EP0245236B1 - Process and device for measuring the warp tension in automatic looms and similar - Google Patents

Process and device for measuring the warp tension in automatic looms and similar Download PDF

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Publication number
EP0245236B1
EP0245236B1 EP85904080A EP85904080A EP0245236B1 EP 0245236 B1 EP0245236 B1 EP 0245236B1 EP 85904080 A EP85904080 A EP 85904080A EP 85904080 A EP85904080 A EP 85904080A EP 0245236 B1 EP0245236 B1 EP 0245236B1
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EP
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Prior art keywords
vibrating device
fabric
threads
tension
vibrating
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EP85904080A
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German (de)
French (fr)
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EP0245236A1 (en
Inventor
Ernst Felix
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Zellweger Uster AG
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Zellweger Uster AG
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Priority to AT85904080T priority Critical patent/ATE47435T1/en
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    • D—TEXTILES; PAPER
    • D03—WEAVING
    • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
    • D03D49/00—Details or constructional features not specially adapted for looms of a particular type
    • D03D49/04—Control of the tension in warp or cloth
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H59/00—Adjusting or controlling tension in filamentary material, e.g. for preventing snarling; Applications of tension indicators
    • B65H59/40—Applications of tension indicators
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2701/00—Handled material; Storage means
    • B65H2701/30—Handled filamentary material
    • B65H2701/31—Textiles threads or artificial strands of filaments

Definitions

  • warp tension regulators The measurement of the warp tension on weaving machines and the like is an essential factor for keeping them constant by means of warp tension regulators.
  • a constant warp tension is crucial for a perfect failure of the fabric. For this reason, methods and devices have always been used to measure this warp tension and to derive control variables from the measured value, with which organs can be controlled to influence the warp tension.
  • the most original way of measuring the warp tension and converting it into a measurement signal is to use the force exerted on a deflection element, which acts on the match tree from the entire chain (see, for example, DE-A-2206781).
  • the disadvantages of this measurement of the total warp tension are above all the large masses to be moved, which, however, only result in a relatively small deflection of the spring-loaded match tree.
  • Another disadvantage is that the total number of warp threads is used for force measurement, whereas differences in warp tension across the width of the warp thread family are not expressed.
  • the warp thread family is preferably locally partially set into resonance vibrations, be it by connecting an auxiliary mass with a part of the warp threads and stimulating this system to vibrate, or be it that the warp threads are vibrated alone.
  • the thread tension can be determined from the resulting resonance frequency and the known mass of the warp threads according to the principle of the vibrating string. This method solves the problem of zero point constancy.
  • the present invention now relates to a method for measuring the warp tension on the chain and / or on the fabric in textile machines and the like, which is characterized by the features listed in claim 1.
  • the invention also includes an apparatus for performing the method with the features according to claim 10.
  • the chain 10 to be checked with regard to its tension or the fabric 11 is normally clamped between transport elements, such as, for example, rear cylinder rollers 1, 2 and front cylinder rollers 3, 4.
  • a vibrating element 20 is attached between these clamping lines. This causes a rotational oscillation around the axis.
  • the oscillating member 20 can rotate on its axis, on the one hand, and on the other hand, when it is deflected from the straight line, a restoring force arises which is proportional to the deflection and the tension.
  • Formula (1) which can be derived mathematically, shows that the voltage can be determined from the resonance frequency.
  • a vibrating element 20 In contact with the chain 10 or the fabric 11, a vibrating element 20 is rotatably mounted about a central axis 23. So that the web always lies against the vibrating element, the web is slightly deflected upwards. In other words, the material web (chain 10 or fabric 11) lies on the vibrating element 20 under the influence of the tension P.
  • the vibrating element 20 can also be designed as a rotatably mounted plate, the contact surface 24 with the web (10, 11) being advantageously treated as a wear-resistant surface (FIG. 3). This method is suitable for. B. in weaving and in equipment.
  • parts of the processing machine can also be used for supporting the chain or the fabric, such as, for example, warp beam, match beam, breast beam of the weaving machine or squeeze rollers, deflection rollers of the sizing machine, etc.
  • the vibrating element 20 is used in the machine in an area where the distance between the support and the vibrating element is variable, e.g. B. with radially resilient deflection rollers of the sizing machine.
  • a special case is the measurement of the fabric tension on the weaving machine.
  • the breast tree 12 (FIG. 4) is a precisely defined contact surface.
  • the fabric stop edge 13 forms an apparent point of contact when the shed is open.
  • the distance between the vibrating element and the edge of the goods is also defined in this way. However, when the compartment is closed, the point of contact moves into the harness. If the dimensions of the vibrating organ are small in relation to the distance of the vibrating organ from the edge of the goods or from the harness, the influence of this variable distance becomes negligible.
  • variable a is several times larger than c, and thus the quotient - in relation (1) - only makes a negligibly small contribution to the summand
  • FIG. 4 also shows a possible mounting of the vibrating element 20 by means of a cutting edge 27 and a notch 26 stamped into the vibrating element.
  • the material web 10, 11 holds the vibrating element 20 firmly on the cutting edge 27.
  • the vibrating organ should also have a significantly larger mass in relation to the goods. With different weft densities in the fabric, the different fabric weight does not interfere.
  • the vibrating element 20 is now excited with its resonance frequency.
  • Methods for exciting mechanical vibration structures are known. As a rule, these consist of a drive element, feedback element and amplifier.
  • an electromechanical excitation arrangement 30 according to FIG. 2 with the aid of an electromagnet causes a deflection of the vibrating element 20 about the axis 23.
  • Known inductive, capacitive, optical or pneumatic distance meters with subsequent amplifiers can be used as feedback means.
  • a drive coil 31 and a feedback coil 32 with amplifier 33 are required.
  • the vibrating element vibrates automatically at the resonance frequency.
  • the resulting frequency f o of the vibrating element 20 is directly dependent on the tension P of the material web resting on the vibrating element 20, according to the relationship of formula (1).
  • formula (1) only applies if the deflection angle a around the oscillating plate is very small and the pivot point of the vibrating element lies completely against the product (FIG. 5). Otherwise the swinging motion is no longer perpendicular to the goods plane. If the chain 10 or the fabric 11 adhere to the vibrating member by friction, changes in the length of the sections a and b and thus tensile forces of the chain or the fabric occur. There are therefore additional forces which are dependent on the size of the deflection, as a result of which Formula 1 is no longer valid and the force measurement is therefore no longer accurate.
  • the fulcrum can also be deliberately placed outside the intersection 14, whereby vibrations (which are never exactly constant) are excited when the chain 10 or fabric 11 is moving.
  • the frequency of this vibration is close to the resonance frequency.
  • the vibration system can be made to vibrate by means of a sensor 34 and a transducer 35, the frequency f o that is established and the force P can be determined from this frequency.
  • the vibrating member 20 can have rotatably mounted rollers 21, 22 so that minimal friction between the chain or fabric and the vibrating member 20 occurs (FIG. 9). This process is preferably used in sizing and finishing.
  • Formula (1) also only applies exactly if the center of gravity of the oscillating structure at the pivot point, i. H. lies in the longitudinal axis 23 (FIG. 10).
  • a counterweight 25 can be attached to an axis of symmetry 28 laid by the oscillating member 20.

