Electric trucks

Abstract

In an electric truck, the protection performance of the battery pack during a collision is ensured while suppressing the increase in weight. An electric truck (3) is provided with a plurality of battery packs (4) each having a pair of first side surfaces (42, 43) facing the vehicle length direction (D1) in a manner adjacent to each other in the vehicle length direction (D1). The electric truck includes a battery side bracket (5) arranged on both sides of each battery pack (4) in the vehicle length direction (D1), and a frame side bracket (6) connecting the battery side bracket (5) and the longitudinal beam (21). Among the battery side brackets 5), the middle brackets (5A) adjacent to each other in the vehicle length direction (D1) are provided with lightweight holes on the facing surface (51) facing the first side surfaces (42, 43) of the battery pack (4). On the other hand, the outermost bracket (5B) arranged in the vehicle length direction (D1) is not provided with a lightweight hole on the facing surface (51).

Description

Technical Field

[0001] The present application relates to an electric truck equipped with multiple battery packs. Background Art

[0002] In the past, electric vehicles such as electric vehicles and hybrid vehicles have been developed to reduce environmental impact by supplying power from a driving battery to a motor. In recent years, electric vehicle development has also been progressing in the field of commercial vehicles such as trucks (see, for example, Patent Document 1). In order to reduce costs, research is underway to utilize the same general-purpose battery packs used in passenger vehicles in these electric commercial vehicles.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-113063 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, battery packs for passenger vehicles are designed to be mounted inside the vehicle body, resulting in relatively low load-bearing strength in the housing itself. Therefore, in electric trucks where such battery packs are mounted below the ladder frame, the support device (bracket) that supports the battery pack requires high load-bearing strength.

[0008] On the other hand, electric trucks are heavier than passenger cars and therefore require multiple battery packs similar to those used in passenger cars. Therefore, if only the aforementioned load-bearing strength requirements were considered, the total weight of the support system would likely increase, leading to an increase in the weight of the electric truck.

[0009] The present application has been made in view of the above-mentioned problems, and one of its objects is to ensure the protection performance of the battery pack during a collision in an electric truck while suppressing an increase in weight.

[0010] Means for solving problems

[0011] The present application is made to solve at least a part of the above-mentioned problems, and can be implemented as the following aspects or application examples.

[0012] (1) The electric truck involved in this application example is provided with a plurality of battery packs arranged adjacent to each other in the vehicle length direction, the battery packs are mounted below the longitudinal beam constituting the trapezoidal frame and have a pair of first side surfaces facing the vehicle length direction, and a pair of second side surfaces located at a position closer to the outside of the longitudinal beam in the vehicle width direction and facing the vehicle width direction, characterized in that the electric truck includes: a battery side bracket, the battery side bracket being arranged on both sides of each battery pack in the vehicle length direction and having an opposing surface facing the first side surface and a pair of extension surfaces extending from the upper and lower edges of the opposing surface and overlapping with the upper and lower surfaces of the battery pack; and a frame side bracket connecting the battery side bracket to the longitudinal beam, middle brackets of the battery side brackets adjacent to each other in the vehicle length direction are provided with lightweight holes on the opposing surfaces, and outer brackets arranged on the outermost sides in the vehicle length direction are not provided with lightweight holes on the opposing surfaces.

[0013] In this electric truck, during a side collision (lateral impact), the impact load is transferred from the impacted side to the opposite side via the battery-side bracket. This allows the impact load to be absorbed not only by components on the impacted side but also by components on the opposite side. This improves the protection of the battery pack during a side collision.

[0014] However, in the battery-side bracket, the corners between the facing surface and the extended surface (relatively high rigidity) primarily transmit side impact loads. Therefore, the central region of the battery-side bracket's facing surface, in the vehicle's height direction, does not contribute much to side impact load transmission. Furthermore, the facing surfaces of adjacent intermediate brackets are not exposed, making contact with other components less likely during a collision (front-end or side impact). Consequently, intermediate brackets do not require high load-bearing strength compared to outer brackets with exposed facing surfaces.

[0015] Therefore, by providing lightweight holes on the battery-side bracket's surface facing the intermediate bracket, the aforementioned side impact load transfer function is ensured while meeting load-bearing strength requirements and simultaneously reducing the weight of the intermediate bracket. Meanwhile, by not providing lightweight holes on the outer bracket's surface facing the battery-side bracket, the outer bracket's load-bearing strength is maintained. This ensures protection of the battery pack during a collision while minimizing weight gain.

[0016] (2) In the electric truck according to this application example, the outer bracket may have a device mounting portion on the facing surface for mounting an onboard device.

