JP2008168881A - Drive structure of electric bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive structure of an electric bicycle enabling the safe and easy post-fitting of the functions as an electric vehicle to conventional bicycles without modification by a simple structure, and also enabling the easy changeover between an electric driving and a treading drive as necessary. <P>SOLUTION: An electric geared motor 13 with variable rotational speed is detachably fitted to the intermediate portion of a seat tube 8. A drive wheel body 15 around which an engagement surface a is formed is pivotally supported on the output shaft 13a of the electric geared motor 13. A sheet-like ring body 17 formed by arranging an engagement surface b in the circumferential direction is stuck on one peripheral surface 16a of a rim 16 forming a rear wheel 3. The rear wheel 3 is rotatingly driven by the engagement of the drive ring body 15 with the ring body 17 of the electric geared motor 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an electric bicycle, and more particularly to a drive structure for an electric bicycle that can be easily retrofitted to a conventional foot-operated bicycle without any new modifications.

2. Description of the Related Art Conventionally, an electric bicycle that can easily travel on a slope or the like by adding a driving force of an auxiliary driving unit including an electric motor to a driving force by a stepping force has already been put into practical use. As a configuration of this type of electric bicycle, a drive mechanism via an electric motor is additionally provided in a chain wound between a chain wheel provided with a crank pedal and a sprocket of a rear wheel. -208565, Japanese Patent Laid-Open No. 2001-130476, or Japanese Patent Laid-Open No. 2001-219886 in which the rear wheels are rotationally driven by a driving roller pressed against the ground contact surface of the rear tire are proposed.

However, in each of the above proposals, the structure of a normal bicycle is significantly changed to attach the auxiliary drive unit, and the weight is complicated, the cost is high, and the normal bicycle structure is not changed as much as possible. However, because it is a complicated structure, it can be retrofitted, and thus there remains room for improvement, such as requiring advanced adjustment techniques for attachment and removal.

Japanese Patent Laid-Open No. 11-208565 JP 2001-130476 A JP 2001-219886 A

The present invention was created in the course of research and development in pursuit of improved usability and improved functionality in conventional electric bicycles in view of the above circumstances, and the object of the present invention is a machine tool In addition to knowing that the power transmission mechanism of "Rack & Pinion", which is widely known in the field of mechanical technology, can be used for bicycle rear wheel drive, Providing a drive structure for an electric bicycle that can be retrofitted with the functions of an electric vehicle safely and easily without retrofitting with a simple structure, and can easily switch between electric drive and stepping drive as needed. It is something to try.

In order to solve the problem, the technical means adopted by the present invention is a driving wheel in which an electric gear motor having a variable rotation speed is detachably attached to an intermediate portion of a seat tube, and an engagement surface is provided around an output shaft of the electric gear motor. A thin plate-like annular body having meshing surfaces arranged in the circumferential direction is attached to one side circumferential surface of a rim that forms a rear wheel while supporting the body, and the driving wheel body and the circle of the electric gear motor are attached. The rear wheel is configured to rotate by meshing with the ring body.

Therefore, according to the present invention, an annular body having a meshing surface on one side surface of the rear wheel rim (without changing a basic bicycle body without changing the basic bicycle body) Bicycle) that can be stepped on by a very simple retrofitting operation, in which the drive wheel body (equivalent to the pinion gear) of the electric gear motor attached to the middle part of the seat tube is engaged with the above-mentioned torus. Can be made to function as an electric bicycle and the number of mounting parts is extremely small, so it is possible to reduce costs and improve reliability while achieving compactness and weight reduction. It becomes possible to provide an electric bicycle at a low cost to the person.

A driving wheel body that is pivotally supported on the output shaft of an electric gear motor with a variable rotational speed is a thin plate-shaped ring body in which meshing surfaces that are attached to one circumferential surface of a rim that forms a rear wheel are arranged in the circumferential direction. The rear wheels are driven to rotate by meshing.

