DEVICE AND METHOD FOR MANUFACTURING A COMPONENT

Description

[0001] The invention relates to a device and a method for manufacturing a component. In particular, the invention relates to a device and a method for manufacturing the component by means of two mold elements (also referred to as "tooling") and a hose arranged in a cavity of one of the mold elements.

[0002] For example, US 2010 / 0196637 A1 concerns the production of hollow components. For this purpose, at least one semi-finished product ("prepreg") is placed between two mold halves, containing at least one mold tube. By using a vacuum envelope or vacuum bag around the mold halves and introducing a higher gas pressure into the mold tubes, the semi-finished product can be pressed against the inside of the mold halves.

[0003] However, forming an end face is difficult in the production of components, especially those containing resin and / or fiber-reinforced materials. An end face, in this context, is defined as a narrow, oriented side of the component located between two larger sides (those with a greater surface area than the end face itself). This specific shape can lead to damage to the end face during resin curing or even in the molded, unfinished state.

[0004] For example, in Figure 1 A component 20 is shown, which has a section with an end face 21. At the end face 21, the... Figure 1 On the end face 21 shown above, cracks may form during the curing of the resin, or air inclusions 101 may occur that remain after curing, as shown on the left. Figure 1 is shown.

[0005] Similarly, a similarly undesirable effect can occur with fiber-reinforced components 20 (composite elements). Here, after the fibers are introduced into the mold (or when a prefabricated component with a fiber-reinforced insert (pre-preg) is introduced into the mold), the fibers can be compressed or forced sideways by a shape or mold section forming the end face 21. For example, different fibers or fiber layers can be forced apart, as in delamination. This is due to the Figure 1 The fibers are shown as dashed lines. In the later finished (cured) component 20, an undesired gap 101 can form in the end face 21.

[0006] Another adverse effect, also known as the book effect, occurs during the production of fiber-reinforced, curved components. In this process, different layers of superimposed fibers are shifted relative to each other by the curvature, similar to the pages of a book, so that at one end (an end face of the component) the fiber layers terminate in different positions.

[0007] Thus, the book effect can also lead to a gap similar to gap 101 arising due to the different lengths of the fiber layers, which is at least partially filled by additional resin 102, as shown on the right. Figure 1As illustrated, an attempt was made to provide some extra space in the mold at the end face and to introduce more resin than necessary, although the excess cured resin 102 must later be removed to bring the component into the desired shape (size). Otherwise, all fiber layers at one end (the future end face of the component) would first have to be cut to the same length. In both cases, an additional work step is necessary.

[0008] The invention is based on the objective of providing a device and a method for manufacturing a component with which the component can be manufactured more uniformly, reliably and also faster.

[0009] This problem is solved by a device having the features of claim 1 and by a method having the features of claim 9.

[0010] According to a first aspect for a better understanding of the present disclosure, a device for manufacturing a component comprises a first forming element and a second forming element. The first forming element may be configured on one side to form at least a section of the component to be manufactured, with the exception of an outer end face of the component to be manufactured, and the second forming element may have a cavity and be configured to be arranged on the first forming element such that the cavity spans the end face of the component to be manufactured.

[0011] The component to be manufactured can be made of a resin that needs to be cured. Alternatively or additionally, the component to be manufactured can be a fiber-reinforced component and / or a fiber-reinforced composite component. The side of the component to be manufactured does not necessarily have to protrude into the cavity of the second mold element (after the component has fully cured). Rather, the side can also be formed in an area defined by the first mold element that corresponds to the cavity of the second mold element.

[0012] The cavity of the second mold element thus serves to create the area in which the side is to be formed. Instead of being formed by a rigid mold element, the side of the component to be manufactured is formed by other components. For example, an inflatable tube can be arranged in the cavity. Therefore, the cavity does not serve to hold material for manufacturing the component, as with conventional molded parts, but rather enables the flexible production of the component's side without rigid, form-giving mold elements.

[0013] The device may further comprise a cover that covers the first and second forming elements and seals them against the surrounding atmosphere. The cover may completely enclose the first and second forming elements. Alternatively or additionally, the first and / or second forming element may be supported on a work surface or other substrate, with the cover being fluid-tightly attached to the work surface or substrate.

[0014] The interior of the inflatable tube is fluidically coupled to the surrounding atmosphere. In other words, the interior of the inflatable tube is not sealed off from the surrounding atmosphere by the cover. For example, the cover may have an opening, while the tube around the opening is fluidly sealed. Alternatively or additionally, the cover may be tubular at the opening, with the tubular section of the cover being connected to or integrated into the tube.

