DE10058115A1 - Auxiliary frame module for vehicle has at least two parallel lines for gas or liquid on front traverse - Google Patents

Abstract

The auxiliary frame module has front, rear and longitudinal traverses connected to each other to form a closed auxiliary frame (1). The front traverse (2) has at least two parallel lines (63, 64) for gas or fluid, extending across the width of the frame, connected so that at least two of them carry their flow in opposite directions.

Description

The invention relates to a subframe module for a motor vehicle, comprising a front crossmember and a rear crossmember that over two longitudinal crossmembers are connected to a closed subframe, which is designed to to be attached to a vehicle body from below and in the attached Condition to surround an engine compartment.

Such subframe modules, which are also referred to as full subframes, because they form a ring-like closed frame, for example from DE 39 32 295 A1, WO 96/19373 A or EP 0 678 441 A1. The subframe is there mostly below the vehicle engine or encloses it or components the same, so that the term engine compartment is to be understood here in a broad sense.

Subframe modules are usually used to cover parts of the Pre-assemble the front end of a motor vehicle and then the pre-assembled unit insert into the body of the vehicle and connect to it. To the Subframe modules become vehicle components such as a Wheel suspension or hydraulic units for vehicle steering and the like attached. Furthermore, it is possible to directly drive the vehicle engine itself to be supported on the subframe module, as described in WO 96/19373 A.

In addition to the highest possible stiffness in terms of driving dynamics and one high energy absorption capacity in the event of a vehicle accident or crash the conception and construction of a subframe module, especially manufacturing and assembly aspects are taken into account. Because of the cramped Space conditions in the engine compartment due to a large number of those to be arranged there Elements and units, such as an ABS system, power steering, the largest possible vehicle battery, units for air conditioning, etc. there are further design and assembly restrictions. this applies  especially for vehicles with a short front end, such as at Passenger cars in the compact class and small cars. Especially with such In the event of a crash, vehicles are used for deformation and thus for Energy absorption available paths are relatively short, so that the aim is to achieve the best possible deformation potential of the existing components exploit to the best possible advantage of the vehicle occupants and the opponents of the accident to protect effectively. Furthermore, there is a great interest in one, if possible large proportion of assembly of the components to be arranged in the engine compartment outside the vehicle body to make because of the limited space immediate installation in the engine compartment would be inefficient and also prone to errors.

The applicant has in the patent application DE 199 23 693.3 published later already proposed a subframe module of the type mentioned, with which considerable progress in active and passive crash safety, assembly and the rigidity of the front end when driving. Characteristic of this is the additional, self-contained subframe, which is another crash plane below a main crash plane of the front end, which is the case with conventional Vehicle bodies by two extending in the vehicle longitudinal direction Side member is defined, but also formed by other body structures can be. Because of its arrangement or attachment from below to one Motor vehicle body will reduce the deformations occurring in the Floor area of the passenger compartment and thus a reduction in the risk of injury in the Footwell reached.

In particular, the front crossmember means an additional one Weight and cost factor. In addition, the additional crossbar limits the available space. This is precisely the case with a compact design of the Front end problematic. In the subframe module according to DE 199 23 693.3 was therefore already part of a line for a charge air cooler in the front Crossbar integrated by the front crossbar at its in the width direction of the Subframe side edge areas with sockets and the front Crossbeam was used as a connecting tube.

The invention has for its object an auxiliary frame module of the beginning mentioned type in terms of a compact design while maintaining a  high crash safety as well as favorable assembly and driving dynamics properties to improve.

This task is solved by an auxiliary frame module of the type mentioned at the beginning at least two parallel to the front cross member Lines for a gaseous or liquid medium are provided, each one extend essentially across the width of the subframe and its connections are arranged such that at least two lines can be flowed through in the opposite direction are.

The forward and return lines of the crossbeam are exposed due to their Arrangement in the front of the vehicle is preferably used for cooling purposes cooling medium, for example, the compressed charge air of a charger on the way the motor suction side. It is also possible to use the lines for engine cooling to use. The crossbar can be used as a main cooler or in addition another cooler can be used. As a result, come as a cooling medium liquid media such as water or oil in question. It is also possible to use the crossbar to be used as a condenser for air conditioning purposes. Leave in all cases corresponding piping in the engine compartment can be saved, which in the end both a gain in space and a simplification of assembly as well as a Reduction of parts diversity is obtained. Moreover, it results from the usage the double width of the subframe as a cooling section is a particularly effective one Cooling that cannot be achieved with previous solutions.

The front crossmember preferably has a hollow chamber profile with at least one hollow chamber extending essentially over the width of the subframe, wherein at least one line runs within the hollow chamber profile. In principle it is possible in or on the front crossmember cables in the form of tubes or Lay hoses. However, the hollow chamber can also be used directly as Line are used, which makes the construction of the line system very simple. Furthermore, the forward and return lines form a compact unit, so that the front Crossbeam can be manufactured as a sub-module. The hollow chamber profile can be used as Cast part or extrusion can be made. It is also possible to do this through To produce internal high pressure forming or from individual sheet metal elements put together.  

Preferably, two lines can flow through in the opposite direction within the Hollow chamber profile, which results in a particularly compact structure. Will be at the front crossmember provided more than two lines, so it is continuing this consideration is advantageous if all lines are through hollow chambers at the front Crossbar are formed.

In a further advantageous embodiment of the invention, the connections from in In the opposite direction flowable lines on one side in the width direction of the Subframe shorted. This will further simplify the structure the radiator structure and the necessary cables in the engine compartment. The Short circuit can be done through a short connector, making the front Cross beam remains simple in shape. The connections on one side in However, the width direction of the subframe can also be within the hollow chamber profile be short-circuited, which results in a somewhat more compact design. Will the Lines directly on the short-circuit side via an overflow opening connected, the assembly effort can be kept particularly low.

