JP2009205844A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack which is desired with respect to the above problem, wherein the maximum value of a spacing between respective batteries to be separated by expansion is inhibited from becoming higher than required. <P>SOLUTION: This battery pack includes: a pair of batteries 3 and 4; a spacer 5 for making the respective vertically-stacked batteries 3 and 4 have a predetermined spacing; and a connection board 6 having a connection portion 17 for connecting mutual electrodes formed on rear end faces 3b and 4b while vertically stacking the respective batteries 3 and 4, wherein a slit 21 for branching the connection portion 17 to branching portions 19 and 20 of which the number corresponds to that of the batteries 3 and 4 to be connected is formed on the connection portion 17; and the chips of the branching portions 19 and 20 are fixed to the electrodes of the respective batteries 3 and 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a battery pack having a plurality of batteries.

  Generally, a battery pack having a plurality of batteries formed in a square shape is known. For example, Patent Document 1 discloses a battery in which square battery cells are arranged so as to be stacked in the thickness direction.

  FIG. 9 is a perspective view showing an example of a battery pack in which a plurality of batteries are stacked in the thickness direction. 10 is an enlarged side view showing a part of the battery pack of FIG. 9, (a) is a state before expansion of the battery, (b) is a state where the battery is expanded, and (c) is a state where the batteries are expanded. Each separated state is shown.

  The battery pack shown in FIGS. 9 and 10 includes a pair of batteries 101 and 102 formed in a square shape, a spacer 103 and an insulating plate 104 provided between the batteries 101 and 102, and the batteries 101 and 102. And a cover (not shown) that covers the batteries 101 and 102, the spacer 103, the insulating plate 104, the connection plate 105, and the substrate 106.

  The battery 101 has a positive electrode 101a formed on one end face facing in a direction perpendicular to the thickness direction and a negative electrode 101b formed on the other end. Similarly, the battery 102 has a positive electrode 102a formed on one end face facing in a direction perpendicular to the thickness direction and a negative electrode 102b formed on the other end.

  The connecting plate 105 includes a connecting portion 105a for connecting the positive electrode 101a of the battery 101 and the negative electrode 102b of the battery 102, and a lead portion 105b extending from the connecting portion 104a to the end face of the battery 101 on which the negative electrode 101b is formed. It has.

  The substrate 106 is electrically connected to the negative electrode 101 b of the battery 101, the positive electrode 102 a of the battery 102, and the lead portion 105 b of the connection plate 105.

The spacer 103 is for forming a predetermined gap between the battery 101 and the battery 102 in order to avoid interference between the batteries 101 and 102 when the batteries 101 and 102 expand due to overcharge or the like. It is. Specifically, the spacers 103 are provided along the short sides of the opposing surfaces of the batteries 101 and 102, so that the gap between the batteries 101 and 102 is as shown in FIG. S1 is formed.
JP 2003-86158 A

  In the battery pack shown in FIGS. 9 and 10, when each of the batteries 101 and 102 expands, an interference portion P1 between each of the batteries 101 and 102 and the spacer 103 increases as shown in FIG. The batteries 101 and 102 try to be separated from each other.

  However, since the end surfaces of the batteries 101 and 102 are fixed to each other by the connection portion 105a of the connection plate 105, the end surfaces on the opposite side to which the connection plate 105 is not fixed are going to be separated from each other in FIG. ), The batteries 101 and 102 are displaced in a C shape. In this way, when the batteries 101 and 102 spread in the shape of a letter C with the connecting portion 105a as a fulcrum, the bottom of the battery 101 is compared with the case where the batteries 101 and 102 are separated from each other while maintaining a parallel state. The distance from the position to the uppermost position of the battery 102, that is, the maximum value of the distance at which each battery tries to be separated increases, which may cause damage to the cover.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a battery pack capable of suppressing an unnecessarily large maximum distance at which each battery tends to separate due to expansion. Yes.

