Double-center tube longitudinal fold tandem folding frame

Abstract

The utility model discloses a double middle tube longitudinal folding associated axle folding frame, including front frame, upper middle tube, lower middle tube, rear frame, upper seat pipe clamp, lower seat pipe clamp, seat rod, five -way pipe, rotation axis, the front frame includes upper crossbeam, lower crossbeam, car head pipe, upper crossbeam, lower crossbeam one end is connected with the side of car head pipe, and the other end of upper crossbeam is connected with the side of upper middle tube, and the other end of lower crossbeam is connected with the top of axle cylinder, and the rear frame includes rear upper fork, rear lower fork, and one end of rear upper fork is connected with the upper end side of lower middle tube, and the other end passes through the both sides of lower middle tube and is connected with lower crossbeam through rotation axis rotation, and the other end of rear upper fork, rear lower fork is connected with each other through rear insert piece, upper seat pipe clamp and lower seat pipe clamp are respectively sleeved in the top of upper middle tube and lower middle tube, and the seat pipe is worn in the inner hole of upper middle tube and lower middle tube. The utility model discloses through the lock catch of upper seat pipe clamp and lower seat pipe clamp to control the folding and unfolding between seat rod and front frame, rear frame, and the folding of bicycle is completed, and there is no influence to the overall strength of frame.

Description

Technical Field

[0001] This utility model relates to the technical field of bicycle folding frames, and particularly to a double-center-tube longitudinal folding coupling folding frame. Background Technology

[0002] The top of the bicycle's bottom tube connects to the seat, and the bottom connects to the pedal axle. The frame between the bottom tube and the front wheel is called the front frame, and the frame between the bottom tube and the rear wheel is called the rear frame. To facilitate carrying and storing bicycles when not in use, folding bicycles were developed. Typically, the frame crossbeams can be folded, reducing the bicycle's space-consuming nature. However, by breaking the crossbeams to create a folding frame, its vertical load-bearing capacity is weakened. Another type of longitudinally folding bicycle has a disconnect lock at the rear of the bottom tube, folding via a bottom bracket connector. While this also allows the bicycle to fold, the force exerted during riding creates gaps between the front and rear frames, weakening its lateral rigidity. Overall, the frame's strength is reduced for riding. Utility Model Content

[0003] The purpose of this invention is to optimize the existing folding bicycle structure and propose a double-center tube longitudinal folding coupling folding frame. This allows the bicycle to be folded without breaking the frame crossbeam or the rear frame, without affecting the overall strength of the frame.

[0004] To achieve the above objectives, this utility model proposes a double-center tube longitudinal folding frame, including a front frame, upper center tube, rear frame, lower center tube, bottom bracket tube, swivel shaft, upper seat tube clamp, lower seat tube clamp, and seat tube; the front frame includes an upper crossbeam, a lower crossbeam, and a head tube, with one end of the upper and lower crossbeams connected to the side of the head tube; the other end of the upper crossbeam is connected to the side of the upper center tube, and the other end of the lower crossbeam is connected to the top of the axle tube; the rear frame includes a rear upper fork and a rear lower fork, the rear upper... One end of the fork is connected to the upper side of the lower center tube. One end of the rear lower fork passes through both sides of the lower center tube and is rotatably connected to the lower crossbeam via a rotating shaft. The other ends of the rear upper fork and rear lower fork are connected to each other via rear inserts. The bottom bracket is fixedly connected to the lower crossbeam or rear lower fork, and the axis of the bottom bracket is perpendicular to the axis of the upper crossbeam. The bottom bracket connects to the pedal assembly. The upper and lower center tubes connect to the bicycle seat post. The upper seat post clamp and lower seat post clamp are respectively fitted onto the top ends of the upper and lower center tubes. The seat post is sequentially fitted into the inner holes of the upper seat post clamp, upper center tube, lower seat post clamp, and lower center tube.

[0005] In this design, the upper center tube, upper crossbeam, lower crossbeam, head tube, and axle tube form the front frame, while the lower center tube, rear upper fork, rear lower fork, rear sprocket, and axle lugs form the rear frame. The front and rear frames are assembled into a single, seamless folding structure by locking the seatpost, upper center tube, lower center tube, and seatpost clamp. After opening the seatpost clamp and pulling out the seatpost, it can be rotatably connected to the aforementioned whole structure via a rotating shaft to form the folding part. The upper and lower center tubes are locked on the same load-bearing line by the seatpost, and a double-locking structure is completed, which greatly strengthens the overall load-bearing structure. Maintaining its integrity ensures that the overall strength is not affected by folding, while the length of the folded bicycle is greatly reduced, making it easy to carry and store.

[0006] As a preferred embodiment of this utility model, a reinforcing tube is provided in the middle of the upper rear fork, and a reinforcing plate is provided in the middle of the lower rear fork.

