Abstract:
A texturing machine for draw texturing a plurality of synthetic multi-filament yarns and which includes a plurality of side by side processing stations. Each of the processing stations comprises a plurality of processing units for advancing, texturing, drawing, and winding the yarn. At least one of the processing units is driven by an electrical individual drive, with the individual drives of the processing units of adjacent processing stations being controlled by a common group frequency changer. To enable a separate connection and disconnection of the individual drives with a simultaneous group control, the electrical individual drive of each processing unit includes an asynchronous unit and a synchronous unit. In the case of a predetermined desired frequency, this permits an automatic startup and maintenance of the desired frequency, which leads to a high degree of uniformity of the yarn treatment in each processing station.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     The present application is a continuation of international application PCT/EP03/01486 filed 14 Feb. 2003 and designating the U.S. The disclosure of the referenced international application is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The invention relates to a texturing machine for draw texturing a plurality of synthetic multi-filament yarns. A texturing machine of this general type is disclosed in DE 100 26 942 A1 and Patent Publication US 2002/0088218A1.  
         [0003]     For draw texturing a plurality of yarns, texturing machines of the described type possess a corresponding plurality of side by side processing stations. Each of the processing stations comprises a plurality of processing units, such as, for example, feed systems, false twist texturing units, and takeup devices, which serially advance, texture, draw, and wind the yarn to a package.  
         [0004]     To drive the processing units, basically two different variants are known. In a first variant, all processing units of a group, for example, all first feed systems of the processing stations together are synchronously driven by one drive. However, this variant has in general the disadvantage that it does not permit an individual control of the processing stations. To avoid such disadvantage, the above cited documents disclose a variant of the drive, which uses individual drives to drive the processing units within the processing stations. In this process, a group frequency changer activates the individual drives of a group of processing units of adjacent processing stations, such as, for example, all individual drives of the first feed systems. However, it has now been found that the individual activation of the processing stations results in that the individual drives of the processing units are more often connected and disconnected separately from one another. In this connection, it must be ensured that in the operating state, each of the individual drives of a group of processing units have the same operating parameters, for example, drive speed.  
         [0005]     It is therefore an object of the invention to further develop a texturing machine of the initially described type in such a manner that even after shutting down certain individual drives, it is always possible to operate the processing units of a functional group of a plurality of processing stations in a certain operating state without requiring a larger number of control systems.  
       SUMMARY OF THE INVENTION  
       [0006]     The above and other objects and advantages of the invention are achieved by providing a texturing machine composed of a plurality of side by side processing stations, and wherein at least one of the processing units of each station is driven by an electrical individual drive. Also, the electric individual drive of the processing unit comprises an asynchronous unit for starting up to a predetermined desired frequency and a synchronous unit for maintaining the predetermined desired frequency.  
         [0007]     The invention thus has the advantage that a group frequency changer may be provided which permits activating the individual drives in a simple manner so that only a desired frequency is applied to each individual drive. In this connection, the desired frequency forms the operating state (e.g. rotational speed) that is necessary for the processing unit. In the individual drive, the asynchronous unit sees to it that after starting up, the individual drive starts operating directly until the desired frequency is reached. Upon reaching the desired frequency, the synchronous unit of the individual drive becomes operative and prevents the processing unit from being driven with a frequency that deviates from the desired frequency. The processing unit thus reaches automatically an operating state that corresponds to the desired frequency. With that, it is possible to use a group frequency changer for controlling a plurality of individual drives in a simple manner. After each connection, it is thus possible to operate the processing units of a functional group in the operating state reliably with the respectively predetermined desired parameters. This ensures an identical treatment of all yarns in the processing stations.  
         [0008]     The electric individual drives may be constructed both as asynchronous motors and as synchronous motors. In the case that the asynchronous motor forms the asynchronous unit of the individual drive, the asynchronous motor includes a field magnet which forms part of a synchronous unit. The field magnet is formed preferably by a plurality of permanent magnets, which are mounted on the rotor of the asynchronous motor. With that, it is accomplished that the asynchronous motor can automatically maintain the predetermined desired frequency after the acceleration phase. The field magnet ensures that the rotor operates synchronously with the rotating field of the stator of the asynchronous motor. This further development of the invention is suitable in particular for processing units, which require a relatively high starting torque.  
         [0009]     It is preferred to form the synchronous unit by a synchronous motor, which comprises as an asynchronous unit an auxiliary winding arranged on the rotor. This ensures that during an activation of the individual drive at a constantly predetermined desired frequency, the synchronous motor starts up without delay, until the rotor of the synchronous motor is in sync with the rotating field of the stator.  
