A method for adjusting the supply air pressure of a loom facility equipped with a plurality of air jet looms, a system for adjusting the supply air pressure of a loom facility, and a loom facility

Abstract

In a method for adjusting the supply air pressure (pV) of a loom installation (1) comprising a plurality of air jet looms (2) each having a plurality of pneumatic loads (5) for introducing the weft, the pressure demand (pB) of the air jet looms (2) is determined using a central control unit (4), and the supply air pressure (pV) is set depending on the determined pressure demand (pB). At that time, during the weaving process, for each of the air jet looms (2), at set time intervals, the current pressure demand (pB) of the maximum load (5) is determined from each of the plurality of pneumatic loads (5), and the maximum pressure demand (pB) of all the current loads (5) is determined by the control unit (4). Similarly, in each of the air jet looms (2), the current input pressure (pE) is measured, and the minimum input pressure (pEmin) currently measured for all the air jet looms (2) is determined by the control unit (4). If the measured minimum input pressure (pEmin) is lower than the maximum pressure demand (pBmax) of all the loads (5), the supply air pressure (pV) is increased, or if the measured minimum input pressure (pEmin) is higher than the maximum pressure demand (pBmax) of all the loads (5), the supply air pressure (pV) is decreased.

Description

Technical Field

[0001] The present invention relates to a method for adjusting the supply air pressure of a loom facility comprising a plurality of air jet looms each having a plurality of pneumatic loads for inserting weft yarns, in which method the pressure demand of the air jet looms is determined using a central control unit and the supply air pressure is adjusted depending on the determined pressure demand. Furthermore, the present invention relates to a system for adjusting the supply air pressure of such a loom facility, as well as to a corresponding loom facility.

[0002] Air jet looms have a number of pneumatic loads, such as main nozzles, relay nozzles, corner feeders and further loads, for the insertion of the weft yarn and, in some cases, also for other functions. For this reason, air jet looms need to be connected to a compressed air supply device that always guarantees a sufficiently high compressed air level for all the pneumatic loads of the loom. Furthermore, it is also important to maintain precisely the air pressure required by each individual load in order to insert the weft yarn in good time. For example, it is necessary to set different pressures depending on the type of weft yarn in order to ensure, as far as possible, a constant weft flight time and thus proper weft insertion. Otherwise, the weft yarn may reach the end of the weft insertion channel either excessively early or excessively late, leading to weaving errors. Similarly, different pressures may be required in the various looms of a loom facility, for example if these looms produce different products.

[0003] In order to supply compressed air to a plurality of air jet looms of a loom facility, it is known from German Patent Application Publication No. 19517748 to assign to each loom a dedicated compressor and adjustment means for setting a specific operating mode.

[0004] However, generally, a plurality of air-jet looms of a loom facility are supplied by a central compressed air system to which all or at least a plurality of looms are connected. Here, the supply pressure is generated by a central compressed air source and distributed to individual looms. The setting of an appropriate pressure level for each pneumatic load is achieved here by each loom, and in some cases, by a pressure reducer and / or a pressure control valve assigned to each individual load. The supply pressure of the central compressed air supply unit is always adjusted high here, so that even considering pipeline losses and other losses, it can still surely supply a loom that requires the maximum pressure. Therefore, the supply of compressed air to the air-jet loom is very energy-consuming. A further problem arises from the fact that the adaptation of the pressure level of the pneumatic load is frequently carried out during the weaving process. In this case, the loom and / or the load are often supplied with an overly high supply pressure, and thus this overly high supply pressure must be reduced again by the pressure control valve. This leads to unnecessarily high compressed air consumption and thus energy consumption.

[0005] Therefore, in Japanese Patent Application Laid-Open No. 03-104962, a control unit for a loom facility that enables automatic adaptation of the supply pressure in the central compressed air supply unit has already been proposed. Each loom here has a pressure regulator that notifies the control unit of the adjusted pressure for the weft insertion nozzle as a control value. The control unit determines the maximum pressure value therefrom. In some cases, a fixed correction value is further added to the maximum pressure value for compensation of pressure loss. Subsequently, the control unit compensates for the thus obtained minimum pressure requirement using the central supply pressure of the compressor. This is obtained by a sensor in the main compressed air tank and transmitted to the control unit as well. Subsequently, the supply air pressure is variably adapted to each minimum pressure requirement.