  In order to solve the above problems, the present invention provides at least two batteries each having an electrode formed on an end face that is formed in a square shape and faces in a direction orthogonal to the thickness direction, and each battery stacked in the thickness direction is a predetermined one. A spacer for spacing and a connection part for electrically connecting electrodes formed on end surfaces facing substantially the same direction orthogonal to the thickness direction in a state where the batteries are stacked in the thickness direction. A slit for branching the connection portion into the number of branch portions corresponding to the number of batteries to be connected, and the tip of each branch portion is connected to each battery. A battery pack is provided which is fixed to the electrode.

  According to the present invention, since the slit is formed in the connecting portion, even when each battery expands, the maximum value of the distance to which the batteries try to separate is increased by the expansion as follows. Can be suppressed.

  That is, when each battery expands due to overcharging or the like in the battery pack according to the present invention, first, the respective batteries expand without contacting each other within a predetermined interval defined by the spacer. When each battery expands beyond the predetermined interval, the batteries come into contact with each other (including contact through an insulating member) and receive a reaction force in a direction away from the counterpart battery.

  When each battery is further expanded, in the present invention, since the connection portion is branched into a plurality of branch portions by the slit, the connection portion is deformed so that the branch portions are separated from each other according to the movement of each battery. Thus, relative movement of each battery is allowed.

  Therefore, unlike the case where the movement of each battery is constrained by the connecting portion as in the prior art (see FIG. 10), it is possible to prevent each battery from opening in a square shape with the connecting portion serving as a fulcrum. Therefore, it is possible to suppress an increase in the distance at which the batteries are about to be separated.

  In the battery pack, it is preferable that the connection portion is configured to be broken when an interval in a thickness direction of each battery exceeds a predetermined dimension.

  According to this configuration, when each battery is relatively displaced by expansion of the battery beyond a predetermined dimension (for example, a dimension corresponding to a predetermined interval defined by the spacer), each connection portion is broken, The battery can also be disconnected electrically. Therefore, according to the above configuration, when the degree of overcharge or the like exceeds a predetermined reference value, not only prevents the relative movement of each battery but also electrically disconnects each battery, The sex can be increased.

  In the battery pack, the connecting portion is disposed to face an end surface of the battery facing the substantially same direction, and the connecting member extends from the connecting portion to an end surface facing the opposite direction to the substantially same direction. It is preferable to further include a lead portion.

  According to this configuration, the lead portion extending to the opposite end surface of the battery can be combined into one while the connecting portion having each branching portion is disposed facing one end surface of each battery, so that the lead The part can be made compact to easily avoid a short circuit due to contact between the lead part and the battery.

  The said battery pack WHEREIN: It is preferable that the said spacer has a some support part which can be point-contacted with respect to the side surface of each said battery.

  According to this configuration, since the side surface of each battery is supported by a point by each support portion, even if the angle of the side surface of the battery that contacts each support portion changes due to the expansion of each battery, The reaction force in the direction of separating the batteries is less likely to be received from each support portion. Therefore, according to this configuration, unlike the conventional case where the side surface of the battery is supported by surface contact (see FIG. 10), each battery receives the reaction force accompanying the expansion of each battery from each support portion. It is possible to suppress separation from each other.

  In the battery pack, it is preferable that opposite side surfaces of the batteries are formed in a polygonal shape, and the support portions are disposed only at corners of the polygon.

  According to this structure, since each support part can be arrange | positioned in the position where it is hard to receive the influence by expansion | swelling among the side surfaces of each battery, when each battery expand | swells, the reaction force which the said battery receives from each support part Thus, the relative displacement amount of each battery can be further reduced.

  In other words, in the battery having a polygonal side shape, the center part of the side shape is most susceptible to expansion, and the midpoint part of each side has the most influence on expansion when viewed on each side of the polygon. Easy to receive. And in the said structure, since each support part is arrange | positioned at the corner | angular part used as the edge of each side and the edge of each side, the influence received when each battery expand | swells can be made small. Thus, the reaction force applied to each battery can be reduced, and the relative displacement amount of each battery can be reduced.

