Device for insertion into a component opening of an automobile

Abstract

Device for insertion into an opening (26) of a component (28) of an automobile, comprising a shaft body (12) and a circumferential first flange (14) arranged at one end of the shaft body (12), and at least one annularly circumferential second flange (16) provided on the shaft body (12), wherein the device (10) can be inserted into the opening (26) in the axial direction of the shaft body (12) such that the shaft body (12) projects through the opening (26) and the first flange (14) bears against a first component surface and the device (10) is attached to the opening (26) by the second flange (16) engaging a second component surface of the component (28) opposite the first component surface, wherein an annularly circumferential cavity (32) is defined at least between an outer surface (30) of the shaft body (12), an inner surface of the first flange (14) and the first component surface.further comprising a hot-melt adhesive material (24) applied circumferentially to the first and second flanges (14, 16), which, when heated, adheres the flanges (14, 16) to the first and second component surfaces in a sealing manner and tightly closes the cavity (32), characterized in that the hot-melt adhesive material (24) is an expanding hot-melt adhesive material (24) which, when the component (28) cools after painting, expands into the cooling cavity (32) and automatically compensates for any pressure change in the cavity (32) through this expansion.

Description

[0001] The invention relates to a device for insertion into an opening of a component of an automobile according to the preamble of claim 1.

[0002] For example, automobile bodies or body parts are immersed in suitable baths for treatment and painting. Openings are provided in the body panels to allow the fluid to penetrate cavities and drain out of them again. Primarily for corrosion protection reasons, these openings must then be sealed. To seal such openings, plugs are known. These are usually made of plastic and are installed by hand by simply pressing them into the openings. Such plugs have at least one flange that rests against one side of the body panel, as well as fastening means that engage behind the other side of the panel and thus secure the device. A plug of this type is known, for example, from DE 101 48 493 B4.

[0003] To prevent the ingress of air and / or water, sealing means, such as hot melt adhesive, are provided between the flange and the sheet metal. For assembly, such sealing plugs are inserted into the opening of, for example, a freshly painted body part and the body part is then placed in an oven to cure the paint. The sealing plug heats up along with the body part and the hot melt adhesive melts, ensuring that the plug is tightly bonded to the opening. When the device is inserted into the opening, a cavity is defined by the inner surfaces of the sealing plug, including any seals, and the sheet metal, which is sealed by the hot melt adhesive. The volume of the cavity is fixed by the geometry of the plug.If a body component fitted with such a sealing plug is removed from the oven after the paint has cured, the gas trapped in the cavity cools down along with the body component. The gas in the cavity may cool down more slowly than the air surrounding the device. Due to the temperature change in the cavity, the pressure in the cavity also decreases. This creates a vacuum, which can lead to bubbles or channels forming in the still-soft sealing material, through which air is drawn into the cavity. This can impair the sealing effect, allowing air and / or water to subsequently penetrate the cavity and cause corrosion problems.

[0004] To solve this problem, DE 10 2006 007 914 B4 proposes a pressure compensation chamber that is connected to the cavity and compensates for temperature-related pressure changes within the cavity by changing the volume of the pressure compensation chamber. In particular, when the plug cools, gas from the pressure compensation chamber enters the cavity, thus compensating for the pressure change. However, this solution is relatively complex in design and thus results in considerable costs.

[0005] Further information on similar and other plugs can be found in US 4 588 104 A, DE 696 00 896 T2, DE 31 00 498 A1 and US 2008 / 0226412 A1.

[0006] Based on the prior art explained above, the object of the invention is to provide a device of the type mentioned at the outset with which reliable sealing and thus safe corrosion protection can be achieved at all times in a structurally simple and thus cost-effective manner.

[0007] This object is achieved according to the invention by the subject matter of claim 1. Advantageous embodiments can be found in the dependent claims, the description and the figures.

