FR3025740A1 - METHOD FOR MANUFACTURING A CARRIAGE PIECE OF A VEHICLE - Google Patents

Abstract

The invention relates to a method for the manufacture of a vehicle dressing part with an injection molding tool, the injection molding tool having one upper tool half (100) and one half of tooling. lower (102), the method comprising: - setting up a ply (108), respectively in the upper half tooling (100) and in the lower half tooling (102), the plies each presenting fibers (300) woven, the fibers (300) extending into the web (108) with corrugations or zigzags, - closing the upper tooling half (100) and the lower half tooling (102), a hollow space (202) being generated between the two plies in the closed state of the tool halves, - injecting an injection molding material (200) into the hollow space (202) for obtaining a composite material, the composite material comprising the two layers and the injection molding material (200) lying therebetween, - demolding the composite material.

Description

The invention relates to a method for manufacturing a vehicle trim part and to the vehicle trim part in question.

Spaces for passengers of "vehicles" such as boats, trains and motor vehicles, for example, cars and trucks, are provided with trim parts. Dressing parts are primarily aesthetic, but may find other uses, for other reasons, such as the deposit of objects. In this context, interior trim parts of vehicles must meet various requirements regarding weight and stability. Thus, for example, it is necessary that the interior trim parts of the vehicle provide some protection to the passengers of the vehicle in case of impact. Undoubtedly, the vehicle trim parts should not be too heavy, so that the energy expenditure for the operation and movement of the corresponding vehicle is not too high. WO 99/63141, for example, discloses a textile, which can be used as a reinforcing material in fiber-based composite materials. The purpose of the patent is to provide a method of manufacturing a vehicle trim part and a corresponding vehicle trim part. The features of the claims independent of the patent disclose the purposes underlying the invention. Preferred embodiments of the invention are set forth in the dependent patent claims. A method of manufacturing a vehicle trim piece using injection molding tooling is disclosed wherein the injection molding tool has one upper tool half and one half tooling portion. lower. The method comprises: - laying a web on the upper half of the tool and on the lower half of the tool, respectively, where the webs have woven fibers, where the fibers extend with ripples or zigzags in the sheet. 5 - the closure of the upper tooling half and the lower tooling half, where there is created a hollow space between the two sheets for a closed state of the tooling halves, - the injection of a material injection molding in the hollow space for obtaining a composite material, wherein the composite material comprises the two plies and the injection molding material lying between the two, the demolding of the composite material. The wavy shape of the fiber should be understood to be an elongate curved shape similar, for example, to a sinusoidal curve. Embodiments of the invention may have the advantage that, by the combination of the webs having fibers woven into the edge region and the injection molding material therebetween, a very strong vehicle trim part 20 and yet lightweight can be manufactured. The injection molding materials that may be employed herein may have a very low density. This can be attributed to a property specific to the material chosen, and / or may result from a high proportion of air inclusions, which reduces the density of the vehicle trim part as a whole. However, thanks to the presence of the layers at the edge areas located on either side of the composite material, a high tensile strength, and therefore a higher rigidity of the vehicle trim part, are obtained. For example, as fibers, carbon fibers, glass fibers, metal fibers, etc. may be used, the glass and carbon fibers having in particular a very high tear resistance.

Because the fibers extend into the web with corrugations or zigzags, it is possible to obtain a tight plating of the web against the corresponding half of tooling, also in very curved areas of the halves. upper, respectively lower, of the tooling. In this case, there could be local traction on the web in the curved areas due to the corrugations, respectively, of the zigzag shape of the fibers, so that the web could press against half of the tooling in these curved areas. It would thus be possible to prevent too high mechanical tensions from being created in the ply, particularly in the curved areas, which could lead to reduced resistance of the ply in these areas to the composite material produced. The fibers with corrugations or zigzags can thus play a "damping" role so that a flexibility adjustment of the web on the curved areas of the lower tooling halves, respectively, is possible.

