Honeycomb core, method of producing a honeycomb core, and sandwich panel comprising a honeycomb core

Abstract

A honeycomb core having a lattice structure which includes a resin-impregnated matrix, a method for producing such a honeycomb core, a sandwich panel having such a honeycomb core, and use of such a honeycomb core or such a sandwich panel in automobile construction. The matrix is impregnated inhomogeneously with the resin.

Claims

1. A method of producing a motor vehicle component, the method comprising: providing a honeycomb core having a plurality of regions, including a lattice structure having corrugated strips with linear strips arranged therebetween, and a plurality of lattice elements which form a nodal point, each lattice element comprising a matrix; and impregnating each matrix by spraying resins of different types at different spray durations and spray intensities inhomogeneously two-dimensionally such that zones of the motor vehicle component located in preselected regions of the honeycomb core have different stiffnesses than other regions based upon a probability of impact in an accident by the motor vehicle.

2. The method of claim 1, further comprising, connecting, after the impregnation of each matrix, cover layers to the honeycomb core.

3. The method of claim 1, wherein impregnating resins comprises impregnating the resins for different lengths of time.

4. A method of producing a motor vehicle component, the method comprising: providing a honeycomb core having a plurality of regions, including a lattice structure having corrugated strips with linear strips arranged therebetween, and a plurality of lattice elements which form a nodal point, each lattice element comprising a matrix composed of a homogeneous material; impregnating each matrix, by spraying resins of different types at different spray durations and spray intensities inhomogeneously and two-dimensionally, such that zones of the motor vehicle component located in preselected regions of the honeycomb core have different stiffnesses than other regions based upon a probability of impact in an accident by the motor vehicle.

5. The method of claim 4, further comprising, connecting, after the impregnation of each matrix, cover layers to the honeycomb core.

6. The method of claim 4, wherein each matrix is impregnated such that the inhomogeneity is distributed over the height of the lattice structure.

7. The method of claim 4, wherein the lattice structure comprises polygonal honeycombs.

8. A method of producing a motor vehicle component, the method comprising: connecting cover layers, including an outer layer and an inner layer, to a honeycomb core having a plurality of regions arranged between the cover layers, the honeycomb core including a lattice structure having corrugated strips with linear strips arranged therebetween, and a plurality of lattice elements which form a nodal point, each lattice elements comprising a matrix composed of a homogeneous material; and impregnating resins; in each matrix inhomogeneously and two-dimensionally, by spraying resins of different types at different spray durations and spray intensities such that zones of the motor vehicle component located in preselected regions of the honeycomb core have different stiffnesses based upon a probability of impact in an accident by the motor vehicle.

9. The method of claim 8, wherein each matrix is impregnated such that the inhomogeneity is distributed over the height of the lattice structure.

10. The method of claim 8, wherein the lattice structure comprises polygonal honeycombs.

11. The method of claim 8, further comprising providing a gap between the lattice elements at the nodal point.

12. The method of claim 11, wherein the lattice elements are not connected to one another at the gap.

Description

DRAWINGS

(1) The present invention will be explained in greater detail hereafter on the basis of the exemplary embodiments indicated in the schematic figures of the drawing. In the figures:

(2) FIG. 1 illustrates a honeycomb core having polygonal honeycombs in an inclined view.

(3) FIG. 2 illustrates a sandwich panel having such a honeycomb core in section.

(4) FIG. 3 illustrates a honeycomb core which is immersed upright in a container filled with resin.

(5) FIG. 4 illustrates a honeycomb core regionally impregnated with resin.

(6) FIG. 5 illustrates a honeycomb core in which the impregnation of the honeycomb core with a resin is distributed inhomogeneously over the surface.

(7) FIG. 6 illustrates a honeycomb core which is immersed horizontally in a container filled with resin.

(8) FIG. 7 illustrates a sandwich panel in which the impregnation of the honeycomb core with a resin is distributed inhomogeneously over its height.

(9) FIG. 8 illustrates a honeycomb core which is sprayed with resin.

(10) FIG. 9 illustrates a honeycomb core having corrugated strips.

(11) FIG. 10 illustrates a honeycomb core having corrugated strips and linear strips arranged between them.

(12) FIG. 11 illustrates a detail of a honeycomb core in which a lattice element only loosely touches the adjacent lattice elements at a contact point.

(13) FIG. 12 illustrates the honeycomb core of FIG. 11, but with a gap.

(14) FIG. 13 illustrates a detail of a honeycomb core in which all lattice elements of a node only loosely touch one another.

(15) FIG. 14 illustrates the honeycomb core of FIG. 13, but with a gap.

(16) FIG. 15 illustrates a detail of a honeycomb core having an interrupted lattice element.

(17) FIG. 16 illustrates a detail of a honeycomb core in which lattice elements extending in parallel between two adjacent nodal points only touch one another loosely.

