Vehicle body lower structure

Abstract

To protect a battery in a front collision in a vehicle body which has the battery arranged on a rear side of a front suspension member.SOLUTION: A vehicle body lower structure includes: a front suspension member; a lower arm which is supported by the front suspension member; and a battery case which is arranged on a rear side of the front suspension member and stores a battery. The battery case includes a front plate and a frame which extends in a left and right direction in a lower section of the front plate. Furthermore, a block is mounted in a front section of the frame so that the battery case is positioned on a rear side of the lower arm. In a front collision, the lower arm is retreated together with the suspension member. The retreated lower arm comes into contact with the block and stops.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a vehicle underbody structure. [Background technology]

[0002] Patent Document 1 discloses a vehicle underbody structure in which a battery is disposed behind a front suspension member. The battery is housed in a case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-158688 A Summary of the Invention [Problem to be solved by the invention]

[0004] If the impact of a collision is large, the suspension member may move backward and come into contact with the battery, causing damage to the battery. In particular, there is a high possibility that the lower arm supported by the suspension member may come into contact with the battery. This specification provides a technology for protecting the battery during a collision. [Means for solving the problem]

[0005] The vehicle underbody structure disclosed in this specification includes a front suspension member, a lower arm supported by the front suspension member, and a battery case disposed rearward of the front suspension member and housing a battery. The battery case includes a front plate and a frame extending in the left-right direction below the front plate. Furthermore, a block is attached to the front of the frame so as to be located rearward of the lower arm.

[0006] If the suspension member retracts during a collision and the lower arm comes into contact with the front plate of the battery case, there is a risk that the lower arm will break through the front plate and come into contact with the battery inside the case. A block is placed at the front of a strong frame. The block is located behind the lower arm. When the lower arm retracts together with the suspension member, the lower arm comes into contact with the block rather than the front plate of the case. The block is supported by a frame extending in the left-right direction. The lower arm stops retracting when it comes into contact with the block. Therefore, the lower arm does not come into contact with the front plate and the battery housed in the battery case is protected. It is preferable that the frame is fixed to one of the side frames and rockers of the vehicle body. The frame can firmly absorb the impact of a collision.

[0007] The front suspension member includes a pair of suspension side beams whose front and rear ends are fixed to the vehicle body, and a suspension cross member connecting the pair of suspension side beams. In this case, it is preferable that the distance between the block and the lower arm is shorter than the distance between the front plate and the suspension cross member. This also makes it possible to prevent the suspension cross member from coming into contact with the battery case in the event of a collision.

[0008] The refrigerant pipe that sends refrigerant to the cooler that cools the battery may protrude forward from the front plate of the battery case. In that case, it is preferable that the distance between the block and the lower arm is shorter than the distance between the refrigerant pipe and the suspension cross member. This will also protect the refrigerant pipe in the event of a collision.

[0009] It is preferable that the vehicle further includes a reinforcing plate that connects the front suspension member and the block. The reinforcing plate receives part of the impact of the collision, thereby weakening the force that retracts the lower arm. Furthermore, it is preferable that the reinforcing plate extends below the battery case. When the reinforcing plate retracts together with the front suspension member, the reinforcing plate slides under the battery case, and the reinforcing plate does not damage the battery case.

[0010] Details and further improvements of the technology disclosed in this specification are described in the following "Forms for Carrying Out the Invention". [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a bottom view of a vehicle body employing the vehicle body underbody structure of the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 4 is a cross-sectional view showing the position of a suspension member during a frontal collision. [Figure 4] FIG. 11 is a bottom view showing the vehicle underbody structure of the second embodiment. [Diagram 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The vehicle body underbody structure of the first embodiment will be described with reference to the drawings. FIG. 1 shows a bottom view of a vehicle body 2 employing the vehicle body underbody structure of the first embodiment. FIG. 2 shows a cross-sectional view taken along line II-II in FIG. 1. FIG. 1 is a bottom view of the front part of the vehicle body. The vehicle body 2 is the body of an electric vehicle. A front suspension member 10 supporting the front wheels is disposed in the front part of the vehicle body. The front suspension member 10 includes a pair of suspension side beams 11a, 11b and a pair of suspension cross members 12a, 12b. The suspension side beams 11a (11b) extend in the front-rear direction of the vehicle body, and the front end is connected to the side member 3a (3b), and the rear end is connected to the torque box 5a (5b) of the vehicle body 2. The torque boxes 5a, 5b are box-shaped members provided in the lower part of the dash panel, and increase the rigidity of the vehicle body 2 around the roll axis. The side members 3a, 3b and the torque boxes 5a, 5b are part of the vehicle body 2. In the following, for ease of explanation, the front suspension member 10 may be simply referred to as the suspension member 10.

