DE102017201876A1 - Method for producing an exterior attachment of a vehicle and exterior attachment - Google Patents

Abstract

The invention relates to a method for producing an exterior attachment (1) of a vehicle, which comprises at least one outer skin (2) forming the visible side of the exterior attachment, and a substructure (3), comprising the steps:
Injection molding of the outer skin (2), for which a first plastic material is introduced into a first cavity (9) formed by two molded parts (6, 7) of an injection molding tool (5) and hardens or solidifies there,
Injection molding of the substructure (3) on an inner side of the outer skin (2), for which a second plastic material is introduced into a second cavity (10), which contains the outer skin (2) and receives form-fitting, where it hardens or solidifies, wherein the substructure (3) cohesively and / or positively connects with the outer skin (2). Furthermore, an exterior attachment produced by the method is specified.

Description

The invention relates to a method for producing an exterior attachment of a vehicle, in particular a passenger car and an exterior attachment.

As exterior attachment parts parts are referred to, which are attached to a vehicle body and make the exterior of the vehicle at least partially. Therefore, the exterior attachment parts high demands are made in terms of surface quality, as they often contain design-relevant surfaces and are perceived on the finished vehicle as part of the outer skin. Exterior attachment parts are e.g. Bumper panels or spoilers.

Such exterior attachment parts are increasingly being manufactured from plastics in the context of lightweight construction. For bumper panels, it is e.g. known to produce a plastic outer skin, which has the necessary surface quality and to stiffen it with a substructure. So far, the substructure is made as a separate component, and e.g. Connected to the outer skin by means of clip fastening. In addition to a force absorption, the substructure also has the task of receiving additional components, e.g. Sensors or ventilation grille to act. These attachments are e.g. clipped into the finished substructure or attached by means of additional mounting hardware.

Furthermore, it is from the document DE 10 2004 044 159 A1 known to produce a body attachment as a composite component, wherein an outer skin is provided as a film and formed by deep drawing and provided with a recess. In the recess a guide rail is inserted. Subsequently, the outer skin is back-injected with a plastic layer, whereby an inner layer is produced which presses the outer skin firmly against the guide rail and fixes it.

Against this background, it is an object of the present invention to provide a way with which an improved exterior attachment can be produced in a simple and cost-effective manner.

The object is achieved by a method according to claim 1 and an exterior attachment according to claim 8. Further advantageous embodiments will be apparent from the dependent claims and the description below.

The invention relates to a method for producing an exterior attachment of a vehicle, wherein the exterior attachment comprises an outer skin and a substructure molded onto it. The outer skin forms on its outer side the visible side of the exterior attachment and the substructure is placed on the inside of the outer skin. According to the invention, the outer skin is produced by injection molding, for which a first plastic material is introduced into a first cavity enclosed by two mold parts of an injection molding tool, where it cures or solidifies, and the substructure is injection-molded onto an inner side of the outer skin, including a second plastic material in one second cavity is introduced, which includes the outer skin and receives form-fitting, and there hardens or solidifies, wherein the substructure materially and / or positively connects to the outer skin.

In injection molding a flowable plastic is introduced into an injection mold and remains there under pressure and possibly at elevated temperature. After the plastic material is solidified (in thermoplastics) or cured (in thermosets), it can be removed from the mold.

An injection molding tool usually comprises two mold parts, which enclose a cavity in the closed state. The plastic mass is filled into the cavity and, after solidification or hardening, essentially (taking into account the material shrinkage of the plastic material) has the shape of the cavity.

After the outer skin has been produced in this way in a first cavity, the substructure is injected onto the outer skin using a second cavity. The second cavity is shaped such that the outer skin in the closed mold is receivable in the second cavity and, adjacent to the outer skin, a cavity remains which substantially corresponds to the shape of the substructure to be formed. The outer skin lies with its outer side in a form-fitting manner in a molded part of the injection molding tool. Now, if the plastic material for the substructure is introduced into the injection mold, the plastic compound fills the second cavity and comes in direct contact with the outer skin. When using suitable materials, it is possible to form a cohesive connection at the contact surface between outer skin and substructure, e.g. in that a thermoplastic outer skin is partially remelted as a result of the energy input of the molten plastic mass for the substructure. Likewise, it is also possible by design of the second cavity, e.g. by the provision of undercuts or the like, form a positive connection between the outer skin and substructure.

