Motor vehicle body assembly

Abstract

Assembly of a motor vehicle body with a reinforcement plate (1) of a side sill, wherein the reinforcement plate (1) is made of a readily weldable steel material and is arranged in a cavity between an inner shell and an outer shell of the side sill, extends in the longitudinal direction (x) of the vehicle and has a C-shaped cross-section in cross-section, the open side of which, viewed in the transverse direction (y) of the vehicle, faces the center of the vehicle, and wherein the reinforcing plate (1) in the area of ​​the connection of a B-pillar to the side sill is spot-welded to the lowest section (5) of a pillar reinforcement (4), which is a sheet metal component made of a readily weldable steel material, which extends over the entire height of the B-pillar to reinforce the B-pillar, wherein the lowest section (5) of the column reinforcement (4) is angled towards the center of the vehicle and encompasses the C-shaped section of the reinforcement plate (1), and the reinforcement plate (1) and the column reinforcement (4) are connected to each other by several weld points (6) which are arranged one behind the other in the longitudinal direction (x) of the vehicle, wherein the reinforcing plate (1) is stiffened at least in the area of ​​the connection of the B-pillar by a reinforcing component (7) made of a fiber composite material attached to it over a flat surface, wherein the reinforcement component (7) has at least one recess (8), and the reinforcement plate (1) is spot-welded to the column reinforcement (4) in the area of ​​the recess (8), wherein a spot welding gun can reach through the recess (8).

Description

[0001] The invention relates to a motor vehicle body assembly with a reinforcing plate of a side sill.

[0002] US Patent 7,264,302 B2 discloses a side sill as a component of a motor vehicle body with a reinforcing plate made of a readily weldable steel material, which is arranged in a cavity between an inner and an outer shell of the side sill. The reinforcing plate extends longitudinally in the direction of the vehicle and has a C-shaped cross-section, the open side of which faces the center of the vehicle when viewed transversely. In the area where a B-pillar connects to the side sill, the reinforcing plate is welded to the lowermost section of a pillar reinforcement.

[0003] From DE 10 2004 003 190 A1, a component assembly of a motor vehicle body in shell construction with an outer and an inner shell is known, which is stiffened by at least one reinforcing component. The reinforcing component consists of a fiber-reinforced plastic and is bonded over its entire surface to one of the shells. Carbon fiber-reinforced plastics are particularly suitable.

[0004] Furthermore, it is known from CH 512 287 A to weld a plastic-coated sheet metal component to another sheet metal component. For this purpose, the plastic coating is removed by machining at the joint point so that the plastic does not interfere with the welding process.

[0005] Furthermore, DE 10 2010 034 183 A1 discloses a method for joining components, wherein a first component is made of plastic or non-ferrous metal, and a second component is made of steel, non-ferrous metal, or plastic. For the joining process, steel rivets are arranged in openings in the first component in the area of ​​overlap with the second component, wherein the rivets are in contact at least on the side facing away from the second component, and the rivets are welded directly to a second steel component by means of resistance spot welding.

[0006] The object of the invention is to create a motor vehicle body assembly that has high rigidity and can be joined in a simple way.

[0007] This problem is solved with an assembly of a motor vehicle body having the features of claim 1.

[0008] According to the invention, a motor vehicle body assembly comprises a sheet metal component stiffened by a reinforcing component made of a fiber-reinforced composite material, which is attached to the sheet metal component over a flat area. The reinforcing sheet metal has at least one recess. The sheet metal component is joined to another sheet metal component in the area of ​​the recess using a conventional joining method.

[0009] The sheet metal component with the reinforcement element exhibits high stiffness, significantly exceeding that of the unreinforced sheet metal component. However, such hybrid components typically cannot be joined to other components in the area of ​​the reinforcement element using conventional joining methods common in car body construction, such as spot welding. By incorporating recesses, these conventional joining techniques can now be used in the area of ​​the reinforcement element of such a hybrid component. Previously, hybrid components could only be bonded and / or riveted to other components. However, the strength of an adhesive bond or riveted joint is limited. Furthermore, the costs of these joining techniques are relatively high. Integration into a conventional body-in-white production line is very difficult.By omitting the reinforcement component according to the invention, classic, cost-effective joining techniques, such as welding, can be used. Integration into a conventional body-in-white production line is easily possible.

