DE102012004171A1 - Drive unit for electric bicycle e.g. mountain bicycle, has electric motor and battery that are provided on base portion, and bicycle frame which is supported on base portion - Google Patents

Abstract

The drive unit (20) has an electric motor (100) and a battery (50) which are provided on cast metal base portion (21). The bicycle frame (16) is supported on the base portion provided with lower tube portion (22). The lower tube portion is connected with the bottom bracket (24). The lower tube portion is provided with a recess (72) for releasably receiving the battery. An independent claim is included for bicycle frame.

Description

Technical area

The present invention relates to a drive unit for a bicycle, in particular an auxiliary drive unit for an electric bicycle, and a frame for a bicycle.

background

Electric bikes or electric bicycles typically have an electric motor designed as an auxiliary drive, which can be mounted either in the front wheel or in the rear wheel as a hub motor or in the bottom bracket of such a bicycle in the form of a so-called center motor. The electric motor in this case provides a driving assistance, which can be requested by an initiated by the end user pedal operation. The power supply of the electric motor is typically carried out via a detachably arranged on the bicycle accumulator. In addition to limited as well as unlimited pedal assist, electric bicycles can also have a pedal-independent auxiliary drive. The carrying of the batteries is often on or on a luggage rack of the bicycle.

In the DE 10 2010 032 801 A1 Further, an electric bicycle is described, wherein in the space between a seat tube and extending from the seat post and the bottom bracket to the steering head tubes an energy storage module is removably mounted by means of a clamping device.

The weight distribution of common electric bicycles and their center of gravity are often not optimal, in particular because of the inevitably entrained batteries. Furthermore, the integration of the auxiliary drive components in or on the frame of two-wheelers proves to be in need of improvement

It is therefore an object of the present invention to provide an improved drive unit for a bicycle, in particular for an electric bicycle, on the one hand enables a space-saving and safe arrangement replaceable mitzuführender accumulators and on the other hand has a shapely design. In this case, it is a further object to provide a frame that is as cost-effective as possible and suitable for mass production for a two-wheeler provided with an auxiliary drive, which has a high degree of functional integration.

Advantageous embodiments

This object is achieved with a drive unit according to claim 1 and with a bicycle frame according to claim 12, wherein advantageous embodiments are each the subject of dependent patent claims.

Accordingly, a drive unit for a bicycle is provided, which has a base, which also acts as a supporting component of the bicycle frame. In the base part of the drive unit, at least one electric motor is arranged, which typically operates as an auxiliary motor for providing pedal assistance, for example according to the pedelec principle. Furthermore, at least one energy store, preferably in the form of one or more accumulators, can be arranged on the base itself. By the base is formed as a supporting component of the bicycle frame, it forms a mounting platform for other frame components of the bicycle, to which further supporting components of the bicycle frame are fastened.

The base part of the drive unit can act as a strut or as a frame part of a bicycle frame so far. Further, the drive unit may for example act as a kind of seat tube or as a kind of down tube of a bicycle frame. It is provided in particular that the electric motor is in force-transmitting operative connection with the bottom bracket of the bicycle. So is basically also conceivable to form the drive unit, or its base in the form of one or more rear struts or chain stays about a bicycle frame.

In particular, it is provided that the drive unit or its basic part functioning as a housing for the motor and the energy store can be connected to a large number of different further bicycle frame components, so that a wide range of different two-wheeled vehicles can basically be manufactured with only a single type or with a few types of drive units can be. The frame size as well as the two-wheeled type can be determined solely by the other two-wheel frame components which are to be fastened to the always uniformly configured or identically designed base part of the drive unit.

In this way, a wide range of electric bicycles can be provided with largely identically designed drive units, so that the drive units can be produced comparatively inexpensively even in a comparably large number in a mass production process and can be used differently in their subsequent use or installation situation on or in the two-wheeled vehicle.

Due to the modular construction of a bicycle frame, which consists of the drive unit and at least one or more other supporting frame components, the unit costs be lowered for the production of relatively high-priced drive unit in an advantageous manner.

