JP6156546B2 - Battery module - Google Patents

Description

  The present invention includes a plurality of battery cells to be stacked, a plurality of holders made of an insulating material sandwiched between the battery cells and butted against each other at a butting portion, and both ends of the battery cells and the holder in the stacking direction. The present invention relates to a battery module including a pair of end plates that are overlapped with each other and a conductive restraining shaft that is fastened to the end plate through a through hole formed in a butting portion of the holder.

  A plurality of batteries and a plurality of battery holders made of a non-conductive material are alternately stacked, a pair of end plates are overlapped on both ends in the stacking direction, and conductive restraint bolts penetrating through holes formed in the battery holder Patent Document 1 below discloses a battery assembly in which a battery, a battery holder, and an end plate are integrated by fastening both ends to a pair of end plates.

JP 2002-042753 A

  By the way, the battery cells that make up such a battery module generate heat when charging / discharging and the temperature rises, and when charging / discharging stops, the temperature decreases, so that moisture in the air condenses on the surface of the battery cell when the temperature drops. Condensation water may be generated. Further, when the battery cell is left in a low temperature environment, condensed water may be generated. When the condensed water flows from the surface of the battery cell to the metal part of the battery module, a phenomenon (liquid junction) may occur in which the terminal of the battery cell is short-circuited to the vehicle body frame or the like via the metal part of the battery module.

  In the above conventional one, the conductive restraint bolt penetrates the inside of the through hole of the non-conductive battery holder, but the condensed water generated in the battery cell enters the gap between the abutting surfaces of the adjacent battery holders. Then, there is a possibility that the terminal of the battery cell may have a liquid junction with the vehicle body frame through the restraint bolt and the end plate.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to prevent a liquid junction from being generated through a constraining shaft of a battery module.

In order to achieve the above object , according to the first configuration, a plurality of battery cells to be stacked, and a plurality of holders made of an insulating material sandwiched between the battery cells and abutted against each other at a butting portion, And a pair of end plates that are superimposed on both ends of the battery cell and the holder in the stacking direction, and a conductive constraining shaft that is fastened to the end plate through a through-hole formed in the butted portion of the holder. In the battery module,
The waterproof structure that waterproofs the restraint shaft includes a cover that protrudes from the butted surface of the butted portion of one of the holders and covers the outer peripheral surface of the restraint shaft, and the cover is the butted portion of the other holder A battery module is proposed that fits inside the through hole that opens to the butting surface, and that the butting surfaces of two adjacent holders of the plurality of holders closely contact each other.

According to the second configuration, the plurality of battery cells to be stacked, the plurality of holders made of an insulating material sandwiched between the battery cells and abutted against each other at the abutting portion, the battery cell and the holder A pair of end plates stacked on both ends in the stacking direction, and a conductive constraining shaft that is fastened to the end plate through a through-hole formed in the butted portion of the holder, waterproofing the constraining shaft The structure portion has a cover portion that protrudes from the butting surface of the butting portion of one of the holders and covers the outer peripheral surface of the restraining shaft, and the covering portion opens to the butting surface of the butting portion of the other holder. In the method of manufacturing a battery module that fits inside the through hole, the cover shaft projects from the constraining shaft. It said abutting surface and being inserted it from the opposite side of the method of manufacturing a battery module with is proposed.

According to the third configuration, the plurality of battery cells to be stacked, the plurality of holders made of an insulating material sandwiched between the battery cells and abutted against each other at the abutting portion, the battery cell and the holder A battery module comprising: a pair of end plates that are overlapped at both ends in the stacking direction; and a conductive restraint shaft that is fastened to the end plate through a through-hole formed in the butted portion of the holder. The waterproof structure portion that waterproofs includes a cover portion that protrudes from the butting surface of the butting portion of one of the holders and covers the outer peripheral surface of the restraining shaft, and the covering portion is on the butting surface of the butting portion of the other holder It fits inside the through-hole that opens, and the cover portion tapers toward the tip side. The battery module to the butterfly is proposed.

According to the fourth configuration, in addition to the third configuration, the cover portion is formed of an elastic body made of an insulating material, and the base end portion of the cover portion is fitted with a diameter of the base end portion. A battery module is proposed in which a bulging portion that is larger than the diameter of the through-hole and that is generated when the base end portion bulges radially outward is sandwiched between the two butting surfaces facing each other. The

According to the fifth configuration, in addition to the fourth configuration, a battery module is proposed in which a radially outer end of the bulging portion protrudes outward from an outer edge of the abutting surface.

