DE60013683T2 - Method and device for controlling rotation signals of the yarn feed tube in yarn delivery devices for weaving machines - Google Patents

Description

The The present invention relates to a method and an apparatus for controlling the rotation signals of the weft winding arm in weft feeds for looms, in particular yarn feeds and pre-facilities for Jet looms.

in the Weft feeders are known and will be in the field of weaving technology widely used in the case of jet looms also as Vormess facilities for act the weft.

With fulfill other words these devices, between the weft bobbin and the loom are used, the special task, a preset thread length for each Supply weft insertion, by picking it from a weft supply that is on its own Drum is wound, in the form of windings, on the drum are wound, release, and by also giving the released weft to replenish, that they rewind a corresponding amount of thread on the drum, so the weft reserve essentially unchangeable to keep.

in the typical case works, as can be seen from the description below clearly shows a system for weft feeding in jet looms with pre-measurement of the yarn fed at each weft insertion with a weft pre-gauge and thread feeding, and has the following: a fixed drum on which a rotating arm winds the thread windings, which the To form weft stock; a weft holding finger for stopping of the thread associated with the fixed drum and is electromagnetically operated that he releases the thread while taking it from the drum to handle, and to stop the unwinding of the thread when the previously measured Amount is reached; a device for counting the windings of the thread, which are released at each weft insertion; a direction to count the rewound windings to the weft reserve on the drum of the feeder / pre-gauge replenish as well a microcontroller for monitoring, which receives a weft release signal from the loom and the operation of the weft holding finger, counting the unwinded windings and the operation of the motor for moving the rotating arm monitors, which for filling the Weft reserve rewinds the windings.

In order to keep the weft reserve substantially invariable over time, the microcontroller processes in particular the pulsed signals coming from a first optical sensor which detects the passage of the windings running from the drum and a second magnetic sensor which detects the Rotation signals of the weft winding arm are provided by detecting the passage of a moving magnet which rotates in rigid connection with the arm thereby generating a momentum upon each rotation of the arm which winds a corresponding winding on the drum of the supply / pre-gauge , To this end, the microcontroller compares the number of pulses of signals generated by the first and second sensors and accordingly activates the motor of the rotating arm, matching the number of pulses so as to maintain the weft reserve unchanged on the drum the feed / pre-gauge is present (see, for example, the US Patent A-471541 ).

A correct control of the stock by means of the above usual Systems is guaranteed for so long as long as the first and the second sensor together the microcontroller provide the correct signals, but there are special ones Operating conditions under which this is not possible. In these make the system is no longer able to correctly replenish the Ensure weft reserve.

A typical condition, under the system control of the recovery the weft reserve runs off very easily when the second magnetic sensor Provides incorrect signals that are not a full turn of the Weft winding arm and the corresponding application of a winding on the drum of the feeder / pre-meter correspond.

Of the Magnetic sensor, which is typically a Hall-effect sensor indeed very sensitive to the passage of the moving permanent magnet usually supported on a flywheel, the at the foot of the Drum of the feeder is arranged and in rigid connection with the weft winding arm circulates.

Accordingly runs under normal operating conditions with each angular movement of the flywheel through 360 ° of moving magnet passes in front of the sensor, which sends a corresponding pulse signal generated, which is a full turn of the weft winding arm around the drum of the feeder / pre-gauge corresponds, on which the arm accordingly a thread winding applies.

Under However, abnormal operating conditions may cause the flywheel to go down and move around and with a corresponding back and forth Movement a variety of larger or smaller Perform angular movements. For example, these abnormal operating conditions occur on when the controlled weft insertion of the feeder to a great extent is irregular, for example, when weaving narrow strips of fabric. In such make learns the weft wrapping arm quick decelerations and accelerations, the for the steps during braking or restarting characteristic are, and these dynamic loads lead to a short-term Settle.

If the position of the sensor within the moment in question the angular range of the swinging motion of the flywheel carried by the flywheel Magnet is located, each time the magnet passes in front of the sensor generates a pulse, even if the pulse generated does not mean that a winding was wound up. In this way, the monitoring counts Microcontroller incorrectly too many windings, which are wound on the drum; if this short-term phenomenon quite common, It can happen that the supply of weft windings, the on the drum of the feeder are wound up, exhausted which is a serious drawback, as a result a stop of the weaving operation is forced to the weft stock to refill by hand.

In Likewise, it may happen that too high a number of counted windings counted is compared to the actual on the drum of the feeder existing windings, if the supply / pre-measuring device due to its not moved that the magnetic sensor Impulses generated in connection with angular movements, with which the machine operator that Flywheel applied by hand and unintentionally, for example then, if he has settings on the feeder or on the entire weft feeding system performs.