[0015] The side of the component to be manufactured is its end face. The first forming element is designed on one side to form at least a section of the component, excluding the end face. Furthermore, the position of the cavity corresponds to the end face of the component to be manufactured, thus spanning it.

[0016] In a further embodiment, the device can include a semi-permeable membrane positioned between the inflatable tube and the (future) (end) face of the component being manufactured. The semi-permeable membrane thus prevents the inflatable tube from coming into contact with the component being manufactured, for example, its end face. On the other hand, the semi-permeable membrane protects the inflatable tube from the material of the component being manufactured, allowing the tube to be reused for multiple components without requiring cleaning. The semi-permeable membrane allows gases, particularly air, to escape but is impermeable to substances of higher viscosity, such as resin.

[0017] To improve the removal of gas, especially air, a venting layer, a so-called breather, can be inserted between the semi-permeable membrane and the hose.

[0018] In a further development, the semi-permeable membrane can be positioned between the first and second mold elements and span the side of the component being manufactured. In other words, the semi-permeable membrane covers a cavity or opening in the first mold element, within which the component is formed. For example, the semi-permeable membrane can be clamped between the first and second mold elements, eliminating the need for a separate support for the membrane. Due to the membrane's semi-permeability, the cavity or opening can be fully utilized for forming the component up to the membrane, with the membrane retaining resin and thus forming the side of the component.

[0019] Alternatively or additionally, the device can include a sealing element arranged between the semi-permeable membrane and the first molded element and / or between the semi-permeable membrane and the second molded element. Two sealing elements can also be arranged on either side of the semi-permeable membrane, with one sealing element facing the first molded element and the other facing the second molded element. In each case, a seal against resin leakage between the two molded elements is achieved.

[0020] In another embodiment, the semi-permeable membrane can be tubular and enclose the inflatable tube. Here, too, the inflatable tube is protected from the resin of the component being manufactured. For example, the semi-permeable membrane can be pulled over the tube. Alternatively, the tube can be coated with a material that forms the semi-permeable membrane. Again, a breather can be provided between the membrane and the tube to improve venting.

[0021] Alternatively or additionally, the semi-permeable membrane can be pre-formed, at least in sections. For example, the semi-permeable membrane can be made of a material that is dimensionally stable with respect to resin. Furthermore, the pre-formed section or the entire semi-permeable membrane can be designed to shape the side of the component being manufactured. In other words, the semi-permeable membrane holds the resin of the component in shape until it cures.

[0022] In a further embodiment, the device includes a vacuum source configured to apply a vacuum in the area sealed by the cover, where the first and second mold elements are located. This removes air from a space defined by the first and second mold elements, in which the component is manufactured.

[0023] This facilitates the introduction of resin or other material to be cured and reduces the formation of gas bubbles (air bubbles) in the resin / material being cured. Furthermore, the cover is pressed onto the first and second mold elements, ensuring that the component being manufactured retains its shape.

[0024] Since the interior of the inflatable tube is fluidically coupled to the surrounding atmosphere, the tube expands when a vacuum is applied to the cavity of the second mold element. The tube is, in effect, indirectly inflated. This allows the tube to form a mold element that shapes the (front) face of the component. In particular, when a pre-formed semi-permeable membrane is used, the tube can support it from the cavity side, so that the semi-permeable membrane forms a dimensionally stable mold element for the front face of the component being manufactured. The inflatable tube ensures a homogeneous pressure distribution on the semi-permeable membrane, thus creating a homogeneous surface (more precisely, the surface area) of the component being manufactured.

[0025] If resin is injected under pressure into the first mold element during the manufacturing process, the interior of the inflatable tube can also be pressurized. For example, air can be pumped into the tube to counteract the injection pressure. The pressure inside the tube should always be slightly higher than the injection pressure.

[0026] In a further embodiment, the first mold element can be designed in two parts. A gap is provided between the two parts of the mold element, in which the component to be manufactured is produced. For example, the two parts of the mold element can be spaced apart from each other so that they form the sides of the component, between which the component's side edge lies. The gap can be fixed between the two parts of the first mold element by means of suitable spacers. The spacers are preferably arranged outside the area in which the component is manufactured.

[0027] The spacers can also be formed by, or supported by, another inflatable tube. If this additional inflatable tube is also fluidically coupled to the surrounding atmosphere, it inflates in the space between the two parts of the molded element. This pressurizes both parts of the molded element evenly, thus keeping them uniformly separated. Such an inflatable tube can also serve as a spacer between two molded elements, each forming a different component or a completely different section of the component being manufactured.