[0017] If the outer bracket has a device mounting portion, onboard devices can be mounted on the outer bracket's facing surface, thereby improving onboard device mounting capabilities. Furthermore, by transmitting the impact load to the onboard devices before it is transmitted to the outer bracket during a front-end collision of the electric truck, the initial impact load can be absorbed by the onboard devices before being absorbed by the outer bracket. This reduces the impact load transmitted to the battery pack via the outer bracket, thereby improving battery pack protection during front-end collisions.

[0018] (3) In the electric truck according to this application example, the on-vehicle equipment may be a power distribution device that distributes the electric power output from the battery pack to a plurality of auxiliary machines.

[0019] If the vehicle-mounted equipment mounted on the equipment mounting portion is a power distribution device, the power distribution device, as an associated device for the battery pack, can be mounted on an outer bracket near the battery pack, thereby improving wiring harness routing. Furthermore, the power distribution device can be moved together (integrally) with the battery-side bracket and battery pack, thereby improving the ease of installation and removal of the power distribution device.

[0020] (4) In the electric truck according to this application example, the intermediate bracket may be provided with the lightweight hole in a central region of the facing surface in the vehicle height direction.

[0021] By positioning the lightweight holes in the center of the facing surface in the vehicle height direction, rather than at the corner between the center bracket's facing surface and the extension surface, a decrease in rigidity at the corner between the facing surface and the extension surface can be prevented. This ensures that the center bracket's side impact load transfer function is more appropriately maintained, further reliably protecting the battery pack during a side impact.

[0022] (5) In the electric truck according to this application example, the arrangement of the lightweight holes in two adjacent intermediate brackets may be identical.

[0023] According to the arrangement of the lightweight holes, the same member can be applied as the two intermediate brackets, thereby achieving cost reduction. In addition, since the rigidity of the two adjacent intermediate brackets is equal to each other, the rigidity can be equalized.

[0024] (6) In the electric truck according to this application example, the arrangements of the lightweight holes in two adjacent intermediate brackets may be different from each other.

[0025] This arrangement of lightweight holes allows the area of ​​one intermediate bracket with lightweight holes to be reinforced using the area of ​​the other intermediate bracket without lightweight holes. This makes it easier to maintain rigidity at any position within the unit, while treating the two intermediate brackets as a single unit. Furthermore, while maintaining rigidity, the thickness reduction achieved by the lightweight holes can be increased (by enlarging the lightweight holes in each intermediate bracket), further reducing the weight of the intermediate brackets.

[0026] (7) The electric truck according to this application example may include a leaf spring suspension arranged adjacent to the outer bracket in the vehicle length direction.

[0027] In electric trucks equipped with leaf spring suspensions, there's a risk of contact between the leaf spring suspension and the outer bracket during a front-end collision. However, the outer bracket, which lacks lightweight holes on its facing surface as described above, ensures load-bearing strength. Therefore, even in the event of contact with the heavy leaf spring suspension, the impact on the battery pack is minimized. Consequently, the battery pack's protection during a front-end collision is ensured.

[0028] Effects of the Invention

[0029] According to the present application, in an electric truck, it is possible to ensure protection of the battery pack during a collision while suppressing an increase in weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a plan view of the main parts of the electric truck according to the embodiment.

[0031] Figure 2 This is an exploded perspective view of the battery pack, battery side bracket, and auxiliary bracket.

[0032] Figure 3 It is from Figure 1 The ladder frame and frame side brackets are omitted in the figure.

[0033] Figure 4 This is a rear view showing the two intermediate brackets exploded from top to bottom.

[0034] Figure 5 This is a rear view showing two intermediate brackets of a modified example broken down into two parts. Figure 4 corresponding figure).

[0035] Figure 6 This is a rear view showing two intermediate brackets of a modified example broken down into two parts. Figure 4 corresponding figure).

[0036] Figure 7 It is a front view (front or rear view) of the outer bracket.

[0037] Figure 8 It is a schematic cross-sectional view showing an example of a device mounting portion.

[0038] Figure 9 It is a schematic cross-sectional view showing an example of a device mounting portion. DETAILED DESCRIPTION

[0039] The embodiments of the present application are described with reference to the accompanying drawings. The following embodiments are merely illustrative and are not intended to exclude various modifications or technical applications not explicitly described in the embodiments. The various components of the following embodiments can be implemented with various modifications without departing from the scope of their main purpose. In addition, they can be selected or combined as needed.

