Electric bicycle and electric vehicle

Abstract

To provide an electric bicycle battery layout for improving the handling thereof upon turning.SOLUTION: 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 so that it does not overlap the front wheel 3 and 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 for storing electric power to be fed to the electric motor 32; and a battery holder 22. The pedals 9 are arranged in pairs on the left and right. The crank 10 transmits force applied by a driver to the pedals 9. The bottom of the battery unit 20 is lower than a crank shaft 10a as the rotational shaft of the crank 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present application relates primarily to electric bicycles and electric vehicles, and more particularly to the layout of a battery unit provided in an electric bicycle or electric vehicle. [Background technology]

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

[0003] [Patent Document 1] JP 2023-30689 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the layout of Patent Document 1, the battery, which is a heavy object, is placed in a relatively high position, which may make the electric bicycle difficult to handle when turning. Furthermore, 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 consideration of the above circumstances, and its main object is to provide a battery layout for an electric bicycle that improves handling when turning. [Means for solving the problem]

[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 described.

[0007] In accordance with the aspects of the present application, there is provided an electric bicycle having the following configuration. That is, the electric bicycle comprises a front wheel, a rear wheel, a motor unit, a battery unit, pedals, and a crank. The motor unit is arranged in a position that does not overlap with the front wheel and the rear wheel in a side view, and has an electric motor and a motor case. The battery unit has a battery and a battery holder that stores electricity to be supplied to the electric motor. The pedals are arranged in a pair on the left and 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. Effect of the Invention

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

[0009] [Figure 1] FIG. 1 is a side view of an electric bicycle according to a first embodiment. [Diagram 2] FIG. 4 is a perspective view showing how a battery is attached to and detached from the battery holder. [Diagram 3] Block diagram of an electric bicycle. [Figure 4] FIG. 11 is a side view of an electric bicycle according to a second embodiment. [Diagram 5] FIG. 11 is a side view of an electric bicycle according to a third embodiment. [Figure 6] FIG. 13 is a side view of an electric bicycle according to a fourth embodiment. [Figure 7] FIG. 13 is a side view of an electric bicycle according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 seen by a rider riding the electric bicycle 1. Therefore, the front-rear direction coincides with the vehicle length direction, and the left-right direction coincides with the vehicle width direction. In addition, the vertical direction and the up-down direction coincide with the height direction.

[0011] The electric bicycle 1 shown in Fig. 1 is a vehicle (saddle-type vehicle) that a rider straddles and rides, and travels using the force applied by the rider to the pedals and the force generated by an electric motor. In particular, since the electric bicycle 1 of this embodiment is an electrically assisted bicycle, the electric motor generates force on the condition that the rider applies force to the pedals. However, the electric bicycle 1 is not limited to electrically assisted bicycles. In other words, the electric bicycle 1 may travel by generating force from the electric motor 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 parts of the electric bicycle 1 are attached to the frame 2. The frame 2 is formed by combining a number of tubes. Details of the frame 2 will be described later.

[0014] Each of the front wheels 3 and the 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. The inner tube is inserted into the outer tube, and the two are connected via a coil spring. The coil spring reduces the impact transmitted between the outer tube and the inner tube. This reduces the impact transmitted from the road surface to the frame 2 via the front wheel 3, i.e., the impact transmitted to the rider. The front fork 6 may be an air suspension that uses air to reduce impact. Also, the front fork 6 does not need 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, a handlebar, and a grip. The steering force by 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 his / her feet while holding the grips of the handle unit 7 with his / her hands to steer.

