Shaping tool for producing a composite component

Abstract

The invention relates to a shaping tool (10) for producing a composite component (1) which has a carrier layer (2), a decorative layer (3) which is connected to the carrier layer (2), and at least one plastic part (4) which is moulded onto the carrier layer (2) and / or the decorative layer (3), having at least one upper tool (11) and at least one lower tool (12) which form a cavity which encloses the composite component (1), wherein at least one lifting insert (13) which presses the composite component (1) against the upper tool (11) and / or lower tool (12) is arranged between the upper tool (11) and the lower tool (12), wherein the at least one lifting insert (13) is of movable design, in order to set a gap, corresponding to a layer thickness of the composite component (1), between the lifting insert (13) and the upper tool (11) and / or lower tool (12). Furthermore, the invention relates to a vehicle part (50) produced using a shaping tool (10) of this type, and to a vehicle (100) having a vehicle part (50) of this type.

Description

[0001] Forming tool for producing a composite component

[0002] The invention relates to a molding tool for producing a composite component comprising a carrier layer, a decorative layer bonded to the carrier layer, and at least one plastic part molded onto the carrier layer and / or the decorative layer. Furthermore, the invention relates to a vehicle part produced using such a molding tool and to a vehicle comprising such a vehicle part.

[0003] In vehicle construction, plastic support elements covered with fabric or leather as a decorative layer are used in modern vehicles, particularly in interior trim, such as the headliner, dashboards, doors, seats, etc. In addition to visual and tactile aspects, the support elements primarily serve to seal the vehicle interior in terms of acoustics, moisture, and air permeability. For both sustainability and cost reasons, the need arose to at least partially replace fossil materials such as plastic with new, renewable raw materials. The usually invisible support elements are therefore increasingly made of natural fiber composites, i.e. natural fiber-reinforced plastics as the support layer. These materials have favorable mechanical properties and are also relatively low in production costs.In addition, they are lighter than glass-fiber-reinforced plastics, have good acoustic properties, and are less prone to splintering. However, due to the problem that natural-fiber-reinforced plastics often fail to meet the requirements for appearance and feel, they are laminated with decorative layers such as fabric, leather, but also other textiles, artificial leather, fleece, leather, foils, wood veneers, bamboo, flax fabrics (e.g., with PP impregnation), etc.

[0004] The most commonly used manufacturing process is compression molding. Injection molding is somewhat less expensive and better suited for high volumes. Both compression molding and injection molding involve the use of molding tools. Their basic structure is similar. Typically, each molding tool consists of two halves: a static side (lower tool), known in injection molding as the nozzle side, and a movable, opposite ejector side (upper tool). These two halves contain the individual components of the tool, such as ejector elements, sprue systems, cores, cavity inserts, and cooling or temperature control. A mold cavity in the shape of the final workpiece remains between the halves. In compression molding, the molding compound is introduced into the cavity of a die consisting of an upper and lower die.These die halves are then pressed together during the pressing process, so that the molding compound takes on the shape of the cavity. The basic structure and sequence of these two processes are well known from the state of the art.

[0005] For example, DE 10 2013 216 191 B4 discloses a method for producing a carrier element, in which a polypropylene natural fiber mat with a basis weight of less than 850 g / m 2preheated and placed in a tool with a rib-shaped cavity. The mat is then pressed into the predefined shape by the tool so that the thickness of the mat after pressing is less than 1.2 mm, preferably equal to or less than 0.8 mm. Immediately after pressing, a material containing polypropylene is "back-injected" into the back-shaped cavity of the mat. Due to the back-injection, the material forms stiffening ribs with the mat. Finally, the mat with the stiffening ribs is demolded. This process does not produce any plastic parts that will be visible later. This process also has the disadvantage that the pressing thickness has to be set to a thickness of the mat in each case, since otherwise, for example, a thicker mat would result in over-pressing and a thinner mat would result in unsightly casting flash.

[0006] Different material thicknesses arise because different materials are used for the carrier layers and decorative layers, which can have different material properties, such as stability, strength, stiffness, weight, density, load-bearing capacity, etc.

[0007] If, for example, a material such as flax fabric is used as the decorative layer, which itself contributes to the load-bearing capacity, i.e., can assume part of the load-bearing capacity of the carrier layer, the thickness of the carrier layer can naturally be smaller, sometimes half as thick. For decorative layers whose material has a purely decorative effect but contributes little to no load-bearing capacity, such as TPU foam film, the carrier layer must therefore assume almost the entire load-bearing capacity, so the carrier layer can sometimes be twice as thick. Accordingly, the layer thickness of the composite component can vary considerably depending on the material selection.