[0013] The suspension cross members 12a, 12b are beams extending in the lateral direction of the vehicle body 2. The suspension cross members 12a, 12b each connect a pair of suspension side beams 11a, 11b. The suspension member 10 supports lower arms 13a, 13b. The lower arms 13a, 13b are components that support hubs (not shown) that rotatably support the axles of the front wheels.

[0014] A battery case 20 is disposed behind the suspension member 10. The battery case 20 houses a battery 30 that supplies power to a traveling motor (not shown). The battery case 20 is fixed to a pair of rockers 4a, 4b. The battery case 20 includes a front plate 21 and a frame 22. The frame 22 is a beam that extends in the lateral direction of the vehicle body 2, and each end of the frame 22 is connected to the rockers 4a, 4b, respectively. The frame 22 ensures the strength of the battery case 20.

[0015] Blocks 23a and 23b are fixed to the front of the frame 22. The block 23a (23b) is located rearward of the lower arm 13a (13b). The distance L1 between the block 23a (23b) and the lower arm 13a (13b) is very short. In other words, the block 23a (23b) is located immediately behind the lower arm 13a (13b). The distance L1 is shorter than the distance L2 between the front plate 21 of the battery case 20 and the suspension cross member 12a (rear suspension cross member 12a).

[0016] FIG. 3 shows a state in which the vehicle body 2 collides frontally and a collision load F is applied to the suspension member 10. Note that a "frontal collision" refers to a state in which a traveling vehicle collides with an obstacle in front of it. When the collision load F is applied to the suspension member 10 from the front, the suspension side beam 11a deforms and the suspension cross member 12a (12b) moves backward. The lower arm 13a (13b) also moves backward together with the suspension cross member 12a (12b). However, as indicated by arrow A in FIG. 3, the lower arm 13a (13b) comes into contact with the block 23a (23b) located immediately behind it. Since the block 23a (23b) is fixed to the frame 22, which has high strength, the collision load F is transmitted from the frame 22 to the rockers 4a, 4b. The rockers 4a, 4b also have high strength. Therefore, after the lower arm 13a (13b) contacts the block 23a (23b), the suspension member 10 stops moving backward. A gap is secured between the suspension member 10 (suspension cross member 12a) and the battery case 20 (see the thick arrow B in FIG. 3). Therefore, the battery 30 housed in the battery case 20 is protected.

[0017] If the blocks 23a, 23b were not provided, the lower arms 13a, 13b would move further backward and up and down during a collision. If the lower arms 13a, 13b move rearward and upward, there is a possibility that the lower arms 13a, 13b may come into contact with the front plate 21 of the battery case 20. Because the front plate 21 is a thin plate, the lower arms 13a, 13b may break through the front plate 21 and come into contact with the battery 30, potentially damaging the battery 30. By providing the blocks 23a, 23b, the lower arms 13a, 13b are prevented from moving backward significantly, and as a result, contact between the lower arms 13a, 13b and the battery 30 is avoided.

[0018] A refrigerant pipe 31 extends forward from the front plate 21 of the battery case 20. The distance L1 between the block 23a (23b) and the lower arm 13a (13b) is shorter than the distance L3 between the refrigerant pipe 31 and the suspension cross member 12a (rear suspension cross member 12a). In the event of a frontal collision, the lower arm 13a (13b) comes into contact with the block 23a (23b) and the rearward movement of the suspension member 10 stops, ensuring a gap in front of the refrigerant pipe 31. In the event of a frontal collision, the refrigerant pipe 31 is also protected.

[0019] (Second embodiment) A vehicle body underbody structure of a second embodiment will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a bottom view of a vehicle body 2a in which the vehicle body underbody structure of the second embodiment is adopted. Fig. 5 is a cross-sectional view taken along line VV in Fig. 4.

