WO2016055040A1

WO2016055040A1 - Mould tray for a tool for the production of a fibre composite component, and use of a mould tray of this type

Info

Publication number: WO2016055040A1
Application number: PCT/DE2015/000481
Authority: WO
Inventors: Alexander Hemmen
Original assignee: Premium Aerotec Gmbh
Priority date: 2014-10-09
Filing date: 2015-10-02
Publication date: 2016-04-14
Also published as: DE102014014743A1

Abstract

The invention relates to a mould tray (10a-1, 10a-2) for a tool (1a) for the production of a fibre composite component via a thermal curing of a preform (P) arranged in the tool (1a) adjacent to the mould tray (10a-1, 10a-2), comprising an outer side (14a-1, 14a-2) provided for supporting via a tool part (2a-1, 2a-2), and an inner side (12a-1, 12a-2) for moulding the fibre composite component to be produced. According to the invention, a number of electrical contacts (20a-1 to 20a-4) are arranged on the inner side (12a-1, 12a-2), in order to permit a current flow via said electrical contacts (20a-1 up to 20a-4) for the resistance heating of the preform (P) arranged in the tool (1a). The invention also relates tp a tool (1a) provided with at least one mould tray (10a-1, 10a-2) of this type, and to the use of a mould tray (10a-1, 10a-2) of this type for the production of a fibre composite component.

Description

Mold shell for a tool for producing a fiber composite component and use of such a mold shell

The present invention relates to a mold shell for a tool for producing a fiber composite component by thermal curing of a preform disposed adjacent the mold shell in the tool, with an outer side provided for support by a tool part and an inner side shaping the fiber composite component to be produced. Furthermore, the invention relates to a tool which is equipped with at least one such mold shell, and a use of such a mold shell for producing a fiber composite component.

Such mold shells as well as tools equipped therewith for the production of fiber composite components are well known from the prior art. An advantage of using shell molds is z. B. a lower to no contamination of the otherwise a tool cavity limiting tool parts. This advantage has great economic importance, in particular in mass production of fiber composite components. In addition, z. B. minor changes of the component geometry can be realized relatively inexpensively by a corresponding change in the shell geometry without having to modify the usually much more expensive tool parts for this.

In the case of processes known from the prior art for producing a fiber composite component by thermal curing of a preform arranged in the tool, the relevant tool parts (eg an upper tool part and a lower tool part) are designed to be heatable in order to effect the thermal curing of the preform.

CONFIRMATION COPY The introduced into the tool preform can z. B. already with matrix material such. B. a thermosetting resin pre-impregnated ("prepreg"). Alternatively, the preform is initially still "dry" and is only infiltrated with the matrix material in the mold (eg in a so-called RTM process).

For the heating of the preform for curing the same relatively much energy is required in the prior art.

A further disadvantage is that, in view of short tool loading times, in fact often preferable rapid temperature changes, both during heating and during cooling, are difficult to achieve in practice, unless extremely high heating or cooling capacities are used.

It is an object of the present invention, in the production of a fiber composite component by thermal curing of a preform to improve energy efficiency.

According to a first aspect of the invention, this object is achieved with a mold shell of the type mentioned above in that several electric contacts are arranged on the inside in order to allow a current flow for resistance heating of the preform arranged in the tool via these electrical contacts.

Unlike in the prior art, in which a heat input from the outside into the preform takes place, the invention advantageously allows heat to be generated in the preform itself. Therefore, heating of the preform, be it for an optionally provided infiltration process and / or for the thermal Curing, much more energy efficient than in the prior art. With regard to the most targeted energization and thus resistance heating of the preform, and to simplify the shell mold with respect to electrical insulation measures, the shell mold z. B. largely be made of an electrically and preferably also relatively thermally poorly conductive material to (z., "Isolation") integration of the electrical contacts, preferably from a relatively electrically conductive, especially metallic material such. As a copper alloy, etc. to accomplish a well-defined current flow. An electrically more or less well insulating "base material" of the shell mold advantageously simplifies any insulation measures or makes such measures dispensable.

The term "electrically relatively poorly conductive" includes z. B. all materials with a specific electrical resistance of more than 10 ⁶ Ω cm, in particular more than 10 ⁸ Ω cm. In contrast, the term "electrically relatively well conductive" z. B. all materials with a resistivity of less than 10 Ω cm, in particular less than 1 Ω cm.