[0008] The object of the present invention is to provide a device with the aid of which composite components of variable thickness, i.e. with decorative and carrier layers of different thicknesses, and possibly of different types, can be pressed with one and the same forming tool, the injection edges are always sealed and with which a vehicle part manufactured with such a device can be manufactured more cost-effectively.

[0009] To achieve this object, a device having the features of claim 1 is proposed.

[0010] Advantageous embodiments of the device are the subject of the dependent claims.

[0011] According to a first aspect of the invention, a forming tool for producing a composite component comprising a carrier layer, a decorative layer bonded to the carrier layer, and at least one plastic part molded onto the carrier layer and / or the decorative layer is proposed. The forming tool comprises at least one upper tool and at least one lower tool, which form a cavity surrounding the composite component. At least one lifting insert is arranged between the upper tool and the lower tool, which presses the composite component against the upper tool in order to bond the carrier layer and the decorative layer to one another. The at least one lifting insert is designed to be movable in order to adjust a gap between the lifting insert and the upper tool and / or lower tool that corresponds to a layer thickness of the composite component.

[0012] Such a molding tool enables the cost-effective manufacture or production of a vehicle part for a vehicle. Furthermore, it creates the possibility of joining composite components with different layer thicknesses and different compressibility and injecting at least one plastic part without over-molding the composite component, since the gap between the upper and lower tools is precisely adjusted to the layer thickness of the composite component before injection. At the same time, the at least one lifting insert cleanly seals an injection edge of the composite component. This eliminates the need for over-molding. Furthermore, it makes it possible for the first time to press composite components of different thicknesses, i.e. parts with different compositions of carrier layer and decorative layer, with the same molding tool and inject at least one plastic part.The invention can also reduce the quality risk caused by different layer thicknesses when injecting the plastic part.

[0013] The cavity is the so-called mold cavity, which, minus the decorative layer and the carrier layer, represents a negative of the plastic part to be molded. To mold the at least one plastic part, the molding tool, as usual, naturally includes an injection molding device of some kind for injecting an injectable molding compound into the cavity of the molding tool, and a clamping unit for applying a clamping force to the upper and lower tools of the molding tool during the injection of the molding compound.

[0014] Alternatively or additionally, at least one lifting insert can press the composite component against the lower tool. For example, the selected carrier layer can be bonded or pressed to the selected decorative layer. If necessary, an additional material, such as adhesive, can be used if a bonded connection without such an adhesive is not sufficiently strong.

[0015] In an advantageous embodiment, the at least one lifting insert can be moved hydraulically and / or mechanically.

[0016] A hydraulic lifting mechanism, for example, using a piston and cylinder, has the technical advantage that the forming tool is very powerful, requires relatively little space for the lifting mechanism, and is generally very low-wear, requiring little maintenance. However, when maintenance is required, a mechanically movable lifting mechanism, such as a spindle drive, is generally easier to maintain and also less expensive to repair. Furthermore, no fluids are required, which may need to be checked and refilled.

[0017] In an advantageous embodiment, the forming tool comprises a control unit which is designed to move the at least one lifting insert to a specific target stroke value matching the layer thickness of the composite component before the injection molding process.

[0018] This achieves the technical advantage that any desired layer thickness can be preset. Preferably, the control unit can have its own memory from which pre-stored layer thicknesses for various, specific composite components can be read. Advantageously, the control unit can also be designed so that it independently detects the layer thickness of the inserted composite component and then sets the target stroke value of the lifting insert accordingly. Alternatively, the composite component can also be entered into the control unit by an operator, and the control unit then selects the appropriate layer thickness for the respective composite component from the memory and sets the corresponding target stroke value accordingly.

[0019] In an advantageous embodiment, the at least one lifting insert is arranged on a rear side of the carrier layer facing away from the decorative layer.

[0020] This achieves the technical advantage that any theoretically possible cosmetic defects can only occur on the back side of the composite component, which back side (blind side) is generally not visible during use, so that cosmetic imperfections there are of no serious relevance for the customer.

[0021] In an advantageous embodiment, at least one lifting insert is sealingly positioned against the rear side of the composite component. This provides the technical advantage that the injection molding edges for the plastic part that is subsequently molded are always cleanly sealed.

[0022] Preferably, it can be positioned so that it rests on the rear side of the composite component within a circumferential edge area.

[0023] For the subsequent injection molding process, it forms a clear sealing edge for the plastic part of the composite component to be molded, which limits the edge surround or the plastic frame of the plastic part.

