How to manufacture an electric bicycle

Abstract

To provide an electric bicycle that is superb in workability in assembling because a detent member, which is used to prevent revolution of a hub motor due to counteraction of drive torque, can be readily attached without cumbersome positioning work.SOLUTION: An electric bicycle includes a hub motor 11 having a rotor 11A, which rotates together with a wheel, and a stator 11B borne by a frame member of a vehicle body, a frame body, and a detent member 13 fixed to the stator 11B of the hub motor 11. The frame member and detent member 13 are secured by a fastening member that pierces the hub motor 11 in an axial direction of the hub motor. Either the frame member or detent member 13 is provided with a jutting part 131 that inhibits turning of the detent member 13 in a revolving direction of the hub motor 11.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electric bicycle, and more particularly to an improvement in a rotation-stop mechanism for a motor in an electric bicycle equipped with an assist motor. [Background technology]

[0002] 2. Description of the Related Art Electric bicycles having an assist motor built into the hub of the front or rear wheel have been known.

[0003] For example, Patent Document 1 describes an electric bicycle in which a hub motor that drives the front wheel is provided on the front hub. In this electric bicycle, a fixed shaft that protrudes outward in the axial direction of the hub motor serves as a fixed part that is fastened and fixed to the tip of the front fork and supported on the vehicle body, and a cylindrical hub main body part on the inside of the axial direction that is rotatably supported on this fixed shaft serves as a rotating part. In addition, a motor mechanism that receives driving power and drives the rotating part is interposed between the fixed part and rotating part of the hub motor. Therefore, when the wheel is driven by the hub motor, a strong reaction torque acts on the fixed part of the hub motor in the opposite direction to the driving torque.

[0004] In response to this, in Patent Document 1, a rotation prevention plate is provided that is connected and fixed to the tip of the front fork and an intermediate connecting part of the front fork located above the tip, and the fixed part of the hub motor is fixed to this rotation prevention plate. As a result, since the hub motor is supported by the front fork via the rotation prevention plate, even if a reaction rotation torque acts on the fixed part of the hub motor, it is possible to prevent the hub motor from rotating due to this, and the hub motor can be reliably fixed to the front fork. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-142631 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned Patent Document 1, a connecting piece for connecting the anti-rotation plate is provided at the intermediate connecting portion of the front fork so as to protrude in the rotation direction of the hub motor, and this connecting piece and the anti-rotation plate are overlapped in the axial direction of the hub motor and fixed using screws (paragraph

[0019] , Figure 7, etc. of Patent Document 1).

[0007] However, in the structure disclosed in Patent Document 1, the alignment work required to overlap the screw holes in the anti-rotation plate and the screw holes in the connecting piece in the axial direction of the hub motor was complicated, posing problems in terms of workability during assembly.

[0008] Therefore, the object of the present invention is to provide an electric bicycle that can be easily installed without complicated alignment work, and that is easy to assemble, by providing an anti-rotation member that is provided to prevent the hub motor from rotating due to a reaction to the driving torque. [Means for solving the problem]

[0009] As a result of intensive research, the present inventors have found that the above problems can be solved by adopting the following configuration, and have thus completed the present invention.

[0010] That is, the manufacturing method of the electric bicycle of the present invention includes manufacturing a hub motor having a rotating part that rotates integrally with the wheel and a fixed part that is supported by a frame member of the vehicle body; a rotation prevention member fixed to the frame member and a fixed portion of the hub motor, The frame member and the anti-rotation member are fixed to each other by a fastening member that penetrates the hub motor in the axial direction, A method for manufacturing an electric bicycle, in which either the frame member or the anti-rotation member is provided with an abutment portion that prevents the anti-rotation member from rotating in the rotation direction of the hub motor, comprising: After the anti-rotation member is fixed to a fixed portion of the hub motor, the anti-rotation member is rotated in the rotational direction of the hub motor to abut the abutment portion against the other of the frame member or the anti-rotation member, thereby aligning the frame member and the anti-rotation member, and then the frame member and the anti-rotation member are fixed with the fastening member.

