BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to an enclosure for accommodating devices, in particular electronic devices, elements and the like comprising a base plate and side walls rising therefrom, wherein an insert element joining the side walls is installed in the contact region between two adjacent side walls. 
         [0002]    It is known to use, for example in communication and control technology, enclosures or small control cabinets, respectively, which accommodate, for example, sensors together with an electronic evaluation circuit, which in turn are or can be provided with connecting, display, fastening and/or actuating elements. Moreover, other substantially self-sustaining electronic devices and elements may be accommodated in small enclosures of this type. Those small enclosures may be accommodated outside or within a larger switchgear cabinet and may be adapted to customer needs. 
         [0003]    A switchgear cabinet comprising a framework is for example known from WO 2010/121588 A2. In order to achieve a high strength and loading capacity of the framework and to realize virtually unlimited dimensions within a short period of time, bars are provided which comprise an outer bar having an open profile. The open region of the outer bar facing inwardly is covered by an inner bar and connected thereto by means of a rivet connection, which inner bar abuts outwardly two sides of the outer bar and comprises at least a bend serving as a supporting surface for a wall surface. 
         [0004]    If smaller, self-sustaining control cabinets or enclosures, respectively, are to be realized, it is known to build small enclosures from metal sheets, wherein the side walls, the rear wall, the bottom and the cover part made from metal sheet are welded together along their contact edges and are subsequently grinded. In order to provide, for example, mounting supports for devices, elements and the like within the small enclosure, for example bolts and mounting brackets are attached by means of spot welding. Door hinges and closures are mounted on the small enclosure. The construction of small control cabinets or enclosures, respectively, of this type requires complex manufacture, in particular because of the required welding work. 
         [0005]    Accordingly, when building small enclosures, corner connectors are used which are plugged into the associated profile walls or are screwed thereto. An example is shown in DE 103 00 418 A1, where the corner connector is provided with webs in sections which engage insert grooves of the wall profile. Boards and other devices are then mounted to the wall profiles. 
         [0006]    It is the object of the invention to disclose an enclosure of the type mentioned in the introductory which is made up simple and has few individual parts and allows simple accommodation of electronic devices, elements and the like. 
       SUMMARY OF THE INVENTION 
       [0007]    This object of the invention is solved by an enclosure for accommodating electronic devices, elements and the like, comprising a base plate and side walls rising therefrom, wherein an insert element joining the side walls is installed in the contact region between two adjacent side walls, wherein respective free edges of the side walls are retained force- or form-fit within holding grooves of the insert element. 
         [0008]    According to the invention, it is provided that respective free edges of the side walls are retained force- or form-fit within holding grooves of the insert element. Thus, the insert element may be moved over the free edges of the side walls in a simple way, the edges being received within the holding grooves and guided therein during assembly. In order to create room for the insert element and to allow easy introduction, the side walls may at least partly be provided with recesses in the contact region. The width of the recesses depends on size and shape of the insert element. Accordingly, a very simple manufacturing process for an enclosure is provided which does no longer require welding and a subsequent finishing of the welding seams, e.g. by grinding. 
         [0009]    In many applications, a box-like enclosure is appropriate where the side walls are perpendicular to another and further perpendicular to the base plate. However, the invention also allows building basin-like structures arranged at an angle to another or with the bottom, respectively, which is different from 90°, in particular is larger than 90°. 
         [0010]    In an advantageous embodiment of the invention, however, the insert is formed as an optionally rounded rectangular profile, where the holding grooves are provided at adjoining sides of the insert element. Further, a circular cylindrical profile or a profile having oval cross-section are conceivable. Designs of that type are exceptionally strong. In particular, the insert element may be manufactured from plastic. Accordingly, the insert element may be manufactured exceptionally easy and is easy to machine. By forming roundings in the region of the edges, the design may be optimized. Additional possibilities of designing are forming of contours and/or colored design elements. 
         [0011]    Further preferred, the insert element may comprise part holding grooves open toward the interior of the enclosure which extend spaced apart from another parallel to the base plate. It is further preferred that the part holding grooves overlap at edges of adjoining sides of the insert element. The part holding grooves serve to accommodate electronic devices or elements, in particular to accommodate mounting plates for such devices or elements. If, for example, the four vertical edge regions of the enclosure are provided with insert elements of this type, the mounting plates may be inserted and retained in part holding grooves respectively arranged on the same level at each insert element. 
