Drive arrangement for automobile

An automobile is provided with a body, a combustion engine and a transmission operationally connected to the engine. The crankshaft of the engine is substantially oriented in vehicle transverse direction and the engine seen in driving direction of the vehicle is arranged behind the transmission.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to German Patent Application No. 102010018469.1, filed Apr. 28, 2010, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The technical field relates to a drive arrangement and to an installation space allocation concept for an automobile, particularly for an automobile.

BACKGROUND

Preferably optimal utilization of the installation space, which in an automobile (PKW) is only available to a limited extent anyhow, is of major importance in the new development of vehicles. Optimized installation space utilization plays a dominating role particularly in the case of small and smallest vehicles even because of the comparatively small outer dimensions of the vehicle. In addition, particularly hybrid drive concepts wherein combustion engines are coupled to alternative drives particularly electric motors, create additional demands in terms of the installation space allocation of the automobile.

With known drive concepts for compact vehicles a substantial weight component of the vehicle drive is additionally located in front of the front axle, which altogether can lead to deficiencies of space utilization and the vehicle behavior on the road. The geometrical dimensions of drives such as engine and transmission require a positioning in front of the front axle of the automobile. Added to this is that the vehicle radiator because of the required fresh air supply is to be arranged on the vehicle front in front of the drive. Such installation space concepts in the recent past resulted in a steadily increasing vehicle front overhang with a correspondingly disadvantageous weight distribution. In addition, pedestrian protection regulations and insurance classifications have additional effects on the installation space allocation of the automobile; so that the vehicle front overhang relative to the vehicle interior space in general is comparatively long.

It is therefore at least one aim particularly in the case of small cars to preferably shorten the vehicle front overhang which, however, because of the radiator arrangement of necessity located in front of the drive engine, is often possible only conditionally. Alternative installation space concepts, where an engine is arranged in the back of the vehicle, result in a center of gravity and weight shift which is not advantageous particularly for small cars, which is particularly reflected in an unfavorable behavior of the vehicle on the road in the case of short wheelbases of the vehicle. Compared with this it is the object of the present invention to provide an improved installation space concept, particularly for small cars and smallest vehicles in the automobile segment. Here, the installation space allocation is to make possible a shortened vehicle front overhang and smaller outer dimensions of the vehicle. In addition, the center of gravity position with respect to the behavior of the vehicle on the road is to improve. Furthermore, other aims, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.

SUMMARY

An automobile is provided with a preferentially self-supporting body, a combustion engine and a transmission operationally connected to the engine. The engine in this case is substantially arranged in vehicle transverse direction. This means its crankshaft or output shaft substantially extends in vehicle transverse direction (y). In addition, the engine is arranged located behind the transmission seen in driving direction of the vehicle. With this engine and transmission arrangement an installation space concept and an installation space allocation are realized, wherein the engine seen in driving direction is arranged located behind the transmission and projecting to the front wall of the automobile body. This means the engine, from an arrangement located in front of or in the region of the front axle of the vehicle, is shifted further to the back, towards the vehicle middle. Because of this, the vehicle front overhang can be reduced and the center of gravity of the vehicle shifted further into the vehicle middle as well as further downwards. Here it is more preferably provided that the engine, relative to the vehicle transverse direction, is substantially arranged in the middle. Such a centered arrangement is an advantage for the weight distribution of the vehicle and for its cornering stability and for the behavior on the road.

According to an embodiment, the engine is arranged in vehicle longitudinal direction, relative to the driving direction, behind a front axle. This means the center of gravity of the engine or of the engine unit is located behind the front axle of the automobile seen in vehicle longitudinal direction. Here it can be additionally provided that the engine even in its entirety comes to lie behind the front axle of the automobile. Thus, an arrangement for example of differential, transmission and engine strung together opposite to the driving direction can be achieved. If the engine is shifted sufficiently far towards the vehicle middle the transmission operationally connected to the engine can come to lie between front axle and engine.

