Patent Application
20240410092
The invention relates to a method for detecting leaks and/or blockages in a spinning unit of a spinning apparatus of a rotor spinning machine or air-jet spinning machine, and to a rotor spinning machine or air-jet spinning machine for carrying out the method.
Rotor spinning machines or air-jet spinning machines are known to comprise at least one section with a defined number of spinning apparatuses each having a spinning unit, which require an air flow in order to process a sliver fed to the respective spinning apparatuses, into a thread in the course of the spinning process. The air flow is usually generated by at least one compressed air source generating an air flow. Depending on the type of spinning machine, it can be a suction air system, which is used in particular with a rotor spinning machine to, e.g., generate a spinning negative pressure, or a source that generates compressed air and is used in particular with an air-jet spinning machine to generate a spinning pressure.
Accordingly, the spinning rotor of the rotor spinning machine, the rotor cup of which is supplied with suction air during regular spinning operation, but also during an initial spinning process, can be regarded as the spinning unit. In the case of an air-jet spinning machine, the air-jet spinneret can be regarded as the spinning unit. Spinning units are generally all devices that are designed to pneumatically generate a thread from fibers of a sliver, either individually or as a sliver.
In order to supply the spinning units of the individual spinning apparatuses, they are each connected to a compressed air supply line so that the compressed air from the at least one compressed air source can be fed to the assigned spinning units via the compressed air supply line. The compressed air flows fed to the respective spinning apparatuses 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 transmitter or volume flow transmitter, for measuring the compressed air flow rate within the compressed air supply line is used in order to monitor the compressed air flow.
For the quality of the thread produced by the rotor spinning machine or air-jet spinning machine, it is necessary that the compressed air flow, in particular the accompanying pressure, negative pressure or volume flow, is within a defined range for proper processing of the sliver or the individual fibers of the sliver by the spinning units. It also maximizes the productivity of the machine if the compressed air flow is provided, if possible, directly after a corresponding request, since the spinning units would otherwise have to spend an unproductive waiting time. On the other hand, dimensioning the compressed air source generating the compressed air flow, for a maximum required compressed air flow demand disadvantageously increases the costs thereof.
Similarly, maintaining a compressed air flow above a compressed air flow currently required increases energy consumption. This may be necessary, for example, if there are losses within the compressed air flow path, e.g., due to leaks. Further losses in the quality of the thread produced can result from blockages of the air nozzles of the spinning units, which can also lead to a complete interruption of the thread production process.
It is known from the prior art to determine the respective compressed air volume flows at the individual spinning apparatuses in order to identify leaks and/or blockages in individual spinning units of a spinning apparatus. However, since this method has considerable inaccuracies, the object of the invention is to provide a method for reliably detecting leaks and/or blockages in a spinning unit of a spinning apparatus of a rotor spinning machine or air-jet spinning machine, and a rotor spinning machine or air-jet spinning machine for carrying out this method.
For the purposes of the present invention, a compressed air flow is understood to mean an air flow generated by negative pressure or positive pressure, wherein the direction of the air flow in a portion of the compressed air supply line is determined by an arrangement of the pressure source or negative pressure source. Thus, an air flow generated by negative pressure can be different from, or the same as, the air flow generated by pressure, in the air flow direction, depending on the arrangement thereof. The rotor spinning machine or air-jet spinning machine has at least one section with a defined number of spinning apparatuses, each having a spinning unit. At least one compressed air source, which is connected to a compressed air supply line conducting the compressed air flow, is assigned to the spinning apparatuses. In order to supply the individual spinning apparatuses with compressed air, they are connected to the compressed air supply line in particular via compressed air flow branch ducts, wherein the compressed air supply lines or the compressed air flow branch ducts are each used to supply the individual spinning units of the spinning apparatuses. A control and regulation unit is coupled to the spinning machine to control and/or regulate the at least one compressed air source and the respective switchable, in particular controllable, compressed air valves assigned to the spinning units to regulate the compressed air flow fed 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 transmitter 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 measured data transmitted by the compressed air flow meter. The compressed air flow value that can be determined by the compressed air flow meter is at least the compressed air volume flow through the compressed air supply line or the prevailing air pressure in the compressed air supply line.
