JP6473634B2 - Folding bicycle - Google Patents

Description

  The present invention relates to a folding bicycle that can be deformed, for example, in a shortened state of a wheelbase.

  For example, Patent Document 1 shows a structure of a folding bicycle that can be folded so that a rear wheel support frame and a seat frame are pivotally supported in an X shape and contracted back and forth.

JP 2000-302079 A

  The folding bicycle needs to be able to be folded with as few inputs as possible in order to minimize the burden on the user when folding. It is also necessary to make the folded state more compact. In the expanded state, high rigidity is required.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a folding bicycle that has a small burden when folded and becomes more compact in a folded state.

  The folding bicycle of the present invention that solves the above problems includes a top tube and a head tube, between the head tube and a down tube, between the down tube and a hanger bracket, and between the hanger bracket and the top tube. A four-bar linkage mechanism that is pivotally supported between the hanger bracket and the hanger bracket and the hanger bracket are separated from each other so that the hanger bracket extends vertically. In a contracted state in which the hanger bracket is disposed across the front and back as the unfolded state, the shaft fulcrum of the down tube and the hanger bracket, and the shaft fulcrum of the top tube and the head tube approach each other. A deformable front frame and attached to the front frame It is characterized in that it comprises a biasing means for biasing the pivot point between said down tube the hanger bracket in a direction toward the pivot point between the head tube and the top tube.

  According to the present invention, when the front frame is deformed from the expanded state to the contracted state, the deformation operation can be assisted by the urging force of the urging means. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

The left view which shows the expansion | deployment state of the folding bicycle in this embodiment. The left view which shows the contraction state of the folding bicycle in this embodiment. The perspective view which shows the expansion | deployment state of the folding bicycle in this embodiment from the left rear. The perspective view which shows the contraction state of the folding bicycle in this embodiment from the left rear. The figure explaining the four-bar linkage mechanism which the front frame of the folding bicycle in this embodiment has. The figure explaining the structure of the urging means in this embodiment.

  1 is a left side view showing the unfolded state of the folding bicycle in the present embodiment, FIG. 2 is a left side view showing the contracted state of the folding bicycle in the present embodiment, and FIG. 3 is an unfolding of the folding bicycle in the present embodiment. FIG. 4 is a perspective view showing the contracted state of the folding bicycle according to the present embodiment from the left rear, and FIG. 5 is a four-bar linkage mechanism included in the front frame of the folding bicycle according to the present embodiment. It is a figure explaining.

  The folding bicycle 1 has a front wheel 3 and a rear wheel 4 attached to a frame 2, and further supports a handle 5 for operating the front wheel 3, a crank gear 6 for rotationally driving the rear wheel 4, and a saddle 7. A seat post 8 is attached. In addition, brakes, brake levers, wires, pedals, etc. are also attached as in normal bicycles, but they are omitted in the figure.

  The frame 2 has a front frame 11 and a rear frame 12. The front frame 11 includes a head tube 21, a top tube 22, a down tube 23, and a hanger bracket 31. In addition, although the name tube is used for the head tube 21, the top tube 22, and the down tube 23, the shape is not limited to a tubular shape, and may be a plate shape or a rod shape. The rear frame 12 includes a hanger bracket 31, a chain stay 32, and a seat stay 33. The hanger bracket 31 constitutes a part of the front frame 11 and also constitutes a part of the rear frame 12.

  The front frame 11 has a four-bar linkage mechanism in which the space between the top tube 22 and the head tube 21, the space between the head tube 21 and the down tube 23, and the space between the down tube 23 and the hanger bracket 31 are respectively supported ( (See FIG. 5). In the front frame 11, the shaft support point 44 between the down tube 23 and the hanger bracket 31 and the shaft support point 41 between the top tube 22 and the head tube 21 are separated from each other by the four-bar linkage mechanism so that the hanger bracket 31 extends vertically. The deployed state (see FIG. 1) can be transformed into the contracted state (see FIG. 2) in which the hanger bracket 31 is disposed in the front-rear direction by the shaft fulcrum 44 and the shaft fulcrum 41 approaching each other.

  The head tube 21 is long in the vertical direction, and a top tube 22 and a down tube 23 are pivotally supported at the upper and lower portions thereof. Therefore, a larger closed region surrounded by the head tube 21, the top tube 22, the down tube 23, and the hanger bracket 31 can be secured in the deployed state of the front frame 11, and high rigidity can be obtained as the front frame 11. A handle post is inserted into the head tube 21 and is rotatably supported. A handle 5 is fixed to the upper portion of the handle post. A front fork that supports the front wheel 3 is fixed to the lower portion of the handle post.