         [0012]    In order to additionally fasten the devices or elements or the mounting plates, respectively, a plurality of mounting holes may be provided near the part holding grooves which are arranged along the edge of adjoining sides alternately with the part holding grooves and spaced apart therefrom. By means of suitable screw connections, the mounting plate supported in the part holding grooves can be safely fixed. In particular, the mounting holes may be arranged on the adjoining sides of the insert element equidistantly to the edge of the adjoining sides. Accordingly, a pre-defined pattern is created which simplifies interior fitting of the enclosure. 
         [0013]    In order to attach, for example, the base plate or a cover part to the inserted insert elements, the free ends of the insert elements may respectively be abutted against the base plate and the cover part which respectively comprise at least one mounting hole for mounting the base plate or the cover part, respectively. For the purpose of easy fixing, the base plate and the cover part may comprise throughbores, respectively corresponding to the mounting holes at the free ends of the insert element. By means of simple screw connection, base plate and cover part of the enclosure may be assembled in a simple way, thus avoiding a weld connection. 
         [0014]    Such a mounting hole, however, may also fix a further component, for example a coupling piece or a locking or closure piece. 
         [0015]    According to a preferred embodiment of the invention, a coupling piece fixed at a free end of the insert element is provided, where sleeves for receiving hinge pins or locking bolts are formed. A door, for example, may be suspended in these sleeves and may be closed. The coupling piece may also be integral with the insert element. 
         [0016]    According to a further embodiment, the coupling piece is contoured to form a support surface for a door, a cover part or a further component. 
         [0017]    It is particularly preferred that the base plate is integral with at least one of the side walls, in particular preferably with all side walls. In this way, an enclosure is formed where the side walls are bent with respect to the base plate. That enclosure may be fabricated in a punching and subsequent bending process, so that assembly of the enclosure by using the insert element is considerably simplified. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The invention is explained in detail below with the aid of the appended drawings which are not necessarily to scale. It is shown in: 
           [0019]      FIG. 1  in a schematic and perspective view the edge region of an enclosure and an insert element according to a preferred embodiment of the present invention; 
           [0020]      FIG. 2  another embodiment of an insert element in a perspective bottom view; 
           [0021]      FIG. 3  the insert element of  FIG. 2  in a perspective top view; 
           [0022]      FIG. 4  the insert element of  FIG. 2  in a side view; 
           [0023]      FIG. 5  an enclosure with door constructed according to the principles of the invention in a partly exploded view, and 
           [0024]      FIG. 6  the enclosure of  FIG. 5  in an assembled state. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]      FIG. 1  shows, in a schematic and perspective view, the edge region of an enclosure, wherein two side walls  12 ,  14  which are bent with respect to a base plate  10 , are to be joined with the aid of an insert element  20 . In order to receive insert element  20 , side wall  12  comprises a recess  32  in a contact region  13 , side wall  14  comprises a recess  34  in contact region  13 . A throughbore  11  is provided in base plate  10 . Side walls  12 ,  14  may be perpendicular to base plate  10 , as illustrated, but can also be at an angle of more than 90° to form a basin-like structure. 
         [0026]    The insert element, here shaped as a rectangular profile, the edges thereof optionally being rounded, comprises holding grooves  22 ,  24  for the free edges  12 ′,  14 ′ of side walls  12 ,  14  in a direction of extension according to arrow E. If a basin-like structure is intended, shaping of the insert element and arrangement of holding grooves, respectively, should be adapted accordingly. Holding grooves  22 ,  24  are formed at adjoining sides  23  and  25  of insert element  20 . In order to simplify interior fitting of the enclosure, insert element  20  further comprises five part holding grooves  26  in the illustrated embodiment, which are open towards the interior of the enclosure. Part holding grooves  26  are arranged vertically one above the other and equidistantly in the direction of extension of the insert element  20  according to arrow E. Part holding grooves  26  are formed at an edge  28  of adjoining sides  23 ,  25  of insert element  20  and extend substantially perpendicular to the direction of extension E of insert element  20 . Above each part holding groove, two mounting holes  30   a  and  30   b  are respectively provided. First mounting hole  30   a  is provided at side  23  of insert element  20  where holding groove  22  for side wall  12  extends. Second mounting hole  30   b  is arranged at side  25  of insert element  20  where wall holding groove  24  for side wall  14  extends. Free end  21   a  of insert element  20  may be abutted against a cover part, not shown here, or a door, for example. Free end  21   b  of insert element  20  may be abutted against base plate  10 . Free ends  21   a,    21   b  of insert element  20  each comprise a mounting hole  29 ,  FIG. 1  showing only mounting hole  29  at upper free end  21   a  of insert element  20 . Mounting hole of lower free end  21   b  (not shown here) of insert element  20  corresponds to the throughbore  11  in base plate  10 , when insert element  20  is inserted, through which a screw bolt may be passed and introduced into the mounting hole and screwed therein. 
