Folding vehicle, folding mechanism, deformed frame, frame deformation mechanism, and turing rear frame

Abstract

To provide a folding vehicle that is reduced in volume when folded, and to provide a folding mechanism, a deformed frame, a frame deformation mechanism, and a turning rear frame.SOLUTION: A folding vehicle has: a deformed frame; a front wheel and a rear wheel; and a front fork to which the front wheel is attached. The deformed frame has a main frame, a rear frame, and a frame deformation mechanism. The frame deformation mechanism has: a frame attachment / detachment portion that enables maintaining and releasing of a coupling state between the main frame and the rear frame; and a rear-frame turning portion. The rear-frame turning portion has two non-parallel shaft members provided so as to turn the rear frame to a front-wheel side together with the rear wheel. When the rear wheel is turned to the front-wheel side and the front wheel is turned to a rear-wheel side together with the front fork, the rear wheel and the front wheel are disposed inclined with respect to a center line.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a folding vehicle, a folding mechanism, a deformable frame, a frame deformation mechanism, and a rotatable rear frame in which the folded volume is reduced.

Background Art

[0002] Conventionally, various vehicles such as automobiles (four-wheel automobiles, motorcycles, etc.), motorized bicycles, light vehicles (bicycles, carts, rickshaws, carriages, etc.), and trolley buses have become widespread. Among them, bicycles are widely popular as a means of transportation commonly used in daily life because they do not require a driver's license for driving and are lightweight. Among bicycles, ordinary bicycles (bicycles that run on two, three, or four wheels and are ridden by a single driver, including bicycles with a driving assist device), and tandem bicycles (bicycles ridden by multiple drivers) are widespread.

[0003] By the way, in order for bicycle users to omit part of their journey, they may carry a bicycle using public transportation or the like. Such an act is called wheeling. As bicycles suitable for wheeling, bicycles having a structure that is easy to disassemble (for example, road bikes) and folding bicycles are known. In particular, folding bicycles are widely used as bicycles suitable for wheeling because they mainly do not require disassembly of removing the wheels and do not require tools for folding and unfolding (returning to a complete vehicle that can run). Folding bicycles mainly have a structure in which the vehicle body is downsized by deformation without disassembling the frame. Conventionally, there have also been bicycles with a structure in which the vehicle body is downsized by deformation involving disassembly of the frame. When the former type of bicycle is type A and the latter type of bicycle is type B, in the present invention, folding bicycles include type B in addition to type A.

[0004] Conventionally, as folding bicycles, the following three types shown in a), b), and c) are known. a) A bicycle in which the frame is folded in two by a hinge mechanism in the middle between the front wheel side and the rear wheel side and is folded so that the front wheel and the rear wheel overlap (hereinafter also referred to as a "two-fold bicycle"), b) A bicycle in which the whole bicycle is folded in three so that the front wheel and the rear wheel overlap along the depth direction (hereinafter also referred to as a "three-fold bicycle"), c) A bicycle in which the frame is bent and folded vertically so that the front wheel and the rear wheel are arranged side by side along the front-rear direction (hereinafter also referred to as a "vertical folding bicycle").

[0005] Since the two-fold bicycle and the vertical folding bicycle are generally divided into two parts, the folding operation and the unfolding operation are easier than those of the three-fold bicycle. However, in terms of the shrinkage rate (the ratio at which the volume in the folded state is reduced with respect to the volume of the completed bicycle), the three-fold bicycle is superior to the two-fold bicycle and the vertical folding bicycle (because it is generally divided into three parts). In this regard, the three-fold bicycle is suitable as a bicycle for wheeling purposes. Also, in the two-fold bicycle, there is a risk that the aesthetics and strength of the bicycle may decrease due to the presence of a hinge mechanism in the middle part of the frame where strength is required, and there is also a risk of an increase in the vehicle body weight due to reinforcement. In terms of these problems being solvable, the three-fold bicycle is preferable.

[0006] And conventionally, as three-fold bicycles, for example, as disclosed in Patent Documents 1 to 4, folding bicycles having various structures are known.

[0007] Patent Document 1 discloses a folding bicycle in which, in the folded state, the front wheel and the rear wheel are arranged so as to sandwich the frame and are arranged substantially parallel to each other. Patent Document 2 discloses a folding bicycle in which, in the folded state, the front wheel and the rear wheel are arranged so as to sandwich the seat post and the seat post holding portion, and the rear wheel is arranged obliquely with respect to the front wheel surface. Further, Patent Document 3 discloses a folding bicycle in which the rear wheel rotates to the front wheel side by a rotation mechanism on the rear side of the frame, the front wheel is inverted to the rear wheel side, the rear wheel and the front wheel are brought close to each other, and the front wheel is arranged inclined with respect to the center line of the rear wheel. Furthermore, Patent Document 4 discloses a folding bicycle in which the rear wheel rotates to the front wheel side about the rotation center axis, and the front wheel is folded to the rear wheel side by a hinge of the main frame.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0009] The conventional three-fold folding bicycles disclosed in Patent Documents 1 to 4 have mechanism parts such as hinge mechanisms in order to achieve folding.

[0010] However, if the mechanism is provided between the seat tube and the head tube of the frame as in the folding bicycles disclosed in Patent Documents 2, 3, and 4, since the frame is the framework of the bicycle, the mechanism is prominent, and the aesthetics of the folding bicycle may be degraded. Further, if a link-shaped reinforcing member that connects the seat tube and the head tube is provided to reinforce the vehicle body as in the folding bicycle disclosed in Patent Document 1, the vehicle body weight may increase due to the reinforcement, and the running performance may be degraded.

[0011] On the other hand, Patent Documents 2 to 4 disclose the idea that the volume (hereinafter also referred to as "folding volume") when the folding bicycle is folded is reduced.

[0012] By the way, conventionally, as a method of representing the folding volume, a method using the width, height, and depth of a rectangular parallelepiped (circumscribed rectangular parallelepiped) that circumscribes the folded bicycle (hereinafter, also referred to as the "circumscribing method" in the present application) is widely known (for example, refer to the magazine "Folding Bicycle & Small Bike Catalog 2018", published on May 10, 2018, by Tatsumi Publishing Co., Ltd.).

[0013] The idea of reducing the folding volume of the folding bicycle measured by the circumscribing method is disclosed in Patent Documents 2 and 3.

[0014] However, for any folding bicycle, there were points that should be improved in terms of the shrinkage rate of the folding volume.

[0015] In this regard, among the folding volume, the ratio of the volume of the front wheel and the rear wheel is the highest. However, for folding bicycles as well as other folding bicycles, due to the influence on the safety, strength, and running performance of the bicycle, the idea of providing a folding mechanism for the wheels and folding the wheels is not appropriate.

[0016] Therefore, it is very important in the concept of reducing the folding volume to determine how the sizes of the front and rear wheels, and the arrangement and orientation of the front and rear wheels when the bicycle is folded, should be. Also, it is desirable that the reduction of the folding volume is achieved without imposing any restrictions on the use of commercially available parts other than the frame as much as possible.

[0017] And in Patent Document 2, a circumscribed quadrilateral is assumed such that the outer diameter of the wheels is approximately the length of one side, and the various parts such as the wheels and the frame when folded are arranged to fit inside it, and the three - fold bicycle is folded.

[0018] However, in Patent Document 2, the front and rear wheels are folded on top of each other inside the circumscribed quadrilateral, and the axles of both are not considered. The axles protrude significantly from the rear - wheel surface and the front - wheel surface (the generally circular surface on which a large number of spokes of the rear and front wheels are arranged). When the front and rear wheels are folded on top of each other, the axles of both overlap in the depth direction, resulting in an increase in depth. Therefore, the concept disclosed in Patent Document 2 is not an effective solution in terms of reducing the folding volume.

[0019] Also, in the three - fold bicycle of Patent Document 3, the structure takes into account the dimensions of the sprocket and the axle, and the folding volume is reduced. Comparing the front wheel with the rear wheel, since a sprocket is attached to the rear wheel, the overhang width from the rear - wheel surface is larger than the overhang width from the front - wheel surface. Therefore, rather than arranging the front wheel diagonally with respect to the rear wheel as in the three - fold bicycle of Patent Document 3, arranging the rear wheel diagonally with respect to the front wheel may reduce the volume of the circumscribed rectangular parallelepiped due to the diagonal orientation of the rear - wheel axle and the sprocket. Therefore, the three - fold bicycle of Patent Document 3 had unresolved problems regarding the reduction of the folding volume. As a practical matter, in existing three - fold bicycles, the number of sprocket stages may be limited to 1 stage or about 2 or 3 stages so as to reduce the folding volume. This has been one of the reasons for the deterioration of the running performance, especially in existing three - fold bicycles.

[0020] In addition, in the folding bicycles of Patent Document 1 and Patent Document 4, when folded, the axle of the rear wheel is inside the front wheel, and the axle of the front wheel is arranged inside the rear wheel. By doing so, the width of the folded volume is likely to be reduced, but interference is likely to occur between the axles and the wheels, frames, etc., so the depth is likely to increase. Therefore, it is difficult to reduce the folded volume. Accordingly, the folding bicycles of Patent Document 1 and the folding bicycles of Patent Document 4 also had unsolved problems regarding the reduction of the folded volume.

[0021] As described above, the conventional folding bicycles had unsolved problems in the following points 1), 2), and 3). 1) Reduction of the folded volume, 2) Deterioration of the aesthetics due to the mechanism parts essential for folding, 3) Increase in the vehicle body weight due to reinforcement and deterioration of the running performance. Therefore, the inventor of the present application repeatedly conducted intensive studies to solve these problems 1), 2), and 3), and found that the structure effective for solving these problems can be applied not only to bicycles but also to vehicles other than bicycles, and thus completed the invention of the present application.

[0022] The present invention has been made to solve the above problems, and an object thereof is to provide a folding vehicle, a folding mechanism, a deformable frame, a frame deformation mechanism, and a rotatable rear frame that can solve the following 1), 2), and 3). 1) The folded volume is reduced 2) There is no deterioration of the aesthetics due to the mechanism parts essential for folding 3) There is no increase in the vehicle body weight due to reinforcement and the running performance is not deteriorated

Means for Solving the Problems

[0023] In order to solve the above problems, the present invention provides a folding vehicle, which has a deformable frame, front wheels and rear wheels, and a front fork to which the front wheels are attached. The deformable frame has a main frame for holding the front fork, a rear frame for holding the rear wheels, and a frame deformation mechanism for enabling frame deformation. The frame deformation mechanism has a frame attachment / detachment part for enabling the connection state between the main frame and the rear frame to be maintained and released without changing their respective shapes, and a rear frame rotation part. The rear frame rotation part is provided such that the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part can rotate together with the rear wheels toward the front wheel side, and has two non-parallel shaft members arranged in different directions. The rear frame rotation part is arranged below the lower end surface of a seat tube through which a seat post is inserted and is connected to the main frame and the rear frame. When the rear wheels are rotated toward the front wheel side by the rear frame rotation part together with the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part, and the front wheels are rotated toward the rear wheel side together with the front fork, the axles of the rear wheels and the front wheels are arranged outside the rear wheels and the front wheels respectively, and the rear wheels and the front wheels are arranged in an inclined manner with respect to the center line along the depth direction in a front view.

[0024] In the folding vehicle described above, the rear frame rotating part has a base member, a first rotating shaft member and a second rotating shaft member as two non-parallel shaft members. The base member is provided with a first frame connection part and a second frame connection part. The first frame connection part is connected to the main frame using the first rotating shaft member as a rotating shaft, and the second frame connection part is connected to the rear frame using the second rotating shaft member as a rotating shaft. The first and second frame connection parts are formed such that the first and second rotating shaft members intersect with respect to the center line when the connection state between the main frame and the rear frame is maintained. The first and second rotating shaft members are arranged along the first and second rotating shaft directions along the first and second rotation angles that are obtuse angles clockwise from the line forward direction from the rear wheel side to the front wheel side in the plan view of the center line, and the first rotation angle can be made larger than the second rotation angle.

[0025] Also, the first frame connection part is arranged on the front wheel side below the lower end surface of the seat tube, and the second frame connection part is arranged on the rear wheel side below the lower end surface thereof. The base member is arranged with a forward downward inclination such that the first frame connection part is closer to the lower end of the front wheel or the rear wheel than the second frame connection part, and the frame attachment / detachment part can be arranged at a position away from the seat tube than the second frame connection part.