The control and regulation unit and the evaluation device are used to carry out the method according to the invention, in which the spinning apparatuses are checked for leaks and/or blockages in the spinning units. For this purpose, the spinning machine is first set to an inspection mode in which the compressed air valves are set to an “open” state, in particular in a controllable manner, in order to release a compressed air flow feed to the spinning units. In a subsequent method step, the compressed air source is then switched on to feed the compressed air flow, provided that the at least one compressed air source is in a switched-off state. The compressed air valves are subsequently closed one after the other in a defined order, in particular in a controllable manner, wherein each time a compressed air valve is closed, the prevailing compressed air flow value is measured and the measurement result is transmitted to the evaluation device and assigned to the respective spinning unit and compared with a specified limit value range stored in the evaluation device or a memory unit connected to the evaluation device. After said comparison has been carried out, the evaluation device then identifies the spinning unit(s) the assigned compressed air flow values of which deviate from the limit value or limit value range, wherein identification is such that it is assessed whether the measured compressed air flow value falls below or exceeds the assigned limit value or limit value range. In particular, the spinning apparatus, spinning unit and/or compressed air supply line relating to the impermissible deviation is indicated by means of a display unit. This means that the deviation can not only be processed within the system, as will be described hereinafter in more detail and by way of example, but can also be visualized for an operator. Furthermore, the extent of the deviation from the assigned limit value or limit value range can preferably be identified by the evaluation device and, in particular, indicated by means of a display unit.
The method according to the invention has the advantage that when the respective compressed air valves assigned to the spinning apparatuses are closed one after the other in a defined order, the differential volume flow or the pressure difference as a result of comparing the compressed air flow values before and after the compressed air valves are closed is used as a measured value in order to identify leaks and/or blockages in a spinning unit. Since, for example, the total volume flow can be detected with a higher relative accuracy than an individual volume flow at the respective spinning units, leaks and/or blockages can be detected in a particularly reliable manner. The method can be carried out in such a way that after a spinning apparatus has been checked, the corresponding compressed air valve is opened again, in particular in a controllable manner, and the next compressed air valve is then closed, in particular in a controllable manner, in the specified defined order. Moreover, the method according to the invention can also be carried out in such a way that the compressed air valves remain in the closed position after the measurement has been carried out, and the compressed air valve which is next in the order is then closed, in particular in a controllable manner.
The compressed air source, the evaluation device and/or the control and regulation unit can preferably be comprised by the rotor spinning machine or air-jet spinning machine. Alternatively, the compressed air source, the evaluation device and/or the control and regulation unit can be arranged separately from the rotor spinning machine or air-jet spinning machine and can be operatively connected to said machine. The invention is characterized in that a compressed air flow meter is provided for measuring the compressed air flow rate within the compressed air supply line and is connected to the evaluation device in a data-transmitting manner, wherein the data transmission can generally be implemented in the usual manner as required, in particular in a wired or wireless manner.
In the course of the method according to the invention, the compressed air flow meter is used to reliably identify spinning units that have leaks and/or blockages, for example via the measured data, transmitted to the evaluation device, of the prevailing total volume flow after the individual compressed air valves are closed. A differential volume flow that exceeds the limit value or limit value range after a compressed air valve is closed suggests that the assigned spinning unit has a leak, whereas the differential volume flow falling below the limit value or limit value range suggests that the spinning unit is blocked.
The provided comparison of the determined compressed air flow values with the limit values or limit value ranges and their assessment are carried out by the evaluation device. An evaluation device within the meaning of the present invention is understood to be such functionally interacting elements or units which are configured to carry out the required processes. Elements or units can be realized separately from one another or in a common assembly. The evaluation device can preferably be integrated into a processor-supported device, such as the control and regulation unit assigned to the rotor spinning machine or air-jet spinning machine. Particularly advantageously, it is provided for the control and regulation unit to be connected to the evaluation device in a data-transmitting manner. This connection makes automated execution of the inspection mode possible, in which the individual spinning units of the spinning apparatus are checked for leaks and/or blockages. This process can be carried out reliably by the control and regulation unit in a processor-controlled manner without the need for operator intervention.
As soon as the assessment shows 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 device transmits a signal suitable for triggering the alarm signal, e.g., directly to a unit triggering the alarm signal or to an intermediate unit. The alarm signal can be a visual, optical, acoustic and/or haptic signal. With such an alarm signal, an operator of the rotor spinning machine or air-jet spinning machine can be notified of improper operation of the rotor spinning machine or air-jet spinning machine that can result in a thread of inferior quality.
