JP7410029B2 - battery pack - Google Patents

Description

The present invention relates to a battery pack that includes a cell holder that holds a plurality of battery cells and a lead plate that electrically connects terminal surfaces of the plurality of battery cells.

For example, a battery pack described in Japanese Patent No. 4761726 is known as a battery pack that is removably mounted on an electric vehicle or the like. Specifically, a battery pack includes a cell holder that holds a plurality of cylindrical battery cells arranged in rows and columns so that their terminal surfaces are arranged on the same plane, and a cell holder that holds a plurality of cylindrical battery cells arranged in rows and columns, and It includes a plurality of lead plates that electrically connect the terminal surfaces to each other. By arranging a plurality of battery cells in a zigzag pattern in the row direction, the cell holder protects the battery cells by maintaining the density of the battery cells held in the cell holder and making the battery cells less likely to be crushed by external forces. ing. In this type of battery pack, the terminal surfaces of the battery cells are arranged in a zigzag pattern in the row direction, and the sides of the lead plates in the row direction also have a zigzag shape.

In order to obtain a lead plate with a complicated shape having zigzag sides with desired processing accuracy, an expensive mold with a complicated shape is required, and there is a concern that manufacturing costs will increase. In addition, when punching such a lead plate from a flat plate, the proportion of unused parts that do not constitute the lead plate to the entire flat plate increases, resulting in a decrease in material yield, and there is a concern that this will also increase manufacturing costs. .

Therefore, the main object of the present invention is to provide a battery pack that has a simple configuration and can protect battery cells without increasing manufacturing costs.

One aspect of the present invention provides a battery cell having a cylindrical shape and having terminal surfaces with different positive and negative polarities at both ends in the axial direction, and a plurality of the battery cells arranged in such a manner that the terminal surfaces are arranged on the same plane. A battery pack comprising: cell holders arranged and held in a direction and a column direction; and a plurality of lead plates electrically connecting at least the terminal surfaces arranged in the row direction, wherein the cell holder holds a plurality of the batteries. A pair of exposed side surfaces are provided with openings that expose the terminal surfaces on both sides of the cell in the axial direction from the cell holder, and the centers of the terminal surfaces adjacent in the row direction are located on one side in the column direction. and the other side, and the plurality of terminal surfaces arranged on the exposed side surface have equal positive and negative polarities of the terminal surfaces adjacent in the row direction, and The terminal surfaces adjacent to the terminal surfaces have different positive and negative polarities, and the plurality of lead plates are arranged at intervals in the column direction with respect to the exposed side surface and are formed to extend in the row direction. Ru.

In this battery pack, the lead plates extend in the row direction, so for example, unlike zigzag-shaped lead plates, it is necessary to obtain lead plates with high precision using a simple mold, and when punching the lead plates from a flat plate. It is possible to improve the material yield by reducing the proportion of unused parts. In addition, in this battery pack, a plurality of battery cells are arranged so that the centers of terminal surfaces adjacent in the row direction are alternately shifted to one side and the other side in the column direction.In other words, the plurality of battery cells are arranged in the row direction. Arrange them in a zigzag pattern. Therefore, even if the battery cells are held in the cell holder at a high density, the battery cells can be made difficult to be crushed by external force.

From the above, according to the battery pack of the present invention, it is possible to protect battery cells with a simple configuration without increasing manufacturing costs.

1 is a schematic perspective view of a battery pack according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the battery core pack of FIG. 1. FIG. 3 is an exploded perspective view of the cell holder of FIG. 2. FIG. FIG. 3 is an explanatory diagram illustrating the relationship between the terminal surface of the first exposed side surface of the cell holder and the lead plate. FIG. 7 is an explanatory diagram illustrating the relationship between the terminal surface of the second exposed side surface of the cell holder and the lead plate. 5 is a sectional view taken along the line VI-VI in FIG. 4. FIG. 5 is a sectional view taken along the line VII-VII in FIG. 4. FIG. The relationship among the radius r of the weld, the diameter D of the battery cell, the distance GP between the outer peripheral surfaces of battery cells adjacent in the column direction, and the distance CL between the sides in the row direction of the lead plates adjacent in the column direction is It is an explanatory diagram to explain. It is a sectional view explaining a lead plate concerning a modification.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the battery pack according to the present invention will be described in detail with reference to the accompanying drawings. In addition, in the following figures, the same reference numerals are given to the component which has the same or similar function and effect, and the repeated description may be omitted.

The battery pack 10 shown in FIG. 1 can be suitably applied to, for example, a portable driving power source that is removably mounted on an electric vehicle (not shown) such as a power-assisted bicycle, an electric motorcycle, or an electric car. . Therefore, an example in which the battery pack 10 is mounted on an electric vehicle will be described below. However, the present invention is not particularly limited thereto, and the battery pack 10 can be applied to various devices that require electric power. In addition, for convenience of explanation, the arrow Z1 side in FIG. 1 will be described as the upper side in the vertical direction, and the arrow Z2 side in FIG. You can.

