JP2008247083A - Folding bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adopt a structure for folding an intermediate part of a main frame even when a rotation transmitting mechanism for transmitting rotation of a rear wheel to a front wheel is provided along the main frame. <P>SOLUTION: A first transmission gear 31 is provided in the vicinity of a connection part 1a of a rear wheel side frame body 2 to a front wheel side frame body 3. A second transmission gear 32 is provided in the vicinity of the connection part 1a of the front wheel side frame body 3 to the rear wheel side frame body 2. When the front wheel side frame body 3 is extended with respect to the rear wheel side frame body 2, the first and second transmission gears 31, 32 are engaged with each other. When the front wheel side frame body 3 is bent with respect to the rear wheel side frame body 2, the engagement of the first and second transmission gears 31, 32 is released. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a folding bicycle in which an intermediate portion of a main frame can be folded.

  In the conventional two-wheel drive type bicycle, the driving force input from the pedal is transmitted to the rear wheels via the main chain. The driving force transmitted to the rear wheels is transmitted to the front wheels via a plurality of transmission sprockets, a plurality of transmission chains wound around the transmission sprockets, and a joint mechanism that eliminates interference caused by turning of the steering shaft ( For example, see Patent Document 1).

WO2006 / 106592

  In the conventional two-wheel drive type bicycle as described above, since a transmission chain for transmitting the rotation of the rear wheel to the front wheel is stretched along the main frame, a structure in which an intermediate portion of the main frame is folded is applied. I couldn't.

  The present invention has been made to solve the above-described problems. Even when a rotation transmission mechanism for transmitting the rotation of the rear wheel to the front wheel is provided along the main frame, the intermediate portion of the main frame is provided. An object of the present invention is to obtain a folding bicycle that can be applied with a folding structure.

  The folding bicycle according to the present invention has a main frame having a rear wheel side frame body and a front wheel side frame body connected to the rear wheel side frame body so as to be able to bend and extend, and is rotatable to the rear wheel side frame body. A rear wheel provided, a front frame having a steering shaft rotatably connected to a front wheel side frame body, a front wheel provided rotatably on the front frame, and a main side transmission mechanism provided on the main frame; A rotation transmission mechanism that has an intermediate transmission mechanism provided between the main frame and the front frame and a front transmission mechanism provided on the front frame, and mechanically transmits the rotation of the rear wheel to the front wheel. The main transmission mechanism is provided in the vicinity of the connecting portion of the rear wheel frame body to the front wheel frame body, and the rotation of the rear wheel is transmitted and rotated. And a second transmission gear provided in the vicinity of the connecting portion between the front wheel side frame body and the rear wheel side frame body, and the front wheel side frame body is extended with respect to the rear wheel side frame body. Then, when the first and second transmission gears mesh with each other and the front wheel side frame body is bent with respect to the rear wheel side frame body, the meshing of the first and second transmission gears is released.

  In the folding bicycle according to the present invention, the transmission chain is not stretched across the connecting portion between the rear-wheel side frame body and the front-wheel side frame body, and the first and the second are separated from each other by extension / bending of the main frame. Since the transmission gear is provided separately for the rear wheel side frame body and the front wheel side frame body, even when a rotation transmission mechanism for transmitting the rotation of the rear wheel to the front wheel is provided along the main frame, A structure in which the part is folded can be applied.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a perspective view showing a folding bicycle according to Embodiment 1 of the present invention. In the figure, the main frame 1 has a rear wheel side frame body 2 and a front wheel side frame body 3 connected to the rear wheel side frame body 2 so as to be able to bend and extend. That is, the main frame 1 can be folded at the connecting portion 1a between the rear wheel side frame body 2 and the front wheel side frame body 3 located at the intermediate portion thereof.

  The rear wheel side frame body 2 is provided with a saddle shaft 4. A saddle (not shown) for the driver to sit on is attached to the upper end of the saddle shaft 4.

  A rear wheel 5 is rotatably connected to a rear end portion of the rear wheel side frame body 2. The rear wheel side frame body 2 is provided with a pair of pedals 6 for rotating the rear wheel 5. The driving force input to the pedal 6 is transmitted to the rear wheel 5 through the main chain 7.

  A steering shaft (handle shaft) 8 is pivotably connected to the front end portion of the front wheel side frame body 3. A handle (not shown) is attached to the upper end portion of the steering shaft 8. A front wheel arm 9 is connected to the lower end portion of the steering shaft 8. The front wheel arm 9 is turned together with the steering shaft 8. The axis of the front wheel arm 9 is offset laterally with respect to the axis of the steering shaft 8. The front frame 10 has a steering shaft 8 and a front wheel arm 9.