[0006] The object of the present invention is to propose a method for adjusting the supply air pressure of a loom facility that enables further energy savings. Furthermore, a corresponding system for adjusting the supply air pressure of such a loom facility as well as a corresponding loom facility should be proposed.

[0007] In a method for adjusting the supply air pressure of a loom facility having a plurality of air-jet looms each having a plurality of pneumatic loads for inserting weft yarns, the pressure demand of the air-jet looms is determined using a central control unit, and the supply air pressure is adjusted depending on the determined pressure demand. Furthermore, the present invention relates to a system for adjusting the supply air pressure of such a loom facility as well as a corresponding loom facility.

[0008] In this method, during the weaving process, - For each of the air-jet looms, at set time intervals, the pressure demand of the current maximum load is determined from a plurality of pneumatic loads respectively, - By the control unit, the pressure demands of the maximum loads of the air-jet looms are compared, and the maximum pressure demand of all the current loads is determined, - In each of the air-jet looms, at set time intervals, the current input pressure is measured and transmitted to the control unit, - By the control unit, the measured input pressures of the air-jet looms are compared, and the minimum input pressure measured at present for all the air-jet looms is determined, - When the measured minimum input pressure is lower than the maximum pressure demand of all the loads, the supply air pressure is increased, or when the measured minimum input pressure is higher than the maximum pressure demand of all the loads, the supply air pressure is decreased is proposed.

[0009] The individual pressure or pressure requirement of each load is here usually adjusted by the operator at the start of the weaving process, depending on the respective application and the respective loom. In this case, during the subsequent weaving process, it is possible to maintain the pressure requirement constant. However, the individual pressure requirements can also be changed during the weaving process according to the type and design of the loom in order to adapt to the current given conditions. Similarly, it is also possible to change the individual pressure requirements depending on each pattern via the tying function. Here, according to the present invention, by determining the pressure requirements of each individual load at set time intervals, it is possible to determine at any time the load with the maximum current pressure requirement among all the loads, and then the supply air pressure is set accordingly. "At set time intervals" can mean that a period during which the respective pressure requirements are subsequently determined, for example a period of 2 seconds, is set. However, similarly, it is also possible to set the number of set weft insertions after which the respective pressure requirements are determined. Therefore, also in this case, the pressure requirements are determined at set time intervals. This is because the duration of the weft insertion under a certain loom speed is also constant. Thereby, a more accurate adaptation of the supply pressure to the pressure required for the maximum load can be achieved, and further energy savings can be achieved. In contrast, in the prior art, only the pressure supplied to the weft insertion nozzles was considered.

[0010] Furthermore, the measurement of the input pressure at set time intervals in each of the air jet looms also contributes to energy savings. Thereby, the pressure losses for each loom at each point in time due to pipeline losses and leaks can be accurately known, and thus it becomes possible to correspondingly consider them when setting the supply air pressure. Therefore, in many cases, the safety factor, which often tends to be an unnecessarily high supply air pressure, is not necessarily required or can at least be kept very low.

[0011] The weaving process is to be understood, within the framework of the present application, as meaning a related production process that starts after the operator has set the pressure requirements and ends immediately when the operator intervenes again to change at least one of the pressure requirements. That is, subsequent optimization of the pressure requirements, as well as thread changes, speed changes, width changes, or product changes, trigger a new weaving process. In contrast, the automatic adaptation by the loom does not fall under this.

[0012] The above advantages can also be achieved in a system for adjusting the supply air pressure within a loom installation equipped with a plurality of air-jet looms, as well as in the corresponding loom installation. Therefore, protection is similarly claimed for these.

[0013] The system for adjusting the supply air pressure has a central control unit for determining the pressure requirements of the air-jet looms and setting the supply air pressure depending on the determined pressure requirements. This control unit is configured to implement the described method, and has at least one comparison device for determining the maximum pressure requirements of all loads, the minimum input pressure of all air-jet looms, and comparing the measured minimum input pressure with the maximum pressure requirements of all loads. The control unit can have one or more comparison devices for this purpose.