Abstract

For measuring the tension of a yarn layer (10) or of a warp (11) in an automatic loom or similar, a vibratory component (20) which can pivot around an axis (23) is arranged in the region of the layer of material from a straight line. The vibratory component (20) is made to vibrate by means of an excitation arrangement (30). The resulting frequency (fo) of the vibratory component (20) depends directly on the tension P of the yarn layer or of the material and can thus be determined from the frequency fo. The vibratory component (20) can, by simply sliding of the yarn layer (10) or material (11) on its surface (24), be made to vibrate at a natural frequency fo, which can be measured by a sensor (34) and converter (35). A particularly advantageous design of the vibratory component (20) can be achieved by giving it the shape of a plate with a notch (26), which is placed on a blade (27). To eliminate vibrations inherent in the vibratory component (20) the latter can be equipped with a counterweight (27) which moves the centre of gravity of the system to the point of intersection fo the tensile forces exerted by the yarn layer or material.

Description

Die Messung der Kettspannung an Webmaschinen und dergleichen bildet einen wesentlichen Faktor für deren Konstanthaltung mittels Kettspannungsreglern. Eine konstante Kettspannung ist für einen einwandfreien Ausfall des erzeugten Gewebes ausschlaggebend. Deshalb sind von jeher Verfahren und Vorrichtungen eingesetzt worden, um diese Kettspannung zu messen und um aus dem Messwert Regelgrössen abzuleiten, mit welchen Organe zur Beeinflussung der Kettspannung angesteuert werden können.The measurement of the warp tension on weaving machines and the like is an essential factor for keeping them constant by means of warp tension regulators. A constant warp tension is crucial for a perfect failure of the fabric. For this reason, methods and devices have always been used to measure this warp tension and to derive control variables from the measured value, with which organs can be controlled to influence the warp tension.

