Flat plastic molded part, in particular an internal air guide part for a motor vehicle, with devices for quick, one-sided and positionally accurate fastening

Abstract

Plastic molded part (1) with - a molded body (2) extending predominantly along a main surface and made of dimensionally stable plastic and - a connecting surface (5) formed on the molded body (2), from which a fastening element (6) formed integrally with the molded body (2) from the plastic projects in order to fasten the plastic molded part (1) to a counterpart (11), characterized in that - that a recess and / or opening (14) is provided in the connection surface (5) adjacent to the fastening element (6), - wherein the recess and / or opening (14) is bridged by an adapting element (10), - which is formed from an elastomer material bonded to the molded body (2) and - which projects above the depression and / or opening (14) relative to the connecting surface (5) adjacent to the depression and / or opening (14).

Description

TECHNICAL AREA OF INVENTION

[0001] The invention relates to a plastic molded part comprising a molded body made of dimensionally stable plastic, extending predominantly along a main surface, and a connecting surface formed on the molded body. A fastening element, integrally formed with the plastic molded body, projects from this connecting surface to attach the plastic molded part to a counterpart. In particular, the plastic molded part is an internal air guide for a motor vehicle. Such an air guide serves, for example, to direct air into a heat exchanger located in the engine compartment of the motor vehicle and / or to seal the engine compartment at the bottom with smooth surfaces that allow the airflow to flow over them with minimal resistance. STATE OF THE ART

[0002] Common air guide components, including their mounting elements, are injection-molded from dimensionally stable plastic. Each mounting element incorporates an elastically compressible detent that engages behind a retaining edge of a mating part. When the air guide component is attached to the mating part, its mounting elements enter enclosed mounting openings in the mating part. The detent is elastically compressed until it engages behind the retaining edges formed by the rear edges of the mounting openings. This secures the air guide component to the mating part. However, this connection is only play-free if, firstly, there is a positive fit between the air guide component and the mating part on all sides, and secondly, the mounting elements securely hold the air guide component in this positive fit.The former requires tighter manufacturing tolerances for both the air guide and its counterpart, while the latter is particularly difficult if the air guide is essentially horizontally oriented and only attached to the counterpart on one side, resulting in a high tilting moment around the fasteners. If this tilting moment causes the free end of the air guide to sag, it can not only create an unfavorable visual impression but also lead to an undesirable increase in flow resistance, which in extreme cases can result in the air guide breaking off.

[0003] Furthermore, air guide components are often installed in confined spaces within a vehicle's engine compartment. To ensure trouble-free installation, the fasteners must be inserted into the mounting holes as easily as possible, which requires a certain amount of play. However, this play prevents a snug, form-fitting connection between the air guide component and its counterpart.

[0004] Omega clips have proven to be generally suitable and reliably manufacturable fastening elements for air duct components. However, before the locking pawls of such omega clips engage, i.e., during the joining of the respective air duct component with its counterpart, omega clips are sensitive to lateral forces and break relatively easily.

[0005] To achieve a secure fit of an air guide element to a counterpart, it is known to form projecting ribs on the air guide element adjacent to the fastening elements, allowing the air guide element to bear against the counterpart along a line. The elasticity of both the air guide element and the counterpart between the ribs can then be used to apply a tensile preload to the fastening of the air guide element to the counterpart via the fastening elements. This preload holds the air guide element in position relative to the counterpart, ensuring it remains oriented correctly even under the influence of its own mass. However, this preload can only be applied to a limited extent if the air guide element is simply pushed together with the counterpart.In order to apply a higher preload, the respective fastening element must be pressed into the corresponding fastening opening in a complex manner, i.e. between the adjacent ribs, against the building-up preload force.

