JP2011233319A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack which can be manufactured at a low cost while securing high reliability.SOLUTION: In a unit cell 10 having a cylindrical appearance configuration, a positive electrode terminal 10b is formed which projects from a sealing plate being an upper end face. In the unit cell 10, the sealing plate is a negative electrode terminal. A holder member 11 is constituted of an insulating material, and a cover part covering a part of the sealing plate other than the protruded positive electrode terminal 10b of the unit cell 10 in a state of being housed in a battery housing part is formed integrally with the holder member 11. The cover part in the holder member 11 has the outer surface 11c which is in a state of being substantially flush with an external end face 10c of the positive electrode terminal 10b exposed to the outside from an opening 11b. In other words, the cover part of the holder member 11 is inserted between the sealing plate in the unit cell 10 and a lead plate connected to the positive electrode terminal 10b.

Description

  The present invention relates to a battery pack, and more particularly to a structure of a battery holder in a battery pack.

The battery pack is widely used as a power source of, for example, an electric tool, an electric assist bicycle, an electric vehicle (PEV), a hybrid electric vehicle (HEV), or a notebook personal computer (for example, Patent Documents 1 and 2). See). The basic structure of the battery pack according to the prior art will be described with reference to FIG.
As shown in FIG. 6, in the battery pack according to the prior art, a plurality (two in FIG. 6) of unit cells 910 are stored in the battery storage portion of the battery holder 911. Each of the unit cells 910 has a cylindrical appearance, and the battery storage portion of the battery holder 911 is also a cylindrical space according to the outer shape of the unit cell 910.

In the unit cell 910, an insulating tube 916 is attached to the outer periphery of the outer can 910a, and the outer periphery 910e is insulated from the outer periphery. In the unit cell 910, the insulating tube 916 is not attached to the other end surface (the bottom surface on the lower side in the Z-axis direction) 910d, and the outer can 910a is exposed as it is.
Further, a positive electrode terminal 910b is projected from one end surface of the unit cell 910 (a sealing plate on the upper end surface in the Z-axis direction).

  In the two unit cells 910 housed in the battery holder 911, an insulating sheet 915 provided with a hole 915a is arranged in a portion corresponding to each positive electrode terminal 910a, and the upper end surfaces 910c of the positive electrode terminal 910b are in a lead state in this state. They are connected by a plate 913. Further, the bottom surfaces 910d of the two unit cells 910, that is, the negative terminals are connected to each other by a lead plate 914.

  Here, the insulating sheet 915 prevents the lead plate 913 from coming into contact with the sealing plate (negative electrode) around the positive electrode terminal 910b of the unit cell 910. The insulating tube 916 is also attached to the outer periphery of the outer can 910a of the unit cell 910 in order to ensure insulation.

JP 2007-157358 A JP 2009-70614 A

However, in the battery pack according to the prior art shown in FIG. 6, the insulating tube 916 must be attached to the unit cell 910, and the insulating sheet 915 must be disposed on the side where the positive electrode terminal 910b is provided. As a result, the number of components increases, leading to an increase in manufacturing costs from the viewpoint of component costs and labor during manufacturing.
Thus, there is room for improvement in battery packs in response to requests for further cost reduction and high reliability.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a battery pack that can be manufactured at a low cost while ensuring high reliability.

In order to achieve the above object, the present invention employs the following configuration.
The battery pack according to the present invention is provided for a unit cell having a cylindrical outer shape, a battery holder having a battery storage portion having a shape corresponding to the outer shape of the unit cell, and a unit cell stored in the battery holder. And a lead plate to be connected. In the battery pack according to the present invention, in the unit cell, the first electrode terminal is formed from one end surface, and the periphery of the region where the first electrode terminal is formed on the one end surface is the second electrode terminal. (A terminal having a polarity different from that of the first electrode terminal), the battery holder is made of an insulating material, and the unit cell in the state where the battery holder is housed in the battery housing portion, The cover part which covers at least one part of the surrounding part of a 1st pole terminal is integrally formed. Furthermore, in the battery pack according to the present invention, at least a part of the first electrode terminal of the unit cell is exposed to the outside while being accommodated in the battery holder, and the exposed part is connected to the lead plate. The cover part of the battery holder is interposed between the second electrode terminal and the lead plate of the unit cell.

