JP5978983B2 - Battery module - Google Patents

Description

  The present invention relates to a battery module including a square battery and a heat transfer plate.

  The prismatic battery is designed to satisfy performance and life when used in a pressurized state. As an example of a module obtained by modularizing a rectangular battery, an assembled battery described in Patent Document 1 can be given.

  In the assembled battery described in Patent Document 1, a plurality of prismatic batteries are stacked in the thickness direction of the prismatic battery. Among the plurality of prismatic batteries, the prismatic batteries located at both ends are provided with restraining plates. The two restraint plates provided at both ends are provided with restraint rods that are bridged between the restraint plates and prevent separation of the restraint plates. The restraining plate pressurizes the square batteries in a direction approaching each other by the restraining rod.

JP 2001-291499 A

  By the way, in order to improve the heat dissipation of the prismatic battery, a flat heat transfer plate may be interposed between the prismatic batteries. When the square battery is pressurized via the heat transfer plate, the load from the heat transfer plate is concentrated on the corner of the square battery, and there is a possibility that a sufficient load is not applied to the pressure range.

  The objective of this invention is providing the battery module which can prevent that the load from a heat-transfer plate concentrates on the corner | angular part of a square battery.

A battery module that solves the above-described problems includes a plurality of prismatic batteries arranged in parallel at intervals, a heat transfer plate disposed between the plurality of prismatic batteries, the prismatic battery, and the heat transfer. A battery module comprising a pressing member that presses a plate in the direction in which the rectangular battery and the heat transfer plate are arranged, wherein the heat transfer plate is a heat absorbing portion facing the widest surface of the square battery. And a heat dissipating part extending from the heat absorbing part, the heat absorbing part being spaced apart from the widest surface at a portion facing the end of the heat dissipating part in the widest surface of the prismatic battery. The heat radiating portion is fixed to a counterweight mounted on an industrial vehicle and is thermally coupled to the counterweight .

According to this, with the pressurization by the pressurizing member, the square battery is pressurized by the heat absorbing part. The endothermic part is separated from the end part on the heat dissipating part side in the widest surface of the prismatic battery, and the end part on the heat dissipating part side in the widest surface of the prismatic battery is not pressurized. For this reason, the load applied to the prismatic battery from the heat transfer plate by the pressurization of the pressurizing member does not concentrate on the corner of the end portion on the heat radiating portion side in the widest surface of the prismatic battery, and The pressurizing range can be pressurized. Further, the heat generated by the square battery is absorbed by the counterweight through the heat radiating portion. For this reason, it is easy to cool the prismatic battery.

About the said battery module, it is preferable that the said heat absorption part is contacting the said square battery in the part which opposes the electrode of the said square battery.
According to this, the electrode of a square battery can be pressurized suitably. When the prismatic battery is charged, the electrodes are expanded by supplying electrons to the electrodes. If the expansion of the electrodes is repeated due to repeated charging of the prismatic battery, the spacing between the electrodes may vary, and the resistance value of the prismatic battery may increase. By suitably pressurizing the electrodes of the rectangular battery as in the present invention, it is possible to suppress the variation in the distance between the electrodes and to suppress the increase in the resistance value of the rectangular battery.
About the said battery module, the said heat absorption part has comprised the rectangular plate shape so that the heat | fever from the said square battery may be absorbed, and the part facing the electrode of the said square battery is contacting the said square battery. Is preferred.
About the said battery module, it is preferable that the said square battery and the said heat-transfer plate are arranged in parallel by turns.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent that the load from a heat exchanger plate concentrates on the corner | angular part of a square battery.

The schematic side view which shows the forklift of embodiment. The perspective view which shows the battery pack of embodiment. The perspective view which shows the battery module of embodiment. The schematic sectional drawing which shows the battery module of embodiment. (A) And (b) is a perspective view which shows the battery holder of embodiment. (A) is a disassembled perspective view which shows the square battery of embodiment, (b) is a disassembled perspective view which shows the electrode assembly of embodiment. (A) is a perspective view which shows the heat-transfer plate of embodiment, (b) is a front view which shows the relationship between a heat-transfer plate and a square battery. (A)-(d) is a schematic sectional drawing which shows the heat-transfer plate of another example.

