Battery unit for electric bicycles and electric folding bicycles

Abstract

To prevent a battery case from being displaced even if there are rough driving operations and the unevenness of a road surface so as to stabilize a current flow at an electrical connection portion and a power feeding to a motor driving unit.SOLUTION: A battery device includes: an attachment base that is fastened on a handle; and a battery case 8 that is placed on the attachment base so as to be detachable. An electrical connection portion 60 that electrically connects a motor driving unit and a battery together is provided at a position where the attachment base and the battery case 8 face with each other. Right and left guide portions each having guiding surfaces at an external side, an upper side and a lower side, and a latch bolt pushed so as to protrude from an upper surface of the attachment base are provided on the attachment base. Right and left side portions 80 each including sliding surfaces 81 to 83 which are engaged with the external, upper and lower guiding surfaces of each guide portion, respectively, and which are slidable along the respective guiding surfaces, and a latch hole 104 where the latch bolt is fitted in are provided at a lower surface of the battery case 8.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a battery device for an electric bicycle for supplying power to a motor drive unit mounted on the electric bicycle. In particular, the present invention relates to a battery device suitable for an electric bicycle that can be folded (hereinafter referred to as an "electric folding bicycle"), and an electric folding bicycle equipped with the battery device.

Background Art

[0002] An electric bicycle is equipped with a battery device using a rechargeable battery such as a lithium-ion battery. Conventionally, since a large-capacity battery is used for that type of battery device, the weight increases, and in consideration of the balance of the vehicle body, it is installed near the center of gravity position of the electric bicycle, for example, in a space sandwiched between the upper post and the lower post of the electric bicycle.

[0003] The applicant has previously proposed a small battery device suitable for an electric folding bicycle and capable of traveling a minimum required distance. This battery device has a mounting base fixed on the handle and a battery case removably mounted on the mounting base. Between the mounting base and the battery case, there are provided an electrical connection part for electrically connecting between the motor drive part and the battery, and a holding mechanism part for positioning the battery case on the mounting base and holding it in a state where the electrical connection part is connected (see, for example, Patent Document 1).

[0004] The electrical connection part includes a first connection terminal provided on the upper surface of the mounting base and a second connection terminal provided on the lower surface of the battery case. When the first and second connection terminals come into contact, the motor drive part and the battery are electrically connected. The holding mechanism consists of a first permanent magnet located around the electrical connection part of the mounting base and a second permanent magnet located around the electrical connection part of the battery case. A magnetic attraction force acts between the first and second permanent magnets, causing the battery case to be positioned on the mounting base and held in a connected state. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-93908 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In electric folding bicycles with the above configuration, if sudden steering or braking occurs frequently while riding, the battery case may be displaced on the mounting base in the left-right and front-back directions. Furthermore, if there are large bumps or unevenness in the road surface, the vehicle body may rattle up and down while driving, and the battery case may vibrate up and down on the mounting base. When the battery case is displaced in any direction—left / right, front / back, or up / down—the contact between the first and second connection terminals becomes unstable, causing intermittent power supply to the electrical connection and resulting in unstable power supply to the motor drive unit.

[0007] This invention addresses the above-mentioned problems and aims to provide an electric bicycle battery device that prevents the battery case from displacing in the left / right, front / back, and up / down directions, even with rough driving operations or uneven road surfaces, and ensures stable power supply to the electrical connection and motor drive unit, as well as an electric folding bicycle equipped with this battery device. [Means for solving the problem]

[0008] The battery device for an electric bicycle according to this invention includes a mounting base fixed to the handlebars of the electric bicycle, and a battery case that is detachably mounted on the mounting base and has a battery storage compartment and battery charging terminals. An electrical connection part is provided at a position where the mounting base and the battery case face each other, electrically connecting the motor drive unit of the electric bicycle and the battery. The mounting base is provided with left and right guide parts having outer and upper and lower guide surfaces, and a latch bolt that is biased upward and can be pushed downward so as to protrude from the upper surface of the mounting base. The lower surface of the battery case is provided with left and right sliding parts having sliding surfaces that engage with the outer and upper and lower guide surfaces of each of the left and right guide parts and can slide in the front-rear direction along each guide surface, and a latch hole into which the latch bolt fits.