Die ursprünglichste Art einer Messung der Kettspannung und deren Umsetzung in ein Messsignal ist die Ausnützung der auf ein Umlenkorgan ausgeübten Kraft, die von der gesamten Kette beispielsweise auf den Streichbaum wirkt (siehe z. B. DE-A-2206781). Die Nachteile dieser Messung der gesamten Kettspannung sind vor allem die grossen zu bewegenden Massen, die aber nur eine relativ kleine Auslenkung des federnd gelagerten Streichbaums zur Folge haben. Ein weiterer Nachteil ist der, dass die Gesamtzahl der Kettfäden zur Kraftmessung herangezogen wird, dagegen Unterschiede in der Kettspannung über die Breite der Kettfadenschar nicht zum Ausdruck kommen.The most original way of measuring the warp tension and converting it into a measurement signal is to use the force exerted on a deflection element, which acts on the match tree from the entire chain (see, for example, DE-A-2206781). The disadvantages of this measurement of the total warp tension are above all the large masses to be moved, which, however, only result in a relatively small deflection of the spring-loaded match tree. Another disadvantage is that the total number of warp threads is used for force measurement, whereas differences in warp tension across the width of the warp thread family are not expressed.

Weiter sind Verfahren und Vorrichtungen vorgeschlagen worden (siehe z. B. GB-A-1 084678), bei denen die Kettfadenschar zwischen zwei Auflagestellen mittels einer belasteten Rolle oder ähnlichem ausgelenkt wird und die Grösse der Auslenkung ein Mass für die Kettspannung ergibt. Im Prinzip lassen sich solche Vorrichtungen überTeilbereiche der Kettfadenschar einsetzen; sie stellen aber in jedem Falle für die Webmaschine, insbesondere für deren Bedienung und Betrieb, eine zusätzliche Behinderung dar. Allen erwähnten Verfahren haftet zudem die Problematik der sog. Nullpunktskonstanz an.Methods and devices have also been proposed (see, for example, GB-A-1 084678), in which the warp thread sheet is deflected between two support points by means of a loaded roller or the like and the size of the deflection gives a measure of the warp tension. In principle, such devices can be used over partial areas of the warp thread family; in any case, however, they represent an additional hindrance for the weaving machine, in particular for its operation and operation. All of the methods mentioned also have the problem of the so-called zero point constancy.

In neuerer Zeit sind Verfahren und Vorrichtung vorgeschlagen worden, die darauf beruhen, dass die Kettfadenschar - vorzugsweise partiell - örtlich in Resonanzschwingungen versetzt wird, sei es dadurch, dass eine Hilfsmasse mit einem Teil der Kettfäden in Verbindung gebracht und dieses System zu Schwingungen angeregt wird, oder sei es, dass die Kettfäden allein in Schwingung versetzt werden. In jedem Fall kann aus der resultierenden Resonanzfrequenz und der an sich bekannten Masse der Kettfäden nach dem Prinzip der schwingenden Saite die Fadenspannung bestimmt werden. Bei diesem Verfahren ist das Problem der Nullpunktskonstanz gelöst.More recently, methods and devices have been proposed which are based on the fact that the warp thread family is preferably locally partially set into resonance vibrations, be it by connecting an auxiliary mass with a part of the warp threads and stimulating this system to vibrate, or be it that the warp threads are vibrated alone. In any case, the thread tension can be determined from the resulting resonance frequency and the known mass of the warp threads according to the principle of the vibrating string. This method solves the problem of zero point constancy.

Aber auch diese Systeme sind nicht frei von Nachteilen; zumindestens ist es der Aufwand und damit die Kosten, die solche Schwingungssysteme erfordern. Bei Messungen im Gewebe ist mit unterschiedlicher Schussdichte zu rechnen, so dass dieses Verfahren versagt.But these systems are not free from disadvantages either; at least it is the effort and thus the costs that such vibration systems require. When measuring in tissue, different weft densities are to be expected, so that this method fails.

Die vorliegende Erfindung betrifft nun ein Verfahren zur Messung der Kettspannung an der Kette und/oder am Gewebe in Textilmaschinen und dergleichen, das durch die in Anspruch 1 aufgeführten Merkmale charakterisiert ist.The present invention now relates to a method for measuring the warp tension on the chain and / or on the fabric in textile machines and the like, which is characterized by the features listed in claim 1.

Die Erfindung umfasst auch eine Vorrichtung zur Durchführung des Verfahrens mit den Merkmalen gemäss Anspruch 10.The invention also includes an apparatus for performing the method with the features according to claim 10.

Anhand der Beschreibung und der Figuren werden Ausführungsbeispiele der Erfindung näher erläutert. Dabei zeigt:

  • Figur 1 eine erste schematische Darstellung des Messprinzips,
  • Figur 2 die Anordnung von Schwingorgan und Fadenschar,
  • Figur 3 schematisch ein Schwingorgan mit zugehörigen Antriebsmitteln,
  • Figur 4 schematisch ein Schwingorgan in Relation zu Teilen der Webmaschine,
  • Figur 5 eine Darstellung geometrischer Verhältnisse zwischen Warenbahn und Schwingorgan,
  • Figur 6 eine weitere Darstellung geometrischer Verhältnisse,
  • Figur 7 eine Variante des Schwingorgans,
  • Figur 8 schematisch ein Schwingorgan mit Sensor,
  • Figur 9 ein Schwingorgan mit Eigenerregung, und
  • Figur 10 ein Schwingorgan mit Gegengewicht.
Exemplary embodiments of the invention are explained in more detail with the aid of the description and the figures. It shows:
  • FIG. 1 shows a first schematic representation of the measuring principle,
  • FIG. 2 shows the arrangement of the vibrating element and the thread sheet,
  • FIG. 3 shows schematically a vibrating element with associated drive means,
  • FIG. 4 shows schematically a vibrating element in relation to parts of the weaving machine,
  • FIG. 5 shows a representation of the geometric relationships between the material web and the vibrating element,
  • FIG. 6 shows a further representation of geometric relationships,
  • FIG. 7 shows a variant of the vibrating organ,
  • FIG. 8 schematically shows a vibrating element with a sensor,
  • 9 shows a vibrating organ with self-excitation, and
  • Figure 10 shows a vibrating organ with a counterweight.

In der schematisch gehaltenen Anordnung gemäss Fig. 1 ist im Normalfall die bezüglich ihrer Spannung zu prüfende Kette 10 bzw. das Gewebe 11 zwischen Transportorganen, wie beispielsweise hintere Zylinderwalzen 1, 2 und vordere Zylinderwalzen 3, 4 eingespannt. Zwischen diesen Einspannlinien wird ein Schwingorgan 20 angebracht. Dieses führt eine Rotationsschwingung um die Achse aus. Das Schwingorgan 20 kann nämlich einerseits um seine Achse rotieren, anderseits entsteht bei einer Auslenkung von der Geraden eine Rückstellkraft, die proportional zur Auslenkung und zur Spannung ist.1, the chain 10 to be checked with regard to its tension or the fabric 11 is normally clamped between transport elements, such as, for example, rear cylinder rollers 1, 2 and front cylinder rollers 3, 4. A vibrating element 20 is attached between these clamping lines. This causes a rotational oscillation around the axis. The oscillating member 20 can rotate on its axis, on the one hand, and on the other hand, when it is deflected from the straight line, a restoring force arises which is proportional to the deflection and the tension.

Das Schwingorgan 20 bildet also in Verbindung mit der Kette bzw. dem Gewebe ein Resonanzsystem mit folgender Resonanzfrequenz:

Figure imgb0001
wobei w = Kreisfrequenz des Schwingorgans

  • P = Spannung der Kette bzw. des Gewebes
  • mR = Rotationsträgheitsmoment des Schwingorgans
  • a = Distanz Auflage links - linke Kante des Schwingorgans 20
  • b = Distanz Auflage rechts - rechte Kante des Schwingorgans 20
  • c, d = Abstände Schwingorganrollen bzw. -kanten - Achse 23
The vibrating element 20 thus forms a resonance system with the following resonance frequency in connection with the chain or the fabric:
Figure imgb0001
 where w = angular frequency of the vibrating organ
  • P = tension of the chain or fabric
  • m R = rotational moment of inertia of the vibrating element
  • a = distance left support - left edge of vibrating organ 20
  • b = distance support on the right - right edge of the vibrating element 20
  • c, d = distances between vibrating organ rollers or edges - axis 23

Die Formel (1), die mathematisch hergeleitet werden kann, zeigt, dass aus der Resonanzfrequenz die Spannung bestimmt werden kann.Formula (1), which can be derived mathematically, shows that the voltage can be determined from the resonance frequency.

Nach der Erläuterung des Grundgedankens wird die schematische Konstruktion gemäss Fig. 2 erläutert. An die Kette 10 bzw. das Gewebe 11 anliegend ist ein Schwingorgan 20 um eine zentrale Achse 23 drehbar gelagert. Damit die Warenbahn stets am Schwingorgan anliegt, wird die Warenbahn leicht nach oben ausgelenkt. Anders ausgedrückt liegt die Warenbahn (Kette 10 bzw. Gewebe 11) unter dem Einfluss der Spannung P auf dem Schwingorgan 20 auf.After explaining the basic idea, the schematic construction according to FIG. 2 is explained. In contact with the chain 10 or the fabric 11, a vibrating element 20 is rotatably mounted about a central axis 23. So that the web always lies against the vibrating element, the web is slightly deflected upwards. In other words, the material web (chain 10 or fabric 11) lies on the vibrating element 20 under the influence of the tension P.

Das Schwingorgan 20 kann auch als drehbar gelagerte Platte ausgebildet sein, wobei die Berührungsfläche 24 mit der Warenbahn (10, 11 ) mit Vorteil als eine verschleissfeste Fläche behandelt ist (Fig. 3). Dieses Verfahren eignet sich z. B. in der Weberei und in der Ausrüstung.The vibrating element 20 can also be designed as a rotatably mounted plate, the contact surface 24 with the web (10, 11) being advantageously treated as a wear-resistant surface (FIG. 3). This method is suitable for. B. in weaving and in equipment.