[0011] In the manufacturing method of the electric bicycle of the present invention, the abutment portion may be formed by bending a plate material that constitutes the anti-rotation member.

[0012] In addition, in the manufacturing method of the electric bicycle of the present invention, it is preferable that the abutment portion is provided in the vicinity of the fastening member. Effect of the Invention

[0013] According to the present invention, it is possible to provide an electric bicycle with excellent workability during assembly by easily installing an anti-rotation member that is provided to prevent the hub motor from rotating due to a reaction to the driving torque, without the need for complicated alignment work. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic side view of an electric bicycle according to a preferred embodiment of the present invention; [Diagram 2] 1 is an enlarged perspective view showing the vicinity of a hub motor provided on a front wheel of an electric bicycle according to a preferred embodiment of the present invention. [Diagram 3] 1 is an enlarged side view showing the vicinity of a hub motor provided on a front wheel of an electric bicycle according to a preferred embodiment of the present invention. [Figure 4] FIG. 2 is an enlarged perspective view showing a rotation-prevention member according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The electric bicycle of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic side view of an electric bicycle according to a preferred embodiment of the present invention. The electric bicycle 1 shown in the figure includes a head tube 2 disposed at the front end, a down tube 3 extending from the head tube 2 at an incline downward toward the rear, and a seat tube 4 connected to the rear of the down tube 3. A seat stay 23 is connected to the upper part of the seat tube 4, and a chain stay 5 is connected to the lower end. The head tube 2 is disposed at the front end of the down tube 3 at an incline downward toward the front. A handle stem 6 is rotatably held at the upper end of the head tube 2, and a handle 7 is integrally connected to the upper end of the handle stem 6. Furthermore, a pair of left and right front forks 8 are connected below the head tube 2. The pair of front forks 8 extend at an incline downward toward the front, and a front wheel 9 is rotatably supported at the lower ends of these, and a rear wheel 10 is rotatably supported at the rear ends of the seat stays 23 and the chain stays 5. A saddle 24 on which a rider sits is attached to the upper end of the seat tube 4.

[0016] The electric bicycle of the present invention is equipped with an assist motor inside the hub of the front wheel or the hub of the rear wheel, and in the electric bicycle 1 according to a preferred embodiment of the present invention shown in the figures, a motor is built into the hub of the front wheel 9 to form a hub motor 11. Fig. 2 is an enlarged perspective view showing the vicinity of the hub motor provided on the front wheel of the electric bicycle according to a preferred embodiment of the present invention, and Fig. 3 is an enlarged side view showing the vicinity of the hub motor provided on the front wheel of the electric bicycle according to a preferred embodiment of the present invention. For ease of explanation, wiring and the like arranged around hub motor 11 have been omitted from the figures.

[0017] As shown in Figures 2 and 3, in the present invention, the hub motor 11 has a rotating part 11A that rotates integrally with a wheel, in this case the front wheel 9, and a fixed part 11B that is supported by a frame member of the vehicle body, in this case the front fork 8.

[0018] Rotating portion 11A of hub motor 11 constitutes a hub main body portion in which the motor is built, is rotatably supported by fixed portion 11B, and is connected to the rim of front wheel 9 via a number of spokes (not shown). Fixed portion 11B of hub motor 11 is disposed axially outwardly of the hub main body portion, and has a shaft portion 112 that protrudes axially outwardly from fixed portion 11B. Furthermore, hub motor 11 is fastened and fixed to tip portion 8A of front fork 8 by a lock nut 12 at shaft portion 112 of fixed portion 11B.

[0019] In the present invention, a rotation-stop member 13 is fixed to fixed portion 11B of hub motor 11, being sandwiched between hub motor 11 and front fork 8. Fig. 4 is an enlarged perspective view showing the rotation-stop member.

