Rotor spinning machine and method for operating a rotor spinning machine

Abstract

The invention relates to a rotor spinning machine and to a method for operating a rotor spinning machine with a control device, an open-end rotor spinning device and a supply unit feeding at least two fiber slivers into the open-end rotor spinning device, which supply unit has an opening roller for opening fiber slivers and a feed apparatus with a first and a second feed roller, which can be operated independently of one another by means of the control device, for a first fiber sliver and a second fiber sliver. In order to provide a rotor spinning machine as well as a method for operating a rotor spinning machine, which enables easy setting of the drafting speeds of the supply unit having at least two feed rollers, it is provided that the control device determines an individual drafting speed of one feed roller for producing a yarn with predetermined yarn properties from a single fiber sliver fed by means of the first feed roller, and coordinates a first drafting speed of the first feed roller and a second drafting speed of the second feed roller with one another in such a way that the sum of the first and second drafting speeds corresponds to the individual drafting speed.

1 . A method for operating a rotor spinning machine ( 1 ) with a control device ( 9 ), an open-end rotor spinning device ( 3 ) and a supply unit ( 11 ) that feeds at least two fiber slivers ( 12 ,  13 ) into the open-end rotor spinning device ( 3 ) and has
 an opening roller ( 14 ) for opening fiber slivers ( 12 ,  13 ) and   a feed apparatus having a first and a second feed roller ( 16 ,  17 ), which can be operated independently of one another by means of the control device ( 9 ), for a first fiber sliver ( 12 ) and a second fiber sliver ( 13 ),   characterized in that   the control device ( 9 )   determines an individual drafting speed of one feed roller ( 16 ,  17 ) which would be required to produce a yarn with predetermined yarn properties from a single fiber sliver ( 12 ,  13 ) fed by means of the one feed roller ( 16 ,  17 ) and   coordinates a first drafting speed of the first feed roller ( 16 ) and a second drafting speed of the second feed roller ( 17 ) with one another in such a way that the sum of the first and second drafting speeds corresponds to the individual drafting speed.   
     
     
         2 . The method according to  claim 1 , characterized in that the control device ( 9 ) detects the twist, the draft and/or the yarn number of the yarn to be produced in order to determine the individual drafting speed. 
     
     
         3 . The method according to  claim 1 , characterized in that the control device ( 9 ) detects the fiber sliver numbers of the fiber slivers ( 12 ,  13 ) to be fed in. 
     
     
         4 . The method according to  claim 1 , characterized in that the control device ( 9 ) calculates the individual drafting speed on the basis of the predetermined yarn properties or retrieves it from a database. 
     
     
         5 . A rotor spinning machine ( 1 ) with a control device ( 9 ), an open-end rotor spinning device ( 3 ) and a supply unit ( 11 ) that feeds at least two fiber slivers ( 12 ,  13 ) into the open-end rotor spinning device ( 3 ) and has
 an opening roller ( 14 ) for opening fiber slivers ( 12 ,  13 ) and   a feed apparatus having a first and a second feed roller ( 16 ,  17 ), which can be operated independently of one another by means of the control device ( 9 ), for a first fiber sliver ( 12 ) and a second fiber sliver ( 13 ),   characterized in that   the control device ( 9 ) is designed   to determine an individual drafting speed of one feed roller ( 16 ,  17 ) which would be required to produce a yarn with predetermined yarn properties from a single fiber sliver ( 12 ,  13 ) fed by means of the one feed roller ( 16 ,  17 ) and   to set a first drafting speed of the first feed roller ( 16 ) and a second drafting speed of the second feed roller ( 17 ) such that the sum of the first and second drafting speeds corresponds to the individual drafting speed.   
     
     
         6 . The rotor spinning machine ( 1 ) according to  claim 5 , characterized in that the control device ( 9 ) is connected to an operating unit ( 10 ) for data input. 
     
     
         7 . The rotor spinning machine ( 1 ) according to  claim 5 , characterized in that the control device ( 9 ) is connected to a computing unit and/or a database.