Process for manufacturing motor vehicles

Abstract

The invention relates to a method (1) for manufacturing motor vehicles, wherein a reduced manufacturing effort and improved sustainability are achieved by - that at least a first module and a second module are manufactured separately from each other (2, 3), - that the first module is equipped with a first interface during its manufacture (2), - that the second module is equipped with a second interface during its manufacture (3), - that the first interface and the second interface are provided for joining (4) the first module to the second module, - that before joining (4) the first module with the second module, a target-actual comparison (5, 8) of geometric dimensions of the first interface and the second interface is carried out, - that after the target-actual comparison (5, 8) and before the joining (4) of the first module with the second module, a post-processing (6, 9) of the first interface and / or the second interface is carried out depending on the target-actual comparison, in which the geometric dimensions of the first interface and / or the second interface are corrected by means of an additive manufacturing process, - that after the post-processing (6, 9) of the first interface and / or the second interface, the joining (4) of the first module to the second module is carried out, in which the first interface and the second interface are fastened to one another.

Description

The present invention relates to a method for producing motor vehicles having the features of the preamble of claim 1.In the series production of motor vehicles, a modular production technique can be used, in which a plurality of modules are first produced separately from one another and are then joined to one another, i.e. firmly connected to one another, within the scope of a body shell of the motor vehicle. The individual modules represent more or less complex assemblies of the motor vehicle and can therefore also be referred to as assemblies. The assemblies or modules can in principle be produced independently of one another. The individual modules can be, for example, a front module, a rear module, a floor module, a cabin module and a roof module. In this case, it is possible in particular to produce the individual modules independently of one another in separate production lines and, depending on requirements, to feed them to a production line of the motor vehicle in which the separate modules are assembled to form the motor vehicle. The problem with this modular vehicle production is comparatively large manufacturing tolerances, which can also depend on different environmental parameters and can accordingly fluctuate within a comparatively large range. To compensate for manufacturing tolerances, it is possible in principle to design the tolerance specifications to be oversized, so that during production a corresponding tolerance compensation can be carried out by material removal. Such material removal represents manufacturing waste. Such manufacturing waste is associated with increased costs and is disadvantageous in terms of sustainability of production.A method of the generic type for producing motor vehicles is known from DE 10 2016 206 981 A1, in which at least a first module and a second module are produced separately from one another, wherein the first module is equipped with a first interface during its production, while the second module is equipped with a second interface during its production. The first interface and the second interface are configured to be complementary to one another and are provided for joining the first module to the second module. According to the method presented here, before the joining of the first module to the second module, a setpoint-actual comparison of geometric dimensions of the first interface and of the second interface is carried out. Furthermore, after the desired-actual matching and before the joining of the first module to the second module, post-processing of the first interface and / or of the second interface is carried out as a function of the desired-actual matching, in which the geometric dimensions of the first interface and / or of the second interface are corrected by means of an additive manufacturing method. Furthermore, in the method presented here, after the post-processing of the first interface and / or of the second interface, the joining of the first module to the second module is carried out, in which the first interface and the second interface are fastened to one another.The present invention is concerned with the problem of showing an improved or at least one other method for the production of motor vehicles, which method is distinguished in particular by less manufacturing waste and improved sustainability.DE 10 2021 208 882 A1 discloses a method for producing electrical functional elements, such as, for example, conductor tracks, sensors, heating elements, antennas and actuators, on and / or in components, such as, for example, a vehicle bumper, by means of additive manufacturing methods. In this case, robot-assisted production with quality control during the additive production method is described.WO 2023 / 094 029 A1 discloses applying supplementary structures to a conventionally produced basic structure by means of additive manufacturing methods.DE 11 2019 002 449 T5 concerns heat-conductive controlled-cure split filler materials.The problem underlying the invention is solved by the subject matter of the independent claim. Advantageous embodiments are the subject of the dependent claims.The invention is based on the general idea of, in the modular production of motor vehicles, measuring mechanical interfaces of the modules, which are provided during the joining of the modules for fastening the modules to one another, before the joining and correcting dimensional deviations, which are no longer tolerable, additively, that is to say by applying material by means of an additive manufacturing technique. In other words, in the case of the procedure proposed here, the tolerance specifications are not designed to be oversized in view of the unavoidable manufacturing tolerances in the individual modules, but can be designed to be oversized, such that possibly missing material can be additively supplemented. This eliminates the need for removal of excess material, as a result of which manufacturing complexity and manufacturing costs can be reduced and the sustainability of the production can be increased.In the present context, a "configuration" corresponds to a "configuration" and / or a "device", such that the phrase "configured such that" is synonymous with the phrase "configured such that" and / or "configured such that".According to a first solution according to the invention, it is provided that corrosion protection and / or painting is applied to the first module and to the second module before the joining, wherein the post-processing of the first interface and / or the second interface is carried out before the application of the corrosion protection and / or painting. The corrections at the interfaces of the modules can thus be carried out in particular with the same materials that are already present at the respective interface. This also has the consequence that the modules are provided with corrosion protection or paint