Abstract:
An attachment element is provided with a central cylinder. The first end of the central cylinder has an internal thread and the other end terminates with an outer disk, where it can be screwed down, and passes through an inner disk between the outer disk and its first end.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to German Patent Application No. DE 102007015866.3, filed Apr. 2, 2007, which is incorporated herein by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    The invention relates to an attachment element for attaching an instrument panel to the front wall of a motor vehicle, in particular a passenger vehicle. 
       BACKGROUND 
       [0003]    During the assembly of a motor vehicle, the instrument panel must be joined with the front wall in a suitable manner. Numerous attachment means have become established in practice for this purpose. Among other things, they are characterized by the fact that the sound insulation performs unsatisfactory, many components are required or the outlay for joining is high. 
         [0004]    At least one object of one of the embodiments of the invention is to provide an attachment element for affixing an instrument panel to the front wall of a motor vehicle, which enables the assembly of the instrument panel with as few parts as possible, improves the sound insulation of the motor vehicle, and makes assembly especially quick and easy. In addition, other objects desirable features and characteristics of invention embodiments will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings, summary, background and abstract. 
       SUMMARY 
       [0005]    One first aspect of the invention relates to an attachment element with a central cylinder, the first end of which has an internal thread, and the second end of which terminates with a disk, hereinafter referred to as outer disk, where it can be screwed down, and passes through another disk, hereinafter referred to as inner disk, between the outer disk and its first end. 
         [0006]    The attachment element can be screwed onto a weld screw by means of the internal thread. Another part can be clamped between the component having the weld screw and the inner disk. If the component is the front wall of a passenger vehicle, sound insulation can be clamped between the inner disk that is rigidly joined with the cylinder and the front wall. To this end, the sound insulation has an opening that is larger than the cylinder diameter and smaller than the inner disk, so that the sound insulation is pressed against the front wall at its opening while screwing the attachment element onto the weld screw. This prevents having to cut out a portion of the sound insulation in the area of the attachment element for assembly reasons, maximizes the front wall surface that can be provided with sound insulation, and hence yields especially low noise inside the vehicle. At the same time, the sound insulation is solidly secured. 
         [0007]    The outer disk arranged on the outermost end of the cylinder can be used to join another component with the component having the weld screw. The other component can exhibit a pocket into which the outer disk can be introduced to secure it in the longitudinal direction of the cylinder. If the other component is an instrument panel, for example, it can be prevented from shifting opposite the longitudinal direction of the motor vehicle and in a vertical direction in this way. As a result, the instrument panel can be easily fixed to the front wall without any ancillary means, such as a screw nut. Therefore, only one attachment element is required to secure two components to the weld screw. The attachment element here represents a combined screwed and plug-in connection, with which the mentioned components can be joined with little assembly outlay. 
         [0008]    In a second embodiment, the attachment element, which can be made out of plastic, consist of two circular disks, so that the position of the disks is not important during assembly. 
         [0009]    The attachment element can be designed so that it can be screwed in the area of the outer disk, for example, by having the cylinder be a hexagon socket. As an alternative to the above, another embodiment provides for the screwing capacity by having the outer disk occupy a depression on the outside, where the cylinder is designed as a hexagon insert bit. 
         [0010]    As explained above, the outer disk can be used to secure another component by introducing it into a corresponding pocket of the other component, or running the pocket over the outer disk laterally reversed. As a result, a certain play might then cause the outer disk to rattle against the pocket walls. To prevent this, another embodiment provides that the plastic attachment element be provided with spring elements molded on the outer disk, which have an outwardly curved contact surface, held by a notch-shaped elastic element. To this end, the spring elements are located in outwardly open openings of the outer disk, and extend slightly over it without mechanical load. Therefore, the contact surface of a spring element hits the pocket wall during use, offsetting the existing play inside the pocket. 
