JP6282125B2 - Battery module - Google Patents

Description

  The present invention relates to a battery module mounted on, for example, an electric vehicle.

  Conventionally, for example, a battery for running an electric vehicle that requires a high voltage is modularized by housing and connecting a large number of secondary batteries in a case (see, for example, Patent Document 1). The battery module of patent document 1 is provided with the bus bar which connects secondary batteries. The secondary battery is provided with an electrode post protruding. This electrode post penetrates the bus bar, and the bus bar is electrically connected to each secondary battery by screwing a nut into a portion of the electrode post penetrating the bus bar.

  In Patent Document 2, the bus bar is welded to the terminal of the secondary battery.

JP 2010-267405 A Special table 2011-521403 gazette

  However, assuming a case where a battery module is mounted on a vehicle such as an automobile, for example, vibration during traveling of the vehicle is applied to the battery module. For this reason, there is a concern that connection failure may occur only by fixing the bus bar with a nut as in Patent Document 1.

  Therefore, a method of welding the bus bar to the terminal of the secondary battery as in Patent Document 2 can be considered. However, the secondary battery is vulnerable to heat and may be damaged by heat during welding.

  The present invention has been made in view of such points, and the object of the present invention is to ensure that the secondary battery is not damaged by the heat during welding when the bus bar is welded to the terminal of the secondary battery. It is to be able to obtain a simple connection state.

  In order to achieve the above object, in the present invention, the portion of the bus bar that is welded to the terminal of the secondary battery is thinned so that it can be reliably welded with a small amount of heat.

The first invention is
A plurality of secondary batteries;
In a battery module comprising a bus bar made of a metal press-molded product that connects the terminals of the secondary battery,
The bus bar includes a main body portion and a connection portion that is integrally formed with the main body portion and is connected to a terminal of the secondary battery by welding,
An extension portion is provided at the edge of the main body,
The connecting portion has an inclined plate portion that is bent from the edge of the extending portion toward the terminal of the secondary battery and extends while inclining in a direction approaching the terminal to a portion welded to the terminal. ,
Portion to be welded to the terminal of the secondary battery in the connecting portion, a plate shape extending along the terminal bent to Rutotomoni the inclined plate portion is formed in a thin-walled as compared with the main body, The inclined plate portion is formed so as to gradually become thinner from the extending portion toward a portion welded to the terminal of the secondary battery.

  According to this structure, since the connection part of a bus bar is thin, even if there is little calorie | heat amount given when welding to the terminal of a secondary battery, it can weld to this terminal. Therefore, it becomes possible to suppress that a secondary battery is damaged with the heat at the time of welding.

  In addition, the connection portion of the bus bar can be easily thinned.

According to a second invention, in the first invention,
The secondary batteries are arranged in a predetermined direction, the bus bar body portion is formed to extend in the secondary battery row direction, and the bus bar connection portion extends in the longitudinal direction of the body portion. It is characterized by being formed on both edges, respectively.

  According to this configuration, when the number of secondary batteries is large, it is possible to integrally form a large number of connection portions while sharing the main body portion of the bus bar.

  According to the first invention, since the connecting portion of the bus bar is thinned and welded to the terminal of the secondary battery, a reliable connection state can be obtained while preventing the secondary battery from being damaged by heat during welding. Can do. Moreover, since the connection part of the bus bar is integrally formed with the main body part, an increase in the number of parts can be suppressed.

  Further, since the bus bar is a press-formed product, the connection portion can be easily thinned.

  According to the second invention, since the connecting portions of the bus bar are respectively formed on both edge portions extending in the longitudinal direction of the main body portion, when the number of secondary batteries is large, the bus bar main body portions are shared, The connecting portion can be integrally formed.

