WO2019065279A1

WO2019065279A1 - Battery pack

Info

Publication number: WO2019065279A1
Application number: PCT/JP2018/034042
Authority: WO
Inventors: 松元隆志; 藤井徳明
Original assignee: 本田技研工業株式会社
Priority date: 2017-09-29
Filing date: 2018-09-13
Publication date: 2019-04-04
Also published as: JP7002270B2; JP2019067563A

Abstract

A battery pack (10) is provided with a battery core pack (16), and a case (14) for accommodating the battery core pack (16). The case (14) has an outer shell case (12) for covering the side surfaces of the battery core pack (16), and a bottom case (26) for covering the bottom surface of the battery core pack (16). A lower side battery core pack frame (36) for supporting the battery core pack (16) is fixed inside the outer shell case (12). A fixing raised part (30) provided at the bottom section of the bottom case (26) has a hollow shape protruding towards the lower side battery core pack frame (36) and has a fixing end surface section (38) on the protruding end side. The fixing end surface section (38) and the lower side battery core pack frame (36) are fixed by a fastening member (52) with a fixing impact absorbing member (50) comprising an elastomer interposed therebetween.

Description

Battery pack

The present invention relates to a battery pack including a battery core pack having a plurality of battery cells held in a cell holder, and a case for housing the battery core pack.

For example, as described in JP-A-2016-534518, a battery having a plurality of battery cells held in a cell holder as a battery pack removably mounted on a motor-assisted bicycle or a motor-driven vehicle such as a motor-driven bike. It is known to provide a core pack and a case for housing the battery core pack.

The case has an outer shell case covering the side surface of the battery core pack, a bottom case attached to the lower end of the outer shell case covering the bottom surface of the battery core pack, and a top case covering the upper surface of the battery core pack. The top case is provided with a handle that can be gripped when carrying the battery pack.

By the way, in this type of battery pack, since it is assumed that the handle provided on the top case is held as described above and the mounting and dismounting work on the electric vehicle etc. is performed, if it falls, from the bottom case side Impact load is likely to be applied by colliding with the ground or the like. When the impact load is transmitted from the bottom case to the battery core pack, there is a concern that a load exceeding the load capacity is applied to the battery cells of the battery core pack.

The main object of the present invention is to provide a battery pack with improved durability by suppressing the transfer of an impact load from the bottom case to the battery core pack.

According to one embodiment of the present invention, there is provided a battery pack comprising: a battery core pack having a plurality of battery cells held in a cell holder; and a case for housing the battery core pack, wherein the case is the battery core A battery core pack frame for supporting the battery core pack is fixed to the inside of the shell case, the shell case covering the side of the pack and the bottom case covering the bottom surface of the battery core pack; The bottom portion of the bottom case has a hollow shape protruding toward the battery core pack frame, and is provided with a fixing convex portion having a fixing end face portion on the protruding end side, and the fixing end face portion and the battery The core pack frame is fixed to the core pack frame by the fastening member with the fixing impact absorbing member made of elastomer interposed therebetween. It has been that the battery pack is provided.

In this battery pack, since a fixing impact absorbing member is interposed between the battery core pack frame and the fixing end face portion, even if an impact load is applied from the bottom case side due to the battery pack falling or the like. The impact load can be absorbed by the fixing impact absorbing member. This can suppress transmission of the above-mentioned impact load from the bottom case to the battery core pack, thereby avoiding application of a load exceeding the load capacity to the battery cells of the battery core pack and the like. As a result, the durability of the battery pack can be improved.

In the above battery pack, the fastening member includes a bolt, a nut, and a collar, and a shaft portion of the bolt includes the battery core pack frame, the shock absorbing member for fixing, and the end face for fixing. The nut is inserted into at least the fixing impact absorbing member and the fixing end face along the stacking direction of the stacking part, and the nut is attached to the tip end side of the shaft inside the hollow of the fixing projection, The collar is interposed between the outer peripheral surface of the shaft portion and the shock absorbing member for fixation and the end face for fixation, and the collar and the end face for fixation are relatively along the axial direction of the collar Preferably it is movable.

