DE3635317A1 - Process and apparatus for stiffening superstructures, and process for producing apparatuses of this type - Google Patents

Abstract

A process and an apparatus serve to stiffen superstructures of motor vehicles, in particular for the subsequent conversion of a limousine into a cabriolet. In this arrangement, a floor assembly of the superstructure is reinforced by additionally installed elements. In order to simplify the reinforcement of the floor assembly and to eliminate problems of corrosion, trough-shaped insert bodies (10; 70) consisting of fibre-reinforced plastic are installed in a positively locking manner into a floor area of a passenger compartment of the motor vehicle and are adhesively bonded there, over their surface areas, to a floor panel and lateral walls of the superstructure. <IMAGE>

Description

The invention relates to a method and a front direction for stiffening car bodies, especially for the retrofitting of a limousine in a convertible in which a floor pan of the body is reinforced by additional elements. The The invention further relates to a method of manufacture len of such devices.  

For modern, self-supporting car bodies in limousine form, i.e. with closed bodies, it is known that the required rigidity of the checks series through their various elements, i.e. the floor group pe, the sides and the roof of the body applied becomes. It is therefore not easily possible by way leave the roof and part of the sides instead of one Limousine making a convertible. This applies equally for the industrial production of convertibles such as also for retrofitting a sedan into a Convertible.

In order to eliminate the roof and part of the sides occurring reduction in the stability of the body compensate, it is known to add additional flooring stiffen reinforcing elements. At industrial Manufactured convertibles you can do these elements from the beginning plan purely in the manufacture of the body. You want to However, a limousine was subsequently converted into a convertible especially because the manufacturer of a particular Motor vehicle model does not offer a convertible version, so such reinforcement elements have subsequently been used built into the finished floor assembly.

Usually this is done by first one Underbody protection of the floor assembly removed and then reinforcement elements in the form of profile iron, sheet metal and the like welded to the floor assembly for its rigidity, in particular to increase torsional rigidity. The essential Liche disadvantage of this approach is that a considerable renovation work is necessary because the first Underbody protection must be completely removed before the  Reinforcing elements can be welded. It is obvious that this also entails corrosion problems stand because with subsequent welding of such Full-surface corrosion protection, as is the case with Manufacture of motor vehicles achieved by immersion baths can become, is no longer possible. You also have to the necessary welding work on a large scale otherwise units, in particular brake systems, cables and the like first remove and after welding the reinforcement Reinstall the cooling elements.

In this way, changeover times and thus also changeover occur cost in an order of magnitude that only a few consume are portable.

The invention is based on the object, a Device and a method of the type mentioned to further train that the remodeling time and remodeling cost minimized and at the same time further problems of the State of the art, in particular long-term corrosion problems me to be avoided.

According to the method initially mentioned at the beginning, this is Object achieved in that trough-shaped Insert body made of fiber-reinforced plastic with a positive fit in a floor space of a passenger compartment of the motor vehicle introduced and there with a bottom plate and side Walls of the body are glued flat.

According to the device mentioned above, the task solved according to the invention in that the device Mostly a trough-shaped insert made of fiber reinforced  tem plastic, which in its shape to the shape of a Floor space of a passenger compartment of the motor vehicle adapted is.

According to the method mentioned at the beginning, the The object is achieved according to the invention by the following steps:

• - Establish a floor space of a passenger cell of a motor vehicle representing Posi active form;
• - Create the floor space minus the Volume of a ribbed, the floor space flat lining foam body Negative form;
• - Manufacture the foam body using formation of the positive form and the negative form;
• - Open the molds and remove the foam body;
• - insertion of at least one fiber-reinforced, resin-soaked mat in the positive form;
• - inserting the foam body on the mat;
• - Placing at least one other fiber reinforcement resin-soaked mat on the foam body by;
• - Place a plastic film on the other Mat;
• - Generating a vacuum between plastic Foil and positive form;
• - Hardening of the mats and the foam existing sandwiches under negative pressure.

