Electric bicycle and electric vehicle

Abstract

An electric bicycle (1) comprises a front wheel (3), a rear wheel (4), a motor unit (30), a battery unit (20), pedals (9), and a crank (10). The motor unit (30) is positioned in a location that overlaps with neither the front wheel (3) nor the rear wheel (4) in a side view, and has an electric motor (32) and a motor case (31). The battery unit (20) has a battery (21) that stores power to be supplied to the electric motor (32), and a battery holder (22). The pedals (9) are arranged in a left-right pair. The crank (10) transmits a force applied by a rider to the pedals (9). The lower end of the battery unit (20) is at a lower location than a crankshaft (10a), which is the rotational axis of the crank (10).

Description

Electric bicycles and electric vehicles

[0001] The present application relates primarily to electric bicycles and electric vehicles, and more particularly to the layout of battery units provided in electric bicycles and electric vehicles.

[0002] Patent Document 1 discloses an electric bicycle equipped with a first battery, a second battery, and an electric motor. The first battery is located in the space in front of the saddle post. The second battery is located along the saddle post. Both the first battery and the second battery are located higher than the rotation axis of the crank arm.

[0003] JP 2023-30689 A

[0004] In the layout of Patent Document 1, the battery, which is a heavy object, is placed at a relatively high position, which can make the electric bicycle difficult to handle when turning. This problem is not limited to electric bicycles, but is a common problem for electric vehicles in general.

[0005] The present application has been made in view of the above circumstances, and its main object is to provide a battery layout for an electric bicycle that allows for easy handling when turning.

[0006] The problem to be solved by the present application is as described above. Next, the means for solving this problem and the effects thereof will be explained.

[0007] According to an aspect of the present application, there is provided an electric bicycle having the following configuration. That is, the electric bicycle includes a front wheel, a rear wheel, a motor unit, a battery unit, pedals, and a crank. The motor unit is positioned so as not to overlap the front wheel or the rear wheel in a side view, and includes an electric motor and a motor case. The battery unit includes a battery and a battery holder that stores power to be supplied to the electric motor. The pedals are arranged in pairs, one on the left and one on the right. The crank transmits the force applied to the pedals by the rider. The lower end of the battery unit is located lower than the crankshaft, which is the axis of rotation of the crank.

[0008] According to the present application, handling during turning can be improved.

[0009] FIG. 1 is a side view of an electric bicycle according to a first embodiment; FIG. 2 is a perspective view showing how a battery is attached to and detached from a battery holder; FIG. 3 is a block diagram of an electric bicycle; FIG. 4 is a side view of an electric bicycle according to a third embodiment; FIG. 5 is a side view of an electric bicycle according to a fourth embodiment; and FIG.

[0010] Next, an embodiment of the present application will be described with reference to the drawings. In the following description, the left-right direction of the electric bicycle 1 is defined as the direction as seen by a rider riding the electric bicycle 1. Therefore, the front-rear direction corresponds to the vehicle length direction, and the left-right direction corresponds to the vehicle width direction. Furthermore, the vertical direction and the up-down direction correspond to the height direction.

[0011] The electric bicycle 1 shown in Fig. 1 is a vehicle (saddle-ride type vehicle) that a rider straddles and rides, and it travels using the force applied by the rider to the pedals and the force generated by the electric motor. Specifically, since the electric bicycle 1 of this embodiment is an electrically assisted bicycle, the electric motor generates power only when the rider applies force to the pedals. However, the electric bicycle 1 is not limited to electrically assisted bicycles. In other words, the electric motor may generate power to travel the electric bicycle 1 even when the rider is not applying force to the pedals.

[0012] As shown in FIG. 1 , the electric bicycle 1 includes a frame 2 , a front wheel 3 , and a rear wheel 4 .

[0013] The frame 2 is a component that forms the framework of the electric bicycle 1. Various components of the electric bicycle 1 are attached to the frame 2. The frame 2 is formed by combining multiple tubes. Details of the frame 2 will be described later.

[0014] Each of the front wheels 3 and rear wheels 4 includes a wheel body and a tire attached to the wheel body. The axle located at the rotation center of the front wheel 3 is the front axle 3a, and the axle located at the rotation center of the rear wheel 4 is the rear axle 4a. In this embodiment, there is one front wheel 3 and one rear wheel 4. Alternatively, there may be multiple front wheels 3 or multiple rear wheels 4.

[0015] The front wheel 3 is rotatably attached to the lower end of the front fork 6. The front fork 6 is a telescopic suspension and includes an outer tube and an inner tube. An inner tube is inserted into the outer tube, and the two are connected via a coil spring. The coil spring reduces the shock transmitted between the outer tube and the inner tube. This reduces the shock transmitted from the road surface to the frame 2 via the front wheel 3, i.e., the shock transmitted to the rider. The front fork 6 may be an air suspension that uses air to reduce shock. Alternatively, the front fork 6 does not have to have a suspension function.

