Battery pack mounting structure for vehicle

Abstract

To provide a vehicle mounting structure of a battery pack.SOLUTION: A vehicle mounting structure includes a battery pack arranged on a vehicle body bottom surface of a vehicle, a support frame which supports the battery pack on a vehicle body bottom surface, and a plurality of fastening members which mechanically fasten the support frame and a bottom part of the battery pack. The plurality of fastening members include a front fastening member arranged in a front center position of a vehicle on the bottom part of the battery pack, a rear fastening member arranged in a rear center position of the vehicle on the bottom part of the battery pack, a left fastening member arranged in a left center position of the vehicle on the bottom part of the battery pack, and a right fastening member arranged in a right center position of the vehicle on the bottom part of the battery pack.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a mounting structure for a battery pack mounted on a vehicle to a vehicle body. [Background technology]

[0002] Patent Document 1 discloses a vehicle with a battery pack mounted on the bottom of the vehicle body. In this conventional vehicle, the battery pack is not mechanically fastened to a frame provided on the bottom of the vehicle. Instead, the battery pack is supported by a support structure attached to the bottom frame of the vehicle. An isolator is provided between the battery pack and the support structure. The isolator is provided for the purpose of isolating the battery pack from a load input to the bottom frame or support structure of the vehicle when the vehicle is running. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2020 / 0070639 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the vehicle of Patent Document 1 is equipped with many isolators. If a large number of isolators are installed, the natural frequency of the battery pack decreases, and resonance during vehicle running may adversely affect the battery pack and its internal components. In addition, the vehicle of Patent Document 1 focuses on the load during vehicle running, but does not focus on the torsion in the roll direction of the vehicle. Therefore, there is room for improvement in terms of reducing the impact of torsion during vehicle running on the battery pack.

[0005] One object of the present disclosure is to provide a technique capable of reducing the impact on a battery pack of twist in the roll direction during vehicle travel. [Means for solving the problem]

[0006] A first aspect of the present disclosure relates to a mounting structure for a battery pack. The battery pack mounting structure is as follows: A battery pack provided on a bottom surface of a vehicle body; a support frame that supports the battery pack on a bottom surface of the vehicle body; a plurality of fastening members for mechanically fastening the support frame and the bottom of the battery pack; Equipped with Multiple fasteners teeth , A front fastening member provided at the bottom of the battery pack in the center of the front of the vehicle. 、 A rear fastening member provided at the bottom of the battery pack in a central position at the rear of the vehicle. 、 A left fastening member provided at the bottom of the battery pack in the center of the left side of the vehicle , and A right fastening member provided at the bottom of the battery pack in the center of the right side of the vehicle. There are four of them. It is characterized by: Effect of the Invention

[0007] According to the first aspect, a support frame that supports the battery pack on the bottom surface of the vehicle body and the bottom of the battery pack are mechanically fastened by a plurality of fastening members. The plurality of fastening members are front, rear, left and right fastening members. There are four These fastening members are provided at the bottom of the battery pack at the front center of the vehicle, the rear center of the vehicle, the left center of the vehicle, and the right center of the vehicle. These positions are locations where twisting in the roll direction when the vehicle is traveling is unlikely to be input. Therefore, according to the first aspect, it is possible to minimize the influence of twisting in the roll direction when the vehicle is traveling on the battery pack. This leads to prevention of a decrease in the strength of the battery pack and its internal components. [Brief description of the drawings]

[0008] [Figure 1]1 is a diagram illustrating an example of a vehicle to which a mounting structure for a battery pack according to an embodiment of the present disclosure is applied; [Diagram 2] 1 is a diagram showing an example of mounting a battery pack according to the present disclosure to the bottom surface of a vehicle body. [Diagram 3] 11A to 11C are diagrams illustrating the effects of the embodiment. [Figure 4] 11A to 11C are diagrams illustrating the effects of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 1. Vehicles in which the battery pack can be installed Fig. 1 is a diagram illustrating an example of a vehicle to which a battery pack mounting structure according to an embodiment of the present disclosure is applied. Note that the direction of "Fr" in Fig. 1 corresponds to the front of the vehicle, and the direction of "UPR" corresponds to the upper side of the vehicle.