The configuration of the present invention will be described in detail based on the embodiments shown in the drawings.
In FIG. 1A, reference numeral 1 denotes a street riding type bicycle in which a crank 2 is driven to rotate by a stepping operation and a rear wheel 3 is driven through a chain (not shown). The rotary table 1 steers a front wheel 4. A steering wheel 5 having a chain ring (not shown) and a crank 2 is pivotally supported at a lower portion of a seat tube 8 provided with a saddle 7 at an upper portion thereof. A conventional bicycle structure is provided in which a chain wound between the chain ring and the sprocket of the rear wheel 3 is rotated by a stepping operation of the left and right pedals 10 and travels. Reference numeral 11 denotes a loading platform, and 12 denotes a shopping basket provided at the front part of the handle 5.

Here, FIG. 4B shows a case where the electric bicycle drive structure of the present invention is adopted for the bicycle 1 in the above-described conventional configuration, and the conventional bicycle 1 configuration is modified as shown in FIG. It is designed to function as an electric bicycle with simple installation without requiring any changes.
That is, as shown in FIGS. 2 to 6, an electric gear motor 13 having a variable rotation speed is detachably attached to the seat tube 8 via an attachment 14, and a driving wheel having a meshing surface a is provided around the seat tube 8. The body 15 is supported by the output shaft 13a of the electric gear motor 13, and a thin plate formed by arranging meshing surfaces b in the circumferential direction on one side circumferential surface 16a of the rim 16 forming the rear wheel 3. In the state where the drive ring body 15 and the ring body 17 are engaged with each other, the electric gear motor 13 is supplied with power from the battery pack 19 attached to the top tube 18. A rotational force is applied to the rear wheel 3 by rotational driving.

As shown in FIG. 4A, the electric gear motor 13 is configured by coaxially arranging an electric motor 20, an electromagnetic clutch 21, and a reduction gear mechanism 22 in a case body 13 b, and from the control unit 23. The electric motor 20 and the electromagnetic clutch 21 are controlled by the control signal, and a torque sensor 24 for detecting a rotational load fluctuation related to the output shaft 13a is interposed between the reduction gear mechanism 22 and the output shaft 13a. The rotational load received by the driving wheel 15 from the rear wheel 3 during the traveling of the bicycle 1 is successively detected, and the detection signal is sent to the control unit 23 to finely control the rotational speed of the electric motor 20. It is configured. Further, the controller 23 is provided with an arm-like adjuster 25, and the other end of the wire cable 26 whose tip is connected to the head 25a is connected to a speed variable lever 27 to be described later. The rotation speed of the electric motor 20 is increased or decreased by operation. Reference numeral 28 denotes a start switch provided on the outer surface of the case body 13b. When the start switch 28 is turned on, the electromagnetic clutch 21 is "contacted", and the rotational driving force of the electric motor 20 is the electromagnetic clutch 21 and the reduction gear mechanism 22. Then, the control unit 23 is turned on and a control operation linked to the operation of the speed variable lever 27 is enabled. 15a is a fixing nut and 15b is a cap cover.

As shown in FIG. 3, the attachment 14 is composed of a main body 29, a tube fixing bracket 30 and a motor fixing bracket 31. When attaching the attachment 14, first, a fixing recess 29a formed in the main body 29 and a tube fixing bracket 30 are formed. The fixing recesses 30a are fixed to each other by fixing bolts 32, 32 with the seat tube 8 interposed therebetween, and then the fixing recesses 29b formed in the main body 29 and the fixing recesses 31a of the motor fixing bracket 31 are sandwiched with the electric gear motor 13 interposed therebetween. The electric motor 13 is attached to the seat tube 8 in a crossing manner by fixing the fixing bolts 33 and 33 so as to face each other.

