WO2018163227A1

WO2018163227A1 - Foldable bicycle

Info

Publication number: WO2018163227A1
Application number: PCT/JP2017/008643
Authority: WO
Inventors: 吉田　明弘
Original assignee: 株式会社テック・ワン
Priority date: 2017-03-06
Filing date: 2017-03-06
Publication date: 2018-09-13
Also published as: JPWO2018163227A1; JP6854021B2

Abstract

The present invention provides a foldable bicycle that is capable of preventing the front wheel from being unexpectedly folded rearward when the bicycle is used. A fork column (33) forming the upper part of a front fork (31) of a foldable bicycle (101) is supported by a head tube (1) so as to be pivotable in a steering direction, and divided into upper and lower fork columns (57, 59) that are connected to each other by a rotary shaft (61) so as to be bendable in the longitudinal direction. In a state where the bicycle (101) is used, the upper and lower fork columns (57, 59) are positioned in the head tube (1), and are prevented from bending about the rotary shaft (61) by the head tube (1). In order to fold the bicycle (101), the fork column (33) is pulled out downward by releasing a restraint member (69), the lower fork column (59) is bent about the rotary shaft (61), and the front wheel (29) is folded rearward.

Description

Folding bicycle

The present invention relates to a folding bicycle that can be reduced in overall length as compared with the use state by folding a front wheel backward and a rear wheel forward.

Conventionally, the technology described in Patent Document 1 is known as this type of folding bicycle. In this prior art, the seat stay can be removed at the connecting portion with the seat tube, and the chain stay can be rotated from below to the front at the connecting portion with the seat tube. It can be folded forward. Further, the front fork is divided into an upper member and a lower member that are connected to each other so as to be foldable, and the front wheel can be folded rearward by folding the lower member rearward of the bicycle. .

However, in the conventional technique described in Patent Document 1, in order to prevent the front fork from being bent during use of the bicycle, high strength is required for the connecting portion that connects the upper member and the lower member. Further, in order to reliably prevent the bending, it is necessary to provide a double mechanism such as a safety pin in the connecting portion, and there is a problem that the structure and operation of the connecting portion become complicated.

JP 2012-91586 JP

The present invention has been made in view of the above-mentioned problems, and the front wheels are rearwardly inadvertently used in the state of use of the bicycle without requiring complicated members with exceptionally high strength and without complicated operations. An object is to provide a folding bicycle that can be prevented from being folded.

In order to solve the above problems and achieve the above object, the first aspect of the present invention is such that the front wheel is folded rearward and the rear wheel is folded forward, thereby reducing the total length as compared with the use state. The folding bicycle includes a handlebar, a head tube, and a front fork as a front wheel steering mechanism. The fork column that forms the upper portion of the front fork passes through the head tube and is pivotally supported by the head tube so as to be rotatable in the steering direction. It is divided into upper and lower fork column portions that are flexibly connected in the front-rear direction or substantially front-rear direction. In the use state, at least a part of the upper fork column part and the lower fork column part including the pivot shaft are located in the head tube in the use state, thereby the upper and lower fork columns. Bending around the pivot axis of the part is prevented by the head tube. The front wheel steering mechanism further includes a restraining member that releasably restrains the fork column from shifting downward. Further, by releasing the restraining member, the fork column can be shifted downward so that the entire lower fork column portion is exposed below the head tube, thereby moving the front wheel rearward. Can be folded.

According to this configuration, when the bicycle is in use, a part of the upper fork column part and at least a part of the lower fork column part including the pivot shaft that connects the upper and lower fork column parts are the head tube. , So that bending of the upper and lower fork column portions around the pivot axis is prevented by the head tube. In use, the fork column is pushed upward by the drag of the ground received by the front wheels, and this upward force acts to prevent the fork column from being displaced downward of the head tube. Further, even if the front wheel floats above the ground in use, the fork column is restrained from being displaced below the head tube by the restraining member. In this way, it is avoided that the front wheel is folded backward in the use state. Further, when the bicycle is in use, it is sufficient that the upper and lower fork column portions are connected by a rotating shaft, and no special member is required for the connecting portion. In addition, the bending of the upper and lower fork column portions is blocked by the head tube, and members that have a particularly complicated structure and require complicated operations to prevent bending are members that have a particularly high strength. It does not need. Further, the restraining member only needs to restrain the fork column from being displaced downward from the head tube by its own weight including the front wheel, and therefore, it does not require a particularly high strength, complicated structure or operation. When the bicycle is not in use, the fork column can be shifted downward so that the entire lower fork column is exposed under the head tube by releasing the restraining member, thereby folding the front wheel backward. It is possible. As described above, according to this configuration, the front wheel is prevented from being folded rearward carelessly in the use state of the bicycle without requiring a complicated member having a particularly high strength and without requiring a complicated operation. A folding bike that can be made is realized.