[0016] The upper end of the front fork 6 passes through the inside of the frame 2 and is connected to the handle unit 7. The handle unit 7 includes a stem, handlebars, grips, etc. The steering force, which is the force with which the rider turns the handle unit 7, is transmitted to the front wheel 3 via the front fork 6. This changes the steering angle of the front wheel 3, allowing the electric bicycle 1 to turn.

[0017] A saddle 8 on which a rider sits is provided behind the handle unit 7. The saddle 8 is connected to a seat post 8a. Pedals 9 are provided below the saddle 8. A pair of pedals 9 are arranged on the left and right. The rider sits on the saddle 8 and drives the electric bicycle 1 by pedaling the pedals 9 with their feet while gripping the grips of the handle unit 7 with their hands to steer the bicycle.

[0018] A crank 10 is connected to the pedal 9. The crank 10 is rotatable around a crankshaft 10a. The crank 10 is connected to a chain wheel 12 disposed within a chain ring 11. By rotating the crank 10, the chain wheel 12 can be rotated. A chain 13 is wound around the chain wheel 12.

[0019] The chain 13 is wound around a sprocket 14 located near the rear axle 4a of the rear wheel 4. The sprocket 14 is fixed to the rear wheel 4, and rotating the sprocket 14 causes the rear wheel 4 to rotate. As described above, the force applied by the rider to the pedals 9 is transmitted to the rear wheel 4 via the chain 13, causing the rear wheel 4 to rotate. Note that instead of using the chain 13 to transmit force, a shaft may be used to transmit force. In this case, a helical gear structure, for example, may be used to transmit power between the crank 10 and the shaft and between the shaft and the rear wheel 4.

[0020] The frame 2 is provided with a rear suspension 15. The rear suspension 15 connects the portion of the frame 2 on the rear wheel 4 side with the portion on the center side in the longitudinal direction. This reduces the impact transmitted from the road surface to the frame 2 via the rear wheel 4, i.e., the impact transmitted to the rider. The rear suspension 15 is not an essential component and can be omitted.

[0021] A side stand 16 is provided on a first side of the rear wheel 4 in the vehicle width direction. In this embodiment, the first side corresponds to the left side, and the opposite second side corresponds to the right side. By using the side stand 16, the electric bicycle 1 can stand upright while leaning slightly toward the first side. The side stand 16 is not an essential component and can be omitted.

[0022] A battery unit 20 and a motor unit 30 are provided in the area between the front wheels 3 and the rear wheels 4 in the longitudinal direction, more specifically, in the area behind the rear end of the front wheels 3 and in front of the front end of the rear wheels 4.

[0023] The battery unit 20 includes a battery 21 and a battery holder 22 .

[0024] The battery 21 stores power. The battery 21 is configured by combining, for example, small cylindrical lithium-ion rechargeable batteries. Therefore, the battery 21 of this embodiment is not limited to a simple shape such as a rectangular parallelepiped, and can be realized in various shapes. The specific shape and layout of the battery 21 will be described later. Methods of combining multiple rechargeable batteries and treating them as a single battery are well known, so explanations will be omitted. The battery is not limited to lithium-ion rechargeable batteries, and other types of rechargeable batteries, such as nickel-metal hydride batteries, may also be used. The battery 21 is not limited to a configuration in which multiple rechargeable batteries are combined, and a single rechargeable battery having a desired shape may be manufactured and used as the battery 21.

[0025] The battery holder 22 is fixed to the frame 2 using bolts or the like. The battery holder 22 allows the battery 21 to be attached and detached. Specifically, as shown in FIG. 2 , the battery holder 22 has an attachment portion 22a. The attachment portion 22a has a slide groove that allows the battery 21 to slide in the vehicle width direction. In this embodiment, the sliding direction of the battery 21 when attaching or detaching is fixed, and the battery 21 cannot be attached or detached in any other direction. Specifically, the worker slides the battery 21 along the slide groove of the attachment portion 22a toward a first side in the vehicle width direction. This allows the battery 21 to be attached to the attachment portion 22a. Various attachment and detachment structures for the battery 21 and the attachment portion 22a can be used, for example, a snap fit. Furthermore, when removing the battery 21 from the attachment portion 22a, the worker operates a predetermined operating piece to release the snap fit, and then slides the battery 21 toward a second side, thereby removing the battery 21 from the attachment portion 22a. Since the sliding direction is determined as described above, the worker can attach or detach the battery 21 to or from the second side surface of the electric bicycle 1.