According to an advantageous embodiment, the base on a bottom bracket receiving bottom bracket. In this case, provision is made in particular for the electric motor of the drive unit to be arranged in the region of the bottom bracket section as close as possible to the bottom bracket or to be integrated as a tubular motor in the bottom bracket. In that regard, the drive unit further comprises a bottom bracket of the two-wheeler.

In addition to a bottom bracket portion, the base part of the drive unit may according to a further advantageous embodiment also have a lower pipe section, which is connectable with a free end portion with a control head portion of the bicycle frame. The lower pipe section acts as a down tube of a conventional bicycle frame and can replace it completely.

In a further preferred embodiment, the lower pipe section and the bottom bracket section of the base part of the drive unit adjoin one another directly. It is advantageous in this case further provided when the lower pipe section and the bottom bracket portion of the base are integrally formed. In that regard, the entire area of a bicycle frame, which connects a bottom bracket with a control head, be formed by the drive unit or by its base. To form a front triangle of a typical bicycle frame this would be only the connection of an example, a seat tube and a top tube having upper frame and possibly. The connection of saddle struts and / or rear struts required.

The drive unit here forms a frame module, which includes the bottom bracket and a down tube of a bicycle frame.

According to a preferred embodiment, the base part is formed as a cast metal component. But it can also be milled from a metal block. Notwithstanding this, it is conceivable that the base part has a plurality of tube or housing sections welded together or that the base part is, for example, at least partially made of a carbon fiber material. In any case, the base part forms a structural unit, by means of which the electric motor and an energy store provided in or on the lower pipe section can be integrated particularly elegantly and shapely as a whole into a two-wheel frame structure.

According to a further preferred embodiment, the base part, in particular in the transition region between the bottom bracket portion and the lower pipe section, at least one attachment portion for a top frame or for a seat tube. The attachment portion may in this case z. B. in the form of a plug-in socket, which is suitable for receiving a seat tube. Alternatively, it is conceivable that substantially identically or symmetrically formed fastening sections are provided on opposite side cheeks or side portions of the base, which are connectable to a fork-like branching leg of a top frame.

The legs of the upper frame can in this case be formed parallel and symmetrical to each other and enclose the base at least partially laterally or border.

According to a further preferred embodiment, the bottom bracket portion is pivotally connected to a rear swing arm. The side facing away from the bottom bracket portion of the rear swing arm in this case has a journal bearing for the rear wheel and also provides a torque transmission to the rear wheel acting as a drive wheel. In this case, it is provided in particular that the bottom bracket itself acts as a rotation axis for a pivoting movement of the rear swinging arm relative to the drive unit.

The pivotable connection of the rear swing arm to the bottom bracket portion of the drive unit allows a resilient mounting of the rear swing arm. Thus, according to a further preferred embodiment, it is provided that the lower pipe section of the drive unit has, at an end section facing the bottom bracket section, a fastening section for a damping element which can be coupled to the rear wheel rocker for a different end. Instead of a connection of the damping element at a lower end portion of the lower pipe section but also a connection to the bottom bracket portion itself is conceivable. By means of a damping element acting on the rear wheel shocks and vibrations can be damped, so that the ride comfort of the bicycle can be improved overall.

According to a further preferred embodiment, the lower pipe section of the base part of the drive unit has a recess for releasably receiving the energy accumulator, which is typically designed as an accumulator. In this case, the lower pipe section may have, at least in sections, a profile which is approximately C-shaped or U-shaped in cross-section and which is accessible from one side in order to replace the battery when required.

By the accumulator receptacle is formed as a shaft-like recess in the lower pipe section, the accumulator can also in Built-in state always be taken by the user. Further, the accumulator may have such a shape that it, for example, provided with a colored accent and located in installation position continues a basic outer contour of the lower pipe section and in this case at least partially fills the cavity formed by the recess of the lower pipe section.

The arrangement of the accumulator in a recess of the lower pipe section immediately and immediately recognizable whether and to what extent an accumulator is properly secured in or on the drive unit. The provided within a receptacle accumulator assembly is also against an arrangement outside the frame of the bicycle or on a luggage carrier in aerodynamic advantage.

