DE102019201145B4 - Front frame structure with integrated engine mount for an electric vehicle, electric vehicle with such a frame structure and method for manufacturing an electric vehicle - Google Patents

Abstract

Front frame structure (10) for a chassis of an electric vehicle (12) with
at least two longitudinal members (14a, 14b), each longitudinal member (14a, 14b) being adjoined in the direction of a body cell (16) by a respective transition element (18a, 18b) which, with the body cell (16) and / or one of the body cell ( 16) supporting cross member (20, 22) is connected,
characterized in that each transition element (18a, 18b) has an integrated motor mount (32a, 32b) for an electric motor (30) accommodated between the longitudinal supports (14a, 14b).

Description

Front

The invention relates to a front frame structure for a chassis of an electric vehicle with at least two longitudinal members, each longitudinal member being connected to a respective transition element in the direction of a body cell, which is connected to the body cell and / or a cross member supporting the body cell. The invention also relates to an electric vehicle with such a frame structure and a method for producing an electric vehicle with such a frame structure.

In vehicles conventionally powered by an internal combustion engine, the unit and gearbox suspension or the engine / gearbox mounting is usually realized via the chassis: the engine and the gearbox are mounted or supported by conventional (rubber) or hydraulic bearings on the chassis. The chassis is then fastened / screwed to the frame structure or the body together with the unit (engine) and the transmission.

From the DE 10 2011 102 322 A1 a motor vehicle frame device is known with a front-side internal combustion engine, with a longitudinal beam, which has a main direction of extent that is aligned parallel to a vehicle longitudinal direction, and with an engine mount, which has an engine mount to support the internal combustion engine on the longitudinal beam, which is provided to a To dampen transmission of vibrations of the internal combustion engine, wherein the engine mount is at least partially integrated in the side member.

the DE 100 32 663 A1 shows a self-supporting body of a motor vehicle made from sheet metal parts.

In the case of electric vehicles, an approach is currently being pursued in which the electric motor is mounted on the chassis by means of additional components or engine supports made of cast aluminum alloys by means of bearing elements (e.g. rubber blocks) and the chassis, together with the electric motor, is then attached to the frame structure or the body.

In the event of a frontal impact (front crash) or a collision with partial overlap in vehicles with internal combustion engines, the load is absorbed by the deformation of the front end and the displacement of the engine / transmission assembly in the direction of the body cell. The motor and gearbox bearings are decoupled (broken). Due to the geometry or structure of the bearings and assembly supports, it is hardly possible to accommodate this intrusion in the given installation space through consistent crash measures. The overlapping of the engine / transmission and body cell as well as the front longitudinal members of the body (and other energy-absorbing components / packages in the front end of the vehicle) ensure that the vehicle is decelerated and that the occupants are protected.

In electric vehicles, a high-voltage battery is usually accommodated in the vehicle architecture; in particular, such a high-voltage battery is arranged below the passenger cell. In the event of a frontal collision, there is therefore the risk that the electric motor will act on the body cell and the front of the high-voltage battery when the unit mounting is decoupled or the assembly breaks, so that the battery can be damaged.

The object on which the invention is based is seen in specifying a front frame structure in which the above disadvantages for electric vehicles can be avoided.

This object is achieved by a front frame structure with the features of claim 1, by an electric vehicle with the features of claim 6 and by a method with the features of claim 7. Advantageous configurations with useful developments are specified in the dependent claims.

A front frame structure is therefore proposed for a chassis of an electric vehicle with at least two longitudinal members, each longitudinal member being connected to a respective transition element in the direction of a body cell, which is connected to the body cell and / or a cross member supporting the body cell. It is provided that each transition element has an integrated motor mount for an electric motor accommodated between the side members.

The structural component referred to here as the transition element is also referred to in technical jargon as the crank area and creates the transition from a front longitudinal member to the body cell. Furthermore, the chassis is usually connected to these transition elements or crank areas.

In a departure from previous mountings or suspensions of drive units on the chassis, the proposed frame structure achieves direct mounting of the electric motor on the transition elements associated with the body. The engine mounts are therefore in one for a frontal impact or for impact with partial overlap defined load path in the front frame structure (front end) so that decoupling can be counteracted.

The respective transition element can have a receiving section for the engine mount connected to the longitudinal member and a support section connected to the body cell and / or a cross member supporting the body cell, the receiving section and the support section being formed at a corner to one another. The transition element is designed in particular as a one-piece die-cast part. Correspondingly, the transition element with its support section and receiving section arranged at a corner or at an angle of essentially 90 ° has a high degree of rigidity.

