DE10240395A1 - Cross-member for vehicle incorporates curved tubes or curved bars in area between A-pillar and propeller shaft tunnel, tubes being made from fiber-reinforced plastic and bars having metal-plastic hybrid structure - Google Patents

Abstract

Cross-member (10) for a vehicle incorporates curved tubes (12) or curved bars in the area between the A-pillar and the propeller shaft tunnel. The tubes are made from fiber -reinforced plastic and the bars have a metal/plastic hybrid structure.

Description

Field of the Invention

The invention relates to a cross member, the under the instrument panel of motor vehicles is provided and as Recording for different cockpit components. In addition, is more common Way on the cross member screwed the instrument panel.

State of the art

Such cross beams are usually made of a steel tube produced using the internal high-pressure process, to which various recordings welded become. These recordings include, for example a recording for the airbag, knee protectors, the instrument panel connection, the Connection to the A-pillars, the support the crossmember, tunnel supports, steering column mounts, etc. However, these show ordinary Steel crossbeam a relatively high one Weight on the vehicle due to the additional the motor vehicle to be carried Weight adversely affects fuel consumption. Further are relatively many Steps required to provide the various connections on the steel cross member. At the same time the welding can of these connections cause that the steel cross member disfiguration.

Therefore, in the past also magnesium cross beams developed, in which the connections are directly die-cast can be molded with and thus opposite the steel cross member Work steps can be saved. Magnesium cross beams are however relatively space-intensive.

From the DE 100 64 522 A1 a cross member is known which consists of a straight, tubular base body, in which at least one channel is provided, the cross base body preferably being made of metal. Inside, the base body is lined with plastic, so that duct walls made of plastic are formed. This means that no additional air routing components such as blowing parts, air hoses or the like need to be provided, since these media can be passed directly through the pipe. Furthermore, the wall thickness of the base body made of metal can be reduced and thus weight can be saved.

From the DE 200 08 201 U1 an instrument panel carrier is known which has an elongated shell-like base body and stabilizing inserts made of metallic materials. These elements are joined together by an injection-molded inner plastic ribbing to form a metal-plastic composite part which is at least partially penetrated by at least one air duct. Together with the plastic ribbing, outwardly projecting holders, brackets and connection points made of plastic are injection molded onto the base body.

It is a task of the present Invention, a cross member for a Provide motor vehicle that requires a relatively small amount of space and is light in weight.

This task is done with a cross member with features of claim 1 solved.

The invention is based on the idea that the main loads on a cross member usually range between left A pillar and tunnel support of the motor vehicle occur. In the area between the tunnel support and on the right A pillar, however hardly any strength left be included. Therefore solve the invention the object in that the cross member in this load-intensive area is provided as an arch, the good Has force absorption properties. For this purpose, the arch in metal-plastic hybrid construction, i.e. H. through a deep-drawn metal profile, into the plastic ribs are used, executed or formed by a pipe bend made of a fiber composite material. Both versions have the property that they have a significant weight saving potential across from usual Steel cross members have, the force absorption properties or strength properties through the choice of materials and shape, i.e. the arch shape, guaranteed are. The strength of the pipe bend made of fiber composite material also contributes in that the bend has a tube cross-section that is in itself increased Stiffness properties and yet little weight Has. In particular, a tube with a circular cross section is advantageous with other closed cross-sectional profiles similar Have strength properties.

Furthermore, in both embodiments it is possible to Insert the arcuate Component in an injection molding tool, i.e. the pipe bend made of fiber composite material or the deep-drawn metal profile, directly other connection elements to inject without additional Work steps required become. Thus, the cross member an elevated Degree of integration.

Advantageous embodiments are characterized by the remaining claims.

Thus, according to a particularly preferred embodiment, for the area between the left A-pillar in the motor vehicle and the cardan tunnel, a pipe bend made of plastic reinforced with carbon fibers, plastic reinforced with glass fibers, with aramid fabric or with mixed fibers is reinforced Plastic provided.