[0008] For a device of the type mentioned above, the invention achieves this objective in that the hot-melt adhesive material is an expanding hot-melt adhesive material that compensates for a pressure change in the cavity caused by changing temperature by partially expanding into the cavity. The hot-melt adhesive used according to the invention is thus a combined adhesive and expansion material that has both an adhesive effect and expands when heated. This expanding hot-melt adhesive is applied in particular to an inner side of the flange, which faces the component surface defining the opening, e.g., the top side of the sheet metal. The cavity is sealed off from the environment, and its volume is predetermined by the geometry of the device and the component.The invention is based on the finding that when using an expanding hot-melt adhesive, a pressure change resulting from cooling of the cavity contained in the gas can be compensated for by the penetration of the expanding hot-melt adhesive material, which is still flowable at that time, into the cavity. In particular, the hot-melt adhesive occupies just such a volume of the cavity, which is cooling, for example after heating to cure a vehicle paint, that the pressure in the cooled cavity is again the same as in the area surrounding the device. This process occurs automatically due to the automatic adjustment of the pressure in the cavity to the ambient pressure. Failure of the seal provided by the hot-melt adhesive material due to the pressure change and the associated risk of corrosion in the area of ​​the opening enclosed in the cavity are reliably prevented according to the invention.At the same time, a structurally complex pressure equalization chamber is unnecessary. Due to the expansion properties of the hot-melt adhesive material and the relatively high material density, the device according to the invention is also less sensitive to installation position. Undesired flow of the material and thus impairment of the seal are reliably prevented.

[0009] The component can be a flat component, such as a sheet metal part, for example, a car body panel. The opening can be a body opening, such as those used for the penetration and drainage of liquids in immersion baths for the body. The surfaces bounding the opening can be the top and bottom surfaces of the sheet metal. It should be noted that the annular cavity does not necessarily have to be circular. It could also have an oval or other shape. The only important thing is that the cavity is closed and circumferential.

[0010] According to one embodiment, the hot melt adhesive material can be attached to the flange so as to protrude in the axial direction of the shaft body such that, when the device is inserted into the opening and the hot melt adhesive material is not in expanded state, the flange rests against the first component surface with the hot melt adhesive material. Furthermore, it can then be provided that the hot melt adhesive material is not visible from the outside of the flange in the axial direction of the shaft body and, when heated, expands radially outwards beneath the edge of the flange so that, after expanding in the axial direction of the shaft body, it is visible from the outside of the flange. When heated, the hot melt adhesive expands and, in this embodiment, protrudes in a ring shape from beneath the flange. This is particularly easy to achieve when using expanding hot melt adhesives.This improves the sealing effect in the contact area between the flange and the component surface, thus improving corrosion protection. Furthermore, successful and complete sealing can be easily verified by a visual inspection from the top of the flange. If the hot melt adhesive has oozed out evenly around the entire circumference of the flange in a ring, a proper seal is assured. However, the current state of the art often presents the problem that hot melt adhesive material that has oozed out unevenly and only in certain sections, but in greater quantities, creates the impression of a leak or an inadequate seal, even if the seal may actually be intact.

[0011] The device can be a closure plug for tightly closing the opening, comprising a closed cover connected to the shaft body for closing the opening. The second circumferential flange arranged on the shaft body opposite the first flange can, when the device is inserted into the opening, bear against a second component surface opposite the first component surface, such that the annular circumferential cavity is delimited between the outer surface of the shaft body, inner surfaces of the first and second flanges, and the first and second component surfaces. A hot-melt adhesive material is also applied circumferentially to the second flange, which, when heated, adheres the second flange to the second component surface in a sealing manner.

[0012] According to the invention, the device therefore has two flanges, in particular lips, which clamp the sheet metal from above and below and each seal it completely all the way around. When installed, the cover spans the opening and, in conjunction with the two flanges, seals it securely. Since the second flange also has a hot melt adhesive, this flange is also bonded to the second component surface to form a seal. This improves the sealing effect and further safeguards the function of the device and the corrosion protection. The expanding hot melt adhesive material attached to the second flange can also compensate for pressure changes in the cavity caused by changing temperature by partially expanding into the cavity. The pressure equalization in the cavity then emanates from both flanges.It is faster and more reliable, with only sufficient expansion material needing to be provided on each flange for a part of the cavity.

[0013] To ensure adequate pressure equalization even during the large temperature changes that occur, for example, during the curing of paint on car body panels in ovens, sufficient expanding hot-melt adhesive material must be provided on the flange(s), and this material must expand sufficiently. Depending on the external parameters, particularly the temperature, the material can therefore exhibit an expansion factor, i.e., a volume increase of at least 10%, preferably more than 15%. Such a volume increase can occur, for example, at a temperature of 100°C. A possible material for the hot-melt adhesive is expanding ethylene vinyl acetate (EVA). However, other expanding materials, such as expanding polymers, are also possible.

[0014] According to a further embodiment, the first and / or second flange can be resiliently elastic at least in the axial direction of the shaft body. Furthermore, when the device is inserted into the opening, the first and / or second flange can bulge from the shaft body toward the component surface assigned to them. This improves the pressing forces of the lip-shaped flanges against the component and thus the sealing of the opening. Due to the pressure equalization according to the invention by means of the expansion material, there are no concerns about forming the cavity of a considerable size by correspondingly curving the flanges, thus further optimizing the pressing forces.