  Hereinafter, an embodiment in which the battery module of the present invention is embodied in a battery module mounted on a forklift will be described with reference to FIGS. In the following description, “front”, “rear”, “left”, “right”, “upper”, and “lower” are “front”, “rear”, and “left” when the forklift driver is facing the front of the forklift. ”,“ Right ”,“ upper ”, and“ lower ”.

  As shown in FIG. 1, drive wheels 12 are provided at the front lower part of a vehicle body 11 of a forklift 10 as an industrial vehicle, and steering wheels 13 are provided at a rear lower part of the vehicle body 11. In addition, a cargo handling device is provided at the front portion of the vehicle body 11. The mast 14 constituting the cargo handling apparatus is erected on the front portion of the vehicle body 11, and the mast 14 is provided with a pair of left and right forks 16 via a lift bracket 15. The fork 16 is lifted and lowered together with the lift bracket 15 by driving a lift cylinder 17 connected to the mast 14. Further, the fork 16 is tilted together with the mast 14 by driving a tilt cylinder 18 connected to the mast 14. A load 19 is mounted on the fork 16. The vehicle body 11 is equipped with a traveling motor M1 as a drive source for the drive wheels 12 and a cargo handling motor M2 as a drive source for the fork 16.

  A cab 20 is provided in the center of the vehicle body 11. The cab 20 is provided with a driving seat 21 on which an operator (driver) can sit. A handle 22 is provided in front of the driving seat 21. A battery pack 30 is mounted below the cab 20. Hereinafter, the battery pack 30 will be described in detail.

  As shown in FIG. 2, the battery pack 30 includes a counterweight 31 made of metal (for example, iron) for balancing with the load 19 mounted on the fork 16. The counterweight 31 is erected in the thickness direction of the weight portion 32 from the short-direction first end portion 32a of the weight portion 32 and the first end portion in the longitudinal direction of the weight portion 32. The weight main body 33 has a rectangular plate shape extending from 32c to the second end portion 32d in the longitudinal direction. In other words, the weight portion 32 is erected from the base end of the weight body 33 in the thickness direction of the weight body 33. At the distal end of the weight body 33 (the end opposite to the base end of the weight body 33), a notch 35 is formed by cutting the weight body 33 in the thickness direction of the weight body 33. A mounting plate 45 having a rectangular flat plate shape is fixed to the upper surface of the notch 35. On the mounting plate 45, a housing case 46 for housing a control device and a junction box 47 for housing a relay, wiring, and the like are disposed.

  An inverted U-shaped frame 36 that is spaced apart from the weight main body 33 is erected from the weight portion 32 at a second end 32 b in the short direction of the weight portion 32. The frame 36 includes a first pillar portion 38 and a second pillar portion 39 that are erected from two corners of the second end portion 32b in the short direction on the upper surface of the weight portion 32, the first pillar portion 38, And a base portion 37 that connects the upper end portion of the second pillar portion 39 (the end portion opposite to the end portion joined to the weight portion 32). That is, the battery pack 30 has a front opening 30 a surrounded by the weight 32 and the frame 36 on the second end 32 b side of the weight 32 in the short direction. In the battery pack 30, the front opening 30a is closed by a lid member 41 having a rectangular plate shape.

  The length in the standing direction of each pillar portion 38, 39 (the length in the longitudinal direction of each pillar portion 38, 39) is the same as the shortest length from the upper surface of the weight portion 32 to the distal end surface of the weight body 33. A top plate 44 is supported on the upper surface of the frame 36 and the upper surface of the weight body 33. The top plate 44 closes an opening (not shown) between the weight body 33 and the frame 36. Further, the battery pack 30 has an opening on one end side surrounded by the weight main body 33, the weight portion 32, the first pillar portion 38, and the top plate 44 on the first end portion 32 c in the longitudinal direction of the weight portion 32. 30b. Further, the battery pack 30 has an opening on the other end side surrounded by the weight main body 33, the weight portion 32, the second pillar portion 39, and the top plate 44 on the second end portion 32 d side in the longitudinal direction of the weight portion 32. Part 30c. The one end side opening 30 b is closed by the one end side lid member 42, and the other end side opening 30 c is closed by the other end side lid member 43.

