JP2011171176A - Battery pack - Google Patents

Abstract

A battery pack that secures the mechanical strength of the battery pack and reduces the size of the battery pack is provided.
A pack case including a plurality of secondary battery cells BT, a storage hole 120 for receiving the secondary battery cell BT, and a plurality of screw receiving holes 110, and a screw continuous with the screw receiving hole 110. And a cover 200 fixed to the pack case 100 with a screw hole 220 and a screw 210 inserted into the screw receiving hole 110, and the secondary battery cell BT has a columnar shape with an oval cross section. The storage hole 120 has a pillar shape having the same cross-sectional shape as the secondary battery cell BT, and the plurality of screw receiving holes 110 are stored in the storage hole 120 at both ends in the longitudinal direction D1 of the cross section of the storage hole 120. Battery pack PCK arranged between storage holes 120 in the direction in which the two are arranged.
[Selection] Figure 1

Description

  The present invention relates to a battery pack, and more particularly, to a battery pack including a plurality of secondary battery cells connected in series or in parallel.

  A battery device used in a vehicle such as a hybrid electric vehicle or an electric vehicle needs to have high output and cope with frequent output changes. Such a battery device is generally constituted by a battery pack including a plurality of secondary battery cells electrically connected in series or in parallel according to a required output and capacity.

  The battery pack mounted on the vehicle needs to be configured to have a strength sufficient to withstand mechanical vibrations that occur during vehicle travel. If a component such as a secondary battery cell is displaced or deformed beyond an allowable value due to vibration, the characteristics of the device may be deteriorated, the life may be reduced, and eventually failure may occur. Therefore, it is necessary to configure the battery pack to have sufficient strength by a method such as increasing the strength of the member that holds and fixes the parts that constitute the battery pack. Further, there is a demand for a reduction in the size of the battery pack according to the design of the vehicle or the like on which the battery pack is mounted.

JP-A-53-163965

  Since the secondary battery cell generates heat when energized, it is essential to provide a heat dissipation mechanism in the battery pack. For example, the heat generated from the secondary battery cell is radiated to the outside of the battery pack through the pack case of the battery pack, or the space around the secondary battery cell is radiated by the cooling medium passing through this space. Is used.

  However, the configuration in which a space is provided around the secondary battery cell as described above or heat is radiated by the pack case of the secondary battery pack may cause an increase in the size of the battery pack. For example, when a plurality of secondary battery cells are housed in a pack case and the cover is fastened and fixed to the pack case with a cover fixing screw, each secondary battery cell is securely held and fixed. It is desirable to fasten the main points in the vicinity of the cell with a cover fixing screw.

  However, when configured as described above, the battery pack has the following problems. First, the size of the pack case may increase. The pack case must receive the cover fixing screw. When the pack case is formed of an insulating material, a necessary number of metal collars having female threads are inserted. In order to securely hold the metal collar, it was difficult to reduce the thickness of the pack case.

  When using a self-tapping screw, a metal collar is not required, but it is necessary to ensure a sufficient thickness to withstand the self-tapping screw formation. When the thickness of the pack case is not sufficient, there is a possibility that a crack occurs or a tightening force is reduced. Therefore, it is difficult to reduce the thickness of the pack case even when the self-tapping screw is used. In any case, it was difficult to increase the size of the pack case and to suppress the increase in the size of the battery pack.

  Moreover, when forming a pack case with an insulating material, the manufacturing method by the injection molding method using a thermoplastic resin is used abundantly. When a member is formed by injection molding of the pack case, it is desirable that the thickness of the member is as uniform as possible. If there is a difference in the thickness of the molded member, there is a high possibility that a manufacturing failure due to a resin flow failure or a deformation increase due to a temperature difference caused by a difference in cooling rate (also a manufacturing failure) occurs. As a result, it has been forced to increase the thickness even to the point where the thickness can be reduced, and the pack case size (that is, the pack size) may be increased.

  Further, when the mutual interval between the cover fixing screws is increased, the fastening force between the cover and the pack case may be weakened when the size (nominal diameter) of the cover fixing screws is small. In order to avoid this, if the size of the cover fixing screw is increased, the thickness of the pack case is increased, and the size of the pack case may be increased. As described above, when the physique of the battery pack increases, it may not be possible to meet the demand for physique reduction corresponding to the design of the mounted device.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a battery pack that secures the mechanical strength of the battery pack and reduces the physique.