[0026] Furthermore, by arranging the first rotating shaft member at the first frame connection part with a downward inclination along the depth direction in the front view and arranging the second rotating shaft member at the second frame connection part with an upward inclination along the depth direction in the front view, the first inclination direction indicating the inclination direction of the first rotating shaft member along the depth direction in the front view and the second inclination direction indicating the inclination direction of the second rotating shaft member along the depth direction in the front view can be made different.

[0027] Furthermore, the rear frame rotating part has an inclination reversing structure, and the inclination reversing structure can be configured such that the second inclination direction is reversed from an upward inclination along the depth direction in a front view to a downward inclination by the rotation of the second frame connection part and the base member with the first rotating shaft member as the rotation axis.

[0028] Also, the rear frame rotating part can have a combined rotation structure, and the combined rotation structure can be configured such that the first rotation in which the rear frame, the rear wheel, the second frame connection part, and the base member are rotated using the first rotating shaft member as the rotation axis and the second rotation in which the rear frame and the rear wheel are rotated using the second rotating shaft member as the rotation axis are realized in parallel.

[0029] Also, when the first rotation is realized and the rear frame, the rear wheel, the second frame connection part, and the base member are rotated to the front wheel side of the first frame connection part, the circular rear wheel surface of the rear wheel is arranged in an upward inclination along the depth direction in a front view. When the second rotation is realized and the rear frame and the rear wheel are rotated to the rear wheel side, the rear wheel approaches the main frame while maintaining the upward inclination along the depth direction of the circular rear wheel surface, and the rear wheel and the front wheel can be arranged in an inverted V shape in a side view where the interval at the upper end is narrower than the interval at the lower end along the depth direction in a front view.

[0030] Furthermore, the rear frame has a locking part that is locked to the side surface of the seat tube. The locking part is arranged at a position above the second frame connection part of the rear frame and close to the seat tube. When the locking part is locked to the side surface of the seat tube, the main frame and the rear frame can be connected without changing their respective shapes by the frame attachment / detachment part.

[0031] Furthermore, the main frame has a truss structure including two link-shaped members fixed to the head tube holding the front fork and the side surface of the seat tube and connected to the frame attachment / detachment part, and a densest filling structure is formed such that the two link-shaped members are accommodated in the wheel gap surrounded by the rear wheel and the front wheel when the rear wheel and the front wheel are arranged in an inverted V shape in side view.

[0032] Also, the folding vehicle further has a front rotation mechanism. The front rotation mechanism has a front shaft member that rotates the front fork together with the front wheel to the rear wheel side. The main frame has a head tube that holds the front fork. The front rotation mechanism has, together with the front shaft member, a holding and releasing member that enables holding and releasing of the connection state between a rod-shaped part inserted into the head tube of the front fork and a fork part that holds the front wheel. When the front shaft member is arranged with an upward inclination along the depth direction in front view, the circular front wheel surface of the front wheel when the front wheel is rotated to the rear wheel side together with the fork part after the connection state with the rod-shaped part is released is arranged with a downward inclination along the depth direction in front view.

[0033] Furthermore, a folding vehicle in which the rear frame has a structure forming a triangular form surrounded by a chain stay, a seat stay, and a link member, the chain is inserted inside the triangular form, and when the rear frame is rotated to the front wheel side, the chain is locked to the link member to maintain the tension of the chain, is preferable.

[0034] The present invention is a folding mechanism having a frame deformation mechanism that enables frame deformation of a deformable frame constituting a folding vehicle and a front rotation mechanism. The deformable frame has a main frame that holds a front fork to which the front wheels of the folding vehicle are attached, and a rear frame that holds the rear wheels of the folding vehicle. The frame deformation mechanism has a frame attachment / detachment part that enables holding and releasing of the connection state between the main frame and the rear frame without changing their respective shapes, and a rear frame rotation part. The rear frame rotation part is provided so that the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part can rotate toward the front wheel side together with the rear wheels, and has two non-parallel shaft members arranged in different directions. The rear frame rotation part is arranged below the lower end surface of a seat tube through which a seat post is inserted and is connected to the main frame and the rear frame. The front rotation mechanism has a front shaft member that rotates the front fork together with the front wheels toward the rear wheel side. When the rear wheels are rotated toward the front wheel side by the rear frame rotation part together with the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part, and the front wheels are rotated toward the rear wheel side by the front rotation mechanism together with the front fork, the axles of the rear wheels and the front wheels are arranged outside the front wheels and the rear wheels respectively, and the rear wheels and the front wheels are arranged in an inclined manner with respect to the center line along the depth direction in a front view. A folding mechanism is provided.

[0035] In the case of the above folding mechanism, the main frame has a head tube that holds the front fork. The front rotation mechanism, together with the front shaft member, has a holding and releasing member that enables holding and releasing of the connection state between a rod-shaped part inserted into the head tube of the front fork and a fork part that holds the front wheels. Since the front shaft member is arranged with an upward inclination along the depth direction in a front view, it is preferable that the circular front wheel surface of the front wheels when the front wheels are rotated toward the rear wheel side together with the fork part after the connection state with the rod-shaped part has been released is arranged with a downward inclination along the depth direction in a front view.

[0036] Furthermore, the present invention relates to a deformable frame constituting a folding vehicle, the deformable frame having a main frame that holds a front fork to which a front wheel of the folding vehicle is attached, a rear frame that holds a rear wheel of the folding vehicle, and a frame deformation mechanism that enables frame deformation. The frame deformation mechanism has a frame attachment / detachment part that enables the connection state between the main frame and the rear frame to be maintained and released without changing their respective shapes, and a rear frame rotation part. The rear frame rotation part is provided so that the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part can rotate toward the front wheel side together with the rear wheel, and has two non-parallel shaft members arranged in different directions. The rear frame rotation part is arranged below the lower end surface of a seat tube through which a seat post is inserted and is connected to the main frame and the rear frame. When the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part is rotated toward the front wheel side by the rear frame rotation part together with the rear wheel, and the front fork to which the front wheel is attached is held by the main frame, when the front wheel is rotated toward the rear wheel side together with the front fork, the axles of the rear wheel and the front wheel are arranged outside the rear wheel and the front wheel respectively, and the rear wheel and the front wheel are arranged in an inclined state with respect to the center line along the depth direction in a front view, a deformable frame is provided.

[0037] In the case of the above-described deformable frame, the rear frame rotating portion has a base member, a first rotating shaft member and a second rotating shaft member as two non-parallel shaft members. The base member is provided with a first frame connection portion and a second frame connection portion. The first frame connection portion is connected to the main frame using the first rotating shaft member as a rotating shaft, and the second frame connection portion is connected to the rear frame using the second rotating shaft member as a rotating shaft. The first and second frame connection portions are formed such that the first and second rotating shaft members intersect with respect to the center line when the connection state between the main frame and the rear frame is maintained. The first and second rotating shaft members are arranged along the first and second rotating shaft directions along the first and second rotation angles that are obtuse angles in the clockwise direction from the line forward direction from the rear wheel side to the front wheel side in the plan view of the center line, respectively. It is preferable that the first rotation angle is larger than the second rotation angle.

[0038] In the case of the above-described deformable frame, the first frame connection portion is arranged on the front wheel side below the lower end surface of the seat tube, and the second frame connection portion is arranged on the rear wheel side below the lower end surface thereof. The base member is arranged with a forward downward inclination such that the first frame connection portion is closer to the lower end portion of the front wheel or the rear wheel than the second frame connection portion, and it is preferable that the frame attachment / detachment portion is arranged at a position away from the seat tube than the second frame connection portion.

[0039] Further, since the first rotating shaft member is arranged at the first frame connection portion with a downward inclination along the depth direction in the front view, and the second rotating shaft member is arranged at the second frame connection portion with an upward inclination along the depth direction in the front view, it is preferable that a first inclination direction indicating the inclination direction of the first rotating shaft member along the depth direction in the front view and a second inclination direction indicating the inclination direction of the second rotating shaft member along the depth direction in the front view are different.

[0040] Furthermore, in the case of the above-described deformed frame, the rear frame rotation part has an inclination inversion structure and a composite rotation structure. The inclination inversion structure is a structure in which, by the rotation of the second frame connection part and the base member having the first rotation shaft member as the rotation shaft, the second inclination direction is inverted from the upward inclination along the depth direction in the front view to the downward inclination. The composite rotation structure is preferably a structure in which the first rotation in which the rear frame, the rear wheel, the second frame connection part, and the base member are rotated using the first rotation shaft member as the rotation shaft and the second rotation in which the rear frame and the rear wheel are rotated using the second rotation shaft member as the rotation shaft are realized in parallel.

[0041] Furthermore, the main frame has a head tube that holds the front fork, and the front fork is a front fork with a mechanism having a front rotation mechanism, and the front fork with the mechanism can be inserted into the head tube to form a front fork with a front fork.

[0042] Furthermore, the present invention relates to a frame deformation mechanism that enables frame deformation of a deformable frame. The deformable frame has a main frame that holds a front fork to which a front wheel is attached and a rear frame that holds a rear wheel. The frame deformation mechanism has a frame attachment / detachment part that enables holding and releasing of the connection state between the main frame and the rear frame without changing their respective shapes, and a rear frame rotation part. The rear frame rotation part is provided so that the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part can rotate toward the front wheel side together with the rear wheel, and has two non-parallel shaft members arranged in different directions. The rear frame rotation part is arranged below the lower end surface of a seat tube through which a seat post is inserted and is connected to the main frame and the rear frame. When the rear wheel is rotated toward the front wheel side by the rear frame rotation part together with the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part, and the front wheel is rotated toward the rear wheel side together with the front fork while the front fork is held by the main frame, the axle of the rear wheel and the axle of the front wheel are arranged outside the rear wheel and the front wheel respectively, and the rear wheel and the front wheel are arranged in an inclined manner with respect to the center line along the depth direction in a front view, thereby providing a frame deformation mechanism that enables frame deformation.

[0043] In the case of the above frame deformation mechanism, the rear frame rotating part has a base member, a first rotating shaft member and a second rotating shaft member as two non-parallel shaft members. The base member is provided with a first frame connection part and a second frame connection part on both sides. The first frame connection part is connected to the main frame using the first rotating shaft member as a rotating shaft. The second frame connection part is connected to the rear frame using the second rotating shaft member as a rotating shaft. The first and second frame connection parts are formed such that the first and second rotating shaft members intersect with respect to the center line when the connection state between the main frame and the rear frame is maintained. The first and second rotating shaft members are arranged along the first and second rotating shaft directions having first and second rotation angles that are obtuse angles clockwise from the line forward direction from the rear wheel side to the front wheel side in the plan view of the center line, respectively, and it is preferable that the first rotation angle is larger than the second rotation angle.

[0044] Furthermore, the present invention provides a rotating rear frame having a rear frame that holds rear wheels and a rear frame rotating part. The rear frame rotating part has two non-parallel shaft members arranged in different directions, and using the two non-parallel shaft members, it has a structure for rotating the rear frame toward the main frame side in a state where the connection state with the main frame that holds the front fork to which the front wheels are attached is released. When the front wheels are rotated toward the rear wheel side together with the front fork, the rear frame rotating part rotates the rear frame such that the axles of the rear wheels and the front wheels are respectively arranged outside the rear wheels and the front wheels, and the rear wheels and the front wheels are arranged in an inclined manner with respect to the center line along the depth direction in the front view.

[0045] In the above-mentioned rotatable rear frame, the rear frame rotating part has a base member, a first rotating shaft member and a second rotating shaft member as the two non-parallel shaft members. The base member is provided with a first frame connection part and a second frame connection part. The first frame connection part is connected to the main frame using the first rotating shaft member as a rotating shaft, and the second frame connection part is connected to the rear frame using the second rotating shaft member as a rotating shaft. The first and second frame connection parts are formed such that the first and second rotating shaft members intersect with respect to the center line when the connection state between the main frame and the rear frame is maintained. The first and second rotating shaft members are arranged along the first and second rotating shaft directions along the first and second rotation angles that form obtuse angles clockwise from the line forward direction from the rear wheel side to the front wheel side in the plan view of the center line, respectively. It is preferable that the first rotation angle is larger than the second rotation angle.

