Pipe extrusion plant

Abstract

A pipe extrusion plant for producing pipes with a variable diameter includes an extruder, an adjustable calibration device, and a cooling device, whereby a pipe to be produced is guided at least in part during the production process. In order to be able to provide a guide that is suited to different pipe diameters, a roll assembly is provided to include a row of rolls which are placed one behind the other in a take-off direction, with each roll mounted in a bracket and supported to allow vertical positioning thereof in dependence on the pipe diameter.

1 . A pipe extrusion plant for producing pipes with different diameter, comprising:
 an extruder for plasticizing a starting material to produce a melt strand;   an adjustable calibration device sizing the melt strand to shape for forming a molten tube;   a cooling device for cooling the tube; and   a roll assembly for guiding the tube during advance through the calibration device and the cooling device, said roll assembly including a plurality of rolls arranged behind one another in a travel direction and constructed to have at least two different roll geometries, and adjustment means for automatically positioning the rolls in vertical direction in dependence on a diameter of a pipe being produced.   
   
   
       2 . The pipe extrusion plant of  claim 1 , wherein the adjustment means are constructed to carry out the positioning of the rolls in dependence on a weight load upon the rolls. 
   
   
       3 . The pipe extrusion plant of  claim 1 , wherein one of the rolls has a first roll geometry to conform to a maximum radius of a pipe being produced, and wherein another one of the rolls has a second geometry to lateral support a smallest pipe to be produced. 
   
   
       4 . The pipe extrusion plant of  claim 2 , wherein each of the rolls is supported by an axle, said adjustment means including an elastic element for movably supporting the roll so as to allow the roll to move downwards as a load on the roll increases. 
   
   
       5 . The pipe extrusion plant of  claim 4 , wherein the elastic element is a spring. 
   
   
       6 . The pipe extrusion plant of  claim 5 , wherein the spring is a spiral spring. 
   
   
       7 . The pipe extrusion plant of  claim 1 , wherein the adjustment device includes a sensor for scanning a pipe diameter, and a drive unit for vertically adjusting the rolls in response to a signal of the sensor commensurate with the ascertained pipe diameter. 
   
   
       8 . The pipe extrusion plant of  claim 7 , wherein the sensor is a laser or mechanical sensor. 
   
   
       9 . The pipe extrusion plant of  claim 7 , wherein the drive is an electric drive, hydraulic drive, or pneumatic drive.