WO2006005203A1

WO2006005203A1 - Method and device for automatically stopping a power loom

Info

Publication number: WO2006005203A1
Application number: PCT/CH2005/000362
Authority: WO
Inventors: Reto Gehrig; Rolf Joss
Original assignee: Uster Technologies Ag
Priority date: 2004-07-15
Filing date: 2005-06-30
Publication date: 2006-01-19

Abstract

The invention relates to a method for automatically stopping a power loom, for example when a monitoring device (6) detects a serious defect in the web of material. The power loom is provided with a warp stop motion (101). Warp breakage is simulated on the warp stop motion (101) by means of specifically provided effective elements, for example contact electrodes (21, 22) and corresponding connecting lines (31, 32), thereby prompting the warp stop motion (101) to automatically stop the power loom. The warp stop motion (101) is easily accessible in almost all generations and types of power looms for fastening the effective elements (21, 22, 31, 32), thereby eliminating the need for complex solutions involving special cables and complicated layout of cables.

Description

Method and device for automatically switching off a

loom

The present invention relates to a method and a device for the automatic shutdown of a loom, according to the preamble of the independent claims.

On the one hand, automatic stopping devices for looms are known, for. B. from the publications CH-636'387 or

CH-639'151. Such stopping devices, the z. B. can be configured as electric warp stop, typically include a across the width of the web parallel to each other, electrically mutually insulated busbar pair. The warp threads to be monitored each carry one. Multilam. Each contact lamella is arranged and arranged so that it at a

Kettfadenbruch the pair of busbars electrically connected together and so closes a circuit. If the circuit is closed, transmits a corresponding electrical circuit a stop signal to the

Machine drive. On the other hand, attempts have been made for a long time to continuously monitor weaving webs moving along a direction of movement in a continuous manner. An automatic monitoring system for a web is z. B. from EP-O'162'134 known. Such monitoring systems typically scan the web along its width with a scanning head containing an optoelectronic sensor. The sensor signal is evaluated in a processor. The evaluation includes the construction of the image of a part of the web, the detection of possible errors and the. Triggering an action associated with a detected error. Such an action may in certain cases be the automatic shutdown of the weaving machine, for example when determining a coarse or impermissible fault in the web.

In theory, the shutdown of a loom is not a problem: It would be possible for the skilled person to connect the monitoring device by means of a suitable connection cable with the control cabinet of the loom so that the transmission of a shutdown signal via the connection cable causes a shutdown of the loom. In practice, however, such a direct approach involves difficulties that should not be underestimated. There are probably several dozen weaving machine types of different ages from different manufacturers. The weaving machines in use have a large variety of interfaces for connecting cables of the type mentioned. Therefore, either the connection cable would have to be individually adapted to the weaving machine in question, or with each monitoring device, a set of several dozen connecting cables would have to be made available, of which, hopefully, one would fit the loom to be monitored. Both alternatives are complex and expensive.

It is therefore an object of the invention to provide a method and apparatus for automatically turning off a

Specify weaving machine, which avoid the above disadvantages.

The object is achieved by the method and the device as defined in the ^' independent patent claims. Advantageous embodiments are given in the dependent claims.

The solution idea for the task is based on the recognition that most weaving machines are equipped with stopping devices, which automatically turn off the loom when a thread breakage is detected. Such stopping devices are usually easily accessible. These findings spurred the idea of a solution to simulate a thread break in order to stop the weaving machine by means of an already existing stopping device. Direct access to the machine control system, which offers complex solutions Special cables or adapters and complicated cable laying would require, is therefore unnecessary.

Accordingly, in the method according to the invention for stopping a weaving machine equipped with an automatic stopping device, an event is simulated which causes the stopping device to stop the loom automatically. In a preferred embodiment, a thread break, preferably a warp, weft, catch, leno thread break or other categories of yarn breaks, simulated.

The device according to the invention for carrying out the method according to the invention includes action means which are suitable for acting on the stopping device in such a way that it causes the weaving machine to be switched off automatically.