The proposed method is a cost-efficient and very reliable way of detecting leaks and/or blockages in a spinning unit of a rotor spinning machine or air-jet spinning machine. The processes of measuring, transmitting, determining, comparing and assessing can preferably be carried out periodically or at fixed points in time, depending on energy consumption requirements, wherein the rotor spinning machine or air-jet spinning machine is set to the inspection mode for this purpose, which makes carrying out the method according to the invention possible. The more frequently such processes are carried out, the higher the corresponding energy requirement of the rotor spinning machine or air-jet spinning machine may be, but the more reliable is also the monitoring and possibility of immediate intervention or troubleshooting, whereby the productivity of the rotor spinning machine or air-jet spinning machine can be optimized and the quality of the thread to be produced is increased.
According to a preferred embodiment, the alarm signal contains not only information about leaks and/or blockages but also information on which spinning apparatus, spinning unit, compressed air supply line and/or compressed air flow branch duct is affected. A corresponding display of information in addition to the type of the impermissible deviation, namely whether it is a blockage or a leak, allows for the existing leak and/or blockage to be rectified in a particularly targeted manner and at short notice so that the rotor spinning machine or air-jet spinning machine can be operated with a high level of productivity overall.
Particularly advantageously, it is provided that after a leak and/or blockage has been detected, the switchable, in particular controllable, compressed air valve assigned to the identified spinning unit remains in the closed position or, if it is open, is moved to the closed position if deviations in the compressed air flow values at the relevant spinning apparatus are assessed to be impermissible. This configuration of the invention reliably ensures that the corresponding spinning apparatus is put out of operation until the defects detected have been rectified, so that the production of a defective thread is reliably prevented.
According to a particularly advantageous configuration of the invention, the method proposed by the invention is suitable for an air-jet spinning machine, wherein the spinning units are formed by the air-jet spinnerets, by means of which a thread is formed from a fed sliver via the air nozzles of the compressed air fed to the air-jet spinneret, which air nozzles generate a vortex air flow within the air-jet spinneret.
According to a further aspect of the present invention, a rotor spinning machine or air-jet spinning machine for carrying out the method according to the invention or a method according to one of the preferred embodiments is proposed. The rotor spinning machine or air-jet spinning machine has
The rotor spinning machine or air-jet spinning machine according to the invention for carrying out the above-described method according to the invention or a developed method is characterized in that it has, or is coupled to,
wherein the evaluation device is set up to compare the measured compressed air flow value prevailing when the compressed air valves are closed one after the other in a defined order during each, in particular controllable, closing of a compressed air valve, with a specified limit value or limit value range stored in the evaluation device or a memory unit connected to the evaluation device, and to identify the spinning unit the assigned compressed air flow values of which deviate from the limit value or limit value range, wherein it is assessed whether the measured compressed air flow value falls below or exceeds the limit value or limit value range.
The rotor spinning machine or air-jet spinning machine according to the invention is characterized in that it allows for identifying, in a particularly simple and reliable manner, spinning apparatuses the spinning units of which have a leak and/or blockage, so that the fault can be rectified at short notice if necessary, thus ensuring high productivity of the rotor spinning machine and air-jet spinning machine. In addition, the production of poor-quality thread is reliably avoided.
According to a particularly advantageous configuration of the invention, the compressed air valve provided for blocking the compressed air flow to the assigned spinning apparatus is arranged in a compressed air flow branch duct, via which the assigned spinning unit is connected to the compressed air supply line so as to guide the compressed air flow. A corresponding arrangement of the compressed air valve reliably ensures that the corresponding spinning apparatus or spinning unit is isolated from the compressed air source. Thus, according to a particularly preferred embodiment, several of the compressed air valves comprised by the rotor spinning machine or air-jet spinning machine, or, according to a further preferred embodiment, all of the compressed air valves comprised by the rotor spinning machine or air-jet spinning machine, can be arranged in a corresponding compressed air flow branch duct.
According to a further configuration of the invention, it is furthermore provided for the control and regulation unit to be connected to the evaluation device in a data-transmitting manner. This configuration of the invention makes it possible to perform the method steps to be carried out in inspection mode for detecting leaks and/or blockages, in an automated manner, e.g., in a process-controlled manner by the evaluation device, without the need for operator intervention.
According to a further preferred embodiment, the evaluation device is connected in a data-transmitting manner to a display unit, as described above by way of example, in a wireless or wired manner and is designed to have the display unit indicate the spinning apparatus, spinning unit, pressure supply line, compressed air flow branch duct relating to the deviation and/or the extent of the deviation from the limit value or limit value range. In this way, the extent of the deviation can be visualized for an operator.