[0026] By using a structure that allows the battery 21 to be attached and detached by sliding it in the vehicle width direction, the battery 21 can be easily attached and detached even in a layout in which the battery 21 is surrounded by the frame 2 or the like in a side view. This improves the flexibility of the layout of the frame 2 or the battery unit 20. Furthermore, the battery 21 is attached and detached while the electric bicycle 1 is in an upright position using the side stand 16. As described above, when the electric bicycle 1 is in an upright position, the electric bicycle 1 is slightly tilted toward the first side, so the second side surface of the electric bicycle 1 faces slightly upward. Therefore, working on the second side surface of the electric bicycle 1 is less stressful than working on the first side surface. In other words, by determining the sliding direction as described above, the battery 21 can be easily attached and detached. The elements necessary for achieving ease of removal are (1) the side stand 16 being positioned on the first side in the vehicle width direction, and (2) the battery 21 being removed to the second side in the vehicle width direction. In order to further enhance the effect of ease of installation, (3) the battery 21 needs to be installed from the second side in the vehicle width direction. Other features can be changed as appropriate.

[0027] The structure for attaching and detaching the battery 21 to the mounting portion 22a is not limited to a snap fit. For example, the battery 21 may be attached to the mounting portion 22a using a bolt, or the battery 21 may be held in the battery holder 22 by attaching a separate holding member to the mounting portion 22a.

[0028] Furthermore, by attaching the battery 21 to the battery holder 22, the terminals of the battery 21 are electrically connected to the conductors of the battery holder 22. The conductors of the battery holder 22 are connected to the motor unit 30 via electric wires or the like that run inside or outside the frame 2. This allows power to be supplied from the battery 21 to the motor unit 30.

[0029] The motor unit 30 is disposed in a position that does not overlap the front wheels 3 and the rear wheels 4 in a side view. Specifically, the motor unit 30 is disposed between the front wheels 3 and the rear wheels 4 in the front-to-rear direction. Therefore, the motor unit 30 is a center motor type, and is not an in-wheel motor.

[0030] The motor unit 30 and the battery unit 20 are arranged adjacent to each other. Adjacent means that the distance between the battery unit 20 and the motor unit 30 is small, regardless of whether they are in contact or not. The specific distance that corresponds to being adjacent is determined based on the sizes of the electric bicycle 1, the battery unit 20, the motor unit 30, etc., as well as common technical knowledge. As an example of being adjacent, the battery unit 20 and the motor unit 30 are close to each other without a tube or with only one tube in between.

[0031] The motor unit 30 includes a motor case 31, an electric motor 32, and a motor driver 93 shown in FIG.

[0032] The motor case 31 is fixed to the frame 2 using bolts or the like. The motor case 31 accommodates an electric motor 32 and a motor driver 93 therein.

[0033] The electric motor 32 generates a force when a drive current is supplied from the motor driver 93. There are various types of electric motors 32, and for example, a brushed DC motor, a brushless DC motor, an AC servo motor, etc. can be used.

[0034] The power generated by the electric motor 32 is transmitted to the motor sprocket via the reducer. The reducer and motor sprocket may be located inside the motor case 31, or may be located outside the motor case 31 and near the chain ring 11. The chain 13 meshes with the motor sprocket. This allows the power generated by the electric motor 32 to drive the rear wheel 4. Because the motor unit 30 is an assembly used in general electric bicycles, an existing motor unit 30 may be attached to the electric bicycle 1.

[0035] As described above, the electric bicycle 1 is an electrically assisted bicycle. Therefore, the following control is performed. As shown in FIG. 3 , the electric bicycle 1 is provided with a control device 90, a pedal sensor 91, and a vehicle speed sensor 92. The control device 90 is a microcomputer having a CPU, ROM, RAM, etc. The pedal sensor 91 is a torque sensor provided on the pedal 9. The pedal sensor 91 detects the torque, i.e., the pedal force, applied to the pedal 9 by the rider and outputs the detected torque to the control device 90. The vehicle speed sensor 92 is, for example, a rotation sensor provided on the front axle 3 a or the rear axle 4 a, which detects the rotation speed of the front axle 3 a or the rear axle 4 a, converts it into vehicle speed, and outputs the detected torque to the control device 90. Note that the control device 90 may also convert the rotation speed into vehicle speed.

[0036] The control device 90 generates a control command including a command value for the magnitude of the drive current based on the torque input from the pedal sensor 91 and the vehicle speed input from the vehicle speed sensor 92, and outputs the control command to the motor driver 93. The motor driver 93 supplies the electric motor 32 with a drive current of a magnitude corresponding to the control command.

[0037] An example of control performed by the control device 90 is shown below. The control device 90 outputs a control command to the motor driver 93 only when the pedal sensor 91 detects torque. This prevents the electric motor 32 from driving the rear wheels 4 when the driver's foot is not on the pedal 9. Furthermore, in order to set an upper limit on the ratio of the force generated by the electric motor 32 to the force applied by the driver, the control device 90 adjusts the magnitude of the drive current according to the magnitude of the torque input from the pedal sensor 91. Furthermore, the control device 90 changes the above-mentioned ratio according to the vehicle speed input from the vehicle speed sensor 92. In other words, the higher the vehicle speed, the smaller the above-mentioned ratio. This control is merely an example, and may be changed according to legal regulations, the region of use, or the like. Furthermore, when used for purposes other than electric assist, the magnitude of the drive current may be changed according to the driver's switch operation, lever operation, or the like.

