DE102017101561B4 - Front end structure and chassis for an electric vehicle - Google Patents

Abstract

Front end structure (8) of an electric motor vehicle, having longitudinal members (13, 17) oriented in the longitudinal direction of the motor vehicle, which are connected to a chassis (1), one longitudinal member (17) each being arranged on the outside on a central structural level (16), the longitudinal members (17) are each connected to a side sill (4) of the electric motor vehicle and, in relation to the motor vehicle vertical direction, at least one longitudinal member (13) is arranged on a lower structural level (12) below it, which is attached to a central wall (14) extending centrally through the motor vehicle or is connected to a tunnel, the longitudinal member (13) in the lower structural level (12) being formed from two longitudinal member parts (13), characterized in that the longitudinal member parts (13) are arranged in a U-shape or in an egg-shape, running towards one another in such a way that they are brought together at the central wall (14) or the tunnel, the two longitudinal beam parts (13) being in one piece and are made of the same material and vertical struts (19) are arranged at a front end and/or that at least one cross member (15) for connecting the longitudinal members (13, 17, 22) is arranged in at least one structural plane.

Description

The present invention relates to a front end structure of an electric motor vehicle according to the features in the preamble of claim 1.

It is known from the prior art for motor vehicle construction to use metallic materials. In particular, the self-supporting motor vehicle body has become established in recent decades. To this end, various structural components are manufactured and then assembled to form the self-supporting motor vehicle body. In particular, thermal joining methods, such as welding, are used. Steel materials or also light metals, and here in particular aluminum materials, are usually processed. These can also be combined with fiber composite materials. In such a self-supporting motor vehicle body, a front end structure is formed in a typical construction, in which an internal combustion engine is used, and which has a transmission gear for the individual gears either directly on the internal combustion engine or in the rear area of the motor vehicle. The passenger compartment is usually provided in a middle area and a corresponding storage space for a trunk and, for example, a tank for fuel is provided in a rear area.

In recent years, however, more and more electric vehicles have come onto the market. In this case, the drive energy is preferably stored purely electrically in the motor vehicle. Batteries or accumulators are known for this purpose, but they have a high intrinsic weight of up to several 100 kg and a correspondingly large space requirement. In order to achieve good driving characteristics with a low center of gravity of the electric vehicle, several batteries are usually arranged in an underfloor area of the electric vehicle. For this purpose, battery containers or battery trays are known from the prior art, in which several of these batteries are accommodated. Typically, such a battery tray is inserted into an electric vehicle from below.

An electric vehicle therefore does not have the installation space requirement of a conventional motor vehicle with a combustion engine drive.

For the safety of motor vehicle occupants, but also of passers-by or those involved in accidents, modern motor vehicles continue to have crash management systems. Here, a front or rear structure of a motor vehicle is designed according to the legally prescribed parameters in the event of a vehicle crash. In most cases, crash boxes are used, which reduce the impact energy through deformation.

From the DE 10 2006 004 045 A1 a vehicle body with a supporting structure is known, in which longitudinal members are formed on two opposite sides of the vehicle, which extend in the direction of the vehicle and provide three load paths to a passenger compartment.

Furthermore, from the DE 10 2016 118 108 A1 previously reported but post-released a design to reduce impact loads. Here, a battery carrier with a battery frame is used in a motor vehicle body. The motor vehicle body is reinforced by the arrangement of lateral, separate rocker panels and additional floor-side frame elements.

The object of the present invention is to provide a front-end structure for an electric motor vehicle that has a structure that is as simple and inexpensive to produce as possible and at the same time offers the possibility of meeting various crash requirements that are placed on a vehicle approved for use on the road.

The aforementioned object is achieved with a front end structure of an electric motor vehicle having the features in claim 1.

The front end structure for an electric motor vehicle has side members which are oriented in the longitudinal direction of the motor vehicle and which are connected to a chassis. At least two, preferably three structural planes are formed in the vertical direction of the motor vehicle. One longitudinal member is arranged on the outside on each middle first structural level. The side members of the central structural level are each connected to a side sill of the electric vehicle. A load path in the event of a frontal vehicle crash is thus introduced from these side members into the side sills of the electric motor vehicle in the longitudinal direction of the motor vehicle.

A lower structure level is also arranged in relation to the vertical direction of the motor vehicle. At least one longitudinal member is arranged in the lower structural level. The side member of the lower structural level is connected to a central wall or a tunnel that extends centrally through the electric motor vehicle or the chassis of the electric motor vehicle.

