Battery pack

The present invention relates to a battery pack, and more particularly to an internal structure in an outer case.

The battery pack is used as a power source for many devices such as notebook-type personal computers (laptops), electric tools, electric vehicles, and electrically assisted bicycles. As shown in FIG. 14, for example, in a battery pack for a notebook computer, an outer case is formed by engaging the upper case member 910 and the lower case member 920, and a core pack composed of a base battery and a substrate is formed inside the outer case. It has a stored configuration. Then, the battery pack is inserted in the direction of the arrow N with respect to the notebook computer body, a part 9a is stored in the notebook computer body, and the remaining part 9b is in a state of protruding outward from the notebook computer body. The electrical connection between the battery pack and the main body of the notebook computer is made via the connector 951.

By the way, when the corner portion of the battery pack that protrudes to the outside touches the ground when it is dropped, a large force (impact force) F is locally applied. At this time, it is important from the viewpoint of safety that the core pack housed inside, particularly the elementary battery, is not deformed. In order to protect the core pack (particularly the elementary battery) housed inside even when the force F is applied to the corner part of the outer case, for example, as shown in FIG. 15, the outer side of the lower case member 920. Regarding the inner wall 926 formed inside the wall 922, a certain length portion from the corner portion is separated from the core pack (elementary battery 949 and lead plate 955 in FIG. 15) (separated portion). .. Then, at a portion separated from the corner portion by a certain length, contact is made with the elementary battery of the core pack (contact portion).

By adopting such a configuration, in the conventional battery pack, while trying to hold the core pack by the inner wall 926, it is attempted to reduce the damage received by the core pack including the elementary battery 949 by the force F applied from the corner part. ing. That is, by providing a buffer area (bumper area) in which the inner wall 926 and the core pack are separated from each other corresponding to the corner portion of the outer case, the core pack base battery or the like due to the force F locally applied to the corner portion can be removed. It is said that the damage received can be reduced.

<p><patcit num="1"><text>Japanese Patent Application Laid-Open No. 2009-224072</text></patcit></p>

<p> However, as shown in FIG. 15, in the conventional battery pack, one or a plurality of ribs 926a and 926b are provided in a state orthogonal to the separated portion in the inner wall 926, and each tip is a base battery 949 in the core pack. Alternatively, since it is in point (or line) contact with the lead plate 955 (the part indicated by the arrow P), the impact force F applied from the outside to the corner part of the outer case is applied to the tip thereof via the ribs 923a and 926b. Is transmitted directly to the core pack locally.</p><p> Therefore, in the conventional battery pack shown in FIG. 15, the portions of the core pack that are in contact with the tips of the ribs 926a and 926b are greatly damaged. The present invention has been made to solve the above problems, and even when an external force is applied to the outer case, the core pack housed inside is not easily damaged, and high safety performance is achieved. It is an object of the present invention to provide a battery pack having a battery.</p>

<p> The present invention employs the following configuration in order to achieve the above object. The battery pack according to the present invention has a dish shape together, and by combining the openings facing each other so as to face each other, the first case member and the second case member constituting the outer case and one or more elementary batteries. It is equipped with a core pack that is stored in the outer case. In the battery pack according to the present invention, in the first case member, an inner wall is erected on the inner bottom surface of the first case member along a part of the side wall, and the inner wall of the first case member is formed. In the extending direction, it is composed of two parts, a separated portion separated from the core pack and a surface contact portion continuous with the separated portion and in surface contact with the core pack.</p><p> Further, in the battery pack according to the present invention, a separated portion of the inner wall of the first case member is provided starting from a corner portion when the first case member is viewed in a plan view.</p>