Advantages of the Invention

[0046] As described in detail above, according to the present invention, a folding vehicle, a folding mechanism, a deformable frame, a frame deformation mechanism, and a rotatable rear frame that can solve the following 1), 2), and 3) can be obtained. 1) The folding volume is reduced. 2) There is no deterioration in aesthetics due to the mechanism parts essential for folding. 3) There is no increase in vehicle body weight due to reinforcement, and the running performance is not deteriorated.

Brief Description of the Drawings

[0047]

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Embodiments for Carrying Out the Invention

[0048] (Embodiments of the folding bicycle) A folding bicycle 1 as an example of a folding vehicle according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7. FIGS. 1 to 4 are views showing the folding bicycle 1 holding a deployed structure (the structure of a complete vehicle capable of traveling). FIG. 1 is a front view with some parts omitted, FIG. 2 is a plan view, FIG. 3 is a rear view, and FIG. 4 is a left side view. FIG. 5 is a perspective view of the folding bicycle 1 having a deformable frame 20 as seen from the rear of the folding bicycle 1, and FIG. 6 is an enlarged view of a main part of the deformable frame 20 shown in FIG. 5 as seen from the rear of the folding bicycle 1. FIG. 7(a) is an enlarged view of a main part of the deformable frame 20 as seen from the direction indicated by arrow e in FIG. 5, and FIG. 7(b) is an enlarged view of a main part of the deformable frame 20 as seen from the direction indicated by arrow f in FIG. 5. In FIG. 1, the illustration of the wire is omitted. In FIGS. 2 to 7, in addition to the wire, the illustrations of the chain, brake, transmission (derailleur), saddle, seat post, and handle are also omitted.

[0049] As shown in FIGS. 1, 2, and 3, the folding bicycle 1 according to the embodiment of the present invention includes a deformable frame 20, a front wheel 40 and a rear wheel 50 as wheels constituting the vehicle, a front fork 41 to which the front wheel 40 is attached, a front rotation mechanism 60, and a drive mechanism 90. In the illustrated folding bicycle 1, mainly the deformable frame 20 has the features according to the present invention. Therefore, in the following description, the deformable frame 20 will be described in detail.

[0050] (Deformable Frame) As shown in detail in FIG. 5, the deformable frame 20 includes a main frame 21, a rear frame 31, and a frame deformation mechanism 70 that enables frame deformation to be described later.

[0051] The deformable frame 20 has a structure capable of frame deformation. Frame deformation mainly means deformation without disassembling the frame. However, in the present invention, deformation involving disassembling the frame (deformation resulting from at least a part of the frame being disassembled to obtain physically separate parts) is also included in frame deformation. And in the deformable frame 20 according to the present embodiment, the frame deformation is realized by a frame deformation mechanism 70. In the present embodiment, the frame deformation in the deformable frame 20 means deformation without disassembling the frame, and the shape of the entire deformable frame 20 changes by the following operations 1), 2), and 3).

[0052] 1) In the integrated shape (also referred to as the unfolded shape) of the deformable frame 20 shown in FIG. 5, an operation to release the connection state between the main frame 21 and the rear frame 31; 2) An operation to rotate the rear frame 31 whose connection state with the main frame 21 has been released to the front wheel 40 side; 3) Reverse operations of 1) and 2). In the deformable frame 20, any of the operations 1), 2), and 3) is realized without changing the shapes of the main frame 21 and the rear frame 31 respectively.

[0053] In the operation of 1), the frame attachment / detachment part 9, which will be described later, of the frame deformation mechanism 70 is used. In the operation of 2), the rear frame rotation part 10, which will be described later, of the frame deformation mechanism 70 is used. Also, in the operation of 3), the rear wheel 50 is rotated from the front wheel 40 side to the rear wheel 50 side together with the rear frame 31 using the rear frame rotation part 10, and then, using the frame attachment / detachment part 9, the rear frame 31 is connected to the main frame 21.

[0054] As shown in FIG. 5, the main frame 21 has a head tube 22, a seat tube 23, and a pair of long link members 24a and 24b. As shown in FIG. 2, the main frame 21 has an asymmetric structure with both sides sandwiching a center line ax (not shown in FIG. 2, refer to FIG. 20). The head tube 22 is a cylindrical member through which the front fork 41 is inserted and is disposed at the tip of the main frame 21. The seat tube 23 is a cylindrical member through which the seat post 19 (the cylindrical member to which the saddle in FIG. 1 is fixed) is inserted and is disposed slightly rearward of the middle in the front-rear direction of the main frame 21. The long link members 24a and 24b have a length that connects from the head tube 22 through the side surface of the seat tube 23 to the frame attachment / detachment portion 9 on the rear side thereof. The long link members 24a and 24b are fixed to the head tube 22 and the side surface of the seat tube 23 and are connected to the frame attachment / detachment portion 9. Further, the long link members 24a and 24b are housed in the wheel space Vg described later when the folding bicycle 1 is folded (when the folding structure 101 described later is held). Thereby, the densest packing structure of the folding bicycle 1 is formed (details will be described later).

[0055] Furthermore, the main frame 21 has a plurality of link members 25a, 25b, 26a, 26b, 27a, 27b, 28a, 28b, 29a, 29b, 30a, and 30b. The main frame 21 has a truss structure formed by the long link members 24a and 24b and the plurality of link members 25a, 25b to 30a, 30b (the long link members 24a, 24b and the plurality of link members 25a, 25b to 30, 30 are connected as shown in FIG. 5). In addition, the main frame 21 has a BB (bottom bracket) hanger 80.

[0056] As shown in FIGS. 5 and 6 (particularly FIG. 6), the BB hanger 80 is fixed to the rear wheel side end portions of the link members 29a and 29b and the lower side surface of the seat tube 23.

[0057] The BB hanger 80 has a hollow BB shell 80a along the depth direction of the folding bicycle 1 (the direction perpendicular to the plane of FIG. 1, and in particular, the direction from the front to the back (the direction Db shown in FIG. 2) is also referred to as the "depth direction in front view"), and an extension 80c protruding downward from the lower side of the BB shell 80a. A BB (bottom bracket) 80b (not shown in FIG. 6, see FIG. 2) is inserted into the BB shell 80a. Also, a crank arm 82 is fixed to one end of the BB 80b together with a chain ring 81, and a crank arm 82 is also fixed to the other end. Pedals 83, 83 are attached to the crank arms 82, 82. The BB 80b, the chain ring 81, and the crank arms 82, 82 constitute an integrated crankset. The drive mechanism 90 is constituted by the crankset and the pedals 83, 83 (see FIGS. 1 and 2).

[0058] Also, as shown in FIG. 6, a rear frame rotation part 10 described later is connected to the extension 80c of the BB hanger 80 by welding, brazing, screwing, etc. The rear frame rotation part 10 is also connected to a pair of chain stays 33a, 33b of the rear frame 31 described later by welding, brazing, screwing, etc. The rear frame rotation part 10, together with a frame attachment / detachment part 9 described later, constitutes a frame deformation mechanism 70.

[0059] As shown in FIG. 5, the folding bicycle 1 has a rotating rear frame 31A having a rear frame 31 and a rear frame rotating portion 10. As will be described later, in the rotating rear frame 31A, the rear frame rotating portion 10 is connected to the rear frame 31. The rear frame 31 has a pair of seat stays 32a, 32b, a pair of chain stays 33a, 33b, and a pair of link members 34a, 34b. The rear frame 31 has a truss structure formed by the seat stays 32a, 32b, the chain stays 33a, 33b, and the link members 34a, 34b. The seat stays 32a, 32b, the chain stays 33a, 33b, and the link members 34a, 34b are connected as shown in FIG. 5 to form triangular forms 31Fa, 31Fb. A chain 91 is inserted through the triangular form 31Fa on the front side thereof (see FIGS. 1, 27, and 28; details will be described later). Also, ends 35a, 35b are fixed to the seat stay 32a and the chain stay 33a, and the seat stay 32b and the chain stay 33b, respectively. Axles 50a, 50b of the rear wheel 50 (not shown in FIG. 5; see FIG. 2) are fitted into the ends 35a, 35b, whereby the rear wheel 50 is held by the rear frame 31.

[0060] Furthermore, as shown in detail in FIG. 6, the front-wheel 40-side ends of the chain stays 33a and 33b and the front-wheel 40-side ends of the link members 34a and 34b are connected. A locking portion 37 is formed at the connection portion. The locking portion 37 is disposed above a rear-frame connection portion 12 (to be described later) of the rear frame 31 and close to the seat tube 23. The locking portion 37 is formed using a metal and a material having flexibility and elasticity (for example, resin or rubber). Further, the locking portion 37 has a shape (for example, a concave curved surface) corresponding to the side surface of the seat tube 23. When a downward force acts on the rear frame 31 due to the influence of gravity, a force (also referred to as a rotational force H, see FIG. 5) that causes the ends 35a and 35b to rotate toward the front-wheel 40 side is generated in the rear frame 31 around the locking portion 37. Receiving the rotational force H, the locking portion 37 is locked to the side surface of the seat tube 23, and the locking portion 37 comes into close contact with the side surface of the seat tube 23 (the connection state between the main frame 21 and the rear frame 31 as shown in FIG. 5). Further, when the locking portion 37 is locked to the side surface of the seat tube 23, the main frame 21 and the rear frame 31 are connected. While the main frame 21 and the rear frame 31 are connected and the connection state is maintained, the close contact between the locking portion 37 and the seat tube 23 continues. On the other hand, when the connection state between the main frame 21 and the rear frame 31 is released and the rear frame 31 is separated from the main frame 21, the locking portion 37 separates from the side surface of the seat tube 23.

[0061] (Frame attachment / detachment portion) As shown in FIG. 5, the frame attachment / detachment portion 9 is disposed at a position farther from the seat tube 23 than the rear-frame rotation portion 10 (specifically, the rear-frame connection portion 12 of the rear-frame rotation portion 10 to be described later).

[0062] The frame attachment / detachment part 9 has a mechanism that enables the connection state between the main frame 21 and the rear frame 31 to be maintained and released without changing their respective shapes. In the folding bicycle 1 according to the present embodiment, the frame attachment / detachment part 9 is configured using a quick release 38 shown in FIG. 2 having a shaft with a release lever and a nut, a bearing part 39 shown in FIG. 17, and ends 36a, 36b. By using such a frame attachment / detachment part 9, the main frame 21 and the rear frame 31 are connected and their connection state is maintained, or the connection state is released and the main frame 21 and the rear frame 31 are separated.

[0063] As shown in FIG. 17, the ends 36a, 36b are members of the rear frame 31 and are formed at the front wheel 40 - side ends of the seat stays 32a, 32b and the link members 34a, 34b. The bearing part 39 is a member of the main frame 21 and is formed at the rear wheel 50 - side ends of the long link members 24a, 24b and the link members 30a, 30b. The bearing part 39 has a cylindrical part 39c and circular end parts 39a, 39b arranged at both ends thereof. In a state where a load corresponding to the weight of the rider acts from the bearing part 39 to the ends 36a, 36b, the ends 36a, 36b engage with the surfaces of the circular end parts 39a, 39b. In that engaged state, the shaft with a release lever of the quick release 38 is inserted through the ends 36a, 36b (and the circular end parts 39a, 39b) and the cylindrical part 39c from one side, and the nut of the quick release 38 is fastened on the other side. Moreover, when the release lever of the shaft with a release lever is tightened, the quick release 38 (the shaft with a release lever and the nut), the ends 36a, 36b, and the bearing part 39 are integrated. As a result, the main frame 21 and the rear frame 31 are connected and their connection state is maintained. Also, when the release lever is released, the integration of the quick release 38 (the shaft with a release lever and the nut), the ends 36a, 36b, and the bearing part 39 is released. Then, the connection state between the main frame 21 and the rear frame 31 is released.

[0064] Note that, for the frame attachment / detachment portion 9, a mechanism different from the quick release (for example, bolts and nuts) may be used.

[0065] (Rear frame rotation part) The rear frame rotation part 10 is a mechanism (also referred to as a two-axis mechanism) in which two shaft members, the first and second shafts 11a and 12a described later, are arranged on one member (a base member 13 described later). By the rear frame rotation part 10, the rear wheel 50 is rotated toward the front wheel 40 side together with the rear frame 31 whose connection state with the main frame 21 has been released, whereby the upside-down V-shaped arrangement in side view (or the V-shaped arrangement in side view described later, the inclined parallel arrangement in plan view) described later is realized.

