JP2016100291A - Reinforcement structure for battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement structure for a battery pack capable of sufficiently protecting a housed battery while suppressing deformation of a bottom part by reinforcing the bottom part and improving a fixing position of the battery.SOLUTION: A reinforcement structure for a battery pack 11 housing a battery module 30 for driving an electric vehicle 1, comprises: a tray 42 that configures a bottom part of the battery pack 11; and a first reinforcement member 50 fitted in the tray 42 so as to be opposed to an inner corner 42c made by a bottom face 42a and an inner wall surface 42b of the tray 42, and that forms a closed cross section formed between the bottom face 42a and the inner wall surface 42b in an annular shape over the whole periphery of the inner corner 42c. The battery module 30 is fixed to the first reinforcement member 50.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a reinforcing structure for a battery pack mounted under a rear floor of an electric vehicle.

  In recent years, electric vehicles such as electric vehicles and hybrid electric vehicles using a motor as a driving source for travel have been widely used. In such an electric vehicle, in order to extend the travel distance, a large number of batteries for supplying electric power to the motor are provided, and these batteries are accommodated in a battery pack serving as a protective container. It is mounted in the state.

  Further, when a plurality of batteries are stored in the battery pack, the battery pack is increased in size and weight. For this reason, in an electric vehicle, it is common to mount a battery pack on the rear part or the lower part of the vehicle from the viewpoint of lowering the center of gravity of the vehicle and ensuring the room capacity. An example of such a conventional battery pack in-vehicle structure is disclosed in Patent Document 1, for example.

  In the conventional vehicle-mounted structure, the battery pack is mounted under the rear floor. When such an electric vehicle collides with the rear surface, the impact force acts directly on the battery pack from the rear side of the vehicle. become. Thereby, especially in the battery pack suspended on the floor surface, the bottom portion thereof is greatly deformed, and the stored battery may be damaged.

  Therefore, conventionally, a battery pack has been reinforced to improve strength and rigidity in order to suppress deformation due to impact. Such a conventional battery pack reinforcing structure is disclosed in, for example, Patent Document 2.

JP 2013-199196 A JP 2014-19203 A

  However, in the above-described conventional reinforcing structure, although the battery pack itself is reinforced, nothing is taken about the fixing position of the battery housed therein. That is, even if the battery pack is reinforced, the battery may not be sufficiently protected from impact if the fixing position of the battery housed therein becomes a fragile part.

  Therefore, the present invention solves the above-mentioned problem, and can reinforce the bottom part and improve the fixing position of the stored battery, thereby sufficiently protecting the battery while suppressing deformation of the bottom part. It aims at providing the reinforcement structure of a battery pack.

The battery pack reinforcing structure according to the first invention for solving the above-mentioned problems is
In the reinforcing structure of the battery pack for storing the battery for driving the electric vehicle,
A tray constituting the bottom of the battery pack;
A closed cross-section formed between the bottom surface and the inner wall surface is fitted to the inner corner portion formed by the bottom surface and the inner wall surface so as to face the inner corner portion formed by the bottom surface and the inner wall surface of the tray. A first reinforcing member formed in an annular shape over the
The battery is fixed to the first reinforcing member.

The battery pack reinforcing structure according to the second invention for solving the above-mentioned problems is as follows.
The first reinforcing member is
A bottom plate portion joined to the bottom surface;
After extending in the direction away from the bottom surface with the outer edge of the bottom plate as a base point, it is bent so as to extend in the direction toward the inner wall surface, and the closed cross section is formed in an annular shape over the entire inner corner An annular bent portion
A second reinforcing member that is disposed in the ring of the annular bent portion and connects at least two points in the annular bent portion is provided.

The battery pack reinforcing structure according to the third invention for solving the above-described problems is
The battery is fixed to the second reinforcing member.

  Therefore, according to the reinforcing structure of the battery pack according to the present invention, the battery is fixed to the first reinforcing member that forms a closed cross section formed between the tray and the entire inner corner portion in an annular shape. Even when an impact force is applied to the tray, the battery can be sufficiently protected while suppressing deformation of the bottom of the tray.

1 is an external perspective view of a lower floor of an electric vehicle to which a battery pack reinforcing structure according to the present invention is applied. It is a bottom view under the rear floor of the electric vehicle to which the battery pack reinforcing structure according to the present invention is applied. It is a back perspective view of a battery pack in the state where an upper cover was removed. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3, and is a vertical cross-sectional view of the battery pack. FIG. 4 is a cross-sectional view taken along line B-B in FIG. 3, and is a cross-sectional view of the battery pack. It is a top view of the tray of the state in which the battery module was accommodated. It is a top view of the tray in the state where the battery module was removed. It is a perspective view of a tray.