In this case, the fixing end surface portion can move along the axial direction of the collar on the outer peripheral surface side of the collar. Therefore, when an impact load is applied from the bottom case side, the fixing end face portion and the battery core pack frame are made to approach smoothly, and the fixing impact absorbing member is favorably elastically deformed between them. It will be possible. That is, the above-mentioned impact load can be efficiently absorbed by the impact absorbing member for fixation. As a result, it is possible to effectively suppress the transfer of the impact load to the battery core pack and to improve the durability of the battery pack.

In the above battery pack, the bottom portion of the bottom case is provided with a contact convex portion having a hollow shape protruding toward the battery core pack frame and having an end surface portion for contact on the projecting end side, Preferably, a shock absorbing member for contact made of an elastomer is provided between the end surface for contact and the battery core pack frame. In this case, since the impact load can be absorbed also by the impact absorbing member for abutment, the transfer of the impact load from the bottom case side to the battery core pack is more effectively suppressed, and the battery pack Durability can be improved.

In the above battery pack, the shock absorbing member for abutment is in a cylindrical shape coaxially disposed with the convex portion for abutment, and the end face portion for abutment projects from the end face portion for abutment. It is preferable that an insertion portion which is inserted into the hollow interior of the shock absorbing member for contact and whose axial length is shorter than a natural length of the shock absorbing member for contact in the axial direction is provided.

In this case, it is possible to separate the battery core pack frame in contact with the upper end surface of the abutting impact absorbing member in a state not elastically deformed and the upper end surface of the insertion portion. For this reason, an impact load is applied from the bottom case side, and while the upper end surface of the insertion portion and the battery core pack frame approach each other, the abutting impact absorbing member can be elastically deformed well. As a result, since the above-mentioned impact load can be efficiently absorbed by the impact absorbing member for abutment, the transfer of the impact load to the battery core pack is effectively suppressed, and the durability of the battery pack is obtained. Can be improved.

In the above battery pack, preferably, the fixing projections are provided at four corners of a rectangular bottom of the bottom case. This makes it possible to absorb the impact load by the impact absorbing member for fixing, regardless of which direction the impact load is applied to the bottom case, so that the durability of the battery pack is effectively achieved. It can be improved.

1 is a schematic perspective view of a battery pack according to an embodiment of the present invention. It is a schematic perspective view of a bottom case. It is principal part sectional drawing of a bottom case, a lower side battery core pack frame, and a part of lower end side of outer shell case. It is an explanatory view explaining a shock absorber for fixation in the state where impact load is not added to the bottom case, and a shock absorber for abutment. It is an explanatory view explaining an impact absorption member for fixation, and an impact absorption member for contact when an impact load is added to a bottom case. It is an exploded perspective view of a battery core pack.

A preferred embodiment of the battery pack according to the present invention will be described in detail with reference to the attached drawings.

FIG. 1 is a schematic perspective view of a battery pack 10 according to the present embodiment. In addition, in FIG. 1, in order to facilitate understanding, the outer shell case 12 is indicated by a two-dot chain line, and components disposed inside the outer shell case 12 are illustrated.

The battery pack 10 can be suitably applied as, for example, a portable battery pack 10 that is removably mounted on an electrically powered vehicle (not shown) such as an electrically assisted bicycle or an electrically driven motorcycle. Therefore, although an example in which battery pack 10 is mounted on an electric vehicle will be described below, the present invention is not particularly limited to this, and battery pack 10 can be applied to various devices that require electric power. . Further, the vertical direction of the battery pack 10 is based on the vertical direction (arrows X1 and X2 in FIG. 1) when the battery pack 10 is mounted on the electric vehicle.

