METHOD FOR MANUFACTURING A COMPONENT ASSEMBLY FOR A MOTOR VEHICLE, COMPONENT ASSEMBLY FOR A MOTOR VEHICLE AND MOTOR VEHICLE WITH THE COMPONENT ASSEMBLY

Description

[0001] The present invention relates to a method for producing a component assembly for a motor vehicle, wherein the component assembly comprises a base body for an instrument panel of the motor vehicle. The present invention further relates to a component assembly for a motor vehicle and to a motor vehicle.

[0002] It is known in the art to assemble complex components for a motor vehicle from various individual components or component structures and then assemble them. This leads to correspondingly high costs, as not only does it take more time to join the various component structures, but the various component structures also have to be manufactured, transported, and stored.

[0003] In a component assembly consisting of a multitude of different component structures, a multitude of different fasteners are also required to connect the respective component structures. This leads to the problem that such a designed component assembly is relatively heavy. However, weight is essential to minimize in vehicle construction.

[0004] To reduce weight, the wall thickness of a component structure or component assembly can be reduced. However, this also leads to a corresponding reduction in stiffness and / or strength. Furthermore, the wall thickness can only be reduced to a certain extent using conventional manufacturing processes. In addition to a minimum required stiffness at certain points of the component structure, a desired surface quality is also a condition that prevents or may not arbitrarily reduce the wall thickness of certain component structures.

[0005] German patent application DE 10 2010 031 814 A1 discloses the production of plastic parts such as trim and cladding components in the automotive sector for instrument panels, door panels, and pillar trims using an external gas pressure process. The application area of ​​the external gas pressure process is limited to small component structures.

[0006] DE 10 2005 038 469 A1 describes a method for producing an injection-molded plastic component and a correspondingly produced plastic component. DE 601 06 348 T2 discloses an injection molding process. DE 10 2006 058 546 A1 shows an airbag flap for a passenger seat and a method for producing the same.

[0007] Another method for producing an injection-molded plastic component is known from FR 2 873 613 A1. Furthermore, a method for producing an airbag assembly is known from US 2005 / 0121818 A1.

[0008] The object of the present invention is to at least partially address the problems described above. In particular, the object of the present invention is to provide an improved method for producing a component assembly for a motor vehicle, an improved component assembly for a motor vehicle, and a motor vehicle with a correspondingly improved component assembly.

[0009] The above object is achieved by the subject matter of the patent claims. In particular, the above object is achieved by the method according to claim 1, the component assembly according to claim 7, and the motor vehicle according to claim 9. Further features and details of the invention emerge from the subclaims, the description, and the drawings. Features described in connection with the method according to the invention naturally also apply in connection with the component assembly according to the invention, the motor vehicle according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0010] According to a first aspect of the present invention, a method for producing a component assembly for a motor vehicle is provided, wherein the component assembly comprises a base body for an instrument panel of the motor vehicle and at least one functional component. In the method, the at least one functional component is injection-molded onto the base body during the production of the component assembly, wherein the component assembly is produced using an external gas pressure process.

[0011] By applying an external gas pressure process during the injection molding of at least one functional component to the base body, it is possible to reduce or even completely eliminate sink marks in the area of ​​the injection-molded functional component on the base body, while still producing a component assembly with a particularly complex and large-area component structure. Sink marks can be prevented by the present process or at least reduced to such an extent that they do not cause any visually detrimental impairment to the base body or structural component for the end customer.

[0012] The at least one functional component is preferably a non-base-body-specific functional component that is fundamentally not an integral part of the base body of the instrument panel and could also be arranged separately from the base body in the motor vehicle. The base body is fundamentally understood to mean a basic instrument panel structure that is designed and can be arranged to form or co-form an instrument panel area of ​​the motor vehicle and to accommodate operating elements for a vehicle occupant. The functional component is not, for example, a mere through-opening in the base body that can accommodate a display or operating element for a vehicle occupant.Rather, the at least one functional component is understood to mean a functional component that interacts with another functional component in the motor vehicle for a significant mechanical interaction, or at least can be designed for this purpose. The functional component can, for example, have or "spanned" a volume greater than 0.1 dm3, for example, between 0.1 dm3 and 100 dm3, preferably between 0.5 dm3 and 50 dm3.

[0013] The external gas pressure does not need to be applied to the entire surface of the component during production or injection molding. Rather, the external gas pressure is applied specifically to at least one area where at least one functional component is molded onto the base body during the production of the component. This allows for targeted counteracting of any subsequent sink marks on the component.