The invention completely solves the underlying problem, because of the full-surface mounting of a plastic one set body in the floor space of the motor vehicle on the one hand the conversion time is minimized because the floor space in the Is generally completely or almost completely free of internals and by taking out a carpet and the like easily can be exposed. The conversion costs will also be significantly reduced, not only because working hours are reduced but because you also have prefabricated ones Manufacture insert bodies for certain types of car inexpensively len and can keep in stock. Finally, also arise no problems with possible corrosion because the full-surface gluing of the insert body in any way Measures on the underbody protection required.

Further advantages of the invention are that infol ge of the insert body introduced according to the invention also the Sound insulation of the motor vehicle increased downwards. It has also shown that the rigidity of the driving guest cell itself is increased, which is particularly the case with Accidents with frontal or side impact positive affects.

Practical tests have also shown that the renovation period According to the invention only about 10% of the conversion time after State of the art.

In a preferred embodiment of the entrance initially mentioned method, the insert body is additional by means of connecting means with the floor panel and / or the connected side walls.  

This measure has the advantage that a full-surface adhesive connection of the positively inserted insert body in the floor space is reached, which is the overall stability of the Body benefits.

Stainless steel rivets are preferred as the connecting means used.

This measure has the advantage that there is no corrosion sion problems arise when the insert body on one Floor panel, on the bulkhead, on side sills Cross members, riveted to the cardan tunnel or the like.

According to the invention, it will then have a particularly good effect targets if a polyurethane adhesive is used as the adhesive becomes.

This type of "floating" attachment of the insert body in the floor space has the advantage that the elasticity of the Bo the group of the vehicle is retained.

The device mentioned at the outset can be according to the invention be further developed in that the insert body as Sandwich is formed.

This measure has the advantage that one depends on the material choice, manufacturing process and shape optimized confi guration of the insert body can be selected.

This is especially true if the sandwich is at least a lower fiber-reinforced, resin-soaked mat, at least  a medium foam body and at least one upper, fiber-reinforced and resin-impregnated mat.

In this way, the shape and stability of the insert body Pers can be chosen freely in wide areas. In particular can be used as fiber-reinforced mats carbon fiber reinforced or carbon fiber reinforced mats can be used, such as under the designation kevlar / carbon are on the market. You can drink resin especially use epoxy resin, but there are also other resins suitable, which are in themselves for fiber reinforced Components are known and suitable.

In a preferred embodiment of the invention Foam body with depressions and / or openings Mistake.

This measure has the advantage that there is a "ribbed" structure with particularly high strength. The resulting irregular shape of the insert body also ensures that tensile stresses always occur on the insert body when the insert body is loaded. If this is fully glued into the floor space of the body with polyurethane glue, the average tensile strength of such an adhesive bond of approx. 7 N / cm ² results in a total tensile strength which by far meets the requirements. One can assume that in modern car bodies about 60% of the Tragar work is included in the floor pan. By means of the insert body according to the invention, the proportion of the floor group can be increased to approx. 70%, so that only approx. 30% of the supporting work has to be absorbed by the sandwich insert body (s) itself when the roof area is cut open.

In a further preferred variant according to the invention the insert body has metallic reinforcement profiles.

This measure has the advantage that a further variabili can be achieved for a wide variety of vehicle types can.

This is especially true if a variant of this the reinforcement profiles two otherwise separate inserts connect with each other.

This measure has the advantage that the invention Insert body also used in such motor vehicles can be, in which no uniformly continuous Floor space is available but rather through additional internals, for example cross members, one Cardan tunnel and the like is separated. In these cases you can use the individual sections of the floor space provided individual insert body and these different Insert body then into one by means of the reinforcement profiles Join the stable bond.

According to the reinforcement profiles in the one cast body or in corresponding openings of the Inserted insert body and then later if necessary additionally be shed.  

In a further preferred variant of this embodiment for example, the reinforcement profiles in the insert body led down to points where the insert body Adjust suspension points of motor vehicle shock absorbers Zen.

This measure has the advantage that the suspension points introduced into the body via the Reinforcement profiles immediately and flat in use be initiated.

Further advantages result from the description and the attached drawing.

