JP5490516B2 - Battery pack - Google Patents

Description

  The present invention relates to a cylindrical battery pack having a plurality of cylindrical batteries, and more particularly to a battery pack capable of reducing the outer shape.

  For applications that require a large current for driving, such as electric bicycles and assist bicycles, battery packs that incorporate a plurality of battery cells to increase the voltage are used. In particular, there is a need for a battery pack that can meet the recent demand for higher output and the demand for smaller size and light weight that are easy to carry.

  In such a battery pack, conventionally, a square battery excellent in space efficiency is often used. This is because in a cylindrical battery, when a large number of batteries are arranged side by side, a gap is generated between the batteries, and the outer shape becomes large. On the other hand, a battery pack having a cylindrical outer shape is also required from the viewpoint of design.

JP 2008-34296 A JP 2003-45505 A JP 2007-213939 A

  However, the battery pack needs to incorporate not only the battery cell but also a substrate on which a discharge circuit for controlling the discharge of the battery cell and a protection circuit are mounted. In this case, since the substrate is usually flat, if an attempt is made to arrange a flat plate in a case having a cylindrical outer shape, the arrangement balance with the battery cells tends to deteriorate and the outer shape tends to increase in size. In particular, a high-power battery pack needs to incorporate a large number of battery cells, and in this case, it is not easy to secure a space for arranging the substrate while maintaining a reduction in size.

  The present invention has been made in view of such a conventional background, and a main object of the present invention is to make the outer shape of the case cylindrical so that the outer shape can be reduced while incorporating the substrate. Is to provide.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, according to the first battery pack of the present invention, the outer shape is cylindrical, the columnar battery cell 26 is inside, and the columnar extending direction is the opening direction of the cylinder. A first battery block 21 provided with a plurality of storage spaces 28 for storing them in a matching posture, a core block 20 in which a plurality of the first battery blocks 21 are stacked in the length direction, and a battery stored in the storage space 28 A flat substrate 30 on which a control circuit for controlling the discharge of the cell 26 is mounted; and an outer case 10 having an outer shape accommodating the core block 20 and the substrate 30 and having a cylindrical shape substantially symmetric with respect to a cross section. A battery pack, which is a battery pack 27B that is curved along the cylindrical side surface and arranged side by side in the cross-sectional view of the outer case 10, and a substantially straight line in the vertical direction at the center side. Arranged side by side A battery cell group 27A, and the battery cell group 27A arranged in the center is arranged at a position lower than the battery cell group 27B arranged in a curved manner and above the battery cell group 27A arranged in the center. The storage space 28 may be provided in the first battery block 21 so that the substrate 30 is disposed. Thereby, a cylindrical battery and a flat board | substrate can be efficiently arrange | positioned inside a cylindrical outer case, and size reduction with sufficient balance can be achieved avoiding the enlargement of an outer case.

  In addition, according to the second battery pack, the plurality of cylindrical battery cells 26 extending in one direction, the outer shape is cylindrical, and the cylindrical battery cells 26 are formed in the cylindrical extension. A first battery block 21 provided with a plurality of storage spaces 28 in which the direction is stored in a posture that coincides with the opening direction of the cylindrical shape, a core block 20 in which a plurality of the first battery blocks 21 are stacked in the length direction, A flat board 30 on which a control circuit for controlling the discharge of the battery cell 26 is mounted; and an outer case 10 in which the outer shape for housing the core block 20 and the board 30 is substantially axisymmetric in a sectional view. And a battery cell group 27B that is curved along the cylindrical side surface and arranged side by side in the longitudinal direction in the cross-sectional view of the outer case 10, and in the vertical direction at the center side. Arranged in a substantially straight line A battery cell group 27A, and the battery cell group 27A arranged in the center is arranged at a position lower than the battery cell group 27B arranged in a curved manner and above the battery cell group 27A arranged in the center. The substrate 30 can be disposed. Thereby, a cylindrical battery and a flat board | substrate can be efficiently arrange | positioned inside a cylindrical outer case, and size reduction with sufficient balance can be achieved avoiding the enlargement of an outer case.