As shown in FIG. 1, the battery pack 10 is housed in a case 16 that includes a battery core pack 12, a battery management unit (BMU) 14, and a connector section (not shown) that constitutes an exterior. In FIG. 1, for ease of understanding, a part of the case 16 is indicated by a two-dot chain line, and components disposed inside the case 16 are illustrated.

As shown in FIG. 2, the battery core pack 12 includes a cylindrical battery cell 20 in which terminal surfaces 18 with different positive and negative polarities are provided at both ends in the axial direction (arrows X1 and X2 directions), and terminal surfaces 18 on the same plane. Two cell holders 22a and 22b that hold a plurality of battery cells 20 side by side in the row direction (arrows Y1, Y2 direction) and column direction (arrows Z1, Z2 direction) so that they are arranged at least in the row direction. It includes a plurality of lead plates 24 that electrically connect the terminal surfaces 18 to each other. In FIG. 2, the horizontal direction viewed from the axial direction of the battery cell 20 is the row direction, and the vertical direction perpendicular to the horizontal direction is the column direction.

As shown in FIGS. 3 to 5, in the battery cell 20, one of the terminal surfaces 18 on both sides in the axial direction is a positive terminal surface 26, and the other is a negative terminal surface 28. A suitable type of battery cell 20 is a lithium ion secondary battery, but is not particularly limited thereto, and for example, a secondary battery such as a nickel hydride battery or a nickel cadmium battery may be used.

As shown in FIG. 2, since the two cell holders 22a and 22b are configured in substantially the same manner as each other, the specific configuration of one cell holder 22a will be explained, and the explanation of the other cell holder 22b will be omitted. The cell holder 22a has a first exposed side surface 32 and a second exposed side surface 34 as a set of exposed side surfaces 30 that respectively expose the terminal surfaces 18 on both sides of the plurality of battery cells 20 in the axial direction from the cell holder 22a. Below, when the first exposed side surface 32 and the second exposed side surface 34 are not particularly distinguished, they are also collectively referred to as the exposed side surface 30. A circular opening 36 corresponding to the shape of the terminal surface 18 is provided in the exposed side surface 30, and the terminal surface 18 is exposed to the outside of the cell holder 22a through the opening 36.

Further, the cell holder 22a holds a plurality of battery cells 20 arranged in a zigzag (staggered) manner in the row direction. As a result, as shown in FIGS. 4 and 5, on the exposed side surface 30, the centers O of the terminal surfaces 18 adjacent in the row direction are located on one side (arrow Z1 side) and the other side (arrow Z2 side) in the column direction. They are arranged alternately and staggered. In this embodiment, the cell holder 22a holds seven rows of battery cells 20 consisting of R1 to R7, and each row of R1 to R7 is composed of six terminal surfaces 18 arranged in a zigzag pattern as described above. There is. That is, the terminal surfaces 18 in each row include three first terminal surfaces 38 whose center O is arranged on one side in the column direction (arrow Z1 side), and three first terminal surfaces 38 whose center O is arranged on the other side in the column direction (arrow Z2 side). It has three second terminal surfaces 40 arranged therein. Note that the number of rows of battery cells 20 held by the cell holder 22a is not limited to seven, and the number of terminal surfaces 18 forming each row is not limited to six.

The terminal surfaces 18 disposed on the exposed side surface 30 have equal positive and negative polarities in the row direction and different positive and negative polarities in the column direction. On the first exposed side surface 32 of this embodiment, as shown in FIG. be done. Therefore, on the second exposed side surface 34, which is the back surface of the first exposed side surface 32, as shown in FIG. A row is formed by the negative terminal surface 28.

As shown in FIG. 3, the cell holder 22a can be configured by combining, for example, a first member 42 having a first exposed side surface 32 and a second member 44 having a second exposed side surface 34. The first member 42 and the second member 44 have a plurality of holding holes 46 and hold the battery cells 20 in a state where they are inserted through the holding holes 46, respectively. An opening 36 that opens to the first exposed side surface 32 is provided at one end of the holding hole 46 of the first member 42, and an opening that opens to the second exposed side surface 34 is provided at one end of the holding hole 46 of the second member 44. An opening 36 is provided.

For example, after interposing the battery cell 20 between the first member 42 and the second member 44 that are spaced apart in the axial direction (arrow X1, X2 direction), while inserting the battery cell 20 into the holding hole 46, By connecting the first member 42 and the second member 44 in close proximity to each other in the axial direction, a cell holder 22a that holds a plurality of battery cells 20 is formed.

As shown in FIGS. 4 and 6, a portion of the first exposed side surface 32 on the arrow Z2 side of the opening 36 that exposes the second terminal surfaces 40 of R1, R3, and R5 is covered with an insulating portion 48, respectively. ing. As shown in FIGS. 4 and 7, a portion of the first exposed side surface 32 on the arrow Z1 side of the opening 36 that exposes the first terminal surfaces 38 of R2, R4, and R6 is covered with an insulating portion 48, respectively. ing.

As shown in FIGS. 5 and 6, a portion of the second exposed side surface 34 on the arrow Z2 side of the opening 36 that exposes the second terminal surfaces 40 of R2, R4, and R6 is covered with an insulating portion 48, respectively. ing. As shown in FIGS. 5 and 7, a portion of the second exposed side surface 34 on the arrow Z1 side of the opening 36 that exposes the first terminal surfaces 38 of R3, R5, and R7 is covered with an insulating portion 48, respectively. ing.