[0006] A fastening device for attaching to plates is known from WO 02 / 029 259 A1. The fastening device comprises two molded parts made of dimensionally stable plastic. Both molded parts have contact surfaces. The contact surfaces of the two molded parts are designed to abut opposite sides of the respective plate. Two elastically deformable fingers project from the contact surface of one molded part, leaving a slot between them. These fingers can be pressed into a guide in the other molded part, causing the fingers to move towards each other and for complementary teeth on the fingers and the guide to engage. Various locking positions are possible, allowing the distance between the contact surfaces on the two molded parts to be adjusted to the thickness of the respective plate. TASK OF INVENTION

[0007] The invention is based on the objective of demonstrating a plastic molded part, particularly suitable as an internal air guide for a motor vehicle, which eliminates the problems described above in the one-sided attachment of known air guides without exceeding the tight cost framework for an air guide for a motor vehicle. SOLUTION

[0008] The object of the invention is achieved by a plastic molded part with the features of independent claim 1. Dependent claims 2 to 12 are directed to preferred embodiments of the plastic molded part according to the invention. Claims 13 and 14 relate to devices with preferred embodiments of the plastic molded part according to the invention and a counterpart. Claim 15 relates to a motor vehicle with a device according to the invention. DESCRIPTION OF THE INVENTION

[0009] A plastic molded part according to the invention comprises a molded body made of dimensionally stable plastic, extending predominantly along a main surface. The main surface along which the molded body predominantly extends need not be a plane. In fact, it will often not be a plane. Rather, the main surface can be curved or angled in one or more directions, or may have offsets. The fact that the molded body extends predominantly along the main surface means that it is predominantly two-dimensional, i.e., planar. However, the molded body can be provided with, for example, stiffening ribs transverse to the main surface to increase its dimensional stability, even in thin-walled versions. The fact that the plastic from which the molded body is formed is described here as dimensionally stable does not preclude the possibility that the plastic is elastically deformable.However, this is also a so-called hard plastic. The molded part made of this hard plastic can transition at its edges into a materially bonded molded part made of a softer plastic or elastomer material, through which the plastic molded part connects to adjacent components with elastic contact.

[0010] The molded plastic part according to the invention has a contact surface on the molded body itself, from which a fastening element, formed integrally with the molded plastic part, projects to attach the molded plastic part to a counterpart. This is not merely a matter of the edges of the molded plastic part elastically contacting adjacent components, but rather of its actual fastening. The fastening element is formed during the injection molding of the molded plastic part, i.e., during the formation of the molded plastic part by injecting the viscous plastic under pressure into a mold cavity of a mold and subsequently curing the plastic by cooling and / or crosslinking.

[0011] To enable quick and accurate positioning of the one-sided fastening of the plastic molded part according to the invention, even in the presence of manufacturing tolerances, a recess and / or opening is provided in the connection surface adjacent to the fastening element, and this recess and / or opening is bridged by an adapting element. The adapting element is made of an elastomer material bonded to the molded body and projects above the recess and / or opening relative to the connection surface adjacent to the recess and / or opening. When the plastic molded part according to the invention is joined to its counterpart, the adapting element can deform not only between the connection surface and the corresponding mating surface of the counterpart, but also form itself into the recess and / or opening it bridges.This forming process can be so extensive that the adapting element protrudes only minimally or not at all beyond the adjacent connection surface. In this way, the adapting element can, on the one hand, bridge relatively large manufacturing tolerances, and on the other hand, apply a defined preload force to the fastening via the associated fastener.

[0012] The functionality of the adapting element described above is fundamentally independent of whether it bridges a recess or an opening in the connection surface. However, for the manufacturability of the plastic molded part according to the invention, an opening in the connection surface is often preferred, through which a projection or slide of a molding tool can extend to give the adapting element its bridge shape when it is injection-molded onto the molded body from below. This implies that the adapting element is also preferably injection-molded from the elastomer material, that is, formed by injection under pressure into a mold cavity of a molding tool.

[0013] The adapter element can bridge the respective recess and / or opening in an arc shape, meaning with a wall thickness that remains at least approximately constant, or with a bead projecting towards the adjacent surface, meaning with a wall thickness that increases and reaches its maximum thickness before the recess and / or opening. This allows the elasticity of the adapter element to be adjusted to the specific requirements within a wide range.