  In the battery pack, the spacer further includes an insulating plate that is disposed between the side surfaces facing each other of the batteries and made of an insulating material, and each of the support portions extends from an edge of the insulating plate. It is preferable to protrude to the battery side.

  According to this configuration, a part of the spacer can be provided with a function for insulating between the batteries, so that the number of parts can be reduced as compared with a case where a member for insulation is separately provided. .

  According to the present invention, it is possible to suppress an unnecessarily large maximum value of the distance at which the batteries are to be separated due to expansion.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing an overall configuration of a battery pack according to an embodiment of the present invention. FIG. 2 is a perspective view showing a state where the case of the battery pack of FIG. 1 is opened. FIG. 3 is a perspective view showing a state in which each battery of FIG. 2 is disassembled. 4 is an enlarged side view showing the main part of FIG.

  With reference to FIGS. 1-4, the battery pack 1 is formed in a substantially rectangular parallelepiped, and the terminal 2 is provided in the end of the longitudinal direction. Note that the longitudinal direction of the battery pack 1 is assumed to be the front-rear direction, the width direction of the battery pack 1 is assumed to be the left-right direction, and the thickness direction of the battery pack 1 is assumed to be the vertical direction.

  The battery pack 1 includes a pair of batteries 3 and 4, a spacer 5 provided between the batteries 3 and 4, a connection plate (connection member) 6 that connects electrodes of the batteries 3 and 4, and the terminals 2, a battery 7, a battery 5, a spacer 5, a connection plate 6, and an upper cover 8 and a lower cover 9 that cover the substrate 7.

  The batteries 3 and 4 are formed in a rectangular shape having a rectangular planar shape extending forward and backward as viewed from above. The battery 3 includes a negative electrode 10 formed on the front end surface 3a and a positive electrode 11 formed on the rear end surface 3b. The battery 4 includes a positive electrode 12 formed on the front end surface 4a and a negative electrode 14 formed on the rear end surface 4b.

  The spacer 5 is provided between the upper surface of the battery 3 and the lower surface of the battery 4 so that the batteries 3 and 4 stacked in the vertical direction have a predetermined interval S2 (see FIG. 4). Specifically, the spacer 5 is a member made of a synthetic resin integrally including an insulating plate 15 for insulating the batteries 3 and 4 and a support portion 16 protruding vertically from the insulating plate 15.

  The insulating plate 15 is formed so that the planar shape when viewed from above is substantially the same as or slightly smaller than the batteries 3 and 4. The peripheral edge portion 15a of the insulating plate 15 has a substantially constant thickness dimension. Moreover, the recessed part 15b is formed in the inner side of the peripheral part 15a in the upper and lower surfaces of the insulating board 15 (only the recessed part 15b of the upper surface is shown in FIG. 3). These concave portions 15b are formed so as to become deeper as they are separated from the peripheral edge portion 15a, that is, the central portion side of the insulating plate 15 is deepened. Such a concave shape of the concave portion 15b is designed in accordance with the shape of the batteries 3 and 4 when they are expanded.

  As shown in detail in FIGS. 3 and 4, the support portions 16 are hemispherical protrusions provided at the four corners of the upper and lower surfaces of the insulating plate 15. These support portions 16 are configured to hold the batteries 3 and 4 at the interval S <b> 2 while being in point contact with the upper surface of the battery 3 and the lower surface of the battery 4. This interval S2 is an interval set so that the batteries 3 and 4 do not contact the insulating plate 15 even when the batteries 3 and 4 expand to a preset level. Therefore, the batteries 3 and 4 can expand without contacting the insulating plate 15 within the preset range.

  On the other hand, when each battery 3 and 4 expands beyond the preset level, each battery 3 and 4 comes into contact with the insulating plate 15 and further expands. A reaction force is received from the other battery through the insulating plate 15. Here, the support portions 16 are provided at the four corners of the batteries 3 and 4 (insulating plate 15), which are relatively loosely deformed when expanded, and thus are affected by the expansion of the batteries 3 and 4. hard. Furthermore, since each support portion 16 is in point contact with each battery 3, 4, even if the upper surface of the battery 3 or the lower surface of the battery 4 is inclined with respect to the support portion 16 according to the expansion, Unlike the case where the contact state is maintained to some extent and the surface is in contact with the battery (see FIG. 10), the occurrence of the interference portion P1 can be suppressed, so that the reaction force received by each of the batteries 3 and 4 can be reduced. .