According to a second aspect of the present invention, there is provided a folding bicycle according to the first aspect, wherein the front wheel steering mechanism is pivotally supported in the head tube so as to be rotatable in the steering direction. Further comprises a constrained tube. The fork column slidably penetrates the tube, and includes at least a part of the upper fork column part and the lower fork column part including the rotating shaft in the use state. In which the bending of the upper and lower fork column portions around the pivot axis is prevented directly by the tube. The restraining member restrains the fork column from being displaced in the steering direction and downward with respect to the pipe in a releasable manner. Further, by releasing the restraining member, the fork column can be slid downward so that the entire lower fork column portion is exposed below the pipe and the head tube, thereby The front wheel can be folded backward.

According to this configuration, when the bicycle is in use, at least a part of the upper fork column part and at least a part of the lower fork column part including the pivot shaft that connects the upper and lower fork column parts are formed of the pipe. Located inside, so that bending of the upper and lower fork column sections around the pivot axis is prevented directly by the tube. In order to prevent the upper and lower fork column portions from bending, the tube in the head tube does not require a special structure and does not require a particularly high strength. Further, the fork column slidably penetrates a tube pivotally supported in the head tube and rotates in the steering direction together with the tube. The backlash of the fork column and the friction between the connecting portion and the inner wall surface of the head tube due to bending at the connecting portion can be suppressed.

According to a third aspect of the present invention, there is provided a folding bicycle according to the second aspect, wherein the tube has an upper exposed portion that is a portion exposed above the head tube, and the upper exposed portion. The part is formed with a cut from the upper end downward. In the use state, the restraining member is configured to releasably tighten a portion of the upper fork column portion exposed above the head tube together with an upper exposed portion of the tube so that the fork column is A member that releasably restrains the pipe from shifting in the steering direction and downward.

According to this configuration, the restraining member can be realized with a particularly simple structure.

According to a fourth aspect of the present invention, there is provided a folding bicycle according to any one of the first to third aspects, wherein the handle bar is divided into left and right handle bar parts, and the front wheel The steering mechanism further includes a handle stem that connects the left and right handlebar portions to the fork column. Then, the handle stem supports the left and right handlebars so that the left and right handlebars can be bent rearward, and the posture in the use state is maintained. There is a rotation stopping member that stops the rotation of the part so as to be releasable.

According to this configuration, when the front wheel is folded backward and the rear wheel is folded forward, the left and right handlebar portions can be folded backward by releasing the rotation restraining member. Thereby, it can avoid that a handlebar protrudes from right and left, and the whole folded bicycle can be made more compact.

According to a fifth aspect of the present invention, there is provided a folding bicycle according to the fourth aspect, wherein the handle bar is a drop-type handle bar whose front end portion extends rearward when in use.

Since the handlebar is a drop-type handlebar whose front end extends rearward when in use, when the left and right handlebar portions are folded rearward, the folded front and rear wheels are left and right by the left and right handlebar portions. By hugging, the entire folded bicycle can be prevented from bulging left and right.

According to a sixth aspect of the present invention, there is provided a folding bicycle according to the fifth aspect, wherein the left handlebar portion and the right handlebar portion are rotatably supported by the handle stem. The positions are shifted from each other back and forth, so that when the left and right handlebar portions are bent rearward, interference between the tip portions of the left and right handlebar portions is avoided.

