Structure for electric vehicle

Abstract

A combined chassis-body structure for an electric vehicle, the structure having an outer framework (10) in frameless form, comprising: four electric drive unit sockets (12), each having a bottom access and accommodating therein an electric drive unit (20), where each electric drive unit (20) comprises a support structure (21) for supporting the outer framework (10); the electric motor housing (23) and the suspension (24) having the drive wheel (25) are connected to the support structure, wherein the support structure (21) of the electric drive unit (20) is connected to the support structure (121) of the corresponding socket (12); a support (13) of the battery pack, which has a bottom inlet and accommodates the battery pack (30) therein; and an outer surface (11) forming the outer contour of the chassis and the lower part of the body of the vehicle and adapted to place the cockpit (17) on top of the outer surface (11); wherein the support (13) for the battery pack (30), the electric drive unit socket (12) and the outer surface (11) are formed as two separate, separate integral elements (10A, 10B) of the outer framework (10) coupled together along the longitudinal axis of the vehicle.

Description

Technical Field

[0001] The present invention relates to a structure for an electric vehicle, in particular an electric truck. Background Art

[0002] Electric vehicles require batteries to provide energy for the electric propulsion system. The larger the battery, the more energy can be provided, resulting in increased utilization of the vehicle and increasing its range. This is especially important for long-haul trucks. In addition, there is continued development in solutions to utilize the available charge at the battery that is not yet used for standard driving purposes, making it even more important to maximize the battery capacity.

[0003] The vehicle chassis is the structure that structurally supports the body of the vehicle and holds its important equipment such as the engine, transmission, drive shafts, differentials, suspension, cargo hold, and cockpit located on top of it. A typical chassis is constructed as a metal frame. Equipment is mounted to the frame by a number of bolts.

[0004] Electric vehicles require a battery pack (or a group of batteries) with as large a capacity as possible to be installed in the vehicle. The size of a battery is proportional to its capacity; therefore an electric truck needs to include a very heavy and very large battery. Such a battery should preferably be installed under the chassis to lower the center of gravity of the vehicle, to simplify maintenance of the battery, and to provide safety data such as in the event of a side collision.

[0005] The presence of a metal frame conflicts with the need to maximize battery size. Space for batteries is limited in a frame-based chassis for electric vehicles, and various solutions have been proposed to accommodate larger batteries.

[0006] For example, European patent application EP3964426A1 discloses a structure in which the battery is placed between the side beams of the truck frame. However, the battery size is limited by the available space between the beams of the frame. The capacity is further reduced due to side impact protection in the event of a collision. The battery housing must support the impact forces which reduce the volume capacity within the battery pack itself.

[0007] Chinese utility model CN205930892U discloses a structure for an electric truck chassis, where the battery is placed on the chassis, which is intended to reduce collision impacts through a layered structure with honeycomb layers. There is no frame, and the battery can occupy the entire width of the chassis. Although this solution has no frame, a chassis on which the battery is placed is still required.

[0008] US patent application US2021155292A1 discloses a vehicle exoskeleton composed of multiple formed metal sheets, but the exoskeleton is mounted on a frame.

[0009] European patent application EP3647165 discloses an integrated chassis for electric vehicles (but not for trucks or semi-trailer vehicles), which includes a left frame, a right frame, at least one lower structural member, and a plurality of upper structural members connected to the left frame and the right frame and extending across them. The lower structural member provides support for one or more rechargeable battery packs. Summary of the invention

[0010] There is a need to provide a novel structure for an electric vehicle that will provide more space to accommodate batteries than a standard frame-based chassis.

[0011] The present invention provides a structure for an electric vehicle, wherein the space between the wheels and the side of the vehicle is maximized for the maximum capacity of the battery. This is achieved by a design in which a frameless exoskeleton is used instead of a typical frame-based chassis, wherein the battery is used as part of the exoskeleton structure. The structural strength is achieved by the shape of the outer surface (preferably composed of two exoskeleton members manufactured by deep drawing, additive manufacturing or injection molding processes) and the battery itself together with the front electric drive unit (EDU) and the rear electric drive unit. The structural battery pack and EDU in the center of the chassis increase the stiffness and strength of the entire exoskeleton structure. In addition, the center of gravity is balanced in the vehicle. The suspended mass of the ICE / DIESEL truck no longer exists. The possibility of oversteering and understeering is significantly reduced by the centered structural battery layout. Relative to traditional flat head (cabinover engine, COE) and long-distance truck designs, the roll caused by strong side winds during turning and vehicle movement is further reduced by the lowered center of gravity. The battery does not require a separate frame for its protection, so the space in the exoskeleton can be effectively used to accommodate the battery unit. The battery pack and the electric drive unit can be conveniently installed in the exoskeleton structure via the electric drive unit socket and the access at the bottom of the battery pack support, thus facilitating the maintenance of the vehicle. The electric drive unit is integrated with the electric motor housing, the suspension and the wheels, which can be removed from the exoskeleton as a separate part to be repaired, and another part can be inserted instead for quick maintenance. The outer surface of the exoskeleton forms the outer contour of the chassis and the lower part of the body of the vehicle, and is suitable for placing the cockpit on top of the outer surface - this design is universal and allows various cockpits to be placed on the same type of exoskeleton structure. The cockpit is located on the top side of the exoskeleton structure and does not limit the possibility of servicing the electric drive unit or the battery pack, which are accessible from the bottom side.