Of the The present invention is essentially based on the object to remedy the serious disadvantage outlined above by a method and apparatus for controlling the rotation signals of the weft wrapping arm Both are designed to receive the signals generated by the magnetic rotation sensor selects and regarding the correct count on the drum of the feeder / pre-gauge applied windings suppresses the pulses of the signals. for the no counterpart in the form of a true full turn of the weft wrapping arm is available.

A Another important object of the present invention is to provide a control method and a control device that are extremely simple, functional and reliable is and in particular designed so that existing Circuitry means for controlling the feed / pre-gauge used to supply weft yarn to the jet loom assigned to the system, no significant modifications have been made Need to become.

These and other objectives, which are more apparent from the following detailed Described in accordance with the present Invention with a method and apparatus for controlling reaches the rotation signals on the weft winding arm, which the in the accompanying claims have specified special features.

Of the The invention is based essentially on the idea of grasping the passage of at least one moving magnet, which associated with the flywheel, which together with the weft winding arm circulates, a first magnetic sensor and insert a second magnetic sensor, which spaced at a preset distance from each other and the circular path of the at least one magnet are adjacent, and the signals of first and second sensor with a frequency whose period is less than or equal to Minimum time between the fronts of the two consecutive Signal pulses is to count out of them in terms of counting Number of windings wound on the drum, transition criteria to extract which indicate that a complete revolution of the arm was, and that the number of windings increased accordingly or has decreased.

Further Features and advantages of the method and apparatus of the invention emerge even more clearly from the detailed below Description with reference to the accompanying drawings, which are given by way of example only Illustrative serve without any limitation and in which:

1 Fig. 10 is a block diagram of a conventional system for feeding the weft yarn to a jet loom equipped with a yarn feeding / pre-measuring device;

2 a schematic view of the device for controlling the rotation signals of the weft winding arm of the supply / pre-measuring device according to an embodiment of the invention;

3 is a timing diagram of the rotation signals generated by the control device according to FIG 2 be generated;

4 in a schematic view of the device for controlling the rotation signals according to a modified embodiment of the invention;

5 a view of a detail 4 in enlarged view shows, and

6 a timing diagram of the device according to 4 generated rotation signals.

In 1 is generally indicated by the reference character SI a typical system for feeding the weft thread F to a jet loom TE, in which the supplied at each shot and unwound from a coil RO thread is premeasured.

To For this purpose, the system SI operates with a weft feeder / pre-gauge, generally referred to as P and a fixed drum TA, to which a rotating arm BR, which is a flywheel VO is assigned and is driven by a motor MO, a Variety of thread windings wound up, which is a weft stock RT form. A weft retaining finger DI for stopping the thread F is the drum TA of the feeder assigned and is controlled by an electromagnetic actuator AE operated, to release the thread and unwind it from the drum TA and to stop the unwinding of the thread when the previously measured quantity or length is reached. A microcontroller MC, which is pre-set, that it monitors the entire system SI, generates an output signal CE for actuating the electromagnet the weft retaining finger DI and an additional set of three output signals a, b, c to operate of the motor MO by means of a power interface MPD (control).

One first feeler UWP of the optical type located at the exit of the drum TA is located, the windings provided by the drum to be settled and send to the microcontroller MC the pulse-shaped signals UWSP, previously in an amplifier and filter circuit CAF were processed.

One another feeler H in magnetic design is intended, the microcontroller MC with a pulse WSP to supply at each rotation of the revolving arm BR, which Winding a corresponding winding on the drum TA; the magnetic sensor speaks sensitive to the passage of a magnet M, which the flywheel carries VO, which is assigned to the arm BR.

One Request signal TR for requesting the weft release, the generated by the loom TE, the microcontroller MC also reaches. If the microcontroller receives the request signal TR, switches she immediately the actuator AE on, which raises the weft holding finger DI and it with it possible makes the windings unwind from the weft reserve RT. At the same time the loom TE, for example a jet loom, activates the fan of the Main Jet and the relay nozzles and shoot insert the weft into the shed. During the weft insertion the microcontroller will turn on using the UWSP signals kept track of how many turns of the drum TA the pre-meter P are settled, and if the required Number of windings is reached, it in turn activates the actuator AE, this time with reverse polarity, causing the lowering of the Weft retaining finger DI brought about and the unwinding of the thread is stopped.

simultaneously the microcontroller MC activates the motor MO in order to control the weft windings, which were taken from the weft reserve RT, to replace and receives at each re-applied winding of the sensor H, a corresponding signal WSP. Essentially around the weft supply RT over time unchanged To hold, the microcontroller compares the number of pulses of the Signal UWSP with the number of pulses of the signal WSP and ensures for this, that the number of these pulses is substantially the same.

If however, one of the reasons mentioned above causes that the feeler H generates one or more WSP pulses; which a current and corresponding winding of one or more windings of Stock RT does not match, the microcontroller MC loses the control over the replenishment the re serve, which accordingly can be completely exhausted, causing the weaving operation is stopped.