[0014] In the plastic molded part according to the invention, the recess and / or opening adjacent to the fastening element can be elongated along a line that runs parallel to the connecting surface adjacent to the recess and / or opening. The line along which the recess and / or opening is elongated need not be straight, but can be curved. One possible shape is therefore a ring around the respective fastening element. However, such a ring cannot easily be formed solely by an opening in the connecting surface of the essentially two-dimensional plastic molded part, because then the support for the fastening element on the rest of the plastic molded part would be lost. With a recess in the connecting surface, however, this is not a problem. Likewise, a ring around the fastening element that is only partially formed as an opening in the connecting surface is possible.

[0015] The adapting element bridges the depression and / or opening preferably transversely to the respective line along which the depression and / or opening is elongated.

[0016] Specifically, two recesses and / or openings, bridged by two adapting elements, can be provided in the connection surface adjacent to the fastening element of the plastic molded part according to the invention. The recesses and / or openings are arranged on opposite sides of the fastening element and are elongated lines running parallel to each other. These lines can, in particular, run transversely to a principal direction of extension of the connection surface, but can also run along this principal direction of extension.

[0017] In the plastic molded part according to the invention, each recess and / or opening bridged by an adapting element can be closed at the edge, i.e., it can end in the connection surface or at least not protrude from the connection surface. Accordingly, the respective adapting element can be connected to the molded body over the entire edge of the respective recess and / or opening.

[0018] The fastening element of the plastic molded part according to the invention can be designed with an elastically compressible detent for engaging behind a retaining edge of the counterpart. This detent can, in particular, be provided with a guide surface over which the retaining edge automatically presses the detent in when the plastic molded part is joined with the counterpart, before the detent then engages behind the retaining edge of the fastening element once it is joined with the counterpart. Specifically, the fastening element can be a so-called omega clip.

[0019] The connecting surface of the plastic molded part according to the invention can be angled relative to the remainder of the main surface of the plastic molded part. In this way, the connecting surface can project at a right angle from the remainder of the main surface. The fastening element projecting from the connecting surface thus runs at least approximately parallel to the remainder of the main surface.

[0020] The plastic molded part according to the invention typically has more than one fastening element. Rather, in addition to the fastening element, at least one further fastening element, formed integrally with the plastic molded part, typically projects from the connection surface, with an adjacent further recess and / or opening bridged by a further adapting element. The number of fastening elements will depend on the absolute length of the connection surface along its main direction of extension.

[0021] In the plastic molded part according to the invention, in addition to the fastening element or elements, a support element formed integrally with the molded plastic body can project from the connection surface. This support element has a lower support surface on its underside near the connection surface for support against a first abutment of the counterpart, and an upper support surface on its upper side near its free end for support against a second abutment of the counterpart. The support element serves to counteract a tilting moment around the fastening element or elements caused by the mass of the plastic molded part itself. The support surfaces on the support element are arranged such that the tilting moment is counteracted with a certain lever arm.

[0022] It is understood that, in addition to the single support element, at least one further support element, formed integrally with the plastic body and featuring lower and upper support surfaces, may project from the support surface. Depending on the extent of the connection surface and the tipping moment to be supported, even more such support elements may be provided.

[0023] In a device according to the invention, comprising a molded plastic part and a counterpart to which the molded plastic part is attached by means of the fastening element, the contact surface of the molded plastic part faces a counter surface of the counterpart. The fastening element engages in a closed-edge fastening opening of the counterpart, the rear edge of which forms the retaining edge behind which the latch engages. The adapting element adjacent to the fastening element rests against the counter surface with elastic preload and is at least partially molded into the recess and / or opening in the contact surface, which it bridges before the molded plastic part is joined to the counterpart.

[0024] Preferably, in the device according to the invention, the additional support element of the molded plastic part according to the invention engages with clearance in a first closed-edge support opening in the mating surface of the counterpart, the lower edge of which forms the first abutment of the counterpart. Beyond the first closed-edge support opening, the support element also engages with clearance in a second closed-edge support opening of the counterpart, the upper edge of which forms the second abutment of the counterpart, or the support element crosses a transverse rib of the counterpart, which forms the second abutment of the counterpart. Although the support element can be easily inserted into the closed-edge support openings or guided over the transverse rib due to the clearance, the support element subsequently ensures positional stabilization of the molded plastic part against the tilting moment caused by its own mass.