[0015] According to an alternative embodiment, the expanding hot-melt adhesive material can be mechanically connected to the first and / or second flange. The mechanical connection can be achieved, for example, via a locking mechanism.

[0016] The device can also be made of a plastic and manufactured in a particularly simple and cost-effective manner using an injection molding process. In a two-component injection molding process, the expanding hot-melt adhesive material can then be molded onto the first and / or second flange.

[0017] According to a further embodiment, the first flange and / or the fastening element or the second flange can have a through-hole. Such a through-hole or such a hole is arranged in particular in a surface of the first flange and / or the fastening element or the second flange, which, or the inside thereof, is provided with the expanding hot-melt adhesive material before assembly of the device. In this way, it is visually recognizable in a simple and reliable manner from the outside of the device before assembly whether the hot-melt adhesive material has been properly applied, for example sprayed, to the respective surface. In this way, it has been recognized according to the invention that in practice the hot-melt adhesive material has been properly and evenly applied or sprayed over the entire desired surface when the hole is closed by the hot-melt adhesive material.However, if part of the hole remains open after the hot melt adhesive has been applied, the hot melt adhesive has been applied incorrectly.

[0018] At the same time, the perforation also provides an indication of whether the device has been properly mounted to the component to form a seal. In particular, the perforation shows whether the hot-melt adhesive material, which expanded during assembly and heating, properly seals the annular cavity and thus the component opening even after the cooling process. During the cooling process, the seal may fail if the expanding hot-melt adhesive material does not adequately compensate for the pressure change in the cavity that occurs during cooling by partially expanding into the cavity. In this case, air is sucked into the annular cavity from outside, and the seal of the component opening is impermissibly interrupted.According to the invention, it has been recognized that if such air is sucked in, it occurs through the through-hole in the first flange and / or the fastening element or second flange, which was sealed before assembly with hot-melt adhesive. In this respect, the through-hole sealed by the hot-melt adhesive represents the weakest link in the device, which compensates for the pressure difference between the cavity and the environment by establishing a connection between the cavity and the environment through the through-hole. This failure of the sealing effect can be visually verified from the outside in a simple and reliable manner after assembly of the device and after the hot-melt adhesive has cooled.

[0019] The through-hole can, in principle, have any cross-sectional shape. For example, it can have a circular cross-section. In a further embodiment, the through-hole can have an oval cross-section. An oval cross-section has been shown to provide particularly reliable defect detection. Thus, incorrect application occurs even if the oval through-hole is filled with hot-melt adhesive with a circular cross-section.

[0020] The invention also relates to a device according to the invention when inserted into the opening of a component of an automobile, in particular a sheet metal part of the automobile, in particular in the expanded state of the hot-melt adhesive. The sheet metal part can be, for example, a body panel. The invention further enables the use of the device according to the invention for insertion into an opening of the component of the automobile or for closing the opening by heating the device when inserted into the opening, so that the expanding hot-melt adhesive material expands in the manner according to the invention and seals the flange(s) to the first or second component surface.

[0021] An embodiment of the invention is explained in more detail below with reference to the figures. They show schematically: Fig. 1 a partial cross-section of a device according to the invention in the unassembled state, Fig. 2 the in Fig. 1 shown partial cross-section in a first operating state, Fig. 3 the in the Fig. 1 and Fig. 2 shown partial cross-section in a second operating state, Fig. 4 a perspective view of the top of the device according to the invention, Fig. 5 a perspective view of the underside of the device according to the invention, Fig. 6 the device according to the invention in the assembled state in a perspective view of the top, Fig. 7 the representation from Fig. 6 in a partially sectioned view, Fig. 8 the device according to the invention in the assembled state in a perspective view of the underside, Fig. 9 the representation from Fig. 8 in a partially sectioned view, and Fig. 10 shows a further partial cross-section of a device according to the invention in the unassembled state.

