Electric vehicle frame

Abstract

To increase the size of a battery while preventing the battery from being damaged by the deformation of a side rail in a side collision.SOLUTION: The electric vehicle frame 2 is provided in the electric vehicle 1 driven by electric power supplied from the battery 9 disposed between the pair of side rails 3R, 3L extending in the vehicle front-rear direction, and includes the pair of side rails 3R, 3L and the plurality of cross members 4a to 4e coupling the side rails 3R, 3L to each other, the side rails 3R, each including the web portion 31 and the pair of flange portions 3233, protruding from the upper edge and the lower edge of the web portion 31 toward the center of the electric vehicle 1. 3L, A plate member 10 arranged in parallel with the web part 31 is fixed to both tips of the flange part 32,33, and the plate member 10 extends in a region corresponding to a position in the vehicle longitudinal direction of the battery 9 and a position in the vertical direction of the battery 9.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a frame for an electric vehicle that is suitable for use in an electric truck. [Background technology]

[0002] In recent years, electric vehicles using electric motors (hereinafter simply referred to as "motors") as a drive source have been developed not only for passenger cars but also for large vehicles with frames such as trucks. In order to extend the driving distance per charge for such electric vehicles such as trucks, studies are underway to increase the battery capacity (i.e., increase the battery size).

[0003] For example, Patent Document 1 discloses an invention relating to a frame for an electric truck that combines strength and rigidity to ensure the viability of the frame while also enabling an increase in the capacity of the battery placed between the side rails. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-196297 Summary of the Invention [Problem to be solved by the invention]

[0005] In an electric vehicle equipped with a ladder frame having side rails, if the battery is located between the side rails, it is necessary to take measures against a side collision, in which another vehicle collides with the side of the vehicle. One example of such a side collision measure is to ensure sufficient space between the side rails and the battery to prevent damage to the battery due to deformation of the side rails that may occur during a side collision.

[0006] However, considering the expected deformation of the side rail during a side collision, a considerable amount of space (e.g., several tens of mm) is required between the side rail and the battery. This space limits the expansion of the battery in the lateral direction of the vehicle, and also limits the increase in battery capacity, which is an issue.

[0007] This invention was conceived with a focus on these issues, and one of its objectives is to provide a frame for an electric vehicle in which a battery is placed between both side rails, which allows for a larger battery size while preventing the battery from being damaged by deformation of the side rails in the event of a side collision. [Means for solving the problem]

[0008] The present invention has been made to solve at least part of the above problems, and can be realized as the following aspects or application examples. The electric vehicle frame according to this application example is provided on an electric vehicle driven by power supplied from a battery arranged between a pair of side rails extending in the fore-and-aft direction of the vehicle, and comprises a pair of side rails and a plurality of cross members connecting the pair of side rails, wherein the side rails comprise a web portion and a pair of flange portions protruding towards the center of the vehicle from each of the upper and lower edges of the web portion, and plate members arranged parallel to the web portions are fixed to both ends of the pair of flange portions, and the plate members extend in an area corresponding to the position of the battery in the fore-and-aft direction of the vehicle and the vertical position of the battery.

[0009] According to this application example, plate members are fixed to both ends of the pair of flanges of the side rail, and are arranged parallel to the web portion. These plate members extend over an area corresponding to the position of the battery in the vehicle's fore-and-aft direction, so that the side rails located to the sides of the battery have a closed cross-sectional structure, improving their rigidity. As a result, deformation of the side rails in the event of a side collision by another vehicle is reduced, and the space between the side rails and the battery can be reduced, allowing for a larger battery.