[0010] The sheet metal components are made of a weldable ferrous material. The most common conventional joining method for connecting two weldable sheet metal components is spot welding. This welding method is by far the most widely used in car body construction. The two sheet metal components can now also be spot welded together in the area of ​​the reinforcement component at at least one recess using a spot welding gun. Ideally, the size and shape of the recess in the reinforcement component are matched to the spot welding gun so that the gun can reach through the recess and weld the two sheet metal components together. The recess is as small as possible. This minimizes the weakening of the reinforcement component by the at least one recess. The hybrid component is thus spot weldable in the area of ​​the reinforcement component and, at the same time, exhibits maximum stiffness.

[0011] The reinforcing component can be made of glass fiber reinforced, aramid fiber reinforced, or carbon fiber reinforced plastic. Glass fiber reinforced plastics are a cost-effective yet very high-quality fiber-reinforced composite. Compared to fiber-reinforced composites made from other reinforcing fibers, glass fiber reinforced plastic has a relatively low modulus of elasticity. Aramid fibers are characterized by very high strength, high impact resistance, high elongation at break, and good vibration damping. However, they are very expensive to produce and are therefore usually only used in applications with very high stresses. Carbon fibers are primarily used when high strength-to-weight ratios and stiffness are required.Advantageously, the reinforcement component is made of carbon fiber reinforced plastic, since in car body construction great care must always be taken to keep the overall weight of the body as low as possible and to ensure the best possible driving dynamics.

[0012] Further advantageous embodiments are the subject of dependent claims.

[0013] The drawing shows an embodiment of the invention, which will be described in more detail below. The individual figures show, in schematic form: Fig. 1 a section through a reinforcement plate of a side sill near a connection of a reinforcement plate of a B-pillar and Fig. 2 a section through a reinforcement plate of a side sill at a connection of a reinforcement plate of a B-pillar.

[0014] In Fig.Figure 1 shows a reinforcing plate 1 of a side sill of a motor vehicle body. The side sill extends in the longitudinal direction x of the vehicle and forms the lateral, lower boundary of the passenger compartment of the motor vehicle. It consists of a shell construction comprising an inner shell and an outer shell, which enclose a common cavity. The inner shell and the outer shell are connected to each other via an upper and a lower flange. The reinforcing plate 1 is arranged in the cavity. Viewed in the vehicle's vertical direction z, it is connected to the upper flange via an upper connecting section 2 and to the lower flange via a lower connecting section 3.

[0015] The reinforcement plate 1 has a C-shaped cross-section between the two connecting sections 2 and 3, the open side of which faces the vehicle's center when viewed in the transverse direction y. The reinforcement plate 1 is made of readily weldable steel sheet. In the area of ​​a B-pillar, the reinforcement plate 1 is welded to a pillar reinforcement 4. The pillar reinforcement 4 is also made of readily weldable steel sheet. Its lower end is connected to the side sill. The lowest section 5 of the pillar reinforcement 4 is angled towards the vehicle's center and encompasses the C-shaped section of the side sill's reinforcement plate 1. The reinforcement plate 1 and the pillar reinforcement 4 are connected to each other by several spot welds 6. The spot welds 6 are arranged one behind the other in the longitudinal direction x of the vehicle.

[0016] In a side impact, the side sill is subjected to high stress, particularly at the B-pillar connection point. Therefore, it is crucial that the side sill exhibits high rigidity, especially in this area. For this reason, the side sill's reinforcement plate 1, at least in the B-pillar connection area, is reinforced with a fiber-reinforced composite reinforcement element 7. This reinforcement element 7 rests against the C-shaped section of the reinforcement plate 1 and extends slightly beyond the B-pillar connection point in both directions along the vehicle's longitudinal axis x. It also has a C-shaped cross-section, adapted to the C-shaped section of the reinforcement plate 1. The reinforcement element 7 is rigidly connected to the reinforcement plate 1, forming an exceptionally rigid hybrid component.

