JP3568502B2 - Electric bicycle - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric bicycle.
[0002]
[Prior art]
The driving force by man power, the addition of driving force of the motor unit with a like electric motor, electric bicycle can comfortably travel in such slope is already put to practical use. In this type of electric bicycle, Japanese Unexamined Patent Publication No. 9-207859 discloses that a main pipe 52, a vertical pipe 53, and a chain stay are supported by a single support bracket 51 for supporting a motor unit 50, as shown in FIGS. 54 is disclosed. According to this frame structure, since the motor unit 50 can be disposed at a position closer to the lower side of the approximate center of the electric bicycle and has a low center of gravity, the motor unit 50 is disposed from below the center of the main pipe as disclosed in JP-A-6-227474. As compared to a motor unit having a motor unit extending over a part, traveling performance is improved, and handling when pushing and walking or at a step is improved.
[0003]
As shown in FIG. 10, a crankshaft 55 to which a pedal 60 (see FIG. 8) is attached is inserted into the motor unit 50, and a bearing portion for rotatably supporting the crankshaft 55 is also incorporated. It is supported. Since the motor unit 50 receives the pedaling force and the weight of the occupant directly from the crankshaft 55, the unit case 56 of the motor unit 50 is formed of a thick metal (aluminum, magnesium alloy, or the like) having sufficient strength. Also, the motor unit 50 itself has been used as a strength component for improving the strength of the vehicle body.
[0004]
[Problems to be solved by the invention]
However, according to the mounting structure of the motor unit 50 as disclosed in Japanese Patent Application Laid-Open No. 9-207859, a thick metal having sufficient strength must be used for the unit case 56 of the motor unit 50. Therefore, there is a problem that the material cost of the unit case 56 becomes extremely high if aluminum or magnesium alloy is used in order to reduce the weight as much as possible, as well as increase its weight.
[0005]
Also, the support bracket 51 for supporting the motor unit 50 must be made heavy, corresponding to the motor unit 50, and further increases the weight. As a result, the weight of the electric bicycle as a whole increases. There were challenges.
[0006]
An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide an electric bicycle that can reduce weight and manufacturing cost while maintaining good strength.
[0007]
[Means for Solving the Problems]
In order to solve the above problems , the present invention provides a motor unit that includes a bearing unit that supports a crankshaft and a holding unit that holds the bearing unit, and applies a driving force of an electric motor to a driving force of human power, and a frame. And a support bracket for supporting the holding unit of the motor unit so that the holding unit holds the holding unit, wherein a support portion of the motor unit supported by the support bracket is the holding unit.
[0008]
According to this configuration, the pedaling force acting on the crankshaft, the weight of the occupant, and the like can be intensively received by the support bracket via the bearing portion and its holding portion. A member such as a resin that can support the motor unit itself can be used. As a result, the manufacturing cost can be reduced and the weight can be reduced.
[0009]
The support bracket is fixed to a hanger lug or a portion of the frame near the hanger lug, and the motor unit is attached to the frame.
Then, a portion of the support bracket that supports the holding portion of the motor unit is projected into a substantially cylindrical shape, and the substantially cylindrical support portion formed on the support bracket is externally fitted to the holding portion of the motor unit.
[0010]
According to this configuration, since the support portion of the support bracket has a substantially cylindrical shape, the force from the bearing portion can be favorably and firmly supported.
It is also conceivable to sandwich both sides of the motor unit with the support brackets.
[0011]
It is desirable to interpose a cushioning material between the support bracket and the holding unit of the motor unit. By doing so, the force from the bearing portion of the crankshaft is transmitted to the support bracket while being well dispersed via the cushioning material, and the force from the bearing portion of the crankshaft can be favorably received by the support bracket.
[0012]
Further, even when there is a difference in the coefficient of thermal expansion between the support bracket and the bearing portion of the crankshaft, such a dimensional difference is absorbed by the cushioning material, and the support bracket can effectively remove the force from the bearing portion of the crankshaft. Can receive.
