Connection module including an external connection bus bar and insulating protector

Provided is a technique that prevents impairment of attachability of an external connection bus bar. The present specification discloses a connection module to be attached to a power storage element group constituted by a plurality of power storage elements each having positive and negative electrode terminals and arranged side by side, the connection module including: a negative-electrode external connection bus bar that includes a plate-shaped extension portion and is configured to be electrically connected to an electrode terminal; and a second protector that holds the negative-electrode external connection bus bar. The second protector includes a placement portion on which the extension portion is placed and a locking portion that has a locking surface facing the placement portion, and the extension portion is provided with an extended locking piece 49 that extends from the extension portion toward the locking surface.

TECHNICAL FIELD

The present specification discloses a technique relating to a connection module.

BACKGROUND ART

A power storage module disclosed in JP 2014-127229A (Patent Document 1 below) is known as an example of a conventional power storage module that includes external connection bus bars connected to output electrode terminals of a power storage element group. A pair of output electrode terminals are provided at two ends of the power storage element group of this power storage module, and the external connection bus bars are connected to the pair of output electrode terminals, respectively. Each of the external connection bus bars is held by a locking piece or the like provided on a resin protector together with bus bars that connect electrode terminals of power storage elements.

JP 2014-127229A is an example of related art.

SUMMARY OF THE INVENTION

However, when electric power is supplied from an end of the power storage element group, an external connection bus bar that is connected to one of the pair of output electrode terminals needs to be disposed extending to the other end of the power storage element group.

However, in the case where the plate thickness of the external connection bus bar is small relative to the width dimension and the external connection bus bar tends to deform such that both end portions in the width direction approach each other, when the external connection bus bar is being attached to the locking piece of the resin protector, the external connection bus bar may be deformed by the locking piece and attachability may be impaired.

The present specification discloses a technique that prevents impairment of attachability of an external connection bus bar.

The technique disclosed in the present specification relates to a connection module to be attached to a power storage element group that is constituted by a plurality of power storage elements that each have positive and negative electrode terminals and are arranged side by side, the connection module including: an external connection bus bar that includes a plate-shaped extension portion extending in an arrangement direction of the power storage elements and is configured to be electrically connected to one of the electrode terminals that is located at an end portion in the arrangement direction of the power storage elements in the power storage element group; and an insulating protector that holds the external connection bus bar, wherein the insulating protector includes a placement portion on which the extension portion is placed and a locking portion that has a locking surface facing the placement portion, and the extension portion is provided with an extended locking piece that extends from the extension portion toward the locking surface of the locking portion and that is locked with the locking surface in a direction in which the external connection bus bar separates from the insulating protector.

According to the above-described configuration of the connection module, rigidity in the plate thickness direction is increased in a part of the extension portion where the extended locking piece is provided, and therefore it is possible to keep the extended locking piece from largely inclining relative to the locking surface of the locking portion and strengthen the lock between the locking surface and the extended locking piece. That is, the extension portion can be kept from being flexurally deformed by the locking portion of the insulating protector. As a result, it is possible to prevent impairment of attachability of the external connection bus bar to the insulating protector and keep the external connection bus bar from coming off from the insulating protector.

The connection module disclosed in the present specification may have the following configuration. The locking portion includes: an elastic piece that extends from the placement portion in a direction perpendicular to a placement surface of the placement portion and is capable of being elastically displaced in a direction along the placement surface; and a locking projection that has the locking surface and projects from the elastic piece, and the extended locking piece extends along the elastic piece in a direction perpendicular to a plate surface of the extension portion in the vicinity of the elastic piece.

According to this configuration, the extended locking piece is disposed along the elastic piece of the locking portion in the vicinity thereof, and therefore when the extension portion is to flexurally deform, the extended locking piece comes into contact with the elastic piece of the locking portion, whereby flexural deformation of the extension portion is prevented. As a result, it is possible to further prevent impairment of attachability of the external connection bus bar to the insulating protector, and the external connection bus bar can be further kept from coming off from the insulating protector.

It is possible to employ a configuration in which the extended locking piece is continuous with a side edge of the extension portion in a width direction perpendicular to an extension direction of the extension portion, and a portion of the extended locking piece that is continuous with the extension portion is a bent portion that is bent to have a round corner and comes into contact with the locking projection of the locking portion when the external connection bus bar is being attached to the insulating protector.