It is a perspective view of the battery module which concerns on embodiment of this invention. It is the II-II sectional view taken on the line in FIG. It is the III-III sectional view taken on the line in FIG. It is a perspective view of a base plate. It is the perspective view which looked at the inner side case where the positive electrode side bus bar and the negative electrode side bus bar were assembled | attached from the positive electrode side. It is the perspective view which looked at the inner side case where the positive electrode side bus bar and the negative electrode side bus bar were assembled | attached from the negative electrode side. It is a perspective view of the inner side case of the state which removed the positive electrode side bus bar and the negative electrode side bus bar. It is a perspective view of the state where the secondary battery was stored in the lower inner case constituent member. It is the perspective view which looked at a lower outside case constituent member from the upper part. It is the perspective view which looked at the lower outside case constituent member from the lower part. It is a bottom view of a lower outer case constituent member. It is a side view of a lower outside case constituent member. It is a top view of a lower outside case constituent member. It is an end elevation of one side of the lower outer case constituent member. It is an end elevation of the other side of the lower outer case constituent member. It is the perspective view which looked at the upper outside case constituent member from the upper part. It is the perspective view which looked at the upper outside case constituent member from the lower part. It is a top view of an upper outside case constituent member. It is a side view of an upper outside case constituent member. It is a bottom view of an upper outer case constituent member. It is an end elevation of one side of the upper outer case constituent member. It is an end elevation of the other side of the upper outer case constituent member. It is the perspective view which looked at the lower inner case structural member from the upper part. It is the perspective view which looked at the lower inner case structural member from the lower part. It is a bottom view of a lower inner case constituent member. It is a side view of one side of a lower inner case constituent member. It is a top view of a lower inner case structural member. It is a side view of the other side of a lower inner case structural member. It is an end view of one side of the lower inner case constituent member. It is an end elevation of the other side of the lower inner case constituent member. It is the perspective view which looked at the upper inner case component from above. It is the perspective view which looked at the upper inner case structural member from the lower part. It is a top view of an upper inner case structural member. It is a side view of one side of the upper inner case constituent member. It is a bottom view of an upper outer case constituent member. It is a side view of the other side of an upper outside case constituent member. It is an end elevation of one side of the upper inner case constituent member. It is an end view of the other side of the upper inner case constituent member. It is a perspective view of a positive electrode side bus bar. FIG. 40 is a cross-sectional view corresponding to the line BB in FIG. 39 in a state where a secondary battery is connected. It is a top view which expands and shows a part of positive electrode side bus bar to which the secondary battery was connected. It is a perspective view of a negative electrode side bus bar.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  FIG. 1 shows a battery module 1 according to an embodiment of the present invention. The battery module 1 is mounted on a vehicle such as an electric vehicle or a hybrid vehicle (including a plug-in hybrid vehicle) and supplies power to a traveling motor or the like. The battery module 1 can be mounted on a vehicle such as an electric forklift, or can be mounted on an electric ship.

  The battery module 1 includes a large number of secondary batteries 2 (shown in FIGS. 2, 3, 7, and 8), an inner case A that houses the secondary battery 2, and an outer case B that houses the inner case A. A positive side bus bar C (shown in FIGS. 5 and 6) connected to the positive terminal of the secondary battery 2, and a negative side bus bar D (shown in FIGS. 5 and 6) connected to the negative terminal of the secondary battery 2. And a base plate (heat radiating member) 7 (shown in FIG. 4). The secondary battery 2 is, for example, a lithium ion battery or the like, and has a cylindrical shape in this embodiment. The positive electrode terminal of the secondary battery 2 is provided at one end in the longitudinal direction, and the negative electrode terminal is provided at the other end.

  In FIG. 1, only one unit Y including the secondary battery 2, the inner case A, the outer case B, the positive side bus bar (positive side connection member) C, and the negative side bus bar (negative side connection member) D is provided. However, it is also possible to adopt a configuration in which a plurality of units Y are arranged in the horizontal direction.

  The base plate 7 is made of a material having thermal conductivity such as an aluminum alloy, for example, and is arranged in a posture extending substantially horizontally. The base plate 7 serves as a heat sink for dissipating heat generated from the secondary battery 2, and is formed larger than the bottom shape of the unit Y. As shown in FIG. 4, a large number of fins 7 a extending in the same direction are formed on the upper surface of the base plate 7. A cooling air passage 7b through which cooling air can flow is provided between adjacent fins 7a and 7a so as to extend along the longitudinal direction of the fin 7a. Both ends of the cooling air passage 7b are open. Cooling air can also be supplied to the cooling air passage 7b from the outside.

  The base plate 7 is formed with a plurality of holes 7c penetrating in the vertical direction. The hole 7c is engaged with a protrusion 65 as an engaging portion of the outer case B described later being inserted.

  Although not shown, a cooling air passage may be formed inside the base plate 7. Further, a refrigerant passage through which the refrigerant flows can be formed inside the base plate 7 so that the refrigerant can be supplied and discharged from the outside.

  As shown in FIGS. 2 and 3, the inner case A includes an upper inner case constituent member (second inner case constituent member) 30 and a lower inner case constituent member (first inner case constituent member) that are divided in the vertical direction. 40. The outer case B includes an upper outer case constituent member (second outer case constituent member) 50 divided in the same direction (vertical direction) as the inner case A, and a lower outer case constituent member (first outer case constituent member). 60. The positive electrode side bus bar C and the negative electrode side bus bar D are assembled to the outside of the inner case A as shown in FIGS. 5 and 6, and are accommodated in the outer case B together with the inner case A as shown in FIGS. ing.

  As shown in FIG. 1, the outer case B is a substantially rectangular parallelepiped, and the divided portion is a central portion in the vertical direction. The upper outer case constituent member 50 and the lower outer case constituent member 60 are both formed by injection molding an insulating resin material.