[0014] This loom installation comprises a plurality of pneumatic loads for inserting the weft yarn respectively, a capturing device for capturing the pressure requirements of the plurality of pneumatic loads, a plurality of air-jet looms having sensors for measuring the input pressure, a compressed air system to which the air-jet looms are connected and to which the supply air pressure is applied, a central control unit for determining the maximum pressure requirements of the air-jet looms, and a compressor having a compressor control unit for setting the supply air pressure depending on the determined maximum pressure requirements. This loom installation is equipped with a system as described above, and the control unit of the system is connected to at least one capturing device, at least one sensor for measuring the input pressure of each air-jet loom, and the compressor control unit of the compressor.

[0015] The capture device may be, for example, a closed-loop control unit of an air-jet loom, and this closed-loop control unit sets or performs closed-loop control on the pressure or pressure demand of the load of the air-jet loom. Within the scope of this application, the term "closed-loop control unit" is used not only when the closed-loop control unit performs closed-loop control on the pressure in any case, but also when it only makes occasional settings, that is, when performing open-loop control. However, alternatively, the capture device may be a pressure sensor directly arranged on the load of the air-jet loom and measuring the pressure of this load.

[0016] Advantageously in this method, the pressure demand at the maximum load of each air-jet loom is determined by the closed-loop control unit of the air-jet loom and transmitted to the central control unit. In this case, it is only necessary to transmit one pressure value for each air-jet loom to the central control unit. Thereby, the amount of data to be transmitted can be reduced. Furthermore, in any case, the existing electronic pressure closed-loop control unit in the latest air (jet) loom can be advantageously used for this purpose.

[0017] In the loom equipment, advantageously correspondingly, each of the air-jet looms has a closed-loop control unit that determines the pressure demand at the maximum load of the pneumatic load of the air-jet loom and transmits it to the central control unit.

[0018] However, according to an alternative embodiment of this method, it is also possible that all the pressure demands of the loads of each air-jet loom are transmitted by the closed-loop control unit to the central control unit, and the pressure demand at the maximum load of each air-jet loom is determined by the central control unit.

[0019] As already explained, alternatively, as a capturing device, one pressure sensor may be provided for each pneumatic load of the air-jet loom, and this pressure sensor directly transmits the pressure demand of each load to the control unit. Here, at least the maximum load of each air-jet loom may be equipped with a pressure sensor. In this case, in this method, the pressure sensors of each air (jet) loom transmit their pressure values to the central control unit, and the pressure demands of the respective maximum loads of each air-jet loom are determined by the central control unit. If it is known which load has the maximum pressure demand, here, it is not necessarily required that all loads of each air-jet loom be equipped with pressure sensors. Usually, in each air-jet loom, it is sufficient if the load with the maximum pressure demand is equipped with a pressure sensor. However, it is of course also possible that all relevant loads of each air-jet loom are equipped with pressure sensors.

[0020] Similarly advantageously, in the loom installation, the closed-loop control unit of the air-jet loom is configured to set or perform closed-loop control of the pressure demand of the load during the weaving process. Such an electronic pressure closed-loop control unit can, for example, very quickly adapt the pressure of the pre-nozzle and the main nozzle in order to achieve proper yarn arrival. This pressure change can also be taken into account by the closed-loop control unit of the air-jet loom transmitting the current pressure value or pressure demand to the central control unit respectively.

[0021] In this method, correspondingly advantageously, the pressure demand of the load, in particular of the pre-nozzle and / or the main nozzle, is automatically adapted by the closed-loop control unit of the air-jet loom during the weaving process.

[0022] The pressure requirements of the relay nozzle and / or the extension nozzle can also be automatically adapted during the weaving process by the closed-loop control unit of the air-jet loom. This can include switching between different pressure levels, as already explained. For example, in a towel fabric, different pressure levels can be set for the edge part and the pile part, and they can be automatically switched between via a stitch. The closed-loop control unit then sets the respective set pressure levels.

[0023] In this method, more preferably, a target value for the supply air pressure is generated by the central control unit and set in the compressor control unit. In this case, this system only includes an interface for the compressor control unit and can be used with various compressors. However, alternatively, it is also possible for the control unit itself to drive and control the compressor or to include the compressor control unit. In the simplest case, the target value is equal to the pressure requirement of the current maximum load respectively. However, preferably, the target value also includes a compensation value for compensating for the pressure loss. These pressure losses can be known from the measurement of the input pressure of the air-jet loom.

