Method for determining leakages and / or blockages of a spinning unit of a spinning device of a rotor or air-jet spinning machine

Abstract

The invention relates to a method for detecting leaks and / or blockages in a spinning unit of a spinning device of a rotor or air-jet spinning machine, and to a rotor or air-jet spinning machine for carrying out the method. To provide a method for reliably detecting leaks and / or blockages in a spinning unit of a spinning device of a rotor or air-jet spinning machine, and to provide a rotor or air-jet spinning machine for carrying out this method, the method comprises the following steps: - placing the spinning machine in a test mode in which the compressed air valves are set to an "open" state, in particular an adjustable state, to allow a supply of compressed air to the spinning units, - switching on the compressed air source to supply a compressed air flow, provided that the at least one compressed air source is switched off, - closing the compressed air valves successively in a defined sequence.wherein, each time a compressed air valve closes, the prevailing compressed air flow rate is measured and the measurement result is transmitted to the evaluation unit and assigned to the at least one spinning unit associated with the compressed air valve and compared with a predetermined limit value or limit value range stored in the evaluation unit or a storage unit connected to the evaluation unit; - Identifying by the evaluation unit the spinning unit whose assigned compressed air flow rates deviate from the limit value or limit value range, whereby it is assessed whether the measured compressed air value is below or above the assigned limit value or limit value range.

Description

[0001] The invention relates to a method for detecting leaks and / or blockages in a spinning unit of a spinning device of a rotor or air spinning machine, and to a rotor or air spinning machine for carrying out the method.

[0002] Rotor or air-jet spinning machines are known to comprise at least one section with a defined number of spinning devices, each with a spinning unit. These devices require an airflow to process a fiber sliver fed to them into a yarn during the spinning process. The airflow is typically generated by at least one compressed air source. Depending on the type of spinning machine, this can be a suction air system, which is used, for example, in a rotor spinning machine to create a negative pressure for spinning, or a compressed air source, which is used, for example, in an air-jet spinning machine to create a positive pressure for spinning.

[0003] The spinning rotor of a rotor spinning machine can be considered an example of a spinning unit, as its rotor cup is supplied with suction air during regular spinning operations as well as during the start-up process. In an air-jet spinning machine, the air-jet nozzle can be considered the spinning unit. Generally, any device designed to pneumatically generate a thread from fibers of a fiber sliver, whether individual fibers or a sliver, can be considered a spinning unit.

[0004] To supply the spinning units of the individual spinning devices, each unit is connected to a compressed air supply line, so that the compressed air from at least one compressed air source can be supplied to the assigned spinning units via the compressed air supply line. The compressed air flows supplied to the respective spinning devices can be adjusted via switchable, in particular controllable, compressed air valves assigned to each spinning unit. At least one compressed air flow meter, such as a mass flow or volume flow transmitter, serves to monitor the compressed air flow within the compressed air supply line.

[0005] For the quality of the yarn produced by the rotor or air-jet spinning machine, it is essential that the compressed air flow, and in particular the associated pressure, vacuum, or volume flow, remains within a defined range to ensure proper processing of the fiber sliver or the individual fibers from the sliver by the spinning units. Furthermore, machine productivity is maximized if the compressed air flow is provided as soon as possible after a corresponding demand, as the spinning units would otherwise have to endure unproductive waiting time. On the other hand, designing the compressed air source to meet the maximum required compressed air flow rate adversely increases its costs.

[0006] Similarly, maintaining a compressed air flow above the required flow rate increases energy consumption. This maintenance may be necessary, for example, if there are losses within the compressed air flow path, such as due to leaks. Further quality losses in the manufactured yarn can result from blockages in the air nozzles of the spinning units, which can also lead to a complete interruption of the yarn production process.

[0007] It is known from the prior art to determine the respective compressed air volume flows at the individual spinning units of a spinning device in order to identify leaks and / or blockages of individual spinning units.

[0008] Identifying spinning units whose associated compressed air flow values ​​deviate from the limit value or limit value range, using an evaluation unit, and assessing whether the measured compressed air flow value falls below or exceeds the associated limit value or limit value range, is known from German patent application DE 10 2020 115287 A1. Further identification methods according to the prior art are known from WO 2011 / 147040 A1 and EP 1 655 393 A2. However, since this method exhibits considerable inaccuracies, the invention aims to provide a method for reliably detecting leaks and / or blockages in a spinning unit of a spinning device of a rotor or air spinning machine, as well as a rotor or air spinning machine for carrying out this method.

