DE102018001580A1 - A method for producing a three-dimensionally shaped structural component, apparatus for producing a three-dimensionally shaped structural component and three-dimensionally shaped structural component - Google Patents

Abstract

The invention relates to a method for producing a three-dimensionally shaped structural component (1), wherein a) a molding tool (3) having a cavity (5) having an inner wall is provided; b) material is introduced into the cavity (5) of the molding tool (3) by means of an extrusion or coextrusion head (7) and a preform (11), in particular a hollow profile hose, having at least one interior space (24) is formed; c) an outer wall of the preform (11) is sucked against the inner wall of the cavity (5) by creating a negative pressure between the outer wall of the preform (11) and the inner wall of the cavity (5); d) a gaseous and / or foam-like medium is introduced under pressure into the at least one inner space (24) of the preform (11); and e) the three-dimensionally shaped, in particular tubular, structural component (1) is obtained. The method is characterized in that the medium is introduced into the interior (24) of the preform (11) by means of at least one blowing device (13) arranged in or on the extrusion or coextrusion head (7), and steps b), c ) and d) are carried out simultaneously.

Description

The invention relates to a method for producing a three-dimensionally shaped structural component, an apparatus for producing a three-dimensionally shaped structural component, and a three-dimensionally shaped structural component.

In the production of hollow body moldings, in particular of thermoplastic materials, different methods are used. In the extrusion blown process, a parison in the form of a tube is extruded and introduced into the cavity of a mold. One end of the extruded tube is drawn through the mold until it reaches the other end of the cavity. Subsequently, the cavity of the mold is closed and compressed air introduced into the inner region of the preform, so that it is inflated, applies to the inner wall of the cavity and thus assumes its contour. After a cooling phase, the mold is opened and removed the finished component.

The suction blowing method is an extrusion method in which a tubular hollow body is extruded and drawn in a mold by means of an applied vacuum through a three-dimensional cavity, after which or during the process, compressed air is introduced into the inner portion of the preform.

3D blow molding techniques can be used to produce hollow body geometries by placing an extruded tube in an open mold. The mold is closed after completion of the deposition process and inflated the tube to form the geometry.

The components thus produced are mainly used in media-carrying areas, such as fuel lines, air ducts and other pipes and hoses application, for example in the automotive sector. The extrusion process can take place with a similar type of plastic (extrusion) or combined with several different types of plastics (coextrusion), whereby individually different properties of the component can be formed, for example to adjust the strength or permeability of the component.

From the European patent application EP 2 236 267 A1 For example, there is known a method for producing a plastic component having a cavity, wherein an extruded preform is introduced into a cavity and the outer wall of the preform is sucked against the inner wall of the cavity by negative pressure between the outer wall of the preform and the inner wall of the cavity.

From the German patent application DE 199 22 490 A1 For example, a method and apparatus for making hollow-bodied articles from thermoplastic by suction-blowing is known wherein suction and extruding are decoupled to reduce cycle times, and wherein a new tube is extruded parallel to the suction.

From the German patent application DE 100 49 446 A1 a method and an apparatus for producing hollow body-shaped articles of thermoplastic material by suction blowing is known, comprising a two of an open and in a lockable closed position movable mold halves existing tool, a suction device connected to the tool at the outlet end and at least one preform hose providing supply head, which is fed by at least one extruder with plastic material. The extrusion or coextrusion process of preforming is decoupled from the process of suction and suction blowing. To improve the moldability, the air to be blown in is heated.

From the German patent application DE 10 2013 222 362 A1 a method for producing a plastic component is known, wherein a blow molded part is obtained by inflating a preform in a shaping blow mold, which corresponds to the inner contour of the component to be produced. The blow-molded part is filled with a free-flowing medium and injection-molded in an injection mold, wherein the filling with the free-flowing medium counteracts the injection pressure and protects the blow molded part from collapse.

However, the known Saugblasverfahren do not allow the production of a variety of geometries in sufficient quality and reliability, especially at a high throughput of the components to be molded.

The invention is therefore based on the object to provide a method for producing a three-dimensionally shaped structural component, an apparatus for producing a three-dimensionally shaped structural component, and a three-dimensionally shaped structural component, wherein said disadvantages do not occur.

The object is achieved by providing the subject matters of the independent claims. Advantageous embodiments will become apparent from the dependent claims and the description.