The term "thermally relatively poorly conductive" includes z. B. all materials with a specific thermal conductivity of less than 5 W / K m, in particular less than 1 W / K m. In contrast, the term "thermally relatively good conductive" z. B. all materials with a specific thermal conductivity of more than 20 W / K m, in particular more than 50 W / K m.

In one embodiment, the shell mold z. B. largely formed from a fiber composite material, for example, glass fiber reinforced plastic.

As is usual for conventional mold shells of the type of interest here, the mold shell according to the invention may also have a plate-like, planar or curved shape. If, as is customary, the preform Hene tool cavity is limited by more than one shell mold, so (eg, circumferential) seal can be arranged between adjacent shell mold edges. In this case, according to one embodiment, provision is made for the mold shell to have on its inner side in an edge region a (for example circumferential) groove for receiving a (for example circumferential) seal.

So that the arrangement according to the invention of the electrical contacts on the inside of the mold shell does not "disturb" the shaping function realized with this inner side, it is provided according to one embodiment that at least one of the electrical contacts has a contact surface arranged flush with the surface of the inner side. It should be considered that the contact surface of the electrical contact has a shaping effect for the preform surface located in this area. On the other hand, such flushing of the electrical contact can also be disadvantageous in that the current supply to the preform takes place only superficially, whereas energization of areas deeper in the preform material would generally be desirable. A possible measure for energizing deeper lying areas is z. As therein, a respective electrical contact not flush but with one or more parts related to the surrounding inner surface of the shell mold protruding (in the preform protruding) form. In a related embodiment, for. B. provided that at least one of the electrical contacts one or more, preferably needle-like inwardly projecting contact portions to direct the flow of current through these contact portions in the interior of the preform. Alternatively or additionally, in order to reduce the disadvantage of only superficial energization can be provided that at least a pair of energization is provided by using at least two shell molds of the type described here, which limit the Werkzeugkavität on opposite sides such that by a paired arrangement of electrical Contacts at the same lateral position of the preform is an energization of the preform simultaneously from two sides. This advantageously equalizes the heat generation in the preform. In one embodiment, it is provided that at least one of the electrical contacts has an elongate, running along the inside shape. The term "shape" in this context refers to the outline contour of the relevant electrical contact resulting in a plan view on the inner side surface of the shell mold.

Although the electrical contacts each z. B. may also have a point-like or extensive flat shape, so the mentioned elongated shape is usually very convenient for most applications. In the elongated shape, it may be z. Example, a strip with a uniform width (and, for example, with a uniform thickness) act.

The elongated or strip-like shape may, for. B. extend straight and / or with curved and / or angled course sections along the inside of the shell mold.

It is understood that when using the shell mold described here, a voltage source or current source is required, by means of which the current flow for energizing the electrical contacts is generated. Such a current source suitably has not only two poles but a (usually larger) number of poles, which preferably corresponds to the number of electrical contacts of the mold shell (s) used for component production.

For a "universal" applicability can be provided on the Bestromungsquelle also a number of poles, which corresponds to a "maximum expected" number of electrical contacts with regard to the use of the same source of supply for the production of various components (with correspondingly different shell molds) ,

For this purpose, a suitable lighting device can be integrated in the tool used or provided as a separate unit and electrically connected to the tool (eg "wired"). In one embodiment, a lighting device is used with at least 3, in particular at least 4 poles.

The Bestromungseinrichtung is preferably formed controllable for the purpose of adaptation to the particular application and can, for. B. by means of a program-controlled control device to achieve a predetermined "temperature program" for a desired in the context of component manufacturing temperature control (comprising a time-dependent heating and / or cooling) of the preform be controlled. The temperature of the preform can, with the aid of the present invention enabled electrical resistance heating in particular for setting or time-dependent control of a certain "infiltration" (to promote the flowability of the preform supplied matrix material) and / or Setting or time-dependent control of a specific "curing temperature" (for thermal curing of the preform) are performed.

The "control" of the energizing device can, for. B. include a voltage control, d. H. a controlled specification of the electrical potentials z. B. at the respective poles (or, using a sensor, to the respective electrical contacts). Also, a current control, so the specification of certain (each signed) electrical currents at the individual poles possible, or a combination of voltage and current control.