According to the configuration of the sixth, in addition to any one of the configurations of the third to fifth, wherein the cover portion is provided on one surface stacking direction of the holder, the restricting shaft head and shank A battery module is proposed in which the shaft portion is inserted from the other surface in the stacking direction of the holder.

According to the seventh configuration, in addition to any one of the third to sixth configurations, the stacking direction position of the butting surface faces the side surface of the battery cell facing the butting surface. A module is proposed.

  The first through hole 12e and the second through hole 12f of the embodiment correspond to the through hole of the present invention, and the bolt 14 of the embodiment corresponds to the restraining shaft of the present invention.

According to the 1st structure, the waterproofness of a restraint shaft is securable by comprising a labyrinth with a cover part and a through-hole, and making it hard to flow in condensed water.

According to the 2nd structure, the waterproof property of a restraint shaft is securable by comprising a labyrinth with a cover part and a through-hole, and making it hard to flow in dew condensation water. Further, when the restraining frame is inserted into the through hole, it is possible to reduce the possibility that the tip of the restraint frame collides with the tip of the cover portion.

According to the third configuration, a plurality of holders made of a plurality of battery cells and an insulating material are alternately stacked, and a pair of end plates are overlapped on both ends, and through holes formed in the butted portions of the end plates and the holders are formed. The battery module is assembled by fastening the conductive constraining shaft that passes through the end plate. The waterproof structure that waterproofs the restraint shaft includes a cover portion that protrudes from the butting surface of the butting portion of one holder and covers the outer peripheral surface of the restraining shaft, and the cover portion penetrates through the butting surface of the butting portion of the other holder. Fits inside the hole, and the cover part tapers toward the tip, so the cover part and the through-hole form a labyrinth to make it difficult for condensed water to flow in, ensuring the waterproofness of the restraint shaft In addition to being able to do this, the cover part can be easily fitted into the through hole, and the assemblability of the battery module is improved.

According to the fourth configuration, the cover portion is made of an elastic body made of an insulating material, and the diameter of the base end portion of the cover portion is larger than the diameter of the through hole into which the base end portion is fitted. When the cover portion is fitted into the through hole, the base end portion of the cover portion bulges radially outward to form a bulge portion, and the bulge portion is sandwiched between two facing surfaces facing each other. By exhibiting the sealing effect, the waterproof property of the constraining shaft is further enhanced.

According to the 5th structure, since the radial direction outer end of the bulging part of a cover part protrudes outside from the outer edge of a butting | matching surface, the sealing effect by a bulging part can further be improved.

According to the sixth configuration, the cover portion of the abutting portion is provided on one surface in the stacking direction of the holder, and the shaft portion of the constraining shaft including the bolt having the head portion and the shaft portion is the other surface in the stacking direction of the holder. Therefore, it is possible to prevent the tip of the shaft portion of the bolt from hitting the tip of the tapered taper and damaging it.

According to the seventh configuration, since the position in the stacking direction of the butting surface of the butting portion of the holder faces the side surface of the battery cell facing the butting surface, the butting surface from the main surface of the battery cell where a large amount of condensed water is likely to occur. By keeping the distance as far as possible, the waterproof property of the constraining shaft can be further enhanced.

The perspective view of a battery module. (First embodiment) The exploded perspective view of a battery module. (First embodiment) FIG. 3 is an enlarged view of part 3 of FIG. 2. (First embodiment) FIG. 4 is a sectional view taken along line 4-4 of FIG. (First embodiment) The enlarged view of the butting | matching part of a holder. (Second Embodiment) The figure corresponding to FIG. (Third embodiment)

First embodiment

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 and 2, a battery module M used as a power supply device for an electric vehicle or a hybrid vehicle includes a predetermined number (12 in the embodiment) of battery cells 11 stacked in the stacking direction. . Each battery cell 11 is formed in a rectangular parallelepiped shape, a pair of main surfaces 11a, 11a facing each other, a pair of side surfaces 11b, 11b facing each other orthogonal to the main surfaces 11a, 11a, and a main surface 11a. , 11a and side surfaces 11b, 11b, and a top surface 11c and a bottom surface 11d that are opposed to each other perpendicularly, and positive and negative electrodes 11e, 11e are provided on the top surface 11c.

