EP1926847B1 - Process for a grinding arrangement - Google Patents

Description

The invention relates to a control method for carrying out maintenance work on a card, in particular for the grinding of rolling stands and / or measuring the carding gap.

• Schleifvorrichtungen für Deckelgarnitur oder Walzengarnituren, insbesondere für die Trommelgarnitur;
• Verstellvorrichtungen, hauptsächlich für den Flexibelbogen, geeignet um den Kardierspalt zwischen Deckel und Trommel einzustellen;
• Messvorrichtungen, insbesondere für das Messen des Kardierspaltes zwischen Trommel und Deckel.

The invention is in the technical field of carding. A carding machine has as its main task to dissolve the cotton to the individual fiber, whereby the nits should be removed. For carding the cotton, inter alia, tighter garniture settings and sharper trimmings are a prerequisite. During the production operation of the card, when actually material from the card is processed, a wear of the covers of the lid and the roller takes place. In order to detect and / or eliminate these at an early stage, various maintenance devices and methods have been developed, some of which are also suitable for use during production. Examples of such maintenance devices are:

• Grinding devices for flat equipment or drum sets, in particular for the drum set;
• Adjusting devices, mainly for the flexible bend, suitable for adjusting the carding gap between the cover and the drum;
• Measuring devices, in particular for measuring the carding gap between the drum and the lid.

There are various non-contact measuring methods and corresponding devices for determining the distance of clothing tips known. For example, in the DE 42 35 610 A1 discloses an inductive sensor associated with the lid of a card and facing the roller assembly. In the DE 102 51 574 A1 an optical sensor is described, which is able to detect the distance between the free ends of the trimmings, as well as corresponding reference surfaces. The DE 39 13 996 A1 also discloses non-contact sensors, in which case capacitive, inductive and optical sensors are mentioned.

Various methods and devices have also been developed for the grinding of trimmings. The traditional method is by means of a full sanding roller. Although with it again a straight ground set arises, the use has some serious disadvantages. The card must be shut down and stripped. The full sanding roller requires a precise handling by trained specialist personnel, as otherwise the clothing can be irreparably damaged. And every grinding cycle removes a larger amount of teeth. The low height of the teeth therefore allows only a few grinding cycles, then the teeth are too far sanded and the set must be replaced. In practice, therefore, one will wait longer to start a grinding cycle with a full grinding roll, taking a loss of quality of the product.

In addition to full grinding rolls, alternative grinding methods have been developed in recent years. In EP 322 637 and EP 497 736 A system has been proposed which can be installed in the card and can grind a clothing, in particular that of the drum, without interrupting production. Grinding takes place with the help of a small grindstone that grinds minimal amount off the teeth. This system does not require precise delivery and can be operated without personnel monitoring. Therefore, this grinding system can be used without interrupting the processing of the cotton and more often than the full grinding roll. A drop in quality due to truncated tooth sets is less serious.

In EP 565486 a control is disclosed as to how a grinding cycle could proceed. This process takes place each time after a predetermined amount of material has been processed by the card. Regardless of the state of the card, a grinding cycle is initiated and carried out. Only the drum speed, which is necessary to ensure a satisfactory grinding result, the initiation by the controller is required. In practice, therefore, even when the card is processing the maximum amount of material is being ground. With today's card generation, this can mean a production of more than 200 kg per hour.

The latest generation of high-performance cards, for example the C60 card from Rieter, no longer has a drum with a working width of 1 m, but a working width of 1.5 m. In addition, the diameter of the drum is reduced from the usual 1.3 m to around 0.84 m. A card with a reduced drum diameter is preferably driven at a relatively high speed to achieve a higher peripheral speed. Due to the changed geometry and production parameters, the card can process more than 200 kg / h of cotton today. The higher production that is desired today, in particular coupled with a changed geometry of the drum, but also has an effect on the functionality of the maintenance processes, such as measuring or grinding.

Many of these grinding or measuring methods work only or at least better when there is little or no material on the trimmings. Cotton fibers can distort the measurement results or even make them useless. The high flow of material can cause problems in the execution of intermittent processes, such as the grinding of trimmings or measuring the carding nip. Due to the very high throughput of material, an air draft is created, especially in the area of the drum surface, which swirls up fibers. These fluidized fibers can interfere with the cycle during a grinding cycle. They can be swept away and so pollute the device.

The present invention is therefore based on the object to provide a control method, which determines the optimal time for performing a due measuring or grinding process.

This object is achieved according to the invention by a control method having the features of independent patent claim 1. By initiating and / or implementing a maintenance process when the flow of material is interrupted, fouling of the operating device with fiber fly or distortion of the measured values is minimized without actually stopping the card. Unintentional interruptions are thereby positively exploited. A grinding or measuring cycle only takes a few seconds to a few minutes, so a small interruption of material is already sufficient to carry out a gentle measuring and / or grinding process.