The front frame structure can have at least two engine support elements which form the connection between the respective engine mount and the electric motor. The respective support section can serve as a stop for the respective motor support element in the event of a collision.

Thus, in the event of a collision between the engine support elements and the transition elements, a type of form fit can occur if a decoupling or a break occurs in the area of the engine mount and the electric motor is shifted together with the engine support elements in the direction of the body cell. As a result of the form fit, further energy can be absorbed in the area of the support section in order to be able to prevent the electric motor from penetrating into the body cell or even into the receiving space of the high-voltage battery. Correspondingly, the frame structure presented here provides improved protection for the body cell and the high-voltage battery.

The respective motor bearing can have a bearing sleeve arranged in a corresponding opening on the respective transition section. Such a bearing sleeve can, for example, be pressed into the opening. Alternatively, a bearing sleeve can be fastened or screwed to the transition section by means of an additional part.

The above-mentioned object is also achieved by an electric vehicle with a chassis that has a front frame structure as described above, and with an electric motor that is arranged between the two longitudinal members and is mounted on the motor bearings of the transition sections.

• Bereitstellen eines Chassis mit einer oben beschriebenen, vorderen Rahmenstruktur;
• Bereitstellen eines Elektromotors;
• Bereitstellen von Motorstützelementen;
• Bereitstellen eines Fahrwerks;
• Montieren des Elektromotors zusammen mit dem Fahrwerk an dem Chassis, wobei die Motorstützelemente mit den Motorlagern an den Übergangsabschnitten und mit dem Elektromotor verbunden werden.

For a method for manufacturing an electric vehicle, it is proposed that it comprise the following steps:

• Providing a chassis having a front frame structure as described above;
• Providing an electric motor;
• Providing engine support elements;
• Providing a landing gear;
• Mounting the electric motor together with the chassis on the chassis, the motor support elements being connected to the motor mounts at the transition sections and to the electric motor.

In the method, the engine support elements can be secured to the transition section by means of a respective screw connection in the width direction of the electric vehicle, access to the corresponding screw connection point being in the area of a respective wheel house.

When connecting the chassis and the electric motor to the chassis, the motor support elements can first be attached to the respective motor bearings. The electric motor can then be connected or screwed to the motor support elements that are already supported or mounted on the body.

• 1 eine vereinfachte und schematische Ansicht einer vorderen Rahmenstruktur eines Elektrofahrzeugs von unten;
• 2 eine vereinfachte und schematische vergrößerte Ansicht eines linken Motorlagers mit zugeordnetem Motorstützelement von unten;
• 3 in den Teilfiguren A) und B) eine perspektivische Darstellung eines linken bzw. rechten Motorstützelements, das in einem Motorlager angeordnet ist, und in C) eine Gesamtansicht auf das linke und rechte Motorstützelement;
• 4 eine vergrößerte Darstellung des linken Motorstützelements und Motorlagers der 3A von oben;
• 5 eine Ansicht der vorderen Rahmenstruktur mit Elementen der 3 und 4 von oben in einer vereinfachten Draufsicht.

Further advantages and details of the invention emerge from the following description of preferred embodiments and with reference to the drawings. It shows:

• 1 a simplified and schematic view of a front frame structure of an electric vehicle from below;
• 2 a simplified and schematic enlarged view of a left engine mount with associated engine support element from below;
• 3 in the sub-figures A) and B) a perspective view of a left and right engine support element, which is arranged in an engine mount, and in C. ) an overall view of the left and right engine support element;
• 4th an enlarged view of the left engine support member and engine mount of FIG 3A from above;
• 5 a view of the front frame structure with elements of the 3 and 4th from above in a simplified plan view.

1 Figure 11 shows a schematic and simplified view from below of a front frame structure 10 of an only partially shown electric vehicle 12th . The front frame structure 10 includes two side members 14a , 14b related to a forward travel direction VR of the electric vehicle 12th are arranged on the left or right. The side members 14a , 14b point in the direction of a body cell 16 of the electric vehicle 12th a respective transition element 18a , 18b on. The transition elements 18a , 18b especially form the transition between the longitudinal members 14a , 14b and a front wall 20th the body cell 16 and / or one of the body cells 16 supporting cross member 22nd .