According to this configuration, when the external connection bus bar is being attached to the insulating protector, the bent portion having a round corner comes into contact with the locking portion to elastically displace the elastic piece, and therefore as compared with, for example, a case where the bent portion has an angular corner, the extended locking piece of the external connection bus bar can be smoothly attached to the locking portion of the insulating protector and attachability of the external connection bus bar to the insulating protector can be improved. Also, as a result of the extended locking piece of the external connection bus bar being smoothly attached to the locking portion, the locking portion can be kept from being damaged. Therefore, the external connection bus bar can be kept from coming off from the insulating protector as a result of the locking portion being damaged.

It is possible to employ a configuration in which the extension portion includes a locking hole to which a fit-locking piece provided in the placement portion is fitted and a protruding portion that is provided on a side of the locking hole and protrudes in a width direction by a protrusion dimension equal to or greater than a width dimension of the locking hole in the width direction, and an extension dimension of the extended locking piece is equal to or less than the protrusion dimension of the protruding portion.

When a hole or the like is provided in the extension portion, the area of a widthwise cross section of the extension portion decreases, and therefore the area of the widthwise cross section of the extension portion can be maintained by providing the protruding portion that protrudes in the width direction on a side of the locking hole. Further, in a laid-out state of the external connection bus bar in which the bent portion is not yet bent, the extended locking piece has a dimension equal to or less than the protrusion dimension of the protruding portion.

That is, when the protruding portion provided for maintaining the area of the widthwise cross section of the extension portion is formed through punching or the like, the extended locking piece can be formed by effectively utilizing a portion that would otherwise have been wasted. As a result, wasting of the material can be reduced as compared with a case where the extended locking piece is formed from a part of the base material other than a portion to be wasted, such as a case where the extension dimension of the extended locking piece is greater than the protrusion dimension of the protruding portion, and thus the yield of the external connection bus bar can be improved.

According to the technique disclosed in the present specification, it is possible to prevent impairment of attachability of the external connection bus bar.

EMBODIMENTS OF THE INVENTION

Embodiment

The following describes an embodiment of the technique disclosed in the present specification with reference toFIGS. 1 to 10.

The present embodiment describes, as an example, a power storage module10that is installed in a vehicle such as an electric automobile or hybrid automobile and used as a power source for driving the vehicle. As illustrated inFIGS. 1 to 3, the power storage module10includes a power storage element group70that is constituted by a plurality of power storage elements71arranged side by side and a connection module20that is attached to the power storage element group70.

Each of the power storage elements71is, for example, a secondary battery, and, as illustrated inFIG. 6, the power storage element group70is constituted by a plurality of (five in the present embodiment) power storage elements71housed in a frame75that is substantially rectangular in a plan view.

As illustrated inFIG. 6, a pair of flat electrode terminals73are disposed on an upper surface of each power storage element71at positions near respective ends in the left-right direction. One of the electrode terminals73is a positive electrode terminal73P and the other is a negative electrode terminal73N.

As illustrated inFIG. 6, the power storage elements71are housed in the frame75so as to be lined up in the front-rear direction such that electrode terminals73of different polarities are adjacent to each other in two power storage elements71that are adjacent in the front-rear direction (that is, a positive electrode terminal73P of one of the adjacent power storage elements71and a negative electrode terminal73N of the other power storage element71are adjacent to each other).

As illustrated inFIG. 6, a to-be-locked portion77to which non-illustrated fit-locking portions provided in the connection module20are to be fitted is provided between each pair of electrode terminals73disposed on the top of each power storage element71. When the fit-locking portions are fitted to the to-be-locked portion77and the fit-locking portions and the to-be-locked portion77are locked in the up-down direction, the connection module20is fixedly held above the power storage element group70.

As illustrated inFIGS. 1 to 3, the connection module20includes: a plurality of bus bars21that each connect a positive electrode terminal73P and a negative electrode terminal73N of power storage elements71that are adjacent in the front-rear direction; end bus bars25that are each connected to one of electrode terminals73that are located at the front and rear ends in the arrangement direction of the power storage elements71of the power storage element group70; a pair of external connection bus bars30that are connected to the end bus bars25and to which a non-illustrated external device is to be connected; and an insulating protector40that holds these bus bars21and41while insulating the bus bars21and41from each other.