According to the invention, it is provided in particular that a battery carrier of the electric motor vehicle is arranged in an underfloor area. esp In particular, the battery carrier is arranged in a self-supporting chassis of the electric vehicle. The battery tray is preferably also trough-shaped, with the outer walls of the trough or a frame of the battery tray running in the longitudinal direction of the motor vehicle and forming the side sills of the electric motor vehicle or the side sills of the chassis. The side members of the central structural level are therefore connected to the side skirts, in particular on the front side.

A middle wall preferably also runs centrally in the longitudinal direction of the motor vehicle through the battery tray. This is done in the manner of a transmission tunnel. The at least one longitudinal member of the lower structural level is preferably connected to the middle wall.

The side members themselves are made of metallic material. In particular, the longitudinal beams are formed from hollow profiles produced by forming. The side members can also be made of light metal. In particular, in this case they are produced as extruded components or extruded profiles.

The longitudinal member in the lower structural level is formed from two longitudinal member parts, these two longitudinal member parts being arranged in a U-shaped or egg-shaped manner towards one another. Each side member part is oriented in the longitudinal direction of the motor vehicle. This is done in such a way that the two longitudinal beam parts arranged in a U-shape or egg-shape relative to one another are brought together at the center wall or the tunnel. For this purpose, in particular, the two longitudinal member parts in the lower structural level are designed in one piece and made of the same material. For example, the longitudinal beam parts can be produced by an extrusion profile, which is then bent so that it forms a U-shape or egg-shape. This measure makes it possible to introduce the impact force in a vehicle crash in the lower structural level from two points at the vehicle front spaced apart in the vehicle transverse direction via a load path extending in the vehicle longitudinal direction into the center wall or the tunnel. At the same time, a particularly simple and effective production can be provided by the one-piece component made of the same material.

The lower structural level is arranged to run essentially horizontally. This means that it is located in a plane that is essentially spanned by the vehicle's transverse direction and vehicle's longitudinal direction. As an alternative or in addition, the central structural plane can be designed to fall backwards at an angle. This makes it possible to introduce the energy that occurs in a vehicle crash at a vehicle front from a higher point in the vertical direction of the vehicle. Due to the fact that the middle structural level is designed to slope backwards at an angle, the side members of the middle structural level can introduce the energy that occurs in the process into the side sills.

Furthermore, particularly preferably, in relation to the vertical direction of the motor vehicle, an upper structural level is arranged above the middle structural level, which preferably also has two side members. The two side members of the upper structural level are connected in particular to a spray protection wall or to the A pillars of the electric vehicle. This makes it possible to provide a load path which directs a frontal impact force in the event of a vehicle crash not only through the chassis located below in the vertical direction of the vehicle, but also through parts of the body, here via the A pillars or roof pillars.

Furthermore, at least one cross member is arranged in one or more, preferably in all, structural levels. The cross beams are used to provide additional reinforcement for the longitudinal beams. At the same time, however, the cross members also serve to connect other body components, for example axle components, lines or also to accommodate a trunk arranged in the front end structure.

Furthermore, chassis components, in particular links, are preferably connected to the side members. The cross members between the longitudinal members give the front end structure additional rigidity based on the principle of an axle subframe or a strut brace.

A transverse leaf spring is also particularly preferably connected, in particular below the lower structural level. This serves in particular as a spring for the front axle of the electric vehicle.

Furthermore, particularly preferably, triggers can be formed on one, in particular on several and very particularly preferably on all longitudinal members, such that in the event of a vehicle crash, wrinkling is initiated in a targeted manner for energy dissipation. In this case, in particular, additional or complex crash boxes, which are arranged in front of the front end structure, can be dispensed with. The overall length of the motor vehicle can thus be shortened. In particular, the triggers can be weakened areas. These can be due to different wall thicknesses or different strength values can be made in the side members by various measures. For example, tailored blanks can be used or tailored manufacturing processes such as tailored tempering.

Furthermore, vertical struts and/or preferably cross members for connecting the longitudinal members are arranged at a front end of the front end structure. A vehicle front is thus provided on the front-end structure. In front of it in the longitudinal direction of the motor vehicle, for example, a cross member can also be arranged. In particular, this cross member can continue to be fixed to crash boxes. Alternatively or additionally, only crash boxes can be arranged in the area in front of the front end structure.

