FIELD OF THE INVENTION

The present invention relates to a component for a motor vehicle in accordance with claim 1.

BACKGROUND

Vehicle body parts consist of formed sheet steel and/or are manufactured from aluminum. Sheet parts are formed to profiles and connected by welding, soldering, flanging (rolling) to other components. It is known in the case of aluminum to manufacture profile parts as extruded parts. Profile parts are used in particular in the area of bumpers, in which the forces are received and forwarded in provided directions.

The connecting of profile parts by welding is expensive and the expenditure of time for the welding process - independent of the welding method - depends on the connection length, i.e., the length of the welding seam. Also, the heat charge that takes place during the welding process during the shaping of the component must be considered.

Even connections by welding, hard welding, cause the cited disadvantages. Basically, the partial heat charge is less here but the solder required for the process must be added.

The use of solder-plated sheets in the construction of motor vehicles is known. For instance, heat exchangers are manufactured using such materials. A hard solder - usually AlSil2 - is applied by a rolling process on a sheet in the case of a solder-plated sheet. An appropriately thin layer results from the rolling. The thin hard solder layer forms the connection layer, the carrier material and the sheet yields the required strength. The joining takes place by a furnace soldering, during which the solder is made available via the solder- plated aluminum sheets. The components are held by fixing elements in the position in which the connection is to take place. The furnace soldering takes place at approximately 590°C. SUMMARY OF EMBODIMENTS OF THE INVENTION

The basic problem is to make a vehicle body component available in a form that is improved in comparison to the known solutions.

The solution of this problem takes place by a vehicle body component with the features of claim 1. Further developments of the invention result from the subclaims.

According to the invention a component is provided that comprises at least one solder-plated sheet part that is connected by a furnace soldering procedure to another component, in particular to another sheet part.

The component in accordance with the invention preferably comprises a solder-plated aluminum sheet that is fumace-soldered to another aluminum sheet or to a steel sheet. It is advantageous here that given an appropriately flat shaping of the contact areas of the components a transfer of force, a connection strength and characteristic such as in the case of an adhesion can be achieved.

The number of the joining positions is not relevant for the cycle time. The components to be connected are brought in contact to each other and with each other and fixed and then subjected to a heat treatment in a soldering furnace.

Combination parts of aluminum and steel can be readily manufactured. If necessary, depending on the material used and the forces provided, an adhesion-imparting layer is generated, for example, by galvanizing, on the steel part, the steel sheet.

Combination parts of aluminum-steel make possible a weight-optimized manner of construction so that the components can be very well adapted to the forces to be received. Thus, the steel part can offer the high strength and the aluminum component is the completion on account of the lower density with correspondingly low weight.

In the case of a pure aluminum structural group different aluminum alloys can be used as carrier sheets. When using 3xxx (AIMn), 5xxx (AlMg) and 6xxx (AlMgSi) as carrier material a soft state can be approximately achieved by a furnace soldering. Precisely in the case of a crash box a 5182 (AlMg4,5Mn) in a soft state can be advantageous. Therefore, material states with very good deformability can be manufactured.

Another property can be achieved if low-alloyed 7xxx alloys such as, e.g., 7020 (AlZn4,5Mgl) are used as carrier material 7020. This material is so insensitive to the quenching after the solution annealing (hard soldering) that it still has a super-saturated mixed crystal even after having cooled off in calm air and can therefore be subsequently aged warm. Therefore, a required component characteristic can be achieved by a purposeful heat treatment after the furnace soldering. This can take place by an air current quenching of the component soldered in the furnace with a subsequently 2-phase ageing at, e.g., 100 °C and 140 °C.

A preferred embodiment of the invention provides a bumper system. The latter consists of a total of three structural groups, namely, the bumper strut extending transversely to the direction of travel, two carriers as well as receiving plates receiving the strut on the left and the right side of the vehicle frame, by means of which the carriers can be mounted and fastened to the vehicle frame.

The bumper strut constructed as a transverse strut is formed from a cap-shaped profile part and from a plate terminating this cap profile. The two parts are furnace-soldered - the plate is solder-plated aluminum sheeting and the cap profile is heat-transformed steel or aluminum 7020 (AlZn4,5Mgl). The cap profile and the plate terminating the cap profile are in flat contact with one another at the two edge ends of the profile and connected to one another metallurgically by the solder of the solder-plated aluminum sheet.

