Abstract:
An apparatus for producing thermoplastic corrugated pipes may include an extrusion device with an extruder and an extrusion die device and a corrugator device with traveling mold jaws. The extrusion device and the corrugator device are positionally movable in relation to one another, for example for adjustment. The extrusion device is positionally movable in relation to the corrugator device in a horizontal plane, while the corrugator device is movable exclusively in height here.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a national phase entry under 35 U.S.C. §371 of International Application No. PCT/EP2008/004540, filed Jun. 6, 2008, published in German, which claims the benefit of German Patent Application No. 10 2007 049 653.4, filed Oct. 12, 2007. The disclosures of said applications are incorporated by reference herein. 
     FIELD 
     The invention relates to an apparatus for producing thermoplastic corrugated pipes, the apparatus having an extrusion device with an extruder device and an extrusion die device and a corrugator device with traveling mold jaws, and the extrusion device and the corrugator device being positionally movable in relation to one another, for example for adjustment. 
     BACKGROUND 
     Known apparatuses of this type with a horizontal direction of production (X direction) provide that the corrugator can be made to move in the direction of production, to be precise on the one hand for adjustment in the X direction and on the other hand to move the corrugator away from the extrusion device in the event of operational failure and for changing the mold. For adjustment in the Y direction, i.e. transversely in relation to the direction of production, and for adjustment in the vertical direction (Z direction), the conventional extrusion devices have corresponding Y and Z adjusting devices. 
     The moving of the corrugator device when carrying out an adjustment and in particular when moving the corrugator away in the event of operational failure and for changing the mold causes relative displacements with respect to the peripheral devices downstream of the corrugator device, such as downstream cutting and transporting devices. In the case of the conventional installations, these downstream peripheral devices are therefore usually connected in the manner of a concertina connection, which however causes disadvantages in terms of equipment and layout. The disadvantages are particularly great in the case of configurations for producing corrugated pipes of large nominal widths, since the components of the installations are then relatively voluminous and heavy. 
     SUMMARY 
     The invention is based on the object of providing an apparatus of the type mentioned at the beginning which is structurally designed in such a way that designs for producing corrugated pipes of large nominal widths can also be created with simple constructions. 
     The invention achieves this object by the subject matter of the present disclosure. The fact that the extrusion device is positionally movable in relation to the corrugator device, in that the extrusion device can be made to move linearly in the X direction and in the Y direction, makes it possible to design the possibly heavy and voluminous corrugator device without the capability of moving in the X and Y directions. This is of particular advantage if the direction of production is arranged in the X direction. This is so because the capability of the extrusion device of moving in the X direction can then be designed such that on the one hand the adjustment in the X direction and on the other hand the moving of the extrusion device away from the corrugator device in the X direction can be accomplished if an operational failure occurs or a mold change is to be carried out. The corrugator device is preferably designed to be positionally movable in the vertical direction, in order to accomplish the adjustment in the vertical direction by making the corrugator device move in the vertical direction. 
     In the case of preferred designs, it is provided that the corrugator device is movable such that it is positionally movable exclusively in the vertical direction and therefore is not positionally movable in the X direction or in the Y direction. In the case of modified designs, however, the corrugator device may also additionally be positionally movable in both the other directions. Furthermore, designs in which the extrusion device is positionally movable in the X, Y and Z directions are conceivable. 
     In the adjustment, the adjusting devices that are present on the extrusion device and on the corrugator device may complement one another with an identical direction in the movement path, whereby simplifications in the structural design of the individual adjusting devices and handling advantages in the adjustment can be obtained. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Further features and advantages of the invention emerge from the following description of an exemplary embodiment with reference to the figures, in which: 
         FIG. 1  shows a perspective view of an exemplary embodiment of the apparatus for producing thermoplastic corrugated pipes with an extrusion device and a corrugator device, seen obliquely from above, 
         FIG. 2  shows a side view of the exemplary embodiment in  FIG. 1 ; 
         FIG. 3  shows a sectional end-on view of the corrugator device of the exemplary embodiment in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The apparatus represented in the figures has as the main components an extrusion device  1  and a corrugator device  2 . In the case represented, the extrusion device  1  is made up of two extruders  1   a  and a common die device  1   b . The extrusion device  1  has a frame  1   o , on which the two extruder devices  1   a  and the common die device  1   b  are installed. The common die device  1   b  is exchangeably mounted on an angular stand  1   w  fixedly installed on the frame  1   o . The extruders  1   a  are mounted displaceably along the direction of production by means of rollers on rails on the frame  1   o . The extruder devices  1   a  are connected to the die device  1   b  by means of flexible lines  1   f . In addition, a switch cabinet is arranged on the frame  1   o.    