According to this configuration, when the handlebar is a drop-type handlebar whose front end portion extends rearward when in use, the left and right handlebar portions are bent when the left and right handlebar portions are bent rearward. Interference between the tips is avoided.

According to the seventh aspect of the present invention, the front wheel can be folded rearward and the rear wheel folded forward, so that the overall length can be reduced as compared with the use state. The handlebar is a drop-type handlebar whose front end extends rearward when in use, and is divided into a left-hand side and a right-hand handlebar, and the front wheel steering mechanism is provided with the left-hand side and the right-hand side. A handle stem that connects the handle bar portion to a fork column that forms an upper portion of the front fork is further provided. Then, the handle stem supports the left and right handlebars so that the left and right handlebars can be bent rearward, and the posture in the use state is maintained. A rotation stopping member that stops the rotation of the part so as to be releasable is provided. In addition, the left handlebar portion and the right handlebar portion are pivotally supported by the handle stem so that the left and right handlebar portions are shifted rearward. When bent, interference between the tip portions of the left and right handlebar portions is avoided.

According to this configuration, when the front wheel is folded backward and the rear wheel is folded forward, the left and right handlebar portions can be folded backward by releasing the rotation restraining member. Thereby, it can avoid that a handlebar protrudes from right and left, and the whole folded bicycle can be made more compact. In addition, since the handlebar is a drop-type handlebar whose front end portion extends rearward when in use, when the left and right handlebar portions are folded rearward, the folded front and rear wheels are moved by the left and right handlebar portions. It can be hugged from the left and right so that the entire folded bicycle does not swell from side to side. Further, when the handlebar is a drop-type handlebar whose front end portion extends rearward when in use, when the left and right handlebar portions are bent rearward, the left and right handlebar portions may Interference is avoided.

As described above, according to the present invention, the front wheel is prevented from being folded rearward carelessly in the use state of the bicycle without requiring a complicated member having a particularly high strength and without requiring a complicated operation. A folding bike that can be made is realized.
The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

FIG. 1 is a side view showing an appearance of a folding bicycle according to an embodiment of the present invention. FIG. 2 is a bottom view of the bicycle frame of FIG. FIG. 3 is an exploded view of the steering mechanism of the bicycle of FIG. 4 is a cross-sectional view showing the internal structure of the steering mechanism of FIG. 5A and 5B are views showing a use state of the handlebar of the bicycle of FIG. 1, in which FIG. 5A is a plan view and FIG. 5B is a perspective view. 6A and 6B are views showing an intermediate state between the use state and the folded state of the handle bar of FIGS. 5A and 5B, FIG. 6A is a plan view, and FIG. 6B is a perspective view. 7A and 7B are views showing the folded state of the handle bar of FIGS. 5A and 5B, where FIG. 7A is a plan view and FIG. 7B is a perspective view. 8A to 8C are views showing the folded state of the bicycle shown in FIG. 1. FIG. 8A is a plan view, FIG. 8B is a side view, and FIG. 8C is a front view.

FIG. 1 is a side view showing the appearance of a folding bicycle according to an embodiment of the present invention. The bicycle 101 includes a head tube 1, a top tube 3, a down tube 5, a seat tube 7, a seat stay 9, and a chain stay 11 as a frame 10. Further, a reinforcing pipe 13 for reinforcement is connected between the head tube 1 and the down tube 5.

The base end portion of the chain stay 11 is pivotally supported on a rotation shaft 15 near the lower end portion of the seat tube 7 so as to be rotatable. The rotation shaft 15 is a horizontal axis or a substantially horizontal axis. The front end portion of the seat stay 9 and the front end portion of the chain stay 11 are fixed to a support member 23 that supports the axle 21 of the rear wheel 19. Thereby, the seat stay 9 and the chain stay 11 are fixedly connected to each other. The base end portion of the seat stay 9 is detachably connected by a connecting mechanism 25. As an example of the coupling mechanism 25, a structure in which a metal protrusion is inserted into a concave portion of an elastic body such as rubber and the coupling state is maintained by the frictional force of both can be employed. The connected state of the connecting mechanism 25 can be released by lifting the bicycle 101 to lift the rear wheel 19 off the ground and kicking the rear wheel 19 backward with a leg. When the coupling state of the coupling mechanism 25 is released, the chain stay 11 can be rotated downward around the rotation shaft 15 together with the seat stay 9 and the rear wheel 19, and can be further rotated forward. it can. Thereby, the rear wheel 19 can be folded forward.