However, it can be flowed through in the opposite direction between the connections of two Lines on one side in the width direction of the subframe also outside the Crossbar arranged cooler can be coupled to the cooling effect by a to further improve the larger heat exchange surface. For example, a Charge air cooler can be connected to one side of the subframe. Since the Connections on a common side of the subframe can be additional Lines in the engine compartment can be avoided. The one from the lines of the front Cross-beam caused additional cooling effect of the charge air can be used to to further optimize the engine combustion process or to Make the intercooler a little smaller.

The forward and return routing of the lines of the front crossmember allows in one a further advantageous embodiment, the external connections of the in In the opposite direction flowable lines on the same side in the width direction of the To arrange subframes. This is particularly advantageous if, as in Engines installed in the transverse direction of the intake and exhaust tract of the engine with respect to the subframe are on the same side. The connections between  the charge air connections and the engine then remain short. Moreover, the Flow losses in the charge air line are minimal. This applies accordingly of course also for other media to be cooled in relation to their engine or other unit connections.

The hollow chamber profile of the front crossmember can be in an advantageous embodiment three - shell sheet metal construction with an upper element, a lower element and an intermediate element are formed. The upper element then forms with the Intermediate element a first hollow chamber and the lower element with the Intermediate element a second hollow chamber. Both cavities are through one Overflow opening in the intermediate element on one side in the width direction of the Subframe are interconnected, with the external connections on the in Width direction opposite side of the subframe are arranged.

In this context, it is also possible to use two of the sheet metal elements in the essentially in the direction of the rear crossmember as a flat wall structure to extend the engine compartment floor cover. Between the extended ones Sheet metal elements are then formed flat hollow chambers that extend in the width direction of the subframe and to the lines through which flow can flow in the opposite direction are connected in parallel. For example, some of the flat hollow chambers assigned to the outgoing line and others to the flat hollow chambers of the return line to increase the heat exchange area. It is also possible to do the forwarding to be arranged only in the hollow chamber profile and in the flat wall structure only to provide return lines, or to reverse this. In addition to the reinforced The areal wall structure has a cooling effect, encapsulating the floor Engine compartment, resulting in an improvement in sound insulation. Moreover, the Stiffness of the front end structure increased in a way that is favorable for driving dynamics. In addition, the energy absorption capacity increases in the case of a frontal or Offset crash.

In a further advantageous embodiment of the invention is in the Hollow chamber profile a separate cooler with a variety of widthwise Subframe running lines attached, the connections of which are arranged that these lines in the opposite direction to one within the Hollow chamber profile arranged line can be flowed through. These lines of  separate cooler can in the manner already described above be interconnected. Despite the separate cooler remains because of this a compact unit directly on the front crossmember get the effect of a full cooler with large heat exchange area in integrated in a particularly compact manner. The cooler carries with it Component structure organically to increase the rigidity of the vehicle structure as well crash safety.

Preferably, the separate cooler is essentially a plurality of parallel tubes are formed, which are at least two across the tubes extending slats connected together and attached to the hollow chamber profile are.

In an alternative embodiment, the cooler is made by a one-piece casting formed, which is attached to the hollow chamber profile and on its attachment side has the ribs adjacent to the hollow profile, which with the hollow profile Form lines in the form of hollow chambers which extend in the width direction. In addition, the casting has on its outside facing away from the fastening side further ribs, which are arranged essentially transversely to the first-mentioned ribs are. This results in a particularly large one with simple manufacture Heat exchange surface.

In a further advantageous embodiment, the front crossmember can be detached with front ends of the longitudinal beams are coupled. This not only enables one First separate manufacture of the front crossbeam separately from the others Elements of the sub-framework, but also the formation of a defined interface, which allows assembly-related division of the subframe module into sub-modules, which are first assembled individually and then to the subframe module be put together, before this in turn as a unit in the Vehicle body is installed.

The front crossmember preferably faces the longitudinal crossmembers at its ends bent legs, at the ends of which the longitudinal beams are coupled, whereby the longitudinal beams continue the respective leg. This allows the subframe be trained relatively wide, so as to be a variety of  To carry vehicle components that are on the subframe before it Attachment to the vehicle body. The bow-shaped formation the front crossmember also allows for a compact design of the Front of the vehicle the inclusion of large gearboxes with their often after lids and oil pans protruding from the outside.

The bow shape of the front crossbar can still be used to Connections of the lines integrated in the front crossmember even closer to the to bring associated mating connections, for example on the engine block, without this would have to give up the sub-module structure of the subframe module. The The wiring effort in the engine compartment remains particularly low. Preferably extends there is at least one line in one or both legs of the front Crossbar into it. The legs can do this up to the wheel height in the direction of Longitudinal beams are guided to the rear.

The lines through which flows in the opposite direction form a first system. In a Another advantageous embodiment of the invention are in addition to this system second or further, similar systems independent of the first system intended. The systems can be connected in series or in parallel. This makes it possible to use the front cross-beam simultaneously for different To use cooling tasks. For example, it is possible in the vehicle's longitudinal direction Arrange a condenser on the front, a water cooler or one behind Charge air cooler and an oil cooler behind it. These coolers can also each can be provided as an additional cooler to a main cooler.

In a further advantageous embodiment of the invention is on the front Cross traverse provided a flat floor covering that to the Hollow chamber profile in the direction of the rear crossmember connects to the engine compartment partially or completely cover the floor. In this way an encapsulation is achieved which improves the energy absorption capacity of the subframe. At a Collision is the areal floor covering, for example as a sheet metal element is formed, but can also consist of other materials, deformed to thereby absorbing crash energy. The attachment to the front crossbar makes it possible first to cross the front cross beam with the areal Prefabricate floor cover and then this unit on the longitudinal beams  Fasten. In addition to an increase in crash safety, the areal Floor covering achieved an additional stiffening effect in the vehicle transverse direction become. In addition, the areal floor covering acts as sound insulation, so that the Noise emissions from the engine compartment can be reduced.

