Method for producing a component from a composite material and component

Abstract

Method for manufacturing a component from a composite material, comprising the following steps: - Providing a tape (1; 9) of a first material; - Making two parallel incisions (2) into the strip, wherein the strip (1; 9) is divided by the two incisions (2) into a central area (3) and two edge areas (4) which are connected to each other.; - Attaching the tape (1; 9) to a first inner wall (5) which defines a cavity, wherein the first inner wall (5) has holes (8), wherein the tape (1; 9) is attached to the first inner wall (5) by creating a vacuum in the holes (8); - Injection of a second material through an injection opening (7) in the first inner wall (5) onto the central area (3) of the strip (1; 9) which is arranged between the incisions (2), so that the central area (3) is pressed against a second inner wall (6) which limits the cavity, while at the same time the two edge areas (4) are pressed against the first inner wall (5) by both the second material and the vacuum in the openings (8).

Description

[0001] The invention relates to a method for manufacturing a component from a composite material according to claim 1.

[0002] Composite materials in sandwich construction are known from the prior art. DE 10 2017 210 047 A1 discloses an injection molding process for producing a plastic cladding part stiffened by a band. The band is made of the same material as the overmolded plastic.

[0003] From US patent 2005 / 0127564 A1, a method for producing a composite product is known, comprising a plastic body and a cover layer formed from a metal blank, which is bonded to the plastic body over at least part of its surface. The metal blank is arranged in a die comprising a mandrel movable relative to the blank holder and a support die. A liquid plastic is injected into the die, bringing the liquid plastic into contact with the metal blank. The liquid plastic is transformed into a solid plastic body, which is bonded to the metal blank to produce the composite product.

[0004] US patent 2015 / 0291265A1 discloses an insert for a watersports board. The insert features a pre-impregnated flange extending outwards from an injection-molded central body to achieve improved interlayer bonding between the injection-molded central body and a surface polymer.

[0005] From DE 10 2011 102 722 A1, a method for producing a molded part decorated by means of in-mold decoration and in-mold labeling is known using an injection molding device that has a decoration-side mold half and a core-side mold half. The decoration-side mold half is movable and the core-side mold half is fixed to a frame.

[0006] In contrast, the invention aims to create an efficient method for manufacturing a composite material. Furthermore, it seeks to create a component for a motor vehicle manufactured using this method.

[0007] This problem is solved by a method according to claim 1 and by a component according to claim 9. Embodiments of the invention are specified in the dependent claims.

[0008] According to the method, a strip of a first material is provided. Two parallel incisions are made in this strip. The strip is divided by the two incisions into a central area and two edge areas, which are connected to each other. The strip is attached to a first inner wall that defines a cavity.

[0009] The first inner wall has holes. The tape is attached to the first inner wall by creating a vacuum in the holes. This can be done, for example, by drawing air out of the holes. In this case, the tape is suctioned to the first inner wall. The first inner wall can define a cavity of an injection mold, an injection compression mold, or a compression mold, into which an injection molding material can be injected for the injection molding, compression molding, or compression molding process. The first inner wall could, for example, be an upper inner wall.A second material is injected through an injection port in the first inner wall onto the central area of ​​the strip, which is positioned between the incisions. This causes the central area to be pressed against a second inner wall that defines the cavity, while simultaneously the two outer areas are pressed against the first inner wall by both the second material and the negative pressure in the incisions. The second inner wall can be positioned opposite the first. If the first inner wall is an upper inner wall, the second inner wall can be a lower inner wall. It is possible that the area covering the injection port is present before injection.

[0010] This process creates a composite material in a particularly efficient manner, in which the area pressed against the second inner wall during injection is bonded to a first side of a base body made of the second material. On a second side of the base body, the parts of the strip from which the area was detached during injection are bonded.

[0011] According to one embodiment of the invention, the first material can comprise fibers arranged parallel to one another in a fiber direction. The incisions can run in the fiber direction. This has the advantage that, during injection molding, the area can be separated from the rest of the strip particularly easily by further tearing the incisions.