[0012] The object of the present invention is a combined chassis-body structure for an electric vehicle, which has an exoskeleton in a frameless form, comprising: four electric drive unit sockets, each of which has a bottom entrance and accommodates an electric drive unit therein, wherein each electric drive unit comprises a supporting structure, to which an electric motor housing and a suspension with a drive wheel are connected, wherein the supporting structure of the electric drive unit is connected to the supporting structure of the corresponding socket; a support for a battery pack, which has a bottom entrance and accommodates the battery pack therein; and an outer surface, which forms the outer contour of the chassis and the lower part of the vehicle's body and is suitable for placing a cockpit on top of the outer surface; wherein the support for the battery pack, the electric drive unit socket and the outer surface are formed as two separate, individual integral elements of the exoskeleton coupled together along the longitudinal axis of the vehicle.

[0013] The elements of the exoskeleton may be formed at least partially by an injection molding process and / or at least partially by deep drawing and / or at least partially by additive manufacturing.

[0014] The mount may include a longitudinal bar for mounting the battery pack.

[0015] The invention also relates to an electric vehicle comprising a structure according to any of the preceding claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The invention is herein presented by way of example embodiments in the accompanying drawings, in which:

[0017] Figure 1A A top view of the structure is shown;

[0018] Figure 1B A bottom view of the structure is shown;

[0019] Figure 2A shows a top view of the structure with a battery pack and an electric drive unit mounted therein;

[0020] Figure 2B shows a top view of the structure with a battery pack and an electric drive unit mounted therein;

[0021] Figure 3 The structure is shown assembled from two parts;

[0022] Figure 4A shows a pair of EDUs, Figure 4B A single EDU is shown;

[0023] Figure 5 A first example of a vehicle including the structure is shown;

[0024] Figure 6 A second example of a vehicle including the structure is shown. DETAILED DESCRIPTION

[0025] An example implementation of the structure is Figure 1A and 1B is shown separately in Figure 2A and 2B 1 is shown together with the electric drive unit and the battery pack. It has an exoskeleton 10 in frameless form, i.e. an external skeleton that serves as a support for the electric drive unit (EDU) 20 and the battery pack 30 and its cover. The exoskeleton 10 thus provides the combined functions of a conventional vehicle frame, chassis and body part. The EDU 20 is mounted in the electric drive unit socket 12 and the battery pack 30 is mounted in the battery pack support 13. The outer surface 11 forms the outer contour of the vehicle chassis, i.e. it covers the inner volume of the exoskeleton on the sides and on the top (i.e. it serves as the body of a standard vehicle).

[0026] In particular, the outer surface 11 is integrally formed with a battery pack support 13 for accommodating the battery pack 30 and an electric drive unit socket 12 for accommodating the EDU 20. The outer frame is composed of two separate, individual integral components 10A, 10B, such as Figure 3 As shown, they are coupled together along the longitudinal axis of the vehicle. Such separate elements 10A, 10B can be manufactured by suitable techniques, such as deep drawing of steel sheets or injection molding or 3D printing of plastics, and then coupled together, for example, by welding or form-filling fasteners. By forming the entire exoskeleton 10 as two elements, the overall manufacturing complexity is limited and the assembly of the vehicle becomes faster (e.g., fewer bolts are required to assemble the vehicle).

[0027] The exoskeleton may include various reinforcing elements, such as bends 15 or ribs 16 that reinforce its outer profile. However, in addition to the internal structural features of the exoskeleton, its structure is significantly strengthened by mounting the EDU 20 and battery pack 20 therein.