An exemplary embodiment of the invention is explained below with reference to the accompanying drawings. In the drawings:
At one end of the machine, the spinning machine 1 comprises a machine frame with a control housing 2, from which a plurality of spinning apparatuses 3 extend in rows on and along a longitudinal machine side of the spinning machine 1, wherein the respective spinning apparatuses 3 are connected on the data transmission side to a central control and regulation unit 14 shown in the control housing 2. Each spinning apparatus 3 has a spinning unit 4 for producing a thread from a sliver provided at the respective spinning apparatus 3.
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 set up to generate a compressed air flow caused by negative or positive pressure. The compressed air source 6 is connected to a compressed air supply line 8 so as to guide the compressed air flow, wherein several compressed air flow branch ducts 9 branching off from the compressed air supply line 8 are arranged on said compressed air supply line. Each of the branching compressed air flow branch ducts 9 leads to a spinning apparatus 3 and to the spinning unit 4 assigned to the spinning apparatus 3, in order to supply them with the compressed air flow that can be generated by the compressed air source 6.
In a compressed air flow branch duct 9 between the compressed air source 6 and a compressed air flow branch duct nearest to the compressed air source 6, the compressed air supply line 8 has a compressed air flow meter 10 for measuring a compressed air flow value (namely the compressed air volume flow in the present exemplary embodiment), which compressed air flow meter is arranged in the control housing 2 according to the preferred exemplary embodiment shown. The compressed air flow meter 10 can be accessible in the control housing 2 through a maintenance flap and, in particular, can be visible through a viewing window integrated in the maintenance flap. According to a preferred exemplary embodiment, the compressed air flow meter 10 can have a display for the scaled and/or digital display of the measurable compressed air volume flow passing through.
In the respective compressed air flow branch ducts 9 leading to the spinning apparatuses 3, a switchable, in particular controllable, compressed air valve 12 is arranged between the compressed air supply line 8 and the spinning units 4, which compressed air valve is adjustable, in particular in a controlled manner, between an open and closed position. In the open position, a compressed air flow can be passed through the corresponding compressed air flow branch duct 9 via the compressed air valve 12, whereas the corresponding compressed air flow branch duct 9 is blocked for the compressed air flow when the compressed air valve 12 is in the closed position.
An evaluation device 13 is connected directly to the compressed air flow meter 10 and indirectly, via the control and regulation unit 14, to the compressed air valves 12 of the individual spinning apparatuses 3. In this way, the measured compressed air volume flows can be transmitted to the evaluation device 13 from the compressed air flow meter 10. The control and regulation unit 14 can furthermore be used to adjust the respective compressed air valve 12 between the open and closed positions, in particular in a controllable manner. Even though the data transmission path is shown to be only unidirectional in the schematic representation of
The evaluation device 13 is set up to detect leaks and/or blockages in a spinning unit 4 of the spinning apparatuses 3 during an inspection mode carried out by the control and regulation 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 to an inspection mode in the control and regulation unit 14, wherein, in the inspection mode, the compressed air valves 12 of the individual spinning apparatuses 3 are set to the open position, in particular in a controllable manner, in order to release a compressed air flow feed to the spinning units 4.
In a next step 120, the compressed air source 6 is then activated or switched on, provided that it is in the configured state. In the subsequent step 130 relating to a testing process, the control and regulation unit 14 adjusts the compressed air valves 12 on the individual spinning apparatuses 3 one after the other in a defined order to the closed position, in particular in a controllable manner, and subsequently records the compressed air volume flow determined on the compressed air flow meter 10 in each case. This measured value is assigned to the respective spinning unit 4 and compared in the evaluation device 13 with a specified limit value or limit value range, which is stored in the evaluation device 13 or in a memory unit (not shown here) that is connected to the evaluation device 13.
If the evaluation device 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 in a subsequent step 140 by the evaluation device 13, which evaluates whether the measured compressed air value exceeds or falls below the stored limit value or limit value range and, in particular, to what extent there is a deviation from the limit value or limit value range. An exceedance or shortfall, in particular the extent of the deviation from the limit value or limit value range, is indicated by the evaluation device 13 via a display unit 15 designed as an alarm signal display unit.
The alarm signal display unit 15 provides information about the type of deviation, wherein the measured compressed air flow value falling below the limit value or limit value range is signaled as a blockage of the spinning unit 4, whereas a compressed air flow value exceeding the limit value or limit value range is indicated on the alarm signal display unit 15 as a leak at the spinning unit 4.
| Number | Date | Country | Kind |
|---|---|---|---|
| 504416 | Jun 2023 | LU | national |