         [0010]     To enable an individual startup and shutdown of the processing stations independently of one another, a very advantageous further development of the invention proposes to connect each of the individual drives of the group of processing units to the group frequency changer via a controllable switching element. This makes it possible to shut down one or more of the individual drives associated to the group frequency changer without influencing adjacent individual drives and processing units.  
         [0011]     Moreover, it will be of advantage, when each of the individual drives comprises a sensor for monitoring the rotational speed. This sensor connects to a control unit that controls the switching elements. Thus, it is possible to avoid with advantage an overload of the individual drives by a comparison of actual and desired values.  
         [0012]     For example, to switch from a threading speed to an operating speed, while threading the yarns in the processing stations, a particularly preferred further development of the invention proposes to connect the control unit and the group frequency changer to an overriding central machine control system.  
         [0013]     With the use of a plurality of individual drives for a plurality of processing units, one frequency changer each is associated to the individual drives of a group of processing units, with all group frequency changers being coupled with the machine control system. To increase the flexibility of a texturing machine, a further advantageous embodiment of the invention proposes to divide the plurality of processing stations into one or more sections, with each section comprising a plurality of processing stations. In this case, the group frequency changers of the section connect to a field control system that is connected to the section. The processing units of the processing stations in the particular section can thus be controlled independently of the processing units of the processing stations of adjacent sections.  
         [0014]     The processing units driven by individual drives may advantageously be formed for each processing station by a first feed system, and/or a second feed system, and/or a third feed system. This makes it possible to adjust and vary in an accurate manner both the yarn speed and the draw ratio for drawing the yarn.  
         [0015]     The group of processing units, which are driven by individual drives, may also include in each processing station a drive roll of a takeup device and/or by a false twist texturing unit.  
         [0016]     Basically, all rotatably driven processing units are suited for operating with a substantially predetermined desired frequency while draw texturing the yarns. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     In the following, embodiments of a texturing machine according to the invention are described in greater detail with reference to the attached drawings, in which:  
         [0018]      FIG. 1  is a schematic side view of a first embodiment of a yarn texturing machine according to the invention;  
         [0019]      FIG. 2  is a schematic fragmentary top view of a further embodiment of a yarn texturing machine;  
         [0020]      FIG. 3  is a schematic view of an embodiment of an individual drive for a feed system;  
         [0021]      FIG. 4  is a schematic view of a further embodiment of an individual drive for a feed system; and  
         [0022]      FIG. 5  shows an embodiment of an individual drive for a drive roll of a takeup device. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]      FIG. 1  schematically illustrates a first embodiment of a yarn texturing machine according to the invention. The texturing machine comprises a feed module  3 , a processing module  2 , and a takeup module  1 , which are arranged in a machine frame composed of frame sections  4 . 1 ,  4 . 2 , and  4 . 3 . The frame section  4 . 1  mounts the feed module  3 , and the frame section  4 . 3  mounts the processing module  2  and takeup module  1 . The frame sections  4 . 1  and  4 . 3  are interconnected by frame section  4 . 2 , which is arranged above the feed module  3  and processing module  2 . Between the processing module  2  and the feed module  3 , a service aisle  5  extends below the frame section  4 . 2 . In the frame section  4 . 2 , the processing module  2  is arranged on the side facing the service aisle  5 , and the takeup module  1  on the opposite side thereto.  
         [0024]     A doffing aisle  6  is provided along the takeup module  1 . In its longitudinal direction (in  FIG. 1 , the plane of the drawing corresponds to the transverse plane) the texturing machine comprises a plurality of side by side processing stations, one processing station for each yarn. Takeup devices  18  occupy a width of three processing stations. Therefore, three takeup devices  18  are superposed in the takeup module  1  in a column, as will be described in more detail further below.  
         [0025]     The view of  FIG. 1  shows the processing units of a processing station, which are accommodated respectively in the feed module  3  and processing module  2 . Each processing station thus comprises a plurality of processing units  10 ,  11 ,  12 ,  13 ,  14 ,  15 ,  16 ,  17 , and  18 , one following the other in the path of an advancing yarn.  
         [0026]     A first group of the processing units is formed in each processing station by a first feed system  10 , which is mounted to the feed module  3 . The adjacent first feed systems of adjacent processing stations are arranged side by side (not shown). A feed yarn package  8  in a creel  7  is associated to each first feed system  10 . Next to the feed yarn package  8 , the creel  7  of each processing station accommodates a reserve package  43 . In each processing station, the first feed system  10  withdraws a yarn  36  via a plurality of yarn deflection guides  9 . 1  and  9 . 2 .  