[0025] In a motor vehicle according to the invention with a device according to the invention, the plastic molded part is an internal air guide element, the connection surface of which optionally runs transversely to a longitudinal axis of the motor vehicle. In this way, the air guide element can easily deflect relative to its counterpart in the event of a crash by deformation and / or buckling.

[0026] Advantageous further developments of the invention result from the patent claims, the description and the drawings.

[0027] The advantages of features and combinations of features mentioned in the description are merely exemplary and can have an effect alternatively or cumulatively, without the advantages necessarily having to be achieved by embodiments according to the invention.

[0028] Regarding the disclosure content—not the scope of protection—of the original application documents and the patent, the following applies: Further features can be derived from the drawings—in particular, the geometries depicted and the relative dimensions of several components to one another, as well as their relative arrangement and functional connection. The combination of features from different embodiments of the invention or from features of different claims is also possible, deviating from the chosen cross-references of the claims, and is hereby encouraged. This also applies to features that are illustrated in separate drawings or mentioned in their description. These features can also be combined with features from different claims.Likewise, features listed in the patent claims may be omitted for further embodiments of the invention, but this does not apply to the independent patent claims of the granted patent.

[0029] The features mentioned in the claims and the description are to be understood, with regard to their number, as meaning that exactly that number or a greater number than the stated number is present, without the need for the explicit use of the adverb "at least". Thus, for example, if a latching mechanism is mentioned, this is to be understood as meaning that exactly one latching mechanism, two latching mechanisms, or more latching mechanisms are present. The features listed in the claims may be supplemented by further features or may be the only features that the respective product possesses.

[0030] The reference numerals contained in the patent claims do not constitute a limitation of the scope of the subject matter protected by the patent claims. They serve only the purpose of making the patent claims easier to understand. BRIEF DESCRIPTION OF THE FIGURES

[0031] The invention will now be further explained and described with reference to preferred embodiments shown in the figures. Fig. Figure 1 is a perspective view of a plastic molded part according to the invention, which is mounted on a counterpart. Fig. Figure 2 shows a detail of the plastic molded part according to Fig. 1 from a different perspective. Fig. Figure 3 shows a section through the detail according to Fig. 2 with the plastic molded part mounted on the counterpart. Fig. Figure 4 shows a further detail of the plastic molded part mounted on the counterpart according to Fig. 1 from yet another perspective. Fig. 5 is perpendicular to the section according to Fig. 3. Section through the detail of the assembled plastic molded part according to Fig. 4. Fig. 6 is another section through the detail according to Fig. 4 and Fig. 5 along a in Fig. 5 drawn section line VI-VI and Fig. 7 is another section through the detail according to Fig. 4 to 6 along a Fig. 5 section line VII-VII shown. FIGURE DESCRIPTION

[0032] The in Fig. The plastic molded part 1 shown in Figure 1 has a molded body 2 made of a substantially dimensionally stable plastic. A further molded body 3 made of a less dimensionally stable plastic is bonded to the molded body 2. Specifically, the molded body 2 is injection-molded from the dimensionally stable plastic, and the molded body 3 is injection-molded from an elastomer material, possibly using so-called 2K technology. The plastic molded part 1 is generally planar, meaning it extends essentially two-dimensionally, albeit along a curved and angled main surface. A connection surface 5 is formed on the molded body 2 as part of the main surface and angled relative to the rest of it.From the connection surface 5, two fastening elements 6, formed integrally with the molded body 2 made of the dimensionally stable plastic 3, protrude in the form of so-called omega clips 7, and between the fastening elements 6, a support element 16, also formed integrally with the molded body 2 made of the dimensionally stable plastic 3, extends. The fastening elements and the support element engage in fastening openings 13 and support openings 17 and 18 in an edge region 4 of a counterpart 11.

[0033] The plastic molded part 1 can in particular be an internal air guide part for a motor vehicle, which, for example, directs air into a heat exchanger and is attached with its molded body 2 to an air guide frame 25 of the heat exchanger as counterpart 11, while it elastically rests against other components of the motor vehicle with its further molded body 3.

