EP2857567A1 - Method and device for monitoring the production of a knitting machine - Google Patents

Abstract

A method for monitoring the production of a knitting machine, wherein the yarn delivery of at least one yarn feeding device is monitored by a sensor device (19) and a control unit (20). In this case, a sensor signal (S) with a measuring pulse (I) per unit length of a yarn delivery path ("XF) is generated by the sensor device (19). The sensor signal (S) is evaluated by the control unit (20) and, if necessary, a stop signal (ST) for the knitting machine is generated by the control unit (20). A clock unit provides the control unit (20) with a clock signal (S2), wherein a clock pulse (T) of the clock signal (S2) corresponds to a length unit of the knitting path ("XS). The length unit of the knitting path ("XS") is smaller by a factor (Z) of at least 2, preferably from 3 to 10, than the length unit of the yarn feeding path ("XF"). The evaluation of the sensor signal (S) by the control unit (20) takes place as a function of the clock signal (S2).

Description

The invention relates to a method and a device for monitoring the production of a knitting machine.

In the knitting technique monitoring of the current production is often desired. This is from the EP 0 752 631 B1 known to monitor the supply of a variety of threads in a textile machine. Sensor devices are provided which detect the state of supply of the threads with which they are fed to the machine, in particular the movement or the stopping, the tension and the speed of the threads. The sensor devices are connected to a control unit which controls the operation of the machine on the basis of the sensor signals. The control unit is connected to the sensor devices via at least one communication conductor.

The control unit polls the sensor devices individually based on a periodic reference signal that is a function of the operating position of the textile machine, according to the data regarding the state of supply of the threads. The control unit controls the operation of the textile machine with the data from the sensor devices. It interrupts the operation of the textile machine when a difference occurs between the data obtained from at least one sensor device and the corresponding stored data.

A production monitoring / adjustment device and a corresponding method for a knitting machine, in particular a circular knitting machine are in the EP 1 370 720 B1 described. The apparatus comprises a plurality of knitting systems, a plurality of delivery devices and a computerized unit, the delivery devices being connected to the computerized unit. The production monitor / adjuster receives trig signals.

In operation, yarn is delivered to the active knitting systems of a plurality of non-positive delivering delivery devices according to at least two distinct yarn delivery principles. The individual yarn quantities are continuously measured by means of sampled actual rotation signals at the delivery devices. The individual yarn quantities are compared in the computerized unit with nominal yarn quantities of about a masterpiece and information and / or adjustment measures derived from the comparisons. Tolerances are defined for the comparisons, which are matched in their width to yarn quality and / or yarn path parameters. Exceeding the different tolerance ranges is used to trigger different measures, such as alarm signals, adjustment measures or switching off the knitting machine. The individual Yarn quantities are also used to determine a total amount of yarn and / or a yarn weight, being converted or converted into equal units or weight units.

The knitting machine with its machine control, the production monitoring / adjustment device and the delivery devices are connected via a bus system, e.g. a CAN bus system or a daisy chain linked.

In the abovementioned publications, individual data about states of the thread feed ( EP 0 752 631 B1 ) or over yarn quantities ( EP 1 370 720 B1 ) detected. In a central control unit, which is supplied with a synchronization signal designated as reference signal or trigger signal, the data are evaluated and used to control and possibly interrupt the operation of the knitting machine.

When in the EP 1 370 720 described production monitoring based on individual yarn quantities yarn quantities of a certain size are compared with their target yarn quantities. The individual yarn quantities are determined, for example, for knitting paths which correspond to one or more revolutions of the knitting cylinder of the circular knitting machine.

It is also for example from the WO 2008/083691 A1 known to use for production monitoring mechanical yarn feeler on a yarn feeding device, for example, produce a stop signal for the knitting machine at yarn breakage.

The EP 2 270 269 B1 describes a method for detecting the stopping of yarn unwinding from a yarn feeder to a downstream machine. The yarn feeder has a stationary drum and a sensor, through whose sensor signal one pulse is generated per loop unwound from the drum. The machine is stopped when a measured time since the last pulse exceeds a setpoint for the time between two pulses. The setpoint is updated in real time depending on the yarn unwinding speed.

In the in the EP 2 270 269 B1 described method is complicated to determine the respective Garnabwickelgeschwindigkeit very quickly in real time. In particular, it is complicated to determine in each case the time between two pulses and the desired value as a function of the take-off speed.

The object of the invention is to improve a method and a device for monitoring the production of a knitting machine. In particular, it is the task of Invention to allow a quick stop the knitting machine at yarn standstill or yarn breakage with little effort.

The object is achieved by a method according to claim 1.

An inventive method relates to the monitoring of the production of a knitting machine and allows in particular with little effort a rapid stopping of the knitting machine in yarn standstill or yarn breakage.

A knitting machine is designed, for example, as a circular knitting machine or a flat knitting machine.