  In the battery pack according to the present invention, the battery holder is provided with a cover portion that covers at least a part of the peripheral portion of the first electrode terminal of the unit cell to be stored. Since the battery holder is made of an insulating material, it is not necessary to separately arrange an insulating sheet (insulating sheet 915 in FIG. 6) or the like on the end surface of the unit cell. It can prevent that a surrounding part and a lead board contact undesirably.

In addition, in the battery pack according to the present invention, it is not necessary to separately provide an insulating sheet for the insulation as described above, unlike the battery pack according to the prior art. Such component costs can be reduced.
Therefore, the battery pack according to the present invention can be manufactured at a low cost while ensuring high reliability.

The present invention can employ the following variations, for example.
In the battery pack according to the present invention, in the above configuration, the first electrode terminal of the unit cell protrudes from the peripheral portion on the one end surface toward the outside in the cylinder axis direction, and the unit cell is accommodated in the battery holder. In this state, the outer end surface of the first electrode terminal may be substantially flush with the outer surface of the cover portion of the battery holder. Thus, if the configuration in which the outer end surface of the first electrode terminal and the outer surface of the cover portion of the battery holder are substantially flush, the first electrode terminal and the lead plate are connected by spot welding. High welding strength can be ensured. That is, if the configuration in which the outer end surface of the first electrode terminal is substantially flush with the outer surface of the cover part in the battery holder, the outer surface of the first electrode terminal and the outer surface of the cover part in the battery holder are used. Since the stress caused by the step is not applied to the lead plates connected by spot welding, a high welding strength can be ensured.

Further, in the battery pack according to the present invention, in the above configuration, the outer end surface of the first electrode terminal and the outer surface of the cover portion of the battery holder are specifically flush with each other or have a step of 1 [mm] or less. It is also possible to adopt a configuration that is.
Moreover, in the battery pack which concerns on this invention, the structure that the outer peripheral surface of the exterior can of a unit cell is directly in contact with the surrounding wall which faces the battery storage part in a battery holder in the said structure is also employable. . In this way, the outer can of the unit cell is in direct contact with the peripheral wall facing the battery housing part in the battery holder, that is, the insulating tube 916 is the unit of the unit cell as in the battery pack according to the prior art shown in FIG. Since it is not attached to the outer can, the cost of parts can be reduced by the amount of omitting the insulating tube, and the labor required for attaching the insulating tube can be saved. Therefore, when such a configuration is adopted, further cost reduction can be achieved.

  Further, in the battery pack according to the present invention, in the above configuration, the battery holder is configured by a combination of the first holder member and the second holder member, and the first holder member and the second holder member are: A configuration in which the unit cell is held in a state of being sandwiched in the cylinder axis direction can be employed. In the case of adopting such a configuration, even if the battery holder has a cover part, when the unit cell is stored in the battery storage part, the cover part does not hinder the storage, and it is troublesome in manufacturing. It is desirable from the viewpoint that it can be reduced.

It is a schematic perspective view which shows a part of structure of the battery pack 1 which concerns on embodiment. FIG. 2 is a schematic developed perspective view showing a positional relationship between a unit cell 10 and holder members 11 and 12 as well as lead plates 13 and 14 in the battery pack 1. 3 is a schematic cut-away view showing an arrangement relationship between the unit cell 10 and the holder members 11 and 12 in the battery pack 1. 3 is a schematic cross-sectional view showing a state in which a unit cell 10 is stored in a holder member 11. (A) is a schematic cross section which shows the state in which the unit cell 10 was accommodated with respect to the holder member 111 which concerns on the modification 1, (b) is a unit cell 10 with respect to the holder member 211 which concerns on the modification 2. It is a schematic cross section which shows the state accommodated. It is a schematic cross section which shows a part of structure of the battery pack which concerns on a prior art.

Below, the form for implementing this invention and its modification are demonstrated, referring 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. Schematic Configuration of Battery Pack 1 A schematic configuration of the battery pack according to the embodiment will be described with reference to FIG.