As a fiber material, those which are conceivable are those which are used industrially and which are suitable for lightweight construction. The fibers may include carbon, glass and metal fibers. In addition, other very strong fibers are also conceivable, such as natural fibers such as, for example, flax, kenaf, sisal, hemp, jute, bamboo. In addition, synthetic fibers are also possible, such as aramid (polyamide), as well as ceramic fibers or basalt fibers.

According to one embodiment of the invention, at least one of the plies is designed with open pores on a planar area, the open porosity allowing the injection molding material to pass through this ply during the period of time. injecting the injection molding material into the hollow space. The open porosity therefore does not concern only a point location of the web, but the open porosity is present on a larger area of the web. For example, one of the tooling halves has a functional hollow space, the functional hollow space being implanted above the planar open-pore area of the web, i.e. between the web and the web. half of corresponding tooling. Basically, it should be possible, because of the open porosity of the webs, that the web is completely traversed by the injection molding material. The ply is thus subjected, for example, because of its open porosity, to complete penetration by the injection molding material so that an optimal bond, respectively by complementarity of material can be achieved between the ply and the material of the invention. injection molding. To the extent that said functional hollow space is implanted above the surface area of the web with the pores open, the injection molding material can penetrate the hollow space upon injection of the molding material. injection through the open pores of the web and also penetrate the functional hollow space. Thus, it would be possible that, in a single injection process, in addition to making the composite material, functional elements and rib-like structures could be formed simultaneously on the composite material. If it is, for example, in the case of rib-like structures, stiffening ribs, the overall stability and rigidity of the manufactured vehicle trim part could be considerably improved for this reason. Functional elements would be, for example, supports for functional elements such as cables, loudspeakers, window regulators, etc.

Overall, the process would thus make it possible to manufacture three-dimensional surfaces thanks to the zig-zag-shaped corrugated fibers, in which, in addition to high mechanical stability, it would be possible to have a vehicle trim part manufactured with great lightness.

According to one embodiment of the invention, the method further comprises pressing at least one of the plies onto a plastic plate, the pressing being carried out at a softening temperature of the plastic plate, the softening temperature and the pressure for pressing are thus chosen, that due to the pressing, a complementarity connection of shapes and / or materials is obtained between the sheet and the plastic plate, the tablecloth being placed together with the plastic plate in the same tooling half. It can be envisaged that the webs are pressed onto, for example, a preheated plastic plate which has a temperature sufficient to provide a connection to the web. This could in turn be shaped by a thermoforming treatment.

The use of the combination of a plastic plate and a web could simplify setting up the web in the injection molding tool. While a single web could only be set up with difficulty in the injection molding tool because of its lightness and lack of rigidity, this problem would be avoided by providing for the implementation of the invention. place the combination of the tablecloth with the plastic plate. Overall, the manufacturing process of the vehicle trim part in the form of a composite material would thus be simplified by the combination of a sheet and a plastic plate.

As already mentioned, according to one embodiment of the invention, the plastic plate bonded to the web could be preformed into a geometric shape, in which case, in this case, this geometric shape corresponding to the web , would be suitable for the first or second half of tooling. However, it is also conceivable that, for a higher intrinsic stiffness of the plies, a preforming of the raw plies or at least one of these plies, in a predefined geometrical shape takes place before the introduction of the ply into the ply. half of corresponding tooling. This, however, depends to a certain extent on the rigidity of the sheet itself.

According to one embodiment of the invention, the fibers are woven together together in the form of warp and weft threads, in which a warp thread spans at least three weft threads and / or a weft thread spans at least three warp threads, due to the wavy or zigzag shape. This could result in a greater period of the corrugations or the zigzag shape of the warp or weft yarns, which overall could improve the extensibility of the plies during the setting up in the tooling and the machine. subsequent injection molding process.