system only after the correction, as a result of which the corrected interfaces including the additively added regions are necessarily also provided with corrosion protection or paint system. Alternatively, it is also possible in principle to carry out the post-processing of the first interface and / or of the second interface after the application of the corrosion protection and / or the painting.According to an alternative second solution according to the invention, it is provided that corrosion protection and / or paintwork is applied to the first module and to the second module before the joining, wherein a first desired-actual comparison of the geometric dimensions of the first interface and of the second interface is carried out before the application of the corrosion protection and / or paintwork. In addition, after the first desired-actual adjustment and before the corrosion protection and / or the paint is applied, a first post-processing of the first interface and / or the second interface is carried out as a function of the first desired-actual adjustment, in which the first interface and / or the second interface are corrected with respect to the geometric dimensions by means of a first additive manufacturing method. It is also proposed that the application of the corrosion protection and / or the paint system is carried out after the first post-processing and that after the application of the corrosion protection and / or the paint system a second desired-actual comparison of the geometric dimensions of the first interface and of the second interface is carried out. In addition, after the second desired-actual matching and before the joining of the first module to the second module, a second post-processing of the first interface and / or of the second interface is carried out as a function of the second desired-actual matching, in which the first interface and / or the second interface are corrected with respect to the geometric dimensions by means of a second additive manufacturing method. After the second post-processing, the joining of the first module to the second module can then be carried out. In this procedure, dimensional deviations can be taken into account which occur only as a result of the application of the corrosion protection and / or the paint system. The application of corrosion protection and / or paintwork can frequently be accompanied by a thermal treatment which can lead to distortion of the frequently complex structures, in particular in the case of larger modules. By carrying out two separate desired actual matching and two separate post-processing operations by means of two separate additive manufacturing methods, the interfaces to be joined can be matched very exactly to one another, as a result of which a high accuracy of fit for the joining operation can be realized.According to an advantageous embodiment of the second solution according to the invention, it can be provided that the first additive manufacturing method, which is carried out during the first post-processing, i.e. before the application of the corrosion protection or the paint system, differs from the second additive manufacturing method, which is carried out during the second post-processing, i.e. after the application of the corrosion protection or the paint system. For example, the first additive manufacturing method may be a three-dimensional metal print, while the second additive manufacturing method may be a three-dimensional plastic print. It is likewise conceivable that the two additive manufacturing methods differ from one another by the temperatures which have to be applied during additive manufacturing. For example, a high-temperature method which is unsuitable for surfaces which are provided with corrosion protection or with a coating, and a low-temperature method which is suitable for surfaces which are provided with corrosion protection or with a coating, can be used.In principle, it is conceivable that the desired-actual matching of the respective interface is carried out in such a way that for each interface the actual dimensions are compared with predetermined desired dimensions in order to correct the dimensions of the respective interface by the additive manufacturing method as a function thereof. In this case, the interfaces are corrected quasi independently of one another with regard to a common, predetermined, optimum desired configuration. For this purpose, both interfaces must generally be corrected.According to a preferred embodiment, however, it can be provided that for the respective desired-actual matching, the geometric actual dimensions of the first interface and of the second interface are separately detected, wherein after the separate detection of the actual dimensions, a matching of the detected actual dimensions of the first interface with the detected actual dimensions of the second interface is carried out. Furthermore, a correction requirement of the first interface and / or of the second interface with respect to the geometric dimensions is then determined as a function of the comparison. In other words, by comparing the actual dimensions of the first interface with the actual dimensions of the second interface, it can be decided whether only the dimensions of the first interface or only the dimensions of the second interface or both the dimensions of the first interface and the dimensions of the second interface have to be corrected by means of the additive manufacturing method. This decision can be made with a view to the lowest possible outlay, in particular with regard to the material use, for the correction to be carried out. The respective post-processing can then be carried out as a function of the determined correction requirement. In other words, in this procedure, the interfaces are not corrected independently of one another, but rather within the scope of an overall observation, as a result of which ultimately the outlay and the material requirement can be reduced and sustainability can be increased.According to an advantageous embodiment, the respective desired-actual comparison can be carried out inline, that is to say within a production line or production line for producing the respective module or for producing the motor vehicle. This simplifies the manufacture of the module or of the vehicle.The respective desired-actual adjustment can expediently be carried out by means of a robot. This allows a complex measurement to be carried out in an automated manner even in the case of larger modules.In an advantageous embodiment, it can be provided that the respective additive manufacturing method is carried out in-line, i.e. within a manufacturing line or manufacturing line for producing the respective module or for producing the respective motor vehicle. This simplifies the manufacture of the module or of the vehicle.In an advantageous embodiment, the respective additive manufacturing method can be carried out by means of a robot. This measure also supports cost-effective production of the modules or of the motor vehicles.The respective additive manufacturing method can expediently be configured as a three-dimensional printing method, wherein, depending on the module, a three-dimensional metal print or a three-dimensional plastic print can be used. A selective laser sintering method is