Front wheels 24a , 24b are on a chassis shown in dashed lines 26th or a subframe 28 with the side members 14a , 14b and thus connected to the body. Between the side members 14a , 14b is an electric motor 30th arranged. The electric motor 30th is at two in the transition elements 18a , 18b trained engine mounts 32a , 32b supported. In addition, there are respective motor support elements 34a . 34b used, which is the connection between the electric motor 30th and the respective engine mount 32a , 32b produce. The rear area of the electric motor is therefore on the body, in particular the transition elements 18a , 18b that with the side members 14a , 14b are connected, supported or stored.

In a front area, the electric motor is in a known manner on a cross member 36 by means of further engine bearings 38a , 38b supported, the cross member 36 Part of the subframe 28 or the chassis 26th is. The electric motor 30th is in operative connection with the front wheels 24a , 24b so this by the electric motor 30th can be driven. In an area behind the front wall 20th the body cell 16 a cross-hatched high-voltage battery illustrated here 40 be arranged.

2 shows a simplified and schematic view from below of a left engine mount 32a and an associated engine support member 34a . The engine support element 34a assigns one to the electric motor 30th facing side 35 on that to the outer contour 37 or shape of the electric motor 30th is adapted, in particular is formed substantially complementary to this. By dotted lines 42 are connections, in particular screw connections, between the engine support element 34a and the electric motor 30th illustrated.

The (left) transition element 18a is described in more detail below. The following for this left transition element 18a What is described applies in the same way to a right transition element which is not shown or described in more detail here 18b as it is simplified and schematically in 1 is illustrated. The transition element 18a comprises a receiving portion 44 and a support portion 46 . The receiving section 44 and the support section 46 are arranged at a corner to each other. In other words, the receiving section extends 44 in which the engine mount 32a is received, essentially in the longitudinal direction X of the electric vehicle and the support section 46 extends essentially in the width direction Y of the electric vehicle. The arrangement of the receiving section 44 and support section 46 to each other is designed so that stresses in the corner connection can be avoided or kept low. With the reference numerals 44 respectively. 46 The dotted dimension lines provided are intended to indicate which area of the transition element 18a approximately as a receiving section 44 or as a support section 46 can be understood. It is clear that the length of the dotted dimension lines drawn here 44 , 46 are purely exemplary and the two sections 44 , 46 also as shorter parts of the transition element 18a can be understood that are connected to one another by a connecting section formed at a corner.

The transition element 18a has a the engine support member 34a facing stop surface 50 on. In the assembled normal state of the electric vehicle, the motor support elements are 34a and the transition element 18a or its support section 46 arranged at a distance from one another. In the event of an impact in which the side member 14a Is strongly deformed in the longitudinal direction X, loads can also be applied to the electric motor 30th works. These loads can be carried out via the motor support element 34 and the engine mount 32a be introduced into the body. In the event of such a severe impact that the engine support 34a from the engine mount 32a is decoupled or a break between the motor support element 34a and engine mounts 32a occurs, the engine support element 34a against the stop surface 50 of the transition element 18a or its support section 46 emotional. In the area of the stop surface 50 Then there is a kind of form fit between the engine support element 34a and the transition element 18a so that further loads can be absorbed in this area and a movement of the electric motor 30th towards the body cell 16 can be counteracted.

In the 3A and 3B are the left and right engine support members 34a , 34b shown in a perspective view. An associated overall view from the front shows 3C . Both engine support element 34a , 34b are in their respective engine mounts 32a , 32b recorded in the respective recording section 44 of the associated transition element 18a , 18b is arranged. As from the representation of the 3 the two engine support elements can be seen 34a , 34b usually not designed identically, but each engine support element 34a , 34b has a configuration adapted to the shape of the electric motor or the shape of the housing of the electric motor. The respective support section is in both representations 46 of the transition element 18a , 18b evident. There are also short pieces of the respective longitudinal member 14a , 14b shown. The engine mounts 32a , 32b have a respective sleeve element 33a , 33b on, the one in the respective engine bearing opening in the transition element 18a , 18b is recorded.

4th shows another to 2 Similar illustration, an embodiment being shown in a perspective illustration from above. The electric motor can be seen 30th , the left engine support element 34a , the left side member 14a and the left transition element 18a . There is also a part of the subframe 28 shown. The subframe 28 is in the area of the transition element 18a connected to the body. In this example, the engine support member 34a one to the support section 46 or recess directed towards the body cell 52 on. By such a recess 52 On the one hand, weight can be saved and, on the other hand, the engine support element 34a designed at a deliberately chosen point so that in the event of an impact, deformation of the engine support element 34a to absorb loads or energy is enabled. In particular, an inner section 54 , which is further inward than an outer section in relation to the width direction Y of the electric vehicle 56 to be kinked when the electric motor 30th is shifted in the longitudinal direction X to the rear of the body cell.