Thanks to the inventive method and the inventive device, it is possible to turn off a loom in a simple manner. Virtually all generations, types and sub-variants of weaving machines in use can be covered in a simple way.

Hereinafter, preferred embodiments of the invention will be explained in detail with reference to the accompanying drawings.

Here are shown schematically: 1 shows an automatic warp stop motion according to the prior art in a partially cutaway perspective view,

2 shows a first embodiment of a process stop device according to the invention in a partially cutaway perspective view,

3 shows an adapter for use in the process stop device according to FIG.

4 shows a second embodiment of a process ^{stop device according to the} invention in a partially cutaway perspective view,

Fig. 5 is a theoretical, caused by a Kettfadenbruch electrical signal of a warp stop as a function of time, and

FIG. 6 shows a theoretical electrical signal of a warp thread monitor as a function of time, generated according to the method according to the invention. FIG.

In Figure 1, an automatic warp stopper 101 is shown according to the prior art. The warp stop motion detector 101 has a contact rail 102 running in the weft direction. The contact rail 102 includes a U-shaped first bus bar 121, in which a second bus bar 122 is housed with the interposition of an electrical insulation 123. On an unbroken, to be monitored warp 107 each hangs a contact blade 104, at least partially made of electrically conductive material is made. In the case of a warp yarn break, the contact lamella 104 drops to a lower position due to gravity and electrically connects the first bus bar 121 to the second bus bar 122. This completes a circuit and shuts off the loom (not shown).

In the method according to the invention, a warp thread breakage is simulated in order to force a shutdown of the weaving machine in a simple manner. The simulation can be done directly or indirectly, as the following figures 2 and 4 explain.

FIG. 2 shows a first embodiment of a device 1, hereinafter referred to as "process stop device", for carrying out an "immediate" shutdown method according to the invention. According to this embodiment, the first bus bar 121 and the second bus bar 122 are respectively directly contacted by means of suitable contact electrodes 21, 22, which are indicated very schematically in FIG. 2. The contact electrodes 21, 22 may be mounted on an adapter 2 according to FIG. 3, which can be placed on the contact rail 102.

The required parking signal is from a known monitoring device 6 for the woven (not shown) web, for example. By means of two

Connecting lines 31, 32, to the process stop device 1 transmitted. The monitoring device 6 can for this purpose z. B. a shut-off relay 61 include, which acts as a switch for closing the circuit formed by the bus bars 121, 122, - the contact electrodes 21, 22 and the connecting lines 31, 32. The shut-off relay 61 in turn is controlled by a program driver, which is assigned to a present in the monitoring device 6 or the monitoring device 6

Processor (not shown) is running. The program typically causes the loom to be shut down if a gross or impermissible fault in the web is detected during automatic monitoring. Of course, instead of a relay another switching element with an analogous function, eg. As a transistor, an opto-coupler, etc., can be used.

An example of an adapter 2 which can be used for contacting the busbars 121, 122 is shown in FIG. The adapter 2 is designed as composed of two parts 23, 24 block, which the

Contact rail 102 encloses. The busbars 121, 122

(see Fig. 2) are embedded in corresponding contact electrodes 21, 22 of the adapter 2. The contact electrodes 21, 22 can be connected by means of connecting lines 31, 32 to the monitoring device 6 indicated in FIG. 2.

As explained with reference to FIG. 2 inventive

Shutdown the busbars 121, 122 directly In contrast, Figure 4 shows a possible embodiment of a process stop device 1 for carrying out an "indirect" shutdown method according to the invention. This second embodiment includes a plate carrier 5 which can be mounted on the contact rail 102. The plate carrier 5 has an actuatable holding element 51 for its own simulation contact plate 4. The simulation contact blade 4 depends in the illustrated state of readiness on the holding element 51, in a similar manner as the other contact blades 104 each depend on their associated warp threads 107, - see. FIG. 1. The holding element 51 can be actuated by means of an actuating element (not shown) such that it can drop the simulation contact lamella 4 onto the contact rail 102 in response to a corresponding stop signal. A suitable actuator may, for. B. be designed as an electromagnet, with the movable armature, the finger-shaped holding member 51 is operatively connected. Dropping the simulation contact blade 4 results in the weaving machine stopping because the stopping device does not distinguish between the simulation contact blade and another contact blade.

