Plastic cover

Abstract

A plastic cover (10) with a flat underside (11) extending over at least two adjacent sections (16, 17), wherein the at least two sections (16, 17) are connected to each other via a straight bending region, and wherein a trench-shaped recess (21) is formed along the bending region (20) between the two sections (16, 17), characterized in that at least one rib (22) projecting from the underside (11) is arranged within the trench-shaped recess (21), extending along the bending region (20).

Description

[0001] The invention relates to a plastic cover with a flat underside extending over at least two adjacent sections, wherein the at least two sections are connected to each other via a straight bending area along which a trench-shaped depression is formed.

[0002] In principle, plastic components – both injection molding and 3D printing – can be used to create elements such as covers in almost any shape. For example, angled elements can be printed directly in an angled mold, such as with FDM (Fused Deposition Molding) printing. Similarly, with appropriate mold design, an angled element can also be produced using injection molding.

[0003] However, it can be advantageous to first manufacture the elements as flat as possible and only then bend them into a shape, for example, an angled one. One reason is that flat elements are easier to stack and / or ship than angled elements.

[0004] Another reason for manufacturing the components using injection molding is that flatter, and therefore significantly less expensive, injection molds can be used for flat components. Flatter injection molds also require a smaller opening stroke, which contributes to shorter production cycle times.

[0005] When manufacturing elements using 3D printing, another reason is that in 3D printing, and especially in FDM printing, surfaces printed in different orientations typically exhibit different appearances and textures. This is due to the manufacturing process itself, in which the element is built up layer by layer on a print bed. Surfaces in contact with the print bed have a structure that differs significantly from the structure of vertical or other non-contacting wall surfaces.

[0006] A high-quality appearance can be achieved particularly for surfaces that rest on a roughened print bed. A roughened print bed can be created, for example, using erosion techniques.

[0007] The cover described at the beginning can, for example, be produced with both adjacent sections on the roughened print bed, so that both sections have the same surface structure and thus the same appearance and feel, even though in later use, both surfaces have different orientations after the bending process. The groove-shaped indentation, similar to a foil hinge, allows the bending to occur due to material expansion and also defines a bending line.

[0008] However, a disadvantage is that plastic material often exhibits white fracturing when bent, meaning a color change along the bending edge. Furthermore, plastic material tends to develop rough or torn bending edges when bent with a small radius.

[0009] It is therefore an object of the present invention to create a plastic cover of the type mentioned above which can be bent along the bending line without or with only slight white fracturing and with clean bending edges.

[0010] This problem is solved by a plastic cover with the features of the independent claim. Advantageous embodiments and further developments are the subject of the dependent claims.

[0011] A plastic cover according to the invention of the type mentioned above is characterized in that at least one rib projecting from the underside is arranged within the trench-shaped depression, extending along the bending area.

[0012] Similar to a foil hinge, the indentation reduces the material thickness of the cover in the sections along the bending area, allowing bending without the material breaking.

[0013] When the cover is bent or folded along the bending areas, the at least one rib does not create a single fold for the entire bending angle, but rather at least two folds, along which the material is only folded by a portion of the total bending angle. Along each side of each rib, the material is accordingly folded or bent by a smaller angle, which reduces or ideally completely prevents white breakage.

[0014] In an advantageous embodiment of the cover, the recess has a trapezoidal cross-section and widens in one direction away from the underside. Preferably, the at least one rib is arranged centrally in the recess, with a gap preferably remaining between the at least one rib and the sides of the recess. More preferably, the at least one rib projects to approximately the height of an upper surface of the sections.

[0015] Due to material tolerances, the material will not initially bend perfectly symmetrically along each of the creases, i.e., on each side of the web, during the bending process. Once one side has reached its intended bend, the web on that side, where the material has been bent at a larger angle than on the other side, rests against the edge of the indentation, thus preventing further bending. In this way, a symmetrical chamfer is formed in the bending area.

[0016] In a further advantageous embodiment of the cover, the at least one web extends over the entire length of the bending area. This results in a clean bend over the entire length of the bending area.