As shown in FIGS. 6 and 7, the insulating part 48 protrudes further toward the outside in the axial direction of the cell holder 22a than the openings 36 adjacent in the column direction that are not covered by the insulating part 48 due to its thickness. ing. Therefore, a step 48a is formed between the portion of the opening 36 covered with the insulating section 48 and another opening 36 adjacent in the column direction that is not covered with the insulating section 48.

Further, each insulating section 48 is provided with an insulating wall 50 that protrudes toward the outside in the axial direction of the cell holder 22a from an end facing toward the center of the opening 36 that is partially covered by the insulating section 48. The insulating walls 50 are protrusions extending linearly along the row direction, and three insulating walls 50 are provided at intervals in the column direction for each of the first exposed side surface 32 and the second exposed side surface 34. ing.

As shown in FIGS. 4, 5, etc., side wall portions 52 of protrusions extending linearly along the column direction are provided at the edges of both ends of the first exposed side surface 32 and the second exposed side surface 34 in the row direction. Each is provided. In this embodiment, the protruding heights (heights in the directions of arrows X1 and X2) of the side wall portion 52 and the insulating wall 50 are set to be the same. Further, a plurality of grooves 56 are provided in the side wall portion 52 provided on the arrow Y1 side of the first exposed side surface 32 and the second exposed side surface 34, into which connection ends 54 of the lead plate 24, which will be described later, are respectively inserted. There is.

The plurality of lead plates 24 are arranged at intervals from each other in the row direction with respect to the exposed side surface 30, and have a substantially circular welded portion 58 when viewed in the axial direction of the battery cell 20 (see FIGS. 4 and 5). It is electrically connected to the terminal surface 18 via. Further, the row direction sides 60 of the lead plate 24 each extend in a straight line (row direction) orthogonal to the column direction.

Specifically, as shown in FIG. 2, the lead plate 24 includes output lead plates 62a, 62b, and intermediate lead plates 64a, 64b, 64c, 64d, 64e, and 64f. Each of the output lead plates 62a and 62b connects one row of terminal surfaces 18 arranged at the ends of the exposed side surface 30 in the column direction in parallel. Further, each of the output lead plates 62a and 62b has tab portions 66a and 66b that allow the battery cell 20 held by the cell holder 22a to be electrically connected to the outside of the cell holder 22a. The intermediate lead plates 64a, 64b, 64c, 64d, 64e, and 64f connect the two rows of terminal surfaces 18 in series in the column direction and in parallel in the row direction.

That is, as shown in FIG. 4, on the first exposed side surface 32, one row R1 on one end side (arrow Z1 side) in the column direction is connected to one output lead plate 62a, and the remaining rows are connected to one output lead plate 62a. Two adjacent rows of certain R2 to R7 are connected to three intermediate lead plates 64a, 64b, and 64c, respectively.

Therefore, the terminal surfaces 18 forming R1 are connected in parallel by the output lead plate 62a. Further, the terminal surfaces 18 forming R2 and R3 are connected in parallel in the row direction and in series in the column direction by the intermediate lead plate 64a. The terminal surfaces 18 forming R4 and R5 are connected in parallel and in series by an intermediate lead plate 64b, and the terminal surfaces 18 forming R6 and R7 are connected by an intermediate lead plate 64c, respectively.

As shown in FIG. 5, on the second exposed side surface 34, one row R7 on the other end side in the column direction (arrow Z2 side) is connected to one output lead plate 62b, and the remaining row R1 Two adjacent rows of R6 are connected to three intermediate lead plates 64d, 64e, and 64f, respectively.

Therefore, the terminal surfaces 18 forming R7 are connected in parallel by the output lead plate 62b. Further, the terminal surfaces 18 forming R1 and R2 are connected to each other by an intermediate lead plate 64d, the terminal surfaces 18 forming R3 and R4 are connected to each other by an intermediate lead plate 64e, and the terminal surfaces 18 forming R5 and R6 are connected to each other by an intermediate lead plate 64e. They are connected in parallel and in series, respectively, by an intermediate lead plate 64f.

By providing the lead plate 24 on the first exposed side surface 32 and the second exposed side surface 34 as described above, all the battery cells 20 held in the cell holder 22a have terminal surfaces 18 in each row parallel to each other. and adjacent rows are connected in series.

As shown in FIG. 4, on the first exposed side surface 32, the output lead plate 62a covers the entirety of the first terminal surface 38 at R1 as a covered terminal surface 68. Further, the output lead plate 62a covers more than half and less than the entirety of the second terminal surface 40 in R1 as the exposed terminal surface 70 in the column direction. As a result, one of the sides 60 in the row direction of the output lead plate 62a on the side facing the intermediate lead plate 64a (arrow Z2 side) is arranged to cross the exposed terminal surface 70.