It is understood that the above and the Features explained below not only in the combination given in each case but also in others Combinations or alone can be used without to leave the scope of the present invention.

Embodiments of the invention are in the drawing are shown and are described in the following description explained in more detail. Show it:

Fig. 1 is a perspective view of an exemplary embodiment of an insert body used according to the invention;

FIG. 2 shows a perspective illustration of a floor space of a motor vehicle, into which an insert body according to FIG. 1 can be inserted;

Fig. 3 is a sectional view, partial and on a greatly enlarged scale, for explaining the construction of an insert body of the invention and its connection with a floor pan of a motor vehicle;

Fig. 4 is a further fragmentary, enlarged sectional view of an embodiment for explaining two interconnected A set body;

Fig. 4 to 11 highly schematic representations of phases of a method used according to the invention for producing an insert body, as shown for example in Fig. 1.

In FIG. 1, an insert body is designated by 10 as a whole, as can be used in a floor space 11 of the illustration according to FIG. 2.

The insert body 10 has front walls 15 , 16 which are separated from one another by an intermediate space 17 . The front walls 15 , 16 are to create a bulkhead 18 of the floor space 11 and the space 17 is provided to leave space for accelerator pedals 19 of the motor vehicle.

Side walls 20 , 21 of the insert body 10 rest against sills 22 , 23 of the floor space 11 .

Rear walls 24 , 25 of the insert body 10 are adapted to the shape of a crossbar 26 , which delimits a front portion of the floor space 11 to the rear.

In the middle, the insert body 10 is provided with an intermediate space 27 at its rear end and with a continuous bridge 28 towards the front. In the installed state, the bridge 28 covers a cardan tunnel 29 , while the intermediate space 27 serves to leave space for a shift lever 30 and a hand brake lever 31 of the motor vehicle.

Behind the crossbar 26 extends a rear footwell 33 into which another insert body, not shown in FIG. 1, can be inserted.

It can also be seen from FIG. 1 that the insert body 10 is designed to adapt to the shape of the floor space 11 . At the edges of the insert body 10 , relatively thin areas 36 can be seen which delimit thicker areas 37 . The thicker areas 37 are provided over the surface of the insert body 10 with recesses 38 , between which ribs 39 remain as a result. It goes without saying that the number and shape of the depressions 38 or the ribs 39 can be selected within wide limits and can be determined individually depending on the motor vehicle model at hand.

Fig. 3 shows a sectional view on a greatly enlarged scale, the structure of the insert body 10 and its attachment in the floor space 11th

A first layer 51 of a fiber-reinforced mat lies on a floor panel 50 of the motor vehicle. The mat can be a glass fiber reinforced, a carbon fiber reinforced or a glass and carbon fiber reinforced mat or the like. A second layer 52 and a third layer 53 lie on the first layer 51 , but more or less than three layers 51 , 52 , 53 can also be used. In the third layer 53 , a foam body 54 can be seen in regions, on which in turn a fourth layer 55 and a fifth layer 56 of a fiber-reinforced mat lie.

The first layer 51 is glued to the base plate 50 by means of a first adhesive layer 57 . A polyurethane adhesive is preferably used as the first adhesive layer 57 . Between the first, the second and the third layer 51 , 52 , 53 there are second adhesive layers 58 , between the third layer 53 and the foam body 54 or the fourth layer 55 there is a third adhesive layer 59 and the fourth layer 55 and fifth layer 56 are finally connected to one another with a fourth adhesive layer 60 . The second to fourth adhesive layers 58 to 60 are preferably made of an epoxy resin with which the layers 51 to 53 , 55 , 56 are soaked.

In the embodiment according to FIG. 3, the foam body is provided with apertures 54, 38 form the recesses of the insert body 10. However, it goes without saying that the foam body 54 in the region of the recess 38 can also be formed continuously over a relatively thin layer between the third layer 53 and the fourth layer 55 .

As will be explained further below with the aid of FIGS. 5 to 11, the sandwich structure 51 to 56 and 58 to 60 is first produced separately as a separate component, namely as insert body 10 , before the insert body 10 is then in the floor space 11 used and attached there.