  The battery pack according to the first aspect of the present invention includes a pack case including a plurality of secondary battery cells, a storage hole for accommodating the secondary battery cell, and a plurality of screw receiving holes, and the screw receiving holes. A continuous screw hole, and a cover fixed to the pack case by a screw inserted into the screw hole and the screw receiving hole, and the secondary battery cell has a columnar shape with an oval cross section. The storage hole has a columnar shape having the same cross-sectional shape as the secondary battery cell, and the plurality of screw receiving holes are arranged at both ends in the longitudinal direction of the cross section of the storage hole. It is a battery pack arrange | positioned between the said storage holes in the direction to arrange.

  The battery pack according to the second aspect of the present invention is surrounded by a plurality of secondary battery cells, a bottom portion and a wall portion substantially orthogonal to the bottom portion, and a storage hole in which the plurality of secondary battery cells are stored, A plurality of columnar bodies extending in a direction substantially orthogonal from the bottom, and a plurality of columnar bodies projecting from the wall portion toward the storage hole, and at the upper ends of the plurality of columnar bodies and the plurality of columnar bodies A pack case provided with a screw receiving hole, a screw hole continuous with the screw receiving hole, and a cover fixed to the pack case with the screw hole and a screw inserted into the screw receiving hole, The secondary battery cell has a columnar shape with an oval cross section, and in a cross section substantially parallel to the bottom, the cylindrical body and the columnar body are arranged so as to circumscribe the secondary battery cell. It is a pack.

  ADVANTAGE OF THE INVENTION According to this invention, while ensuring the mechanical strength of a battery pack, the battery pack which reduces a physique can be provided.

It is a figure which shows roughly the example of 1 structure of the battery pack which concerns on 1st Embodiment of this invention. It is a figure for demonstrating one structural example of the secondary battery cell of the battery pack which concerns on 1st Embodiment of this invention. It is a disassembled perspective view for demonstrating one structural example of the battery pack which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the example of 1 structure of the secondary battery cell of the battery pack which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating one structural example of the pack case of the battery pack which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating one structural example of the secondary battery cell and pack case of the battery pack which concern on 2nd Embodiment of this invention. It is a figure for demonstrating the example of 1 structure of the secondary battery cell of the battery pack which concerns on 3rd Embodiment of this invention. It is a figure for demonstrating one structural example of the pack case of the battery pack which concerns on 3rd Embodiment of this invention. It is a figure for demonstrating the example of 1 structure of the secondary battery cell of a battery pack and pack case which concerns on 3rd Embodiment of this invention. It is a figure for demonstrating one structural example of the pack case of the battery pack which concerns on 4th Embodiment of this invention. It is a figure for demonstrating the example of 1 structure of the secondary battery cell of a battery pack and pack case which concerns on 4th Embodiment of this invention. It is a figure for demonstrating one structural example of the pack case of the battery pack which concerns on 5th Embodiment of this invention. It is a figure for demonstrating one structural example of the pack case of the battery pack which concerns on 6th Embodiment of this invention. It is a figure for demonstrating the example of 1 structure of the secondary battery cell of a battery pack and pack case which concerns on 6th Embodiment of this invention.

  Hereinafter, a first embodiment of the present invention will be described in detail. As shown in FIGS. 1 and 2, the battery pack PCK according to the present embodiment includes a plurality of secondary battery cells BT, a pack case 100 in which the plurality of secondary battery cells BT are accommodated, and an opening of the pack case 100. And a conductive member 300 for connecting a plurality of secondary battery cells BT in series or in parallel.

  As shown in FIG. 2, the secondary battery cell BT includes a box-shaped outer container 10 made of aluminum or the like, and an electrode body (not shown) housed in the outer container 10 together with a nonaqueous electrolyte (not shown). (Not shown).

  The outer container 10 has a container main body 12 having an open upper end and a substantially rectangular plate-like lid body 14 welded to the container main body 12 and closing the opening of the container main body, and is formed airtight. The container body 12 includes a bottom wall (not shown) facing the opening, two main walls 1 extending between the opening and the bottom wall and facing each other, and two side walls 3 extending between the two main walls 1. With. For example, the electrode body is formed into a columnar shape having a substantially elliptical cross section by winding a positive electrode plate and a negative electrode plate in a spiral shape with a separator interposed therebetween and further compressing the electrode plate in the radial direction.