The intermediate lead plate 64a covers the second terminal surface 40 at R2 and the first terminal surface 38 at R3 as a covering side terminal surface 68, respectively. Further, the intermediate lead plate 64a covers more than half and less than the entirety of each of the first terminal surface 38 at R2 and the second terminal surface 40 at R3 as exposed terminal surfaces 70 in the column direction. As a result, each of the pair of row-direction sides 60 of the intermediate lead plate 64a is arranged to cross the exposed terminal surface 70. The intermediate lead plate 64b is also arranged in the same manner with respect to R4 and R5, and the intermediate lead plate 64c is also arranged in the same manner with respect to R6 and R7.

As shown in FIG. 5, on the second exposed side surface 34, the intermediate lead plate 64d covers the second terminal surface 40 at R1 and the first terminal surface 38 at R2 as a covering side terminal surface 68, respectively. . Further, the intermediate lead plate 64d covers more than half and less than the entirety of each of the first terminal surface 38 at R1 and the second terminal surface 40 at R2 as exposed terminal surfaces 70 in the column direction. As a result, each of the pair of row-direction sides 60 of the intermediate lead plate 64d is arranged to cross the exposed terminal surface 70. The intermediate lead plate 64e is similarly arranged with respect to R3 and R4, and the intermediate lead plate 64f is also arranged similarly with respect to R5 and R6.

Further, the output lead plate 62b is arranged such that the second terminal surface 40 at R7 becomes the covered terminal surface 68, and the first terminal surface 38 at R7 becomes the exposed terminal surface 70. Furthermore, one of the sides 60 in the row direction of the output lead plate 62b on the side facing the intermediate lead plate 64f (arrow Z1 side) is arranged to cross the exposed side terminal surface 70.

As shown in FIG. 8, one side of a pair of lead plates 24 adjacent in the column direction (for example, the output lead plate 62a in FIG. 4) is used as the first lead plate 72, and the other side (for example, the intermediate lead plate in FIG. The plate 64a) is used as a second lead plate 74. Also, one side (for example, R1 in FIG. 4) of two rows of terminal surfaces 18 adjacent in the column direction is designated as the first row Ra, the other side (for example, R2 in FIG. 4) is designated as the second row Rb, and the first The lead plate 72 covers the entire covered side terminal surface 68 of the first row Ra and more than half but less than the entire exposed side terminal surface 70 of the first row Ra, and the second lead plate 74 covers the entire covered side terminal surface 68 of the first row Ra. The entire covered terminal surface 68 and more than half but less than the entire exposed terminal surface 70 of the second row Rb are covered. Note that in FIG. 8, illustration of the insulating portion 48, the insulating wall 50, and the convex portion of the positive electrode terminal surface 26 is omitted.

At this time, the first lead plate 72 faces the portion of the exposed terminal surface 70 of the second row Rb exposed from the second lead plate 74 via the insulating portion 48 (see FIGS. 4 to 7). The second lead plate 74 faces the portion of the exposed terminal surface 70 of the first row Ra exposed from the first lead plate 72 via the insulating portion 48 (see FIGS. 4 to 7). As a result, the first lead plate 72 can be prevented from being electrically connected to the exposed terminal surface 70 of the second row Rb, and the second lead plate 74 can be electrically connected to the exposed terminal surface 70 of the first row Ra. connection can be avoided.

Further, the welded portion 58 is provided approximately at the center of the terminal surface 18, the radius of the welded portion 58 is r, the diameter of the battery cell 20 is D, and the distance between the outer peripheral surfaces of the battery cells 20 adjacent in the column direction is When CL is the distance between the sides 60 of lead plates 24 adjacent in the column direction in the row direction, the relationship r≦((D/2+GP/2)−CL)/2 is satisfied.

Further, the distance between the center O of the exposed side terminal surface 70 of the first row Ra and the row direction side 60 of the first lead plate 72 is set as L1, and the distance between the center O of the exposed side terminal surface 70 of the second row Rb and the second When the distance from the lead plate 74 to the side 60 in the row direction is L2, the relationship L1=L2=((D/2+GP/2)-CL)/2 is satisfied.

As shown in FIGS. 4 and 8, when the first lead plate 72 is the intermediate lead plate 64a, the second lead plate 74 is the intermediate lead plate 64b, the first row Ra is R3, and the second lead plate 74 is the intermediate lead plate 64b. Row Rb is R4. As a specific combination of "first lead plate 72, second lead plate 74, first row Ra, second row Rb" other than the above, on the first exposed side surface 32 of FIG. 4, "intermediate lead plate 64b, In the second exposed side surface 34 of FIG. 5, "intermediate lead plates 64d, intermediate lead plates 64e, R2, R3", "intermediate lead plates 64e, intermediate lead plates 64f, R4, R5", "intermediate lead plate 64f, output lead plate 62b, R6, R7".

As shown in FIGS. 4 to 7, the insulating wall 50 provided in the insulating portion 48 protrudes between the row-direction sides 60 of the lead plates 24 adjacent to each other. That is, the insulating wall 50 is interposed between the sides 60 in the row direction. Thereby, the lead plates 24 adjacent to each other are insulated from each other.