[0040] [1. Composition]

[0041] [1-1. Overall composition]

[0042] like Figure 1 As shown, the electric truck 3 according to the present embodiment is an electric vehicle (electric vehicle, hybrid vehicle) having a ladder frame 2 and travels by supplying power stored in a plurality of driving battery packs 4 to a motor (not shown).

[0043] Hereinafter, the front-to-back direction of the electric truck 3 is also referred to as the vehicle length direction D1, and the left-to-right direction of the electric truck 3 is also referred to as the vehicle width direction D2. In addition, the up-down direction perpendicular to both the vehicle length direction D1 and the vehicle width direction D2 is also referred to as the vehicle height direction D3. In the accompanying drawings, the front is represented by "FR", the right is represented by "RH", and the top is represented by "UP". In addition, Figure 1 , the lower structure of the electric truck 3 is shown, and the upper structure (main body) arranged above the ladder frame 2 is omitted.

[0044] The ladder frame 2 is a member constituting the skeleton of the electric truck 3 and has high rigidity and strength. The ladder frame 2 includes a pair of longitudinal beams 21 extending in the vehicle length direction D1 and a plurality of transverse beams 22 extending in the vehicle width direction D2 and connecting the longitudinal beams 21 to each other.

[0045] A pair of longitudinal beams 21 are spaced apart from each other in the vehicle width direction D2. Each longitudinal beam 21 has a channel shape (U-shaped cross section) with a pair of plate-like flanges extending inward in the vehicle width direction D2 from the upper and lower edges of a plate-like web extending along the vehicle length direction D1 and the vehicle height direction D3.

[0046] The plurality of cross beams 22 are arranged to be separated from each other in the vehicle length direction D1. Figure 1 Although three cross beams 22 are illustrated in the figure, the number of cross beams 22 provided in the electric truck 3 is not particularly limited.

[0047] In the electric truck 3, a plurality of battery packs 4 are provided adjacent to each other in the vehicle length direction D1. In this embodiment, an electric truck 3 is illustrated in which two battery packs 4 are provided side by side in the vehicle length direction D1. The two battery packs 4 have the same configuration.

[0048] Each battery pack 4 is, for example, a general-purpose high-voltage battery pack used in passenger cars. In the electric truck 3, each battery pack 4 is mounted below a pair of longitudinal beams 21, projecting outward from each longitudinal beam 21 in the vehicle width direction D2. Here, a box-shaped battery pack 4 is illustrated, with its dimension in the vehicle height direction D3 being smaller (thinner) than its dimensions in the vehicle length direction D1 and the vehicle width direction D2. However, the shape of the battery pack 4 is not particularly limited.

[0049] Each battery pack 4 has a pair of first side surfaces 42 and 43, each facing in the vehicle length direction D1, and a pair of second side surfaces 41, each facing in the vehicle width direction D2. Hereinafter, the first side surface 42 facing forward will also be referred to as the "front surface 42," and the first side surface 43 facing rearward will also be referred to as the "rear surface 43."

[0050] The pair of second side surfaces 41 are respectively located outward in the vehicle width direction D2 relative to the pair of longitudinal beams 21. More specifically, the right second side surface 41 is located to the right of the right longitudinal beam 21, and the left second side surface 41 is located to the left of the left longitudinal beam 21.

[0051] As described above, the second side surface 41 of each battery pack 4 is disposed outside the side members 21 in the vehicle width direction D2. Therefore, the dimension in the vehicle width direction D2 is ensured to be larger than the distance between the webs of the side members 21. This increases the capacity of each battery pack 4.

[0052] Hereinafter, of the two battery packs 4 , the one arranged at the front is also referred to as the “front battery pack 4 ,” and the other one arranged at the rear is also referred to as the “rear battery pack 4 .”

[0053] In the electric truck 3 of this embodiment, leaf spring suspensions 1 are disposed in front of the front battery pack 4 and behind the rear battery pack 4. The leaf spring suspensions 1 are heavy elastic bodies formed by overlapping plate-shaped spring leaves, and they function to absorb vibrations transmitted from the wheels (not shown) to the longitudinal beams 21.

[0054] The leaf spring suspension 1, located in front of the front battery pack 4, is part of the front suspension and absorbs vibrations transmitted from the left and right front wheels to the left and right side members 21. Meanwhile, the leaf spring suspension 1, located behind the rear battery pack 4, is part of the rear suspension and absorbs vibrations transmitted from the left and right rear wheels to the left and right side members 21.