  In the top tube 22, a front portion of the top tube 22 is pivotally supported on an upper portion of the head tube 21 by a pivot point 41, and a rear portion of the top tube 22 is pivotally supported on an upper portion of the hanger bracket 31 by a pivot point 42. The top tube 22 is formed to be curved so that an intermediate portion between the front portion and the rear portion is convex upward. Therefore, it is possible to secure a larger closed area in the front frame 11 in the contracted state and avoid interference with other components. As shown in FIGS. 3 and 4, the top tube 22 is provided as a pair and spaced apart from each other in the lateral width direction, and the seat tube 24 is inserted between them so that the top tube 22 can move back and forth. ing.

  In the down tube 23, the front portion of the down tube 23 is pivotally supported on the lower portion of the head tube 21 by the pivot point 43, and the rear portion of the down tube 23 is pivotally supported on the lower portion of the hanger bracket 31 by the pivot point 44. The down tube 23 is disposed substantially parallel to the top tube 22 in the deployed state and faces the head tube 21, and is disposed to face the head tube 21 in the contracted state. A seat tube 24 is fixed to the down tube 23.

  The seat tube 24 is a position between the front portion and the rear portion of the down tube 23, that is, a portion where the down tube 23 is connected to the head tube 21 and a shaft fulcrum 43 where the down tube 23 is connected to the hanger bracket 31. It arrange | positions between the shaft fulcrum 44, and is extended upwards.

  The seat tube 24 is in contact with the hanger bracket 31 in the deployed state, and is fixed at a position away from the hanger bracket 31 in the contracted state. The seat tube 24 can hold the seat post 8 inserted therein, and the height position of the saddle 7 can be adjusted by adjusting the insertion length of the seat post 8. The lower part of the seat tube 24 is fixed to the down tube 23, and the upper part projects between the pair of top tubes 22 and protrudes upward. The lower portion of the seat tube 24 penetrates the down tube 23, and the lower end of the seat post 8 can be protruded downward from the lower end of the seat tube 24 when the seat post 8 is lowered. The upper portion of the seat tube 24 is disposed in the vicinity of the rear portion of the top tube 22 in the deployed state, and moves forward between the pair of top tubes 22 when deformed from the deployed state to the contracted state. 22 is disposed in the vicinity of the front portion. In the present embodiment, since the seat tube 24 is fixed to the down tube 23, for example, the seat tube 24 has a mounting position and a seat angle as compared with a structure in which the seat tube forms a part of the link mechanism. It can be set arbitrarily and has a high degree of design freedom.

  As shown in FIGS. 2 and 4, the seat tube 24 is provided with a contact portion 24 a that contacts the upper portion of the hanger bracket 31 in the unfolded state. When the front frame 11 is in the contracted state, the contact portion 24a is separated from the top of the hanger bracket 31, gradually approaches the top of the hanger bracket 31 during the deformation from the contracted state to the expanded state, and the hanger in the expanded state. The front frame 11 is held in an unfolded state by contacting the upper portion of the bracket 31. The contact portion 24a is made of an elastic resin material such as rubber, and also has an effect as a cushion of the rear frame 12.

  A reinforcing frame 25 is provided between the seat tube 24 and the down tube 23. The reinforcing frame 25 has one end fixed to the front portion of the down tube 23 and the other end fixed to a position facing the contact portion 24 a of the seat tube 24. Then, the force input to the seat tube 24 from the upper portion of the hanger bracket 31 through the contact portion 24a in the deployed state of the front frame 11 can be transmitted to the down tube 23 and dispersed.

  In the hanger bracket 31, the upper portion of the hanger bracket 31 is pivotally supported at the rear portion of the top tube 22, and the lower portion of the hanger bracket 31 is pivotally supported at the rear portion of the down tube 23. The hanger bracket 31 is disposed over the top and bottom in the deployed state, and is disposed in parallel with the head tube 21 to face each other. And it arrange | positions over front and back in a contracted state, and opposes the top tube 22. A chain stay 32 is joined to the lower part of the hanger bracket 31, and a seat stay 33 is joined to the upper part of the hanger bracket 31. The chain stay 32 and the seat stay 33 are joined to each other at the rear portion, and the rear wheel 4 is supported by the rear wheel support portion. The hanger bracket 31 constitutes the rear frame 12 that supports the rear wheel 4 in cooperation with the chain stay 32 and the seat stay 33. The rear wheel 4 is disposed behind the hanger bracket 31 in the deployed state, and is disposed below the hanger bracket 31 in the contracted state.