The actuating element is, for example, connected via two electrical connecting lines 31, 32 to the parking relay 61 in the monitoring device 6. Such Monitoring device 6 with Abstellrelais 61 is already indicated in Fig. 2. The parking relay 61 controls the actuator 51 and causes its operation when the loom is to be turned off. For this purpose, z. B. the relay contacts to be connected to the supply of an electromagnet, which may be present as an actuator in the plate carrier 5. Of course, the actuator 51 can be controlled in other ways known in the art.

In the practice of the invention, attention should be paid to the following aspect. In modern weaving machines, the existing sensors, including the stopping devices 101, are connected to an evaluation unit, which evaluates the sensor signals. Often a loom integrated into the loom process control unit of the loom takes over this task; instead or in addition, an external data acquisition system or expert system may perform the evaluation. Among other things, the evaluation unit can keep a statistic of the detected shutdowns. Such a statistic could be falsified by the inventive method in an undesirable manner, because yes in the inventive method, a thread break is simulated, which is none, but is detected in the statistics as such. However, at least in the embodiment of Figs. 2 and 3, corruption of the statistics may be avoided, as shown below. The idea for preventing statistical corruption is based on the finding that a contact blade 104 falling down due to yarn breakage and a closing shut-off relay 61 cause different electrical signals at the two busbars 121, 122. In addition, the parking relay 61 in a controlled manner, for. B. during a predefined time, be operated.

5 illustrates a theoretical, of ^'caused a yarn breakage electrical signal 91 as a function of time t recorded. The signal 91 is initially at a first level, e.g. In the warp break, the signal 91 shows a typical transient response with a variety of signal peaks, which is explained by the partially elastic rebound of the contact blade 104 of the contact rail 102. Only after the contact blade 104 by damping has come to rest, the signal 91 remains constant at a second level, for example at the value "1". The second signal level "l ^w" is maintained until the yarn break has been rectified and the contact blade 104 is again in the suspended ready state. If necessary, the signal could already be debounced in the warp stop motion, so that any signal peaks would have already been filtered out.

From the signal 91 at a genuine yarn break the signal 92 can be distinguished with simulated yarn breakage. The latter is also recorded theoretically and as a function of time t in FIG. Also, this signal 92 has when switching on the Abstellrelais 61 some caused by oscillations signal peaks, and this signal could possibly also be entprellt already in the warp stop, so that any signal peaks would be filtered out. Important for the discrimination of the signal 92 (FIG. 6) from signal 91 (FIG. 5) is the fact that the shutdown relay 61 for the simulation of the thread break remains switched on only during a defined time interval T and can then be switched off again. In other words, the loom is turned off by a pulse of well-defined pulse duration T. The pulse duration T can be chosen to be significantly shorter than the time it takes to fix a thread break, for example between fractions of a second and a few seconds. The evaluation of the loom, z. As the process control unit and / or the corresponding data acquisition or expert system, can determine with a simple routine, how long the signal remains at the second signal level "1"^' Is the dwell time at the second signal level "1 ^λλ only short - just predefined pulse duration T -, this is a simulated thread break, which must not be taken into account in the statistics.A longer dwell time at the second signal level "1" is a real thread break, which must be included in the statistics.

Of course, the above is analogous in the case apply where the first signal level is higher (eg, "1") than the second (eg, "0").

As an extension of the method explained with reference to FIG. 6, instead of just one pulse having a well-defined pulse duration T, a well-defined sequence of pulses and intervening pauses, according to a predetermined signal pattern, can be used

Turn off the loom to be used. About the

Connecting lines 31, 32 (FIGS. 2, 3) can thus supply signals with different shapes and meanings to the

Contact rail and transmitted to the evaluation of the loom.

