JP2012003953A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack which can prevent warpage of a substrate even when external force is applied and which has a structure advantageous in reducing size, weight and cost.SOLUTION: A battery pack comprises: a unit cell 10; a strip-like substrate 40 arranged along a principal plane of a sealing plate 10a of the unit cell 10; and a cap 20 covering the principal plane of the sealing plate 10a of the unit cell 10 with the substrate 40 contained inside. The cap 20 has a bottomed cylindrical shape and part of a cylinder end edge is arranged so as to cover a corresponding position on an outer peripheral side wall of the unit cell. In the battery pack, hook parts 20e and 20f ... projecting inward are formed respectively on two side walls arranged vertically in a z-axis direction of the cap 20. Edges 40f and 40g ... of the substrate 40 are engaged with the respective hook parts 20e and 20f ... of the cap 20 and are housed in an inner bottom side via the engagement.

Description

  The present invention relates to a battery pack, and more particularly, to a structure for attaching a substrate and a cap to a unit cell.

Battery packs are used as a power source for mobile devices such as mobile phones (for example, Patent Document 1). The configuration of the battery pack according to the prior art will be described with reference to FIG.
As shown in FIG. 7, the battery pack according to the prior art includes a unit cell 911 having a flat rectangular parallelepiped appearance, a protective element 913, a substrate holder 923, and a substrate 922 arranged along an end surface (sealing plate) 911a thereof. And a cap 921, a cover 931 attached to the bottom surface of the unit cell 911, and an exterior label 930 attached to cover the outer peripheral surface of the unit cell 911. An insulating plate 932 is interposed between the bottom surface of the unit cell 911 and the cover 931. The exterior label 930 is attached so as to cover each part of the cap 921 and the cover 931.

  The protection element 913 is connected to a terminal 911 b provided on the end surface 911 a of the unit cell 911 by the element lead 914. An insulating plate 912 is interposed between the end surface 911a of the unit cell 911 and the protective element 913 and its element leads 914 and 915, and the element lead 914 and the terminal 911b are opened in the insulating plate 912. It is connected through the opening 912a.

  The substrate 922 is positioned relative to the end surface 911a of the unit cell 911 with the substrate holder 923 sandwiched therebetween. The substrate 922 is provided with substrate leads 922d and 922e at two positions on the right rear side in the X-axis direction, and one of the substrate leads 922d is connected to the element lead 915 of the protection element 913, and One substrate lead 922e is connected to an end face (sealing plate) 911a of the unit cell 911 via a clad plate 911c and a lead plate 916.

  The end surface 911a of the unit cell 911 is covered with a cap 921 in a state where the protection element 913, the substrate holder 923, the substrate 922, and the like are attached. The cap 921 is joined to the outer can of the unit cell 911, and the three external connection terminals 922a to 922c of the substrate 922 are exposed through the three windows 921a to 921c, respectively.

Japanese Patent Laid-Open No. 2003-1325959

  However, the battery pack is required to be further reduced in size, weight, and cost. However, in the battery pack according to the related art, the substrate 922 is connected to the external connection terminals 922a to 922c when the device terminals are connected. In order to prevent bending, a substrate holder 923 is interposed between the end surface 911 a of the unit cell 911 and the substrate 922. For this reason, when adopting the structure of the battery pack according to the prior art, there is a limit to downsizing, weight reduction, and cost reduction.

  The present invention has been made to solve such a problem, and can prevent the substrate from being bent even when an external force is applied, and is advantageous in downsizing, weight reduction, and cost reduction. An object is to provide a battery pack having a simple structure.

In order to achieve the above object, the battery pack according to the present invention employs the following configuration.
The battery pack according to the present invention includes a unit cell, a strip-shaped substrate disposed along one end surface of the unit cell, and a cap that covers the one end surface of the unit cell while enclosing the substrate. The cap in the battery pack according to the present invention has a bottomed cylindrical shape, and is arranged so that a part of the cylindrical end edge covers the position of the outer peripheral side wall of the unit cell.

  In the battery pack according to the present invention, a hook-like hook portion is formed to project inwardly on each of two opposing side walls of the cap, and the edge portion of the substrate is locked by the hook portion of the cap. Thus, the cap is housed in the inner bottom side of the cap.

  In the battery pack according to the present invention, the substrate is locked by the hook portion provided inside the side wall of the cap. For this reason, in the battery pack according to the present invention, the substrate can be held without interposing the substrate holder between the substrate and one end surface (main surface of the sealing plate) of the unit cell. That is, in the battery pack according to the present invention, the substrate is locked to the cap, and the cap is attached to the unit cell. As a result, the substrate is coupled to the unit cell. Therefore, in the battery pack according to the present invention, even when a force is applied from the outside, the board is prevented from being bent by the engagement with the hook portion of the cap.