<p> The battery pack according to the present invention has a separated portion arranged at a position separated from the core pack on the inner wall of the first case member. Since this separated portion is provided at the corner portion of the first case member, the space between the separated portion and the core pack cushions the force applied from the corner portion against the impact force applied from the outside. Functions as an area (bumper area). Thus, in the battery pack according to the present invention, it is possible to prevent the force applied from the outside to the corner portion of the outer case from being directly transmitted to the core pack (elementary battery or substrate).</p><p> Further, in the battery pack according to the present invention, the inner wall is composed of two portions, the separated portion and the surface contact portion. That is, in the battery pack according to the present invention, there is no portion of the first case member that comes into contact with the core pack by point contact or line contact as indicated by the arrow P in FIG. Therefore, even when an external force is applied to the corner portion of the outer case, the force is locally transmitted to the core pack (particularly, the elementary battery) via the inner wall of the first case member. There is no.</p><p> From the above, the battery pack according to the present invention has high safety performance because the core pack housed inside is not easily damaged even when a force is applied to the outer case from the outside. In the battery pack according to the present invention, for example, the following variations can be adopted.</p><p> In the battery pack according to the present invention, in the above configuration, the separated portion in the inner wall extends obliquely from the starting point of the corner portion in the first case member with respect to the side wall corresponding to the portion, and the surface of the inner wall. It is possible to adopt a configuration in which the contact portion is abutted diagonally and is continuous. As described above, when the configuration in which the separated portion of the inner wall extends diagonally with respect to the side wall is adopted, the force applied from the outside to the corner portion of the outer case is applied through the inner wall. When transmitted to the core pack, the force is distributed at the abutting portion with the surface contact portion. This prevents a large local force from being applied to the core pack. Therefore, when the above configuration is adopted, higher safety can be ensured.</p><p> In the above configuration, the battery pack according to the present invention can adopt a configuration in which a region in which the inner wall is cut out exists in a direction different from the above-mentioned separated portion, starting from the corner portion of the first case member. .. As described above, when the inner wall is provided with a notched region, the notched region exerts a function of suppressing the direct application of force to the core pack. In particular, as described above, when the region where the inner wall is cut out is provided at a position starting from the corner portion of the first case member, the impact force applied from the outside to the corner portion is generated. It is not directly transmitted to the core pack, which is preferable from the viewpoint of protecting the core pack.</p><p> In the battery pack according to the present invention, in the above configuration, a locking claw is provided on one of the inner wall of the first case member and the side wall of the second case member, and a locking hole or locking that engages with the locking claw is provided on one side. A recess is provided, and the first case member and the second case member are engaged with each other by locking the locking claw and the locking hole or the locking recess, and the first case member has a recess. , A slit is provided in a portion of the side wall closer to the opening edge than the portion related to locking to guide a cutting tool used for cutting the corresponding portion of the second case member fitted in the portion. Can be adopted.</p><p> It is desirable to actively recycle used battery packs from the viewpoint of safety and the environment. Further, as described above, when the slit is provided in the above-mentioned part of the first case member, the position where the cutting tool is inserted is clarified in advance, so that the safety at the time of disassembly can be ensured. .. That is, it is possible to prevent the core pack and the like housed inside from being damaged during the dismantling work. Then, the engagement portion between the first case member and the second case member must be reliably disengaged from the first case member and the second case member without checking the design drawing or the like on the corresponding battery pack. Can be done.</p><p> In the above configuration, the battery pack according to the present invention can adopt a configuration in which both the first case member and the second case member are formed by using a resin material. In the battery pack according to the present invention, in the above configuration, when mounted on the device, a part of the outer case protrudes to the outside of the device, and the corner portion serving as the starting point of the separated portion on the inner wall of the first case member is the device. It is possible to adopt a configuration in which the battery exists in a portion protruding to the outside. As described above, when the corner portion is present in the externally protruding portion of the outer case, the configuration of the present invention is particularly effective against the force applied from the outside to the corner portion.</p><p> In the above configuration, the battery pack according to the present invention can adopt a configuration in which the core pack is held in the outer case by an inner wall.</p>