[0010] The vehicle 1 shown in FIG. 1 is, for example, a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a fuel cell vehicle, etc. The vehicle 1 may be a vehicle having a ladder frame, or may be a vehicle not having a ladder frame. An example of a vehicle not having a ladder frame is a vehicle having a monocoque structure. In general, many vehicles having a ladder frame are manufactured with a high vehicle height and large diameter tires for the purpose of running off-road. On the other hand, many vehicles having a monocoque structure have a spacious interior and are manufactured for the purpose of running on paved roads with good fuel efficiency.

[0011] A battery pack 2 is mounted on the vehicle 1. The battery pack 2 is attached to the underside of the body of the vehicle 1. The longitudinal direction of the battery pack 2 extends, for example, in the front-rear direction of the vehicle 1. The battery pack 2 includes, for example, a plurality of battery cells. The battery cells are, for example, lithium-ion secondary batteries.

[0012] 2. Example of battery pack installation on the bottom of the vehicle Fig. 2 is a diagram showing an example of mounting the battery pack 2 to the bottom surface of a vehicle body. Fig. 2 corresponds to a bottom view of the surrounding structure of the battery pack 2 mounted on a vehicle having a ladder frame 5. Note that the direction of "LH" in Fig. 2 corresponds to the left side of the vehicle, and the direction of "RH" corresponds to the right side of the vehicle.

[0013] Figure 2 shows support frames 3a-3f, a front fastening member 4a, a rear fastening member 4b, a left fastening member 4c, and a right fastening member 4d (hereinafter, when fastening members 4a-4d are not to be distinguished from one another, they will be collectively referred to as "fastening members 4") as a structure for attaching battery pack 2 to the bottom surface of the vehicle body.

[0014] In the example shown in FIG. 2, the bottom of the battery pack 2 is supported by support frames 3a to 3f (hereinafter, when the support frames 3a to 3f are not particularly distinguished, they will be collectively referred to as "support frame 3"). The support frame 3 is connected to a ladder frame 5. In the case of a vehicle that does not have a ladder frame 5, the support frame 3 is connected to a monocoque structure. In the example shown in FIG. 2, the bottom of the battery pack 2 is supported by support frames 3a to 3f (hereinafter, when the support frames 3a to 3f are not particularly distinguished, they will be collectively referred to as "support frame 3"). The support frame 3f corresponds to the "front support frame" in this disclosure. The support frame 3a corresponds to the "rear support frame" in this disclosure. The support frame 3d corresponds to the "middle support frame" in this disclosure.

[0015] The fastening member 4 mechanically fastens the support frame 3 to the bottom of the battery pack 2. The fastening member 4 is, for example, a combination of a bolt and a nut. For example, a bolt is passed through holes formed in the support frame 3 and the bottom of the battery pack 2 from the bottom side of the vehicle body, and combined with a nut provided inside the battery pack 2. In another example, this bolt is combined with a female screw provided in the bottom of the battery pack 2. In this way, the support frame 3 and the bottom of the battery pack 2 are fastened together.

[0016] The front fastening member 4a is provided at the front center of the bottom of the battery pack 2. The rear fastening member 4b is provided at the rear center of the bottom of the battery pack 2. The left fastening member 4c is provided at the left center of the bottom of the battery pack 2. The right fastening member 4d is provided at the right center of the bottom of the battery pack 2.

[0017] In this disclosure, the "center" in the front center, rear center, left center, and right center at the bottom of the battery pack 2 is not intended to mean the exact center. That is, the front center may include a certain amount of error in the left-right direction from the front center at the bottom of the battery pack 2. The left center may include a certain amount of error in the front-rear direction from the front center at the bottom of the battery pack 2. The rear center is considered the same as the front center. The right center is considered the same as the left center.

[0018] In Fig. 2, the elastic body 6 is further drawn by a dashed line. The elastic body 6 is drawn by a dashed line because it is located between the support frame 3 and the bottom of the battery pack 2. The elastic body 6 is, for example, a rubber mount. In the example shown in Fig. 2, two elastic bodies 6 are provided on each of the rear faces of the support frames 3b, 3c, and 3e.

[0019] 3. Effects of battery pack mounting structure Figures 3 and 4 are diagrams for explaining the effects of the embodiment. Figures 3 and 4 show the mounting structure described in Figure 2, excluding the battery pack 2. Figure 3 shows the state before the ladder frame 5 is twisted in the roll direction of the vehicle 1. On the other hand, Figure 4 shows the state after the ladder frame 5 is twisted.