For example, a circular knitting machine has several or a plurality of identical or different yarn feeding devices. Yarn feeding devices are, for example, positive yarn feeding devices, thread tension controlled yarn feeding devices or storage yarn feeding devices. Thread tension controlled thread feeders and store thread feeders are used when making knitwear with patterns.

The thread delivery takes place at storage yarn feeding devices in which the thread is withdrawn from, for example, a winding body. In the case of yarn tension-controlled yarn feeding devices, the yarn delivery takes place, in which the thread tension is regulated and the yarn is delivered accordingly. The yarn delivery of the Postiv yarn feeding devices is a feeding of the thread synchronously to the speed of the knitting machine.

In a method according to the invention, the yarn delivery of at least one yarn feeding device is monitored by a sensor device and a control unit. By the sensor device, a sensor signal is generated with one measurement pulse per unit length of a yarn delivery path. This sensor signal is evaluated by the control unit. Depending on the result of the evaluation, a stop signal for the knitting machine is generated by the control unit.

The respective control unit is provided by a clock unit, a clock signal available. A clock pulse of the clock signal corresponds to a unit length of a knitting path. The length unit of the knitting path is smaller by a factor of at least 2 than the unit length of the yarn feeding path. Preferably, the factor is 3 to 10.

The sensor signal indicating the yarn delivery path is evaluated by the control unit as a function of the clock signal indicating the knitting path. As mentioned, a stop signal for the knitting machine is possibly generated by the control unit.

The knitting path is defined in the context of the invention in a circular knitting machine as the distance traveled by the outer diameter of the knitting cylinder, on which the knitting needles are. That in one revolution of the knitting cylinder, the knitting path corresponds to the outer circumference of the knitting cylinder.

The knitting path is defined in a flat knitting machine as the path traveled along the needle bed by the carriage.

In the present invention, individual measuring pulses are evaluated in response to a specific clock signal, which represents a measure of the knitting path, for monitoring yarn delivery, for example, for yarn breakage. The clock signal is selected or generated so that at least 2 clock pulses are available per measuring pulse.

The use of a clock signal which provides clock pulses as a function of the knitting path makes possible a simple evaluation of a sensor signal which generates measurement pulses as a function of a yarn delivery path.

A certain number of these clock pulses corresponds to a certain length of the knitting path. It is independent of the machine speed of the knitting machine and also of the withdrawal speed of the thread. In operation, a number of clock pulses can be determined simply by counting.

The use of multiple clock pulses per measurable length unit of the yarn delivery path, i. per measuring pulse, enables a very fast evaluation and reaction to errors of the thread delivery, such as thread breakage.

This is a stopping of the knitting machine at yarn standstill or yarn breakage by a simple and reliable process without any computational effort.

In one embodiment, the length unit of the knitting path is 2 to 8 cm. It is preferably 4 to 6 cm.

In one embodiment, a number of clock pulses of the clock signal are counted by the control unit for evaluating the sensor signal in each case starting with a measurement pulse. The number of detected clock pulses is compared with a predetermined number.

The predetermined number corresponds to the factor given above, which corresponds to the ratio of the unit length of the yarn delivery path to the length unit of the knitting path, or is determined from the factor.

The predetermined number for a yarn feeding device is selected in one embodiment, depending on the binding, such as mesh, float and handle, the knitted product. In this case, the predetermined number in the case of binding floats corresponds, for example, to the order of magnitude of the factor Z. For example, in the binding loop, it is reduced to one-third of the factor Z. For example, when changing binding within a product, an average value is chosen.

In one embodiment, a predetermined number plus a safety constant or multiplied by a safety value is selected as a predetermined number as determined.

When the predetermined number of clock pulses is exceeded, a stop signal for the knitting machine is generated by the control unit. Exceeding the given number indicates that the thread is being delivered too slowly or broken.

The number of clock pulses that trigger a stop signal is constant even if the withdrawal speed of the thread changes by changing the speed of the knitting machine. An additional consideration of the take-off speed is not necessary. This monitoring of the yarn delivery is possible only by using a dependent of the knitting path clock signal.

In one embodiment, the length unit of the yarn delivery path corresponds to a wound from a winding body of the yarn feeding device yarn winding or a part of the unwound Garnwindung.

In one embodiment, the yarn feeding device are designed as a storage yarn feeding device and the winding body as a storage drum.

In one embodiment, the clock unit is provided with a clock signal. The clock signal is generated by a clock unit depending on the knitting route of the knitting machine. The clock signal is used by the clock unit as the clock signal or the clock signal is generated from the clock signal.

The clock signal is extracted in one embodiment by the timing unit of the machine controller of the knitting machine or generated from one or more machine signals. The clock signal is generated in an alternative embodiment by the clock unit by means of a measurement of the traveled knit path.

In a further embodiment, the clock signal is provided by a clock unit designed as a clock unit.