The extension of the areal floor cover can be the desired one Crash behavior can be coordinated. For example, it is possible to use the areal Form the floor cover so that one towards the rear crossbar pointing rear edge of the same lies between the legs. However, it is also possible that the areal floor covering in the direction of the rear crossmember protrudes beyond the thighs. To increase the rigidity of the sheet The floor cover is preferably cambered. This prevents the extensive floor covering during driving operation to disturbing vibrations is excited.

In addition, air guiding channels can be provided in the areal floor cover to provide a concentrated air supply at selected locations in the engine compartment cause. This can a. specifically for cooling temperature-sensitive units be used. For example, cooling air can be directed to a via the air duct Pendulum support, a gear oil and / or engine oil pan, a V-belt and the like are performed. There are preferably separate guide elements on the Base cover attached. The air ducts can, however, also directly in the areal floor covering can be formed, which simplifies production becomes.

The areal floor covering is preferably designed as a deep-drawn part. It is it is possible to form the front crossmember in one piece with the base cover. However, since a higher rigidity is sought in the area of the frame structure, the areal floor cover preferably formed as a separate part, which on the front crossbar is attached.

Furthermore, a flat area can be found on the legs of the front crossmember Side cover are provided, which differ from the respective leg in essentially perpendicular to the main plane of extension of the subframe upwards extends and at its upper edge for connection to the vehicle body  is trained. On the one hand, this can increase the energy absorption capacity. On the other hand, a further improvement in sound insulation is achieved. Preferably the areal floor cover becomes one piece with the side covers formed so that the entire capsule is easy to manufacture as a component that forms a sub-module of the subframe module together with the front crossmember.

Furthermore, a motor vehicle is proposed in which an auxiliary frame module type described above is attached to the body. The invention is suitable especially for passenger cars in a compact design with a short Front end with the engine installed in the transverse direction. The subframe can in doing so on two substantially extending in the longitudinal direction of the vehicle Sides of the vehicle body are attached. The side members can carry a bumper at the front end and a main crash plane at the front Train vehicle body in the range of 20 to 40 cm above the Subframe lies. In this case, longitudinal beams are preferably used which lead to the front end are cranked up so that the subframe in Fastening state, so to speak, of sections of the side members lying further back or the bottom of the vehicle body continues substantially horizontally.

The invention is illustrated below with reference to the drawing Exemplary embodiments explained in more detail. The drawing shows in:

Fig. 1 is a view from above of a first embodiment of a subframe module according to the invention,

Fig. 2 is a side view of the subframe module according to Fig. 1,

Fig. 3 is a vertical section in the vehicle transverse direction by a longitudinal beam of the auxiliary frame module along the line AA in Fig. 2,

Fig. 4 shows a further vertical section in the vehicle transverse direction by a fastening point of the longitudinal beam on the bodywork of a motor vehicle taken along line BB in Fig. 2,

Fig. 5 shows a vertical section in the vehicle transverse direction by a leg of a front crossmember of the auxiliary frame module along the line CC in Fig. 2,

Fig. 6 is a view from above on the front transverse member of the subframe module of FIG. 1,

Fig. 7 shows a vertical section in the vehicle longitudinal direction by the sub-frame module,

Fig. 8 is a vertical section in the vehicle longitudinal direction by the rear cross-beam of Fig. 1 in the region of mounting a pendulum support for a vehicle engine,

Fig. 9 shows a vertical section in the vehicle transverse direction by a truss assembly of the rear cross-member in the area of pendulum support along the line DD in Fig. 8,

Fig. 10 is a view from above on a rear cross-member of another embodiment of a subframe module according to Fig. 1,

Fig. 11 is a vertical section in the vehicle longitudinal direction by the rear cross-beam of Fig. 10 in the region of the attachment to a center tunnel of a vehicle body,

Fig. 12 is a view from above on a rear cross-member of a third embodiment of a subframe module according to Fig. 1,

Fig. 13 is a vertical section in the vehicle longitudinal direction by the rear cross-beam of Fig. 12 in the region of the attachment to a center tunnel of a vehicle body,

Fig. 14 is a view from above on a rear cross-member of a fourth embodiment of a subframe module according to Fig. 1,

Fig. 15 is a view from above of a variant of the front cross-member, which is alternatively applicable to a subframe module according to Fig. 1 to 14, and

Fig. 16 is a view from above of a further variant of the front cross-member, which is alternatively used in a subframe according to FIGS. 1 to 14,

Fig. 17 is a section through one leg of the front cross-member of FIG. 16,

Fig. 18 is a section through one leg of a further front cross-member,

Fig. 19 is a section through one leg of a further front cross-member with a separate cooler, and in

Fig. 20 is a section through one leg of a further front cross-member with a further, separate cooler.

The first exemplary embodiment according to FIG. 1 shows an auxiliary frame 1 for a motor vehicle, which is formed from a front cross member 2 , a rear cross member 3 and two longitudinal cross members 4 . All elements 2 to 4 of the subframe 1 are detachably connected to one another to form a closed frame structure which is fastened to the body of the same in the lower region of an engine compartment of the motor vehicle. Of the vehicle body, only two side members 5 are shown in FIG. 1, which, as can be seen from the side view in FIG. 2, are cranked upwards in the direction of the front end of the vehicle body and, among other things, carry a bumper 6 at their front end. The longitudinal beams 5 define a crash plane of the vehicle body. The subframe 1 is releasably attached to the two longitudinal beams 5 from below via four attachment points. It forms an additional, underlying crash plane, which is arranged approximately 20 to 40 cm below the longitudinal beams 5 . The subframe 1 continues the floor of the vehicle body essentially horizontally. In the event of a crash, the four fastening points here, which are located on sections of the subframe 1 extending in the longitudinal direction of the vehicle and are spaced apart, prevent the sections of the subframe 1 extending in the longitudinal direction of the vehicle from buckling prematurely. With larger forces, however, it is provided that the connections between the subframe 1 and the vehicle body tear off, so that the subframe 1 can be pushed under the floor of the passenger compartment to prevent penetration into the passenger compartment. In addition, the rear crossmember 3 is detachably connected to a center tunnel of the vehicle body via two further fastening points.