  The lid 14 and the bottom wall of the container body 12 are oval in a field track shape. That is, the lid body 14 is a plate-like body having a main surface with a shape formed by two arcs and a straight line connecting the two arcs. In the present embodiment, the shape of the lid 14 and the bottom wall of the container main body 12 is a shape formed by two circular arcs having the same radius and these two circumscribed lines. The lid 14 and the bottom wall of the container body 12 are formed so as to have a shape substantially similar to the cross-sectional shape of the electrode body accommodated in the container body 12.

  The positive electrode terminal 5 and the negative electrode terminal 4 are provided at both ends in the longitudinal direction (first direction D1) of the lid body 14 and project from the lid body 14. The positive electrode terminal 5 and the negative electrode terminal 4 are electrically connected to the positive electrode plate and the negative electrode plate of the electrode body, respectively.

  The negative electrode terminal 4 extends through the lid body 14. A sealing material made of an insulating material such as synthetic resin or glass, for example, a gasket (not shown) is provided between the negative electrode terminal 4 and the lid body 14, and the gap between the negative electrode terminal 4 and the outer container 10 is airtight. And is electrically insulated. The positive electrode terminal 5 and the negative electrode terminal 4 protrude from the surface of the lid body 14 toward the outside of the outer container 10.

  When the outer container 10 having such a shape is used, the inner volume of the outer container is smaller than the secondary battery cell having a substantially rectangular parallelepiped shape. However, the wound body (electrode body) of the positive electrode plate and the negative electrode plate housed in the outer container 10 of the secondary battery cell BT of the battery pack PCK according to the present embodiment has an oval cross section like the outer container 10. Therefore, the electrode body can be accommodated even when the outer container 10 having an oval cross section is adopted. That is, even when the outer container 10 having an oval cross section substantially parallel to the bottom wall as described above is used, the capacity of the secondary battery cell BT is not reduced.

  As shown in FIG. 3, the plurality of secondary battery cells BT are arranged in a matrix in the longitudinal direction (first direction D1) of the lid body 14 and the direction in which the main wall 1 faces (second direction D2). ing. In the case shown in FIG. 3, nine secondary battery cells BT are arranged in the second direction D2, and these nine secondary battery cells BT are arranged in two rows in the first direction D1, and 18 secondary battery cells. BT is provided.

  The negative electrode terminal 4 and the positive electrode terminal 5 of the plurality of secondary battery cells BT are electrically connected by a conductive member 300. The conductive member 300 includes an opening 301 into which the negative electrode terminal 4 or the positive electrode terminal 5 is inserted. The conductive member 300 is welded to the negative electrode terminal 4 or the positive electrode terminal 5 in the opening 301.

  The pack case 100 is made of an insulating material. In the present embodiment, the pack case 100 is formed by, for example, an injection molding method using a thermoplastic resin. The storage hole 120 is a column-shaped hole whose bottom is the same shape (oval) as the bottom wall of the secondary battery cell BT, and is substantially perpendicular to the main surface of the lid 14 of the secondary battery cell BT (first The width of the storage hole 120 in the three directions D3) is substantially equal to the width of the outer container 10 of the secondary battery cell BT. The secondary battery cell BT is accommodated in the accommodation hole 120 provided in the pack case 100, and is insulated from the exterior container 10 of the secondary battery cell BT disposed next to the secondary battery cell BT.

  The pack case 100 includes a first screw receiving hole 130 that is continuous with the screw hole 303 of the conductive member 300, and a second screw receiving hole 110 into which the cover fixing screw 210 is inserted. A screw 310 is inserted into the screw hole 303 and the first screw receiving hole 130 to fix the conductive member 300 and the pack case 100. The screw 310 is inserted into the screw hole 303 and electrically connected to the conductive member 300, and is used as an electrode terminal of the battery pack PCK.

  The second screw receiving holes 110 are disposed near both ends of the storage hole 120 in the first direction D1 and between the storage holes 120 in the second direction. The pack case 100 is formed so that the wall surrounding the second screw receiving hole 110 has a predetermined thickness or more. In the present embodiment, in the radial direction of the second screw receiving hole 110, for example, the width of the second screw receiving hole 110 and the surrounding wall in the direction passing through the center of the second screw receiving hole 110 is at least the second screw receiving hole. The diameter of the hole 110 is 2.5 times or more. Note that the widths of the second screw receiving holes 110 and the surrounding walls are designed to appropriate values according to the material forming the pack case 100.