As shown in FIG. 1, the battery pack 10 includes a case 14, a connector 18 in which two battery core packs 16 a and 16 b are connected, a battery management unit (BMU) 24, and a connector (not shown). Mainly equipped with The case 14 can be formed of, for example, a metal such as aluminum, a resin (including a fiber reinforced resin), or the like. The case 14 is a bottom case 26 covering the bottom of the connector 18, an outer shell case 12 attached to the upper end of the bottom case 26 and covering the side of the connector 18, and an upper end of the outer shell 12. And a top case 28 that covers the top surface of the connector 18.

As also shown in FIG. 2 and FIG. 3, the bottom case 26 is a housing having an opening at its upper end, and a connector portion and the like are accommodated inside. The connector portion is exposed to the outside of the case 14 through, for example, a notch 26a (see FIG. 2) or the like formed in the bottom wall of the bottom case 26 and charges the power supply port of the electric vehicle or the connector 18 It is possible to connect to the charging device for The power supply port and the charging device described above are not shown. By connecting the connector portion to the power supply port or the charging device, the power supply port or the charging device and the coupling body 18 can be electrically connected via the BMU 24 by a lead wire (not shown) or the like.

At four corners of the rectangular bottom of the bottom case 26, fixing projections 30 are provided. Further, the abutting projections 32 are respectively provided between the fixing projections 30 on the bottom of the bottom case 26. The details of the fixing convex portion 30 and the abutting convex portion 32 will be described later.

As shown in FIGS. 2 and 3, a thin wall portion 26b is provided on the upper end side of the peripheral wall of the bottom case 26, and a thick wall portion 26c is provided on the lower end side of the thin wall portion 26b. The thickness of the thin portion 26 b is smaller than the thickness of the thick portion 26 c. Due to these differences in thickness, a step surface 26d is formed between the thin portion 26b and the thick portion 26c.

The outer shell case 12 is provided with openings at both end portions in the vertical direction. A part of the upper end side of the thin portion 26 b of the bottom case 26 is inserted into the opening on the lower end side of the outer shell case 12. That is, the dimension of the thin portion 26 b and the dimension of the opening on the lower end side of the outer shell case 12 are set so that the clearance 27 is formed between the lower end face of the outer shell case 12 and the step surface 26 d of the bottom case 26. Is set.

A lower fixing groove 34 is formed along the circumferential direction of the outer shell case 12 on the inner wall of the outer shell case 12 above the upper end of the thin-walled portion 26b of the bottom case 26 inserted in the outer shell case 12 There is. A lower battery core pack frame 36 supporting the connector 18 from below is fixed to the lower fixing groove 34.

Specifically, as shown in FIGS. 1 and 3, the lower battery core pack frame 36 has a flange portion 40, an abutment portion 42 and a connection portion 44. The flange portion 40 extends outward from the outer peripheral edge on the lower end side of the connection portion 44 in the horizontal direction, and is inserted into the lower fixing groove 34. The contact portion 42 is in the form of a frame plate in which the lower end surface of the connector 18 partially contacts. Further, a reinforcing portion 46 is provided on the contact portion 42 so as to cross a substantially central portion in the horizontal direction, and openings 48 are provided on both sides in a direction orthogonal to the extending direction of the reinforcing portion 46. The outer peripheral edge portion of the contact portion 42 is disposed at a distance from the inner surface of the outer shell case 12.

The connection portion 44 has a lower end connected to the flange portion 40 and an upper end connected to the contact portion 42, and the outer shell case 12 from the flange portion 40 side (lower side) to the contact portion 42 side (upper side) The plate is inclined in the direction in which the distance from the inner surface of the

As also shown in FIGS. 4 and 5, the fixing convex portion 30 and the abutting convex portion 32 are respectively directed from the bottom portion of the bottom case 26 toward the abutting portion 42 of the lower battery core pack frame 36. It is a hollow shape which protrudes. The fixing convex portion 30 has a fixing end surface 38 on the side of the protruding end (upper end). The fixing end face portion 38 and the lower battery core pack frame 36 are fixed by the fastening member 52 with the fixing impact absorbing member 50 interposed therebetween.