[0010] Furthermore, because the plate member extends to an area corresponding to the vertical position of the battery, even in a case where the battery is extended to an area vertically below the lower end of the side rail, the side surface of the battery that protrudes downward from the side rail can be protected from being hit by flying stones, etc. Similarly, the side surface of the battery can be prevented from being directly hit by wind when the vehicle is stopped or when the vehicle is running, thereby preventing the battery from cooling down. [Effects of the Invention]

[0011] This technology reduces the space between the side rail and the battery, allowing for larger batteries, which in turn extends the driving distance per charge of electric vehicles. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a plan view of the frame for an electric vehicle according to the embodiment. [Figure 2] 2 is a cross-sectional view (a cross-sectional view taken along the line AA in FIG. 1) of the frame for an electric vehicle according to the embodiment. [Figure 3] 10 is a cross-sectional view (corresponding to FIG. 2) of a frame for an electric vehicle according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following embodiments will be described with reference to the drawings. The following embodiments are merely examples, and are not intended to exclude various modifications or applications of techniques not explicitly described in the embodiments. The configurations of the following embodiments can be modified in various ways without departing from the spirit of the invention. Furthermore, they can be selected or combined as needed.

[0014] The electric vehicle according to the embodiment described below is an electric truck equipped with a drive motor (hereinafter simply referred to as a "motor") as a drive source, and the electric vehicle frame according to the embodiment is a frame for an electric truck. However, the electric vehicle frame of this invention is not limited to trucks and can be applied to other electric vehicles as well. The electric vehicle includes not only those equipped with only a drive motor as a drive source, but also hybrid vehicles equipped with a motor and an engine (internal combustion engine) as a drive source, and hybrid vehicles equipped with only a motor as a drive source and also equipped with a generator engine.

[0015] 1 to 3, the vehicle is assumed to be on a horizontal plane, and the front of the vehicle is indicated by arrows as "FR," the rear of the vehicle is indicated by "RR," the right side in the vehicle width direction is indicated by "RH," the left side in the vehicle width direction is indicated by "LH," the vertically upward direction is indicated by "UP," and the vertically downward direction is indicated by arrows as "DW."

[0016] [1. Overall structure] As shown in FIG. 1, the electric truck 1 according to this embodiment includes an electric truck frame (hereinafter simply referred to as "frame") 2, a cab 5, a cargo box 6, front wheels 7, rear wheels 8, a drive unit (not shown) such as a drive motor, a drive power supply unit (not shown), a battery 9, and a power distribution unit (PDU; not shown).

[0017] The frame 2 has a pair of side rails, a left side rail 3L and a right side rail 3R (when there is no need to distinguish between them, they may simply be referred to as "side rails 3"), and multiple cross members 4a to 4e. The left side rail 3L and the right side rail 3R extend along the vehicle front-rear direction of the electric truck 1 and are arranged parallel to each other in the vehicle width direction. The multiple cross members 4a to 4e connect the left side rail 3L and the right side rail 3R at their respective positions. This makes the frame 2 a so-called ladder frame. The frame 2 supports a cab 5, a cargo box 6, a drive unit, a drive power supply unit, a battery 9, and other heavy objects mounted on the electric truck 1. The cab 5, which includes a driver's seat (not shown), is supported above the front of the frame 2, and the cargo box 6 is supported above the rear of the frame 2.

[0018] The left and right front wheels 7 and the left and right rear wheels 8, each consisting of dual tires, are suspended from the electric truck frame 2 via a suspension mechanism (not shown) and support the weight of the electric truck 1. Driving force is transmitted to the left and right rear wheels 8, and the rear wheels 8 function as drive wheels. Although not shown in detail, the drive unit has a motor, a reduction mechanism, and a differential mechanism. The motor receives AC power from a power distribution unit and generates the driving force required for the electric truck 1 to travel. The driving torque of this motor is reduced to a rotational speed suitable for vehicle travel and transmitted to the rear wheels 8, which are the drive wheels. This allows the electric truck 1 to travel.

[0019] The battery 9 is a secondary battery that mainly supplies power to the motor as an energy source for propelling the electric truck 1, and is provided with a plurality of relatively large, high-capacity battery modules inside its casing 9A to store the power required for the electric truck 1. In Figures 1 and 2, only the outer shape of the casing 9A of the battery 9 is shown, and the internal structure is not shown.