[0020] In the illustrated embodiment, the anti-rotation member 13 has, on one end 13A side fixed to the fixed portion 11B of the hub motor 11, a shaft insertion hole 13a through which the shaft 112 is inserted and a bolt insertion hole 13b through which the bolt 14 is inserted, and is fixed to the fixed portion 11B by the bolt 14 via the bolt insertion hole 13b with the shaft 112 inserted into the shaft insertion hole 13a.

[0021] Meanwhile, the anti-rotation member 13 also has a bolt insertion hole 13c on the other end 13B side different from the one end 13A fixed to the fixed part 11B of the hub motor 11, and as shown in Fig. 2, the other end 13B side is fixed to the front fork 8 by a bolt 15 serving as a fastening member that penetrates the hub motor 11 in the axial direction through the bolt insertion hole 13c. By providing the anti-rotation member 13 in this manner while being fixed to the front fork 8 and the fixed part 11B of the hub motor 11, the hub motor 11 is supported by the front fork 8 via the anti-rotation member 13. Therefore, even if a reaction torque acts on the fixed part 11B as the rotating part 11A of the hub motor 11 rotates, the hub motor 11 can be prevented from rotating due to this, and the hub motor 11 can be reliably fixed to the front fork 8.

[0022] When attaching the anti-rotation member 13 during assembly of the electric bicycle 1, first, the shaft 112 of the hub motor 11 is inserted into the shaft insertion hole 13a at one end 13A, and the anti-rotation member 13 is fixed to the fixed part 112 of the hub motor 11 with the bolt 14 via the bolt insertion hole 13b. Next, the shaft 112 of the hub motor 11 is engaged with the recessed groove 8a formed in the tip 8A of the front fork 8, and the tip 8A of the front fork 8 is temporarily fixed to the hub motor 11, thereby sandwiching the anti-rotation member 13 between the hub motor 11 and the front fork 8. In this state, the anti-rotation member 13 is supported rotatably around the shaft 112 of the hub motor 11 as a rotation axis.

[0023] Next, the anti-rotation member 13 is rotated in the rotation direction of the hub motor 11 to align the bolt insertion hole 8b of the front fork 8 with the bolt insertion hole 13c of the anti-rotation member 13. In this state, the anti-rotation member 13 is fixed to the front fork 8, and the tip portion 8A of the front fork 8 is fixed to the shaft portion 112 of the hub motor 11 via the anti-rotation member 13, thereby allowing the anti-rotation member 13 to be attached.

[0024] In the technique disclosed in Patent Document 1, the work of aligning the bolt insertion hole of the anti-rotation member with the bolt insertion hole of the front fork in the attachment process of the anti-rotation member is complicated, and there is a problem with the workability during assembly. In contrast, in the illustrated embodiment, the anti-rotation member 13 is provided with an abutment portion 131 for preventing the rotation of the anti-rotation member 13 in the rotation direction of the hub motor 11. Therefore, when the anti-rotation member 13 is rotated clockwise from the left side of the drawing, the bolt insertion hole 8b of the front fork 8 and the bolt insertion hole 13c of the anti-rotation member 13 overlap at the point where the abutment portion 131 abuts against the front fork 8, and the alignment can be easily performed. As a result, the work of aligning the front fork 8 and the anti-rotation member 13 can be substantially omitted, and the electric bicycle 1 can be made to have excellent workability during assembly.

[0025] The shape and dimensions of the abutment portion 131 of the anti-rotation member 13 are not particularly limited as long as it is formed so as to abut against the front fork 8 at a position where the bolt insertion hole 8b of the front fork 8 and the bolt insertion hole 13c of the anti-rotation member 13 overlap to prevent rotation of the anti-rotation member 13. The abutment portion 131 is not limited to being provided in one location, and may be provided in two or more locations. In the illustrated embodiment, the abutment portion 131 is provided near the bolt insertion hole 13c through which the bolt 15 for fixing the anti-rotation member 13 to the front fork 8 is inserted.