[0009] Before riding the electric bicycle, the battery is charged by connecting an external power source to the charging terminals of the battery case, and then the battery case is placed on a mounting base fixed to the handlebars. This electrically connects the electric bicycle's motor drive unit and the battery via an electrical connection, and power is supplied to the motor drive unit from the battery in the battery case. When riding is finished, the battery case is removed from the mounting base, disconnecting the electrical connection and stopping the power supply to the motor drive unit. After removal, the battery case is carried with the user, so the battery unit is not subject to theft.

[0010] To mount the battery case onto the mounting base, the left and right sliding parts on the underside of the battery case are engaged from the outside with the left and right guide parts on the mounting base, and the sliding surfaces of the sliding parts are slid along the guide surfaces of the guide parts. Since the sliding parts engage with the outer and upper and lower guide surfaces of the guide parts, displacement of the battery case in the left, right and up and down directions is prevented by rough driving operations or uneven road surfaces. Furthermore, when the battery case is slid, the latch bolts protruding from the mounting base engage with the latch holes on the underside of the battery case, thereby preventing the battery case from being displaced in the front-to-back direction. During operation, the battery case does not displace in any direction (left / right, up / down, forward / backward), ensuring stable power supply to the electrical connections and the motor drive unit.

[0011] In a preferred embodiment, the electrical connection portion consists of a connection terminal provided so as to protrude forward between the left and right guide portions of the mounting base, an insertion hole provided between the left and right sliding portions of the battery case so as to allow insertion and removal of the connection terminal, and a terminal plate disposed within the insertion hole.

[0012] According to this embodiment, when the battery case is moved in the front-to-back direction on the mounting base, the connection terminals are inserted into and removed from the insertion holes, thereby connecting or disconnecting the connection terminals from the terminal board.

[0013] In a preferred embodiment, the latch bolt is located at the front end of the mounting base, and an operating lever is provided on one side of the mounting base for pushing down the latch bolt to release it from engaging with the latch hole.

[0014] When the latch bolt is engaged with the latch hole, the battery case is positioned on the mounting base. By operating the operating lever, the latch bolt is released from the latch hole, allowing the battery case to be moved on the mounting base and removed.

[0015] In a preferred embodiment, the sliding portion has multiple reinforcing ribs integrally formed in the longitudinal direction at intervals.

[0016] According to this embodiment, the sliding portion is strengthened by reinforcing ribs, thereby preventing deformation or damage to the sliding portion due to sliding or engagement.

[0017] The scope of this invention includes, in addition to the battery device described above, an electric folding bicycle equipped with the battery device described above. Since the battery case is attached to the mounting base fixed on the handle, the electric folding bicycle looks good and it is easy to attach and remove the battery case.

Advantages of the Invention

[0018] According to this invention, against rough driving operations and road surface irregularities, the battery case does not displace in the left - right, up - down, and front - rear directions, and the power supply at the electrical connection part and the power supply to the motor drive part are stable.

Brief Description of the Drawings

[0019] [Figure 1] It is a front view showing the appearance of an electric folding bicycle to which a battery device is attached. [Figure 2] It is a perspective view showing the fixing base of the battery device. [Figure 3] It is a plan view of the battery case seen from above. [Figure 4] It is a perspective view showing the lower surface of the battery case. [Figure 5] It is a side view of one side of the battery device. [Figure 6] It is a side view of the other side of the battery device. [Figure 7] It is a rear view showing the state where the battery case is placed on the mounting base. [Figure 8] It is a front view showing the state where the battery case is placed on the mounting base. [Figure 9] It is a cross - sectional view showing the engagement state between the guide part of the mounting base and the slide part of the battery case.

