JP5843177B2 - Battery pack for electric vehicles - Google Patents

Description

The present invention provides a battery pack for an electric vehicle in which a plurality of batteries are placed on a battery tray having a cooling passage connected to a cooling air inlet and a cooling air outlet, and the batteries are cooled by cooling air flowing through the cooling passage. about the click.

  The single battery cell group is supported on the upper surface of the heat sink covering the upper surface opening of the box-shaped partition wall, and the heated single battery cell group is cooled with the cooling air by flowing cooling air through the cooling passage inside the partition wall. This is known from the following patent document 1.

Japanese Unexamined Patent Publication No. 2009-301877

  By the way, when a plurality of batteries, which are heat generating members, are supported side by side on the upper surface of the battery tray, the central portion of the battery tray is likely to be relatively hot because the entire circumference is surrounded by the battery. The end portion tends to be relatively low temperature because only the surrounding half circumference is surrounded by the battery.

  However, the cooling effect is the same at the center and the end of the battery tray simply by flowing cooling air from one end to the other end of the cooling passage formed inside the battery tray. There is a problem that the battery located on the end side of the battery tray becomes low temperature due to the high temperature of the battery located on the center side and the life of the high temperature battery is shortened.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to equalize the temperatures of a plurality of batteries supported on a battery tray through which cooling air flows.

To achieve the above object, according to the present invention, a plurality of batteries are placed on a battery tray having a cooling passage connected to a cooling air inlet and a cooling air outlet, and these batteries are placed in the cooling passage. A battery pack for an electric vehicle that indirectly cools with cooling air flowing through the battery tray , wherein the cooling passage includes a first cooling passage whose upstream end is connected to the cooling air inlet, Two second cooling passages disposed on both sides of the first cooling passage and having a downstream end connected to the cooling air discharge port, and a third cooling passage connecting the first cooling passage and the two second cooling passages A battery pack for an electric vehicle characterized by comprising:

  According to the invention, in addition to the first feature, the first cooling passage is connected to the first passage through which cooling air flows in a first direction and the downstream side of the first passage, and And a second passage through which cooling air flows in a second direction opposite to the first direction, wherein the first passage and the second passage are adjacent to each other. Is proposed.

  According to the invention, in addition to the first or second feature, the first cooling passage includes an upstream portion connected to a part of the third cooling passage, and the third cooling passage. A downstream portion connected to a part of the downstream portion, wherein the downstream end of the upstream portion and the downstream end of the downstream portion are attached to each other with a blocking member for blocking the flow of cooling air interposed therebetween. The battery pack for an electric vehicle having the third feature is proposed.

  According to the invention, in addition to the third feature, a fourth cooling passage connecting the first cooling passage and the second cooling passage is provided, and an inlet portion of the fourth cooling passage is the first cooling passage. A battery pack for an electric vehicle is proposed, which is provided in the upstream portion of the passage.

  The battery module 42 of the embodiment corresponds to the battery of the present invention, the third passage forming member 45c of the embodiment corresponds to the blocking member of the present invention, and the second passage b of the embodiment is the present invention. Corresponding to the downstream portion, the third passage c of the embodiment corresponds to the upstream portion of the present invention.

According to the first feature of the present invention, the cooling passage for indirectly cooling the battery via the battery tray by the cooling air flowing through the inside is the first cooling passage whose upstream end is connected to the cooling air inlet. Two second cooling passages disposed on both sides of the first cooling passage and having downstream ends connected to the cooling air discharge ports, and a third cooling passage connecting the first cooling passage and the two second cooling passages. Since the cooling air flowing through the first cooling passage located on the center side of the battery tray that tends to be relatively hot is low in temperature and large in flow rate, it is located on both ends of the battery tray that is likely to be relatively low in temperature. Since the cooling air flowing through the second cooling passage has a high temperature and a small flow rate, the temperatures of the plurality of batteries can be made uniform.

  According to the second aspect of the present invention, the first passage of the first cooling passage through which the cooling air flows in the first direction and the first passage connected to the downstream side of the first passage are opposite to the first direction. Since the second passage of the first cooling passage through which the cooling air flows in the second direction is adjacent to each other, the relatively low temperature cooling air flowing through the first passage on the upstream side and the second passage on the downstream side are arranged. By exchanging heat with the relatively high-temperature cooling air that flows, the temperature of the cooling air in the first passage and the second passage can be made uniform to cool the battery uniformly.