Two parallel lines 63 and 64 are provided on the front crossmember 2 and each extend essentially over the width of the subframe 1 . The two lines 63 and 64 have two external connections 65 and 66 . In the exemplary embodiment shown, they serve to couple a charge air line system to an engine, the inflow direction and the outflow direction being indicated by arrows in FIG. 1. The lines 63 and 64 and the outer connections 65 and 66 are arranged such that the two lines 63 and 64 are flowed through in the opposite direction by the charge air, so that it cools down while driving. Since the two outer connections 65 and 66 lie on one side in the width direction of the subframe 1 , there are short connection paths to the corresponding connection pieces of the motor.

The front cross member 2 is bent at its ends in the direction of a longitudinal cross member 4 , so that the ends of the front cross member 2 each form an approximately L-shaped leg 7 in the view from above. The legs 7 are each connected at their rear end to a front connecting section 8 of a longitudinal cross member 4 , the longitudinal cross members 4 initially continuing the legs 7 essentially in the longitudinal direction of the vehicle in order to ensure a favorable introduction of force into the longitudinal cross members 4 in the event of a frontal or offset crash ,

The connection point between the leg 7 and the longitudinal cross member 4 is in the area of a vehicle wheel, which is only indicated in FIG. 1 by its swivel area 9 . For the purpose of the largest possible frame width, in particular in the area of the front crossmember 2 , the legs 7 have drawn-in sections 10 in the area of the vehicle wheels towards the center of the subframe 1 , ie in the direction of the vehicle's longitudinal center axis, in order on the one hand to ensure the greatest possible distance between the legs 7 , on the other hand to rule out collisions with the vehicle wheels. In the exemplary embodiment shown, a transmission oil pan 11 and an engine oil pan 12 are located within the subframe 1 when viewed from above.

Furthermore, a condenser 13 and a cooler 14 arranged in parallel therewith and also a charge air cooler 15 are fastened to the front crossmember 2 within the subframe 1 . The charge air cooler 15 is coupled between the lines 63 and 64 on the side opposite the connections 65 and 66 , so that the line 63 a forward line from a charger on the engine to the charge air cooler 15 and the return line 64 a line from the charge air cooler 15 to one Intake tract of the engine represents. The front crossmember 2 is combined with the units and elements attached to it to form a sub-module of the subframe module, which is first preassembled and then as an assembly unit on a further sub-module, which includes, among other things, the longitudinal beams 4 and the rear crossmember 3 , is attached before the entire unit is connected to the vehicle body.

At the connection points between the two sub-modules, that is to say between the legs 7 and the longitudinal cross members 4, there is an increased risk of the subframe 1 buckling in the event of a crash. In addition, the legs 7 could wind up in the event of an unfavorable introduction of force, as a result of which a large part of the energy absorption capacity of the subframe 1 would be lost. In order to prevent this, the four fastening points 16 , 17 , 18 and 19 on each side of the subframe 1 , which each support a section of the subframe 1 extending essentially in the longitudinal direction of the vehicle along a longitudinal member 5 , are spaced apart from one another. A first attachment point 16 is located as far forward as possible on the front crossmember 2 directly behind the bend of the same on a leg 7 . Two further attachment points 17 and 18 are arranged in the front end region of the associated longitudinal cross member 4 , the second attachment point 17 located further forward, which serves to support the bending moment at the connection point, being provided on the connection section 8 . This second attachment point 17 is still in front of the wheel axis of a vehicle wheel. The third attachment point 18 is already located behind the wheel axle essentially in a straight extension of the two attachment points 16 and 17 . As can be seen in FIG. 1, the fastening points 17 and 18 of the longitudinal cross member 4 are in an area which is limited by the swivel area 9 of a vehicle wheel. The fourth fastening point 19 is arranged at the rear end of the longitudinal cross member 4 . However, it is also possible to already form them on the rear cross member 3 . In the area of the fourth, rear fastening point 19 , the vehicle body is reinforced in each case by a stiffening strut 61 , which each extend essentially in the transverse direction of the vehicle. The stiffening struts 61 are arranged between a side member 5 and a sill 62 of the vehicle body which is further outward in the transverse direction of the vehicle.

The attachment to the attachment points 16 to 19 takes place in each case by means of fastening screws to be screwed in from below, ie from the bottom side. This is advantageous because during assembly, the subframe module is moved up to the vehicle body from below and, after complete assembly, the attachment points remain easily accessible for the purpose of possible disassembly.

To further improve the absorption of forces and moments in the event of a crash, the front attachment point 17 on the connecting section 8 of the longitudinal cross member 4 is designed to be both rigid and resistant to moments. In the exemplary embodiment shown here, a spacer sleeve 20 is used to support the vehicle body or a longitudinal member 5 thereof. This spacer sleeve 20 extends substantially perpendicular to the main plane of extension 21 of the subframe 1 upwards. A fastening screw 22 is provided for bracing the longitudinal cross member 4 with the longitudinal member 5 , which is guided from below through the spacer sleeve 20 and braced against the longitudinal member 5 .