According to the invention the composite of outer skin and substructure at the same time with the Produced producing the substructure, which eliminates additional assembly steps. Unlike deep-drawn outer skins, which are produced by forming a plastic film, the outer skin is in the erfindungsmäßen process urgeformt directly in the desired shape. A subsequent forming step and concomitant variations in thickness or shear stresses in the material of the outer skin omitted. The outer skin is positively received in the molded part of the injection molding tool, whereby the outer side of the outer skin is fully supported and undergoes no relative movement to the injection mold during back injection. This makes it possible to dispense with additional measures to protect the outside, such as a protective film. Advantageously, eliminates the storage of separate components. Furthermore, the influence of manufacturing tolerances is reduced because, due to the process, the substructure optimally adapts to the shape of the outer skin.

It is conceivable first to produce the outer skin, then insert it into the molded parts of a second injection molding tool and then to inject the substructure. However, the method achieves particular advantages when the outer skin is back-injected with the substructure in the same molded part in which it was produced and which images its outer surface. More specifically, in this process for producing the substructure, only the one part of the injection molding tool which faces the inside of the outer skin is replaced. In addition to the omission of a repositioning of the outer skin, the visible side of the same is protected and protected from damage, e.g. from scratches when inserting into another injection molding tool.

Basically, the method is suitable for all plastic materials that can be processed in the injection molding process, such as. Thermoplastic or thermosetting plastics with and without fiber reinforcement. Polypropylene (PP), acrylonitrile-butadiene-styrenes (ABS) and acrylonitrile-styrene-acrylate copolymers (ASA) can be used with particular preference.

In order to achieve a particular surface quality, it may be advantageous if, in one embodiment of the invention, the substructure is formed from a foamed plastic material. The pressures in the mold, which occur in the injection molding of foamed plastics, are much lower than in the injection molding of compact plastics, whereby prints in the outer skin are avoided. The formation of foamed plastic layers is conventionally known and can e.g. by the use of chemical blowing agents in the plastic melt.

In the injection molding process, it is further possible to use attachments that can be made in plastic, such as Mounts in which, for example, sensors or lamps are used, or ventilation grille, etc., in the same injection molding step in which the outer skin or the substructure is formed. The cavity of the respective molding tool can be enlarged in accordance with the shape of the attachment and the plastic material which forms the outer skin or the substructure, then also forms the attachment. Likewise, with the substructure or outer skin, attachment means, such as e.g. Clips or the like, are formed with, which serve to attach the exterior attachment to the vehicle body.

If a greater variance in terms of the design of the attachments is to be made possible, it is provided in one embodiment that at least one attachment in a separate injection molding material and / or form fit to the outer skin or to the substructure or both to the outer skin as well as to the Substructure is injected. The separate injection molding step allows the use of a different type of plastic material, e.g. in color, strength, thickness, etc. different from the plastic material of the outer skin or substructure. In addition, it is also possible by a separate step to connect the attachment only in a form-fitting manner to the outer skin or substructure, e.g. through the use of plastic materials that do not form a material bond at their contact surface.

It is particularly advantageous here if the injection molding of the attachment takes place in the same mold with which the substructure is also formed. For this purpose, the molding tool may, for example, have a secondary cavity, which images the attachment, and which is formed by a closing mechanism, e.g. a slider, relative to the second cavity releasable and closable. By injecting a plastic compound in the Nebenkavität the attachment is formed. This can optionally be done before, after or at the same time as the formation of the substructure.

After curing or solidification of all injection-molded component components, the exterior attachment is removed from the mold. Additional manufacturing steps may follow, e.g. a painting process or similar

The exterior parts which can be produced by the method have a high surface quality and can be produced with reduced logistics costs compared to conventional production methods. The reduction of the manufacturing process to several injection molding steps simplifies the process management, also the gap dimensions and Groove geometries are improved. Furthermore, it is possible to produce multicolored bumper linings by direct coloring of the plastic granulate without subsequent painting.

Preferably, the method is used to make a bumper fascia or spoiler. It is particularly preferred that the molded attachment is a ventilation grille, e.g. in a bumper cover.

Furthermore, an exterior attachment is specified, which comprises an outer skin and a substructure, wherein the outer skin is produced by injection molding and the substructure is injection-molded by an injection molding process to the outer skin and is connected by molding in positive and / or cohesive with this.