According to a further preferred embodiment, at least one plug-in connection for a power cable is provided on a side accessible from the outside and / or from below of the lower pipe section, which allows the connection of a power or charging cable directly to the drive unit. The arranged in or on the lower pipe section accumulator can thus be charged directly via the drive unit. The connector can be realized in many different ways. There are here common types of plugs but also magnetic plug conceivable, which z. B. have waterproof flat contacts, which are only applied to power when a magnetically coded mating connector is in operative connection with the flat contact.

According to a further independent aspect, a bicycle frame is further provided for a bicycle, which has at least one previously described and as a bicycle frame component formed drive unit and which at least one further hereby connected frame part. The frame part can in this case be designed, for example, as a tubular frame part, for example as a seat tube or as a top tube of a front frame triangle of a bicycle.

In a preferred embodiment, it is provided according to a development that the frame part is connected to the drive unit with two opposite end portions. The frame part is preferably formed as an upper frame, which is fastened with one end portion to a provided in the transition region between the bottom bracket and bottom tube section fixing portion of the drive unit and which is connected to an opposite, formed as a control head end portion with the free end portion of the lower pipe section.

The frame member formed as an upper frame may provide, together with the drive unit, the structural functionality of a front or upper frame triangle of a bicycle frame. The upper frame in this case has a substantially curved or C-shaped contour. Advantageously, it extends in the connection area to the bottom bracket section in about comparable to a seat tube. In the region of the opposite upper end portion, however, the upper frame extends approximately comparable to a top tube adjacent to a control or steering head. Finally, the upper frame may provide a one-piece connection between an upper free end portion of the lower pipe section and the bottom bracket section.

According to a further preferred embodiment, the upper frame two, each of a sheet metal blank punched or formed from a corresponding blank, at least partially interconnected half shells with their open profiles, which are connected to each other, for example, to form a closed at least partially closed frame profile. The formation of the upper frame by two half shells corresponding to one another is particularly cost-effective and can be realized in particular in a mass production process.

The half shells are in this case connected to each other at least in the opposite attachment points in the region of the free upper end portion of the lower pipe section and in the region of a transition section between the lower pipe section and the bottom bracket. It is also conceivable that the half shells are attached directly to the bottom bracket portion of the base. Furthermore, the two half-shells can also be connected directly to one another outside of those connecting sections of the drive unit, for example welded or glued together.

The upper frame, regardless of its connection to the drive unit and the connection of its half shells with each other preferably also act as a support for a saddle and / or for a seat post.

According to a further preferred embodiment, it is finally provided that the half-shells of the upper frame at least partially laterally surround and / or engage the drive unit at fastening sections provided for this purpose. By assembling the half shells thus further frame components, such as a control or steering head and a seat post and, if necessary,. Sattelstreben can be connected to the upper frame, such as by the respective frame components provided for this purpose recesses adjacent half-shell profiles are used.

Brief description of the figures

Other objects, features and advantageous embodiments are described in the following description of exemplary embodiments with reference to the figures. Hereby show:

1 a side view of a provided with a drive unit electric bicycle,

2 a perspective view of the bicycle according to 1 viewed from diagonally behind and below

3 another perspective view of the electric bicycle viewed obliquely from the front and

4 an isolated representation of a drive unit,

5 a further embodiment of an electric bicycle with a tubular frame structure and

6 an isolated and perspective view of two a top frame forming half-shells.

Detailed description

That in the 1 to 3 shown, designed as an electric bicycle two-wheeler has a frame 16 a front wheel 12 and a rear wheel 14 on. The frame 16 is executed here at least two-component. Provides a trained as a frame component drive unit 20 and a bow-like upper frame connected thereto 18 on. In addition, at the in 4 separately shown drive unit 20 a rear swingarm 30 pivotally mounted, which with its the drive unit 20 remote end portion receives the rear hub.

Further, on the upper frame 18 a seatpost 46 with a saddle 48 arranged. The front wheel 12 is in a fork 60 stored in the area of a control head section 66 with the frame 16 connected is. The wheels 12 . 14 are also with brakes 36 . 38 provided, which are preferably designed as hydraulically actuated disc brakes.

The bicycle 10 can also be a circuit 34 have, which may be formed, for example, as a hub or derailleur. The power transmission between the bottom bracket 24 , the cranks stored there 26 and the rear wheel 14 can by means of a chain or by means of a belt 32 respectively.