  The cover 200 includes a screw hole 220 into which the cover fixing screw 210 is inserted, and an opening 230 that exposes the screw 310 attached to the screw hole 303 and the first screw receiving hole 130. In the first direction D1 and the second direction D2, the widths of the pack case 100 and the cover 200 are substantially equal. The cover 200 is attached to the pack case 100 so as to face the lid 14 of the plurality of secondary battery cells BT so as to close the opening of the storage hole 120 of the pack case 100.

  The screw holes 220 are arranged side by side in the second direction D2 in the vicinity of the end in the first direction D1 and in the center of the cover 200 so as to be continuous with the second screw receiving hole 110 of the pack case 100.

  The pack case 100 and the cover 200 are aligned so that the screw hole 220 and the second screw receiving hole 110 are continuous and the screw 310 is exposed from the opening 230, and are fixed by attaching the cover fixing screw 210. The

  Here, as shown in FIG. 2 and FIG. 3, in the present embodiment, the cross-sectional shape of the outer container 10 of the secondary battery cell BT is an oval shape that is substantially similar to the cross-sectional shape of the electrode body. The volume of the secondary battery cell BT is reduced.

  Thus, for example, when four secondary battery cells BT are arranged in a matrix of 2 rows and 2 columns in the first direction D1 and the second direction D2, a space is formed in a portion surrounded by the four secondary battery cells BT. Occurs. Further, for example, a space is generated in a portion surrounded by the above-described surface and the two secondary battery cells BT along the surfaces substantially parallel to the third direction D3 and the second direction D2 of the two secondary battery cells BT. .

  In the present embodiment, the space surrounded by the secondary battery cells BT and the portion corresponding to the space surrounded by the surface and the secondary battery cells BT form the second screw receiving holes 110 as described above. Used in the area. Therefore, as compared with the case where secondary battery cells having a substantially rectangular parallelepiped shape are used, the interval at which the secondary battery cells BT are arranged in the longitudinal direction (first direction D1) of the lid body 14 can be shortened.

  That is, when a secondary battery cell having a substantially rectangular parallelepiped shape is used, in order for the battery pack PCK to have sufficient strength, if a wall having a predetermined thickness or more is provided around the second screw receiving portion 110, the pack case 100 The thickness surrounding the secondary battery cell BT is uniformly formed to be equal to or greater than a predetermined thickness.

  On the other hand, in the present embodiment, the secondary battery cell is similarly provided in the first direction D1 and the second direction D2 even when a wall having a predetermined thickness or more is provided around the second screw receiving portion 110. It is possible to reduce the interval for arranging the BT. Therefore, the physique of the pack case 100 can be reduced by an amount corresponding to the reduction in the interval at which the secondary battery cells BT are arranged.

  That is, according to the battery pack PCK according to the present embodiment, it is possible to provide a battery pack that secures the mechanical strength of the battery pack and reduces the physique.

  Next, a battery pack according to a second embodiment of the invention will be described below with reference to the drawings. In the following description, the same components as those in the battery pack according to the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 4, the battery pack PCK according to the present embodiment is different from the battery pack according to the first embodiment described above in the configuration of the secondary battery cell BT and the configuration of the pack case 100. The secondary battery cell BT of the battery pack PCK according to the present embodiment includes a box-shaped outer container 10 formed of aluminum or the like, and an electrode body housed in the outer container 10 together with a nonaqueous electrolyte (not shown). (Not shown).

  The outer container 10 has a container main body 12 having an open upper end and a substantially rectangular plate-like lid body 14 welded to the container main body 12 and closing the opening of the container main body, and is formed airtight. The container body 12 includes a bottom wall (not shown) facing the opening, two main walls 1 extending between the opening and the bottom wall and facing each other, and two side walls 3 extending between the two main walls 1. With. For example, the electrode body is formed in a columnar shape having a substantially oval cross section by winding a positive electrode plate and a negative electrode plate in a spiral shape with a separator interposed therebetween and further compressing the electrode plate in the radial direction.

  The lid body 14 and the bottom wall of the container body 12 have a substantially field track shape. In the present embodiment, one of the two arcs of the lid 14 and the bottom wall of the container main body 12 in the first embodiment includes deformed portions having different curvatures. For example, one of the two arcs is a quarter arc of a circle having the same radius as the other arc and an arc having a radius different from the arc or a deformed arc having a straight line.