The fixing impact absorbing member 50 is formed in a tubular shape from an elastomer capable of absorbing an impact load by being elastically deformed. In addition, an elastomer is a generic term of the material which shows rubber elasticity at normal temperature, and contains thermosetting elastomers, such as natural rubber and a synthetic rubber, a thermoplastic elastomer, etc.

The fastening member 52 has a bolt 54, a nut 56 and a collar 58. The head portion 60 of the bolt 54 is disposed on the upper surface side of the lower battery core pack frame 36 in the laminated portion 62 in which the fixing end face portion 38, the fixing impact absorbing member 50, and the lower battery core pack frame 36 are laminated. Ru. The head 60 of the bolt 54 and the lower battery core pack frame 36 may be joined by welding or the like.

The shaft portion 64 of the bolt 54 has a through hole 36a provided in the lower battery core pack frame 36 so as to penetrate the laminated portion 62 along the laminating direction, the hollow interior of the impact absorbing member 50 for fixation, and The through holes 38 a provided in the end face portion 38 are inserted. The nut 56 is attached to the tip end side of the shaft 64 at the hollow interior 30 a of the fixing projection 30.

The collar 58 is in the form of a tube interposed between the outer peripheral surface of the shaft 64 and the impact absorbing member 50 for fixation and the end face 38 for fixation. The upper end surface of the collar 58 abuts on the lower surface of the lower battery core pack frame 36. Further, a flange portion 66 is provided at the lower end of the collar 58, and the flange portion 66 is interposed between the lower surface of the fixing end surface portion 38 and the nut 56 in the hollow interior 30a of the fixing protrusion 30.

The collar 58 and the fixing end face 38 are relatively movable along the axial direction of the collar 58. That is, the outer diameter of the collar 58 is smaller than the diameter of the through hole 38 a of the fixing end surface portion 38.

The abutting convex portion 32 has an abutting end surface 68 on the side of the projecting end (upper end). An abutting impact absorbing member 70 is interposed between the abutting end face 68 and the lower battery core pack frame 36. The shock absorbing member for abutment 70 is in the form of a tube made of an elastomer capable of absorbing an impact load by deformation, and is disposed coaxially with the convex portion for abutment 32. The abutting end surface 68 is provided with an insertion portion 72 which protrudes from the abutting end surface 68 and is inserted into the hollow interior of the abutting impact absorbing member 70. The axial length of the insertion portion 72 is set to be shorter than the natural length of the shock absorbing member 70 for contact in the axial direction.

As shown in FIG. 1, a part of the lower end side of the top case 28 is inserted into the opening on the upper end side of the outer shell case 12. An upper fixing groove 74 is formed on the inner wall of the outer shell case 12 below the lower end of the top case 28 inserted into the outer shell case 12. An upper battery core pack frame 76 in contact with the upper end surface of the connector 18 is fixed to the upper fixing groove 74. The upper battery core pack frame 76 may be substantially similar in shape to the lower battery core pack frame 36, and may be fixed to the upper fixing groove 74 with the lower battery core pack frame 36 upside down. it can. The coupling body 18 is held between the upper battery core pack frame 76 and the lower battery core pack frame 36 fixed to the outer shell case 12 as described above.

The top case 28 is a housing provided with an opening at the lower end portion, and a handle portion 78 that can be gripped when carrying the battery pack 10 is provided on the upper end surface. Further, a convex portion protruding toward the upper battery core pack frame 76 is provided on the inner side of the top case 28, and the convex portion and the upper battery core pack frame 76 are fixed by bolts or the like. Shown).

