The invention relates to a method for operating a weaving machine with a shedding machine, which comprises activatable and deactivatable movements of the shedding means and is driven by a single rotational speed-changeable drive, which is controlled or actuated independently of a rotational speed-changeable drive of the weaving machine.
The shedding machine is of the type that the movements of the individual shedding means, for example heald frames or Jacquard hooks or wires, can be controlled, that is to say activated or deactivated, through an electronic control in an individually programmable manner by electromechanical elements. Such shedding machines are known to the skilled worker under the name dobby or Jacquard machine. In dobby or Jacquard machines in the sense of this invention, a drive of the main shaft of the shedding machine and rotating masses of the shedding machine connected therewith, including possibly present additional inertial or balancing masses, is possible independent of the actuatable movement of the shedding means. A dobby machine that works according to this principle is described, for example, in the EP 570 628 A1. In contrast to shedding machines in which each shedding means comprises its own motor, a shedding machine as it is pertinent here as an underlying basis needs only a single drive motor.
Moreover, in the present method, one speaks of electric motorized drives which have a changeable rotational speed through an electronic control, and which are able to drive the weaving and the shedding machine with their regular operating rotational speed.
An independent motorized drive of the shedding machine makes it possible, in certain operating conditions, to suspend the operation, which is essentially synchronous in normal weaving operation, of the shedding machine and weaving machine. At this point, reference is made to the fact that both the weaving machine as well as the shedding machine have components that are moved unequally or irregularly or non-continuously in most cases via drive means. In the weaving machine these are usually the components for the reed beat-up and if applicable components for the mechanical weft insertion. In the shedding machine these are the shedding means. The irregular movements of these components cause inertial moments that fluctuate independently of one another on the shaft of the respective drive motor. These in turn cause fluctuating rotational speeds over respectively one operating or working cycle of the weaving and shedding machine. Depending on the size of the drive units and depending on how the associated drive control is laid out or designed in terms of the regulation technology, these fluctuations turn out larger or smaller. This factual situation is described, among other things, in the EP 0 893 525 A1. That means that the weaving and the shedding machine with drive motors that are independent of one another, generally over the course of one working cycle are angularly synchronous and physically exactly at the same rotational speed only at certain functionally absolutely necessary time points. In other angular ranges of a working cycle, it is permissible to deviate from this exact synchronicity. In this regard, an essentially synchronous operating manner means that e.g. within one working cycle the instantaneous rotational speed of weaving or shedding machine amounts to only 85% of the actual operating rotational speed, however that both machines run with the same operating rotational speed when averaged over several working cycles. For the described operating manner it is necessary that the weaving and shedding machine, or their drives in connection with the associated electronic control or regulating arrangements including rotational angle transducers or other sensors, are equipped to allow a determination of the instantaneous position of weaving and shedding machine as well as a synchronizing of both.
A method of operating a weaving machine with a shedding machine with drives independent from one another is known from the EP 1 328 673 B1. This includes the suggestion, that the running-up of the shedding machine can take place without the motion of the shedding means and without motion of the weaving machine. That has the advantage that the drive moments on the shedding machine are reduced, because the time for the run-up of the shedding machine with its rotational masses including possibly present inertial or balancing masses can be longer than with a synchronous run-up of weaving and shedding machine; moreover the masses of the shedding means are not moved along in this process. Furthermore the suggestion according to the EP 1 328 673 B1 rests on the consideration that the weaving machine is operated in such a manner during the run-up process of the weaving and shedding machine, that no “empty” reed beat-ups against the binding or interlacing point of the woven web are carried out before the first reed beat-up with a rotational speed that is near or equal to the operating rotational speed, because this can lead to an undesired compressing of the woven web and to a micro-roughening of the weft and warp threads at the interlacing point.
Beginning from the method according to the EP 1 328 673 B1, considerations were established, that it is not the same or indifferent regarding in which position the shedding means come to a standstill if the weaving operation must be interrupted due to a weft thread break or a warp thread break. With a weft thread break, for example, the open position of the loom shed is necessary so that the broken weft thread or threads can be removed. The open position of the loom shed means that all shedding means are positioned in one of the two extreme positions of the motion (high or low). A longer standstill of the weaving machine or of the shedding means in the open position of the looms shed is, however, disadvantageous for the quality of the arising woven web; namely thereby the warp threads are loaded, the interlacing point can wander, and start-up marks can arise in the woven web upon the renewed running-up of the weaving machine with its reed beat-ups. One therefore strives to keep as short as possible, the time in which the loom shed stands in the open position during operating malfunctions or interferences. Therefore, whenever possible, outside of the normal weaving operation, the loom shed is brought into the closed position.