     The frame  1   o  with the components  1   a  and  1   b  arranged on it is mounted on a lower base frame  1   u . Arranged on the lower base frame  1   u  is a linear rail device  1   x , which runs in the X direction and in which the upper frame  1   o  is linearly displaceable in the X direction by means of a ball bearing guide. The sliding guidance in the X direction allows the extrusion devices with the extruders  1   a  together with the die device  1   b  to be displaced by about 3 m away from the corrugator device  2  in the event of operational failure or in the case of a mold change. Furthermore, the sliding guidance allows the extruder device to be moved in the X direction in the course of adjustment on the frame  1   o.    
     The base frame  1   u  can be made to move in the Y direction, i.e. transversely to the X direction, on fixedly installed base plates  1   p . Arranged for this purpose on the base plates  1   p  are rail devices  1 Y, which run in the Y direction and in which the lower base frame  1   u  is displaceable by means of rollers. The sliding guidance in the Y direction allows the extrusion device to move in the Y direction in the course of the adjustment. 
     To provide propulsion for the movement in the X direction, hydraulic drives with hydraulic pressure cylinders are provided. They are mounted on the lower base frame  1   u  and act on the upper frame  1   o . Provided in case of emergency is a pressure accumulator, which ensures that the extrusion device is moved sufficiently far away from the corrugator by means of the hydraulic drive even in the event of a power failure. When the hydraulic drives are switched off, the frame  1   o  is arrested on account of the self-locking of the hydraulic drives. Consequently, the frame  1   o , and with it the extrusion device  1 , can be arrested in a selectable position on the base frame  1   u  in the course of the adjustment in the X direction by means of the switching off of the hydraulic drives. 
     To provide propulsion for the movement in the Y direction, electric geared motors are provided, each providing propulsion by means of cardan shaft rams. In the case represented, three such geared motors  1   m  are provided. The geared motors  1   m  are mounted in fixed base plates  1   p . The driven rams are mounted in gearboxes on the base plates and act on the base frame  1   u  in the sense of providing propulsion in the Y direction in the adjustment. When the geared motors  1   m  are switched off, the base frame  1   u  is arrested on account of the self-locking of the gear mechanisms. Consequently, the base frame  1   u , and with it the extrusion device  1 , can be arrested in a selectable position on the base plates  1   p  in the course of the adjustment in the Y direction by means of the switching off of the geared motors. 
     The corrugator device  2  comprises a machine table  2   t , which in the case represented is horizontal, with mold jaws  2   f  guided on it. In the representation in  FIG. 1 , only one of the corrugator mold jaws if is shown in order to provide a clearer overall view. Pairs of the mold jaws  2   f  respectively form a mold cavity. The mold jaw halves are guided on the machine table  2   t  in a linear molding section  2   ms  to form a linear mold channel  6 . In this linear molding section, the pairs of mold jaws are guided such that they are arranged in series one behind the other. The propulsion for the mold jaws  2   f  in the molding section  2   ms  is provided by a drive motor  2   a , which is arranged in the machine table  2   t  and has an output pinion  2   r . The output pinion  2   r  meshes here with the bottom toothed racks of the mold jaws guided in the molding section. Consequently, the mold jaws are advanced in the molding section in the X direction away from the extrusion device. By means of grippers  2   gr , the mold jaws  2   f  are returned from the end of the molding section  2   ms  to the beginning of the molding section. The beginning of the molding section  2   ms  follows on directly from the die device  1   b . The die device may protrude here into the mold channel, to be precise preferably to the extent that the end of the die from which the tube of polymer melt emerges from the die device already lies in the mold cavity enclosed by the corrugator jaws. It reaches into the cooling mandrel of the die device. The axis of the mold channel  6  is linearly in line with the axis of the die device l b  and forms the axis of the direction of production X. 