[0024] Particularly preferably, the target value for the supply air pressure is generated from the maximum pressure requirement of all loads, the measured minimum input pressure, and a safety value. According to the safety value, for example, short-term pressure fluctuations of the supply air pressure can also be captured, and such short-term pressure fluctuations could otherwise cause the minimum input pressure to drop in one of the air-jet looms, and thus potentially lead to the stoppage of the loom.

[0025] Furthermore, preferably, the pressure requirement of the load is adjusted before the start of the weaving process. This setting is preferably done by the operator. In particular, preferably, the pressure requirements of the relay nozzle and / or the extension nozzle are adjusted by the operator according to the requirements of the current application.

[0026] In this method, more preferably, at the time of product change before the start of the weaving process, the pressure requirements of the pneumatic load of the air-jet loom, and / or the pressure requirements of each maximum load of the air-jet loom, and / or the maximum pressure requirements of all loads, and / or the input pressure of the air-jet loom are determined. Based on the determined pressure requirements and / or input pressure, the compressed air supply of the loom equipment is optimized. Thereby, a kind of simulation can be carried out at the time of product change, and the influence of the change on the compressed air supply can be inspected. Then, depending on the result of this simulation, production can be planned so that only as little compressed air consumption and as little pipeline loss as possible occur. For example, a specific application can be planned for a specific time point, or a specific application with a large pressure requirement can be planned in a loom existing near the compressor.

[0027] In the following examples, further advantages of the present invention will be explained.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

[0029] In the description of the following examples, the same reference numerals are assigned to the same features, or features that are at least comparable in their design and / or mode of operation. Further, these features will be described in detail only in their first mention, but in subsequent examples, only the differences from the previously described examples will be mentioned. Further, for the sake of clarity, in many cases only one or only a few of a plurality of identical components or features are labeled.

[0030] Figure 1 schematically shows an air-jet loom 2 having a plurality of pneumatic loads 5. The air-jet loom 2 usually has one or more warp systems, a shed-forming device, a take-up device, and a fabric beam, but they are not shown here. Among the components of the air-jet loom 2, only the components involved in weft insertion are shown. These usually include one or more supply bobbins 18 from which the weft yarn 17 is unwound and supplied to the pre-winder 19. From there, the weft yarn 17 extends through the balloon limiter 20 towards the weft insertion device of the air-jet loom 2. By using the weft insertion device, each weft yarn 17 is inserted into an opened shed (not shown) and beaten in using the reed 21. A separating device 22 is arranged on the insertion side for separating the weft yarn 5 after weft insertion. Optionally, the separating device 22 may also be arranged on the side opposite to the insertion side as shown here.

[0031] The weft insertion device is pneumatically configured in this embodiment and includes a main nozzle 10 arranged on the insertion side of the air-jet loom 2 in this embodiment, and a pre-nozzle 9 to which compressed air can be applied. By using these main nozzle 10 and pre-nozzle 9, the weft yarn 17 is brought into the insertion channel 24 of the reed 21. Further conveyance of the weft yarn 17 through the insertion channel 24 is supported by a plurality of relay nozzles 11 distributed on the reed 21, and these relay nozzles 11 also operate pneumatically, and compressed air can be applied to these relay nozzles 11 for this purpose.

[0032] According to this figure, on the side opposite to the insertion side of the air-jet loom 2, there is also provided a stretching nozzle 13 that operates pneumatically with compressed air in the same manner. This stretching nozzle 13 holds the weft yarn 17 inserted into the reed opening in a stretched state up to the weft stopper. In the situation shown in this example, the weft yarn 17 is inserted straight and is accommodated by the stretching nozzle 13. Further, in this air-jet loom 1, insert bodies 14 for inserting the end portion of the inserted weft yarn 17 into the subsequent open reed opening are arranged on both sides of the reed opening. According to the figure shown here, this insert body 14 is also a pneumatic insert body 14, and compressed air can be applied to this insert body 14.

