JP3676226B2 - Battery pack for electric vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a battery pack for an electric vehicle that is mounted on an electric vehicle such as an assist bicycle and supplies electric power to a driving motor.
[0002]
[Prior art]
The assist bicycle is built in so that the battery pack can be attached to and detached from a vertical frame having a saddle fixed to the upper end. An assist bicycle incorporating a battery pack here can stably travel because a heavy battery pack is disposed near the center of gravity. The battery pack housed here is manufactured in an elongated shape so that it can be built into the frame in an upright position. In this battery pack, a battery core connecting a plurality of batteries in an elongated shape is housed in a case. The battery core is connected to the discharge connector and the charge connector with lead wires, and these connectors are fixed to the upper and lower ends of the case. A discharge plug is inserted into the discharge connector, and a charge plug is inserted into and connected to the charge connector. The discharge plug is connected to the motor and supplies power to the motor. The charging plug is connected to the charger when charging the battery pack. Furthermore, the battery pack of the assist bicycle includes a display unit that calculates and displays the remaining amount of the battery. The battery pack is charged while attached to the bicycle, or removed from the bicycle and charged.
[0003]
[Problems to be solved by the invention]
In addition, battery packs for assist bicycles control charge / discharge to prevent overcharge and overdischarge of the battery, or calculate the remaining amount of battery to display the distance that the bicycle can travel with the battery. Built-in printed circuit board for mounting electronic circuits. Further, a discharge connector for supplying electric power to an assist bicycle driving motor is also connected to the printed circuit board. This discharge connector is arranged at the lower part of the case almost without exception in order to be connected to the discharge terminal of the bicycle. For this reason, also from the point which simplifies the wiring of a discharge connector and a printed circuit board, the printed circuit board is arrange | positioned under the case. Thus, the printed circuit board disposed at the lower part of the case has a feature that it is not heated by the heat generated by the battery.
[0004]
Battery packs for assist bicycles that have a printed circuit board built in the bottom can cause damage if rainwater enters the case. In particular, the structure in which the printed circuit board is arranged in the lower part of the case has a drawback that most of the rainwater that enters the case flows down to the lower printed circuit board part, so that the printed circuit board is likely to break down due to the rainwater entering the case. . However, since bicycles are used outdoors, it is impossible to completely avoid rain. Rainwater that enters the battery pack corrodes the metal part of the printed circuit board, causing disconnection and poor contact, and also causes electric leakage due to leakage due to a decrease in insulation. If the battery pack can be made completely waterproof, the harmful effects of water can be eliminated. However, since the battery pack is attached to the bicycle so as to be removable, it is necessary to provide the charging connector and the discharging connector so as to be exposed to the outside of the case, so that it is difficult to achieve a complete waterproof structure.
[0005]
In addition, the part assembled as part of the waterproof structure can also prevent the ingress of water in the new state where the packing has sufficient elasticity, but as the years pass, the packing deteriorates and the elasticity is lost, In addition, due to deformation of the case, water can easily enter the waterproof structure. In particular, battery packs for assist bicycles used in extremely harsh environments that have extremely heavy batteries and are subject to severe vibration when the bicycle is running and are exposed to hot direct sunlight in the summer are plastic cases. And the gasket is subject to deformation and deterioration. For this reason, the battery pack used for this purpose is extremely difficult to have a sufficient waterproof structure, although a better waterproof structure is required.
[0006]
The present invention was developed for the purpose of realizing this, and an important object of the present invention is to effectively prevent failure caused by rain water without heating electronic components mounted on a printed circuit board by heat generated by the battery. It is an object of the present invention to provide a battery pack for an electric vehicle that can be prevented.
[0007]
[Means for Solving the Problems]
The battery pack for an electric vehicle of the present invention includes a battery core 2 in which a plurality of batteries are connected in an elongated shape, a case 1 housing the battery core 2, and a case 1 provided in the case 1 to the outside. A discharge connector 5 for supplying power, a charge connector 6 for charging a battery provided in the case 1, and a charge connector 6 built in the case 1 for controlling charge / discharge of the battery or detecting a remaining amount of the battery And a printed circuit board 7 on which an electronic circuit is mounted. Further, the battery pack is provided with a waterproof cover 17 that prevents the water entering the case 1 from flowing down under the battery core 2, and the printed circuit board 7 and the discharge connector 5 are disposed under the waterproof cover 17. A charging connector 6 is provided.