  According to a third aspect of the present invention, the first cooling passage includes an upstream portion and a downstream portion, the upstream portion is connected to a part of the third cooling passage, and the downstream portion is the third cooling passage. Connected to the other part of. Since the downstream end of the upstream portion and the downstream end of the downstream portion are abutted against each other with a blocking member for blocking the flow of the cooling air, supplied from the cooling air suction port to the upstream portion of the first cooling passage The cooling air can be blocked by the blocking member and actively supplied to a part of the third cooling passage. As a result, the cooling air in the upstream portion of the first cooling passage flows into the downstream portion and is supplied only to the other part of the third cooling passage, and is difficult to be supplied to a part of the third cooling passage. The situation can be avoided.

  According to the fourth aspect of the present invention, the inlet portion of the fourth cooling passage connecting the first cooling passage and the second cooling passage is provided in the upstream portion of the first cooling passage. The cooling air flowing in the upstream portion can be blocked by the blocking member and can be positively supplied from the inlet portion to the fourth cooling passage.

FIG. 1 is a side view of an electric vehicle. (First embodiment) FIG. 2 is a perspective view of the battery pack. (First embodiment) FIG. 3 is an exploded perspective view of the battery tray. (First embodiment) FIG. 4 is a view showing a cooling air passage in the battery tray. (First embodiment) 5 is a cross-sectional view taken along line 5-5 of FIG. (First embodiment) 6 is a cross-sectional view taken along line 6-6 of FIG. (First embodiment) 7 is a cross-sectional view taken along line 7-7 of FIG. (First embodiment) 8 is a cross-sectional view taken along line 8-8 in FIG. (First embodiment) 9 is a view taken in the direction of arrow 9 in FIG. (First embodiment)

28a Inlet part 38 Battery tray 42 Battery module (battery)
45c 3rd channel | path formation member (blocking member)
48a Cooling air inlet 49a Cooling air outlet P1 First cooling passage P2 Second cooling passage P3 Third cooling passage P4 Fourth cooling passage a First passage b Second passage (downstream portion)
c Third passage (upstream part)

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

First embodiment

  As shown in FIGS. 1 and 2, a body frame 11 of an electric vehicle includes a pair of left and right floor frames 12 and 12 extending in the longitudinal direction of the vehicle body, and left and right extending forward while bending upward from the front ends of the floor frames 12 and 12. A pair of front side frames 13, 13, a pair of left and right rear side frames 14, 14 that extend rearward while bending upward from the rear ends of the floor frames 12, 12, and the floor frames 12, 12 are disposed on the outside in the vehicle width direction. A pair of left and right side sills 15, 15, a pair of left and right front outriggers 16, 16 that connect the front ends of the side sills 15, 15 to the front ends of the floor frames 12, 12, and the rear ends of the side sills 15, 15 are the floor frames 12, 12. A pair of left and right rear outriggers 17, 17 connected to the rear end, and a pair of left and right front side frames A front bumper beam 18 that connects the front end portions of the front and rear portions 13 and 13 in the vehicle width direction, a front cross member 19 that connects the front end portions of the pair of left and right floor frames 12 and 12 in the vehicle width direction, and a pair of left and right floor frames A middle cross member 20 that connects between the front and rear intermediate portions of 12 and 12 in the vehicle width direction, a rear cross member 21 that connects the front and rear intermediate portions of the pair of left and right rear side frames 14 and 14 in the vehicle width direction, A rear bumper beam 22 that connects the rear end portions of the pair of rear side frames 14, 14 in the vehicle width direction is provided.