  Furthermore, according to the third battery pack, the core block 20 further includes the adjacent first battery blocks 21 connected to each other via a hinge member 24 so that the hinge member 24 can be bent. The first battery block 21 can be provided at different positions with respect to the first battery block 21 adjacent to the left and right. As a result, the first battery blocks can be connected alternately on different sides and bent in a zigzag shape, and the work performed on the end face of the first battery block can be efficiently performed and the workability can be improved. It is done.

  Furthermore, according to the fourth battery pack, the bent lead plate 42 for electrically connecting the adjacent first battery blocks 21 to each other can be disposed on the hinge member 24. Thereby, the lead board which bears an electrical connection can be arrange | positioned together with a hinge member required in order to connect 1st battery blocks.

  Furthermore, according to the fifth battery pack, each first battery block 21 is further provided with a screw hole 52 between the battery cell group 27A on the central side and the battery cell group 27B on the side surface. Each of the first battery blocks 21 can be configured to be penetrated by one through screw 50 through the screw hole 52 in a state where the hinge member 24 is bent and overlapped in a laminated state. Thereby, a some 1st battery block can be fixed to a lamination | stacking state with one penetration screw, and mechanical strength can be improved.

  Furthermore, according to the sixth battery pack, the first battery block 21 includes an odd number of battery cell groups 27 each including a plurality of battery cells 26, and the battery cell groups 27 are arranged in a mutually parallel posture. In addition, the positive and negative terminals of the adjacent battery cell groups 27 are arranged in opposite orientations, and the terminals of the adjacent battery cell groups 27 having opposite positive and negative polarities arranged in substantially the same plane are connected. Thus, the battery cell groups 27 can be connected to each other in series. As a result, since the first battery block has one of the positive and negative electrodes located on one end face and the other electrode located on the other end face, the connection site when connecting the plurality of first battery blocks in series Without interfering with each other, there is an advantage that wiring can be smoothly performed in the configuration in which a plurality of first battery blocks are connected.

Furthermore, according to the seventh battery pack, the battery pack further includes a second battery block 22 connected to the battery cell group 27 located on at least one of the odd number of battery cell groups 27 , The number of battery cells 26 included in the second battery block 22 can be smaller than that of the first battery block 21. Thereby, another member can be efficiently arrange | positioned in the remaining space which does not arrange | position a battery cell.

  Furthermore, according to the eighth battery pack, the output terminal connector 16 of the battery pack can be further provided in the second battery block 22. Thereby, the output terminal connector can be arranged using the empty space of the second battery block with a small number of battery cells, and the necessary output terminal connector can be arranged without changing the size of the outer shape.

  Furthermore, according to the ninth battery pack, the substrate 30 has a shape extended so as to coincide with the extending direction of the case, and the upper surface of the core block 20 is placed on a plane on which the substrate 30 is placed. Can be formed. Thereby, a board | substrate can be mounted and arrange | positioned on the upper surface of a core block, and a battery cell and a board | substrate can be accommodated compactly inside a cylindrical outer case.

  Furthermore, according to the tenth battery pack, the first battery block 21 can include three battery cell groups 27. Thereby, three rows of battery cell groups are arranged in a balanced manner at the center and both sides of the cylindrical first battery block, and an odd number of battery cell groups are connected in series to be different at both end faces of the first battery block. An electrode can be positioned, and a form suitable for stacking a plurality of first battery blocks is provided.

  Furthermore, according to the eleventh battery pack, the cylindrical shape in cross section of the outer case (10) can be made symmetrical.

  Furthermore, according to the twelfth battery pack, the cylindrical shape of the outer case (10) when viewed in cross section can be a substantially cylindrical shape.

  Furthermore, according to the thirteenth battery pack, the cylindrical battery can be a lithium ion secondary battery.

  Furthermore, according to the fourteenth battery pack, the battery cell 26 may not be stored in a part of the storage space 28. Thereby, it is not necessary to insert battery cells in all the storage spaces, and only the required number of battery cells can be inserted into the required storage spaces to adjust the output voltage.

  Furthermore, according to the fifteenth battery pack, the battery pack can be used as a power supply device for driving a bicycle.