[0018] A crank 10 is connected to the pedal 9. The crank 10 is rotatable about 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 arranged near the rear axle 4a of the rear wheel 4. The sprocket 14 is fixed to the rear wheel 4, and the rear wheel 4 can be rotated by rotating the sprocket 14. As described above, the force applied by the rider to the pedal 9 is transmitted to the rear wheel 4 via the chain 13, causing the rear wheel 4 to rotate. Note that instead of a configuration in which the force is transmitted using the chain 13, the force may be transmitted using a shaft. In this case, for example, a helical gear structure may be used for power transmission 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 to a portion on the center side in the front-rear direction. This makes it possible to reduce 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 in the vehicle width direction of the rear wheel 4. 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 be made to stand on its own 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 fore-and-aft direction, more specifically, in the area rearward of the rear end of the front wheels 3 and forward 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 electric power. The battery 21 is configured by combining small cylindrical lithium ion rechargeable batteries, for example. 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. A method of combining multiple rechargeable batteries and treating them as one battery is well known, so an explanation 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 be used. The battery is not limited to a configuration in which multiple rechargeable batteries are combined, and a single rechargeable battery having a shape according to requirements 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 can attach and detach the battery 21. Specifically, as shown in FIG. 2, the battery holder 22 has an attachment portion 22a. The attachment portion 22a has a slide groove that slides the battery 21 in the vehicle width direction. In this embodiment, the slide direction of the battery 21 when attaching and detaching the battery 21 is determined, and the battery 21 cannot be attached or detached from a direction that is not determined. Specifically, the worker slides the battery 21 along the slide groove of the attachment portion 22a to the first side in the vehicle width direction. This allows the battery 21 to be attached to the attachment portion 22a. There are various attachment and detachment structures for the battery 21 and the attachment portion 22a, but for example, a snap fit can be used. In addition, 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 to the second side, thereby removing the battery 21 from the attachment portion 22a. Since the sliding direction is determined as described above, the worker performs the work of attaching and detaching the battery 21 to and from the second side surface of the electric bicycle 1.

[0026] By using a structure in which the battery 21 is slid in the vehicle width direction to be attached and detached, the battery 21 can be easily attached and detached even in a layout in which the periphery of the battery 21 is covered by the frame 2 or the like in a side view. This improves the degree of freedom in the layout of the frame 2 or the battery unit 20. In addition, the battery 21 is attached and detached in a state in which the electric bicycle 1 is self-supporting using the side stand 16. As described above, when the electric bicycle 1 is self-supporting, the electric bicycle 1 is slightly leaned over on the first side, so that the second side surface of the electric bicycle 1 faces slightly upward. Therefore, the work on the second side surface of the electric bicycle 1 is less burdensome than the work on the first side surface. In other words, by determining the above-mentioned sliding direction, the work of attaching and detaching the battery 21 can be easily performed.

[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 another 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 passing through the inside or outside of 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 at a position that does not overlap with the front wheels 3 and the rear wheels 4 in a side view. In detail, the motor unit 30 is disposed between the front wheels 3 and the rear wheels 4 in the front-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 via only one tube.

[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. Inside the motor case 31, an electric motor 32 and a motor driver 93 are housed.

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

[0034] The force generated by the electric motor 32 is transmitted to the motor sprocket via the reduction gear. The reduction gear and the motor sprocket may be disposed inside the motor case 31, or may be disposed outside the motor case 31 and in the vicinity of the chain ring 11. The chain 13 meshes with the motor sprocket. This allows the rear wheel 4 to be driven using the force generated by the electric motor 32. Since 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 applied to the pedal 9 by the rider, i.e., the pedal force, and outputs it to the control device 90. The vehicle speed sensor 92 is, for example, a rotation sensor provided on the front axle 3a or the rear axle 4a, and detects the rotation speed of the front axle 3a or the rear axle 4a, converts it into vehicle speed, and outputs it to the control device 90. Note that the control device 90 may convert from rotation speed to vehicle speed.

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

[0037] An example of the 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 can prevent the electric motor 32 from driving the rear wheel 4 when the driver is not putting his / her foot on the pedal 9. In addition, 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 magnitude of the drive current is adjusted according to the magnitude of the torque input from the pedal sensor 91. In addition, 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 is. This control is one example, and may be changed according to legal regulations, the region of use, and the like. In addition, when used for purposes other than electric assist, the magnitude of the drive current may be changed according to the driver's switch operation or lever operation, and 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. Each tube constituting the frame 2 is an elongated, cylindrical member. In the bicycle field, the name of the frame is called "tube," so it will also be called 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 collectively described.