  Therefore, the side wall 3 of the container main body 12 extending between the deformed arcs of the lid body 14 and the low wall includes a deformed portion 3 </ b> A having a shape different from that of the other side wall 3. The negative electrode terminal 4 is disposed in the vicinity of the end of the lid 14 on the arc side, and the positive terminal 5 is disposed in the vicinity of the end of the deformed arc side.

  The storage hole 120 of the pack case 100 has a shape corresponding to the shape of the outer container 10 of the secondary battery cell BT. That is, the storage hole 120 has the same bottom surface as the bottom wall of the container body 12. That is, as shown in FIGS. 5 and 6, the storage hole 120 includes a curved surface (or plane) 120 </ b> A that faces the deformed portion 3 </ b> A.

  The direction (position between the negative electrode terminal 4 and the positive electrode terminal 5) in which the secondary battery cell BT is arranged in the longitudinal direction (first direction D1) of the lid body 14 is such that the secondary battery cells BT are connected in parallel or in series. It depends on what you do.

  Here, when the secondary battery cell BT is rotated 180 degrees around the axis substantially parallel to the third direction D3 through the center of the width in the first direction D1, the two side walls 3 of the outer container 10 Since the shapes are different, the shape of the outer container 10 does not match before and after the rotation. Therefore, it is possible to determine the direction of the secondary battery cell BT from the shape of the side wall 3.

  Further, the storage hole 120 of the pack case 100 is provided with a curved surface (or plane) 120A having the same shape as the deformed portion 3A at a position corresponding to the deformed portion 3A according to the direction in which the secondary battery cell BT is stored. ing. In the present embodiment, as shown in FIG. 6, a curved surface (or flat surface) 120A having a shape corresponding to the deformed portion 3A is provided in the storage hole 120 facing the side wall 3 on the side where the positive electrode terminal 5 is disposed. .

  Therefore, when assembling the battery pack PCK according to the present embodiment, the secondary battery cell BT cannot be inserted into the storage hole 120 in the direction opposite to the predetermined direction. That is, as shown in FIG. 6, the secondary battery cell BT is accommodated in the pack case 100 so that the deformed portion 3 </ b> A and the curved surface (or plane) 120 </ b> A of the accommodation hole 120 face each other, whereby the secondary battery cell. The direction of the BT can be a predetermined direction. Therefore, when the secondary battery cell BT is inserted into the pack case 100 and the terminals are electrically connected by the conductive member 300, a short-circuit failure does not occur, and the defective product generation rate during assembly is reduced. Can do.

  Further, in the battery pack according to the present embodiment, as in the case of the battery pack according to the first embodiment described above, the cross-sectional shape of the outer container 10 of the secondary battery cell BT is made into an approximately oval shape, The volume of the secondary battery cell BT is reduced. Therefore, compared with the case where the substantially rectangular parallelepiped secondary battery cell is used, the interval at which the secondary battery cell BT is arranged in the first direction D1 and the second direction can be shortened.

  That is, according to the battery pack PCK according to the present embodiment, it is possible to provide a battery pack that secures the mechanical strength of the battery pack and reduces the physique, similarly to the battery pack according to the first embodiment.

  Next, a battery pack according to a third embodiment of the invention will be described below with reference to the drawings. As shown in FIG. 7, the battery pack PCK according to this embodiment is different from the battery pack according to the first embodiment in the configuration of the secondary battery cell BT and the configuration of the pack case 100. The secondary battery cell BT of the battery pack PCK according to the present embodiment includes a box-shaped outer container 10 formed of aluminum or the like, and an electrode body housed in the outer container 10 together with a nonaqueous electrolyte (not shown). (Not shown).

  The outer container 10 has a container main body 12 having an open upper end and a substantially rectangular plate-like lid body 14 welded to the container main body 12 and closing the opening of the container main body, and is formed airtight. The container body 12 includes a bottom wall (not shown) facing the opening, two main walls 1 extending between the opening and the bottom wall and facing each other, and two side walls 3 extending between the two main walls 1. With. For example, the electrode body is formed in a columnar shape having a substantially oval cross section by winding a positive electrode plate and a negative electrode plate in a spiral shape with a separator interposed therebetween and further compressing the electrode plate in the radial direction.

  As shown in FIG. 7, in the present embodiment, a convex portion 3 </ b> B is provided on one of the two side walls 3 of the container body 12. The convex portion 3B extends from the upper end of the side wall 3 (the end portion on the opening side of the container body 12) toward the bottom wall side by a predetermined width in a direction substantially parallel to the third direction D3, and from the side wall 3 to the first direction D1. Projecting in a direction substantially parallel to the. In the present embodiment, the convex portion 3B is provided on the side wall 3 on the positive electrode terminal 5 side.