[0008]
The battery pack of claim 2 is provided with an inner case 4 made of plastic at the lower part of the case 1. The inner case 4 has an inner peripheral wall 16 that protrudes upward, and an inner chamber is provided inside the inner peripheral wall 16. A printed circuit board 7, a discharge connector 5, a charge connector 6, and a printed circuit board 7 are disposed in the inner chamber. Further, the upper opening of the inner peripheral wall 16 is closed with a waterproof cover 17. In the battery pack having this structure, the opening of the inner chamber is closed by the waterproof cover 17 so that the printed circuit board 7 and the like can be waterproofed in a more ideal state.
[0009]
The battery pack according to claim 3 of the present invention is provided with a wrap projection 18 that is superimposed on the outer surface of the inner peripheral wall 16 so as to protrude from the lower surface of the waterproof cover 17. Since the inner case 4 allows water that enters the case 1 to flow down to the outside of the wrap projections 18, the inner chamber can be waterproofed in an ideal state.
[0010]
In the battery pack according to claim 4 of the present invention, the load receiving plate 10 that supports the load of the battery core 2 is used in combination with the waterproof cover 17. In this structure, the load receiving plate 10 and the waterproof cover 17 are manufactured as separate parts and do not need to be assembled.
[0011]
In the battery pack according to claim 5 of the present invention, the discharge connector 5, the charge connector 6, and the printed board 7 are fixed to the inner case 4 to form an integrated charge / discharge block 3, and the charge / discharge block 3 is built in the lower part of the case 1. Thus, the discharge connector 5 and the charge connector 6 are exposed outside the case 1. The battery pack having this structure can simplify the entire structure and can waterproof the printed circuit board 7, the charging connector 6, and the discharging connector 5 in a more preferable state.
[0012]
The battery pack according to claim 6 of the present invention has a remaining amount calculation circuit for calculating the remaining amount of the battery mounted on the printed circuit board 7, and the battery pack according to claim 7 is blown out when an overcurrent flows through the battery. The fuse is connected to the printed circuit board 7. These battery packs can be used conveniently by displaying the remaining amount, and can be used while protecting the battery from overcurrent.
[0013]
Furthermore, in the battery pack according to claim 8 of the present invention, the inner case 4 is provided with a holding portion for holding a fuse, and a fuse terminal for directly connecting the fuse to the printed circuit board 7 is fixed. This structure is simple and has the advantage that the fuse can be held firmly in place.
[0014]
In the battery pack according to claim 9 of the present invention, the metal terminal 12 of the discharge connector 5 is directly fixed to the inner case 4, and the metal terminal 12 is directly fixed to the printed circuit board 7. In the battery pack according to the tenth aspect, the metal terminal 13 of the charging connector 6 is directly fixed to the inner case 4, and the metal terminal 13 is directly fixed to the printed circuit board 7. These battery packs have the feature that the loss due to a voltage drop due to a large current can be reduced while the discharge connector 5 and the charge connector 6 are securely fixed.
[0015]
Furthermore, the battery pack for an electric vehicle according to claim 10 of the present invention is attached to an assist bicycle.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below exemplifies a battery pack for an electric vehicle for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows.
[0017]
Further, in this specification, in order to facilitate understanding of the scope of claims, the numbers corresponding to the members shown in the examples are referred to as “the scope of claims” and “the means for solving the problems”. It is added to the member shown by. However, the members shown in the claims are not limited to the members in the embodiments.
[0018]
The battery pack of the present invention is mounted on an electric vehicle and supplies power to a driving motor. In this specification, an electric vehicle means a vehicle driven by electric power of a battery pack to be mounted. Therefore, the battery pack of the present invention can be used for all vehicles that are electrically driven with the battery pack mounted, such as an assist bicycle, an electric motorcycle, an electric wheelchair, an electric tricycle, and an electric cart. Hereinafter, an embodiment in which the electric vehicle is an assist bicycle will be described in detail.
[0019]
The battery pack shown in the front view of FIG. 1, the rear view of FIG. 2, and the cross-sectional view of FIG. 3 houses a battery core 2 in which a plurality of batteries are connected in an elongated shape, and the battery core 2 is accommodated. A case 1, a discharge connector 5 provided in the case 1 for supplying electric power to the outside, a charging connector 6 provided in the case 1 for charging a built-in battery, and a built-in case 1, And a printed circuit board 7 on which an electronic circuit for controlling charge / discharge or detecting the remaining amount of the battery is mounted.