Of course, the invention is not limited to the embodiments exemplified here. With knowledge of the invention, the skilled person is quite able to derive further embodiments. In particular, not only warp thread breaks, but also other yarn breaks such as weft, catch or leno thread breaks can be simulated to effect a shutdown of the loom. Another variant of the invention ^' is to access an output line of an existing thread monitor and to create an electrical signal to this, which corresponds to a stop signal of the thread monitor and turns off the loom. Alternatively, such a shutdown signal can also be introduced to a suitable location directly in the control box of the loom to a

To turn off the weaving machine. LIST OF REFERENCE NUMBERS

1 process stop device

2 adapters

21, 22 contact electrodes

23, 24 adapter parts

31, 32 connecting cables

4 simulation contact lamella

5 plate carrier 51 holding element

β monitoring device

61 Shutdown relay

91 Signal when stopping due to yarn breakage 92 Signal when parking due to simulated yarn breakage

101 stopping device

102 Contact rail 121, 122 Busbars 123 Isolation

104 contact lamella for monitoring warp thread breaks

107 warp thread

Claims

claims

1. A method for stopping one with an automatic

Lashing device (101) equipped loom, characterized in that an event is simulated, which causes the stopping device (101) to turn off the weaving machine automatically.

2. The method of claim 1, wherein as an event a yarn break, preferably a warp, weft, catch or leno thread break, is simulated.

3. The method according to claim 2, wherein the automatic stopping device (101) as Kettfadenwächter with

Contact lamellae (104) is executed, a contact blade

(4) is held by an actuatable holding element (51) and the holding element (51) is actuated such that the contact blade (4) closes a circuit in the same way ^' as in a Kettfadenbruch.

4. The method of claim 2, wherein the automatic stopping means _(101), preferably designed as a warp stop motion, two mutually electrically insulated busbars (121, 122), which by means of a respective electrical line (31, 32) are contacted, and the two lines (31, 32) are electrically shorted.

5. The method of claim 4, wherein the two lines

(31, 32) are short-circuited according to a predetermined signal pattern, for example, only during a predetermined period of time (T).

6. The method according to claim 5, wherein an evaluation unit connected to the automatic stopping device, preferably a process control unit of the weaving machine and / or a data acquisition or expert system, determines whether there is a short circuit or a sequence of multiple short circuits according to the predetermined signal pattern , and detects a short circuit as a thread break only if it does not correspond to the predetermined signal pattern, otherwise not.

A method according to any one of the preceding claims, wherein a web produced by the weaving machine is monitored by means of a monitoring device (6) and the simulated event is initiated by the monitoring device (6).

8. Device (1) for carrying out the method according to one of the preceding claims, characterized by

Active means (21, 22, 31, 32, 4, 5) which are suitable for acting on the stopping device (101) in such a way this is caused to turn off the loom automatically.

9. Device (1) according to claim 8, wherein the automatic stopping device (101) as Kettfadenwächter ... with

Contact blades (104). and the active means (4, 5) comprise a contact blade (4) held by an actuatable retaining element (51), which retaining element (51) can be actuated such that a circuit is produced by the contact blade (4) in the same way as in a warp thread break is closable.

10. Device (1) according to claim 8, wherein the automatic stopping device as Kettfadenwächter (101) with two mutually electrically insulated busbars (.121, 122) is executed and the active means two electrical lines (31, 32), which in each case one of two busbars (121, 122) contacted and short-circuited with each other, include.

11. Device (1) according to claim 10, wherein a switching element

(61), for example, a relay, a transistor or an opto-coupler, for short-circuiting the two lines (31, 32) is present.

12. Device (1) according to any one of claims 8-11, wherein the device (1) at least one line (31, 32) for

Transmitting a stop signal from one Monitoring device (6) for monitoring a web produced by the loom includes.