In order to avoid this disadvantage, according to a preferred embodiment of the present invention, a control device is provided, as described in US Pat 2 is shown; this has a first magnetic sensor H1 and a second magnetic sensor H2 - or sensors with Hall effect - run, which are mounted on the fixed frame of the feed / pre-measuring device P and arranged so that they are behind each other next to the circular path of the moving magnet M are spaced from each other by a distance D from which they are further spaced by a gap H. are. In this arrangement, the signals WSP1 and WSP2 respectively generated by the sensors H1-H2, with the passage of time at a constant rotational speed of the flywheel VO, assume the pattern shown schematically in the diagram in FIG 3 is shown. This diagram shows that at each moment reading the pair of values assuming the signals WSP1-WSP2 makes it possible to uniquely deduce in which of the circular sectors SX-C-DX-OUT - those in 2 where M is the center sector and SX and DX are the sectors to the left and right of the central sector, with respect to the direction of rotation of the magnet M in the clockwise direction indicated by the arrow in FIG 2 is specified.

By checking the transition in the state of the signal pairs WSP1 and WSP2 at successive timings, it is also possible to detect the direction of rotation of the magnet M as it passes near the sensors H1-H2. Suppose that the direction of rotation of the arrow is clockwise in accordance with 2 is the working direction, the microcontroller MC is programmed for this purpose to pick up the pair of signals at a speed of f ≥ 1 / DT, where DT is the minimum time between the leading edges of two signal pulses at the maximum rotational speed of the flywheel VO, and the variable NS representing the number of wound coils to increase one unit when the microcontroller detects the following state transition: a) DX → OUT, ie, the passage of the magnet M from the sector DX to the sector OUT which is to the right of For this purpose, the following equations are checked: C = OUT and C1 = DX, where C is the value of the signal pairs WSP1, WSP2 at the general detection time t and C1 is the value of the same signal pair at the detection time t1 preceding t , Similarly, the microcontroller MC decreases the numerical variable NS by one unit when it detects the opposite transition: b) OUT → DX, checking for this purpose the equations C = DX and C1 = OUT; this transition means that the last applied winding was unwound.

This is equivalent to assign a positive value (upshift NS by one Unit) to the signals at the transition, as indicated at point a) and to assign a negative value (Reduction of NS by one unit) to the signals at the transition, as indicated in point b). This is the case in the case a fluctuation of the magnet M in the vicinity of the sensor H1-H2 at the final signal, that to the increase or reducing the number of windings NS is useful to the algebraic sum of the positive and negative transition signals, the while the fluctuation have accumulated.

If Naturally the rotation of the weft winding arm BR m operation against the Clockwise expires, then leads the transition OUT → DX to an increase the numerical variable NS while the opposite transition DX → OUT to whose reduction leads.

In the embodiment according to 4 to 6 In turn, two Hall-effect magnetic sensors H1-H2 are provided which are mounted on the frame of the feeder / pre-feeder P, but here are mounted in such a way that one is inverted with respect to the other, such that, for example, the sensor H 'is responsive to the flux lines of a magnetic field traveling in the direction of arrow F1 in FIG 5 whereas sensor H2 is sensitive to the lines of force of a magnetic field aligned in the direction of arrow F2 in the same figure. Accordingly, the flywheel VO of Zuführeinrich device P is equipped with a permanent magnet Mo, which is preferably made of neodymium or samarium cobalt and its magnetic field has a polarity (N-S), which is aligned like the arrow F1 and therefore as the field, to which the sensor H 'responds; In addition, a plurality of additional permanent magnets M1-M4 (for example four) are provided, all of which have a magnetic polarization opposite to the polarity of the magnet Mo and therefore with the orientation of the arrow F2 in FIG 4 and the field to which the sensor H2 responds; the magnets of the group M1-M4 are at regular intervals spaced from each other by a constant angular pitch.

at This arrangement is generated by the sensor H 'a signal pulse WSP1 only when the magnet Mo passes through in its vicinity, and also generates the sensor H2 a signal pulses WSP2 only if one of the magnets M1-M4 passes through in his vicinity.

Accordingly, the timing diagram shows the rotation signals generated by the sensors H'-H2 (FIG. 6 ) are generated, that between two consecutive pulses of the signal WSP1 there are always N pulses of the signal WSP2; the example shows four. If A denotes a numerical variable representing the number of pulses of the signal WSP2 present between a transition t1 of the signal WSP1 and the previous transition to, then the microprocessor μP at the device is programmed to use the numerical variable NS, which represents the number of windings. increases by one unit when checking the inequality AA ≥ N, and that in the opposite case it reduces the variable by one unit if the inequality A <N exists. In the second case, in fact, the flywheel VO certainly did not make a full turn (in either direction), so winding a coil is out of the question.