[0055] The electric truck 3 includes battery-side brackets 5 and frame-side brackets 6 as support devices for the battery packs 4. The battery-side brackets 5 are outer walls located on both sides (front and back) of each battery pack 4 in the vehicle length direction D1, protecting the battery packs 4 from impact loads. Meanwhile, the frame-side brackets 6 extend outward and downward from the longitudinal beams 21 in the vehicle width direction D2, suspending the battery packs 4 from the longitudinal beams 21.

[0056] The electric truck 3 of this embodiment is further equipped with an auxiliary bracket 7, which, together with the battery-side bracket 5 and the frame-side bracket 6, constitutes the aforementioned support device. The auxiliary bracket 7 is an outer wall disposed on both sides (left and right) of each battery pack 4 in the vehicle width direction D2, and has the function of protecting each battery pack 4 from impact loads. Thus, in this embodiment, the battery-side bracket 5 and the auxiliary bracket 7 are arranged to surround the battery pack 4 on all four sides, thereby accommodating the battery pack 4.

[0057] Here, refer to Figure 2 , illustrating a pair of battery side brackets 5 and a pair of auxiliary brackets 7 provided for one battery pack 4. Figure 2 In FIG. 4 , the rear battery pack 4 is exemplified as the battery pack 4 .

[0058] The battery-side bracket 5 and auxiliary bracket 7 are both formed from steel plates and have a channel shape (U-shaped cross-section). The pair of battery-side brackets 5 are identical (front-to-back symmetry) except for the facing surfaces 51 described later. Furthermore, the pair of auxiliary brackets 7 are also identical (left-to-right symmetry).

[0059] Each battery-side bracket 5 extends in the vehicle width direction D2. Each battery-side bracket 5 has a facing surface 51 that faces the first side surface 42, 43 (front surface 42 or rear surface 43) of the battery pack 4, and a pair of extension surfaces 52 that extend from the upper and lower edges of the facing surface 51 toward the battery pack 4. Specifically, the battery-side bracket 5 positioned on the front side of the battery pack 4 has a facing surface 51 that faces the front surface 42 of the battery pack 4, and a pair of extension surfaces 52 that extend rearward from the upper and lower edges of the facing surface 51. Furthermore, the battery-side bracket 5 positioned on the rear side of the battery pack 4 has a facing surface 51 that faces the rear surface 43 of the battery pack 4, and a pair of extension surfaces 52 that extend forward from the upper and lower edges of the facing surface 51.

[0060] The pair of extended surfaces 52 of each battery-side bracket 5 overlap the upper and lower surfaces of the battery pack 4. Specifically, the extended surface 52 extending from the upper edge of the facing surface 51 is positioned above the battery pack 4, while the extended surface 52 extending from the lower edge of the facing surface 51 is positioned below the battery pack 4.

[0061] Each auxiliary bracket 7 extends in the vehicle length direction D1. Each auxiliary bracket 7 has a web surface 71 that faces the second side surface 41 of the battery pack 4, and a pair of flange surfaces 72 that extend from the upper and lower edges of the web surface 71 toward the battery pack 4 (inward in the vehicle width direction D2). The pair of flange surfaces 72 of the auxiliary bracket 7 overlap with the pair of extended surfaces 52 of the battery-side bracket 5 and are connected to the extended surfaces 52 of the battery-side bracket 5 using a fixing member (not shown).

[0062] like Figure 1 As shown, the frame-side bracket 6 connects the battery-side bracket 5 to the longitudinal beam 21. In this embodiment, the frame-side bracket 6 is fixed to both the upper extension surface 52 of the battery-side bracket 5 and the web portion of the longitudinal beam 21, thereby connecting the battery-side bracket 5 to the longitudinal beam 21. The number of frame-side brackets 6 is not particularly limited, but this example shows two frame-side brackets 6 provided on each side of each battery pack 4 (a total of four per battery pack).

[0063] [1-2. Main components]

[0064] Figure 3 It is from Figure 1 The ladder frame 2 and the frame side bracket 6 are omitted. Figure 3 As shown, the battery-side bracket 5 includes two intermediate brackets 5A adjacent to each other in the vehicle length direction D1, and two outer brackets 5B arranged on the outermost sides in the vehicle length direction D1. Furthermore, the number of intermediate brackets 5A included in the battery-side bracket 5 is not limited to two. For example, in an electric truck with three battery packs 4 arranged adjacent to each other in the vehicle length direction D1, two sets of two intermediate brackets 5A (a total of four) are provided between adjacent battery packs 4.

[0065] The intermediate bracket 5A is a battery-side bracket 5 having a facing surface 51 disposed between the battery packs 4. Since the intermediate bracket 5A is adjacent to other intermediate brackets 5A, the facing surface 51 is not exposed.