According to another embodiment, it is additionally provided that the engine with its side facing away from the driving direction comes to lie in a depression of the front wall of the vehicle body formed towards the vehicle back. Thus, the engine shifted in vehicle longitudinal direction towards the middle protrudes into the region of a center console of the passenger cell as a result of which through that depression in the vehicle front wall a hermetic separation of engine and passenger cell is still provided. However, the front wall has a bulge projecting into the passenger cell in a manner of speaking for accommodating or housing the engine shifted towards the vehicle middle.

According to another embodiment, it is provided here that the front wall depression or the front wall-sided mounting merges into a center tunnel of the vehicle body, more preferably of the body floor. Here it can be more preferably provided that the mounting or depression for the engine for example widening trapezium-like towards the front in driving direction in the direction of the back of the vehicle directly terminates in or merges into an approximately box or in cross section trapezium-like center tunnel profile. Advantageously it is additionally provided here that the center tunnel supports itself via at least one transverse tunnel to a side sill of the self-supporting body substantially extending in vehicle transverse direction. Advantageously, at least one transverse tunnel each is provided on both sides of the center tunnel which supports itself on the corresponding left or right side sill. The transverse tunnel or tunnels form a structure-stiffening corset for the floor region of the vehicle body. Through the transverse bracing provided by the transverse tunnel the torsional stiffness and torque stiffness of the body floor structure can be significantly improved. Furthermore supplementary stowage space for additional vehicle components can be made available through the transverse tunnel preferentially designed open towards the bottom and through the center tunnel correspondingly open towards the bottom.

According to another embodiment, it is provided that the center tunnel has a cross-sectional profile which substantially remains the same in vehicle longitudinal direction and protrudes as far as to a heel plate of the body. The center tunnel thus continuously extends from the front wall as far as to the heel plate. Thus it forms a continuous stowage and mounting region for additional components to be arranged in or on the lower floor of the vehicle.

According to another embodiment, the center tunnel and/or the at least one transverse tunnel acts as stowage space for energy storage modules. Thus, a fuel tank or vehicle batteries, more preferably for a hybrid or pure electric drive can for example be stowed in the middle or transverse tunnel region.

According to another embodiment of the transmission, which is located in front of the engine, is arranged relative to the vehicle transverse direction almost in the middle. Preferentially the engine and the transmission are arranged on a center longitudinal axis of the vehicle. With respect to the weight distribution and center of gravity position of the vehicle such a centered arrangement is particularly advantageous.

According to another embodiment, further preferred configuration it is additionally provided that the transmission is designed as continuously variable transmission, namely as a so called continuously variable transmission (CVT). By means of a CVT transmission the torque provided by the engine can remain in the region of the middle longitudinal axis of the vehicle and centrally transmitted to a differential coupled to the drive axle. Alternatively or additionally to a CVT transmission, multiple shaft transmissions can also be employed.

In a further embodiment, the engine is designed as a horizontal one or two-cylinder engine, while the stroke movement of the cylinders does not lie in the vertical but is substantially oriented horizontally or slightly inclined relative to the horizontal. More preferably through the realization of a horizontal one or two-cylinder engine the engine, relative to the vehicle longitudinal direction, can be shifted towards the vehicle middle without foot space available to the driver and/or the front passenger would be noticeably reduced as a result.

According to another embodiment, the engine is designed as a V2 or as a V3-engine, wherein the engine is arranged and oriented in such a manner that one of its cylinders directed to the back opposing the driving direction is substantially oriented horizontally. A horizontal orientation in this case means a stroke movement of the cylinder which substantially lies in the horizontal or only deviates from the latter to a minor extent, for example by a maximum of 15 to 30° thereof.

In a further embodiment, it is provided that the engine for maintenance or repair purposes can be pivoted about its drive axis downwards into a maintenance position. Advantageously, the engine in this case is suspended in a vibration-decoupled manner. For maintenance purposes, for example a toothed belt change, the engine, after disconnecting the suspension, can be pivoted downwards about the drive axis and out of the floor plane.