[0014] In this context, a composite component is understood to be a composite of two different and / or separate components that are connected to one another to save space and achieve a targeted positive interaction. The production of the composite component is not limited to the at least one functional component being molded onto the base body only after completion of the latter. Rather, it is preferred in this case that the at least one functional component is integrated into the base body or molded onto it directly during the production of the composite component.

[0015] The motor vehicle in this case is not limited to a road vehicle or a passenger car. Thus, the method according to the invention can also be used to produce a component assembly for a truck, a watercraft, a rail vehicle, an aircraft, and / or a robot.

[0016] According to the present invention, in the method, the at least one functional component has an airbag firing channel or is configured as such. This means that the airbag firing channel is molded onto the base body for the instrument panel during the production of the component assembly using an external gas pressure process. Since molding the airbag firing channel previously resulted in significant surface damage or sink marks, as well as distortions in the base body, which could subsequently negatively impact the corresponding component assembly, molding the airbag firing channel onto a base body for a bright-sprayed instrument panel has been avoided.Therefore, it has previously been common practice to weld an airbag firing channel as an additional part to a base body for the instrument panel for a spray-finished instrument panel and then to cover a surface of the instrument panel, for example, with a so-called slush skin. However, this is time-consuming and correspondingly expensive. Within the scope of the present invention, it has now been discovered that the external gas pressure process can also be used for large-area structural components such as the base body for an instrument panel. Furthermore, the airbag firing channel can be molded onto the base body particularly advantageously using this process. The resulting component composite can be manufactured accordingly quickly and cost-effectively.In addition, when molding the airbag firing channel onto the base body using the external gas pressure process, very little or no additional material is used, allowing the component assembly to be produced in a weight-saving manner. This airbag firing channel serves to guide a gas bag of the airbag, especially a passenger airbag, during its deployment.

[0017] It is advantageous if the at least one functional component, in particular the airbag firing channel, is injection-molded onto a rear side of the base body facing away from a visible side of the base body. The use of the external gas pressure process effectively counteracts surface impairments or sink marks as well as tensions on the visible side of the base body, which can otherwise occur when the functional component is injection-molded onto the rear side of the base body, so that the visible side of the base body of the instrument panel remains at least substantially unaffected. The visible side of the base body of the instrument panel is understood to mean the side of the base body of the instrument panel that, when the instrument panel is installed in the vehicle, at least substantially faces the vehicle interior.

[0018] Furthermore, it is provided within the scope of the present invention that, during production of the component assembly, external gas pressure is applied to a flat region of the base body around the at least one functional component. For the reasons already described, the flat region of the base body is preferably arranged on a rear side of the base body facing away from a visible side of the base body. In this way, a large part of a volume shrinkage during a solidification process can be compensated for and eliminated or at least greatly reduced as a cause of sink marks on the surface of the base body. A flat region is to be understood as an area of, for example, more than 50 cm², in particular between 50 cm² and 1000 cm², preferably between 100 cm² and 500 cm², in which no projection or the like is formed or which extends homogeneously or essentially homogeneously and preferably planar.

[0019] Furthermore, according to the present invention, it can be advantageous if, during the production of the component assembly, the at least one functional component is cooled at least in sections with CO2 spot cooling, which is applied in particular by a mold for producing the component assembly. In this case, CO2 cooling or CO2 spot cooling is introduced into a tool-side contour of the mold, which is designed to complement an associated section of the component assembly or the base body and / or the functional component, in order to prevent excessive heating of contour areas in the mold. This avoids hot spots in the product, which are partly responsible for the sink marks already mentioned above.

[0020] It can be further advantageous in a method according to the invention if, during the production of the component assembly, at least one recessed section of the at least one functional component is specifically cooled by CO2 spot cooling, which is applied in particular by a molding tool for producing the component assembly. The at least one recessed section is preferably cooled by a complementarily designed projection section of the molding tool, wherein the CO2 spot cooling is introduced at least partially into the associated or complementary recessed section by the at least one projection section. By means of the targeted CO2 spot cooling of the functional component also in the at least one recessed section, i.e. in an inner region of the functional component, it is possible to particularly reliably reduce or even prevent any sink marks.The at least one recessed section can be configured, for example, as at least one recessed section or as a plurality of recessed sections of a stiffening structure of an airbag firing channel. The at least one recessed section of the functional component is preferably configured as at least one pocket section of the functional component.