This embodiment of the control device allows it unlike the previously with reference to the 2 and 3 described embodiments, no distinction of the direction of rotation of the arm BR and is therefore not able to detect the winding of a complete winding in the opposite direction, with respect to the working direction.

Without The principle of the invention to change something, of course, the Details in the execution of the method and in the embodiments the device over a wide area opposite changed are described by way of non-limiting example and without thereby departing from the scope of the invention.

At the places where on technical features, in any the claims mentioned are followed by reference numerals, these reference numerals have become exclusive used for the purpose, the intelligibility the claims to increase, and thus, such reference signs have no limiting effect to the perimeter of each element, denoted by these reference numerals by way of example becomes.

Claims (7)

Method for controlling the rotation signals (WSP) of the weft winding arm (BR) in weft feeders (P) for looms (TE), characterized in that it consists in detecting the passage of at least one moving magnet (M) belonging to the Flywheel (VO) is associated, which rotates together with the weft winding arm (M), a first magnetic sensor and a second magnetic sensor (H1-H2) spaced by a preset distance (D) from each other and the circular path of the at least one magnet adjacent, and to pick up the signals (WSP1-WSP2) of the first and second probes (H1-H2) to be counted therefrom in terms of counting the number (NS) of windings wound on the drum (TA); To extract transition criteria (DX → OUT, OUT → DX and vice versa A ≥ N) indicating that one complete revolution of the arm (BR) has been performed and that the number (NS) of windings is decreasing has increased or decreased accordingly. Control method according to Claim 1, characterized the rate of picking up the signals (WSP1-WSP2) has one period, which is less than or equal to the least time between the leading edges of two consecutive signal pulses elapses. Process according to claims 1 or 2, characterized that the transition criteria (DX → OUT and reversed), which indicate that one complete revolution of the weft winding arm (BR) in a clockwise direction, and vice versa the equations C = OUT; C 1 = DX and vice versa, where C is the value of the pair of signals (WSP1-WSP2) at the moment (t) of generic tapping and C1 is the value of the same pair of Signals to the previous tapping point (t1) is. Method according to claims 1 or 2, characterized in that the first and the second sensor (H'-H2) respond to magnetic fields which have opposite polarities and from a magnet (Mo) or from a plurality of magnets (M1-M2 ) carried by the flywheel (VO) and that the criterion indicating that a complete revolution of the weft winding arm has been performed is represented for a preset direction of rotation of the arm (BR) by the inequality A≥N, where A is a numerical variable representing the detected number of intervening pulses of the second sensor signal (WSP2) occurring between two consecutive pulses of the first sensor signal (W ') (W'), and wherein N is the preset number of intervening pulses corresponding to the number of the plurality of magnets (M1-M2). Device for carrying out the control method according to one of Claims 1 to 3, characterized in that it comprises two magnetic sensors (H1-H2) associated with the flywheel (VO) of the weft winding arm (BR) resting on the stationary drum of the yarn feeder (P) spaced apart by a preset distance (D) and adjacent to the path of a moving magnet (M) carried by the flywheel (VO) of the weft winding arm, and a microcontroller (MC ) programmed in such a way that the signals (WSP1-WSP2) generated by the two magnetic sensors (H1-H2) are tapped when the magnet (M) passes by, the transitions are checked indicating that the weft wrapping arm has made one complete revolution in the working direction or in the opposite direction and accordingly increases or decreases the number (NS) of rotations forming the weft supply (RT) wound on the drum (TA) of the yarn supply / pre-metering device. Device for carrying out the control method according to one of the claims 1, 2 and 4, characterized in that it comprises: a first and a second magnetic sensor (H'-H2), the magnetic sensor so supported are that they are separated by a distance (D) from the fixed frame the thread feed (P) are kept at a distance from each other and arranged in such a way that that they are facing the magnetic flux lines of the magnetic fields, which accordingly in opposite Directions are aligned, are sensitive; a first yourself moving magnet (Mo), which has the same polarity as the Has field lines opposite which the first feeler (H ') sensitive is, being the first feeler from the flywheel (VO) of the weft winding arm (BR) of the yarn feeding device / Pre-measuring device (P) is worn; a multitude of additional, moving magnets (M1-M4), which are also carried by the flywheel (VO) and the same polarity how the field lines are opposite to those of the second sensor (H2) is sensitive; a microcontroller (MC), which at the input the selective signals (WSP1-WSP2) receives that of the first and second feelers are generated when the first moving magnet (Mo) or the Variety of other moving magnets (M1-M4) passes or pass; where the microcontroller is programmed to that they check the inequalities (A <N) and increase the numeric variable (NS) or decrease the number of times the drum (TA) of the Thread feeder wound up Windings represents. Device according to claims 5 or 6, characterized that the first and the second magnetic sensor are formed from Hall sensors.