As can be seen from FIGS. 2 to 4, the spacer sleeve 20 is supported in two superimposed planes on the longitudinal cross member 4 , which are spaced apart from one another in the longitudinal direction of the spacer sleeve 20 . For this purpose, the lower end of the spacer sleeve 20 is inserted through an upper wall section 23 and a lower wall section 24 of the longitudinal cross member 4 and guided closely in the corresponding openings. In this way, in particular a moment that results from the height difference d indicated in FIGS. 3 and 5 of the centroids of the profile of the legs 7 and the longitudinal cross members 4 is supported.

In a modified embodiment, a fastening projection which extends upward to the vehicle body and is formed directly on the longitudinal cross member 4 can also be formed on the connecting section 8 . This is particularly advantageous when producing the longitudinal cross member 4 as a cast part, but is also possible with molded sheet metal parts.

As can be seen in particular in FIG. 2, the legs 7 of the front crossmember 2 are slightly inclined to the horizontal. In order to ensure the most stable possible connection between the legs 7 and the longitudinal cross members 4 , the legs 7 and the subsequent longitudinal cross members 4 are guided parallel to one another parallel to the main extension plane 21 of the subframe 1 . For this purpose, a sleeve 25 with a through opening is formed at the rear end of each leg 7 , the longitudinal axis of which extends essentially perpendicular to the main extension plane 21 . In the attached state, this sleeve 25 lies between two flange sections 26 and 27 at the front end of the associated longitudinal cross member 4 , which also each have a through opening. The sleeve 25 is braced with the flange sections 26 and 27 via a screw-nut connection, the screw 28 being passed through the through-openings.

The longitudinal cross members 4 have bearings 29 and 30 for supporting wheel links 31 on the vehicle. In order to create movement space for these wheel links 31 , the auxiliary frame 1 is tapered in its width in the area of the wheel links 31 in the direction of the rear crossmember 3 . A section 32 , which extends essentially in the transverse direction of the vehicle, is adjoined in the direction of the rear crossmember 3 by a further section 33 which extends essentially in the longitudinal direction of the vehicle. A stiffening element 34 in the form of a web or a rib is provided between these two sections 32 and 33 in order to prevent the longitudinal cross member 4 from buckling in the region of the step-like taper when the connecting section 8 is loaded in the longitudinal direction of the vehicle as a result of a crash.

On the further section 33 of the longitudinal cross member 4 , which extends essentially in the longitudinal direction of the vehicle, a bracket 35 is formed which extends upwards and outwards to the wheel side and which has the third fastening point 18 at its free end. When viewed from above, the bracket 35 protrudes at least partially with the third fastening point 18 beyond the section 33 of the longitudinal cross member 4 below it in order to overlap the wheel control arm 31 .

Fig. 6 shows a plan view of the front crossbar 2 , which is provided with an encapsulation. The encapsulation comprises a flat bottom cover 36 in the form of a deep-drawn part made of sheet metal, which connects to the front crossmember 2 in the direction of the rear crossmember 3 . In the connection area with the front crossmember 2 , the flat bottom cover 36 forms a hollow profile in cross section. In the event of a crash, the areal base cover 36 crumples and thereby absorbs crash energy. Instead of a sheet metal part, a floor covering made of another material with a high energy absorption capacity can also be used here. For example, fiber composite materials can be used for this.

In the illustrated first exemplary embodiment, the areal floor cover 36 is fastened from below to a section 37 which extends essentially in the transverse direction of the vehicle and also to the legs 7 of the front cross member 2 and extends under the engine compartment to the rear cross member 3 , as shown in FIG Fig. 7 is shown. To completely encapsulate the engine compartment from below and to avoid oscillations and vibrations, the areal floor cover 36 is still connected to the longitudinal cross members 4 and the rear cross member 3 by means of detachable connecting elements. As a result, the areal floor cover 36 can already be integrated into the sub-module of the front crossmember 2 during the pre-assembly. To further stiffen the areal floor cover 36 is additionally cambered.

Furthermore, openings 38 are formed in the areal floor cover 36 , via which air can flow into the engine compartment. The incoming air can be directed to the engine, but can also be directed to specific locations within the engine compartment for cooling purposes. For channeling the inflowing air, air guiding channels 39 are also provided on the areal floor cover 36 , with which a kind of nozzle effect is produced, for example, by tapering the channel cross section. In the first exemplary embodiment, correspondingly shaped guide plates 40 are attached to the planar base cover 36 from below to form the air guiding channels 39 , each of which guides with its rear end to an opening 38 .

On the two-dimensional floor cover 36 , two- dimensional side covers 41 are additionally formed, which surround the outside of the legs 7 of the front crossmember 2 and are pulled up to the vehicle body, in particular its side members 5 . The areal side covers 41 are coupled to the vehicle body, in this case its side members 5 , via releasable connecting elements 42 , as can be seen in particular from FIG. 5. The side covers 41 are formed in one piece with the base cover 36 and enclose an angle of approximately 90 degrees with the latter.

In the following, the rear crossmember 3 of the first embodiment will now be explained in more detail, which is shown in FIGS. 1 and 7 to 9. As shown in FIG. 7, the rear crossmember 3 has a trough-shaped, upwardly open cross-sectional profile. The profile floor 43 , which is provided with a plurality of beads running in the transverse direction of the vehicle, is relatively ready in the longitudinal direction of the vehicle, so that elements and assemblies of the motor vehicle can be accommodated within the trough-shaped profile and, moreover, a long crumple zone is formed. In the example shown here, a steering gear 44 , an ABS unit 45 and an electro-hydraulic pump unit 46, among others, are at least partially received and supported in the profile.

The rear crossmember 3 is fastened to the longitudinal cross members 4 by means of connecting screws 47 , for which corresponding fastening flanges 50 and 51 are formed on the upper edges of the profile side walls 48 and 49, respectively.