The number and arrangement of electrical contacts on or on the mold shells in conjunction with the current control determines the properties of the resistance heating of the preform realized therewith. It is also understood that when using a shell mold of the type described here, an "electrical continuity" is required, by which all electrical conductors or electrical line arrangements are to be understood, which the energizing means (or their poles) with the electrical contacts of the used Electrically connect the mold shell (s).

In the following, some embodiments of the molding shell which are advantageous with regard to the electrical forward connection will be explained.

In one embodiment, it is provided, for example, that in the area of at least one of the electrical contacts, a recess extending from the rear side of the relevant electrical contact to the outside of the shell is provided for the passage of an electrical continuation. A passing through the recess electrical continuity can z. B. be integrally formed with the relevant electrical contact and in this case z. B. extend to at least the level of the outside of the shell mold.

Alternatively, the recess of the molding shell can also be provided "empty", wherein an electrical continuity (eg a contacting pin, etc.) engages the recess only in the situation of use of the molding shell and an electrical connection is made by contact with the rear side of the relevant electrical contact to make this electrical contact.

Accordingly, with this embodiment, an electrical continuity extending from an electrical contact to the rear side of the shell mold can be realized.

However, it may also be advantageous if, starting from an electrical contact, an electrical further connection initially runs away from the electrical contact in a lateral direction. A related embodiment provides, for example, that at least one of the electrical contacts for electrical continuity is electrically connected to an electrical conductor extending away from this electrical contact in the interior of the shell mold. Such an electrical connection can advantageously z. Example, be integrally formed with the respective electrical contact, so to speak represent a running in the shell inside extension of the electrical contact.

In a further development it is provided that in the region of the electrical conductor, in particular z. B. at a distal end of this electrical conductor, one of the back or front of the electrical conductor to the outside or Inside the mold shell through recess is provided for the passage of an electrical continuation.

An advantage of the embodiment with a laterally running in the interior of the shell mold electrical continuation exists z. Example, in that a plurality of contacts of the same mold shell "can be electrically connected to each other internally", approximately to be able to reduce the required for a particular configuration of electrical contacts number of electrical connections that lead out of the Formsdcha- le.

A further advantage of this embodiment is that with an electrical continuity extending in the interior of the mold shell an electrical connection between on the one hand a "laterally inner region" of the mold shell (in which electrical contacts are located) and on the other hand a "laterally outer region" of the mold shell (FIG. eg laterally beyond a seal towards an adjacent other mold shell).

In particular, z. B. a running in the edge region of the shell mold on its inner side extending groove (for receiving a circumferential seal) of the relevant electrical conductor (electrical continuation) "submerged" are.

Starting from the "laterally outer region", a simpler electrical further connection can then be realized out of the mold shell (and, for example, out of the mold) in most cases, since this mold shell region does not directly adjoin the mold cavity. In particular, the latter electrical connection can then easily pass through another, adjacent shell mold. In addition, it is in the context of the invention may be advantageous, starting from an electrical contact, an electrical connection not to the back of the shell mold, but to the front (inside) of the shell mold to run. In this case, z. B. in the region of the respective electrical contact a from the front of the electrical contact to the inside of the mold shell continuous recesses are provided for the passage of the electrical connection. However, the problem here is that the preform to be processed is arranged on the inner side of the mold shell, at least in an inner region viewed laterally, so that an electrical continuity leading further to the energizing device at this point is generally difficult.

Therefore, an electrical forward connection extending towards the front side (inner side) of the mold shell is generally better not to be provided directly starting from an electrical contact of the mold shell but, as already explained above, starting from a region, in particular z. B. distal end of a laterally away from an electrical contact, z. B. extending inside the shell mold electrical continuity. With this variant is z. For example, an advantageous tool arrangement can be realized in which the tool cavity for the preform is bounded by (at least) a first (eg upper) and (at least) a second (eg lower) mold shell, wherein both the first mold shell and also has the second shell (eg paired) electrical contacts, wherein the electrical contacts of the first shell mold are electrically connected to the back of the first shell mold, whereas the electrical contacts of the second shell mold initially further connected laterally away from these electrical contacts are and in an edge region of the second mold shell corresponding distal ends of these further connections laterally outside a sealing area (eg. Outside circumferential seal) to the front (inside) of the second shell mold and then further electrically connected through the first shell mold. For this purpose, the first mold shell can have one or more corresponding continuous recesses (for the passage of the electrical connection (s) coming from the first mold shell).