[0038] All of the above explanations apply not only to the electric bicycle 1 of the first embodiment, but also to the electric bicycles 1 of the second to fifth embodiments.

[0039] Next, the frame 2 of the electric bicycle 1 of each embodiment will be described in detail. The frame 2 is made of, for example, chrome molybdenum steel, aluminum, or carbon fiber, but may be made of other materials. Furthermore, each tube constituting the frame 2 is an elongated, tubular member. Since the term "tube" is used in the bicycle field to refer to a frame, it will also be referred to as a tube in this specification. However, each tube is not limited to being hollow and may be, for example, partially solid. Below, each tube constituting the frame 2 of the first to fifth embodiments will be described together.

[0040] 1, 4, 5, 6, and 7, the frame 2 of each embodiment includes a head tube 41, a seat tube 42, seat stays 45, and chain stays 46. The layout, connection destinations, and orientation of each tube are examples, and different examples may be adopted.

[0041] The head tube 41 is located at the front end of the frame 2 in an area overlapping the front wheel 3 in the front-to-rear direction. The front fork 6 is inserted into the head tube 41. The head tube 41 is inclined so as to extend diagonally upward and rearward.

[0042] The seat tube 42 is located in the center of the frame 2, behind the front wheel and in front of the rear wheel 4. The seat post 8a is inserted into the seat tube 42. The seat tube 42 is inclined so as to extend diagonally upward and rearward.

[0043] The seat stays 45 are located at the rear of the frame 2 and overlap the rear wheel 4 in a side view. The seat stays 45 are inclined so as to extend diagonally upward and forward. The front ends of the seat stays 45 are connected to the seat tube 42 via the rear suspension 15. The seat stays 45 are rotatable relative to the seat tube 42. Alternatively, the seat stays 45 may be fixed so as not to be rotatable relative to the seat tube 42. The rear ends of the seat stays 45 are rotatably connected to the rear wheel 4.

[0044] The chainstays 46 are located at the rear of the frame 2, overlapping the rear wheel 4 in a side view, and below the seat stays 45. The chainstays 46 are arranged to extend in the front-to-rear direction. The front ends of the chainstays 46 are rotatably connected to the seat tube 42. The chainstays 46 may be fixed so as not to rotate relative to the seat tube 42. Furthermore, when a portion of the battery unit 20 or the motor unit 30 is used as a frame component, the front ends of the chainstays 46 may be connected to the battery unit 20 or the motor unit 30. The rear ends of the chainstays 46 are rotatably connected to the rear wheel 4.

[0045] The tubes disposed between the head tube 41 and the seat tube 42 in the front-to-rear direction are referred to as front and rear tubes. The frame 2 includes a top tube 43 and a down tube 44 as the main front and rear tubes.

[0046] The top tube 43 has a front end connected to the head tube 41 and a rear end connected to the seat tube 42. The top tube 43 is the highest of the front and rear tubes. As shown in each embodiment, the top tube 43 may be straight or may be bent. Alternatively, the top tube 43 may include a curved portion.

[0047] The down tube 44 has a front end connected to the head tube 41 and a rear end connected to the seat tube 42. When a part of the battery unit 20 or the motor unit 30 is used as a frame structure, the rear end of the down tube 44 may be connected to the battery unit 20 or the motor unit 30. The down tube 44 is located at the lowest position of the front and rear tubes. As shown in each embodiment, the down tube 44 may be straight or may be bent. Alternatively, the down tube 44 may include a curved portion.

[0048] Of the front and rear tubes, the tube located between the top tube 43 and the down tube 44 in the height direction is called a middle tube. Middle tubes are classified into the following six types. Each type of middle tube is a member for reinforcing portions that are not reinforced by the top tube 43 and the down tube 44 alone. In other words, each type of middle tube is technically independent. Therefore, any one or more types of middle tubes can be selected and applied to the frame 2. Furthermore, multiple middle tubes of the same type may be provided. In other words, the frames 2 of the first embodiment (FIG. 1) to (FIG. 7) merely illustrate examples of combinations of specific middle tubes, and other combinations of middle tubes are also applicable.

[0049] The first middle tube 51 connects the head tube 41 and the seat tube 42. The first middle tube 51 is shown in FIGS. 4 and 5. The second middle tube 52 connects the seat tube 42 and the top tube 43. The second middle tube 52 is shown in FIGS. 1 and 6. The third middle tube 53 connects the seat tube 42 and the down tube 44. The third middle tube 53 is shown in FIGS. 1 and 7. The fourth middle tube 54 connects the top tube 43 and the down tube 44. The fourth middle tube 54 is shown in FIGS. 1, 6, and 7. The fifth middle tube 55 connects the seat tube 42 and the middle tubes (particularly the first middle tube 51). The fifth middle tube 55 is shown in FIGS. 4 and 5. The sixth middle tube 56 connects the down tube 44 and the middle tubes (particularly the first middle tube 51). The sixth middle tube 56 is shown in FIGS. 4 and 5.