(18) FIG. 17 illustrates a honeycomb core having interruptions distributed over the surface.

DESCRIPTION

(19) FIG. 1 illustrates a honeycomb core 1a having a lattice structure, which consists of a plurality of lattice elements 2a, which are connected to one another at nodal points K. In this example, the honeycomb core 1a or its lattice structure comprises polygonal honeycombs, specifically hexagonal honeycombs.

(20) FIG. 2 illustrates a sandwich panel 3, comprising the honeycomb core 1a and cover layers 4 and 5 connected thereto.

(21) In order to control the stiffness of the honeycomb core 1a or the sandwich panel 3, a resin-impregnated matrix, which is part of the lattice structure, is impregnated inhomogeneously with the resin. If the honeycomb core 1a or the sandwich panel 3, which comprises the honeycomb core 1a, respectively, is subjected to a load, this mentioned inhomogeneity has the result that the honeycomb core 1a/the sandwich panel 3 deforms in different ways.

(22) For this purpose, the matrix can be brought into contact with a resin or a plurality of resins:

(23) a) only regionally and/or

(24) b) regionally for different lengths of time and/or

(25) c) regionally at different strengths.

(26) For example, the matrix can be immersed for this purpose in a container 6 filled with resin, as illustrated in FIG. 3. If the matrix is only partially immersed, the matrix is therefore only regionally impregnated with resin. In this manner, a honeycomb core can be produced which is impregnated in a region A with resin, but is not impregnated in a region B, as illustrated in FIG. 4, for example. It would also be conceivable to impregnate the region B with another resin in a further step. Of course, regions which were brought into contact with different resins can also overlap.

(27) Furthermore, a movement of the matrix during the immersion procedure can be used for the purpose of impregnating it inhomogeneously. For example, the matrix can be immersed completely in the resin and withdrawn therefrom again at different speeds and also continuously or discontinuously. Of course, the movement during the immersion into the container 6 can also be varied. In this manner, the matrix is regionally brought into contact with the resin for different lengths of time, so that the resin is deposited differently in the matrix. FIG. 5 illustrates an example of how the intensity I of the resin can be distributed over the honeycomb core 1a or the sandwich panel 3, respectively.

(28) As is clearly obvious from FIG. 5, the inhomogeneity is distributed two-dimensionally over the lattice structure. Of course, this method can also be applied with different resins.

(29) FIG. 6 illustrates a further method, in which the matrix is immersed horizontally in a container 6 filled with resin. Similarly to the method described in FIGS. 4 and 5, the matrix can also be only partially immersed, in order to impregnate the matrix only regionally. Similarly, a movement of the matrix during the immersion procedure can be varied. In this manner, the matrix is again brought into contact with the resin for different lengths of time, so that the resin is deposited differently in the matrix.

(30) FIG. 7 illustrates an example of how the intensity I of the resin can be distributed over the honeycomb core 1a or the sandwich panel 3, respectively. As is clearly obvious from FIG. 7, the inhomogeneity is distributed over the height of the honeycomb core 1a.

(31) FIG. 8 illustrates a further method, in which the matrix is sprayed with resin by two spray heads 7 and 8. In this manner, the matrix is brought into contact with a resin regionally at different strengths. For example, the resin accumulates in the edge regions of the matrix, which face toward the spray heads 7 and 8, more strongly than in the middle. Of course, it is also conceivable that the spray head 7 applies a different resin than the spray head 8. Inhomogeneous impregnation can also be controlled over the surface of the honeycomb core 1a by horizontal movement of the matrix.

(32) It is to be noted here that the above-described variants can be combined with one another arbitrarily. For example, a matrix can be immersed in one resin and sprayed with another resin.

(33) The above examples were explained on the basis of a honeycomb core 1a having hexagonal honeycombs. Of course, the use thereof is not obligatory. It is also possible, of course, to use polygonal honeycombs having a different number of corners. In particular, it is also possible to combine different polygons with one another, for example, hexagons with rectangles.

(34) FIG. 9 illustrates a further variant of a honeycomb core 1b, in which the lattice structure comprises corrugated strips. Individual corrugated strips are typically connected to one another during the production of such a structure, however, this lattice structure can also be understood geometrically so that it consists of a plurality of lattice elements 2b, which are connected to one another at nodal points K.

(35) FIG. 10 illustrates a honeycomb core 1c having a lattice structure which comprises corrugated strips having linear strips arranged between them. This lattice structure can also be understood so that it consists of a plurality of lattice elements 2a, which are connected to one another at nodal points K.

(36) In principle, the cover layers 4 and 5 can also be applied inhomogeneously to a honeycomb core 1a . . . 1c during the production of a sandwich panel 3, for example, by differing distribution of an adhesive provided for this purpose. This can be omitted in most cases due to the inhomogeneous impregnation of the honeycomb core 1a . . . 1c, however, so that the production of a sandwich panel 3 is simplified. The matrix preferably consists of a substantially homogeneous material, whereby it can also be produced in a simple manner.