The present invention further relates to a self-supporting chassis for an electric motor vehicle, which has a front-end structure with at least one of the features mentioned above. The self-supporting chassis is characterized in that it has a central area and a front-end structure with a front axle and a rear-end structure with a rear axle. The front axle is arranged on the front end structure. The rear axle is arranged on a rear structure, also known as a rear structure. The front-end structure and the rear-end structure are connected by a centrally located battery tray. The side skirts of the self-supporting chassis are formed by a surrounding frame of the battery tray. The front end structure and the rear structure are connected to the battery carrier. The respective axle components are connected to the front-end structure and rear-end structure. An electric motor for driving the electric motor vehicle can be arranged in the rear-end structure, alternatively also in the front-end structure or also in the front-end structure and rear-end structure. The self-supporting chassis would thus be able to drive independently. A body is then placed on this with a corresponding passenger compartment and other operating components as well as comfort components for operating the electric vehicle.

The aforementioned features can be combined with one another as desired within the scope of the invention without departing from the disclosure content.

• 1 ein selbsttragendes Chassis eines Elektrokraftfahrzeuges in perspektivischer Ansicht,
• 2 sowie in Draufsicht,
• 3 eine perspektivische Ansicht einer erfindungsgemäßen Vorderwagenstruktur und
• 4 eine Seitenansicht der erfindungsgemäßen Vorderwagenstruktur

Further advantages, features, properties and aspects of the present invention are the subject of the following description. Preferred design variants are explained in schematic figures. These serve to make the invention easier to understand. Show it:

• 1 a self-supporting chassis of an electric vehicle in a perspective view,
• 2 as well as in top view,
• 3 a perspective view of a front end structure according to the invention and
• 4 a side view of the front end structure according to the invention

In the figures, the same reference numbers are used for the same and similar components, even if a repeated description is omitted for reasons of simplification.

1 shows the self-supporting chassis 1 according to the invention in a perspective view from behind. A battery carrier 2 is arranged in the center, the battery carrier 2 having a frame 3 running around the outside. A lateral part of the frame 3 is designed as a side sill 4 of the chassis 1, with the side sill 4 extending in the longitudinal direction of the motor vehicle. The frame 3 also has parts oriented in the transverse direction Y of the vehicle. Various batteries 5, also called accumulators, are arranged inside the battery carrier 2. A cooling system 9 for cooling the batteries 5 is also integrated.

A rear structure 6 is arranged behind the battery carrier 2 in relation to the motor vehicle longitudinal direction X. Among other things, an electric motor 7 for driving the electric motor vehicle is also provided in the rear structure 6 .

A front-end structure 8 according to the invention is arranged in front of the battery carrier 2 in relation to the longitudinal direction X of the motor vehicle, the front-end structure 8 having a plurality of longitudinal members 13, 17, 22 extending in the longitudinal direction of the motor vehicle on different structural levels 12, 16, 21 according to 4 having. Furthermore, for example, shock absorbers 10 and a transverse leaf spring 11 are also suspended or coupled to the front end structure 8 .

2 shows a plan view of the chassis 1 according to the invention.

3 and 4 each show the front end structure 8 in a perspective view and a side view. A longitudinal member is formed by two longitudinal member parts 13 in a lower structural level 12 . The two longitudinal beam parts 13 are produced in one piece and from the same material by processing a profile by forming. In a plan view, the two longitudinal support parts 13 particularly preferably run in a U-shape or egg-shape. Thus, they can be connected to a middle wall 14 extending through the battery tray 2 and in the event of a frontal crash, the force directed in the longitudinal direction X of the motor vehicle is introduced centrally into the center wall 14 . A cross member 15 can be arranged between the two longitudinal member parts 13 . Below the longitudinal member parts 13, the transverse leaf spring 11 can be attached.

Two longitudinal members 17 are also arranged on a central structural level 16 located above, the longitudinal members 17 being arranged on the outside in relation to the transverse direction Y of the motor vehicle, but between the wheels 24 . The side members 17 are then connected to the side sills 4 of the battery tray 2 . A plug-in profile 25 or fitting can be used for this purpose, for example, which connects the battery carrier 2 or frame 3 of the battery carrier 2 to the longitudinal members 17 .

The side members 17 of the middle structural level 16 are designed to slope backwards at an angle α in the longitudinal direction X of the motor vehicle, so that they provide a higher force application point on a vehicle front 18 in relation to the vertical direction Z of the motor vehicle, but this is then in the area of the underfloor or the side skirts 4 is initiated.

Vertical struts 19 can be arranged on the vehicle front 18, which connect the longitudinal members 13, 17, 22 of the individual structural levels 12, 16, 21 to one another. In addition, an additional cross member 15 can be arranged, for example, on the longitudinal members 13 of the lower structural level 12 . This is then preferably coupled to the vertical struts 19 .