  A front wheel 11 is rotatably connected to a lower end portion of the front wheel arm 9. The rotating shaft of the front wheel 11 is cantilevered by the front wheel arm 9. The rotation of the rear wheel 5 is mechanically transmitted to the front wheel 11 via the rotation transmission mechanism 12. Thereby, the front wheel 11 is rotated at the same speed as the rear wheel 5.

  The rotation transmission mechanism 12 includes a main transmission mechanism 13 provided on the main frame 1, an intermediate transmission mechanism 14 provided between the main frame 1 and the front frame 10, and a front transmission provided on the front frame 10. And a mechanism 15.

  The main transmission mechanism 13 includes a rear wheel sprocket 16, first to fourth transmission sprockets 17 to 20, a transmission gear mechanism, and first to third transmission chains 21, 22, and 23.

  The rear wheel sprocket 16 is rotated integrally with the rear wheel 5. The first transmission sprocket 17 is provided on the side surface of the rear wheel side frame body 2. The second transmission sprocket 18 is provided on the side surface of the front wheel side frame body 3. The third transmission sprocket 19 is provided closer to the front frame 10 than the second transmission sprocket 18 on the side surface of the front wheel side frame body 3. The fourth transmission sprocket 20 is provided coaxially with the third transmission sprocket 19 and rotates integrally with the third transmission sprocket 19.

  The first transmission chain 21 transmits the rotation of the rear wheel sprocket 16 to the first transmission sprocket 17. The transmission gear mechanism is provided in the main frame 1 and transmits the rotation of the first transmission sprocket 17 to the second transmission sprocket 18.

  The second transmission chain 22 transmits the rotation of the second transmission sprocket 18 to the third transmission sprocket 19. The third transmission chain 23 transmits the rotation of the fourth transmission sprocket 19 to the intermediate transmission mechanism 14.

  The front transmission mechanism 15 includes a front wheel sprocket 24 that rotates integrally with the front wheel 11, and a fourth transmission chain 25 that transmits rotation on the output side of the intermediate transmission mechanism 14 to the front wheel sprocket 24.

  An attachment arm 26 for attaching the intermediate transmission mechanism 14 is fixed to the front end portion of the main frame 1. The intermediate transmission mechanism 14 is disposed between the mounting arm 26 and the front wheel arm 9 so that the axial direction is horizontal and parallel to the left-right direction when the steering shaft 8 is in the straight traveling direction. The mounting arm 26 is parallel to the front wheel arm 9. Further, the axis of the mounting arm 26 is offset to the opposite side of the front wheel arm 9 with respect to the axis of the steering shaft 8.

  The intermediate transmission mechanism 14 transmits the driving force input from the third transmission chain 23 to the fourth transmission chain 25 while allowing the steering shaft 8 to turn. Further, the intermediate transmission mechanism 14 transmits the driving force from the third transmission chain 23 to the fourth transmission chain 25 without receiving interference due to the turning of the steering shaft 8. Further, the intermediate transmission mechanism 14 allows the steering shaft 8 to turn without receiving interference due to transmission of the driving force.

  2 is a plan view showing a main part of the main frame 1 in FIG. 1, FIG. 3 is a perspective view showing the main frame 1 in FIG. 2, and FIG. 4 is a perspective view showing a state in which the main frame 1 in FIG. . In the figure, the rear wheel side frame body 2 and the front wheel side frame body 3 are connected via a hinge 27.

  Inside the rear wheel side frame body 2 and the front wheel side frame body 3, first to third transmission gears 31 to 33 are provided. The first transmission gear 31 is provided in the vicinity of the connecting portion 1 a between the rear wheel side frame body 2 and the front wheel side frame body 3. The second transmission gear 32 is provided in the vicinity of the connecting portion 1 a with the rear wheel side frame body 2 of the front wheel side frame body 3.

  When the front wheel side frame body 3 is extended with respect to the rear wheel side frame body 2, the first and second transmission gears 31 and 32 mesh with each other. Further, when the front wheel side frame body 3 is bent with respect to the rear wheel side frame body 2, the meshing of the first and second transmission gears 31 and 32 is released.