The two battery core packs 16a, 16b constituting the coupling body 18 are configured substantially the same as each other. Therefore, components corresponding to each other of the two battery core packs 16a and 16b will be described in common by attaching the same reference numerals. When the two battery core packs 16 a and 16 b are not distinguished from one another, they are also collectively referred to as a battery core pack 16.

The battery core pack 16 has a plurality of battery cells 80 (see FIG. 6) and a cell holder 82. As shown in FIG. 1, in the present embodiment, battery core pack 16 is formed so as to form a space 83 (see FIGS. 1 and 3) for accommodating wiring (not shown) or the like between battery core pack 16 and the connector portion. A part of the lower end side is notched.

As shown in FIG. 6, the battery cell 80 has, for example, a cylindrical shape, and a positive electrode terminal 84 and a negative electrode terminal 86 are respectively provided at both ends in the axial direction. Although a lithium ion secondary battery can be mentioned as a suitable type of the battery cell 80, the present invention is not particularly limited thereto. For example, a secondary battery such as a nickel hydrogen battery or a nickel cadmium battery may be used.

The cell holder 82 is configured by combining the positive electrode side holder 82a and the negative electrode side holder 82b, and holds the holding portion 90 for holding the plurality of battery cells 80, the pressing plate portion 93 provided with the exposed portion 92, the holding portion 90 and the exposure And a peripheral wall portion 94 surrounding the portion 92. The positive electrode terminal 84 is exposed from the exposed portion 92 of the positive electrode side holder 82a, and the negative electrode terminal 86 is exposed from the exposed portion 92 of the negative electrode side holder 82b.

In the following, with regard to the cell holder 82, the above-mentioned vertical direction (hereinafter also referred to as X direction), the axial direction of the battery cell 80 (arrow Y1, Y2 direction in FIG. 1, hereinafter also referred to as Y direction), and vertical direction The description will be made with reference to a direction orthogonal to both the axial direction and the axial direction (directions of arrows Z1 and Z2 in FIG. 1, hereinafter also referred to as Z direction).

The holding portion 90 has a plurality of insertion holes 96, and holds the battery cell 80 in a state of being inserted into the insertion holes 96 respectively. The insertion hole 96 extends along the Y direction, and exposes the positive electrode terminal 84 or the negative electrode terminal 86 of the battery cell 80 from the openings at both ends in the extending direction. The diameter of the insertion hole 96 is a size corresponding to the outer diameter of the battery cell 80. In the plurality of battery cells 80 held by the holding unit 90, the respective positive electrode terminals 84 are disposed flush with one another, and the respective negative electrodes 86 are disposed flush with one another. Further, a potting material (not shown) made of an insulating resin or the like may be filled between the circumferential surfaces of the plurality of battery cells 80 held by the holding unit 90.

The pressing plate portions 93 are respectively provided on both end sides of the holding portion 90 in the Y direction, and through holes are provided as exposed portions 92 at positions corresponding to the openings of the insertion holes 96. The positive electrode terminal 84 and the negative electrode terminal 86 (hereinafter, also collectively referred to as electrode terminals) are exposed to the outside of the cell holder 82 through the opening of the insertion hole 96 and the exposed portion 92. Further, a plurality of bus bar plates 100 (see FIG. 1) are attached to the pressing plate 93 so as to cover the exposed portion 92 exposing the positive electrode terminal 84 and the exposed portion 92 exposing the negative electrode terminal 86. The pressing plate portion 93 is provided with protruding portions 102 interposed between the bus bar plates 100 to insulate them from each other.

The two battery core packs 16a and 16b are connected so that the negative electrode terminal 86 side of one battery core pack 16a and the positive electrode terminal 84 side of the other battery core pack 16b face each other to form a connected body 18 It is done.

The side of the positive electrode terminal 84 of one battery core pack 16 a and the side of the negative electrode terminal 86 of the other battery core pack 16 b, in other words, the side surfaces on both sides in the Y direction of the connector 18 face the inner surface of the outer shell case 12.