  As shown in FIG. 1, 21 unit cells 10 (see FIG. 2 for the number of unit cells 10) are arranged so that the cylinder axes are parallel to each other, that is, in a state parallel to each other. Yes. The 21 unit cells 10 are held between the holder members 11 and 12 from above and below in the Z-axis direction. The unit cells 10 are connected to each other by lead plates 13 disposed above and below the holder members 11 and 12 (the lead plates disposed below the holder member 12 are not shown in FIG. 1). Yes.

Here, each of the plurality of unit cells 10 has a cylindrical appearance. Further, in the battery pack 1, the battery holder is configured by a combination of the holder member 11 and the holder member 12.
Although not shown, the battery pack 1 according to the present embodiment may be covered with a case member, a sheet member, or the like on the outer periphery of the external configuration shown in FIG.

2. Detailed Configuration of Battery Pack 1 The detailed configuration of the battery pack 1 will be described with reference to FIG.
As shown in FIG. 2, in the battery pack 1, 12 out of 21 unit cells 10 are arranged such that the projecting portion which is a positive electrode terminal faces upward in the Z-axis direction, and the remaining 9 The unit cell 10 is arranged so that the bottom of the can, which is a negative electrode terminal, faces upward in the Z-axis direction.

The holder member 11 has a window portion 11 b corresponding to each of the plurality of unit cells 10. The lead plate 13 is connected to the positive electrode terminal or the negative electrode terminal (the bottom surface of the outer can) of the unit cell 10 through the window portion 11 b of the holder member 11.
The holder member 11 is formed with a plurality of cylindrical portions protruding downward in the Z-axis direction, that is, toward the holder member 12. The cylindrical portion has a battery housing portion 11 a whose internal space has a shape corresponding to the external shape of the unit cell 10.

  The holder member 12 arranged on the lower side in the Z-axis direction with respect to the unit cell 10 also has a cylindrical portion that protrudes upward in the Z-axis direction, and a battery housing portion 12a is formed by the cylindrical portion. Has been. Although not shown in FIG. 2, the holder member 12 also has a window corresponding to each unit cell 10, and the lead plate 14 and the positive terminal or negative electrode of the unit cell 10 are passed through the window. The terminal is connected.

3. Arrangement relationship between holder members 11 and 12 and unit cell 10 The arrangement relationship between holder members 11 and 12 and unit cell 10 will be described with reference to FIG. .
As shown in FIG. 3, the holder members 11 and 12 have cover portions so as to cover a part of the end surface of the unit cell 10 (the sealing plate or the bottom surface of the outer can) at the edges of the window portions 11b,. Is provided. The cover portions of the holder members 11 and 12 are formed integrally with other components using an insulating material (resin material). As a result, the entire bottom surface of the sealing plate or the outer can of the unit cell 10 is not exposed to the outside, but portions necessary for connection with the lead plates 13 and 14 are exposed to the outside.

  In the battery pack 1 according to the present embodiment, the unit cell 10 does not have an insulating tube attached to its outer can, and as shown in FIG. 2 and FIG. Or, an insulating sheet or the like is not arranged on the bottom surface of the outer can. That is, in the battery pack 1 according to the present embodiment, the peripheral wall that faces the battery storage portions 11a and 12a of the holder members 11 and 12 and the peripheral wall of the outer can of the unit cell 10 are in direct contact with each other. Since each of the holder members 11 and 12 has a cover portion, an insulating sheet is not interposed between the end surface of the unit cell 10 (the sealing plate or the bottom surface of the outer can) and the lead plates 13 and 14. Insulation between the lead plates 13 and 14 is ensured.

As described above, in the battery pack 1 according to the present embodiment, even if the insulating sheet between the end surface of the unit cell 10 (the sealing plate or the bottom surface of the outer can) and the lead plates 13 and 14 is omitted, it is between each other. Therefore, it is possible to reduce the manufacturing cost while maintaining high quality.
4). Positional relationship between positive electrode terminal 10b and holder members 11 and 12 in unit cell 10 Positive electrode terminal 10b and holder member 11 in unit cell 10 when unit cell 10 is stored in battery storage portions 11a and 12a of holder members 11 and 12 , 12 will be described with reference to FIG. In FIG. 4, only the corresponding part of the holder member 11 is illustrated.