[0013]
Furthermore, even if there is a gap between the support bracket and the holding part of the motor unit due to aging due to long-term use of the electric bicycle, cushioning material enters the gap between them, and the force concentrates partially. Is prevented. Further, when a metal material is used as the support bracket and a resin member is used as the case of the motor unit, if a cushioning material is not interposed, a resin material is formed at a contact point between the support bracket and the holding portion of the case. there is a possibility that cases are worn at, but by interposing a buffer material, it is possible to prevent such wear occurs.
[0014]
A bridge fitting is bridged between the standing pipe and the chain stay which are connected to each other via the hanger lug, and the rear part of the motor unit is attached to the bridge fitting, whereby the rear part of the motor unit is securely supported by the bridge fitting. In addition to the above, the strength of the vicinity of the hanger lug can be increased by the bridge fitting.
[0015]
The support bracket has a side portion disposed respectively on both sides of the motor unit, and a lower surface portion connecting the both side portions, the lower surface portion of the support bracket is disposed below the bottom of the case portion of the motor unit By doing so, even if there are protrusions, stones, etc. at the bottom of the electric bicycle during running, or if there are steps, these will hit the lower surface of the support bracket, and the bottom of the motor unit will be Is prevented, and the motor unit is protected.
[0016]
The supporting portion of the substantially cylindrical shape of the support bracket, the division support of the bisected substantially arc shape vertically, be configured in conjunction with a by a connecting means, such as during maintenance of the motor unit, installation and removal of the motor unit Can be performed relatively easily.
[0017]
Of course, the case of the motor unit can be made of resin from the above.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5. Here, FIG. 1 is a left side view of the electric bicycle according to the embodiment of the present invention (a chain cover and the like are omitted), and FIGS. 2A and 2B are motors in the electric bicycle. FIG. 3 is a left side view of a main part of the unit mounting device and a partial cutaway left side view of the main part, FIG. 3 is a right side view of the main part of the motor unit mounting device, and FIG. 4 is a sectional view taken along line IV-IV of FIG. FIG. 5 is a perspective view of a main part of the motor unit mounting device, and FIG.
[0019]
As shown in FIGS. 1 to 5, in the electric bicycle of the present embodiment, the motor unit 20 is supported on the hanger lug 4 that connects the upright pipe 1, the chain stay 2, and the main pipe 3, each of which is a frame. A metal support bracket 5 is attached. The support bracket 5 supports, in particular, holding portions 20a and 20b holding the bearing portion 22 of the crankshaft 21 in the motor unit 20. 1 and 2, reference numeral 10 denotes a pedal, 13 denotes a large gear, and 14 denotes a battery unit.
[0020]
The motor unit 20 includes left and right bearing bearings that rotatably support a crankshaft 21 to which the pedal 10 is attached (here, in the description of the present embodiment, left and right refer to when an occupant rides on an electric bicycle). bearing portion 22A of the corresponding right and left direction in the state), and 22B, the electric motor 23 as a driving source of driving force, reduction gear group for transmitting the rotational driving force of the electric motor 23 (not shown), A unit case 24 that covers these bearings 22A and 22B, the electric motor 23, the reduction gear group, and the like; and an electric motor that is exposed to the outside of the unit case 24 and that is disposed via a reduction gear group (not shown). An output gear 25 to which the rotational driving force of the motor 23 is transmitted is provided. Here, the unit case 24 is made of resin to reduce the weight, and is manufactured at low cost by resin molding.
[0021]
Further, the electric bicycle, the pedal force input from the pedal 10, while adding the power drive that is transmitted from the rotational driving force of the motor unit 20, so that the vehicle can run.
[0022]
The support bracket 5 includes mounting portions 5a and 5b whose upper portions are attached to the hanger lug 4 from the side so as to cover the hanger lug 4, and lower surfaces 5e and 5f connecting between lower ends of both side portions 5c and 5d. Become. At the center of each of the mounting portions 5a, 5b, support portions 5g, 5h projecting in a substantially cylindrical shape are integrally formed, and these support portions 5g, 5h are attached to the holding portions 20a, 20b of the motor unit 20 on both sides. The holding portions 20a and 20b on both sides holding the bearing portion 22 by the support portions 5g and 5h are sandwiched between the support portions 5g and 5h.