[0017] If a web is present in the bending area and, for example, a total bending angle of 90° is desired, the gap is chosen so that a bending angle of 45° is possible on each side of the web. In the bent state, this results in a chamfer with two 45° kinks instead of a single 90° kink. Alternatively, it is also possible to arrange at least two webs in the trench-shaped recess, spaced apart and running parallel to each other. Here, too, the webs' contact with the edge of the recess or with each other leads to a uniform distribution of the bending angle across the various kinks, thus forming an edge with multiple facets. With a greater number of webs, the chamfer transitions into a rounded shape. The webs can have different heights, so that contact between the webs occurs at both desired bending angles along the kinks.When three bridges are used in the trench-shaped depression, preferably one of the middle bridges protrudes less high than the two outer bridges.

[0018] The cover is advantageously manufactured using 3D printing, particularly FDM printing, which is cost-effective even for larger dimensions and small production runs. Preferably, the cover is printed with its underside resting on a print bed. This ensures that the visible surfaces of the folded sections have a uniform appearance, shaped by the print bed. In particular, the cover can be printed on a textured print bed, such as a metallic print bed with an erosion texture. The erosion texture transferred from the print bed to the underside of the cover prevents it from looking like a typical FDM-printed component on its visible surfaces, giving it a more premium appearance.

[0019] Furthermore, it is advantageous to print the underside in the bending area in a printing direction that runs parallel or perpendicular to the longitudinal extent of the bending area. This is based on the understanding that a fold edge frays less when it is folded either parallel to the material strands laid side by side during printing or perpendicular to them.

[0020] As an alternative to 3D printing, the cover can also be manufactured using an injection molding process.

[0021] In a further advantageous embodiment of the cover, two bending areas are provided that run parallel to each other and are spaced apart. This creates three sections: a central section and two outer sections, the outer sections of which can be bent relative to the central section. The cover is thus well suited for cladding angles, particularly angles for joining profile bars.

[0022] In a further advantageous embodiment of the cover, four bending areas are provided, running parallel to each other in pairs and spaced apart in pairs. This creates five sections: a central section and four outer sections, the outer sections of which can be bent relative to the central section. After bending, the cover forms a cap, which can be used, for example, to cover the ends of profile bars.

[0023] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying figures. The figures show: Fig. 1 a spatial view of an arrangement of profile bars with two plastic covers according to the invention; Fig. 2a - 2c different views of the cover Fig. 1; Fig. 3 a side view of the cover Fig. 1 including a close-up; Fig. 4a - 4c Sectional views of bending areas of various covers; and Fig. 5a - 5c Side views of various covers after bending.

[0024] In all figures, identical reference symbols denote identical or equivalent elements or features. For the sake of clarity, not every element in every figure is marked with a reference symbol. Relative terms used in the text, such as "left," "right," "above," and "below," refer to their respective representations in the figures unless explicitly stated otherwise.

[0025] Fig. Figure 1 shows a spatial representation of an arrangement of profile bars 1 connected to each other by angles 2. Such profile bars 1 are frequently used as flexible structural elements for frames, machine housings, or even as parts of the machines themselves. In the example shown, the upward-projecting profile bar 1 is connected to the lower profile bar 1 by means of two angles 2.

[0026] For optical reasons and / or to reduce the risk of injury at the edges of angle 2, in the example of the Fig. One of the two inserted angle brackets 2 is covered with a cover 10. Holes are provided in the angle bracket 2 for fastening, into which expansion rivets 3 can be inserted to fix the cover 10 to the angle bracket 2. Another cover 10, in the form of a cap, is located on the upper end of the vertical profile bar 1.

[0027] The covers 10 in the example shown are manufactured using 3D printing, in particular FDM printing, or can alternatively be manufactured using injection molding.

[0028] The cover used to cover angle 2 is in the Fig. 2a to 2c and 3 are shown in different views. The special feature of cover 10 is that it is printed as an essentially flat element and is folded before use as cover 10 to accommodate the in Fig. To obtain the form shown in point 1.