  As shown in FIGS. 9 to 15, the lower outer case constituent member 60 is formed in a box shape that is open upward, and is substantially upward from the bottom wall portion 61 that is substantially rectangular in plan view and the peripheral portion of the bottom wall portion 61. And a peripheral wall portion 62 extending to the front. As shown in FIGS. 10 and 11, four protrusions 65 are formed on the bottom surface of the bottom wall portion 61 so as to protrude downward. The protrusion 65 has a circular cross section, and is disposed in the vicinity of the four corners of the bottom wall 61. The protrusion 65 is engaged when the outer peripheral surface of the protrusion 65 is in contact with the inner peripheral surface of the hole 7 c in a state where the protrusion 65 is inserted into the hole 7 c of the base plate 7. Accordingly, the unit Y is positioned with respect to the base plate 7 so as not to move in the horizontal direction.

  Although not shown, for example, a protrusion may be formed on the base plate 7, and a recess or hole as an engaging portion may be formed on the bottom wall portion 61 of the lower outer case constituent member 60. In this case, the protrusion of the base plate 7 can be inserted into the recess or hole of the lower outer case constituent member 60 and engaged. Moreover, as an engaging part, a recessed part, a hole part, a protrusion, etc. can also be provided combining, for example.

  Of the peripheral wall portion 62 of the lower outer case constituent member 60, the side wall portions 62a and 62a extending in the longitudinal direction are formed with cutout portions 62b that open upward. In addition, a plurality of engagement holes 62c are formed below the side wall 62a below the notch 62b. A claw portion 41h provided in the inner case A, which will be described later, is engaged with the engagement hole 62c.

  Of the peripheral wall portion 62 of the lower outer case constituent member 60, the end wall portions 62d and 62d are respectively formed with cutout portions 62e that open upward. Further, on both sides of the notch 62e in the end wall 62d, an engagement hole 62f is formed so as to penetrate therethrough. A claw portion 41i provided in the inner case A, which will be described later, is engaged with the engagement hole 62f.

  As shown in FIG. 15, a negative electrode mark 63 indicating the negative electrode side is provided on one end wall portion 62 d of the lower outer case constituent member 60. Further, ribs 64 extending along the peripheral edge of the notch 62e are formed on the both end walls 62d and 62d so as to protrude outward from the lower outer case constituent member 60, respectively.

  As shown in FIGS. 16 to 22, the upper outer case constituting member 50 is formed in a box shape opened downward, and is substantially downward from the upper wall portion 51 of the substantially rectangular shape and the peripheral portion of the upper wall portion 51 in plan view. And a peripheral wall portion 52 extending to the front. As shown in FIGS. 16 and 18, four protrusions 55 are formed on the upper surface of the upper wall portion 51 so as to protrude upward. The protrusion 55 has a circular cross section, and is disposed in the vicinity of the four corners of the upper wall 51.

  Of the peripheral wall portion 52 of the upper outer case constituent member 50, the side wall portions 52a and 52a extending in the longitudinal direction are respectively formed with cutout portions 52b that open downward. The open portion of the cutout portion 52b of the upper outer case component member 50 coincides with the open portion of the cutout portion 62b of the lower outer case component member 60, and the upper outer case component member 50 and the lower outer case component In the state where the member 60 is combined, the notch 52b and the notch 62b open openings 1a (shown only in FIG. 1) as ventilation openings through which the cooling air can flow on both side walls of the outer case B. Will do.

  Further, a plurality of engagement holes 52c are formed through the upper side case constituent member 50 above the cutout portion 52b of the side wall portion 52a. A claw portion 31h provided in the inner case A, which will be described later, is engaged with the engagement hole 52c.

  Of the peripheral wall portion 52 of the upper outer case constituent member 50, the end wall portions 52d and 52d are formed with cutout portions 52e that open upward. The open part of the notch 52e of the upper outer case component 50 is made to coincide with the open part of the notch 62e of the lower outer case component 60, and the upper outer case component 50 and the lower outer case structure In the state where the member 60 is combined, the notches 52e and the notches 62e respectively form openings 1b (shown only in FIG. 1) at both end wall portions of the outer case B.

  Further, engaging holes 52f are formed on both sides of the notch 52e in the end wall 52d of the upper outer case constituting member 50 so as to penetrate therethrough. The engaging hole 52f is adapted to engage a claw portion 31i provided in the inner case A described later.

  As shown in FIG. 16 and the like, a positive electrode mark 53 indicating the positive electrode side is provided on one end wall portion 52d of the upper outer case constituting member 50. Furthermore, ribs 54 extending along the peripheral edge of the notch 52e are formed on the both end walls 52d and 52d so as to protrude outward from the upper outer case constituent member 50, respectively.

  As shown in FIGS. 2 and 3, the gas discharged from the secondary battery 2 in the event of an abnormality is between the bottom wall portion 31 b of the battery housing recess 31 of the inner case A and the upper wall portion 51 of the outer case B. Is formed to the outside of the outer case B. That is, although not shown, the secondary battery 2 is provided with a discharge valve on the positive electrode terminal side for discharging gas when there is an abnormality. The secondary battery 2 is arranged so that the positive electrode terminal is located on the upper side. Therefore, when an abnormality occurs, gas is discharged from the upper part of the secondary battery 2 and flows out to the gas outlet passage R. The detailed structure of the gas flowing out into the gas outlet passage R will be described later.