  Hereinafter, the reinforcing structure of a battery pack according to the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1 and 2, a pair of left and right rear wheels 12 are rotatably supported at the rear portion of the electric vehicle 1 that travels by the driving force of the motor. A battery pack 11 is mounted on the rear side of the rear wheel 12, and a plurality of battery cells (batteries) 31 for supplying stored electric power to the motor described later are provided in the battery pack 11. It is stored individually.

  The rear portion of the electric vehicle 1 is provided with a rear floor panel that constitutes the floor surface of the luggage compartment, and a pair of left and right side members 14 are supported on both sides in the vehicle width direction on the lower surface of the rear floor panel. Yes. The side member 14 extends in the vehicle front-rear direction, and the rear ends of a pair of left and right chassis members 15 are connected to the front end thereof.

  The chassis member 15 has a front end portion and a rear end portion arranged on the outermost side in the vehicle width direction, and an intermediate portion in the vehicle front-rear direction is arranged on the innermost side in the vehicle width direction. That is, the chassis member 15 is formed so as to curve inward in the vehicle width direction from the front end portion and the rear end portion toward the intermediate portion. Further, a chacyclo member 16 is provided between the intermediate portions close to each other.

  On the other hand, the rear wheel 12 is supported at the front end of the suspension arm 13 so as to be rotatable in the vertical direction. The base end side of the suspension arm 13 is formed in a bifurcated shape. At this time, the base end portion on the front side is supported by the middle portion of the chassis member 15 so as to be rotatable in the vertical direction, and the base end portion on the rear side is rotated in the vertical direction on the side portion of the chassis member 16. It is supported movably.

  On the other hand, a rear bumper force 17 is supported between the rear ends of the side members 14, and the rear bumper force 17 extends in the vehicle width direction. A rear bumper can be attached to the rear surface side of the rear bumper reinforcement 17.

  A battery pack 11 is attached between the vehicle front and rear intermediate portions of the side members 14.

  Therefore, the chassis member 15 and the chassis member 16 are arranged on the vehicle front side of the battery pack 11. A rear bumper force 17 is disposed behind the battery pack 11 in the vehicle. Further, side members 14 are disposed on both sides of the battery pack 11 in the vehicle width direction. In other words, the battery pack 11 is surrounded by the side member 14, the chassis member 15, the chassis member 16, and the rear bumper reinforcement 17, and the bottom (a tray 42, which will be described later) is formed by the rear floor panel and the rear bumper. It arrange | positions so that it may be located below the reinforcement 17. FIG.

  Next, the configuration of the battery pack 11 will be described in detail with reference to FIGS.

  As shown in FIGS. 1 to 5, the battery pack 11 serving as a protective container includes a tray 42 that forms the bottom of the battery pack 11 and an upper cover 41 that serves as a lid member of the tray 42. The lower opening end of the upper cover 41 and the upper opening end of the tray 42 are flange-joined. A storage space is formed inside the joined upper cover 41 and tray 42, and a plurality of battery modules (batteries) 30 can be stored in the storage space.

  A pair of left and right frame members 43 are provided on both sides of the tray 42 in the vehicle width direction, and the frame members 43 extend in the vehicle front-rear direction. Brackets 45 are supported on the outer surface of the frame member 43 in the vehicle width direction, and these brackets 45 are fixed to the lower surface of the side member 14 with bolts.

  Further, a beam member 44 is provided on the rear outer surface of the tray 42. The beam member 44 extends in the vehicle width direction and is disposed below the rear bumper force 17. Both ends of the beam member 44 in the vehicle width direction are supported by the rear end of the frame member 43.

  That is, the left and right side portions of the tray 42 are reinforced by the frame member 43, and the rear portion of the tray 42 is reinforced by the beam member 44.

  Here, as shown in FIGS. 3 to 8, the upper cover 41 and the tray 42 are formed in a bowl shape, and are formed from a single metal plate by deep drawing using a press machine or the like. Among these, a first reinforcing member 50 and a plurality of second reinforcing members 60 for reinforcing the bottom of the tray 42 are fitted inside the tray 42, and these reinforcing members 50 and 60 are also pressed. It is formed from a single metal plate by drawing with a machine or the like.

  The first reinforcing member 50 is formed in a bowl shape with a depth shallower than the depth of the tray 42, and is joined to the bottom surface 42 a and the inner wall surface 42 b of the tray 42. Further, the second reinforcing member 60 extends in the vehicle front-rear direction and is joined to the surface of the first reinforcing member 50.

  Specifically, the first reinforcing member 50 includes a bottom plate part 51, an annular bent part 52, and a vertical wall part 53.