[0024] In an advantageous embodiment, the at least one lifting insert is resiliently mounted relative to the upper tool or lower tool by means of a spring element.

[0025] This achieves the technical advantage that the target stroke value is adjusted automatically in response to a counterpressure due to the layer thickness of the composite component.

[0026] Preferably, the spring strength of the spring element can be adjusted so that the lifting insert always presses the composite component with a visible surface of the decorative layer flat against a corresponding opposing part of the molding tool. The visible surface of the decorative layer is thus sealed sufficiently tightly against an opposing part of the molding tool during injection molding to form a visually appealing inner edge of the plastic part.

[0027] In an advantageous embodiment, the forming tool comprises several lifting inserts arranged side by side and separated from one another. "Side by side" means that the lifting inserts are arranged parallel to a visible surface of the composite component, butt-to-butt or spaced apart. "Separated" means that the lifting inserts can be moved or adjusted individually or separately.

[0028] This achieves the technical advantage that, in the case of composite components with several sections of different layer thicknesses, a gap corresponding to a respective layer thickness can be set equally in all sections between the respective lifting insert and the upper tool and / or lower tool.

[0029] According to a further aspect of the invention, a vehicle part is proposed that is manufactured using such a forming tool. Preferably, such a forming tool can be used to manufacture a vehicle interior trim part for the vehicle interior.

[0030] Such a vehicle part is cheaper to manufacture and, as mentioned, can be manufactured with different materials using one and the same forming tool without first having to prepare or manufacture a new forming tool adapted to a different layer thickness.

[0031] According to a further aspect of the invention, a vehicle is proposed which has at least one such vehicle part.

[0032] Below, a vehicle with a vehicle part and a forming tool for producing the vehicle part, as well as further features and advantages, are explained in more detail using an exemplary embodiment, which is schematically illustrated in the figures. Here:

[0033] Fig. 1 is a perspective view of the vehicle; and

[0034] Fig. 2 a side view of the forming tool.

[0035] Figure 1 shows a vehicle 100, here for example a motor vehicle 100, which has a vehicle part 50 (not shown) in the vehicle interior, which was manufactured with the shaping tool 10 shown in Figure 2.

[0036] As can be seen from Figure 2, the shaping tool 10 is shown in a highly simplified manner and is therefore limited to the components relevant to the invention. The other components (injection molding device, clamping unit, etc.) are sufficiently known to the person skilled in the art from the prior art, which is why they are only mentioned here insofar as they are relevant for the description of the invention. The shaping tool 10 has two mold halves, namely an upper tool 11 and a lower tool 12 that is movable relative to the upper tool (see Figure 2). The components of the subsequent composite component 1 that are not to be injection molded can be inserted between the mold halves 11, 12 in the open, i.e. spaced-apart, state (not shown).In the closed state shown in Figure 2, a cavity is accordingly created between the mold halves 11, 12, which represents a negative of the composite component 1 and can then be filled in an injection molding step with a molding compound from an injection molding device (not shown) in order to enclose the previously inserted (non-injectable) components of the laterally formed composite component 1, inter alia, laterally, if necessary all around, with a plastic part 4, namely, for example, the fork-head-shaped plastic frame shown in Figure 2.

[0037] The components of the composite component 1 that are not injection-molded include a carrier layer 2. The carrier layer 2 is a material layer that is responsible, among other things, for the load-bearing capacity of the composite component 1. Accordingly, the carrier layer 2 can be, for example, a natural fiber composite material, such as a natural fiber-reinforced plastic mat or plate, since, among other positive properties, this has a comparatively low weight, low splintering tendency, and good acoustic properties.

[0038] Secondly, the composite component 1 includes a decorative layer 3. The decorative layer 3 fulfills the task of concealing or covering the usually visually unsightly surface of the carrier layer 2. Accordingly, the decorative layer 3 is often only a thin film, textile, artificial leather, fleece, leather, wood veneer, bamboo or similar. Decorative layers 3 made of such materials are usually not load-bearing themselves and therefore serve a purely optical purpose (unless, for example, they are particularly thick, etc.). If the decorative layer 3 consists of a flax fabric impregnated with PP, for example, it can under certain circumstances assume part of the load-bearing capacity of the carrier layer 2 even with a small thickness. This means that the carrier layer 2 can then generally be considerably thinner, which can potentially save weight and material costs.By using different combinations of materials for the carrier layer 2 and the decorative layer 3, very different layer thicknesses can be achieved for the composite component 1 (apart from the plastic part 4). To illustrate this, two possible, significantly different layer thicknesses of the composite component 1 are shown as examples in Fig. 2. A solid line represents a composite component 1 with a "thinner" carrier layer 2. The dashed line indicates the layer thickness of an overall thicker composite component.