Furthermore, a pendulum support 52 for an engine (not shown here) is fastened to the profile side wall 48 lying forward in the vehicle longitudinal direction in order to support its reaction moment against the body. This pendulum support 52 is shown in more detail in FIGS. 8 and 9. The pendulum support 52 extends essentially in the longitudinal direction of the vehicle and is supported against the outside of the front profile side wall 48 . Furthermore, the pendulum support 52 acts at the height of the center of gravity of the profile of the rear crossmember 3 . The rear crossmember 3 is additionally stiffened in the area of the force application of the pendulum support 52 by a reinforcing plate 53 . The reinforcing plate 53 is fastened between the inside of the profile side wall 48 and the profile base 43 , as a result of which a hollow cross section is formed in the region of the pendulum support 52 in the longitudinal direction of the vehicle, as shown in FIG. 9. Lateral striking plates 58 and 59 are provided to further stiffen the front profile side wall 48 against the profile base 43 . These form a box with the reinforcement plate 53 .

FIGS. 10 and 11 show a further exemplary embodiment of an auxiliary frame module, which differs from the above-described auxiliary frame module only by means of additional stiffening of the rear transverse cross arm 3. These additional stiffeners are highlighted in FIG. 10. First of all, stiffening struts 54 arranged in the manner of trusses are provided in FIG. 10 within the trough-shaped profile and are arranged here in a W-shape. The stiffening struts 54 are sheet metal elements which are dotted or continuously welded to the profile base 43 and which support the profile side edges 48 and 49 against one another, so that they cannot easily buckle under a load. The stiffening struts 54 are oriented in such a way that force is introduced into the center tunnel 55 of the vehicle body to which the rear crossmember 3 is attached here. For this purpose, a fastening flange 51 in the form of an essentially horizontal wall section, which is provided on the profile side wall 49 lying at the rear in the vehicle longitudinal direction, is drawn over the entire length of the rear crossmember 3 in the vehicle transverse direction and has two fastening points for connection to the center tunnel 55 or screwing brackets 56 provided thereon , The latter can be seen particularly well in FIG. 11. Fastening is carried out here using fastening screws 57 inserted from the bottom.

In contrast to the first exemplary embodiment, for further stiffening, the fastening flange 50 on the profile side wall 48 lying forward in the longitudinal direction of the vehicle is extended in the transverse direction of the vehicle and pulled up to the third fastening points 18 on the longitudinal cross members 4 . The belt formed in this way is tensioned together with the longitudinal cross members 4 at the fastening points 18 with the vehicle body. This further improves the rigidity in the transverse direction of the vehicle.

FIGS. 12 and 13 show a third embodiment of a subframe module that differs from the just described second embodiment, only the arrangement structure of the stiffening struts 54. This is roughly X-shaped in order to avoid collisions with the ABS unit 45 and the electro-hydraulic pump unit 46 . However, in the event of a crash, force is also introduced in the direction of the center tunnel 55 , so that the deformability of the rear crossmember 3 is well utilized. In particular, this allows the deformation in the foot area of the passenger compartment of the motor vehicle to be reduced.

Fig. 14 shows a fourth embodiment which corresponds essentially to the third embodiment. However, two striking plates 58 and 59 are additionally provided in the area of the pendulum support 52 , which additionally support the front profile side wall 48 against the stiffening struts 54 and here extend in the longitudinal direction of the vehicle. Here, too, the profile of the rear crossmember 3 can be stiffened by a reinforcing plate 53 such that a box-shaped hollow body is formed in the fastening area of the pendulum support 52 .

In an averted embodiment, the rear crossmember 3 is designed as a casting. In this case, the stiffening elements 54 and any striking plates 58 and 59 which may be present are integrally formed as integral ribs on the rear crossmember 3 .

Furthermore, FIG. 15 shows a simplified example of the front crossbar 2 , which can be used in the exemplary embodiments instead of the crossbar described above. On the simplified crossbar 2 , in turn, a flat bottom cover 36 is formed, which does not, however, extend to the rear crossbar 3 , but already ends with its rear edge 60 between the legs 7 . In addition, the air ducts have been dispensed with here.

Furthermore, the two lines 63 and 64 on the side opposite the external connections 65 and 66 in the width direction of the auxiliary frame 1 within the profile of the front crossmember 2 are short-circuited by an overflow opening 67 between the hollow chambers of the profile, which form the lines 63 and 64 here is provided. In this case, the front cross member 2 itself serves as an intercooler, so that the additional intercooler 15 can be omitted from FIG. 1.

Figs. 16 and 17 show a further variant of the front cross-member 2 which can be used in the above-described embodiments. This variant corresponds essentially to the front crossmember according to FIG. 15, but a flat floor covering or capsule is omitted. The path of the medium to be cooled is again indicated by arrows in FIG. 16. The entry takes place here in the region of a leg 7 of the front crossmember 2 through the outer connection 65 , which is designed as an upwardly projecting connection piece. The medium to be cooled then flows through the front crossmember 2 through to the other side of the auxiliary frame 1 , where it enters the return line 64 via an overflow opening 67 , around the auxiliary frame 1 through the outer connection 64 , which also acts as an upwardly projecting connection piece is trained to leave.

As shown in FIG. 17 in particular, the front crossmember 2 has a hollow chamber profile with two hollow chambers here, which essentially extend over the width of the auxiliary frame 1 . The two hollow chambers directly form the two lines 63 and 64 . In the exemplary embodiment shown, the hollow chambers lie one above the other, the hollow chamber lying below, which represents the outgoing line 63 , extending into a leg 7 of the front crossmember 2 .

The hollow chamber profile of the front crossmember 2 is designed as a three-shell sheet metal construction and has an upper element 69 , a lower element 70 and an intermediate element 71 . A first hollow chamber between the upper member 69 and the intermediate member 71 and between the lower member 70 and the intermediate member 71 is formed a second hollow chamber. The lower element 70 forms together with the intermediate member 70 at the same time, the legs 7 of the front cross-member 2, while the upper member is placed only in the extending portion 37 in the transverse direction of the front cross-member 2 69th The overflow opening 67 is formed by a simple opening in the intermediate element 71 .