[0012] According to one embodiment of the invention, the strip can be torn at the longitudinal ends of the incisions in the fiber direction during injection, until the strip is divided into three individual parts. The area of ​​one of these three parts is defined as [insert area here]. The tearing can be caused, in particular, by the injection process. For the purposes of this description, "longitudinal ends" refers specifically to the ends of the incisions in the longitudinal direction of the incisions. The longitudinal direction is the direction in which the incisions have their greatest extent.

[0013] According to one embodiment of the invention, the incisions can be arranged parallel to a longitudinal direction of the strip. In this description, the longitudinal direction of the strip is understood to be, in particular, the direction in which the strip has its greatest extent. Preferably, a longitudinal geometric axis is an axis of symmetry of the strip before the incisions are made.

[0014] According to one embodiment of the invention, ends running in a transverse direction of the strip can be free of the incisions. For the purposes of this description, the transverse direction is understood to mean, in particular, the direction perpendicular to the longitudinal direction and in which the strip has its second greatest extent. Because the transversely running ends of the strip are free of the incisions, the area is stably connected to the sections of the strip outside this area before injection. This connection is then broken by the injection process.

[0015] According to one embodiment of the invention, the first material can be a continuous fiber-reinforced thermoplastic. The continuous fibers can be, for example, carbon fibers. The thermoplastic can be, for example, polypropylene, a polyamide, polybutylene terephthalate, polycarbonate, or acrylonitrile butadiene styrene. The use of a continuous fiber-reinforced thermoplastic is particularly advantageous for dissipating forces acting on the component to be manufactured, thus minimizing their effect on the second material, which is preferably more cost-effective to produce. In this way, the component can be both stable and inexpensive to manufacture. Furthermore, the use of the continuous fiber-reinforced thermoplastic results in a lower temperature dependence of the component's mechanical properties.

[0016] In one embodiment, the second material can comprise the thermoplastic that is a component of the first material. For example, the second material can be or comprise natural fiber-filled polypropylene or recycled polypropylene. Preferably, the second material is less expensive to produce than the first material. It is advantageous for the second material to comprise the thermoplastic that is a component of the first material, as this creates a particularly stable, metallurgical bond between the first and second materials during injection molding.

[0017] According to one embodiment of the invention, a number of groups of two parallel incisions can be made in the strip. The second material can be injected through the same number of injection openings in the first inner wall onto the same number of areas of the strip, so that the areas are pressed against the second inner wall. Exactly one of the injection openings can inject the second material onto exactly one of the areas. This embodiment increases the flexibility in component design, as different strip lengths and widths can be achieved.

[0018] The strip may have a thickness between 0.1 and 0.3 mm. Such a relatively small thickness is advantageous for achieving relatively small bending radii and preventing fiber breakage during cold forming.

[0019] The distance between the first and second inner walls can be, for example, between 1 and 7 mm.

[0020] The component according to claim 9 is manufactured using a method according to an embodiment of the invention. Preferably, it can be a planar and / or load-bearing component in the structural area of ​​the motor vehicle.

[0021] Further features and advantages of the present invention will become clear with reference to the following description of a preferred embodiment and the accompanying figures. The same reference numerals are used for identical or similar components and for components with identical or similar functions. Fig. 1 a schematic perspective view of a band made of a first material with incisions; Fig. 2 A a schematic sectional view of the band arranged in a cavity made of Fig. 1, while a second material is injected into the cavity; Fig. 2B a schematic perspective view of the band made of Fig. 1 with a similar to in Fig. 2A depressed middle area; Fig. 3A a schematic sectional view of the band made of Fig. 2A, which is divided into three parts due to the injection of the second material; Fig. 3B a schematic perspective view of the band made of Fig. 1 in a three-part state, as also seen in Fig. 3A is present; Fig. 4 a schematic perspective view of a band with a number of groups of two parallel incisions; Fig. 5A a schematic sectional view of the band arranged in a cavity made of Fig. 4, while a second material is injected into the cavity; Fig. 5B a schematic perspective view of the band made of Fig. 4 with a similar to in Fig. 5A depressed middle area; Fig. 6A a schematic sectional view of the band made of Fig. 5A, which is divided into five parts due to the injection of the second material; Fig. 6B a schematic perspective view of the band made of Fig. 4 in a five-part state, as also seen in Fig. 6A is present.