<figref num="1">It is a schematic perspective view which shows the appearance structure of the battery pack 1 which concerns on embodiment.</figref><figref num="2">It is a schematic development perspective view which shows the schematic structure of the inside of a battery pack 1.</figref><figref num="3">It is a schematic perspective view (partially, the schematic development perspective view) which shows the structure of the core pack 40 built in the battery pack 1.</figref><figref num="4">It is a schematic perspective view which shows the structure of the upper case member 10 in a battery pack 1.</figref><figref num="5">It is a schematic perspective view which shows the structure of the lower case member 20 in a battery pack 1.</figref><figref num="6">It is a schematic plan view which shows the mutual positional relationship between the lower case member 20 and the elementary battery 49.</figref><figref num="7">It is a schematic cross-sectional view which shows the mutual positional relationship between the lower case member 20 and the elementary battery 49.</figref><figref num="8">It is a schematic perspective view which shows the mutual positional relationship between the lower case member 20 and the elementary battery 49.</figref><figref num="9">It is a schematic plan view which shows the mutual positional relationship with the lower case member 120 in the battery pack which concerns on modification 1. FIG.</figref><figref num="10">It is a schematic perspective view which shows the structure of the lower case member 220 in the battery pack which concerns on modification 2. FIG.</figref><figref num="11">(a) is a schematic cross-sectional view showing a state in which the battery pack according to the modified example 2 is in use, and (b) is a schematic cross-sectional view showing a state in which the battery pack according to the modified example 2 is being disassembled. ..</figref><figref num="12">(a) is a schematic perspective view showing the configuration of the fitting receiving portion 325 included in the lower case member 320 in the battery pack according to the modified example 3, and (b) is the configuration of the fitting receiving portion 325 in the lower case member 320. It is a schematic plan view which shows.</figref><figref num="13">(a) is a schematic perspective view showing the configuration of the fitting receiving portion 825 included in the lower case member 820 according to the comparative example, and (b) is a schematic cross-sectional view showing the configuration of the fitting receiving portion 825 in the lower case member 820. Is.</figref><figref num="14">It is a perspective view which shows the appearance structure of the battery pack which concerns on the prior art.</figref><figref num="15">It is a top view which shows the mutual positional relationship between the lower case member 920 and the elementary battery 949 in the battery pack which concerns on the prior art.</figref>

Hereinafter, modes for carrying out the present invention and examples of modifications thereof will be described with reference to the drawings. In addition, the specific example shown below is an example used for explaining the structure of the present invention and the action / effect produced from the structure in an easy-to-understand manner. The following specific examples are not limited in any way. [Embodiment] In the embodiment, the structural features and the actions / effects to be produced will be described by taking the battery pack 1 for a notebook computer as an example.

1. Appearance configuration The external configuration of the battery pack 1 according to the embodiment will be described with reference to FIG. As shown in FIG. 1, in the battery pack 1, the outer case is composed of a combination of the upper case member 10 and the lower case member 20. A label 30 is attached to the top surface of the upper case member 10 (the outer bottom surface on the upper side in the Z-axis direction). Label 30 describes, for example, precautions for use for the user, precautions for recycling, and the like.

Battery pack 1 is inserted into the laptop computer in the direction of arrow A (front side in the X-axis direction), part 1a is stored in the laptop computer, and the remaining part 1b protrudes from the laptop computer. It becomes. The battery pack 1 is electrically connected to the notebook computer via the connector 51. 2. Internal outline configuration The schematic internal configuration of the battery pack 1 will be described with reference to FIG.

As shown in FIG. 2, in the pack battery 1, the upper case member 10 and the lower case member 20 are fitted in a state where their openings face each other, and the core pack 40 is formed in an internal space formed by the upper case member 10 and the lower case member 20. Is stored. The core pack 40 also includes the connector 51 as a component. Further, as described above, the label 30 is attached to the outer bottom surface (upper surface in the Z-axis direction) of the upper case member 10.