[0020]
The discharge connector 5, the charge connector 6, and the printed circuit board 7 are fixed to an inner case 4 that is a plastic molded body to form a charge / discharge block 3 having an integral structure. The charge / discharge block 3 is built in the lower part of the case 1 and exposes the discharge connector 5 and the charge connector 6 to the outside of the case 1.
[0021]
The battery core 2 is connected in a slender shape by connecting secondary batteries, which are cylindrical batteries or square batteries, in series or in parallel. The secondary battery is a rechargeable battery such as a nickel-hydrogen battery, a nickel-cadmium battery, or a lithium ion secondary battery. The battery core 2 is connected in an elongated shape, for example, by arranging cylindrical batteries in two rows, so that the batteries in one row are located in the valleys of the batteries in the other row, that is, piles are stacked. The battery cores 2 are connected by lead wires, and the surfaces are further covered with a heat shrink film or the like to be connected to an integral structure.
[0022]
The case 1 includes a first case 1A and a second case 1B that are molded of plastic, and the first case 1A and the second case 1B are connected by screws 19. 1st case 1A and 2nd case 1B are shape | molded in the shape which can accommodate the battery core 2 in the upper part, and the charging / discharging block 3 in the lower part. Further, the case 1 accommodates the charge / discharge block 3 and opens connector windows 1a and 1b for exposing the charge connector 6 and the discharge connector 5 of the charge / discharge block 3 to the outside. In the case 1 in the figure, the connector window 1b of the discharge connector 5 is opened at the corners of the bottom surface and the bottom side surface, and the connector window 1a of the charging connector 6 is opened at the bottom side surface. In this structure, since the weight of the battery pack acts in a direction in which the discharge connector 5 is pressed against the discharge terminal of the bicycle, the discharge terminal 5 can be reliably inserted into and electrically connected to the discharge connector 5.
[0023]
The connector window 1a for exposing the charging connector 6 to the outside is closed by an open / close lid 8 that is elastically closed. This battery pack can reduce the contact failure of the charging connector 6. The connector window 1b that exposes the discharge connector 5 to the outside is not closed with an opening / closing lid. This is because the discharge connector 5 is always connected to the discharge terminal of the bicycle while the battery pack is attached to the bicycle. The charging connector 6 does not always connect a charging plug. Connect the charging plug only when charging the battery pack. The connector window 1a with the open / close lid 8 prevents foreign matter from adhering to the charging connector 6 in a state where the charging plug is not connected, thereby reducing contact failure.
[0024]
Furthermore, in the case 1 shown in the figure, a handle 9 is integrally formed at the upper end so that the battery pack removed from the bicycle can be easily held and also can be easily attached to and detached from the bicycle. Furthermore, the case 1 has a load receiving plate 10 that supports the load of the battery core 2 between the battery core 2 and the charge / discharge block 3. The load receiving plate 10 has a structure in which both side edges are connected to a locking portion 11 provided on the case 1 and is not pushed downward by the battery core 2. The case 1 shown in the figure is provided with a protruding portion 11 </ b> A protruding on the inner surface to serve as a locking portion 11, and further provided with a bent portion 11 </ b> B protruding inside the case 1 as a locking portion 11. The case 1 provided with the load receiving plate 10 can effectively prevent the charge / discharge block 3 from being damaged by the load of the battery core 2.
[0025]
The inner case 4 of the charge / discharge block 3 directly fixes the metal terminal 12 of the discharge connector 5. The metal terminal 12 is directly soldered and fixed to the printed circuit board 7. The metal terminal 12 of the discharge connector 5 is inserted into the metal terminal of the discharge plug fixed to the bicycle. Therefore, as shown in the enlarged view of FIG. 4, the metal terminal 12 of the discharge connector 5 is formed by folding back a metal plate that can be elastically deformed and bending both ends thereof further inwardly, so that the inserted metal terminal 20 is elastic. The shape can be sandwiched between the two.
[0026]
In the inner case 4, the metal terminal 13 of the charging connector 6 is also directly fixed, and the metal terminal 13 is also directly fixed to the printed circuit board 7 by soldering. The inner case 4 is provided with a connecting recess that can be connected by inserting a charging plug, and the metal terminal 13 of the charging connector 6 is fixed inside the connecting recess.