[0009] For the purposes of the present invention, a compressed air flow is understood to be an air flow generated by negative or positive pressure, wherein the direction of the air flow in a section of the compressed air supply line is determined by the arrangement of the pressure or negative pressure source. Thus, an air flow generated by negative pressure can differ from or be the same in direction as an air flow generated by pressure, depending on their arrangement. The rotor or air spinning machine has at least one section with a defined number of spinning devices, each with a spinning unit. At least one compressed air source is assigned to the spinning devices, which is connected to a compressed air supply line carrying the compressed air flow. To supply the individual spinning devices with compressed air, they are connected to the compressed air supply line, in particular via compressed air flow branch channels, wherein the compressed air supply lines or...The compressed air branch channels each serve to supply the individual spinning units of the spinning devices. A control and regulation unit is coupled to the spinning machine for controlling and / or regulating the at least one compressed air source and the respective switchable, in particular controllable, compressed air valves assigned to the spinning units for regulating the compressed air flow supplied to the assigned spinning units. Furthermore, an evaluation device for evaluating measured values ​​from the at least one compressed air flow meter, such as a mass flow or volume flow transmitter for measuring the compressed air flow rate within the compressed air supply line, is assigned to the spinning machine, wherein the evaluation device evaluates the measurement data transmitted by the compressed air flow meter.The compressed air flow rate value that can be determined by the compressed air flow meter is at least the compressed air volume flow rate through the compressed air supply line or the prevailing air pressure in the compressed air supply line.

[0010] The inventive method is carried out by means of the control and regulation unit and the evaluation unit, in which the spinning devices are checked for leaks and / or blockages in the spinning units. For this purpose, the spinning machine is first put into a testing mode in which the compressed air valves are set to an "open" state, in particular an adjustable state, in order to allow a supply of compressed air to the spinning units. In a subsequent process step, the compressed air source for supplying the compressed air flow is then switched on, provided that the at least one compressed air source is in a switched-off state.The compressed air valves are then closed sequentially in a defined, and in particular controllable, order. With each closure of a compressed air valve, the prevailing compressed air flow rate is measured, and the measurement result is transmitted to the evaluation unit, assigned to the respective spinning unit, and compared with a predefined limit range stored in the evaluation unit or a storage unit connected to it. After this comparison, the evaluation unit identifies the spinning unit(s) whose assigned compressed air flow rates deviate from the limit or limit range. This identification is performed by assessing whether the measured compressed air flow rate falls below or exceeds the assigned limit or limit range.In particular, the spinning device, spinning unit, and / or compressed air supply line affected by the impermissible deviation is indicated by a display unit. This allows the deviation to be processed not only internally within the system, as described in more detail below by way of example, but also to be visualized for an operator. Furthermore, preferably, the degree of deviation from the assigned limit value or limit value range can be identified by the evaluation unit and, in particular, displayed by means of a display unit.

[0011] The method according to the invention has the advantage that, when the respective compressed air valves assigned to the spinning devices are closed successively in a defined sequence, the differential volume flow rate or the pressure difference is used as a measured value to identify leaks and / or blockages in a spinning unit by comparing the compressed air flow rates before and after closing the compressed air valves. Since, for example, the total volume flow rate can be determined with higher relative accuracy than an individual volume flow rate at the respective spinning units, leaks and / or blockages can be detected in a particularly reliable manner.The method can be carried out by reopening the corresponding compressed air valve, particularly an adjustable one, after a spinner has been checked, and then closing the next compressed air valve, particularly an adjustable one, in the predetermined, defined sequence. Alternatively, the method according to the invention can also be carried out by leaving the compressed air valves in the closed position after the measurement and then closing the next compressed air valve in the sequence, particularly an adjustable one.

[0012] The compressed air source, the evaluation unit, and / or the control unit can preferably be encompassed by the rotor or air spinning machine. Alternatively, the compressed air source, the evaluation unit, and / or the control unit can be arranged separately from the rotor or air spinning machine and operatively connected to it. The invention is characterized in that a compressed air flow meter for measuring the compressed air flow rate within the compressed air supply line is provided and is connected to the evaluation unit for data transmission, wherein the data transmission can generally be implemented in the usual manner as required, in particular wired or wirelessly.

