JP6975605B2 - Battery pack - Google Patents

Description

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

For example, as described in Patent Document 1, a battery core pack having a plurality of battery cells held in a cell holder as a battery pack that is detachably mounted on an electric vehicle such as an electrically assisted bicycle or an electric motorcycle. Those provided with a case for accommodating the battery core pack are known.

Special Table 2016-534518

In this type of battery pack, it is conceivable to provide a support member for supporting the battery core pack inside the case. Since the support member receives a load according to the weight of the battery core pack and the like, it is necessary to have a structure having durability that can withstand the load.

However, if the durability of the support member is improved by increasing the volume so as to be able to cover the entire battery core pack, the weight of the support member also increases. Therefore, the weight of the battery pack is reduced. Will be difficult.

The present invention has been made to solve the above-mentioned problems, and provides a lightweight and durable battery pack.

In order to achieve the above object, the present invention is a battery pack including a battery core pack having a plurality of battery cells held in a cell holder and a case for accommodating the battery core pack, and the inside of the case. Is provided with a battery core pack frame that supports the battery core pack, and the battery core pack frame includes a plurality of frame members arranged so as to extend the inner surface of the case along the circumferential direction, and the frame. The frame member has a connecting member for connecting the members to each other, and a flange portion inserted into a fixing groove formed along the circumferential direction on the inner surface of the case is provided on the outer surface of the frame member. Inclined surfaces inclined with respect to the extending direction are provided at both ends in the extending direction, and the corners of the battery core pack frame are formed by facing the inclined surfaces, and the connecting member is formed with the connecting member. The intervening portion interposed between the inclined surfaces and one of the set of the frame members connected to the intervening portion and facing the inclined surfaces are supported from the side opposite to the side facing the battery core pack. It is characterized by having one support portion and a second support portion connected to the intervening portion and supporting the other side of the set of frame members from the side facing the battery core pack and the side opposite to the side facing the battery core pack.

When a load corresponding to the weight of the battery core pack is applied to the battery core pack frame of this battery pack, the flange portion inserted into the fixing groove is used as a fulcrum for the frame member toward the inside of the outer shell case. Force is applied in the direction of tilting. In this case, as described above, the connecting members provided at both ends of the frame member in the extending direction may generate a tensioning force of the intervening portion with respect to the inner surface of the case so as to regulate the tilt of the frame member. can.

As a result, the battery core pack frame can remain firmly fixed to the case even when a load is applied from the battery core pack. That is, the battery core pack can be satisfactorily supported by withstanding the above load without detaching from the case.

As described above, the durability of the battery core pack frame can be enhanced by a simple configuration having the frame member and the connecting member. Therefore, for example, by increasing the volume of the battery core pack frame, the weight of the battery core pack frame can be reduced as compared with the case where the durability thereof is increased.

From the above, this battery pack includes a battery core pack frame that is lightweight yet has excellent durability. This makes it possible to firmly support the battery core pack while suppressing the increase in weight, so that it is possible to reduce the weight and improve the durability of the battery pack itself.

In the above battery pack, the frame member preferably has a hollow structure. In this case, the weight of the battery core pack frame can be further reduced.

According to the present invention, it is possible to reduce the weight and improve the durability of the battery pack.

It is a schematic perspective view of the battery pack which concerns on embodiment of this invention. It is an exploded perspective view of a part of the lower end side of the outer shell case and the lower battery core pack frame. It is a cross-sectional view of a part of the lower end side of the outer shell case and the main part of the lower battery core pack frame. It is an enlarged perspective view of a part of the lower end side of the outer shell case and the corner of the lower battery core pack frame. It is another enlarged perspective view of a part of the lower end side of the outer shell case and the corner of the lower battery core pack frame. It is a perspective view of a frame member. It is a perspective view of a connecting member. 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 accompanying drawings.

FIG. 1 is a schematic perspective view of the battery pack 10 according to the present embodiment. In FIG. 1, the outer shell case 12 is shown by a two-dot chain line for easy understanding, and the components arranged inside the outer shell case 12 are shown.

