability and production efficiency.
Patent Information
- Application Number
- CN202423305394.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing scooter frames are difficult to modularize and standardize due to space limitations at the middle pedal area, and their insufficient rigidity results in a large number of parts, heavy weight, and high cost.
The frame adopts a truss structure design, which is connected by triangular support units between the main tube, cross tube and side tube to form a frame structure with more ideal front torsional stiffness and longitudinal stiffness. The adjustable overlap section can be adapted to different wheelbase models, reducing the number of parts and welding stress concentration.
This design achieves lightweight, modular, and universal chassis design, improving handling stability, reducing costs, and eliminating the need to design different wheelbase models, thus simplifying the production process.
Smart Images
Figure CN223644907U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of scooter technology, and in particular to a frame and a scooter. Background Technology
[0002] Current scooter frames, limited by space at the center pedal area, can only employ a non-truss structure. The frame uses a single main tube extending to the cradle mount, such as... Figure 1 As shown, an existing scooter frame has a main pipe 1' extending rearward and across the space of the middle pedal to the position of the rocker mount 2'. This frame structure is difficult to modularize and standardize; different wheelbase models require corresponding frame parts to be designed and manufactured, resulting in poor compatibility. Furthermore, the rigidity of this frame structure needs improvement. To achieve greater rigidity, more components need to be added to the frame to enhance the stability of the connection points, for example... Figure 1 The addition of stiffeners 3' increases the number of parts, resulting in greater weight, increased complexity of the frame structure, and higher costs, making it difficult to achieve lightweight design. Utility Model Content
[0003] In view of this, the present invention proposes a frame and a scooter, with the aim of making the frame structure lightweight, modular and universal, while ensuring that the frame has sufficient rigidity margin.
[0004] In a first aspect, the solution provided by this utility model includes:
[0005] A frame, comprising:
[0006] Front frame, middle frame, and rear frame;
[0007] The front frame includes a main tube and a front horizontal tube. The front horizontal tube includes a horizontally arranged horizontal tube body, with first overlapping sections extending rearward from both ends of the horizontal tube body. The main tube extends vertically and its bottom end is fixed to the middle of the horizontal tube body.
[0008] The intermediate frame includes left and right intermediate side tubes. Each of the left and right intermediate side tubes includes a second overlapping section, a transition connecting section, and a rear extension section connected in sequence. The length direction of the second overlapping section is the same as the length direction of the main tube, and the second overlapping section overlaps the main tube. The length direction of the rear extension section is the same as the length direction of the first overlapping section, and the first overlapping section overlaps the rear extension section.
[0009] The rear frame includes left and right rear tubes. Each of the left and right rear tubes has a third overlapping section at one end near the middle frame. The length direction of the third overlapping section is the same as the length direction of the rear extension tube section, and the third overlapping section overlaps the rear extension tube section.
[0010] As a further optional solution, the main pipe includes a first pipe segment and a second pipe segment connected in sequence, wherein the angle between the first pipe segment and the horizontal plane is greater than the angle between the second pipe segment and the horizontal plane;
[0011] The second overlapping section overlaps the outer side of the first pipe section near one end of the second pipe section.
[0012] As a further alternative, the second pipe segment is perpendicular to the main body of the horizontal pipe, and the main body of the horizontal pipe is perpendicular to the first overlapping segment.
[0013] As a further optional solution, the intermediate frame also includes a rear cross tube and a cradle mounting bracket;
[0014] The rear horizontal tube is arranged laterally between the left and right middle side tubes. The two ends of the rear horizontal tube are respectively welded to the rear extension tube sections on the left and right middle side tubes. The rear horizontal tube is located at the end of the rear extension tube section that is close to the rear frame.
[0015] The cradle mounting bracket is located at the bottom of one end of the rear extension tube section near the rear frame.
[0016] As a further optional solution, the intermediate frame also includes two foot pedal support tubes, which are respectively installed on the left and right intermediate side tubes. One end of the foot pedal support tube is welded to the transition connection section near the end of the second overlapping section, and the other end of the foot pedal support tube is welded to the rear extension tube section.
