Upper case structure of battery pack, and battery pack support structure

Abstract

In an upper case (7) constituting a lid section of a battery pack (1) that is positioned below a seat (2) of a vehicle, a covering section of the lid section, said covering section covering an upper surface of the battery pack (1), is configured using two or more sheet members, an opening (11) is formed in a center section of a center sheet member (10), and the center sheet member (10) in which the opening (11) is formed has a thicker sheet thickness than another side sheet member (9).

Description

Upper Case Structure and Battery Pack Support Structure of Battery Pack

[0001] The present invention relates to an upper case structure and a battery pack support structure of a battery pack, and is particularly suitable for a battery pack disposed below a vehicle seat.

[0002] In Patent Document 1 below, an upper case constituting a lid portion of a battery pack having a substantially rectangular parallelepiped shape is composed of one plate member.

[0003] Japanese Patent No. 6510633

[0004] When disposing a main part of a battery pack such as a battery module below the front left and right seats, it becomes possible to use the inside of a console (console box) between the front left and right seats as a part of the battery pack. The positions (heights) in the vehicle up and down direction are different between below the seat and inside the console, with the former being low and the latter being high. Although the lid portion of the battery pack is called an upper case, in order to communicate between below the seat and inside the console, an opening is formed in the center portion in the vehicle width direction of this upper case, and devices (parts) other than the battery module can be arranged through this opening. In order to enhance the function as a battery pack, it is desired to make this opening as large as possible to secure the size of the devices that can be arranged in the opening. However, when the upper case is composed of one plate member as in Patent Document 1 above, if an opening is formed in the plate member, the rigidity of the plate member decreases. If the plate thickness of the entire plate member is increased to suppress this decrease in the rigidity of the plate member, it leads to an increase in the weight of the upper case, and thus an increase in the weight of the battery pack. If ribs are formed on the plate member of the upper case in order to suppress an increase in the weight of the upper case, the size of the entire upper case increases.

[0005] An object of the present invention is to provide an upper case structure and a battery pack support structure of a battery pack capable of forming an opening as large as possible in the center portion in the vehicle width direction of the upper case while suppressing an increase in the weight and size of the upper case.

[0006] One aspect of the present invention relates to an upper case structure that constitutes the lid of a battery pack located below the seat of a vehicle, wherein the covering portion of the upper surface of the battery pack in the lid is made up of two or more plate members, an opening is formed in the center of one of the plate members, and the plate member in which the opening is formed is thicker than the other plate members.

[0007] According to one aspect of the present invention, it is possible to form the largest possible opening in the vehicle width direction center of the upper case while suppressing an increase in the weight and size of the upper case. The object and advantages of the present invention are embodied and achieved using the elements and combinations thereof set forth in the claims. Both the above general description and the following detailed description are merely illustrative and explanatory and should be understood not to limit the present invention as in the claims.

[0008] This is a perspective view of an in-vehicle configuration showing one embodiment of the battery pack. This is an explanatory diagram of the battery pack arrangement. This is a perspective view of the battery pack coupled to the cross member. This is a perspective view of the battery pack alone. This is a perspective view of the battery pack with the upper case removed. This is a perspective view of the cover portion of the upper case. This is a rear view of the battery pack. These are cross-sectional views taken along lines B-B and C-C in Figure 7.

[0009] The battery pack 1 in the embodiment shown in Figure 1 is supported, as shown in Figure 2, by spanning across two vehicle body cross members 3 located on each side in the front-rear direction of the vehicle, below the front seats 2 of the vehicle. These cross members 3 are attached across the left and right side sills 31 in the passenger compartment, and front side members 32 protrude toward the front of the vehicle from both the left and right ends of the cross member 3 on the front side of the vehicle, and are connected to the side sills 31 at their respective protruding base ends. When this battery pack 1 is viewed in the A-A section of Figure 2a at the front seats 2, as shown in Figure 2b, the battery module 4, which is the main part of the battery pack 1, is located below each of the front left and right seats 2 in a part closer to the center in the vehicle width direction, and the center part of the battery pack 1 in the vehicle width direction protrudes into the (center) console (not shown) between the front left and right seats 2. The battery pack 1 is positioned away from the side sills 31, on the inside of the left and right side sills 31 in the vehicle width direction. The battery module 4 within the battery pack 1 is positioned between the floor carpet 33 and the floor panel 34 below the front seats 2. An under cover 37 is attached below the floor panel 34 to protect the battery pack 1 and other components.