FIG. 2 is a bottom view of the frame 10 of the bicycle 101. As shown in the drawing, the axial direction of the rotation shaft 15 of the chain stay 11 is somewhat inclined from the left-right direction. For this reason, when the rear wheel 19 is folded forward, the rear wheel 19 is folded so as to overlap the left side of the seat tube 7 and the down tube 5 without interfering with the seat tube 7 or the down tube 5.

FIG. 3 is an exploded view of the steering mechanism of the bicycle 101. FIG. 4 is a cross-sectional view showing the internal structure of the steering mechanism, showing the structure after assembly. In the steering mechanism 20, a support tube 27 is pivotally supported inside the head tube 1 so as to be rotatable in the steering direction. The support pipe 27 is a member that supports the fork column 33 by passing a fork column (also referred to as “steering pipe”) 33 that is an upper portion of the front fork 31 that supports the axle 35 of the front wheel 29 inside.

The support tube 27 is formed by screwing the upper tube portion 39 and the lower tube portion 41 together. A flange-like grip 43 is formed near the upper end portion of the upper tube portion 39, for example, to be gripped and screwed with a spanner, and a female screw 45 is formed at the lower end portion. A similar grip 47 is formed at the lower end portion of the lower tube portion 41, and a male screw 48 is formed at the upper end portion. Concavities and convexities for facilitating screwing are formed on the outer peripheral surfaces of the flange-shaped

grips

43 and 47.

An annular cup (upper one) 49 and a cup (lower one) 51, which are bearing receivers, are fitted to the upper end and lower end of the head tube 1, respectively.

Ring bearings

53 and 55 are fitted inside the

cups

49 and 51, respectively. The upper tube portion 39 of the support tube 27 is inserted into the head tube 1 from the upper end so as to pass through the bearing 53. Similarly, the lower pipe portion 41 is inserted into the head tube 1 from the lower end so as to pass through the bearing 55. Then, by gripping the

grips

43 and 47 with, for example, a spanner and turning them opposite to each other, the female screw 45 of the upper tube portion 39 and the male screw 48 of the lower tube portion 41 are screwed together, and the upper tube portion 39 and The lower pipe portion 41 is fastened to each other. As a result, the cup 49 and the bearing 53 are sandwiched between the upper end portion of the head tube 1 and the grip 43 and are restrained in the axial direction. Similarly, the cup 51 and the bearing 55 are sandwiched between the lower end portion of the head tube 1 and the grip 47 and are restrained in the axial direction. In this way, the support tube 27 is pivotally supported on the upper end portion and the lower end portion of the head tube 1 via the

bearings

53 and 55 so as to be rotatable in the steering direction.

The fork column 33 is inserted into the support tube 27. The fork column 33 is tubular in the most part, and its diameter is set to have a slight play with respect to the inner diameter of the support tube 27. For this reason, the fork column 33 is slidable with respect to the support tube 27 with almost no backlash.

The fork column 33 is divided into an upper fork column portion 57 and a lower fork column portion 59. The upper and lower

fork column portions

57 and 59 are connected to each other by a rotation shaft 61 so that they can be bent in the front-rear direction or substantially front-rear direction. When the bicycle 101 is in use, the fork column 33 is inserted through the support tube 27 and is pulled up until the lower end of the lower fork column portion 59 contacts the lower end of the support tube 27. At this time, the upper end portion of the upper fork column portion 57 protrudes upward from the upper end of the support tube 27. The support tube 27 has an upper exposed portion 63 that extends to above the grip 43 and is exposed above the head tube 1 in the vicinity of the upper end portion thereof. The upper exposed portion 63 has a notch 65 formed downward from the upper end. An annular spacer 67 is placed on the grip 43 so that the upper exposed portion 63 is inserted, and an annular clamp 69 is placed thereon. The clamp 69 fastens the upper exposed portion 63 of the support tube 27 together with the upper fork column portion 57 inside thereof. Accordingly, the fork column 33 is restrained so as not to be displaced from the head tube 1.