  The third transmission gear 33 is provided on the front wheel side frame body 3 and meshes with the second transmission gear 32. The first transmission sprocket 17 is provided coaxially with the first transmission gear 31 located closest to the rear wheel 5 among the first to third transmission gears 31 to 33, and is integrated with the first transmission gear 31. It is rotated. Accordingly, the first transmission gear 31 is rotated by the rotation of the rear wheel 5 being transmitted.

  The second transmission sprocket 18 is provided coaxially with the third transmission gear 33 located closest to the front frame 10 among the first to third transmission gears 31 to 33, and is integrated with the third transmission gear 33. It is rotated. The second transmission gear 32 is disposed between the first transmission gear 31 and the third transmission gear 33, and meshes with the first transmission gear 31 and the third transmission gear 33. Accordingly, the first transmission sprocket 17 and the second transmission sprocket 18 are rotated in the same direction.

  The rear wheel 5 is rotated by the rear wheel sprocket 16, the first transmission chain 21, the first transmission sprocket 17, the first transmission gear 31, the second transmission gear 32, the third transmission gear 33, Via the transmission sprocket 18, the second transmission chain 22, the third transmission sprocket 19, the fourth transmission sprocket 20, the third transmission chain 23, the intermediate transmission mechanism 14, the fourth transmission chain 25 and the front wheel sprocket 24 It is transmitted to the front wheel 11.

  In such a foldable bicycle, the transmission chain is not stretched across the connecting portion 1 a between the rear wheel side frame body 2 and the front wheel side frame body 3, but the first and the second are connected to and separated from each other by extension and bending of the main frame 1. Since the second transmission gears 31 and 32 are provided separately for the rear wheel side frame body 2 and the front wheel side frame body 3, the rotation transmission mechanism 12 for transmitting the rotation of the rear wheel 5 to the front wheel 11 is provided in the main frame 1. Even when it is provided along, the structure which folds the intermediate part of the main frame 1 is applicable.

  The transmission gear mechanism includes first to third transmission gears 31 to 33, and the first and third transmission gears 31 and 33 positioned at both ends of the transmission gear mechanism are connected to the first and third transmission shafts. Since the second transmission sprockets 17 and 18 are fixed, the rotation directions of the first and second transmission sprockets 17 and 18 can be made the same, and the front wheel 11 can be moved in the same direction as the rear wheel 5 with a simple configuration. Can be rotated.

  Further, as shown in FIG. 4, when the front wheel side frame body 3 is bent with respect to the rear wheel side frame body 2, the first and second transmission sprockets 17 and 18 are positioned outside the main frame 1. Therefore, the first and second transmission sprockets 17 and 18 do not interfere with each other, and the size of the bicycle when folded can be reduced.

Embodiment 2. FIG.
Next, FIG. 5 is a plan view showing an essential part of a folding bicycle according to Embodiment 2 of the present invention. In this example, the third transmission gear 33 is provided on the rear wheel side frame body 2 and meshes with the first transmission gear 31.

  The first transmission sprocket 17 is provided coaxially with the third transmission gear 33 located closest to the rear wheel 5 among the first to third transmission gears 31 to 33, and is integrated with the third transmission gear 33. It is rotated. The second transmission sprocket 18 is provided coaxially with the second transmission gear 32 located closest to the front frame 10 among the first to third transmission gears 31 to 33. It is rotated together. Other configurations are the same as those in the first embodiment.

  Even with such a configuration, the rotation directions of the first and second transmission sprockets 17 and 18 can be made the same.

Embodiment 3 FIG.
Next, FIG. 6 is a plan view showing an essential part of a folding bicycle according to Embodiment 3 of the present invention. In this example, the first transmission sprocket 17 is provided coaxially with the first transmission gear 31 and is rotated integrally with the first transmission gear 31. Further, the second transmission sprocket 18 is provided coaxially with the second transmission gear 32 and is rotated integrally with the second transmission gear 32. Therefore, the rotation directions of the first and second transmission sprockets 17 and 18 are opposite to each other.

  The front-wheel-side frame body 3 has a third transmission gear 34 that rotates integrally with the third transmission sprocket 19, and a fourth transmission gear that meshes with the third transmission gear 34 and rotates integrally with the fourth transmission sprocket 20. A transmission gear 35 is provided. Therefore, the rotation directions of the third and fourth transmission sprockets 19 and 20 are opposite to each other. Other configurations are the same as those in the first embodiment.

  In such a configuration, the rotation directions of the first transmission sprocket 17 and the fourth transmission sprocket 20 can be made the same, and the front wheel 11 can be rotated in the same direction as the rear wheel 5 with a simple configuration. .