  A BB shell is provided at a joint portion between the hanger bracket 31 and the chain stay 32, and the crank gear 6 is rotatably supported. The BB shell is disposed at a position between the shaft fulcrum 44 and the support portion of the rear wheel 4.

  The shaft fulcrum 42 is provided with a fixing means 45 that can fix the front frame 11 in the expanded state and the contracted state and release the fixing. The fixing means 45 can take various known configurations, but in this embodiment, when the front frame 11 is in the expanded state and the contracted state, the claw portion engages with the groove portion and the top tube 22 and the hanger. It has a ratchet structure that restricts rotation with the bracket 31 and holds the front frame 11 in a deployed state and a contracted state. When releasing the fixing by the fixing means 45, the release operation lever 46 is lifted upward in the expanded state or the contracted state to disengage the claw portion from the groove, and the rotation restriction between the top tube 22 and the hanger bracket 31 is controlled. Is released.

  As shown by a solid line in FIG. 5, the front frame 11 has the head tube 21 and the hanger bracket 31 arranged substantially in parallel and the top tube 22 and the down tube 23 arranged substantially in parallel in the unfolded state. A substantially rectangular closed region surrounded by the top tube 22, the down tube 23 and the hanger bracket 31 is formed. Then, as shown by a broken line in FIG. 5, in the contracted state, the down tube 23 faces the head tube 21 and the hanger bracket 31 faces the top tube 22 to form a closed region that is crushed into a substantially triangular shape.

  In the front frame 11, the total length of the length L1 of the head tube 21 and the length L2 of the top tube 22 is longer than the addition length obtained by adding the length L3 of the down tube 23 and the length L4 of the hanger bracket 31. Each length dimension is set so as to be (L1 + L2> L3 + L4).

  In the present embodiment, as shown by a broken line in FIG. 5, the center of the rear wheel 4 is disposed below the pivot point 44 in the contracted state, and further, the expanded state shown by the solid line in FIG. In both of the states, the length dimensions of the head tube 21, the top tube 22, the down tube 23, and the hanger bracket 31 are set so that the head angles θ are substantially the same.

  Specifically, the length L1 between the shaft fulcrum 41 and the shaft fulcrum 43 of the head tube 21 is 260 mm, the length L2 between the shaft fulcrum 41 and the shaft fulcrum 42 of the top tube 22 is 372 mm, and the down tube 23 The length L3 between the shaft fulcrum 43 and the shaft fulcrum 44 is set to 347 mm, and the length L4 between the shaft fulcrum 42 and the shaft fulcrum 44 of the hanger bracket 31 is set to 162 mm.

FIG. 6 is a diagram for explaining the structure of the urging means in the present embodiment.
A gas spring 51 is attached to the front frame 11 as an urging means for urging the shaft fulcrum 44 between the down tube 23 and the hanger bracket 31 in a direction approaching the shaft fulcrum 41 between the top tube 22 and the head tube 21. Yes. The gas spring 51 has a front end portion 52 that is one end supported by the front bracket 55 of the head tube 21, and a base end portion 53 that is the other end supported by the rear bracket 54 of the hanger bracket 31. And the base end portion 53 are urged in the direction of increasing the distance. As shown in FIG. 6A, the rear bracket 54 has the base end portion 53 of the gas spring 51 disposed at the first dead center position in front of the pivot point 44 in the unfolded state, as shown in FIG. 6B. As described above, the base end portion 53 of the gas spring 51 is disposed at the second dead center position behind the pivot point 44 in the contracted state.

  The gas spring 51 urges the front frame 11 in a direction to widen an inner angle that is an angle between the down tube 23 and the hanger bracket 31. Therefore, the operation of the front frame 11 is assisted when the front fulcrum 44 is deformed from a developed state in which the shaft fulcrum 44 is separated from the shaft fulcrum 41 to a contracted state in which the shaft fulcrum 44 approaches the shaft fulcrum 41.

  Therefore, when the user performs the folding operation, the front frame 11 can be deformed from the expanded state to the contracted state with a smaller force, which reduces the burden on the user and facilitates the folding operation even by a less powerful user such as a woman or girl. Can be done. For example, even if the user releases the hand during the folding operation, the gas spring 51 is urged, so that it can be prevented from returning to a deployed state at a rapid speed due to its own weight, and the folding operation is easy. Can be done.