[0028] Furthermore, the second element can rest on both parts of the first element. In other words, the second element spans both parts of the first element. The cavity of the second element corresponds to the space between the two parts of the first element. At the very least, the space transitions into the cavity. For example, the cavity can have a greater width than the distance between the two parts of the first element that defines the space.

[0029] The device thus allows the production of a component, in particular a component with an end face, without the device having any (rigid or fixed) mold elements. The cavity and space between the two mold elements allow the insertion of reinforcing fibers or a prepreg without subjecting the fibers to stress (e.g., compression). This also allows the production of a component without the need for subsequent rework. In other words, components can be produced directly with the desired shape, i.e., so-called "near net shape" components.

[0030] According to another aspect, a method for manufacturing a component that has an outer end face and two adjacent side faces, wherein the end face has a smaller area than the two side faces, comprises the following steps: Arranging a first mold element having a shape that corresponds to at least one section of the component to be manufactured, with the exception of an outer end face of the component to be manufactured; arranging a second mold element having a cavity on the first mold element, such that the cavity spans the outer end face of the component to be manufactured adjacent to the section of the component to be manufactured; inserting an inflatable tube into the cavity; inserting a prefabricated component and / or a material to be cured into the first mold element; covering the first mold element and the second mold element with a cover that seals the first mold element and the second mold element against the surrounding atmosphere;Applying a vacuum to the area sealed by the cover, in which the first and second forming elements are located, wherein the interior of the inflatable tube is fluidically coupled to the surrounding atmosphere, so that the tube expands when the vacuum is applied and forms a forming element that shapes the outer end face of the component to be manufactured.

[0031] The order of the arranging and insertion steps is irrelevant, and these steps can be performed in any sequence. For example, the inflatable tube can be inserted into the cavity only after the prefabricated component and / or the material to be cured have been inserted.

[0032] In a further development, the process can also include inserting a semi-permeable membrane between the inflatable tube and the side of the component being manufactured. In other words, a semi-permeable membrane can be inserted and positioned between the cavity of the second mold element and an area of ​​the first mold element in which the component is being manufactured. This step can also be performed independently of the sequence of process steps listed above. For example, the semi-permeable membrane can be inserted before the inflatable tube is inserted into the cavity.

[0033] The aspects, developments, designs and variants described here can be combined in any way, so that further design variants not explicitly described are included in the present disclosure.

[0034] Exemplary embodiments of the invention are described in more detail below with reference to the drawings. Figure 1 schematically shows cross-sections of conventionally manufactured components with a defective end face, Figure 2 schematically shows a cross-section of a device for manufacturing a component comprising an end face, Figure 3 schematically shows a cross-section of a variant of a device for manufacturing a component comprising an end face, and Figure 4 shows a flowchart of an exemplary method for manufacturing a component comprising an end face.

[0035] According to the present invention, a device and a method for manufacturing a component comprising an end face are described.

[0036] Figure 2Figure 1 schematically shows a cross-section of a device 10 for manufacturing a component 20 comprising an end face 21. The arrangements and processes described here with regard to the end face 21 can, of course, also apply to and be carried out on another side or section of the component 20 to be manufactured. The component 20 is manufactured using a first forming element 11 and a second forming element 13. The first forming element 11 can be designed as a single piece or in multiple parts (for example, as shown, in two parts). The first forming element 11 has at least one side 12 that forms a section of the component 20 to be manufactured, excluding the end face 21. The first forming element 11 shown serves to manufacture a T-shaped component 20.

[0037] While the in Figure 2Since the end faces 21 shown below are formed by the first mold element 11, the end face 21 of the component 20 to be manufactured lies in an area defined by a cavity 14 of the second mold element 13. In other words, neither the first mold element 11 nor the second mold element 13 has a rigid section that forms the end face 21 of the component 20 to be manufactured. Instead, an inflatable tube 16 is provided in the cavity 14, the interior of which is fluidically coupled to the surrounding atmosphere.

[0038] A cover 18 is arranged around the first form element 11 and the second form element 13, covering these two form elements 11, 13 and sealing them against the surrounding atmosphere. The cover 18 can be, as shown in Figure 2 shown, can be fluid-tightly attached to a worktable (not shown) or alternatively can completely enclose the form elements 11, 13.