[0010] Figure 3 shows the mounting structure (support structure) of the battery pack 1 to the two cross members 3. The battery pack 1 is separated from the left and right side sills 31 and is therefore attached to and supported by the cross members 3 only on the front-rear side of the vehicle. This prevents external forces from the side from directly acting on the battery pack 1, as will be described later. Figure 4 is a perspective view of the battery pack 1 alone after it has been removed from the cross member 3. As shown in Figure 5, the battery pack 1 is broadly divided into a lower case 6 which constitutes a housing with an open top surface and an upper case 7 which constitutes the lid of the lower case 6. The central part of the bottom surface of the lower case 6 in the vehicle width direction bulges upward over the entire front-rear direction of the vehicle in order to avoid the exhaust pipe EX (see Figure 2b) that is piped from the front of the vehicle. Therefore, the battery module 4, which requires the most volume, is housed in the parts of the lower case 6 on both sides in the vehicle width direction, excluding the central part in the vehicle width direction.

[0011] On the other hand, auxiliary components other than the battery module 4, such as the jacking box 35 and battery controller 36, are arranged in a stacked manner in the center of the lower case 6 in the vehicle width direction (see also the C-C section in Figure 8). One reason for these auxiliary components being positioned high is to keep them away from the exhaust pipe EX (and its heat). The upper parts of these auxiliary components are located above the upper end of the battery module 4 and protrude into the interior of the console. A resin console interior cover 8 is attached to the center of the upper case 7 in the vehicle width direction to cover the upper parts of these auxiliary components, and Figure 6 shows the upper case 7 in its standalone state with this console interior cover 8 removed. The upper case 7 has a covering portion that covers the opening top surface of the lower case 6, and this covering portion consists of three parts: two lateral plate members 9 that cover both sides in the vehicle width direction of the lower case 6 where the battery module 4 is housed, and one central plate member 10 that covers the center in the vehicle width direction of the lower case 6 where the auxiliary components are housed. However, since many of the auxiliary components protrude into the interior of the console, the central part of the central plate member 10 is largely open to allow them to pass through from below to above, forming an opening 11. In addition, brackets 12 made of individual plate members are attached to each of the vehicle's front-rear ends of the side plate members 9, and these brackets 12 are used to attach the side plate members 9 (together with the lower case 6) to the cross member 3. In contrast, the central plate member 10 does not have individual brackets attached for attachment to the cross member 3, and the central plate member 10 is directly attached to the cross member 3 (together with the lower case 6).

[0012] The side plate members 9, which are positioned to be housed below the front seats 2, do not require rigidity. Therefore, the thickness of these side plate members 9 is thin. In contrast, the central plate member 10 requires rigidity to ensure the rigidity of the central part in the vehicle width direction on the upper surface of the battery pack 1, and since a large opening 11 is provided in the center, the rigidity must be ensured by the remaining part of the central plate member 10 other than the opening 11. For this reason, the thickness of the central plate member 10 is greater than that of the side plate members 9, thereby ensuring rigidity with only the remaining part other than the opening 11. Furthermore, if the rigidity of the central part in the vehicle width direction of the battery pack 1 is improved in this way, the rigidity of the central part in the vehicle width direction of the vehicle body when the battery pack 1 is attached to the cross member 3 will also be increased. The central plate member 10 is fastened (connected) to the cross member 3 together with the lower case 6 by bolts inserted through through holes 38 provided at its front-rear end. In other words, a bracket for connecting to the cross member 3 is integrally formed on the central plate member 10. On the other hand, as mentioned above, brackets 12 made of thicker individual plate members (i.e., highly rigid) are welded to the vehicle's front-rear ends of the thin-walled side plate members 9, and the side plate members 9 are fastened (connected) to the cross member 3 together with the lower case 6 by bolts inserted through through holes 39 provided in these brackets 12. Of the three through holes 39, 39s provided in each bracket 12, the middle through hole 39s is a so-called service hole for inserting a carabiner or the like during assembly or maintenance. Furthermore, directly connecting the highly rigid central plate member 10 to the cross member 3 also serves to avoid the opening 11 becoming smaller due to structures such as overlapping plate materials when joining (welding) individual mounting brackets.