In an embodiment where the clock signal is generated by the clock unit from the clock signal, every N th pulse of the clock signal is used as the clock pulse, where N is an integer number. With this method, a clock signal with a reduced number of clock pulses per knitting path is provided. The generated clock signal is independent of the machine size and the generation of the clock signal. A clock signal having a smaller number of clock pulses results in less stress on a communication link between the clock unit and the control units.

In one embodiment, the clock signal of a knitting machine designed as a circular knitting machine is determined by the clock unit as a function of the rotation of a knitting cylinder of the circular knitting machine. For this purpose, the clock unit has, for example, a mechanical or electronic measuring unit.

wobei ΔXS die Längeneinheit des Strickweges, m die Anzahl der Impulse m des Taktgebersignals pro Umdrehung des Strickzylinders und U der Umfang des Strickzylinders ist. Die Anzahl m der Impulse wird in einem Beispiel bei einer Initialisierung der Überwachungsvorrichtung durch die Takteinheit mit Hilfe der der Maschinensteuerung ermittelt. Der Umfang U und die Längeneinheit ΔXS des Strickweges werden beispielsweise durch einen Bediener vorgegeben.In one embodiment, the integer N is calculated as follows: $$\mathrm{N}=\mathrm{integer}\left(\mathrm{\Delta XS\; x}\left(\mathrm{m}/\mathrm{U}\right)\right).$$

where ΔXS is the length unit of the knitting path, m is the number of pulses m of the clock signal per revolution of the knitting cylinder, and U is the circumference of the knitting cylinder. The number m of pulses is determined in one example in an initialization of the monitoring device by the clock unit using the machine control. The circumference U and the length unit ΔXS of the knitting path are predetermined, for example, by an operator.

With an integer N equal to 1, each pulse is used as a clock pulse, i. the clock signal is used as a clock signal.

In one embodiment, the clock signal generator signal is generated from sensor signals by the clock unit designed as a clock unit, wherein the sensor signals are provided by sensor devices of one or more yarn feeding devices.

In one example, measurement pulses of the sensor signals from, for example, 6 to 10, storage yarn feeding devices are interpreted by the clock unit designed as a clock unit as pulses of the clock signal. Of these pulses of the clock signal is used by the clock unit, if necessary, every Nth, for example second, pulse as a clock pulse of the clock signal.

The object is also achieved by a device according to the invention for monitoring the production of a knitting machine, referred to below as monitoring device, according to claim 11 and knitting machine according to claim 20. Features and advantages of claims 11 to 19 correspond to those of claims 1 to 10 and vice versa.

A monitoring device comprises at least one yarn feeding device. Each yarn feeding device of the monitoring device is associated with a sensor device and a control unit. The sensor device is designed to generate a sensor signal as a function of a yarn delivery path, i. from the length of the yarn supplied to the knitting machine. The sensor device generates a sensor signal with one measurement pulse per unit length of the yarn delivery path. The control unit is designed to evaluate the sensor signal of the sensor device and, if necessary, to generate a stop signal for the knitting machine.

In one embodiment, the control unit for evaluating the sensor signal is connected to the sensor device. For example, the control unit is directly connected to the sensor device or connected to it via a communication line.

The control unit is integrated in one embodiment in the sensor device. It is integrated into the yarn feeder in an alternative. In an alternative, the control unit is designed as a separate device.

The monitoring device comprises a clock unit, which is designed to provide the control unit (s) with a clock signal dependent on the knitting path of the knitting machine. As described, a clock pulse of the clock signal corresponds to a unit length of a knitting route. The length unit of the knitting path is selected so that it is smaller by a factor of at least 2 than the length unit of the yarn delivery path. Preferably, the factor is 3 to 10. The control unit evaluates the sensor signal as a function of the clock signal provided.

As mentioned, in one embodiment, the length unit of the knitting path is 2 to 8 cm. It is preferably 4 to 6 cm.

The clock unit is formed in one embodiment as a control unit for the yarn feeding devices or integrated into a control unit. In an alternative embodiment, the clock unit is formed as a separate unit.

In one embodiment, the control unit or units are integrated into the clock unit. That the clock unit comprises the control unit of one, several or all sensor devices.

In one embodiment, the control unit is designed in each case to count a number of clock pulses beginning with one measurement pulse and to compare the number of clock pulses with a predetermined number. The predetermined number corresponds to the factor mentioned above or is determined from it. The control unit is configured to generate a stop signal for the knitting machine when the determined number of clock pulses exceeds the predetermined number.

In one embodiment, the yarn feeding device has a winding body, wherein the length unit corresponds to a wound from the wound body of the yarn feeding device yarn winding or a part of the unwound Garnwindung.

In one embodiment, the yarn feeding device is designed as a storage yarn feeding device and the winding body as a storage drum. The sensor device is arranged, for example, at the discharge end of the storage drum. It comprises, for example, an optical sensor which transmits one pulse per passing, i. From the drum withdrawn yarn winding generated.

