Bicycle main frame folding and locking structure

Abstract

The invention belongs to the technical field of folding bicycle structures, and particularly relates to a bicycle main frame folding and locking structure which is characterized in that a handlebar connecting frame is hinged to the upper portion of a steering shaft on a front fork, a steering shaft connecting part in front of an upper girder is hinged to the steering shaft in a left-right rotating mode, and a front wheel is hinged to the lower portion of the front fork through a front wheel connecting part; an upper girder connecting part at the rear end of the upper girder is hinged to a lower girder connecting part at the front end of the lower girder in a longitudinal rotating mode, a rear wheel connecting part at the rear end of the lower girder is hinged to a rear wheel, and a driving structure is arranged in front of the rear wheel connecting part. According to the locking structure, the upper and lower girder connecting part hinge point serves as the rotating axis to be in butt joint or open the upper and lower girder locking connecting part, the seat tube connecting part is hinged to the upper girder locking connecting part through a quick release shaft, and a handle is hinged to one side of the quick release shaft.

Description

Technical Field

[0002] This invention pertains to folding bicycles as a means of transportation, and specifically relates to a folding and locking structure for the main frame of a bicycle. Background Technology

[0004] Folding bicycles, as a green mode of transportation, also offer fitness and recreational benefits. Generally speaking, folding bicycles on the market come in both large-wheel and small-wheel versions. Current folding bicycle frames are only suitable for either small or large wheel diameters, unable to accommodate both simultaneously. Most importantly, the placement of the seat after folding remains a significant issue, resulting in an irregular shape and wasted space. Current folding bicycles are primarily horizontally folding, with a few having vertically folding frames. The advantage of vertically folding frames over horizontally folding frames is their ease of folding, but their structure is relatively complex and difficult to manufacture. Therefore, horizontally folding frames are predominant on the market. Vertically folding bicycle frames are commonly available in one-fold, two-fold, and three-fold designs. However, due to the numerous folding points or unreasonable design, the main frame of these mainstream vertically folding bicycles experiences a loss of power during riding. This loss of power is caused by loosening during riding due to the numerous folding points, requiring more locking mechanisms and increasing manufacturing costs. There's a product called Gi Fiy on Douyin (TikTok) that addresses this issue. The Bike large-wheel folding bicycle has an overly protruding seat, making it inconvenient to store when folded, and it doesn't shrink much when folded. The complexity and manufacturing difficulty are self-evident. There is also a large-wheel folding bicycle frame with the English name BASTILLE on Douyin. This folding bicycle has multiple folding points on the seat and frame. The many folding points increase material and manufacturing costs and introduce certain manufacturing errors. Moreover, the two wheels form an "eight" shape when folded, making it unsuitable for pushing. The design of this bicycle is too complex and not conducive to mass production. Even if it were produced, it would not be easy for the general public to buy.

[0005] To overcome the above deficiencies, this invention designs a bicycle main frame folding and locking structure, which effectively solves the above problems. Summary of the Invention

[0007] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a folding and locking structure for bicycle main frames.

[0008] The technical solution adopted in this invention is: a bicycle main frame folding and locking structure includes: a seat post, a seat, a front fork, a handlebar connector, a front wheel, a rear wheel, a drive structure, a main frame, and a locking structure;

[0009] The main frame includes: an upper beam and a lower beam;

[0010] The upper beam is fixedly connected to a steering shaft connecting part at the front end, the upper beam is fixedly connected to an upper beam connecting part at the lower rear end, and the upper beam is fixedly connected to an upper beam locking connecting part at the upper rear end.

[0011] The lower beam is fixedly connected to the front end of the lower beam with a lower beam connecting part, and a lower beam locking connecting part is fixedly connected above the front end of the lower beam. The locking connecting part of the lower beam has an opening in front of the central hole, and the height of the opening is less than the diameter of the central hole. A drive structure is fixedly connected below the lower beam connecting part. The rear end of the drive structure has a rear wheel connecting part that hinges the rear wheel. A magnet is provided on one side of the rear wheel connecting part and attracts the magnet on one side of the front wheel connecting part.

[0012] The magnet on one side of the rear wheel connection part attracts the magnet on one side of the front wheel connection part, which is not described in the drawings of the prior art specification.