The battery pack 10 can be suitably applied as, for example, a portable battery pack 10 that is detachably mounted on an electric vehicle (not shown) such as an electric assist bicycle or an electric motorcycle. Therefore, an example in which the battery pack 10 is mounted on an electric vehicle will be described below, but the present invention is not particularly limited to this, and the battery pack 10 can be applied to various devices requiring electric power. .. Further, the vertical direction of the battery pack 10 is based on the vertical direction (directions of 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 connecting body 18 connecting two battery core packs 16a and 16b, a battery management device (Battery Management Unit: BMU) 24, and a connector (not shown). Mainly equipped with a department. The case 14 can be formed of, for example, a metal such as aluminum, a resin (including a fiber reinforced resin), or the like. Further, the case 14 has a bottom case 26 that covers the bottom surface of the connecting body 18, an outer shell case 12 that is attached to the upper end portion of the bottom case 26 and covers the side surface of the connecting body 18, and an upper end portion of the outer shell case 12. It has a top case 28 which is attached to and covers the upper surface of the connecting body 18.

The bottom case 26 is a housing having an opening at the upper end portion, and a connector portion or the like is housed therein. The connector portion is exposed to the outside of the case 14 through, for example, a notch formed in the bottom wall of the bottom case 26, and serves as a power supply port of an electric vehicle or a charging device for charging the connecting body 18. However, it is possible to connect. The notch, the power supply port, and the charging device 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 connecting body 18 can be electrically connected via the BMU 24 by a lead wire or the like (not shown).

The outer shell case 12 is provided with openings at both ends in the vertical direction. A part of the upper end side of the bottom case 26 is inserted into the opening on the lower end side of the outer shell case 12. A lower fixing groove 30 is formed on the inner wall of the outer shell case 12 above the upper end of the bottom case 26 inserted into the outer shell case 12 along the circumferential direction of the outer shell case 12. A lower battery core pack frame 32 that supports the connecting body 18 from the lower side (bottom side) is fixed to the lower fixing groove 30.

Specifically, as shown in FIGS. 2 to 7, the lower battery core pack frame 32 includes a plurality of frame members 34 arranged so as to extend the inner surface of the outer shell case 12 along the circumferential direction. , A connecting member 36 that connects the frame members 34 to each other.

In the present embodiment, since the cross section of the outer shell case 12 orthogonal to the vertical direction is rectangular, the lower battery core pack frame 32 includes four frame members 34 extending along the four sides of the rectangular shape. Have. These frame members 34 have a hollow structure. Further, the frame member 34 is provided with a flange portion 38 on the lower end side of the outer surface 34a facing the inner surface of the outer shell case 12, and the flange portion 38 is inserted into the lower fixing groove 30.

As shown in FIG. 6, inclined surfaces 34b inclined with respect to the extending direction are provided at both ends of the frame member 34 in the extending direction. The inclined surface 34b is inclined from the outer surface 34a side of the frame member 34 toward the inner side surface 34c side so that the length of the frame member 34 in the extending direction becomes shorter. As a result, as shown in FIG. 4 and the like, the portion where the frame member 34 is arranged so that the inclined surfaces 34b face each other becomes the corner of the lower battery core pack frame 32.

Further, inside the lower end side of the frame member 34 in the circumferential direction, there is a fixed surface 34d that inclines from the outer surface 34a side toward the inner side surface 34c side so that the length of the frame member 34 in the vertical direction becomes shorter. It is provided.

As shown in FIGS. 5 and 7, the connecting member 36 has an intervening portion 40, a first support portion 42, and a second support portion 43. The intervening portion 40 is interposed between the inclined surfaces 34b of the frame member 34 and extends along a direction (vertical direction) orthogonal to the extending direction of the frame member 34.

The first support portion 42 is connected to the lower end of the intervening portion 40, and one of a set of frame members 34 having inclined surfaces 34b facing each other (hereinafter, also simply referred to as one frame member 34) is viewed from the lower end side thereof. To support. The second support portion 43 is connected to the lower end of the intervening portion 40, and the other side of the set of frame members 34 having the inclined surfaces 34b facing each other (hereinafter, also simply referred to as the other frame member 34) is viewed from the lower end side thereof. To support.