         [0027]     In the following, the further processing units of a processing station are described with reference to the path of yarn  36 . In the direction of the advancing yarn, downstream of the first feed system  10 , an elongate primary heater  11  extends, through which the yarn  36  advances. In so doing, the yarn  36  is heated to a predetermined temperature. The primary heater  11  could be constructed as a high-temperature heater, whose heating surface has a temperature above 300° C. In the direction of the advancing yarn, downstream of the primary heater  11 , a cooling device  12  is provided. The primary heater  11  and cooling device  12  are arranged in one plane, one following the other, and supported by the frame section  4 . 2  above the service aisle  5 . In the inlet region of the primary heater  11 , a deflection roll  9 . 3  is arranged, so that the yarn  36  crosses the service aisle  5  in the configuration of an inverted V.  
         [0028]     On the side of the service aisle  5  opposite to the feed module  3 , the frame section  4 . 3  mounts the processing module  2 . In the direction of the advancing yarn, the processing module  2  supports, one below the other, a false twist unit  13 , a second feed system  14 , and a third feed system  15 . In this arrangement, the yarn  36  advances from the outlet of the cooling device  12 , which is preferably formed by a cooling rail or a cooling tube, to the false twist texturing unit  13 . The false twist texturing unit  13 , which may be formed, for example, by a plurality of overlapping friction disks, is driven by a false twist drive  26 . The false twist drive  26  is constructed as an individual drive  27 , which is likewise arranged on the processing module  2 .  
         [0029]     The second feed system  14  withdraws the yarn  36  from the false twist zone, which extends between the false twist texturing unit  13  and the first feed system  10 . The second feed system  14  and the first feed system  10  are driven at different speeds for drawing the yarn  36  in the false twist zone.  
         [0030]     Downstream of the second feed system  14 , the third feed system  15  is positioned, which advances the yarn  36  directly into a secondary heater  16 . To this end, the secondary heater  16  is arranged on the underside of frame section  4 . 3  and, thus, below the processing module  2  and takeup module  1 . The secondary heater  16  represents the yarn passage from the processing module to the takeup module  1 . As a result of integrating in the frame section  4 . 3 , the processing module  2 , secondary heater  16 , and takeup module  1 , a very short yarn path is realized, which is substantially U-shaped. To this end, the underside of the takeup module  1  mounts a fourth feed system  17 , which withdraws the yarn  36  directly from the secondary heater  16 , and advances it after a deflection to the takeup device  18 .  
         [0031]     The third feed system  15  and fourth feed system  17  may be driven at different speeds, so as to enable a shrinkage treatment of the yarn  36  within the secondary heater  16 . To this end, the secondary heater  16  may comprise a biphenyl-heated contact heater, which is inclined relative a horizontal by an angle α. The angle ranges from 5° to 45°. With that, it is made certain that within a heating channel of the secondary heater  16 , the yarn  36  undergoes a uniform heating caused by contact.  
         [0032]     In the present embodiment, the takeup device  18  is schematically identified by a yarn traversing device  20 , a drive roll  19 , and a package  21 . The takeup device  18  also includes a tube magazine  22  for performing an automatic package doff. Auxiliary devices that are needed for doffing full packages are not shown in greater detail.  
         [0033]     In the present embodiment, the feed systems  10 ,  14 ,  15 , and  17  are made identical. They are each formed by a godet  23  and a guide roll  24  associated therewith. The godet  23  is driven by a godet drive  25 . The guide roll  24  is supported for free rotation, so that the yarn  36  advances over godet  23  and guide roll  24  by looping them several times.  
         [0034]     In the embodiment of the texturing machine shown in  FIG. 1 , the godet drive  25  of the first feed system  10  is constructed as an individual drive  27 . The individual drive  27 , whose construction is described in greater detail in the following, is coupled with a group frequency changer  30  via a switching element  32 . The group frequency changer  30  is likewise associated to adjacent individual drives of adjacent first feed systems in adjacent processing stations not shown. Thus, it is possible to associate, for example, all individual drives of the first feed systems within a texturing machine to a common group frequency changer  30 . The group frequency changer  30  connects to a central machine control system  44 . Thus, the first feed system  10  represents a first functional group of processing units, which are driven within the machine by individual drives  27 .  
         [0035]     A second functional group of processing units is formed by the false twist units  13 . The false twist drives  26  are likewise constructed as individual drives  27 , which are associated to a second group frequency changer  45 . Likewise, a switching element  32  is used to connect the individual drives  27  to the second group frequency changer  45 , which likewise connects to the machine control system  44 .  