[0028] In particular, if Figure 4A , 4BAs shown, a pair of EDUs 20A, 20B are mechanically fixed to each other to form a single unit defining the vehicle axis. In this case, once the EDUs 20A, 20B are installed in their corresponding electric drive unit sockets 12 within the exoskeleton, the exoskeleton is additionally reinforced over the width of the vehicle. In order to provide a more stable connection, each EDU 20 has a pair of support structures 21 for connecting to the corresponding support structures 121 at the electric drive unit sockets 12, wherein the support structures 21, 121 are joined together at multiple points, for example, by mounting bolts. Each electric drive unit 20 includes a support structure 21 connected to an electric motor housing 23 (which contains an electric motor and gearbox components, if present) and a suspension 24 (including shock absorbers 22) having a drive wheel 25. Therefore, since the two EDUs 20A, 20B at the same axis are connected to the exoskeleton 10 at multiple points and can be further connected together, for example, at the electric drive, the strength of the exoskeleton with EDUs at the axis region can be made comparable to the level of a conventional frame-based chassis construction. The EDUs are mounted at the electric drive unit sockets 12 via their bottom access so they can be easily removed from the bottom of the exoskeleton 10 as coupling connections to the electric motor housing 23, suspension 24 and drive wheels 25 and replaced for repair when necessary.

[0029] The battery pack 30 is mounted to its battery pack support 13 via at least two longitudinal bars 31, which are connected to the corresponding longitudinal bars 131 at the battery pack support 13, for example, by screws or by using shape-filling fasteners or by welding. The battery pack 30 can be mounted by solid plates 32 via a U-shaped frame 31, which is joined by shape-filling fasteners between 131, 16 and the top bars of the exoskeleton. The batteries in the battery pack 30 can be stacked closely adjacent to each other, so that they provide a solid structure of the battery pack 30. Multiple layers consisting of cells and metal plates are stacked on each other in height and length to form a waffle-type structure. As a result, the battery pack 30 acts as a solid element in the middle part of the exoskeleton, so that the exoskeleton is reinforced in the middle part between the axles along its length and width. The battery 30 is accommodated in the battery pack support 13 via a bottom entrance, so that it can be easily removed, replaced and installed in the battery pack support 13 from the bottom of the vehicle when necessary.

[0030] Thus, a solid construction is provided on which other elements of the vehicle can be mounted. For example, if the vehicle is a semi-trailer truck, elements such as a cab 17 or a saddle 18 can be mounted thereon, such as Figure 5 As shown. Since all the powertrain components (EDU) are located in the electric drive unit socket 12 at the bottom of the exoskeleton 10 , the exoskeleton 10 can have a flat top surface, which enables design freedom for the cockpit 17 .

[0031] Figure 6 Another example of a vehicle including the above-described structure is shown—namely, a box truck having a driver cabin 17 and a load compartment 19 mounted on an exoskeleton 10 .

[0032] Although the present invention is presented in conjunction with its preferred embodiments in the drawings and the description, these embodiments do not constrain or limit the invention presented. Therefore, it is obvious that changes within the equivalent meaning and scope of the essence of the present invention can be made. Therefore, the embodiments presented should be considered in all aspects as illustrative and not restrictive. According to the above, the scope of the present invention is not limited to the embodiments presented, but is represented by the attached claims.

Claims

1. A combined chassis-body structure for an electric vehicle, the structure having an outer frame (10) in a frameless form, comprising: Four electric drive unit sockets (12), each having a bottom entrance and accommodating an electric drive unit (20) therein, wherein each of said electric drive units (20) comprises a support structure (21) to which an electric motor housing (23) and a suspension (24) having a drive wheel (25) are connected, wherein said support structure (21) of said electric drive unit (20) is connected to a support structure (121) of a corresponding socket (12); a battery pack support (13) having a bottom access and accommodating the battery pack (30) therein; and an outer surface (11) forming the outer contour of the chassis and the lower part of the body of the vehicle and adapted to place a cockpit (17) on top of said outer surface (11); The support (13) for the battery pack (30), the electric drive unit socket (12) and the outer surface (11) are formed as two separate, individual integral components (10A, 10B) of the exoskeleton (10), and the two separate, individual integral components (10A, 10B) are coupled together along the longitudinal axis of the vehicle.

2. The structure according to claim 1, wherein: The elements (10A, 10B) of the exoskeleton (10) are at least partially formed by an injection molding process.

3. A structure according to any preceding claim, wherein: The elements (10A, 10B) of the exoskeleton (10) are at least partially formed by deep drawing.

4. A structure according to any preceding claim, wherein: The elements (10A, 10B) of the exoskeleton (10) are at least partially formed by additive manufacturing.

5. A structure according to any preceding claim, wherein: The support (13) comprises a longitudinal rod (131) for mounting the battery pack (30).

6. An electric vehicle comprising a structure according to any preceding claim.

Images