Modes for Carrying Out the Invention

[0020] Figure 1 shows one embodiment of the electric folding bicycle 1. This invention is applicable not only to electric folding bicycles with a folding structure, but also to electric bicycles without a folding structure. The electric folding bicycle 1 is equipped with a motor drive unit 5, which is an auxiliary drive device, and a battery device 6 that supplies power to the motor drive unit 5. The top tube 11, which forms the center of the frame 10, has a structure that allows it to be folded in half approximately in the middle of its length. The folded portion is joined by a joint 2. The joined state of the joint 2 can be fixed or released by operating a lever 20.

[0021] At the rear end of the top tube 11, a pair of rear forks 13L and 13R are provided via a seat tube 12 that faces vertically. The top tube 11 and the seat tube 12, and the seat tube 12 and the left and right rear forks 13L and 13R are integrally connected by welding. At the front end of the top tube 11, a pair of front forks 15L and 15R are provided via a head tube 14 that faces vertically. The head tube 14 is also foldable, and the folded portion is connected by a joint 21 having a lever 22. The top tube 11 and the head tube 14, and the head tube 14 and the left and right front forks 15L and 15R are integrally connected by welding.

[0022] A seatpost 16 is supported on the seat tube 12 in an adjustable height manner. A saddle 16a is attached to the upper end of the seatpost 16. A stem 17 is supported on the head tube 14 in an adjustable height manner. A handlebar 19 is provided at the upper end of the stem 17. The left and right rear forks 13L and 13R extend diagonally downward, and the rear wheel 3 is supported to rotate freely between their rear ends. The left and right front forks 15L and 15R extend almost straight down, and the front wheel 30 is supported to rotate freely between their lower ends.

[0023] The seat tube 12 is equipped with a series of extensions 12a that extend downward. A support pipe 18 is welded to the lower rear surface of the top tube 11, and a bearing cylinder 40 is welded between the lower end of the extension 12a and the lower end of the support pipe 18. The bearing cylinder 40 supports the drive shaft 4 so that it can rotate freely. Crank arms 41 are attached to both ends of the drive shaft 4. Pedals 42 are attached to the ends of each crank arm 41. Rotational driving force is transmitted to the drive shaft 4 from the motor drive unit 5. The rotation of the drive shaft 4 and the crank arms 41 is transmitted to the rear wheel 3 via the chain 43.

[0024] The top tube 11, seat tube 12, rear forks 13L, 13R, head tube 14, and front forks 15L, 15R constitute the frame 10 of the electric folding bicycle 1. Each component of the frame 10 is made of wrought aluminum alloy. It is also possible to make the top tube 11 and rear forks 4L, 4R, or all components of the frame 10, from wrought magnesium alloy.

[0025] A battery unit 6 is mounted on the center of the handlebars 19 of the electric folding bicycle 1. The battery unit 6 in the illustrated example has a small battery capacity, is small and lightweight, so it can be installed on the handlebars 19, which is far from the center of gravity of the electric folding bicycle 1.

[0026] The battery unit 6 includes a metal mounting base 7, such as aluminum, fixed to the handlebars 19, and a synthetic resin battery case 8 that is removablely mounted on the mounting base 7. Connection terminals 61, 61 (details described later) assembled on the mounting base 7 are electrically connected to the motor drive unit 5 via a wire 51. The wire 51 passes inside the stem 17 and head tube 14, is then brought out to the outside, and then passes inside the top tube 11 and support pipe 18 to connect to the motor drive unit 5.

[0027] As shown in Figures 2 and 5 to 7, the mounting base 7 comprises a mounting plate 71, a retaining plate 72 screwed to the rear side of the upper surface of the mounting plate 71, and a mounting base 70 attached to the front side of the upper surface of the mounting plate 71 by screwing or adhesive. A concave curved support groove 73 is formed in the left-right direction on the rear upper surface of the mounting plate 71, and a through hole (not shown) is provided in the vertical direction, through which the stem 17 passes. The outer surface of the stem 17 and the lower surface of the mounting plate 71 are welded together to form a single unit. The handle 19 is horizontally supported on the support groove 73, and the retaining plate 72 is placed over the handle 19. The retaining plate 72 and the mounting plate 71 are screwed together at the four corners.