  The gas outlet passage R is formed so as to extend in the longitudinal direction of the outer case B. Both end portions of the gas lead-out passage R communicate with opening portions 52g and 52g formed at upper portions of both end wall portions 52d and 52d of the upper outer case constituent member 50 and are always open to the outside of the outer case B. The opening 52g has an elongated shape extending in the vicinity of both ends in the width direction of the end wall 52d, and has an opening area sufficient for discharging gas.

  As shown in FIGS. 5 to 7, the inner case A has a shape that is long in the same direction as the outer case B, and the divided portion is a central portion in the vertical direction. Both the upper inner case constituent member 30 and the lower inner case constituent member 40 are formed by injection molding a resin material having insulating properties.

  As shown in FIGS. 23 to 30, the lower inner case constituent member 40 is formed in a box shape opened upward, and includes a bottom wall portion 42 having a large number of battery accommodating recesses 41, and a peripheral edge of the bottom wall portion 42. And a peripheral wall portion 43 extending upward from the portion. In this embodiment, the battery accommodating recesses 41 are arranged so as to be aligned in the longitudinal direction of the inner case A and also in the width direction, and the substantially lower half part (negative electrode terminal side) of the secondary battery 2 is arranged in each. It fits in the inserted state, and the secondary battery 2 is hold | maintained by this.

  The peripheral wall 41a of each battery accommodating recess 41 is formed in a substantially cylindrical shape. The peripheral wall part 41a of the adjacent battery accommodation recessed part 41 is made common, and the clearance gap between the adjacent secondary batteries 2 is minimized. As shown in FIG. 24, the bottom wall portion 41b of the adjacent battery accommodating recess 41 is formed to be continuous.

  A plurality of grooves 41m extending in the vertical direction are formed on the inner surface of each peripheral wall portion 41a so as to be separated from each other in the circumferential direction. By forming the groove 41m, the contact area between the outer peripheral surface of the secondary battery 2 and the inner peripheral surface of the peripheral wall portion 41a is reduced, and the secondary battery 2 can be easily inserted into the battery accommodating recess 41. Thereby, the surrounding wall slit 41c can be formed shallowly, and the rigidity of the inner case A can be kept higher. In a state where the secondary battery 2 is housed in the battery housing recess 41, a groove 41m is formed so as to correspond to a portion where the gap between the adjacent secondary batteries 2 and 2 is wide.

  A peripheral wall slit 41 c extending in the depth direction of the battery accommodating recess 41 is formed in the peripheral wall 41 a of each battery accommodating recess 41. In addition, a bottom wall slit 41d that extends in the radial direction of the battery accommodating recess 41 is formed in the bottom wall 41b of each battery accommodating recess 41 so as to be continuous with the peripheral wall slit 41c. The bottom wall slits 41d of the battery accommodating recesses 41, 41,... Arranged in the longitudinal direction of the inner case A are all formed to be continuous. Accordingly, in the bottom wall portion 42 of the lower inner case constituent member 40, the bottom wall slit 41 d constitutes a slit extending in the longitudinal direction of the lower inner case constituent member 40.

  The bottom wall slit 41d is formed so as to expose the negative electrode terminal of the secondary battery 2. That is, the central portion in the longitudinal direction of each bottom wall slit 41d is an opening that is wider than both sides and can expose the negative terminal. The negative electrode terminal exposed from the bottom wall slit 41d is covered with the lower outer case constituent member 60.

  A claw portion 41 h that engages with the engagement hole 62 c of the lower outer case constituent member 60 is provided on the outer surface of the battery accommodating recess 41.

  Further, a claw portion 41 i that engages with an engagement hole 62 f of the lower outer case constituent member 60 is provided on the peripheral wall portion 43 of the lower inner case constituent member 40. Furthermore, as shown in FIGS. 26 and 28, a plurality of ventilation holes 43c through which cooling air flows are spaced apart in the longitudinal direction on the side wall 43b extending in the longitudinal direction of the peripheral wall 43 of the lower inner case constituting member 40. Is formed. A plurality of upper engagement holes 43g are provided in the upper edge portion of the peripheral wall portion 43 of the lower inner case constituent member 40.

  As shown in FIGS. 31 to 38, the upper inner case component 30 is formed in a box shape opened downward, and includes an upper wall portion 32 having a large number of battery accommodating recesses 31, and a peripheral edge of the upper wall portion 32. And a peripheral wall portion 33 extending downward from the portion. The battery housing recess 31 is an upward recess and is formed so as to be positioned directly above the battery housing recess 41 of the lower inner case constituent member 40. The battery accommodating recesses 31 are fitted with the substantially upper half (positive electrode terminal side) of the secondary battery 2 inserted therein, whereby the secondary battery 2 is held.