  One surface of the weight body 33 in the thickness direction (the surface of the weight body 33 on the weight portion 32 side in the thickness direction) is an installation surface 33a on which the battery module 50 is installed. A plurality of battery modules 50 are provided on the installation surface 33a at intervals. Two battery modules 50 are provided side by side in the longitudinal direction of the weight main body 33, and three battery modules 50 are provided side by side in the short direction of the weight main body 33.

  As shown in FIGS. 3 and 4, the battery module 50 includes a plurality of prismatic batteries 52 (for example, secondary batteries such as lithium ion secondary batteries and nickel / hydrogen storage batteries) held by a battery holder 51. The heat transfer plates 53 are arranged in parallel with the prismatic batteries 52. In the present embodiment, the widest surface of the prismatic battery 52 is both surfaces in the thickness direction of the prismatic battery 52. In the following description, both sides in the thickness direction of the prismatic battery 52 are referred to as a first side surface 52a and a second side surface 52b. In the battery module 50, end plates 54 and 55 are provided at both ends of the prismatic battery 52 in the juxtaposition direction.

  As shown in FIGS. 5A and 5B, the battery holder 51 includes a rectangular frame-shaped holder main body 61 that holds the square battery 52 and insertion portions 62 provided at the four corners of the holder main body 61. Have. In the following description, the vertical direction in the figure will be described as the vertical direction of the battery holder 51, and the horizontal direction in the figure will be described as the horizontal direction of the battery holder 51. In addition, the vertical direction of the battery holder 51 and the direction orthogonal to the horizontal direction are defined as the front-rear direction of the battery holder 51. 5A and 5B are reversed in the left and right and front and rear directions.

  The holder body 61 includes a U-shaped plate holding portion 92 that opens to the right, and a U-shaped battery holding portion 93 that extends forward from the front end surface of the plate holding portion 92 and opens upward. Become. The plate holding portion 92 includes a rectangular parallelepiped lower wall portion 66, a rectangular parallelepiped left wall portion 67 extending upward from the left end of the lower wall portion 66, and a rectangular parallelepiped upper portion extending rightward from the upper end of the left wall portion 67. And a wall portion 68. An opening 69 in which the heat transfer plate 53 is provided is formed inside the plate holding portion 92.

  Next, the battery holding part 93 will be described. The battery holding portion 93 extends forward from the front end surface of the lower wall portion 66 and extends to the entire left and right direction of the lower wall portion 66, and the left covering portion 63 left from the left end of the lower covering portion 63. A rectangular flat plate-like left side covering portion 64 extending upward along the front end surface of the wall portion 67 and a rectangular flat plate-like right side covering portion 48 extending upward from the right end of the lower side covering portion 63 are provided. And the accommodating part 65 is formed inside the battery holding | maintenance part 93, and the square battery 52 is hold | maintained at this accommodating part 65. FIG. The prismatic battery 52 is covered with the left covering portion 64 and the right covering portion 48 on the surface in the width direction and with the lower covering portion 63 on one surface in the height direction.

  A rectangular parallelepiped insertion portion 62 is provided in each of the left and right lower portions of the lower wall portion 66 and the lower covering portion 63, and insertion portions 62 are provided in the left and right upper portions of the upper wall portion 68, respectively. . Each insertion portion 62 is provided with an insertion hole 62a through which the bolt B is inserted so as to penetrate the insertion portion 62 in the front-rear direction.

  The left-right direction of the battery holder 51 is the longitudinal direction of the lower covering portion 63, the lower wall portion 66, and the upper wall portion 68, and the up-down direction of the battery holder 51 is the left covering portion 64, the left wall portion 67, and the right side. This is the longitudinal direction of the covering portion 48. The front-rear direction of the battery holder 51 is the short direction of the lower covering portion 63, the left covering portion 64 and the right covering portion 48.