likewise conceivable, known as an SLS method.It is clear that in principle three or more modules can also be joined to one another for the production of the motor vehicle. Furthermore, it is clear that the at least one of the modules can also have two or more interfaces, in particular if two or more other modules are to be mounted on this module. The method presented here can then be applied accordingly to these configurations with more than two modules or more than one interface in at least one of the modules.Further important features and advantages of the invention are evident from the dependent claims, from the drawing and from the associated description of the figures with reference to the drawing.It is understood that the features mentioned above and those still to be explained below can be used not only in the respectively specified combination, but also in other combinations or alone, without departing from the scope of the invention. The above-mentioned components of a superordinate unit, such as a device, a device or an arrangement, which are designated separately, and which will be mentioned below, can form separate components or components of this unit or can be integral regions or sections of this unit, even if this is illustrated differently in the drawing.Preferred exemplary embodiments of the invention are illustrated in the drawing and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally the same components.The single FIG. 1 shows a greatly simplified flow diagram of a method for producing motor vehicles.According to FIG. 1, a method 1 for manufacturing motor vehicles has a step 2 in which a first module is manufactured, the first module being equipped with a first mechanical interface. In a further step 3, a second module is produced separately from the first module, wherein the second module is equipped with a second mechanical interface.Method 1 is explained in more detail below with reference to an example in which only two modules are taken into account, each having only one interface. However, the method 1 can also be used in a corresponding manner if three or more modules have to be joined, each of which has at least one interface. Method 1 can likewise be applied in a corresponding manner if at least one of the modules has two or more interfaces.The interfaces of the two modules are configured for joining the two modules, i.e. for fastening the two modules to one another, which is carried out in a step 4. Before the joining according to step 4 of the first module to the second module, a setpoint-actual comparison of geometric dimensions of the first interface and of the second interface is carried out in a step 5. After the desired actual adjustment according to step 5 and before the joining of the modules according to step 4, a post-processing of the first interface and / or of the second interface is carried out in a step 6, in which the geometric dimensions of the first interface and / or of the second interface are corrected by means of an additive manufacturing method. After the post-processing of the first interface or the second interface according to step 6, the joining of the modules follows in step 4, in which the first interface and the second interface are fastened to one another.In a step 7, corrosion protection and / or paintwork can be applied to the first module and to the second module before the joining according to step 4. The post-processing of the first interface and / or of the second interface in step 6 takes place before the application of the corrosion protection and / or the painting in step 7.It can be expediently provided that the desired-actual adjustment according to step 5, which is carried out before the application of the corrosion protection or the paint system according to step 7, represents a first desired-actual adjustment, which is carried out before the application of the corrosion protection and / or the paint system, in order to record and adjust the geometric dimensions of the first interface and the second interface. The post-processing carried out in step 6, which is carried out before the application of the corrosion protection and / or the painting in step 7, then represents a first post-processing which is carried out as a function of the first desired actual compensation according to step 5, wherein a first additive manufacturing method is used for correcting the geometric dimensions of the first interface and / or of the second interface. After the corrosion protection and / or the paint system according to step 7 has been applied, a second desired-actual comparison of the geometric dimensions of the first interface and of the second interface can be carried out in a step 8. After this second desired-actual adjustment according to step 8 and before joining the modules according to step 4, a second post-processing of the first interface and / or of the second interface can now be carried out in a step 9, in which a second additive manufacturing method for correcting the geometric dimensions of the first interface and / or of the second interface can be used.In this case, the first additive manufacturing method which is used in the context of the first post-processing according to step 6 can differ from the second additive manufacturing method which is used in the context of the second post-processing according to step 9.A configuration of method 1 is particularly advantageous in which the respective desired-actual matching according to step 5 or according to step 8 is carried out in that the dimensions of the first interface and of the second interface are detected separately, wherein after the separate detection of the actual dimensions a matching of the detected actual dimensions of the first interface with the detected actual dimensions of the second interface is carried out. Depending on this adjustment, a correction requirement of the first interface and / or of the second interface with respect to the geometric dimensions is then determined. In other words, it is determined whether only the first interface or only the second interface or whether both interfaces have to be corrected by material application by means of the additive manufacturing method. The respective post-processing according to step 6 or according to step 9 is then carried out as a function of the determined correction requirement.The respective desired-actual adjustment according to step 5 or according to step 8 is preferably carried out in-line. Likewise, the respective additive manufacturing method according to step 6 or according to step 9 is preferably carried out in-line. In this case, it can be provided in particular that the respective desired-actual adjustment according to step 5 or according to step 8 is carried out by means of a robot. Additionally or alternatively, it can be provided that the respective additive manufacturing method according to step 6 has been modified. According to step 9, a robot is used. The respective additive manufacturing method is expediently a 3D printing method in which, in particular before the application of the corrosion protection and / or the coating according to step 7, metal is applied additively or in which, in particular after the application of the corrosion protection and / or the coating according to step 7, plastic is applied additively.