[0022] Strip 1, made of a first material, has two incisions 2, which may have been cut into the strip 1. The incisions 2 extend in the longitudinal direction of the strip 1. However, they do not run over the entire length of the strip 1. The ends running in the transverse direction of the strip 1 are free of the incisions 2. The strip 1 is divided by the two incisions into a central region 3 and two edge regions 4, which are connected to each other.

[0023] The strip 1 is arranged in a cavity, for example, an injection mold. It is attached to a first inner wall 5, which delimits the cavity, by drawing air out through holes 8 in the first inner wall 5, so that the negative pressure in the holes 8 draws the strip 1 against the first inner wall 5. Fig. For the sake of clarity, only some of the holes 8 in section 2A are marked with reference symbols.

[0024] In the first inner wall 5, an injection opening 7 is also arranged, through which a second material is injected into the cavity. This is shown in the Fig. 2A and Fig. 3A is shown by arrows. During injection, the second material presses the central region 3 of the strip 1, located at the injection opening, against a second inner wall 6 of the cavity. At this point, the central region 3 and the two outer regions 4 are still connected to each other (see also Fig. 2B). However, the force acting on the central region 3 causes the strip 1 to tear at the ends of the incisions 2 in the direction of the ends of the strip 1 that run in the transverse direction. It is particularly advantageous if the first material has fibers that are arranged parallel to the longitudinal direction of the incisions.

[0025] In Fig. Figure 3A depicts the state in which the connection between the central region 3 and the two outer regions 4 has broken due to the injection of the second material. The central region 3 is pressed against the second inner wall by the injection, while simultaneously the two outer regions 4 are pressed against the first inner wall 5 by both the second material and the negative pressure in the openings 8. After the second material has cooled, a component with a base body made of the second material is created. The central region 3 is bonded to one side of the base body, and the outer regions 4 are bonded to a second side of the base body.

[0026] The in the Fig. Volume 9, as depicted in sections 4 to 6B, has two groups of incisions 2. A procedure is carried out for each group as was also carried out for volume 1 in the Fig.Sections 1 to 3b were described. In volume 9, there is a section 10 located between the two groups of incisions. This section remains attached to the first inner wall during the execution of the process. After the second material has cooled, section 10 is thus bonded to the first side of the base body.

Claims

[1] Method for manufacturing a component from a composite material, comprising the following steps: - Providing a tape (1; 9) of a first material; - Making two parallel incisions (2) into the strip, wherein the strip (1; 9) is divided by the two incisions (2) into a central area (3) and two edge areas (4) which are connected to each other.; - Attaching the tape (1; 9) to a first inner wall (5) which defines a cavity, wherein the first inner wall (5) has holes (8), wherein the tape (1; 9) is attached to the first inner wall (5) by creating a vacuum in the holes (8); - Injection of a second material through an injection opening (7) in the first inner wall (5) onto the central area (3) of the strip (1; 9) which is arranged between the incisions (2), so that the central area (3) is pressed against a second inner wall (6) which limits the cavity, while at the same time the two edge areas (4) are pressed against the first inner wall (5) by both the second material and the vacuum in the openings (8). [2] Method according to claim 1, characterized by , that the first material comprises fibers arranged parallel to each other in a fiber direction, wherein the incisions (2) run in the fiber direction. [3] Method according to the previous claim, characterized by , that during injection the band (1; 9) is torn at the longitudinal ends of the incisions (2) in the fiber direction until the band (1; 9) is divided into three parts (3, 4; 4). [4] Method according to any one of the preceding claims, characterized by , that the incisions (2) are arranged parallel to a longitudinal direction of the strip (1; 9). [5] Method according to any one of the preceding claims, characterized by , that ends running in a transverse direction of the band (1; 9) are free from the incisions (2). [6] Method according to any one of the preceding claims, characterized by , that the first material is an endless fiber-reinforced thermoplastic. [7] Method according to any of the preceding claims, characterized by , that the second material comprises the thermoplastic that is a component of the first material. [8] Method according to any one of the preceding claims, characterized by, that a number of groups of two parallel incisions (2) are introduced into the strip (1; 9), wherein the second material is injected through the same number of injection openings (7) in the first inner wall (5) onto the same number of areas (3) of the strip (1; 9), so that the areas (3) are pressed against the second inner wall (6). [9] Component for a motor vehicle, manufactured by a method according to any of the preceding claims.

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