On the other hand, between the seat stay 34 and the chain stay 35 that support the rear wheel 3, a roller mounting bracket 36 is mounted on the other side of the electric gear motor 13 fixed to the seat tube 8, and FIG. ) As shown in (b), a fixing portion 37 for holding the seat stay 34 and a fixing portion 38 for holding the chain stay 35 are integrally formed at both ends of the bracket main body 36a with a folding structure. In addition, a pressing roller 39 that is opposed to the driving wheel body 15 with the rim 16 interposed therebetween is pivotally supported between both side walls 36b and 36b that are integrally formed on the bracket body 36a so as to be spaced apart and in parallel. 39 is abutted along the circumferential direction of the other peripheral surface 16b of the rim 16 so that the rim 16 is clamped between the driving wheel bodies 15 and the disengagement is smoothly removed. And it is configured to allow the rotation of the rear wheel 3 reliable.

Since the present invention is configured as described above, when a drive structure for an electric bicycle is incorporated into a conventional stepping-type bicycle 1, first, the rear wheel 1 is removed and the resin toroid 17 is connected to the meshing surface. The b is attached to the one peripheral surface 16a of the rim 16 with the front side. At this time, it is desirable that the adhesive used for sticking has a property of having an adhesive force to both the resin and the metal, and it is important that the stick is circular with respect to the rim 16 when sticking.

Next, after attaching the electric gear motor 13 to the seat tube 8 via the attachment 14, the engagement surface a of the driving wheel body 15 pivotally supported by the output shaft 13a is adhered to the one peripheral surface 16a of the rim 16. In the state of being in contact with the meshing surface b of the ring body 17, the attachment of the motor fixing bracket 31 to the main body 29 of the attachment 14 is temporarily fixed, and the attachment position of the electric gear motor 13 is adjusted. After the adjustment is completed, the outer 26a of the wire cable 26 connected in the case main body 13b of the electric gear motor 13 is guided to the position of the right grip 5a of the handle 5 along the upper surface of the top tube 18, and the outer 26a is appropriately covered with a plastic band. And the tip of the wire cable 26 is connected to the speed variable lever 27 that is fixed to the right grip 5a in advance. In the case where a shift gear switching lever or the like is already attached to the fixed position of the variable speed lever 27, the variable speed lever 27 may be disposed in the vicinity of a left grip (not shown).

Further, as described above, on the other side of the electric gear motor 13 fixed to the seat tube 8, a roller mounting bracket 36 is mounted between the sheet stay 34 and the chain stay 35, and the driving wheel 15 and the pressing roller 39 with the rim 16 interposed therebetween. Are adjusted so that the roller mounting brackets 36 are opposed to each other. Then, when the battery pack 19 is attached and fixed to the top tube 18 and the power supply line 19a is connected to the electric gear motor 13, the assembly of the drive structure as an electric bicycle is completed.

Next, an actual driving operation method of the bicycle 1 that can be used as an electric bicycle as described above will be described below.
First, prior to the driving operation, when the start switch 28 of the electric gear motor 13 is turned on, the electromagnetic clutch 21 in the electric gear motor 13 is “contacted”, and the rotational driving force of the electric motor 20 causes the electromagnetic clutch 21 and the reduction gear mechanism 22 to switch. As a result, the control unit 23 is turned on and a control operation linked to the operation of the speed variable lever 27 is enabled. When the rider of the bicycle 1 rotates the speed variable lever 27 fixed to the grip 5a of the handle 5 in the direction of the phantom line shown in FIG. 6A, the wire cable 26 is connected according to the amount of rotation. As shown in FIG. 5B, the regulator 26 connected to the wire cable 26 is tilted. When the controller 23 detects the change in tilt of the regulator 25, variable control of the rotational speed of the electric motor 20 is performed, and the rotational driving force is transmitted to the rear wheel 3 as a rotational speed change of the output shaft 13a. At the same time, if the operation position of the speed variable lever 27 is maintained, the rotation speed of the electric gear motor 13 corresponding to the operation amount is kept constant, and the bicycle 1 runs at a constant speed.

Here, when the speed variable lever 27 is released, the tension of the wire cable 26 is released, and the electric motor 20 automatically returns to the stop of rotation while lowering the rotation speed, and the bicycle 1 slowly moves at a low speed by the inertial force. However, if the rider of the bicycle 1 performs a stepping operation on the pedals 10 and 10 as necessary, the bicycle 1 can run as in a normal bicycle.