Specifically, the first support portion 42 is in contact with the fixed surface 34d of one frame member 34, and the second support portion 43 is in contact with the fixed surface 34d of the other frame member 34. The first support portion 42 and the second support portion 43 are formed on the fixed surface 34d, for example, through holes 42a and 43a provided in the first support portion 42 and the second support portion 43, respectively. It is fixed by a screw (not shown) stopper or the like via the screw hole 35 (see FIG. 6). As a result, the frame member 34 and the connecting member 36 are fixed.

When fixing the lower battery core pack frame 32 to the inside of the outer shell case 12, for example, first, the flange portion 38 of each of one frame member 34 and the other frame member 34 has a lower fixing groove 30. It is arranged along the inner surface of the outer shell case 12 so as to be inserted into the outer shell case 12. Next, the intervening portion 40 is interposed between the inclined surfaces 34b of the frame member 34, and the first support portion 42 and the second support portion 42 and the second support portion 42 are placed on the fixed surfaces 34d of each of the one frame member 34 and the other frame member 34. The support portions 43 are brought into contact with each other. Then, the frame member 34 and the connecting member 36 are fixed by screwing as described above. In this way, by fixing the connecting members 36 to all the corners of the frame member 34 arranged along the inner surface of the outer shell case 12, the connecting members 36 are fixed to the lower fixing groove 30 inside the outer shell case 12. The lower battery core pack frame 32 in the open state can be formed.

The bottom surface of the bottom case 26 is provided with a convex portion that protrudes toward the lower battery core pack frame 32, and the convex portion and the lower battery core pack frame 32 are fixed by bolts or the like (neither is possible). Illustrated).

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 44 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. The upper battery core pack frame 46 that abuts on the upper end surface of the connecting body 18 is fixed to the upper fixing groove 44.

The upper battery core pack frame 46 has substantially the same shape as the lower battery core pack frame 32, and is fixed to the upper fixing groove 44 in a state where the lower battery core pack frame 32 is turned upside down in the vertical direction. Therefore, a detailed description of the upper battery core pack frame 46 will be omitted. The connecting body 18 is sandwiched between the upper battery core pack frame 46 fixed to the outer shell case 12 and the lower battery core pack frame 32 as described above.

The top case 28 is a housing having an opening at the lower end, and a handle 48 that can be gripped when carrying the battery pack 10 is provided on the upper end surface. Further, the top case 28 and the upper battery core pack frame 46 are also fixed by bolts (not shown) or the like like the bottom case 26 and the lower battery core pack frame 32.

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

The battery core pack 16 has a plurality of battery cells 50 (see FIG. 8) and a cell holder 52. As shown in FIG. 1, in the present embodiment, the battery core pack 16 is a part of the lower end side thereof in order to form a space 53 for accommodating wiring and the like (not shown) between the battery core pack 16 and the connector portion. Has a notched shape.

As shown in FIG. 8, the battery cell 50 has, for example, a cylindrical shape, and positive electrode terminals 54 and negative electrode terminals 56 are provided at both ends in the axial direction, respectively. Preferable types of the battery cell 50 include, but are not limited to, a lithium ion secondary battery, and for example, a secondary battery such as a nickel hydrogen battery or a nickel cadmium battery may be used.

The cell holder 52 is configured by combining a positive electrode side holder 52a and a negative electrode side holder 52b, and has a holding portion 60 for holding a plurality of battery cells 50, a holding plate portion 63 provided with an exposed portion 62, a holding portion 60, and an exposed portion. It has a peripheral wall portion 64 that surrounds the portion 62. The positive electrode terminal 54 is exposed from the exposed portion 62 of the positive electrode side holder 52a, and the negative electrode terminal 56 is exposed from the exposed portion 62 of the negative electrode side holder 52b.