[0021] Furthermore, according to the present invention, it is possible for the component composite to be produced using the external gas pressure process and using polypropylene (PP). In this case, the base body, in particular, is produced using polypropylene. By using polypropylene, the component composite or the base body can be provided with particularly advantageous material and corresponding surface properties. The component composite is produced in such a way that, after its production, it predominantly comprises polypropylene or consists essentially, completely or at least essentially completely of polypropylene. By using the polypropylene, the component composite or at least one surface of the base body, which is arranged towards a vehicle cabin when used in a motor vehicle, can be produced with a spray-finished or grained finish in combination with the external gas pressure process.A bright or grained production process refers to the manufacture of the component assembly with a defined surface quality or structure after injection molding, at least in some sections. This means that if the component assembly is manufactured with a bright finish, for example, one surface of the component assembly will have a defined surface quality after injection molding. The desired surface quality can be achieved in particular through the external gas pressure process during injection molding. Due to the external gas pressure process used, combined with the polypropylene used, the component assembly has no or no significant visible sink marks and a correspondingly bright surface. This means that immediately after injection molding, the surface of the component assembly or the base body is "bright" or grained as desired.

[0022] According to a further aspect of the present invention, a component assembly for a motor vehicle is provided, wherein the component assembly is manufactured according to a method as described in detail above. Thus, the component assembly according to the invention offers the same advantages as those described in detail with reference to the method according to the invention.

[0023] Within the scope of the present invention, a component assembly for a motor vehicle is further provided, wherein the component assembly comprises a base body for an instrument panel and at least one functional component, and the base body, together with the at least one functional component, is manufactured as an integral plastic injection-molded part using an external gas pressure process. Due to the integral manufacture or the correspondingly integral construction of the component assembly, it can be provided in a particularly lightweight yet stable manner. In the present case, an integral injection-molded part is understood to mean a one-piece or monolithic injection-molded component.

[0024] According to the present invention, the at least one functional component is preferably provided as an airbag firing channel, in particular as a passenger airbag firing channel. Accordingly, the base body and the airbag firing channel are provided as a one-piece or monolithic injection-molded component or as a corresponding composite component that does not have or require a weld seam or any other additional material-, form-, and / or force-fitting connecting element.

[0025] According to a further aspect of the present invention, a motor vehicle with a component assembly as described above is provided. Thus, the motor vehicle according to the invention also offers the same advantages as those described in detail with reference to the method according to the invention.

[0026] Further measures improving the invention will become apparent from the following description of various embodiments of the invention, which are schematically illustrated in the figures. All features and / or advantages arising from the claims, the description, or the drawings, including structural details and spatial arrangements, may be essential to the invention both individually and in various combinations. The figures schematically show: Fig. 1 a component assembly according to an embodiment of the present invention, Fig. 2 a section of a component assembly according to the Fig. 1 illustrated embodiment of the present invention, Fig. 3 a motor vehicle with the Fig. 1 shown component assembly, and Fig. 4 a flow chart for explaining a method according to the invention for producing a component composite.

[0027] Elements with the same function and mode of action are listed in the Figuren 1 bis 4 each provided with the same reference numerals.

[0028] Fig. 1 shows a component assembly 100 for a motor vehicle 1 according to a preferred embodiment of the present invention. The component assembly 100 according to Fig. 1 comprises a base body 10, consisting essentially of polypropylene, for an instrument panel of the motor vehicle 1, as well as a functional component 20, wherein the functional component 20 is designed as an airbag firing channel on a rear side of the base body 10, which represents a rear side of the base body 10 facing away from a visible side of the base body 10. The rear side or rear side of the base body 10 corresponds to a side of the base body 10 for the instrument panel, which faces toward or essentially toward a front side of the motor vehicle 1 when the component assembly 100 is installed in the motor vehicle 1, and thus, in the installed state of the component assembly 100, faces away from the vehicle interior of the motor vehicle 1.Accordingly, a front side of the base body 10 for the instrument panel is to be understood as a visible side which points in the direction of or substantially in the direction of a vehicle interior of the motor vehicle 1 when the component assembly 100 is installed in the motor vehicle 1.

[0029] The base body 10 is according to Fig. 1 Manufactured together with the functional component 20 configured as an airbag firing channel using an external gas pressure process as an integral or one-piece plastic injection-molded part. The plastic airbag firing channel 20 is configured as an airbag firing channel for a passenger airbag or as a passenger airbag firing channel and is arranged at a correspondingly suitable position on the base body 10 for the instrument panel, namely on the rear side or back of the base body 10.