1. a) Bereitstellen eines Formwerkzeugs mit einer eine Innenwand aufweisenden Kavität;
2. b) Einbringen von Material mittels eines Extrusions- oder Coextrusionskopfs in die Kavität des Formwerkzeugs und Bilden eines mindestens einen Innenraum aufweisenden Vorformlings, insbesondere eines Hohlprofil-Schlauchs;
3. c) Ansaugen einer Außenwand des Vorformlings an die Innenwand der Kavität durch Erzeugen eines Unterdrucks zwischen der Außenwand des Vorformlings und der Innenwand der Kavität;
4. d) Einbringen eines gasförmigen und/oder schaumförmigen Mediums unter Druck in den mindestens einen Innenraum des Vorformlings; und
5. e) Erhalten des dreidimensional geformten, insbesondere schlauchförmigen Strukturbauteils.

The object is achieved in particular by a method for producing a Three-dimensionally shaped structural component is provided, wherein the method comprises the following steps:

1. a) providing a mold with a cavity having an inner wall;
2. b) introducing material by means of an extrusion or coextrusion head into the cavity of the mold and forming a preform having at least one inner space, in particular a hollow profile hose;
3. c) sucking an outer wall of the preform against the inner wall of the cavity by creating a negative pressure between the outer wall of the preform and the inner wall of the cavity;
4. d) introducing a gaseous and / or foam-like medium under pressure into the at least one interior of the preform; and
5. e) obtaining the three-dimensionally shaped, in particular tubular, structural component.

The method according to the invention is characterized in that the medium is introduced into the interior of the preform by means of at least one blowing device arranged in or on the extrusion or coextrusion head, and that steps b), c) and d) are carried out simultaneously. In this way, the three-dimensionally shaped structural component is ultimately obtained. The inner wall of the cavity has a structure that is complementary to the desired outer wall of the structural component. The method is suitable for the production of a large number of structural components, in particular for the production of pipes, hoses, containers, packaging articles, in particular for the production of components in the automotive sector.

In the method according to the invention, therefore, an extruded, hollow preform, which preferably has the shape of a hollow tube, is introduced directly from the extrusion or coextrusion head into the cavity of the closed molding tool. The front end of the preform is thereby passed from the extruder, which is arranged at one end of the cavity, to the other end of the cavity. Simultaneously with the extrusion of the material of the preform, the introduction of the preform into the cavity and the formation of the preform is improved by sucking the preform to the inner wall of the cavity and by introducing a gaseous and / or foamy medium under pressure into the interior of the preform. Preferably, the cavity is completely sealed against external air. Preferably, the inner wall of the cavity of the mold is provided with a non-stick coating.

Preferably, the gaseous medium is air, nitrogen or CO ₂ . Preferably, the gaseous medium is heated prior to introduction into the interior of the preform. This prevents in particular that the preform cools down too quickly and can no longer be formed correctly. Preferably, the foam-like medium is foamed physically and / or chemically. Preferably, the foamy medium is a surfactant-containing aqueous solution. The introduction of a medium under pressure into the interior of the preform assists the precise and rapid adaptation of the preform to the shape of the cavity of the mold.

Preferably, the molded structural component is completely or partially cooled, preferably before removal from the mold or preferably after removal from the mold.

Preferably, the introduced into the cavity by the extrusion or coextrusion head material is a plastic, preferably a thermoplastic material. By the extrusion or coextrusion head is preferably a liquid material, in particular a molten material, pressed through a nozzle into the cavity.

Preferably, the medium is introduced into the interior of the preform with the blowing device arranged at the extrusion or coextrusion head at the rear end of the preform. As a result, no further openings in the structural component to be formed for introducing the medium need to be created.

Preferably, a gaseous and a foam-like medium are introduced into the interior of the preform, whereby an increase in strength of the shape of the preform and / or the structural component is achieved.

Advantageously, the method according to the invention enables the production of three-dimensionally shaped structural components in the one-shot principle. The combination of the injection molding, the suction blowing with the introduction of a gaseous and / or foam-like medium under pressure, a high strength and high accuracy of the resulting structural components is achieved. Furthermore, the simultaneous process steps, namely the simultaneous extrusion of the preform, the suction of the preform and introduction of the medium under pressure into the preform, allow a particularly rapid, preferably continuous production of the three-dimensionally shaped structural components. Due to the high strength of the resulting structural components lightweight components that replace steel components, for example, produced. Advantageously, the inventive A method of simplifying and improving manufacturing of structural members having a three-dimensional geometry as compared to known methods which do not involve coextrusion of the preform, suction and introduction of a medium under pressure into the preform. The inventive method can be realized with high quality and precision geometries in a particularly fast process.

