The invention relates to a method for producing a roof rack for a vehicle and to an extruded profile for use in such a method.
It is known to attach a roof rack to the roofs of motor vehicles at each of the two longitudinal edges of the vehicle roof. Such a roof rack often consists of a rail extending over the entire length with a constant cross-section and separate feet or adapters to attach the roof rack at its ends to the vehicle roof. A two-footed roof rack is known, as well as a three-footed roof rack or multi-footed roof rack, in which the rail extends at a distance from the vehicle roof when the roof rack is installed on the vehicle roof. Such a spaced-apart rail can also be achieved in a roof rack that consists of a rail and the end feet as a single piece, as is shown in the document WO 95/11144 A1. Furthermore, in addition to a roof rack raised on fixed supports, a roof rack that is surface-mounted on the vehicle roof is known, namely from document DE 20 2014 102,150 U1, in which the rail and the feet are manufactured from an extruded profile, wherein the end feet are produced by bending, and the foot region or the entire contact surface is processed by milling. The known roof rack produced from the extruded profiles has a constant cross-section over the entire length of the rail, extending partway into the bend region, i.e., the region of the feet. Although a roof rack can be matched to different roof contours by bending the extruded profile, namely through differing bend radii, nonetheless the rail is identical in cross-section for every roof rack that was made from the same extruded profile.
A roof rack is known from document DE 199 48 475 A1 in which a hydroforming of the tubular extruded profile takes place after bending of the extruded profile, and different cross-sections of the extruded profile are produced in this way, especially in the region of the railing feet. Such a hydroforming process is a very expensive process. In such a process, moreover, the material properties of the aluminum material of the roof rack are also changed in the formed regions, and the rail has different wall thicknesses in these formed regions, which is undesirable.
Moreover, the desire exists to provide a roof rack that includes a lighting element, wherein the components for activating the lighting element can be accommodated in the feet so as not to be visible from outside.
The object of the present invention is to provide an improved roof rack that can be manufactured by a simple method.
This object is attained with a method according to claim 1. Advantageous embodiments are described by the dependent claims.
In the novel method according to the invention for producing a novel roof rack, an extruded profile is made from aluminum by extrusion, namely, an extruded profile section with a tubular profile part and with at least one additional profile web on the tubular profile part. The tubular profile part has a hollow space enclosed by profile walls. The additional profile web is connected at its first end to the tubular profile part, and its second, free end projects downward, which is to say is essentially vertical.
After extrusion, a cutting-to-length of the extruded profile section takes place, which is to say a cutting of the extruded profile section into extruded profiles of the desired length for a roof rack, or into a desired preliminary length that is longer than a roof rack to be created so that, in the event of a bending process that may, if applicable, be performed on the cut extruded profile, the ends that are clamped and deformed in the stretch-bending fixture can be removed after the stretch-bending process.
After the cutting-to-length, the cut extruded profiles are subjected to a machining process, namely the additional profile web or the additional profile webs of these extruded profiles are suitably machined to achieve a desired lateral contour. To achieve the desired lateral contour line, the applicable profile web is, in particular, trimmed, wherein the trimming is the same or different over the entire length of the extruded profile, and thus any desired lateral profile line can be created. The trimmed profile web forms this special lateral contour line with its free end along the extruded profile. In the case of different trimming of the profile webs in the longitudinal direction of the extruded profile, different profile cross-sections are created in the longitudinal direction of the extruded profile at the same time. Such machining can be accomplished by milling, stamping, water-jet cutting, laser machining or by other known machining processes. Milling is chosen particularly for the profile webs that are located on the extruded profile such that a sidewall of the tubular profile part of the extruded profile is located behind the profile web to be machined, for example, for profile webs that extend in front of a sidewall of the rail to be created of the roof rack. Here, jet processing would adversely affect the surface of the sidewall.
A bending process may take place before or after the machining, preferably a stretch-bending of the extruded profile. If the bending process takes place before the machining, then the support surfaces of the end feet, or the contact surface of the roof rack in the foot region, or the contact surface over the entire longitudinal orientation of the roof rack can also be machined in addition in accordance with the contour of the motor vehicle roof on which the roof rack is to be installed.
As a result of the machining, any profile web can be trimmed to different degrees in the longitudinal direction of the extruded profile, and a freely selectable lateral contour line can be produced. In one embodiment, a lateral contour line can even be created that extends in a gradual curve into the region of the feet of the roof rack. In particular, the end feet constitute a bend section of the extruded profile. As a result of the machining, a freely selectable lateral contour line, in particular, is produced in the longitudinal direction of the roof rack. In addition to smooth transitions to the end feet, the suggestion of at least one central foot in the region between the end feet can also be provided by leaving regions of the additional profile web untouched.
A prerequisite for the creation of a freely selectable lateral contour line for the roof rack is the special cross-section of the extruded profile made of aluminum that is created in the first step in the method according to the invention, producing a roof rack. This profile shall be described in greater detail below. It consists of a tubular profile part with a hollow space enclosed by profile walls in a known manner. In the finished roof rack, this tubular profile part becomes the rail of the roof rack. Moreover, end feet can be created by bending the tubular profile part. As a special feature, the extruded profile additionally has at least one profile web that is attached at one end (its first end) to the tubular profile part and faces away from the tubular profile part at its second, free end, namely. points downward from the tubular profile part of the extruded profile.
In one embodiment, two such profile webs are provided that project downward from the bottom profile wall of the extruded profile, and form an extension of the sidewalls of the extruded profile, for example. Such an extruded profile has two parallel or nearly parallel foot-like profile webs.