• durch einen Unterbruch in der Materiallieferung, wenn zum Beispiel Putzereimaschinen ein Problem aufweisen;
• durch einen Bandbruch am Ausgang der Karde, zwischen Karde und Bandablage oder nachfolgende Strecke;
• durch einen Unterbruch in der Materialabnahme durch der Karde nachgeordneten Vorrichtungen, wie zum Beispiel Bandablage oder Strecke.

An interruption of the material flow can arise in particular:

• a disruption in the delivery of materials, for example, when cleaning machines have a problem;
• by a band break at the card's exit, between card and reel rack or subsequent track;
• by an interruption in the material removal by the card downstream devices, such as tape storage or track.

Material interruptions can be measured at the exit of the card, among other things. For example, by means of a speed measurement of the produced card sliver, an interruption on the card can be detected. The speed goes to 0. By means of a light sensor, a band break can be detected directly, u. a. at the transition from the card to a subsequent machine, such as a tape tray or a track. Also control signals from the blowroom or from subsequent machines can be used to detect a material interruption.

If there is a material interruption, the control of the card will react with the shutdown of the pickup roller and / or the feed roller. The rollers can be turned off individually, in parallel or one after another, depending on the cause of the interruption. Unless there is a serious interruption, the remaining carding elements such as drum, licker-in, cover or suction will continue working without interruption or alteration. This briefly frees the elements of most of the material. Exactly this material gap during operation is the optimal time according to the invention for carrying out the maintenance process.

The control of the maintenance devices requires several control steps. Basically, it requires a control of the maintenance process itself in a maintenance cycle, for example, a grinding or measuring cycle. An example of such a grinding cycle is in EP 565486 disclosed. In addition, it needs a controller that decides when a maintenance cycle is due again. For example, after x kg of production, after x hours of operation or when a measured value, for example that of a Nissen sensor, reaches a specified threshold.

These control conditions can be accommodated in the maintenance devices own control units or in sub-controls or integrated in the card control or in a higher-level control system.

In addition comes to the above listed controls nor a control according to the invention thereto. This control works like a traffic light, it does not decide whether a maintenance process is actually carried out, but only when a maintenance process can be performed. He can, but does not need to know, whether a maintenance process is actually due, but merely indicates whether the status of the card has an optimal window of time.

During the interruption period until the full flow of material is present again, the controller according to the invention can approve a due maintenance procedure such as a grinding and / or measuring cycle; the control of the respective maintenance procedure is then responsible for the actual initiation and / or execution. This can be initiated directly by the same control unit at the relevant device or passed on to an under control for the device in question.

Figur 1

Schematische Zeichnung einer Karde

Figur 2

Beispiel des Steuerungsverfahrens gemäss Erfindung

The invention will be explained below with reference to exemplary embodiments.

FIG. 1

Schematic drawing of a card

FIG. 2

Example of the control method according to the invention

FIG. 1 shows a revolving flat card, for example the Rieter card C60 with a working width of 1.5 meters. Fiber flakes are transported through transport channels (not shown) through the various cleaning process steps and finally fed to the cleaner shaft (6) of the card. Instead of a cleaner shaft, a normal hopper can be provided. This then passes the fiber flakes to the card as cotton wool. The feed device feeds the fiber flakes to the lickerins (3). The lickerins open the fiber flakes and remove some of the dirt particles. The last licker-in roller transfers the fibers to the card drum (1). The carding drum cooperates with the covers (2) and parallelises the fibers even further. The covers are cleaned by a cover cleaning (7) and possibly Reground by means of a grinding device (8). After the fibers have partially performed several rounds on the card drum, they are removed from the doffer roller (4) from the card drum, fed to the removal area (5) and finally deposited as a card sliver in a can can in a pot (not shown). A sensor between the nip rolls can measure the strip thickness, but also detect a band break.

For the inventive control, a permanent built-in maintenance device, for example a grinding (8) and / or measuring device (9), is a prerequisite. In principle, this grinding device must be able to manage after commissioning without additional manual settings. In addition to the grinding and measuring devices described in the introduction, there are alternative grinding devices (disclosed, inter alia, in EP 790 099 . EP 1 068 927 and EP 1 430 997 ), which have a similar construction and / or a similar principle. These can be permanently installed in a card even with a few adjustments and then own for the inventive control method. The control method according to the invention is also suitable for other measuring or grinding methods. Also other intermittent methods on the card, which penalize the carding process or which are penalized by the carding process with high material volume, can be controlled according to the inventive control method.

An example of a controller according to the invention may be as follows.

The grinding device (8) has its own control (not shown) that can initiate and execute a grinding cycle. An example of such a grinding cycle is in EP 565486 described. In this control itself is determined when a grinding cycle is due and which basic conditions for the grinding are necessary, for example, the minimum speed of the drum, otherwise the set is ground unevenly or too sharply. For the actual triggering, however, an additional signal is necessary, namely a release / approval for a suitable interruption. Once the interruption has ended and / or the material flow is maximum again, the release is set again. A cycle, which is due later, then has to wait again until a next interruption takes place.