Each of the bus bars21is formed, for example, by pressing a plate of metal that has excellent electric conductivity such as copper, a copper alloy, aluminum, an aluminum alloy, or stainless steel (SUS), or a metal plate obtained by sticking together an aluminum plate and a copper plate, to have the shape of a substantially rectangular plate that is slightly elongated in the left-right direction (seeFIG. 4).

As illustrated inFIGS. 2 and 3, each bus bar21is large enough that it is placed on electrode terminals73of power storage elements71that are adjacent in the front-rear direction, spanning from an electrode terminal73of one of the adjacent power storage elements71to an electrode terminal73of the other power storage element71, and as a result of end portions of the bus bar21in the front-rear direction being electrically connected to the respective electrode terminals73through welding or the like, the bus bar21serially connects the adjacent power storage elements71.

Note that, in the present embodiment, the adjacent power storage elements71are serially connected by arranging the adjacent power storage elements71such that electrode terminals73of different polarities are adjacent to each other. However, some adjacent power storage elements71of the power storage element group70may be connected in parallel by arranging the adjacent power storage elements71such that electrode terminals73of the same polarity are adjacent to each other.

Each of the end bus bars25is formed, for example, by pressing a plate of metal that has excellent electric conductivity such as copper, a copper alloy, aluminum, an aluminum alloy, or stainless steel (SUS) to have the shape of a substantially rectangular plate that is elongated in the left-right direction, and as illustrated inFIG. 4, the length dimension of the end bus bars25in the front-rear direction is approximately half of that of the bus bars21. In the present embodiment, the end bus bars25are respectively located at the rear left end and the front right end, where the end bus bar25located at the rear left end is a negative-electrode end bus bar25N that is connected to the negative electrode terminal73N of the power storage element71located at the rear end, and the end bus bar25located at the front right end is a positive-electrode end bus bar25P that is connected to the positive electrode terminal73P of the power storage element71located at the front end.

One of the pair of external connection bus bars30is a positive-electrode external connection bus bar31that is short in the front-rear direction, and the other of the pair of external connection bus bars30is a negative-electrode external connection bus bar (an example of “external connection member”)41that is long in the front-rear direction. In the present embodiment, the positive-electrode external connection bus bar31is located on the right as illustrated inFIGS. 1 and 2, and the negative-electrode external connection bus bar41is located on the left as illustrated inFIGS. 1 and 3.

As illustrated inFIGS. 1 and 2, the positive-electrode external connection bus bar31includes: a first bus bar connecting portion32that is connected to the positive-electrode end bus bar25P of the power storage element group70; a first terminal connecting portion34that is fastened to a positive electrode terminal TP provided on a non-illustrated external device using a bolt; and a short linkage portion33that connects the first bus bar connecting portion32and the first terminal connecting portion34.

The short linkage portion33is formed continuously from the front edge of the first bus bar connecting portion32to be located at a position higher than the first bus bar connecting portion32. On the other hand, the first terminal connecting portion34is formed continuously from the front edge of the short linkage portion33to extend upward from the front edge of the short linkage portion33.

The first bus bar connecting portion32is disposed on the positive-electrode end bus bar25P such that it extends along an upper surface of the positive-electrode end bus bar25P and is electrically connected to the positive-electrode end bus bar25P through welding or the like. Accordingly, when the connection module20is attached to the power storage element group70and the plurality of power storage elements71are serially connected by the bus bars21, electric power from a positive electrode of the power storage element group70is output via the positive-electrode end bus bar25P to the positive-electrode external connection bus bar31.

The first terminal connecting portion34is disposed along a front face of the insulating protector40, and the first terminal connecting portion34has a bolt hole35into which a fastening bolt BT can be inserted.

As illustrated inFIGS. 1 and 3, the negative-electrode external connection bus bar41includes: a second bus bar connecting portion42that is connected to an upper surface of the negative-electrode end bus bar25N of the power storage element group70; a second terminal connecting portion44that is fastened to a negative electrode terminal TN provided on the non-illustrated external device using a bolt; and a long linkage portion43that connects the second bus bar connecting portion42and the second terminal connecting portion44.

The second bus bar connecting portion42is disposed on the negative-electrode end bus bar25N such that it extends along the upper surface of the negative-electrode end bus bar25N, and is electrically connected to the negative-electrode end bus bar25N through welding or the like. Accordingly, when the connection module20is attached to the power storage element group70and the plurality of power storage elements71are serially connected by the bus bars21, electric power from a negative electrode of the power storage element group70is output via the negative-electrode end bus bar25N to the negative-electrode external connection bus bar41.