It is an external view which shows the battery pack which concerns on one embodiment of this invention. It is a disassembled perspective view which shows the state which removed the end surface board from the battery pack of FIG. It is an external view which shows the core block of FIG. It is a cross-sectional view of a core block. It is a longitudinal cross-sectional view of a core block. It is a perspective view which shows a 1st battery block. It is a disassembled perspective view which shows the state which removed the lead board from the 1st battery block of FIG. It is a perspective view which shows a 2nd battery block. It is a disassembled perspective view which shows the state which removed the board | substrate from the core block. It is a perspective view which shows the state which bends the hinge member which connects 1st battery blocks. It is a perspective view which shows the state which bent the 1st battery blocks with the hinge member and set it as the attitude | position with which an electrode end surface was located in the same surface. It is an enlarged view of a hinge member.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows. In addition, the member shown by the claim is not what specifies the member of embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing. In addition, the contents described in some examples and embodiments may be used in other examples and embodiments.

1 to 12 show a battery pack 100 according to an embodiment of the present invention. In these drawings, FIG. 1 is an external view of a battery pack, FIG. 2 is an exploded perspective view showing a state where an end face plate is removed from the battery pack of FIG. 1, FIG. 3 is an external view showing a core block of FIG. FIG. 5 is a longitudinal sectional view of the core block, FIG. 6 is a perspective view of the first battery block, and FIG. 7 is an exploded perspective view showing a state where the lead plate is removed from the first battery block of FIG. 8 is a perspective view of the second battery block, FIG. 9 is an exploded perspective view showing a state in which the substrate is removed from the core block, and FIG. 10 is a perspective view showing a state in which the hinge member connecting the first battery blocks is bent. FIGS. 11 and 11 are perspective views showing a state in which the first battery blocks are bent by the hinge member so that the electrode end faces are arranged on the same plane, and FIG. 12 is an enlarged view of the hinge member. The battery pack 100 shown in these drawings illustrates a battery pack for an electrically assisted bicycle. For this reason, the battery pack 100 has a substantially cylindrical outer case 10 constituting the outer shape, and as a fixing member 12 for fixing to the bicycle, a pair of fixing pieces bent in a U-shape are separated from each other in a symmetrical manner. They are arranged in two columns in the vertical direction. Accordingly, the battery pack 100 can be easily attached to the bicycle by inserting the plate-like connecting member provided on the bicycle side so as to be guided by the U-shaped opening. Note that the fixing member is not limited to this configuration, and various connection mechanisms known or developed in the future can be used as appropriate. Moreover, the cross-sectional view shape of the outer case is not limited to a cylindrical shape, and various cylindrical shapes that are substantially line-symmetric can be used. The line symmetry may be left-right symmetry, up-down symmetry, or up-down left-right symmetry.
(Outer case 10)

In this battery pack 100, both end faces of a cylindrical outer case 10 as shown in FIG. 1 are closed with end face plates 14, and a core block 20 is housed therein as shown in FIGS. . The outer case 10 is made of metal such as aluminum having excellent strength and heat dissipation. The end face plate 14 is formed in the same circular shape as the opening so as to close the opening end of the outer case 10. Further, the material is made of a metal excellent in durability and heat dissipation as in the case 10. This end face plate 14 is fixed to the outer case 10 by screwing four corners. Further, an output terminal connector 16 is provided on one end face plate 14 (left end face plate 14A in FIG. 2).
(Core block 20)

As shown in the perspective view of FIG. 3 and the longitudinal sectional view of FIG. 5, the core block 20 is configured by laminating a plurality of first battery blocks 21 in the length direction. In the example of FIG. 3, three first battery blocks 21 and one second battery block 22 connected to the end face are stacked on each other. The first battery blocks 21 are connected to each other via a hinge member 24 so as to be bent. The hinge member 24 is a plate-like member that connects the first battery blocks 21 to each other.
(First battery block 21)

  The external shape of the first battery block 21 is shown in the perspective views of FIGS. The first battery block 21 has a substantially cylindrical shape and is open at both ends, and is provided with irregularities along the appearance of the cylindrical battery cell 26 so that the cylindrical battery cell 26 is disposed along the peripheral wall. When the first battery block 21 having such irregularities is inserted into the cylindrical outer case 10, a gap is formed between the first battery block 21 and the outer case 10 as shown in the sectional view of FIG. 4. Is done. A screw hole 52 for fixing the end face plate 14 to the outer case 10, a hinge member 24 for connecting the first battery blocks 21, and the like are disposed using this gap.