Embodiment 4 FIG.
Next, FIG. 7 is a perspective view showing a folding bicycle according to Embodiment 4 of the present invention. In FIG. 7, the rotation transmission mechanism 12 shown in the first embodiment is not shown. However, a rear-wheel-drive bicycle without the rotation transmission mechanism 12 may be used. It can also be a wheel-driven bicycle.

  In the figure, a steering shaft 8 includes a lower steering shaft body 41 connected to the front wheel side frame body 3 and an upper steering shaft body connected to the upper end portion of the lower steering shaft body 41 so as to be rotatable (bendable / extendable). 42. That is, the steering shaft 8 can be folded at the connecting portion 8a located at the intermediate portion thereof. A handle 48 (FIGS. 8 and 9) is supported on the upper steering shaft body 42.

  The rear wheel side frame body 2 includes a rear wheel side main tube 43 connected to the front wheel side frame body 3, a seat tube 44 fixed to the rear wheel side main tube 43 and connected to the saddle shaft 4, and a seat tube 44 A rear wheel arm 45 fixed to which the rear wheel 5 is connected, a down tube 46 fixed between the rear wheel side main tube 43 and the lower end portion of the seat tube 44, a side surface of the rear wheel side main tube 43 and the rear side. It has a rod-like handle (gripping member) 47 fixed between the side surfaces of the wheel arm 45.

  The connecting portion of the rear wheel arm 45 with the seat tube 44 is curved, and the axis of the rear wheel arm 45 is offset to the same side as the front wheel arm 9 with respect to the axis of the rear wheel main tube 43. . The rotating shaft of the rear wheel 5 is cantilevered by the rear wheel arm 45. The handle 47 serves as both a gripping part that is gripped when carrying the folded bicycle and a reinforcing material for the rear wheel side frame body 2.

  FIG. 8 is a plan view showing a state in which the steering shaft 8 of FIG. 7 is folded. When the steering shaft 8 is viewed from directly above, the rotation shaft of the upper steering shaft body 42 with respect to the lower steering shaft body 41 is inclined by an angle θ1 with respect to a straight line perpendicular to the longitudinal direction of the bicycle. The inclination angle θ1 is preferably 45 °, for example.

  FIG. 9 is a side view of the steering shaft 8 of FIG. 8 viewed from the direction of the arrow IX. The pivot shaft of the upper steering shaft body 42 with respect to the lower steering shaft body 41 is arranged so as to avoid interference with the front wheel arm 9 of the handle 48 when the upper steering shaft body 42 is bent with respect to the lower steering shaft body 41. It is inclined by an angle θ2 with respect to the horizontal plane. The inclination angle θ2 is preferably 10 ° to 15 °, for example 12 °.

  10 is a plan view showing the rear wheel side frame body 2 of FIG. 7, and FIG. 11 is a front view of the rear wheel side frame body 2 of FIG. 10 viewed from the direction of the arrow XI. The intermediate portion of the down tube 46 is curved, whereby the lower end is offset from the center in the width direction of the bicycle to the same side as the rear wheel arm 45.

  In such a foldable bicycle, the pivot shaft of the upper steering shaft body 42 with respect to the lower steering shaft body 41 is inclined by a predetermined angle with respect to the horizontal plane, so that when the steering shaft 8 is folded, the handle 48 is Interference with the front wheel arm 9 is prevented, and the size of the bicycle when folded can be reduced.

Further, since the handle 47 is fixed between the side surface of the rear wheel side main tube 43 and the side surface of the rear wheel arm 45, the handle 47 can be provided with both a function as a reinforcing material and a function as a grip portion. it can.
Furthermore, by curving the intermediate portion of the down tube 46, the rigidity of the down tube 46 in the compression direction can be reduced, and the absorption capacity of vibration and impact can be increased. Thereby, the stress which generate | occur | produces in the rear-wheel side frame body 2 can be disperse | distributed suitably, and the damage by stress concentration can be prevented.