3. Core pack 40 configuration The configuration of the core pack 40 included in the battery pack 1 will be described with reference to FIG. As shown in FIG. 3, the core pack 40 includes nine elementary batteries 41 to 49 as components. The nine elementary batteries 41 to 49 both have a cylindrical appearance shape and are the same size as each other. Further, the nine elementary batteries 41 to 49 are, for example, lithium ion secondary batteries, and the exterior thereof is made of a metal material.

The nine elementary batteries 41 to 49 are connected to each other by lead plates 52 to 55 and lead wires 57, 58, and a thermal fuse 56 is also connected to each other. In addition to the elementary batteries 41 to 49, the core pack 40 also includes a board 50 on which the connector 51 is mounted as a component. Although not shown in FIG. 3, electronic components such as charge / discharge control ICs and FET elements are mounted on the substrate 50 together with the connector 50.

4. Configuration of upper case member 10 and lower case member 20 Each configuration of the upper case member 10 and the lower case member 20 constituting the outer case of the battery pack 1 will be described with reference to FIGS. 4 and 5. First, as shown in FIG. 4, the upper case member 10 has a dish shape as a whole and includes four side walls 11 to 14. The side walls 11 to 14 are provided with a plurality of hooks 11a, 12a, ... Used for engaging with the lower case member 20 on the inner wall surface side thereof. The side walls 11 to 14 of the upper case member 10 are erected in the Z-axis direction from the inner surface of the bottom wall, and each of the plurality of hooks 11a, 12a, ... It is formed like this.

Next, as shown in FIG. 5, the lower case member 20 also has a dish shape as a whole and includes four outer walls 21 to 24. From the inner surface of the bottom wall of the lower case member 20, inner walls 25 to 28 are erected in the Z-axis direction along each of the four outer walls 21 to 24. A space corresponding to the thickness of the side walls 11, 12, 14 of the upper case member 10 is provided between the outer side walls 21, 22, 24 and the corresponding inner walls 25, 26, 28. Further, a space for accommodating the substrate 50 in the core pack 40 is provided between the outer wall 23 and the inner wall 27.

Holes 25a, ... Are formed in the inner walls 25 to 28 of the lower case member 20 at locations corresponding to hooks 11a, 12a, ... Provided on the side walls 11 to 14 of the upper case member 10. In the upper case member 10 and the lower case member 20, the side walls 11 to 14 of the upper case member 10 are fitted into the spaces provided between the outer walls 21 to 24 and the inner walls 25 to 28 of the lower case member 20. The hooks 11a, 12a, ... Provided on the side walls 11 to 14 of the upper case member 10 are locked to the holes 25a, ... The member 10 and the lower case member 20 engage with each other.

5. Composition of inner walls 25, 26, 28 in the lower case member 20 The configuration of the inner walls 25, 26, 28 in the lower case member 20 will be described with reference to FIGS. 6 to 8 by taking the inner walls 25, 26 as an example. 6 to 8 are a schematic enlarged view of the portion indicated by the arrow B in FIG. 5, or a schematic cross-sectional view thereof. The part indicated by the arrow B corresponds to the corner part (see FIG. 1) of the part 1b that protrudes to the outside when the battery pack 1 is attached to the notebook computer.

First, as shown in FIG. 6, the inner wall 26 of the lower case member 20 is separated from the elementary battery 49 of the core pack 40 with a space 20a, and the lead plate 55 of the core pack 40. It is composed of a surface contact portion 26b that makes surface contact with the battery. The separated portion 26a is provided in a partial region in the X-axis direction, starting from the corner portion of the lower case member 20. The separated portion 26a is not parallel to the corresponding outer wall 22, but extends diagonally with respect to the X axis (extending direction of the outer wall 22) starting from the corner portion.