The full-area first adhesive layer 57 , preferably made of polyurethane adhesive, is used primarily to fasten the insert body 10 in the floor space 11 . However, in order to ensure a full-area, positive fit of the insert body 10 in the floor space 11 , in addition, vorzugwei se in the area of the depressions 38 , connecting means can be provided to the insert body 10, in particular as long as the first adhesive layer 57 is still curing, over the entire area to the floor space 11 to press. For this purpose, stainless steel rivets 61 are preferably provided, by means of which the insert body 10 is riveted flat onto the bulkhead 18 , the sills 22 , 23 , the base plate 50 and the crossbar 26 .

Fig. 4 shows a variant for the case that in a floor space 11 , as shown in Fig. 2, different sections from the floor space 11 are available. The crossbar 26 shown in Fig. 2 can not be removed from the body for reasons of stability, in addition, this crossbar 26 is required to attach the front seats of the motor vehicle.

In these cases, in addition to the insert body 10 according to FIG. 1, a rear insert body 70 can also be used for the front section of the floor space 11 , the shape of which is adapted to the rear foot space 32 . The two insert bodies 10 , 70 can then preferably be connected to each other by means of pro filstangen 71 , so that a stable structure is created.

The profile rod 71 can either be cast from the start into the insert body 10 , 70 , but one can also provide the insert body 10 , 70 with aligned openings 72 , 73 , into which the profile rod 71 is inserted after the insert body 10 , 70 both sides of the crossbar 26 was introduced in the manner explained in FIG. 3. For this purpose, the openings 72 , 73 can be made greater in length than the length of the profile rod 71 , so that the profile rod 71 can be inserted to one side and then pushed over to the other side. After the profile rod 71 has been inserted, it can then be cast in the insert bodies 10 , 70 or fastened in some other way.

A method is preferably used for producing an insert body 10 of the type described, as will be explained below in phase diagrams with reference to FIGS. 5 to 11.

First, a positive mold 80 is produced, the inner surface of which is formed exactly according to the floor space 11 of the motor vehicle.

Next, a negative mold 81 which fits into the positive mold 80 is produced, the outer surface of which corresponds to the inner surface of the positive mold 80 , but less the volume desired for the foam body 54 . As shown in FIG. 6, the negative mold 81 is now inserted into the positive mold and it can be produced by spraying or foaming the foam body 54 in a cavity 82 which has remained free between the positive mold 80 and the negative mold 81 .

After molding, the foam body 54 shown in FIG. 7 is now available as a separate component.

In a next method step according to FIG. 8, the positive mold 80 or another mold that is identical to it in this respect is now lined with the three layers 51 to 53 of the fiber-reinforced mat and these layers 51 to 53 are, as indicated by the second adhesive layer 58 , by means of a resin, especially epoxy resin, soaked.

As shown in FIG. 9 shows, is placed in a next process step on the resin impregnated layers 51 to 53 of the foam body 54 after previously, preferably, the third adhesive layer was applied 59 to the layers 51 to 53 and the foam body 54 is then fifth to the fourth and Layer 55 , 56 covered, which are also resin-impregnated, as indicated by the fourth adhesive layer 60 .

On the resin- or adhesive-soaked composite of the layers 51 to 53 , the foam body 54 and the layers 55 , 56 , a film, in particular a plastic film 83 , is now completely laid on. The film 83 is sealed at the edges of the positive mold 80 . By means of a between the film 83 and the interior of the male mold 80 suction line 84 will now be introduced through a valve 85 and a pump 86, a negative pressure generated between the film 83 and positive mold 80th As indicated by arrows 87 , this negative pressure acts as a flat pressure on the film 83 or the sandwich below it. A relatively small negative pressure of the order of 0.2 to 0.3 bar is sufficient to generate a pressure of 5 tons and more over the entire area of the positive mold 80 . Under this strong negative pressure, which also ensures complete degassing of the sandwich, the sandwich is now allowed to harden. After curing, the insert body 10 can then be removed as a ready-to-use part from the positive mold 80 .