  FIG. 5 is a schematic perspective view showing a wiring state of the connection plate of FIG. 6 is an enlarged front view showing a part of the connection plate of FIG. 5, where (a) shows a normal state and (b) shows a deformed and opened state.

  2 to 6, the connection plate 6 is obtained by bending a conductive metal plate in place by press working or the like. The connection plate 6 includes a connection portion 17 disposed to face the rear end surface 3b of the battery 3 and the rear end surface 4b of the battery 4, and a lead portion 18 extending from the connection portion 17 to the front end surface 3a of the battery 3. ing.

  A slit 21 for branching the connection portion 17 into two branch portions 19 and a branch portion 20 is formed in the connection portion 17. A welding hole 19 a penetrating in the front-rear direction is formed at the tip of the branch portion 19. Similarly, a welding hole 20 a penetrating in the front-rear direction is formed at the distal end of the branch portion 20. The branch portions 19 and 20 are fixed by welding to the batteries 3 and 4 through the holes 19a and 20a, respectively.

  The slit 21 is formed in a range from the right end portion of the connecting portion 17 to the left position beyond the portion where the holes 19a and 20a are formed. More specifically, the slit 21 is formed in a range from the right end portion of the connecting portion 17 to the left position beyond the welded portion between the branch portions 19 and 20 and the batteries 3 and 4. Therefore, even when the batteries 3 and 4 are separated from each other due to expansion, the branch portions 19 and 20 can be spread relatively flexibly as shown in FIG.

  The lead portion 18 extends leftward from the connection portion 17 and extends forward along the left side surface of the battery 3 and is folded rightward so as to hold a substrate 7 described later. Thus, in the present embodiment, the lead portions 18 extending to the front end surfaces 3a, 4a of the batteries 3, 4 while disposing the branch portions 19, 20 facing the rear end surfaces 3b, 4b of the batteries 3, 4, respectively. Therefore, it is possible to make the lead portion 18 compact and to easily avoid a short circuit caused by contact between the lead portion 18 and the batteries 3 and 4.

  1 to 3 again, the substrate 7 has solder lands 7a, 7b, and 7c for electrically connecting the negative electrode 10 of the battery 3, the positive electrode 12 of the battery 4, and the lead portion 18, respectively. ing. The substrate 7 is formed with a terminal 2 protruding forward.

  The upper cover 8 and the lower cover 9 are each formed in a bottomed container shape, and are arranged so that the openings of each other are butted up and down. The terminal 2 of the substrate 7 is sandwiched between the upper cover 8 and the lower cover 9, and the terminal 2 is exposed to the outside when both the covers 8 and 9 are closed.

  In the battery pack 1 configured as described above, the behavior when the batteries 3 and 4 expand due to overcharge or the like will be described with reference to FIGS. FIG. 7 is an enlarged side view showing the main part of FIG. 2, in which (a) shows a state where the battery is expanded, and (b) shows a state where each battery is separated.

  When the batteries 3 and 4 start to expand due to overcharge or the like, the batteries 3 and 4 expand without contacting the insulating plate 15 within the interval S2 defined by the spacer 5 (see FIG. 4). To do.

  As shown in FIG. 7A, when the expansion of the batteries 3 and 4 proceeds beyond the range defined by the interval S2, the batteries 3 and 4 come into contact with the insulating plate 15, respectively. The reaction force as shown by the arrow Y2 is received from the battery of the other party through the plate 15 and tries to be further separated from each other.

  When the reaction force indicated by the arrow Y2 exceeds the reaction force defined in the connection portion 17, the connection portion 17 is deformed so that the branch portions 19 and 20 are separated from each other as shown in FIG. . As a result, the batteries 3 and 4 fixed to the branch portions 19 and 20 are separated from the support portions 16 as shown in FIG. Will do.