Slits 76 are provided in the column direction in the portions of the lead plates 24 facing the insulating portions 48, respectively. Further, as shown in FIG. 1 and the like, protruding piece-shaped connection ends 54 that protrude outward in the row direction and are inserted into the grooves 56 are provided on each side 78 of the lead plate 24 in the column direction on the arrow Y1 side. ing. By connecting lead wires (not shown) to these connection ends 54, the plurality of lead plates 24 are connected to the connector section via the BMU 14.

As shown in FIG. 2, the two cell holders 22a and 22b configured as described above are arranged such that their second exposed side surfaces 34 face each other with the insulating member 80 in between. Intermediate lead plates 64d, 64e, and 64f provided on the second exposed side surfaces 34 facing each other are insulated by an insulating member 80. Furthermore, the output lead plates 62b provided on the second exposed side surfaces 34 facing each other are electrically connected to each other via the tab portions 66b. As a result, the terminal surfaces 18 of the two cell holders 22a and 22b on the other end side in the column direction (arrow Z2 side, R7 in FIG. 5) are connected in series.

The output lead plate 62b of the cell holder 22a, the tab portion 66b, and the output lead plate 62b of the cell holder 22b are integrally formed from a single metal plate. The tab portion 66b extends from approximately the center in the row direction of the output lead plate 62b of the cell holder 22a, curves below the insulating member 80, and heads toward the approximately center in the row direction of the output lead plate 62b of the cell holder 22b.

The output (voltage and current) of the plurality of battery cells 20 held in the cell holders 22a, 22b is transmitted through the tab portions of a set of output lead plates 62a provided on the first exposed side surface 32 side of each of the cell holders 22a, 22b. 66a. The tab portions 66a extend upward from the cell holders 22a and 22b from one of the sides 60 in the row direction of the output lead plate 62a that are not adjacent to the intermediate lead plate 64a (arrow Z1 side). Extending.

In the present embodiment, the tab portions 66a, 66b are provided at approximately the center of the side 60 in the row direction of the output lead plates 62a, 62b, but the tab portions are not particularly limited to this, and for example, , may be provided on the side 78 of the output lead plates 62a, 62b in the column direction.

As shown in FIG. 1, the BMU 14 is disposed above the battery core pack 12 within the case 16. Note that the BMU 14 may be provided below or to the side of the battery core pack 12 in the case 16. The BMU 14 includes, for example, a control unit that controls charging and discharging of the battery core pack 12, a communication unit that communicates with the electric vehicle and the charging device, and a state of the battery core pack 12 detected from the temperature, voltage, etc. of the battery cells 20. (both not shown).

The case 16 can be made of, for example, metal such as aluminum, resin (including fiber-reinforced resin), or the like. Further, the case 16 includes a bottom case 82 that covers the bottom surface of the battery core pack 12, an outer shell case 84 that covers the side surfaces of the battery core pack 12, and a top case 86 that covers the top surface of the battery core pack 12.

The bottom case 82 is a casing with an open top end, and the above-mentioned connector section and the like are housed inside. The connector portion is exposed to the outside of the case 16 through, for example, a notch formed in the bottom wall of the bottom case 82, and is connected to a power supply port of an electric vehicle or a charging device for charging the battery pack 10. connection is possible. Note that the above-mentioned notch, power supply port, and charging device are all not shown. By connecting the connector portion to the power supply port or the charging device, the power supply port or the charging device and the battery core pack 12 can be electrically connected via the BMU 14.

The outer shell case 84 has a square cylindrical shape with openings provided at both ends in the vertical direction. The top case 86 is a casing with an open bottom end, and is provided with a handle 88 on the top side that can be gripped when carrying the battery pack 10.

With the bottom case 82 covering the opening on the lower end side of the outer shell case 84 and the top case 86 covering the opening on the upper end side of the outer shell case 84, the bottom case 82, the outer shell case 84, and the top case 86 are connected to each other. be integrated. The battery core pack 12 supported by a support frame (not shown) is housed in the internal space of the case 16 thus formed.

In the battery pack 10 according to this embodiment, which is basically configured as described above, for example, the battery pack 10 can be carried near the charging device by grasping the handle 88, and the connector portion and the charging device can be connected. Accordingly, the battery cell 20 can be charged. On the other hand, for example, the battery cells 20 can be discharged by carrying the battery pack 10 by grasping the handle 88 and mounting the battery pack 10 on an electric vehicle so that the connector part and the power supply port are connected. I can do it.

From the above, in this battery pack 10, the lead plate 24 extends in the row direction, that is, the side 60 of the lead plate 24 in the row direction is a straight line orthogonal to the column direction. For this reason, for example, unlike the case where the side 60 in the row direction has a zigzag shape, it is possible to obtain the lead plate 24 with high precision using a simple mold, and to remove the unused portion when punching the lead plate 24 from a flat plate. The proportion can be reduced to improve material yield.

In addition, in this battery pack 10, since the plurality of battery cells 20 are arranged in a zigzag pattern in the row direction, even if the battery cells 20 are held in high density in the cell holders 22a and 22b, external forces especially from the radial direction of the battery cells 20 However, the battery cell 20 can be made less likely to be crushed.

Therefore, according to the battery pack 10, it is possible to protect the battery cells 20 with a simple configuration without increasing manufacturing costs.