[0066] As shown in detail in FIG. 6, the rear frame rotation part 10 includes a base member 13 and the first and second shafts 11a and 12a. The rear frame rotation part 10 has a structure in which a main frame connection part 11 and a rear frame connection part 12 are provided on both sides in the length direction of the base member 13, respectively.

[0067] The main frame connection part 11 corresponds to the first frame connection part according to the present invention. The first shaft 11a is arranged in the main frame connection part 11. The main frame connection part 11 is connected to a bearing part (not shown) of the extension part 80c so that the first shaft 11a is used as a rotation axis.

[0068] The rear frame connection part 12 corresponds to the second frame connection part according to the present invention. The second shaft 12a is arranged in the rear frame connection part 12. The rear frame connection part 12 is connected to a bearing part (not shown) of the downward extension part 33c so that the second shaft 12a is used as a rotation axis. The downward extension part 33c is formed on the chain stays 33a and 33b.

[0069] Further, as shown in FIGS. 5 and 6, the main frame connection portion 11 is disposed on the front wheel side 40 of the seat tube 23 below the lower end surface 23a of the seat tube 23. The rear frame connection portion 12 is disposed on the rear wheel side 50 of the seat tube 23 below the lower end surface 23a.

[0070] In the present embodiment, the base member 13 has a structure as shown in FIG. 7(a) in order to ensure torsional rigidity. The base member 13 has a structure in which two base rods 13a and 13b and a plurality of connection rods 13c are connected and integrated by welding, brazing, or the like. The main frame connection portion 11 is provided on one of the longitudinal directions of the two base rods 13a and 13b, and the rear frame connection portion 12 is provided on the other. The two base rods 13a and 13b both have a length that exceeds the lower end surface 23a. The two base rods 13a and 13b are arranged such that the interval between them gradually narrows from the main frame connection portion 11 side toward the rear frame connection portion 12 (the interval between the two base rods 13a and 13b may be constant, or may gradually narrow from the rear frame connection portion 12 side toward the main frame connection portion 11). Each connection rod 13c bridges the two base rods 13a and 13b. Further, the base member 13 is arranged in a forward downward inclination in the deployed shape of the deformable frame 20. That is, as shown in FIGS. 5 and 6, the base member 13 is arranged such that the main frame connection portion 11 is closer to the lower end portion of the front wheel 40 or the rear wheel 50 than the rear frame connection portion 12. Furthermore, the base member 13 is disposed below the lower end surface 23a of the seat tube 23 (preferably without contacting the lower end surface 23a as shown). The base member 13 has the main frame connection portion 11 and the rear frame connection portion 12 connected to the extension portion 80c (a part of the main frame 21) and the downward extension portion 33c (a part of the rear frame 31), respectively.

[0071] The first shaft 11a and the second shaft 12a are separate and independent shaft members. The first and second shafts 11a, 12a are arranged in different directions and correspond to the non-parallel shaft members according to the present invention. The first and second shafts 11a, 12a are arranged on different planes in a three-dimensional space (not shown). The first shaft 11a penetrates through the main frame connection portion 11 and a bearing portion (not shown) of the extension portion 80c. The first shaft 11a is used as a rotation shaft that enables the main frame connection portion 11 and the extension portion 80c to rotate. The second shaft 12a penetrates through the rear frame connection portion 12 and a bearing portion (not shown) of the downward extension portion 33c. The second shaft 12a is used as a rotation shaft that enables the rear frame connection portion 12 and the downward extension portion 33c to rotate. The first and second shafts 11a, 12a are connected using nuts or the like (not shown).

[0072] Subsequently, in addition to FIGS. 5 and 6, FIGS. 20 to 21 are referred to and the rear frame rotation portion 10 will be described in detail. Here, FIG. 20 is a plan view schematically showing a main part of a deployment structure 100 (to be described later) of the folding bicycle 1, FIG. 21(a) is an enlarged plan view showing the main part of FIG. 20, and (b) is a left side view schematically showing the rear frame rotation portion 10. In FIGS. 20 and 21, in order to mainly clarify the structure and operation of the rear frame rotation portion 10, each part is simplified. Also, in FIG. 21, the shapes and dimensions of the deformed frame 20 and the rear frame rotation portion 10 are changed. Although it will be described in detail later, in the deployment structure 100, the connection state between the main frame 21 and the rear frame 31 is maintained, and the folding bicycle 1 is in a state of a complete vehicle capable of traveling.

[0073] As shown in Fig. 21(a), the main frame connection part 11 and the rear frame connection part 12 are formed such that the first and second shafts 11a and 12a intersect with respect to the center line ax of the deployment structure 100. The center line ax is a virtual line along the depth direction in the front view of the front wheel 40 and the rear wheel 50. Also, the first and second shafts 11a and 12a are arranged along the rotation axis directions R11 and R12, respectively. The rotation axis directions R11 and R12 are set in the directions of the rotation angles A11 and A12, respectively. The rotation angles A11 and A12 are obtuse angles in the clockwise direction from the line forward direction Fd of the center line ax in the plan view as shown in Figs. 20 and 21(a) of the folding bicycle 1 (deformable frame 20). The line forward direction Fd is the direction from the rear wheel 50 side to the front wheel 40 side of the center line ax. The rotation angles A11 and A12 are different. Although the rotation angle A11 > the rotation angle A12 can be set (the rotation angle A11 < the rotation angle A12 may also be acceptable), the difference is small.

[0074] And the first shaft 11a is arranged at the main frame connection part 11 with a downward inclination along the depth direction Db in the front view (also referred to as "downward inclination in the front view"). Also, the second shaft 12a is arranged at the rear frame connection part 12 with an upward inclination along the depth direction Db in the front view (also referred to as "upward inclination in the front view"). Fig. 7(a) shows the shaft lines L11 and L12 related to the first and second shafts 11a and 12a. The shaft lines L11 and L12 are lines indicating the inclination directions (corresponding to the first and second inclination directions in the present invention) along the depth direction Db in the front view of the first and second shafts 11a and 12a, respectively. The shaft line L11 is shown with a downward inclination from the right side to the left side of the paper surface (the direction from the right side to the left side of the paper surface corresponds to the depth direction Db in the front view). The shaft line L12 is shown with an upward inclination from the right side to the left side of the paper surface.

[0075] Since the first and second shafts 11a and 12a are arranged as described above, in the deformable frame 20 according to Fig. 2, the main frame connection part 11 and the rear frame connection part 12 are visually recognized as follows.

[0076] As shown in Fig. 21(a), for the main frame connection portion 11, the right end face 11c is visible, but the left end face 11d is hidden behind the main frame connection portion 11 and not visible (because the first shaft 11a is arranged with a downward slope, and the left end portion of the first shaft 11a is arranged below the right end portion along the direction perpendicular to the paper surface). On the other hand, for the rear frame connection portion 12, the left end face 12d is visible, but the right end face 12c is hidden behind the rear frame connection portion 12 and not visible (because the right end portion of the second shaft 12a is arranged below the left end portion along the direction perpendicular to the paper surface).

[0077] Furthermore, the rear frame rotating portion 10 has an inclination inversion structure. The inclination inversion structure means a structure in which the second inclination direction (the inclination direction along the depth direction Db of the second shaft 12a in the front view) is inverted from an upward inclination to a downward inclination. Such an inversion of the second inclination direction occurs when the rear frame 31 and the rear wheel 50 are rotated together with the rear frame connection portion 12 and the base member 13 using the first shaft 11a as a rotation axis (details will be described later).

[0078] And the rear frame rotating portion 10 has a compound rotation structure. The compound rotation structure means a structure in which the first rotation and the second rotation are realized in parallel. The first rotation and the second rotation respectively mean rotations using the first and second shafts 11a and 12a as rotation axes.

[0079] The main frame connection part 11 and the rear frame connection part 12 are provided on the base member 13 to form the rear frame rotation part 10. As shown in FIG. 6, the rear frame connection part 12 is connected to the downward extension part 33c, and the downward extension part 33c is integrated with the chain stays 33a and 33b. Therefore, after the rear frame 31 is separated from the main frame 21, when the locking part 37 of the rear frame 31 is separated from the side surface of the seat tube 23, the rear frame 31 rotates using the second shaft 12a of the rear frame connection part 12 as the rotation axis. This is the second rotation. Also, after the second rotation is realized, from the rear frame 31, the rear frame connection part 12, the base member 13, and the main frame connection part 11 are integrated and rotate using the first shaft 11a of the main frame connection part 11 as the rotation axis. This is the first rotation.

[0080] In this way, when the second rotation is realized, the first rotation is also realized, but the second rotation is also realized when the first rotation is realized. Therefore, the rear frame rotation part 10 has a structure (compound rotation structure) in which the first rotation and the second rotation are realized in parallel.

[0081] (Front rotation mechanism) The front rotation mechanism 60 is a mechanism that enables the following 1) and 2). 1) Holding the front wheel 40 and the front fork 41 in a travelable state, 2) Rotating the front wheel 40 together with the front fork 41 toward the rear wheel 50 side to realize the later-described upside-down V-shaped arrangement in side view. In the folding bicycle 1, the folding conversion described later is realized by the frame deformation mechanism 70 of the above-described deformable frame 20 and the front rotation mechanism 60. Therefore, the frame deformation mechanism 70 and the front rotation mechanism 60 constitute the folding mechanism 65 (see FIG. 3) according to the present invention.

[0082] As shown in FIGS. 1 and 2, the front rotation mechanism 60 has a holding release tool 61 and a hinge portion 62. The holding release tool 61 is a member that enables holding and releasing the connection state between the rod-shaped portion 41a and the fork portion 41b of the front fork 41. As shown in FIG. 18, the rod-shaped portion 41a is a portion of the front fork 41 that is inserted into the head tube 22. The fork portion 41b is a portion having a bifurcated structure for holding the front wheel 40 (although not shown, the fork portion may have a single-pronged structure). For example, the holding release tool 61 can be composed of a bolt and a nut. The holding release tool 61 may use a quick release. In that case, holes through which the bolt or the shaft of the quick release is inserted are formed in the rod-shaped portion 41a and the fork portion 41b. The bolt or the shaft is inserted into the holes. The nut is tightened or released, and the release lever is operated. By such operations, holding and releasing the connection state between the rod-shaped portion 41a and the fork portion 41b are realized. As shown in FIG. 23(c), the hinge portion 62 has a shaft 62a as a front shaft member according to the present invention. The shaft 62a is used as a rotation axis, and the front wheel 40 and the front fork 41 rotate. The shaft 62a is arranged with an upward inclination in a front view, similar to the second shaft 12a before the inclination inversion (when the folding bicycle 1 holds the unfolded structure 100).

[0083] (Structure conversion of the folding bicycle 1) In the folding bicycle 1 having the above-described configuration, two structural conversions, namely, folding conversion and unfolding conversion, are realized. The folding conversion is the conversion from the unfolded structure 100 shown in FIGS. 1 to 4 to the folded structure 101 shown in FIGS. 14 to 16. The unfolding conversion is the conversion from the folded structure 101 to the unfolded structure 100. The unfolded structure 100 is a structure in which the deformable frame 20 is unfolded, and is a structure in which the folding bicycle 1 can run (the structure of a completed bicycle). The folded structure 101 is a structure in a state where the folding conversion including the deformation of the deformable frame 20 and the rotation of the front wheel 40 and the front fork 41 is completed. Here, FIGS. 14 to 16 are diagrams showing the folded structure 101 of the folding bicycle 1, FIG. 14 is a rear view, FIG. 15 is a front view, FIG. 16(a) is a plan view seen from the back of FIG. 14, and FIG. 16(b) is a right side view corresponding to FIG. 14. Both the folding conversion and the unfolding conversion are realized by the frame deformation of the deformable frame 20 and the rotation of the front wheel 40 and the front fork 41 by the front rotation mechanism 60.

[0084] (Folded Structure) In the folded structure 101 of the folding bicycle 1, as shown in FIGS. 16(b) and 19, the interval DH is narrower than the interval DL (DH < DL). The interval DH is the interval along the depth direction Db in the front view between the upper end portion 40H of the front wheel 40 and the upper end portion 50H of the rear wheel 50. The interval DL is the interval along the depth direction Db in the front view between the lower end portion 40L of the front wheel 40 and the lower end portion 50L of the rear wheel 50.