  A battery pack 31 serving as a power source for a motor / generator 23 which is a driving source for driving an electric vehicle is supported by being suspended from the lower surface side of the body frame 11. That is, a front suspension beam 32, a middle suspension beam 33, and a rear suspension beam 34 extending in the vehicle width direction are fixed to the lower surface of the battery pack 31, and both ends of the front suspension beam 32 are a pair of left and right floor frames. 12, both ends of the middle suspension beam 33 are fixed to the rear of the pair of left and right floor frames 12, 12, and both ends of the rear suspension beam 34 are in front of the pair of left and right rear side frames 14, 14. It fixes to the lower end of the supporting members 35 and 35 which hang down from a part. Further, the vehicle width direction center portion of the front end of the battery pack 31 is supported by the front cross member 19 via the front bracket 36, and the vehicle width direction center portion of the rear end of the battery pack 31 is supported via the rear bracket 37. Supported by the cross member 21. Further, the battery pack 31 is supported on the lower surface of the middle cross member 20 at an intermediate position between the front hanging beam 32 and the middle hanging beam 33.

  In a state where the battery pack 31 is supported on the vehicle body frame 11, the upper surface of the battery pack 31 faces the lower part of the passenger compartment 25 via the floor panel 26. That is, the battery pack 31 of the present embodiment is disposed outside the vehicle compartment 25.

  The battery pack 31 includes a metal battery tray 38 and a synthetic resin battery cover 39 superimposed on the battery tray 38 from above. The peripheral portion of the battery tray 38 and the peripheral portion of the battery cover 39 are fastened by a large number of bolts 41 with the seal member 40 (see FIG. 2) interposed therebetween, so that the interior of the battery pack 31 is basically sealed. Space. On the upper surface of the battery tray 38, a plurality of battery modules 42 are stacked in which a plurality of battery cells are stacked in series. The battery tray 38 and the battery cover 39 constitute the battery case 24 of the present invention.

  As shown in FIGS. 3 to 6, the battery tray 38 is formed by connecting an upper plate 43 and a lower plate 44 with a plurality of passage forming members 45 a to 45 i sandwiched therebetween, and a cooling passage through which cooling air flows. Is formed, heat exchange is performed with the battery modules 42 contacting the upper surface of the upper plate 43, and the battery modules 42 that generate heat by charging and discharging are cooled. Further, a battery support member 27 is supported at a position higher by a pair of left and right legs 28 and 29 at the rear portion of the battery tray 38, and two battery modules 42 and 42 are supported on the upper surface thereof. A cooling passage is formed inside the battery support member 27.

  The cooling device 46 provided at the rear portion of the battery pack 31 includes a suction duct 48 disposed at the center in the vehicle width direction and a pair of left and right discharge ducts 49, 49 disposed on both sides of the suction duct 48 in the vehicle width direction. Prepare. The lower end of the suction duct 48 is connected to the upstream end of the cooling passage of the battery tray 38, and the lower ends of the left and right discharge ducts 49, 49 are connected to the downstream end of the cooling passage of the battery tray 38. A cooling air suction port 48a for sucking air outside the battery pack 31 as cooling air is provided in the upper front surface of the suction duct 48 in which the upstream suction passage 54 and the downstream suction passage 55 are formed. Open forward. Further, the discharge ducts 49, 49 are upstream discharge passages 56, 56 that rise upward from the downstream ends of the left and right cooling passages of the battery tray 38, and downstream sides that are continuous from the upper ends of the upstream discharge passages 56, 56 to the inside in the vehicle width direction. Discharge passages 57 and 57 are provided, and cooling fans 47 and 47 are disposed immediately below the downstream discharge passages 57 and 57. The outer periphery of the cooling fans 47, 47 is surrounded by spiral fan casings 58, 58, and cooling air discharge ports 49a, 49a are opened at the outer ends thereof.

  Accordingly, when the cooling fans 47 and 47 are driven, the cooling air sucked from the cooling air suction port 48a of the suction duct 48 is supplied to the inside of the battery tray 38, and flows through the cooling passage inside the battery tray 38. After exchanging heat with 42..., The air passes through the cooling fans 47 and 47 of the discharge ducts 49 and 49 and is discharged from the cooling air discharge ports 49a and 49a. Part of the cooling air flows through the cooling passage inside the battery support member 27 and cools the two battery modules 42 and 42 supported on the upper surface thereof.

  Next, the structure of the cooling passage of the battery tray 38 will be described with reference to FIGS.