In the battery pack 10 according to the above embodiment, the terminal surfaces 18 and the lead plates 24 are electrically connected by welding through the welding portions 58, and the terminal surfaces 18 arranged in the row direction have their centers O in the column direction. The lead plate 24 has a first terminal surface 38 disposed on one side of the terminal surface 38 and a second terminal surface 40 whose center O is disposed on the other side in the column direction. Covers the entire covered side terminal surface 68, which is either one of the surfaces 40, and covers more than half and less than the whole of the exposed side terminal surface 70, which is the other of the first terminal surface 38 and the second terminal surface 40, in the column direction. Thus, the side 60 of the lead plate 24 in the row direction is arranged to cross the exposed terminal surface 70, the radius of the welded portion 58 is r, the diameter of the battery cell 20 is D, and the battery cells adjacent in the column direction are When the distance between the outer peripheral surfaces of the leads 20 is GP, and the distance between the row direction sides 60 of the lead plates 24 adjacent in the column direction is CL, r≦((D/2+GP/2)−CL)/2. I decided to satisfy the relationship.

In this battery pack 10, by setting the radius r of the welding portion 58 as described above, even if the side 60 in the row direction of the lead plate 24 is made straight, the terminal surface 18 is not connected to the lead plate 24 to be connected. It is possible to effectively avoid being electrically connected to different lead plates 24 or electrically connecting adjacent lead plates 24 to each other via the welded portion 58.

In the battery pack 10 according to the above embodiment, the exposed side surface 30 is provided with an opening 36 that exposes the terminal surface 18 and an insulating section 48 that partially covers the opening 36, and the insulating section 48 is provided adjacent to the opening 36 in the column direction. One side of a set of lead plates 24 is used as a first lead plate 72, the other side is used as a second lead plate 74, one side of two rows of terminal surfaces 18 adjacent in the column direction is used as a first row Ra, and the other side is used as a first lead plate 72. is the second row Rb, and the first lead plate 72 covers the entire covered side terminal surface 68 of the first row Ra and more than half but less than the entire exposed side terminal surface 70 of the first row Ra. When the plate 74 covers the entire covered side terminal surface 68 of the second row Rb and more than half but less than the entire exposed side terminal surface 70 of the second row Rb, the first lead plate 72 covers the entire covered side terminal surface 68 of the second row Rb. The part of the exposed side terminal surface 70 exposed from the second lead plate 74 is opposed to the part exposed from the second lead plate 74 through the insulating part 48, and the second lead plate 74 is formed from the first lead plate 72 of the exposed side terminal surface 70 of the first row Ra. The exposed portion is opposed to the insulating portion 48 with the insulating portion 48 interposed therebetween.

In this case, even if the distance between the outer peripheral surfaces of the battery cells 20 held by the cell holders 22a and 22b is reduced, the insulating portion 48 prevents the terminal surface 18 from electrically connecting with the lead plate 24 to which the terminal surface 18 is not connected. connection can be avoided. Therefore, it is possible to increase the density of the battery cells 20 held by the cell holders 22a and 22b while effectively suppressing the occurrence of short circuits in the battery cells 20 and the lead plates 24.

In the battery pack 10 according to the above embodiment, the insulating section 48 is provided with an insulating wall 50 that protrudes between the opposing sides 60 of the first lead plate 72 and the second lead plate 74 in the row direction. The first lead plate 72 and the second lead plate 74 are insulated by the insulating wall 50 interposed between the sides 60 in the row direction. In this case, the insulating wall 50 extending linearly in the row direction is, for example, an insulating wall provided in a zigzag shape in the row direction to insulate lead plates (not shown) whose sides 60 in the row direction are zigzag. (not shown), it can be easily provided. This also makes it possible to reduce the cost of the battery pack 10.

In the battery pack 10 according to the above embodiment, the slits 76 are provided in the column direction in the portions of the lead plates 24 facing the insulating portions 48 . As shown in FIGS. 6 and 7, there is a step between the part of the opening 36 covered with the insulating part 48 and the other opening 36 adjacent in the column direction that is not covered with the insulating part 48. 48a is formed. Even if the step 48a is formed in this way, the lead plate 24 can be placed along the terminal surface 18 well because the lead plate 24 is provided with the slit 76. That is, it is possible to suppress stress from being generated in the lead plate 24 in the direction of pulling it away from the welded portion 58. Thereby, the lead plate 24 and the terminal surface 18 can be well connected via the weld portion 58.

In the battery pack 10 according to the above embodiment, the distance between the center O of the exposed side terminal surface 70 of the first row Ra and the side 60 of the first lead plate 72 in the row direction is L1, and the exposed side of the second row Rb is When the distance between the center O of the terminal surface 70 and the side 60 in the row direction of the second lead plate 74 is L2, the relationship L1=L2=((D/2+GP/2)-CL)/2 is satisfied. And so.

In this case, both the distance L1 and the distance L2 may be set to a size that allows the welding portion 58 of a size that allows the exposed side terminal surface 70 and the lead plate 24 to be satisfactorily welded. can. Therefore, the exposed side terminal surface 70 of the first row Ra and the first lead plate 72 can be easily welded, and the exposed side terminal surface 70 of the second row Rb and the second lead plate 74 can be easily welded. becomes possible.