[0050] Next, the shape and layout of the battery unit 20 will be described. In the following explanation, the shape and layout of the battery unit 20 will be described when the electric bicycle 1 is stopped and upright, with only the weight of the electric bicycle 1 being applied to the suspension. Unless otherwise specified, the following explanation will be of the shape and layout as seen from the side.

[0051] Ideally, to improve the dynamic characteristics of the electric bicycle 1, particularly the handling when turning, it is preferable that the weight be concentrated in a low position in the center of the front-to-rear direction of the electric bicycle 1. In each embodiment, the shape and layout of the battery unit 20, which is a heavy object, are designed to improve the handling when turning the electric bicycle 1.

[0052] First, a preferred shape of the battery unit 20 will be described.

[0053] Conventional battery units have a long, thin columnar shape. With conventional shapes, the weight of the battery unit 20 is distributed in the height direction or the front-to-rear direction. In contrast, the battery unit 20 of each embodiment has a shape that is spread out in a balanced manner in the height direction or the front-to-rear direction. Specifically, the front-to-rear size of the battery unit 20 is between one-third and three times the height direction size. As a result, the weight of the battery unit 20 is not distributed much, improving the maneuverability characteristics of the electric bicycle 1. The height direction size refers to the length from the top to the bottom of the battery unit 20. The front-to-rear direction size refers to the length from the front end to the rear end of the battery unit 20.

[0054] As described above, the shape of the battery unit 20 can be freely designed. Therefore, the shape of the battery unit 20 can be determined taking into consideration the shape of the frame 2 or the motor unit 30, i.e., so as to fit the frame 2 or the motor unit 30. This makes it difficult for excess space to be formed, making it easy to concentrate the weight of the battery unit 20. Specifically, the battery units 20 of the first and fifth embodiments have a polygonal shape. The battery units 20 of the second, third, and fourth embodiments have a shape obtained by removing a portion of a polygon (the shape of a portion that interferes with the motor unit 30). Note that the polygonal shape includes a substantially polygonal shape.

[0055] Furthermore, the battery unit 20 in some embodiments includes a portion that narrows toward the top. Strictly speaking, the battery unit 20 includes a portion where the front and rear ends of the battery unit 20 approach each other in the front-to-rear direction as it moves upward. In other words, at least a portion of the outline of the battery unit 20 changes so that the front and rear ends of the battery unit 20 approach each other in the front-to-rear direction as the height increases. For example, the upper portion of the battery unit 20 in the first embodiment is triangular, and therefore includes a portion that narrows toward the top. The upper portion of the battery unit 20 in the second and third embodiments has a shorter upper base than a lower base, and therefore includes a portion that narrows toward the top. Note that in the first to third embodiments, due to the influence of the positional relationship with the motor unit 30, the battery unit 20 includes a portion that narrows toward the top at a position higher than the motor unit 30.

[0056] As described above, the shape of the battery unit 20 is designed to concentrate the weight at a low position in the center of the front-to-rear direction of the electric bicycle 1. This facilitates easy handling when turning the electric bicycle 1. Note that the above-mentioned features are independent, and even if each feature is used individually, it is possible to achieve the effect of facilitating easy handling when turning the electric bicycle 1.

[0057] Next, the layout of the battery unit 20 will be described.

[0058] As described above, the battery unit 20 is disposed between the front wheel 3 and the rear wheel 4 in the longitudinal direction, so the battery unit 20 is located in the center in the longitudinal direction. In addition, the lower end of the battery unit 20 is located lower than the crankshaft 10a, so the battery unit 20 is located lower in the height direction. As a result, the battery units 20 are concentrated in the center in the longitudinal direction and at a low position in the height direction.

[0059] More specifically, the upper end of the battery unit 20 is located lower than the upper end of the rear suspension 15. Furthermore, in the fourth embodiment, the upper end of the battery unit 20 is located lower than the lower end of the rear suspension 15. In addition, the upper end of the battery unit 20 is located lower than the upper end of the front wheel 3.

[0060] The range in the height direction from the upper end of the frame 2 (e.g., the upper end of the top tube 43) to the lower end of the frame 2 (e.g., the lower end of the down tube 44 or the chainstay 46) is referred to as the frame height range. The frame height range is indicated by the symbol FH in each drawing. The center of gravity of the battery holder 22 in each embodiment is located lower than the center in the height direction of the frame height range FH. Furthermore, the upper end of the battery holder 22 in each embodiment is located in the center or lower region when the frame height range FH is divided into thirds in the height direction. In other words, even when the frame 2 is used as a reference, the battery holders 22 are concentrated in the center in the fore-and-aft direction and at a low position in the height direction.