[0029] In the Fig. Figures 2a to 2c and 3 show the cover 10 in its state after the printing process and before folding or bending, and thus as an essentially flat element.

[0030] Fig. Figure 2a shows the cover with a view of its underside 11, whereby this underside 11 faces downwards during the manufacture of the cover 10, i.e., rests on a print bed of the 3D printer used. Further details are shown in the Fig. 2a Two fastening holes 12 can be seen, through which the expansion rivets 3 are inserted when the cover 10 is mounted.

[0031] Fig. 2b shows a similar perspective to Fig. 2a the cover 10 from its upper side 13. Unlike the flat underside 11, the upper side 13 has recesses 14 and also a raised stiffener 15, which provide stability while simultaneously saving material. With the cover 10 mounted according to Fig. Only the underside 11, which forms the outside of the cover 10, is visible. The more textured printed top side 13 faces angle 2 and is not visible.

[0032] In the Fig. 2b shows sections 16, 17 which are to be bent or folded relative to each other, specifically a middle rectangular section 16 and two outer triangular sections 17. Before the cover 10 is mounted, the outer sections 17 are bent upwards relative to the middle section 16, so that the undersides 13 of the outer sections 17 face each other. Fig. 2c shows in a similar way to Fig. 2b the cover 10 before the outer sections 17 are bent upwards again from a different angle, specifically in the top view.

[0033] At the also in Fig. The cover 10 shown for the end of the profile bar 1 has a rectangular middle and central section and four outer sections, which are also rectangular in this case. There are four bending areas, of which two are parallel and spaced apart from each other.

[0034] The material of the cover 10 is bent into bending areas 20, which are formed in a straight line between sections 16, 17 and whose structure is described in more detail below.

[0035] Fig. Figure 3 shows the cover 10 in a side view, with one of the bending areas 20 in the lower part of the Fig. 3 is shown enlarged.

[0036] The bending area 20 has a trench-shaped recess 21 that extends along the entire bending area 20 and allows sections 16 and 17 to bend relative to each other. Similar to a foil hinge, the recess 21 reduces the material thickness of the cover 10 in sections 16 and 17 along the bending area 21 to such an extent that bending is possible without the material breaking.

[0037] The recess 21 has a trapezoidal cross-section, with the inclined sides of the recess 21 forming an angle of approximately 45°. A rib 22, projecting upwards (i.e., perpendicularly from the bottom of the recess 21), is arranged centrally within the recess 21 and stabilizes the bottom of the recess 21. The rib extends approximately to the top surface 13 of sections 16 and 17.

[0038] When the outer section 17 is bent upwards relative to the middle section 16, the web 22 does not form a single kink for the entire bending angle, for example 90°, but instead two kinks, along which the material is each bent by half the bending angle, i.e., by 45°. The two kinks form to the left and right of the web 22 in the area of ​​the bottom of the recess 21. Because the material of the cover 10 is only bent by half the bending angle along the kinks, white breakage is reduced or, ideally, completely prevented.

[0039] In the Fig. 4a to 4c are similar in cross-section to those in the Fig. Three different possible configurations of bending areas 20 of covers 10 are shown schematically. The one in Fig. The bending range shown in 4a corresponds to that in Fig. 3 shown, whereas the one in Fig. The bending area 20 shown in 4b has a wider recess 21 with a wider web 22. In the example of the Fig. In 4c, the recess 21 is made even wider and several, specifically three, webs 22 are arranged symmetrically in the center of the recess 21, with the two outer webs 22 having a similar height to those in the embodiments of Fig. 3 and Fig. 4a and Fig. 4b, whereas the middle one has a lower height.

[0040] In the Fig. 5a to 5c correspond to the Fig. 4a to 4c show the corresponding arrangement after bending sections 16 and 17 at an angle of 90° to each other.

[0041] In the Fig. 5a are the two kinks where the material is bent at an angle of 45° and which are related to the Fig. 3 and Fig. As can be seen, these two parallel and spaced-apart kinks form a chamfer in the bending area 20 on the underside 11, the width of which corresponds approximately to the width of the depression 21 at its bottom.