In a state where the fork column 33 is restrained from being lowered by the clamp 69, the rotation shaft 61 that connects the upper and lower

fork column portions

57 and 59 is in the support tube 27. A part of the upper fork column portion 57 and the lower fork column portion 59 are also in the support tube 27. For this reason, the upper and lower

fork column portions

57 and 59 cannot be bent around the rotation shaft 61, and the fork column 33 is maintained in a single straight bar shape. That is, the support pipe 27 prevents the upper and lower

fork column portions

57 and 59 from bending. In this way, it is possible to prevent the fork column 33 from being bent carelessly when the bicycle 101 is in use.

In order not to bend the upper and lower

fork column portions

57 and 59, the support tube 27 does not require a special structure and does not require a particularly high strength. For example, an aluminum alloy tube having a thickness of about 2 mm can be used as the support tube 27. When the bicycle 101 is in use, the fork column 33 is pushed upward by the ground drag received by the front wheels 29, and this upward force acts to prevent the fork column 33 from coming out of the head tube 1. As a mechanism for preventing the fork column 33 from coming out of the head tube 1 when the bicycle 101 is in use, it is sufficient to prevent the fork column 33 from coming off due to the weight of the front wheel 29, the front fork 31, and the like. For this reason, as a mechanism for preventing the fork column 33 from coming off, it is possible to employ a clamp 69 that does not require special strength, has a simple structure, and is easy to operate.

Since the fork column 33 is slidably inserted into the support tube 27 and there is almost no play, play of the fork column 33 due to bending of the upper and lower

fork column portions

57 and 59 is suppressed. Further, since the support tube 27 rotates together with the fork column 33 in the steering direction, the fork column 33 is bent between the fork column 33 and the support tube 27 in accordance with the steering operation. There is no friction. Further, the fork column 33 is supported by the head tube 1 through the support tube 27 and does not directly contact the head tube 1, so that friction between the fork column 33 and the head tube 1 occurs with steering. Will not occur.

When the bicycle 101 is not used, for example, when stored, the fork column 33 can be pulled out from the head tube 1 by releasing the tightening of the clamp 69. When the fork column 33 is pulled out so that the entire lower fork column portion 59 is exposed from the head tube 1, the lower fork column portion 59 is moved around the rotation shaft 61 with respect to the upper fork column portion 57. Can be bent. Thereby, the front wheel 29 can be folded back.

As described above, the bicycle 101 can fold the front wheel 29 or return it to the use state by a simple operation. As described above, the clamp 69 is a fastening member that can be tightened and released. The clamp 69 is preferably a well-known quick clamp that can be tightened and released by a substantially half turn of the lever for easier operation.

The length of the lower fork column portion 59 is the length that the fork column 33 protrudes upward from the head tube 1 when the bicycle 101 is in use, and the position of the rotary shaft 61 in the head tube 1 that is also in use. And the overall length before and after the bicycle 101 is folded. Considering these effects, the length of the lower fork column portion 59 is set.

FIG. 5A and FIG. 5B are diagrams showing a use state of the handle bar of the bicycle 101, FIG. 5A is a plan view, and FIG. 5B is a perspective view. The handle bar 71 is a drop-type handle bar whose front end extends rearward when in use. The handle bar 71 is divided into a left handle bar portion 73 and a right handle bar portion 75, and these

handle bar portions

73 and 75 are connected to the fork column 33 by a handle stem 77. The handle stem 77 supports the left and

right handlebar portions

73 and 75 so as to be able to be bent rearward. The handle stem 77 is provided with a clamp 79. By tightening the clamp 79, the

handle bar portions

73 and 75 can be held in the posture shown in FIGS. 5A and 5B.

6A and 6B are views showing an intermediate state between the use state and the folded state of the handle bar 71, FIG. 6A is a plan view, and FIG. 6B is a perspective view. 7A and 7B are views showing the folded state of the handle bar 71, where FIG. 7A is a plan view and FIG. 7B is a perspective view. When the bicycle 101 is not used, the

handlebar portions

73 and 75 can be bent backward by loosening the clamp 79. By doing so, when the bicycle 101 is folded, the

handlebar portions

73 and 75 can be prevented from projecting to the left and right, and the entire folded bicycle 101 can be made more compact. The clamp 79 is preferably the quick clamp described above for easier operation.