Claims

Method (1) for producing motor vehicles, - wherein at least a first module and a second module are produced (2, 3) separately from one another, - wherein the first module is equipped with a first interface during its production (2), - wherein the second module is equipped with a second interface during its production (3), - wherein the first interface and the second interface are provided for joining (4) the first module to the second module, - wherein a desired-actual alignment (5, 8) of geometric dimensions of the first interface and of the second interface is carried out before the joining (4) of the first module to the second module, - wherein after the desired-actual alignment (5, 8) and before the joining (4) of the first module to the second module, a post-processing (6, depending on the desired-actual alignment, is carried out, 9) of the first interface and / or of the second interface, in which the geometric dimensions of the first interface and / or of the second interface are corrected by means of an additive manufacturing method, - wherein after the post-processing (6, 9) of the first interface and / or of the second interface, the joining (4) of the first module to the second module is carried out, in which the first interface and the second interface are fastened to one another, characterized - in that corrosion protection and / or painting is applied (7) to the first module and to the second module before the joining (4), - in that the post-processing (6, 9) of the first interface and / or of the second interface is carried out before the application (7) of the corrosion protection and / or painting or after the application (7) of the corrosion protection and / or painting.Method (1) according to the preamble of claim 1, characterised in that - corrosion protection and / or paintwork are applied to the first module and to the second module before joining (4), - a first desired-actual comparison (5) of the geometric dimensions of the first interface and of the second interface is carried out before applying (7) the corrosion protection and / or paintwork, - after the first desired-actual comparison (5) and before applying (7) the corrosion protection and / or paintwork, a first post-processing (6) of the first interface and / or of the second interface is carried out as a function of the first desired-actual compensation, in which the first interface and / or the second interface are corrected with respect to the geometric dimensions by means of an additive manufacturing method, - the application (7) of the corrosion protection and / or the paint system is carried out after the first post-processing (6), - after the application (7) of the corrosion protection and / or the paint system a second desired-actual adjustment (8) of the geometric dimensions of the first interface and of the second interface is carried out, - after the second desired-actual adjustment (8) and before the joining (4) of the first module to the second module, a second post-processing (9) of the first interface and / or of the second interface is carried out as a function of the second desired-actual adjustment (8), in which the first interface and / or the second interface are corrected with respect to the geometric dimensions by means of an additive manufacturing method, - after the second post-processing (9) the joining (4) of the first module to the second module is carried out.Method (1) according to Claim 2, characterized - in that the additive manufacturing method which is carried out during the first post-processing (6) differs from the additive manufacturing method which is carried out during the second post-processing (9).Method (1) according to one of the preceding claims, characterized - in that for the respective desired-actual matching (5, 8) the geometric actual dimensions of the first interface and of the second interface are detected separately, - in that after the separate detection of the actual dimensions a matching of the detected actual dimensions of the first interface with the detected actual dimensions of the second interface is carried out, - in that a correction requirement of the first interface and / or of the second interface with respect to the geometric dimensions is determined as a function of the matching, - in that the respective post-processing (6, 9) is carried out as a function of the determined correction requirement.Method (1) according to one of the preceding claims, characterized - in that the respective desired-actual adjustment (5, 8) is carried out inline.Method (1) according to one of the preceding claims, characterized - in that the respective desired-actual adjustment (5, 8) is carried out by means of a robot.Method (1) according to one of the preceding claims, characterized - in that the respective additive manufacturing method is carried out in-line.Method (1) according to one of the preceding claims, characterized - in that the respective additive manufacturing method is carried out by means of a robot.Method (1) according to one of the preceding claims, characterized - in that the additive manufacturing method is configured as a 3D printing method.

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