[0061] In each embodiment, the motor unit 30 is disposed adjacent to the battery unit 20, and therefore the motor units 30 are also concentrated in the center in the front-to-rear direction and at a low position in the height direction. The motor units 30 may be oriented such that the longitudinal direction and the height direction coincide with each other, as in the first embodiment, or such that the longitudinal direction and the front-to-rear direction coincide with each other, as in the second to fifth embodiments. In this specification, "coincidence" includes not only perfect coincidence but also a state of approximately coinciding.

[0062] As a result, both the battery unit 20 and the motor unit 30 are arranged so that they are concentrated in the center in the fore-and-aft direction and at a low position in the height direction. Therefore, for example, the center of gravity of the assembly of the battery unit 20 and the motor unit 30 is located between the front wheel 3 and the rear wheel 4 in the fore-and-aft direction, and more specifically, is located forward of the crankshaft 10a. In the height direction, the center of gravity of this assembly is located lower than the bottom end of the top tube 43 and lower than the center in the longitudinal direction of the seat tube 42. Furthermore, the center of gravity of this assembly in the fourth embodiment is located lower than the front axle 3a.

[0063] The positional relationship between the battery unit 20 and the motor unit 30 will be described in more detail. In the first to fourth embodiments, at least a portion of the battery unit 20 and at least a portion of the motor unit 30 are adjacent to each other in the front-to-rear direction. Furthermore, in the second to fifth embodiments, at least a portion of the battery unit 20 and at least a portion of the motor unit 30 are adjacent to each other in the height direction. Therefore, in the second to fourth embodiments, the battery unit 20 includes a portion adjacent to the motor unit 30 in the front-to-rear direction and a portion adjacent to the motor unit 30 in the up-down direction. More specifically, a portion of the battery unit 20 is located in front of the motor unit 30, and a portion of the battery unit 20 is located above the motor unit 30. By having at least one of the above-described features, the battery unit 20 can be efficiently arranged taking into account the shape of the motor unit 30. Note that a portion of the battery unit 20 may be located below the motor unit 30.

[0064] The layout features of the battery unit 20 and the motor unit 30 described above can also be combined in part. For example, in the second to fourth embodiments, the motor unit 30 is arranged so that its longitudinal direction coincides with the front-to-rear direction, and a portion of the battery unit 20 is arranged further forward. This combination can further lower the center of gravity of the assembly of the battery unit 20 and the motor unit 30. Other features can also be combined as appropriate.

[0065] Next, the layout of the battery unit 20 relative to the frame 2 will be described. The battery unit 20 is positioned lower than the top tube 43. Furthermore, the battery units 20 other than those of the fourth embodiment have portions that fit along multiple front and rear frames and are further connected to multiple front and rear frames. This allows the battery unit 20 to be positioned using the gaps between the frames. This makes it easier to increase the capacity of the battery 21. Furthermore, by connecting to multiple front and rear frames, the battery unit 20 can be firmly connected. Furthermore, since the front and rear frames are connected to each other by the battery unit 20, there is a possibility that rigidity will be improved.

[0066] Specifically, the battery unit 20 in the first embodiment is disposed along the down tube 44 and the third middle tube 53. The battery units 20 in the second and third embodiments are disposed along the down tube 44, the first middle tube 51, and the sixth middle tube 56. The battery unit 20 in the fourth embodiment is disposed along the seat tube 42. The battery unit 20 in the fifth embodiment is disposed along the seat tube 42 and the down tube 44. The third middle tube 53 and the sixth middle tube 56 are middle tubes that are connected to the down tube 44, or in other words, correspond to tubes that intersect with the down tube 44.

[0067] The above-described layout is one example, and the battery unit 20 can be arranged along or connected to any one or more of the tubes that make up the frame 2. Tubes to be selected can include the down tube 44 in order to position the battery unit 20 in a low position. Alternatively, the seat tube 42, which is expected to be located near the crank 10 or the motor unit 30, or any of the middle tubes (second middle tube 52, third middle tube 53, fifth middle tube 55) connected to the seat tube 42 may be selected.

[0068] As described above, the layout of the battery unit 20 is designed to concentrate the weight in a low position in the center of the front-to-rear direction of the electric bicycle 1. This makes it easier to handle the electric bicycle 1 when turning. The above-mentioned features are independent, and even if each feature is used individually, it is possible to achieve the effect of making it easier to handle the electric bicycle 1 when turning. Furthermore, the features related to the shape and layout of the battery unit 20 are independent, and the same effect can be achieved even if only one of them is used.

[0069] Next, a vehicle to which the above-described features can be applied will be described.

[0070] The above-described features can be applied to electric vehicles other than electric bicycles, such as electric motorcycles. In this case, the pedals 9 and crank 10 can be removed from the electric bicycle 1 of the above embodiment, and footrests or steps can be provided for feet. Also, the grip of the handle unit 7 can be replaced with a throttle grip, which can be electrically connected to the control device 90. All other parts can be reused from the electric bicycle 1 of the above embodiment. Note that, because electric motorcycles themselves are well known, illustrations and detailed explanations will be omitted. The electric vehicle to which the present invention is applicable may also be an electric tricycle with two front or two rear wheels.