[0020] For example, when the vehicle 1 travels off-road, a large twist in the roll direction may occur in the ladder frame 5. However, as can be seen from Figures 3 and 4, the change in the position where the front fastening member 4a is provided is small before and after the ladder frame 5 is twisted. Also, the change in the positions where the rear fastening member 4b, the left fastening member 4c, and the right fastening member 4d are provided is small before and after the ladder frame 5 is twisted. This means that the installation positions of the fastening members 4 such as the front fastening member 4a are positions where twisting in the roll direction is unlikely to be input.

[0021] Therefore, according to the embodiment, even if the vehicle 1 is twisted in the roll direction, it is possible to prevent the twist from being input to the battery pack 2. This makes it possible to minimize the effect of the twist in the roll direction on the battery pack 2. This leads to prevention of a decrease in the strength of the battery pack 2 and its internal components.

[0022] Also, according to the embodiment, it is possible to minimize the influence of twisting in the roll direction on the battery pack, particularly when the vehicle 1 is traveling off-road. Furthermore, according to the embodiment, the elastic body 6 is provided in addition to the fastening member 4. Therefore, it is possible to suppress the transmission of vibrations generated when the vehicle 1 is traveling to the battery pack 2.

[0023] 4. Variations The present disclosure is not limited to the above-described embodiment, and various modifications are possible. For example, the support frame 3 is provided in the left-right direction of the vehicle 1, but the support frame 3 may be provided in the front-rear direction of the vehicle 1. In this case, the front fastening member 4a and the rear fastening member 4b may be provided on the same support frame extending in the front-rear direction at the center of the vehicle. In addition, the left fastening member 4c may be provided on a support frame extending in the front-rear direction on the left side of the vehicle, and the right fastening member 4d may be provided on a support frame extending in the front-rear direction on the left side of the vehicle.

[0024] In addition, although the total number of fastening members 4 is four in the embodiment, this total number may be more than four. In this case, however, it is desirable to identify, in advance by simulation or the like, locations where the positional change is small when twisting occurs in the roll direction of the vehicle 1, and to install additional fastening members at these locations.

[0025] Also, in the embodiment, the total number of the support frames 3 is six, but the total number may be less than six or more than six. However, the total number of the support frames 3 is at least three. Of the at least three support frames 3, one is fastened to the bottom of the battery pack 2 by two fastening members 4 (e.g., the left fastening member 4c and the right fastening member 4d). The remaining two are each fastened to the bottom of the battery pack 2 by one fastening member 4 (e.g., the front fastening member 4a or the rear fastening member 4b).

[0026] In addition, while the total number of elastic bodies 6 is six in the embodiment, this total number may be less than or more than six. However, as an increase in the total number of elastic bodies 6 may cause a problem of a decrease in the natural frequency of the mounting structure, it is desirable to set an upper limit on this total number. [Explanation of symbols]

[0027] 1 vehicle, 2 battery pack, 3a-3f support frame, 4a-4d fastening member, 5 ladder frame, 6 elastic body

Claims

1. A battery pack provided on a bottom surface of a vehicle body; a support frame that supports the battery pack on a bottom surface of the vehicle body; a plurality of fastening members that mechanically fasten the support frame and a bottom of the battery pack; Equipped with The plurality of fastening members include a front fastening member provided at a bottom portion of the battery pack at a central position in a front direction of the vehicle; a rear fastening member provided at a bottom portion of the battery pack at a central position toward the rear of the vehicle; a left fastening member provided at a bottom portion of the battery pack at a central position on the left side of the vehicle; and Four right fastening members provided at the bottom of the battery pack in the center of the right side of the vehicle. A battery pack mounting structure comprising:

2. The vehicle has a ladder frame, The support frame extends in the left-right direction of the vehicle and is spanned across the ladder frame.

2. The battery pack mounting structure according to claim 1.

3. The battery pack further includes an elastic body provided between the support frame and the battery pack.

3. The battery pack mounting structure according to claim 1 or 2.

4. The support frame is at least three. The at least three support frames each extend in a left-right direction of the vehicle, The at least three support frames are: a front support frame coupled to the front fastening member; a rear support frame coupled to the rear fastening member; an intermediate support frame combined with the left fastening member and the right fastening member; Includes 3. The battery pack mounting structure according to claim 1 or 2.

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