Anstelle der Zylinderwalzen können auch Teile der Verarbeitungsmaschine für die Auflage der Kette bzw. des Gewebes eingesetzt werden, wie beispielsweise Kettbaum, Streichbaum, Brustbaum der Webmaschine oder Quetschwalzen, Umlenkwalzen der Schlichtemaschine usw.Instead of the cylinder rollers, parts of the processing machine can also be used for supporting the chain or the fabric, such as, for example, warp beam, match beam, breast beam of the weaving machine or squeeze rollers, deflection rollers of the sizing machine, etc.

Für den Fall, dass a > c und b > d sind, reduziert sich Beziehung (1) zuIn the event that a> c and b> d, relationship (1) reduces to

Figure imgb0002
Figure imgb0002

Diese Eigenschaft wird dann von spezieller Bedeutung, wenn das Schwingorgan 20 in der Maschine in einem Bereich eingesetzt ist, wo die Distanz zwischen Auflage und Schwingorgan veränderlich ist, z. B. bei radial federnd gelagerten Umlenkwalzen der Schlichtemaschine. Ein Spezialfall ist die Messung der Gewebespannung auf der Webmaschine. Der Brustbaum 12 (Fig. 4) ist dabei eine genau definierte Auflagefläche. Auf der anderen Seite des Schwingorgans bildet jedoch die Gewebeanschlagkante 13 einen scheinbaren Auflagepunkt, wenn das Webfach geöffnet ist. Die Distanz zwischen Schwingorgan und Warenrand ist zwar derart auch definiert. Wenn das Fach jedoch geschlossen ist, verlagert sich der Auflagepunkt ins Webgeschirr. Wenn die Abmessungen des Schwingorgans im Verhältnis zum Abstand des Schwingorgans zum Warenrand bzw. zum Webgeschirr klein sind, so wird der Einfluss dieser variablen Distanz vernachlässigbar.This property becomes particularly important when the vibrating element 20 is used in the machine in an area where the distance between the support and the vibrating element is variable, e.g. B. with radially resilient deflection rollers of the sizing machine. A special case is the measurement of the fabric tension on the weaving machine. The breast tree 12 (FIG. 4) is a precisely defined contact surface. On the other side of the vibrating organ, however, the fabric stop edge 13 forms an apparent point of contact when the shed is open. The distance between the vibrating element and the edge of the goods is also defined in this way. However, when the compartment is closed, the point of contact moves into the harness. If the dimensions of the vibrating organ are small in relation to the distance of the vibrating organ from the edge of the goods or from the harness, the influence of this variable distance becomes negligible.

In diesem Falle ist die variable Grösse a um ein Mehrfaches grösser als c, und somit liefert der Quotient - in der Beziehung (1 ) - nur einen vernachlässigbar kleinen Beitrag im SummandenIn this case the variable a is several times larger than c, and thus the quotient - in relation (1) - only makes a negligibly small contribution to the summand

Figure imgb0003
Figure imgb0003

Figur 4 zeigt auch eine mögliche Lagerung des Schwingorgans 20 mittels einer Schneide 27 und einer in das Schwingorgan eingeprägten Kerbe 26. Die Warenbahn 10, 11 hält das Schwingorgan 20 auf der Schneide 27 fest.FIG. 4 also shows a possible mounting of the vibrating element 20 by means of a cutting edge 27 and a notch 26 stamped into the vibrating element. The material web 10, 11 holds the vibrating element 20 firmly on the cutting edge 27.

Das Schwingorgan soll im Verhältnis zur Ware auch eine wesentlich grössere Masse aufweisen. Bei unterschiedlicher Schussdichte im Gewebe stört dann das unterschiedliche Gewebegewicht nicht.The vibrating organ should also have a significantly larger mass in relation to the goods. With different weft densities in the fabric, the different fabric weight does not interfere.