  FIG. 9 is a view of the lower plate 44 to which the passage forming members 45a to 45i are fixed as viewed from above, and the cooling passage of the battery pack 31 is the first cooling that extends in the vehicle width direction center of the lower plate 44 in the front-rear direction. Passing between the passage P1, the pair of left and right second cooling passages P2 and P2 extending in the front-rear direction at both ends in the vehicle width direction of the lower plate 44, and the first cooling passage P1 and the second cooling passages P2 and P2 in the vehicle width direction The plurality of third cooling passages P3... Extending, and a fourth cooling passage P4 (see FIG. 3) formed in the rear portion of the lower plate 44 in the vehicle width direction.

  The first cooling passage P1 is composed of a first passage forming member 45a made of corrugated plate, and second passage forming members 45b surrounding the front portion and the left and right side portions, and is an outlet at the lower end of the suction duct 48. The part 48b faces the rear end of the first passage forming member 45a. Three parallel first passages a extending forward from the outlet portion 48b are formed in the first passage forming member 45a. The downstream end of the first passage a is U-turned to the left and right, and is connected to the left and right second passages b and b extending rearward between the front half of the first passage forming member 45a and the second passage forming members 45b and 45b. The Further, left and right third passages c, c extending forward between the second half of the first passage forming member 45a and the second passage forming members 45b, 45b are formed. The second passages b and b and the third passages c and c are arranged on the same straight line, and the abutting portions of both are blocked by third passage forming members 45c and 45c extending in the vehicle width direction.

  The third cooling passages P3 are constituted by fourth passage forming members 45d made of twelve corrugated plates, and a plurality of fourth passages d extending from the inner side to the outer side in the vehicle width direction are formed therein. The The second and third passages b, b; c, c and the fourth passages d are communicated by communication holes p (see FIG. 8) formed in the left and right second passage forming members 45b.

  The left and right second cooling passages P2, P2 are formed substantially symmetrically, and the outer ends in the vehicle width direction of the four fourth passage formation members 45d, which are located in front of the third passage formation members 45c, 45c. The left and right fifth passage forming members 45e, 45e extending in the front-rear direction are arranged, and the left and right fifth passages e extending in the front-rear direction between the fourth passage forming member 45d... And the fifth passage forming members 45e, 45e. , E are formed.

  Left and right sixth passage forming members 45f, 45f extending in the front-rear direction are disposed at the outer ends in the vehicle width direction of the four fourth passage forming members 45d ... located behind the third passage forming members 45c, 45c, Left and right eighth passages h, h extending in the front-rear direction are formed between the fourth passage formation member 45d... And the sixth passage formation members 45f, 45f, and the sixth passage formation members 45f, 45f are outside in the vehicle width direction. Left and right sixth passages f, f extending in the front-rear direction are formed. The downstream end of the fifth passages e, e and the upstream end of the sixth passages f, f are connected by seventh passage forming members 45g, 45g.

  The left and right eighth passage forming members 45h, 45h extending in the front-rear direction are disposed at the outer ends in the vehicle width direction of the four fourth passage forming members 45d located at the rearmost positions, and the fourth passage forming members 45d,. Left and right ninth passages i, i extending in the front-rear direction are formed between the eighth passage forming members 45h, 45h, and left and right second passages extending in the front-rear direction outward of the eighth passage forming members 45h, 45h in the vehicle width direction. Seven passages g and g are formed. The downstream ends of the sixth passages f, f and the eighth passages h, h are connected to the upstream ends of the seventh passages g, g. The downstream ends of the seventh passages g, g and the ninth passages i, i are connected to the left and right discharge ducts 49, 49 via a pair of inlet portions 49b, 49b.

A tenth passage j extending from the inner side to the outer side in the vehicle width direction is formed between the second and third fourth passage forming members 45 d , 45 d from the rear on the left side. The upstream end of the tenth passage j communicates with the third passage c on the left side through a communication hole q (see FIG. 8) formed in the second passage formation member 45b. The downstream end of the tenth passage j blocked by the ninth passage forming member 45 i is connected to the inlet portion 28 a at the lower end of the left leg portion 28. An outlet 29a at the lower end of the right leg 29 is connected between the sixth and eighth passages f and h on the right side and the seventh passage g.