[0085] Since the interval DH is narrower than the interval DL, the interval between the circular front wheel surface 40S of the front wheel 40 and the circular rear wheel surface 50S of the rear wheel 50 gradually narrows from the lower side (the lower ends of the front wheel 40 and the rear wheel 50) toward the upper side (the upper ends of the front wheel 40 and the rear wheel 50). Therefore, in the folding structure 101, in a side view, the front wheel 40 and the rear wheel 50 are arranged in a shape like an upside-down "V" (in an upside-down V shape in side view). Such an arrangement of the front wheel 40 and the rear wheel 50 in the folding structure 101 is the "upside-down V shape arrangement in side view". The circular front wheel surface 40S of the front wheel 40 is a generally circular surface surrounded by the wheel (wheel) of the front wheel 40 and on which the spokes 43 are arranged. The circular rear wheel surface 50S of the rear wheel 50 is a generally circular surface surrounded by the wheel of the rear wheel 50 and on which the spokes 52 are arranged. In the unfolding structure 100, the circular front wheel surface 40S is the surface on the back side of the front wheel 40, and the circular rear wheel surface 50S is the surface on the front side (see FIGS. 1 to 3).

[0086] Also, in the folding structure 101, the front wheel 40 and the rear wheel 50 are arranged such that their respective axles 40a, 40b and axles 50a, 50b do not overlap along the depth direction Db in a front view. In addition, as shown in FIG. 24(a), the axles 40a, 40b are arranged outside the rear wheel 50, and the axles 50a, 50b are arranged outside the front wheel 40.

[0087] Furthermore, as shown in detail in FIGS. 16(a) and 16(b), in the folding structure 101, a part of the main frame 21 (mainly, a part of the long link members 24a, 24b and the link members 28a, 28b) is accommodated in the wheel space Vg (in FIG. 19, the illustration of the main frame 21 is omitted). Such a structure corresponds to the densest packing structure of the folding bicycle 1. As shown in FIG. 19, the wheel space Vg is a space sandwiched between the front wheel 40 and the rear wheel 50 and is formed when the upside-down V shape arrangement in side view is realized. In the wheel space Vg, the size of the space gradually increases from the upper side toward the lower side according to the upside-down V shape arrangement of the front and rear wheels in side view.

[0088] (Procedures for folding conversion and unfolding conversion) Next, with reference to FIGS. 1, 5, 6, FIGS. 8 to 13, and FIGS. 21 to 23, the folding conversion procedure and the unfolding conversion procedure in the folding bicycle 1 will be described. The folding conversion is realized by the operations shown in the following procedures 1, 2, 3, and 4. The unfolding conversion is realized by the reverse operations of the operations shown in procedures 1, 2, 3, and 4. Among procedures 1, 2, 3, and 4, the features of the present invention are included in procedures 1 and 2. Procedure 1 must be realized before procedure 2, and procedure 4 must be realized after procedure 2. Procedure 3 may be realized before procedure 1 or may be realized after procedure 2.

[0089] Procedure 1 For the deformable frame 20, release the connection state between the main frame 21 and the rear frame 31 Procedure 2 Rotation of the rear frame 31 and the rear wheel 50 toward the front wheel side 40 Procedure 3 Rotation of the front wheel 40 and the front fork 41 toward the rear wheel 50 Procedure 4 Lowering of the seat post 19 and rotation of the handle

[0090] (Procedure 1) In Procedure 1, for the deformable frame 20, the connection state between the main frame 21 and the rear frame 31 is released using the frame attachment / detachment portion 9. As a result, the rear frame 31 can be separated from the main frame 21. At this time, the rear frame 31 has a truss structure, and is separated from the main frame 21 without changing the shape of the truss structure.

[0091] (Procedure 2) In Procedure 2, first, after the rear frame 31 is separated from the main frame 21, the locking portion 37 moves away from the side surface of the seat tube 23. Thereafter, by the action of two non-parallel shaft members (the first and second shafts 11a, 12a) of the rear frame rotating portion 10, the rear frame 31 is rotated together with the rear wheel 50 toward the front wheel side 40. This will be described in detail with reference to FIGS. 21, 22, and 23.

[0092] First, since the rear frame 31 is connected to the rear frame rotating part 10, the rear frame rotating part 10 rotates as the rear frame 31 moves. As shown in FIG. 21, the rear frame rotating part 10 is a biaxial mechanism and has a main frame connection part 11, a rear frame connection part 12, and first and second shafts 11a and 12a disposed respectively thereon. Since the first and second shafts 11a and 12a are separate and independent shaft members, two separate rotations, the first and second rotations described later, are realized by each of them. Further, since the first and second shafts 11a and 12a are arranged in different directions, the first and second rotations realized are rotations in different directions. In the second rotation, the rear frame 31 rotates together with the rear wheel 50, but in the first rotation, the rear frame connection part 12 and the base member 13 also rotate together with the rear frame 31 and the rear wheel 50. Therefore, the range in which each member moves in the first rotation is larger than the range in which each member moves in the second rotation. Thus, in step 2, mainly, the rear frame 31, the rear wheel 50, the rear frame connection part 12, and the base member 13 rotate in the first rotation. In parallel with this, the rear frame 31 and the rear wheel 50 rotate in the second rotation.

[0093] (First rotation) In the first rotation, using the first shaft 11a as the rotation axis, the rear frame connection part 12 and the base member 13 rotate as indicated by the arrow r1 shown in FIGS. 21(b) and 22(a). At this time, as shown in FIG. 21(a), the rear frame 31 and the rear wheel 50 rotate together with the rear frame connection part 12 and the base member 13. The rear frame connection part 12 and the base member 13 move along a plane parallel to the direction d11 orthogonal to the first shaft 11a. The first shaft 11a is arranged along the rotation axis direction R11, and the rotation axis direction R11 is set in the direction of a rotation angle A11 that forms an obtuse angle clockwise from the front direction Fd of the line. Therefore, in the first rotation, as shown in FIG. 22(a), the rear frame 31 and the rear wheel 50 rotate in a state of deviating from the center line ax to the left side in plan view (the depth direction in front view). Then, similar to the right end face 11c of the main frame connection part 11 (see FIG. 21(a)), the circular rear wheel surface 50S of the rear wheel 50 becomes visible in the plan view of the folding bicycle 1. In FIGS. 22(a) to (c), the circular rear wheel surface 50S of the rear wheel 50 is shown to clarify this point. In FIGS. 22 and 23, among the first and second shafts 11a and 12a, the one with the black circle mark is shown to be used as the rotation axis (in FIGS. 22 and 23(a), it is the first shaft 11a, and in FIG. 23(b), it is the second shaft 12a).

[0094] Subsequently, as shown in FIG. 22(b), when the first rotation continues as indicated by the arrow r2, the rear frame connection part 12 approaches the farthest point 12e that is the farthest from the main frame 21. Then, as shown in FIG. 8(a), the rear wheel 50 is arranged below the chain ring 81. Further, when the first rotation continues, the rear wheel 50, the rear frame 31, and the base member 13 rotate in the direction indicated by the arrow g1 in FIG. 8(a).

[0095] After that, as shown in FIG. 22(c), when the first rotation continues as indicated by the arrow r3, the rear frame connection part 12 passes beyond the farthest point 12e (below the main frame connection part 11) and turns toward the front wheel 40 side. The rear frame 31 and the rear wheel 50 pass below the chain ring 81 and approach the front wheel 40.

[0096] When the rear frame connection part 12 passes beyond the farthest point 12e (below the main frame connection part 11) and the magnitude of the rotated angle exceeds about 120 to 130 degrees from the start of the first rotation (see Fig. 21(b)), the arrangement of the base member 13 is reversed. That is, it changes from the forward downward inclination from the rear frame connection part 12 toward the main frame connection part 11 (see Fig. 21(b)) to the forward downward inclination from the main frame connection part 11 toward the rear frame connection part 12 (see Fig. 22(c)).

[0097] In this way, as the arrangement of the base member 13 is reversed, as shown in Fig. 22(c), the inclination directions of the first shaft 11a and the second shaft 12a change to upward inclination in front view and downward inclination in front view, respectively. Regarding the second shaft 12a among these, the structure in which the inclination direction changes (the structure reversed from upward inclination to downward inclination) corresponds to the inclination reversal structure of the rear frame rotation part 10.

[0098] Since the inclination direction of the base member 13 is forward downward inclination in the deployment structure 100, when the magnitude of the rotated angle is up to about 180 degrees from the start of the first rotation (see Fig. 23(a)), the inclination direction of the base member 13 remains forward downward inclination.

[0099] However, as described above, during the realization of the first rotation, since the arrangement of the base member 13 is reversed (from the rear frame connection part 12 → the main frame connection part 11 to the main frame connection part 11 → the rear frame connection part 12), the inclination directions of the first and second shafts 11a and 12a are interchanged with each other. As a result, in the rear frame rotation part 10, the above-described inclination reversal structure is obtained. In the deformed frame 20, by using the rear frame rotation part 10 having such an inclination reversal structure, an upside-down V-shaped arrangement in side view is realized.

[0100] Then, as shown in Fig. 23(a), as indicated by arrow r4, when the rotation continues, the first rotation ends. Then, as shown in Figs. 8(b), 9, and 23(a), the rear wheel 50 is arranged along the front wheel 40 at a position shifted to the front side from the center line ax. At this time, as shown in Fig. 23(a), the rear wheel 50 is separated from the main frame 21 by a distance d1.

[0101] (Second rotation) The second rotation is realized in parallel with the first rotation. In the following description, for the sake of clarity, it is assumed that the second rotation is realized after the first rotation ends. When the second rotation starts, as shown in Fig. 23(b), the rear wheel 50 rotates toward the front wheel 40 side together with the rear frame 31 using the second shaft 12a as the rotation axis. At this time, the rear wheel 50 and the rear frame 31 move obliquely upward as indicated by arrow r5 in Fig. 23(b) along a plane parallel to the direction d12 orthogonal to the second shaft 12a, away from the front wheel 40. Also, due to the tilt inversion structure of the rear frame rotation part 10 described above, the tilt direction of the second shaft 12a changes to a downward tilt in the front view. Therefore, the rear wheel 50 approaches the center line ax (main frame 21) and rotates so as to contact the main frame 21 from the outside thereof, as shown in Figs. 11, 12, and 23(b). The rear wheel 50 rotates until the rotation axis 50b is arranged above the chain ring 81.

[0102] Also, due to the change in the tilt direction of the second shaft 12a to a downward tilt in the front view, the rear wheel 50 rotates while maintaining its initial tilt direction (while the circular rear wheel surface 50S remains tilted upward in the front view). Then, the rear wheel 50 is arranged at a position separated from the main frame 21 by a distance d2 smaller than the distance d1 (d2 < d1). Since the circular rear wheel surface 50S is tilted upward in the front view, the rear wheel 50 is arranged so as to tilt toward the main frame 21.

[0103] With the above, Procedure 2 is completed. In Procedure 2, by the first rotation, the rear wheel 50 and the rear frame 31 are first rotated from the center line ax to a position significantly closer to the front wheel 40 side at an interval d1 (the position in Fig. 8(b)). Then, by the subsequent second rotation, it moves toward the rear wheel 50 side away from the front wheel 40 and is pulled back to a position at an interval d2 from the center line ax (the positions in Figs. 11 and 12). At this time, since the rotation angle A12 of the second shaft 12a is smaller than the rotation angle A11 of the first shaft 11a, the angle by which the rear wheel 50 shifts from the center line ax is smaller than the angle of shift in the first rotation. Therefore, when the rear wheel 50 is pulled back from the front wheel 40 side to the rear wheel 50 side by the second rotation, it is arranged at a position closer to the main frame 21.