Zur Messung der Spannung P der Kette 10 bzw. der Gewebebahn 11 wird nun das Schwingorgan 20 mit seiner Resonanzfrequenz angeregt. Verfahren zur Anregung von mechanischen Schwingungsgebilden sind bekannt. In der Regel bestehen diese aus Antriebsglied, Rückkopplungselement und Verstärker. So kann z. B. eine gemäss Fig. 2 elektromechanische Erregeranordnung 30 mit Hilfe eines Elektromagneten eine Auslenkung des Schwingorgans 20 um die Achse 23 bewirken. Als Rückkopplungsmittel können an sich bekannte, induktiv, kapazitiv, optisch oder pneumatisch wirkende Abstandsmesser mit nachfolgenden Verstärkern eingesetzt werden. Zum Beispiel wird eine Antriebsspule 31 benötigt sowie eine Rückkopplungsspule 32 mit Verstärker 33. Das Schwingorgan schwingt dadurch selbsttätig mit der Resonanzfrequenz. Die sich dabei einstellende Frequenz fo des Schwingorgans 20 ist direkt abhängig von der Spannung P der auf dem Schwingorgan 20 aufliegenden Warenbahn, gemäss der Beziehung von Formel (1).In order to measure the tension P of the chain 10 or the fabric web 11, the vibrating element 20 is now excited with its resonance frequency. Methods for exciting mechanical vibration structures are known. As a rule, these consist of a drive element, feedback element and amplifier. So z. B. an electromechanical excitation arrangement 30 according to FIG. 2 with the aid of an electromagnet causes a deflection of the vibrating element 20 about the axis 23. Known inductive, capacitive, optical or pneumatic distance meters with subsequent amplifiers can be used as feedback means. For example, a drive coil 31 and a feedback coil 32 with amplifier 33 are required. As a result, the vibrating element vibrates automatically at the resonance frequency. The resulting frequency f o of the vibrating element 20 is directly dependent on the tension P of the material web resting on the vibrating element 20, according to the relationship of formula (1).

Die Formel (1) gilt aber nur, wenn der Umlenkwinkel a um die oszillierende Platte sehr klein ist und der Drehpunkt des Schwingorgans ganz an der Ware anliegt (Fig. 5). Andernfalls ist die Schwingbewegung nicht mehr senkrecht zur Warenebene. Wenn die Kette 10 bzw. das Gewebe 11 durch Reibung am Schwingorgan haften, treten Längenänderung der Abschnitte a und b und somit Dehnkräfte der Kette bzw. des Gewebes auf. Es treten somit zusätzliche Kräfte auf, die von der Grösse der Auslenkung abhängig sind, wodurch Formel 1 nicht mehr gültig und somit die Kraftmessung nicht mehr genau ist.However, formula (1) only applies if the deflection angle a around the oscillating plate is very small and the pivot point of the vibrating element lies completely against the product (FIG. 5). Otherwise the swinging motion is no longer perpendicular to the goods plane. If the chain 10 or the fabric 11 adhere to the vibrating member by friction, changes in the length of the sections a and b and thus tensile forces of the chain or the fabric occur. There are therefore additional forces which are dependent on the size of the deflection, as a result of which Formula 1 is no longer valid and the force measurement is therefore no longer accurate.

Dieser Einfluss lässt sich eliminieren, wenn der Drehpunkt des oszillierenden Gebildes in den Schnittpunkt 14 der verlängert gedachten Richtungen der Zugkräfte der Kette 10 bzw. des Gewebes 11 gelegt wird (Fig. 6). Die Schwingungen sind dann genau senkrecht zur Warenebene, und es treten dadurch bei kleinen Schwingamplituden praktisch keine Längenänderungen der Ware auf. Die genannten Längenänderungen lassen sich auch eliminieren, wenn der Drehpunkt des Schwingorgans nicht mehr fest, sondern in Richtung der Ware 10, 11 beweglich ist. Ein solches Beispiel zeigt Fig. 7. Die Schneide 27 ist hiebei als Blatt-Feder 29 ausgebildet, womit der Drehpunkt des Schwingorgans ausgelenkt werden kann. Der scheinbare Drehpunkt liegt dann wiederum im gewünschten Schnittpunkt der Zugkräfte.This influence can be eliminated if the fulcrum of the oscillating structure is placed at the intersection 14 of the elongated directions of the tensile forces of the chain 10 or of the fabric 11 (FIG. 6). The vibrations are then exactly perpendicular to the plane of the goods, and there are practically no changes in length of the goods with small vibration amplitudes. The changes in length mentioned can also be eliminated if the pivot point of the vibrating element is no longer fixed but can be moved in the direction of the goods 10, 11. Such an example is shown in FIG. 7. The cutting edge 27 is designed as a leaf spring 29, by means of which the pivot point of the oscillating member can be deflected. The apparent pivot point is then again at the desired intersection of the tensile forces.

Anderseits kann gemäss Fig. 8 der Drehpunkt auch bewusst ausserhalb des Schnittpunktes 14 gelegt werden, wodurch bei bewegter Kette 10 bzw. Gewebe 11 Schwingungen durch Reibungskräfte (die nie genau konstant sind) angeregt werden. Die Frequenz dieser Schwingung liegt dabei in der Nähe der Resonanzfrequenz. Somit kann also ohne zusätzliches Erregersystem das Schwingsystem zum Schwingen gebracht, mittels eines Sensors 34 und eines Wandlers 35, die sich dabei einstellende Frequenz fo und aus dieser Frequenz die Kraft P bestimmt werden.On the other hand, according to FIG. 8, the fulcrum can also be deliberately placed outside the intersection 14, whereby vibrations (which are never exactly constant) are excited when the chain 10 or fabric 11 is moving. The frequency of this vibration is close to the resonance frequency. Thus, without an additional excitation system, the vibration system can be made to vibrate by means of a sensor 34 and a transducer 35, the frequency f o that is established and the force P can be determined from this frequency.