[0013] Stud bolts 40 with male threads protruding upward are attached to the connection (welding) portion between the central plate member 10 and the side plate member 9, and the console interior cover 8 is attached to the center of the upper case 7 in the vehicle width direction via these stud bolts 40. As mentioned above, this console interior cover 8 covers the auxiliary equipment that protrudes into the interior of the console, but as shown in the rear view of the battery pack 1 in Figure 7, a hole 41 is provided in the wall on the rear side of the vehicle, and an exhaust duct 42 extending toward the rear of the vehicle is provided through this hole 41 (see section C-C in Figure 8). For example, as shown in the section B-B in Figure 8, the battery modules 4 housed on both sides of the lower case 6 in the vehicle width direction are arranged in two rows so as to extend toward the front and rear of the vehicle, respectively, and the case interior duct 13 is provided between them. As shown in Figure 5, the internal duct 13 of the case is curved towards the rear of the vehicle at the center in the vehicle width direction and is connected to the exhaust duct 42 as shown in the cross-sectional view C-C in Figure 8. The outer end of the internal duct 13 in the vehicle width direction opens into the outer wall of the lower case 6 in the vehicle width direction, and the air drawn in from this opening 13a cools the inside of the battery pack 1, especially the battery module 4. In other words, by making the opening 11 of the central plate member 10 larger, a cooling path can be created that leads from the outside in the vehicle width direction of the lower case 6 below the front seat 2 to the inside of the console.

[0014] Figure 8 shows the connection points to the rear cross member 3 on the side plate member 9 and the connection points to the rear cross member 3 on the central plate member 10, indicated by dashed lines. These connection points are the connection points of the upper case 7 to the cross member 3, as well as the connection points of the battery pack 1 to the cross member 3. The connection points of the left and right side plate members 9 to the cross member 3 are the same in the vehicle's vertical direction, while the connection point of the central plate member 10 to the cross member 3 differs from the connection points of the side plate members 9 in the vehicle's vertical direction. In this example, the connection point of the battery pack 1 to the cross member 3 on the central plate member 10 is higher than the connection point of the battery pack 1 to the cross member 3 on the side plate member 9, so these connection points are not aligned in a straight line at the same height. As a result, the connection points of the battery pack 1 to the cross member 3 are not aligned in a straight line, and therefore the cross member 3 can support the battery pack 1 with high rigidity against external forces from various directions, improving the support rigidity of the battery pack 1 by the cross member 3.

[0015] The battery pack 1 and its support structure according to the embodiment have been described above, but the present invention is not limited to the configuration described in the above embodiment, and various modifications are possible within the scope of the gist of the present invention. For example, in the above embodiment, the cover portion was made up of three plate members: a central plate member 10 in the center in the vehicle width direction and side plate members 9 on both sides in the vehicle width direction. However, the present invention is based on making the thickness of the plate member for which the opening 11 is required greater than the thickness of the other plate members in order to ensure the rigidity of that plate member. Therefore, it is sufficient to have at least two plate members, one plate member for which the opening 11 is provided and the other plate members. An example in which the cover portion that covers the top surface of the battery pack 1, among the upper case 7 that constitutes the lid portion of the battery pack 1, is made up of two plate members, and an opening 11 is provided in one of the plate members, is a cover portion made up of a central plate member 10 positioned at the console in the above embodiment and one of the side plate members 9. Furthermore, it is possible to use a highly rigid material to ensure the rigidity of the central plate member 10 in which the opening 11 is formed. In this case, the side plate members 9, which do not require high rigidity, can be made of a material with less rigidity. In other words, the central plate member 10 and the side plate members 9 may be made of materials with different rigidities. For example, the central plate member 10 may be made of steel and the side plate members 9 may be made of resin, or the central plate member 10 may be made of aluminum and the side plate members 9 may be made of resin. By using such a material configuration, it is possible to effectively reduce the weight of the side plate members 9 in particular. In addition, the brackets 12 on both sides (left and right) in the vehicle width direction may be connected to reduce the number of plate members used in the upper case 7 (four or more). In this case, rigidity is required in the part where the side plate members 9 are connected to the cross member 3, so the plate thickness needs to be increased, but rigidity is not required in the central plate member 10, so the plate thickness in that part can be reduced, making it possible to achieve both improved vehicle body rigidity and reduced mass.

[0016] As described above, in this embodiment, in the upper case 7 which constitutes the lid of the battery pack 1 located below the vehicle seat 2, the covering portion of the upper surface of the battery pack 1 in the lid is made up of two or more plate members, and an opening 11 is formed in the center of the central plate member 10, and the central plate member 10 in which the opening 11 is formed is thicker than the other side plate members 9. This makes it possible to make the opening 11 as large as possible while ensuring the rigidity of the central plate member 10 in which the opening 11 is provided. In addition, it is possible to lighten the side plate members 9 that do not require the opening 11, thereby suppressing an increase in the weight of the upper case 7 or the battery pack 1.