As shown in FIG. 1, each of the plurality of bus bar plates 100 connects the positive electrode terminals 84 or the negative electrodes 86 in parallel by a predetermined number, and enters the exposed portion 92 to be in contact with the electrode terminals The projecting portion 104 is provided, for example, by embossing. Connection end portions 108 to be inserted into grooves 106 provided on the end surfaces of the peripheral wall portions 94 are provided on the bus bar plate 100, respectively. A plurality of bus bar plates 100 are connected to the connector portion via the BMU 24 in a state of being connected in series with each other by connecting the connection end portion 108 and the above-described lead wires and the like.

In addition, it is preferable to interpose a heat dissipation sheet (not shown) between the bus bar plate 100 and the inner surface of the outer shell case 12. In this case, the heat generated in the battery cell 80 can be effectively dissipated through the heat dissipation sheet, so that the temperature rise of the connector 18 can be suppressed.

The upper end portion of one end side (the arrow Y2 side in FIG. 1) of the positive side holder 82a of the battery core pack 16a and the other end side (the arrow Y1 side in FIG. 1) of the negative side holder 82b of the battery core pack 16b The projecting wall 110 which protrudes toward an upper side is each provided in the upper end part of. The upper battery core pack frame 76 abuts on the upper end surface of the projecting wall 110. Thus, a space 112 is formed between the connector 18 and the upper battery core pack frame 76, and the BMU 24 is disposed in the space 112 (see FIG. 1).

For example, the BMU 24 controls the charge and discharge of the battery core pack 16, the communication unit for communicating with the electric vehicle and the charging device, and the state of the battery core pack 16 detected from the temperature and voltage of the battery cell 80. And a storage unit for storing (all not shown).

The battery pack 10 according to the present embodiment is basically configured as described above. In the battery pack 10, for example, the battery cell 80 can be charged by holding the handle portion 78, carrying the battery pack 10 near the charging device, and connecting the connector portion and the charging device. On the other hand, for example, the battery cell 10 can be discharged by mounting the battery pack 10 carried by gripping the handle portion 78 on the electric vehicle and connecting the connector portion and the power supply port.

In the battery pack 10, it is assumed that the handle portion 78 provided on the top case 28 is gripped and carried while the bottom case 26 side is disposed on the lower side in the vertical direction. For this reason, the impact load is likely to be applied by colliding with the ground from the bottom case 26 side by dropping or the like at the time of attachment / detachment work to the electric vehicle etc.

In the battery pack 10 according to the present embodiment, as described above, the fixing impact absorbing member 50 is interposed between the lower battery core pack frame 36 and the fixing end surface portion 38. Therefore, even if an impact load is applied from the bottom case 26 side by the battery pack 10 falling, etc., the impact load can be absorbed by the impact absorbing member 50 for fixing and the impact absorbing member 70 for abutment. .

Specifically, as shown in FIG. 4, when the above impact load is applied as shown in FIG. 5 from the state where the above impact load is not applied, the fixing end face portion 38 is the lower battery core. The pack frame 36 is approached. As a result, the fixing impact absorbing member 50 interposed between the fixing end surface portion 38 and the lower battery core pack frame 36 is elastically deformed in the direction in which the fixing impact absorbing member 50 is compressed. As a result, the above-mentioned impact load can be absorbed.

Under the present circumstances, as above-mentioned, the collar 58 and the end surface part 38 for fixation are relatively movable along the axial direction of this collar 58. As shown in FIG. For this reason, the fixing end face portion 38 can move along the axial direction of the collar 58 on the outer peripheral surface side of the collar 58. Therefore, when the above impact load is applied, the fixing end face portion 38 and the lower battery core pack frame 36 are made to approach smoothly, and the fixing impact absorbing member 50 is elastically deformed well between them. It becomes possible. That is, the above-described impact load can be efficiently absorbed by the fixing impact absorbing member 50.