  As shown in FIG. 8, the storage hole 120 of the pack case 100 is provided with a recess 120B at a position corresponding to the protrusion 3B of the secondary battery cell BT. The recess 120B extends from the opening of the storage hole 120 toward the bottom surface by a predetermined width in a direction substantially parallel to the third direction D3 and is recessed in a direction substantially parallel to the first direction D1. The recess 120B is provided at a position facing the side wall 3 on the positive electrode terminal 5 side of the secondary battery cell BT.

  Here, as in the case of the second embodiment, the secondary battery cell BT rotates through 180 degrees about an axis substantially parallel to the third direction D3 through the center of the width in the first direction D1. If it does, since the shape of the two side walls 3 differs, the shape of the exterior container 10 does not correspond before and after rotation. Therefore, it is possible to determine the direction of the secondary battery cell BT from the shape of the side wall 3.

  Furthermore, when assembling the battery pack PCK according to the present embodiment, if the secondary battery cell BT is inserted into the storage hole 120 in the direction opposite to the predetermined direction, the positions of the convex portion 3B and the concave portion 120B do not match. Therefore, the secondary battery cell BT cannot be inserted into the storage hole 120.

  That is, as shown in FIG. 9, the secondary battery cell BT is stored in the pack case 100 so that the convex portion 3 </ b> B is inserted into the concave portion 120 </ b> B of the storage hole 120. The orientation can be determined in advance. Therefore, when the secondary battery cell BT is inserted into the pack case 100 and the terminals are electrically connected by the conductive member 300, a short-circuit failure does not occur, and the defective product generation rate during assembly is reduced. Can do.

  Further, in the battery pack according to the present embodiment, as in the case of the battery pack according to the first embodiment described above, the cross-sectional shape of the outer container 10 of the secondary battery cell BT is made into an approximately oval shape, The volume of the secondary battery cell BT is reduced. Therefore, compared with the case where the substantially rectangular parallelepiped secondary battery cell is used, the interval at which the secondary battery cell BT is arranged in the first direction D1 and the second direction D2 can be shortened.

  That is, according to the battery pack PCK according to the present embodiment, it is possible to provide a battery pack that secures the mechanical strength of the battery pack and reduces the physique, similarly to the battery pack according to the first embodiment.

  Next, a battery pack according to a fourth embodiment of the invention will be described below with reference to the drawings. The battery pack PCK according to the present embodiment is different from the battery pack according to the first embodiment in the configuration of the pack case 100. The battery pack PCK according to the present embodiment includes a plurality of secondary battery cells BT similarly to the battery pack according to the first embodiment.

  As shown in FIG. 10, the pack case 100 includes a storage hole 140 that stores a plurality of secondary battery cells BT. That is, the pack case 100 includes a substantially rectangular bottom portion and four wall portions 100A extending in a direction substantially orthogonal to the bottom portion from the four end sides of the bottom portion, and the storage hole 140 includes the bottom portion and the four wall portions 100A. Surrounded by

  A plurality of cylindrical bodies 110A are arranged side by side in the second direction D2 in the central portion of the storage hole 140 in the first direction D1. The wall portion 100 </ b> A is provided with a plurality of columnar bodies 110 </ b> B protruding inside the pack case 100. A second screw receiving hole 110 is provided at the upper ends of the columnar body 110A and the columnar body 110B.

  In the present embodiment, the cylindrical body 110 </ b> A is formed integrally with the pack case 100. The cylindrical body 110A is desirably formed so that the diameter of the bottom surface (a cross section substantially parallel to the first direction D1 and the second direction D2) is greater than or equal to a predetermined value, depending on the material to be formed. In the present embodiment, for example, the diameter of the bottom surface of the cylindrical body 110 </ b> A is formed to be 2.5 times or more the diameter of the second screw receiving hole 110.

  The columnar body 110B protrudes from the wall portion 100A so that the wall surrounding the second screw receiving hole 110 has a predetermined thickness or more. For example, in the direction passing through the diameter of the second screw receiving hole 110, the widths of the second screw receiving hole 110, the columnar body 110 </ b> B, and the wall portion 100 </ b> A are 2.5 times or more the diameter of the second screw receiving hole 110.