[0104] (Procedure 3) In Procedure 3, the front wheel 40 is rotated toward the rear wheel 50 side together with the front fork 41 using the front rotation mechanism 60. First, using the retainer release tool 61 of the front rotation mechanism 60, the connection state between the rod-shaped portion 41a and the fork portion 41b of the front fork 41 is released. Then, the fork portion 41b is detached from the rod-shaped portion 41a, and as shown in Figs. 18 and 23(c), the fork portion 41b and the front wheel 40 are rotated using the shaft 62a of the hinge portion 62 as the rotation axis. Also, the rod-shaped portion 41a is inserted into the head tube 22. Therefore, it is used as a rotation axis while the rod-shaped portion 41a is inserted into the head tube 22 and is rotatable along the rotation surface 41s orthogonal to the head tube 22.

[0105] When the rod-shaped portion 41a rotates along the rotation surface 41s, the front fork 41 also rotates along the rotation surface 41s. Then, as shown in Fig. 23(c), together with the front fork 41, the front wheel 40 is shifted in a direction inclined with respect to the center line ax (an inclination such that the rear wheel 50 side is farther from the center line ax than the front wheel 40). Also, the front wheel 40 is rotated toward the rear wheel 50 side using the shaft 62a of the hinge portion 62 as the rotation axis. When the front wheel 40 rotates from the position shown in Figs. 1 and 3 (the position when the folding bicycle 1 holds the unfolded structure 100, which is also referred to as the initial position) to the position shown in Fig. 14 (the position when the folding bicycle 1 holds the folded structure 101, which is also referred to as the completion position), Procedure 3 ends.

[0106] As shown in Figs. 14 and 24(a), in the completion position, the front wheel 40 partially overlaps the chain ring 81 and is in contact with or very slightly separated from the axle 50b of the rear wheel 50 (the rear wheel 50 is in contact with or very slightly separated from the axle 40a of the front wheel 40). Also, the shaft 62a of the hinge portion 62 is arranged with an upward inclination in a front view. As a result, the front wheel 40 inclines toward the rear wheel 50 side, but the inclination direction is different from that of the rear wheel 50, and as shown in Fig. 23(c), the circular front wheel surface 40S of the front wheel 40 is arranged with a downward inclination in a front view. In this way, the reverse V-shaped arrangement of the front wheel 40 and the rear wheel 50 in a side view is realized.

[0107] As shown in Fig. 16(a), when Procedures 1 to 3 are completed and the front wheel 40 and the rear wheel 50 are arranged in the reverse V shape in the side view as described above, a part of the main frame 21 (mainly, a part of the long link members 24a, 24b, and the link members 28a, 28b) is arranged in the wheel space Vg. In this way, the densest filling structure is formed.

[0108] Subsequently, in Procedure 4, the lowering of the seat post 19 and the rotation of the handle are realized. Thus, the folding conversion is completed.

[0109] (Function and Effect of the Folding Bicycle 1) As described above, in the folding bicycle 1 according to the embodiment of the present invention, the front wheel 40 and the rear wheel 50 are arranged in an upside-down V shape in a side view by folding and conversion. Therefore, the folding volume of the folding bicycle 1 is reduced compared to conventional folding bicycles. This point will be described in detail as follows.

[0110] In the folding structure 101 of the folding bicycle 1 according to the embodiment of the present invention, the front wheel 40 and the rear wheel 50 are arranged in an upside-down V shape in a side view. Therefore, as shown in Fig. 24(a), the circular front wheel surface 40S and the circular rear wheel surface 50S of the front wheel 40 and the rear wheel 50 respectively are visible in a plan view. Further, in the folding structure 101, the axles 40a, 40b of the front wheel 40 and the axles 50a, 50b of the rear wheel 50 are arranged in an inclined state. Then, as shown in Fig. 24(b), the distance (corresponding to the depth of the folding structure 101) D200 from the tip of the axle 40b of the front wheel 40 to the tip of the axle 50a of the rear wheel 50 is smaller than the depth D299 (D200 < D299). The depth D299 corresponds to the depth when the front wheel 40 and the rear wheel 50 are not in an upside-down V shape in a side view, the distance between them is constant, and the front and rear wheels (front wheel 601, rear wheel 602) are arranged in parallel (see the circumscribed rectangular parallelepiped 700, Fig. 25(a) described later).

[0111] And, as shown in Fig. 24(a), the circumscribed rectangular parallelepiped 200 of the folding bicycle 1 has a width W200 and a depth D200. When the sizes of the front wheel 40 and the rear wheel 50 are the same as those of the front wheel 601 and the rear wheel 602, the width W200 of the circumscribed rectangular parallelepiped 200 is the same as the width W700 of the circumscribed rectangular parallelepiped 700. Therefore, since the depth D200 < the depth D299 and the height of the circumscribed rectangular parallelepiped 200 is also smaller than the height of the circumscribed rectangular parallelepiped 700, the circumscribed rectangular parallelepiped 200 is smaller than the circumscribed rectangular parallelepiped 700 (the difference between the folding volume of the circumscribed rectangular parallelepiped 200 and the folding volume of the circumscribed rectangular parallelepiped 700 is slight).

[0112] As shown in Fig. 25(a), in the circumscribed rectangular parallelepiped 700, in plan view, the front wheels 601 and the rear wheels 602 (width direction line L600) are arranged in an inclined state with respect to the center line ax. Also, the distance d70 between the front wheels 601 and the rear wheels 602 is constant, and the front wheels 601 and the rear wheels 602 are arranged in parallel (the arrangement of the front and rear wheels like the circumscribed rectangular parallelepiped 700 is also referred to as "parallel arrangement in an inclined state in plan view"). The circumferential side surface 601c of the front wheel 601 contacts the axle 602a or is slightly separated therefrom. The circumferential side surface 602c of the rear wheel 602 contacts the axle 601a or is slightly separated therefrom.

[0113] As shown in Fig. 25(b), also in the circumscribed rectangular parallelepiped 750, similar to the circumscribed rectangular parallelepiped 700, the distance d70 between the front wheels 601 and the rear wheels 602 is constant, and the front wheels 601 and the rear wheels 602 are arranged in parallel. The circumferential side surface 601c contacts the axle 602a or is slightly separated therefrom. The circumferential side surface 602c contacts the axle 601a or is slightly separated therefrom. However, in the circumscribed rectangular parallelepiped 750, the front wheels 601 and the rear wheels 602 (width direction line L600) are arranged in the direction along the center line ax.

[0114] When the front wheels 601 and the rear wheels 602 are arranged in an inclined state with respect to the center line ax like the circumscribed rectangular parallelepiped 700, compared with the case where the front wheels 601 and the rear wheels 602 are arranged along the center line ax like the circumscribed rectangular parallelepiped 750, the volume of the circumscribed rectangular parallelepiped becomes smaller. By arranging the front wheels 601 and the rear wheels 602 in an inclined state with respect to the center line ax, the influence on the dimensions due to the overhang of the axles is alleviated. Therefore, the width W700 and the depth D700 of the circumscribed rectangular parallelepiped 700 are smaller than the width W750 and the depth D750 of the circumscribed rectangular parallelepiped 750.

[0115] Therefore, even if the distance d70 between each other is constant and the front wheels 601 and the rear wheels 602 are arranged in parallel, by optimizing the arrangement of the front wheels 601 and the rear wheels 602 like the circumscribed rectangular parallelepiped 700 (in this case, the parallel arrangement in an inclined state in plan view corresponds to the optimization of the wheel arrangement), it becomes possible to reduce the folding volume.

[0116] Moreover, as described above, the folded volume of the folded rectangular parallelepiped 200 is smaller than that of the outer circumscribed rectangular parallelepiped 700. That is, by optimizing the arrangement of the wheels like the folding bicycle 1 (in this case, the inverted V-shaped arrangement in side view corresponds to the optimization of the wheel arrangement), the folded volume can be further reduced. In particular, in the case of the folded rectangular parallelepiped 200, the wheel space Vg described above is formed, and a structure (the densest packing structure) in which a part of the main frame 21 is accommodated therein is realized. Therefore, with respect to the reduction of the folded volume, the inverted V-shaped arrangement in side view is even more preferable.

[0117] For reducing the folded volume of the folding bicycle 1 as described above, it is effective to provide a two-axis mechanism such as the rear frame rotating part 10 having the first and second shafts 11a, 12a. Suppose that instead of the rear frame rotating part 10, a shaft member is provided with a single mechanism (for example, a single-axis mechanism having only the first shaft 11a, not shown). Then, only the rotation by the shaft member (in this case, the first rotation) is realized. At this time, the rear wheel 50 is arranged as shown in Fig. 23(a) described above, but the arrangement as shown in Fig. 23(b) is not realized (because the second shaft 12a is absent). Therefore, even if a single-axis mechanism is provided, the reduction of the folded volume like the folded rectangular parallelepiped 200 is not realized. The alignment of both the first and second shafts 11a, 12a realizes the inverted V-shaped arrangement in side view like the folded rectangular parallelepiped 200.

[0118] The above-described upside-down V-shaped arrangement of the front wheels 40 and rear wheels 50 in side view is a preferable arrangement for realizing the closest packing structure. To achieve such a preferable arrangement, a biaxial mechanism such as the rear frame rotating part 10 is required, rather than a uniaxial mechanism. Even when the number of shaft members is more than two (such as a triaxial mechanism), the upside-down V-shaped arrangement in side view can be realized. However, with an increase in the number of shaft members, there are problems such as increased structural complexity, increased number of parts, increased weight, and decreased running performance. Therefore, a triaxial or more shaft mechanism is not preferable. Thus, in order to arrange the front and rear wheels at the target positions, a biaxial mechanism is effective. Realizing the optimization of the arrangement of the wheels (front and rear wheels) using such a biaxial mechanism, and thereby realizing the reduction of the folding volume, this is the main concept of the present invention.

[0119] Regarding the present invention, it is important that the two axes (the first and second shafts 11a, 12a according to the embodiment) are arranged in different directions. When the first and second shafts 11a, 12a are arranged in the directions as described above, the above-described first and second rotations are realized, and as a result, the upside-down V-shaped arrangement in side view is realized.

[0120] The first and second shafts 11a, 12a only need to be arranged in different directions, and they may be arranged in directions different from the above-described case. For example, although the above-described first shaft 11a is arranged with a downward inclination in front view, it may be arranged flat along the depth direction Db in front view. At this time, in FIG. 22(a), the circular rear wheel surface 50S cannot be visually recognized, and the rear wheel 50 is arranged like the above-described rear wheel 602. Even in this case, since the second shaft 12a has an upward inclination in front view, the first and second shafts 11a, 12a are arranged in different directions. In addition, when the shaft 62a of the hinge part 62 is not arranged with an upward inclination in front view but is arranged flat along the depth direction Db in front view, the front wheel 40 is arranged like the above-described front wheel 601. Therefore, an inclined parallel arrangement in plan view such as the circumscribed rectangular parallelepiped 700 can be obtained, and the reduction of the folding volume is realized.

[0121] On the other hand, in the folding bicycle 1, the rear frame rotating part 10 is arranged below the lower end surface 23a (preferably without contacting the lower end surface 23a as shown in the figure). When the folding bicycle 1 travels, a load due to the weight of the person riding is applied to the seat tube 23. Also, a load during pedal operation is applied to the BB hanger 80. Therefore, the seat tube 23 and the BB hanger 80 are parts that particularly require strength among the members of the deformable frame 20. In the folding bicycle 1, the rear frame rotating part 10, which is essential for folding, is separated from the seat tube 23, and an extension part 80c is provided on the BB hanger 80, and the rear frame rotating part 10 is connected to the extension part 80c. In the folding bicycle 1, since the rear frame rotating part 10 is provided, reinforcement such as thickening a part of the deformable frame 20 is unnecessary. There is no increase in weight. The folding bicycle 1 can be folded and has good running performance without a decrease in running performance. Since the sprocket 51 is a multi-stage (9 - 13 stages) type used for a road bike, road bike-level running performance can be obtained.

[0122] Also, in the folding bicycle 1, the main frame 21 has a truss structure in which a plurality of link members are combined. Since the front wheel 40 and the rear wheel 50 are arranged in an upside-down V shape in side view, in the wheel space Vg, the interval between the lower side is wider than that between the upper side. Therefore, a structure is realized in which the main frame 21 fits into the narrow wheel space Vg.

[0123] As described above, the circumscribed rectangular parallelepiped 200 of the folding structure 101 has a smaller folding volume than the circumscribed rectangular parallelepiped 700, and the main frame 21 fits into the wheel space Vg. Therefore, the folding structure 101 has a structure in which the density is the highest when each member such as the deformable frame 20 is filled in the circumscribed rectangular parallelepiped 200, and such a structure is the closest packing structure.