[0007] In a preferred embodiment of this invention, the rotating shaft includes a shaft sleeve, shaft lugs, and a set of locking screws. A shaft lug is located on each of the two lower sides of the rear frame. The shaft sleeve is connected to the lower crossbeam. The two shaft lugs are respectively fitted against both sides of the shaft sleeve and rotatably connected to the shaft sleeve via the locking screws. The locking screws include a first connecting sleeve, a second connecting sleeve, and a fixing bolt. The first and second connecting sleeves pass through the shaft lugs from both sides and extend into the shaft sleeve. The fixing bolt passes through the first or second connecting sleeve and is threadedly fixed to the other connecting sleeve. This design utilizes a set of locking screws as the rotating shaft, with the first and second connecting sleeves rotatably connected to the shaft lugs on both sides.

[0008] In a preferred embodiment of this invention, the bottom bracket is fixedly connected to the rear chainstay, the rotating shaft is fixedly connected to the lower crossbeam, and the rear chainstay is rotatably connected to the rotating shaft. In this design, the bottom bracket rotates together with the rear frame when the rear frame rotates.

[0009] In a preferred embodiment of this utility model, a reinforcing plate is provided at the connection between the upper middle tube and the upper crossbeam; a reinforcing plate is also provided at the connection between the head tube and the upper crossbeam. This serves to secure the connection between the upper middle tube, the upper crossbeam, and the head tube.

[0010] As a preferred embodiment of this utility model, the bottom side of the upper middle tube and the top side of the lower middle tube are provided with C-groove connecting strips to connect and fix the upper middle tube and the lower middle tube.

[0011] The beneficial effects of this utility model are: the bicycle can be folded without disconnecting the frame crossbeam or the rear frame, and the overall strength of the frame is not affected.

[0012] The features and advantages of this utility model will be described in detail through embodiments and accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of a vehicle frame according to this utility model.

[0014] Figure 2 yes Figure 1 A schematic diagram of a folded frame structure.

[0015] Figure 3 yes Figure 1 An exploded view of a vehicle frame structure.

[0016] Figure 4 Is adopted Figure 1 A schematic diagram of a folding bicycle frame.

[0017] Figure 5 yes Figure 4 A schematic diagram of the folded structure of a folding bicycle.

[0018] Figure 6 This is a schematic diagram of another overall frame structure of this utility model.

[0019] Figure 7 yes Figure 6 An exploded view of a vehicle frame structure.

[0020] Figure 8 Is adopted Figure 6 A schematic diagram of the folded structure of a folding bicycle frame.

[0021] In the diagram: 1-Front frame, 2-Upper center tube, 3-Rear frame, 4-Lower center tube, 5-Bottom tube, 6-Swivel shaft, 7-Upper crossbeam, 8-Lower crossbeam, 9-Head tube, 10-Upper seat clamp, 11-Lower seat clamp, 12-Seat tube, 13-C-groove connecting strip, 15-Rear upper fork, 16-Rear lower fork, 17-Rear insert, 61-Shaft sleeve, 62-Shaft lug, 64-First connecting sleeve, 65-Second connecting sleeve, 66-Fixing bolt. Detailed Implementation

[0022] See Figures 1-8 This utility model provides the following technical solution:

[0023] The double-center tube longitudinal folding frame includes a front frame 1, an upper center tube 2, a rear frame 3, a lower center tube 4, a bottom bracket tube 5, a swivel shaft 6, an upper seat tube clamp 10, a lower seat tube clamp 11, and a seat post 12. The front frame 1 includes an upper crossbeam 7, a lower crossbeam 8, and a head tube 9. One end of the upper crossbeam 7 and the lower crossbeam 8 is connected to the side of the head tube 9, the other end of the upper crossbeam 7 is connected to the side of the upper center tube 2, and the other end of the lower crossbeam 8 is connected to the top of the axle tube 61. The rear frame 3 includes a rear upper fork 15 and a rear lower fork 16. The rear upper fork 15... The upper end is connected to the upper side of the lower middle tube 4. One end of the lower fork 16 passes through both sides of the lower middle tube 4 and is rotatably connected to the lower crossbeam 8 via the rotating shaft 6. The other ends of the upper fork 15 and the lower fork 16 are connected to each other via the rear insert 17. The bottom bracket 5 is fixedly connected to the lower fork 16. The axis of the bottom bracket 5 is perpendicular to the axis of the upper crossbeam 7. The bottom bracket 5 is connected to the pedal device. The upper middle tube 2 and the lower middle tube 4 are connected to the self-propelled seat tube 12. The upper seat tube clamp 10 and the lower seat tube clamp 11 are respectively fitted onto the top ends of the upper middle tube 2 and the lower middle tube 4. The seat tube is sequentially fitted into the inner holes of the upper seat tube clamp, the upper middle tube, the lower seat tube clamp, and the lower middle tube. A reinforcing tube is provided in the middle of the upper rear fork, and a reinforcing plate is provided in the middle of the lower rear fork. The rotating shaft 6 includes a shaft sleeve 61, shaft lugs 62, and a set of locking screws. A shaft lug 62 is located on each of the two lower sides of the rear frame 3. The shaft sleeve 61 is connected to the lower crossbeam 8. The two shaft lugs 62 are respectively close to both sides of the shaft sleeve 61 and are rotatably connected to the shaft sleeve 61 via locking screws. The locking screws include a first connecting sleeve 64, a second connecting sleeve 65, and a fixing bolt 66. The first connecting sleeve 64 and the second connecting sleeve 65 pass through the shaft lugs 62 from both sides and extend into the shaft sleeve 61. The fixing bolt 66 passes through the first connecting sleeve 64 or the second connecting sleeve 65 and is threadedly fixed to the other connecting sleeve. The bottom bracket 5 is connected and fixed to the lower crossbeam 8. The rotating shaft 6 is connected and fixed to the lower center tube 4 and the bottom bracket 5. The rotating shaft 6 is rotatably connected to the rear lower fork 16. (The last sentence is a repetition of the previous one and can be omitted.)