[0013] In the course of the method according to the invention, spinning units exhibiting leaks and / or blockages are reliably identified by means of the compressed air flow meter, e.g., via the measurement data of the prevailing total volume flow after the closing of the individual compressed air valves, which are transmitted to the evaluation unit. A differential volume flow exceeding the limit value or limit value range after closing a compressed air valve indicates that the associated spinning unit has a leak, whereas a differential volume flow below the limit value or limit value range indicates a blockage of the spinning unit.

[0014] The evaluation unit performs the intended comparison of the determined compressed air flow values ​​with the limit values ​​or limit value ranges and their assessment. For the purposes of this invention, an evaluation unit is understood to be functionally interacting elements or units designed to carry out the necessary processes. These elements or units can be separate or implemented in a common assembly. The evaluation unit can preferably be integrated into a processor-based device, such as the control unit associated with the rotor or air spinning machine. It is particularly advantageous that the control unit is connected to the evaluation unit via data transmission.This connection enables automated execution of the inspection mode, during which the individual spinning units of the spinning device are checked for leaks and / or blockages. Processor-controlled, this process can be carried out reliably by the control unit without requiring any operator intervention.

[0015] As soon as the evaluation reveals an impermissible deviation of the compressed air flow values ​​from the limit value or limit value range, an alarm signal can be activated according to a preferred embodiment of the present invention. The alarm signal is activated when the evaluation unit transmits a signal suitable for triggering the alarm, e.g., directly to a unit that triggers the alarm signal or to an intermediate unit. The alarm signal can be a visual, optical, acoustic, and / or haptic signal. Such an alarm signal can alert an operator of the rotor or air spinning machine to improper operation of the machine, which could result in a yarn of inferior quality.

[0016] The proposed method represents a cost-effective and highly reliable way to detect leaks and / or blockages in a spinning unit of a rotor or air-jet spinning machine. Depending on energy consumption requirements, the processes of measuring, transmitting, determining, comparing, and evaluating can preferably be carried out periodically or at fixed intervals. For this purpose, the rotor or air-jet spinning machine is placed in a monitoring mode that enables the execution of the method according to the invention. While the higher the energy consumption of the rotor or air-jet spinning machine may be with increasing frequency, the more reliable the monitoring and the possibility of immediate intervention or troubleshooting become. This optimizes the productivity of the rotor or air-jet spinning machine and increases the quality of the yarn produced.

[0017] According to a preferred embodiment, the alarm signal includes, in addition to information about a leak and / or blockage, information about which spinning device, spinning unit, compressed air supply line, and / or compressed air branch channel is affected. A corresponding display of information, along with the type of impermissible deviation—namely, whether it is a blockage or a leak—makes it possible to rectify the existing leak and / or blockage in a particularly targeted and rapid manner, so that the rotor or air spinning machine can be operated with high productivity overall.

[0018] It is particularly advantageous that, after the detection of a leak and / or blockage, the switchable, and in particular controllable, compressed air valve assigned to the identified spinning unit remains in the closed position or, if it is open, is moved into the closed position if deviations in the compressed air flow values ​​at the spinning device in question are deemed unacceptable. This embodiment of the invention reliably ensures that the corresponding spinning device is taken out of service until the identified defects are rectified, thus reliably preventing the production of a defective yarn.

[0019] According to a particularly advantageous embodiment of the invention, the method proposed by the invention is suitable for an air spinning machine, wherein the spinning units are formed by the air spinning nozzles, by means of which a thread is formed from a supplied fiber ribbon via compressed air supplied to the air spinning nozzle, which generates a vortex air flow within the air spinning nozzle.

[0020] According to a further aspect of the present invention, a rotor or air spinning machine is proposed for carrying out the method according to the invention or a method according to one of the preferred embodiments. The rotor or air spinning machine has at least one section comprising a defined number of spinning devices, each with a spinning unit; at least one compressed air source; compressed air supply lines, each coupled to at least one spinning unit of the spinning units, wherein the compressed air flow from the at least one compressed air source can be supplied to the at least one spinning unit associated with it via the compressed air supply line; a switchable, in particular controllable, compressed air valve associated with at least one spinning unit, wherein the compressed air valve is designed to at least keep the pressure constant regardless of the pressure volume flow and in particular to control the supplied compressed air flow; at least one compressed air flow meter for measuring the compressed air flow rate within the compressed air supply line. on.