In the battery pack 10 according to the above embodiment, the lead plate 24 includes output lead plates 62a, 62b and intermediate lead plates 64a, 64b, 64c, 64d, 64e, 64f, and the output lead plates 62a, 62b are , one row of terminal surfaces 18 arranged at the ends of the exposed side surface 30 in the column direction are connected in parallel, and intermediate lead plates 64a, 64b, 64c, 64d, 64e, 64f connect two rows of terminal surfaces 18 in a column. We decided to connect them in series in the direction and in parallel in the row direction. In this case, the plurality of battery cells 20 held in the cell holders 22a, 22b are connected in parallel and in series to increase the output, and the output of these plurality of battery cells 20 is connected via the output lead plates 62a, 62b. can be obtained easily.

In the battery pack 10 according to the embodiment described above, the number of rows of the plurality of battery cells 20 held in the cell holders 22a and 22b is an odd number, and one of the set of exposed side surfaces 30 is the first exposed side surface 32, and the other side is the first exposed side surface 32. is the second exposed side surface 34, in the first exposed side surface 32, one row (R1) on one end side in the column direction is connected to the output lead plate 62a, and the remaining rows (R2 to R7) are connected to the intermediate leads. On the second exposed side surface 34, one row (R7) on the other end side in the column direction is connected to the output lead plate 62b, and the remaining rows (R1 to R6) are connected to the output lead plate 62b. It is assumed that the lead plates 64d, 64e, and 64f are connected to the lead plates 64d, 64e, and 64f.

In this case, it becomes possible to arrange the output lead plates 62a, 62b on each of the pair of exposed side surfaces 30 of the cell holders 22a, 22b. This makes it easy to arrange, for example, the exposed side surfaces 30 (second exposed side surfaces 34) of the plurality of cell holders 22a, 22b facing each other, which in turn makes it easier to increase the output and reduce the size of the battery pack 10. Become.

Note that the number of rows of battery cells 20 held by the cell holders 22a and 22b may be an even number. In this case, for example, output lead plates 62a and 62b are provided at both ends of the first exposed side surface 32 in the column direction, and the second exposed side surface 34 may be provided with only a plurality of intermediate lead plates 64d, 64e, 64f, etc.

The battery pack 10 according to the embodiment described above includes a plurality of (two) cell holders 22a, 22b, and the plurality of cell holders 22a, 22b are arranged such that their exposed side surfaces 30 (second exposed side surfaces 34) face each other. The intermediate lead plates 64d, 64e, and 64f provided on the exposed side surfaces 30 facing each other are insulated via the insulating member 80, and the output lead plates 62b provided on the exposed side surfaces 30 facing each other are insulated from each other through tabs. It is assumed that the electrical connection is made through the portion 66b. In this case, the output of the battery pack 10 can be further increased by electrically connecting the plurality of battery cells 20 held by the plurality of cell holders 22a and 22b with a simple and compact configuration. Note that the number of cell holders 22a included in the battery pack 10 may be one, or may be three or more.

In the battery pack 10 according to the above embodiment, the pair of output lead plates 62b and the tab portion 66b provided on the exposed side surfaces 30 (second exposed side surfaces 34) facing each other are integrally formed from a single metal plate. It was formed in a particular way. In this case, the configuration of the battery pack 10 can be further simplified and manufacturing costs can be further reduced. Note that the output lead plate 62b of the cell holder 22a, the output lead plate 62b of the cell holder 22b, and the tab portion 66b may be configured separately from each other.

The present invention is not particularly limited to the embodiments described above, and various modifications can be made without departing from the gist thereof.

For example, as shown in FIG. 9, instead of the slit 76, the lead plate 24 is provided with a step corresponding to the thickness of the insulating part 48 between the part facing the terminal surface 18 and the part facing the insulating part 48. 90 may be provided. Even in this case, it is possible to keep the lead plate 24 well along the terminal surface 18 and prevent stress from being generated in the lead plate 24 in the direction of separating it from the welded portion 58. It becomes possible to connect them well through the welded portion 58.

DESCRIPTION OF SYMBOLS 10... Battery pack 12... Battery core pack 14... BMU (battery management unit) 18... Terminal surface 20... Battery cell 22a, 22b... Cell holder 24... Lead plate 30... Exposed side surface 32... First exposed side surface 34... Second exposed side surface 36... Opening 38... First terminal surface 40... Second terminal surface 48... Insulating section 50... Insulating wall 58... Welding section 60... Side in the row direction 62a, 62b... Output lead plate 64a, 64b, 64c, 64d, 64e , 64f... Intermediate lead plate 66a, 66b... Tab portion 68... Covered side terminal surface 70... Exposed side terminal surface 72... First lead plate 74... Second lead plate 76... Slit 80... Insulating member 90... Level difference

Claims (11)