[0027]
The printed circuit board 7 is mounted with a remaining amount calculation circuit (not shown) for calculating the remaining amount of the battery. The remaining amount calculation circuit calculates the remaining amount of the battery by accumulating the charge / discharge current of the battery, and displays the remaining amount. The remaining amount calculation circuit in the figure displays the remaining amount by the number of lighting of the plurality of light emitting diodes 15 and increases the number of light emitting diodes 15 to be lit as the remaining amount increases. The light emitting diode 15 is fixed to the display unit 14 that is integrally formed with the inner case 4. In order that the light emitting diode 15 of the display unit 14 can be seen from the outside of the case 1, a display window 1c that exposes the display unit 14 to the outside is opened in the case 1, and the display unit 14 is provided in the display window 1c. ing.
[0028]
In order for the remaining amount calculation circuit to detect the charging / discharging current of the battery, the printed circuit board 7 is connected in series with the battery, and a shunt resistor (not shown) for detecting the current is fixed. The voltage at both ends of the shunt resistor is amplified by an amplifier, and the charge / discharge current of the battery is detected.
[0029]
Furthermore, as shown in FIG. 5, the printed circuit board 7 is equipped with a fuse 21 that is blown when an overcurrent flows through the battery. The fuse 21 is connected in series with the battery. When an excessive current flows through the battery, the fuse 21 is blown to interrupt the current. The fuse 21 is mounted on the printed circuit board so that it can be replaced. Therefore, a fuse terminal for connecting the fuse 21 is fixed to the printed circuit board. The fuse terminal is a metal plate that can be elastically deformed, and the terminals of the fuse 21 are elastically sandwiched and connected. In order to hold the fuse 21 in a fixed position, the inner case 4 is provided with a holding portion 22 for fitting and holding the fuse 21.
[0030]
Furthermore, the printed circuit board 7 is also provided with a protection circuit for preventing overcharge and overdischarge of the battery. The protection circuit prevents overcharging by cutting off the charging current when the battery is fully charged. Further, when the battery is discharged and the remaining amount reaches a predetermined capacity, the discharge current is cut off to prevent overdischarge.
[0031]
The inner case 4 is integrally formed of plastic as a whole, and an inner peripheral wall 16 protrudes around the upper surface, and a printed circuit board 7 is disposed in an inner chamber inside the inner peripheral wall 16. The opening of the inner chamber is closed with a waterproof cover 17. As shown in FIG. 3, the waterproof cover 17 is provided with a wrap projection 18 that wraps outside the inner peripheral wall 16 so as to protrude from the lower surface. The inner peripheral wall 16 is inserted inside the wrap projection 18, and the waterproof cover 17 is connected to the inner peripheral wall 16. With this structure, water that enters the inside of the case 1 flows down to the outside of the inner peripheral wall 16, so that it is possible to reliably prevent water from entering the inner chamber.
[0032]
The waterproof cover 17 may be integrated with the load receiving plate 10 as shown in FIG. The load receiving plate 10 in this figure is formed by integrally forming a wrap projection 18 projecting from the lower surface. The inner peripheral wall 16 is placed inside the wrap projection 18, and the load receiving plate 10 closes the upper surface opening of the inner peripheral wall 16 with a waterproof structure. This structure can prevent water from entering the inner case 4 while protecting the inner case 4 with the load receiving plate 10.
[0033]
The inner case 4 is fitted in the lower part of the case 1 and stored in a fixed position. The inner case 4 can also be provided with convex portions that are inserted into the connector windows 1a, 1b and the display window 1c, and the convex portions can be inserted into the connector windows 1a, 1b and the display window 1c to be disposed at fixed positions. . Further, it can be bonded to the inner surface of the case 1 or fixed by screwing.
[0034]
【The invention's effect】
The battery pack for an electric vehicle according to the present invention has an advantage that failure due to rain water can be effectively prevented without heating electronic components mounted on a printed circuit board by heat generated by the battery. In the battery pack of the present invention, a waterproof cover for preventing the water entering the case from flowing down is arranged under the battery core, and the printed circuit board, the discharge connector, and the charging connector are arranged under the waterproof cover. This is because it is installed. In the battery pack having this structure, the waterproof cover can prevent the water that has entered the case from flowing down to the printed board portion, so that it is possible to effectively prevent the printed board from being damaged due to the entered water. Therefore, the battery pack of the present invention is waterproof with a very simple structure even though the printed circuit board on which the electronic component is mounted is built in the lower part of the case so as not to be heated by the heat generated by the battery. Thus, the harmful effects caused by the invading water can be eliminated.