1 is a perspective view showing a folding bicycle according to Embodiment 1 of the present invention. FIG. It is a top view which shows the principal part of the main frame of FIG. It is a perspective view which shows the main frame of FIG. It is a perspective view which shows the state which folded the main frame of FIG. It is a top view which shows the principal part of the foldable bicycle by Embodiment 2 of this invention. It is a top view which shows the principal part of the folding bicycle by Embodiment 3 of this invention. It is a perspective view which shows the folding bicycle by Embodiment 4 of this invention. It is a top view which shows the state which folded the steering shaft of FIG. It is the side view which looked at the steering shaft of FIG. 8 from the arrow IX direction. It is a top view which shows the rear-wheel side frame body of FIG. It is the front view which looked at the rear-wheel side frame body of FIG. 10 from the arrow XI direction.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Main frame, 1a Connecting part, 2 Rear wheel side frame body, 3 Main frame, 5 Rear wheel, 8 Steering shaft, 9 Front wheel arm, 10 Front frame, 11 Front wheel, 12 Rotation transmission mechanism, 13 Main side transmission mechanism, 14 Intermediate transmission mechanism, 15 Front transmission mechanism, 17 First transmission sprocket, 18 Second transmission sprocket, 19 Third transmission sprocket, 21 First transmission chain, 22 Second transmission chain, 31 First transmission Gear, 32 Second transmission gear, 33 Third transmission gear, 41 Lower steering shaft body, 42 Upper steering shaft body, 43 Rear wheel side main tube, 45 Rear wheel arm, 47 Handle, 48 Handle.

Claims (4)

A main frame having a rear wheel side frame body and a front wheel side frame body connected to the rear wheel side frame body so as to be able to bend and extend;
A rear wheel rotatably provided on the rear wheel side frame body;
A front frame having a steering shaft connected to the front-wheel-side frame body so as to be able to turn;
A front wheel rotatably provided on the front frame; a main transmission mechanism provided on the main frame; an intermediate transmission mechanism provided between the main frame and the front frame; and the front frame. A rotation transmission mechanism that mechanically transmits the rotation of the rear wheel to the front wheel.
The main side transmission mechanism is provided in the vicinity of a connecting portion of the rear wheel side frame body to the front wheel side frame body, and transmits a rotation of the rear wheel to transmit the first transmission gear and the front wheel side. A second transmission gear provided in the vicinity of the connecting portion of the frame body with the rear wheel side frame body,
When the front wheel side frame body is extended with respect to the rear wheel side frame body, the first and second transmission gears mesh with each other, and the front wheel side frame body is bent with respect to the rear wheel side frame body. When this is done, the folding bicycle is characterized in that the meshing of the first and second transmission gears is released. The main transmission mechanism is
A third transmission gear provided on one of the rear wheel side frame body and the front wheel side frame body and meshing with one of the first transmission gear and the second transmission gear;
A first transmission sprocket that is rotated integrally with a transmission gear that is located closest to the rear wheel among the first to third transmission gears;
A first transmission chain for transmitting the rotation of the rear wheel to the first transmission sprocket;
A second transmission sprocket that rotates integrally with a transmission gear that is located closest to the front frame among the first to third transmission gears;
A third transmission sprocket provided closer to the front frame than the second transmission sprocket of the front wheel side frame body;
The folding bicycle according to claim 1, further comprising: a second transmission chain that transmits the rotation of the second transmission sprocket to the third transmission sprocket. A main frame having a rear wheel side frame body and a front wheel side frame body connected to the rear wheel side frame body so as to be able to bend and extend;
A rear wheel rotatably provided on the rear wheel side frame body;
A lower steering shaft that is pivotably connected to the front-wheel-side frame body, an upper steering shaft that is connected to the lower steering shaft so as to be able to bend and extend, and an axis of the lower steering shaft A front frame with a laterally offset front wheel arm,
A front wheel whose cantilever is supported by the front wheel arm, and a handle supported by the upper steering shaft,
The pivot shaft of the upper steering shaft body with respect to the lower steering shaft body is configured to avoid interference with the front wheel arm of the handle when the upper steering shaft body is bent with respect to the lower steering shaft body. A folding bicycle characterized by being inclined at a predetermined angle with respect to a horizontal plane. A main frame having a rear wheel side frame body and a front wheel side frame body connected to the rear wheel side frame body so as to be able to bend and extend;
A rear wheel rotatably provided on the rear wheel side frame body;
A front frame having a steering shaft rotatably connected to the front wheel side frame body, and a front wheel rotatably provided on the front frame,
The rear wheel side frame body includes a rear wheel side main tube coupled to the front wheel side frame body, a rear wheel arm offset laterally with respect to an axis of the rear wheel side main tube, and the rear wheel A foldable bicycle comprising a handle fixed between a side surface of the side main tube and a side surface of the rear wheel arm.

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