         [0036]     The drives and drive control of the remaining processing units are not described in greater detail. They could likewise be formed, for example, by individual drives with a control system via group frequency changers or by individually controlled drives.  
         [0037]     In operation, the individual drives  27  of the feed systems  10  and false twist units  13  are controlled with a desired frequency that is defined by the machine control system  44 , so that the feed system  10  has a certain circumferential speed for advancing the yarn  36 , and so that the false twist unit  13  likewise reaches a drive speed that is needed for texturing the yarn. As is known, in the processing station, the yarn  36  is advanced, drawn, textured, and wound to a package  21 . In the case that a breakdown occurs in the illustrated processing station, for example, by a yarn break, the switching element  32  separates the individual drives  27  of the feed system  10  and the false twist unit  13  from their respective group frequency changer  30  or  45 . The first feed system  10  and the false twist unit  13  are shut down. Adjacent processing stations remain unaffected by this action. The individual drives associated to the group frequency changers  30  and  45  remain in an unchanged operating state.  
         [0038]     After eliminating the breakdown in the processing station, a reconnection to the group frequency changers  30  and  45  will occur via the switching elements  32 , so that it is again possible to activate the individual drives  27 . With that, the desired frequency is applied to the individual drives  27 .  
         [0039]     To enable the connection and disconnection as well as the startup and continuation in the operating state of the individual drives  27  without requiring a larger number of control means, each individual drive  27  includes a synchronous unit and an asynchronous unit.  FIG. 3  illustrates a first embodiment of an individual drive  27 , which is constructed as an asynchronous motor  35 . The asynchronous motor  35  thus represents the asynchronous unit  29  that comprises a stator winding  39  and a rotor winding  41 . To this end, the rotor winding  41  is attached to a rotor  40 . Inside the stator winding  39 , the rotor  40  mounts a field magnet  36 , which represents the synchronous unit  28  together with the stator winding  39 . The field magnet  36  of this embodiment is formed by a plurality of permanent magnets, which are mounted on the circumference of the rotor  40 . With its end projecting from the motor casing, the rotor  40  connects to the godet  23  of the first feed system  10 .  
         [0040]     To start up the asynchronous motor  35 , a desired frequency is applied via the group frequency changer  30 . After applying current to the stator winding  39 , the rotor  40  is accelerated. As soon as the rotational frequency of the rotor  40  corresponds to the desired frequency, a coupling occurs between the rotating field of the stator winding  39  and the rotational frequency of the rotor  40  by means of the field magnet  36 . In its operating state, the individual drive  27  performs similarly to a synchronous machine. With that, it is made sure that the desired frequency as determined by the group frequency changer  30 , is automatically adjusted by the activated individual drive  27 . This is important in particular for the processing units, which are arranged in the texturing machine in the form of feed systems. The yarn is thus advanced and drawn under identical conditions in each processing station.  
         [0041]      FIG. 4  illustrates a further embodiment of an individual drive  27  with a synchronous unit  28  and an asynchronous unit  29 . Components having the same function are provided with identical reference numerals. The synchronous unit  28  is formed by a synchronous motor  38 . To this end, the synchronous motor  38  comprises a stator winding  39  and a rotor  40  with at least one permanent magnet  37 . In this case, the rotational frequency of the rotor  40  equals the desired frequency, so that the rotor  40  rotates in sync with the rotating field of the stator winding. To enable a startup without changing the desired frequency after a shutdown of the individual drive  27 , the synchronous motor  38  includes an asynchronous unit  29 , which is formed by an auxiliary winding  42  on the rotor and the stator winding  39 . The auxiliary winding  42  is arranged inside the stator winding  39 . This ensures that the rotor  40  is accelerated with a predetermined desired frequency of the stator winding  39 .  
         [0042]     The embodiments of the individual drive as shown in  FIGS. 3 and 4  are suited preferably for driving the feed systems of a texturing machine or for driving a false twist friction unit.  
         [0043]      FIG. 5  illustrates a further embodiment of an individual drive  27 , which is suited preferably for driving a drive roll  19  in a takeup device  18 . To this end, the jacket of the drive roll  19  is directly driven by the individual drive  27  arranged inside the drive roll  19 . For this purpose, the individual drive  27  comprises a cylindrical rotor  40 . The inner side of the cylindrical rotor  40  mounts the rotor winding  41 . In facing relationship with the rotor winding  41 , a stationary axle  46  mounts a stator winding  39 . In the axial direction, the stator winding  39  extends beyond the rotor winding  41  to cover a field magnet  36  arranged on the cylindrical rotor  40 . The field magnet  36  and the stator winding  39  thus form the synchronous unit  28  of the individual drive  27 . As a result of construction, the asynchronous unit  29  is provided as an asynchronous motor  35 . The operation of the embodiment shown in  FIG. 5  is identical with that described with reference to  FIGS. 3 and 4 .  