[0022] Unless otherwise stated, the same reference symbols in the figures refer to the same objects. Fig. 1 shows a cross-section of part of the device 10 according to the invention, which in the example shown is a sealing plug for insertion into an opening in a body panel of a not shown automobile. The rotationally symmetrical device has a cylindrically circumferential shaft body 12 and a lip-shaped first flange 14 which is integrally connected to the shaft body 12 at the upper end thereof and is also circumferential. The flange 14 curves downwards from the upper end of the shaft body 12 and is resiliently elastic in the axial direction of the shaft body 12. In the region of the lower end of the shaft body 12, a second lip-shaped flange 16 is also integrally connected to the shaft body 12 and is located in the Fig. 1, extends obliquely upwards from the shaft body 12. This flange 16 is also resiliently elastic in the axial direction of the shaft body 12. The device 10 furthermore has a pot-like, closed cover 18 integrally connected to the underside of the cylindrical shaft body 12, which is annular in plan view and merges integrally into a central hollow-cylindrical elevation 20, as shown, for example, in Fig. 4. In the view of the device 10 from below in Fig. 5 shows that three stiffening ribs 22 are arranged in the hollow cylindrical elevation 20, offset at an angle of 120° to one another. Both flanges 14, 16 are provided with an expanding, annular hot-melt adhesive material 24 in their radially outer region on their respective inner surfaces. On the inside of the first flange 14, several serrated projections 15 are also formed in an annular manner, which improve the adhesion of the hot-melt adhesive material 24. It can be seen that the hot-melt adhesive material protrudes on both flanges 14, 16 in the axial direction of the shaft body 12.

[0023] In the example shown, the device 10 was manufactured from a plastic using an injection molding process. The hot-melt adhesive material 24 was subsequently molded onto the device 10 using an injection molding process, in particular a two-component injection molding process.

[0024] In Fig. 2, the device 10 is shown in a state inserted into a circular opening 26 of a component 28 such as a body panel. In Fig. 2 shows the state before heating the hot melt adhesive material 24. The device 10 is manually moved in the axial direction of the shaft body 12, in the illustration in Fig. 2 downwards, into the opening 26 of the component 28. The lower flange 16 is initially pressed in the direction of the shaft body 12 and, after passing through the opening 26, moves outwards again away from the shaft body 12 and locks onto the underside of the sheet metal, as shown in Fig. 2. In this state, both the first and second flanges 14, 16 are under pressure relative to their Fig. 1 shown relaxed position, as shown in Fig. 2. As a result, the flanges 14, 16 each exert a compressive force in the direction of the sheet metal side assigned to them. Due to the axial protrusion of the hot-melt adhesive material 24, the flanges 14, 16 in this state rest with the hot-melt adhesive material 24 on the sheet metal side assigned to them, with a distance existing between the edge of the flanges 14, 16 and the sheet metal surface. Furthermore, Fig. 2 that an annular circumferential cavity 32 is delimited by the outer surface 30 of the shaft body 12, the inner surfaces of the flanges 14, 16 or the hot-melt adhesive material 24 as well as the sheet metal surfaces.

[0025] If the component 28 is now heated in an oven together with the device 10 inserted into the opening 26, for example to cure a paint applied to the component 28, the expandable hot-melt adhesive material 24 is softened and expanded. This results in the hot-melt adhesive material 24 and thus the flanges 14, 16 bonding to the respective surface of the component 28. While the hot-melt adhesive material 24 is still flowable, the component 28 is then removed from the oven with the device 10, and cooling occurs, in particular also of the gas enclosed in the cavity 32. This results in a pressure reduction in the cavity 32 and thus a negative pressure compared to the ambient pressure acting in the area around the device 10. Due to this negative pressure, the still flowable hot-melt adhesive material 24 penetrates further into the cavity 32 and thereby takes up part of the original cavity volume, as shown in Fig. 3. The hot-melt adhesive material 24 penetrates into the cavity 32 just far enough to compensate for the pressure loss resulting from the cooling of the gas contained in the cavity 32 due to the reduction in volume, without impairing the sealing effect of the hot-melt adhesive material. Furthermore, during the heating and expansion, the hot-melt adhesive material 24 protrudes in a radial direction beneath the ends of the flanges 14, 16 facing the component 28 and forms an annular bead of hot-melt adhesive material 24 on the top side of the component 28 and the bottom side of the component 28, as shown in the Fig. 6 and Fig. 8 can be seen, where a perspective view of the top side ( Fig. 6) or on the underside ( Fig. 8) of the device 10 mounted in a component 28 shown in detail. In the Fig. 7 and Fig. 9 is shown partially cut away for illustrative purposes, showing the bead of hot-melt adhesive material 24. The radial protrusion of the hot-melt adhesive material 24 allows for a simple visual inspection of the seal created in the area of ​​the flange ends during the heating of the hot-melt adhesive material 24.