In one embodiment, the monitoring device comprises a clock unit, which is designed to provide a clock signal which is designed as a signal dependent on the knitting path of the knitting machine.

In one embodiment, the clock unit is configured to use the clock signal as the clock signal or to generate the clock signal from the clock signal.

In an alternative embodiment, the clock unit is designed as a clock generator unit.

In one embodiment, the clock unit is connected to or integrated into the machine control. The timing unit is connected, for example, to the drive system of the knitting machine.

In one embodiment, the clock unit is configured to generate the clock signal from the clock signal and to use every Nth pulse of the clock signal as a clock pulse. N is an integer.

In one embodiment, the knitting machine is designed as a circular knitting machine. The clock unit is adapted to generate the clock signal in response to the rotation of a knitting cylinder of the circular knitting machine.

In one embodiment, the clock unit is configured to generate the clock signal at 200 to 2000 or more pulses per revolution of the knitting cylinder of the circular knitting machine.

With an outer circumference of the knitting cylinder of, for example, about 250 cm, i. with a diameter of about 30 inches, for example, the clock signal is generated at approximately 1000 pulses per revolution of the knitting cylinder. For example, with a length unit of the knitting path of 5 cm, the number of pulses of the clock signal per unit length of the knitting path is about 20 in this example.

In one embodiment, the clock unit is configured to use from the clock signal every Nth pulse to generate the clock signal. The integer number N to be selected, for example, for one clock pulse of the clock signal per unit length of the knitting path ΔXS is calculated from the length unit of the knitting path ΔXS, the number of pulses m of the clock signal per revolution of the knitting machine and the circumference U of the knitting cylinder: $$\mathrm{N}=\mathrm{integer}\left(\mathrm{\Delta XS\; x}\left(\mathrm{m}/\mathrm{U}\right)\right)\mathrm{,}$$

In one embodiment, the clock unit comprises a measuring unit for measuring the knitting path of the knitting machine.

In an embodiment, the measuring unit comprises e.g. a gear disposed on a drive shaft of the knitting machine or on a shaft connected to the drive shaft.

In one embodiment, the measuring unit is designed as a rotary encoder, wherein the rotary encoder is arranged on the drive of the knitting machine.

In another embodiment, the clock unit comprises a measuring unit which is connected to the drive of positive yarn feeding devices. This measuring unit has, for example, a measuring wheel connected to the drive with a sensor. In one example, the timing unit is integrated into such a specially designed sensor device for determining the delivered yarn amount of one or more positive yarn feeding devices.

In one embodiment, the clock unit designed as a clock unit is designed to generate the clock signal from sensor signals of a plurality of yarn feeding devices. In one example, the timing unit is connected to control units of, for example, 6 to 10, storage yarn feeding devices. The clock unit is designed to be a Clock signal, as described above, to generate from the sensor signals of the storage yarn feeding devices.

• Figur 1 eine schematische Ansicht einer Rundstrickmaschine mit Elementen einer erfindungsgemäßen Vorrichtung eines ersten Beispiels;
• Fig. 2a ein Speicher-Fadenliefergerät;
• Fig. 2b eine schematische Darstellung einer Anordnung einer Taktgebereinheit;
• Fig. 3 ein Blockdiagramm einer erfindungsgemäßen Vorrichtung des ersten Beispiels;
• Fig. 4 ein Ablaufdiagramm einer Auswertung eines Sensorsignals durch eine Kontrolleinheit;
• Fig. 5a eine schematische Ansicht einer Rundstrickmaschine mit Elementen einer erfindungsgemäßen Vorrichtung eines zweiten Beispiel;
• Fig. 5b eine als Taktgebereinheit ausgebildete Sensor-Vorrichtung von Positiv-Fadenliefergeräten des zweiten Beispiels;
• Fig. 6 ein Blockdiagramm einer erfindungsgemäßen Vorrichtung des zweiten Beispiels;
• Fig. 7 eine schematische Anordnung von Fadenliefergeräten und einer als Steuereinheit ausgebildeten Takteinheit eines dritten Beispiels;
• Fig. 8 ein Blockdiagramm einer erfindungsgemäßen Vorrichtung des dritten Beispiels.

The invention will be further explained with reference to examples shown schematically in the drawing. Show it:

• FIG. 1 a schematic view of a circular knitting machine with elements of a device according to the invention of a first example;
• Fig. 2a a storage yarn feeding device;
• Fig. 2b a schematic representation of an arrangement of a clock generator unit;
• Fig. 3 a block diagram of a device according to the invention of the first example;
• Fig. 4 a flowchart of an evaluation of a sensor signal by a control unit;
• Fig. 5a a schematic view of a circular knitting machine with elements of a device according to the invention of a second example;
• Fig. 5b a trained as a clock generator sensor device of positive yarn feeding devices of the second example;
• Fig. 6 a block diagram of a device according to the invention of the second example;
• Fig. 7 a schematic arrangement of yarn feeding devices and designed as a control unit clock unit of a third example;
• Fig. 8 a block diagram of a device according to the invention of the third example.