  The bottom plate portion 51 is formed at the center of the first reinforcing member 50 and can come into contact with the bottom surface 42 a of the tray 42. The annular bent portion 52 extends over the entire outer edge portion of the bottom plate portion 51 in a direction away from the bottom surface 42 a of the tray 42 with the outer edge portion of the bottom plate portion 51 as a base point, and then the inner wall surface of the tray 42. It is formed by being bent so as to extend in a direction toward 42d, and can be opposed to an inner corner portion 42c formed by the bottom surface 42a and the inner wall surface 42b. Further, the vertical wall portion 53 is formed so as to stand up from the outer edge portion of the entire circumference of the outer edge portion of the annular bent portion 52, and can come into contact with the inner wall surface 42 b of the tray 42. .

  Therefore, when the first reinforcing member 50 is fitted inside the tray 42, the first reinforcing member 50 is inserted into the tray 42, and then the bottom plate portion 51 is joined to the bottom surface 42a, and the vertical wall portion 53 is It joins with the inner wall surface 42b. At this time, the annular bent portion 52 is opposed to the inner corner portion 42c constituting the bottom portion of the tray 42, and forms a closed cross section between the bottom surface 42a and the inner wall surface 42b. Thereby, the closed cross section is formed in an annular shape over the entire circumference of the inner corner portion 42c. In addition, although mentioned later for details, the cyclic | annular upper surface 52a of the cyclic | annular bending part 52 is a seat surface for fixation for fixing the battery module 30. FIG.

  The second reinforcing member 60 includes a convex portion 61, a flange portion 62, and a flat plate portion 63.

  The convex portion 61 is formed in a convex shape so as to protrude upward along the vehicle front-rear direction (longitudinal direction) at the vehicle width direction central portion of the second reinforcing member 60. Further, the flange portion 62 is formed along the vehicle front-rear direction on both sides of the convex portion 61 in the vehicle width direction, and can come into contact with the bottom plate portion 51 of the first reinforcing member 50. Further, the flat plate portion 63 is formed in a flat plate shape at both ends of the second reinforcing member 60 (the convex portion 61 and the flange portion 62) in the vehicle front-rear direction, and the annular bent portion 52 and the vertical wall of the first reinforcing member 50 are formed. It is possible to make contact with the portion 53. That is, the flat plate portion 63 is a portion in which both ends of the convex portion 61 and the flange portion 62 in the vehicle front-rear direction are made flat and bent upward.

  Therefore, when fitting the second reinforcing member 60 inside the tray 42, first, the second reinforcing member 60 is inserted into the first reinforcing member 50 joined to the tray 42, and then the longitudinal direction thereof is changed. Match the vehicle longitudinal direction. Next, the flange portion 62 is overlap-bonded to the bottom surface 42 a and the bottom plate portion 51. At the same time, the flat plate portion 63 is joined to the annular upper surface 52 a of the annular bent portion 52 and is superposed and joined to the inner wall surface 42 b and the vertical wall portion 53. Accordingly, the second reinforcing member 60 linearly connects at least two points between the vehicle front side portion and the vehicle rear side portion within the ring (inside) of the annular bent portion 52. become. In addition, although mentioned later for details, the convex surface (top surface) 61a of the convex part 61 is a fixing seat surface for fixing the battery module 30. FIG.

  As shown in FIGS. 3 to 7, the battery module 30 is, for example, one in which eight battery cells 31 are arranged side by side and their electrodes are combined in series into one solid, Twelve battery modules 30 are housed in the battery pack 11. The battery modules 30 are arranged in an array state such that the battery modules 30 are stacked in three stages in the vertical direction by the array bracket 32 and arranged in four rows in the vehicle width direction.

  The array brackets 32 are provided in three upper and lower tiers so as to surround the periphery of the battery modules 30 in an array of four rows. The front bracket 32a, the rear bracket 32b, and the left bracket are arranged in a lattice shape. 32c, the right side bracket 32d, and the connection bracket 32e.

  The brackets 32a to 32d are arranged in three upper and lower horizontal lattice members having an L-shaped cross section, and the front side, the rear side, the left side, and the battery module 30 arranged in the above-described arrangement state. The right side is supported. And the connection bracket 32e arrange | positions the vertical lattice member in which cross-sectional shape makes L shape in four corners, Comprising: One end and the other end of brackets 32a-32d are connected in the up-down direction.

  Further, the upper portion of the arranging bracket 32 is fixed to the inner wall surface 42 b of the tray 42 by a plurality of fixing brackets 71. The lower portion of the array bracket 32 is fixed to the reinforcing members 50 and 60 by a plurality of fixing brackets 72.

  Specifically, the horizontal lattice member located in the middle stage of the brackets 32 b, 32 c, and 32 d is fixed to the inner wall surface 42 b of the tray 42 by the fixing bracket 71. Further, the horizontal lattice member positioned at the lowermost stage in the brackets 32 a and 32 b is fixed to the convex surface 61 a of the convex portion 61 by the fixing bracket 72. Further, the horizontal lattice member located at the lowest stage in the brackets 32 c and 32 d is fixed to the annular upper surface 52 a of the annular bent portion 52. That is, the plurality of battery modules 30 arranged by the arranging bracket 32 are fixed to the annular upper surface 52a and the convex surface 61a via the fixing bracket 72.