[0023]
A cushioning member 7 made of hard urethane rubber is interposed between the unit case 24 at a location (the holding portions 20a and 20b) covering the bearing portion 22 and the support portions 5g and 5h of the support bracket 5. ing. Further, the lower surfaces 5e and 5f of the support bracket 5 are arranged below the front bottom surface of the unit case 24.
[0024]
In this embodiment, the support bracket 5 includes a first member including a left mounting portion 5a, a side surface portion 5c, and a left portion of a lower surface portion 5e bent rightward from a lower end of the side surface portion 5c. And a second member comprising a right mounting portion 5b, a side surface portion 5d, and a right portion of a lower surface portion 5f bent leftward from the lower end of the side surface portion 5d. The lower surface 5e of the first member and the lower surface 5f of the second member are connected by fixing them with screws 5i (see FIG. 4).
[0025]
The upper part of the mounting portion 5b of the second member on the right side is welded to the hanger lug 4 (see FIG. 4), and the upper portion of the mounting portion 5b is substantially cylindrical along the hanger lug 4 so as to be easily welded to the hanger lug 4. It is shaped. Further, the first member on the left side is fixed by the screw 5i on the lower surface 5e, and at the upper part of the mounting portion 5a which is in contact with the hanger lug 4, the side of the hanger lug 4 is attached to the mounting portion of the first member. The fixing bolt 31 and the nut 32 are fixed by screwing between the fixing bolt 31 and the nut 32 while being sandwiched between the mounting member 5a and the mounting portion 5b of the second member. Incidentally, or welded to both members, even or a screwing structure such as bolts no problem.
[0026]
As shown in FIGS. 2 and 3, a bridge fitting 8 is bridged and welded between the upright pipe 1 and the chain stay 2 connected to each other via a hanger lug 4. A rear portion of the motor unit 20 (specifically, a rear flange portion 24 a formed on the unit case 24) is screwed and supported at an upper end thereof by the mounting bracket 9 on the bridge fitting 8.
[0027]
In addition, a mounting screw 11 is inserted into the front part of the motor unit 20 through left and right side surfaces 5c and 5d of the support bracket 5, and is fixed to the support bracket 5 by the mounting screw 11.
[0028]
According to the above configuration, since the holding portions 20a and 20b of the motor unit 20 that holds the bearing portion 22 of the crankshaft 21 are supported by the support bracket 5, the pedaling force or the riding force acting on the crankshaft 21 from the pedal 10 is provided. Even when a force such as a person's weight acts, the force can be concentrated and received by the support bracket 5 connected to the hanger lug 4. Further, in this case, since the support portions 5g and 5h of the support bracket 5 have a substantially cylindrical shape, the force from the bearing portion 22 can be favorably and firmly supported.
[0029]
Therefore, the motor unit 20 itself is not directly affected by the force such as the pedaling force or the weight of the occupant, and the unit case 24 is made of a material having a strength enough to hold the weight of the motor unit 20 itself. The use of a resin having a lower strength than a metal does not cause a problem. Accordingly, by employing resin as the unit case 24, it is possible to reduce the weight and the manufacturing cost, and the unit case 24 does not need to have a large strength. The size can be further reduced.
[0030]
In addition, since the cushioning member 7 is interposed between the support portions 5g and 5h of the support bracket 5 and the holding portions 20a and 20b of the motor unit 20, the force from the crankshaft 21 acts on the bearing portion 22 without bias. Even in this case, the force is transmitted to the support bracket 5 while being well dispersed via the cushioning member 7, and the force from the bearing portion 22 can be satisfactorily received by the support bracket 5.
[0031]
In addition, since the support bracket 5 is made of metal and the unit case 24 covering the bearing portion 22 is made of resin, a dimensional difference may occur due to a coefficient of thermal expansion. It can be absorbed by the cushioning material 7. Further, there may be a gap between the support portions 5g and 5h of the support bracket 5 and the holding portions 20a and 20b of the unit case 24 due to aging due to long-term use of the electric bicycle. The cushioning material 7 enters the gap, preventing the force from being partially concentrated, and the support bracket 5 can favorably receive the force from the bearing portion 22.