[0020] The battery 9 extends vertically downward from the lower ends of the side rails 3R, 3L, thereby increasing the size of the battery 9, i.e., increasing its capacity. In this embodiment, the casing 9A of the battery 9 is formed into a rectangular parallelepiped, but the shape of the casing 9A is not limited to this. The battery 9 is disposed between the side rails 3L, 3R and supported by the side rails 3L, 3R. The battery 9 also supplies power to a group of electric accessories (not shown) mounted on the electric truck 1.

[0021] [2. Main components of the electric truck frame] As shown in Figures 1 and 2, each side rail 3R, 3L has a web portion 31 extending in the longitudinal direction and vertical direction of the vehicle, and a pair of flange portions 32, 33 protruding from the upper and lower edges of the web portion 31 toward the vehicle center CL and extending in the longitudinal direction and width direction of the vehicle.

[0022] Plate members 10 are fixed to both ends of the pair of flange portions 32, 33 of each side rail 3R, 3L, and are arranged parallel to the web portion 31. In this embodiment, the plate members 10 are fixed to both ends of the flange portions 32, 33 by welding.

[0023] 1, the plate member 10 extends in a region corresponding to the position of the battery 9 in the vehicle longitudinal direction. That is, the plate member 10 extends in a region including the front end to the rear end of the casing 9A, specifically, in a region from a predetermined margin α1 in front of the front end of the casing 9A to a predetermined margin α2 behind the rear end of the casing 9A.

[0024] The primary purpose of the plate member 10 is to improve the rigidity of the side rail 3 so as to suppress deformation of the side rail 3 toward the battery 9 in the event of a side collision of the electric truck 1. In this case, the region of the side rail 3 where it is desired to improve the rigidity is the region extending from a margin α1 in front of the front end of the casing 9A to a margin α2 behind the rear end of the casing 9A, and the plate member 10 is required in this region. Note that the margin α1 and the margin α2 may be equal or different.

[0025] 2, the plate member 10 extends in a region corresponding to the vertical position of the battery 9. That is, the plate member 10 extends in a region including the upper end to the lower end of the casing 9A, specifically, in a region extending from a predetermined margin β1 above the upper end of the casing 9A to a predetermined margin β2 below the lower end of the casing 9A.

[0026] In addition to the first purpose described above, the plate member 10 has a second purpose of protecting the side of the battery 9 from flying stones and the like and of keeping the battery 9 warm by preventing wind from directly hitting the side of the battery 9 when the vehicle is stopped or when the vehicle is running. Thus, to protect and keep the battery 9 warm in addition to improving the rigidity of the side rail 3, the plate member 10 is required in an area extending from a predetermined margin β1 above the upper end of the casing 9A to a predetermined margin β2 below the lower end of the casing 9A. Note that the margins β1 and β2 may be equal or different.

[0027] In this embodiment, the plate member 10 includes a plate main body 11 and flange-like portions 12, 13 bent at the upper and lower edges thereof outward in the vehicle width direction. The flange-like portions 12, 13 are bent at approximately 45° outward in the vehicle width direction at portions corresponding to the margins β1, β2. This bending is intended to improve the rigidity of the plate member 10 while reducing its thickness (reducing its weight).

[0028] In this case, the extent of the area to be bent in the vertical direction and the angle of bending can be set as appropriate. In other words, increasing the bending area or the bending angle (approaching a right angle) can further improve the rigidity, but on the other hand, this will result in an increase in the size (weight) of the plate member 10. Therefore, it is preferable to set the size of the bending area and the bending angle taking these factors into consideration.

[0029] [3. Actions and Effects] The frame for an electric vehicle according to this embodiment is configured as described above, and can provide the following functions and effects.

[0030] Plate members 10, which are arranged parallel to the web portions 31, are fixed to both ends of a pair of flange portions 32, 33 of the side rails 3R, 3L, and these plate members 10 extend over an area corresponding to the position of the battery 9 in the vehicle's fore-and-aft direction. This gives the side rails 3R, 3L located to the sides of the portion where the battery 9 is located a closed cross-sectional structure, improving their rigidity. As a result, the amount of deformation of the side rails 3R, 3L in the event of a side collision by another vehicle is reduced, and the space S1 (distance d1) between the side rails 3R, 3L and the battery 9 can be reduced, allowing for larger batteries.