Therefore, in the battery pack according to the present invention, it is possible to effectively prevent the substrate from being bent without inserting the substrate holder as described above, and to reduce the size and weight and to reduce the manufacturing cost by omitting the substrate holder. Can be reduced.
In the battery pack according to the present invention, for example, the following variations can be employed.

  The battery pack according to the present invention may employ a configuration in which at least two hook portions of the cap are formed on each of two opposing side walls in the above configuration. As described above, when at least two hook portions in the cap are formed on each of the two side walls, the substrate is more stably disregarded as compared with the case where only one hook portion is provided. be able to.

  The battery pack according to the present invention may employ a configuration in which, in the above configuration, three sides around the hook portion of the cap are cut out in a U-shape. When adopting such a configuration, when the cap and the substrate are locked in the manufacturing process of the battery pack, the hook portion can use flexibility when contacting the edge portion of the substrate, Does not require complicated work or great force. Therefore, it is excellent from the viewpoint of reducing the manufacturing cost.

  In the battery pack according to the present invention, in the above configuration, a label is attached to the outer surface of the side wall of the unit cell, and the label covers the outer surface of the side wall of the cap so as to cover the notched portion of the cap. It is possible to adopt a configuration in which a part is attached. Thereby, the notch part for the structure of a hook part can be hidden so that it cannot be visually recognized from the outside, and it is excellent from a viewpoint of appearance quality. Further, by covering the notch portion by sticking the label in this way, it is possible to prevent moisture and dust from entering the package through the notch portion. Therefore, when such a configuration is adopted, higher quality can be ensured.

  In the battery pack according to the present invention, in the configuration described above, the cap has a protrusion protruding toward one end surface of the unit cell, and the one end surface of the unit cell has a recess for receiving insertion of the protrusion of the cap. It is formed and the structure that the protrusion part of the cap is inserted with respect to the recessed part in the end surface of a unit cell is employable. Thus, when adopting a configuration in which the protrusion of the cap is fitted into the recess provided on one end surface (sealing plate) of the unit cell, the open end of the cap and the one end surface of the unit cell are in contact with each other. Compared to the case, the bending and twisting strength of the cap can be increased. Therefore, when adopting the above configuration, it is not necessary to provide a separate member for improving the bending and twisting strength of the cap. The twist strength can be improved.

  In the battery pack according to the present invention, in the above configuration, a positive / negative bipolar terminal is provided on one end surface of the unit cell, and the substrate is connected to the positive / negative bipolar terminal of the unit cell via a lead plate. can do. In this case, it is possible to adopt a configuration in which the lead plate related to connection with at least one of the positive and negative bipolar terminals is bent into a crank shape. In the case of adopting such a configuration, the lead plate is bent into the above shape to improve the mechanical synthesis, and when the cap comes into contact with the hook portion, the substrate is In addition to the effect of fixing, the substrate can be fixed at a plurality of locations by joining the lead plates. Therefore, it is excellent from the viewpoint of the mounting strength of the substrate.

The battery pack according to the present invention can employ a configuration in which the cap is formed of a resin material in the above configuration. By forming the cap with a resin material in this way, even when the hook portion is provided, it is effective in reducing the manufacturing cost of the battery pack without increasing the cost for manufacturing the cap. is there.
In the battery pack according to the present invention, in the configuration described above, the substrate resin portion formed by integrally molding the electronic component group mounted on the substrate is provided on the surface of the substrate facing the one end surface of the unit cell. The resin portion of the substrate has a rectangular parallelepiped shape, and the main surface is arranged in a state of facing one terminal projectingly formed on one end surface of the unit cell or a lead plate connected to the one terminal. Can be adopted. When such a configuration is adopted, the substrate can be fixed when the cap is inserted. In addition, after the cap is inserted, when an external pressing force is applied to the substrate, it is possible to obtain an effect that the substrate can be prevented from being bent and the substrate can be fixed.