[0066] On the other hand, the outer bracket 5B is a battery-side bracket 5 having a facing surface 51 arranged not only between the battery packs 4 but also in front of the frontmost battery pack 4 and behind the rearmost battery pack 4. The outer bracket 5B is not adjacent to other battery-side brackets 5, and the facing surface 51 is exposed. In the electric truck 3 of this embodiment, the leaf spring suspension 1 is arranged adjacent to the outer bracket 5B in the vehicle length direction D1.

[0067] like Figure 4As shown, lightweight holes 53 are provided on the facing surface 51 of the intermediate bracket 5A. Here, an example is shown in which three lightweight holes 53 of the same circular shape are arranged at equal intervals in the vehicle width direction D2 on the facing surface 51 of each intermediate bracket 5A. However, the shape, number, and arrangement of the lightweight holes 53 are not limited to those exemplified here.

[0068] The lightweight holes 53 of this embodiment are provided in the center bracket 5A, avoiding the corners formed by the facing surface 51 and the extended surface 52. In other words, the lightweight holes 53 are provided in the central region of the facing surface 51 of the center bracket 5A in the vehicle height direction D3 (the region of the facing surface 51 excluding the upper and lower edges).

[0069] The intermediate brackets 5A in this embodiment are all bilaterally symmetrical and identically formed. Furthermore, the lightweight holes 53 in the two adjacent intermediate brackets 5A are arranged identically. That is, the lightweight holes 53 in the two intermediate brackets 5A are arranged in mirror-image symmetry. Thus, in this embodiment, the lightweight holes 53 provided in the two intermediate brackets 5A completely overlap when viewed in the vehicle length direction D1.

[0070] On the other hand, Figure 5 、 6 As shown, the two intermediate brackets 5A may also have different configurations of the lightweight holes 53. Figure 5 , an example is shown in which a plurality of lightweight holes 53 arranged at equal intervals in the vehicle width direction D2 are arranged in two intermediate brackets 5A, 5A and staggered by half a pitch. Figure 6 , an example is shown in which a light-weight hole 53 is provided in the left half of one intermediate bracket 5A and the right half of the other intermediate bracket 5A. Figure 5 The circular lightweight hole 53 is shown in FIG. Figure 6 Although the lightweight holes 53 are exemplified as being in an oval shape, the shape of the lightweight holes 53 is not limited to these examples.

[0071] As in Figure 5 、 6 As indicated by the two-dot chain line, the lightweight holes 53 in the two intermediate brackets 5A of the modified example are not mirror-symmetrical. Therefore, the lightweight holes 53 provided in the two intermediate brackets 5A do not overlap when viewed in the vehicle length direction D1 (specifically, they are offset in the vehicle width direction D2).

[0072] With respect to the intermediate bracket 5A provided with the lightweight hole 53, as shown in FIG. Figure 7As shown, the facing surfaces 51 of the outer brackets 5B are not provided with lightweight holes. Therefore, the facing surfaces 51 of the outer brackets 5B are ensured to have higher rigidity and strength than the facing surfaces 51 of the intermediate brackets 5A. In other words, by providing the lightweight holes 53 in each intermediate bracket 5A, the rigidity and strength are reduced compared to the outer brackets 5B without lightweight holes.

[0073] Here, if Figure 3 As shown, two adjacent intermediate brackets 5A are considered a single intermediate unit 50. In this embodiment, the rigidity of one intermediate unit 50 is set equal to the rigidity of one outer bracket 5B. This rigidity setting can be achieved, for example, by appropriately adjusting the material, thickness, and shape of each battery-side bracket 5 (intermediate bracket 5A and outer bracket 5B). Furthermore, the rigidity of the intermediate unit 50 can also be adjusted by varying the shape, number, and arrangement of the lightweight holes 53 provided on the facing surface 51.

[0074] like Figure 3 As shown by the double-dashed line in FIG, the outer bracket 5B may also include a device mounting portion 9 for mounting an onboard device 10 on the facing surface 51. As the onboard device 10 mounted on the device mounting portion 9, for example, a power distribution unit (PDU) that distributes the power output from the battery pack 4 to a plurality of auxiliary devices can be cited. Figure 3 and the following Figure 8 、 9 , the device mounting portion 9 is shown as being provided on the outer bracket 5B arranged on the front side of the front battery pack 4 , but the device mounting portion 9 may be provided on the outer bracket 5B arranged on the rear side of the rear battery pack 4 instead of (or in addition to) this.