(37) In order to control the stiffness of a honeycomb core 1a . . . 1c or a sandwich panel 3, respectively, additionally or alternatively to the inhomogeneous impregnation of the lattice structure with a resin, it can also be provided that at least one lattice element only loosely touches an adjacent lattice element or that a gap is provided between them or that one lattice element is interrupted. This means that the mentioned lattice elements are not connected to one another. If the honeycomb core 1a or the sandwich panel 3, which comprises the honeycomb core 1a, respectively, is subjected to a load in a direction which is in the plane of the drawing of FIG. 4, these non-connected lattice elements thus have the result that the honeycomb core 1a/the sandwich panel 3 is particularly soft at this point. The stiffness of the honeycomb core 1a/the sandwich panel 3 can be controlled well in this manner. If the honeycomb core 1a/the sandwich panel 3 is loaded normally to the mentioned plane of the drawing, the stiffness thereof does not differ or only differs slightly from the stiffness of a honeycomb core/a sandwich panel which does not have such interruptions.

(38) FIG. 11 illustrates a detail from a honeycomb core having hexagonal honeycombs for this purpose, in which one lattice element 2a only loosely touches the adjacent lattice elements 2a at the contact point C.

(39) A gap is additionally implemented at the point C in FIG. 12.

(40) FIG. 13 illustrates a detail from a further honeycomb core, which has a nodal point K, at which all lattice elements 2a which form this nodal point K only loosely touch one another.

(41) In addition, a gap is provided between the lattice elements in FIG. 14.

(42) FIG. 15 illustrates a detail from a honeycomb core in which one lattice element 2a is interrupted at the point C. In addition, the ends of the affected lattice element 2a are bevelled, so that they can slide past one another more easily in the event of a pressure load. This is not necessarily the case, however, the ends can also be implemented as linear. Vice versa, the interruptions illustrated in FIGS. 11 to 14 can also be bevelled.

(43) FIG. 16 illustrates a detail from a honeycomb core in which lattice elements 2a extending in parallel between two adjacent nodal points only touch one another loosely. This is the case at the contact point D (illustrated by a dotted line). Alternatively, a gap can also be provided at the point D.

(44) FIG. 17 illustrates an example of how the interruptions marked with a X can be distributed two-dimensionally over the lattice structure of a honeycomb core 1d. In FIG. 17, the interruptions X are distributed irregularly, however, they can also be distributed regularly depending on the application, of course. In FIG. 17, the interruptions X are furthermore arranged within the lattice structure, so that no loose lattice elements 2a arise at the edge of the lattice structure. It is also obvious from FIG. 17 that the honeycomb core 1d is implemented in one piece. In this manner, the manipulation thereof, or also the production of the sandwich panel 3, is particularly simple.

(45) The above examples were explained on the basis of a honeycomb core 1a having hexagonal honeycombs. The use thereof is not obligatory, of course. It is also possible, of course, to use polygonal honeycombs having a different number of corners. Finally, lattice structures having corrugated strips (FIG. 9) or having corrugated strips having linear strips arranged between them (FIG. 10) can also have such interruptions. For example, such a lattice structure can be produced in that no adhesive is applied at the affected nodal points K during the gluing of the strips. In this case, respectively two lattice elements 2b, 2c of the four lattice elements 2b, 2c delimiting this nodal point K are connected to one another.

(46) The measures illustrated in the figures can be combined arbitrarily. For example, the honeycomb core 1d from FIG. 17 can be impregnated with resin in the same manner as the honeycomb core 1a from FIG. 4. Or, a honeycomb core as illustrated in FIG. 14 can be sprayed with resin as illustrated in FIG. 8. A person skilled in the art can apply the disclosed teaching readily to further examples.

(47) A honeycomb core 1a . . . 1d or a sandwich panel 3 can be used in vehicle construction, for example, as an engine hood or as an interior component, for example. In both cases, it is important that persons are not injured or are not injured severely in the event of an impact on the mentioned components. The measures for controlling the strength of a honeycomb core 1a . . . 1d now offer the possibility of forming an engine hood of a vehicle so it has different stiffnesses in a simple manner. Various zones can thus be formed, at which in all probability a pedestrian will strike with the legs, with the torso, or with the head on the engine hood if a vehicle runs into him. The same applies for an interior component, for example, a dashboard. Zones of various stiffnesses can also be formed thereon in a simple manner.

(48) Finally, it is to be noted that the parts of the figures are possibly not illustrated to scale and that the individual variants illustrated in the figures can also form the subject matter of an independent invention. Location specifications such as right, left, top, bottom, and the like relate to the illustrated location of the respective component and are to be mentally adapted accordingly in the event of change of the mentioned location.