[0017] As a further optional solution, the front frame also includes a ventilation duct, the interior of which forms an airflow channel extending along its axial direction, and the side of the ventilation duct is provided with an air outlet opening radially thereon, the air outlet communicating with the airflow channel;
[0018] The main pipe has a through mounting hole running from front to back. The ventilation pipe passes through the mounting hole, and the air outlet on the ventilation pipe faces upward. An air vent is formed between the outer side of the ventilation pipe and the inner sidewall of the main pipe.
[0019] As a further optional feature, the central axis of the ventilation duct has an angle of 5-30° with the horizontal plane.
[0020] As a further alternative, the cross-section of the ventilation duct is non-circular.
[0021] As a further optional solution, the intermediate frame also includes a counterweight;
[0022] The counterweight is located at one end of the rear extension pipe section near the rear frame.
[0023] Secondly, the solution provided by this utility model includes:
[0024] A scooter comprising any of the aforementioned frames.
[0025] Compared with the prior art, the frame and scooter of this application have at least the following advantages:
[0026] 1. Two triangular support units are formed between the main tube, the horizontal tube body, and the left and right middle side tubes, so that the whole structure forms a truss structure, making the torsional stiffness and longitudinal stiffness trend of the front of the frame more ideal, improving the handling stability of the vehicle; the frame has a large stiffness margin, which helps to reduce the number of parts, achieve lightweight frame structure, and reduce costs; the front frame, middle frame and rear frame are fixed by the first overlapping section, the rear extension tube section and the third overlapping section, the stress distribution of the whole frame is reasonable, there are no stress concentration points, and the requirements for welding process are low;
[0027] 2. The rear frame and the intermediate frame are connected by a third overlapping section and the rear extension tube section. The rear frame is adjusted to move back and forth by setting the overlapping position of the second overlapping section on the rear extension tube section to adapt to different wheelbase models. Compared with the existing technology, when producing different wheelbase models, there is no need to design corresponding front frame, intermediate frame and rear frame, which is conducive to the modularization and universalization of the frame structure. Attached Figure Description
[0028] Figure 1 This is a structural diagram of a scooter frame based on existing technology;
[0029] Figure 2 This is a schematic diagram of the structure of a vehicle frame according to an embodiment of the present invention;
[0030] Figure 3 This is an exploded schematic diagram of a vehicle frame according to an embodiment of the present invention;
[0031] Figure 4 This is a top view schematic diagram of a vehicle frame according to an embodiment of the present utility model;
[0032] Figure 5 yes Figure 4 Schematic diagram of the cross section of AA;
[0033] Figure 6 yes Figure 4 Cross-sectional view of BB;
[0034] Figure 7 yes Figure 6 Enlarged view of C in the middle;
[0035] Figure 8 yes Figure 7 Cross-sectional view of DD;
[0036] Figure 9 This is an exploded schematic diagram of the ventilation pipe and the main pipe in an embodiment of this utility model;
[0037] Figure 10 Is Figure 1 A structural diagram showing the addition of a foot pedal support tube and a rear cross tube based on the previous embodiment.
[0038] Figure 2-10 In the middle, 1. Front frame; 11. Main pipe; 111. First pipe section; 112. Second pipe section; 113. Mounting hole; 12. Front horizontal pipe; 121. Horizontal pipe body; 122. First overlapping section; 13. Ventilation pipe; 131. Airflow channel; 132. Air outlet; 14. Vent.
[0039] 2. Intermediate frame; 21a. Left intermediate side tube; 21b. Right intermediate side tube; 211. Second overlapping section; 212. Transition connection section; 213. Rear extension tube section; 22. Counterweight block; 23. Cradle mounting bracket; 24. Rear horizontal tube; 25. Foot pedal support tube;
[0040] 3. Rear frame; 31a. Left rear tube; 31b. Right rear tube; 311. Third lap joint. Detailed Implementation
[0041] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.