According to one embodiment of the invention, the contour of the upper and / or lower tooling half oriented towards the hollow space has a curvature, where the sheet to be disposed in this tooling half has the corrugated shape. or zigzags fibers exclusively in the areas of the curvature. Thus, extremely high extensibility could be imparted to the web outside the areas of the curvature. However, in the curved areas, an extension of the wavy or zigzag shapes of the fibers has already occurred during the setting up of the sheet in the tooling and the subsequent injection molding process, so that subsequently Orientations of the drawn fibers also occur in these curved areas. Thus, the overall stability of the vehicle trim part could be significantly increased, especially with regard to the tensile strength. According to one embodiment of the invention, the fibers are woven together in the form of warp and weft threads, in which the warp and weft threads intersecting at regular distances are integrally connected together or by complementarity of matter. Such a connection may, for example, be achieved by a spot weld. The interpenetration of the warp and weft yarns at regular distances could have the advantage that a too high relative displacement of the fibers relative to each other could be avoided in the tooling during the injection process. . Thus one could keep the structure of the fibers conferring stability during the manufacturing process of the composite material.

For example, the fibers are integrally or integrally connected exclusively in areas of the web which do not have corrugated or zigzag-shaped fibers. This could have the advantage that a highly flexible adjustment ability to the geometric contour of the respective tooling halves remains retained in areas with corrugated or zigzag-shaped fibers. In areas where adjustment of the web material to a geometric contour is, however, not necessary, it could be avoided from the outset that a structural change in the web during the eventual injection molding process takes place. According to one embodiment of the invention, it is an interior trim part of a motor vehicle in the case of the vehicle trim part.

In another aspect, the invention relates to a vehicle trim part comprising a composite material, wherein the composite material comprises two spaced apart webs and an injection molding material binding the two webs to each other. located between them, in which the plies 15 each have woven fibers, wherein the fibers extend into the web in a wavy zigzag shape. The two layers thus each time form the outer faces of the composite material. In the following, the embodiments of the invention are explained in more detail with the help of the diagrams. FIG. 1 is a diagrammatic view of an injection molding tool with plies to be put in place, in FIG. 2 a schematic view of the injection molding tool of FIG. 1 in the closed state, FIG. 3 is a diagrammatic view of a ply in the set-up state in the tooling; FIG. 4 is a diagrammatic view of a composite material made with a rib providing stiffness, in FIG. a flowchart of a method of manufacturing a vehicle trim part, in Figure 6 a schematic view of intersecting warp and weft yarns. Subsequently, similar elements will be designated with the same references. In addition, in the following, and without limitation of the general character, it is assumed that the vehicle trim part is used in a motor vehicle as part of the interior trim of the vehicle. Figure 1 shows a schematic view of an injection molding tool for manufacturing an interior trim part of the vehicle. The injection molding tool is comprised of one upper tool half 100 and one lower tool half 102. The upper tool half 100 has a protruding contour 104, and the lower tool half 102 has a complementary depression 106 in the form of a surface contour. Webs 108 with woven fibers are placed each time in the upper half tooling 100, respectively in the lower tooling half 102. This step corresponding to step 500 in the flow chart of Figure 5.

The webs 108 have woven fibers such that these fibers extend into the web in the form of corrugations or zigzags. This is not shown in more detail in Figure 1 for reasons of clarity. Due to the fibers extending in the form of corrugations or zigzags, they may allow "stretching" of the spring-like web 108 in question. This is possible even if it is in the case of fibers, preferably fibers, which are hardly stretchable themselves. For example, it is carbon fiber in the case of fibers. Thus, the web, because of the wavy fibers, will be able to fit the contour of a shaped surface 30 of a bulge 104, ie, it will press against it. when the ply 108 is placed in the upper tooling half 100 without this producing excessive local stretches and consequently weaknesses in the material of the ply 108.