         [0044]      FIG. 2  illustrates a further embodiment of a texturing machine as a fragmentary top view thereof. The embodiment of  FIG. 2  is made substantially identical with the preceding embodiment of  FIG. 1 . In this respect, the arrangement of the processing units within a processing station is made identical, so that the foregoing description is herewith incorporated by reference.  
         [0045]     The top view illustrated in  FIG. 2  shows only the yarn feed to the machine with creel  7  and feed module  3 . The processing module  2  and takeup module  1  are not shown. As a whole,  12  processing stations are shown in side-by-side relationship. In this connection, the creel  7  accommodates in tiers the feed yarn packages  8  of three juxtaposed processing stations, with one package overlying the other, as can be noted from  FIG. 1 . However, for the sake of clarity, the yarn path is not shown in  FIG. 2 .  
         [0046]     The feed module  3  mounts in side-by-side relationship the feed systems  10 , which withdraw each yarn  36  from respectively one feed yarn package  8  of the creel  7 . Each processing station is provided with one first feed system  10 . Each feed system  10  comprises an individual drive  27 , which is coupled with a godet  23  and a guide roll  24  associated thereto.  
         [0047]     To control the individual drive  27 , the drive connects via a switching element  32  to a group frequency changer  30 . The group frequency changer  30  supplies the individual drives  27  of a total of six feed systems of a plurality of processing stations. In this connection, six processing stations form one section, which is controlled by means of a field control system  34 . 1  or  34 . 2 . Thus, the group frequency changer  30  connects to a field control system  34 . 1  of a first section I of processing stations. Accordingly, the individual drives  27  of the feed systems  10  of a second section II are controlled via a further group frequency changer  30 , which in turn is coupled with an associated field control system  34 . 2 .  
         [0048]     The field control systems  34 . 1  and  34 . 2  connect to additional group frequency changers or control units or drive units for controlling the processing stations.  
         [0049]     Furthermore, the individual drives  27  of a section are associated with a control unit  33 , which connects to each of the switching elements  32  associated to the individual drives  27  of a section. Each of the individual drives  27  also includes a sensor  31 , which connects to the control unit  33 . The control unit  33  is also coupled with the field control system  34 . 1  or  34 . 2 .  
         [0050]     The field control systems  34 . 1  and  34 . 2  and additional adjacent field control systems connect to a central machine control system (not shown).  
         [0051]     In the texturing machine shown in  FIG. 2 , a group frequency changer  30  activates in the operating state, the individual drives  27  of the first feed systems  10  of each section with a predetermined desired frequency. To is this end, the field control system  34 . 1  or  34 . 2  applies both to the group frequency changer  30  and to the control unit  33 , the corresponding desired frequency, which corresponds to a certain withdrawal speed of the yarns from the feed yarn packages  8 . At the beginning of the process, each of the individual drives  27  is accelerated because of the asynchronous unit accommodated therein. As soon as the rotational frequency of the rotor reaches the desired frequency, the synchronous unit of the individual drives  27  maintains a predetermined circumferential speed on each of the feed systems  10 .  
         [0052]     In the case that one of the individual drives  27  shows a malfunction, which indicates an unacceptable deviation from the desired frequency, the group frequency changer  30  shuts down the particular individual drive  27  via the sensor  31 , control unit  33 , and switching element  32 . To this end, a comparison occurs in the control unit  33  between the actual condition signaled by the sensor  31  and a desired condition that is set by the field control system  34 . 1  or  34 . 2 . In the case of an unacceptable deviation of the actual condition from the desired condition, the control unit  33  activates the respective switching element  32 . In this process, information is exchanged between the control unit  33  and the field control system. As soon as the malfunction is eliminated, the corresponding switching element is activated via control unit  33  for starting the individual drive. In this process, individual drives  27  adjacent the group frequency changer  30  remain unaffected in their control.  
         [0053]     The synchronous units and asynchronous units formed in the individual drives  27  ensure an independent startup and adjustment of the desired circumferential speed on the feed systems. This achieves a great uniformity of the yarn treatment in each of the processing stations of the texturing machine without reducing the flexibility in the activation of the individual processing stations. With that, the texturing machine of the present invention combines the advantages of a group drive for processing units of the same function with the advantages of a processing station with individually driven processing units.