As can be understood from these drawings, each of the left and

right handlebar portions

73 and 75 has

base end members

81 and 83 on the base end side thereof. The base end portions of the

base end members

81 and 83 are rotatably supported by the handle stem 77, whereby each of the

handle bar portions

73 and 75 is rotatably supported by the handle stem 77. Yes. As shown in FIG. 5A, the

base end members

81 and 83 are members that extend front and rear or substantially front and rear when the handle bar 71 is in use. The

base end members

81 and 83 have different lengths. As an example, the base end member 83 is set longer than the base end member 81. Therefore, the rotation shaft that rotatably supports the base end member 83 on the handle stem 77 is located rearward (upward in FIG. 5A) than the rotation shaft that rotatably supports the base end member 81. ing. As a result, when the left and

right handlebar portions

73 and 75 are bent rearward by rotating these

base end members

81 and 83 from the position in which the handlebar 71 is in use, FIG. 7A and FIG. As shown, the front and rear positions of the grip portions are shifted from each other. That is, although the handle bar 71 is a drop-type handle, the

handle bar portions

73 and 75 can be bent backward without interfering with each other.

8A to 8C are views showing the folded state of the bicycle 101, in which FIG. 8A is a plan view, FIG. 8B is a side view, and FIG. 8C is a front view. By folding the rear wheel 19 forward, folding the front wheel 29 rearward, and further folding the

handlebar portions

73 and 75 rearward, the bicycle 101 has front and rear, left and right, and height as shown in FIGS. 8A to 8C. In either case, it can be made much more compact than in use. 8A and 8B illustrate dimensions in mm. This dimension is a size that can be stored in a 500 yen coin locker installed in a station in Japan. Since the handlebar 71 is a drop-type handle, the folded bicycle 101 is folded so that the folded front wheel 29 and rear wheel 19 are held from the left and right by the

handlebar portions

73 and 75 folded backward. However, it can be prevented from swelling to the left and right.
(Other embodiments)

In the bicycle 101, a form in which the fork column 33 is rotatably supported by the head tube 1 via the

cups

49 and 51 and the

bearings

53 and 55 without providing the support tube 27 is also possible. As the fork column 33 rotates in the steering direction, friction may occur between the bent portions of the upper and lower

fork column portions

57 and 59 and the inner wall surface of the head tube 1. It is also possible to reduce friction, for example, by placing a hard metal in the area to be obtained.

In the bicycle 101, the chain stay 11 together with the seat stay 9 and the rear wheel 19 is rotated downward around the horizontal or substantially horizontal rotation shaft 15 and further rotated forward, whereby the rear wheel 19 is moved forward. It was possible to fold it. On the other hand, by rotating the chain stay 11 and the seat stay 9 together with the rear wheel 19 to the left or right around a vertical or substantially vertical rotation shaft, the bicycle 101 is folded forward. May be configured.

The bicycle 101 has a head tube 1, a top tube 3, a down tube 5, a seat tube 7, a seat stay 9, and a chain stay 11 as a frame 10. However, not all of them are indispensable as elements of the frame 10 of the bicycle 101, and it is well known in the art that there are various variations in the configuration and shape of the frame 10.

The above description of specific embodiments of the present invention has been presented for purposes of illustration. They are not intended to be exhaustive or to limit the invention to the precise form described. It will be apparent to those skilled in the art that many modifications and variations are possible in light of the above description.