The invention further proposes a tool for producing a fiber composite component by thermal curing of a preform, which comprises at least one shell mold of the type described here.

Such a tool can, for. Example, a provided with a first mold shell first tool part and provided with a second mold shell second tool part for forming a mold cavity for the preform between respective inner sides of the two mold shells, wherein at least one of the mold shells is designed as a mold shell of the type described herein, and wherein the tool has means for energizing the electrical contacts of the mold shell for resistance heating of the mold cavity arranged in the preform. In accordance with yet another aspect of the present invention, the use of a mold shell of the type described here for producing a fiber composite component is provided by thermal curing of a preform arranged adjacent to the mold shell in a tool, resistance heating of the preform being performed by energizing the electrical contacts of the mold shell becomes.

The by means of the tool to be processed preform z. B. already with matrix material (in particular, for example, thermosetting resin) pre-impregnated (prepreg). Alternatively or additionally, the preform initially comprises "dry" nes "fiber material and is infiltrated in the tool with (possibly further) matrix material.

The invention will be further described by means of embodiments with reference to the accompanying drawings. They show:

1 shows a sectional view of a tool for producing a fiber composite component according to a first exemplary embodiment, FIG. 2 shows a diagram for illustrating exemplary temporal temperature profiles during the thermal curing of a preform,

3 is a sectional view of a tool for producing a fiber composite component according to a further embodiment,

Fig. 4 is a plan view of a first tool part together with inserted first

Mold shell in the tool of FIG. 3, and

5 shows a plan view of a second tool part together with an inserted second mold shell in the tool according to FIG. 3.

Fig. 1 shows the understanding of the invention essential components of a mold 1 according to a first embodiment. The tool 1 is used to produce a fiber composite component by thermal curing of a preform P according to a so-called RTM ("resin transfer molding") method. In the example according to FIG. 1, the tool 1 comprises a first tool part 2-1 provided with a first mold shell 10-1 and a second tool part 2-2 provided with a second mold shell 10-2. Between respective inner sides 12-1 and 12-2 of the shell molds 10-1 and 10-2, a tool cavity for the preform P is created in the closed state of the tool 1 (as shown in FIG. 1).

The outer parts of the mold shells 10-1, 10-2 facing the tool parts 2-1 and 2-2 are designated 14-1 and 14-2, respectively.

The reference numbers of multiply provided components in an exemplary embodiment, but whose effect is analogous (such as, for example, shell molds 10-1 and 10- 2), are numbered, in each case supplemented by a hyphen and a consecutive number. Individual components or the entirety of such components will also be referred to below by the non-supplemental reference number.

In the example shown, the tool parts 2 form an "upper tool half" 2-1 and a "lower tool half" 2-2 of the molding tool 1. FIG. 1 shows the tool 1 in its already closed state together with the inserted preform P.

The initially dry preform P is fed via a resin feed channel 3 with a matrix material, here z. As an epoxy resin infiltrated, wherein before and / or during this Harzinjektion an evacuation or venting of the Werkzeugkavität via an air or Harzauslasskanal 4 takes place. In the example shown, the infiltration of the preform P and its subsequent thermal curing produce a flat (plate-like) component with a reinforcing structure (eg, a fuselage shell component with a so-called omega stringer) attached thereto on one side.

The first (in Fig. 1 upper) mold shell 10-1 is z. B. made of glass fiber reinforced plastic (GRP) and as can be seen in a shell of the first (upper) tool part 2-1 added. In the illustrated situation of use, the outer side 14-1 of the mold shell 10-1 is supported by a bottom of this mold shell receptacle, whereas the inner side 12-1 of the mold shell 10-1 in a laterally inner region for limiting the mold cavity and thereby also for the shaping of serves to be produced fiber composite component. In a laterally outer region (circumferential), the inner side 12-1 bears against a laterally outer region of the inner side 12-2 of the second (lower) shell 10-2. The lower molded shell 10-2, also made of GRP, delimits the tool cavity from below in a laterally inner region of its inner side 12-2 and penetrates on its outer side 14-2 through the bottom of a corresponding shell receptacle of the second (lower) tool part 2 -2 supported.