[0021] The rotor or air spinning machine according to the invention for carrying out the above-described method according to the invention or a further developed method is characterized by the fact that it has or is coupled with a control and regulation unit coupled with the at least one compressed air source and the compressed air valves for controlling and / or regulating the at least one compressed air source and the respective compressed air valves, and an evaluation device connected to the compressed air flow meter for data transmission and evaluation of measurement data from the compressed air flow meter, where the evaluation device is set up to detect when the compressed air valves are closed. to compare the prevailing measured compressed air flow value with a predetermined limit value or limit value range stored in the evaluation unit or a storage unit connected to the evaluation unit, one after the other in a defined sequence, at each, in particular controllable, closing of a compressed air valve, and to identify the spinning unit whose assigned compressed air flow values ​​deviate from the limit value or limit value range, whereby it is evaluated whether the measured compressed air flow value falls below or exceeds the limit value or limit value range.

[0022] The rotor or air spinning machine according to the invention is characterized by the fact that it allows, in a particularly simple and reliable manner, the identification of spinning devices whose spinning units exhibit a leak and / or blockage, so that the malfunction can be rectified quickly if necessary, thus ensuring high productivity of the rotor and air spinning machine. Furthermore, the production of defective yarn is reliably prevented.

[0023] According to a particularly advantageous embodiment of the invention, the compressed air valve provided for shutting off the compressed air flow to the associated spinning device is arranged in a compressed air branch channel through which the associated spinning unit is connected to the compressed air supply line. Such an arrangement of the compressed air valve reliably ensures that the corresponding spinning device or spinning unit is shut off from the compressed air source. Thus, according to a particularly preferred embodiment, several of the compressed air valves encompassed by the rotor or air spinning machine, or according to a further preferred embodiment, all of the compressed air valves encompassed by the rotor or air spinning machine, can be arranged in a corresponding compressed air branch channel.

[0024] According to a further embodiment of the invention, the control unit is also connected to the evaluation unit for data transmission. This embodiment of the invention makes it possible to carry out the process steps to detect leaks and / or blockages in the inspection mode in an automated manner, e.g., process-controlled by the evaluation unit, without requiring any operator intervention.

[0025] According to a further preferred embodiment, the evaluation unit is wirelessly or wired to a display unit as described above by way of data transmission and is designed to display the spinning device, spinning unit, pressure supply line, compressed air branch channel, and / or the extent of the deviation from the limit value or limit value range by means of the display unit. In this way, the extent of the deviation can be visualized for an operator.

[0026] An embodiment of the invention is explained below with reference to the accompanying drawings. The drawings show: Fig. 1 a schematic view of an embodiment of a spinning machine and Fig. 2 a schematic representation of a flowchart of an embodiment of a method for detecting leaks and / or blockages of a spinning unit of a spinning device of the spinning machine.

[0027] Figure 1 Figure 1 shows a purely schematic representation of a spinning machine 1, which has several spinning devices 3, shown here only in part, grouped together as a section, each with a spinning unit 4. The spinning devices 3 can be those of a rotor or air spinning machine.

[0028] The spinning machine 1 comprises a machine frame with a control housing 2 at one end, from which a plurality of spinning devices 3 extend in a row along one longitudinal side of the spinning machine 1, the respective spinning devices 3 being connected to a central control and regulation unit 14 shown in the control housing 2 for data transmission. Each spinning device 3 has a spinning unit 4 for producing yarn from a fiber sliver provided at the respective spinning device 3.

[0029] The spinning machine 1 comprises a compressed air source 6, which generates a compressed air flow and is arranged in the control housing 2. The compressed air source 6 is designed to generate a compressed air flow induced by negative or positive pressure. The compressed air source 6 is connected to a compressed air supply line 8, with several compressed air flow branch channels 9 extending from the compressed air supply line 8. Each of the branching compressed air flow channels 9 leads to a spinning device 3 and the spinning unit 4 associated with the spinning device 3, in order to supply them with the compressed air flow generated by the compressed air source 6.