[0032]
Further, as described above, when a metal material is used for the support bracket 5 and a resin member is used for the unit case 24 of the motor unit 20, the support bracket 5 and the unit case 24 may be used unless the cushioning material 7 is interposed. the holding portion 20a, in a region of contact between the 20b, there is a risk of wear,, by interposing a buffer member 7, it is possible to prevent such wear occurs.
[0033]
In addition, by providing the bridge fitting 8, a triangular truss structure can be formed in the vicinity of the hanger lug 4 by using the bridge fitting 8, the standing pipe 1, and the chain stay 2 in a side view. Not only can the rear part of the motor unit 20 be firmly supported by the bridge fitting 8, but also the strength of the frame body near the hanger lug 4 can be improved.
[0034]
Further, even when there are protrusions or stones protruding above the road surface side during traveling, or when traveling in a place having a step, the lower surface 5e of the support bracket 5 is provided on the protrusion, the stone, the step or the like. By hitting 5f, the bottoming of the motor unit 20 is prevented, and the motor unit 20 is protected.
[0035]
The cushioning material 7 is not limited to a hard urethane rubber material, but may be any other material having elasticity, such as another rubber or resin. In addition, the support portions 5g and 5h of the support bracket 5 are formed slightly smaller than the diameter of the bearing portion 22, and the location of the bearing portion 22 in the unit case 24 is press-fitted into the support portions 5g and 5h of the support bracket 5. It is also possible to omit the cushioning material 7 by making it adhere closely.
[0036]
Further, in the above-described embodiment, the case where the substantially cylindrical support portions 5g and 5h are integrally formed has been described. However, the present invention is not limited to this, and as shown in FIGS. The divided substantially arc-shaped divided support portions 5j, 5k, 5m, 5n are connected to each other by connecting screws 41, 42 as connecting means at their brim-shaped portions, so that the bearing portion 22 of the crankshaft 21 in the unit case 24 is formed . The holding portions 20a and 20b may be supported. In this case, the motor unit 20 can be relatively easily attached or detached by removing the connecting screws 41 and 42 and the lower divided support portions 5k and 5n during maintenance of the motor unit 20 or the like. . Further, at the time of mounting, by adjusting the degree of tightening of the connecting screws 41 and 42, the assembling force by the divided support portions 5j, 5k, 5m and 5n can be adjusted.
[0037]
Further, in the above-described embodiment, the case where the support bracket 5 is fixed to the hanger lug 4 has been described. However, the present invention is not limited to this, and each frame such as the main pipe 3, the vertical pipe 1, and the chain stay 2 near the hanger lug 4. The same effect can be obtained even if the fixing is performed over any one or a plurality of portions.
[0038]
【The invention's effect】
As described above, according to the present invention, by using the support bracket to support the holding portion that holds the bearing portion of the crankshaft in the motor unit, it is possible to use an inexpensive and light material such as resin for the case of the motor unit. While it is possible, the support bracket can favorably receive the pedaling force and weight acting on the crankshaft, and as a result, the manufacturing cost can be reduced and the weight can be reduced.
[0039]
Further, a substantially cylindrical support portion is formed on the support bracket, and the support portion supports the holding portion of the bearing portion of the motor unit so as to hold the holding portion from both sides. Can be favorably and firmly supported.
[0040]
Also, by interposing a cushioning material between the support bracket and the holding portion for holding the bearing portion of the crankshaft, the force from the bearing portion of the crankshaft is dispersed well through the cushioning material to the support bracket. The transmitted power can be favorably received by the support bracket from the bearing portion of the crankshaft. Also, even if a gap occurs between the support bracket and the holding part due to a difference in the coefficient of thermal expansion between the support bracket and the holding part of the bearing part or aging due to long-term use, the gap is absorbed by the cushioning material. Thus, the force from the bearing of the crankshaft can be favorably received by the support bracket. Further, by interposing the cushioning material, it is possible to prevent the case-side portion and the like from being worn at the contact portion between the support bracket and the holding portion of the bearing portion .