[0039] Optionally, a semi-permeable membrane 17 can be provided in addition to the inflatable tube 16. This membrane can be arranged between the tube 16 and the component 20 to be manufactured, in particular at its end face 21. For example, the semi-permeable membrane 17 can be pre-formed, at least in sections, so that the pre-formed section of the membrane 17 forms the end face 21 of the component 20 to be manufactured.

[0040] In the Figure 2 In the depicted variant, the semi-permeable membrane 17 is arranged between the first mold element 11 and the second mold element 13 and spans the end face 21 of the component 20 to be manufactured. In other words, the membrane 17 spans a gap in the first mold element 11 in which the component 20 to be manufactured is produced.

[0041] Figure 3Figure 1 schematically shows a cross-section of a variant of a device 10 for manufacturing a component 20 comprising an end face 21. In this variant, the semi-permeable membrane 17 encloses the inflatable tube 16. For this purpose, the membrane 17 is tubular in shape or is applied to an outer surface of the tube 16.

[0042] Although only in Figure 2 As shown, in each of the two variants of the device 10, a sealing element 19 can be arranged between the first forming element 11 and the second forming element 13. For example, a sealing element 19 can be arranged between the first forming element 11 and the semi-permeable membrane 17 or between the semi-permeable membrane 17 and the second forming element 13.

[0043] A vacuum source 30 can be provided such that a vacuum is applied to the area sealed by the cover 18, in which the first mold element 11 and the second mold element 13 are located. In other words, a fluid (gas or liquid) is removed from all the spaces and cavities of the first and second mold elements 11, 13 by the vacuum source 30. Before or simultaneously, the material (e.g., resin) for the production of the component 20 can be introduced into the spaces and cavities of the mold elements 11, 13. The component 20 to be produced can also include fibers, which are previously inserted, in particular, into the spaces of the first mold element 11, for example, in the form of a pre-preg. The vacuum source 30 also removes any fluid, especially air, contained between the fibers. The material (resin) used to produce the component 20, on the other hand, is retained by the semi-permeable membrane 17.

[0044] By applying a vacuum and fluidically coupling the interior of the inflatable tube 16 with the surrounding atmosphere, the tube 16 expands within the cavity 14. Due to atmospheric pressure, the tube 16 presses against the material of the component 20 to be manufactured, in particular the end face 21 to be formed / manufactured, or against the optionally provided semi-permeable membrane 17. Fluid from the space between the first forming element 11 can be guided to the vacuum source 30 through the semi-permeable membrane. For improved fluid drainage, a breather layer, which is not shown in the figures for clarity, can be arranged on the semi-permeable membrane 17. This type of forming of the end face 21 avoids the deformation of fibers in the component to be manufactured, which typically occurs with a rigid forming element.Furthermore, the interior of the mold elements is also limited, so that no excess accumulation of resin can form that would later have to be removed.

[0045] This forms the end face 21 in the shape intended for the component 20 without the need for rework (so-called "near net shape" manufacturing). Naturally, the other end faces 21 of the component 20 to be manufactured, as well as the intermediate sides and other elements of the component 20, can also be formed using such a second forming element 13 and inflatable tube 16, and optionally a membrane 17.

[0046] The shape of the second forming element 13 and the cavity 14 contained therein, as shown in the figures, can be adapted depending on the component to be manufactured. For example, the cavity 14 can occupy almost the entire volume shown in the figures by the second forming element 13. Therefore, it is sufficient if the second forming element 13 consists only of a thin layer of stable material that prevents the cover 18 from compressing the inflatable tube 16 when a vacuum is applied.

[0047] Figure 4Figure 1 shows a flowchart of an exemplary process for manufacturing such a component 20, comprising an end face 21. First, in step S201, a first forming element 11 is arranged, which has a shape corresponding to at least one section of the component 20 to be manufactured (excluding the end face 21). Subsequently, a second forming element 13, having a cavity 14, is arranged on the first forming element 11 (step S202). The cavity 14 can correspond to the position of the end face 21 of the component 20 to be manufactured.

[0048] The process can further include inserting (step S203) an inflatable tube 16 into the cavity 14 and inserting (step S204) a prefabricated component and / or a material to be cured into the first mold element 11. The order of steps S201 to S204 is irrelevant.

[0049] In an optional variant of the process, a semi-permeable membrane 17 can be inserted between the inflatable tube 16 and the (front) face 21 of the component 20 to be manufactured in step S210. The membrane 17 is inserted at least partially into the cavity 14 of the second mold element 13, so that the membrane 17 covers a space within the first mold element 11, in which the component 20 is manufactured. The membrane 17 can be designed such that it forms the front face 21 of the component 20 within this space.