As long as a break persists, the controller-parent or custom-can allow actual initiation. Immediately after such a release, a due cycle can be performed, but also a cycle, which is due in a release window, can be performed directly. Whether a cycle is due depends on the control of the device concerned. For example, it can be regulated according to the actual production or working time of the card or according to additional factors, for example grinding after x times, the carding gap is measured and a possible correction initiated.

• Nach X kg Baumwolle wird ein 5. Schleifzyklus (8) fällig, die Untersteuerung oder Steuereinheit der Unterhaltsvorrichtung wartet auf eine Genehmigung des übergeordneten Steuerungssystems;
• Das übergeordnete Steuerungssystem erkennt das Vorliegen eines Materialunterbruchs, dieses Signal kommt zum Beispiel von einem Sensor (11) am Ausgang der Karde.
• Die Hauptsteuerung schaltet erst die Abnahme- und oder Speisewalze ab
• Nach Abschaltung wird die Initiierung von allfälligen Unterhaltszyklen freigegeben;
• Der 5. Schleifzyklus, der fällig war, wird jetzt tatsächlich ausgeführt.
• Der Unterbruch ist aufgehoben, die Kardenproduktion wird wieder gesteuert und die Freigabe für die Initiierung neuer Unterhaltszyklen eingezogen.

In practice, the control can then proceed as follows ( FIG. 2 ):

• After X kg of cotton a fifth grinding cycle (8) is due, the sub-control or control unit of the maintenance device waits for approval of the higher-level control system;
• The higher-level control system detects the presence of a material interruption, this signal comes, for example, from a sensor (11) at the output of the card.
• The main control first switches off the intake and / or feed roller
• After switching off the initiation of any maintenance cycles is released;
• The 5th grinding cycle that was due is now actually being executed.
• The interruption is canceled, the card production is controlled again and the release for the initiation of new maintenance cycles is withdrawn.

Additional maintenance procedures, for example a measurement procedure (9), may be granted in parallel.

Now it can happen that a measuring cycle for the carding gap becomes due after the 5th grinding cycle has been completed. If the interruption is canceled before initiation, the measurement cycle remains due until the next interruption. But it can also happen that the interruption is canceled before a measuring or grinding cycle is finished. Then, depending on the type of cycle in progress, production control may be halted until the cycle is complete or directly reconnected.

Preferably, no more than one due cycle per maintenance device is halted until the next interruption. If it happens that a cycle is due a second time within a break interval, then there are several possibilities for the control: a cycle is carried out independently of the status of the card or it is nevertheless waited for an interruption. In particular, measurement methods that serve general monitoring can probably wait until the optimal measuring conditions are met. In a grinding process, the quality of the material is crucial and implementation is rather announced. An alternative solution is a counter for the due cycles, whereby a maximum number of due cycles can be determined depending on the production condition and the type of maintenance that is present. For example, the measuring of the carding gap should take place after every 8 hours of operation, but at the latest after 48 hours. The counter can then display a maximum of 5, if the 6 cycle is still due, is no longer waiting for an interruption, but directly initiated the cycle. Of course, after each initiated and actually performed cycle, the counter is reset to zero.

Depending on the nature of the maintenance work, it may also be beneficial to make the calculation of any subsequent cycle conditional upon the actual execution of the due cycle. For example, one grinding cycle is due every 50th hour of operation. The actual execution of a cycle, however, takes place after 75 hours. Performing the following cycle after just 25 hours would make no sense and the control will be adjusted accordingly.

The control of the maintenance devices is preferably integrated in the control of the card. However, it may happen that retrofit of the card with a support device this is not directly possible. Then, a maintenance device can be operated with an autonomous control according to the inventive control. For this, the controller must be able to detect a material interruption itself, for example, the controller can measure the speed of the take-off roll and / feed roll by means of a sensor and thus detect an interruption.

Claims (8)

1. A control process for a carding machine comprising at least one maintenance device which comprises a control unit, wherein the control unit can initiate and/or execute a maintenance cycle, characterised in that the control only authorises a maintenance cycle which is due during an interruption of the material flow during production.
2. The control process according to claim 1, wherein the maintenance device is a grinding device and/or a measuring device and the maintenance cycle corresponds to a grinding cycle and/or a measuring cycle.
3. The control process according to any one of the preceding claims, wherein the interruption of the material flow is detected by the stopping of the doffer roller.
4. The control process according to any one of the preceding claims, wherein the interruption of the material flow is detected by the sliver speed.
5. The control process according to any one of the preceding claims, wherein a counter is provided for maintenance cycles which are due.
6. The control process according to any one of the preceding claims, wherein the control for at least one maintenance device is integrated in the main control of the carding machine.
7. The control process according to any one of the preceding claims, wherein the control for at least one maintenance device is formed as an independent control and this receives the authorisation for a due cycle from a higher-level control.
8. The control process according to any one of the preceding claims, wherein at least one maintenance device has an independent control, wherein this can detect an interruption by means of its own sensor.

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