Insert body 10 can be industrially manufactured in this way in the required series and kept in stock until they are inserted in the form described above.

Claims (14)

1. A method for bracing bodies of motor vehicles, especially for the subsequent conversion of a sedan into a convertible, in which a Bo dengruppe the body is reinforced by additional elements, characterized in that trough-shaped insert body ( 10 ; 70 ) made of fiber reinforced Plastic inserted into a floor space ( 11 ) of a passenger compartment of the motor vehicle and there with a floor panel ( 50 ) and since Lichen walls ( 18 , 22 , 23 , 26 ) of the body are glued flat. 2. The method according to claim 1, characterized in that the insert body ( 10 ; 70 ) is additionally connected by means of connec tion means with the bottom plate ( 50 ) and / or the side walls ( 18 , 22 , 23 , 26 ). 3. The method according to claim 2, characterized in that the connecting means are stainless steel rivets ( 61 ). 4. The method according to any one of claims 1 to 3, characterized characterized in that as a polyurethane adhesive is used. 5. Device for stiffening bodies of motor vehicles, in particular for the subsequent conversion of a limousine into a convertible, in which a Bo dengruppe the body is reinforced by additional elements, characterized in that the device has at least one trough-shaped A set body ( 10 ; 70 ) made of fiber-reinforced plastic, which is adapted in its shape to the shape of a floor space ( 11 ) of a passenger compartment of the motor vehicle. 6. The device according to claim 5, characterized in that the insert body ( 10 ; 70 ) is designed as a sandwich. 7. The device according to claim 6, characterized in that the sandwich at least one lower fiber reinforced te, resin-impregnated mat ( 51 , 52 , 53 ), at least one middle foam body ( 54 ) and at least one upper, fiber-reinforced, resin-impregnated mat ( 55 , 56 ) having. 8. The device according to claim 7, characterized in that the foam body ( 54 ) is provided with depressions ( 38 ) and / or openings. 9. Device according to one of claims 5 to 8, characterized in that the insert body ( 10 ; 70 ) has metallic reinforcing profiles ( 71 ). 10. The device according to claim 9, characterized in that the reinforcing profiles ( 71 ) connect two otherwise separate insert bodies ( 10 ; 70 ) together. 11. The device according to claim 9 or 10, characterized in that the reinforcing profiles ( 71 ) in the insert body ( 10 ; 70 ) are cast. 12. The apparatus according to claim 11, characterized in that the reinforcing profiles ( 71 ) in openings ( 72 , 73 ) of the insert body ( 10 ; 70 ) are inserted. 13. Device according to one of claims 9 to 12, characterized in that the reinforcing profiles (71) in the insert bodies (10; 70) are guided up to points at which the insert body (10; 70) to Aufhän branching points of shock absorbers of the motor vehicle limit. 14. A method for producing devices according to one of claims 5 to 13, characterized by the steps:

• - producing a positive mold ( 80 ) representing a floor space ( 11 ) of a passenger compartment of a motor vehicle;
• Producing a negative mold ( 81 ) representing the bottom space ( 11 ) minus the volume of a ribbed foam body ( 54 ) lining the bottom space ( 11 );
• - Manufacturing the foam body ( 54 ) using the positive mold ( 80 ) and the negative mold ( 81 );
• - Opening the molds ( 80 , 81 ) and removing the foam body ( 54 );
• - Inserting at least one fiber-reinforced, resin-impregnated mat ( 51 , 52 , 53 ) into the positive form ( 80 );
• - Inserting the foam body ( 54 ) on the mat ( 51 , 52 , 53 );
• - Placing at least one further fiber-reinforced, resin-impregnated mat ( 55 , 56 ) on the foam body ( 54 );
• - Placing a plastic film ( 83 ) on the further mat ( 55 , 56 );
• - Generating a negative pressure between plastic film ( 83 ) and positive mold ( 80 );
• - Hardening of the mats ( 51 , 52 , 53 , 55 , 56 ) and the foam body ( 54 ) existing jerky under vacuum.