[0041]
In addition, a bridge fitting is bridged between the standing pipe and the chain stay that are connected to each other via the hanger lug, and the rear part of the motor unit is attached by the bridge fitting. Not only can it be reliably supported, but also the strength of the vicinity of the hanger lug can be increased by the bridge fitting.
[0042]
Further, by disposing the lower surface of the support bracket below the bottom of the case of the motor unit, bottoming of the motor unit is prevented and the motor unit is protected, thereby improving reliability.
[Brief description of the drawings]
FIG. 1 is a left side view of an electric bicycle according to an embodiment of the present invention, with a chain cover and the like omitted.
2 (a) and 2 (b) are a left side view of a motor unit attaching device of the electric bicycle and a partially cut left side view of the motor unit attaching device with a part of an attaching portion cut out.
FIG. 3 is a right side view of a main part of the motor unit mounting device.
FIG. 4 is a front sectional view of a main part of the motor unit mounting apparatus, taken along line IV-IV in FIG. 3;
FIG. 5 is a perspective view of a main part of the motor unit mounting device.
FIG. 6 is a right side view of a main part of a motor unit mounting device according to another embodiment of the present invention.
FIG. 7 is a front sectional view of a main part of the motor unit mounting device, taken along line VII-VII in FIG. 6;
FIG. 8 is a left side view of a conventional electric bicycle.
FIG. 9 is a left side view of the conventional electric bicycle, omitting a chain cover and the like.
FIGS. 10 (a) and (b) are left side views of main parts of the conventional electric bicycle motor unit mounting device.
[Explanation of symbols]
1 standing pipe (frame)
2 Chain stay (frame)
3 Main pipe (frame)
Reference Signs List 4 Hanger lug 5 Support brackets 5a, 5b Mounting parts 5c, 5d Side parts 5e, 5f Lower parts 5g, 5h Support parts 5j, 5k, 5m, 5n Split support parts 7 Buffer material 8 Bridge fitting 10 Pedal 20 Motor unit
20a, 20b Holding part 21 Crankshaft 22 (22A, 22B) Bearing part 23 Electric motor 24 Unit cases 41, 42 Connection screw (connection means)

Claims (9)

A bearing portion for supporting the crankshaft and holding portion for holding the bearing portion is provided, the motor unit to add driving force of the electric motor to the drive force by human power,
A support bracket attached to the frame and supporting the motor unit to hold the holding unit,
An electric bicycle , wherein a portion of the motor unit supported by the support bracket is the holding portion . The electric bicycle according to claim 1, wherein the support bracket is fixed to a hanger lug or a portion of the frame near the hanger lug, and the motor unit is attached to the frame. A portion of the support bracket for supporting the holding portion of the motor unit is projected into a substantially cylindrical shape, and the substantially cylindrical support portion formed on the support bracket is externally fitted to the holding portion of the motor unit. Item 3. The electric bicycle according to item 1 or 2 . The electric bicycle according to any one of claims 1 to 3, wherein both sides of the motor unit are sandwiched by support brackets . The electric bicycle according to any one of claims 1 to 4, wherein a cushioning material is interposed between the support bracket and the holding portion of the motor unit . A bridge bracket is bridged between the standing pipe and the chain stay that are connected to each other via the hanger lug, and connected,
The electric bicycle according to any one of claims 1 to 5, wherein a rear portion of the motor unit is attached to the bridge fitting . The support bracket has side portions respectively arranged on both sides of the motor unit, and a lower surface portion connecting between both side portions,
The electric bicycle according to any one of claims 1 to 6, wherein a lower surface of the support bracket is disposed below a case bottom of the motor unit . 4. The electric bicycle according to claim 3, wherein the substantially cylindrical support portion of the support bracket has a configuration in which a substantially arc-shaped divided support portion vertically divided into two portions is connected by connecting means . 5. The electric bicycle according to any one of claims 1 to 8, wherein a case of the motor unit is made of resin .

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