It is the underlying object of the present invention, upon an operating interference or malfunction, to shorten the time duration for the elimination of the operating malfunction, and to avoid as much as possible the slowdown of the shedding machine and the rotating masses connected therewith and the possibly present inertial masses down to a standstill. In connection with operating malfunctions due to weft break, thereby the time duration with an open position of the loom shed is further shortened, and moreover less electrical energy is needed, because the shedding machine does not need to be stopped and then again set into operation, in order to eliminate or remove a weft break.
The object is achieved according to the invention by the features of the claim 1. In that regard, the shedding machine is further operated with a high working rotational speed, e.g. the previous operating rotational speed, and if the weft break elimination was successful, it is then transitioned again into the regular weaving operation, without stopping.
In the prior art, for starts, stops and rotational speed changes of the weaving and shedding machine with drives that are independent from one another, it is already suggested not to also operate or drive the shedding means for certain reasons, and e.g. to leave the shedding means standing preferably in an open shed position with a running-up or running-down shedding machine.
According to the present invention, in connection with an operating interference or malfunction, with a shedding machine that continues to run, the shedding means are activated or deactivated in a suitable manner via a programmable process sequence control, so that a broken weft thread can be removed and then again newly inserted. In that regard, only the weaving machine is reduced in its rotational speed and if applicable brought completely to a standstill by the control of its own drive. Then the weaving machine with its own drive again runs up to the operating rotational speed desired for the further weaving operation, and in that regard synchronizes itself with the shedding machine, which already runs with this operating rotational speed, so that the weaving operation is again further carried on in a pattern-correct manner.
For certain reasons it can be necessary that the operating rotational speed of the weaving and shedding machine at the first reed beat-up after an operating malfunction must be different from the operating rotational speed at the last reed beat-up before an operating malfunction. This can, for example, be based on the fact that the control of the weaving machine is programmed in such a manner so that it automatically reduces the operating rotational speed of the weaving and shedding machine upon the occurrence of a large number of successive operating malfunctions, until fewer operating malfunctions arise. An opposite process is naturally also conceivable in connection with less frequent operating malfunctions. Moreover, there may be other weaving technical requirements that require a different operating rotational speed of the weaving and shedding machine upon the first reed beat-up after an operating malfunction than upon the last reed beat-up before the operating malfunction. For this reason it is also provided within the scope of the method according to the invention, to adapt the rotational speed of the shedding machine to the requirements that are prescribed by the weaving machine control, before again taking up the regular pattern-correct weaving operation, that is to say, to reduce or to increase the rotational speed of the shedding machine within certain limits, so that it again runs essentially synchronously with, that is to say with the operating rotational speed of, the weaving machine, which carries out the reed beat-ups, in the following regular weaving operation. To this also belongs, if applicable, an adjusting of the angular relationship or the relative position between the weaving machine and the shedding machine. Due to weaving technical reasons, it can be necessary to change this angular relationship or relative position in the working cycle of the weaving and shedding machine at the time point of the closed position of the loom shed for the further regular weaving operation, either permanently or also from weft pick to weft pick. A phase shifting takes place between the working cycles of weaving and shedding machine. That must be taken into consideration, if applicable, upon the renewed synchronisation after an operating malfunction, by a suitable programming of the controls of the drive motors, but does not change anything in the essentially synchronous operating manner in the normal weaving operation of the weaving and shedding machine.
Under certain conditions, for eliminating or removing the causes for the operating malfunction it can also be necessary to reduce the rotational speed of the shedding machine during the non-synchronous operation of weaving and shedding machine. In order that the advantage of the method claimed here still remains existing, one will avoid a standstill of the shedding machine, however; it is sensible not to reduce the rotational speed of the shedding machine below 50% of the operating rotational speed.