[0033] To operate the pneumatic load 5, a plurality of valves 25 are provided, and these valves 25 are driven and controlled by the closed-loop control unit 6 of the air-jet loom 2 as represented by the dashed line. The pneumatic load 5 is connected to the compressed air system 3 of the textile factory or the loom equipment 1 (see Fig. 2) via these valves 25 and the pressure pipeline 23. In this example, a plurality of relay nozzles 11 are integrated into a nozzle group, and they are operated by a common valve 25. For a highly reliable supply of compressed air to the relay nozzles 11 and for compensating for pressure fluctuations, these relay nozzles 11 are here connected to the compressed air system 3 via a relay nozzle tank 12. Further, the air-jet loom 2 has a sensor 16 for measuring the input pressure pE that has reached the air-jet loom 2.

[0034] In this example, the closed-loop control unit 6 is configured as an electronic pressure closed-loop control unit and provides the required pressure to each of the pneumatic loads 5. The pressure required by each individual load 5 is usually determined as the pressure demand pB by the operator according to the requirements of each product or each application at the start of the weaving process for each load 5 and input into the air-jet loom 2. Subsequently, the input pressure demand pB can be maintained constant throughout the further weaving process. However, particularly advantageously for the pre-nozzle 9 and the main nozzle 10, the required pressure or pressure demand pB is changed by the closed-loop control unit 6 according to the flight time of the yarn, and thus the arrival of the yarn is closed-loop controlled. This is described, for example, in European Patent No. 1260622, and the specification is hereby expressly incorporated by reference.

[0035] For the adjustment and adaptation of the supply (air) pressure pV (see Figure 2) for the air-jet loom 2, here, by the air-jet loom 2, the input pressure pE is measured at set time intervals and transmitted to the central control unit 4 (see Figure 2). Similarly, at least one pressure demand pB is transmitted from each air-jet loom 2 to the central control unit 4. Here, only the maximum pressure demand pB of the current load 5 of the air-jet loom 2 can be transmitted at set time intervals by the closed-loop control unit 6. This is schematically shown in Figure 3. However, according to other embodiments of the method, it is also possible to transmit a plurality or all of the pressure demands pB of the load 5 of the air-jet loom 2 at set time intervals.

[0036] FIG. 2 shows a schematic view of a loom facility 1 including a plurality of air-jet looms 2 and a system for adjusting the supply air pressure pV. In this loom facility 1, in this example, as already described based on FIG. 1, it includes four air-jet looms 2 having a plurality of pneumatic loads 5. Further, these air-jet looms 2 also have, as already described, a sensor 16 for the input pressure pE and at least one capturing device for capturing the pressure demand pB of the pneumatic load 5. In this example, this capturing device is also formed by a closed-loop control unit 6 for the electronic pressure closed-loop control unit inside the air-jet loom 2. However, basically, it is also possible to provide one pressure sensor each as the capturing device for the most important load 5. Further, the loom facility 1 includes a compressed air system 3 having a central compressor 7 for generating the supply air pressure pV, a compressor control unit 8, and a compressed air tank 26 for compensating for pressure fluctuations. The compressed air is supplied to the individual air-jet looms 2 via a pressure pipeline 23.

[0037] The system for adjusting the supply air pressure pV includes a central control unit 4. Using this central control unit 4, the maximum pressure demand pBmax of the air-jet loom 2 is determined, and the supply air pressure pV is adjusted according to the determined maximum pressure demand pBmax. Similarly, using this control unit 4, the minimum input pressure pEmin of all the air-jet looms 2 is also determined. The control unit 4 has at least one comparison device 15 for this purpose. In this example, this control unit has a first comparison device 15 for the input pressures pE1, pE2, pE3, and pE4 of the air-jet loom 2 and a second comparison device 15 for the respective maximum pressure demands pB1, pB2, pB3, and pB4 of the air-jet loom 2. The sensor 16 and the capturing device, here the closed-loop control unit 6, of each air-jet loom 2 are connected to the control unit 4 in a signal transmission manner as shown by the dotted arrows. Similarly, this control unit 4 is also connected to the compressor control unit 8 in a signal transmission manner.