The main surfaces 11a of the twelve battery cells 11 and 13 square plate-shaped holders 12 made of an insulating synthetic resin are alternately stacked, and the two holders 12 at both ends in the stacking direction. , 12 are superposed on a pair of end plates 13, 13 made of conductive metal. In this state, the bolt holes 13a at the four corners of the pair of end plates 13 and 13 and the butted portions 12a at the four corners of the holders 12 are made of four bolts made of conductive metal. 14 penetrates in the stacking direction. Then, in a state where the head portion 14a of each bolt 14 is in contact with the outer surface of one end plate 13, the nut 15 that is screwed into the female screw at the tip of the shaft portion 14b is in contact with the outer surface of the other end plate 13, The end plates 13, 13, the battery cells 11 and the holders 12 are fastened in the stacking direction.

  3 and 4, the shape of the butted portion 12a of the two holders 12 and 12 positioned at both ends in the stacking direction among the twelve holders 12 is 10 holders 12 on the inner side in the stacking direction. Since the shape of the butted portions 12a is slightly different, the structure of the butted portions 12a of the latter holders 12 will be described as a representative.

  Each abutting portion 12a includes a pair of abutting surfaces 12b and 12c that come into contact with the adjacent abutting portion 12a, and a truncated conical covering portion 12d that tapers out from one abutting surface 12b projects. The abutting portion 12a includes a first through hole 12e and a second through hole 12f through which the bolt 14 passes, and the first through hole 12e extending to the inside of the cover portion 12d is substantially equal to the diameter of the shaft portion 14b of the bolt 14. Although it has a constant diameter, the second through-hole 12f is larger in diameter than the shaft 14b of the bolt 14 and tapers inwardly from the other butted surface 12c. The outer peripheral surface of the cover portion 12d and the inner peripheral surface of the second through hole 12f have the same shape so as to be in close contact with each other.

  The positions in the stacking direction of the butted surfaces 12b and 12c generally correspond to the center position C in the stacking direction of the side surface 12b of the battery cell 11 (see FIG. 4A). That is, the positions of the butting surfaces 12b and 12c are set to positions farthest from the main surfaces 11a and 11a of the battery cell 11.

  Of the two holders 12 and 12 located at both ends, each butted portion 12a of the holder 12 on the nut 15 side does not include the second through hole 12f, and the holder 12 on the head 14a side of the bolt 14 is not provided. Each butting portion 12a (details not shown) is slightly different from the other butting portions 12a in that the covering portion 12d is not provided.

  Next, the operation of the first embodiment of the present invention having the above configuration will be described.

  As shown in FIG. 4, when the end plates 13, 13, the battery cells 11, and the holders 12 are stacked, one of the butted portions 12 a among the butted portions 12 a and 12 of the two adjacent holders 12 and 12. When the cover portion 12d is fitted into the second through hole 12f of the other butted portion 12a, the two adjacent holders 12 and 12 are positioned with respect to each other. As a result, the first through holes 12e of the twelve holders 12 are connected in series, and the four bolts 14 can pass through the first through holes 12e. In this state, the butted surfaces 12b and 12c of the two adjacent butted portions 12a and 12a are in close contact with each other, and a cover is provided between the outer edge of the butted surfaces 12b and 12c and the outer peripheral surface of the shaft portion 14b of the bolt 14. A long labyrinth formed by the contact surfaces of the outer peripheral surface of the portion 12d and the inner peripheral surface of the second through hole 12f is formed.

  Even if moisture in the air condenses on the surface of the battery cells 11 to generate condensed water, and the condensed water flows and reaches the outer edges of the abutting surfaces 12b and 12c, the condensed water is blocked by the labyrinth and is bolted. 14 cannot reach the outer peripheral surface of the shaft portion 14b, and the electrodes 11e of the battery cells 11 ... are liable to liquid-contact with the body frame or the like via the dew condensation water, the bolts 14 ... and the end plates 13, 13. Can be prevented.

Further, since the cover portion 12d of the abutting portion 12a is tapered toward the tip, the operation of inserting the tip into the second through hole 12f is facilitated, and the assemblability of the battery module M is improved. Moreover, since the stacking direction positions of the butting surfaces 12b and 12c of the butting portions 12a and 12a substantially correspond to the stacking direction center position C (see FIG. 4A) of the side surface 11b of the battery cell 11, a large amount of condensed water is present. If the butted surfaces 12b and 12c are as far away as possible from the main surfaces 11a and 11a of the large-area battery cell 11 that easily occurs, the waterproofness of the bolts 14 can be further enhanced.

Second embodiment

  Next, a second embodiment of the present invention will be described with reference to FIG.