  Each battery accommodating recess 31 is configured in the same manner as the battery accommodating recess 41 of the lower inner case constituent member 40. That is, the battery accommodating recess 31 has a peripheral wall portion 31a and a bottom wall portion 31b, and a peripheral wall slit 31c extending in the depth direction of the battery accommodating recess 31 is formed in the peripheral wall portion 31a. The bottom wall portion 31b is formed with a bottom wall slit 31d that extends in the radial direction of the battery housing recess 31 continuously from the peripheral wall slit 31c.

  A plurality of grooves 31m extending in the vertical direction are formed on the inner surface of each peripheral wall portion 31a so as to be separated from each other in the circumferential direction. By forming the groove 31m, the contact area between the outer peripheral surface of the secondary battery 2 and the inner peripheral surface of the peripheral wall portion 31a is reduced, and the secondary battery 2 can be easily inserted into the battery accommodating recess 31. Thereby, the surrounding wall slit 41c can be formed shallowly, and the rigidity of the inner case A can be kept higher. In a state where the secondary battery 2 is housed in the battery housing recess 31, a groove 31m is formed so as to correspond to a portion where the gap between the adjacent secondary batteries 2 and 2 is wide.

  The bottom wall slit 31d is formed so as to expose the positive electrode terminal of the secondary battery 2. That is, the central portion in the longitudinal direction of each bottom wall slit 31d is an opening that is wider than both sides and can expose the positive electrode terminal. The positive terminal exposed from the bottom wall slit 31 d is covered with the upper outer case constituent member 50. Further, the bottom wall slit 31d of the battery accommodating recess 31 is a communicating portion that communicates with the outside of the inner case A, and the gas outlet passage R provided between the inner case A and the outer case B is the bottom. It communicates with the wall slit 31d.

  A claw portion 31 h that engages with the engagement hole 52 c of the upper outer case constituent member 50 is provided on the outer surface of the battery housing recess 31.

  The peripheral wall 33 of the upper inner case component 30 is provided with a claw portion 31 i that engages with the engagement hole 52 f of the upper outer case component 50. Furthermore, as shown in FIGS. 34 and 36, a plurality of ventilation holes 33c through which cooling air flows are spaced apart in the longitudinal direction on the side wall 33b extending in the longitudinal direction of the peripheral wall 33 of the upper inner case constituting member 30. Is formed. Further, a claw portion 33g that engages with the lower engagement hole 43g of the lower inner case constituent member 40 is provided below the peripheral wall portion 33 of the upper inner case constituent member 30 so as to correspond to the lower engagement hole 43g. Yes.

  Further, as shown in FIG. 8, a heat conducting member 70 made of a member having heat conductivity is accommodated in the inner case A. The heat conducting member 70 is made of, for example, silicon or an aluminum alloy, and has many insertion holes 71 into which the secondary battery 2 is inserted. The heat conducting member 70 is formed so that the upper and lower portions of the secondary battery 2 can be exposed from the insertion hole 71. Further, the heat conducting member 70 is disposed so as to be visible from the outside through the ventilation port 33c and the ventilation port 43c of the inner case A, that is, facing the outside. A combination of the heat conductive member 70 made of silicon and the heat conductive member 70 made of aluminum alloy may be used.

  As shown in FIGS. 5, 6, and 39, the positive electrode bus bar C is made of a conductive metal material that is electrically connected to the terminals of the secondary battery 2, and has an upper plate portion (main body portion) 81. And a tab (connecting portion) 95.

  The upper plate portion 81 is formed by press-molding a thick plate material, and extends in the longitudinal direction along the upper wall portion 31 of the upper inner case constituting member 30. The positive-side bus bar C further includes a first side plate 82 that extends downward from one longitudinal end of the upper plate 81 and a second side plate 83 that extends downward from the other longitudinal end of the upper plate 81. doing. In the upper plate portion 81, through portions 81 a that penetrate in the vertical direction are formed in portions corresponding to the positive electrode terminal of the secondary battery 2. Therefore, the penetration part 81a coincides with a part where the width of the bottom wall slit 31d in the upper wall part 31 of the inner case A is wide, and becomes a part through which the gas discharged from the secondary battery 2 can flow.

  The substantially upper half portion of the first side plate portion 82 extends along the peripheral wall portion 33 of the upper inner case constituting member 30. An engagement hole (positive electrode side second engagement portion) 82 a that engages with a claw portion 33 d provided on the peripheral wall portion 33 of the upper inner case constituting member 30 is formed in a substantially upper half portion of the first side plate portion 82. Has been.

  The substantially lower half portion of the first side plate portion 82 is formed so as to protrude in a direction away from the peripheral wall portion 33 of the upper inner case constituting member 30. An electrode portion 84 serving as a positive electrode of the battery module 1 is fixed to a substantially lower half portion of the first side plate portion 82.