For an improved mutual sealing of the two shell molds 10 in the laterally outer regions, a circumferential seal may be appropriate. In the illustrated embodiment, this is the lower mold shell 10-2 provided with a circumferential groove 16-2 for receiving such a seal in the groove 16-2.

A special feature of the shell molds 0 is that at least one of the shell molds 10, in the example of Fig. 1, only the lower mold shell 10-2, on the inside 12-2 more (here: four) electrical contacts 20-1 to 20-4 having, in order to enable a current flow for resistance heating of the preform P arranged in the tool 1 via these electrical contacts 20.

The temperature of the preform P thus made possible by using electrical resistance heating is advantageously very energy-efficient, since the heat output required for heating is produced exactly where it is needed, namely in the preform P itself , B. steel-made tool parts 2-1 and 2-2 can be kept relatively stable in temperature at a "temperature cycle" for infiltration and / or thermal curing of the preform P. This is especially true when a body or a "base material" of the shell molds 10 used from a thermally relatively poorly conductive material such. B. GFK is formed. The shell molds 10 in this case act more or less as a thermal insulation for the Werkzeugkavität.

In the illustrated in Fig. 1 use of the mold shells 10 for producing a fiber composite component by thermal curing of the preform P energizing the electrical contacts 20 of the lower mold shell 10-2 is performed to accomplish a resistance heating of the preform P.

For energizing the illustrated preform P to be applied to the contacts 20-1 to 20-4 electrical potentials V1 to V4 can in principle be set individually in a variety of ways or controlled time-dependent. In the present example of Fig. 1, these potentials V1 to V4 z. B. expediently be chosen so that the following applies: V1 <V2 <V3 <V4. In the case of a preform shape which is symmetrical with respect to a yz-plane as shown, the fulfillment of the condition V2-V1 = V4-V3 is expedient in this case (for a spatially uniform possible temperature control). This heating of the preform P can z. B. be carried out as part of a temperature cycle, as shown by way of example in Fig. 2.

2 shows a temperature cycle 22 that can be achieved with the tool 1 from FIG. 1 (application of a temperature T of the preform against the time t), in which the temperature T of the preform P starts from a starting temperature T ₀ (eg room temperature). is first increased rapidly to a so-called "holding temperature" Ti. The temperature Ti is then held for a certain time and the injection of the resin material into the preform P is carried out. After completion of this injection, the temperature T is again increased rapidly from Ti to a "hardening temperature" T ₂ and held for a while to harden the infiltrated preform P to the fiber composite component. After this curing process, the temperature T is rapidly reduced to the temperature To by switching off the current supply. The entire temperature cycle 22 requires a time t _ges .

If one were to carry out the temperature control in the mold 1 in a conventional manner, ie by heating the tool parts 2, then much more energy would be required for this purpose. In addition, the system would be thermally "carrier", whereby no steep temperature gradient edges would be achieved. Such a conventional temperature cycle is also shown in FIG. 2 and designated by 22 '. The corresponding temperature flanks are substantially flatter, so that the time t'ges required for the entire temperature cycle 22 'is substantially greater than in the tempering according to the invention. In the example according to FIG. 1, the electrical contacts 20-1 to 20-4 on the inner side 12-2 of the mold shell 10-2 each protrude slightly into the tool cavity. Alternatively, the electrical contacts 20 could also have a contact surface arranged flush with the surface of the inner side 12-2. The electrical contacts 20 may, for. Example, an elongated, along the inner side 12-2 extending shape, ie in Fig. 1 z. B. extend orthogonal to the plane elongated. This elongated course of the contacts 20 in a direction indicated in Fig. 1 y direction is z. For example, it is particularly expedient if the preform P and the fiber composite component to be produced therefrom have a shape which is to be designated as a profile elongated in this direction y.