[0028] The battery case 8 is mounted and supported on the upper surfaces of the retaining plate 72 and the mounting base 70. The mounting base 70 has a main body portion 70A that is fixed on a fixed substrate 71. A support plate portion 70B is integrally provided on the upper surface of the main body portion 70A. The support plate portion 70B has approximately the same width as the fixed substrate 71, and its front end extends to approximately the same position as the front end of the fixed substrate 71. The rear end surfaces of the main body portion 70A and the support plate portion 70B abut against the front end surface of the retaining plate 72. The upper surface of the support plate portion 70B is continuous with the upper surface of the retaining plate 72.

[0029] The mounting base 70 has a latch mounting portion 70C that protrudes forward from the front end of the fixed base plate 71. The latch mounting portion 70C protrudes downward along the front end surface of the fixed base plate 71, and its protruding portion abuts against the front end surface of the fixed base plate 71. The latch mounting portion 70C is provided with a latch mounting hole 74 in the vertical direction for supporting the latch bolt 100 to move freely up and down. The latch mounting hole 74 opens on the upper surface of the latch mounting portion 70C.

[0030] A latch bolt 100 and a compression spring (not shown) are inserted into the latch mounting hole 74. The spring biases the latch bolt 100 upward so that it protrudes from the upper surface of the latch mounting portion 70C and supports it so that it can be pushed down. The upper end of the latch bolt 100 is formed on an inclined surface 101 at the front and a vertical surface 102 at the rear. When the inclined surface 101 is pressed, the latch bolt 100 is pushed down, but when the vertical surface 102 is pressed, the latch bolt 100 is not pushed down and maintains its protruding state. An operating lever 103 is provided on one side of the latch mounting portion 70C, which is connected to the latch bolt 100 and is used to forcibly push down the latch bolt 100.

[0031] On both end faces of the support plate portion 70B of the mounting base 70, left and right guide portions 75 are formed in a strip-like shape at symmetrical positions on the left and right. Each guide portion 75 protrudes forward at its front end, with the outer vertical surface being the first guide surface 76 and the upper and lower horizontal surfaces being the second and third guide surfaces 77 and 78, respectively. As shown in Figure 9, the left and right sliding portions 80 of the battery case 8, which will be described later, engage freely with the first to third guide surfaces 76, 77, and 78 of each guide portion 75 from the outside in the front-rear direction.

[0032] At the position where the mounting base 70 and the battery case 8 (described later) face each other, an electrical connection section 60 is provided for electrically connecting the motor drive unit 5 of the electric folding bicycle 1 and the battery via a cord 51. The electrical connection section 60 in this embodiment consists of a plurality of connection terminals 61 that protrude forward between the left and right guide sections 75, 75 of the support plate section 70B, an insertion hole 62 provided on the lower surface of the battery case 8 (described later), and a connection terminal plate 63 arranged inside the insertion hole 62, with the cord 51 connected to the connection terminals 61.

[0033] As shown in Figure 3, the battery case 8 has a rectangular shape in plan view, with a small thickness relative to its length and width, and is flattened. Although not shown in the figure, the battery case 8 has a battery storage compartment inside. The battery storage compartment houses a battery consisting of multiple lithium-ion batteries.

[0034] Inside the battery case 8 is a circuit board (not shown) on which a battery charging / discharging circuit, an LED lighting circuit, an LED display circuit, a power supply circuit, and a switch switching circuit are mounted. The battery charging / discharging circuit controls the charging and discharging of the battery. The LED lighting circuit controls the lighting operation of the LED 85 (shown in Figure 8), which will be described later, for illumination. The LED display circuit controls the lighting operation of the LEDs that make up the LED display unit 89, which will be described later. The power supply circuit outputs power voltage from the battery to the USB terminal 84 for power supply, which will be described later. The switch switching circuit enables operation of any of the above circuits in response to the operation of the switch 86, which will be described later.