The second terminal connecting portion44is disposed along the front face of the insulating protector40, and the second terminal connecting portion44has a bolt hole45into which a fastening bolt BT can be inserted.

The long linkage portion43is longer than the short linkage portion33and extends in the front-rear direction from the position of the negative-electrode end bus bar25N to the end portion on the side where the positive-electrode end bus bar25P is located. As illustrated inFIG. 3, the long linkage portion43includes: an inclined portion43A that extends from the front edge of the second bus bar connecting portion42to a position higher than the short linkage portion33while being inclined diagonally forward; an extension portion46that extends forward from the front edge of the inclined portion43A; and an L-shaped portion43B that extends upward from the front edge of the extension portion46and is bent to extend forward.

The extension portion46is elongated in the front-rear direction to extend from the position of the negative-electrode end bus bar25N to the position of the bus bar21that is located at the front left end, and as illustrated inFIGS. 9 and 10, the plate thickness of the extension portion46is set to be extremely small as compared with the width dimension of the extension portion46in the left-right direction. Therefore, the extension portion46is very thin and tends to flexurally deform in a direction in which side edges of the extension portion46approach each other (direction in which the extension portion46contracts in the left-right direction).

The L-shaped portion43B is continuous to the upper edge of the second terminal connecting portion44, and as a result of the L-shaped portion43B being continuous to the second terminal connecting portion44, the L-shaped portion43B is attached together with the second terminal connecting portion44to a first bus bar holding portion62of a second protector60described below so as to cover the first bus bar holding portion62from above.

The insulating protector40includes a first protector50that holds the plurality of bus bars21and the pair of end bus bars25, and the second protector60that holds the pair of external connection bus bars30. The first protector50is an insulating member made of a synthetic resin and includes a protector body51that has the shape of a substantially rectangular frame. The inside of the protector body51is partitioned with partition walls53to provide bus bar holding portions55that individually hold the plurality of bus bars21and the pair of end bus bars25.

Each of the bus bar holding portions55has a substantially rectangular shape in a plan view, is open at the top and the bottom, and holds a bus bar21or an end bus bar25therein. The upper opening of the bus bar holding portion55has a substantially rectangular shape that is approximately the same as the external shape of a bus bar21or an end bus bar25, and the bus bars21are held within the bus bar holding portions55by supporting portions56that are provided at the bottom of the bus bar holding portions55.

As illustrated inFIG. 4, the same number of (three in the present embodiment) bus bar holding portions55are provided on the left side and the right side of a wiring path52that is provided in an approximately central portion of the protector body51in the left-right direction and extends in the front-rear direction.

Among bus bar holding portions55located on the right side of the wiring path52out of the bus bar holding portions55, a bus bar holding portion55that is located at the front right end holds the positive-electrode end bus bar25P, and two bus bar holding portions55that are located on the rear side respectively hold bus bars21. On the other hand, among bus bar holding portions55located on the left side of the wiring path52out of the bus bar holding portions55, a bus bar holding portion55that is located at the rear left end holds the negative-electrode end bus bar25N, and two bus bar holding portions55that are located on the front side respectively hold bus bars21.

Accordingly, the bus bar holding portions55of the first protector50are arranged in a staggered manner in the front-rear direction on the respective sides of the wiring path52, and the plurality of power storage elements71are serially connected by the bus bars21held by the plurality of bus bar holding portions55of the first protector50.

The second protector60is an insulating member made of a synthetic resin and is formed as a member separate from the first protector50as illustrated inFIG. 5. The second protector60includes the first bus bar holding portion62on which a front end portion of the negative-electrode external connection bus bar41and the positive-electrode external connection bus bar31are placed, and a second bus bar holding portion65on which the long linkage portion43of the negative-electrode external connection bus bar41is placed.

As illustrated inFIGS. 1 and 5, the first bus bar holding portion62is elongated in the left-right direction, and as a result of a pair of front-side locking pieces62A provided in respective end portions of the first bus bar holding portion62and non-illustrated to-be-locked portions of the first protector50being locked in the up-down direction, the second protector60is fixed to the first protector50.