It can furthermore be sensible, to further operate also the weaving machine at a low rotational speed at least temporarily during the non-synchronous operation of weaving and shedding machine, in order to enable the removal or elimination of the causes of the operating malfunction. This can, for example, be necessary when one wishes to bring the weaving reed of the weaving machine into a certain position for the automatic removal of weft breaks. During the described process, the weaving machine will be run down to a creeping speed that is e.g. compatible with the weft break removal (that is to say sufficiently slow). In the present case, the term creeping speed means rotational speeds that are smaller than 10% of the normal operating rotational speed. The removal of an operating malfunction, e.g. the weft break removal, can take place automatically or manually by the weaving mill personnel. Automatic weft break removal, e.g. by means of air jet, is the state of the art in modern weaving machines and does not need to be described here in more detail. For the case of the manual removal of operating malfunctions, for safety reasons in the scope of the method described here, correspondingly adapted method process sequences will be necessary. The operation of the weaving machine with a low rotational speed (creeping gear) and again taking up the normal weaving operation after weft break removal can, e.g., be first started by corresponding input at the operating console of the weaving machine by the weaving mill personnel.
The desired operating types pre-programmed in the control and regulating arrangement, as well as the rotating speeds of weaving and shedding machine during and after performing the measures for the removal of an operating malfunction are pre-selectable by the operator by corresponding input menus or keys on the control and regulating arrangement of weaving and shedding machine.
In connection with longer operating interruptions, e.g. in connection with an unsuccessful attempt to remove or eliminate the cause of an operating malfunction, the weaving and shedding machine are stopped. The loom shed is then brought to a closed position as soon as possible by suitable control of the drive of the shedding machine and corresponding actuation of the shedding means. In connection with operating malfunctions that do not require a weft break removal and thus also do not require an open position of the loom shed, the driving or operation to a closed position of the loom shed can similarly be achieved very early, namely while the shedding machine is still being run down or slowed down, that is to say has not yet come to a standstill after recognition of the operating malfunction. This can be sensible, for example, in connection with an operating interference due to a warp break. The inventive method has particular advantages for the case that the cause of the operating malfunction is a weft break on the weaving machine. According to the prior art, this is signaled by a transducer to the control and regulating arrangement of the weaving machine, which can thereby recognize whether or not a weft thread has been properly inserted. Namely, certain positions of the shedding means, which form the loom shed, are necessary for the removal of a broken weft pick out of the loom shed and the renewed insertion of this broken weft pick into the pattern-correct loom shed. These are achieved according to the method according to the invention without a standstill of the shedding machine by activating or deactivating the movement of the shedding means. In connection with a weft break, e.g. for removing the broken weft thread, the loom shed must be in that pattern-correct position which existed upon the insertion of this broken weft pick into the loom shed. Thereafter, this weft pick must be inserted anew and the pattern-correct weaving operation must be continued with the next weft pick. It is, however, to be considered, that in connection with the interrupted synchronisation between weaving and shedding machine and in connection with rotational speed reduction or complete run-down of the weaving machine, the activation of the shedding means with a still-running shedding machine may only take place, if no collision with mechanical weft insertion elements (e.g. grippers) that might possibly still be present in the loom shed can still occur. If applicable, a signal transducer is to be provided, which detect the position of the insertion elements and transmit signals to the control of the weaving or the shedding machine, which prevent or interrupt an activation of the shedding means, as long as the danger of a collision with the insertion elements exists.
For weaving technical reasons it can be generally sensible, to carry out a so-called start with missing or lost pick after an operating malfunction or a longer standstill of the weaving machine. In that regard, the weaving machine starts up without a weft pick being inserted, that is to say the last previous correctly inserted weft pick experiences anew a reed beat-up, preferably however only this one, for which the weaving machine starts within one weaving cycle. Before that, the shedding means must be brought into that pattern-correct open position of the loom shed that was necessary for inserting this last weft pick into the loom shed. With independent drives for weaving and shedding machine it is possible to carry out any desired movements of the shedding means driven by the shedding machine, without the weaving machine being moved thereby. That is to say, no undesirable reed beat-ups become necessary, for example with a slow reverse running of the weaving machine into the necessary starting position.