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

Since the battery modules 42 accommodated in the battery case 24 of the battery pack 31 generate heat due to charging / discharging , they are indirectly cooled by the cooling air supplied to the inside of the battery tray 38 by the cooling device 46 via the battery tray 38. Is done. That is, when the cooling fans 47 are driven, the air between the upper surface of the battery case 24 and the lower surface of the floor panel 26 is sucked as cooling air from the cooling air intake port 48a of the intake duct 48, and the upstream intake passage of the intake duct 48 54 and the downstream suction passage 55 to be supplied into the battery tray 38 (see FIG. 5).

As shown in FIG. 9, the lower end of the exit portion 48b of the intake duct 48, three first passage a ... and the formed by the first passage forming member 45a, first passage forming member 45a and the second passage forming Cooling air flows into the left and right third passages c, c formed by the members 45b, 45b. The cooling air that has flowed forward through the three first passages a is U-turned to the left and right at the end, and the left and right second passages b formed by the first passage formation member 45a and the second passage formation members 45b and 45b, b flows backward and hits the third passage forming members 45c and 45c. Meanwhile, the cooling air passes through the fourth passage d formed by the four fourth passage forming members 45d through the communication holes p formed in the second passage forming members 45b and 45b (see FIG. 8). After flowing outward in the direction, the left and right fifth passages e and e formed by the four fourth passage forming members 45d... And the left and right fifth passage forming members 45e and 45e flow backward, and further the seventh passage is formed. The sixth passages f and f outside the sixth passage forming members 45f and 45f in the vehicle width direction and the eighth passage forming members 45h and 45h outside the vehicle width direction are deflected by the members 45g and 45g toward the outside in the vehicle width direction. 7 flows backward through the passages g and g, and is discharged from the inlet portions 49b and 49b to the discharge ducts 49 and 49.

  The cooling air flowing forward in the left and right third passages c, c formed by the first passage formation member 45a and the second passage formation members 45b, 45b hits the third passage formation members 45c, 45c, and a part thereof is the first The fourth passage d formed by the four fourth passage formation members 45d ... behind the third passage formation members 45c, 45c from the communication holes p ... (see Fig. 8) formed in the two passage formation members 45b, 45b. And the left and right eighth passages h and h formed by the four fourth passage forming members 45d... And the left and right sixth passage forming members 45f and 45f. The eighth passage forming members 45h and 45h are discharged from the inlet portions 49b and 49b to the discharge ducts 49 and 49 via the seventh passages g and g outside the vehicle width direction. Other part of the cooling air flowing forward in the left and right third passages c, c is the four fourth passage formation members 45d at the rearmost from the communication holes p ... formed in the second passage formation members 45b, 45b. The left and right ninth passages i formed by the four fourth passage forming members 45d and the left and right eighth passage forming members 45h, 45h are allowed to flow through the fourth passage d formed by the , I flows rearward and is discharged from the inlet portions 49b, 49b to the discharge ducts 49, 49.

  The other part of the cooling air flowing forward through the left third passage c flows into the tenth passage j from the communication hole q (see FIG. 8) formed in the second passage forming member 45b, and from there into the inlet portion 28a. Then, it flows from the left to the right through the tenth passage j inside the battery support member 27 through the left leg portion 28, and flows into the right seventh passage g through the right leg portion 29 and the outlet portion 29a.

  As described above, while the cooling air flows through the first passage a to the tenth passage j formed in the battery tray 38, the battery modules 42 supported on the upper surfaces thereof can be cooled.

  By the way, since the entire periphery of the battery tray 38 is surrounded by the battery modules 42..., Heat is difficult to escape and the temperature becomes relatively high. On the other hand, in the outer periphery of the battery tray 38, only the surrounding half circumference is surrounded by the battery modules 42, so that heat easily escapes to the outside of the battery tray 38, and the temperature becomes relatively low. Therefore, in order to make the temperature of the plurality of battery modules 42... Uniform and enhance the durability, it is necessary to set the cooling efficiency of the central portion of the battery tray 38 higher than the cooling efficiency of the outer peripheral portion.