In the following, the cell holder 52 will be referred to in the vertical direction (hereinafter, also referred to as the X direction), the axial direction of the battery cell 50 (the arrows Y1 and Y2 directions in FIG. 1, hereinafter, also referred to as the Y direction), and the vertical direction. And the direction orthogonal to both the axial direction (the arrows Z1 and Z2 directions in FIG. 1, hereinafter also referred to as the Z direction) will be described as a reference.

The holding portion 60 has a plurality of insertion holes 66, and holds the battery cell 50 in a state of being inserted into the insertion holes 66, respectively. The insertion hole 66 extends along the Y direction, and exposes the positive electrode terminal 54 or the negative electrode terminal 56 of the battery cell 50 from the openings at both ends in the extending direction. The diameter of the insertion hole 66 is a size corresponding to the outer diameter of the battery cell 50. In the plurality of battery cells 50 held in the holding portion 60, the positive electrode terminals 54 are arranged flush with each other, and the negative electrode terminals 56 are arranged flush with each other. Further, a potting material (not shown) made of an insulating resin or the like may be filled between the peripheral surfaces of the plurality of battery cells 50 held by the holding portion 60.

The holding plate portions 63 are provided on both ends of the holding portion 60 in the Y direction, and through holes are formed as exposed portions 62 at positions corresponding to the openings of the insertion holes 66. The positive electrode terminal 54 and the negative electrode terminal 56 (hereinafter, collectively referred to as electrode terminals) are exposed to the outside of the cell holder 52 through the opening of the insertion hole 66 and the exposed portion 62. Further, a plurality of bus bar plates 70 (see FIG. 1) are attached to the holding plate portion 63 so as to cover each of the exposed portion 62 that exposes the positive electrode terminal 54 and the exposed portion 62 that exposes the negative electrode terminal 56. The holding plate portion 63 is provided with a ridge portion 72 that is interposed between the bus bar plates 70 and insulates each other.

The two battery core packs 16a and 16b are connected to form a connector 18 so that the negative electrode terminal 56 side of one battery core pack 16a and the positive electrode terminal 54 side of the other battery core pack 16b face each other. Has been done.

The positive electrode terminal 54 side of one battery core pack 16a and the negative electrode terminal 56 side of the other battery core pack 16b, in other words, both side surfaces of the connecting body 18 in the Y direction face the inner surface side of the outer shell case 12.

Each of the plurality of bus bar plates 70 connects the positive electrode terminals 54 to each other or the negative electrode terminals 56 to each other in parallel by a predetermined number, and the protruding portion 74 that enters the exposed portion 62 and comes into contact with the electrode terminals is embossed, for example. It is provided by processing or the like. The bus bar plate 70 is provided with a connection end portion 78 to be inserted into a groove 76 provided on the end surface of the peripheral wall portion 64, respectively. By connecting the connection end portion 78 and the above-mentioned lead wire or the like, a plurality of bus bar plates 70 are connected to the connector portion via the BMU 24 in a state of being connected in series with each other.

It is preferable to interpose a heat dissipation sheet (not shown) between the bus bar plate 70 and the inner surface of the outer shell case 12. In this case, the heat generated in the battery cell 50 can be effectively dissipated through the heat radiating sheet, so that the temperature rise of the connecting body 18 can be suppressed.

The upper end of the positive electrode side holder 52a of the battery core pack 16a in the Y direction (arrow Y2 side in FIG. 1) and the other end side of the negative electrode side holder 52b of the battery core pack 16b in the Y direction (arrow Y1 side in FIG. 1). A protruding wall 80 projecting upward is provided at the upper end portion of the above. The upper battery core pack frame 46 abuts on the upper end surface of the protruding wall 80. As a result, a space 82 is formed between the connecting body 18 and the upper battery core pack frame 46, and the BMU 24 is arranged in the space 82 (see FIG. 1).

The BMU 24 has, for example, a control unit that controls charging and discharging of the battery core pack 16, a communication unit that communicates with an electric vehicle and a charging device, and a state of the battery core pack 16 detected from the temperature, voltage, and the like of the battery cell 50. It has 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 50 can be charged by grasping the handle portion 48, carrying the battery pack 10 in the vicinity of the charging device, and connecting the connector portion and the charging device. On the other hand, for example, the battery cell 50 can be discharged by mounting the battery pack 10 carried by gripping the handle portion 48 on the electric vehicle and connecting the connector portion and the power supply port.