Notwithstanding the number and arrangement of the illustrated in Fig. 1 electrical see 20-1 to 20-4 could resist heating of the preform P z. B. only the electrical contacts 20-1 and 20-4 are used. In this case, could then be replaced by a z. B. predetermined electrical potential difference V4 - V1 between the electrical contacts 20-1 and 20-4 a current flow through the preform P can be achieved, but due to the lack of an xy plane symmetry of Preformgestalt a more irregular flow distribution and thus uneven heating effect would be achieved. For this reason, in the illustrated example, the additional arrangement and use of the electrical contacts 20-2 and 20-3 (already described above) is advantageous. By suitably applying potential to these contacts 20-2 and 20-3 with the potentials V2 and V3, it is possible to influence the flow of current "splitting" in the middle of the illustrated preform P with respect to the direction z in the sense of equalizing the heating effect.

It is understood that a certain desired spatial distribution of the heating effect within the preform P can be achieved more or less precisely by suitably loading the electrical contacts 20-1 to 20-4 with individual electrical potentials. By appropriate modification of the number and arrangement of electrical contacts can be tailored to each need the concrete nature and geometry of the preform to be heated are made.

The provision and supply of the required electrical potentials (and the electric currents driven therewith) is effected by a 4-pole energizing means, not shown in FIG. 1, which is suitably controlled to achieve the desired temperature cycle by a control means and not in FIG shown electrical line connections to the four electrical contacts 20-1 to 20-4 is connected. Each of the four poles of the energizing device is electrically connected via "electrical connections" to one of the contacts 20-1 to 20-4. The energizing device is z. B. arranged together with the control device outside the tool 1 and connected via a "wiring" with the tool 1. In the example shown in FIG. 1, it is advisable to carry out the "electrical continuity" between the electrical contacts 20 and said energizing device, starting in each case from a rear side of the electrical contacts 20 in a "vertical" direction z to the outside 14-2 of the shell 0 -2 and continue through the lower tool part 2-2 through to the current supply device.

Notwithstanding the example of FIG. 1, alternatively or additionally, the upper shell 10-1 could be equipped with electrical contacts for energizing the preform P. In particular, in a pairwise arrangement of the electrical contacts (each with an upper and a lower electrical contact at the same point in the xy plane) can thus be achieved advantageously with respect to the direction z symmetric or more uniform current flow distribution. Such a paired arrangement of electrical contacts is provided in the embodiment described below (FIGS. 3 to 5). In the following description of a further embodiment, the same reference numbers are used for equivalent components, in each case supplemented by a small letter "a" to distinguish the embodiment. Here, essentially only the differences from the already described embodiment will be discussed and incidentally hereby expressly referred to the description of this previous embodiment. FIGS. 3 to 5 illustrate a further embodiment of a tool 1a.

Fig. 3 is a vertical sectional view of the tool 1 a, from which an elongated in the lateral direction y course of paired electrical contacts 20a-1, 20a-2 can be seen. The electrical contacts 20a-1 and 20a-2 are each designed as "contact strips" and allow (in the y-z-plane of Fig. 3) an energization of the preform P simultaneously "from above and below". The current flow introduced in the drawing plane then extends, starting from this contact pair 20a-1, 20a-2, in the negative x direction (cf., for this, FIGS. 4 and 5).

4 is a plan view of the upper tool part 2a-1 in FIG. 3 with the mold shell 10a-1 inserted therein (bottom-up view), and FIG. 5 is a plan view of the lower tool part 2a-2 in FIG inserted shell 10a-2 (viewing direction from top to bottom).

It can be seen from FIGS. 4 and 5 that, in addition to the "contact strip pair" 20a-1, 20a-2, another such contact strip pair 20a-3, 20a-4 in the tool 1 a is formed. This further pair of electrical contacts 20a-3, 20a-4 can not be seen in the sectional plane of FIG.

The electrical contact 20a-3 is arranged on an inner side 12a-1 of the mold shell 10a-1, and the electrical contact 20a-4 is arranged on an inner side 12a-1 of the mold shell 10a-1.

The electrical continuation of the electrical contacts 20a-1, 20a-3 arranged on the inner side 12a-1 of the upper shell 10-1 takes place from the rear sides of these contacts in the z-direction through a respective recess in the material of a body of this shell 10a -1 through and further through the tool part 2a-1.