[0038] According to this method, which will be explained in more detail once again using the example of FIG. 3, here the control unit 4 determines, at set time intervals, for example every 2 seconds, or after a set number of weft insertions, the maximum pressure demand pBmax of all the loads 5 of the air-jet loom 2 of the current loom installation 1. According to this example, for this purpose, the individual closed-loop control units 6 of the air-jet loom 2 each determine their current maximum load 5 and its pressure demand pB, and notify them to the control unit 4. In this example, the pressure demands pB1, pB2, pB3 and pB4 are transmitted from the air-jet loom 2 to the control unit 4 accordingly. The comparison device 15 compares these transmitted pressure demands pB and determines from them the maximum pressure demand pBmax of all the loads 5 of the current loom installation 1. Similarly, the input pressure pE to the individual air-jet looms 2 is measured at set time intervals, for example every 2 seconds, and notified to the control unit 4 as input pressures pE1, pE2, pE3 and pE4. Using a further (or the same) comparison device 15, the input pressures pE1, pE2, pE3 and pE4 transmitted from the individual air-jet looms 2 are compared, and from them the minimum input pressure pEmin of each of the current air-jet looms 2 is determined.

[0039] Subsequently, using a further (or the same) comparison device 15, the minimum input pressure pEmin of the current air-jet loom 2 is compared with the maximum pressure demand pBmax of the current air-jet loom 2 or its loads 5, and depending on the result of this comparison, the target value pVSoll that the control unit 4 sets for the compressor control unit 8 is generated. In this case, if the measured minimum input pressure pEmin is lower than the maximum pressure demand pBmax of all the loads 5, the supply air pressure pV is increased. Similarly, if the measured minimum input pressure pEmin is higher than the maximum pressure demand pBmax of all the loads 5, the supply air pressure pV is decreased.

[0040] This ensures that, for example, even for an air-jet loom 2 located further away from the compressor, it is still possible to obtain a sufficiently high input pressure pE. As a result, by measuring the input pressure pE of each air-jet loom 1 and transmitting it to the control unit 4, the control unit 4 can also compensate considering pipeline losses. However, at the same time, the supply air pressure pV can also be limited to the maximum value actually required, which results from the maximum pressure demand pBmax and the pipeline losses known from the measurement of the input pressure pE. Since the compensation of the measured minimum input pressure pEmin using the maximum pressure demand pBmax of all loads 5 is carried out continuously during the weaving process, the supply air pressure pV in the compressed air system 3 can thus be adjusted in an optimal way at all times, thereby enabling significant energy savings.

[0041] According to this example, the target value pVSoll further includes a safety value S, which is taken into account by the control unit 4 when generating the target value pVSoll. Each of the air-jet looms 2 requires a minimum input pressure, and if it falls below this minimum input pressure, the air-jet loom 2 is forced to stop. According to this safety value S, it is possible to ensure that relatively small short-term fluctuations in the supply (air) pressure pV do not lead to the stoppage of the air-jet loom 2. However, basically, it is also possible to operate without such a safety value.

[0042] Similarly, different from the method shown here, the closed-loop control unit 6 of the air-jet loom 2 can also transmit not only the pressure demand pB of its respective maximum load 5 but also the pressure demands pB of all its loads 5. Subsequently, the determination of the pressure demand pB of the respective maximum load of each loom is carried out by the central control unit 4.

[0043] The method for setting the supply air pressure will be explained once again based on the example of FIG. 3. In this example, a loom installation 1 equipped with six air-jet looms 2 is shown. Each of the air-jet looms 2 has, in this example, five pneumatic loads 5.

[0044] For each of the air-jet looms 2, the individual pressure demands pB of the individual loads 5, here two relay nozzle tanks 12, stretching nozzles 13, inserts 14, and pre-nozzles and main nozzles 9, 10 respectively (see FIG. 1), are shown. For the air-jet loom 2, the pressure demand pB of its maximum load 5 is determined and transmitted to the central control unit 4. Accordingly, the pressure demand pB of the maximum load 5 of each (air-jet) loom 2 is characterized by being enclosed in a circle. Similarly, for each of the air-jet looms 2, the input pressure pE is determined and transmitted to the control unit 4. The control unit 4 finally determines, as already explained, from the transmitted pressure demand pB the respective maximum pressure demand pBmax of all the loads 5 of the air-jet loom 2. In this regard, in this example, the pressure demand pB of the stretching nozzle 13 of the air-jet loom No. 4 is "5.0 bar", which is shown in bold for characterization. In contrast, for the minimum input pressure pEmin, loom No. 6 is measured at "5.8 bar", which is also shown in bold for clarification. Thereby, even for the air-jet loom 2 with the minimum input pressure pEmin, the input pressure pE of 5.8 bar is still significantly higher than the pressure demand pBmax of the maximum load of 5.0 bar.