[0075] The device mounting portion 9 is a location where the vehicle-mounted device 10 is mounted and has a structure capable of mounting the vehicle-mounted device 10. Figure 8 、 9 As shown in FIG, the device mounting portion 9 may also include a welding bolt 91 and a welding nut 94 for mounting the vehicle-mounted device 10 on the facing surface 51 of the outer bracket 5B.

[0076] like Figure 8 As shown, weld bolt 91 includes a head portion 92 welded to the inner side of facing surface 51 (on the battery pack 4 side) and a threaded portion 93 projecting from head portion 92 outward from facing surface 51 (on the side away from battery pack 4). Specifically, weld bolt 91 is fixed to the inner side of facing surface 51 with threaded portion 93 inserted from the battery pack 4 side through hole 55 extending through facing surface 51 of outer bracket 5B.

[0077] The threaded portion 93 of the welding bolt 91 is inserted into a through hole (not shown) formed in the vehicle-mounted device 10 (or its bracket, etc.) and then fastened to the nut 14. Thus, the vehicle-mounted device 10 is mounted on the device mounting portion 9 including the welding bolt 91.

[0078] like Figure 9 As shown, the weld nut 94 is welded to the inner side of the facing surface 51. Specifically, the weld nut 94 is fixed to the inner side of the facing surface 51 in a state where it is arranged coaxially with the hole portion 55.

[0079] The weld nut 94 is fastened to the bolt 15 inserted from the outside into a through hole (not shown) formed in the vehicle-mounted device 10 (or its bracket, etc.).

[0080] The method for mounting the vehicle-mounted device 10 on the device mounting portion 9 is not limited to the method using the welded bolts 91 and welded nuts 94 described above; various known methods can be applied. For example, the vehicle-mounted device 10 can be mounted on the device mounting portion 9 using conventional bolts and nuts (not shown) that are not welded to the facing surface 51. Alternatively, the vehicle-mounted device 10 can be directly welded to the device mounting portion 9.

[0081] [2. Function and Effect]

[0082] (1) The battery side brackets 5 disposed on both sides of each battery pack 4 in the vehicle length direction D1 enable the side impact load to be transferred from the impacted side to the opposite side along the vehicle width direction D2 during a side impact of the electric truck 3. This allows the side impact load to be absorbed not only by components on the impacted side (e.g., either left or right longitudinal beam 21, frame side brackets 6, auxiliary bracket 7), but also by components on the opposite side of the impacted side, thereby improving the protection of the battery pack 4 during a side impact.

[0083] However, the side impact load is mainly transmitted to the relatively rigid portion of the battery side bracket 5. Specifically, the side impact load is mainly transmitted along the vehicle width direction D2 through the corner of the facing surface 51 and the extension surface 52. Therefore, the central area of ​​the facing surface 51 of the battery side bracket 5 in the vehicle height direction D3 does not contribute much to the transmission of the side impact load. In addition, in the adjacent middle brackets 5A in the battery side bracket 5, the facing surface 51 is not exposed. Therefore, even in the event of a collision of the electric truck 3, it is difficult for the middle bracket 5A to come into contact with other components (components other than the middle bracket 5A). Therefore, compared with the outer bracket 5B with the facing surface 51 exposed, the middle bracket 5A is not required to have high load resistance strength.

[0084] Therefore, by providing lightweight holes 53 on the facing surface 51 of the intermediate bracket 5A in the battery-side bracket 5, the side impact load transfer function can be ensured as described above, while also meeting the required load-bearing strength, while also reducing the weight of the intermediate bracket 5A. Meanwhile, by not providing lightweight holes on the facing surface 51 of the outer bracket 5B, the load-bearing strength of the outer bracket 5B can be ensured. Therefore, even if the outer bracket 5B comes into contact with other components during a front-to-rear collision of the electric truck 3, the impact on the battery pack 4 can be reduced. Thus, according to the electric truck 3, the protection performance of the battery pack 4 during collisions (side and front-to-rear collisions) can be ensured while suppressing increased weight.

[0085] When the rigidity of each battery-side bracket 5 (the middle bracket 5A and the outer bracket 5B) is equal, the rigidity of the middle unit 50 formed by two adjacent middle brackets 5A is higher than the rigidity of a single outer bracket 5B that is not adjacent to the other battery-side brackets 5. Therefore, an imbalance in rigidity occurs between the area where the middle unit 50 is provided and the area where the single outer bracket 5B is located, potentially leading to differences in the side impact load transfer function.