  As shown in FIG. 4, in a state where the unit cell 10 is housed in the battery housing portion of the holder member 11, the positive electrode terminal 10 b is exposed to the outside through the window portion 11 b of the holder member 11. In the unit cell 10, the sealing plate around the positive electrode terminal 10 b is covered with a cover portion in the holder member 11. Further, the outer can 10 a of the unit cell 10 is also insulated from the outside by the holder member 11. In the above description, the sealing plate corresponds to the “peripheral portion” of the positive electrode terminal 10b that is the first electrode terminal, and the cover portion of the holder member 11 covers at least a part of the sealing plate that is the peripheral portion of the positive electrode terminal 10b. It is formed to cover.

  Here, in the battery pack 1 according to the present embodiment, the outer end surface 10 c of the positive electrode terminal 10 b in the unit cell 10 is flush with the outer surface 11 c of the cover portion of the holder member 11. Here, “level” means not only a case where the steps are completely “0”, but also a step caused by a dimensional error in manufacturing the unit cell 10 and the holder member 11. .

  As described above, in the battery pack 1 according to the present embodiment, the outer end surface 10c of the positive electrode terminal 10b in the unit cell and the outer surface 11c of the cover portion of the holder member 11 are flush with each other, thereby positive electrode terminal 10b. The connection strength of the lead plate 13 connected to the outer end face 10c can be kept high. That is, the positive electrode terminal 10b of the unit cell 10 and the lead plate 13 are connected by spot welding, but the force applied to the lead plate 13 when vibration or the like is applied is eliminated by eliminating the step.

  In addition, as described above, in the battery pack 1 according to the present embodiment, since the insulating tube is not attached to the outer can 10a of the unit cell 10, the manufacturing cost can be reduced by the amount of omitting the insulating tube. In addition, the heat generated from the unit cell 10 is not generated by the insulating tube. For this reason, the heat generated from the unit cell 10 is released to the outside through the holder member 11, and the unit cell 10 is hardly damaged and can maintain high quality.

  Furthermore, in the battery pack 1 according to the present embodiment, since the insulating tube is not attached to the outer can 10a of the unit cell 10, when the size of the outer can 10a of the unit cell 10 is the same as the conventional size, the insulating tube It is possible to reduce the size of the package by the thickness of. Alternatively, the thickness of the partition wall of the holder member 11 can be increased by the thickness of the insulating tube, which is excellent from the viewpoint of improving heat dissipation and mechanical strength.

In FIG. 4, the relationship between the unit cell 10 and the holder member 11 is illustrated, but the relationship between the unit cell 10 and the holder member 12 is the same.
[Modification 1]
With respect to the configuration of the battery pack according to the first modification, only differences from the above embodiment will be described with reference to FIG.

As shown in FIG. 5A, in the battery pack according to the first modification, the outer surface 111c of the cover portion of the holder member 111 is not flush with the outer end surface 10c of the positive electrode terminal 10b of the unit cell 10, A configuration having a step d ₁ is employed. For step d _1, for example, it is defined in the range of 1 [mm] or less. That is, the relationship 0 [mm] <d ₁ ≦ 1 [mm] is satisfied.

In other words, in the battery pack according to the first modification, the outer end surface 10 c of the positive electrode terminal 10 b in the unit cell 10 is in a state of being recessed inside the edge of the window 111 b of the holder member 111. Note that it is not appropriate to make the step d ₁ too large from the viewpoint of maintaining the bonding strength of the lead plate.
[Modification 2]
With respect to the configuration of the battery pack according to the modified example 2, only the difference from the above embodiment will be described with reference to FIG.

As shown in FIG. 5B, in the battery pack according to the second modification, the outer end surface 10 c of the positive electrode terminal 10 b in the unit cell 10 is flush with the outer surface 211 c of the cover portion in the holder member 211. rather, it employs a form that it protrudes to the outside (upward in the Z-axis direction) has a step d _2. For step d _2, for example, it is defined in the range of 1 [mm] or less. That is, the relationship 0 [mm] <d ₂ ≦ 1 [mm] is satisfied.