In one refinement, the exterior attachment can furthermore have at least one injection-molded attachment which is injection-molded onto the outer skin and / or the substructure and is connected to it in a material and / or form-fitting manner. The exterior attachment can also have several such sharpened attachments, which may be the same or different attachments, such as grille for the cooling air passage and brackets, which are molded with the inventive method to the outer skin and / or the substructure.

The exterior attachment is preferably a bumper fascia or spoiler. It is particularly preferred that the molded attachment is a ventilation grille, e.g. in a bumper cover.

The exterior attachment is preferably made by the method described above so that the same technical effects and advantages as described for the method according to the invention are achieved.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood with reference to the drawings and in conjunction with the following description of the embodiments. If the term "can" is used in this application, it is both the technical possibility and the actual technical implementation.

• 1 eine schematische Schnittansicht eines beispielhaften Exterieuranbauteils und
• 2A bis 2E schematische Darstellungen eines Spritzgusswerkzeugs zur Erläuterung einer beispielhaften Verfahrensführung.

Embodiments will be explained below with reference to the accompanying drawings. Show:

• 1 a schematic sectional view of an exemplary exterior attachment and
• 2A to 2E schematic representations of an injection molding tool to explain an exemplary process management.

1 shows a schematic sectional view of an exemplary exterior attachment 1 in the form of a bumper cover. Such a bumper fascia, for example, attached to the front of a vehicle where it covers a bumper cross member and possibly a pedestrian cross member. The bumper panel 1 has an outer skin 2 on, a substructure 3 and one or more attachments 4 , In the in 1 shown section is exemplified a single attachment in the form of a grid for a cooling air passage shown. In the further course, not shown, the bumper cover 1 In addition, have more attachments, such as holders for sensors or lamps or other grid.

Is the bumper fascia 1 mounted on the vehicle, so has the outer skin 2 away from the vehicle and the substructure 3 and the grid 4 are facing the vehicle. The outer skin 2 has been made by injection molding of a thermoplastic. Was injected with it, also in an injection molding process, the substructure 3 which is formed of a foamed plastic material. Through the injection molding process has been between outer skin 2 and substructure 3 a cohesive connection is formed, the two layers (at least in sections) connects flat with each other. In another injection molding step, the grid was 4 to the substructure 3 molded, with the attachment 4 cohesively connected to the plastic of the substructure. Due to the production by injection molding tolerances between the individual components of the exterior attachment can be reduced and the joint geometries can be reduced.

An exemplary sequence of a method for producing the exterior attachment is schematically based on 2A to 2E explained.

First, an injection mold 5 provided with a first molding 6 , a second molded part 7 and a third molding 8th , To close the injection mold 5 are the first molding 6 and the second molding 7 opposite the fixed molding 8th moveable and deliverable to this. The closed injection mold 5 is in 2A shown. In the closed state remains between the first molding 6 and the second molded part 7 a first cavity 9 which are essentially the shape of the outer skin to be produced 2 equivalent. When shaping the cavity is Among other things, the material shrinkage due to the solidification process is considered.

For the production of the outer skin 2 will now be in the first cavity 9 of the closed injection mold 5 introduced a plastic compound. In order to form the Anspritzmarken on the inside, filled (not shown) injection unit, the first cavity 9 for example, by a feed channel, not shown in the first molding 6 , The injected plastic compound solidifies in the injection mold 5 (or hardens if it is a duromer) to the outer skin 2 , Now the injection mold opens 5 , including the moldings 6 and 7 from the fixed molding 8th to be reduced, see 2 B , The outer skin 2 remains in the second molding 7 , By a turn D 180 ° becomes the second molded part 7 now compared to the other moldings 6 . 8th twisted, shown in 2C , The outer skin 2 points with its inside now in the direction of the third molding 8th ,

The injection mold 5 is closed again, whereby the outer skin 2 between the second molding 7 and the third molding 8th is included. The closed injection mold 5 between the moldings 7 and 8th formed second cavity 10 , is now partially through the outer skin 2 filled. The remaining cavity essentially forms the shape of the substructure to be produced 3 to. The substructure 3 is now formed by the second cavity 10 is filled with a plastic compound in the closed injection mold 5 solidifies or hardens. The plastic material for the substructure 3 gets in direct contact with the skin during injection molding 2 and forms, for example, a material connection with the outer skin 2 out. Likewise, the second cavity may be shaped so that the substructure 3 an undercut to the outer skin 2 forms and thus creates a positive connection. After opening the injection mold 5 can the exterior extension 1 be removed.