In addition, it is provided that the entire drive unit formed of engine, transmission and if applicable differential is mounted on a part frame or sub frame and fastened thereon, while not being directly connected to the body side members.

On the whole, improved crash behavior of the vehicle can also be achieved through the shifting of the vehicle drive to the bottom and to the back. The shifting of the drive, for example into the center tunnel region of the vehicle body can contribute to reducing load on the frame structure of the body located outside. The outer regions, for example the side sills and side members of the vehicle body thus merely have to remove energies and forces due to a collision in the event of a collision. Here, they merely have to provide to a smaller degree a holding function for the engine and the transmission.

DETAILED DESCRIPTION

The automobile10schematically shown inFIG. 1toFIG. 3has a body, preferentially a self-supporting body12as well as an engine50and a transmission52coupled to the engine50. The body12comprises a floor structure in the shape of a floor plate16, which in driving direction located at the front merges into a front wall14projecting upwards and via a heel plate18merges into a loading floor32to the back. In the region between front wall14and heel plate18, in which the passenger cell of the vehicle is also located, the body has a tunnel structure20,22,24of cross-like appearance. Thus, a center tunnel extends in vehicle longitudinal direction (x) from the front wall14as far as to the heel plate (18). In vehicle transverse direction (y) two transverse tunnels22,24are provided, wherein the right transverse tunnel22on the left borders on the center tunnel20and on the right on a side sill28.

Accordingly, the left transverse tunnel24on the right borders on the center tunnel20and on the left on the left side sill26. The center tunnel20towards the front, towards the front wall14, merges into a tunnel widening30which can be unitarily designed with the front wall14and/or with the center tunnel20. The tunnel widening30serves as housing and mounting for the engine50schematically shown inFIG. 2, which seen in driving direction of the vehicle is arranged behind the front-mounted transmission52shifted towards the vehicle center. As show, the area formed by the tunnel widening (or depression)30includes sidewall portions30a,30b, a rear portion30c, and an upper portion30d. The sidewall portions30a,30bextend into side portions14a,14bof the front wall14.

In addition, the engine50with this configuration relative to the driving direction of the vehicle is located behind the front axle of the automobile which in the present exemplary embodiment simultaneously acts as drive axle. The position of the front axle is indicated by the body-sided wheel suspensions38,40, which in turn are fastened to the side members42,44of the body. The engine50or the drive unit formed by engine50and transmission52is fastened to a part frame or sub frame48, which seen in vehicle transverse direction is located within or between the two side members42,44. Side members42,44and/or sub frame components48can additionally be interconnected via a cross member46.

As additionally illustrated by means ofFIG. 2, the engine50comes to lie in the region of the front wall14. Through the tunnel enlargement30projecting in the direction of the passenger cell a kind of front wall-sided engine housing is created. On the whole, the position of the engine50and/or of the associated transmission52compared with previous installation space concepts is also shifted downwards, so that on the whole a center of gravity position shifted towards the vehicle center and towards the bottom can be achieved.

The center tunnel20as well as the transverse tunnel22,24can serve to accommodate vehicle components such as an exhaust system54. In addition, the vehicle tank36for example can protrude into a portion of the center tunnel20. Thus, the fuel tank36seen in vehicle transverse direction can be arranged approximately centrally in the automobile and with a T-shaped basic structure extend from a spare wheel trough34forward as far as to the transverse tunnels22,24.

If the vehicle10for example is designed as hybrid vehicle battery modules can be accommodated in the position of the fuel tank36as well as in the transverse tunnels22,24, which because of their comparatively high weight contribute to a further downward shift of the center of gravity.

The position of the engine50is evident in the sectional representation according toFIG. 4. The block of the engine50protrudes into the front wall14and at least in certain regions is encased by the widening30of the center tunnel20located at the front. As shown, the engine50is also arranged located comparatively deep in the vehicle10, which brings with it a center of gravity shifted downwards.