  In the second embodiment, the cover 12d of the butting portion 12a of the holder 12 is made of an elastic body such as rubber, and is bonded to the butting surface 12b of the butting portion 12a by bonding or the like. The diameter D1 of the base end of the cover portion 12d is set to be slightly larger than the diameter D2 of the open end to the butting surface 12c of the second through hole 12f into which the cover portion 12d is fitted.

  As a result, when the cover portion 12d is fitted into the second through-hole 12f and fastened with the bolt 14, the base end portion of the cover portion 12d cannot be completely fitted into the second through-hole 12f. It becomes an annular bulging portion 12g and protrudes radially outward and is sandwiched between the butted surfaces 12b and 12c of the adjacent two butted portions 12a and 12a. The annular bulging portion 12g made of elastic rubber functions as a seal member such as an O-ring. Therefore, the gap between the abutting surfaces 12b and 12c is effectively sealed, and the dew condensation water forms on the shaft portion 14b of the bolt 14. Reaching the surface can be prevented more reliably. At this time, as shown in an enlarged manner in the circle of FIG. 5A, the sealing effect is improved by projecting at least a part of the tip of the bulging portion 12g outward from the outer edges of the butted surfaces 12b and 12c. To do.

  As described above, according to the second embodiment, synergy between the bulging portion 12g of the cover portion 12d and the labyrinth formed between the outer peripheral surface of the cover portion 12d and the inner peripheral surface of the second through hole 12f. With the effect, the occurrence of liquid junction can be prevented more reliably.

Third embodiment

  Next, a third embodiment of the present invention will be described with reference to FIG.

  In the first embodiment, the shaft portion 14b of the bolt 14 passes through each holder 12 from the first through hole 12e side to the second through hole 12f side. However, the third embodiment The insertion direction is reversed, and the insertion is made from the second through hole 12f side to the first through hole 12e side.

  In the first embodiment, when the tip of the shaft portion 14b of the bolt 14 is inserted into the first through hole 12e, the tip may collide with the thin portion at the tip of the cover portion 12d and be damaged. According to the third embodiment, since there is no such concern, the insertion operation of the bolt 14 is facilitated and the assembling property is improved. Moreover, since there is little possibility that a thin part will be damaged, it can prevent that the waterproofness of the cover part 12d falls.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the structure of the waterproof structure is not limited to the embodiment, and the restraint shaft itself may be covered with an insulating film such as a synthetic resin to be electrically insulated.

  Moreover, the restraint shaft of this invention is not limited to the volt | bolt 14 of embodiment, The rod-shaped member etc. which formed the internal thread in the both ends may be sufficient.

DESCRIPTION OF SYMBOLS 11 Battery cell 11b Side surface 12 Holder 12a Butting part 12b Butting surface 12c Butting surface 12d Covering part 12e 1st through-hole (through-hole)
12f Second through hole (through hole)
12g bulge 13 end plate 14 bolt (restraint shaft)
14a Head 14b Shaft D1 Diameter of the base end of the cover D2 Diameter of the through hole

Claims (2)

A plurality of Batterise Le laminated, a plurality of Hol da made of an insulating material which is butted to each other in the Batterise Le is sandwiched butted portion between, superimposed across the stack of the Batterise Le us and the Hol da in the battery module comprising a pair of end plates being, a restricting shafts preparative conductive fastened through the through hole formed in the abutting portion of the formates da to said end plates,
Waterproof structure for waterproofing the restraining shafts DOO includes a cover portion in which one of the Hol da said butt portion abutting surfaces do we projecting to of covering the outer peripheral surface of the restraining shafts DOO,
The cover portion is fitted into the inside of the through holes opening in the abutting surface of the abutting portion of the other of the Hol da,
The butting surfaces of two adjacent holders among the plurality of holders are in close contact with each other.
Bas Tsu Teri module. A plurality of battery cells to be stacked, a plurality of holders made of an insulating material sandwiched between the battery cells and butted against each other at a butting portion, and a pair of layers stacked on both ends of the battery cell and the holder in the stacking direction An end plate, and a conductive constraining shaft that is fastened to the end plate through a through-hole formed in the butted portion of the holder,
The waterproof structure that waterproofs the restraint shaft has a cover that protrudes from the abutment surface of the abutment portion of one of the holders and covers the outer peripheral surface of the restraint shaft,
In the manufacturing method of the battery module, the cover portion is fitted into the inside of the through hole that opens to the butting surface of the butting portion of the other holder.
The constraining shaft is inserted from a side opposite to the abutting surface on the side from which the cover portion protrudes;
A method for manufacturing a battery module.

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