Abstract:
The present invention relates to a vehicle interior trim part with a first part and a second part which is fastened thereto, wherein the first and the second part have different coefficients of length expansion with respect to at least one influencing variable.

Description:
This application claims priority from and the benefit of PCT Application No. PCT/EP2011/003304, filed on Jul. 4, 2011; and German Patent DE 10 2010 025 941, filed on Jul. 2, 2010; both entitled “Vehicle Interior Trim Part, In Particular Inside Door Lining”, which are herein incorporated by reference. 
     BACKGROUND 
     The present invention relates to a vehicle interior trim part with a first part and a second part which is fastened thereto, wherein the first and the second part have different coefficients of linear expansion with respect to at least one influencing variable. 
     Such vehicle interior trim parts, for example inside door linings, are sufficiently well known from the prior art and have a first part, in particular a lining part, on which a second part, for example a fastening means, is arranged. If these two parts then have a different coefficient of linear expansion with respect to at least one influencing variable, for example temperature and/or humidity, and/or shrinkage occurs during the curing of one part, this often leads to cracks and/or deformations, in particular of the lining part. 
     It was therefore the object of the present invention to provide a vehicle interior trim part that does not have the disadvantages of the prior art. 
     The object is achieved by a vehicle interior trim part with a first part and a second part which is fastened thereto, wherein the first part and the second part have different coefficients of linear expansion with respect to at least one influencing variable and/or one part tends to shrink during curing, at least one part having an elastic fastening region. 
     SUMMARY 
     The present invention relates to a vehicle interior trim part, for example an inside door lining. This trim part has a first, generally two-dimensional part, preferably a lining part, which is preferably produced from a natural material and/or a plastic. Fastened to this first part is a second part. The fastening is preferably a material bond, which is achieved for example by adhesion, sealing, insert molding, injection in-mold lamination and/or compression in-mold lamination. The second part is preferably produced from a plastic. 
     According to the invention, the first and the second part have different coefficients of linear expansion with respect to at least one influencing variable. The influencing variable is, for example, temperature and/or humidity. Alternatively or in addition, one of the parts shrinks during curing. 
     Furthermore, according to the invention, the fastening region of the first and/or second part, preferably the second part, is provided as elastic. This elasticity has the effect of preventing material failure and/or deformation, in particular of the first part, so that it remains in particular visually attractive. 
     The fastening region according to the present invention is the region, in particular of the second part, that is connected with a material bond to the other part, the first part. 
     The fastening region is preferably provided as elastically deformable in the fastening plane. 
     The fastening region preferably has an elastic layer, which is preferably provided between the first and the second part. 
     It is preferred furthermore that the fastening region extends in the manner of a finger or fingers. This at least one finger may then preferably extend and retract and bend in the fastening plane. 
     The thickness of the fastening region is preferably reduced toward the edge, so that the elasticity of the fastening region increases toward the edge of the second part. 
     It is preferred furthermore that the fastening region is provided as hollow, at least in a portion or portions, whereby its elasticity is likewise increased. 
     According to a further preferred embodiment of the present invention, the vehicle interior trim part has a number of fastening regions, which extend in different spatial directions. This allows forces that act from different spatial directions to be absorbed better. 
     The fastening region of the second part preferably has relieving clearances, for example in the form of slits, which additionally increases the elasticity of the second component and/or of its connecting region. 
     The second part is preferably an injection-molded part of plastic, which with particular preference is molded directly onto the first part. During the curing, the material bond between the first and the second part preferably occurs. These injection-molded parts generally have an injection opening, which with most particular preference is part of the fastening region of the second part. 
     According to a further preferred embodiment, the second part has an extensible and/or resilient element, which is provided in particular between two fastening regions and/or two fastening clearances. 
     The first part is preferably a lining means and/or the second part is preferably a fastening means. 
    