[0050] Furthermore, the process can include covering (step S205) the first mold element 11 and the second mold element 13 with a cover 18, which seals the first mold element 11 and the second mold element 13 from the surrounding atmosphere. Subsequently, in step S206, a vacuum can be applied in the area sealed by the cover 18, in which the first mold element 11 and the second mold element 13 are located. The interior of the inflatable tube 16 is fluidically coupled to the surrounding atmosphere. As a result, when the vacuum is applied (S206), the tube 16 expands and forms a flexible but defined shape for the end face 21 of the component 20 to be manufactured.

[0051] The variants, embodiments and examples discussed above serve only to describe the claimed teaching, but do not limit it to these variants, embodiments and examples.

Claims

1. Device (10) for producing a component (20), wherein the device (10) comprises: - a first mould element (11) which on one side (12) is configured for shaping at least one portion of the component (20) to be produced, with the exception of an end side (21) of the component (20) to be produced; wherein the end side (21) of the component (20) to be produced is disposed between two lateral surfaces of the component (20) to be produced and has a smaller surface than the two lateral surfaces of the component (20) to be produced that are adjacent to the end side (21); - a second mould element (13) which has a cavity (14), wherein the second mould element (13) is specified to be disposed on the first mould element (11) such that the cavity (14) spans the end side (21) of the component (20) to be produced and does not have any rigid portion for shaping the end side (21); - an inflatable tube (16) which is disposed in the cavity (14); and - a cover (18) which covers the first mould element (11) and the second mould element (13) and seals them in relation to the surrounding atmosphere, wherein the interior of the inflatable tube (16) is fluidically coupled to the surrounding atmosphere in such a way that the tube (16) during expansion of the tube (16) forms a mould element that shapes the end side (21) of the component (20) to be produced and is disposed externally in relation to the component (20) to be produced.

2. Device (10) according to Claim 1, furthermore comprising: - a semi-permeable membrane (17) which is disposed between the inflatable tube (16) and the component (20) to be produced.

3. Device (10) according to Claim 2, wherein the semi-permeable membrane (17) is disposed between the first mould element (11) and the second mould element (13) and spans the end side (21) of the component (20) to be produced.

4. Device (10) according to Claim 3, furthermore comprising: - a seal element (19) which is disposed between the semi-permeable membrane (17) and the first mould element (11), or between the semi-permeable membrane (17) and the second mould element (13).

5. Device (10) according to Claim 2, wherein the semi-permeable membrane (17) is configured so as to be tubular and encloses the inflatable tube (16).

6. Device (10) according to one of Claims 2 to 5, wherein the semi-permeable membrane (17) at least in portions is pre-shaped and the pre-shaped portion is specified for shaping the end side (21) of the component (20) to be produced.

7. Device (10) according to one of Claims 1 to 6, furthermore comprising: - a vacuum source (30) which is specified to apply a vacuum in the region which is sealed by the cover (18) and in which the first mould element (11) and the second mould element (13) are situated.

8. Device (10) according to one of Claims 1 to 7, wherein the first mould element (11) is configured in two parts, and wherein the second mould element (13) bears on both parts of the first mould element (11).

9. Method for producing a component (20) which has an outer end side (21) and two adjacent lateral surfaces, wherein the end side (21) has a smaller surface than the two lateral surfaces, wherein the method comprises the following steps: disposing (S201) a first mould element (11) which has a shape which corresponds to at least one portion of the component (20) to be produced, with the exception of the outer end side (21); disposing (S202) a second mould element (13) having a cavity (14) on the first mould element (11) such that the cavity (14) spans that outer end side (21) of the component (20) to be produced that is adjacent to the portion of the component (20) to be produced; incorporating (S203) an inflatable tube (16) in the cavity (14); incorporating (S204) a prefabricated component and / or a material to be cured in the first mould element (11); covering (S205) the first mould element (11) and the second mould element (13) with a cover (18) which seals the first mould element (11) and the second mould element (13) in relation to the surrounding atmosphere; applying (S206) a vacuum in the region which is sealed by the cover (18) and in which the first mould element (11) and the second mould element (13) are situated, wherein the interior of the inflatable tube (16) is fluidically coupled to the surrounding atmosphere in such a way that the tube (16) expands during application (S206) of the vacuum and forms a mould element that shapes the outer end side (21) of the component (20) to be produced.

10. Method according to Claim 9, furthermore comprising the step: incorporating (S210) a semi-permeable membrane (17) between the inflatable tube (16) and the end side (21) of the component (20) to be produced.