[0013] The drive structure consists of pedals, a central axle, a flywheel, a wheel, a large crank, a chain, etc.

[0014] The drive structure includes, for example, belt drive, sprocket and chain drive, drive shaft drive, motor drive, etc. The specific parts of the drive structure are not described in the accompanying drawings of this invention specification.

[0015] The seat tube is provided with a seat tube connection part that is hinged to the upper beam locking connection part below the seat tube, and the seat is hinged to the upper part of the seat tube.

[0016] The front wheel is hinged to the front wheel below the front fork via a front wheel connection part, and a steering shaft is fixedly connected to the top of the front fork. The steering shaft and the steering shaft connection part are hinged to each other and can rotate left and right. A handlebar connector is hinged to the top of the steering shaft.

[0017] The handlebars and specific parts on the handlebars are not described in the accompanying drawings of this invention.

[0018] The locking structure uses the hinge point of the upper and lower beam connection as the rotation axis to connect or open the upper and lower beam locking connection. The seat post connection is hinged to the upper beam locking connection via a quick-release shaft. The quick-release shaft is a non-rotatable hinge on the seat post connection. A handle is hinged to one side of the quick-release shaft. The quick-release shaft has a flat section. The seat post-linked quick-release shaft rotates back and forth on the upper and lower beam locking connection to lock or open the main frame. The above description constitutes the locking structure.

[0019] The quick-release shaft hinge handle is an existing quick-release technology, commonly used for seat tube clamp locking.

[0020] The beneficial effects of this invention are as follows: The main frame is divided into two sections, the upper beam and the lower beam, forming part of a folding locking structure. Locking the upper and lower beams simultaneously locks the seatpost, forming a locking structure. The upper and lower beams are locked or opened via a quick-release shaft linked to the seatpost's rotation. The quick-release shaft, hinged to a handle, locks the seatpost before and after folding, and also locks the seatpost in the pushing state. In riding mode, pressing down on the seat causes the seatpost to tilt backward, assisting in locking the main frame. This invention has certain advantages in manufacturing. The main frame is divided into two connected sections, and the seatpost and main frame only have a connection without welding, thus ensuring overall frame stability and reducing manufacturing costs. The fewer locking structures involved, the lower the manufacturing cost and the less error. The design prevents loosening and loss of power. The two-wheel locking mechanism is achieved by the mutual attraction and locking of magnets on one side of the front wheel connection and one side of the rear wheel connection. The main frame of this invention is suitable for wheels of various diameters. When the small wheel is paired with this invention, rotating the handlebars causes the front fork to rotate backward, reducing the space occupied by the front wheel. This locking structure not only solves the locking of the main frame but also the problems of locking the seat post and finding a place to put the seat. The main frame folds into a continuous and regular shape, allowing it to be pushed or pulled along. When not in use, it can be stored indoors or in the trunk of a car. The structure is simple, occupies little space, and has low production costs, as shown in the figure. Attached Figure Description

[0022] To make the technical solution of the present invention clearer, the present invention will be further described in conjunction with the following embodiments and accompanying drawings.

[0023] Figure 1 This is an analytical diagram of the main structure.

[0024] Figure 2 This is the folded analytical diagram.

[0025] Figure 3 This is an analytical diagram showing the position of the two wheels parallel after folding and the seat after folding.

[0026] Figure 4 This is the first step in folding and also an analytical diagram of the locking connection of the lower beam.

[0027] Figure 5 This is a diagram of the main beam.

[0028] Figure 6 This is the analytical diagram of the lower beam.

[0029] Figure 7 This is a diagram of the seat tube.

[0030] Figure 8 This is a diagram of the front fork.

[0031] Figure 9 This is an analytical diagram of the locking structure.

[0032] Figure 10 This is a top view analysis of the locking structure.

[0033] Figure 11 This is a diagram illustrating the quick-release hinge and handle.

[0034] Figure 12 It involves implementing a state analysis diagram.