As illustrated inFIGS. 1 and 5, a pair of bus bar locking pieces62B are provided on the left side of an approximately central portion of the first bus bar holding portion62in the left-right direction. The pair of bus bar locking pieces62B are located above respective front end side edges of the extension portion46in the long linkage portion43of the negative-electrode external connection bus bar41. Therefore, as a result of the pair of bus bar locking pieces62B and respective front end side edge portions of the extension portion46being locked in the up-down direction, a front end portion of the extension portion46is kept from moving up relative to the first bus bar holding portion62. On the right side of the approximately central portion of the first bus bar holding portion62in the left-right direction, the positive-electrode external connection bus bar31is attached from below and is fixed with a non-illustrated fixing means.

As illustrated inFIGS. 2 and 3, nuts N that are respectively coaxial with the bolt hole35in the first terminal connecting portion34of the positive-electrode external connection bus bar31and the bolt hole45in the second terminal connecting portion44of the negative-electrode external connection bus bar41are attached to respective end portions of the first bus bar holding portion62in the left-right direction. The power storage module10and the external device are electrically connected by disposing the positive electrode terminal TP and the negative electrode terminal TN provided on the external device on the front faces of these nuts and fastening the fastening bolts BT.

As illustrated inFIGS. 1, 5, and 7, the second bus bar holding portion65is formed as a member separate from the first bus bar holding portion62and includes a placement portion67on which the extension portion46of the negative-electrode external connection bus bar41is placed and a pair of fixing pieces68that respectively extend left and right from side edges of the placement portion67in the left-right direction.

The placement portion67has the shape of a plate extending in the front-rear direction from the position of the first bus bar holding portion62to the position of the negative-electrode end bus bar25N. Also, the width dimension of the placement portion67in the left-right direction is greater than that of the extension portion46of the negative-electrode external connection bus bar41, and when the extension portion46of the negative-electrode external connection bus bar41is placed on the placement portion67, the bus bars21and the extension portion46are insulated from each other by the placement portion67.

A pair of fit-locking pieces69are provided in a rear end portion of the placement portion67at a central portion thereof in the width direction (left-right direction). The pair of fit-locking pieces69stand upright from the placement portion67and can be elastically displaced in the width direction to approach each other. At distal ends of the fit-locking pieces69, fitting projections69A that project in the width direction away from each other are provided, and each fitting projection69A has a rear-end locking surface69B that is a lower surface of the fitting projection69A, faces the placement portion67in the up-down direction, and locks the extension portion46of the negative-electrode external connection bus bar41from above.

On the other hand, a locking hole47to which the pair of fit-locking pieces69can be fitted from below is provided in the rear end portion of the extension portion46. The locking hole47penetrates through the extension portion46in the up-down direction, which is the plate thickness direction, and has a substantially rectangular shape in a plan view as illustrated inFIG. 8. When the negative-electrode external connection bus bar41is being attached to the second protector60, the pair of fit-locking pieces69enter the locking hole47while being elastically displaced to come up onto the opening edge of the locking hole47. When the negative-electrode external connection bus bar41is attached to its normal position relative to the second protector60, the rear-end locking surface69B of the fitting projection69A of each fit-locking piece69, which has passed through the locking hole47, is located on the opening edge of the locking hole47, and as a result of the rear-end locking surface69B of the fitting projection69A and the opening edge of the locking hole47being locked in the up-down direction, the rear end portion of the long linkage portion43is kept from moving up relative to the second bus bar holding portion65.

As illustrated inFIG. 8, the extension portion46includes protruding portions48that protrude in the width direction from respective side edges of the rear end portion thereof. The protruding portions48are provided at side edges that are located on respective sides of the part of the extension portion46where the locking hole47is provided, and the protrusion dimension L1of each protruding portion48is approximately half of the width dimension L2of the locking hole47. That is, the area of a widthwise cross section of the part of the extension portion46where the locking hole47is provided is approximately the same as the area of a widthwise cross section of a part of the extension portion46where the locking hole47is not provided. Therefore, the area of the widthwise cross section of the extension portion46can be kept at at least a predetermined area over the entire length in the extension direction to prevent heat quantity from becoming high in a part of the negative-electrode external connection bus bar41.

As illustrated inFIGS. 1 and 5, the fixing pieces68extend from a rear portion of the placement portion67to respective end portions of the first protector50in the left-right direction, and a pair of rear-side locking pieces68A that can be locked with non-illustrated to-be-locked portions of the first protector50in the up-down direction are provided in extended end portions of the fixing pieces68. The pair of rear-side locking pieces68A are locked to the to-be-locked portions of the first protector50together with the pair of front-side locking pieces62A of the first bus bar holding portion62to fix the second protector60to the first protector50.