As shown in FIG. 6, the separated portion 26a in the inner wall 26 extends diagonally away from the outer wall 22 from the upper side to the lower side in the X-axis direction. That is, the separated portion 26a of the inner wall 26 is formed so as to be closest to the outermost wall 22 at the corner portion of the lower case member 20 and to be separated from the outer wall 22 toward the abutting portion with the surface contact portion 26b. The separated portion 26a and the surface contact portion 26b are butted so as to be oblique to both the X-axis and the Y-axis.

The space 20a between the separated portion 26a on the inner wall 26 and the elementary battery 49 on the core pack 40 is against an impact force (arrow F shown in FIG. 6) applied from the outside to the corner portion of the protruding portion of the lower case member 20. It serves as a buffer area (bumper area) with the core pack 40. The lower case member 20 is made of a resin material, and the outer walls 21 to 24 and the inner walls 25 to 28 are integrally formed with the bottom wall and the like.

Next, as shown in FIG. 7, in the battery pack 1, the elementary battery 49 and the like in the core pack 40 are brought into surface contact with the surface contact portion 26b (see FIG. 6) of the inner wall 26 of the lower case member 20 (arrow). The part indicated by D) is held in a state where the movement inside is restricted. Specifically, the elementary battery 49 in the core pack 40 receives surface contact with the inner wall 26 via the lead plate 55, and its movement to the right in the Y-axis direction is restricted. Similarly, the movement of the core pack 40 is restricted by surface contact with the inner walls 25, 27, 28 of the lower case member 20.

As shown in FIG. 7, a space corresponding to the thickness of the inner walls 25 to 28 of the lower case member 20 is provided between the upper case member 10 and the core pack 40, and the upper case member 10 has a space corresponding to the thickness of the inner walls 25 to 28. The side walls 11 to 14 and the core pack 40 do not come into direct contact with each other. Returning to FIG. 6, most of the inner walls 25 extending in the Y-axis direction of the lower case member 20 come into contact with the outer peripheral surfaces of the elementary batteries 49, ..., And regulate the movement of the core pack 40. To work. However, a part of the inner wall 25 is cut out in the area corresponding to the corner portion of the lower case member 20. Specifically, as shown in FIG. 8, a part of the inner wall 25 starting from the corner portion is cut out (the portion indicated by the arrow E). In this portion, the elementary battery 49 in the core pack 40 does not come into contact with the inner wall 25, and the space formed between the elementary battery 49 and the side wall 21 serves as a shock absorbing region (bumper area).

6. Superiority In the battery pack 1 according to the present embodiment, the inner wall 26 of the lower case member 20 has a separated portion 26a arranged at a position separated from the elementary battery 49 of the core pack 40 and the surface contact portion 26b in surface contact. It is composed of two parts. Of these, the separated portion 26a of the inner wall 26 is provided starting from the corner portion of the lower case member 20 and is continuous with the surface contact portion 26b. , The space 20a between the separated portion 26a and the elementary battery 49 of the core pack 40 functions as a buffer area (bumper area) against the impact force F. From this, in the battery pack 1 according to the present embodiment, the impact force F applied from the outside to the corner portion is directly transmitted to the core pack 40 (elementary battery 49, ..., and the substrate 50) due to the presence of the buffer region. It can be prevented from being done.

Further, in the battery pack 1, since the inner wall 26 of the lower case member 20 is composed of two parts, a separated portion 26a and a surface contact portion 26b, point contact or point contact as indicated by the arrow P in FIG. 15 or There is no part that comes into contact with the core pack by wire contact. Therefore, even when an impact force F is applied to the corner portion of the lower case member from the outside, the impact force F is locally applied to the core pack 40 (particularly, the elementary battery 49) via the inner wall 26 of the lower case member 20. , ) Is not transmitted.