[0034] One of the Omega Clips 7 is detailed according to Fig. Figure 2 shows an enlarged perspective view from below. The Omega clip 7 has a detent 8 that can be elastically pressed in. A guide surface 9 is formed on the Omega clip 7 to automatically depress the detent 8 when the fastening element 6 is inserted into a fastening opening of a counterpart to the plastic molded part 1. Rib-shaped adaptation elements 10 extend over the connection surface 5 on both sides of the Omega clip 7. The adaptation elements 10 are made of an elastomer material that is bonded to the plastic of the molded part 2, in particular by injection molding onto the molded part 2.

[0035] The cut according to Fig. Figure 3 shows how the locking pawl 8 of the omega clip 7 engages behind a retaining edge 12 when the plastic molded part 1 is attached to its counterpart 11, after the fastening element 6 has been inserted into the fastening opening 13 of the counterpart 11. The adapting elements 10 on both sides of the fastening element 6 bear against a mating surface 23 of the counterpart 11 and exert an elastic preload between the plastic molded part 1 and the counterpart 11, which acts on the fastening of the plastic molded part 1 to the counterpart 11 and secures this fastening. To apply the elastic preload, the adapting elements 10 are not only made of elastomer material and are therefore elastically deformable, but they also bridge openings 14 in the connection surface 5 and can elastically deflect into these openings 14 when the plastic molded part 1 is joined with the counterpart 11.The openings 14 in the connection surface 5 are elongated along lines 24 running straight from here and perpendicular to a main extension direction of the connection surface 5, see . Fig. 2, and end within the connection surface 5, thus being edge-closed. In the embodiment according to Fig. 3. The adapting elements 10 bridge the openings 14 with a bead 15 made of the elastomeric material, so that they have their maximum wall thickness above the respective opening 14. On both sides of the opening 14, the adapting elements 10 made of the elastomeric material are bonded to the connecting surface 5.

[0036] The detail according to Fig. Figure 4 shows a perspective view of the support element 16, which projects additionally from the support surface 5 and engages in the two consecutive support openings 17 and 18 of the counterpart 11. The function of this support element 16 is explained in the Fig. 5 to 7.

[0037] Fig. Figure 5 shows how, with the plastic molded part 1 attached to the counterpart 11, the support element 16 projects with play through the two closed support openings 17 and 18. The connecting opening 17 formed in the counter surface 23, with its lower edge, forms a first abutment 19 for a lower support surface 20 of the support element 19, and the second support opening 18, located at a distance behind the counter surface 23, with its upper edge, forms a second abutment 21 for an upper support surface 22 of the support element 16. The contact of the support element 16 with its support surfaces 20 and 22 against the abutments 19 and 21, as well as the engagement of the fastening element 16 with play in the support openings 17 and 18, is particularly evident in the sections according to the figures. Fig. 6 and Fig. 7. The support element 16, with a lever arm defined by the distance between the abutments 19 and 21, counteracts a tilting moment that, due to the mass of the plastic molded part 1 itself, acts on its attachment to the counterpart 11 and that is particularly significant when the plastic molded part 1 is oriented substantially horizontally, as in Fig. As shown in section 5, it can reach a considerable scale. REFERENCE MARK LIST 1 plastic molded part 2 molded bodies 3 molded bodies 4 Edge area 5 Connection area 6 Fastening element 7 Omega clip 8 latching pawls 9 Guide surface 10 Adjustment element 11 counterpart 12 Holding edge 13 Mounting opening 14 Opening 15 bulge 16 support element 17 Support opening 18 Support opening 19 abutments 20 support surface 21 abutments 22 Support surface 23 Opposite surface Line 24 25 air guide frames