[0040] 1, 4, 5, 6, and 7, the frame 2 in each embodiment includes a head tube 41, a seat tube 42, seat stays 45, and chain stays 46. The layout, connection destinations, and orientations of each tube are merely 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 with the front wheel 3 in the front-to-rear direction. A 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. A 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 at the rear of the frame 2 and are positioned so as to overlap the rear wheel 4 in a side view. The seat stays 45 are inclined so as to extend diagonally upward toward the front. 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. 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 chain stay 46 is located at the rear of the frame 2, overlapping with the rear wheel 4 in a side view, and below the seat stay 45. The chain stay 46 is disposed so as to extend in the front-to-rear direction. The front end of the chain stay 46 is rotatably connected to the seat tube 42. The chain stay 46 may be fixed so as not to rotate relative to the seat tube 42. Furthermore, when a part of the battery unit 20 or the motor unit 30 is used as the frame configuration, the front end of the chain stay 46 may be connected to the battery unit 20 or the motor unit 30. The rear end of the chain stay 46 is rotatably connected to the rear wheel 4.

[0045] The tubes disposed between the head tube 41 and the seat tube 42 in the front-rear direction are referred to as front-rear tubes. The frame 2 includes a top tube 43 and a down tube 44 as main front-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 located at the highest position among the front and rear tubes. As shown in each embodiment, the top tube 43 may be straight or 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 configuration, 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 among the front and rear tubes. As shown in each embodiment, the down tube 44 may be straight or bent. Alternatively, the down tube 44 may include a curved portion.

[0048] Of the front and rear tubes, a tube that is disposed 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. Also, multiple middle tubes of the same type may be provided.

[0049] The first middle tube 51 connects the head tube 41 and the seat tube 42. The first middle tube 51 is shown in FIG. 4 and FIG. 5. The second middle tube 52 connects the seat tube 42 and the top tube 43. The second middle tube 52 is shown in FIG. 1 and FIG. 6. The third middle tube 53 connects the seat tube 42 and the down tube 44. The third middle tube 53 is shown in FIG. 1 and FIG. 7. The fourth middle tube 54 connects the top tube 43 and the down tube 44. The fourth middle tube 54 is shown in FIG. 1, FIG. 6, and FIG. 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 FIG. 4 and FIG. 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 FIG. 4 and FIG. 5.

[0050] Next, a description will be given of the shape and layout of the battery unit 20. In the following description, the shape and layout of the battery unit 20 will be described when the electric bicycle 1 is stopped and upright, and only the weight of the electric bicycle 1 is applied to the suspension. Furthermore, unless otherwise specified, the following description will be of the shape and layout as viewed from the side.

[0051] Ideally, to improve the dynamic characteristics of the electric bicycle 1, particularly the ease of handling when turning, it is preferable for the weight to be concentrated in a low position in the center in the fore-and-aft 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 ease of 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. In the conventional shape, the weight of the battery unit 20 is distributed in the height direction or the front-rear direction. In contrast, the battery unit 20 of each embodiment has a shape that spreads out in a balanced manner in the height direction or the front-rear direction. Specifically, the front-rear size of the battery unit 20 relative to its height direction size is 1 / 3 or more and 3 / 10 or less. Therefore, the weight of the battery unit 20 is not distributed much, and the movement characteristics of the electric bicycle 1 are improved. The height direction size is the length from the top end to the bottom end of the battery unit 20. The front-rear direction size is 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 in consideration of the shape of the frame 2 or the motor unit 30, i.e., 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 are polygonal. The battery units 20 of the second, third, and fourth embodiments are polygonal in shape, with a portion of the shape (the shape of the portion interfering with the motor unit 30) removed. Note that the polygonal shape includes an approximately polygonal shape.

[0055] Also, the battery unit 20 of some embodiments includes a portion that becomes smaller as it approaches the top. Strictly speaking, it includes a portion where the front end and the rear end of the battery unit 20 approach each other in the front-rear direction as it moves upward. In other words, at least a part of the contour of the battery unit 20 changes so that the front end and the rear end of the battery unit 20 approach each other in the front-rear direction as the height increases. For example, the upper part of the battery unit 20 of the first embodiment is triangular, so it has a portion that becomes smaller as it approaches the top. The upper part of the battery unit 20 of the second and third embodiments has a portion that becomes smaller as it approaches the top because the upper base is shorter than the lower base. 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 has a portion that becomes smaller as it approaches 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 makes it easier to handle the electric bicycle 1 when turning. Note that 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.

[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 wheels 3 and the rear wheels 4 in the front-rear direction, so the battery unit 20 is located in the center in the front-rear direction. Also, the lower end of the battery unit 20 is located lower than the crankshaft 10a, so the battery unit 20 is located at the bottom in the height direction. As a result, the battery units 20 are concentrated in the center in the front-rear 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. Also, the upper end of the battery unit 20 is located lower than the upper end of the front wheel 3.