[0026] With reference to the Fig. 5 and Fig. 10, a further embodiment will be explained. As can be seen in these figures, in the example shown, the second flange 16 has a through-bore 34, which in the example has an oval cross-section. As shown in Fig.10, the through-hole 34 is completely closed in the unassembled state by the hot-melt adhesive material 24 sprayed onto the second flange 16. From the outside, this complete closure of the through-hole 34 by the hot-melt adhesive material 24 can be easily visually inspected. If the through-hole 34 is completely closed, the hot-melt adhesive material 24 has been properly applied to the inner surface of the second flange 16. In the fully assembled state of the device, the through-hole 34 then indicates the proper sealing of the component opening. Proper sealing is only achieved if the through-hole 34 is also closed by the then expanded hot-melt adhesive material after assembly and the cooling process.

Claims

[1] Device for insertion into an opening (26) of a component (28) of an automobile, comprising a shaft body (12) and a circumferential first flange (14) arranged at one end of the shaft body (12), as well as at least one annular circumferential second flange (16) provided on the shaft body (12), wherein the device (10) can be inserted into the opening (26) in the axial direction of the shaft body (12) such that the shaft body (12) projects through the opening (26) and the first flange (14) bears against a first component surface and the device (10) is fastened to the opening (26) by the second flange (16) engaging a second component surface of the component (28) opposite the first component surface, wherein an annular circumferential cavity (32) is delimited at least between an outer surface (30) of the shaft body (12), an inner surface of the first flange (14) and the first component surface,further comprising a hot-melt adhesive material (24) circumferentially applied to the first and second flanges (14, 16), which, when heated, seals the flanges (14, 16) to the first and second component surfaces, respectively, and tightly closes the cavity (32), , characterized by that the hot-melt adhesive material (24) is an expanding hot-melt adhesive material (24) which expands into the cooling cavity (32) when the component (28) cools down after painting and automatically compensates for a pressure change in the cavity (32) by this expansion. [2] Device according to claim 1, characterized by that the hot-melt adhesive material (24) is attached to the first flange (14) in such a way that it projects in the axial direction of the shaft body (12) that the first flange (14) rests against the first component surface with the hot-melt adhesive material (24) when the device (10) is inserted into the opening (26) and in the non-expanded state of the hot-melt adhesive material (24). [3] Device according to one of claims 1 or 2, characterized by that the hot-melt adhesive material (24) is not visible from the outside of the flange in the axial direction of the shaft body (12) and expands radially outwards under the edge of the first flange (14) when heated, so that it is visible from the outside of the flange after expansion in the axial direction of the shaft body (12). [4] Device according to claim 1, characterized by that the hot-melt adhesive material (24) is attached to the second flange (16) in such a way that it projects in the axial direction of the shaft body (12) that the second flange (16) rests against the second component surface with the hot-melt adhesive material (24) when the device (10) is inserted into the opening (26) and in the non-expanded state of the hot-melt adhesive material (24). [5] Device according to one of claims 1 to 4, characterized bythat the hot-melt adhesive material (24) is not visible in the axial direction of the shaft body (12) from an outer side of the second flange (16) and expands radially outwards under the edge of the second flange (16) when heated, so that it is visible from the outer side of the second flange (16) after expansion in the axial direction of the shaft body (12). [6] Device according to one of the preceding claims, characterized by that the expanding hot-melt adhesive material (24) has an expansion factor of at least 10%. [7] Device according to one of the preceding claims, characterized by that the first and / or the second flange (14, 16) are resiliently elastic at least in the axial direction of the shaft body (12). [8] Device according to one of the preceding claims, characterized bythat the first and / or the second flange (14, 16) curve from the shaft body (12) in the direction of the component surface assigned to them in each case when the device (10) is inserted into the opening (26). [9] Device according to one of the preceding claims, characterized by that the device (10) consists of a plastic produced by injection molding. [10] Device according to claim 9, characterized by that the expanding hot-melt adhesive material (24) is injection-molded onto the first and / or second flange (14, 16). [11] Device according to one of claims 1 to 10, characterized by that the expanding hot-melt adhesive material (24) is mechanically connected to the first and / or second flange (14, 16). [12] Device according to one of the preceding claims, characterized by that the first flange (14) and / or the second flange (16) has a through-bore. [13] Device according to claim 12, characterized by that the bore (34) has an oval cross-section. [14] Device according to one of the preceding claims, in the state inserted into the opening (26) of the component (28), in particular a body panel, of the automobile.

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