[0086] In contrast, in the electric truck 3, each intermediate bracket 5A is formed to have lower rigidity than each outer bracket 5B by means of lightweight holes 53. This suppresses the aforementioned imbalance in rigidity. Consequently, both the area where the intermediate unit 50 is located and the area where the outer brackets 5B are positioned can adequately transmit side impact loads. Consequently, the battery pack 4 can be more effectively protected during a side impact.

[0087] Furthermore, in the electric truck 3, the second side surface 41 of the battery pack 4 is located outboard of the longitudinal beam 21 in the vehicle width direction D2, thereby enabling a larger capacity battery pack 4. However, in the event of a side impact, the side impact load may be transmitted to the second side surface 41 of the battery pack 4 before being transmitted to the longitudinal beam 21, thus requiring improved protection of the battery pack 4. To address this issue, the battery side bracket 5 ensures the side impact load transmission function and meets the load-bearing strength requirements, thereby enabling a larger capacity battery pack 4 while ensuring protection of the battery pack 4 during a side impact.

[0088] (2) According to the outer bracket 5B having the device mounting portion 9, since the vehicle-mounted device 10 is mounted on the facing surface 51 of the outer bracket 5B, the mounting performance of the vehicle-mounted device 10 can be improved. In addition, during a front-to-rear collision of the electric truck 3, by inputting the impact load to the vehicle-mounted device 10 before inputting it to the outer bracket 5B, the initial input of the impact load can be absorbed by the vehicle-mounted device 10 before being absorbed by the outer bracket 5B. As a result, the impact load transmitted to the outer bracket 5B can be reduced, and therefore the impact load transmitted to the battery pack 4 through the outer bracket 5B can also be reduced. Therefore, the protection performance of the battery pack 4 during a front-to-rear collision can be improved.

[0089] (3) If the vehicle-mounted equipment 10 mounted on the equipment mounting portion 9 is a power distribution device that distributes the power output from the battery pack 4 to a plurality of auxiliary machines, the power distribution device, which is an associated device of the battery pack 4, can be mounted on the outer bracket 5B near the battery pack 4. Therefore, for example, the routing of the wiring harness connecting the battery pack 4 to the power distribution device can be improved. In addition, when the battery pack 4 supported by the battery side bracket 5 is removed from the longitudinal beam 21, the power distribution device is moved together with the battery side bracket 5 and the battery pack 4 (integrally). Therefore, the installation and removal workability of the power distribution device can be improved.

[0090] (4) The intermediate bracket 5A, which has a lightweight hole 53 in the center region of the facing surface 51 in the vehicle height direction D3, can prevent a decrease in rigidity at the corner between the facing surface 51 and the extended surface 52. Consequently, the intermediate bracket 5A can more appropriately ensure the transmission function of the side impact load. Consequently, the protection performance of the battery pack 4 during a side impact can be more reliably ensured.

[0091] (5) If the arrangement of the lightweight holes 53 in two adjacent intermediate brackets 5A is identical, the same components can be used for these intermediate brackets 5A. This can reduce costs. In addition, since the rigidity of the two adjacent intermediate brackets 5A is equal, the rigidity can be equalized.

[0092] (6) In contrast, if the configurations of the lightweight holes 53 in the two adjacent intermediate brackets 5A are different from each other, the portion of the intermediate bracket 5A on one side having the lightweight holes 53 can be reinforced by using the portion of the intermediate bracket 5B on the other side having no lightweight holes 53. Thus, it is easy to ensure rigidity at any position of the intermediate unit 50 in which the two intermediate brackets 5A are combined into one, thereby suppressing local deformation of each intermediate bracket 5A even in the event of a collision with the electric truck 3. Furthermore, as described above, it is possible to ensure rigidity throughout the entire area of ​​the intermediate unit 50 and increase the amount of thinning caused by the lightweight holes 53 (by enlarging the lightweight holes 53 in each intermediate bracket 5A), thereby achieving further lightweighting of the intermediate bracket 5A.

[0093] (7) In an electric truck 3 in which the leaf spring suspension 1 is arranged adjacent to the outer bracket 5B in the vehicle length direction D1, there is a possibility that the leaf spring suspension 1 and the outer bracket 5B may come into contact during a front-to-rear collision. In contrast, the outer bracket 5B, which does not have a lightweight hole in its facing surface 51 as described above, can ensure load-bearing strength. Therefore, even in the event of contact with the heavy leaf spring suspension 1, the impact of the leaf spring suspension 1 on the battery pack 4 can be reduced. Consequently, the protection performance of the battery pack 4 during a front-to-rear collision can be ensured.