According to the present embodiment, relatively low-temperature cooling air before heat exchange flows through the first cooling passage P1 disposed in the vehicle width direction central portion of the battery tray 38, and both end portions of the battery tray 38 in the vehicle width direction. In the left and right second cooling passages P2 and P2 arranged in the left and right, the relatively high-temperature cooling air after heat exchange flows, and the flow rate of the cooling air flowing through the central first cooling passage P1 is the right and left second cooling passages. since twice the flow rate of the cooling air flowing through the passages P2, P2, uniformly cooled all battery modules 42 a to compensate for the temperature difference between the center and the outer peripheral portion of the battery tray 38, their temperature difference Can be reduced.

  Further, the first cooling passage P1 has upstream first passages a through which the cooling air flows forward and downstream second passages b and b through which the cooling air flows backward. The relatively low-temperature cooling air flowing through the first passages a on the side and the relatively high-temperature cooling air flowing through the second passages b, b on the downstream side exchange heat, so that the first passage a ... The temperature of the cooling air flowing through the second passages b and b can be made uniform to cool the battery modules 42.

  Also, if the third passages c and c and the third passage forming members 45c and 45c are abolished and the second passages b and b are extended to the rear end portion of the battery tray 38, an extended portion of the second passages b and b. Is far away from the cooling air inlet 48a, the flow rate of the cooling air is reduced, and there is a possibility that a sufficient amount of cooling air cannot be supplied to the third cooling passages P3.

  However, according to the present embodiment, in place of the extended portions of the second passages b and b, the third passages c and c through which the cooling air directly supplied from the cooling air suction port 48a flows forward are provided. Since the downstream ends of the passages c and c and the second passages b and b facing each other are partitioned by the third passage forming members 45c and 45c, all the passages connected to the third passage c and c and the second passages b and b are all made. A sufficient amount of cooling air can be evenly supplied to the third cooling passages P3.

  The fourth cooling passage P4 provided at a position spaced upward from the battery tray 38 is difficult to be supplied with a sufficient amount of cooling air because the flow passage resistance is increased, but is stopped by the third passage forming member 45c. Since the cooling air is branched from the third passage c to the fourth cooling passage P4, a sufficient amount of cooling air can be positively supplied to the fourth cooling passage.

  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, in the embodiment, the cooling air suction port 48a and the cooling air discharge port 49a are provided at the rear end portion of the battery tray 38, but they may be provided at the front end portion or one of the left and right side portions of the battery tray 38. .

Claims (4)

A plurality of batteries (42) are placed on a battery tray (38) having a cooling passage connected to a cooling air inlet (48a) and a cooling air outlet (49a), and these batteries (42) are the electric vehicle battery pack be indirectly cooled via the battery tray by the cooling air flowing through the passageway (38),
The cooling passage is disposed on both sides of the first cooling passage (P1) whose upstream end is connected to the cooling air suction port (48a) and the first cooling passage (P1), and the downstream end is the cooling air exhaust. Two second cooling passages (P2) connected to the outlet (49a), and a third cooling passage (P3) connecting the first cooling passage (P1) and the two second cooling passages (P2). A battery pack for an electric vehicle, comprising:   The first cooling passage (P1) is connected to the first passage (a) through which cooling air flows in a first direction and the downstream side of the first passage (a) and is opposite to the first direction. The second passage (b) through which cooling air flows in a second direction, wherein the first passage (a) and the second passage (b) are adjacent to each other. Battery pack for electric vehicles.   The first cooling passage (P1) is connected to an upstream portion (c) connected to a part of the third cooling passage (P3) and another part of the third cooling passage (P3). A downstream portion (b), and the downstream end of the upstream portion (c) and the downstream end of the downstream portion (b) are attached to each other with a blocking member (45c) blocking the flow of cooling air. The battery pack for an electric vehicle according to claim 1, wherein the battery pack is applied.   A fourth cooling passage (P4) connecting the first cooling passage (P1) and the second cooling passage (P2) is provided, and an inlet portion (28a) of the fourth cooling passage (P4) is the first cooling passage. The battery pack for an electric vehicle according to claim 3, wherein the battery pack is provided in the upstream portion (c) of (P1).

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