  Furthermore, the 1st battery block 21 has divided the storage space 28 which accommodates the battery cell 26 inside. These storage spaces 28 define the opening direction of the storage space 28 so that when the battery cells 26 are stored, the extending direction of the battery cells 26 matches the opening direction of the first battery block 21. ing.

  As shown in FIGS. 4 and 7, the storage space 28 is a battery cell group 27 in which three battery cells 26 are grouped, one on the side and one on the center. At this time, the central battery cell group 27 is disposed lower than the side battery cell group 27. Thus, a space is provided above the central battery cell group 27, and a substrate arrangement space 31 in which the substrate 30 is arranged can be formed. In particular, the central battery cell 26 can be used effectively because the battery cell 26 is arranged in a substantially straight line, and the lower part of the circular cross section protrudes slightly in the central part. Moreover, since the battery cell group 27 arrange | positioned at a side surface is each arrange | positioned so that it may curve along a side surface, distance becomes long and it can maintain a balance even if it positions relatively higher than the center battery cell group 27. . In this way, the arrangement of the battery cell group 27 is offset downward only in the center portion, thereby effectively utilizing the limited cylindrical space, and the flat substrate 30 between the cylindrical battery cells 26. Can be secured.

  In this example, the end surface of the outer case 10 is substantially circular, and the first battery block 21 can be inserted into the inner case without any gaps, while the housing space 28 for housing the battery cells 26 has irregularities. A circumscribed circle is formed in an outer shape along a perfect circle. However, the present invention is not limited to a cylindrical shape having an end face that is a perfect circle, and the end face may have an oval shape, for example, depending on the number of battery cells accommodated. For example, when five battery cells are arranged in parallel, the battery cells can have an elliptical shape that is long in the horizontal direction.

The above first battery block 21 includes three battery cell groups 27 connected in parallel, and the battery cell groups 27 are connected in series, so that one battery block 21 includes nine batteries. The cells 26 can be connected in three lines and three lines. Further, as shown in FIG. 3, three such first battery blocks 21 are connected in series, and a total of 27 battery cells 26 can be connected in a series of nine. In addition, a second battery block 22 is further connected to the first battery block 21 on the end face (second from the left in FIG. 2). As shown in the perspective view of FIG. 8, the second battery block 22 defines a storage space 28 into which three battery cells 26 are inserted on one side surface (left side in FIG. 8), and the other portion is hollow. It is said. Thereby, as shown in FIG. 2 etc., a hollow part can be utilized as an arrangement space of the output terminal connector 16. In addition, by connecting the three battery cells 26 in series with the first battery block 21, the three first battery blocks 21 and one second battery block 22 are combined to make a total of 30 battery cells 26 10 Can be connected in 3 rows. Thereby, for example, when a 3.6V lithium ion secondary battery is used as the battery cell 26, 10 batteries can be connected in series to obtain a 36V output.
(Second battery block 22)

  The second battery block 22 has an outer shape that is substantially the same as that of the first battery block 21, and is provided with a storage space 28 that stores a smaller number of battery cells 26 than the first battery block 21. In the example of FIG. 8, the first battery block 21 of FIG. 7 has a space for storing up to three battery cells 26 as compared to the capacity of storing up to nine battery cells 26. The remaining space where the storage space 28 is not provided can be used as a space for arranging various members.