[0094] [3. Modifications]

[0095] The configuration of the electric truck 3 described above is merely an example. Alternatively, three or more battery packs 4 may be arranged adjacent to each other in the vehicle length direction D1 in the electric truck 3. Even in this case, by providing lightweight holes 53 on the facing surfaces 51 of the adjacent intermediate brackets 5A in the vehicle length direction D1 and omitting lightweight holes on the facing surfaces 51 of the outer brackets 5B, which are positioned outermost in the vehicle length direction D1. This ensures the protection of the battery packs 4 during a collision while suppressing increased weight, similar to the above-described embodiment.

[0096] The configuration, arrangement, and number of the frame-side brackets 6 are not limited to the above-described examples.

[0097] The specific structure of the equipment mounting portion 9 is not limited to the above-described example. The equipment mounting portion 9 may include both the weld bolts 91 and the weld nuts 94, or may include a structure other than the weld bolts 91 and the weld nuts 94. Furthermore, the vehicle-mounted equipment 10 mounted on the equipment mounting portion 9 is not limited to the power distribution device described above, and various equipment mounted on the electric truck 3 may be employed.

[0098] The leaf spring suspension 1 can also be omitted. According to the above-mentioned outer bracket 5B, the lack of lightweight holes in the facing surface 51 ensures load-bearing strength. Therefore, even if it contacts components other than the leaf spring suspension 1 during a front-to-rear collision, the impact on the battery pack 4 can be reduced.

[0099] Description of Reference Numerals

[0100] 1 leaf spring suspension

[0101] 2 ladder frame

[0102] 3 Electric Trucks

[0103] 4 battery packs

[0104] 5 Battery side bracket

[0105] 5A intermediate bracket

[0106] 5B Outer bracket

[0107] 6 Frame side brackets

[0108] 7 Auxiliary bracket

[0109] 9 Equipment mounting section

[0110] 10 Vehicle-mounted equipment

[0111] 14 Nut

[0112] 15 bolts

[0113] 21 longitudinal beam

[0114] 22 beam

[0115] 41 Side 2

[0116] 42 front surface (first side)

[0117] 43 rear surface (first side)

[0118] 50 intermediate units

[0119] 51 Opposite surface

[0120] 52 Extended Surface

[0121] 53 Lightweight Holes

[0122] 55 hole

[0123] 71 Beam belly

[0124] 72 flange surface

[0125] 91 welding bolts

[0126] 92 Head

[0127] 93 threaded part

[0128] 94 Weld Nut

[0129] D1 Vehicle length direction

[0130] D2 Vehicle width direction

[0131] D3 vehicle height direction

Claims

1. An electric truck comprising a plurality of battery packs arranged adjacent to each other in a vehicle length direction, wherein the battery packs are mounted below a longitudinal beam constituting a ladder frame and have a pair of first side surfaces facing the vehicle length direction and a pair of second side surfaces facing the vehicle width direction, wherein: The electric truck includes: a battery side bracket, the battery side bracket being arranged on both sides of each battery pack in the vehicle length direction and having an opposing surface opposing the first side surface and a pair of extending surfaces extending from upper and lower edges of the opposing surface and overlapping with the upper and lower surfaces of the battery pack; a frame side bracket connecting the battery side bracket and the longitudinal beam, Among the battery-side brackets, adjacent intermediate brackets in the vehicle length direction have lightweight holes on their facing surfaces, while outer brackets disposed outermost in the vehicle length direction have no lightweight holes on their facing surfaces.

2. The electric truck according to claim 1, characterized in that: The outer bracket has a device mounting portion on the facing surface for mounting an in-vehicle device.

3. The electric truck according to claim 2, characterized in that: The in-vehicle equipment is a power distribution device that distributes the electric power output from the battery pack to a plurality of auxiliary machines.

4. The electric truck according to any one of claims 1 to 3, characterized in that: The intermediate bracket is provided with the lightweight hole in a central area of ​​the facing surface in the vehicle height direction.

5. The electric truck according to claim 1, wherein: In two adjacent intermediate brackets, the configurations of the lightweight holes are identical.

6. The electric truck according to claim 1, characterized in that: In two adjacent intermediate brackets, the arrangements of the lightweight holes are different from each other.

7. The electric truck according to claim 1, characterized in that: The electric truck includes a leaf spring suspension disposed adjacent to the outer bracket in the vehicle length direction.

8. The electric truck according to claim 1, wherein: The pair of second side surfaces are located on the vehicle width direction outer side of the longitudinal beam.

Images