Das Schwingorgan 20 kann drehbar gelagerte Rollen 21, 22 aufweisen, so dass minimale Reibung zwischen Kette bzw. Gewebe und Schwingorgan 20 auftritt (Fig. 9). Dieses Verfahren findet vorzugsweise Anwendung in der Schlichterei und Ausrüstung.The vibrating member 20 can have rotatably mounted rollers 21, 22 so that minimal friction between the chain or fabric and the vibrating member 20 occurs (FIG. 9). This process is preferably used in sizing and finishing.

Formel (1) gilt auch nur genau, wenn der Schwerpunkt des oszillierenden Gebildes im Drehpunkt, d. h. in der Längsachse 23 liegt (Fig. 10). Zur Verlagerung des Schwerpunktes des oszillierenden Gebildes, bestehend aus Schwingorgan 20 und gegebenenfalls mit diesen verbundenen Rollen 21,22, in die Gegend des Drehpunktes kann ein Gegengewicht 25 auf einer durch das Schwingorgan 20 gelegt gedachten Symmetrieachse 28 angebracht werden.Formula (1) also only applies exactly if the center of gravity of the oscillating structure at the pivot point, i. H. lies in the longitudinal axis 23 (FIG. 10). In order to shift the center of gravity of the oscillating structure, consisting of oscillating member 20 and possibly rollers 21, 22 connected to it, into the region of the pivot point, a counterweight 25 can be attached to an axis of symmetry 28 laid by the oscillating member 20.

LiegtderSchwerpunktdesoszillierenden Gebildes nicht im Drehpunkt, so kann z. B. auch bei der Kraft Null das System als Pendel schwingen. Allerdings wird das Resultat nur wenig verfälscht, wenn die Resonanzfrequenz des gesamten Systems und die Frequenz der Schwingung des leeren Pendels weit auseinander liegen. Zudem ist die Frequenzabweichung konstant und berechenbar.If the center of gravity of the oscillating structure is not in the center of rotation, e.g. B. even at zero force swing the system as a pendulum. However, the result is only slightly falsified if the resonance frequency of the entire system and the frequency of the oscillation of the empty pendulum are far apart. In addition, the frequency deviation is constant and predictable.

Claims (19)

1. Method for measuring the tension of a set of threads or a fabric, characterised in that a vibrating device (20) is provided in the region of the set of threads (10) or fabric (11) whose tension is to be measured, the said set of threads (10) of fabric (11) moving over this vibrating device (20), and in that the tension (P) of the set of threads or of the fabric is determined from the resonance frequency (fo) of the vibrating device (20).
2. Method according to claim 1, characterised in that the vibrating device (20) is set into vibrations about its longitudinal axis by means of a back coupled electro-mechanical activating device (30).
3. Method according to claim 1, characterised in that the vibrating device (20) is set into vibrations by the web of material (group of threads (10) or fabric (11 )) gliding over it, which vibrations are converted into electric signals of a frequency (fo) by means of a sensor (34) and transducer (35).
4. Method according to claim 1, characterised in that the set of threads (10) or the fabric (11) is deflected from the straight line by the vibrating device (20).
5. Method according to claim 4, characterised in that the true or apparent center of rotation of the vibrating device (20) lies at least approximately at the point of intersection (14) of the deflected forces of tension of the web of material.
6. Method according to claim 1, characterised in that the set of threads (10) or the fabric (11) is moved over rollers (21, 22) which are mounted in the vibrating device (20).
7. Method according to claim 1, characterised in that the set of threads (10) or the fabric (11) is passed over a surface (24) of the vibrating device (20).
8. Method according to claim 1, characterised in that the vibrating device (20) is balanced by a counterweight (25).
9. Method according to claim 1, characterised in that the rotating mass of the vibrating device (20) is chosen to be large compared with the corresponding mass of the group of threads (10) or of the fabric (11).
10. Apparatus for carrying out the method according to claim 1, characterised in that a vibrating device (20) rotatably mounted about a central longitudinal axis (23) is provided, that the group of threads (10) or the fabric (11) is in contact with the vibrating device (20) and that the vibrating device (20) can be set into movements of vibration about the aforesaid longitudinal axis (23).
11. Apparatus according to claim 10, characterised in that the group of threads (10) or the fabric (11) is deflected from the straight line by the vibrating device (20).
12. Apparatus according to claims 10 and 11, characterised in that the vibrating device (20) has rotatably mounted rollers (21, 22).
13. Apparatus according to claims 10 and 11, characterised in that the longitudinal axis (23) of the vibrating device (20) is formed by a notch (26) and a knife edge (27).
14. Apparatus according to claim 13, characterised in thatthe knife edge (27) is mounted at the end of a unilaterally fixed spring (29).
15. Apparatus according to claims 10 and 11, characterised in that the vibrating device (20) has a wear-resistant surface (24) facing the group of threads (10) or the fabric (11).
16. Apparatus according to claim 10, characterised in that the vibrating device (20) is balanced about its longitudinal axis (23) by a counterweight (25).
17. Apparatus according to claim 10, characterised in that the vibrating device (20) is arranged in the region of an electro-mechanical activating device (30).
18. Apparatus according to claim 17, characterised in that the electro-mechanical activating device (30) has an oscillating coil (31), a back coupling coil (32) and an oscillator/am- plifier (33).
19. Apparatus according to claim 10, characterised in that a sensor (34) with transducer (35) is associated with the vibrating device (20) whereby vibrations of the vibrating device (20) which has been activated by the group of threads (10) or the fabric (11) to vibrate in its own mode are converted into electrical signals.
EP85904080A 1985-07-26 1985-08-27 Process and device for measuring the warp tension in automatic looms and similar Expired EP0245236B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85904080T ATE47435T1 (en) 1985-07-26 1985-08-27 METHOD AND DEVICE FOR MEASURING WARP TENSION ON LOOPPING MACHINES AND THE LIKE.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH3255/85 1985-07-26
CH3255/85A CH668443A5 (en) 1985-07-26 1985-07-26 METHOD AND DEVICE FOR MEASURING THE TENSION OF A THREAD SHAFT OR A FABRIC ON A TEXTILE MACHINE.