In the variant shown in FIG. 18, the lower element 70 and the intermediate element 71 are substantially extended in the direction of the rear crossmember 3 as a flat wall structure 72 for covering the engine compartment on the bottom, which takes over the function of a flat bottom cover. Flat hollow chambers 73 and 74 are formed between the elongated sheet metal elements 70 and 71 , which extend in the width direction of the front crossmember 2 and are connected in parallel to the lines 63 and 64 through which flow can flow in the opposite direction. The hollow chambers 73 and 74 serve here as lines from the engine side of the subframe 1 to the transmission side and thus supplement the supply line 63 for the purpose of increasing the heat exchange surface of the air coming from a charger.

Two further variants with a separate cooler 75 , which is, however, organically integrated into the front crossmember 2, are shown in FIGS. 19 and 20. The cooler 75 has a plurality of lines extending in the width direction of the subframe 1 , which run parallel to the lines in the hollow profile of the front crossmember 2 . Their connections are arranged such that these lines are flowed through in the opposite direction to a line arranged within the hollow chamber profile. In this case, the front crossmember 2 is formed with a single hollow chamber for a line 64 which extends through the section 37 which extends in the transverse direction. The crossbar 2 is formed here with two shells, but can also be made in one piece, for example as a cast or extruded part. The structure of the hollow chamber profile remains simple. The separate cooler 75 is attached to this hollow chamber profile from below.

With this design too, it is possible to couple a further cooler, which is arranged outside the hollow chamber profile of the cross-beam 2 , between the outward and return lines 63 and 64 on one side of the auxiliary frame 1 . However, since the separate cooler 75 can be designed with large heat exchange surfaces, it can also function as the main cooler on its own, so that the lines 63 and 64 are directly connected to one another at their connections on one side in the width direction of the subframe 1 , ie are short-circuited.

In the example shown in FIG. 19, the separate cooler 75 is formed by a multiplicity of substantially parallel tubes 76 , which serve as feed lines 63 . The tubes 76 , which again lead transversely from the engine to the transmission side, are connected to one another via at least two fins 77 extending transversely to the tubes 76 and are fastened to the hollow chamber profile. The slats are aligned with the direction of travel. This achieves a strong cooling effect on the medium to be cooled, in particular on the way through the pipes 76 .

Alternatively, as shown in FIG. 20, the separate cooler 75 can also be a one-piece casting which is fastened to the hollow chamber profile and has ribs 78 which abut the hollow chamber profile on its fastening side. With an outer wall of the hollow chamber profile, the ribs 78 form further hollow chambers which serve as lines 63 extending in the width direction. The cast part has on its outer side facing away from the fastening side further ribs 79 which run essentially transversely to the first-mentioned ribs 78 and extend longitudinally to the direction of travel. For example, it is made of cast magnesium with a wall thickness of approximately 2 mm, so that the overall weight of the structural unit with an integrated cooler is not significantly increased.

The separate coolers 75 according to FIGS. 19 and 20 are preferably fastened from below to a front crossmember 2 with a short capsule according to FIG. 15, for example screwed, riveted or glued.

The cooling line system of the front crossmember 2 has been explained above in connection with charge air cooling. However, it is also possible to use this cooling line system for other cooling purposes, for example for engine cooling or for a condenser of an air conditioning system. In these cases, liquid cooling media such as water or oil are used.

In addition to a first cooling system, a second or further, Similar systems are provided independently of the first system, the Systems that can be arranged in parallel or in series.

The subframe modules according to the embodiments described above are characterized by a high energy absorption capacity and thus enable a motor vehicle with high crash safety in a frontal or offset crash. In addition, the subframe modules described can be installed efficiently. moreover they have a positive influence on the driving dynamics of the motor vehicle Wise.

The front crossmember can perform the functions of a cooler, especially one Intercooler, a crash element and an engine compartment capsule in one unit combine.  

LIST OF REFERENCE NUMBERS

1

subframe

2

front crossbar

3

rear crossbar

4

Main beam

5

longitudinal beams

6

bumper

7

leg

8th

front connection section

9

Swivel range of a vehicle wheel

10

indented section

11

Transmission oil pan

12

Engine oil pan

13

capacitor

14

cooler

15

Intercooler

16

to

19

fastening point

20

Stand Off

21

Main plane

22

fixing screw

23

upper wall section

24

lower wall section

25

shell

26

flange

27

flange

28

screw

29

camp

30

camp

31

Radlenker

32

Section of the longitudinal cross member running in the transverse direction of the vehicle

33

Section of the longitudinal crossmember running in the longitudinal direction of the vehicle

34

stiffener

35

console

36

extensive floor covering

37

transverse section of the front crossmember

38

opening

39

air duct

40

guide plate

41

side cover

42

connecting element

43

Duct floor

44

steering gear

45

ABS-unit

46

electro-hydraulic pump unit

47

connecting screw

48

front profile side wall

49

rear profile side wall

50

mounting flange

51

mounting flange

52

Stabilizer

53

Support panel

54

stiffener

55

center tunnel

56

connection console

57

fixing screw

58

striking plate

59

striking plate

60

trailing edge

61

Versteifungsstrebe

62

sill

63

(Forward) line

64

(Return) line

65

external connection

66

external connection

67

overflow

69

top element

70

lower element

71

intermediate element

72

extensive wall structure

73

flat hollow chamber

74

flat hollow chamber

75

separate cooler

76

pipe

77

lamella

78

rib

79

another rib
d distance

Claims (20)