[0042] Due to material tolerances, the material will not initially bend perfectly symmetrically along each of the bends during the bending process. However, if the intended bend of approximately half the bending angle has already been reached at a bend, the web 22 on that side rests against the edge of the recess 21, thus preventing further bending along this bend. As a result, a symmetrical chamfer is formed in the bending area 20.

[0043] The one in Fig. 5a The remaining part of the recess 21 not filled by the web 22 in the final state makes it possible to bend sections 16, 17 to each other by slightly more than the required bending angle of 90°, which allows plastic deformation to the desired bending angle, i.e. 90°, even after elastic re-bending of the material.

[0044] Fig. Figure 5b shows that, due to the wider web 22, the resulting chamfer is also wider than in the embodiment of the Fig. 5a.

[0045] For example, the Fig. Finally, in section 5c, not just two kinks are formed along which the bending angle is divided, but four kinks, creating the appearance of a curve. Here, too, the contact of the webs 22 with each other or with the edge of the recess 21 leads to an even distribution of the bending angle across the various kinks and thus to the formation of the most uniform curve possible. The different lengths of the webs 22 relative to each other are dimensioned such that the webs 22 contact each other along the kinks at the desired bending angles.

[0046] The number of bridges is 22 in the examples of the Fig. 4a, b or 5a, b and of three bridges 22 in the examples of the Fig. 4c and Fig. 5c is not to be understood as restrictive. It is also possible to provide two webs 22 or more than three webs 22, depending on the desired shape of the bending area 20 after bending. Reference symbol list 1 profile bar 2 angle brackets 3 expansion rivets 10 Cover 11. Bottom 12 mounting holes 13 Top 14 In-depth study 15 Stiffening Sections 16 and 17 20 bending range 21 In-depth study 22 Bridge

Claims

[1] Cover (10) made of plastic with a flat underside (11) extending over at least two adjacent sections (16, 17), wherein the at least two sections (16, 17) are connected to each other via a straight bending area, and wherein a trench-shaped depression (21) is formed along the bending area (20) between the two sections (16, 17), characterized by , that within the trench-shaped depression (21) at least one rib (22) extending from the underside (11) is arranged, which extends along the bending area (20) [2] Cover (10) according to claim 1, wherein the recess (21) has a trapezoidal cross-section and widens in one direction away from the underside (11). [3] Cover (10) according to claim 1 or 2, wherein the at least one web (22) is arranged centrally in the recess (21). [4] Cover (10) according to one of claims 1 to 3, wherein a gap remains between the at least one web (22) and sides of the recess (21). [5] Cover (10) according to one of claims 1 to 4, wherein the at least one web (22) extends over the entire length of the bending area (20). [6] Cover (10) according to claim 5, wherein the at least one web (22) extends approximately to the height of a top surface (13) of the sections (16, 17). [7] Cover (10) according to one of claims 1 to 6, wherein at least two webs (22) are arranged in the trench-shaped depression (21), which are spaced apart from each other and run parallel to each other at a distance from each other. [8] Cover (10) according to claim 7, wherein three ribs (22) are arranged in the trench-shaped depression (21), wherein a middle rib (22) is less high than the outer ribs (22). [9] Cover (10) according to any one of claims 1 to 8, manufactured by an injection molding process. [10] Cover (10) according to any one of claims 1 to 8, manufactured using a 3D printing process. [11] Cover (10) according to claim 10, manufactured by FDM printing. [12] Cover (10) according to claim 11, printed with its underside (11) resting on a print bed. [13] Cover (10) according to claim 12, printed with its underside (11) resting on a structured printing bed. [14] Cover (10) according to one of claims 11 to 13, wherein in the bending area (20) the underside (11) is printed in a printing direction that runs parallel or perpendicular to the longitudinal extent of the bending area (20). [15] Cover (10) according to one of claims 1 to 14, comprising two bending areas (20) which run parallel to each other and are spaced apart from each other. [16] Cover (10) according to any one of claims 1 to 14, comprising four bending areas (20) which run parallel to each other in pairs and are spaced apart from each other in pairs.

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