[0071] From another perspective, the above-described features contribute to maneuverability during cornering, and therefore are preferably applied to saddle-ride type vehicles or lean-type vehicles, in which maneuverability during cornering is important. A lean-type vehicle is a vehicle that turns by leaning the body inward in the turning direction.

[0072] <Feature 1> As described above, the electric bicycle 1 of the first to fourth embodiments includes a front wheel 3, a rear wheel 4, a motor unit 30, a battery unit 20, pedals 9, and a crank 10. The motor unit 30 is positioned so as not to overlap the front wheel 3 or the rear wheel 4 in a side view, and includes an electric motor 32 and a motor case 31. The battery unit 20 includes a battery 21 that stores power to be supplied to the electric motor 32, and a battery holder 22. The pedals 9 are arranged in pairs, one on each side. The crank 10 transmits the force applied to the pedals 9 by the rider. The lower end of the battery unit 20 is located lower than the crankshaft 10a, which is the axis of rotation of the crank 10.

[0073] Since the battery unit 20, which is a heavy object, is disposed at the bottom of the electric bicycle 1, it is possible to lower the center of gravity of the electric bicycle 1. As a result, it is possible to improve the handling when turning.

[0074] <Feature 2> In the electric bicycles 1 of the first to fourth embodiments, the motor unit 30 is disposed between the front wheel 3 and the rear wheel 4 in the fore-and-aft direction. At least a portion of the battery unit 20 and at least a portion of the motor unit 30 are disposed side by side in the fore-and-aft direction.

[0075] The motor unit 30, which is a heavy object, is located in the center of the front-to-rear direction of the electric bicycle 1. Furthermore, both the motor unit 30 and the battery unit 20, which are heavy objects, are located in relatively low positions. This allows the center of gravity of the electric bicycle 1 to be located in the center of the front-to-rear direction and at a low position. As a result, handling during cornering can be further improved.

[0076] <Feature 3> In the electric bicycles 1 of the first to fourth embodiments, the battery unit 20 includes a portion located in front of the motor unit 30. The battery unit 20 has a portion located above or below the motor unit 30.

[0077] The battery unit 20 can be arranged by utilizing the area around the motor unit 30.

[0078] <Feature 4> In the electric bicycles 1 of the first to fifth embodiments, the size of the battery unit 20 in the front-to-rear direction relative to the size of the battery unit 20 in the height direction is between 1 / 3 and 3.

[0079] This prevents the size of the battery unit 20 from becoming too long in the height direction or the front-to-rear direction, allowing the center of gravity of the electric bicycle 1 to be located in the center and low position in the front-to-rear direction.

[0080] <Feature 5> In the electric bicycles 1 of the first to third and fifth embodiments, the battery unit 20 and the motor unit 30 are disposed adjacent to each other. At least a portion of the outline of the battery unit 20 changes so that the front and rear ends of the battery unit 20 approach each other in the fore-and-aft direction as the height increases.

[0081] This allows the battery unit 20 to be larger at the bottom than at the top, thereby lowering the center of gravity of the electric bicycle 1.

[0082] <Feature 6> The electric bicycle 1 of the first to fifth embodiments includes a frame 2 having multiple tubes. In a side view, the battery unit 20 has sides (in other words, outlines, the same applies below) that run along at least two of the tubes.

[0083] This allows the battery unit 20 to be placed using the gap between the tubes.

[0084] <Feature 7> The electric bicycle 1 of the first to fifth embodiments includes a frame 2 having multiple tubes. The frame 2 includes a head tube 41, a seat tube 42, and multiple front and rear tubes. The front and rear tubes are arranged between the head tube 41 and the seat tube 42 in the fore-and-aft direction. A battery unit 20 is arranged in an area surrounded by at least two tubes. The battery unit 20 is connected to at least two tubes.

[0085] This allows the battery unit 20 to be held firmly.

[0086] <Feature 8> In the electric bicycle 1 of the first to third embodiments, the front and rear tubes include a top tube 43, a down tube 44, and a middle tube. The middle tube is disposed between the top tube 43 and the down tube 44 in the height direction. The battery unit 20 is connected to both the down tube 44 and the middle tube.

[0087] By providing the middle tube, the battery unit 20 can be connected to two tubes while being positioned relatively low.

[0088] <Feature 9> In the electric bicycles 1 of the first to fifth embodiments, the battery holder 22 has an attachment portion 22a that allows the battery 21 to be slid in the vehicle width direction to attach and detach the battery 21.

[0089] The battery can be easily attached and detached even in a layout where there is no space in front of, behind, or above and below the battery holder.

[0090] <Feature 10> The electric bicycle 1 of the first to fifth embodiments includes a side stand 16 that is located on a first side in the vehicle width direction. The mounting portion 22a is configured so that the battery 21 slides toward the second side in the vehicle width direction when removed from the mounting portion 22a.