The second molding 7 is how in 2A shown on two opposite sides, each with an identical inner contour 11 Mistake. While now in the in 2C shown process step the outer skin 2 with the second molding 7 towards the third molding 8th is turned, becomes an empty inner contour 11 the first molded part 5 facing. In the subsequent closing process, not only the second cavity can 10 but it can also be the first cavity 9 be refilled. So it is possible that at the same time as forming the substructure 3 also another outer skin 2 will be produced. 2D shows the injection mold 5 after both the first and second cavities have been filled with plastic material. In the enlarged view of 2D it can be seen that the substructure 3 in this process step to the outer skin 2 is injected.

To the exterior attachment further attachments, such as the grid shown 4 to inject, can the injection mold 5 at least one additional Nebenkavität 12 exhibit. This can in the second molding 7 or third molding 8th be educated. The secondary cavity 12 is shaped according to the shape of the attachment to be produced and has, for example, the in 2E shown grid structure. About a non-illustrated locking mechanism in the form of a slider, the Nebenkavität 12 from the second cavity 10 be disconnected or opened to this. When filling the second cavity 10 becomes the secondary cavity 12 separated by the slider and remains empty. In a subsequent injection molding step, the slider is opened and the secondary cavity 12 is, for example, by a feed channel in the second molding 7 , filled with plastic material.

Opening the injection mold 5 and demolding the exterior attachment 1 takes place when the molded attachments are hardened or solidified. The demolding can be done for example by a robot.

The embodiments are not to scale and are not restrictive. Modifications in the context of expert action are possible.

LIST OF REFERENCE NUMBERS

1

Exterior attachment

2

shell

3

substructure

4

attachment

5

injection mold

6, 7, 8

moldings

9, 10

cavity

11

inner contour

12

secondary cavity

D

rotation

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102004044159 A1 [0004]

Claims (11)

Method for producing an exterior attachment (1) of a vehicle, which comprises at least one outer skin (2) which forms the visible side of the exterior attachment, and a substructure (3), with the steps: Injection molding of the outer skin (2), for which a first plastic material is introduced into a first cavity (9) formed by two molded parts (6, 7) of an injection molding tool (5) and hardens or solidifies there, Injection molding of the substructure (3) on an inner side of the outer skin (2), for which a second plastic material is introduced into a second cavity (10), which contains the outer skin (2) and receives form-fitting, where it hardens or solidifies, wherein the substructure (3) cohesively and / or positively connects with the outer skin (2). Method according to Claim 1 in which the outer skin (2) is left in the same mold half (7) during back injection with the substructure (3) in which the outer skin (2) was previously produced. Method according to one of the preceding claims, wherein the substructure (3) is formed of a foamed plastic material. Method according to one of the preceding claims, with the further step: Producing at least one attachment (4) by means of injection molding, wherein the at least one attachment (4) material and / or positive fit to the outer skin (2) or to the substructure (3) or both to the outer skin (2) and to the substructure (3) is injected. Method according to one of the preceding claims, wherein the molding of the attachment (4) takes place in the same molding, with which the substructure is formed, for which the injection molding tool (5) has a side cavity (12) forming the attachment (4) a closing mechanism relative to the second cavity (10) is releasable or closable and can be filled with a plastic compound. Method according to one of the preceding claims, which is used for producing a bumper cover or spoiler. Method according to one of the preceding claims, in which the molded attachment (4) is a ventilation grille. Exterior attachment part of a vehicle with an outer skin (2) forming the visible side of the exterior attachment (1) and a substructure (3) which is formed by an injection molding process and bonded to the outer skin (2) in a positive and / or cohesive manner by injection molding , Exterior of a vehicle after Claim 8 , Further comprising at least one injection-molded attachment (4) molded onto the outer skin (2) and / or the substructure (3) and material and / or positively connected thereto. Exterior attachment after one of the godfathers claims 8 or 9 which is a bumper panel or spoiler Exterior attachment after Claim 10 in which the at least one attachment is a ventilation grille.

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