  At this time, when the plurality of battery modules 30 arranged in the arrangement state are stored in the tray 42, the battery modules 30 are fixed to the vehicle rear side in the tray 42 as a whole. As a result, an accessory storage space 42d is secured on the vehicle front side in the tray 42. In this auxiliary machine storage space 42d, electronic devices related to power supply of the battery module 30 (battery cell 31) are stored. For example, a current sensor, a leakage sensor, a fuse, a service plug, and the battery modules 30 are connected to each other. A connection device, a disconnecting device for disconnecting the connection between the battery module 30 and an apparatus such as an inverter, and the like are installed.

  Therefore, according to the battery pack reinforcing structure of the present invention, the first reinforcing member 50 is fitted in the tray 42, and the closed cross section formed by the bottom surface 42a, the inner wall surface 42b, and the annular bent portion 52 is formed. Is formed in an annular shape over the entire circumference of the inner corner portion 42, whereby the bottom portion of the tray 42 can be reinforced. In addition, the battery module 30 can be firmly fixed by fixing the battery module 30 to the annular upper surface 52 of the annular bent portion 52 and setting the fixing position of the battery module 30 to a reinforced position. Thus, even when the electric vehicle 1 collides rearward and an impact force acts directly on the battery pack 11 mounted under the rear floor from the rear side of the vehicle, the battery is suppressed while preventing deformation of the bottom of the tray 42. The pack 11 can be sufficiently protected.

  Further, the second reinforcing member 60 is fitted in the ring of the annular bent portion 52, and the annular bent portion 52 is reinforced by connecting at least two points in the annular bent portion 52 linearly in the vehicle front-rear direction. Not only can this be done, but the extending direction (longitudinal direction) of the second reinforcing member 60 and the direction of action of the impact force generated at the time of a rear collision can be matched. Thereby, since the impact force can be further resisted by the rigidity of the second reinforcing member 60, the deformation of the bottom portion of the tray 42 can be effectively suppressed. When the second reinforcing member 60 is fitted, the extending direction does not necessarily coincide with the vehicle front-rear direction, and the extending direction may be inclined with respect to the vehicle body front-rear direction.

  Furthermore, by fixing the battery module 30 to the convex surface 61a of the second reinforcing member 60, the battery module 30 can be firmly fixed and the auxiliary equipment storage space 42d can be secured with a sufficient capacity. That is, by fixing the fixing bracket 72 to the convex surface 61a, the fixing bracket 72 is positioned at the lowermost part in the accessory storage space 42d, and therefore, the interference of the fixing bracket 72 to the electronic device can be prevented. it can.

  The battery pack reinforcing structure according to the present invention can effectively reinforce the tray for storing the battery, and thus can be used extremely beneficially in the safety performance of the electric vehicle at the time of a rear collision.

DESCRIPTION OF SYMBOLS 1 Electric vehicle 11 Battery pack 30 Battery module 31 Battery cell 32 Arrangement bracket 42 Tray 42a Bottom surface 42b Inner wall surface 42c Inner corner 42d Auxiliary storage space 50 First reinforcing member 51 Bottom plate part 52 Annular bent part 52a Annular upper surface 53 Vertical Wall portion 60 Second reinforcing member 61 Convex portion 61a Convex surface 62 Flange portion 63 Flat plate portions 71 and 72 Fixing bracket

Claims (3)

In the reinforcing structure of the battery pack for storing the battery for driving the electric vehicle,
A tray constituting the bottom of the battery pack;
A closed cross-section formed between the bottom surface and the inner wall surface is fitted to the inner corner portion formed by the bottom surface and the inner wall surface so as to face the inner corner portion formed by the bottom surface and the inner wall surface of the tray. A first reinforcing member formed in an annular shape over the
The battery is fixed to the first reinforcement member. A battery pack reinforcement structure, wherein: The reinforcing structure of the battery pack according to claim 1,
The first reinforcing member is
A bottom plate portion joined to the bottom surface;
After extending in the direction away from the bottom surface with the outer edge of the bottom plate as a base point, it is bent so as to extend in the direction toward the inner wall surface, and the closed cross section is formed in an annular shape over the entire inner corner An annular bent portion
A reinforcing structure for a battery pack, comprising: a second reinforcing member that is disposed in a ring of the annular bent portion and connects at least two points in the annular bent portion. The battery pack reinforcement structure according to claim 2,
The battery is fixed to the second reinforcing member. A battery pack reinforcing structure, comprising:

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