[0020] The vehicle underbody structure of the second embodiment has a reinforcing plate 40 added to the vehicle underbody structure of the first embodiment. The reinforcing plate 40 is connected to the suspension member 10 and the blocks 23a, 23b. The reinforcing plate 40 and the blocks 23a, 23b are connected by bolts 42. In addition, two tabs 41 extend rearward from the rear edge of the reinforcing plate 40. The tabs 41 extend below the battery case 20. Furthermore, several beads 43 are provided on the underside of the reinforcing plate 40.

[0021] The reinforcing plate 40 supports the suspension member 10 from behind in the event of a frontal collision. That is, the reinforcing plate 40 reduces the amount of rearward movement of the suspension member 10 in the event of a frontal collision. Adding the reinforcing plate 40 enhances the ability to protect the battery 30 in the event of a collision.

[0022] A plurality of beads 43 extending in the front-rear direction of the vehicle body are provided on the reinforcing plate 40. The plurality of beads 43 contribute to increasing the strength of the reinforcing plate 40.

[0023] A tab 41 on the rear edge of the reinforcing plate 40 extends along the underside of the battery case 20. During a frontal collision, the reinforcing plate 40 moves backward together with the suspension member 10. The retracting reinforcing plate 40 is guided by the tab 41 and slides under the battery case 20. The retracting reinforcing plate 40 is prevented from contacting the front plate 21 of the battery case 20. The retracting reinforcing plate 40 does not damage the battery case 20.

[0024] As described above, the vehicle underbody structure of the embodiment protects the battery 30 in the event of a frontal collision. In particular, in the vehicle underbody structure of the embodiment, the blocks 23a, 23b arranged immediately behind the lower arms 13a, 13b contribute greatly to protecting the battery 30.

[0025] Points to note regarding the techniques described in the embodiments are as follows. The blocks 23a and 23b are preferably lumps of metal. In the case of the vehicle underbody structure of the second embodiment, the blocks 23a and 23b also function as brackets that fix the reinforcing plate 40 to the battery case 20.

[0026] In the vehicle underbody structure of the embodiment, the frame 22 of the battery case 20 is fixed to a pair of rockers 4a, 4b. In the case of a vehicle body that employs long side members 3a, 3b, the frame 22 may be fixed to the side members 3a, 3b. In other words, it is sufficient that the frame 22 of the battery case 20 is fixed to either the rockers 4a, 4b or the side members 3a, 3b.

[0027] Although specific examples of the present invention have been described above in detail, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful. [Explanation of symbols]

[0028] 2, 2a: Body 3a, 3b: Side member 4a, 4b: Rocker 5a, 5b: Torque box 10: Front suspension member 11a, 11b: Suspension side beam 12a, 12b: Suspension cross member 13a, 13b: Lower arm 20: Battery case 21: Front plate 22: Frame 23a, 23b: Block 30: Battery 31: Refrigerant pipe 40: Reinforcement plate 41: Tab 42: Bolt 43: Bead

Claims

1. Front suspension member, a lower arm supported by the front suspension member; a battery case disposed behind the front suspension member and housing a battery; Equipped with the battery case includes a front plate and a frame extending in the left-right direction below the front plate, a block attached to a front portion of the frame so as to be located rearward of the lower arm;

2. The front suspension member includes a pair of suspension side beams whose front and rear ends are fixed to a vehicle body, and a suspension cross member connecting the pair of suspension side beams, 2. The vehicle underbody structure according to claim 1, wherein a distance between the block and the lower arm is shorter than a distance between the front plate and the suspension cross member.

3. a refrigerant pipe for supplying a refrigerant to a cooler for cooling the battery protrudes forward from the front plate; 3. The vehicle underbody structure according to claim 2, wherein a distance between the block and the lower arm is shorter than a distance between the refrigerant pipe and the suspension cross member.

4. The vehicle underbody structure according to claim 1 , further comprising a reinforcing plate connecting the front suspension member and the block.

5. The vehicle underbody structure according to claim 4 , wherein the reinforcing plate extends below the battery case.

6. 2. The vehicle underbody structure according to claim 1, wherein the frame is fixed to one of a side frame and a rocker of the vehicle body.

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