This can be seen in Fig. 3 for the example of the electrical contact 20a-1. A contacting bolt 30a-1 passing through the tool part 2a-1 from above on the tool part 2a-1 abuts with its lower end against the rear side of the electrical contact 20a-1 in order thus to produce an electrical continuity from this contact 20a-1. A recess (passage opening) of the tool part 2a-1 and a coaxially arranged recess 32a-1 (passage opening) of the shell mold 10a-1 allow this passage of the Kontaktierungsbolzens 30a-1 from outside of the tool part 2a-1 to the back of the electrical contact 20a -1 .

An upper section of the contacting pin 30a-1 can be screwed in, for example, in an electrically insulating sleeve of the upper tool part 2a-1. This sleeve then provides the mentioned recess (passage opening). A lower portion of the contacting bolt 30a-1 passes through the recess 32a-1, wherein at this point, no special electrical insulation measures are required due to the poor electrical conductivity of the material of the upper shell mold 20a-1.

An upper end of the Kontaktierungsbolzens 30a-1 is electrically connected to a corresponding pole of the current application device used (not shown in Fig. 3). The lower electrical contact 20a-2 in FIG. 3 could be electrically further contacted in an analogous manner downwards, ie starting from the rear side of the contact 20a-2, first through a recess of the shell mold 10a-2 downwards and further through a corresponding recess or recess Insulating sleeve of the lower tool part 2a-2.

In the example shown in FIG. 3, however, the lower electrical contact 20a-2 is also ultimately electrically contacted upwardly and through the upper tool part 2a-1, in the following manner:

The electrical contact 20a-2 is electrically unmitttelbar first connected to a in the interior of the shell mold 10a-2 of this electrical contact 20a-2 laterally in the direction y away electrical conductor 34a. In the illustrated example, the electrical conductor 34a is integrally connected to the contact 20a-2, so to speak represents a "lateral extension" of the contact 20a-2, which in a lateral edge region of the shell mold 10a-2 in the lateral y-direction from the extending from the circumferential groove 16a-2 bounded inner region of the mold shell 10a-2 out. At a (in Fig. 3 left) distal end of the electrical conductor 34a then takes place a "vertical" electrical connection in the z-direction. For this purpose, in the region of the distal end of the electrical conductor 34 a from the front of the electrical conductor 34 a to the inside of the shell 10 a-2 continuous recess 36 a and coaxial thereto, a further recess (through hole) in the upper tool part 2 a-1 (again z. B. provided by an insulating sleeve) is provided. These coaxial recesses allow the passage of an electrical connection.

In the example shown, a further contacting bolt 30a-2 passes through at this location as an electrical further connection, the lower end face of which rests against the front side of the electrical conductor 34a (here: at its distal end). In the further course of the contacting pin 30a-2 passes through this in the z-direction continuous recess 38a of the upper shell mold 10a-1 and in the z-direction continuous recess (or insulating sleeve) of the upper tool part 2a-1. The contacting pin 30a-2, like the contacting pin 30a-1 already described above, is screwed from above into the recess or passage opening of the upper tool part 2a-1 and, like the contacting pin 30a-1, is likewise electrically connected, for example. B. connected by a "wiring" with the associated pole of the current supply device used.

As a result, both electrical contacts 20a-1 and 20a-2 are thus ultimately electrically connected upwards through the upper tool part 2a-1. The accessible at the top of the tool part 2a-1 ends of the two Kontaktierungsbolzen 30a-1 and 30a-2 can thus in a simple manner a (not shown) line connection with the current supply device used are connected. In order that the electrical continuity provided for in the lower electrical contact 20a-2 in FIG. 3 does not interfere with the predetermined shaping of the tool cavity, this electrical continuity has, starting from the lower electrical contact 20a-2, first the lateral (in FIG left) and the sealing groove 16a-2 "submerged" section (conductor 34a), wherein only in a laterally outside the sealed area then an electrical continuity takes place at the top (Kontaktierungsbolzen 30a-2).

In Fig. 5 can be clearly seen how the "sunk" in the material of the shell mold 10a-2 extending conductor 34a, the groove provided for the seal 16a-2 "submerged".

The electrical further connection described above for the contact pair 20a-1, 20a-2 by means of two contacting bolts 30a-1 and 30a-2 is analogous to the further contact pair 20a-3, 20a-4 (compare FIG. 4 and FIG 5). These contacts 20a-3, 20a-4 are further electrically connected via corresponding (not shown) Kontaktierungsbolzen at another lateral point of the tool 1 a upwards and outside of the tool part 2- 1 finally electrically connected to the energizing device.