According to one embodiment of the invention, it is provided that in a further step f) during or after step d) an external structure having at least one functional element and / or reinforcing element is applied by encapsulation of the preform or the structural component. Preferably, further components, for example sheets or fiber structures, are incorporated during encapsulation of the preform or of the structural component. In this embodiment, the advantages already described realize in a special way. Preferably, the outer wall of the preform or the structural component is completely or partially encapsulated.

Preferably, the three-dimensionally shaped structural component is integrally formed, preferably in one piece.

According to one embodiment of the invention, it is provided that the negative pressure between the outer wall of the preform and the inner wall of the cavity is generated by means of suction of a gas through at least one opening formed in the inner wall of the cavity. In this embodiment, the advantages already described realize in a special way.

According to one embodiment of the invention, it is provided that by means of the extrusion or coextrusion head, a wall thickness and / or a cross section of the preform is adjusted according to existing requirements, whereby wall thickness jumps or a uniform wall thickness can be obtained at different degrees of deformation of the preform. Preferably, the cross section of the preform may be formed round or oval and / or formed with ribs and / or reinforcements. As a result, the structural component can be individually adapted to the later required load. In this embodiment, the advantages already described realize in a special way.

Preferably, the material applied by encapsulation of the preform is a plastic, preferably a thermoplastic material. Preferably, the material applied by overmoulding the preform is the same material as the material introduced into the cavity by means of the extrusion or coextrusion head.

The object is also achieved by providing a device for producing a three-dimensionally shaped structural component, in particular for producing a three-dimensionally shaped structural component according to the method of the invention. The device comprises a molding tool with a cavity for introducing a preform, in particular a hollow profile hose, into the cavity, the cavity being delimited by an inner wall, wherein the molding tool has two mold halves which are movable into an open position and a closed position to form the cavity at least one extrusion or coextrusion head having at least one nozzle, in particular an annular gap, for introducing material into the cavity to form a preform, and a suction device connected to the mold for generating a negative pressure between the inner wall of the cavity and an outer wall of the preform. The device is characterized in that the at least one extrusion or coextrusion head has at least one integrated blowing device, so that a gaseous and / or foam-like medium can be introduced into the interior of the preform via the blowing device during extrusion. In connection with the device, in particular, the advantages which have already been explained in connection with the method are realized.

According to a development of the invention, it is provided that the blowing device has at least one lancet, preferably two lancets, preferably three lancets, preferably four lancets, preferably five lancets, preferably six lancets or more lancets. In This embodiment realizes the advantages already described in a special way. As a result, in particular a structural component with different geometries, in particular with an interior divided into at least two chambers, preferably three chambers, preferably four chambers, preferably five chambers, preferably six chambers, or preferably more chambers, can be created. By designing a different number of chambers, in particular cavities, in the interior of the structural component, the structural component is stabilized, which is for example relevant to load-bearing structural components, such as cockpit cross member, Frontendträger, module mounts or module segments. Preferably, the device has at least two lancets for each chamber.

According to one embodiment of the invention, it is provided that the device has an injection unit for encapsulating the preform and / or the structural component with at least one functional element and / or reinforcing element. In this embodiment, the advantages already described realize in a special way.

According to one embodiment of the invention, it is provided that the molding tool has at least one opening for sucking the outer wall of the preform against the inner wall of the cavity. In this embodiment, the advantages already described realize in a special way. The at least one opening may preferably be formed in the inner wall of the cavity.

According to one embodiment of the invention it is provided that the device has a punching and / or squeezing unit, so that the preform can be sealed at the front end and / or cut off at the rear end. In this embodiment, the advantages already described realize in a special way.

The object is also achieved by providing a three-dimensionally shaped structural component which is produced by the method according to the invention or in the device according to the invention. In connection with the structural component, in particular the advantages that have already been explained in connection with the method and / or the device are realized.

The invention will be explained in more detail with reference to the drawing.

• 1 eine schematische Darstellung eines Ausführungsbeispiels einer Vorrichtung zur Durchführung einer Ausführungsform des erfindungsgemäßen Verfahrens;
• 2 eine schematische Darstellung eines Ausführungsbeispiels eines Extrusions- oder Coextrusionskopfs, und
• 3 Beispiele verschiedener Geometrien bevorzugter Strukturbauteile gemäß der Erfindung.

Showing:

• 1 a schematic representation of an embodiment of an apparatus for performing an embodiment of the method according to the invention;
• 2 a schematic representation of an embodiment of an extrusion or coextrusion head, and
• 3 Examples of different geometries of preferred structural components according to the invention.