[0060] Moreover, 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 chain stay 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. Moreover, the upper end of the battery holder 22 in each embodiment is located in the center region or the 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 holder 22 is concentrated in the center in the front-rear 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 unit 30 is also concentrated in the center in the front-rear direction and at a low position in the height direction. The motor unit 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-rear direction coincide with each other as in the second to fifth embodiments. In this specification, "coincidence" includes not only a 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 as to be concentrated in the center in the front-rear 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 front-rear 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 lower end of the top tube 43 and lower than the center in the longitudinal direction of the seat tube 42. Moreover, 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 part of the battery unit 20 and at least a part of the motor unit 30 are adjacent to each other in the front-rear direction. In the second to fifth embodiments, at least a part of the battery unit 20 and at least a part 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 part adjacent to the motor unit 30 in the front-rear direction and a part adjacent to the motor unit 30 in the up-down direction. More specifically, a part of the battery unit 20 is located in front of the motor unit 30, and a part of the battery unit 20 is located above the motor unit 30. By having at least one of the above-mentioned features, the battery unit 20 can be efficiently arranged in consideration of the shape of the motor unit 30. Note that a part 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-rear direction, and a part 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 disposed at a position lower than the top tube 43. Also, the battery units 20 other than those of the fourth embodiment have a portion that fits along multiple front and rear frames, and are further connected to multiple front and rear frames. This allows the battery unit 20 to be disposed by utilizing the gap between the frames. Therefore, the capacity of the battery 21 is likely to be large. Also, by being connected to multiple front and rear frames, the battery unit 20 can be firmly connected. Also, 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 connected to the down tube 44, in other words, they correspond to tubes that intersect with the down tube 44.

[0067] The above-described layout is one example, and any one or more of the tubes constituting the frame 2 can be selected, and the battery unit 20 can be arranged along or connected to the selected tubes. The tubes to be selected can include the down tube 44 in order to place the battery unit 20 in a low position. Alternatively, the seat tube 42, which is assumed to be located near the crank 10 or the motor unit 30, or a middle tube (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 at 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 even if only one of them is used, the same effect can be achieved.

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

[0070] The above-mentioned features can be applied to electric vehicles other than electric bicycles, for example, electric motorcycles. In this case, the pedals 9 and cranks 10 can be removed from the electric bicycle 1 of the above embodiment, and a footrest or step can be provided to place the feet. The grip of the handle unit 7 can be changed to a throttle grip and electrically connected to the control device 90. The other parts can be the same as those of the electric bicycle 1 of the above embodiment. Note that since electric motorcycles themselves are well known, illustrations and detailed explanations will be omitted. The electric vehicle to which the present invention is applicable may be an electric three-wheeler equipped with two front or two rear wheels.

[0071] From another perspective, since the above-mentioned features contribute to maneuverability during turning, it is also preferable to apply the present invention to a saddle-type vehicle or a lean-type vehicle, in which maneuverability during turning is important. A lean-type vehicle is a vehicle that turns by tilting the body toward the inside of the turning direction.

[0072] <Feature 1> As described above, the electric bicycle 1 of the first to fourth embodiments includes the front wheel 3, the rear wheel 4, the motor unit 30, the battery unit 20, the pedals 9, and the crank 10. The motor unit 30 is disposed in a position that does not overlap with the front wheel 3 and 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 electricity to be supplied to the electric motor 32, and a battery holder 22. The pedals 9 are disposed in a pair on the left and right. 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 crank shaft 10a, which is the rotation axis 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 maneuverability 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 front-rear 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 front-rear direction.

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

[0076] <Feature 3> In the electric bicycle 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 bicycle 1 of the first to fifth embodiments, the size of the battery unit 20 in the front-rear direction relative to the size of the battery unit 20 in the height direction is 1 / 3 or more and 3 or less.

[0079] This prevents the size of the battery unit 20 from becoming too long in the height direction or the front-to-rear direction, so that the center of gravity of the electric bicycle 1 can 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. In at least a portion of the contour of the battery unit 20, the front end and rear end of the battery unit 20 change so as to approach each other in the front-to-rear direction as the height increases.