In both the first battery block and the second battery block, it is not necessary to insert battery cells in all the storage spaces, but the voltage required for the battery pack and the number of battery cells connected in parallel are required. Needless to say, it is appropriately changed according to the specifications. Further, the number of stacked first battery blocks and second battery blocks is not limited to the above example, and can be appropriately changed according to similarly required specifications. For example, without using the second battery block, only the first battery block can be stacked to form the core block, or conversely, the core block can be configured only by the second battery block. Furthermore, it goes without saying that a second battery block may be provided on each side of the first battery block laminate, or a plurality of second battery blocks may be laminated and connected to the first battery block laminate. . The first battery block 21 and the second battery block 22 are made of a member having excellent insulating properties such as resin. Further, the first battery block 21 and the second battery block 22 shown in FIGS. 6, 7, and 8 are divided into two in the opening direction because of the need for die cutting, and these are fixed by an adhesive or a screw. .
(Battery cell 26)

The battery cell 26 uses a columnar or cylindrical battery cell 26 extending in one direction. As the battery cell 26, a secondary battery such as a lithium ion secondary battery, a nickel hydrogen battery, or a nickel cadmium battery can be suitably used.
(Substrate 30)

  The substrate 30 is mounted with an electronic circuit such as a control circuit that controls discharge or charge / discharge of the battery cell 26. The board | substrate 30 is flat form, and is extended along the length direction of the core block 20, as shown in FIG.3 and FIG.9. Further, the core block 20 is designed so as to form a substantially same substrate mounting surface 32 on the upper surface when the first battery block 21 and the second battery block 22 are stacked. Thereby, the board | substrate 30 is fixed to the upper surface of the core block 20, and after performing required wiring, it comes to be easily accommodated in the outer case 10. FIG. In particular, since the substrate is conventionally arranged on the end face side of the core block, if the intermediate potential of each battery cell is to be detected, it is necessary to extend the lead wire from the substrate to the position of the desired battery cell and make an electrical connection. In addition, it takes time for wiring, and as the number of battery cells increases, the number of lead wires also increases, and there is a problem in mechanical strength due to twisting and rubbing of the lead wires. On the other hand, by disposing the extended substrate 30 along the length direction in which the battery cells 26 are connected in series, the distance from the substrate 30 to each battery cell 26 is shortened, and detection of an intermediate potential is performed. The advantage that wiring to each battery cell 26 becomes extremely easy is obtained. In the example of FIGS. 3 and 6, the wiring is performed by the bent piece 44 extended from the edge facing the substrate 30 of the lead plate 40 of each battery block without providing individual lead wires. In addition to simplifying the process, a separate lead wire is not required.

Further, as can be confirmed in FIG. 3, the L-shaped bent pieces of the end surface leads 40 </ b> A disposed on the front and rear end surfaces of the core block 20 are connected to the substrate 30. Further, as shown in FIGS. 3 and 9, an insulating sheet 47 is disposed between the end face lead 40 </ b> A and the end face plates 14 </ b> A and 14. The output from the board 30 is output to the output terminal connector 16 via a lead wire (not shown), through an internal connector.
(Hinge member 24)

  The adjacent first battery blocks 21 and the interfaces between the first battery block 21 and the second battery block 22 are connected to each other via a hinge member 24 so as to be bent as shown in FIGS. As shown in the enlarged view of FIG. 12, the hinge member 24 is composed of a plate material, and is connected by making the plate material bendable in a butterfly plate shape. In this example, a part of the lead plate for electrically connecting the battery cells 26 of the adjacent first battery blocks 21 is bent, and the bent lead plate 42 functions as the hinge member 24. . As described above, when the mechanical strength of the bent lead plate 42 permits, the bent lead plate 42 can be used as the hinge member 24, and the mechanical connection and the electrical connection are realized by the same member. The number of parts can be reduced. However, the lead plate and the hinge member can be configured as separate members. In this case, when the hinge member is bent by disposing the hinge member and the lead plate on the same side of the first battery block, the lead plate can be bent similarly.

  Further, as shown in FIG. 10, the hinge member 24 has a position where the hinge member 24 is provided on one end surface of the first battery block 21 and the position where the hinge member 24 is provided on the other end surface is different. , Preferably, it arrange | positions so that it may become an opposing position. For example, when the hinge member 24 is provided on the left side on one end face, the hinge member 24 is provided on the right side on the opposite end face. As described above, the first battery block 21 can be bent in a zigzag manner by alternately providing the hinge members 24 at the opposite positions for each of the first battery blocks 21. As a result, as shown in FIG. 11, it can be set as the attitude | position bent so that the opening surface of the 1st battery block 21 may face the same surface. In this posture, the lead plate 40 provided on the end surface of each first battery block 21 faces the same surface. Therefore, the work of fixing the lead plate 40 to the battery cell 26 with each first battery block 21 (for example, spot welding) ) Can be performed collectively from the same surface, so that the work efficiency is improved in each stage as compared with the conventional method in which each first battery block 21 is individually operated on each surface. When the lead plate 40 is fixed, the hinge member 24 is bent from the posture shown in FIG. 11, and can be laminated as the core block 20 as shown in FIGS. 2, 3, and 5 through FIG. It can fix with the penetration screw 50 (after-mentioned).