  In the above-described embodiment, the connecting portion 17 is deformed as shown in FIGS. 6A and 6B. However, as shown in FIG. It can also be configured such that the connecting portion 22 breaks when the range is exceeded. FIG. 8 is a front view showing a connecting portion according to another embodiment, in which (a) shows a state before breaking and (b) shows a state after breaking.

  As shown to (a) of FIG. 8, the connection part 22 is formed with notches 24a and 24b from both right and left sides in the connecting part 23 that connects the branch parts 19 and 20. Therefore, when the expansion of each of the batteries 3 and 4 is within the range until the contact with the connection plate 15 as shown in FIG. 7A, the electrical connection state as shown in FIG. Is held. When the reaction force indicated by the arrow Y2 exceeds the reaction force defined by the connecting portion 23, the connecting portion 23 is broken as shown in FIG. Will be severed.

  As described above, according to the battery pack 1, since the slits 21 are formed in the connection portion 17, even when the batteries 3 and 4 are expanded, the maximum of the battery pack 1 is as follows. It can suppress that a thickness dimension becomes large.

  That is, when the batteries 3 and 4 expand in the battery pack 1 due to overcharge or the like, first, the batteries 3 and 4 expand without contacting each other within the range of the interval S2 defined by the spacer 5. . When the batteries 3 and 4 expand beyond the distance S2, the batteries 3 and 4 come into contact with each other via the insulating plate 15 and receive a reaction force indicated by an arrow Y2 from the other battery. .

  When the batteries 3 and 4 are to further expand, in the battery pack 1, since the connection portion 17 is branched into the pair of branch portions 19 and 20 by the slit 21, The connecting portion 17 is deformed so that the branch portions 19 and 20 are separated from each other, and the relative movement of the batteries 3 and 4 is allowed.

  Therefore, unlike the case where the movement of each battery is constrained by the connecting portion as in the prior art (see FIG. 10), it is possible to suppress the opening of each battery in a C shape with the connecting portion serving as a fulcrum. Since it can do, it can suppress that the distance which each battery 3 and 4 tends to separate becomes large.

  According to the configuration in which the connecting portion 23 is broken when the batteries 3 and 4 are relatively displaced beyond a predetermined dimension as in the connection portion 22 (see FIG. 8), the batteries 3 and 4 are electrically connected. Can also be cut. Therefore, according to the above-described configuration, when the degree of overcharge or the like exceeds a predetermined reference value, not only the relative movement of the batteries 3 and 4 is prevented, but also the batteries 3 and 4 are electrically connected. By cutting, safety can be further improved.

  According to the configuration including the lead portion 18 as in the above-described embodiment, the connecting portion 17 having the branch portions 19 and 20 is disposed facing the rear end surfaces 3b and 4b of the batteries 3 and 4, respectively. Since the lead portions 18 extending to the front end surfaces 3a and 4a of the three and four can be combined into one, the lead portion 18 can be made compact to easily avoid a short circuit due to the contact between the lead portion 18 and the batteries 3 and 4. can do.

  According to the configuration provided with the support portion 16 that can make point contact with each battery 3, 4, the upper surface of the battery 3 and the lower surface of the battery 4 are supported by the respective support portions 16 at points. Even if the angle of the surface of the battery 3 or 4 that contacts the support 16 changes due to the expansion of the battery, the reaction force in the direction of separating the batteries 3 or 4 is received from the support 16. It becomes difficult. Therefore, according to this configuration, unlike the conventional case where the surfaces of the batteries 3 and 4 are supported by surface contact, the reaction force associated with the expansion of each battery 3 and 4 is received from each support portion 16 and It is possible to suppress the batteries 3 and 4 from being separated from each other.

  According to the configuration in which the support portions 16 are arranged only at the four corners of the quadrangular surfaces of the batteries 3 and 4, that is, at the corner portions, as in the above embodiment, of the surfaces of the batteries 3 and 4. Since each support part 16 can be arranged at a position where it is difficult to be affected by the expansion, the reaction force that each battery 3, 4 receives from each support part 16 when each battery 3, 4 expands is further reduced. Accordingly, the relative displacement of the batteries 3 and 4 can be further reduced.