  As shown in FIG. 6A, the square battery 52 includes an electrode assembly 71 and an aluminum case 72 that houses the electrode assembly 71. The case 72 includes a bottomed rectangular box-shaped case main body 73 that houses the electrode assembly 71, and a rectangular plate-shaped lid member 74 that closes the opening of the case main body 73.

  As shown in FIG. 6B, the electrode assembly 71 has a separator 76 interposed between the adjacent positive electrode 77 and negative electrode 78. The positive electrode 77 and the negative electrode 78 as electrodes include a rectangular active material layer 79 configured by applying an active material to a metal foil, and a tab 80 protruding from one end of the metal foil.

  As shown in FIG. 7A, the heat transfer plate 53 is extended in the thickness direction of the heat absorbing portion 81 from the heat absorbing portion 81 having a rectangular plate shape and the first end portion 81 a in the longitudinal direction of the heat absorbing portion 81. It comprises a heat radiating portion 82 having a rectangular flat plate shape. Both surfaces in the thickness direction of the heat absorbing portion 81 are defined as a first surface 81c and a second surface 81d. On the first end portion 81a side in the longitudinal direction of the heat absorbing portion 81, a concave portion 84 that is recessed from the first surface 81c and the second surface 81d in the thickness direction of the heat absorbing portion 81 is formed. When the heat transfer plate 53 is provided adjacent to the rectangular battery 52 so as to close the opening 69 formed in the battery holder 51, the heat dissipating part 82 faces the left covering part 64 in the right covering part 48. The opposite surface is covered and exposed to the outside of the battery holder 51.

  As shown in FIG. 7B, the heat absorbing portion 81 of the heat transfer plate 53 includes a positive electrode 77 and a negative electrode 78 in which the planar shape of the first surface 81 c and the second surface 81 d is accommodated in the case 72 of the prismatic battery 52. It is formed larger than the surface in the stacking direction (surface having the largest area). That is, the heat absorption part 81 is formed in a size such that the entire surfaces of the positive electrode 77 and the negative electrode 78 face each other.

  As shown in FIGS. 3 and 4, the square battery 52 is accommodated in the accommodating portion 65 of the battery holder 51. The square battery 52 is provided such that the first side surface 52 a faces the opening 69. The battery holder 51 is provided with a heat transfer plate 53 so as to close the opening 69, and the square battery 52 and the heat transfer plate 53 are adjacent to each other in the thickness direction of the square battery 52 (facing each other). ) The battery holder 51, the square battery 52, and the heat transfer plate 53 are arranged side by side, and end plates 54 and 55 are provided at both ends in the direction of arrangement. Insertion holes (not shown) are formed in the end plates 54, 55, and bolts B inserted through the insertion holes 62 a formed in the insertion portions 62 of the battery holder 51 are screwed into the nuts N to be connected to the battery. A module 50 is formed. In the battery module 50, the bolt B is screwed into the nut N, so that the pair of end plates 54 and 55 pressurize the battery holder 51 and the square battery 52 from both sides in the juxtaposition direction. That is, in this embodiment, the bolt B, the nut N, and the end plates 54 and 55 function as pressure members. The battery module 50 is fixed to the weight body 33 of the counterweight 31 by brackets 91 provided on the end plates 54 and 55. The heat radiating portion 82 is in surface contact with the counterweight 31, and the heat transfer plate 53 is thermally coupled to the counterweight 31 through the heat radiating portion 82.

  As shown in FIG. 4, the heat absorbing portion 81 has the first surface 81 c facing the second side surface 52 b of one of the square batteries 52 sandwiching the heat absorbing portion 81, and the second surface 81 d facing the other end of the heat absorbing portion 81. It faces the first side surface 52a of the prismatic battery 52. The concave portion 84 of the heat absorbing portion 81 is located at least at a portion facing the end portion 52c on the heat radiating portion 82 side of the first side surface 52a and the second side surface 52b of the square battery 52 adjacent to the heat absorbing portion 81. The concave portion 84 formed in the heat absorbing portion 81 is separated from the square battery 52, and the portion of the heat absorbing portion 81 where the concave portion 84 is formed does not contact the square battery 52. That is, in the prismatic battery 52, the corner portion C of the end portion 52c on the heat radiating portion 82 side and the heat absorbing portion 81 are separated from each other.