  Moreover, said structure is implement | achieved because the connection of the adjacent 1st battery blocks 21 is located in a line so that the position of the hinge member 24 may be replaced by the reverse direction alternately. That is, the position of the hinge member 24 is made to coincide with the fixing of the adjacent first battery blocks 21 by the lead plate 40, and the position of the lead plate 40 of the first battery block 21 is configured so that this position appears alternately. It is realized by. In order to realize this, each first battery block 21 includes an odd number of battery cell groups 27 each including a plurality of battery cells 26, and the battery cell groups 27 are connected in series. Specifically, the odd number of battery cell groups 27 are arranged so that the end faces of the adjacent battery cell groups 27 are arranged in substantially the same plane in parallel postures. At this time, the adjacent battery cell groups 27 are arranged in the postures in which the directions of the end faces are opposite so that the positive and negative terminals of the adjacent battery cell groups 27 are opposite to each other. The battery cells 27 in the first battery block 21 are connected in series with each other by connecting terminals having opposite positive and negative polarities with lead plates 40 at the end faces of the adjacent battery cell groups 27 arranged in the same plane. Connected to. Thus, each first battery block 21 connects an odd number of battery cell groups 27 in parallel and in series, so that either positive or negative electrode is located on one end face, and the other end face is on the other end face. The other electrode will be located. As a result, the connection site | part at the time of laminating | stacking several 1st battery blocks 21 and connecting them in series does not interfere, and can perform the wiring at the time of the structure which connects the several 1st battery block 21 smoothly.

  In addition, each battery cell group 27 connects the battery cells 26 included therein in parallel. For this reason, the lead plate 40 connects all the battery cells 26 included in the same battery cell group 27 in parallel. At the same time, the adjacent battery cell groups 27 are also connected via the lead plate 40 as shown in FIG. And, as shown in FIG. 12, each can be connected in series via the bent lead plate. Accordingly, it is possible to connect the battery cells 26 in parallel and the battery cell group 27 in series with a small number of lead plates 40 and bent lead plates 42. In addition, the number of lead plates, etc. is reduced, and these are arranged on the same surface so that they can be connected (welded) to the battery cell 26, so that the efficiency of battery pack assembly work is greatly improved compared to the prior art. Is done.

An insulating sheet 46 may be interposed between the bent lead plate 42 and the lead plates 40 that are bent. As a result, it is possible to avoid a situation in which an unintended discharge occurs between the opposing lead plates.
(Screw hole 52)

  Each of the first battery block 21 and the second battery block 22 is bent by a hinge member 24 at each connection interface to form a laminated core block 20, and is fixed by a fixing member in order to maintain this core block state. . The core block 20 shown in FIGS. 2 and 3 uses a through screw 50 as a fixing member. For this reason, each battery block has a screw hole 52 as shown in FIGS. The screw hole 52 is preferably provided in a spacer 54 disposed between the battery cell group 27A on the center side and the battery cell group 27B on the side surface side. Preferably, the spacer 54 is formed by integral molding with members constituting the battery block. In the example shown in the cross-sectional view of FIG. 4, the spacers 54 are provided on the left and right of the battery cell group 27 </ b> A on the center side. In particular, the battery cell group 27A on the central side is arranged in a straight line, whereas the battery cell group 27B on the side surface side is curved and arranged along the cylindrical side surface of the battery block. A gap is formed between the battery cell group 27A and the battery cell group 27 on the side surface. By utilizing this gap as a space for providing the screw hole 52, the screw hole 52 can be effectively arranged in a limited space. Further, the spacer 54 that defines the screw hole 52 is formed of an insulating member, thereby partitioning the battery cell group 27A on the central side and the battery cell group 27B on the side surface side as shown in the cross-sectional view of FIG. The effect of insulating with a plate can also be obtained. In particular, by separating the battery cell group 27A on the central side and the battery cell group 27 on the side surface thermally, even if the battery cell 26 of any one of the battery cell groups 27 becomes high temperature, other battery cell groups 27 can be reduced.