Claims

[1] Plastic molded part (1) with - a molded body (2) extending predominantly along a main surface and made of dimensionally stable plastic and - a connecting surface (5) formed on the molded body (2), from which a fastening element (6) formed integrally with the molded body (2) from the plastic protrudes in order to fasten the plastic molded part (1) to a counterpart (11), characterized by , - that a recess and / or opening (14) is provided in the connection surface (5) adjacent to the fastening element (6), - wherein the recess and / or opening (14) is bridged by an adapting element (10), - which is formed from an elastomer material bonded to the molded body (2) and - which projects above the depression and / or opening (14) relative to the connecting surface (5) adjacent to the depression and / or opening (14). [2] Plastic molded part (1) according to claim 1, characterized by , that the adapting element (10) bridges the recess and / or opening (14) in an arc shape or with a bead (15) projecting towards the connecting surface (5) adjacent to the recess and / or opening (14). [3] Plastic molded part (1) according to claim 1 or 2, characterized by , that the depression and / or opening (14) is elongated along a line (24) that runs parallel to the connecting surface (5) adjacent to the depression and / or opening (14). [4] Plastic molded part (1) according to claim 3, characterized by , that the adjusting element (10) bridges the depression and / or opening (14) perpendicular to the line (24). [5] Plastic molded part (1) according to claim 3 or 4, characterized by, that adjacent to the fastening element (6) two recesses and / or openings (14) bridged by two adapting elements (10) are provided in the connection surface (5), wherein the recesses and / or openings (14) are arranged on opposite sides of the fastening element (6) and are elongated along parallel lines (24). [6] Plastic molded part (1) according to claim 5, characterized by , that the lines (24) run perpendicular to a main extension direction of the connecting surface (5). [7] Plastic molded part (1) according to any of the preceding claims, characterized by that the or each depression and / or opening (14) is closed at the edge. [8] Plastic molded part (1) according to any one of the preceding claims, characterized by , that the fastening element (6) has an elastically compressible detent latch (8) for engaging behind a retaining edge (12) of the counterpart (11). [9] Plastic molded part (1) according to any of the preceding claims, characterized by , that the connecting surface (5) is angled relative to the remainder of the main surface. [10] Plastic molded part (1) according to any of the preceding claims, characterized by , that in addition to the fastening element (6) at least one further fastening element (6) formed in one piece with the molded body (2) made of plastic with an adjacent further recess and / or opening (14) bridged by a further adapting element (10) protrudes from the connection surface (5). [11] Plastic molded part (1) according to any of the preceding claims, characterized by, that in addition to the fastening element (6) a support element (16) formed in one piece with the molded body (2) made of plastic projects from the connection surface (5), wherein the support element (16) is formed on its underside near the connection surface (5) with a lower support surface (20) for support against a first abutment (19) of the counterpart (11) and on its upper side near its free end with an upper support surface (22) for support against a second abutment (21) of the counterpart (11). [12] Plastic molded part (1) according to claim 11, characterized by , that in addition to the support element (16) at least one further support element (16) formed in one piece with the molded body (2) made of plastic, with lower and upper support surfaces (20, 22) protrudes from the connection surface (5). [13] Device with - a plastic molded part (1) according to claim 8 or one of claims 9 to 12, insofar as directly or indirectly related to claim 8, and - a counterpart (11) to which the plastic molded part (1) is attached with the fastening element (6), - wherein the connecting surface (5) of the plastic molded part (1) is opposite a counter surface (23) of the counterpart (11), - wherein the fastening element (6) engages in a closed fastening opening (13) of the counterpart (11), the rear edge of which forms the retaining edge (12), and - wherein the adjusting element (10) adjacent to the fastening element (6) rests against the opposite surface (23) with elastic preload. [14] Device according to claim 13, insofar as directly or indirectly related to claim 11, characterized by , - that the support element (16) engages with clearance in a first edge-closed support opening (17) in the opposite surface of the counterpart (11), the lower edge of which forms the first abutment (19) of the counterpart (11), and - that the support element beyond the first edge-closed support opening (17) - also engages with play in a second edge-closed support opening (18) of the counterpart (11), the upper edge of which forms the second abutment (22) of the counterpart (11), or - a transverse rib of the counterpart (11) crosses, which forms the second abutment (22) of the counterpart (11). [15] Motor vehicle with a device according to claim 13 or 14, wherein the plastic molded part (1) is an internal air guide part, the connection surface (5) of which optionally extends transversely to a longitudinal axis of the motor vehicle.

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