  In particular, in the present embodiment, the gas spring 51 is in the most contracted state in the unfolded state, as shown in FIG. 6A, and the base end portion 53 is the first front of the shaft fulcrum 44. It is arranged at the dead center position. The axis of the gas spring 51 connecting the distal end portion 52 and the base end portion 53 is substantially parallel to the axis of the down tube 23 connecting the shaft fulcrum 43 and the shaft fulcrum 44. On the other hand, as shown in FIG. 6 (b), it is in the most stretched state in the contracted state, and the base end portion 53 is disposed at the second dead center position behind the pivot point 44. As in the case of the first dead center position, the axis of the gas spring 51 is substantially parallel to the axis of the down tube 23.

  Along with the deformation of the front frame 11 from the expanded state to the contracted state, the base end portion 53 of the gas spring 51 has an arc shape from the first dead center position to the second dead center position with the pivot point 44 as the rotation center. It moves while drawing a trajectory, and passes through a position farthest from the axis of the down tube 23 at the midpoint between the first dead center position and the second dead center position. Therefore, the gas spring 51 can apply the greatest urging force to the hanger bracket 31 when the base end portion 53 is located at the intermediate point.

  Therefore, the deformation of the front frame 11 can be prevented from stopping between the expanded state and the contracted state, and the front frame 11 can be urged to be in either the expanded state or the contracted state.

  In the present embodiment, the case where the gas spring 51 is used as the urging means has been described. However, the present invention is not limited to such a configuration, and the front frame 11 can be urged in the direction of deformation from the expanded state to the contracted state. Anything is acceptable. Therefore, for example, a spring can be used instead of or in addition to the gas spring 51. When using a spring, it can be provided, for example, on at least one of the shaft fulcrum 41 to the shaft fulcrum 44.

  However, the gas spring 51 has less change in force than the spring spring and can be moved slowly. Therefore, when the front frame 11 is deformed from the expanded state to the contracted state, a sudden movement may occur. And there is no risk of hands getting caught. Further, the adjustment of the attachment position is easy, and it is not necessary to increase the frame accuracy for attachment. Therefore, it is preferable to use the gas spring 51 as the biasing means.

  When the folding bicycle 1 having the above configuration is folded, the release operation lever 46 of the fixing means 45 is lifted upward, and the rotation restriction between the top tube 22 and the hanger bracket 31 by the fixing means 45 is released. When the entire front frame 11 is moved upward in the direction of holding the release operation lever 46, the operation of deforming the front frame 11 from the expanded state to the contracted state by the urging force of the gas spring 51 is assisted. It can be transformed into a contracted state.

  Due to the deformation of the front frame 11 to the contracted state, the hanger bracket 31 rotates forward with the pivot point 42 as the center of rotation, and the rear wheel 4 rolls on the ground GL along with the rotation. And are arranged in a line on the rear side of the front wheel 3. The seat tube 24 moves forward between the pair of top tubes 22 according to the movement of the down tube 23 and is disposed from the position near the rear portion of the top tube 22 to the position near the front portion. Is disposed above the handle 5.

  When the front frame 11 is deformed to a contracted state, the claw portion engages with the groove portion of the fixing means 45, and the rotation of the top tube 22 and the hanger bracket 31 is restricted, and the front frame 11 is fixed to the contracted state. Therefore, the folding bicycle 1 is in a folded state in which the wheel base is shortened.

  Since the folding bicycle 1 is urged by the gas spring 51 in the direction in which the front frame 11 is deformed from the expanded state to the contracted state, the folding bicycle 1 only needs to be lifted lightly upward by holding the release operation lever 46. Therefore, the user's force required for folding can be reduced and it can fold easily.

  The folding bicycle 1 has the effect that the head angle θ does not change before and after folding, so that the folding bicycle 1 has good operability and is easy to move when pushed forward while being folded. Further, since the center of the rear wheel 4 is arranged below the pivot point 44, it is prevented from being automatically deformed by its own weight from the contracted state to the expanded state before being fixed in the contracted state by the fixing means 45, and the contracted state. Can be maintained.

  On the other hand, when the folding bicycle 1 is changed from the folded state to the normal traveling state, the release operation lever 46 of the fixing means 45 is pulled upward, and the top tube 22 and the hanger bracket 31 are rotated by the fixing means 45. Remove restrictions. Then, the front frame 11 can be deformed from the contracted state to the expanded state by moving the entire rear frame 12 so as to be pulled slightly rearward, and then moving the saddle 7 under the weight.

  The front frame 11 is urged in a direction to be deformed from the expanded state to the contracted state by the gas spring 51. However, when the weight is applied to the saddle 7, the urging force can be resisted, and the front frame 11 can be easily brought into the expanded state. Can be deformed. When the front frame 11 is deformed to the deployed state, the claw portion is engaged with the groove portion of the fixing means 45, and the rotation of the top tube 22 and the hanger bracket 31 is restricted, and is fixed to the deployed state. Thereby, the folding bicycle 1 is in a state in which it can normally travel.