[0031] In particular, in this embodiment, the upper and lower edges of the plate member 10 are provided with flange-like portions 12, 13 that are bent outward in the vehicle width direction, so that the rigidity of the plate member 10 can be improved while reducing the thickness (weight) of the plate member 10, and the rigidity of the side rails 3R, 3L can be efficiently improved by the plate member 10. Furthermore, the bending direction of the flange-like portion 12 on the upper edge and the flange-like portion 13 on the lower edge of the plate member 10 is directed outward in the vehicle width direction, so that the leading edge of the bent plate member 10 is prevented from colliding with the battery 9 in the event of a side collision.

[0032] For example, FIG. 3 shows the space S2 (distance d2) between the side rails 3R, 3L and the battery 9 that is required when the plate member 10 is removed from the structure shown in FIG. Here, the thickness of the side rails 3R, 3L is set to about 4 to 5 mm, and the thickness of the plate member 10 is set to about 3 to 5 mm. In this case, the distance d2 required for the structure shown in Fig. 3 in which the plate member 10 is removed is about 55 mm, while the distance d2 required for the structure with the plate member 10 of this embodiment shown in Fig. 2 is about 25 mm. Even if the plate member 10 has a thickness of about 3 to 5 mm, the size of the battery 9 can be expanded by at least 25 mm in the width direction on one side alone, and 50 mm in total on both sides.

[0033] Furthermore, because the plate member 10 extends to an area corresponding to the vertical position of the battery 9, even in the present embodiment where the battery 9 extends to an area vertically below the lower ends of the side rails 3R, 3L, the plate member 10 covers the side surfaces of the battery 9 that extend downward from the side rails 3R, 3L. This protects the battery 9 from being hit by flying stones and the like. Similarly, the battery 9 can be kept warm by preventing the side surfaces from being directly hit by wind when the vehicle is stopped or when the vehicle is running, and the battery 9 can be prevented from cooling down.

[0034] [4. Other] The configuration of the above embodiment is merely an example, and can be appropriately modified and implemented without departing from the spirit of the present invention. For example, in the above embodiment, the casing 9A of the battery 9 is formed into a rectangular parallelepiped, but the shape of the casing 9A is not limited to this, and regardless of the shape of the casing 9A, the plate member 10 can be configured to extend in an area corresponding to the vehicle fore-and-aft position of the battery 9 and the vertical position of the battery 9, thereby achieving the same effect as the above embodiment. [Explanation of symbols]

[0035] 1. Electric trucks (electric vehicles) 2. Electric truck frame (electric vehicle frame, frame) 3 Side Rails 3L Left side rail 3R right side rail 4a~4e Cross members 5 Cab 6 packing boxes 7 Front wheels 8 rear wheels 9 Battery 9A Casing 10 Plate member 11 Plate body portion of plate member 10 12 flange-shaped portion of plate member 10 13 Flange-shaped portion of plate member 10 31 Side rail 3 web 32, 33 Flange portion of side rail 3 FR Front of vehicle RR rear of vehicle RH Right side of vehicle width LH Left side of vehicle width UP vertically upward DW Vertical downward S1, S2 Space between side rail 3 and battery 9 d1,d2 Distance between spaces S1 and S2 α1, α2 Margin in the front-rear direction of the vehicle β1, β2 Vertical margin

Claims

[Claim 1] An electric vehicle frame is provided in an electric vehicle driven by power supplied from a battery disposed between a pair of side rails extending in a vehicle front-rear direction, the electric vehicle frame comprising the pair of side rails and a plurality of cross members connecting the pair of side rails, The side rail includes a web portion and a pair of flange portions protruding from an upper edge and a lower edge of the web portion toward the center of the vehicle, Plate members are fixed to both ends of the pair of flange portions so as to be parallel to the web portion, The plate member extends in a region corresponding to the position of the battery in the vehicle front-rear direction and the position of the battery in the vertical direction. A frame for an electric vehicle.

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