In the next processing step (step 502 of FIG. 5), the two tool halves 100 and 102 are closed so that a hollow space 202 enters between these tool halves, which is delimited by the tablecloths108. The plies 108 are each pressed against the lower half tooling, respectively, upper. In step 504, an injection molding material 200 is then injected into the hollow space 202 to obtain a composite material. In the liquid state, the flows of injection molding material are distributed between the webs 108, as sketched in FIG. 2. Since the webs 108 preferably have an open pore material, the injection molding material 200 passes through the web. less partially the webs during the deployment process and thus causes an intimate connection with the webs after cooling.

In the last step 506, there is finally a release of the composite material thus produced, comprising both said plies and the injection molding material cooled between them.

The vehicle interior trim part thus manufactured can, for example, be used in the form of a very stable airbag cover. Since the airbag covers usually have to be weak, to allow opening when the airbag is deployed, it should be sufficient, for example, to break the fibers at predefined points with the aid of a laser.

Figure 3b shows again a part of a vehicle interior trim part manufactured with a web 108, and above it the cooled injection molding material 200. In Fig. 3a the same ply 108 is schematically shown in a plunging view. It can clearly be seen that the zigzag-shaped, corrugated fibers 300 are passed through a substantially rectilinear fiber structure in the areas of high stretching, ie, for example, in the area 302 of the part 5. vehicle interior trim. The corrugated or zigzag-shaped fibers 300 have thus been disentangled by stretching so that the result is a stretching of the period of the undulations, respectively, of the zigzags, similar to that of a spring stretch. In the edge regions 304 of the vehicle interior trim piece, however, the fiber structure does not exhibit a change in the shape of the corrugations or zigzags due to the absence of curvature in the interior trim piece. of vehicle. Figure 4 shows a schematic view of a vehicle interior trim piece with a stiffness rib 400. This rigidity rib is located on one of the webs 108 and has been generated by the fact that corresponding injection molding tooling had a recess in the tooling half which was in front of the rib 400. When injecting the injection molding material 200 into the hollow space between the two plies, the molding material By injection, it was possible to pass through the lower open-pore web 108 and thus simultaneously penetrate into the hollow space forming the rib of the lower tooling half. After cooling, a layer consisting of a single injection molding material is formed between the two plies 108 forming an assembly and a rib providing rigidity 400 on the lower ply 108.

Basically, this principle can be used for integrating functional areas as desired with higher rigidity into the vehicle interior trim part. Such functional areas may comprise, in addition to ribs providing rigidity, also other rib-like structures such as cable supports and mounting clips for fixing the vehicle interior trim part to the vehicle.

Overall, it may be possible, by the method described above, to set up woven webs made of a very strong material such as glass fibers, carbon fibers, metal fibers, etc. in injection molding equipment. An injection molding material is then injected between these two webs and is optionally presented in the form of a cake between them, as for forming by pressing of supports. The sandwich thus obtained, consisting of a web, injection molding material, a web, thus results forming a highly resistant structure. Due to the corrugated fibers, respectively in the form of zigzags, it is possible to have stretching of the fibers with highly curved areas of the injection molding tooling. Otherwise, it may be difficult to fill the three-dimensional cavities, respectively, to press the plies in the desired position. The plies are optionally welded in a complementary manner to prevent excessive movement in the tooling during injection. As already described above, it could also be possible to pre-form the webs and put them in place, for example, with robots. In addition, it could be possible to press the webs on preheated plastic plates which have a temperature sufficient to make a connection with the web. These could again be shaped by a thermoforming process. Overall, one could obtain lighter vehicle trim parts with a simultaneous increase in stiffness. The described method could make it possible to manufacture vehicle trim parts less expensive than usual solutions. The sheets could be varied according to the various requirements concerning the choice of material. Overall, automation would be possible so that very strong supports overall, especially with carbon fibers, would be possible with the 3d surface representation practically as desired because of the corrugated fibers. Figure 6 shows a schematic representation of the intersecting warp and weft yarns, in which the ripple path of the warp yarns was omitted, simply because it is obvious, in order to more clearly set the type of travel in ripples in evidence. For example, the warp threads extend in the horizontal direction, whereas the weft threads are rippled in Figure 6a. In Figure 6b, the weft yarns extend triangularly, i.e. zigzag-shaped. In addition, three warp threads are always "surrounded" by the wavy path of the weft threads. As regards the warp threads, this should be the same, that is to say that three weft threads are always "surrounded" by the corrugated path of the warp threads. The number three is given here only by way of example, it is possible that there are at least 2 wires, 3, 4, 5 or more wires wrapped around each other. This results in an increase in the extensibility of the layers. The use of the more drawn warp or weft yarns corresponds to a pre-stretching of the yarns in the starting position, which makes further stretching more difficult or impossible.