  As shown in FIG. 11, the plurality of secondary battery cells BT are inserted between the columnar body 110A and the columnar body 110B. That is, the columnar body 110A and the columnar body 110B are formed so as to circumscribe the side wall 3 of the secondary battery cell BT. Each cylindrical body 110A is in contact with four secondary battery cells BT. Each columnar body 110B is in contact with two secondary battery cells BT. Each secondary battery cell BT is in front contact with the cylindrical body 110A and the columnar body 110B at four locations, and is fixed in the first direction D1 and the second direction D2.

  As mentioned above, in this embodiment, the volume of the secondary battery cell BT is made small by making the cross-sectional shape of the exterior container 10 of the secondary battery cell BT into a substantially oval shape. Further, by providing the pack case 100 with a columnar body 110A and a columnar body 110B for fixing the secondary battery cell BT, as shown in FIG. 11, a partition wall between the plurality of secondary battery cells BT is provided on the pack case 100. Without this, the outer packaging container 10 of the secondary battery cell BT can be fixed in a separated state.

  Therefore, similarly to the case of the first embodiment, the interval at which the secondary battery cells BT are arranged in the first direction D1 and the second direction D2 can be shortened. Furthermore, the configuration of the pack case 100 can be further simplified as compared with the battery pack according to the first embodiment, the weight of the battery pack PCK can be reduced, and the manufacture of the battery pack PCK can be facilitated.

  That is, according to the battery pack PCK according to the present embodiment, it is possible to provide a battery pack that secures the mechanical strength of the battery pack and reduces the physique, similarly to the battery pack according to the first embodiment.

  Next, a battery pack according to a fifth embodiment of the invention will be described below with reference to the drawings. The battery pack PCK according to the present embodiment is different from the battery pack according to the fourth embodiment in the configuration of the pack case 100. As shown in FIG. 12, in the battery pack PCK according to the present embodiment, the cylindrical body 110A of the pack case 100 is formed separately from the bottom portion and the wall portion 100A.

  When the cylindrical body 110A of the pack case 100 is integrally formed by injection molding or the like, the bottom surface (a cross section substantially parallel to the first direction D1 and the second direction D2) has a columnar shape with a thin diameter. May occur. Therefore, in the present embodiment, the cylindrical body 110A and the bottom and wall portions 100A are separately formed and joined to a predetermined position with an adhesive or the like.

  If the cylindrical body 110A and the bottom and wall portions 100A are separately formed as described above, the configuration of the pack case 100 can be further simplified, and the manufacture of the pack case 100 is further facilitated. It is also possible to form the bottom and wall portions 100A of the pack case 100 and the cylindrical body 110A using different materials. For example, the strength of the pack case 100 can be partially enhanced by forming the cylindrical body 110A with an insulating material having a strength higher than that of other members.

  That is, according to the battery pack PCK according to the present embodiment, it is possible to provide a battery pack that secures the mechanical strength of the battery pack and reduces the physique, similarly to the battery pack according to the first embodiment.

  Next, a battery pack according to a sixth embodiment of the invention will be described below with reference to the drawings. The battery pack PCK according to the present embodiment is different from the battery pack according to the fourth embodiment in the configuration of the pack case 100.

  As shown in FIGS. 13 and 14, the pack case 100 of the battery pack PCK according to the present embodiment is provided with vent holes 150 </ b> A and 150 </ b> B provided so as to be continuous with the space between the plurality of secondary battery cells BT. And a vent hole 150A provided in the cylindrical body 110A and a vent hole 150B provided in the wall portion 100A provided with the columnar body 110B and the columnar body 110B.

  The vent hole 150A provided in the cylindrical body 110A is provided so as to penetrate the cylindrical body 110A in the first direction D1. The vent holes 150B provided in the columnar body 110B and the wall portion 100A are provided so as to penetrate the columnar body 110B and the wall portion 100A provided with the columnar body 110B in the first direction D1.

  When the vent holes 150A and 150B are provided in this way and a plurality of secondary battery cells BT are stored in the storage holes 140 as shown in FIG. 14, the space between the main walls 1 of the secondary battery cells BT arranged side by side is obtained. , It continues to the space outside the battery pack PCK through the vent holes 150A, 150B. Therefore, when air is forced to flow into the pack case 100 from the one vent hole 150B side of the pack case 100, the air sent into the pack case 100 becomes the main wall of the secondary battery cell BT. It passes through the space between 1 and the vent hole 150A and is discharged from the other vent hole 150B.