1 shows a schematic representation of a preferred device according to the invention, in particular for carrying out a preferred method according to the invention for producing a three-dimensional structural component 1 , The device comprises a molding tool 3 with a cavity 5 for introducing a preform 11 , in particular a hollow profile hose, into the cavity 5 , where the cavity 5 is bounded by an inner wall. In this embodiment, the molding tool 3 two mold halves as mold elements to form the cavity 5 on, wherein the two mold halves are movable into an open and closed position. The mold 3 but can also be formed from more than two form elements, in particular for the formation of more complex structures of the structural component 1 , The device comprises at least one extrusion or coextrusion head 7 for producing the preform 11 required material by means of an extruder (not shown) is supplied. By means of the at least one extrusion or coextrusion head 7 with at least one nozzle 15 , in particular in the form of an annular gap, material is in the cavity 5 for the formation of the preform 11 introduced, in particular in the form of a hollow profile hose. In the cavity 5 of the provided mold 3 becomes material by means of the extrusion or coextrusion head 7 introduced, wherein the at least one interior 24 having preform 11 , in particular a hollow profile hose, is formed. A wall thickness and / or a cross section of the preform 11 can through the extrusion or coextrusion head 7 , in particular by variation of the annular gap, to be adjusted. The extruded material is preferably a plastic, in particular a thermoplastic.

One to the mold 3 connected suction device 23 creates a negative pressure between the inner wall of the cavity 5 and an outer wall of the preform 11 , The outer wall of the preform 11 is applied to the inner wall of the cavity 5 by creating the negative pressure between the outer wall of the preform 11 and the inner wall of the cavity 5 sucked, causing the extruded preform 11 through the cavity 5 guided and at the same time applied to the inner wall.

The extrusion or coextrusion head 7 has at least one integrated blowing device 13 on, so that a gaseous and / or foamy medium at the same time when extruding the preform on the blowing device 13 in the interior 24 of the preform 11 can be introduced. The gaseous and / or foamy medium is simultaneously conveyed by means of the in or on the extrusion or coextrusion head 7 arranged blowing device 13 in the interior 24 of the preform 11 brought in. The preform 11 expands until he is at the Inner wall of the cavity 5 is applied. This will be the structural component 1 formed and takes the complementary shape of the cavity 5 at.

The generation of the vacuum for sucking the preform 11 to the inner wall of the cavity 5 and the bubbles in the interior 24 of the preform 11 finds according to the invention at the same time during the extrusion of the preform 11 instead of. By the simultaneous introduction of material of the preform 11 into the cavity 5 , the gaseous and / or foamy medium in the interior 24 of the preform 11, and the suction of the outer wall of the preform 11 to the cavity 5 is the three-dimensionally shaped, in particular tubular structural component 1 get, so that the preform 11 precise and fast on the inner wall of the cavity 5 is applied. This allows the preform 11 particularly accurate to the shape of the cavity 5 be adapted, and it will be a high quality of the resulting structural component 1 obtained at high throughput.

The structural component 1 can be completely or partially cooled before leaving the mold 3 is removed, for example, by separating the at least two mold elements and / or release by a slider. The structural component 1 can subsequently be reworked, for example, production-related slugs can be removed and / or attachment points are attached.

In a further embodiment, the device has an injection unit (not shown). Through the injection unit, the preform 11 and / or the structural component 1 be encapsulated with at least one functional element and / or reinforcing element. By overmolding the preform 11 or the structural component 1 , Especially after reaching a foam boundary strength of the medium, an external structure 9 applied with at least one functional element and / or reinforcing element. As a result, in particular the strength and / or the rigidity of the structural component 1 increase.

In a further embodiment, the inner wall of the cavity 5 at least one opening, wherein the negative pressure between the outer wall of the preform 11 and the inner wall of the cavity 5 by sucking a gas through the at least one in the inner wall of the cavity 5 formed opening is generated.

In a further embodiment, the blowing device 13 at least one lancet for introducing the gaseous and / or foam-like medium into the interior 24 of the preform 11 on.

In another embodiment, the front end becomes 19 of the preform 11 sealed and / or the rear end 21 of the preform 11 cut off. The device has for this purpose a punching and / or squeezing unit 17 on, leaving the preform 11 at the front end 19 sealed and / or at the back end 21 can be cut off.

2 shows a schematic representation of an embodiment of an extrusion or coextrusion head 7 the inventively preferred device (see 1 ). The same and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description.

The extrusion or coextrusion head 7 has a nozzle 15 , in particular a nozzle designed as an annular gap 15 , and a blowing device 13 on. The nozzle 15 puts material under pressure into the cavity 5 of the mold 3 one, wherein the material is a preform 11 forms, in particular a hollow profile hose. The blowing device 13 brings a gaseous and / or foamy medium under pressure into an interior 24 of the preform 11 one, leaving the preform 11 is pressed against the inner wall of the cavity 5.