Thus, it is preferable that both the warp and weft yarns are wavy.

20 3 0 2 5 7 4 0 13 REFERENCES 100 Half of tooling 5 102 Half of tooling 104 Bulge 106 Hollow 108 Tablecloth 200 Injection molding material 10 202 Hollow space 300 Fibers 302 Zone 304 Zone 400 Rib 15

Claims (12)

REVENDICATIONS1. A method of manufacturing a vehicle trim part with an injection molding tool, wherein the injection molding tool has one upper tool half (100) and one lower tool half. (102), wherein the method comprises: placing a web (108) in the upper tooling half (100) and in the lower tooling half (102), where the webs each have fibers (300), wherein the fibers (300) extend in the ply (108) with corrugations or zigzags, closing the upper tooling half (100) and the lower tooling half ( 102), wherein a hollow space (202) is formed between the two plies in the closed state of the tool halves, injecting an injection molding material (200) into the hollow space (202). ) for obtaining a composite material, wherein the composite material comprises the two layers and the material of mo injection molding (200) lying between them, the demolding of the composite material. The method of claim 1, wherein at least one of the webs is open-pore in a planar area, wherein the open porosity allows penetration through said web (108) by the injection molding material (200). ) in the hollow space (202) during injection of the injection molding material (200). The method of claim 2, wherein one of the tooling halves has a functional hollow space, wherein the functional hollow space is designed above the open-pore planar area of the web (108). 302 5 7 40 15 A method according to any one of the preceding claims, further comprising pressing at least one of the plies onto a plastic plate, wherein the pressing is performed below a softening temperature of the plate in plastic material, wherein the softening temperature and the pressure for pressing are chosen so that a complementarity bond of the shapes and / or complementarity of the materials is obtained between the ply (108) and the plastic plate because of the pressing, wherein the web (108) is disposed together with the bonded plastic plate 10 in the corresponding tooling half. The method of any of the preceding claims, further comprising preforming at least one of the webs (300) into a predefined geometric shape. 15 6. The method of claim 5, wherein the preforming is performed in the state of the web (108) bonded with the plastic plate. A method according to any one of the preceding claims, wherein the fibers (300) in the web (108) are woven together as warp and weft yarns, in which, due to the wavy shape or zigzags, a warp thread spans at least three weft threads, and / or a weft thread spans at least three warp threads. 25 A method according to any one of the preceding claims, wherein the hollow space oriented contour (202) of the upper and / or lower tooling half (102) has a curvature, wherein the web (108) Implementation in this tooling half has the wavy or zigzag shape of the fibers (300) exclusively in the areas of the curvature. A method according to any one of the preceding claims, wherein the fibers (300) in the web (108) are woven together in the form of warp and weft yarns, wherein the warp yarns and wefts intersecting at regular intervals are connected together in solidarity or complementarity of materials. 5 A method according to claim 9, wherein the fibers (300) are bonded together integrally and by complementarity of materials only in areas of the web that are free of corrugated or zigzag-shaped fibers (300). 10 11. A method according to any one of the preceding claims, wherein it is an interior trim part of a motor vehicle in the case of the vehicle trim part. 12. A vehicle trim part comprising a composite material, wherein the composite material comprises two spaced-apart webs and an injection molding material (200) lying between the two webs binding them together, wherein the webs each have woven fibers (300), wherein the fibers (300) extend in the web (108) with corrugations or zigzags.