1. Subframe module for a motor vehicle, comprising a front crossmember ( 2 ) and a rear crossmember ( 3 ), which are connected via two longitudinal crossbars ( 4 ) to form a closed subframe ( 1 ), which is designed to be attached to a vehicle body from below to be fastened and to surround an engine compartment in the fastened state, at least two lines ( 63 , 64 , 73 , 74 ) for a gaseous or liquid medium, which are each essentially provided, being provided on the front cross member ( 2 ) Extend the width of the subframe ( 1 ) and the connections ( 65 , 66 , 67 ) of which are arranged such that at least two lines can be flowed through in the opposite direction. 2. Subframe module according to claim 1, characterized in that the front crossmember ( 2 ) forms a hollow chamber profile with at least one substantially over the width of the subframe ( 1 ) extending hollow chamber, and at least one line ( 64 ) runs within the hollow chamber profile. 3. Auxiliary frame module according to claim 1 or 2, characterized in that two lines ( 63 , 64 ) which can be flowed through in the opposite direction run inside the hollow chamber profile. 4. Subframe module according to one of claims 1 to 3, characterized in that all the lines ( 63 , 64 , 73 , 74 ) are formed by hollow chambers in the front crossmember ( 2 ). 5. Subframe module according to one of claims 1 to 4, characterized in that the connections of lines through which flows in the opposite direction ( 63 , 64 ) are short-circuited on one side in the width direction of the subframe ( 1 ). 6. Subframe module according to one of claims 1 to 5, characterized in that the connections of lines through which flow in the opposite direction ( 63 , 64 ) are short-circuited on one side in the width direction of the subframe ( 1 ) within the hollow chamber profile. 7. Auxiliary frame module according to one of claims 1 to 6, characterized in that the lines ( 63 , 64 ) directly on the short-circuit side via an overflow opening ( 67 ). 8. Subframe module according to one of claims 1 to 7, characterized in that between the connections of two flowable in the opposite direction lines ( 63 , 64 ) on one side in the width direction of the subframe ( 1 ) an outside of the crossbar ( 2 ) arranged cooler, in particular a charge air cooler ( 15 ) is coupled. 9. Auxiliary frame module according to one of claims 1 to 8, characterized in that external connections ( 65 , 66 ) of the through-flow lines ( 63 , 64 ) are arranged on the same side in the width direction of the auxiliary frame ( 1 ). 10. subframe module according to one of claims 1 to 9, characterized in that the hollow chamber profile of the front transverse member is designed as a three-skinned plate construction with an upper member (69), a lower member (70) and an intermediate element (70) (2), wherein the upper element ( 69 ) forms a first hollow chamber with the intermediate element ( 71 ) and the lower element ( 70 ) forms a second hollow chamber with the intermediate element ( 71 ), the hollow chambers opening through an overflow opening ( 67 ) in the intermediate element ( 71 ) one side in the width direction of the subframe ( 1 ) are connected to one another, and that the outer connections ( 65 , 66 ) are arranged on the opposite side in the width direction of the subframe ( 1 ). 11. Subframe module according to claim 10, characterized in that two of the sheet metal elements are extended substantially in the direction of the rear crossmember ( 3 ) as a flat wall structure ( 72 ) for the bottom cover of the engine compartment, wherein flat hollow chambers are formed between the extended sheet metal elements extend in the width direction of the subframe ( 1 ) and are connected in parallel with the lines ( 63 , 64 ) through which flow can flow in the opposite direction. 12. Auxiliary frame module according to one of claims 1 to 9, characterized in that a separate cooler ( 75 ) with a plurality of lines ( 63 ) extending in the width direction of the auxiliary frame ( 1 ) is attached to the hollow chamber profile, the connections of which are arranged such that that these lines can be flowed through in the opposite direction to a line ( 64 ) arranged within the hollow chamber profile. 13. Subframe module according to claim 12, characterized in that the separate cooler ( 75 ) is formed by a plurality of substantially parallel tubes ( 76 ) which are connected to one another via at least two fins ( 77 ) extending transversely to the tubes ( 76 ) and are attached to the hollow chamber profile. 14. Subframe module according to claim 12, characterized in that the cooler ( 75 ) is formed by a one-piece casting which is attached to the hollow chamber profile and on its fastening side on the hollow chamber profile has ribs ( 78 ) which with the hollow chamber hollow chambers as lines ( 63 ), which extend in the width direction, and that the cast part further has ribs ( 79 ) on its outer side facing away from the fastening side, essentially transverse to the first-mentioned ribs ( 78 ). 15. Subframe module according to one of claims 1 to 16, characterized in that the front cross member ( 2 ) is detachably coupled to the front ends of the longitudinal cross members ( 4 ). 16. Subframe module according to one of claims 1 to 17, characterized in that the front cross member ( 2 ) at its ends to the longitudinal cross members ( 4 ) has bent legs ( 7 ), at the ends of which the longitudinal cross members ( 4 ) are coupled, the Longitudinal cross members ( 4 ) continue each leg ( 7 ). 17. Subframe module according to claim 18, characterized in that at least one line ( 63 ) extends into one or both legs ( 7 ) of the front crossmember ( 2 ). 18. Subframe module according to one of claims 1 to 19, characterized in that on the front crossmember ( 2 ) a flat bottom cover ( 36 ) is provided which connects to the hollow profile in the direction of the rear crossmember ( 3 ) to the engine compartment partially on the bottom or to cover completely. 19. Subframe module according to one of claims 1 to 20, characterized in that the flow through lines in the opposite direction ( 63 , 64 ) form a first system, and that in addition to this system, a second or further, similar systems regardless of the first system on the front crossmember ( 2 ) are provided. 20. Motor vehicle, in particular a passenger vehicle, characterized by an auxiliary frame module according to one of the preceding claims, which is fastened to the body of the motor vehicle, for example to two longitudinal members ( 5 ) of the motor vehicle which extend substantially in the longitudinal direction of the vehicle.