The fiber composite pipe can be wound or by applying a braided hose made of fiber composite material on a core and a subsequent one Laminating can be made. The cores used for this can e.g. B. wood, foam or sand cores, which after laminating the Pipe either remain in the component or removed from it become. The process of making curved tubes in internal pressure or hose blowing method is known in the art. The lamination as such takes place, for example, in the resin injection process or by vacuum pressing. It is also possible to make a pipe bend from fiber composite material, pre-impregnated To use fiber composites (prepregs) and in the autoclave process To form elbows. Can also for the production of the fiber composite tube with fiber braiding hoses incorporated thermoplastic threads (e.g. PA) can be used after forming and cooling Form fiber composite pipe.

These pipe bends are advantageous the A-pillar fixed with a clamp connection and additional gluing, wherein the clamp connection is advantageously made of steel is and openings for screwing to the A-pillar having. The additional Bonding offers damping properties and also works notch stress reducing, so that the component increased strength properties having. This clamp connection can also be supported by positive locking, d. H. the fiber composite pipe can, for example, in this area have a polygonal profile that twists the clamp connection prevented. The spraying of a connection fake on the fiber composite pipe for attachment to the A-pillar is also possible.

Are preferably attached to the cross member, i. H. the bow, in addition Connection components, fastening components for those to be attached to the instrument panel Components and / or safety components, such as knee protectors, in Injection molding process injection molded. An instrument panel connection can also be injection molded onto the elbow directly. connecting elements can easily and without significant additional manufacturing steps to get integrated. It is therefore possible to have several connection elements in a single manufacturing step, namely the injection molding step, to connect with the arch element. If a metal-plastic hybrid arch is used, so at Inject the plastic ribs into the metal profile at the same time the connecting parts are molded using the injection molding process. In this case only the open sheet metal profiles inserted into the injection mold and the stiffening ribs as well as the connecting parts can in be molded onto a manufacturing step.

The cross member preferably has, in particular if it is made as a pipe bend from fiber composite material, generally a circular one Cross section on. In the area of the connection of the knee protectors, the Instrument panel connection or the like points the cross member advantageously a cross-sectional shape with the inner cross-section a fastening area of the connecting parts, such as, for example the knee protectors or the instrument panel connection, is form-fitting. For example Polygon profiles, preferably triangular profiles, are used, that prevent twisting of the plastic injections in the pipe bend. This ensures that in addition to the clamping effect caused by the injection itself occurs, a positive connection is provided and Z. B. the knee protectors nevertheless yield sufficiently in the event of a crash can and powers be able to record.

According to one, the cross member comprises preferred embodiment also a connecting strut, which is currently designed, for example is between the tunnel support and the right A pillar. This Connecting strut is preferably designed as an injection molded component and can be attached directly to the pipe bend made of fiber composite material or Metal-plastic hybrid construction sheets are molded. The The connecting strut itself can also be knee protectors, a recording for the passenger airbag and a connection for the instrument panel and the A pillar have, these elements preferably also directly in Injection molding processes are injection molded. This allows additional manufacturing steps be avoided. Because additionally the main force absorption in the area between the left A-pillar and Cardan tunnel, it is sufficient for strength reasons, make the connecting strut as an open profile with stiffening ribs.

When connected to a fiber composite pipe, the is manufactured in the internal pressure or hose blowing process, connecting elements should be injection molded, the fiber composite tube is preferably during the Injection molding process with internal pressure. Alternatively, the pipe bend for example also filled with sand before injection molding, equipped with wooden cores become or can Fluids are introduced. This prevents the fiber composite pipe squeezed at the high pressures that occur during the injection molding process becomes.

The steering column connection, which is usually a is metallic component, is preferably on the pipe bend by means of a positive, non-positive and / or material connection. Especially when using a material connection by means of adhesive, if necessary additionally to a form and / or non-positive Connection, can stress peaks in the fiber composite pipe are relieved in the event of a load be, which in turn has a notch effect and thus a reduced Strength of the component prevented.