  The screw holes 52 are provided in the first battery block 21 and the second battery block 22 so that the screw holes 52 coincide with each other in the stacked state. The through screw 50 inserted through the screw hole 52 is designed to have a length that penetrates all the stacked battery blocks. The through screw 50 is a member having sufficient mechanical strength, such as a metal screw. Thereby, since all the battery blocks can be made into a lamination | stacking state and the penetration screw 50 can be penetrated and fixed, a battery block is fixed with sufficient intensity | strength integrally. In particular, as compared with the conventional method in which only adjacent battery blocks are connected to each other with claws or the like, the mechanical strength is extremely high by passing the through screw 50 in a core shape that penetrates the entire battery block. In terms of reliability, the reliability is greatly improved. In the example of FIG. 4, the screw hole 52 is provided in the right spacer 54 among the spacers provided on the left and right of the battery cell group 27 </ b> A on the center side, and the battery block is fixed with one through screw 50. doing. However, it goes without saying that a structure that is fixed with two or more through screws can also be appropriately employed according to the required strength. Furthermore, the position at which the screw hole is provided is not limited to the spacer, and for example, it may be arranged in a gap portion formed between the core block and the outer case.

  In this way, a strong connection structure between the battery blocks can be realized. In particular, in the past, battery packs have been configured to store battery cells divided into multiple blocks because of problems such as output adjustment and ease of assembly. It was not easy to perform at a high strength. In addition, conventionally, the structure in which the battery blocks are locked together with claws integrally molded with the battery blocks was mainly adopted, but in this configuration, only the interface between adjacent battery blocks is connected, In a configuration in which a large number of battery blocks are stacked, the structure is merely a connection between adjacent interfaces, and a structure for fixing the entire battery block is lacking. Therefore, a structure with higher mechanical strength is required. However, when such a fixing structure is added, the outer shape is further increased, which contradicts the demand for downsizing. On the other hand, the entire battery block laminated as described above is penetrated by the through screw 50, and the screw hole 52 for this is arranged in the space between the battery cell groups 27, so that the claw is placed on the outer periphery. Compared with the structure etc. which provide, the situation where the external shape of a battery pack becomes large can be avoided.

  The battery pack according to the present invention can be suitably used as a power supply device for an assist bicycle.

DESCRIPTION OF SYMBOLS 100 ... Battery pack 10 ... Outer case 12 ... Fixing member 14, 14A ... End face plate 16 ... Output terminal connector 20 ... Core block 21 ... First battery block 22 ... Second battery block 24 ... Hinge member 26 ... Battery cell 27 ... Battery cell group 27A ... Battery cell group 27B on the central side ... Battery cell group 28 on the side surface ... Storage space 30 ... Substrate 31 ... Substrate placement space 32 ... Substrate mounting surface 40, 40A ... Lead plate 42 ... Bent lead plate 44 ... Folded pieces 46, 47 ... Insulating sheet 50 ... Through screw 52 ... Screw hole 54 ... Spacer

Claims (15)