[0042] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0043] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0044] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0045] refer to Figure 1-3 This utility model discloses a vehicle frame, including a front frame 1, a middle frame 2, and a rear frame 3. The front frame 1 includes a main tube 11 and a front cross tube 12. The front cross tube 12 includes a transversely arranged cross tube body 121, with both ends of the cross tube body 121 extending rearward to form first overlapping sections 122. The main tube 11 extends vertically, and its bottom end is fixed to the middle of the cross tube body 121. The middle frame 2 includes left and right middle side tubes 21a and 21b. Each of the left and right middle side tubes 21a and 21b includes a second overlapping section 211, a transition connecting section 212, and a rear extension tube section 213 connected in sequence. The length direction of the second overlapping section 211 is the same as the length direction of the main pipe 11, and the second overlapping section 211 overlaps the main pipe 11; the length direction of the rear extension pipe section 213 is the same as the length direction of the first overlapping section 122, and the first overlapping section 122 overlaps the rear extension pipe section 213; the rear frame 3 includes left and right rear side pipes 31a and 31b, and each of the left and right rear side pipes 31a and 31b is provided with a third overlapping section 311 at one end near the middle frame 2, the length direction of the third overlapping section 311 is the same as the length direction of the rear extension pipe section 213, and the third overlapping section 311 overlaps the rear extension pipe section 213.
[0046] Among them, such as Figure 1 and Figure 3 As shown, two triangular support units are formed between the main tube 11, the horizontal tube body 121, and the left and right middle side tubes 21a and 21b, so that the whole structure forms a truss structure, making the torsional stiffness and longitudinal stiffness of the front of the frame more ideal and improving the handling stability of the vehicle; the frame has a large stiffness margin, which is conducive to reducing the number of parts, realizing the lightweight frame structure, and reducing costs.
[0047] like Figure 2 and Figure 4As shown, the first overlapping section 122, the second overlapping section 211, and the third overlapping section 311 are all formed by flattening the pipe fitting, resulting in an externally formed groove with an arc-shaped cross-section (not marked in the figure). The inner wall contour of this groove matches the outer wall contour of the required overlapping position. For example, the inner wall contour of the groove on the first overlapping section 122 matches the outer wall contour of the subsequent pipe section 213. The first overlapping section 122 overlapping the subsequent pipe section 213 means that the first overlapping section 122 first overlaps the subsequent pipe section 213. The extension section 213 is then welded and fixed, and the second lap section 211 and the second lap section 211 are similarly welded. The first lap section 122, the second lap section 211, and the third lap section 311 all have a certain length, which makes the welding stress surface at the lap position large and the connection stable. The front frame 1, the middle frame 2, and the rear frame 3 are fixed by welding through the first lap section 122, the rear extension section 213, and the third lap section 311, so that the stress distribution of the whole frame is reasonable, there are no stress concentration points, and the requirements for welding process are low. Preferably, such as Figure 5 As shown, the vertical projection of the first overlapping section 122 on the installation position of the rear extension pipe section 213 at least partially overlaps with the vertical projection of the third overlapping section 311 on the installation position of the rear extension pipe section 213, making the force distribution between the front frame 1, the middle frame 2 and the rear frame 3 more stable.
[0048] like Figure 2 , Figure 3 and Figure 5 As shown, the rear frame 3 and the intermediate frame 2 are connected by a third overlapping section 311 and a rear extension tube section 213. The overlapping position of the second overlapping section 211 on the rear extension tube section 213 can be selected according to the different wheelbase models, that is, the rear frame 3 can be moved back and forth to adjust to adapt to different wheelbase models. Compared with the prior art, when producing models with different wheelbases, there is no need to design corresponding front frame 1, intermediate frame 2 and rear frame 3, which is conducive to the modularization and universalization of the frame structure.