In addition to the use of a metallic steering column connection a steering column connection is also preferred with thermoplastic matrix in the deep-drawing process. The plastic parts are preferably by screwing, gluing or welding on the pipe bend attached.

Overall, the use of a pipe bend indicates or a sheet of fiber composite material or in metal-plastic hybrid construction in Improved vibration properties compared to steel components on what in particular means that the required natural frequency value from a cross member due to the matrix and fiber composite better than with a steel component Fulfills becomes.

According to a particularly preferred embodiment includes the cross member also in the passenger area, d. H. in the area between the cardan tunnel and right A-pillar also a bow in metal-plastic hybrid construction or one Pipe bend made of fiber composite material. This arch ends on the left Cardan tunnel wall and is screwed to the right A-pillar. knee protectors and other connection elements can just like the arch between the left A-pillar and Cardan tunnel is provided, molded: be.

The knee protectors on one or both of the arches are attached, preferably as open, with ribs increased Components or alternatively designed as loops.

If two sheets are used, i. H. a first Arch from the left A pillar leads to the cardan tunnel wall, and a second arch that goes from the cardan tunnel wall to the right A-pillar leads, these will be Bows preferably by a receiving device, for example, also molded on for an audio and / or navigation device or a connecting strut which, for. B. as an open profile with ribbing accomplished is connected. These items can alternatively, otherwise, d. H. subsequently attached to the arches be, however, this additional Work steps required and is therefore less preferred.

Are preferably at the respective Bows additionally fasteners provided in the form of clamp connections and / or latches, into the cables, especially flat or round conductors can. This eliminates the need to attach such cables to the cross member with cable connectors.

Short description of the drawings

In the following the invention will be pure exemplary with reference to the attached Described drawings in which:

1 shows a first embodiment of the cross member according to the invention;

2 shows a second embodiment of the cross member according to the invention;

3 shows a further embodiment of the cross member according to the invention; and

4 shows an alternative embodiment in the area of the steering column connection.

Ways to Execute the invention

The cross member according to the invention 10 who in 1 is shown, comprises a pipe bend between the connection to the left A-pillar of the motor vehicle and the cardan tunnel wall 12 made of a fiber composite material, preferably CFRP (plastic reinforced with carbon fibers). There is a column connection for attachment to the left A-pillar (not shown) 14 provided, which in turn made of metallic material and on the pipe bend 12 is jammed, that is connected positively and frictionally, and is additionally fastened with adhesive. The adhesive with which the connection 14 on the elbow 12 attached, has a damping effect and reduces notch stress on the pipe bend 12 , The connection 14 , ie mostly a clamp connection, is preferably made of steel and has openings for screwing to the A-pillar.

Furthermore, the in 1 shown cross member in the area of the pipe bend 12 knee protectors 16 injection molded. One of the knee protectors 16 , the left one in 1 , is also integral with an instrument panel connection 18 molded, which in turn is injection molded and incorporates stiffening ribs. In the 1 used knee protectors 16 have a loop-like shape. As it cut from AA 1 can be seen in the area of the knee protectors 16 the elbow 12 shaped with a polygon profile, ie a triangular profile, so that the molded knee protector 16 together with the integrally manufactured instrument panel connection 18 (or with the right knee protector 16 without the instrument panel connection) opposite the pipe bend 12 not twisted even when loads occur.

Instead of the instrument panel connection 18 integral with the knee protector 16 to shape, it is also possible to separate both elements on the pipe bend 12 to install.

Furthermore, in the area of the pipe bend 12 of the cross member 10 a steering column connection 20 intended. The steering column connection 20 , on which the screw plate of the steering column (also not shown) is mounted, can be used with the pipe 12 enter into a positive, non-positive and / or integral connection. Adhesive for the connection, at least additionally to be provided, is preferred, since in this way stress peaks in the fiber composite tube are reduced in the event of a load and thus the strength of the fiber composite tube 12 is not affected. The steering columns binding 20 itself is preferably made of metallic material, ie steel or the like.