     The corrugator device  2  operates as follows: 
     The tube of polymer melt emerging from the die device.  1   b  passes through the mold channel of the pair of mold jaws arranged one behind the other in the molding section. The tube of melt is thereby cooled and molded to form a corrugated pipe. At the end of the mold channel, the finished corrugated pipe emerges as a continuous pipe. 
     For the molding and cooling in the mold channel, the corrugator device  2  has vacuum and cooling devices known per se. In the present case, these are not specifically represented in the figures. In the case represented, these vacuum and cooling devices are supplied by means of a supply bridge  2   b  arranged above the machine table  2   t.    
     The corrugator device  2  is adjustable in the vertical direction, in that the position of the machine table  2   t  can be changed in the vertical direction by means of pushing spindles. Four pushing spindles  2   s  are provided. They are arranged in the region of the corners of the machine table  2   t , which is rectangular in plan view, to be precise two pushing spindles  2   s  at the front, i.e. in the region of the beginning of the molding section, and two pushing spindles  2   s  at the rear, i.e. in the region of the end of the molding section. 
     The pushing spindles  2   s  are respectively mounted such that they are axially displaceable in the vertical direction, in a threaded nut  2   g  mounted rotatably in a fixed bearing block. At their upper free end, the pushing spindles  2   s  respectively act on the underside of the corrugator table  2   t.    
     The front and rear pairs of pushing spindles are respectively driven by means of a front and rear geared motor  2   m . The geared motor  2   m  drives the two pushing spindles  2   s  of the respective pair of pushing spindles synchronously by means of a common output shaft  2   w.    
     The case represented concerns an apparatus for producing corrugated pipes of large nominal width, i.e. in the range of nominal widths from 600 to 2400 mm, preferably for nominal widths of 1800 mm. Because of the large mold jaws  2   f  that are used, the corrugator device  2  is relatively voluminous and heavy. Usually six pairs of mold jaws with a further pair of socket-type mold jaws are used on the machine table  2   t , so that the overall weight of the corrugator device  2  is of the order of 60 t. It is therefore of significant advantage if the corrugator device  2  does not have to have an adjusting device in the X and/or Y direction but only an adjusting device in the vertical direction, as is the case in the exemplary embodiment that is represented in the figures. 
     In the case represented, the adjustment in the X and Y directions takes place by means of the relevant X and Y adjusting devices of the extrusion device  1 . A major advantage in this connection is that the setting device in the X direction both accomplishes the adjustment in the X direction and allows the displacing movement of the extrusion device  1  away from the corrugator device  2  if an operational failure occurs or a mold change is performed. A movement path of 3 m is available for this case. 
     In modified exemplary embodiments, the extrusion device  1  may also have in addition to the adjusting device in the X and Y directions an adjusting device in the vertical direction. In such a case, the vertical adjustment may then also take place by means of the vertical displacement of the extrusion device  2 . 
     LIST OF DESIGNATIONS 
     
         
           1  Extrusion device 
           1   a  Extruder 
           1   b  Die device 
           1   o  Frame 
           1   w  Angular stand 
           1   f  Flexible line 
           1   s  Switch cabinet 
           1   u  Base frame 
           1   x  Rail device 
           1   p  Base plate 
           1   x  Rail device 
           1   m  Electric drive motor 
           2  Corrugator device 
           2   t  Machine table 
           2   f  Mold jaws 
           2   ff  Socket-type mold jaws 
           2   ms  Linear molding section 
           2   a  Drive motor 
           2   r  Output pinion 
           2   gr  Gripper 
           2   b  Supply bridge 
           2   s  Pushing spindle 
           2   g  Threaded nut 
           2   m  Geared motor 
           2   w  Output shaft