The frame 16 or an upper or main triangle is in this case of the drive unit 20 and the associated upper frame 18 educated. The drive unit 20 here has a basic part 21 auf, which as a recording for a in the 1 to 3 merely indicated electric motor 100 as well as for an energy storage 50 , which is preferably formed in the form of one or more accumulators, acts. The basic part 21 here has a bottom bracket 25 receiving bottom bracket section 24 and a hereby preferably integrally connected lower pipe section 22 on, which is from the bottom bracket section 24 along and obliquely upward, in the area of the control head section 66 extends.

The lower pipe section 22 is at his the top frame 18 facing side formed largely straight. At his the front wheel 12 facing bottom, however, he has a in 3 to be recognized shaft-like recess 72 on which of the detachable recording of the energy storage 50 serves. The recess 72 Here is sweeping extensively formed to the lower pipe section 22 to give a very aesthetic appearance and a high torsional rigidity.

The integration and attachment of the energy storage in the recess 72 can shift the comparatively heavy, designed approximately in the form of an accumulator energy storage relative to the frame geometry in a focal point position, so that the center of gravity of the entire frame is as low as possible.

As in 3 also shown, is in the region of the bottom bracket section 24 facing end face of the recess 72 a plug connection 70 provided for a charging cable, by means of which the energy storage 50 by connecting a charging cable in one or on the lower pipe section 22 mounted position can be charged. The plug connection 70 can be designed here as a magnetic plug.

As in 1 shown, the energy storage 50 one with the lower pipe section 22 have corresponding shape, so that, for example, the front wheel 12 facing housing portion of the energy storage 50 substantially parallel to the upper, the upper frame facing the boundary of the lower pipe section 22 extends. Downwards adjacent to the lower pipe section 22 is at the base 21 the bottom bracket section 24 provided, which is both with cranks 26 and pedals 28 coupled bottom bracket 25 as well as an electric motor 100 receives. The electric motor 100 and the energy storage 50 are together at the base 21 attached, in particular, the energy storage releasably on the base 21 is arranged. The basic part 21 is here also as the main component of the frame 16 educated.

The basic part 21 or the drive unit 20 form, as it were, a mounting platform or mounting base for the frame 16 , therefore, for the entire bicycle 10 , Other frame components, such as the upper frame 18 and the rear swingarm 30 Here are to be regarded only as attachments, depending on the intended size and intended use of the bicycle 10 individually adapted to different needs. In this way, a generic drive unit 20 for a variety of different bikes 10 Find use.

The two-wheeler preferably designed as an electric bicycle can be configured, for example, as a mountain bike as an all-terrain bike, as a city bike, as a cruiser or as a racing bike. For all of these various types of bicycles can always one and the same drive unit 20 be used so that the drive unit 20 can be produced inexpensively in large quantities and in mass production.

The basic part 21 can in this case in particular as a metal casting or as a milled from a metal block housing for the electric motor 100 as well as for the releasably arranged thereon energy storage 50 be educated. It is also conceivable that the basic part 21 is formed of a plurality of stamped and correspondingly formed, interconnected metal sheets.

The rear swingarm 30 which has two parallel legs, between which the rear wheel 14 is stored, preferably can be pivoted on the bottom bracket section 24 of the basic part 21 be stored, wherein a rotation axis of the rear swing arm 30 and basic part 21 with the bottom bracket 25 coincides. In the embodiment according to the 1 to 3 is the rear swingarm 30 further via a damping element 40 with the lower pipe section 22 of the basic part 21 coupled. The damping element 40 is here preferably designed as a hydraulic or as a gas pressure spring and extends between a hinterradschwingenseitigen attachment portion 44 and one at a lower end of the lower pipe section 22 provided attachment section 42 ,

The upper frame 18 has an approximately C-like or curved contour. A downwardly protruding lower section 19 is here in a transition region between bottom bracket section 24 and lower pipe section 22 of the basic part 21 fastened while the free end of an upper section 17 with a free and upper end section 23 of the sub-pipe section 22 of the basic part 21 connected is. The connection of upper section 17 and the upwardly projecting end portion 23 of the down tube 22 in this case forms a control head section 66 of the frame 16 , which further the steering head 64 , a tax rate 65 and the fork 60 receives.