[0026] In the illustrated example, the front fork 8 and the anti-rotation member 13 are provided with bolt insertion holes 8b and 13c, respectively, and the anti-rotation member 13 is fixed to the front fork 8 using a bolt 15 as a fastening member, but the type of fastening member is not limited to this. Specific examples of fastening members include screws, bolts alone, a combination of a bolt and a nut, a combination of a rivet or a pin and a retaining ring, etc.

[0027] In the present invention, as shown in the figure, it is preferable to provide the butt portion 131 near the fastening member for fixing the front fork 8 and the anti-rotation member 13. If the position of the butt portion 131 is closer to the bolt insertion hole 13a, which is the center of rotation, than the bolt insertion hole 13c corresponding to the fastening member, even a slight positional deviation of the butt portion 131 will result in a large deviation in the positions of the bolt insertion hole 8b and the bolt insertion hole 13c, so strict dimensional control is required for the butt portion 131. In contrast, by providing the butt portion 131 near the bolt insertion hole 13c, the anti-rotation member 13 can be aligned without significantly increasing the dimensional accuracy, making parts control easier.

[0028] In the illustrated embodiment, the anti-rotation member 13 has a substantially flat body 130, an abutment portion 131 erected in a substantially vertical direction on the side where the front fork 8 is arranged with respect to the body 130, and a rising portion 132 erected in a substantially vertical direction on the side where the front fork 8 is arranged with respect to the body 130, but the specific shape of the anti-rotation member 13 is not limited thereto. By forming the anti-rotation member 13 in such a shape, the abutment portion 131 can be formed by bending the plate material constituting the anti-rotation member 13, for example, by pressing a metal plate, and the manufacturing process can be simplified. In the illustrated embodiment, the rising portion 132 is composed of a side wall surface 132A extending in a substantially vertical direction with respect to the body 130, and an upper wall surface 132B extending from the upper end of the side wall surface 132A in a substantially parallel direction with respect to the body 130, and a hole portion 132a is provided in the upper wall surface 132B.

[0029] In the illustrated embodiment, the front fork 8 is provided with a generally flat fixing plate 81 that protrudes in the direction of rotation of the hub motor 11 toward the side where the anti-rotation member 13 is disposed, and this fixing plate 81 is provided with bolt insertion holes 8b for fixing the anti-rotation member 13, but the specific shape of the fixing portion between the front fork 8 and the anti-rotation member 13 is not limited to this. The position of the fixing plate 81 on the front fork 8 is a position spaced a predetermined distance from the tip 8A of the front fork 8 fixed to the shaft 112 of the hub motor 11 along the extension direction of the front fork 8, and can be set appropriately depending on the dimensions of the anti-rotation member 13.

[0030] In the illustrated embodiment, the rotation prevention member 13 is provided with an abutment portion 131 to align the rotation prevention member 13, but the present invention is not limited to this, and an abutment portion may be provided on a frame member such as a front fork. For example, if the illustrated rotation prevention member 13 does not have the abutment portion 131 and the illustrated front fork 8 has an abutment portion that protrudes in the axial direction of the hub motor 11 on the side where the rotation prevention member 13 is disposed, when the rotation prevention member 13 is rotated clockwise from the left side of the drawing, the rotation of the rotation prevention member 13 in the rotation direction of the hub motor 11 is prevented when the rotation prevention member 13 abuts on the abutment portion, and the bolt insertion hole 8b of the front fork 8 and the bolt insertion hole 13c of the rotation prevention member 13 overlap, thereby aligning the rotation prevention member 13. In this case, it is preferable to provide the abutment portion near the bolt insertion hole 8b corresponding to the fastening member.