Further, as shown in FIG. 7, in the battery pack 1, the side walls 11 to 14 of the upper case member 10 do not directly contact the core pack 40, and the impact applied from the outside to the corner portion of the upper case member 10. The force does not directly affect the internal core pack 40. Further, in the battery pack 1, the separated portion 26a of the inner wall 26 of the lower case member 20 extends diagonally from the starting point of the corner portion of the lower case member 20 with respect to the side wall 22 corresponding to the portion 26a. , The structure is adopted in which the inner wall 26 is continuously abutted against the surface contact portion 26b in the oblique direction. As described above, in the battery pack 1 according to the present embodiment, which adopts the configuration in which the separated portion 26a of the inner wall 26 extends diagonally with respect to the side wall 22, the battery pack 1 is outside the corner portion of the lower case member 20. When the impact force F applied from the above is transmitted to the elementary battery 49 or the like of the core pack 40 via the inner wall 26, the force is dispersed at the abutting portion with the surface contact portion 26b. As a result, it is possible to prevent local force from being applied to the elementary battery 49 of the core pack 40 or the like. Therefore, when the above configuration is adopted, high safety can be ensured.

In the battery pack 1, as shown in FIG. 8 and the like, a part of the lower case member 25 starting from the corner portion is cut out (the portion indicated by the arrow E in FIG. 8), so that the cutout is made. The region plays a role in suppressing the direct transmission of force to the core pack 40's battery 49, .... That is, the space formed by the cutout also becomes a buffer region in relation to the impact force F applied from the outside to the corner portion.

From the above, the battery pack 1 according to the present embodiment is the core pack 40 housed inside even when an impact force F is applied to the outer case (upper case member 10, lower case member 20) from the outside. The elementary batteries 41 to 49 and the substrate 50 are not easily damaged and have high safety performance. [Modification example 1] The battery pack 2 according to the first modification will be described with reference to FIG. In the following, only the difference from the battery pack 1 according to the above embodiment will be described, and other configurations are the same as those of the battery pack 1 according to the above embodiment.

As shown in FIG. 9, in the battery pack 2 according to the modified example, there is a space (the portion indicated by the arrow G) between the inner wall 126 of the lower case member 120 and the base battery 49 of the core pack starting from the corner portion. The same applies to the fact that it has a separated portion with a gap and has a surface contact portion 126b that makes surface contact with the lead plate 55 of the core pack.

However, in the lower case member 120 of the battery pack 2 according to this modification, the separated portion is parallel to the extending direction (X-axis direction) of the corresponding outer wall 122. Therefore, the surface contact portion 126b in the separated portion is abutted in a substantially orthogonal direction (part 126a). Therefore, the force cannot be dispersed as in the battery pack 1 according to the above embodiment with respect to the impact force applied to the corner portion of the lower case member 120 from the outside. Therefore, the battery pack 2 according to the present modification is slightly disadvantageous to the battery pack 1 according to the above embodiment from the viewpoint of impact resistance.

However, when compared with the battery pack according to the prior art shown in FIG. 15, even in the battery pack 2 according to this modification, the lower case member 120 and the core pack (particularly, the elementary battery 49) are in point contact or a line. Since it does not come into contact with each other, it is effective in terms of impact resistance. [Modification 2] The configuration of the battery pack according to the second modification will be described with reference to FIGS. 10 and 11. In the following, only the difference from the battery pack 1 according to the above embodiment will be described, and other configurations are the same as those of the battery pack 1 according to the above embodiment. ..

First, as shown in FIG. 10, a plurality of slits 221a are formed on the outer wall 221 of the lower case member 220. The slit 221a is provided corresponding to a portion of the inner wall 225 provided in parallel where the hole 225a is formed. Specifically, in this modification, the slit 221a is provided so as to correspond to the three holes 225a in the inner wall 225 and to cover a wider area in the Y-axis direction. The size of the slit 221a is the height H from the opening edge of the outer wall 221 as shown in the portion surrounded by the alternate long and short dash line in FIG.₂Only at the bottom, height H₁And also the width W₁With respect to, the width W on each side of the width of the strip-shaped portion provided with the three holes 225a in the inner wall 225.₂Is only widely formed. In addition, height H₁For example, it can be in the range of about 0.3 [mm] to 0.7 [mm] (for example, 0.5 [mm]), and the width W.₂Can be in the range of about 2 [mm] to 6 [mm] (for example, 4 [mm]).