The lower section 19 of the upper frame 18 is here approximately in the transition region between the bottom bracket section 24 and the sub-pipe section 22 at the base 21 attached. As based on the 2 and 3 can be seen, the upper frame 18 in the overlap area with the base part 21 a fork-like structure with two lateral thighs 54 . 56 on which the basic part 21 or a fastening section provided there 58 enclose at least partially laterally. The damping element 40 Here comes also between the laterally outwardly projecting legs 54 . 56 a corresponding fork section 52 of the upper frame 18 to lie.

The seat post 46 extends approximately in rectilinear extension of the legs 54 . 56 and is so far in a transition region or curvature section 15 between lower section 19 and upper section 17 of the upper frame 18 tethered.

The upper frame 18 is in the embodiment according to the 1 to 3 composed of two stamped and formed sheet metal parts, which were punched out of a sheet metal blank and then brought about by means of a Pressumformoperation in the desired shape. The upper frame 18 in this respect has two corresponding, in 6 separately shown half shells 18a . 18b auf, which are in the in the 1 to 3 shown mounting position on the base 21 each from the connection portion 58 to the end portion 23 of the sub-pipe section 22 extend.

So form the right half shell 18a a thigh 54 and the left half shell 18b , a thigh 56 , which has a fastening section 58 of the basic part 21 between them. In the transition area between the lower section 19a . 19b and upper section 17a . 17b the two half shells are directly connected. The seat post 46 can be used as an insert between the two half-shells 18a . 18b be attached.

The forward, in the direction of travel protruding free end of the upper section 17 can advantageously also two the end portion 23 of the sub-pipe section 22 laterally enclosing or laterally enclosing, as appropriate Control head sections 66a . 66b trained half-shell sections, which both the end portion 23 as well as the steering head 64 or the fork 64 and the tax rate 65 enclose while the control head section 66 form. In the area of the control head sections 66a Show the half-shells 18a . 18b in each case corresponding recesses, of which only those recesses 90a . 92a the right half shell 18a in 6 are shown explicitly. In the recesses are other frame components, in particular the upper end portion 23 the lower pipe section 22 as well as the tax rate 65 used. By connecting and mutually fixing, such as by screwing the half shells 18a . 18b can the frame components 22 . 65 and the half-shells 18a . 18b be fastened together and with each other.

As in 1 and 3 shown, the control head section 66 of the upper section 17 at least slightly forward, from the fork 60 protrude. The two half shells 18a . 18b of the upper frame 18 This can be a recording about for a lighting module 68 form. The steering head 64 is also in a manner known per se with a handlebar 62 connected.

The preferred as an accumulator replaceable on or in the lower pipe section 22 provided energy storage 50 can have a lateral ribbing 51 have, as a handle for gripping the energy storage 50 serves and its removal and reinsertion in the shaft-like recess 72 of the sub-pipe section 22 should facilitate.

The further, in 5 shown embodiment of an electric bicycle has comparable to the embodiment according to 1 to 3 also an almost identical drive unit 20 with a bottom bracket section 24 and with a sub-pipe section 22 on. bottom bracket 24 and lower pipe section 22 of the basic part shown there 21 However, they are provided with individual pipe sections or push-in joints, the connection of other frame parts, such as a seat tube 80 , a head tube 88 , a top tube 78 , a saddle strut 82 and a chain or rear strut 84 enable.

The frame formed in this way 76 can one with a saddle 48 as well as a front fork 86 take up. As a power transmission means for the rear wheel 14 can also be a chain or a belt here 32 serve.

The comparison of the two embodiments according to the 1 to 3 on the one hand and the embodiment according to 5 clarifies that a largely identical design drive unit 20 in different ways as a frame component for an electric bicycle 10 Can be used. Other frame components for forming a bicycle frame 16 . 76 can as attachments to the from the bottom bracket section 24 up to a control head section 66 extending drive unit 20 to be assembled.