(A) is a schematic perspective view which shows the external appearance structure of the battery pack 1 which concerns on embodiment, (b) is a schematic perspective view which shows the state which removed the exterior label 30 from the battery pack 1. FIG. 2 is a schematic exploded perspective view showing an internal configuration of the battery pack 1. FIG. 2 is a schematic side view showing how the substrate 40 and the cap 20 are attached to the unit cell 10. FIG. (A) is a schematic perspective view which shows the attachment form of the board | substrate 40 and the cap 20 with respect to the unit cell 10, (b) is a schematic perspective view which shows the principal part of the cap 20. As shown in FIG. 3 is a schematic cross-sectional view showing how the substrate 40 and the cap 20 are attached to the unit cell 10. FIG. (A) is a schematic perspective view which shows the attachment form of the board | substrate 40 and the cap 22 with respect to the unit cell 10 in the battery pack which concerns on a modification, (b) is the schematic cross section. It is a model expansion perspective view which shows the structure of the battery pack which concerns on a prior art.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In addition, the specific example shown below is an example used to explain the configuration of the present invention and the operations and effects produced from the configuration in an easy-to-understand manner. The following specific examples are not limited at all.
[Embodiment]
1. External Configuration of Battery Pack 1 The external configuration of the battery pack 1 will be described with reference to FIG. FIG. 1B shows a state where the exterior label 30 is removed from the battery pack 1 shown in FIG.

As shown in FIG. 1A, the battery pack 1 according to the present embodiment has a flat rectangular parallelepiped unit cell (not shown in FIG. 1), and a cap 20 and a cover 21 are attached to the end face thereof. It has been. And the exterior label 30 is affixed on the outer peripheral surface of the unit cell.
The cap 20 has four windows 20a to 20d, and the external connection terminals 40a to 40c are exposed to the outside through the windows 20a to 20c. The window portion 20 d of the cap 20 is covered with a test point label 31.

As shown in FIG. 1 (b), the side wall of the Z-axis direction vertical in the cap 20, the hook portion 20e of the two places, 20f, · · are provided _{(A 1} moiety, _{A 2} parts). In addition, in FIG.1 (b), illustration is abbreviate | omitted about the hook part of the side wall of the Z-axis direction lower side.
The hook portions 20e, 20f,... In the cap 20 protrude in a bowl shape toward the inside of the cap 20 having a bottomed cylindrical shape. The functions performed by the hook portions 20e, 20f,... In the cap 20 will be described later.

2. Internal Configuration of Battery Pack 1 The internal configuration of the battery pack 1 according to the present embodiment will be described with reference to FIG.
As shown in FIG. 2, a negative electrode terminal 10b protrudes from one end surface (end surface on the left front side in the X-axis direction) 10a of the unit cell 10, and a sealing member that is an end surface 10a is formed at the right end portion in the Y-axis direction. A clad plate 10c is joined to the outer surface of the plate. In the unit cell 10, the outer surface portion excluding the negative electrode terminal 10b has a function as a positive electrode terminal. A concave portion 10d having a depth in the X-axis direction is provided at the left end portion in the Y-axis direction on the end surface 10a of the unit cell 10. This will be described later.

An element lead 41 a of a protection element (for example, a PTC element) 41 is connected to the negative electrode terminal 10 b of the unit cell 10. An insulating plate 43 is interposed between the protection element 41 and the end face 10a of the unit cell 10. The other element lead 41 b in the protection element 41 is connected to a conductive land (not shown in FIG. 2) of the substrate 40.
On the other hand, a lead plate 42 bent into a crank shape is connected to the clad plate 10c joined to the end face 10a of the unit cell 10. The other end of the lead plate 42 is connected to a conductive land (not shown in FIG. 2) of the substrate 40.

  The board 40 has a substantially strip-like appearance, and three external connection terminals 40a to 40c and test points 40d and 40e are provided on the main surface on the left front side in the X-axis direction. The substrate 40 is enclosed in a cap 20 having a substantially bottomed cylindrical shape. The cap 20 is provided with windows 20a to 20c at locations corresponding to the external connection terminals 40a to 40c of the substrate 40 on the outer surface of the bottom wall, and at locations corresponding to the test points 40d and 40e of the substrate 40. A window portion 20d is provided. Among these, the window portion 20d is hidden by attaching the test point label 31 at the final stage of the manufacturing process of the battery pack 1.

Further, the cap 20 is provided with two hook portions 20e, 20f,... On each side wall located in the vertical direction in the Z-axis direction. The board 40 is fixed in a state where it is housed on the inner bottom side of the cap 20 by the edge portions 40f, 40g being locked by the hook portions 20e, 20f,.
The opposite end surface (end surface on the right side in the X-axis direction) of the unit cell 10 is covered with a cover 21 made of a resin material or the like. Then, the outer peripheral surface of the unit cell 10, a part of the outer surface of the side wall of the cap 20, and the edge portion of the cover 21 are covered by sticking the exterior label 30. The exterior label 30 is attached so as to cover the outer periphery of the hook portions 20e, 20f,.