  That is, the batteries 3 and 4 having a quadrangular surface shape are most susceptible to the central portion of the surface shape, and the midpoint portion of each side is the most affected by the expansion even when viewed on each side of the quadrangular shape. It is easy to receive. And in the said embodiment, since each support part 16 is arrange | positioned at the corner | angular part used as the edge of each surface shape and the edge of each side, the influence received when each battery 3 and 4 expand | swells is made small. Thus, the reaction force applied to each battery 3 and 4 can be reduced, and the relative displacement amount of each battery 3 and 4 can be reduced.

  According to the configuration in which the spacer 5 integrally includes the insulating plate 15 and the support portions 16 as in the embodiment, a part of the spacer 5 has a function for insulating the batteries 3 and 4 from each other. Therefore, the number of parts can be reduced as compared with the case where a member for insulation is separately provided.

It is a perspective view which shows the whole structure of the battery pack which concerns on embodiment of this invention. It is a perspective view which shows the state which opened the case of the battery pack of FIG. It is a perspective view which shows the state which each decomposed | disassembled each battery of FIG. It is a side view which expands and shows the principal part of FIG. It is the schematic diagram perspective view which shows the wiring state of the connection board of FIG. FIG. 6 is an enlarged front view showing a part of the connection plate of FIG. 5, (a) shows a normal state, and (b) shows a deformed and opened state. FIG. 3 is an enlarged side view showing a main part of FIG. 2, where (a) shows a state where the battery is expanded, and (b) shows a state where each battery is separated. It is a front view which shows the connection part which concerns on another embodiment, (a) has shown the state before a fracture | rupture, (b) has each shown the state after a fracture | rupture. It is a perspective view which shows an example of the battery pack which piled up the some battery in the thickness direction. It is a side view which expands and shows a part of battery pack of Drawing 9, (a) is a state before expansion of a battery, (b) is a state where a battery expanded, (c) is a state where batteries were separated. Each is shown.

Explanation of symbols

S2 Interval 1 Battery pack 3, 4 Battery 5 Spacer 6 Connection plate (connection member)
7 Substrate 15 Insulating plate 16 Support portion 17 Connection portion 18 Lead portion 19 Branch portion 20 Branch portion 21 Slit 22 Connection portion

Claims (6)

At least two batteries each having an electrode on an end face that is formed in a square shape and faces in a direction perpendicular to the thickness direction thereof;
A spacer for setting a predetermined interval between the batteries stacked in the thickness direction;
A connection member having a connection portion for electrically connecting electrodes formed on end surfaces facing substantially the same direction perpendicular to the thickness direction in a state where the batteries are stacked in the thickness direction;
In the connection part, slits for branching the connection part are formed in the number of branch parts corresponding to the number of batteries to be connected, and the tip part of each branch part is fixed to the electrode of each battery. A battery pack characterized by having   2. The battery pack according to claim 1, wherein the connection portion is configured to be broken when an interval in a thickness direction of the batteries exceeds a predetermined dimension.   The connection portion is disposed to face an end surface of the battery facing the substantially same direction, and the connection member further includes a lead portion extending from the connection portion to an end surface facing the opposite direction with respect to the substantially same direction. The battery pack according to claim 1 or 2, wherein the battery pack is provided.   The battery pack according to any one of claims 1 to 3, wherein the spacer has a plurality of support portions that can make point contact with the side surfaces of the batteries.   5. The battery pack according to claim 4, wherein the opposing side surfaces of each battery are formed in a polygonal shape, and each of the support portions is disposed only at a corner portion of the polygonal shape.   The spacer further includes an insulating plate made of an insulating material and disposed between the opposing side surfaces of each battery, and each of the support portions protrudes from the edge of the insulating plate toward the battery side. The battery pack according to claim 4, wherein the battery pack is a battery pack.

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