First example

FIG. 1 shows a schematic view of a circular knitting machine 1 with elements of a device according to the invention for monitoring the production of the knitting machine, hereinafter referred to as monitoring device.

The circular knitting machine 1 has a plurality of yarn feeding devices, namely as storage yarn feeding devices 2, as voltage-controlled yarn feeding devices 3 and trained as positive yarn feeding devices 4 yarn feeding devices.

The yarn feeding devices are arranged on a plurality of carrier rings 5 of the circular knitting machines 1. In FIG. 1 only some of the yarn feeding devices are shown, wherein on an upper carrier ring 5 three storage yarn feeding devices 2, on a central carrier ring 5 three Thread tension controlled yarn feeding devices 3 and on a lower carrier ring 5 three positive yarn feeding devices 4 can be seen.

The circular knitting machine 1 has, for example for the production of a patterned knitted fabric, for example a jacquard knit, several knitting points 6 on its knitting device, wherein each knitting point 6 is associated, for example, with a yarn feeding device. The knitting device comprises z. B. a knitting cylinder 7, the in FIG. 1 is covered by knitting locks 8 and is displayed as an arrow. FIG. 1 also shows that the knitting point 6, a thread 9 is fed by a storage yarn feeding device 2.

In a circular knitting machine 1, as is known, the knitting device is rotatably arranged in a frame 10, which is surrounded by a housing 11 in the region below the knitting device and to which the carrier rings 5 are fastened in the region above the knitting device. A machine control 12 u. a. for a non-visible drive of the knitting device is arranged adjacent to the housing 10.

The monitoring device according to the invention comprises at least one yarn feeding device whose yarn delivery is monitored. For this purpose, the monitoring device of this example has a clock unit. The clock unit is designed as a control unit 13 or integrated into the control unit 13. In this example, the clock unit is integrated into the control unit 13. The control unit 13 is how FIG. 1 shows attached to a central part of the frame 11 of the circular knitting machine 1.

In an alternative, the control unit 13 is detachably held on the frame 11.

In an alternative, the control unit 13 is integrated in the machine control 12.

FIG. 2a shows a yarn feeding device of the monitoring device. The yarn feeding device is a storage yarn feeding device 2 with a winding body designed as a storage drum 14.

The stationary storage drum 14 is arranged in front of a housing 15. At the inlet end of the storage drum 14, a take-up element 16 for winding yarn turns on the storage drum 14 is arranged. At the other end, i.e. at the outlet end, the storage drum 14, is e.g. a cone brake 17 is provided. The cone brake 17 is supported by a boom 18 of the housing 15.

The memory yarn feeding device 2 is associated with a sensor device 19 and a control unit 20. The sensor device 19 is designed to generate a sensor signal with one measurement pulse I per unit length of a yarn delivery path .DELTA.XF. In this By way of example, the unit length of the yarn delivery path ΔXF corresponds to a yarn turn taken from the storage drum 14. The sensor device 19 is designed, for example, as an optical sensor which generates a measuring pulse I for each unwound yarn winding.

In one example, the circumference of the storage drum 14, and thus the length of a yarn turn, is 20 cm, i. the unit length of the thread delivery path ΔXF is 20 cm.

The control unit has, for example, a microprocessor. It is designed to evaluate the sensor signal of the sensor device 19 and possibly to generate a stop signal ST for the knitting machine. The control unit 20 is integrated in the housing 15, but in FIG. 2a shown separately for clarity.

The clock unit integrated in the control unit 13 is designed to provide the respective control unit 20 with a clock signal S2. In this example, the clock unit is designed to generate the clock signal S2 from a clock signal S1 of a clock unit.

FIG. 2b shows a schematic representation of an arrangement of the clock unit, which has a measuring unit, namely a rotary encoder 21. The rotary encoder 21 is arranged on a drive 22 which is connected via a drive belt 23 to a drive wheel 24 for the knitting cylinder 7.

The clock unit with the rotary encoder 21 generates the clock signal S1, which in this example has a number m of approximately 1000 pulses P per revolution of the knitting cylinder 7.

FIG. 3 shows on the basis of a block diagram that devices of the circular knitting machine 1 are interconnected by communication links 30. The communication links 30 are formed as lines and guided on the support rings 5 and parts of the frame 11. The communication links 30 are in FIG. 1 not shown. Data is exchanged between the connected devices via the communication links 30. The communication links 30 are designed, for example, as two lines of CAN-BUS connections via which a serial data transmission takes place.

In this example, the storage yarn feeding devices 2, the voltage-controlled yarn feeding devices 3, the positive yarn feeding devices 4, the timer unit with the Measuring unit 21, the control unit 13 and the machine control 12 connected to the communication links 30 and connected to each other.