Next, as shown in FIG. 11A, in the battery pack according to the present modification, the upper case member 210 and the lower case member 220 are slightly below the inside of the slit 221a of the outer wall 221 of the lower case member 220. There is a locking structure between the hook 211a and the hole 225a related to the engagement with the slit 221a, and the slit 221a is provided as a mark for disassembling the case at the time of reuse / recycling.

Specifically, as shown in FIG. 11B, when reusing and recycling, it is necessary to disengage the collected battery pack between the upper case member 210 and the lower case member 220. In the case of the battery pack according to this modification, the cutter blade 501 of the cutter 500 is inserted through the slit 221a provided in the outer wall 221 of the lower case member 220, and the outer wall 221 of the lower case member 220 is divided into parts 221b. Divide into part 221c. At this time, the outer wall 211 of the upper case member 210 is also cut, and the upper case member 210 and the lower case member 220 can be separated.

If the outer wall 221 of the lower case member 220 is provided with a slit 221a for dismantling work at the time of reuse / recycling as in the battery pack according to this modification, the worker performing the dismantling work is the dismantling work part. Can be accurately recognized, and high work efficiency can be achieved. Further, as shown in FIG. 11 (b), if the stopper 502 is attached to a certain place from the cutter blade 501 of the cutter 500, the elementary battery 49, the board, the wiring, etc. housed inside will not be damaged. High safety in work can be ensured without being easily damaged. Specifically, the thickness of the outer wall 211 of the upper case member 210 is T.₁When, the thickness T₁Effective length L of cutter blade 501 that is the same as or slightly longer than that₁By attaching the stopper 502 so that the stopper 502 comes into contact with the outer surface 221f of the outer wall 221 of the lower case member 220 and stops by the time the cutter blade 501 reaches the internal battery 49. Become.

As described above, when the structure of the battery pack according to this modification is adopted, the upper case member 210 and the lower case at the time of reuse / recycling are provided by providing the slit 221a on the outer wall 221 of the lower case member 220. The engagement with the member 220 can be disengaged with high safety and high work efficiency. [Modification 3] The configuration of the battery pack according to the third modification will be described with reference to FIGS. 12 and 13. In the following, only the difference from the battery pack 1 according to the above embodiment will be described, and other configurations are the same as those of the battery pack 1 according to the above embodiment. ..

As shown in FIG. 12, in the battery pack according to the present modification, the structure related to the locking of the outer wall 321 of the lower case member 320 is different from the battery pack 1 according to the above embodiment. That is, the structure of the portion indicated by the arrow C in FIG. 5 is different, and the other portions are the same as those in the above embodiment. As shown in FIG. 12A, in the battery pack according to this modification, it is used to lock a part of the inside of the side wall 321 of the lower case member 320 with a hook provided on the outer wall of the upper case member. The fitting receiving portion 325 is provided corresponding to the hook. The fitting receiving portion 325 has an inverted L shape when viewed from the lower left side in the X-axis direction, and as shown in FIG. 12B, when viewed from the upper side in the Z-axis direction, the fitting receiving portion 325 has an inverted L shape. It has a character shape. As shown in FIG. 12 (a), the hook on the outer wall of the upper case member is inserted in the direction of arrow I with respect to the gap 325 c in FIG. 12 (b).