A battery cell (20) having a cylindrical shape and provided with terminal surfaces (18) having different positive and negative polarities at both ends in the axial direction, and a plurality of the battery cells are arranged in the row direction so that the terminal surfaces are arranged on the same plane. A battery pack (10) comprising: cell holders (22a, 22b) held side by side in the column direction; and a plurality of lead plates (24) electrically connecting at least the terminal surfaces arranged in the row direction. hand,
The cell holder has a set of exposed side surfaces (30) provided with openings (36) that respectively expose the terminal surfaces on both sides of the plurality of battery cells in the axial direction from the cell holder, and Holding the terminal surfaces so that the centers (O) of the adjacent terminal surfaces are alternately shifted to one side and the other side in the column direction,
In the plurality of terminal surfaces arranged on the exposed side surface, the terminal surfaces adjacent in the row direction have the same positive and negative polarities, and the terminal surfaces adjacent in the column direction have different positive and negative polarities,
The plurality of lead plates are arranged with respect to the exposed side surface at intervals in the column direction, and have a side (60) extending linearly in the row direction and a side (60) in the column direction. and a side (78) extending linearly along the
The terminal surfaces arranged in the row direction include a first terminal surface (38) in which the center is arranged on one side in the column direction, and a second terminal surface (38) in which the center is arranged in the other side in the column direction. 40) and
The lead plate covers the entire covered side terminal surface (68), which is one of the first terminal surface and the second terminal surface, and is the other of the first terminal surface and the second terminal surface. The battery pack is arranged such that the side (60) of the lead plate in the row direction crosses the exposed terminal surface by covering more than half but less than the entirety of the exposed terminal surface (70) in the column direction. . The battery pack according to claim 1,
The terminal surface and the lead plate are electrically connected by welding through a welding part (58) ,
The radius of the welded portion is r, the diameter of the battery cell is D, the distance between the outer peripheral surfaces of the battery cells adjacent in the column direction is GP, and the rows of the lead plates adjacent in the column direction are A battery pack that satisfies the relationship r≦((D/2+GP/2)−CL)/2, where CL is the distance between the sides in the direction. The battery pack according to claim 2,
The exposed side surface is provided with an opening (36) that exposes the terminal surface, and an insulating part (48) that partially covers the opening,
One side of the pair of lead plates adjacent in the column direction is a first lead plate (72), the other side is a second lead plate (74), and the terminal surfaces of two rows adjacent in the column direction are One side is a first row (Ra) and the other side is a second row (Rb), and the first lead plate covers the entire covered side terminal surface of the first row and the exposed terminal surface of the first row. The second lead plate covers more than half and less than the entirety of the side terminal surface, and the second lead plate covers the entire covered side terminal surface of the second row and half or more but less than the entirety of the exposed side terminal surface of the second row. When covering
The first lead plate faces a portion of the exposed terminal surface of the second row exposed from the second lead plate, with the insulating portion interposed therebetween;
In the battery pack, the second lead plate faces a portion of the exposed terminal surface of the first row exposed from the first lead plate, with the insulating portion interposed therebetween. The battery pack according to claim 3,
The insulating portion is provided with an insulating wall (50) that protrudes between the row direction sides of the lead plates adjacent to each other, and the insulating wall interposed between the row direction sides . A battery pack, wherein the lead plates adjacent to each other are insulated from each other. The battery pack according to claim 3 or 4,
In the battery pack, a slit (76) is provided in a portion of the lead plate facing the insulating portion in the column direction. The battery pack according to claim 3 or 4,
In the battery pack, the lead plate is provided with a step (90) corresponding to the thickness of the insulating part between a part facing the terminal surface and a part facing the insulating part. In the battery pack according to any one of claims 3 to 6,
The distance between the center of the exposed terminal surface of the first row and the side of the first lead plate in the row direction is L1, and the distance between the center of the exposed terminal surface of the second row and the second lead is L1. A battery pack that satisfies the relationship L1=L2=((D/2+GP/2)-CL)/2, where L2 is the distance from the side of the plate in the row direction. In the battery pack according to any one of claims 1 to 7,
The lead plate includes an output lead plate (62a, 62b) and an intermediate lead plate (64a, 64b, 64c, 64d, 64e, 64f),
The output lead plate connects in parallel one row of the terminal surfaces arranged at the ends of the exposed side surface in the column direction,
In the battery pack, the intermediate lead plate connects the terminal surfaces of two rows in series in the column direction and in parallel in the row direction. The battery pack according to claim 8,
The number of rows of the plurality of battery cells held in the cell holder is an odd number,
When one of the set of exposed side surfaces is a first exposed side surface (32) and the other is a second exposed side surface (34),
On the first exposed side surface, one row on one end side in the column direction is connected to the output lead plate, and the remaining rows are connected to the intermediate lead plate,
On the second exposed side surface, one row on the other end side in the column direction is connected to the output lead plate, and the remaining rows are connected to the intermediate lead plate. The battery pack according to claim 8 or 9,
comprising a plurality of the cell holders,
The plurality of cell holders are arranged so that the exposed side surfaces thereof face each other,
The intermediate lead plates provided on the exposed side surfaces facing each other are insulated via an insulating member (80),
In the battery pack, the output lead plates provided on the exposed side surfaces facing each other are electrically connected to each other via a tab portion (66b). The battery pack according to claim 10,
In the battery pack, the pair of output lead plates provided on the exposed side surfaces facing each other and the tab portion are integrally formed from a single metal plate.

Images