[0035] In the diagram, 1-upper beam, 1-1-steering shaft connection, 1-2-upper beam connection, 1-3-upper beam locking connection, 2-lower beam, 2-1-lower beam connection, 2-2-lower beam locking connection, 2-3-drive structure, 2-4-rear wheel connection, 3-seat post, 3-1-seat post connection, 10-front fork, 10-1-steering shaft, 10-2-front wheel connection, 5-handlebar connector, 7-seat, 8-front wheel, 9-rear wheel, 11-quick release axle, 12-handlebar. Detailed Implementation

[0037] The invention will be further illustrated with reference to the accompanying drawings.

[0038] The handlebar connector 5 is hinged above the steering shaft 10-1 on the front fork 10, and the front wheel 8 is hinged to the front wheel connector 10-2 below the front fork 10. A magnet is provided on one side of the front wheel connector 10-2 that attracts the rear wheel connector 2-4.

[0039] The magnet on one side of the rear wheel connection part 2-4 is attracted to the magnet on one side of the front wheel connection part 10-2, which is not described in the drawings of the prior art specification.

[0040] The main frame includes an upper beam 1 and a lower beam 2;

[0041] The upper beam 1 has a front steering shaft connecting part 1-1 that can rotate left and right and is hinged to a steering shaft 10-1. The upper beam 1 has a rear end upper beam connecting part 1-2 that can rotate longitudinally and is hinged to the lower beam 2 has a front end lower beam connecting part 2-1. The lower beam 2 has a rear wheel connecting part 2-4 that is hinged to a rear wheel 9. The rear wheel connecting part 2-4 has a drive structure 2-3 fixedly connected to the front.

[0042] The drive structure consists of a large crank, a central axle, a wheel, pedals, a flywheel, a chain, etc.

[0043] The drive structure includes, for example, motor drive, belt drive, transmission shaft drive, sprocket and chain drive, etc. The specific parts of the drive structure are not described in the accompanying drawings of this invention specification.

[0044] When folded, the axis of the longitudinal rotatable hinge between the upper beam connecting part 1-2 and the lower beam connecting part 2-1 is biased towards one side of the main frame, that is, the axis is not perpendicular to one side of the main frame, so that the front and rear wheels will not overlap but will be parallel. The parallel width between the front wheel 8 and the rear wheel 9 is adjustable. The narrowest adjustable range is to the two wheels being close together. It can also be adjusted to a non-parallel state as needed. Adjusting the axis of the hinge between the upper beam 1 and the lower beam 2 can make the two wheels close together or non-parallel. This invention is a parallel state of the two wheels.

[0045] The seat 7 is hinged above the seat tube 3, and the seat tube connection part 3-1 below the seat tube 3 is rotatably hinged to the upper beam locking connection part 1-3 via a quick-release shaft 11. The quick-release shaft 11 is non-rotatably hinged to the seat tube connection part 3-1.

[0046] The seat post connection 3-1 is connected to the upper beam locking connection 1-3 via a quick-release shaft 11. The axial direction of the quick-release shaft 11 is biased towards one side of the main frame, so the folding seat post 3 can be linked to the seat 7 to the side of the main frame. The axial direction of the quick-release shaft is also adjustable, and the adjustment range can be to any side of the main frame or the middle position of the main frame. In this invention, the main frame is on one side. The axial direction of the quick-release shaft 11 can also be parallel to the hinge axis of the upper beam connection 1-2 and the lower beam connection 2-1.

[0047] The locking structure is based on the hinge axis of the upper and lower beams as the rotation axis to connect or open the upper and lower beams locking connection. The seat tube connection 3-1 below the seat tube 3 is hinged to the upper beam locking connection 1-3 via the quick release shaft 11. The handle 12 is hinged to one side of the quick release shaft 11. The above description constitutes the locking structure.