Two longitudinal members 22 are also preferably arranged on an upper structural plane 21 located above it in the vertical direction z. These are coupled, for example, with a cross strut 23 for connection to a splash guard or to A pillars, not shown in detail. Furthermore, the side members 22 of the upper structural plane 21 can also preferably be arranged at an angle β in the longitudinal direction X of the motor vehicle to a horizontal line H. In particular, this angle β is designed to increase towards the rear of the vehicle.

Furthermore, an upper and/or lower cross member 26, 27 can be provided on the vehicle front 18.

Furthermore, triggers 28 are formed on the longitudinal members 17 in order to initiate a targeted drape.

Reference List

1

chassis

2

battery carrier

3

frame

4

side skirts

5

battery

6

rear structure

7

electric motor

8th

front end structure

9

cooling system

10

shock absorber

11

transverse leaf spring

12

lower structural level

13

Longitudinal member for 12

14

center wall

15

Cross member to 13

16

middle structural level

17

Longitudinal beam to 16

18

vehicle front

19

vertical brace

20

cross member

21

upper structural level

22

Longitudinal member to 21

23

cross brace

24

wheel

25

plug-in profile

26

lower cross member

27

upper cross member

28

triggers

a

angle

β

angle

X

motor vehicle longitudinal direction

Y

vehicle transverse direction

Z

motor vehicle vertical direction

H

horizontal

Claims (11)

Front end structure (8) of an electric motor vehicle, having longitudinal members (13, 17) oriented in the longitudinal direction of the motor vehicle, which are connected to a chassis (1), one longitudinal member (17) each being arranged on the outside on a central structural level (16), the longitudinal members (17) are each connected to a side skirt (4) of the electric motor vehicle and on the motor vehicle At least one longitudinal member (13) is arranged in the vehicle vertical direction on a lower structural level (12) below it, which is connected to a central wall (14) extending centrally through the motor vehicle or to a tunnel, with the longitudinal member (13) in the lower structural level (12 ) is formed from two longitudinal beam parts (13), characterized in that the longitudinal beam parts (13) are arranged in a U-shape or egg-shaped towards one another, in such a way that they are brought together at the central wall (14) or the tunnel, the two longitudinal beam parts ( 13) are designed in one piece and of the same material and vertical struts (19) are arranged at a front end and/or that at least one cross member (15) for connecting the longitudinal members (13, 17, 22) is arranged in at least one structural level. Front end structure (8) according to claim 1 , characterized in that the side members (13, 17) are connected to a battery holder (2) of the electric motor vehicle, with the side skirts (4) and the central wall (14) preferably being covered by the battery holder (2) and/or a frame (3) of the battery carrier (2) are formed. Front end structure (8) according to claim 1 or 2 , characterized in that the longitudinal beams (13, 17) are made of metallic material, in particular of hollow profiles produced by forming, or that the longitudinal beams are made of light metal, in particular of extruded profiles. Front end structure (8) according to one of Claims 1 until 3 , characterized in that the lower structural level (12) is arranged to run essentially horizontally and/or that the central structural level (16) is designed to fall backwards at an angle (α). Front end structure (8) according to one of Claims 1 until 4 , characterized in that an upper structural level (21) is arranged above the middle structural level (16) in the vertical direction of the motor vehicle, which has two longitudinal members (22), the two longitudinal members (22) being attached in particular to a spray protection wall or to the A pillars of the Electric vehicle are connected. Front end structure (8) according to one of Claims 1 until 5 , characterized in that at least one cross member (20) is arranged in one, several or in all structural levels (12, 16, 21). Front end structure (8) according to one of Claims 1 until 6 , characterized in that in the longitudinal beams (13, 17, 22) triggers (28) are formed, such that in a vehicle crash wrinkle formation is specifically initiated to reduce energy. Front end structure (8) according to one of Claims 1 until 7 , characterized in that cross members (20) for connecting the longitudinal members (13, 17, 22) are arranged at a front end. Front end structure (8) according to one of Claims 1 until 8th , characterized in that crash boxes are arranged in front of the front end. Front end structure (8) according to one of Claims 1 until 9 , characterized in that a transverse leaf spring (11) is connected to the lower structural level (12), in particular below the lower structural level (12). Front end structure (8) according to one of Claims 1 until 10 , characterized in that links for the front axle suspension are connected to the longitudinal beams (13, 17, 22) of the structural planes (12, 16, 21).

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