[0035] As shown in Figures 4 and 9, left and right sliding parts 80 are provided parallel to each other at a predetermined distance from each other at both ends of the lower surface of the battery case 8. Each sliding part 80 has a U-shaped cross-section perpendicular to the longitudinal direction, with the vertical inner surface being the first sliding surface 81 and the upper and lower substantially horizontal inner surfaces being the second and third sliding surfaces 82 and 83. The left and right sliding parts 80 engage from the outside with the guide parts 75 formed on both end faces of the support plate part 70B of the mounting base 70. The first sliding surface 81 can slide in the front-rear direction along the first guide surface 76 on the outside of the guide part 75, and the second and third sliding surfaces 82 and 83 can slide in the front-rear direction along the upper and lower second and third guide surfaces 77 and 78 of the guide part 75.

[0036] The distance D1 between the first sliding surfaces 81, 81 of the left and right sliding parts 80 is approximately equal to the distance d1 between the first guide surfaces 76, 76 of the left and right guide parts 75. Also, the distance D2 between the second and third sliding surfaces 82, 83 of the left and right sliding parts 80 is approximately equal to the distance d2 between the second and third guide surfaces 77, 78 of the left and right guide parts 75. As a result, the left and right sliding parts 80 engage tightly with the left and right guide parts 75 from the outside, restricting the displacement of the battery case 8 in the left and right and up and down directions. As shown in Figures 4 to 6, multiple reinforcing ribs 87 are integrally formed on the outer surface of each sliding portion 80 in the vertical direction at intervals.

[0037] Between the left and right sliding parts 80, 80 on the lower surface of the battery case 8, a terminal board assembly part 88 is integrally formed, having a thickness approximately equal to the height of the sliding parts 80. The terminal board assembly part 88 has a plurality of insertion holes 62 that open from the front end surface to the lower surface. Each insertion hole 62 allows for the insertion and removal of a plurality of connection terminals 61 provided between the left and right guide parts 75, 75 on the upper surface of the mounting base 70. A terminal board 63 that makes electrical contact with the connection terminal 61 is placed in each insertion hole 62, and the motor drive unit 5 and the battery are electrically connected by the contact between the connection terminal 61 and the terminal board 63. Note that the electrical connection part 60 is not limited to a plug and socket type as in this embodiment, but may also be a type in which terminal boards make surface contact with each other.

[0038] A latch hole 104 is provided on the rear side of the terminal board assembly portion 88, into which a latch bolt 100 is tightly fitted. When the left and right sliding portions 80 are slid along the left and right guide portions 75 to the end position of the guide portions 75, the latch bolt 100 engages with the latch hole 104, thereby positioning the battery case 8 on the mounting base 70 and restricting the displacement of the battery case 8 in the front-rear direction.

[0039] As shown in Figure 3, a charging terminal 64 connected to a battery charging / discharging circuit is provided on one side of the battery case 8. Charging from an external power source is performed by connecting a charging device to this charging terminal 64. On the other side of the battery case 8, a USB terminal 84 for power supply is provided, which can supply power to smartphones and other devices. Each charging terminal 64 and USB terminal 84 is covered with rubber covers 64a, 84a. As shown in Figure 8, an LED 85 for illumination is provided on the front end surface of the battery case 8. The illumination operation of this LED 85 is controlled by an LED lighting circuit.

[0040] As shown in Figure 3, a switch 86 and an LED display unit 89 are provided on the top surface of the battery case 8. This switch 86 constitutes a switching circuit. When the switch 86 is pressed once, the battery charging / discharging circuit, power supply circuit, and LED display circuit are turned on. When the switch 86 is pressed again, the LED lighting circuit is turned on, and the illumination LED 85 shown in Figure 8 lights up. Pressing and holding the switch 86 turns all circuits off. When the LED display unit 89 is turned on by the switch 86, the number of LEDs corresponding to the remaining charge of the battery 81 lights up.