The illustrated embodiments show only possible embodiment of the invention to which further numerous variants are conceivable and within the scope of the invention. The exemplary embodiments shown are in no way to be construed as limiting the scope, applicability or configuration possibilities of the invention. The present description merely shows the person skilled in the art a possible implementation of an exemplary embodiment according to the invention. Thus, the most varied modifications can be made to the function and arrangement of elements described without thereby abandoning the scope of protection or its equivalents as defined by the following claims.

LIST OF REFERENCE NUMBERS

10

bicycle

12

front

14

rear wheel

16

frame

17

upper section

18

top frame

19

lower section

20

drive unit

21

base

22

Downtube section

23

end

24

bottom bracket

25

bottom bracket

26

crank

28

pedal

30

swingarm

32

belt

34

circuit

36

brake

38

brake

40

damping element

42

access point

44

access point

46

seatpost

48

saddle

50

energy storage

51

knurl

52

fork portion

54

leg

56

leg

58

attachment section

60

fork

62

handlebars

64

Caster

65

tax rate

66

Control header

68

lighting module

70

connector

72

recess

76

frame

78

top tube

80

seat tube

82

seat stay

84

rear strut

86

fork

88

head tube

90a

recess

92a

recess

100

electric motor

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010032801 A1 [0003]

Claims (15)

Drive unit for a two-wheeler with a basic part ( 21 ), in which at least one electric motor ( 100 ) and at which at least one energy store ( 50 ) and the basic part ( 21 ) as the main component of a bicycle frame ( 16 ) is trained. Drive unit according to claim 1, wherein the base part ( 21 ) one a bottom bracket ( 25 ) receiving bottom bracket section ( 24 ) having. Drive unit according to one of the preceding claims, wherein the base part ( 21 ) a sub-pipe section ( 22 ), which with a free end portion ( 23 ) with a control head section ( 66 ) of the bicycle frame ( 16 ) is connectable. Drive unit according to claim 3, wherein the lower pipe section ( 22 ) and the bottom bracket section ( 24 ) directly adjoin one another. Drive unit according to claim 3 or 4, wherein the lower pipe section ( 22 ) and the bottom bracket section ( 24 ) are integrally formed. Drive unit according to one of the preceding claims, wherein the base part ( 21 ) is designed as a milled and / or as a cast metal component. Drive unit according to one of the preceding claims 4 to 6, wherein the base part ( 21 ) in a transition region between bottom bracket section ( 24 ) and lower pipe section ( 22 ) an attachment portion ( 58 ) for a top frame ( 18 ) or for a seat tube ( 80 ) having. Drive unit according to one of the preceding claims 2 to 7, wherein the bottom bracket section ( 24 ) with a rear swing arm ( 30 ) is pivotally connectable. Drive unit according to claim 8, wherein the lower pipe section ( 22 ) on a bottom bracket section ( 24 ) facing end portion a fastening portion ( 42 ) for another end with the rear swing arm ( 30 ) couplable damping element ( 40 ) having. Drive unit according to one of the preceding claims 3 to 9, wherein the lower pipe section ( 22 ) a recess ( 72 ) for detachably receiving the energy accumulator designed as an accumulator ( 50 ) having. Drive unit according to one of the preceding claims 3 to 10, wherein on an externally and / or from below accessible side of the lower pipe section ( 22 ) at least one plug connection ( 70 ) is provided for a power cable. Two-wheeler frame for a two-wheeler with a drive unit ( 20 ) according to one of the preceding claims and with at least one frame part ( 18 ; 78 . 80 . 84 . 86 ). A bicycle frame according to claim 12, wherein the frame part is used as a top frame ( 18 ) which is provided with a leg provided at one end portion (FIG. 54 . 56 ) at one in the transition region between bottom bracket section ( 24 ) and lower pipe section ( 22 ) provided attachment portion ( 58 ) of the drive unit ( 20 ) and which with an opposite, as a control head ( 66 ) formed end portion having a free end portion ( 23 ) of the lower pipe section ( 22 ) connected is. A bicycle frame according to claim 13, wherein the upper frame ( 18 ) has two, each of a sheet metal blank punched or reshaped, with its open profile section at least partially interconnected half shells. A bicycle frame according to claim 14, wherein the half-shells of the upper frame ( 18 ) the drive unit ( 20 ) a designated attachment section ( 58 ) at least partially border laterally.

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