The two carriers that carry the bumper strut and are supported against the vehicle frame, the body of the motor vehicle, consist of two furnace-soldered, solder-plated aluminum sheets. The two parts profiled in a Z shape make a flat contact on their outer areas and are connected to one another in a flat manner in this contact area by the furnace soldering procedure.

The two carriers comprise the cap rail area of the bumper strut, the two outer flanks of the cap rail running parallel to one another. Since the two Z profiles of the carrier consist of solder-plated aluminum sheeting, the connection between carrier and cap rail or the bumper strut can also be achieved by a furnace soldering. The connection of the receiving plates to the carriers is achieved by a welding connection. The receiving plates are manufactured, e.g., as an aluminum extruded profile.

BRIEF DESCRIPTION OF THE DRAWINGS

The explanation of an exemplary embodiment of the invention takes place in the following using the drawings.

Figure 1 shows a bumper for a motor vehicle (not shown) in a top view.

Figure 2 shows the bumper strut SFT in profile, as a section taken along line A— A in figure 1.

Figure 3 shows a section through one of the carriers T, taken along line B— B in figure 1.

Figure 4 shows a section in the longitudinal direction of the carrier T, taken along the line C— C in figure 1.

DETAILED DESCRIPTION OF THE DRAWINGS

Figure 1 shows a bumper for a motor vehicle (not shown) in a top view. A bumper strut SFT constructed in a curved manner in the direction of travel is carried by two carriers T extending in the direction of travel. The bumper strut SFT is therefore a transverse strut extending substantially over the width of the vehicle.

The carriers T have a holding and carrier plate TP on the end facing away from the bumper strut SFT by means of which the carriers T and therefore the entire bumper arrangement can be mounted on the body (not shown) of the vehicle. The carrier plates TP have openings to this end so that the bumper device can be mounted by screws on the motor vehicle, the body.

Figure 2 shows the bumper strut SFT in profile as a section taken along the line A— A in figure 1. The bumper strut SFT consists of a cap profile HP and a strip L closing the open profile. The cap profile HP and the strip closing the profile are designed to be curved in the direction of travel, wherein the components have this curvature already before the joining together. The cap profile HP is manufactured from heat-deformed steel. Alternatively, the cap profile HP can also be manufactured from aluminum, e.g., 7020 (AlZn4,5Mgl). The strip L closing the profile in the direction of travel is manufactured from a solder-plated aluminum sheet, wherein the solder-plate inside, surface of the strip L, faces the cap profile side.

The strip L as well as the cap profile HP have a flat contact in the area of the bent ends of the cap profile HP. The metallurgical connection of the components is then produced in this contact area by a furnace soldering. During the construction of the cap profile HP as a steel profile it preferably has an adhesion-imparting layer, a galvanization.

Figure 3 shows a section through one of the carriers T, taken along the line B— B in figure 1. The carrier T is therefore composed of carrier sheets TBI, TB2 with a Z-shaped form. The two carrier sheets TBI, TB2 have a flat contact in the outside profile areas. The carrier sheets TBI, TB2 consists of solder-plated aluminum sheeting and the solder-plated sides of the sheets TBI, TB2 lie opposite and facing one another. The connection of the two carrier plates TBI, TB2 takes place by a furnace procedure.

Figure 4 shows a section in the longitudinal direction of the carrier T, taken along the line C— C in figure 1. The cap profile HP of the bumper strut SFT makes flat contact with the middle profile areas of the carrier sheets TBI, TB2 forming the carrier T. Since the solder- plated sides of the carrier sheets TBI, TB2 are opposite and facing one another the carrier sheets TBI, TB2 make contact with the cap profile HP, the two outer surfaces of the cap profile HP running parallel to one another, via the solder-plated surface.

The carrier plate TP is constructed as an extruded aluminum profile and set on the end of the carrier T opposite the bumper strut SFT. The connection of the carrier plate TP and of the carrier T formed by the two carrier sheets TBI, TB2 is produced by a welding procedure.

In order to manufacture the described bumper the parts are brought in contact with each other in the provided position, fixed, e.g., by clamping devices and then thermally treated in a furnace soldering procedure. In order to reduce the expense and/or the number of required clamping devices in the furnace process the parts can also be pre-fixed by a passage joining process.

List of reference numerals

SFT bumper strut, traverse

T carrier

TP carrier plate, base plate

HP cap profile, cap profile rail

L strip

TBI carrier sheet

TB2 carrier sheet