Next, the operation of the battery module 50 of the present embodiment will be described.
Due to the pressurization from the end plates 54 and 55, the heat absorbing portion 81 of the heat transfer plate 53 presses the square battery 52 in the thickness direction of the square battery 52 from the first side face 52a and the second side face 52b. . At this time, the recessed part 84 is separated from the part facing the end part 52c on the heat radiating part 82 side of the square battery 52. For this reason, when the square battery 52 is pressurized through the heat transfer plate 53 due to the pressurization from the end plates 54 and 55, the end 52c of the square battery 52 on the side where the heat radiating portion 82 is provided. The load is applied only to the pressurizing range of the prismatic battery 52 (the range where the endothermic portion 82 of the prismatic battery 52 contacts) without the load being concentrated on the corner C.

  Further, when the prismatic battery 52 is charged, electrons are supplied to the electrodes (the positive electrode 77 and the negative electrode 78), so that the electrodes (the positive electrode 77 and the negative electrode 78) expand. When charging of the prismatic battery 52 is repeated, the expansion of the electrodes (the positive electrode 77 and the negative electrode 78) is repeated. As a result, the distance between the electrodes (the positive electrode 77 and the negative electrode 78) is increased, or the resistance value of the prismatic battery 52 is increased by distorting the electrodes (the positive electrode 77 and the negative electrode 78). As the resistance value increases, Joule loss increases.

  In the present embodiment, the load applied to the prismatic battery 52 from the heat absorbing portion 81 is applied from the direction in which the positive electrode 77 and the negative electrode 78 are arranged side by side, thereby suppressing an increase in the interval between the positive electrode 77 and the negative electrode 78.

  Further, the heat radiating portion 82 of the heat transfer plate 53 is thermally coupled to the counterweight 31. For this reason, when the square battery 52 generates heat, this heat is absorbed by the heat absorbing portion 81 and further radiated from the heat radiating portion 82 to the counterweight 31.

Therefore, according to the above embodiment, the following effects can be obtained.
(1) A recess 84 is formed in the heat absorption part 81 of the heat transfer plate 53, and a part of the heat absorption part 81 is separated from the end 52 c on the side where the heat dissipation part 82 of the prismatic battery 52 is provided. doing. For this reason, a part of the heat absorbing portion 81 is separated from the corner portion C of the end portion 52 c of the square battery 52. Therefore, even if the heat absorption part 81 pressurizes the square battery 52 in the thickness direction by pressurization of the end plates 54 and 55, the heat absorption part 81 does not press the corner C of the square battery 52, and the square battery. It is possible to pressurize the pressurizing range without concentrating the load on the corner C of 52.

  (2) The heat absorption part 81 is provided corresponding to the negative electrode 78 and the positive electrode 77. For this reason, the negative electrode 78 and the positive electrode 77 can be pressurized suitably. As a result, even if the interval between the positive electrode 77 and the negative electrode 78 is increased as the prismatic battery 52 is charged, the increase in the interval between the positive electrode 77 and the negative electrode 78 is suppressed by pressurizing the positive electrode 77 and the negative electrode 78. can do.

  (3) The heat radiating portion 82 of the heat transfer plate 53 is thermally coupled to the counterweight 31. For this reason, the heat absorbed by the heat absorbing portion 81 as the square battery 52 generates heat is radiated to the counterweight 31 via the heat radiating portion 82. For this reason, the heat transfer plate 53 is not easily overheated, and the prismatic battery 52 can be efficiently cooled.