[0039] In order that the visible surface 3o of the decorative layers 3 of a thicker as well as a thinner composite component 1, i.e. regardless of the thickness, is pressed upwards equally securely and flush against the upper tool 11 (so that, among other things, the thickness of the enclosing plastic part 4 above the decorative layer 3 is always the same and no sink marks are created), the shaping tool 10 (as here, for example) has at least one lifting insert 13 or tool core 13 (the rectangular plastic parts 4 in Fig. 2 are two domes, i.e. the lifting insert is actually formed continuously around them here), which presses the composite component 1 in the closed state of the mold halves 11, 12 (at several points evenly over its longitudinal extent) from below against the rear side 5, 5' of the carrier layer 2 by pressure contact during the injection of the molding compound.

[0040] Depending on the thickness of the carrier and decorative layers 2, 3, the lower leg of the edge-side border in the form of the fork-shaped plastic part 4 of the composite component 1 can be thicker or thinner, as can be seen from the enlarged view in Figure 2. However, the mold halves 11, 12 of the forming tool 10 are designed such that a sufficiently stable lower plastic leg of the plastic part 4 is always molded onto the plastic part 4 during the injection molding step.

[0041] To produce the composite component 1, the carrier layer 2 and the decorative layer 3 are inserted between the mold halves 11, 12, and the movable upper tool 11 is lowered from above onto the static lower tool 12. During this process, or in advance using a control unit, a target stroke value for the stroke insert 13 is set. After the carrier layer 2 has been pressed together with the decorative layer 3, molding compound is injected into the mold cavity of the mold halves 11, 12, and the plastic part 4 is molded onto the remaining component (including at the edges) to form the composite component 1. After curing, the composite component 1 is finally removed from the molding tool 10.

[0042] The forming tool 10 is characterized by the ability to produce composite components of varying thicknesses, something that was previously only possible with multiple forming tools or with significant quality losses. This allows process times to be shortened and possible tolerances in the production of composite components to be minimized, resulting in increased product quality. Furthermore, raw materials and costs for the production of additional forming tools can be saved.

[0043] List of reference symbols

[0044] 1 composite component

[0045] 2 Carrier layer

[0046] 3 decorative layers

[0047] 3o Visible surface of the decorative layer

[0048] 4 plastic part

[0049] 5 Back side / blind side of a “thinner” composite component

[0050] 5' backside / blind side of a "thicker" composite component

[0051] 10 Shaping tool

[0052] 11 Upper tool

[0053] 12 Lower tool

[0054] 13 Lifting insert / tool core

[0055] 50 vehicle parts

[0056] 100 vehicles

Claims

Claims 1. A shaping tool (10) for producing a composite component (1) comprising a carrier layer (2), a decorative layer (3) connected to the carrier layer (2), and at least one plastic part (4) injection-molded onto the carrier layer (2) and / or the decorative layer (3), comprising at least one upper tool (11) and at least one lower tool (12) which form a cavity surrounding the composite component (1), wherein at least one lifting insert (13) is arranged between the upper tool (11) and the lower tool (12), which presses the composite component (1) against the upper tool (11) and / or lower tool (12), wherein the at least one lifting insert (13) is designed to be movable in order to set a gap between the lifting insert (13) and the upper tool (11) and / or lower tool (12) which corresponds to a layer thickness of the composite component (1).

2. Shaping tool according to claim 1, characterized in that the at least one lifting insert (13) is hydraulically and / or mechanically movable.

3. Shaping tool according to claim 1 or 2, characterized in that the at least one lifting insert (13) is arranged on a rear side (5, 5') of the carrier layer (2) facing away from the decorative layer (3).

4. Shaping tool according to one of the preceding claims, characterized in that the at least one lifting insert (13) lies sealingly against a rear side (5, 5') of the composite component (1).

5. Shaping tool according to one of the preceding claims, characterized in that the at least one lifting insert (13) is resiliently mounted relative to the upper tool (11) or lower tool (12) by means of a spring element, wherein a spring strength of the spring element is preferably set such that the lifting insert (13) always presses the composite component (1) with a visible surface of the decorative layer (3) flat against the upper tool (11) and / or lower tool (12).

6. Shaping tool according to one of the preceding claims, comprising a plurality of separate lifting inserts (13) arranged next to one another.

7. Vehicle part (50) manufactured with a forming tool (10) according to one of the preceding claims.

8. Vehicle (100) comprising at least one vehicle part (50) according to claim 7.

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