[0030] Fig. 2 shows an enlarged view of the arrangement of the functional component 20 designed as an airbag firing channel on the base body 10. In Fig. 2 A flat area 11 of the base body 10 is shown, which is designed around the airbag firing channel 20 and over which an external gas pressure is applied during the production of the component assembly 100. The flat area 11 is arranged on the rear side or back of the base body 10. In Fig. 2 Also shown are several recesses 21 of a stiffening structure of the airbag firing channel 20.

[0031] In Fig. 3 is a roughly schematic representation of a motor vehicle 1 with a Fig. 1 shown component assembly 100, wherein the component assembly 100 is arranged in an instrument panel area of ​​the motor vehicle 1 or as a component of an instrument panel of the motor vehicle 1.

[0032] With reference to Fig. 4A method for producing a component assembly 100 according to the invention for an instrument panel or a motor vehicle 1 with this instrument panel is then described.

[0033] To produce the component assembly 100, a plastic base body 10 for an instrument panel and a plastic functional component 20 in the form of an airbag firing channel are provided in a first step S1. The plastic material used is preferably polypropylene, a filled polypropylene, a fiber-reinforced polypropylene, or a polypropylene derivative.

[0034] In a second, subsequent or at least partially parallel step S2, the functional component 20 is injection-molded onto the base body 10 during the production of the component assembly 100, wherein the component assembly 100 is produced using an external gas pressure process. External gas pressure is applied to a flat region 11 of the base body 10 around the at least one functional component 20, wherein the flat region 11 is arranged on the rear side of the base body 10 facing away from the visible side of the base body 10.

[0035] In a third step, which is performed during the production of the component assembly 100, the functional component 20 is cooled section by section using CO2 spot cooling, which is applied by a mold for producing the component assembly 100. More specifically, in this step, several pockets or recessed sections 21 of a stiffening structure of the functional component 20 are specifically cooled using CO2 spot cooling, which is applied by the mold for producing the component assembly 100.

[0036] In addition to the described embodiments, the present invention allows for further embodiments. List of reference symbols

[0037] 1Motor vehicle 10Main body 11Flat area 20Functional component, in particular airbag firing channel 21Recessed section 100Component composite

Claims

1. Method for manufacturing a component assembly (100) for a motor vehicle (1), the component assembly (100) having a base body (10) for an instrument panel of the motor vehicle (1), and at least one functional component (20), the at least one functional component (20) having an airbag ejection channel or being designed as such, characterized in that the at least one functional component (20) is injection-molded onto the base body (10) during the manufacture of the component assembly (100) and the component assembly (100) is manufactured by using an external gas pressure method, external gas pressure being applied to a flat region (11) of the base body (10) around the at least one functional component (20) during the manufacture of the component assembly (100).

2. Method according to the preceding claim, characterized in that the at least one functional component (20) is injection-molded onto a rear side of the base body (10) facing away from a visible side of the base body (10).

3. Method according to any of the preceding claims, characterized in that the flat region (11) of the base body (10) is arranged on a rear side of the base body (10) facing away from a visible side of the base body (10).

4. Method according to any of the preceding claims, characterized in that during the manufacture of the component assembly (100), the at least one functional component (20) is cooled, at least in portions, using CO2 spot cooling, which is applied in particular by a molding tool for manufacturing the component assembly (100).

5. Method according to any of the preceding claims, characterized in that during the manufacture of the component assembly (100), at least one recessed portion (21) of the at least one functional component (20) is cooled using CO2 spot cooling, which is applied in particular by a molding tool for manufacturing the component assembly (100).

6. Method according to any of the preceding claims, characterized in that the component assembly (100) is manufactured by using the external gas pressure method and by using polypropylene.

7. Component assembly (100) for a motor vehicle (1), comprising a base body (10) for an instrument panel of the motor vehicle (1), and at least one functional component (20), characterized in that the base body (10) is manufactured together with the at least one functional component (20) as an integral injection-molded part by using an external gas pressure method, the at least one functional component (20) having an airbag ejection channel or being an airbag ejection channel, the component assembly (100) being manufactured according to a method according to any of the preceding claims.

8. Component assembly according to claim 7, characterized in that the at least one functional component (20) is injection-molded onto a rear side of the base body (10) facing away from a visible side of the base body (10).

9. Motor vehicle (1) comprising a component assembly (100) according to claim 7 or claim 8.