[0091] When the vehicle is standing on the side stand 16, the second side in the vehicle width direction faces slightly upward, making it easier to remove the battery.

[0092] <Feature 11> The electric bicycle 1 of the first to fifth embodiments includes a rear suspension 15. The upper end of the battery unit 20 is located lower than the upper end of the rear suspension 15.

[0093] The battery unit 20, which is a heavy object, can be placed at a lower position compared to the rear suspension.

[0094] <Feature 12> An electric vehicle such as the electric bicycle 1 of the first to third and fifth embodiments includes a front wheel 3, a rear wheel 4, a motor unit 30, a battery unit 20, and a frame 2. The motor unit 30 is disposed between the front wheel 3 and the rear wheel 4 in the front-to-rear direction, and includes an electric motor 32 and a motor case 31. The battery unit 20 includes a battery 21 that stores power to be supplied to the electric motor 32 and a battery holder 22, and is adjacent to the motor unit 30. The frame 2 includes a plurality of tubes. The frame 2 includes tubes including a down tube 44. In a side view, the battery unit 20 has a side that follows the down tube 44 and a side that follows tubes other than the down tube 44.

[0095] <Feature 13> The battery unit 20, which is a heavy object, is located at the center and bottom of the electric vehicle in the longitudinal direction, which allows for easy handling during cornering. Furthermore, the battery unit 20 has edges that run along the down tube and other tubes, allowing the battery unit 20 to be located at a low position by utilizing the gaps between the tubes. Furthermore, the other tubes can be tubes that intersect with the down tube 44.

[0096] The above-described features 1 to 13 can be combined as long as no contradiction occurs. For example, feature N (N=1, 2, ..., 13) can be combined with at least one of features 1 to N-1.

Claims

1. An electric bicycle comprising: a front wheel; a rear wheel; a motor unit arranged in a position not overlapping with the front wheel or the rear wheel in a side view and having an electric motor and a motor case; a battery unit having a battery and a battery holder for storing electricity to be supplied to the electric motor; a pair of pedals arranged on the left and right; and a crank for transmitting force applied to the pedals by a rider, wherein the lower end of the battery unit is positioned lower than the crank shaft which is the axis of rotation of the crank.

2. An electric bicycle as described in claim 1, wherein the motor unit is disposed between the front wheel and the rear wheel in the fore-and-aft direction, and at least a portion of the battery unit and at least a portion of the motor unit are disposed side-by-side in the fore-and-aft direction.

3. An electric bicycle as described in claim 1, wherein the battery unit has a portion located in front of the motor unit, and the battery unit has a portion located above or below the motor unit.

4. An electric bicycle as described in claim 1, wherein the longitudinal size of the battery unit is greater than or equal to 1 / 3 and less than or equal to 3 / 4 of the height size of the battery unit.

5. An electric bicycle as described in claim 1, wherein the battery unit and the motor unit are arranged adjacent to each other, and in at least a portion of the contour of the battery unit, the front and rear ends of the battery unit change so as to approach each other in the fore-and-aft direction as the height increases.

6. An electric bicycle according to claim 1, comprising a frame having a plurality of tubes, and in a side view, the battery unit has sides that run along at least two of the tubes.

7. An electric bicycle as claimed in claim 1, comprising a frame having a plurality of tubes, the frame including: a head tube; a seat tube; and a plurality of front and rear tubes arranged between the head tube and the seat tube in the fore-and-aft direction, the battery unit being arranged in an area surrounded by at least two of the tubes, and the battery unit being connected to at least two of the tubes.

8. An electric bicycle as described in claim 7, wherein the front and rear tubes include a top tube, a down tube, and a middle tube disposed between the top tube and the down tube in the height direction, and the battery unit is connected to both the down tube and the middle tube.

9. An electric bicycle as described in claim 1, wherein the battery holder is provided with an attachment portion that allows the battery to be slid in the vehicle width direction to attach and detach the battery.

10. An electric bicycle as described in claim 9, comprising a side stand arranged on a first side in the vehicle width direction, and the mounting portion is configured so that the sliding direction of the battery when removing the battery from the mounting portion is the second side in the vehicle width direction.

11. An electric bicycle according to claim 1, comprising a rear suspension, and wherein an upper end of the battery unit is located lower than an upper end of the rear suspension.

12. An electric vehicle comprising: front wheels; rear wheels; a motor unit arranged between the front and rear wheels in the fore-and-aft direction and having an electric motor and a motor case; a battery unit adjacent to the motor unit and including a battery and a battery holder for storing power to be supplied to the electric motor; and a frame having a plurality of tubes, wherein the frame has a plurality of tubes including a down tube, and in a side view, the battery unit has an edge that runs along the down tube and an edge that runs along the tubes other than the down tube.

13. An electric vehicle according to claim 12, wherein the battery unit has a side along the down tube and a side along the tube that intersects with the down tube.

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