The monitoring device, the at least one yarn feeding device, namely at least the in FIG. 2a illustrated storage yarn feeding device 2, the clock unit with the in FIG. 2b shown encoder 21 and the control unit 13 is connected via the communication links 30 to the machine control 12.

The control unit 13 is in the in FIG. 3 embodiment shown as an electronic device and provided with an input unit 31 and a display unit 32. The control unit 13 is possibly designed CAN-bus capable and provided, for example, with a microprocessor.

As mentioned, the clock unit in the control unit 13 is designed to generate from the clock signal S1 from the clock unit with the rotary encoder 21 the clock signal S2 and to provide the control unit or units 20. That the control unit 13 receives the clock signal S1 from the clock unit and sends the generated clock signal S2 to the control units of the yarn feeding devices, in particular to the control units 20 of the storage yarn feeding devices 2.

The clock unit in the control unit 13 is configured to use every Nth pulse P of the clock signal S1 as clock pulse T of the clock signal S2, where N is an integer number. The integer number N is calculated from the length unit of the knitting distance ΔXS, the number m of the pulses P of the clock signal S1 per revolution of the knitting cylinder 7 and the circumference of the knitting cylinder U as follows: $$\mathrm{N}=\mathrm{integer}\left(\mathrm{\Delta XS\; x}\left(\mathrm{m}/\mathrm{U}\right)\right)\mathrm{,}$$

Upon initialization of the monitoring device, the clock unit once determines the number m of pulses P per revolution of the knitting cylinder 7. For this purpose, the clock unit receives a machine cycle signal from the machine control 12, for example.

The integer number N is determined on the basis of these data by the clock unit possibly once and automatically.

For a selected length unit of the knitting distance ΔXS of, for example, 5 cm, the number m of about 1000 and a circumference of the knitting cylinder 7 of 250 cm results in an integer of 20. That is, the clock unit is adapted to every 20th pulse P of the clock signal S1 as Clock pulse T of the clock signal S2 to use.

The clock signal S2 has a clock pulse T per unit length of the knitting path .DELTA.XS. That the clock pulses T of the clock signal S2 provided by the control unit 13 of the control unit 20 correspond to a unit length of the knitting path ΔXS, respectively.

The length unit of the knitting path ΔXS is smaller than the length unit of the yarn delivery path ΔXF by a factor Z of at least 2, preferably from 3 to 10.

With a length unit of the knitting path ΔXS of 5 cm and a length unit of the yarn delivery path ΔXF of 20 cm described above, the factor Z has the value 4.

Each control unit 20 is designed to evaluate the sensor signal S as a function of the clock signal S2 by counting, starting with a pulse I of the sensor signal S, a number A of clocks T2, comparing it with a predetermined number Ac and, if exceeded, a stop signal ST for the Knitting machine generated.

In operation, to monitor the circular knitting machine 1, the yarn delivery of at least one yarn feeding device, namely the storage yarn feeding device or devices 2, is monitored by corresponding sensor devices 19 and control units 20. By the respective sensor device 19 is a sensor signal S with a measuring pulse I per unit length of the yarn delivery path .DELTA.XF, i. per deducted from the storage drum 14 of the storage yarn feeding device 2 yarn winding generated. The respective control unit 20 evaluates the sensor signal S as a function of the clock signal S2 provided by the central control unit 13 with a clock pulse T per unit length of the knitting path ΔXS.

The clock signal S2 is generated by the control unit 13 from the clock signal S1, in this example using every 20th pulse P of the clock signal S1 as the clock pulse T of the clock signal S2. The clock signal S1 is, as described, provided by the clock unit with the rotary encoder 21, which determines it as a function of the rotation of the knitting cylinder 7 of the circular knitting machine 1.

FIG. 4 shows by means of a flow chart, the evaluation of the sensor signal S by a control unit 20. The control unit 20 counts starting with a measuring pulse I a number A of clock pulses T. At each clock pulse T, the control unit 20 compares the number A with a predetermined number Ac. The number Ac is a constant that is given depending on the knitted product. The number Ac is entered by an operator over the

Input unit 31 of the control unit 13 is inputted and provided by the clock unit to the control units 20.

The number Ac is determined in this example from the factor Z. For example, according to the formula: Ac = Z + z, a value Ac is determined which is greater than the factor Z by a safety value z, for example of 2.

In an alternative, according to the formula: Ac = x Z, a value Ac is determined which is greater by a safety factor x of 1.5 or 3 than the factor Z. The factor Z, the ratio of the length units of the knitting path ΔXS and the yarn delivery path ΔXF , is 4 as described above.

The predetermined number Ac is chosen depending on the pattern of the product, depending on the bond. The predetermined number Ac is determined, for example, in a binding float from the factor Z of 4 multiplied by a safety factor x of 2 to the value 8. In a binding stitch, about one-third of this, for example a value of 3, is determined for the given number Ac. That For example, in a product using bonds with higher thread consumption, a predetermined number Ac may be less than the Z factor. For example, for a product using both mesh and float bindings, a predetermined number Ac of 6 is determined.