Further, as shown in FIG. 4, when the above impact load is applied as shown in FIG. 5 from the state where the above impact load is not applied, the abutting end face 68 is the lower battery core pack frame Approach 36. For this reason, the shock absorbing member 70 for contact interposed between the end face 68 for contact and the lower battery core pack frame 36 is elastically deformed in the direction in which it is compressed. Also by this, the above-mentioned impact load can be absorbed.

Under the present circumstances, as above-mentioned, the length of the axial direction of the insertion part 72 penetrated by the impact-absorbing member 70 for contact | abutting is set shorter than the natural length of the axial direction of the impact-absorbing member 70 for contact. As a result, as shown in FIG. 4, the lower battery core pack frame 36 in contact with the upper end surface of the impact shock absorbing member 70 in a non-elastically deformed state is separated from the upper end surface of the insertion portion 72. Can. For this reason, as shown in FIG. 5, while the above-mentioned impact load is applied and the upper end surface of the insertion portion 72 and the lower battery core pack frame 36 approach each other, the abutting shock absorbing member 70 is made better. It can be elastically deformed. As a result, the above-described impact load can be efficiently absorbed by the abutting impact absorbing member 70.

As described above, by forming the clearance 27 (see FIG. 3) between the lower end surface of the outer shell case 12 and the step surface 26 d of the bottom case 26, the bottom case 26 is subjected to the above-mentioned impact load. And the shell case 12 can be made easy to approach. That is, it is possible to easily bring the fixing end surface portion 38 and the contact end surface portion 68 of the bottom case 26 and the lower battery core pack frame 36 fixed to the outer shell case 12 close to each other. As a result, the fixing impact absorbing member 50 and the abutting impact absorbing member 70 interposed between the fixing end surface portion 38 and the abutting end surface portion 68 and the lower battery core pack frame 36 are favorably made in the compression direction. By elastic deformation, it is possible to effectively absorb the above-mentioned impact load. Further, since the clearance 27 is formed as described above, the impact load transmitted from the bottom case 26 to the outer shell case 12 can be reduced, and damage to the bottom case 26 and the outer shell case 12 can be suppressed.

Furthermore, as described above, since the fixing projections 30 are respectively provided at the four corners of the rectangular bottom of the bottom case 26, the above-described impact load is applied to the bottom case 26 from any direction. Even in this case, the impact load can be absorbed by the impact absorbing member 50 for fixing.

From the above, in the battery pack 10, it is possible to effectively suppress the transmission of the impact load from the bottom case 26 to the connecting member 18, so that a load exceeding the load capacity is applied to the battery cells 80 and the like of the connecting member 18. It can be avoided. As a result, the durability of the battery pack 10 can be improved.

The present invention is not particularly limited to the embodiment described above, and various modifications can be made without departing from the scope of the invention.

For example, in the battery pack 10 according to the above-described embodiment, the fixing projections 30 are provided at the four corners of the rectangular bottom of the bottom case 26, respectively, and contact between the fixing projections 30 at the bottom of the bottom case 26 is achieved. The contacting convex portions 32 are provided. However, the locations and the number of the fixing projections 30 and the abutting projections 32 are not particularly limited. As an example, the fixing convex portion 30 and the abutting convex portion 32 may be provided so as to protrude toward the reinforcing portion 46 of the lower battery core pack frame 36.

In the above embodiment, the head 60 of the bolt 54 is disposed on the upper surface side of the lower battery core pack frame 36, and the shaft 64 of the bolt 54 is the through hole 36 a of the lower battery core pack frame 36. The hollow portion of the fixing impact absorbing member 50 and the through hole 38 a of the fixing end surface portion 38 are inserted. However, for example, the lower battery core pack frame 36 may not be provided with the through holes 36 a, and the head portion 60 may be joined to the lower surface of the lower battery core pack frame 36 by welding or the like. In this case, the shaft portion 64 is inserted into the hollow interior of the fixing impact absorbing member 50 and the through hole 38 a of the fixing end surface portion 38, and the upper end surface of the collar 58 abuts on the head portion 60.