[0049] It should be noted that different wheelbases refer to the distance between the front and rear wheels of the scooter. In reality, changing the wheelbase by a small distance can result in significant differences in the appearance of the scooter products. However, the internal frame structure of the scooter does not differ much; for example, the diameter and wall thickness of the tubing used can be the same. In this embodiment, the frame can achieve wheelbase changes by simply adjusting the mounting position of the rear frame 3 in the front-rear direction while keeping the front frame 1, middle frame 2, and rear frame 3 unchanged, thus making it compatible with models with different wheelbases. In contrast, in the prior art, when the mounting position of the rear frame 3 in the front-rear direction is changed, other structures on the frame need to be adjusted accordingly. Therefore, the frame in the prior art cannot be modularized.
[0050] In addition, such as Figure 5As shown, the length direction of the extended pipe section 213 is horizontal or tends to be horizontal, so that when the third overlapping section 311 of the rear frame 3 is adjusted along the length direction of the extended pipe section 213, the position adjustment of the rear frame 3 in the front-rear direction is relatively obvious.
[0051] In some embodiments, such as Figure 1 , Figure 3 and Figure 5 As shown, the main pipe 11 includes a first pipe segment 111 and a second pipe segment 112 connected in sequence. The angle between the first pipe segment 111 and the horizontal plane is greater than the angle between the second pipe segment 112 and the horizontal plane. The second overlapping segment 211 overlaps the outer side of the first pipe segment 111 near the end of the second pipe segment 112. The first pipe segment 111 and the second pipe segment 112 are straight pipe segments. A triangular support unit is formed between the second pipe segment 112, the transition connecting segment 212, and the horizontal pipe body 121. Since both the second pipe segment 112 and the horizontal pipe body 121 are straight pipe segments, the resulting triangular support unit structure is more stable, resulting in better torsional and longitudinal stiffness at the front of the frame.
[0052] Furthermore, the second pipe segment 112 is perpendicular to the horizontal pipe body 121, and the horizontal pipe body 121 is perpendicular to the first overlapping segment 122. For example... Figure 5 and Figure 8 As shown, the bottom end of the second pipe segment 112 is welded to the midpoint of the horizontal pipe body 121. Two triangular support units are symmetrically formed on both sides of the second pipe segment 112. The second pipe segment 112 is perpendicular to the horizontal pipe body 121, which makes the force-bearing structure between the second pipe segment 112 and the horizontal pipe body 121 more stable. This is beneficial for the second pipe segment 112 to better transmit the force to the horizontal pipe body 121. At the same time, the horizontal pipe body 121 is perpendicular to the first overlapping section 122, so that the first overlapping section 122 and the extended pipe segment 213 provide more stable lateral support for both ends of the horizontal pipe body 121.
[0053] In some embodiments, such as Figure 9As shown, the intermediate frame 2 also includes a rear horizontal tube 24 and a cradle mounting bracket 23. The rear horizontal tube 24 is laterally arranged between the left and right intermediate side tubes 21a and 21b. Both ends of the rear horizontal tube 24 are welded to the rear extension tube sections 213 on the left and right intermediate side tubes 21a and 21b, respectively. The rear horizontal tube 24 is located at one end of the rear extension tube section 213 near the rear frame 3. The cradle mounting bracket 23 is located at the bottom of the rear extension tube section 213 near the rear frame 3. The rear horizontal tube 24 further enhances the structural stability between the left and right intermediate side tubes 21a and 21b. Preferably, the connection position of the rear horizontal tube 24 on the rear extension tube section 213 is within the vertical projection range of the third overlapping section 311, so as to further improve the positional stability between the two third overlapping sections 311 on the rear frame 3.
[0054] In some embodiments, such as Figure 9 As shown, the intermediate frame 2 also includes two foot pedal support tubes 25, which are respectively mounted on the left and right intermediate side tubes 21a and 21b. One end of each foot pedal support tube 25 is welded to the transition connection section 212 near the end of the second overlapping section 211, and the other end is welded to the rear extension tube section 213. Thus, the foot pedal support tubes 25, the front horizontal tube 12, the left intermediate side tube 21a, the right intermediate side tube 21b, the left rear side tube 31a, and the right rear side tube 31b are stacked to form a spatial truss structure.