[Brief description of the drawings]
FIG. 1 is a front view of a battery pack for an electric vehicle according to an embodiment of the present invention. FIG. 2 is a rear view of the battery pack for an electric vehicle shown in FIG. FIG. 4 is an enlarged cross-sectional view showing metal terminals of the discharge connector. FIG. 5 is a bottom view of the inner case of the battery pack shown in FIG. 3. FIG. Sectional view of vehicle battery pack [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Case 1A ... 1st case 1B ... 2nd case 1a ... Connector window 1b ... Connector window 1c ... Display window 2 ... Battery core 3 ... Charging / discharging block 4 ... Inner case 5 ... Discharge connector 6 ... Charging connector 7 ... Printed circuit board DESCRIPTION OF SYMBOLS 8 ... Open / close lid 9 ... Handle 10 ... Load receiving plate 11 ... Locking part 11A ... Projection 11B ... Bending part 12 ... Metal terminal 13 ... Metal terminal 14 ... Display part 15 ... Light emitting diode 16 ... Inner peripheral wall 17 ... Waterproof cover 18 ... Wrap ridge 19 ... Screw 20 ... Inserted metal terminal 21 ... Fuse 22 ... Holding part

Claims (11)

A battery core (2) in which a plurality of batteries are connected in an elongated shape, a case (1) containing the battery core (2), and the case (1) provided to supply power to the outside Discharge connector (5), charge connector (6) for charging the battery built in the case (1), and electronic circuit built in the case (1) to control the charge / discharge of the battery A battery pack for an electric vehicle comprising a printed circuit board (7),
A waterproof cover (17) that prevents the water entering the case (1) from flowing down is arranged under the battery core (2), and the printed circuit board (7) and A battery pack for an electric vehicle comprising a discharge connector (5) and a charge connector (6). A plastic inner case (4) having an inner peripheral wall (16) projecting upward and having an inner chamber inside the inner peripheral wall (16) is disposed at the lower part of the case (1). The discharge connector (5), the charging connector (6), and the printed circuit board (7) are arranged in the inner chamber, and the upper opening of the inner peripheral wall (16) is closed with the waterproof cover (17). The battery pack for an electric vehicle according to claim 1. The waterproof cover (17) is provided with a wrap projection (18) that overlaps the outer surface of the inner peripheral wall (16) on the lower surface, and water flows down to the outer side of the wrap projection (18) to enter the inner chamber. The battery pack for an electric vehicle according to claim 2, wherein the battery pack is prevented from flowing in. The battery pack for an electric vehicle according to claim 1, wherein the waterproof cover (17) is a load receiving plate (10) that is connected to the case (1) and supports the load of the battery core (2). The discharge connector (5), charge connector (6), and printed circuit board (7) are fixed to the inner case (4) to form an integrated charge / discharge block (3). The battery pack for an electric vehicle according to claim 1, wherein the battery pack is incorporated in a lower part of the battery and the discharge connector (5) and the charge connector (6) are exposed to the outside of the case (1). The battery pack for an electric vehicle according to claim 1, wherein a remaining amount calculation circuit for calculating a remaining amount of the battery is mounted on the printed circuit board (7). The battery pack for an electric vehicle according to claim 1, wherein a fuse that is blown when an overcurrent flows through the battery is connected to the printed circuit board (7). The inner case (4) is provided with a holding part (22) for holding the fuse (21), and a fuse terminal for directly connecting the fuse (21) to the printed circuit board (7) is fixed. Battery pack for electric vehicles to be used. The metal terminal (12) of the discharge connector (5) is directly fixed to the inner case (4), and the metal terminal (12) is directly fixed to the printed circuit board (7). Battery pack for electric vehicles to be used. The metal terminal (13) of the charging connector (6) is directly fixed to the inner case (4), and the metal terminal (13) is directly fixed to the printed circuit board (7). Battery pack for electric vehicles to be used. The battery pack for an electric vehicle according to claim 1, wherein the electric vehicle is an assist bicycle.

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