[0124] Even if the front wheel 40 and the rear wheel 50 are arranged in an upside-down V shape in side view, if each member constituting the folding bicycle 1 is arranged outside the front wheel 40 and the rear wheel 50, there is a possibility that the volume of the circumscribed rectangular parallelepiped will not be reduced. Further, like the conventional folding bicycle disclosed in Patent Document 1, if the frame is formed by combining tubular members, even if the frame is housed between the front wheel and the rear wheel, it is difficult to narrow the interval between the front wheel and the rear wheel, and therefore, it is difficult to reduce the depth of the circumscribed rectangular parallelepiped.

[0125] In this regard, in the folding bicycle 1, the main frame 21 has a truss structure in which a plurality of link members are combined, whereby a structure is realized in which the main frame 21 is housed in the narrow wheel space Vg. Therefore, in the folding bicycle 1, the reduction of the folding volume is more effective.

[0126] And in the folding bicycle 1, since the rear frame rotation part 10, which is indispensable for realizing the upside-down V shape in side view, is arranged at an inconspicuous position below the lower end surface 23a of the seat tube 23, the rear frame rotation part 10 is inconspicuous. Therefore, the rear frame rotation part 10 does not impair the appearance of the folding bicycle 1. Since the frame attachment / detachment part 9 is arranged at a position farther from the seat tube 23 than the rear frame connection part 12, the frame attachment / detachment part 9 does not impair the appearance of the folding bicycle 1 either. Further, at the time of folding conversion, after the main frame 21 and the rear frame 31 are separated by the frame attachment / detachment part 9, the rear frame rotation part 10 operates. If the rear frame rotation part 10 operates before the main frame 21 and the rear frame 31 are separated, there is a possibility of affecting the running performance, but the folding bicycle 1 is not affected by such running performance.

[0127] Since the optimization of the arrangement by the upside-down V-shaped arrangement in side view of the aforementioned wheels (front and rear wheels 40, 50) is realized, the folding bicycle 1 is provided with a rear frame rotating portion 10 and a front rotation mechanism 60. The front rotation mechanism 60 has a two-axis mechanism including the rod-shaped portion 41a and the shaft 62a because the rod-shaped portion 41a is used as a rotation axis. In this case, in order to realize the arrangement optimization, although there is a difficulty in that high precision is required for the angle adjustment of the shaft 62a arranged with an upward inclination in front view, there is no such difficulty for the rod-shaped portion 41a. On the other hand, the rear frame rotating portion 10 has two shaft members (first and second shafts 11a, 12a), and precise angle adjustment for realizing the arrangement optimization is required for both of them. The present invention has a technical significance in that the difficulty in realizing the arrangement optimization is overcome in the rear frame rotating portion 10.

[0128] Next, with reference to FIGS. 5, 27, and 28, the tension holding structure will be described. FIGS. 27 and 28 are perspective views of the main part seen from the rear of the front side of the folding bicycle 1, FIG. 27 shows before the folding conversion, and FIG. 28 shows after the folding conversion. As shown in FIGS. 27 and 28, in the deformed frame 20, the triangular forms 31Fa and 31Fb are surrounded by the seat stays 32a and 32b, the chain stays 33a and 33b, and the link members 34a and 34b, respectively. The chain 91 is inserted inside the triangular form 31Fa. Before the folding conversion, the chain 91 is arranged near the locking portion 34ab of the link member 34a (the portion indicated by C27 in FIG. 27).

[0129] Since the chain 91 is inserted inside the triangular form 31Fa, the chain 91 will not come off from the inside to the outside (the outside of the seat stay 32a, the chain stay 33a, and the link member 34a) even after the folding conversion. Then, as shown in FIG. 28, when the rear frame 31 is rotated to the front wheel side 40, the locking portion 34ab contacts the chain 91 from the inside thereof. Therefore, the chain 91 is locked by the locking portion 34ab (the portion indicated by C28 in FIG. 28). Therefore, in addition to the chain ring 81 and the sprocket 51, the chain 91 is held by the locking portion 34ab. Accordingly, the tension of the chain 91 is maintained even after the folding conversion. That is, the folding bicycle 1 further has a tension holding structure.

[0130] Generally, in a folding bicycle, the distance between the rear wheel and the chain ring often changes with folding. Accordingly, the chain is likely to loosen. There is also a risk that the chain may come off.

[0131] In this regard, since the folding bicycle 1 has the above-described tension holding structure, the chain 91 does not loosen even after being folded. The tension of the chain 91 is maintained as before the rotation of the rear frame 31. Therefore, in the folding bicycle 1, there is no risk that the chain 91 will come off even after folding.

[0132] (Modification example) In the case of the folding bicycle 1 described above, in the folding structure 101, the front wheel 40 and the rear wheel 50 were arranged in an inverted V shape in side view. In addition, the front and rear wheels may be arranged in a V shape in side view, such as the front wheel 40V and the rear wheel 50V shown in FIG. 26. (Such an arrangement is also referred to as an "arrangement in a V shape in side view"). The present invention is also applicable to the optimization of the wheel arrangement by the arrangement in a V shape in side view.

[0133] In the case of the front wheel 40V and the rear wheel 50V, the interval between the upper ends is formed wider than the interval between the lower ends. Note that FIG. 26 is a diagram schematically showing the main parts of the front wheel 40V and the rear wheel 50V of the folding bicycle arranged in a V shape in a side view, as viewed from the side. The depth D200V of the V-shaped arrangement in the side view as shown in FIG. 26 is not different from the depth D200 of the inverted V-shaped arrangement in the side view as shown in FIG. 24, and the width and height are also not different. Therefore, the folding volume of the V-shaped arrangement in the side view is not different from the folding volume of the inverted V-shaped arrangement in the side view. In the case of the inverted V-shaped arrangement in the side view, since the interval between the lower ends is wider than the interval between the upper ends, the folding structure 101 is stably installed. In this regard, the inverted V-shaped arrangement in the side view is preferable. Note that the V-shaped arrangement in the side view as shown in FIG. 26 is realized by changing the inclination direction of the second shaft 12a and the shaft 62a (from the upward inclination in the front view to the downward inclination in the front view).

[0134] In the above embodiment, the deformable frame 20 has the rear frame rotating portion 10, and the arrangement on the rear wheel 50 side in the inverted V shape in the side view is realized by the rear frame rotating portion 10. In order to realize the arrangement on the front wheel 40 side in the inverted V shape in the side view, the front rotation mechanism 60 is used. A two-axis mechanism having a structure different from that of the rear frame rotating portion 10 may be used to realize the inverted V-shaped arrangement of the front wheel 40 and the rear wheel 50 in the side view, or a known mechanism different from the front rotation mechanism 60 may be used. For example, an inverted V-shaped arrangement in the side view is realized by a mechanism different from the deformable frame 20 having the rear frame rotating portion 10 and the front rotation mechanism 60 for the front wheel 40 (a mechanism for rotating the front wheel 40 to the rear wheel 50 side and arranging the circular front wheel surface 40S in a downward inclination in the front view).

[0135] Also, in the above embodiment, the case where the deformable frame 20 does not have the front rotation mechanism 60 is described as an example, but a deformable frame having the front rotation mechanism 60 may be used instead of the deformable frame 20. For example, a front fork 41 with a mechanism having the front rotation mechanism 60, and a deformable frame (a deformable frame with a front fork, not shown) in which the front fork with the mechanism is inserted into the head tube 22 may be used.

[0136] In the above embodiment, the deformable frame 20 having a truss structure is taken as an example for explanation. The present invention is also applicable to the following deformable frames (not shown) and folding bicycles having such deformable frames. The deformable frame is a frame formed by combining tubular members such as a top tube and a down tube, and is divided into a main frame and a rear frame. Further, a rotating part similar to the rear frame rotating part 10 is provided. In the above embodiment, the folding bicycle 1 is described as an example of a folding vehicle, but the present invention is also applicable to other vehicles. Furthermore, although the folding bicycle 1 has a front rotation mechanism 60, as long as the front wheel 40 has a structure that can be rotated, it may have a known mechanism different from the front rotation mechanism 60.

[0137] The above description is an explanation of the embodiments of the present invention, and does not limit the devices and methods of this invention, and various modifications can be easily implemented. In addition, devices or methods configured by appropriately combining the components, functions, features, or method steps in each embodiment are also included in the present invention.

Industrial Applicability

[0138] By applying the present invention, a folding vehicle, a folding mechanism, a deformable frame, a frame deformation mechanism, and a rotating rear frame can be obtained, which can solve the following 1), 2), and 3). 1) The folding volume is reduced. 2) There is no reduction in aesthetics due to the mechanism parts essential for folding. 3) There is no increase in vehicle body weight due to reinforcement, and the running performance is not degraded. The present invention can be used in the field of folding vehicles.

Explanation of Reference Numerals

[0139] 1…Folding bicycle, 9…Frame attachment part, 10…Rear frame rotation part, 11…Main frame connection part, 11a…First shaft, 12…Rear frame connection part, 12a…Second shaft, 13…Base member, 19…Seat post, 20…Deformable frame, 21…Main frame, 23…Seat tube, 23a…Lower end face, 24a, 24b…Long link members, 31…Rear frame, 40, 40V, 601…Front wheels, 40S…Circular front wheel surface, 41…Front fork, 41a…Rod-shaped part, 41b…Fork part, 50, 50V, 602…Rear wheels, 50S…Circular rear wheel surface, 60…Front rotation mechanism, 61…Retention release tool, 62…Hinge part, 65…Folding mechanism, 70…Frame deformation mechanism, 100…Deployment structure, 101…Folding structure, ax…Center line.

Claims

1. A folding vehicle, the folding vehicle having a deformable frame, a front wheel and a rear wheel, and a front fork to which the front wheel is attached, wherein the deformable frame has a main frame for holding the front fork, a rear frame for holding the rear wheel, and a frame deformation mechanism for enabling frame deformation, the frame deformation mechanism having a frame attachment / detachment part for enabling the holding and release of the connection state between the main frame and the rear frame without changing their respective shapes, and a rear frame rotation part, the rear frame rotation part being provided so that the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part can rotate together with the rear wheel toward the front wheel side, and having two non-parallel shaft members arranged in different directions, the rear frame rotation part being arranged below the lower end surface of a seat tube through which a seat post is inserted and connected to the main frame and the rear frame, a folding vehicle in which when the rear wheel is rotated toward the front wheel side by the rear frame rotation part together with the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part, and the front wheel is rotated toward the rear wheel side together with the front fork, the axles of the rear wheel and the front wheel are respectively arranged outside the rear wheel and the front wheel, and the rear wheel and the front wheel are arranged in an inclined manner with respect to the center line along the depth direction in a front view.

2. the rear frame rotation part having a base member, and a first rotation shaft member and a second rotation shaft member as the two non-parallel shaft members, the base member being provided with a first frame connection part and a second frame connection part, the first frame connection part being connected to the main frame using the first rotation shaft member as a rotation shaft, the second frame connection part being connected to the rear frame using the second rotation shaft member as a rotation shaft, the first and second frame connection parts being formed such that the first and second rotation shaft members intersect with respect to the center line when the connection state between the main frame and the rear frame is being held. The folding vehicle according to claim 1, wherein the first and second rotating shaft members are arranged along first and second rotating shaft directions along first and second rotation angles that are obtuse angles in the clockwise direction from the line forward direction from the rear wheel side to the front wheel side in the plan view of the center line, and the first rotation angle is larger than the second rotation angle.

3. The first frame connection portion is disposed on the front wheel side below the lower end surface of the seat tube, and the second frame connection portion is disposed on the rear wheel side below the lower end surface. The base member is disposed with a forward downward inclination such that the first frame connection portion is closer to the lower end portion of the front wheel or rear wheel than the second frame connection portion. The folding vehicle according to claim 2, wherein the frame attachment / detachment portion is disposed at a position away from the seat tube than the second frame connection portion.

4. The first rotating shaft member is disposed at the first frame connection portion with a downward inclination along the depth direction in the front view, and the second rotating shaft member is disposed at the second frame connection portion with an upward inclination along the depth direction in the front view. Thus, a first inclination direction indicating the inclination direction of the first rotating shaft member along the depth direction in the front view and a second inclination direction indicating the inclination direction of the second rotating shaft member along the depth direction in the front view are different. The folding vehicle according to claim 3.