The described start with a lost or missing pick may now be integrated in an advantageous further development in the method according to the invention for operating a weaving machine with a shedding machine, if this option is required for the renewed start of the weaving process after an operating malfunction. Described in connection with an example of an operating malfunction due to weft break, this further development of the method is represented as follows: While carrying out the measures for the weft break removal, the shedding machine is further operated with a high working rotational speed, and after removal of the broken weft thread it brings the loom shed of the last correctly inserted weft thread into an open position and thus freely exposes this weft thread. For that purpose, the associated shedding means are activated or deactivated in a suitable manner. During this process, on its part the weaving machine can already be located in the starting phase or it only starts after complete opening of this shed. In any case, the weaving machine with its drive starts again to the operating rotational speed desired for the further weaving operation and is synchronized with the independent drive of the shedding machine by the control after completion of the measures for removing the operating malfunction, whereby the shedding machine then also runs with this operating rotational speed, so that the weaving operation is again carried on in a pattern-correct manner. In this process, the weaving machine control receives a signal that no weft pick is to be inserted before the first reed beat-up, which can be carried out by corresponding electromechanical devices of modern gripper or air jet weaving machines.
It can also occur that several weft picks are inserted with faults or breaks before the weaving machine with drive is stopped by its stop motions or monitoring devices and the process of the weft break removal is started. In this case, the method described here is to be carried out analogously for several broken or incorrectly inserted weft picks. For that, with the shedding machine running and the weaving machine stopped or operating in the creeping gear, the shedding means must be brought into the correct pattern-dependent open positions of the loom shed by activation or deactivation of their motion one after another, in order to be able to remove the associated weft picks.
The desired sequence of the measures for the removal of an operating malfunction, which are pre-programmed in the control and regulating arrangement, is selectable by the operator by corresponding input menus or keys on the control and regulating arrangement of the weaving and shedding machine.
At the time point t1.2, which may e.g. occur together with the reed beat-up of the weaving machine, thus 360°, the braking process of the weaving machine begins. In the illustrated case, the weaving machine is braked down to a standstill, that is to say n1.1 is then=0. As a result of the above described loom shed change, the loom shed N+1 is now open. The associated weft thread S_N+1 is here not inserted (X), because of course the weft thread S_N that was not correctly inserted (or was broken) must first be removed. Therefore, through a corresponding actuation of the shedding means, it is changed back to the loom shed N. The incorrectly inserted weft thread can now be removed manually or by a so-called automatic weft break removal. During the entire process, the shedding machine has not changed its operating rotational speed n1.2, that is to say it is still the same as that with which it was operated also already up to the beginning of the occurrence of the weft break. The drive for the shedding machine must thus not provide a power or torque peak for a braking process. The corresponding time is also saved; only the weaving machine, which brakes more quickly due to lower rotational masses or without additional inertial masses, has been stopped.
Once the broken or incorrectly inserted weft thread is removed, then the weaving machine starts again. In the example, the point as of which the weaving and shedding machine are again synchronously operated with the same rotational speed and in the manner required for the regular weaving operation was set to the reed beat-up, which falls on the time point t1.4. Shortly before t1.4, t1.3 is run through, which specifies the time point for the closed position of the loom shed. The weft thread S_N is correspondingly to be inserted at a proper time before t1.3, so that it can properly move through the loom shed and finally be bound up.
If several weft threads are broken or not correctly inserted, then first the loom shed of the last broken weft pick is opened, as this has occurred in
If the last broken weft thread was automatically removed, then all further sheds are opened and the weft threads are removed preferably also in an automatic manner with a running shedding machine, until also the first broken weft thread S_N−i (with i>0) can be removed. After this removal, the weaving machine starts again automatically; either from the standstill or from the creeping motion. If its starts from the standstill, then the point as of which the weaving and shedding machine are again synchronously operated with the same rotational speed and in the manner required for the operation falls at t1.4. Shortly before t1.4, t1.3 is run through, which specifies the time point of the closed position of the loom shed. If it starts from the creeping motion, then the point as of which the weaving and shedding machine again is synchronously operated with the same rotational speed and in the manner required for the operation falls at t2.4. Shortly before t2.4, t2.3 is run through, which specifies the time point for the closed position of the loom shed.
Also
In the process sequence,
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE09/00296 | 3/6/2009 | WO | 00 | 8/12/2011 |