Publications (2)

Publication Number Publication Date
EP0245236A1 EP0245236A1 (en) 1987-11-19
EP0245236B1 true EP0245236B1 (en) 1989-10-18

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ID=4252020

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EP85904080A Expired EP0245236B1 (en) 1985-07-26 1985-08-27 Process and device for measuring the warp tension in automatic looms and similar

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US (1) US4794802A (en)
EP (1) EP0245236B1 (en)
JP (1) JPS63500472A (en)
CH (1) CH668443A5 (en)
DE (1) DE3573810D1 (en)
WO (1) WO1987000562A1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3905881C2 (en) * 1989-02-25 1999-08-19 Dornier Gmbh Lindauer Device for measuring warp tension in a weaving machine
EP1060376B8 (en) 1998-03-05 2004-10-13 Klaus Jürgen Nord Method and device for monitoring the area of technical rolling bodies
US20030066362A1 (en) * 2001-08-29 2003-04-10 Lee Shih Yuan Seat belt tension sensor
CN104389090B (en) * 2014-11-14 2016-08-24 广东丰凯机械股份有限公司 Warp tension harvester
CN110186607A (en) * 2019-06-14 2019-08-30 无锡先导智能装备股份有限公司 Tension detecting apparatus and its vibration trigger
CN110186608A (en) * 2019-06-14 2019-08-30 无锡先导智能装备股份有限公司 Pile bailing band tension detection device and its tension detecting apparatus
WO2022216673A1 (en) * 2021-04-05 2022-10-13 Purdue Research Foundation Systems and methods for measuring tension distribution in webs of roll-to-roll processes

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2923150A (en) * 1957-12-16 1960-02-02 American Viscose Corp Tension measuring apparatus
US3040565A (en) * 1960-01-07 1962-06-26 David A Church Film stress transducer
FR1407184A (en) * 1964-06-17 1965-07-30 Inst Textile De France Warp thread tension sensor on a loom
FR1540535A (en) * 1967-09-06 1968-09-27 Advanced thread breaker
BE768521R (en) * 1971-02-26 1971-11-03 Weefautomaten Picanol N V Meti CHAIN REMOVER FOR
SU391388A1 (en) * 1971-10-25 1973-07-25 Белорусский филиал Энергетического института Г. М. Кржижановского DEVICE FOR MEASUREMENT OF A LINEAR MASS OF MOVING GLASS
CH551922A (en) * 1972-11-21 1974-07-31 Loepfe Ag Geb DEVICE FOR MONITORING RUNNING FAEDS.
SU446781A1 (en) * 1973-03-22 1974-10-15 Предприятие П/Я А-3593 Device for measuring the tension of a magnetic tape
JPS5016585A (en) * 1973-06-09 1975-02-21
BE901112A (en) * 1984-11-22 1985-03-15 Ginderachter Marcel Van Pile yarn tension monitor for weaving loom - has V=shaped yarn loop on pressure sensitive detector between guides, signal can stop loom

Also Published As

Publication number Publication date
CH668443A5 (en) 1988-12-30
DE3573810D1 (en) 1989-11-23
JPS63500472A (en) 1988-02-18
WO1987000562A1 (en) 1987-01-29
EP0245236A1 (en) 1987-11-19
US4794802A (en) 1989-01-03

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