3. Attachment of Cap 20 to Unit Cell 10 As shown in FIG. 3, a cap fixing rib 20 g projects from the opening edge of the cap 20 toward the lower side in the X-axis direction. The ribs 20g in the cap 20 are provided at locations and sizes corresponding to the recesses 10d (see FIG. 2) provided in the end surface 10a of the unit cell 10.

  The cap 20 has a rib 20g provided at an opening edge thereof inserted into the recess 10d of the unit cell 10 and locks the substrate 40 with the hooks 20e, 20f,. It will be attached securely. In addition, since the lead plate 42 bent into a crank shape is inserted between the substrate 40 and the end face 10a of the unit cell 10, the cap is attached at two points including the insertion point into the recess 10d by the rib 20g. 20 will be supported.

4). Detailed Configuration of Cap 20 The detailed configuration of the cap 20 will be described with reference to FIGS. 4 and 5.
As shown in FIG. 4 (a), the hook portions 20e, 20f,... Provided on the side wall of the cap 20 are notched in a U-shape and part of the side wall is left in a tongue shape. It is provided in the part. With such a configuration, when the cap 20 is locked to the edge portions 40f and 40g of the substrate 40, a large force is not required, and it is possible to prevent the substrate 40 from remaining distorted after being attached. it can.

  As shown in FIG. 4B, the rib 20g of the cap 20 is provided so as to be substantially orthogonal to the end face 10a of the unit cell 10 to be attached. Accordingly, when the cap 20 is attached, when the rib 20g is fitted into the recess 10d provided on the end surface 10a of the unit cell 10, no distortion remains in the cap 20 and the unit cell 10.

As shown in FIG. 5, the hook portions 20e, 20f,... Of the cap 20 (only the hook portion 20f is shown in FIG. 5) have a hook-like cross-sectional shape and once the substrate 40 is locked. It is not easy to come off.
Further, the opening side edges 20 h and 20 i of the cap 20 cover a part of the outer peripheral surface 10 e of the unit cell 10. And although not shown in FIG. 5, the exterior label 30 is stuck from above.

5). Superiority In the battery pack 1 according to the present embodiment, the substrate 40 is locked by the edge portions 40f, 40g by the hook portions 20e, 20f,. For this reason, in the battery pack 1, the substrate 40 can be held in the cap 20 without being interposed between the substrate 40 and the end face 10 a of the unit cell 10. That is, in the battery pack 1, the substrate 40 is locked to the cap 20, and the cap 20 is attached to the unit cell 10. As a result, the substrate 40 is coupled to the unit cell 10. Therefore, in the battery pack 1, even when a force is applied to the external connection terminals 40 a to 40 c from the outside due to connection with an external device or the like, the board 40 is locked by the hook portions 20 e, 20 f,. Is prevented from bending.

In addition, the battery pack 1 according to the present embodiment also has an effect that the substrate 40 is locked by the lead plate 42 and the convex negative terminal 10 b in the unit cell 10.
Therefore, in the battery pack 1, it is possible to effectively prevent the bending of the substrate 40 without inserting the substrate holder as described above, and the size and weight can be reduced and the manufacturing cost can be reduced by omitting the substrate holder. Is possible.

[Modification]
The structure of the battery pack according to the modification will be described with reference to FIG. In FIG. 6, the difference from the battery pack 1 according to the above embodiment is mainly illustrated, and other configurations are the same as those of the battery pack 1 according to the above embodiment.
As shown in FIG. 6A, also in the battery pack according to this modification, two hook portions 22e, 22f,... Are provided on the upper and lower side walls of the cap 22 in the Z-axis direction, and the opening edge portion The rib 22g is fitted into the recess 10g provided on the end surface of the unit cell 10 in the same manner as described above.

The battery pack according to this modification is different from the battery pack 1 according to the above embodiment in that the hook portions 22e, 22f,... In the cap 22 have roots on the opening edge side of the cap 22. That is, in the cap 22, each hook portion 22 e, 22 f,... Is formed by cutting out the other three sides with the portion on the left back side in the X-axis direction being the root.
As shown in FIG. 6B, in the battery pack according to this modification, the substrate 40 is locked by the cap 22 without using the substrate holder, similarly to the battery pack 1 according to the above embodiment. Thus, the substrate 40 can be reliably held.

Therefore, also in the battery pack according to this modification, the same effect as described above can be obtained.
[Other matters]
In the above embodiment and modification, the unit cell 10 having a flat rectangular parallelepiped external shape is adopted. However, the shape of the unit cell is not limited to this, and for example, a cylindrical external appearance A unit cell having a shape, a unit cell having a non-flat rectangular shape, and the like can also be employed.