[0055] In some embodiments, reference Figure 1 and Figure 2 The intermediate frame 2 also includes a counterweight 22; the counterweight 22 is disposed within the rear extension tube section 213 near the rear frame 3. Different wheelbase frames are obtained by adjusting the installation position of the rear frame 3 in the front-rear direction. Different wheelbase frames have different natural frequencies. If the natural frequency of the frame is the same as the vibration frequency of the engine, the engine and frame will resonate, resulting in poor vehicle vibration. This embodiment uses the counterweight 22 to change the natural frequency of frames with different wheelbases, preventing resonance between the frame and engine and improving the stability of the entire vehicle. The counterweight 22 is welded into the rear extension tube section 213. The weight of the counterweight 22 can be selected according to the installation position of the rear frame on the rear extension tube section 213, ensuring that the natural frequency of the frame is offset from the vibration frequency of the engine.
[0056] Conventionally, in existing scooters, the transmission box generally uses a belt-driven continuously variable transmission mechanism, which is a dry transmission type. During operation, the frictional resistance is high, generating a lot of heat. To ensure the normal operation of the belt, airflow is required to prevent the temperature inside the transmission box from becoming too high. Therefore, air inlets and outlets are provided on the transmission box housing. The air inlet of the engine transmission box housing is connected to the lower part of the main pipe 11 through a pipe, and an opening is made in the upper part of the main pipe 11 for air intake (this is existing technology and is not shown). However, if the airflow entering the transmission box carries dust and fine sand, it can easily cause wear and slippage of the transmission belt, reducing the service life of the transmission belt.
[0057] Therefore, in some embodiments, reference Figure 1 as well as Figure 5-8 The front frame 1 also includes a ventilation pipe 13, the interior of which forms an airflow channel 131 extending along its axial direction, and the side of the ventilation pipe 13 is provided with an air outlet 132 opening along its radial direction, the air outlet 132 communicating with the airflow channel 131; the main pipe 11 is provided with a front-to-back through mounting hole 113, the ventilation pipe 13 passing through the mounting hole 113, the air outlet 132 on the ventilation pipe 13 facing upward, and an air vent 14 forming between the outer side of the ventilation pipe 13 and the inner sidewall of the main pipe 11.
[0058] Specifically, such as Figure 6 and Figure 7 As shown, when the scooter is in motion, the ventilation pipe 13 on the front frame 1 takes in air from the windward direction, and the air outlet of the ventilation pipe 13 is set upwards. This allows the dense dust carried in the airflow to be discharged along the airflow channel 131 under the action of gravity, while the less dense clean air enters the main pipe 11 from the air outlet 132 above the ventilation pipe 13, and flows downwards from the air inlet 14 until it enters the engine's transmission box. In this way, the amount of dust entering the engine transmission box can be greatly reduced, and the life of the transmission belt can be extended.
[0059] Preferably, such as Figure 6 As shown, the central axis of the ventilation duct 13 has an angle of 5-30° with the horizontal plane. In this embodiment, with this angle configuration, on the one hand, the ventilation duct 13 can maintain a good slope, which is conducive to the discharge of dense dust along the airflow channel 131 under the action of gravity, and avoids the accumulation of dust in the ventilation duct 13; on the other hand, the angle is not too large, so as to prevent dust from easily passing laterally through the air outlet 132 and entering the main pipe 11 when it enters the ventilation duct 13 with the airflow.
[0060] Preferably, such as Figure 8 and Figure 9As shown, the cross-section of the ventilation duct 13 is non-circular. This makes it easier to install the ventilation duct 13 onto the main pipe 11, and during installation, it is easier to ensure that the air outlet 132 on the ventilation duct 13 faces upwards.
[0061] This utility model embodiment also provides a scooter, which includes any of the above-described frames.