  On the lower side of the electrode portion 84 of the first side plate portion 82, a collar portion (positive electrode side first electrode) formed in a collar shape extending in a direction approaching the peripheral wall portion 43 of the lower inner case constituent member 40 and then extending downward. 1 engaging portion) 82b is provided. As shown in FIG. 2, the flange 82 b is engaged in a state in which it is inserted into an engagement hole 43 d formed in the peripheral wall 43 of the lower inner case constituting member 40.

  The second side plate portion 83 is formed shorter than the first side plate portion 82 and extends along the peripheral wall portion 33 of the upper inner case constituting member 30. The second side plate portion 83 is formed with an engagement hole (positive side second engagement portion) 83 a that engages with a claw portion 33 e provided on the peripheral wall portion 33 of the upper inner case constituting member 30.

  Each tab 95 is integrally formed with the upper plate portion 81 so as to extend from the upper plate portion 81, and is formed thinner than the upper plate portion 81. The tab 95 is connected to the positive terminal of the secondary battery 2 by welding.

  The tab 95 is formed flat as shown in FIG. 40 and is laser spot welded to the positive electrode terminal of the secondary battery 2 in a state of being inserted into the bottom wall slit 31d as the opening of the upper inner case constituting member 30. The In FIG. 41, the welded portion is indicated by reference numeral 95a.

  That is, the upper plate portion 81 is provided with extending portions 81c that extend substantially horizontally from the peripheral portions of both edge portions 81b and 81b and the penetrating portion 81a. An inclined plate portion 95b on the base end side of the tab 95 is connected to the edge portion of the extending portion 81c. The inclined plate portion 95b is inclined downward from the edge portion of the extending portion 81c. The inclined plate portion 95b is gradually thinned downward.

  As shown in FIGS. 5, 6, and 42, the negative electrode side bus bar D is configured similarly to the positive electrode side bus bar C. That is, the negative electrode side bus bar D includes a lower plate portion (main body portion) 101 and a thin tab 115. The lower plate portion 101 extends in the longitudinal direction along the bottom wall portion 41 of the lower inner case constituent member 40. The lower plate portion 101 includes a first side plate portion 102 that extends upward from one end portion in the longitudinal direction, and a second side plate portion 103 that extends upward from the other end portion in the longitudinal direction. In the lower plate portion 101, through portions 101a penetrating in the vertical direction are formed in portions corresponding to the negative electrode terminals of the secondary battery 2, respectively. Accordingly, the through portion 101a coincides with a portion where the width of the bottom wall slit 41d in the lower wall portion 41 of the inner case A is wide.

  As shown in FIG. 2, the substantially lower half portion of the first side plate portion 102 extends along the peripheral wall portion 43 of the lower inner case constituting member 40. An engagement hole (negative electrode side second engagement portion) 102 a that engages with a claw portion 43 i provided in the peripheral wall portion 43 of the lower inner case constituent member 40 is formed in a substantially lower half portion of the first side plate portion 102. Has been.

  The substantially upper half portion of the first side plate portion 102 is formed so as to protrude in a direction away from the peripheral wall portion 43 of the lower inner case constituting member 40. An electrode portion 104 serving as a negative electrode is fixed to a substantially upper half portion of the first side plate portion 102.

  On the upper side of the electrode portion 104 of the first side plate portion 102, a hook portion (first negative electrode side first electrode) formed in a hook shape extending in a direction approaching the peripheral wall portion 33 of the upper inner case constituting member 30 and then extending upward. (Engagement part) 102b is provided. The flange portion 102 b is engaged with the flange portion 102 b while being inserted into an engagement hole 33 i formed in the peripheral wall portion 33 of the upper inner case constituting member 30.

  Further, the second side plate portion 103 is formed shorter than the first side plate portion 102 and extends along the peripheral wall portion 43 of the lower inner case constituting member 40. The second side plate portion 103 is formed with an engagement hole (negative electrode side second engagement portion) 103 a that engages with a claw portion 43 e provided on the peripheral wall portion 43 of the lower inner case constituent member 40.

  Each tab 115 is connected to the negative terminal of the secondary battery 2 by welding. The tab 115 is formed flat and is laser spot welded to the negative electrode terminal of the secondary battery 2 while being inserted into the bottom wall slit 41d.

  The lower plate portion 101 is provided with extending portions 101c extending substantially horizontally from the peripheral portions of both edge portions 101b and 101b and the penetrating portion 101a. An inclined plate portion 115b on the base end side of the tab 115 is connected to the edge portion of the extending portion 101c. The inclined plate portion 115b is inclined upward from the edge portion of the extending portion 101c. The inclined plate portion 115b is gradually thinned upward.

  Next, the case where the battery module 1 comprised as mentioned above is assembled is demonstrated. First, the secondary batteries 2 are housed in the battery housing recesses 41 of the lower inner case constituent member 40, respectively. At this time, a peripheral wall slit 41c and a bottom wall slit 41d are formed in the peripheral wall portion 41a and the bottom wall portion 41b of the battery accommodating recess 41, respectively. Even if the outer diameter is slightly larger than the inner diameter of the battery housing recess 41, the secondary battery 2 can be inserted while being elastically deformed so as to expand the battery housing recess 41. Thereby, the inserted secondary battery 2 is fitted and held in the battery accommodating recess 41.