In a further embodiment, the extrusion or coextrusion head 7 several blowing devices 13 on. In a further embodiment, the extrusion or coextrusion head 7 several nozzles 15 on. This allows the interior 24 of the structural component 1 be made more complex. Preferably, this can be an interior 24 with several chambers 25 to be obtained.

In a further embodiment, the blowing device 13 at least one lancet, through which the gaseous and / or foam-like medium in the interior 24 of the preform 11 is introduced. The blowing device 13 can also have several lancets, which in the interior 24 of the preform 11 and / or the structural component 1 a plurality of chambers 25 can be trained.

3 shows a schematic representation of different geometries according to the invention preferred structural components 1 , The structural components 1 have in the embodiments a), b), c) and d) an interior 24 with a different number of chambers 25 on, a) one chamber, b) five chambers, c) two chambers, and d) four chambers. However, it is any number of chambers 25 in the interior 24 conceivable. Due to the shape of the interior 24 of the structural component 1 in particular by designing a different number of chambers 25 and thus virtually the insertion of partitions, the structural component 1 be stabilized according to the requirements, for example, to receive load-bearing structural components, such as cockpit cross member, front end support, module mounts or module segments.

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

• EP 2236267 A1 [0006]
• DE 19922490 A1 [0007]
• DE 10049446 A1 [0008]
• DE 102013222362 A1 [0009]

Claims (10)

Method for producing a three-dimensionally shaped structural component (1), comprising the steps of a) providing a molding tool (3) with a cavity (5) having an inner wall; b) introducing material by means of an extrusion or coextrusion head (7) into the cavity (5) of the molding tool (3) and forming a preform (11), in particular a hollow profile hose, having at least one interior space (24); c) sucking an outer wall of the preform (11) against the inner wall of the cavity (5) by creating a negative pressure between the outer wall of the preform (11) and the inner wall of the cavity (5); d) introducing a gaseous and / or foam-like medium under pressure into the at least one inner space (24) of the preform (11); and e) obtaining the three-dimensionally shaped, in particular tubular, structural component (1); characterized in that - the medium is introduced into the interior (24) of the preform (11) by means of at least one blowing device (13) arranged in or on the extrusion or coextrusion head (7), and in that - the steps b), c) and d) are performed simultaneously. Method according to Claim 1 wherein in a further step f) an external structure (9) with at least one functional element and / or reinforcing element is applied during or after step d) by encapsulation of the preform (11) or of the structural component (1). Method according to Claim 1 or 2 in that the negative pressure between the outer wall of the preform (11) and the inner wall of the cavity (5) is produced by suction of a gas through at least one opening formed in the inner wall of the cavity (5). Method according to one of the preceding claims, wherein by means of the extrusion or coextrusion head (7), a wall thickness and / or a cross section of the preform (11) is adjusted. Device for producing a three-dimensionally shaped structural component (1) according to a method according to one of the Claims 1 to 4 comprising: - a molding tool (3) having a cavity (5) for introducing a preform (11), in particular a hollow profile hose, into the cavity (5), the cavity (5) being bounded by an inner wall, the molding tool (3) has two in one open and one closed position movable mold halves for forming the cavity (5); - At least one extrusion or coextrusion head (7) with at least one nozzle (15), in particular an annular gap, for introducing material into the cavity (5) to form a preform (11); - A suction device (23) connected to the mold (3) for generating a negative pressure between the inner wall of the cavity (5) and an outer wall of the preform (11); characterized in that - the at least one extrusion or coextrusion head (7) has at least one integrated blowing device (13), so that a gaseous and / or foamy medium is extruded via the blowing device (13) into the interior (24) of the preform (13). 11) can be introduced. Device after Claim 5 wherein the blowing device (13) has at least one lancet, preferably at least two lancets. Device after Claim 5 or 6 wherein the device comprises an injection unit for encapsulating the preform (11) and / or the structural component (1) with at least one functional element and / or reinforcing element. Device according to one of Claims 5 to 7 wherein the mold (3) has at least one opening for sucking the outer wall of the preform (11) against the inner wall of the cavity (5). Device according to one of Claims 5 to 8th in that the device has a punching and / or squeezing unit (17), so that the preform (11) can be sealed at the front end (19) and / or cut off at the rear end (21). Three-dimensionally shaped structural component (1), produced by a method according to one of Claims 1 to 4 ,

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