         [0027]      FIG. 2  shows another embodiment of an insert element  20 ′ according to the present invention in a perspective bottom view. Different from the insert element  20  of  FIG. 1 , only three part holding grooves  26  are provided in insert element  20 ′, where mounting holes  30   a,    30   b  are arranged not only between two neighboring part holding grooves  26 , but also between a respective part holding groove  26  and free end  21   a  or  21   b , respectively, of insert element  20 ′. A mounting hole  29 ′ may be recognized at free end  21   b . A coupling piece  40  is provided at free end  21   a  of insert element  20  and is fixed thereto, having sleeves  42 ,  44 , which are intended to receive hinge pins, as will be explained in detail below. 
         [0028]    Coupling piece  40  may be designed for example such that it comprises a post (not visible here) engaging force-fit into mounting hole  29  ( FIG. 1 ). Alternatively, coupling piece  40  can be integral with insert element  20 ′. 
         [0029]      FIG. 3  shows insert element  20 ′ of  FIG. 2  in a perspective top view. Coupling piece  40  is contoured to form a supporting surface  46  against which a door, a cover part or even a further component may be abutted. 
         [0030]      FIG. 4  shows insert element  20 ′ of  FIG. 2  in a side view. Each part holding groove  26  is provided with opposed tapered edges  26   a,    26   b  facilitating introduction, for example, of mounting plates. Insert element  20 ′ further comprises an undercut groove  31   a ,  31   b  arranged at those sides facing away from the interior of the enclosure in an assembled state. 
         [0031]      FIG. 5  shows an embodiment of an enclosure according to the present invention in a partly exploded illustration. Four side walls  12 ,  14 ,  16 ,  18  are vertically bent with respect to a base plate  10 , wherein side walls  14  and  16  or  16  and  18 , respectively, are joined by an insert element  20 ′. Two additional insert elements  20 ′ are provided for joining side walls  12  and  14  or  12  and  18 , respectively, which are prepared to receive a door  19 . To this end, a hinge pin  52  or  54 , respectively, is inserted into sleeve  42  of one of insert pieces  20 ′ and into sleeve  44  of the other insert element  20 ′ or coupling piece  40 , respectively, which is fixed thereto. Corresponding sleeves  19   a,    19   b  are provided at door  19  into which the free ends of hinge pins  52 ,  54  protruding beyond the respective coupling piece  40  are inserted. Finally, both insert elements  20 ′ are brought into contact region  30  and moved over the free edges of side walls  12 ,  14  or  12 ,  18 , respectively. If needed, insert elements  20 ′ may be fixed at base plate  10  by means of a screw, a bolt or the like which is guided through throughbore  11 . 
         [0032]      FIG. 6  shows the enclosure with door  19  in an assembled state. Closed door  19  can overlap the accordingly contoured free edges of at least side walls  14 ,  16 ,  18  with flanged peripheral edges  19   c  and abut against supporting surfaces  46  of insert elements  20 ′. It will be understood that coupling pieces  40  or regions thereof which do not need to receive hinge pins, may be solid and in particular do not need to include sleeves. 
         [0033]    The features of the invention disclosed in the previous description, in the drawings and in the claims may be material for realizing the invention, either individually or in any combination thereof.
An enclosure for accommodating electronic devices, elements and the like comprises a base plate and side walls rising therefrom. An insert element joining the side walls is installed in the contact region between two adjacent side walls, and the respective free edges of the side walls are retained force- or form-fit within holding grooves of the insert element.