  Thereafter, the upper inner case constituent member 30 is combined with the lower inner case constituent member 40 from above the lower inner case constituent member 40. At this time, the secondary battery 2 is inserted into the battery accommodating recess 31 of the upper inner case constituting member 30, but the secondary battery 2 is elastically deformed so as to expand the diameter of the battery accommodating recess 31 as in the case of the lower side. The battery 2 can be inserted.

  When the upper inner case constituent member 30 is combined with the lower inner case constituent member 40, the claw portion 33g of the upper inner case constituent member 30 engages with the lower engagement hole 43g of the lower inner case constituent member 40. This engagement structure is for temporarily coupling the upper inner case constituent member 30 and the lower inner case constituent member 40 together. The inner case A is configured by the above steps.

  Thereafter, the positive electrode side bus bar C and the negative electrode side bus bar D are assembled to the inner case A. The positive bus bar C and the negative bus bar D may be assembled.

  When the positive electrode side bus bar C is assembled to the inner case A, first, the flange portion 82b of the positive electrode side bus bar C is inserted into the engagement hole 43d (shown in FIG. 2) of the lower inner case constituent member 40 and engaged. When inserting the flange 82b, the upper plate 81 of the positive side bus bar C is separated from the upper wall 31 of the inner case A, and the flange 82b is inserted from the front end side. Place on the upper wall 31 of the inner case A. When the upper plate portion 81 is placed on the upper wall portion 31 of the inner case A, the claw portion 33d of the upper inner case constituent member 30 of the inner case A enters and engages with the engagement hole 82a of the positive side bus bar C, The claw portion 33e of the upper inner case constituent member 30 of the inner case A enters and engages with the engagement hole 83a of the positive bus bar C. As a result, the positive side bus bar C is engaged with both the upper inner case constituent member 30 and the lower inner case constituent member 40, so that the upper inner case constituent member 30 and the lower inner case constituent member 40 are formed by the positive side bus bar C. Can be in a coupled state. That is, since the assembly of the upper inner case constituent member 30 and the lower inner case constituent member 40 is completed at the same time as the assembly of the positive electrode side bus bar C is completed, the upper inner case constituent member 30 and the lower inner case constituent member 40 are joined. There is no need to use a fastening member or the like separately.

  Next, the tab 95 of the positive electrode side bus bar C is welded to the positive electrode terminal of the secondary battery 2. Since the tab 95 is thinner than the upper plate portion 81, the tab 95 can be welded to the terminal even when the amount of heat applied to the terminal of the secondary battery 2 is small. Therefore, it becomes possible to suppress that the secondary battery 2 is damaged by the heat at the time of welding.

  When assembling the negative electrode side bus bar D to the inner case A, first, the flange portion 102b of the negative electrode side bus bar D is inserted into the engagement hole 33i (shown in FIG. 2) of the upper inner case component 30 and engaged. When inserting the flange portion 102b, the lower plate portion 101 of the negative electrode side bus bar D is separated from the lower wall portion 41 of the inner case A, and the flange portion 102b is inserted from the front end side. It is made to contact the lower wall part 41 of the inner case A. When the lower plate portion 101 is brought into contact with the lower wall portion 41 of the inner case A, the claw portion 43i of the lower inner case constituent member 40 of the inner case A enters and engages with the engaging hole 102a of the negative side bus bar D, and The claw portion 43e of the lower inner case constituent member 40 of the inner case A enters the engaging hole 103a of the negative electrode side bus bar D and engages therewith. Thereby, the negative electrode side bus bar D engages with both the upper inner case constituent member 30 and the lower inner case constituent member 40. Then, the tab 115 is welded to the negative electrode terminal of the secondary battery 2.

  Thereafter, the inner case A is accommodated in the lower outer case constituent member 60 from above the lower outer case constituent member 60. Then, the claw portion 41 i of the lower inner case constituent member 40 enters and engages with the engagement hole 62 f of the lower outer case constituent member 60.

  Next, the upper outer case constituent member 50 is combined with the lower outer case constituent member 60 from above the lower outer case constituent member 60. Then, the claw portion 31i of the upper inner case constituent member 30 enters and engages with the engaging hole 52f of the upper outer case constituent member 50. That is, since the upper outer case constituent member 50 and the lower outer case constituent member 60 can be fixed and integrated with the inner case A, a fastening member or the like is unnecessary. The outer case B is constituted by the above steps, and the unit Y shown in FIG. 1 is obtained.

  When the unit Y is configured, since the inner case A and the outer case B are divided in the same direction, the outer case B can be assembled without changing the direction of the inner case A. Further, since the positive terminal and the negative terminal of the secondary battery 2 exposed from the inner case A are covered with the outer case B, insulation is reliably performed.