As illustrated inFIGS. 1 and 5, a pair of locking portions66are provided in an approximately central portion of the placement portion67of the second holding portion in the front-rear direction, and a pair of extended locking pieces49that can be locked with the pair of locking portions66in the up-down direction are provided in an approximately central portion of the extension portion46of the negative-electrode external connection bus bar41in the front-rear direction.

As illustrated inFIGS. 1, 5, and 7, the pair of locking portions66are respectively provided in wide portions67A that are located in the approximately central portion of the placement portion67in the front-rear direction and in which the width of the placement portion67is increased in the left-right direction. As illustrated inFIG. 9, each of the locking portions66includes an elastic piece66A that extends upward, which is a direction perpendicular to a placement surface67B of the placement portion67on which the extension portion46is placed, and a locking projection66B that is provided at an upper end thereof, which is an extended end of the elastic piece66A.

The distance between the elastic pieces66A of the pair of locking portions66is set to be approximately the same as the width dimension of the extension portion46of the negative-electrode external connection bus bar41, and each of the elastic pieces66A can be elastically displaced in the left-right direction, which is a direction along the placement surface67B.

The locking projections66B of the pair of locking portions66project inward to face each other, and each of the locking projections66B has an inclined surface66C that inclines downward and inward and a locking surface66D that faces the placement surface67B in the up-down direction.

On the other hand, as illustrated inFIG. 8, the pair of extended locking pieces49are continuous with the side edges of the extension portion46in the width direction perpendicular to the front-rear direction, which is the extension direction of the extension portion46, and extend upward, which is a direction perpendicular to a plate surface46A of the extension portion46and away from the extension portion46, as illustrated inFIG. 9. Therefore, the side edges of the extension portion46provided with the pair of extended locking pieces49have higher rigidity in the plate thickness direction as compared with side edges that are not provided with the extended locking pieces49.

Further, a portion of each extended locking piece49that is continuous with the extension portion46is a bent portion49A that is bent to have a round corner, and in a laid-out state in which the bent portion49A is not yet bent, a portion of each extended locking piece49that is to extend upward has an extension dimension equal to or less than the protrusion dimension by which the protruding portions48protrude from the extension portion46.FIG. 8illustrates the extended locking pieces49of the negative-electrode external connection bus bar41in the laid-out state in which the bent portions49A are not yet bent, and shows the extension dimension L3of the extended locking pieces49set to be approximately the same as the protrusion dimension L1of the protruding portions48.

That is, when the protruding portions48provided for maintaining the area of the widthwise cross section of the extension portion46are formed through punching or the like, the extended locking pieces49can be formed by effectively utilizing portions that would otherwise have been wasted. As a result, wasting of a base material can be reduced as compared with a case where the extended locking pieces are formed from a part of the base material other than portions to be wasted, such as a case where the extension dimension of the extended locking pieces is greater than the protrusion dimension of the protruding portions, and thus the yield of the negative-electrode external connection bus bar41can be improved.

Further, the distance between the pair of extended locking pieces49is set to be greater than the distance between the locking projections of the pair of locking portions66, and the length dimension of each extended locking piece49in the front-rear direction is set to be greater than the length dimension of the locking portions66of the placement portion67in the front-rear direction.

Therefore, when the negative-electrode external connection bus bar41is being attached to the second protector60, the bent portion49A of each extended locking piece49comes into contact with the inclined surface66C of the corresponding locking projection66B and moves along the inclined surface66C to elastically displace the elastic pieces66A outward. When the negative-electrode external connection bus bar41is attached to its normal position relative to the second protector60, as illustrated inFIG. 9, each extended locking piece49fits under the locking surface66D of the locking projection66B and is disposed along the inside of the elastic piece66A of the locking portion66in the vicinity thereof such that the extended end portion of the extended locking piece49and the locking surface66D of the locking projection66B are located opposite each other in the up-down direction.