The invention is particularly suitable for the mass production of fiber composite components, such as CFRP components, and allows a significant reduction in the energy required for heating the mold cavity or the preform. The use of the specially designed shell molds described here, in particular injection mold shells for an RTM production process, makes it possible to use the preform itself as an electrical resistance heater.

Claims

claims

A mold shell (10-1, 10-2; 10a-1, 10a-2) for a tool (1; 1a) for producing a fiber composite component by thermal curing of a mold shell (10-1, 10-2, 10a -1, 10a-2) in the tool (1; 1 a) arranged preform (P), with an intended for support by a tool part (2-1, 2-2, 2a-1, 2a-2) outside (14- 1, 14-2, 14a-1, 14a-2) and an inner side (12-1, 12-2, 12a-1, 12a-2) forming the fiber composite component to be produced, characterized in that on the inner side (12-14) 1, 12-2, 12a-1, 12a-2) a plurality of electrical contacts (20; 20a) are arranged in order, via these electrical contacts (20; 20a), a current flow for resistance heating of the preform (FIG. P).

2. molding shell (10-1, 10-2, 10a-1, 10a-2) according to claim 1, mostly formed by a fiber composite material, in particular CFRP.

3. shell mold (10-1, 10-2, 10a-1, 10a-2) according to one of the preceding claims, wherein at least one of the electrical contacts (20; 20a) is flush with the surface of the inside (12-1, 12- 2, 12a-1, 12a-2) arranged contact surface.

A mold shell (10-1, 10-2; 10a-1, 10a-2) according to any one of the preceding claims, wherein at least one of the electrical contacts (20; 20a) is elongate, along the inner side (12-1, 12- 2, 12a-1, 12a-2) has a running shape. Mold shell (10-1, 10-2; 10a-1, 10a-2) according to one of the preceding claims, wherein in the region of at least one of the electrical contacts (20; 20a) one of the back of the respective electrical contact (20; 20a) to the outer side (14-1, 14-2, 14a-1, 14a-2) of the mold shell (10-1, 10- 2, 10a-1, 10a-2) through recess (32a-1) for the passage of an electrical Forward connection (30a-1) is provided.

Mold shell (10-1, 10-2, 10a-1, 10a-2) according to one of the preceding claims, wherein at least one of the electrical contacts (20; 20a) for electrical continuity is electrically connected to an internal shell (10-1, 10-1, 10a, 10a). 10-2; 10a-1, 10a-2) of electrical contact (34a) extending away from said electrical contact (20; 20a).

Mold shell (10-1, 10-2, 10a-1, 10a-2) according to claim 6, wherein in the region of the electrical conductor (34a) from the back or front of the electrical conductor (34a) to the outside (14-1 , 14-2, 14a-1, 14a-2) and inner side (12-1, 12-2, 12a-1, 12a-2) of the mold shell (10-1, 10-2, 10a-1, 10a) 2) through recess (36a) for the passage of an electrical connection (30a-2) is provided.

A tool (1; 1 a) for producing a fiber composite component by thermally curing a preform (P) comprising a first tool part (2-1; 2a-1) provided with a first mold shell (10-1; 10a-1) and a second tool part (2-2; 2a-2) provided with a second mold shell (10-2; 10a-2) for forming a mold cavity for the preform (P) between respective inner sides (12-1, 12-2; 12a-1) , 12a-2) of the shell molds (10-1, 10-2, 10a-1, 10a-2), characterized in that at least one of the shell molds (10-1, 10-2 10a-1, 10a-2) is formed as a mold shell according to one of claims 1 to 7, and that the tool (1; 1, 30a-2) for energizing the electrical contacts (20; 20a) of the mold shell (10-2; 10a-1, 10a-2) for resistance heating of the mold (P) arranged in the mold cavity.

Use of a mold shell (10-1, 10-2; 10a-1, 10a-2) according to one of claims 1 to 7 for producing a fiber composite component by thermal curing of a mold shell (10-1, 10-2; 1, 10a-2) in a tool (1; 1a) arranged preform (P), wherein by energizing the electrical contacts (20; 20a) of the shell mold (10-1, 10-2, 10a-1, 10a-2 ) a resistance heating of the preform (P) is performed.