In the battery pack 10 which concerns on said embodiment, we decided to provide the connection body 18 which connected two

battery core pack

16a, 16b. However, the battery pack 10 may include only one battery core pack, or may include a connector (not shown) in which three or more battery core packs are connected.

In the battery pack 10 according to the above-described embodiment, the lower battery core pack frame 36 includes the flange portion 40, the contact portion 42, and the connection portion 44. However, the present invention is not particularly limited thereto. The lower battery core pack frame 36 may have any configuration as long as it can support the connector 18 (battery core pack 16) inside the outer shell case 12. The same applies to the upper battery core pack frame 76.

10 ... battery pack 12 ... shell case 14 ... case
16, 16a, 16b: battery core pack 18: connected body 26: bottom case 28: top case 30: fixing convex portion 30a: hollow interior 32: abutting convex portion 36: lower battery core pack frame 38: for fixing End face 50: shock absorbing member for fixing 52: fastening member 54: bolt 56: nut 58: collar 60: head 62: laminated portion 64: shaft portion 66: flange portion 68: contact end surface portion 70: for contact Shock absorbing member 72 ... insertion portion 80 ... battery cell 82 ... cell holder

Claims

A battery pack (10) comprising: a battery core pack (16) having a plurality of battery cells (80) held in a cell holder (82); and a case (14) for housing the battery core pack (16) ,
The case (14) has an outer shell case (12) covering the side surface of the battery core pack (16), and a bottom case (26) covering the bottom surface of the battery core pack (16).
A battery core pack frame (36) supporting the battery core pack (16) is fixed to the inside of the outer shell case (12),
A fixing convex portion (30) having a hollow shape protruding toward the battery core pack frame (36) at a bottom portion of the bottom case (26) and having a fixing end surface portion (38) at a protruding end side Is provided,
The fixing end face portion (38) and the battery core pack frame (36) are fixed by a fastening member (52) in a state in which a fixing impact absorbing member (50) made of an elastomer is interposed therebetween. A battery pack (10).
The battery pack (10) according to claim 1, wherein
The fastening member (52) comprises a bolt (54), a nut (56) and a collar (58).
The shaft portion (64) of the bolt (54) is a lamination direction of the laminated portion (62) of the battery core pack frame (36), the fixing impact absorbing member (50) and the fixing end face portion (38). Along at least the fixing impact absorbing member (50) and the fixing end face (38),
The nut (56) is attached to the tip end side of the shaft (64) in the hollow interior (30a) of the fixing projection (30).
The collar (58) is interposed between an outer peripheral surface of the shaft portion (64), the impact absorbing member for fixing (50) and the end surface portion for fixing (38).
A battery pack (10) characterized in that the collar (58) and the fixing end face (38) are relatively movable along the axial direction of the collar (58).
The battery pack (10) according to claim 1 or 2,
A contact convex portion having a hollow shape projecting toward the battery core pack frame (36) at the bottom portion of the bottom case (26) and having an end surface portion (68) for contact at the projecting end side 32) is provided,
A battery pack (10) is characterized in that a shock absorbing member (70) for contact made of an elastomer is provided between the end face (68) for contact and the battery core pack frame (36). ).
The battery pack (10) according to claim 3, wherein
The abutting impact absorbing member (70) is cylindrically arranged coaxially with the abutting convex portion (32),
The contact end face (68) projects from the contact end face (68) and is inserted into the hollow interior of the contact impact absorbing member (70), and the axial length is the same as the contact end face (68). A battery pack (10) characterized in that an insertion portion (72) shorter than a natural length in the axial direction of a connecting impact absorbing member (70) is provided.
The battery pack (10) according to any one of claims 1 to 4,
A battery pack (10) characterized in that the fixing projections (30) are provided at four corners of a rectangular bottom of the bottom case (26).