The first is provided with a plurality of storage spaces (28) in which the outer shape is cylindrical and the cylindrical battery cells (26) are stored in such a manner that the columnar extending direction coincides with the opening direction of the cylindrical shape. Battery block (21),
A plurality of the first battery blocks (21), a core block (20) laminated in the length direction, and
A flat substrate (30) mounted with a control circuit for controlling the discharge of the battery cell (26) stored in the storage space (28);
An outer case (10) in which the outer shape for housing the core block (20) and the substrate (30) has a substantially line-symmetric cylindrical shape in cross section;
A battery pack comprising:
In a cross-sectional view of the outer case (10),
A battery cell group (27B) that is curved along the side surface of the cylindrical shape and arranged in the vertical direction;
On the center side, the battery cell group (27A) arranged in a substantially straight line in the vertical direction,
And place
The battery cell group (27A) arranged in the center is arranged at a position lower than the battery cell group (27B) arranged in a curve,
The storage space (28) is provided in the first battery block (21) so that the substrate (30) is disposed above the battery cell group (27A) disposed in the center. Battery pack. A plurality of cylindrical battery cells (26) extending in one direction;
The outer shape is cylindrical, and a plurality of storage spaces (28) are provided in which the cylindrical battery cells (26) are stored in a posture in which the cylindrical extending direction coincides with the opening direction of the cylindrical shape. One battery block (21),
A plurality of the first battery blocks (21), a core block (20) laminated in the length direction, and
A flat substrate (30) mounted with a control circuit for controlling the discharge of the battery cell (26);
An outer case (10) in which the outer shape for housing the core block (20) and the substrate (30) has a substantially line-symmetric cylindrical shape in cross section;
A battery pack comprising:
In a cross-sectional view of the outer case (10),
A battery cell group (27B) that is curved along the side surface of the cylindrical shape and arranged in the vertical direction;
On the center side, the battery cell group (27A) arranged in a substantially straight line in the vertical direction,
And place
The battery cell group (27A) arranged in the center is arranged at a position lower than the battery cell group (27B) arranged in a curve,
The battery pack is characterized in that the substrate (30) is arranged above the battery cell group (27A) arranged in the center. The battery pack according to claim 1 or 2, further comprising:
The core block (20)
The adjacent first battery blocks (21) are connected to each other via a hinge member (24) so that they can be bent.
Further, the hinge member (24) is provided in a different position with respect to the first battery block (21) adjacent to the left and right in the first battery block (21). The battery pack according to claim 3,
A battery pack comprising a bent lead plate (42) for electrically connecting adjacent first battery blocks (21) to the hinge member (24). The battery pack according to claim 3 or 4, further comprising:
Each first battery block (21) has a screw hole (52) between the battery cell group (27A) on the center side and the battery cell group (27B) on the side surface inside,
The first battery blocks (21) are penetrated by one through screw (50) through the screw hole (52) in a state where the hinge member (24) is folded and stacked in a stacked state. A battery pack characterized by comprising. The battery pack according to any one of claims 2 to 5,
The first battery block (21)
Equipped with an odd number of battery cell groups (27) consisting of a plurality of battery cells (26),
These battery cell groups (27) are arranged in a mutually parallel posture, and are arranged in a posture in which the positive and negative terminals of adjacent battery cell groups (27) are opposite to each other,
Furthermore, the battery cell groups (27) are connected in series with each other by connecting terminals having opposite positive and negative polarities arranged in substantially the same plane. Battery pack. The battery pack according to claim 6, further comprising:
Wherein among the odd number of battery cell group (27) comprises a second battery block which is connected to the battery cell group (27) located on at least one end edge (22),
The battery pack, wherein the number of battery cells (26) included in the second battery block (22) is smaller than that of the first battery block (21). The battery pack according to claim 7, further comprising:
The battery pack, wherein the second battery block (22) is provided with a battery pack output terminal connector (16). The battery pack according to any one of claims 1 to 8,
The substrate (30) has a shape extended to coincide with the extension direction of the case,
The battery pack, wherein an upper surface of the core block (20) is formed in a planar shape on which the substrate (30) is placed. The battery pack according to any one of claims 1 to 9,
The battery pack, wherein the first battery block (21) includes three battery cell groups (27). The battery pack according to any one of claims 1 to 10,
The battery pack, wherein the outer case (10) has a cylindrical shape in cross-sectional view that is symmetrical. The battery pack according to claim 11,
The battery pack, wherein the outer case (10) has a substantially cylindrical shape in a sectional view. The battery pack according to any one of claims 1 to 12,
The battery pack, wherein the cylindrical battery is a lithium ion secondary battery. The battery pack according to any one of claims 1 to 13,
A battery pack, wherein a battery cell (26) is not stored in a part of the storage space (28). The battery pack according to any one of claims 1 to 14,
The battery pack is a power supply device for driving a bicycle.

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