Also, as illustrated inFIGS. 1 and 5, the length dimension of each extended locking piece49in the front-rear direction is set to be greater than the length dimension of the locking portion66in the front-rear direction, and therefore even when the negative-electrode external connection bus bar41is arranged to be slightly displaced in the front-rear direction relative to the placement portion67due to manufacturing tolerance or attachment tolerance, the extended end portion of the extended locking piece49and the locking surface66D of the locking projection66B can be located opposite each other in the up-down direction.

Therefore, it can be ensured that the extended end portion of the extended locking piece49and the locking surface66D of the locking projection66B are locked in the up-down direction to keep the extension portion46from moving up from the placement portion67of the second bus bar holding portion65.

The present embodiment is configured as described above, and the following describes functions and effects of the connection module20. The extension portion46of the negative-electrode external connection bus bar41in the present embodiment is elongated in the front-rear direction, and the plate thickness of the extension portion46is extremely small as compared with the width dimension thereof in the left-right direction. Therefore, the extension portion46of the negative-electrode external connection bus bar41tends to flexurally deform in a direction in which side edges in the left-right direction approach each other (direction in which the extension portion46contracts in the width direction).

Therefore, for example, in a case where the extension portion46is not provided with the pair of extended locking pieces and respective side edge portions of such an extension portion46are locked from above with the locking surfaces of the pair of elastic locking pieces, when an external force is applied to press the extension portion46in the left-right direction, the extension portion46may flexurally deform in the direction in which the side edges in the left-right direction approach each other, and as a result, the side edge portions of the extension portion46may largely incline relative to the locking surfaces of the pair of elastic locking pieces and the lock between the locking surfaces and the side edge portions of the extension portion46may be released.

However, according to the present embodiment, the extended locking pieces49are respectively provided at positions on the extension portion46corresponding to the pair of locking portions66of the second bus bar holding portion65. That is, the part of the extension portion46in which the pair of extended locking pieces49are provided has higher rigidity in the plate thickness direction as compared with the other part of the extension portion46, and therefore even when an external force is applied to press the extension portion46in the left-right direction, for example, upon contact being made with another member while the connection module is being conveyed, the extension portion46can be kept from flexurally deforming in the direction in which the side edges in the left-right direction approach each other (direction in which the extension portion46contracts in the width direction) and attachability of the negative-electrode external connection bus bar41to the insulating protector40can be prevented from being impaired. Also, the extended locking pieces49can be kept from largely inclining relative to the locking surfaces66D of the locking portions66and the lock between the locking surfaces66D of the locking portions66and the extended locking pieces49can be prevented from being released, and therefore the negative-electrode external connection bus bar41can be kept from coming off from the insulating protector40as a result of flexural deformation of the extension portion46.

Further, according to the present embodiment, when the negative-electrode external connection bus bar41is attached to its normal position relative to the second protector60, each extended locking piece49is disposed along the inside of the elastic piece66A of the locking portion66in the vicinity thereof as illustrated inFIG. 9. Therefore, when the extension portion46is to flexurally deform in the direction in which the side edges in the left-right direction approach each other (direction in which the extension portion46contracts in the width direction), the extended locking pieces49come into contact with the elastic pieces66A from the inner side, whereby flexural deformation of the extension portion46can be prevented. As a result, it is possible to prevent impairment of attachability of the negative-electrode external connection bus bar41to the insulating protector40, and the negative-electrode external connection bus bar41can be further kept from coming off from the insulating protector40.

However, the part of the extension portion46in which the pair of extended locking pieces49are provided has higher rigidity in the plate thickness direction as compared with the other part of the extension portion46, and therefore when the negative-electrode external connection bus bar41is being attached to the second protector60, a large external force acts on portions of the second protector60and the negative-electrode external connection bus bar41that slide relative to each other.

However, according to the present embodiment, when the negative-electrode external connection bus bar41is being attached to the second protector60, the bent portions49A each having a round corner move along the inclined surfaces66C of the locking projections66B of the locking portions66to elastically displace the elastic pieces66A outward. Therefore, as compared with, for example, a case where the bent portions each have an angular corner, the negative-electrode external connection bus bar41can be smoothly attached to the second protector60and the locking projections66B of the locking portions66can be kept from being damaged. That is, attachability of the negative-electrode external connection bus bar41to the insulating protector40can be improved and the negative-electrode external connection bus bar41can be kept from coming off from the insulating protector40as a result of the locking projections66B of the locking portions66being damaged.

Also, according to the present embodiment, the extension dimension L3of the pair of extended locking pieces49extending in the up-down direction is set to be approximately the same as the protrusion dimension L1of the protruding portions48protruding from the extension portion46.