As in 4 shown, instead of the metallic steering column connection ( 20 ) also consider a connection where the in 4 pipe bend shown as an example 12 two fiber-reinforced plastic parts 21 be attached. These are produced in the deep-drawing process, that is to say by inserting the half-shells into a tool, heating and shaping, fiber composite panels with a thermoplastic matrix, ie in particular panels made of oriented continuous fibers with a thermoplastic matrix, which are available as half-shells, being used as the starting material. These molded plastic parts 21 are by screwing or gluing or welding to the pipe elbow 12 attached. The screw holes provided are in 4 recognizable.

The cross member 10 according to 1 also has a connecting strut 22 on. This connecting strut 22 is injection molded on the pipe elbow 12 molded from fiber composite material, whereby in the connection area 24 again a positive connection is used, ie the pipe bend in this area has, for example, a triangular or other polygonal cross-sectional profile. The connecting strut 22 that differ from the connection area 24 on the elbow 12 extends to the right A-pillar (not shown), in turn is designed as an injection molded component with reinforcing ribs.

In the illustrated embodiment, the connecting strut 22 knee protectors 17 for the passenger area, an airbag connection 26 as well as the connection 28 molded directly onto the A-pillar (right A-pillar). This means if the piece of pipe 12 is inserted into the injection mold and, if necessary, is filled with sand or other cores or fluids before the injection molding in order to squeeze the tubular element 12 To avoid during the injection molding process, all other elements can be molded in one step. Thus, the manufacturing process is not very labor intensive. If required, fastening elements for lines (not shown) can also be attached to the pipe bend 12 or the connecting strut 22 be molded on.

The elbow 12 itself is preferably produced by applying a braided hose made of fiber composite material to a core (wood, foam, sand core) and then laminating. The core can be removed from the component after lamination or remains in the component, depending on the type of core.

2 shows a further embodiment of the cross member 10 according to the invention. The area between the left A-pillar (not shown) and the cardan tunnel is essentially identical to that in connection with 1 . described Therefore, the description will not be repeated. Only the knee protectors 16 are in the in

2 shown embodiment executed as open components.

In the area between the cardan tunnel and the right A-pillar, the in 2 crossmember shown 10 through an elbow 32 made of fiber composite material similar to the pipe bend 12 educated. On this elbow 32 are knee protectors 17 in an open embodiment and a connection to the instrument panel 18 molded. The connection to the right A-pillar 34 is according to the connection 14 to the left A pillar.

It is also possible to have additional connecting elements on this pipe bend 32 to attach, for example a receptacle for an airbag or the like.

Another embodiment of the cross member 10 is in 2 also hinted at. The left pipe bend 12 and the right elbow 32 , ie the pipe bend 12 , which covers the area between the left A-pillar and the cardan tunnel and the right pipe bend 32 , which covers the area between the cardan tunnel and the right A-pillar, is connected to each other by adding an injection molded connector between the two elements. This injection molded connection part can, for example, be a receptacle 36 for an audio or navigation device or from a connecting strut 38 made of plastic stiffened with ribs. The connection to the pipe bends 12 or 32 of these connecting elements 36 . 38 can also be done by selecting the appropriate cross-section of the pipe bends 12 . 32 be form-fitting in the respective connection areas.

Another embodiment of the cross member according to the invention 10 is in 3 shown. This embodiment is similar to that in FIG 2 shown, however, the pipe bends 12 . 32 Made of fiber composite material through a metal-plastic hybrid carrier 13 . 33 are replaced, on which the respective connection elements, ie knee protectors 16 . 17 the steering column mount 20 , a connector for the instrument panel 18 , Connections to the A-pillars 14 . 34 and a holder for a glove compartment 40 are injected. These molded elements can be formed simultaneously with the formation of the stiffening ribs in the metal-plastic hybrid carrier, for example by inserting deep-drawn metal profiles into an injection molding tool and connecting them to the metal base carrier via strands and bores. Then injection molding material is introduced, which forms the plastic ribbing as well as the connection elements.