  Thus, by sending the cooling medium into the pack case 100, the secondary battery cell BT can be effectively cooled, and the failure of the battery pack PCK can be reduced and the life can be extended. . That is, according to the battery pack PCK according to the present embodiment, it is possible to provide a more reliable battery pack PCK.

  That is, according to the battery pack PCK according to the present embodiment, it is possible to provide a battery pack that secures the mechanical strength of the battery pack and reduces the physique, similarly to the battery pack according to the first embodiment.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. For example, in the said 2nd Embodiment and 3rd Embodiment, although the two side walls 3 of the secondary battery cell BT were provided with the deformed part 3A or the convex part 3B, the shape of the two side walls 3 of the secondary battery cell BT Need only be asymmetrical with respect to the center in the first direction D1 and the second direction D2 in a cross section substantially parallel to the bottom wall. In that case, by making the storage hole 120 of the pack case 100 the same shape as the shape of the outer container of the secondary battery cell BT, the same effect as the battery pack according to the second embodiment and the third embodiment described above. Can be obtained.

  In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  PCK ... battery pack, BT ... secondary battery cell, 100 ... pack case, 110 ... screw receiving hole, 120, 140 ... storage hole, 200 ... cover, 210 ... cover fixing screw, 220 ... screw hole.

Claims (8)

A plurality of secondary battery cells;
A pack case including a storage hole for storing the secondary battery cell, and a plurality of screw receiving holes;
A screw hole that is continuous with the screw receiving hole, and the screw hole and a cover that is fixed to the pack case by a screw inserted into the screw receiving hole.
The secondary battery cell has a columnar shape with an oval cross section,
The storage hole is a pillar shape having the same cross-sectional shape as the secondary battery cell,
The plurality of screw receiving holes are battery packs arranged between the storage holes in a direction in which the storage holes are arranged at both ends in the longitudinal direction of the cross section of the storage hole. The secondary battery cell includes a bottom wall, a lid disposed to face the bottom wall, a main wall disposed to face each other between the bottom wall and the lid, A first side wall and a second side wall disposed between the main walls,
The cross section of the secondary battery cell substantially parallel to the bottom wall and the lid body includes a first arc, a second arc of a circle having the same radius as the first arc, the first arc and the second arc. The battery pack according to claim 1, wherein the battery pack has a shape surrounded by a circumscribed line. The secondary battery cell includes a bottom wall, a lid disposed so as to face the bottom wall, and two main bodies disposed between the bottom wall and the lid so as to face each other. A wall, and a first side wall and a second side wall extending between the main walls,
The first side wall and the second side wall have an asymmetrical shape with respect to a longitudinal direction of the bottom wall and a central portion in a direction orthogonal to the longitudinal direction in a cross section substantially parallel to the bottom wall. Item 6. The battery pack according to Item 1.   The cross section of the secondary battery cell that is substantially parallel to the bottom wall and the lid has a first arc, a part of an arc having the same radius as the first arc, and an arc of a circle having a different radius from the first arc. 4. The battery pack according to claim 3, wherein the battery pack has a shape surrounded by a deformed arc provided with a straight line and a straight line connecting the first arc and the deformed arc.   The battery pack according to claim 3, wherein the first side wall includes a convex portion protruding in a longitudinal direction of the bottom wall and the lid. A plurality of secondary battery cells;
A bottom portion, a wall portion substantially orthogonal to the bottom portion, a storage hole surrounded by the bottom portion and the wall portion and storing the plurality of secondary battery cells, and a plurality of cylinders extending in a direction substantially orthogonal to the bottom portion A pack case having a body and a plurality of columnar bodies projecting from the wall portion toward the storage hole, wherein screw receiving holes are provided at upper ends of the plurality of columnar bodies and the plurality of columnar bodies;
A screw hole that is continuous with the screw receiving hole, and the screw hole and a cover that is fixed to the pack case by a screw inserted into the screw receiving hole.
The secondary battery cell has a columnar shape with an oval cross section,
In the cross section substantially parallel to the bottom, the cylindrical body and the columnar body are arranged so as to circumscribe the secondary battery cell.   The battery pack according to claim 6, wherein the cylindrical body is formed of a material different from that of the bottom portion and the wall portion.   The columnar body, and the columnar body and the wall portion on which the columnar body is provided further include a vent hole that continues the space between the plurality of secondary battery cells and the outside. Battery pack.

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