[0017] Reinforcing component 7 is made of carbon fiber reinforced plastic to significantly increase stiffness while minimizing weight. To manufacture the hybrid component from reinforcing sheet 1 and reinforcing component 7, so-called "prepregs" are inserted into the C-shaped section of reinforcing sheet 1 and bonded to it. "Prepreg" is short for "pre-impregnated fibers." These prepregs consist of continuous fibers and an uncured thermosetting plastic matrix made from a mixture of resin and hardener. The continuous fibers can be present as a unidirectional layer, a woven fabric, or a non-woven fabric. Hot pressing or autoclave bonding techniques are suitable for bonding. In both techniques, the pressure increases the fiber volume fraction. The highest quality is achieved using autoclave bonding.The combination of pressure and vacuum creates components with very few air inclusions. The actual reinforcing component 7 is only formed during the bonding process. At the same time, a firm bond is also created with the reinforcing sheet 1.

[0018] The hybrid component, consisting of the reinforcement plate 1 and the reinforcement component 7, is manufactured in a prefabrication stage before being welded to the column reinforcement 4 during the actual body-in-white production. To enable the reinforcement plate 1 and reinforcement component 7 to be welded to the column reinforcement 4, the reinforcement component 7 has a recess 8 in the area of ​​each weld point 6. A spot welding gun can pass through this recess 8 and spot weld the reinforcement plate 1 to the column reinforcement 4 using conventional methods. Thus, despite the presence of the reinforcement component 7 in the weld area, a conventional spot welding process can be used, ensuring a high-strength connection. Furthermore, the connection can be produced very quickly and cost-effectively.The recesses 8 are dimensioned as small as possible so that the spot welding gun can just barely reach through them reliably. The recesses 8 have a round shape and are located in the middle of the reinforcement component 7. They only slightly affect the stiffness of the reinforcement component 7 and thus of the hybrid component consisting of the reinforcement sheet 1 and the reinforcement component 7.

[0019] The reinforcement component 7, made of a fiber composite material and attached to the reinforcement plate 1 over its entire surface, significantly increases the stiffness of the reinforcement plate 1 and thus of the side sill. Nevertheless, a conventional spot welding process for joining the reinforcement plate 1 to another body component can also be used in the area of ​​the reinforcement component 7, because the reinforcement component 7 has corresponding recesses 8 through which a spot welding gun can pass.

Claims

[1] Assembly of a motor vehicle body with a reinforcing plate (1) of a side sill, wherein the reinforcing plate (1) is made of a readily weldable steel material and is arranged in a cavity between an inner shell and an outer shell of the side sill, extends in the longitudinal direction (x) of the vehicle and has a C-shaped cross-section in cross-section, the open side of which, viewed in the transverse direction (y) of the vehicle, faces the center of the vehicle, and wherein the reinforcing plate (1) in the area of ​​the connection of a B-pillar to the side sill is spot-welded to the lowest section (5) of a pillar reinforcement (4), which is a sheet metal component made of a readily weldable steel material, which extends over the entire height of the B-pillar to reinforce the B-pillar, wherein the lowest section (5) of the column reinforcement (4) is angled towards the center of the vehicle and encompasses the C-shaped section of the reinforcement plate (1), and the reinforcement plate (1) and the column reinforcement (4) are connected to each other by several weld points (6) which are arranged one behind the other in the longitudinal direction (x) of the vehicle, wherein the reinforcing plate (1) is stiffened at least in the area of ​​the connection of the B-pillar by a reinforcing component (7) made of a fiber composite material attached to it over a flat surface, wherein the reinforcement component (7) has at least one recess (8), and the reinforcement plate (1) is spot-welded to the column reinforcement (4) in the area of ​​the recess (8), wherein a spot welding gun can reach through the recess (8). [2] Assembly according to claim 1, characterized by, that the size and shape of the recess (8) is adapted to the spot welding gun in such a way that the spot welding gun can reach through the recess (8), but the recess (8) is as small as possible. [3] Assembly according to any one of the preceding claims, characterized by , that the reinforcement component (7) is made of a carbon fiber reinforced plastic.

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