In the in 3 illustrated embodiment of the cross member 10 is between the left arch 13 and the right bow 33 of the cross member 10 again a recording for an audio device 36 arranged.

The essential aspect of the invention lies in providing a cross member for a motor vehicle that is inexpensive to manufacture and in which connection elements can be provided as required without considerable additional manufacturing outlay.

Claims (16)

Cross member ( 10 ) for a motor vehicle, comprising a pipe bend ( 12 ) made of a fiber composite material or an arch ( 13 ) in metal-plastic hybrid construction in the area between the left A-pillar in the vehicle and the cardan tunnel. Cross member ( 10 ) according to claim 1, characterized in that the pipe bend ( 12 ) made of plastic reinforced with carbon fiber, plastic reinforced with glass fiber, with aramid fabric or plastic reinforced with mixed fibers. Cross member ( 10 ) according to one of the preceding claims, characterized in that knee protectors ( 16 ) to the bow ( 12 ) are molded. Cross member ( 10 ) according to claim 3, characterized in that in the connection area to the knee protectors ( 16 ) the pipe bend ( 12 ) has a cross section that corresponds to the inner cross section of a fastening area of the knee protectors ( 16 ) is form-fitting. Cross member ( 10 ) according to one of the preceding claims, characterized in that the pipe bend ( 12 ) is produced in the winding process and subsequent lamination. Cross member ( 10 ) according to one of claims 1 to 5, characterized in that the pipe bend ( 12 ) is produced from a braided tube made of a fiber composite material which is laminated in a state applied to a core or is formed from a fiber braided tube with incorporated thermoplastic threads by melting, reshaping and cooling. Cross member ( 10 ) according to one of the preceding claims, characterized in that on the bow ( 12 ) an instrument panel connection ( 18 ) is molded. Cross member ( 10 ) according to one of the preceding claims, characterized in that a connecting strut ( 22 ) is molded between the cardan tunnel support and the right A-pillar. Cross member ( 10 ) according to claim 8, characterized in that the connecting strut ( 22 ) is designed as an open profile stiffened with ribs. Cross member ( 10 ) according to claim 8 or 9, characterized in that to the connecting strut ( 22 ) Knee protectors ( 17 ), a seat for the passenger airbag ( 26 ), a holder for the instrument panel ( 18 ) and / or the connection ( 28 ) are molded onto the A-pillar by injection molding. Cross member ( 10 ) according to one of claims 8 to 10, characterized in that the connection between the arch ( 12 ) and the connecting strut ( 22 ) is form-fitting. Cross member ( 10 ) according to one of claims 1 to 7, further comprising a pipe bend ( 32 ) made of a fiber composite material or an arch ( 33 ) in metal-plastic hybrid construction in the area between the right A-pillar in the vehicle and the cardan tunnel. Cross member ( 10 ) according to claim 12, characterized in that the arch ( 12 . 13 ) between the left A-pillar and the cardan tunnel and the arch ( 32 . 33 ) between the right A-pillar and the cardan tunnel through a receptacle for an audio and / or navigation device ( 36 ) and / or a connecting strut designed as an open profile with ribbing ( 38 ) are connected. Cross member ( 10 ) according to claim 12 or 13, characterized in that on the bow ( 32 . 33 ) between the right A-pillar and the cardan tunnel knee protectors ( 17 ), a seat for the passenger airbag ( 26 ), a holder for the instrument panel ( 18 ) and / or the connection ( 34 ) are molded onto the A-pillar by injection molding. Cross member ( 10 ) according to one of the preceding claims, characterized in that fastening elements are provided for flat and / or round conductors. Cross member ( 10 ) according to one of the preceding claims, characterized in that a steering column connection made of fiber composite panels with a thermoplastic matrix in the deep-drawing process ( 21 ) on the bow ( 12 . 13 ) is attached.