When traveling in the same manner as a normal bicycle as described above, the electric motor 20 of the electric gear motor 13 is connected to the output shaft 13 a via the electromagnetic clutch 21, and the rear wheel 3 is connected via the driving wheel 15. Since the state of being engaged with the torus 17 is maintained, the pedaling force of the pedals 10 and 10 slightly increases. In this case, however, the rotational force of the rear wheel 3 is reversed to the electric motor 20. As a result, the electric motor 20 functions as a generator capable of charging the battery pack 19 and the power consumption is reduced.

In addition, when a heavy load is loaded on the shopping cart 12 or the loading platform 11 shown in FIG. 1, the user of the bicycle 1 does not forcibly get on the bicycle 1 and drives the bicycle 1 by so-called pushing walk. Is desirable for road safety. Also in this case, the user's physical burden can be greatly reduced by appropriately operating the speed variable lever 27 and pushing the bicycle 1 at the same speed as the user's walking speed.

Also, as shown in FIG. 7, when the electric bicycle drive structure of the present invention is applied to a sports-type bicycle 40 having a mountain bike configuration, it can be electrically operated with a simple mounting operation as in the above embodiment. Although it can be used as a bicycle, in this type of bicycle, a caliber brake or a cantilever brake in which the brake structure of the rear wheel sandwiches both sides of the rim and brakes is mounted between the seat stays 34 and 34. Therefore, when the torus 17 is attached to the one peripheral surface 16a of the rim 16 of the rear wheel 3, the brake having the above configuration cannot be used. In this case, after removing the original brake structure, as shown in FIG. 8, a roller mounting bracket 41 in which a band brake mechanism 42 is coaxially mounted on the pressing roller 39 is mounted between the sheet stay 34 and the chain stay 35. At the same time, if the brake wire 43 of the original brake that has been disposed up to the position of the seat stay 34 is connected to the band brake mechanism 42, the rotation of the pressing roller 39 is stopped by a brake operation of a brake lever (not shown), A brake configuration that brakes the rotation of the rim 16 to which the pressing roller 39 presses can be adopted, and a safe traveling can be ensured as in a normal bicycle.

By attaching the drive structure of the electric bicycle of the present invention to both wheels of a manual wheelchair, it can be easily changed to an electric wheelchair.

(A) is a whole side view which shows the conventional bicycle structure, (b) is a whole side view which shows the bicycle structure to which this invention is applied. (A) is a principal part expansion side view of the bicycle traveling direction right side, (b) is a principal part enlarged side view of the bicycle traveling direction left side. It is a principal part expansion perspective view. (A) is explanatory drawing which shows the internal structure of an electric gear motor, (b) is a front view of a driving wheel body, (c) is the same sectional view, (d) is the same rear view, (e) is a driving wheel body and electric It is explanatory drawing which shows attachment of a gear motor. (A) is a plan view of a roller mounting bracket, (b) is a side view thereof, (c) is a plan view of a torus, and (d) is a side view thereof. (A) is explanatory drawing which shows attachment of a speed variable lever, (b) is a partially notched enlarged view which shows the inside of an electric gear motor. (A) is a whole side view which shows the conventional bicycle structure, (b) is a whole side view which shows the bicycle structure to which this invention is applied. It is a principal part expanded side view of the advancing direction left side of a bicycle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bicycle 3 Rear wheel 8 Seat tube 13 Electric gear motor 13a Output shaft 15 Driving wheel body 16 Rim 16a One side surrounding surface 17 Torus body a Engagement surface b Engagement surface

Claims (1)

An electric gear motor having a variable rotational speed is detachably attached to an intermediate portion of the seat tube, and a driving wheel body having a meshing surface is supported on an output shaft of the electric gear motor, and a rim forming a rear wheel is provided. A thin plate-like annular body having meshing surfaces arranged in the circumferential direction is attached to one side circumferential surface, and the rear wheel is driven to rotate by meshing between the driving wheel body and the annular body of the electric gear motor. A structure for driving an electric bicycle, characterized by comprising:

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