[0024] like Figure 3 As shown, a reinforcing plate 72 is provided at the connection between the upper middle tube 2 and the upper crossbeam 7; a reinforcing plate 71 is also provided at the connection between the head tube 9 and the upper crossbeam 7. These serve as the connection and fixation between the upper middle tube 2, the upper crossbeam 7, and the head tube 9.

[0025] like Figure 3 As shown, a C-groove connecting strip 13 is provided on the bottom side of the upper middle tube 2 and the top side of the lower middle tube 4 to serve as a connection and fixation between the upper middle tube 2 and the lower middle tube 4.

[0026] The working process of this utility model:

[0027] The upper center tube, upper crossbeam, lower crossbeam, head tube, and axle tube form the front frame, while the lower center tube, rear upper fork, rear lower fork, rear sprocket, and axle lugs form the rear frame. The front and rear frames are assembled into a single, seamless folding structure by locking the seatpost, upper center tube, lower center tube, and seatpost clamp. After opening the seatpost clamp and pulling out the seatpost, it can be rotatably connected to the aforementioned whole structure via a rotating shaft as a folding part. The upper and lower center tubes are locked onto the same load-bearing straight line by the seatpost.

[0028] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the protection scope of the present invention.

Claims

1. A double-center-tube longitudinal folding coupling folding frame, characterized in that: Includes front frame, upper center tube, rear frame, lower center tube, bottom bracket tube, swivel shaft, upper seat tube clamp, lower seat tube clamp, and seat tube; The front frame includes an upper crossbeam, a lower crossbeam, and a head tube. One end of the upper crossbeam and the lower crossbeam are connected to the side of the head tube, the other end of the upper crossbeam is connected to the side of the upper middle tube, and the other end of the lower crossbeam is connected to the top of the axle tube. The rear frame includes a rear upper fork and a rear lower fork. One end of the rear upper fork is connected to the upper side of the lower center tube. One end of the rear lower fork passes through both sides of the lower center tube and is rotatably connected to the lower crossbeam via a rotating shaft. The other ends of the rear upper fork and the rear lower fork are connected to each other via a rear insert. The bottom bracket is connected and fixed to the lower crossbeam or rear lower fork. The axis of the bottom bracket is perpendicular to the axis of the upper crossbeam. The bottom bracket is connected to the pedal device. The upper and lower middle tubes are connected to the bicycle seat post. The upper and lower tube clamps are respectively fitted onto the top ends of the upper and lower middle tubes; The seat tube is sequentially inserted into the inner holes of the upper seat tube clamp, the upper middle tube, the lower seat tube clamp, and the lower middle tube.

2. The folding frame with double central tube longitudinal folding coupling as described in claim 1, characterized in that: The upper rear fork is provided with a reinforcing tube in the middle, and the lower rear fork is provided with a reinforcing plate in the middle.

3. The double-center-tube longitudinal folding coupling folding frame as described in claim 1, characterized in that: The rotating shaft includes a shaft sleeve, shaft lugs, and a set of male and female locking screws. A shaft lug is provided on each of the two lower sides of the rear frame. The shaft sleeve is connected to the lower crossbeam. The two shaft lugs are respectively close to both sides of the shaft sleeve and are rotatably connected to the shaft sleeve by the male and female locking screws. The male and female locking screws include a first connecting sleeve, a second connecting sleeve, and a fixing bolt. The first connecting sleeve and the second connecting sleeve pass through the shaft lugs from both sides and extend into the shaft sleeve. The fixing bolt passes through the first connecting sleeve or the second connecting sleeve and is threadedly fixed to the other connecting sleeve.

4. The folding frame with double central tube longitudinal folding coupling as described in claim 1, characterized in that: The five-way pipe is fixedly connected to the rear lower fork, the rotating shaft is fixedly connected to the lower crossbeam, and the rear lower fork is rotatably connected to the rotating shaft.

5. The folding frame with double central tube longitudinal folding coupling as described in claim 1, characterized in that: A reinforcing plate is provided at the connection between the upper middle tube and the upper crossbeam; a reinforcing plate is also provided at the connection between the head tube and the upper crossbeam.

6. The folding frame with double center tube longitudinal folding coupling as described in claim 1, characterized in that: The bottom side of the upper middle tube and the top side of the lower middle tube are provided with C-groove connecting strips to connect and fix the upper middle tube and the lower middle tube.

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