In one special embodiment, a first profile web is provided as a downward extension of a side profile wall of the extruded profile, namely the first sidewall, which constitutes the inner side in the completed and installed roof rack. Another profile web is located in front of the second, lateral profile wall, which delimits the hollow space toward the outside in the installed roof rack.
A second such profile web extends downward at the outside, nearly parallel to the second sidewall, wherein a separation is provided between this profile web and the second sidewall. The second sidewall and the profile web form a groove that is open toward the bottom. This groove has the special advantage that a sufficient working space is available during machining of this profile web without the surface of the second sidewall located behind it being damaged. A profile web of this nature can advantageously also partially conceal a passage for a lighting element. In this case, the passage, which is open toward the bottom and extends in the longitudinal direction of the extruded profile, is located at the second sidewall and preferably is located at the upper end of the groove formed between the second sidewall and the profile web. In such an embodiment, it is possible, in particular, for the connection region of the lighting element, with the components for activating the lighting element, that can be provided in the region of the end foot to also be covered completely by the profile web.
In another advantageous embodiment for producing a roof rack, in particular a surface-mounted roof rack, only the last-described, second profile web that is located in front of the second sidewall is provided.
In all the above-described embodiments of the novel extruded aluminum profile for producing a roof rack, the additional profile web or additional profile webs serve, in particular, to create different cross-sections in the longitudinal direction of the rail and thereby to achieve a freely selectable lateral contour for the roof rack, wherein roof racks that look different can be created from one extruded profile.
The roof rack for vehicles produced by means of the novel method consists, in a known manner, of a rail and end feet. The connection to a vehicle roof takes place in the region of the end feet, either indirectly, e.g., through adapters, or directly, e.g., through a screw joint. The rail and the feet of the roof rack are designed as a single piece and are made from the extruded aluminum profile, namely from an extruded profile that has at least one profile web in addition to the tubular profile, wherein the rail is composed of the tubular profile part of the extruded profile, wherein the end feet are composed of a bend section of the tubular profile part, and wherein the rail advantageously has different cross-sections in the longitudinal direction, and these different cross-sections are created by machining of the profile webs that are additionally present on the extruded profile. This means that different lateral contour lines on a roof rack can be created from one extruded profile, especially on the outer side of the roof rack installed on the vehicle roof. The roof rack can be a surface-mounted roof rack, or a roof rack in which the rail extends at a distance from the vehicle roof and the roof rack constitutes a roof rack raised on fixed supports. In an especially advantageous manner, the roof rack can also include a lighting element that is accommodated in an open passage extending in the longitudinal direction of the profile. In this case, the freely selectable machining of the additional profile web achieves a lateral contour line that extends in front of the second sidewall at which the passage is provided and that, on the one hand, can influence the direction of radiation of the lighting element, and, on the other hand, covers the lighting element's connection region with the components for activating the lighting element from the outside.
Exemplary embodiments are described below on the basis of the drawings in order to explain the invention. The drawings show:
For the different embodiments of a roof rack shown in
A first embodiment of a roof rack 10′ produced in accordance with the invention is shown in
In addition, on the extruded profile shown in
Different embodiments of a roof rack can be created from this extruded profile 1 from
This sidewall 4 once again includes a passage 15 extending in the longitudinal direction of the extruded profile 1 for a lighting element 30. In a surface-mounted roof rack 10, the passage 15 ends nearly at the roof surface after the bending of the feet 11, 12 and the machining of the contact surface. In order to be able to route the lighting element 30 in the hollow space 6 of a foot 11, 12, a transition between the passage 15 and the hollow space 6 must be created during the machining, for example, in the form of milled recesses in one of the walls that enclose the hollow space 6. In this process, it is taken into account that a lighting element 30, for example, an optical waveguide, must not be kinked, but instead is routed in the hollow space 6 in as large a curve as possible, and connected there to the components for activating the lighting element 30. Here too, the connection region between the lighting element 30 and the components for activating the lighting element 30 is covered by the profile web 7′ in the transition to the feet 11, 12.
A simple method for producing a roof rack 10, 10′ is provided, wherein in advantageous manner, different lateral contour lines for a roof rack 10, 10′ are possible from one extruded profile by means of the machining of the profile webs 7, 7′, and, thus, a novel roof rack with a variable cross-section in the longitudinal direction of the rail 13 can be created. By retention of the profile webs 7, 7′ in the transition region between the rail 13 and the end feet 11, 12, sufficient space is created for the lighting element 30 to extend into the hollow space 6 in the region of the feet 11, 12 without the connection region between the lighting element 30 and the components for activating the lighting element 30 being visible from outside. In this design, the lateral contour line 20 can be matched to the contour of the vehicle roof, or can be freely selected according to the wishes of the motor vehicle manufacturer, and, for example, can also be designed such that an appropriately available receptacle is created on the roof rack for an insert 40 for a two-color design of the roof rack. The different possible side views of a roof rack that are made possible by this means are achieved by a simple method, without the material of the tubular profile part that forms the rail 13 and the end feet 11, 12 suffering adverse effects as a result of a forming process. The machining to create variable cross-sections is carried out solely on a profile web 7, 7′ that is provided outside the tubular profile part. The tubular profile part has profile walls 2, 3, 4, 5 with constant wall thickness in the longitudinal direction of the rail 13 so that the machining to achieve a differently designed roof rack 10, 10′ has no effect on the strength of the roof rack 10, 10′.
LIST OF REFERENCE SYMBOLS
Number | Date | Country | Kind |
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102018104552.2 | Feb 2018 | DE | national |