That is, when the protruding portions48provided for maintaining the area of the widthwise cross section of the extension portion46are formed through punching or the like, the extended locking pieces49are formed by effectively utilizing portions that would otherwise have been wasted. That is, wasting of the material can be reduced as compared with a case where the extended locking pieces are formed from a part of the base material other than portions to be wasted, such as a case where the extension dimension of the extended locking pieces is greater than the protrusion dimension of the protruding portions, and thus the yield of the negative-electrode external connection bus bar41can be improved

Incidentally, in the present embodiment, unlike the approximately central portion of the extension portion46in the front-rear direction, the front end portion of the extension portion46is not provided with a pair of extended locking pieces49and is kept from moving up by the pair of bus bar locking pieces62B provided in the first bus bar holding portion62, and therefore the lock between the bus bar locking pieces62B and the extension portion46may be released as a result of flexure of the extension portion46. However, in the present embodiment, rigidity in the plate thickness direction is increased in the front end portion of the extension portion46by the L-shaped portion43B formed continuously from the front edge of the extension portion46to extend upward, and therefore it is possible to also prevent impairment of attachability of the negative-electrode external connection bus bar41to the first bus bar holding portion62and prevent a situation in which the lock between the bus bar locking pieces62B and the extension portion46is released as a result of flexure of the extension portion46.

Further, in the rear end portion of the extension portion46, the opening edge of the locking hole47and the rear-end locking surfaces69B of the fitting projections69A of the pair of fit-locking pieces69are locked in the up-down direction to keep the rear end portion of the extension portion46from moving up relative to the second protector60, and thus the lock position is switched between the rear end portion of the extension portion46and the approximately central portion of the extension portion46in the front-rear direction such that the lock position is located at a central portion of the extension portion46in the width direction or side edge portions thereof in the width direction. That is, according to the present embodiment, the rear portion of the extension portion46is further kept from flexurally deforming in the direction in which the side edges in the left-right direction approach each other (direction in which the extension portion46contracts in the width direction) as compared with, for example, a case where the lock position is not switched in the width direction between the rear end portion of the extension portion46and the approximately central portion thereof in the front-rear direction. Thus, it is possible to prevent impairment of attachability of the negative-electrode external connection bus bar41to the second protector60and keep the negative-electrode external connection bus bar41from coming off from the second protector60.

Other Embodiments

The technique disclosed in the present specification is not limited to the embodiment described above with reference to the drawings, and encompasses various alterations such as the following.

(1) In the above-described embodiment, the extension portion46of the negative-electrode external connection bus bar41is configured such that the opening edge of the locking hole47and the pair of fit-locking pieces69are locked in the up-down direction in the rear end portion, and the pair of extended locking pieces49and the pair of locking portions66are locked in the up-down direction in the approximately central portion in the front-rear direction. However, this configuration should not be taken as a limitation, and the extension portion may be configured such that a pair of extended locking pieces and a pair of locking portions are locked in the up-down direction in the rear end portion of the extension portion, and an opening edge of a locking hole and a pair of fit-locking pieces are locked in the up-down direction in the approximately central portion of the extension portion in the front-rear direction.

(2) In the above-described embodiment, the negative-electrode external connection bus bar41is configured to be longer than the positive-electrode external connection bus bar31in the front-rear direction in order to dispose the second terminal connecting portion44of the negative-electrode external connection bus bar41in the front end portion of the second protector60. However, this configuration should not be taken as a limitation, and it is possible to employ a configuration in which the positive-electrode external connection bus bar is longer than the negative-electrode external connection bus bar in the front-rear direction, and the first terminal connecting portion of the positive-electrode external connection bus bar is disposed in the rear end portion of the second protector. That is, an external connection bus bar that is elongated in the front-rear direction may be configured to serve as the positive-electrode external connection bus bar by changing the arrangement of the electrode terminals of the power storage elements.

(3) In the above-described embodiment, the length dimension of the extended locking pieces49in the front-rear direction is set to be greater than the length dimension of the locking portions66in the front-rear direction. However, this configuration should not be taken as a limitation, and the length dimension of the extended locking pieces in the front-rear direction may be equal to or less than the length dimension of the locking portions in the front-rear direction, so long as the extended locking pieces and the locking portions can be locked in the up-down direction.

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