  The unit Y is placed in a state where the bottom wall portion 61 of the outer case B is in contact with the upper surface of the base plate 7. At this time, the protrusion 65 of the bottom wall portion 61 of the outer case B is inserted into and engaged with the hole 7c of the base plate 7, so that the unit Y is positioned with respect to the base plate 7 so as not to move in the horizontal direction. The battery module 1 is obtained. At this time, the protrusion 65 can be reliably inserted into the hole portion 7c by the weight of the unit Y so as not to come off. Although not shown, a plurality of units Y can be placed horizontally on the upper surface of the base plate 7, and these units Y can be connected in series or in parallel.

  When the battery module 1 is used, the secondary battery 2 may generate heat. In this embodiment, the heat of the secondary battery 2 is transmitted to the heat conducting member 70 inside the inner case A and dissipated, and also transmitted to the base plate 7 via the inner case A and the outer case B and dissipated. At this time, the ventilation holes 33c and 43c are formed in the inner case A, and the ventilation holes 1a shown in FIG. 1 are formed in the outer case B by the notches 52b and 62b. After the wind flows into the outer case B and the inner case A from the vent hole 1a on one side wall portion of the outer case B, it is possible to smoothly flow out from the vent hole 1a on the other side wall portion. Further, after the cooling air of the secondary battery 2 is caused to flow from the opening 52g of one end wall portion 52d of the outer case B into the gas outflow path R in the outer case B and the inner case A, the other end wall portion 52d. It is possible to smoothly flow out from the opening 52g. Therefore, it becomes possible to supply cooling air to the portion in which the secondary battery 2 is accommodated, and the cooling performance is improved. Furthermore, since the base plate 7 is disposed outside the outer case B, the cooling air is easily hit and sufficient cooling performance is obtained. In addition, the cooling performance is further improved by positively supplying the cooling air to the cooling air passage 7b of the base plate 7.

  Should the secondary battery 2 become abnormal when the battery module 1 is used and gas is ejected from the positive terminal side, the bottom wall slit 31d of the upper wall portion 31 of the inner case A is over the positive bus bar C. It flows through the penetration part 81 a of the plate part 81 and flows out to the gas outlet passage R. The gas that has flowed out into the gas outlet passage R flows in the longitudinal direction of the outer case B and is led out through the openings 52g and 52g.

  As described above, according to this embodiment, since the tab 95 of the positive electrode bus bar C is thinned and welded to the terminal of the secondary battery 2, the secondary battery 2 is not damaged by heat during welding. Thus, a reliable connection state can be obtained. Moreover, since the tab 95 of the positive electrode bus bar C is integrally formed with the upper plate portion 81, an increase in the number of parts can be suppressed.

  Moreover, the tab 95 can be easily thinned by using the positive electrode side bus bar C as a press-formed product.

  Further, in this embodiment, the tabs 95 of the positive bus bar C are also formed on both edge portions extending in the longitudinal direction of the upper plate portion 81. Thereby, when the number of the secondary batteries 2 is large, a large number of tabs 95 can be integrally formed while the upper plate portion 81 of the positive electrode side bus bar C is made common.

  A similar effect can be achieved with respect to the negative electrode bus bar D.

  The above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  As described above, the battery module according to the present invention can be mounted on, for example, an electric vehicle.

DESCRIPTION OF SYMBOLS 1 Battery module 2 Secondary battery 81 Upper board part (main-body part)
95 Tab (connection part)
A Inner case B Outer case C Positive side bus bar D Negative side bus bar

Claims (2)

A plurality of secondary batteries (2);
In the battery module (1) including the bus bar (C) made of a metal press-molded product that connects the terminals of the secondary battery (2),
The bus bar (C) includes a main body part (81) and a connection part (95) integrally formed with the main body part (81) and connected to a terminal of the secondary battery (2) by welding,
An extension part (81c) is provided at an edge of the main body part (81),
The connection part (95) is inclined in a direction approaching the terminal from the edge part of the extension part (81c) to a part that is bent toward the terminal of the secondary battery (2) and is welded to the terminal. An inclined plate portion (95b) extending while
Portion to be welded to the terminal of the secondary battery (2) in the connection part (95) is bent to Rutotomoni the inclined plate portion is formed in a thin shape (95b) as compared to the body portion (81) a plate-like shape extending along the terminal Te, the inclined plate portion (95b) is gradually thinner toward the extending portion from (81c) to the portion to be welded to the terminal of the secondary battery (2) A battery module (1) characterized by being molded as described above. The battery module (1) according to claim 1,
The secondary batteries (2) are arranged in a predetermined direction,
The main body (81) of the bus bar (C) is formed to extend in the direction in which the secondary batteries (2) are arranged,
The battery module (1), wherein the connection portion (95) of the bus bar (C) is formed on both edge portions extending in the longitudinal direction of the main body portion (81).

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