[0041] Prior to riding the electric folding bicycle 1, the battery is charged by connecting a charging device to the charging terminal 64 provided on the battery case 8. The charging device generally has a plug that plugs into an electrical outlet at one end, a plug that plugs into the charging terminal 64 at the other end, and an AC / DC converter in between.

[0042] After charging the battery, the battery case 8 is placed on the mounting base 70. First, the left and right sliding parts 80 on the lower surface of the battery case 8 are engaged from the outside with the left and right guide parts 75 on the upper surface of the mounting base 70, and the first to third sliding surfaces 81, 82, 83 of the sliding part 80 are slid along the first to third guide surfaces 76, 77, 78 of the guide parts 75. As the battery case 8 moves relative to the mounting base 70, the connection terminals 61 are inserted into the insertion holes 62, and the connection terminals 61 make contact with the terminal plate 63, thereby establishing an electrical connection.

[0043] Since the sliding portion 80 engages tightly with the first guide surface 76 on the outside of the guide portion 75 and the upper and lower second and third guide surfaces 77 and 78, displacement of the battery case 8 in the left-right and up-down directions is prevented by rough driving operations or uneven road surfaces. Furthermore, when the battery case 8 is slid, the latch bolts protruding from the mounting base 70 tightly engage with the latch holes 104 on the lower surface of the battery case 8, thereby preventing the battery case 8 from being displaced in the front-rear direction. During operation, the battery case 8 does not displace in any direction (left / right, up / down, forward / backward), ensuring stable power supply to the electrical connection section 60 and power supply to the motor drive section 5.

[0044] When the electric folding bicycle 1 has finished riding, the battery case 8 can be removed from the mounting base 70 by moving it in the opposite direction from when it was installed relative to the mounting base 70. As a result, the connection terminal 61 of the electrical connection part 60 separates from the terminal plate 63 and becomes non-conductive, stopping the power supply from the battery to the motor drive unit 5. By carrying the removed battery case 8 with you, the battery case 8 will not be stolen. [Explanation of Symbols]

[0045] 1. Electric folding bicycle 5. Motor drive unit 6. Battery device 8 Battery Case 19 Handle 60 Electrical connection 61 Connection terminals 62 insertion holes 63 Terminal board 64 Charging terminal 70 Mounting base 75 Guide section 76.77.78 Information Panel 80 Slide section 81, 82, 83 Sliding surface 100 Latch bolts 103 Operating lever 104 Latch holes

Claims

1. A battery device for an electric bicycle, comprising a mounting base fixed to the handlebars of the electric bicycle, and a battery case detachably mounted on the mounting base and equipped with a battery storage compartment and battery charging terminals, An electrical connection part is provided at a position where the mounting base and the battery case face each other, electrically connecting the motor drive unit of the electric bicycle and the battery; the mounting base is provided with left and right guide parts having guide surfaces on the outside and top and bottom, and a latch bolt that is biased upward and can be pushed downward so as to protrude from the top surface of the mounting base; the bottom surface of the battery case is provided with left and right sliding parts having sliding surfaces that engage with the outer and top and bottom guide surfaces of each of the left and right guide parts and can slide in the front-rear direction along each guide surface, and a latch hole into which the latch bolt fits. An operating lever for pushing down the latch bolt and releasing the engagement with the latch hole is provided on one side of the mounting base. Battery unit for electric bicycles.

2. The battery device for an electric bicycle according to claim 1, wherein the electrical connection portion comprises a connection terminal provided so as to protrude forward between the left and right guide portions of the mounting base, an insertion hole provided between the left and right sliding portions of the battery case so as to be able to insert and remove the connection terminal, and a terminal plate disposed within the insertion hole.

3. The battery device for an electric bicycle according to claim 1, wherein the latch bolt is positioned at the front end of the mounting base.

4. The battery device for an electric bicycle according to claim 1, wherein a plurality of reinforcing ribs are integrally formed in the sliding portion in the vertical direction at intervals.

5. An electric folding bicycle equipped with the battery device described in any one of claims 1 to 4.

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