    
     
       DRAWINGS 
       The invention is explained below on the basis of  FIGS. 1-8 . These explanations are given merely by way of example and do not restrict the general concept of the invention. 
         FIG. 1  shows the vehicle interior trim part according to the invention. 
         FIG. 2  shows an embodiment of a second part. 
         FIG. 3  shows a further embodiment of the vehicle interior trim part according to the invention. 
         FIG. 4  shows a section through the vehicle interior trim part according to  FIG. 3 . 
         FIG. 5-8  show further embodiments of the vehicle interior trim part according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows the vehicle interior trim part  1  according to the invention, here an inside door lining, which has a first lining part  2  of a two-dimensional design. This lining part is preferably produced from a natural material, for example a fibrous natural material, and/or a plastic. Fastened to this first part  2 , in particular to the rear side thereof, i.e. to the side facing away from the passenger compartment, there is or are at least one second part  3 , here a number of second parts  3 . This fastening preferably takes place by a material bond between the first and the second part  2 ,  3 , which is achieved for example by adhesion and/or injection in-mold lamination. In the injection in-mold lamination, the material bond between the first and the second part takes place during the curing of the second part. The fact that the first part  2  and the second part  3  are produced from different materials means that their coefficient of linear expansion, for example under the influence of temperature and/or humidity, differs. Alternatively or in addition, the second part  3  shrinks during curing and/or the first part expands due to moisture that is passed from the second part into the first part. According to the invention, it is thus provided that at least one of the two parts has an elastic fastening region, which elastically deforms under the differing linear expansion. The size of the fastening region is calculated on the basis of the magnitude of the forces to be expected. The second part is, in particular, a fastening means, with which the first part is for example fastened to the door body of the vehicle and/or with which a third element is fastened to the first part. 
       FIG. 2  shows a first embodiment of a second part. This has in its upper part a fastening clearance  9 , by means of which the first part can be fastened to the vehicle body and/or with which a further element can be fastened to the first part. In the region of the second part that is facing away from the fastening clearance, the fastening region  4  is provided, designed in the present case in the manner of fingers  11 . The fingers  11  are dimensioned such that, as represented by the double-headed arrows  13 , they not only extend and retract but also bend in the fastening plane  5 . The thickness of the fastening region  4 , here in particular of the fingers  11 , is dimensioned such that it decreases toward the edge of the second part  3 . As a result, the elasticity of the fastening region increases toward the edge. Furthermore, the fastening region  4  has a relieving clearance  8 , here a relieving slit, which provides additional elasticity for the second part in the fastening region. 
       FIG. 3  shows a further embodiment of the vehicle interior trim part  1  according to the invention. Here, too, the fastening region  4  of the second part  3  is provided in the manner of fingers which, as represented once again by the double-headed arrows  13 , can not only extend and retract but also bend in the fastening plane  5 . Reference is made to the statements made with respect to  FIG. 2 . In the present case, but also in the case of all other parts  2  presented here by way of example, it is an injection-molded part, which has an injection opening  10 , from which the plastics material flows into the corresponding mold. It is thus preferably provided that this injection opening  10  is part of the fastening region  4 . 
       FIG. 4  shows a section through the vehicle interior trim part according to  FIG. 3 . It can be clearly seen that the second part is provided as hollow, at least in a portion or portions, which additionally increases the elasticity of the component and also represents a weight saving. In the present case, the injection opening  10  of the fingers  11  and the edge region of the fastening clearance  9  are provided as hollow  14 . A person skilled in the art understands that it may, however, also be preferred to provide just one of these regions as hollow. 
       FIG. 5  shows a further embodiment of the vehicle interior trim part according to the invention. Reference is made to the statements made with respect to the previously discussed figures. 
       FIG. 6  shows a further embodiment of the vehicle interior trim part according to the invention. In the present case, the second part has extensible and/or resilient means  12 , which can elastically extend and/or retract when there is an expansion of the first part and thereby avoid stresses in the first part. 
       FIG. 7  shows a further embodiment of the vehicle interior trim part according to the invention. Reference is made to the statements made with respect to  FIGS. 1-6 . 
       FIG. 8  shows a further embodiment of the vehicle interior trim part according to the invention. In the present case, the fastening region  4  is of a three-dimensional design. Otherwise, the statements made with respect to the previous figures apply.