  Moreover, in the said embodiment and modification, although the form which has the number of the unit cells in a battery pack was employ | adopted as an example, about the number of the unit cells provided, two or more may be sufficient. For example, it is possible to adopt a form in which unit cells having a flat rectangular parallelepiped shape are stacked in the thickness direction, or a form in which a plurality of cylindrical batteries are bundled. .

In the above-described embodiment and modification, the constituent materials of the caps 20 and 22 are not particularly mentioned. However, the workability, the ease of manufacturing at the time of assembling the battery pack, and the like, and further the reduction of the component cost, etc. In view of the above, it is desirable to use a resin material. However, the present invention is not limited to this, and it is of course possible to use a metal material, for example.
In the embodiment and the modification described above, the number of hook portions 20e, 20f, 22e, 22f,... Formed on the caps 20 and 22 is two for each side wall. Absent. For example, when the hook portion is wide, only one hook portion may be formed. Conversely, three or more narrow hook portions may be provided.

Moreover, in the said embodiment and modification, although the surroundings of each hook part 20e, 20f, 22e, 22f, ... in the caps 20 and 22 were notched, notch is not necessarily required. However, it is desirable to provide a notch in consideration of workability at the time of manufacturing and distortion to the substrate 40 after assembly.
Furthermore, in the battery pack of the present invention, a substrate resin portion formed by integrally molding the mounted electronic component group can be provided on the surface of the substrate 40 on the side facing the end surface 10a of the unit cell 10. . In this case, the substrate resin portion has a rectangular parallelepiped shape, and the main surface thereof is opposed to the negative terminal 10b formed to project from the end surface 10a of the unit cell 10 or the lead plate 42 connected to the negative terminal 10b. It can also be set as the arrangement | positioning by. When such a configuration is adopted, the substrate 40 can be fixed when the cap 20 is inserted. After the cap 20 is inserted, when a pressing force from the outside is applied to the substrate 40, It is possible to obtain an effect that the substrate 40 can be prevented from being bent and fixed.

  The present invention is useful for realizing a battery pack that can be reduced in size, weight, and cost while effectively preventing bending of the substrate.

1. Battery pack 10. Unit cells 20, 22. Cap 21. Cover 30. Exterior label 31. Test point label 40. Substrate 41. Protection element 42. Lead plate 43. Insulation plate

Claims (8)

A battery pack comprising: a unit cell; a strip-shaped substrate disposed along one end surface of the unit cell; and a cap that covers the one end surface of the unit cell in a state of including the substrate;
The cap has a bottomed cylindrical shape, and a part of the cylindrical end edge is arranged so as to cover the position of the outer peripheral side wall of the unit cell,
On each of the two opposing side walls of the cap, a hook-shaped hook portion is formed inwardly,
The battery pack is characterized in that an edge portion of the substrate is locked by a hook portion of the cap and is stored in the inner bottom side of the cap by the locking. The battery pack according to claim 1, wherein at least two hook portions of the cap are formed on each of the two opposing side walls. The battery pack according to claim 1 or 2, wherein the hook portion of the cap is cut out in a U-shape at three sides around the hook portion. A label is attached to the outer surface of the side wall of the unit cell,
4. The battery pack according to claim 3, wherein the label is also attached to a part of the outer surface of the side wall of the cap so as to cover the notched portion. The cap has a protrusion protruding toward one end surface of the unit cell,
On one end surface of the unit cell, a recess for receiving insertion of the protrusion of the cap is formed,
The battery pack according to any one of claims 1 to 4, wherein the protrusion of the cap is fitted into a recess in one end surface of the unit cell. Positive and negative bipolar terminals are provided on one end surface of the unit cell,
The substrate is connected to the positive and negative electrode terminals of the unit cell via a lead plate,
The battery pack according to any one of claims 1 to 5, wherein the lead plate connected to at least one of the positive and negative bipolar terminals is bent into a crank shape. The battery pack according to any one of claims 1 to 6, wherein the cap is formed of a resin material. The substrate is provided with a substrate resin portion formed by integrally molding an electronic component group mounted on the substrate on the side facing the one end surface of the unit cell,
The substrate resin portion of the substrate has a rectangular parallelepiped shape, and a main surface thereof faces one terminal projectingly formed on one end surface of the unit cell or a lead plate connected to the one terminal. The battery pack according to claim 1, wherein the battery pack is arranged in a state.

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