[0017] Furthermore, the cover is constructed with three plate members: a central plate member 10 in the center of the vehicle width direction and lateral plate members 9 on both sides in the vehicle width direction. By forming an opening 11 in the central plate member 10 in the center of the vehicle width direction, and positioning the central plate member 10 in the console area, a battery pack storage space can be formed that connects the inside of the console with the space below the seat 2. In this case, by increasing the thickness of the central plate member 10, the opening 11 can be made as large as possible, thereby increasing the connecting space between the inside of the console and the space below the seat 2, and making it possible to accommodate larger parts and equipment in this area. In addition, by making the opening 11 of the central plate member 10 larger, a cooling path can be formed through this opening 11 that communicates from the space below the seat 2 to the inside of the console.

[0018] Furthermore, the central plate member 10 in the center of the vehicle width direction and the side plate members 9 on both sides in the vehicle width direction may be made of materials with different rigidities. By making the rigidity of the central plate member 10 greater than that of the side plate members 9, it is possible to effectively reduce the weight of the side plate members 9 in particular. In addition, by directly connecting the central plate member 10 in the center of the vehicle width direction to the cross member 3 of the vehicle body, the rigidity of the connection between the two is ensured, and an increase in weight can be avoided compared to the case where individual brackets that connect to the cross member 3 are joined to the central plate member 10. Also, the area of ​​the opening 11 becomes smaller because an area is required to join the individual brackets, but this can be avoided.

[0019] Furthermore, by connecting the side plate members 9 on both sides in the vehicle width direction to the vehicle body's cross member 3 via individual brackets 12, it is possible to ensure connection rigidity only at the connection points between the side plate members 9 and the cross member 3, thereby reducing the rigidity of the remaining parts as much as possible and enabling further weight reduction. In addition, the connection positions of the side plate members 9 on both sides in the vehicle width direction to the cross member 3 are the same in the vehicle's vertical direction, and the connection position of the central plate member 10 in the vehicle width direction to the cross member 3 differs from the connection positions of the side plate members 9 on both sides in the vehicle width direction to the cross member 3 in the vehicle's vertical direction. As a result, the connection positions of the battery pack 1 to the cross member 3 in the upper case 7 are not aligned in a straight line, and the support rigidity of the battery pack 1 by the cross member 3 is ensured.

[0020] Furthermore, by connecting the brackets 12 on both sides in the vehicle width direction and reducing the plate thickness of the connecting portion in the center in the vehicle width direction, it is possible to achieve both improved vehicle body rigidity and reduced mass. In addition, by connecting the battery pack 1 to the vehicle body's cross member 3 only on the front and rear sides of the vehicle, vehicle body rigidity is improved, and external forces from the outside in the vehicle width direction are prevented from directly acting on the battery pack 1.

[0021] 1...Battery pack, 2...Seat (front seat), 3...Cross member, 4...Battery module, 6...Lower case, 7...Upper case, 8...Console interior cover, 9...Side panel member, 10...Center panel member, 11...Opening, 12...Bracket, 13...Case interior duct

Claims

1. An upper case structure for a battery pack, comprising a cover portion for a battery pack located below the seat of a vehicle, wherein the cover portion for the upper surface of the battery pack in the cover portion is made up of two or more plate members, an opening is formed in the center of one of the plate members, and the plate member in which the opening is formed is thicker than the other plate members.

2. The upper case structure of a battery pack according to claim 1, characterized in that the cover portion is composed of three plate members: a plate member in the center in the vehicle width direction and plate members on both sides in the vehicle width direction thereof, and the opening is formed in the plate member in the center in the vehicle width direction.

3. The upper case structure of a battery pack according to claim 2, characterized in that the plate member in the center in the vehicle width direction and the plate members on both sides in the vehicle width direction are made of materials with different rigidities.

4. An upper case structure for a battery pack, characterized in that the plate member in the center of the vehicle width direction is connected to a cross member of the vehicle body.

5. The upper case structure of the battery pack according to claim 4, characterized in that a bracket connected to the cross member of the vehicle body is integrally provided on the plate member in the center in the width direction of the vehicle.

6. The upper case structure of the battery pack according to claim 4, characterized in that the plate members on both sides in the vehicle width direction are connected to the cross member of the vehicle body via individual brackets.

7. The upper case structure of a battery pack according to claim 6, characterized in that the connection positions of the plate members on both sides in the vehicle width direction to the cross member are the same in the vehicle vertical direction, and the connection position of the plate member in the center in the vehicle width direction to the cross member is different in the vehicle vertical direction from the connection positions of the plate members on both sides in the vehicle width direction to the cross member.

8. The upper case structure of the battery pack according to claim 1, characterized in that the upper case is composed of four or more plate members.

9. A battery pack support structure comprising an upper case according to any one of claims 1 to 8, wherein the battery pack is coupled to a cross member of the vehicle body only on the front rear side of the vehicle.

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