As described above, in the battery pack 10, the handle portion 48 provided on the top case 28 is gripped and carried, and the bottom case 26 side is arranged on the lower side in the vertical direction with respect to the electric vehicle. Etc. are assumed. Therefore, a load corresponding to the weight of the connecting body 18 and the like is applied to the lower battery core pack frame 32. As a result, a force is applied to the frame member 34 in a direction of tilting toward the inside of the outer shell case 12 with the flange portion 38 inserted in the lower fixing groove 30 as a fulcrum. In this case, as described above, the intervening portion 40 is provided with respect to the inner surface of the outer shell case 12 so as to regulate the tilt of the frame member 34 by the connecting members 36 provided at both ends in the extending direction of the frame member 34. It can generate tension.

As a result, the lower battery core pack frame 32 can maintain a state of being firmly fixed to the outer shell case 12 even when a load is applied from the connecting body 18. That is, the connecting body 18 can be satisfactorily supported by withstanding the above load without detaching from the outer shell case 12.

As described above, the durability of the lower battery core pack frame 32 can be enhanced by a simple configuration having the frame member 34 and the connecting member 36. Therefore, for example, by increasing the volume of the lower battery core pack frame 32, the weight of the lower battery core pack frame 32 can be reduced as compared with the case where the durability thereof is increased.

Further, since the frame member 34 has a hollow structure, it is possible to further reduce the weight of the lower battery core pack frame 32.

From the above, the battery pack 10 includes a lower battery core pack frame 32 that is lightweight yet has excellent durability. As a result, it is possible to firmly support the connecting body 18 while suppressing the increase in weight, so that it is possible to reduce the weight and improve the durability of the battery pack 10 itself.

In the present embodiment, the upper battery core pack frame 46 is also configured in the same manner as the lower battery core pack frame 32, so that the same effect can be obtained. That is, even when the top case 28 side of the battery pack 10 is arranged and used on the lower side in the vertical direction, the upper battery core pack frame 46 does not separate from the outer shell case 12 and is attached to the connecting body 18. It can withstand a load and can support the coupling 18 well.

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

The battery pack 10 according to the above embodiment includes a connecting body 18 in which two battery core packs 16a and 16b are connected. 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.

10 ... Battery pack 12 ... Outer shell case 14 ... Case 16, 16a, 16b ... Battery core pack 18 ... Connecting body 30 ... Lower fixing groove 34 ... Frame member 34a ... Outer surface 34b ... Inclined surface 34d ... Fixed surface 36 ... Connecting Member 38 ... Flange part 40 ... Intervening part 42 ... First support part 43 ... Second support part 44 ... Upper fixing groove 46 ... Upper battery core pack frame 50 ... Battery cell 52 ... Cell holder

Claims (2)

A battery pack including a battery core pack having a plurality of battery cells held in a cell holder and a case for accommodating the battery core pack.
Inside the case, a battery core pack frame that supports the battery core pack is provided.
The battery core pack frame has a plurality of frame members arranged so as to extend the inner surface of the case along the circumferential direction, and a connecting member for connecting the frame members to each other.
On the outer surface of the frame member, a flange portion to be inserted into a fixing groove formed along the circumferential direction on the inner surface of the case is provided.
Inclined surfaces that are inclined with respect to the extending direction are provided at both ends of the frame member in the extending direction, and the corners of the battery core pack frame are formed by facing the inclined surfaces with each other.
The connecting member has an intervening portion interposed between the inclined surfaces and one of the set of frame members connected to the intervening portions and facing the inclined surfaces facing each other, opposite to the side facing the battery core pack. It is characterized by having a first support portion that supports from the side and a second support portion that is connected to the intervening portion and supports the other side of the set of frame members from the side facing the battery core pack and the opposite side. Battery pack to do. In the battery pack according to claim 1,
A battery pack characterized in that the frame member has a hollow structure.

Images