When the number A of the clock pulses T exceeds the predetermined number Ac, a stop signal ST for the circular knitting machine 1 is generated by the control unit 20 and supplied to the machine controller 12 via the communication link 30 of the knitting machine.

Second example

The second example corresponds to the first example except for the features described below. FIG. 2b shows an alternative timing unit, namely designed as a timing unit sensor device for the positive yarn feeding devices 4, for measuring the knitting path of the circular knitting machine first

The timing unit comprises a measuring unit 41 and a processing unit 42. It is arranged on a drive belt 43 for the positive yarn feeding devices 4. The drive belt or belts 23 are in FIG. 1 only partially shown.

The measuring unit 41 has at least one measuring wheel 44 driven by the drive belt 43 and at least one sensor 45 and a housing 46. The processing unit 42 is arranged in the housing 46.

The measuring wheel 44 is provided with a plurality of measuring points 47 distributed on an outer circumference of the measuring wheel 41.

A measuring point 47 is formed, for example, as a bore in which a magnet is arranged. The sensor 45 is arranged on or partially in the housing 46 and aligned with the measuring points 47 of the measuring wheel 44. The sensor 45 is designed as a Hall sensor.

In an alternative, an optical sensor is provided, for example with a light-emitting diode and a photocell, which are aligned, for example, on light-reflecting measuring points.

When the measuring wheel 44 rotates, the sensor 45 of the measuring unit 41 generates the clock signal S1, each with a pulse P, when one of the measuring points 47 passes the sensor 45. The number of measuring wheels 44 and the sensors 45 corresponds to the number of drive wheels of the positive yarn feeding devices 4. In this example, two measuring wheels 44 and two sensors 45 are provided in each case.

Third example

A third example corresponds to the first example except for the features described below. At a third in the FIGS. 7 and 8th illustrated embodiment, a monitoring device is provided on a circular knitting machine on which at least storage yarn feeding devices 2 are arranged. The monitoring device comprises a plurality of storage yarn feeding devices 2, which are arranged on a machine ring 5 and have sensor devices and control units, and a clock unit, which is integrated into the control unit 13. The storage yarn feeding devices 2 and the control unit 13 are connected to each other via communication lines 30. That is, the clock unit is connected via the communication lines 30 with the control units 20 of the yarn feeding devices 2.

The clock unit of the control unit 13 is designed as a clock unit, specifically to generate a clock signal S1 from sensor signals S with measuring pulses I of the sensor devices 19 of a plurality of storage yarn feeding devices 2.

By means of the sensor devices of, for example, 6 to 10, the storage yarn feeding devices 2, measuring pulses I of the sensor signals S are made available in the control unit 13 via the communication lines 30 of the clock unit. The measuring pulses I of Sensor signals S are interpreted by the clock unit as pulses P of the clock signal S1.

Of these pulses P of the clock signal S1, each Nth pulse P is used by the clock unit as the clock pulse T of the clock signal S2.

The calculation of the integer N is carried out as in the first example, wherein in a starting phase the number m of the pulses P, i. the measuring pulses I of the sensor signals, per revolution of the knitting cylinder 7 is determined. With 8 storage yarn feeding devices and a determination of the number m predominantly at the binding float, with a circumference of the storage drums of 20 cm and a circumference of the knitting cylinder of 250 cm, a number of m of the order of 100 is determined. The integer number N has a value of 2 cm for a length unit of the knitting path of 5 cm. through the clock unit every 2nd pulse P is used as clock pulse T.

If in the determination of the number m of the measuring pulses I per revolution of the knitting cylinder 7 of the clock signal S1, the binding is not known exactly, the predetermined number Ac, which is determined from the factor Z with the value 4, with a greater safety value z or safety factor x determined.

LIST OF REFERENCE NUMBERS

1

Circular knitting machine

2

Storage yarn feeder

3

voltage-controlled yarn feeding device

4

Positive yarn feeder

5

support ring

6

knitting point

7

knitting cylinder

8th

Castles

9

thread

10

frame

11

casing

12

machine control

13

control unit

14

storage drum

15

casing

16

takeup

17

cone brake

18

boom

19

sensor device

20

control unit

21

measuring unit

22

drive

23

drive belts

24

drive wheel

30

communication link

31

input unit

32

display unit

41

measuring unit

42

processing unit

43

drive belts

44

Measuring Wheel

45

sensor

46

casing

47

measuring point

Claims (15)