5. The rear frame rotating portion has an inclination inversion structure. The inclination inversion structure is a structure in which the second inclination direction is inverted from an upward inclination along the depth direction in the front view to a downward inclination by the rotation of the second frame connection portion and the base member with the first rotating shaft member as the rotation axis. The folding vehicle according to claim 4.

6. The rear frame rotating portion has a composite rotation structure. The composite rotation structure is a structure in which a first rotation in which the rear frame, the rear wheel, the second frame connection portion, and the base member are rotated using the first rotating shaft member as the rotation axis and a second rotation in which the rear frame and the rear wheel are rotated using the second rotating shaft member as the rotation axis are realized in parallel. The folding vehicle according to claim 5.

7. When the first rotation is realized, when the rear frame, the rear wheel, the second frame connection part, and the base member are rotated to the front wheel side of the first frame connection part, the circular rear wheel surface of the rear wheel is arranged in an upward slope along the depth direction in the front view. When the second rotation is realized, when the rear frame and the rear wheel are rotated to the rear wheel side, the rear wheel approaches the main frame while maintaining the upward slope of the circular rear wheel surface along the depth direction in the front view, and the rear wheel and the front wheel are arranged in an inverted V shape in side view where the interval at the upper end is narrower than the interval at the lower end along the depth direction in the front view. The folding vehicle according to claim 6.

8. The rear frame has a locking part locked to the side surface of the seat tube. The locking part is arranged at a position above the second frame connection part of the rear frame and close to the seat tube. When the locking part is locked to the side surface of the seat tube, the main frame and the rear frame are connected by the frame attachment / detachment part without changing their respective shapes. The folding vehicle according to any one of claims 2 to 7.

9. The main frame has a truss structure including two link-shaped members fixed to the head tube holding the front fork and the side surface of the seat tube and connected to the frame attachment / detachment part. When the rear wheel and the front wheel are arranged in an inverted V shape in side view, a densest filling structure is formed in which the two link-shaped members are accommodated in the wheel gap surrounded by the rear wheel and the front wheel. The folding vehicle according to claim 7.

10. The folding vehicle further has a front rotation mechanism. The front rotation mechanism has a front shaft member that rotates the front fork together with the front wheel to the rear wheel side. The main frame has a head tube holding the front fork. The front rotation mechanism has, together with the front shaft member, a holding and releasing member that enables holding and releasing of the connection state between a rod-shaped part inserted into the head tube of the front fork and a fork part holding the front wheel. The folding vehicle according to any one of claims 1 to 7, wherein the front wheel has a circular front wheel surface disposed in a downward slope along the depth direction in the front view when the front wheel is rotated toward the rear wheel side together with the fork portion after the connection state with the rod-shaped portion is released because the front shaft member is disposed in an upward slope along the depth direction in the front view.

11. The rear frame has a structure forming a triangular form surrounded by a chain stay, a seat stay, and a link member, a chain is inserted inside the triangular form, and further has a tension holding structure in which the tension of the chain is held by locking the chain to the link member when the rear frame is rotated toward the front wheel side. The folding vehicle according to any one of claims 1 to 7.

12. A folding mechanism having a frame deformation mechanism that enables frame deformation of a deformed frame constituting a folding vehicle and a front rotation mechanism, wherein the deformed frame has a main frame that holds a front fork to which a front wheel of the folding vehicle is attached and a rear frame that holds a rear wheel of the folding vehicle, the frame deformation mechanism has a frame attachment / detachment portion that enables holding and releasing of the connection state between the main frame and the rear frame without changing their respective shapes, and a rear frame rotation portion, the rear frame rotation portion is provided so as to be able to rotate the rear frame, which has been released from the connection state with the main frame by the frame attachment / detachment portion, together with the rear wheel toward the front wheel side, and has two non-parallel shaft members arranged in different directions, the rear frame rotation portion is disposed below the lower end surface of a seat tube through which a seat post is inserted and is connected to the main frame and the rear frame, and the front rotation mechanism has a front shaft member that rotates the front fork together with the front wheel toward the rear wheel side. A folding mechanism in which, when the rear wheel is rotated toward the front wheel side by the rear frame rotation part together with the rear frame whose connection state to the main frame has been released by the frame attachment / detachment part, and when the front wheel is rotated toward the rear wheel side by the front rotation mechanism together with the front fork, the axle of the rear wheel and the axle of the front wheel are respectively arranged outside the front wheel and the rear wheel, and the rear wheel and the front wheel are arranged in an inclined manner with respect to the center line along the depth direction in a front view.

13. The main frame has a head tube that holds the front fork. The front rotation mechanism has a holding / release member that enables holding and releasing of the connection state between a rod-shaped part inserted into the head tube of the front fork and a fork part that holds the front wheel, together with the front shaft member. The folding mechanism according to claim 12, wherein, since the front shaft member is arranged in an upward slope along the depth direction in a front view, when the front wheel is rotated toward the rear wheel side together with the fork part after the connection state with the rod-shaped part is released, the circular front wheel surface of the front wheel is arranged in a downward slope along the depth direction in a front view.

14. A deformed frame that constitutes a folding vehicle, The deformed frame has a main frame that holds a front fork to which the front wheel of the folding vehicle is attached, a rear frame that holds the rear wheel of the folding vehicle, and a frame deformation mechanism that enables frame deformation. The frame deformation mechanism has a frame attachment / detachment part that enables holding and releasing of the connection state between the main frame and the rear frame without changing their respective shapes, and a rear frame rotation part. The rear frame rotation part is provided so as to be able to rotate the rear frame whose connection state with the main frame has been released by the frame attachment / detachment part together with the rear wheel toward the front wheel side, and has two non-parallel shaft members arranged in different directions. The rear frame rotation part is arranged below the lower end surface of a seat tube through which a seat post is inserted and is connected to the main frame and the rear frame. The rear frame, whose connection state with the main frame has been released by the frame attachment / detachment part, is rotated toward the front wheel side by the rear frame rotation part together with the rear wheel, and when the front wheel attached to the front fork held by the main frame is rotated toward the rear wheel side together with the front fork, the axle of the rear wheel and the axle of the front wheel are each disposed outside the front wheel and the rear wheel, and the rear wheel and the front wheel are disposed in an inclined manner with respect to the center line along the depth direction in a front view. A deformable frame.

15. The rear frame rotation part has a base member, a first rotation shaft member and a second rotation shaft member as the two non-parallel shaft members. The base member is provided with a first frame connection part and a second frame connection part. The first frame connection part is connected to the main frame using the first rotation shaft member as a rotation shaft. The second frame connection part is connected to the rear frame using the second rotation shaft member as a rotation shaft. The first and second frame connection parts are formed such that the first and second rotation shaft members intersect with respect to the center line when the connection state between the main frame and the rear frame is maintained. The first and second rotation shaft members are arranged along first and second rotation shaft directions along first and second rotation angles that become obtuse angles clockwise from the line forward direction from the rear wheel side toward the front wheel side in the plan view of the center line, and the first rotation angle is larger than the second rotation angle. The deformable frame according to claim 14.

16. The first frame connection part is disposed on the front wheel side below the lower end surface of the seat tube, and the second frame connection part is disposed on the rear wheel side below the lower end surface. The base member is arranged in a forward downward inclination such that the first frame connection part is closer to the lower end part of the front wheel or the rear wheel than the second frame connection part. The deformable frame according to claim 15, wherein the frame attachment / detachment part is disposed at a position away from the seat tube than the second frame connection part.

17. The first rotating shaft member is arranged at the first frame connection portion with a downward inclination along the depth direction in the front view, and the second rotating shaft member is arranged at the second frame connection portion with an upward inclination along the depth direction in the front view. By this, a first inclination direction indicating the inclination direction of the first rotating shaft member along the depth direction in the front view and a second inclination direction indicating the inclination direction of the second rotating shaft member along the depth direction in the front view are different. The deformable frame according to claim 16.

18. The rear frame rotating portion has an inclination inversion structure and a composite rotation structure. The inclination inversion structure is a structure in which, by rotation of the second frame connection portion and the base member with the first rotating shaft member as a rotation axis, the second inclination direction is inverted from an upward inclination along the depth direction in the front view to a downward inclination. The composite rotation structure is a structure in which a first rotation in which the rear frame, the rear wheel, the second frame connection portion, and the base member are rotated using the first rotating shaft member as a rotation axis and a second rotation in which the rear frame and the rear wheel are rotated using the second rotating shaft member as a rotation axis are realized in parallel. The deformable frame according to claim 17.

19. The main frame has a head tube for holding the front fork. The front fork is a front fork with a mechanism having a front rotation mechanism, and the front fork with a mechanism is inserted into the head tube to be a front fork with a front fork. The deformable frame according to any one of claims 14 to 18.

20. A frame deformation mechanism that enables frame deformation of a deformable frame, The deformable frame has a main frame that holds a front fork to which a front wheel is attached and a rear frame that holds a rear wheel. The frame deformation mechanism has a frame attachment / detachment portion that enables holding and releasing of the connection state between the main frame and the rear frame without changing their respective shapes, and a rear frame rotating portion. The rear frame rotating portion is provided so that the rear frame whose connection state with the main frame has been released by the frame attachment / detachment portion can be rotated together with the rear wheel toward the front wheel side, and has two non-parallel shaft members arranged in different directions. The rear frame rotation part is disposed below the lower end surface of a seat tube through which a seat post is inserted, and is connected to the main frame and the rear frame. A frame deformation mechanism enabling the frame deformation, wherein when the rear wheel is rotated toward the front wheel side by the rear frame rotation part together with the rear frame whose connection state with the main frame is released by the frame attachment / detachment part, and in a state where the front fork is held by the main frame, when the front wheel is rotated toward the rear wheel side together with the front fork, the axles of the rear wheel and the front wheel are respectively disposed outside the rear wheel and the front wheel, and the rear wheel and the front wheel are disposed in an inclined manner with respect to a center line along the depth direction in a front view.

21. The rear frame rotation part has a base member, a first rotation shaft member and a second rotation shaft member as the two non-parallel shaft members. The base member is provided with a first frame connection part and a second frame connection part on both sides. The first frame connection part is connected to the main frame using the first rotation shaft member as a rotation shaft. The second frame connection part is connected to the rear frame using the second rotation shaft member as a rotation shaft. The first and second frame connection parts are formed such that the first and second rotation shaft members intersect with respect to the center line when the connection state between the main frame and the rear frame is maintained. The first and second rotation shaft members are arranged along first and second rotation shaft directions along first and second rotation angles that become obtuse angles clockwise from the line forward direction from the rear wheel side toward the front wheel side in a plan view of the center line, and the first rotation angle is larger than the second rotation angle. The frame deformation mechanism according to Claim 20.

22. A rotatable rear frame having a rear frame that holds a rear wheel and a rear frame rotation part. The rear frame rotation part has two non-parallel shaft members arranged in different directions, and has a structure for rotating the rear frame toward the main frame side in a state where the connection state with the main frame that holds a front fork to which a front wheel is attached is released, using the two non-parallel shaft members. The rear frame rotating portion is a rotating rear frame that rotates the rear frame such that when the front wheel is rotated toward the rear wheel side together with the front fork, the axles of the rear wheel and the front wheel are respectively disposed outside the rear wheel and the front wheel, and the rear wheel and the front wheel are disposed in an inclined manner with respect to the center line along the depth direction in a front view.

23. The rear frame rotating portion includes a base member, a first rotating shaft member and a second rotating shaft member as the two non-parallel shaft members. The base member is provided with a first frame connection portion and a second frame connection portion. The first frame connection portion is connected to the main frame using the first rotating shaft member as a rotating shaft. The second frame connection portion is connected to the rear frame using the second rotating shaft member as a rotating shaft. The first and second frame connection portions are formed such that the first and second rotating shaft members intersect with respect to the center line when the connection state between the main frame and the rear frame is maintained. The first and second rotating shaft members are respectively disposed along first and second rotating shaft directions along first and second rotation angles that become obtuse angles clockwise from the line forward direction from the rear wheel side toward the front wheel side in the plan view of the center line, and the first rotation angle is larger than the second rotation angle. The rotating rear frame according to claim 22.

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