[0048] The locking structure has multiple locking mechanisms. First, the rotation center of the locking structure is located below, while the mating point is above. The pressure of the seat 7 ensures a tight fit at the mating point. Even without a person sitting on it, the mating point remains tightly fitted due to the weight of the main frame itself. Second, the rearward tilt angle of the seat post 3 provides excellent locking. The lower surface of the seat post 3 rotates until it is flush with the upper part of the lower beam 2 and then stops rotating backward. Third, the seat post 3 is linked to the quick-release shaft 11, which rotates back and forth on the lower beam locking connection 2-2 to lock or open the main frame. The height of the flat part on the quick-release shaft 11 is consistent with the height of the front opening of the lower beam locking connection 2-2. The flat part on the quick-release shaft 11 rotates back and forth to lock or open the main frame. The movement from the front opening of the lower frame locking connection 2-2 to the axle hole is consistent with the locking and folding movement of the main frame. The consistent folding movement means that the seat post 3 is unlocked when it is folded close to the upper frame 1, and locked when it is rotated back to the riding position. Even without the flat part on the quick-release axle 11, it does not affect the locking of the main frame and the seat post 3. The flat part is set to prevent the seat post 3 from being dislodged from the lower frame locking connection 2-2 by the force of the rear on bumpy roads. Fourth, the handle 12 hinged on one side of the quick-release axle 11 locks the gap between the upper and lower frame locking connection and the seat post connection 3-1, making the main frame a fixed structure. After the handle 12 is locked, the seat post 3 will no longer rotate forward.

[0049] The combination of the quick-release shaft 11 with the hinged handle 12 on one side is a prior art quick-release mainly used for locking the seat tube clamp of the 7th seat of the vehicle.

[0050] The quick-release mechanism can be either screw-in or cam-type. This invention uses the cam-type mechanism, for example, the Xiaobu folding bike uses the screw-in mechanism.

[0051] The working principle of a bicycle main frame folding and locking structure is as follows: When riding, open the handlebars 12 to unlock the seat post 3, rotate the seat post 3 and the quick-release shaft 11 to rotate longitudinally to be close to the top of the upper beam 1, which also unlocks the lock with the lower beam 2. At this time, rotate the lower beam 2 and the rear wheel 9 and the front wheel 8 are parallel, so that the magnets between the two wheels attract each other. The seat 7 moves to one side of the main frame through the rotation of the seat post 3. After rotating the handlebars 12 to lock the folded seat post 3, the main frame folding is completed.

Claims

1. A bicycle main frame folding and locking structure, comprising: The bicycle includes a handlebar connector (5), a seat (7), a front wheel (8), a rear wheel (9), a drive structure (2-3), and a front fork (10). The main frame includes an upper beam (1), a lower beam (2), and a seat tube (3). The hinge axis of the upper beam (1) and the lower beam (2) is a rotating axis that connects or opens the locking connection part of the upper and lower beams. The seat tube (3) is hinged to the locking connection part (1-3) of the upper beam.

2. According to claim 1, the folding and locking structure of the bicycle main frame, the axis of the longitudinal rotatable hinge between the upper beam (1) and the lower beam (2) is biased towards one side of the main frame, that is, the axis is not perpendicular to one side of the main frame so that the front and rear wheels do not overlap but are parallel.

3. According to claim 1, the bicycle main frame folding locking structure, the handle (12) hinged on one side of the quick-release shaft (11) locks the gap between the upper and lower beam locking connection and the seat post connection (3-1) to make the main frame a fixed structure.

4. According to claim 1, the bicycle main frame folding and locking structure, in the riding state, the seat (7) is pressed down by gravity and the seat tube (3) is tilted backward so that it does not rotate to assist in locking the frame.

5. A bicycle main frame folding and locking structure according to claim 1 or 4, wherein when folding, the seat tube (3) rotates longitudinally to be close to the upper beam (1), and the seat tube (3) is linked to the seat (7) to one side of the main frame.

6. In the bicycle main frame folding and locking structure according to claim 3 or 5, the action of the rotating seat tube (3) and the quick-release shaft (11) locking the lower beam locking connection (2-2) is consistent with the main frame locking and folding action.

7. In the bicycle main frame folding and locking structure according to claim 6, the seat post connection (3-1) and the upper beam locking connection (1-3) are hinged by a quick-release shaft (11).

8. The bicycle main frame folding locking structure according to claim 7, wherein the quick-release shaft (11) is non-rotatably hinged to the seat post connection (3-1).

9. In the bicycle main frame folding locking structure according to claim 8, the quick-release shaft (11) is axially biased to one side of the main frame.

10. A bicycle main frame folding locking structure according to claim 3 or 9, wherein the quick-release shaft (11) hinges to the handle (12) to lock the seat post (3) before and after folding, and also locks the seat post (3) in the push state.

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