[0030] The compressed air supply line 8 includes a compressed air flow meter 10 for measuring a compressed air flow value, in this embodiment the compressed air volume flow, in a compressed air flow branch channel 9 located between the compressed air source 6 and the compressed air flow branch channel 9 nearest the compressed air source 6. According to the preferred embodiment shown, the compressed air flow meter 10 is arranged in the control housing 2. The compressed air flow meter 10 can be accessed in the control housing 2 via a maintenance hatch and, in particular, can be viewed through a viewing window integrated into the maintenance hatch. According to a preferred embodiment, the compressed air flow meter 10 can have a display for the scaled and / or digital display of the measured compressed air volume flow.

[0031] In the respective compressed air branch channels 9 leading to the spinning devices 3, a switchable, in particular adjustable, compressed air valve 12 is arranged between the compressed air supply line 8 and the spinning units 4. This valve is adjustable between an open and a closed position. In the open position, a compressed air flow can be passed through the corresponding compressed air branch channel 9 via the compressed air valve 12, whereas the corresponding compressed air branch channel 9 is closed to the compressed air flow when the compressed air valve 12 is in the closed position.

[0032] An evaluation unit 13 is directly connected to the compressed air flow meter 10 and indirectly, via the control unit 14, to the compressed air valves 12 of the individual spinning devices 3. In this way, the measured compressed air volume flows can be transmitted from the compressed air flow meter 10 to the evaluation unit 13. Furthermore, the respective compressed air valve 12 can be adjusted between the open and closed positions, in particular, via the control unit 14. Even if, in the schematic representation according to Figure 1 If the data transmission path is shown as only unidirectional, then according to a further preferred embodiment it can also be a bidirectional connection, in order in particular to be able to give or receive corresponding feedback.

[0033] The evaluation unit 13 is configured to detect leaks and / or blockages in a spinning unit 4 of the spinning devices 3 within the framework of a verification mode carried out by the control unit 14. The method 100 for detecting leaks and / or blockages in a spinning unit 4 comprises, in a first step 110, setting the spinning machine into a verification mode in the control unit 14, wherein, in the verification mode, the compressed air valves 12 of the individual spinning devices 3 are set to the open position, in particular controllably, in order to release a compressed air supply to the spinning units 4.

[0034] In the next step 120, the compressed air source 6 is activated or switched on, provided it is in its configured state. In the subsequent step 130, concerning a test process, the control unit 14 successively adjusts the compressed air valves 12 on the individual spinning devices 3 to the closed position, in particular to the adjustable position, in a defined sequence, and then records the compressed air volume flow rate measured by the compressed air flow meter 10. This measured value is assigned to the respective spinning unit 4 and compared in the evaluation unit 13 with a predefined limit value or limit value range, which is stored in the evaluation unit 13 or in a storage unit connected to the evaluation unit 13 (not shown here).

[0035] If the evaluation unit 13 detects a deviation of the compressed air flow value determined by the compressed air flow meter 10 from the assigned limit value or limit value range, this is identified by the evaluation unit 13 in a subsequent step 140. The evaluation unit 13 assesses whether the measured compressed air value exceeds or falls below the stored limit value or limit value range and, in particular, to what extent the deviation from the limit value or limit value range occurs. An exceedance or fall below the limit value, and especially the extent of the deviation from the limit value or limit value range, is indicated by the evaluation unit 13 via a display unit 15 designed as an alarm signal indicator unit.

[0036] The alarm signal indicator unit 15 provides information about the type of deviation, whereby a fall below the limit value or limit range of the measured compressed air flow value is signaled as a blockage of the spinning unit 4, whereas a compressed air flow value exceeding the limit value or limit range is indicated on the alarm signal indicator unit 15 as a leakage at the spinning unit 4. Reference symbol list

[0037] 1 Spinning machine 2 Control housing 3 Spinning device 4 Spinning unit 6 Compressed air source 8 Compressed air supply line 9 Compressed air flow branch duct 10 Compressed air flow meter 12 Compressed air valve 13 Evaluation unit 14 Control and regulation unit 15 Display unit 100 Procedure 110 Procedure for setting to a verification mode 120 Procedure for switching on the compressed air source 130 Procedure for closing, transferring and adjusting 140 Procedure for identifying

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