         [0011]    Another aspect of the invention relates to a motor vehicle with a weld screw secured to its front wall. An attachment element according to one of the embodiments described above is screwed onto the weld screw. The inner disk of the attachment element presses sound insulation against the front wall, and the outer disk secures an instrument panel to the front wall. As described above, the instrument panel can have a corresponding pocket to this end, for example as a U-shaped recess, so that the instrument panel is moved or introduced toward the front wall during assembly, so that the attachment element is inserted into the pocket. To simplify the assembly operation, the weld screws can here be aligned vertically, since the instrument panel can then be moved horizontally. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and 
           [0013]      FIG. 1  is a perspective side view of an embodiment of an attachment element, 
           [0014]      FIG. 2  is the attachment element of  FIG. 1  with a view of the bottom side, 
           [0015]      FIG. 3  is the assembly area of the attachment element of  FIG. 1 and 2 , 
           [0016]      FIG. 4  is a section A-A through  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description. 
         [0018]    In the figures, which generally denote the same items using the same reference numbers,  FIG. 1  shows a plastic attachment element  1 , which centrally has a cylinder  2 . The cylinder  2  has an internal thread  4  at one end  3 . It can be screwed at the other end  5  by means of a hexagon insert bit  6 . 
         [0019]    The other end  5  of the cylinder  2  is provided with an outer circular disk  7 . The outer disk  7  has a depression  8  that buts flush with the end  5  of the cylinder  2 . Situated between the outer disk  7  and one end  3  is an inner circular disk  9 . The diameter of the outer disk  7  is greater than the diameter of the inner disk  9 . 
         [0020]    The outer surface of the outer disk  7  of the attachment element  1  has spring elements  10 , which are enlarged in the magnified section A. The spring element  10  is incorporated into an opening  11  of the outer disk  7 , and has an upwardly curved contact surface  12  that is molded via a notch-shaped elastic element  13  to the edge of the opening  11  or the outer disk  7 . 
         [0021]      FIG. 2  shows the attachment element  1  of  FIG. 1  from the bottom, i.e., viewed in the direction of the arrow P on  FIG. 1 . As evident, the bottom side has two strip-shaped recesses  13   a,    13   b  in the area of the spring elements  10 , i.e., it is lowered by a specific distance x. Correspondingly, the contact surfaces  11  of the spring elements  10  project by the same distance x over the outer surface of the outer disk  7 . As will be explained below, the spring elements  10  are used to offset the play inside the receiving pocket. In this regard, the height of the recesses  13   a,    13   b  can also be sued to flexibly offset the expected location deviations. 
         [0022]      FIG. 3  shows a front wall that separates the engine compartment  18  of a motor vehicle (not shown) from the passenger compartment  17 . The attachment element  1  is used to clamp the sound insulation  19  between the inner disk  9  of the attachment element  1  and the front wall  16 . An instrument panel  20  shown only in a sectional view has a U-shaped pocket  21 , which is moved in the direction of the arrow P 1  during assembly. The outer disk  7  moves into the pocket  21  in the process, thereby securing the instrument panel  20  in a vertical direction. As shown on  FIG. 3 , a single attachment element  1  can be used to secure both the sound insulation  19  and the instrument panel  20  to the front wall  16 . Assembly can here be easily performed with a hexagon insert bit and a shifting operation. No additional securing means or the like are required. The danger of incorrect assembly, and hence malfunction during assembly, is slight. 
         [0023]      FIG. 4  shows a section A-A through  FIG. 3  viewed in the direction of the arrows. As evident, the front wall  16  has a weld screw  22 , and the sound insulation  19  is clamped between the inner disk  9  and the insulation  16 . The outer disk  7  is incorporated into the pocket  21 . This secures the instrument panel  20  in a vertical direction. The spring elements  10  visible on  FIG. 1  are used to offset the tolerance of the outer disk  9  in the pocket  21 . As a result, the outer disk  9  does not rattle in the pocket  21 , thereby preventing the generation of noise while driving. 
         [0024]    The weld screw  22  on  FIG. 4  is vertically arranged. This makes it possible to mount the instrument panel  20  with a simple horizontal longitudinal shift, as denoted on  FIG. 3  by the arrow P 1 . 
         [0025]    While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.