[0045] Therefore, according to the first embodiment of the method, the control unit 4 is set to reduce the supply (air) pressure pV for the compressor 7. For example, in this case, the compressor 7 can set a pressure of 5 bar as the target value pVSoll. In this case, the target value pVSoll exactly corresponds to the determined pressure demand pBmax of the maximum load.

[0046] However, since the input pressure pE from all air jet looms 2 is known, the control unit 4 can also calculate the maximum pressure loss in the compressed air system therefrom, which, according to a preferred embodiment of the method, can also be taken into account when generating the target value pVSoll. In this example, the maximum pressure loss in the system is 0.2 bar because in loom No. 6, only an input pressure pE of 5.8 bar can still be measured. If the maximum pressure loss in the compressed air system 3 is taken into account, the control unit 4 will set a pressure of 5.2 bar as the target value pVSoll for the compressor 7 in this case.

[0047] In a further development of this preferred method, it is also possible here to take into account which of the air jet looms 2 has the maximum pressure loss occurring. In this case, the maximum pressure loss could only be taken into account if, at the same time, the load 5 with the maximum pressure demand pBmax of all loads 5 of the air jet loom 2 is present on this air jet loom 2. In this example, this would apply if the pressure demand pB of the relay nozzle tank No. 2 of loom No. 6 had a maximum pressure demand pBmax of 5.0 bar. However, in this example, since the maximum pressure demand pBmax of 5.0 bar occurs in loom No. 4, there would be no need to compensate for the maximum pressure loss in this specific example.

[0048] However, for all three embodiments of the method described, a fixed safety value S can be taken into account when generating the target value as explained in FIG. 2.

[0049] Thereby, the loom installation can always be operated at an optimal pressure level, thereby significantly reducing the energy consumption for compressed air generation. For example, if the input pressure is reduced by about 1 bar, a saving of 10% overall can be achieved. This includes both savings during compressed air generation and reduction of leakage losses.

[0050] Further variations within the scope of the claims are possible in the same way as any combination of the features described, provided that they do not conflict with the teaching of the independent claims, even if they are shown and described in different parts of the description or different embodiments of the claims.

Explanation of Signs

[0051] 1 Loom equipment 2 Air-jet loom 3 Compressed air system 4 Central control unit 5 Pneumatic load 6 Closed-loop control unit 7 Compressor 8 Compressor control unit 9 Prenozzle 10 Main nozzle 11 Relay nozzle 12 Relay nozzle tank 13 Extension nozzle 14 Insertion body 15 Comparison device 16 Sensor for input pressure 17 Weft 18 Yarn supply bobbin 19 Pre-winder 20 Balloon limiter 21 Reed 22 Separation device 23 Pressure pipeline 24 Insertion channel 25 Valve 26 Compressed air tank S Safety value pV Supply air pressure pE Input pressure pE1 Input pressure of the first air-jet loom pE2 Input pressure of the second air-jet loom pE3 Input pressure of the third air-jet loom pE4 Input pressure of the fourth air-jet loom pB Pressure demand pB1 Maximum pressure demand of the first air-jet loom pB2 Maximum pressure demand of the second air jet loom pB3 Maximum pressure demand of the third air jet loom pB4 Maximum pressure demand of the fourth air jet loom pBmax Maximum pressure demand of all loads pEmin Measured minimum input pressure pVSoll Target value of the supply air pressure

Claims

1. A method for adjusting the supply air pressure (pV) of a loom installation (1) comprising a plurality of air jet looms (2) each having a plurality of pneumatic loads (5) for inserting weft yarns (17), wherein the pressure demand (pB) of the air jet looms (2) is determined using a central control unit (4), and the supply air pressure (pV) is set depending on the determined pressure demand (pB). In the method, during the weaving process - for each of the air jet looms (2), at set time intervals, the pressure demand (pB) of the current maximum load (5) is determined from each of the plurality of pneumatic loads (5), - the control unit (4) compares the pressure demand (pB) of the maximum load (5) of each of the air jet looms (2), and determines the maximum pressure demand (pB) of all current loads (5), - in each of the air jet looms (2), at set time intervals, the current input pressure (pE) is measured and transmitted to the control unit (4), - the control unit (4) compares the measured input pressure (pE) of the air jet looms (2), and determines the currently measured minimum input pressure (pEmin) of all air jet looms (2), - if the measured minimum input pressure (pEmin) is lower than the maximum pressure demand (pBmax) of all loads (5), the supply air pressure (pV) is increased, or if the measured minimum input pressure (pEmin) is higher than the maximum pressure demand (pBmax) of all loads (5), the supply air pressure (pV) is decreased characterized by the above method.