As shown in FIG. 12A, the lower side 325a of the fitting receiving portion 325 has a draft gradient θ from the upper left to the lower right in the Y-axis direction.₁Is attached. This draft θ₁Is for pulling out the mold at the time of making the lower case member 320. As indicated by the arrow H in FIG. 12 (a) and the arrow J in FIG. 12 (b), in the battery pack according to this modification, the right end portion in the Y-axis direction of the fitting receiving portion 325 is for mechanical reinforcement. It is characterized in that the triangular rib 325b is provided.

As in the comparative example shown in FIG. 13 (a), in the fitting receiving portion 825 which is not provided with the triangular rib and is not mechanically reinforced, the draft of the lower side 825a is θ.₈Due to this, the plate thickness of the right end portion 825b in the Y-axis direction cannot be secured (the portion indicated by the arrow K). As shown in FIG. 13 (b) when this portion is viewed in the direction of the arrow L, the plate thickness T of the right end portion 825b in the Y-axis direction of the fitting receiving portion 825 according to the comparative example.₈Has to become thinner (the part indicated by the arrow M in Fig. 13 (b)), and the impact force F applied from the outside due to the fall of the battery pack, etc._SWas transmitted through the outer wall 821, there was a risk that the right end portion 825b in the Y-axis direction would be destroyed.

If the right end portion 825b in the Y-axis direction is destroyed, it is possible that the upper case member and the lower case member 820 are disengaged, which causes a problem. As shown in FIGS. 12 (a) and 12 (b), in the battery pack according to this modification, the fitting receiving portion 325 is provided with the triangular rib 325b, so that an impact applied from the outside due to a drop of the battery pack or the like is provided. Force F_SIs transmitted through the outer wall 321 and the fitting receiving portion 325 is not easily destroyed. Therefore, in the battery pack according to this modification, shown in Figure 13 can be compared to the battery pack according to a comparative example to, ensuring high engaging force between the upper case member and the lower case member 320.

[Other matters] The above-described embodiments and modifications 1 to 3 are examples used to explain the characteristic configuration, action, and effect of the present invention, and the present invention is not limited to the above. For example, as shown in FIGS. 1 to 5, battery packs 1, 2, ... Having a flat rectangular parallelepiped appearance shape are adopted as an example, but the appearance shape of the battery pack is not limited to this, and Z The same effect as described above can be obtained even if the height in the axial direction is high, that is, a non-flat shape is used.

Further, as shown in FIG. 3, in the above-described embodiments and modifications 1 to 3, lithium ion batteries having a cylindrical appearance shape are adopted as the elementary batteries 41 to 49, and nine elementary batteries are used in the core pack 40. Although 41 to 49 are included, the form of the elementary battery and the number of elementary batteries in the core pack are not limited to this. For example, the appearance shape of the elementary battery may be square or flat like a laminated battery.

As for the type of battery, alkaline batteries such as nickel-cadmium (Ni-Cd) batteries and nickel-hydrogen (Ni-MH) batteries can be used, and further, the adoption of capacitors and the like is not excluded. Further, in the above-described embodiments and modifications 1 to 3, the lower case members 20, 120, 220, are provided with the inner walls 25 to 28, 126, 225, but the upper case members may be provided with the inner walls. Even in this case, the same effect can be obtained by adopting the above configuration.

Further, as the constituent material of the upper case member and the lower case member, it is possible to adopt a metal material whose surface is insulated or the like, instead of being a resin material.

INDUSTRIAL APPLICABILITY The present invention is useful for realizing a battery pack that maintains high safety against an impact force applied from the outside when it is attached to a mobile device and used.

1,2. Battery pack 10. Upper case member 11 ~ 14. Side wall 20,120,220,320. Lower case member 21 ~ 24,122,221,321. Outer wall 25 ~ 28,126,225. Inner wall 30. Label 40. Core pack 41 ~ 49. Elementary battery 50. Substrate 51. Connector 52 ~ 55. Reed board 56. Thermal fuse 57,58. Leads 325. Fitting receiving part 500. Cutter 501. Cutter blade 502. Stopper