[0081] As a result, the lower part of the battery unit 20 tends to be larger than the upper part, so that the center of gravity of the electric bicycle 1 can be lowered.

[0082] <Feature 6> The electric bicycle 1 of the first to fifth embodiments includes a frame 2 having a plurality of tubes. In a side view, the battery unit 20 has sides that run along at least two of the tubes.

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

[0084] <Feature 7> The electric bicycle 1 of the first to fifth embodiments includes a frame 2 having a plurality of tubes. The frame 2 includes a head tube 41, a seat tube 42, and a plurality of front and rear tubes. The front and rear tubes are disposed between the head tube 41 and the seat tube 42 in the fore-and-aft direction. A battery unit 20 is disposed in an area surrounded by at least two tubes. The battery unit 20 is connected to the 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 is provided with 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 disposed on a first side in the vehicle width direction. The mounting portion 22a is configured so that the sliding direction of the battery 21 when removing the battery 21 from the mounting portion 22a is the second side in the vehicle width direction.

[0091] When the vehicle is supported 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 in 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 disposed 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 has 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] Since the battery unit 20, which is a heavy object, is disposed at the center and lower part in the front-rear direction of the electric vehicle, it can be easily handled when turning. Also, since the battery unit 20 has sides that run along the down tube and other tubes, the battery unit 20 can be disposed in a low position by utilizing the gap between the tubes. Also, as the other tube, a tube that intersects with the down tube 44 can be used (Feature 13).

[0096] The above-mentioned 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. [Explanation of symbols]

[0097] 1. Electric bicycle 3 Front wheel 4 Rear Wheel 9 Pedals 10. Crank 20 Battery Unit 21 Battery 22 Battery holder 30 Motor unit 31 Motor case 32 Electric motor

Claims

1. The front wheel and The rear wheel and a motor unit that is disposed at a position not overlapping with the front wheels and the rear wheels in a side view and includes an electric motor and a motor case; a battery unit including a battery and a battery holder for storing power to be supplied to the electric motor; Pedals arranged in pairs on the left and right, A crank that transmits the force applied by the driver to the pedal; Equipped with An electric bicycle, wherein a lower end of the battery unit is located lower than a crank shaft which is the rotation axis of the crank.

2. 2. The electric bicycle according to claim 1, the motor unit is disposed between the front wheels and the rear wheels in the front-rear direction; An electric bicycle, wherein at least a portion of the battery unit and at least a portion of the motor unit are arranged side by side in the front-to-rear direction.

3. 2. The electric bicycle according to claim 1, the battery unit has a portion located in front of the motor unit, An electric bicycle, wherein the battery unit has a portion located above or below the motor unit.

4. 2. The electric bicycle according to claim 1, An electric bicycle, wherein the size of the battery unit in the front-rear direction relative to the size of the battery unit in the height direction is 1 / 3 or more and 3 or less.

5. 2. The electric bicycle according to claim 1, The battery unit and the motor unit are disposed adjacent to each other, An electric bicycle, wherein in at least a portion of the contour of the battery unit, the front end and rear end of the battery unit change so as to come closer together in the front-to-rear direction as the height increases.

6. 2. The electric bicycle according to claim 1, A frame having a plurality of tubes, An electric bicycle, wherein, when viewed from the side, the battery unit has at least two sides that extend along the tubes.

7. 2. The electric bicycle according to claim 1, A frame having a plurality of tubes, The frame is The head tube and Seat tube and a plurality of front and rear tubes disposed between the head tube and the seat tube in a front-rear direction; Including, The battery unit is disposed in an area surrounded by at least two of the tubes; An electric bicycle, wherein the battery unit is connected to at least two of the tubes.

8. 8. An electric bicycle according to claim 7, The front and rear tubes are The top tube and Down tube and a middle tube disposed between the top tube and the down tube in a height direction; Including, The battery unit is connected to both the down tube and the middle tube.

9. 2. The electric bicycle according to claim 1, 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. 10. The electric bicycle according to claim 9, A side stand is provided on a first side in a vehicle width direction, An electric bicycle, wherein 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. 2. The electric bicycle according to claim 1, Equipped with rear suspension, An electric bicycle, wherein an upper end of the battery unit is located lower than an upper end of the rear suspension.

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

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

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