  The folding bicycle 1 has a head tube 21 that is long in the vertical direction, and a top tube 22 and a down tube 23 that are pivotally supported at the upper and lower portions of the folding bicycle 1. A larger closed region can be ensured, the rigidity is high, and good running stability can be obtained.

  According to the folding bicycle 1 described above, the gas spring 51 is used to urge the front frame 11 in a direction in which the front frame 11 is deformed from the expanded state to the contracted state. Can be further reduced, and the burden on the user when folding can be reduced. Therefore, for example, even a woman and girl with low arm strength can easily perform the folding operation.

  The folding bicycle 1 has a front frame 11 of a four-bar linkage mechanism that can be deformed into an expanded state and a contracted state. Therefore, it can be set as the folded state which shortened the wheel base, and can be made more compact in the folded state.

  In particular, the seat tube 24 is disposed between the front portion and the rear portion of the down tube 23, that is, between the shaft fulcrum 43 and the shaft fulcrum 44, and extends upward. Accordingly, when the seat tube 24 is deformed from the expanded state to the contracted state, the seat tube 24 is rotated about the shaft fulcrum 43 and the rear frame 12 is rotated about the shaft fulcrum 42. As shown in FIG. 2, the seat post 8 and the saddle 7 are tilted to the handle side (forward), and the rear frame 12 is rotated to a position where the seat stay 33 is parallel to the head tube 21. Therefore, in the folded state, the seat post 8 and the saddle 7 fall forward, and the entire rear frame 12 is accommodated in a closed region formed by the head tube 21, the top tube 22, and the seat stay. Therefore, since the bicycle does not spread in the front-rear direction, the whole becomes compact.

  In addition, this invention is not limited to the structure of the above-mentioned embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, in the above-described embodiment, the case where one gas spring 51 is provided along the left side of the down tube 23 has been described as an example, but a pair of gas springs 51 may be provided on the left and right sides. In the above-described embodiment, the case where the hanger bracket 31 constitutes the rear frame 12 by the cooperation of the chain stay 32 and the seat stay 33 has been described. However, the seat stay 33 may be omitted.

DESCRIPTION OF SYMBOLS 1 Folding bicycle 2 Frame 11 Front frame 12 Rear frame 21 Head tube 22 Top tube 23 Down tube 31 Hanger brackets 41 to 44 Shaft support point 51 Gas spring (biasing means)

Claims (6)

A four-bar linkage mechanism is supported between the top tube and the head tube, between the head tube and the down tube, between the down tube and the hanger bracket, and between the hanger bracket and the top tube. An unfolded state in which the shaft fulcrum of the down tube and the hanger bracket and the shaft fulcrum of the top tube and the head tube are separated from each other, and the hanger bracket is arranged over the top and bottom, A front frame that can be deformed into a contracted state in which a shaft fulcrum of the hanger bracket and a shaft fulcrum of the top tube and the head tube approach each other and the hanger bracket is disposed across the front and rear;
An urging means attached to the front frame, for urging the fulcrum of the down tube and the hanger bracket in a direction approaching the fulcrum of the top tube and the head tube ;
The biasing means has an inner angle which is an angle between one end pivotally supported by the head tube and the other end pivotally supported by the hanger bracket and sandwiched between the down tube and the hanger bracket in the front frame. Energize in the direction of spreading,
The hanger bracket has the other end of the urging means disposed at a first dead center position in front of a pivot point of the down tube and the hanger bracket in the unfolded state. A folding bicycle , wherein the other end is disposed at a second dead center position behind a pivot point of the down tube and the hanger bracket . The hanger bracket constitutes a rear frame that supports a rear wheel by cooperation of a chain stay joined to the lower part of the hanger bracket and a seat stay joined to the upper part of the hanger bracket,
The folding bicycle according to claim 1 , wherein the rear wheel is disposed behind the hanger bracket in the unfolded state and is disposed below the hanger bracket in the contracted state. The folding bicycle according to claim 2 , wherein the front frame has the same head angle in the unfolded state and the contracted state. A seat tube that is fixed to the down tube and extends upward;
It said top tube, two are provided spaced in pairs in the lateral directions, to claim 1, characterized in that said seat tube is inserted between the two top tubes Folding bicycle as described. 5. The folding bicycle according to claim 4 , wherein the seat tube contacts the hanger bracket in the unfolded state and is fixed at a position away from the hanger bracket in the contracted state. The folding bicycle according to claim 1 , further comprising a fixing means for fixing the front frame in the unfolded state and the contracted state and releasing the fixing.

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