In addition, you may change embodiment as follows.
As shown in FIGS. 8A to 8B, the shape of the heat transfer plate 53 may be changed. As shown in FIG. 8A, the heat radiating portion 82 may be formed at both longitudinal ends 81 a and 81 b of the heat absorbing portion 81. As shown in FIG. 8B, the heat dissipating part 82 may be formed at both ends 81 a and 81 b in the longitudinal direction of the heat absorbing part 81, and the direction in which each heat dissipating part 82 extends may be opposite. As shown in FIG. 8C, the heat radiating portion 82 does not have to extend in the thickness direction of the heat transfer plate 53. For example, the heat absorption part 81 may extend in the longitudinal direction. As shown in FIG. 8D, the heat transfer plate 53 may be formed such that the center in the longitudinal direction extends to the first side surface 52a and the second side surface 52b of the prismatic battery 52. In this case, both ends in the longitudinal direction of the heat transfer plate 53 are not in contact with the prismatic battery 52, so the corner portion C of the prismatic battery 52 and the heat transfer plate 53 are not in contact. That is, the heat transfer plate 53 may have any shape as long as it includes the heat absorbing portion 81 and the heat radiating portion 82.

  In the embodiment, the heat transfer plate 53 may slightly protrude from the battery holder 51 before the bolt B is screwed into the nut N, that is, before the battery module 50 is modularized.

In the embodiment, the battery module 50 may be mounted other than the forklift 10.
In the embodiment, the heat radiating unit 82 may not be thermally coupled to the counterweight 31. In this case, heat radiation from the heat radiating portion 82 can be promoted by blowing air to the heat radiating portion 82.

  In the embodiment, the planar shape of the endothermic portion 81 is formed slightly larger than the planar shape of the negative electrode 78 and the positive electrode 77 so as to face the entire surface of the negative electrode 78 and the positive electrode 77, thereby corresponding to the negative electrode 78 and the positive electrode 77. However, it is not limited to this. The planar shape of the negative electrode 78 and the positive electrode 77 and the endothermic part 81 may be the same, or the planar shape of the endothermic part 81 may be slightly smaller than the planar shape of the positive electrode 77 and the negative electrode 78.

  In the embodiment, other pressure members may be used. For example, the battery module 50 is accommodated in the housing in a state where the battery module 50 is pressurized in the direction in which the square battery 52 and the heat transfer plate 53 are arranged side by side. The distance between the opposing inner surfaces of the housing is the same as the distance in the direction in which the prismatic battery 52 and the heat transfer plate 53 are juxtaposed in the battery module 50, and the battery module 50 is pressurized by the inner surface of the housing. . In this case, the end plate, the bolt B, and the nut N may not be provided.

In the embodiment, the concave portion 84 may be formed only on one of the first surface 81c and the second surface 81d of the heat absorbing portion 81.
In the embodiment, the battery holder 51 may not be provided.

  In the embodiment, another industrial vehicle such as a power shovel may be adopted as the industrial vehicle, and the counterweight 31 and the heat radiating unit 82 mounted on the industrial vehicle may be thermally coupled.

  C ... Corner, 10 ... Forklift as an industrial vehicle, 31 ... Counterweight, 50 ... Battery module, 52 ... Square battery, 52a ... First side, 52b ... Second side, 53 ... Heat transfer plate, 77 ... positive electrode as electrode, 78 ... negative electrode as electrode, 81 ... heat absorption part, 82 ... heat dissipation part, 84 ... recess.

Claims (4)

A plurality of prismatic batteries arranged in parallel at intervals;
A heat transfer plate disposed between the plurality of prismatic batteries;
A battery module comprising: a pressure member that pressurizes the square battery and the heat transfer plate in a direction in which the square battery and the heat transfer plate are juxtaposed,
The heat transfer plate has a heat absorption part facing the widest surface of the square battery, and a heat dissipation part extending from the heat absorption part,
The endothermic portion is spaced apart from the widest surface at a portion of the widest surface of the square battery that faces the end of the heat dissipation portion .
The battery module , wherein the heat radiating portion is fixed to a counterweight mounted on an industrial vehicle and is thermally coupled to the counterweight .   2. The battery module according to claim 1, wherein the endothermic portion is in contact with the prismatic battery at a portion facing the electrode of the prismatic battery. The heat absorbing part has a rectangular plate shape so as to absorb heat from the square battery,
The battery module according to claim 1 or claim 2 electrode facing the portion of the rectangular battery is characterized that you have contact with the rectangular battery.   The battery module according to any one of claims 1 to 3, wherein the prismatic battery and the heat transfer plate are alternately arranged in parallel.