[0062] In summary, this utility model embodiment provides a frame and a scooter. In this frame, two triangular support units are formed between the main tube 11, the transverse tube body 121, and the left and right middle side tubes 21a and 21b, creating a truss structure. This results in more ideal torsional and longitudinal stiffness at the front of the frame, improving vehicle handling stability. The frame has a large stiffness margin, which helps reduce the number of parts, achieving lightweight frame structure and lower costs. The front frame 1, middle frame 2, and rear frame 3 are connected by a first overlapping section 122, a rear extension tube section 213, and a third overlapping section 3. 11. Welding fixation ensures a reasonable stress distribution across the entire frame, with no stress concentration points, and low requirements for welding processes. Furthermore, the rear frame 3 and the intermediate frame 2 are connected by a third overlapping section 311 and a rear extension tube section 213. The rear frame 3 can be adjusted forward and backward by setting the overlapping position of the second overlapping section 211 on the rear extension tube section 213 to accommodate different wheelbase models. Compared to existing technologies, when producing different wheelbase models, it is not necessary to design corresponding front frame 1, intermediate frame 2, and rear frame 3, which is beneficial for the modularization and universalization of the frame structure.
[0063] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.
[0064] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.
Claims
1. A vehicle frame, characterized in that, include: Front frame, middle frame, and rear frame; The front frame includes a main tube and a front horizontal tube. The front horizontal tube includes a horizontally arranged horizontal tube body, with first overlapping sections extending rearward from both ends of the horizontal tube body. The main tube extends vertically and its bottom end is fixed to the middle of the horizontal tube body. The intermediate frame includes left and right intermediate side tubes. Each of the left and right intermediate side tubes includes a second overlapping section, a transition connecting section, and a rear extension section connected in sequence. The length direction of the second overlapping section is the same as the length direction of the main tube, and the second overlapping section overlaps the main tube. The length direction of the rear extension section is the same as the length direction of the first overlapping section, and the first overlapping section overlaps the rear extension section. The rear frame includes left and right rear tubes. Each of the left and right rear tubes has a third overlapping section at one end near the middle frame. The length direction of the third overlapping section is the same as the length direction of the rear extension tube section, and the third overlapping section overlaps the rear extension tube section.
2. The frame according to claim 1, characterized in that: The main pipe includes a first pipe section and a second pipe section connected in sequence, wherein the angle between the first pipe section and the horizontal plane is greater than the angle between the second pipe section and the horizontal plane; The second overlap is attached to the outside of the first pipe section near one end of the second pipe section.
3. The frame according to claim 2, characterized in that: The second pipe segment is perpendicular to the main body of the horizontal pipe, and the main body of the horizontal pipe is perpendicular to the first overlapping segment.
4. The frame according to claim 1, characterized in that: The intermediate frame also includes a rear horizontal tube and a cradle mounting bracket; The rear horizontal tube is arranged laterally between the left and right middle side tubes. The two ends of the rear horizontal tube are respectively welded to the rear extension tube sections on the left and right middle side tubes. The rear horizontal tube is located at the end of the rear extension tube section that is close to the rear frame. The cradle mounting bracket is located at the bottom of one end of the rear extension tube section near the rear frame.
5. The frame according to claim 4, characterized in that: The intermediate frame also includes two foot pedal support tubes, which are respectively installed on the left and right middle side tubes. One end of each foot pedal support tube is welded to the transition connection section near the second overlapping section, and the other end of each foot pedal support tube is welded to the rear extension tube section.
6. The frame according to claim 1, characterized in that: The front frame also includes a ventilation duct, the interior of which forms an airflow channel that runs through it along its axial direction, and the side of the ventilation duct is provided with an air outlet that opens radially thereto, the air outlet being connected to the airflow channel; The main pipe has a through mounting hole running from front to back. The ventilation pipe passes through the mounting hole, and the air outlet on the ventilation pipe faces upward. An air vent is formed between the outer side of the ventilation pipe and the inner sidewall of the main pipe.
7. The frame according to claim 6, characterized in that: The central axis of the ventilation duct has an angle of 5-30° with the horizontal plane.
8. The frame according to claim 6, characterized in that: The cross-section of the ventilation duct is non-circular.
9. The frame according to any one of claims 1-8, characterized in that: The intermediate frame also includes a counterweight; The counterweight is located at one end of the rear extension pipe section near the rear frame.
10. A scooter, characterized in that, It includes any one of the frames claimed in claims 1-9.