A method for monitoring the production of a knitting machine, wherein the yarn delivery at least one yarn feeding device by a sensor device (19) and a control unit (20) is monitored, wherein a sensor signal (S) with a measuring pulse (I) per unit length of a yarn delivery path (.DELTA.XF) through the Sensor device (19) is generated, the sensor signal (S) by the control unit (20) is evaluated and possibly a stop signal (ST) for the knitting machine by the control unit (20) is generated, characterized in that by a clock unit of the control unit ( 20) a clock signal (S2) is provided, wherein a clock pulse (T) of the clock signal (S2) corresponds to a length unit of the knitting path (ΔXS) and wherein the length unit of the knitting path (ΔXS) is reduced by a factor (Z) of at least 2, preferably from 3 to 10, smaller than the length unit of the yarn delivery path (.DELTA.XF), and that by the control unit (20), the sensor signal (S) in Abh dependence is evaluated by the clock signal (S2). A method according to claim 1, characterized in that a length unit of the knitting path (ΔXS) is 2 to 8 cm. A method according to claim 1 or 2, characterized in that by the control unit (20), for evaluation of the sensor signal (S), each starting with a measuring pulse (I) counts a number (A) of clock pulses (T) and the number (A ) of the clock pulses (T) with a predetermined number (Ac) is compared, wherein the predetermined number (Ac) the factor (Z) corresponds to or is determined from it, and that when exceeding the predetermined number (Ac) a stop signal (ST) is produced for the knitting machine. Method according to one of claims 1 to 3, characterized in that the length unit of the yarn delivery path (.DELTA.XF) corresponds to a unwound from a winding body of the yarn feeding device yarn winding or a part of the unwound Garnwindung. Method according to one of claims 1 to 4, characterized in that the clock signal (S2) is generated by the clock unit from a clock signal (S1) of a clock unit, or is generated by the clock unit and is used by the clock unit, or by the clock unit itself is produced. Method according to Claim 5, characterized in that the clock signal (S2) is generated by the clock unit from the clock signal (S1), each Nth pulse (P) of the clock signal (S1) being used as the clock pulse (T2) and N is an integer number. A method according to claim 5 or 6, characterized in that the clock signal (S1) in dependence on the rotation of a knitting cylinder (8) of a circular knitting machine (1) is determined. A method according to claim 7, characterized in that the integer number (N) of the unit length of the knitting path (ΔXS), the number (m) of the pulses (P) of the clock signal (S1) per revolution of the knitting cylinder and the circumference of the knitting cylinder (U) for a clock pulse T per unit length of the knit path ΔXS is calculated as follows: $$\mathrm{N}=\mathrm{integer}\left(\mathrm{\Delta XS\; x}\left(\mathrm{m}/\mathrm{U}\right)\right)\mathrm{,}$$

Method according to one of claims 1 to 8, characterized in that by the clock generator, the clock signal (S1) from sensor signals (S) of sensor devices (19) of a plurality of storage yarn feeding devices (2) is generated. Device for monitoring the production of a knitting machine having at least one yarn feeding device, which is associated with a sensor device (19) and a control unit (20), wherein the sensor device (19) is adapted to a sensor signal (S) each having a measuring pulse (I) per Length unit of a yarn delivery path (.DELTA.XF) to produce, wherein the control unit (20) is adapted to evaluate the sensor signal (S) of the sensor device (19) and optionally to generate a stop signal (ST) for the knitting machine, characterized by a clock unit (13 ) which is adapted to provide the control unit (20) with a clock signal (S2), wherein a clock pulse (T2) of the clock signal (S2) corresponds to a unit length of the knitting path (.DELTA.XS), wherein the length unit (.DELTA.XS) of the knitting path (ΔXS) by a factor (Z) of at least 2, preferably from 3 to 10, smaller than the length unit of the yarn delivery path (.DELTA.XF), and wherein the evaluation of the sensori gnals (S) in response to the clock signal (S2). Device according to Claim 10, characterized in that the control unit (20) is designed in each case to count a number (A) of clock pulses (T2) starting with a measuring pulse (I) and counting the number (A) of the pulses (T2) by one predetermined number (Ac), wherein the predetermined number (Ac) the factor (Z) corresponds to or is determined from it, and to generate a stop signal (ST) for the knitting machine when the predetermined number (Ac) is exceeded. Apparatus according to claim 10 or 11, characterized in that the yarn feeding device comprises a winding body, wherein the length unit (.DELTA.XF) of the yarn delivery path corresponds to a unwound from the winding body yarn winding or a part of the yarn winding. Apparatus according to claim 12, characterized in that the yarn feeding device as a storage yarn feeding device (2) and the winding body as a storage drum (14) are formed. Device according to one of claims 10 to 13, characterized in that the clock unit is adapted to generate the clock signal (S2) from a clock signal (S1) of a clock generator unit, or a clock signal generated by a clock generator unit (S1) as a clock signal (S2) to use, or that the clock unit is designed as a clock unit. Device according to one of claims 10 to 14, characterized in that the clock generator unit is adapted to generate the clock signal (S1) from sensor signals (S) of sensor devices (19) of several yarn feeding devices (2).

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