That is, in the battery pack according to the second modification, the outer end face 10 c of the positive electrode terminal 10 b in the unit cell 10 is in a state of protruding outward from the edge of the window 211 b of the holder member 211. Note that, as in the first modification, it is not appropriate to make the step d ₂ too large from the viewpoint of maintaining the bonding strength of the lead plate.
[Other matters]
The said embodiment and the said modification 1, 2 are examples used in order to demonstrate the structure of this invention and the effect acquired easily, Comprising: This invention is not limited to the said form. For example, with respect to the unit cell 10, a cylindrical battery is employed in the above-described embodiment and the above-described first and second modifications, but a battery having a rectangular external shape can also be employed.

In the embodiment and the first and second modifications, the battery type of the unit cell 10 is not particularly mentioned. For example, an alkaline battery such as a nickel-cadmium battery or a nickel-hydrogen battery, Furthermore, a nonaqueous battery such as a lithium ion battery can be employed.
Moreover, in the said embodiment and the said modification 1, 2, although the form that the part which protruded from the sealing board was a positive electrode terminal was employ | adopted as an example, conversely, the protruded part was a negative electrode terminal, and an exterior can and A configuration in which the sealing plate is a positive electrode terminal can also be adopted.

  Moreover, in the said embodiment and the said modification 1, 2, although the form which comprises a battery holder by the combination of two holder members 11, 12, and ... was employ | adopted as an example, it does not necessarily have two holder members. The battery holder need not be configured in combination. For example, the battery holder may be configured by combining three or more holder members, or a battery holder that is integrally formed as a whole may be employed.

Moreover, in the said embodiment and the said modification 1, 2, although the holder members 11, 12, 111, 211 were formed from the resin material, the material which has insulation, or at least an outer surface is insulated. As long as it has the property, it is possible to employ other than the resin material.
Moreover, in the said embodiment and the said modification 1, 2, although the structure which does not attach an insulating tube to the outer periphery of the exterior can 10a of the unit cell 10 was employ | adopted as an example, it is good also as attaching an insulating tube. However, it is desirable to omit the insulating tube from the viewpoint of preventing heat generated from the unit cell 10.

  The present invention is useful for realizing a battery pack with a low manufacturing cost while ensuring high reliability.

1. Battery pack 10. Unit cells 11, 12, 111, 211. Holder member 13,14. Lead plate

Claims (5)

A unit cell having a cylindrical outer shape, a battery holder having a battery storage portion corresponding to the outer shape of the unit cell, and a lead connected to the unit cell stored in the battery holder In a battery pack having a plate,
In the unit cell, a first electrode terminal is formed from one end face, and a region around the first electrode terminal on the one end face is different from a polarity of the first electrode terminal. It is a pole terminal,
The battery holder is made of an insulating material and covers at least a part of the peripheral portion of the first electrode terminal on the one end surface of the unit cell in the state of being accommodated in the battery accommodating portion. The cover part is integrally formed,
The first electrode terminal of the unit cell is at least partially exposed to the outside in a state of being accommodated in the battery holder, and is connected to the lead plate at the exposed portion.
The battery pack, wherein the cover portion of the battery holder is interposed between the second electrode terminal and the lead plate of the unit cell. The first electrode terminal of the unit cell protrudes from the peripheral portion of the one end surface toward the outside in the cylinder axis direction,
The said unit cell is the state accommodated in the said battery holder, The outer side end surface of the said 1st electrode terminal is substantially flush with the outer surface of the said cover part in the said battery holder. The battery pack according to 1. The battery pack according to claim 2, wherein the outer end surface of the first electrode terminal and the outer surface of the cover portion of the battery holder are flush with each other or have a step of 1 mm or less. The battery pack according to any one of claims 1 to 3, wherein the outer can of the unit cell is in direct contact with a peripheral wall of the battery holder facing the battery storage portion on an outer peripheral surface thereof. . The battery holder is composed of a combination of a first holder member and a second holder member,
The battery pack according to any one of claims 1 to 4, wherein the first holder member and the second holder member hold the unit cell in a state of being sandwiched in the cylinder axis direction.

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