5 shows the front frame structure in a view from above 10 with the two side members 14a , 14b , the two transition elements 18a , 18b and the electric motor arranged therebetween 30th . From this illustration it can be seen that the engine support elements 34a , 34b by means of screw connections 58 in the engine mounts 32a , 32b are secured. The screw connection 58 can be done from the outside, i.e. from the side of a respective wheel house. For the left engine support element 34a is also in 3C a screw connection 58 shown.

In the 5 it can also be seen again that the two engine support elements 34a , 34b at a distance from the support section 46 of the respective transition element 18a , 18b are arranged. It can also be seen that the two engine support elements 34a , 34b in the event of the electric motor being moved to the body cell 16 in the area of the respective stop surface 50 of the transition element 18a , 18b or the associated support section can form a form fit to allow further movement of the electric motor 30th to the body cell 16 to prevent. The engine support elements 34a , 34b can for this purpose in a rear area, at least in sections, essentially complementary to the stop surface 50 be trained.

In a method for manufacturing an electric vehicle, the following steps can be carried out during assembly. Providing a chassis with a front frame structure as described above 10 . Provision of an electric motor 30th and associated engine support elements 34a , 34b . Provision of a landing gear 26th , 28 . Finally, the electric motor is installed 30th together with the landing gear 26th , 28 on the chassis or on the front frame structure 10 , the engine support elements 34a , 34b with the engine mounts 32a , 32b at the transition sections 18a , 18b and with the electric motor 30th get connected. The engine support elements 34a , 34b can by means of a respective screw connection 58 in the width direction Y of the electric vehicle 12th at the transition section 18a , 18b be secured, with access to the corresponding screw connection in the area of a respective wheel housing. When connecting the chassis 26th , 28 and the electric motor 30th with the chassis or the front frame structure 10 can use the engine support elements 34a , 34b initially on the respective engine mounts 32a , 32b be attached. Then the electric motor 30th with the engine support elements already supported or mounted on the body 34a , 34b be connected or screwed.

Claims (8)

Front frame structure (10) for a chassis of an electric vehicle (12) with at least two longitudinal members (14a, 14b), a respective transition element (18a, 18b) being connected to each longitudinal member (14a, 14b) in the direction of a body cell (16), which is connected to the body cell (16) and / or a cross member (20, 22) supporting the body cell (16), characterized in that each transition element (18a, 18b) has an integrated engine mount (32a, 32b) for one between the longitudinal members (14a, 14b) has received electric motor (30). Front frame structure according to Claim 1 , characterized in that the respective transition element (18a, 18b) has a receiving section (44) connected to the longitudinal beam (14a, 14b) for the engine mount (32a, 32b) and one with the body cell (16) and / or one with the body cell ( 16) has supporting cross member (20, 22) connected support section (46), wherein the receiving section (44) and the support section (46) are formed at an angle to one another. Front frame structure according to Claim 1 or 2 , characterized by at least two motor support elements (34a, 34b) which form the connection between the respective motor mount (32a, 32b) and the electric motor (30). Front frame structure according to Claim 2 and 3 , characterized in that the respective support section (46) serves as a stop (50) for the respective motor support element (34a, 34b) in the event of a collision. Front frame structure according to one of the preceding claims, characterized in that the respective motor bearing (32a) has a bearing sleeve (33a, 33b) arranged in a corresponding opening on the respective transition section (18a, 18b). Electric vehicle with a chassis which has a front frame structure (10) according to one of the preceding claims, and with an electric motor (30) which is arranged between the two longitudinal members (14a, 14b) and on the motor bearings (32am 32b) of the transition sections (18a , 18b) is stored. A method for manufacturing an electric vehicle (12), comprising the steps of: providing a chassis with a front frame structure (10) according to any one of Claims 1 until 5 ; Providing an electric motor (30), providing motor support elements (34a, 34b), providing a chassis (26, 28); Mounting the electric motor (30) together with the chassis (26, 28) on the chassis, the motor support elements (34a, 34b) with the motor bearings (32a, 32b) on the transition sections (18a, 18b) and with the electric motor (30) get connected. Procedure according to Claim 7 , the motor support elements (34a, 34b) being secured to the transition section (18a, 18b) by means of a respective screw connection (58) in the width direction (Y) of the electric vehicle (12), with access to the corresponding screw connection point being in the area of a respective wheel house .

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