[0031] In the electric bicycle of the present invention, it is sufficient that either the frame member or the anti-rotation member is provided with an abutment portion that prevents the anti-rotation member from rotating in the rotation direction of the hub motor, thereby achieving the desired effect of the present invention. Other details of the structure of the electric bicycle can be any known structure and are not particularly limited.

[0032] For example, in the electric bicycle 1 of the illustrated embodiment, a battery 16 that supplies power is removably attached behind the seat tube 4, and wiring 17 for supplying power from this battery 16 to the hub motor 11 is arranged along the frame and connected to the hub motor 11 via a connector (not shown). The wiring 17 and the connector (not shown) are covered by a wiring cover 18 below the front fork 8. Also, in the illustrated embodiment, an operation panel 20 for turning the power of the electric system on and off, displaying various information, turning the headlights 19 on and off, etc. is attached to the handlebars 7.

[0033] Furthermore, the electric bicycle 1 of the present invention may be equipped with a child seat (not shown) in addition to the cargo bed 21 and basket 22 as shown in the figure. In this case, there are no particular limitations on the cargo bed 21, basket 22, and child seat, and any known child seat can be used. The child seat can be either a front child seat or a rear child seat. There are also no particular limitations on the shape of the cargo bed or basket.

[0034] The present invention has been described above as being applied to a front-wheel drive electric bicycle 1 equipped with a hub motor 11 on the front wheel 9, but it goes without saying that the present invention can be applied not only to front-wheel drive electric bicycles, but also to rear-wheel drive electric bicycles equipped with a hub motor on the rear wheel 10. Also, the electric bicycle 1 according to one preferred embodiment of the present invention shown in the drawings is an electric bicycle equipped with one front wheel 9 and one rear wheel 10, but it may also be an electric bicycle with one front wheel and two rear wheels, or a three-wheeled vehicle equipped with three wheels, two front wheels and one rear wheel, or an electric bicycle with four or more wheels. [Explanation of symbols]

[0035] 1. Electric bicycle 2 Head tube 3 Downtube 4 Seat tube 5 Chainstay 6 Handlebar stem 7 Handle 8 Front fork 8A Front fork tip 8a Concave groove 8b Bolt insertion hole 81 Fixing plate 9 Front Wheel 10 Rear wheel 11 Hub Motor 11A Rotating part 11B Fixed part 112 Shaft 12 Lock nut 13 Anti-rotation member 13A One end of the anti-rotation member 13B The other end of the anti-rotation member 13a Shaft insertion hole 13b Bolt insertion hole 13c Bolt insertion hole 130 Main body of anti-rotation member 131 Stop part 132 Start-up Department 132A Side wall 132B Upper wall 132a Hole 14,15 Volts 16 Battery 17 Wiring 18 Wiring cover 19 Headlights 20 Operation Panel 21 Cargo Bed 22 Basket 23 Seat stay 24 Saddle

Claims

1. A hub motor having a rotating part that rotates integrally with a wheel and a fixed part that is supported by a frame member of a vehicle body; a rotation prevention member fixed to the frame member and a fixed portion of the hub motor, The frame member and the anti-rotation member are fixed to each other by a fastening member that penetrates the hub motor in the axial direction, A method for manufacturing an electric bicycle, in which either the frame member or the anti-rotation member is provided with an abutment portion that prevents the anti-rotation member from rotating in the rotation direction of the hub motor, comprising: A manufacturing method for an electric bicycle, characterized in that after the anti-rotation member is fixed to a fixed portion of the hub motor, the anti-rotation member is rotated in the rotational direction of the hub motor to abut the abutment portion against the other of the frame member or the anti-rotation member to align the frame member and the anti-rotation member, and then the frame member and the anti-rotation member are fixed with the fastening member.

2. 2. A method for manufacturing an electric bicycle according to claim 1, wherein the abutment portion is formed by bending a plate material constituting the anti-rotation member.

3. A method for manufacturing an electric bicycle according to claim 1 or 2, wherein the abutment portion is provided in the vicinity of the fastening member.

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