2. The method according to claim 1, wherein the pressure demand (pB) of the maximum load (5) of each air jet loom (2) is determined by a closed-loop control unit (6) of the air jet loom (2) and transmitted to the central control unit (4).

3. The method according to claim 1, wherein the central control unit (4) generates a target value (pVSoll) for the supply air pressure (pV) and sets it in a compressor control unit (8).

4. The method according to claim 3, wherein the target value (pVsoll) for the supply air pressure (pV) is generated from the maximum pressure demand (pB) of all loads (5), the measured minimum input pressure (pE), and a safety value (S).

5. The method according to claim 1, wherein the pressure requirement (pB) of the load (5), in particular of the pre-nozzle (9) and / or of the main nozzle (10), is automatically adapted during the weaving process by the closed-loop control unit (6) of the air-jet loom (2).

6. The method according to claim 1 or 5, wherein the pressure requirement (pB) of the load (5), in particular of the relay nozzle (11) and / or of the stretching nozzle (13), is adjusted before the start of the weaving process.

7. The method according to claim 1, wherein the pressure requirement (pB) of the load (5) of each air-jet loom (2) is transmitted to the central control unit (4), and the pressure requirement (pB) of the maximum load (5) of each air-jet loom (2) is determined by the central control unit (4).

8. At the time of product change before the start of the weaving process, the pressure requirement (pB) of the pneumatic load (5) of the air-jet loom (2), and / or the pressure requirement (pB) of the maximum load (5) of each air-jet loom (2), and / or the maximum pressure requirement (pB) of all the loads (5), and / or the input pressure (pE) of the air-jet loom (2) are determined, and based on the determined pressure requirement (pB) and / or input pressure (pE), the compressed air supply of the loom installation (1) is optimized. The method according to claim 1.

9. A system for adjusting the supply air pressure (pV) in a loom installation (1) comprising a plurality of air-jet looms (2) each having a plurality of pneumatic loads (5) for inserting respective weft yarns (17), wherein the system has a central control unit (4) for determining the pressure requirement (pB) of the air-jet loom (2) and setting the supply air pressure (pV) depending on the determined pressure requirement (pB). In the system, the control unit (4) is configured to carry out the method according to any one of claims 1 to 8, the control unit (4) determines the maximum pressure requirement (pBmax) of all the loads (5) of all the air-jet looms (2) and the minimum input pressure (pE) of all the air-jet looms (2), and has at least one comparison device (15) for comparing the measured minimum input pressure (pEmin) with the maximum pressure requirement (pBmax) of all the loads (5). System, characterized by this.

10. A loom installation (1), A plurality of pneumatic loads (5) for inserting respective weft threads (17), at least one capturing device for capturing the pressure demand (pB) of the plurality of pneumatic loads (5), and at least one sensor (16) for measuring the input pressure (pE), a plurality of air jet looms (2); A compressed air system (3) to which the air jet looms (2) are connected and to which a supply air pressure (pV) is applied; A central control unit (4) for determining the maximum pressure demand (pBmax) of the air jet looms (2); A compressor (7) having a compressor control unit (8) for setting the supply air pressure (pV) depending on the determined maximum pressure demand (pBmax); The system according to claim 9; Comprising; The control unit (4) of the system is connected to the at least one capturing device, at least one sensor (16) of each air jet loom (2), and the compressor control unit (8) of the compressor (7). A loom facility (1).

11. Each of the air jet looms (2) has a closed-loop control unit (6) for determining the pressure demand (pB) of the maximum load (5) of the pneumatic load (5) and transmitting it to the central control unit (4). The loom facility (1) according to claim 10.

12. The closed-loop control unit (6) of the air jet loom (2) is configured to adjust or perform closed-loop control of the pressure demand (pB) of the load (5) during the weaving process. The loom facility (1) according to claim 11.

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