10 frame, 1 head tube, 3 top tube, 5 down tube, 7 seat tube, 9 seat stay, 11 chain stay, 13 reinforcement tube, 15 rotating shaft, 19 rear wheel, 20 steering mechanism, 21 axle, 23 support member 25 coupling mechanism, 27 support tube, 29 front wheel, 31 front fork, 33 fork column, 35 axle, 39 upper tube part, 41 lower tube part, 43 grip, 45 female thread, 47 grip, 48 male thread, 49 cup (upper one) ), 51 cup (lower one), 53, 55 bearing, 57 upper fork column part, 59 lower fork column part, 61 rotating shaft, 63 upper exposed part, 65 notch, 67 spacer 69 clamp (braking members) 71 handlebar 73 left handle bar portion, 75 the right handlebar unit, 77 handlebar stem, 79 clamp (rotation braking members) 81 and 83 proximal member 101 bicycles.

Claims

By folding the front wheel backward and folding the rear wheel forward, the overall length can be reduced compared to the use state, and as a front wheel steering mechanism, a folding bicycle comprising a handlebar, a head tube, and a front fork,
The fork column that forms the upper part of the front fork penetrates the head tube and is pivotally supported by the head tube so as to be rotatable in the steering direction. Or it is divided into upper and lower fork column parts that are connected to bend substantially in the front-rear direction,
In the use state, at least a part of the upper fork column part and the lower fork column part including the pivot shaft are located in the head tube in the use state, thereby the upper and lower fork columns. Bending of the portion around the pivot axis is prevented by the head tube,
The front wheel steering mechanism further includes a restraining member that releasably restrains the fork column from shifting downward,
By releasing the restraining member, the fork column can be shifted downward so that the entire lower fork column portion is exposed below the head tube, thereby folding the front wheel backward. A folding bike that is possible.
The front wheel steering mechanism further includes a tube that is pivotally supported in the steering direction and restrained in the axial direction in the head tube,
The fork column slidably penetrates the tube, and at least a part of the upper fork column part and the lower fork column part including the rotating shaft are in the use state. , Located in the tube, whereby bending of the upper and lower fork column portions around the pivot axis is prevented directly by the tube,
The restraining member restrains the fork column from being displaced in the steering direction and downward with respect to the pipe in a releasable manner,
By releasing the restraining member, the fork column can be slid downward so that the entire lower fork column portion is exposed below the pipe and the head tube. The folding bicycle according to claim 1, wherein the folding bicycle can be folded backward.
The tube has an upper exposed portion that is a portion exposed above the head tube, and the upper exposed portion is formed with a cut from the upper end downward.
In the use state, the restraining member tightens a portion of the upper fork column portion exposed above the head tube so as to be releasable together with an upper exposed portion of the tube, so that the fork column is The folding bicycle according to claim 2, wherein the folding bicycle is a member that releasably restrains the shift in the steering direction and downward with respect to the steering wheel.
The handlebar is divided into left and right handlebar parts,
The front wheel steering mechanism further includes a handle stem that connects the left and right handlebar portions to the fork column,
The handle stem rotatably supports the left and right handlebar portions so that the left and right handlebar portions can be bent backward, and the left and right handlebar portions have a posture in the use state. The folding bicycle according to any one of claims 1 to 3, further comprising a rotation stopping member that stops the rotation so that the rotation can be released.
The folding bicycle according to claim 4, wherein the handlebar is a drop-type handlebar whose front end extends rearward when in use.
The left handlebar portion and the right handlebar portion are pivotally supported by the handle stem so that the left and right handlebar portions are bent rearward. 6. The folding bicycle according to claim 5, wherein interference between the tip portions of the left and right handlebar portions is sometimes avoided.
By folding the front wheel backward and folding the rear wheel forward, the overall length can be reduced compared to the use state, and as a front wheel steering mechanism, a folding bicycle comprising a handlebar and a front fork,
The handlebar is a drop-type handlebar whose front end extends rearward when in use, and is divided into a left handlebar and a right handlebar,
The front wheel steering mechanism further includes a handle stem that connects the left and right handlebar portions to a fork column that forms an upper portion of the front fork,
The handle stem rotatably supports the left and right handlebar portions so that the left and right handlebar portions can be bent backward, and the left and right handlebar portions have a posture in the use state. It has a rotation stopping member that stops the rotation so that it can be released,
The left handlebar portion and the right handlebar portion are pivotally supported by the handle stem so that the left and right handlebar portions are bent rearward. Sometimes, a folding bicycle in which interference between the tip portions of the left and right handlebar portions is avoided.