JP3810561B2 - Yarn tension detection method and apparatus - Google Patents

Description

であり、ここで算出した平均値Ｘと、これに対し予め設定した許容値とによって、正常範囲（平均値Ｘ±許容値）が設定される。
【０００５】
【発明が解決しようとする課題】
しかしながら、上記従来の糸条の張力検出方法にあっては、平均値を用いた正常範囲の設定を行っていたため、急な張力変動に対しては応答性に問題があった。
具体的には、図７に示すように、平均値を出すため、実際の張力変動に対して正常範囲の追従に時間がかかり、この間に急な張力変動があった場合に、正常範囲がこれに追従しきれず、本来なら正常範囲と判定すべき測定値（図７中のｄ1）が異常値と判定されることがあった。
【０００６】
また、このような追従性の要求度合いは加工条件によっても異なってくるが、正常範囲についての追従応答性が一律に設定されるため、糸加工の特定の状態や条件によって異常値の誤判定が生じ易かった。例えば原糸切り替えに伴って、図８に示すようなステップ状の張力変動が生じた場合、その変動幅によって正常範囲の追従時間も異なり、そのうち最も長い追従時間だけ待たなければ異常、正常の判別を正確に行うことはできなかった。
【０００７】
そこで、本発明は、糸加工の状態変化に影響されることなく、張力の急変動等に対しても、張力の異常判定を迅速、正確に行うことのできる糸状の張力検出方法及び装置を実現するものである。
【０００８】
【課題を解決するための手段】
上記課題を解決する手段として、本発明に係る糸条の張力測定方法は、走行糸条の張力を所定の測定周期で測定し、該張力の異常を検出する糸条の張力検出方法であって、前記張力の測定値が基準値に対し所定の許容範囲内にあるか否かを判定し、前記測定値が前記許容範囲内であるとき、前記基準値を該測定値と等しい値に更新し、前記測定値が前記更新後最初に前記許容範囲内から外れたときには、前記基準値を更新することなく次の測定を行い、前記測定値が所定回数だけ前記許容範囲内から同一方向に外れた場合、前記基準値を更新することを特徴とするものであり、さらに、前記所定回数を２回以上の任意の複数回に設定するとともに、前記所定の許容範囲を可変設定するものであってもよい。
【０００９】
この発明では、正常と判定された測定値が次回の異常判定の基準値として使用されることから、急な張力変動に対しても、正常範囲が迅速に追従し、正常範囲と判定すべき測定値を異常値と判定することがない。
また、原糸切り替え時等のようにステップ状の張力変動が生じ易い場合、起動後に機械温度が上昇して加工糸の張力が増加する場合、あるいは環境温度変化による緩やかな張力変化が生じる場合といったように、実際の加工状態に応じて、前記所定回数を変化させることで、正常範囲の追従性の度合いを加工条件に応じて適宜変更することができ、異常判定の誤判定を確実に防止することができる。
【００１０】
また、本発明に係る糸条の張力測定装置は、走行糸条の張力を所定の測定周期で測定する測定手段と、張力の測定値が基準値に対し所定の許容範囲内にあるか否かを判定する判定手段と、前記測定値が前記許容範囲内であるときには、前記基準値を該測定値と等しい値に更新し、前記測定値が前記更新後最初に前記許容範囲内から外れたときには、前記基準値を更新することなく次の測定を行い、前記測定値が2回以上の所定回数だけ前記許容範囲内から同一方向に外れた場合、前記基準値を更新する基準値基準値更新手段と、を備えたことを特徴とするものである。
【００１１】
したがって、上記の方法と同様に、急な張力変動に対しても、正常範囲が迅速に追従し、正常範囲と判定すべき測定値を異常値と判定することがないとともに、前記所定回数を変化させることで、正常範囲の追従性の度合いを加工条件に応じて適宜変更することができ、異常判定の誤判定を確実に防止することのできる糸条の張力測定装置を提供することができる。
【００１２】
【発明の実施の形態】
以下、本発明の好ましい実施形態を図面に基づいて説明する。
図１は本発明に係る糸条の張力測定装置の一実施形態を示す図ある。
図１に示すように、この実施形態の糸条の張力測定装置は、所定の糸条を走行状態で加工する延伸仮撚機（糸加工装置）１０に装備されたものである。
【００１３】
この延伸仮撚機１０は、原糸（preoriented yarn）Ｙを供給する供給部１１と、供給部１１からの糸条Ｙを所定の走行経路で走行させる第１フィードローラ１２及び第２フィードローラ１３と、両２フィードローラ１２、１３の間の所定の通過位置で近接する複数（例えば3枚以上）の摩擦ディスクにより走行糸条Ｙに撚りを加える仮撚ユニット１４と、第１フィードローラ１２と仮撚ユニット１４の間の加撚区間において糸Ｙを加熱する糸条加熱用のヒータ１５と、第２フィードローラ１３を通過した糸Ｙを所定のボビン（例えば紙管）に巻き取る巻取りローラ１６と、を備えている。
【００１４】
また、本実施形態の糸条の張力測定装置は、仮撚ユニット１４を通過し解撚区間に入った加工糸Ｙ（走行糸条）の張力を検出する張力センサ２１と、その張力センサ２１の張力検出情報を所定周期でサンプリングし測定値を図示しない内部メモリに記憶保持する制御回路２２と、を備えている。
これら張力センサ２１及び制御回路２２は、走行糸条Ｙの張力を所定の測定周期で測定する測定手段を構成しており、制御回路２２は、例えばＲＯＭ，ＲＡＭ等の内部メモリとハードディスク等の補助記憶装置とを備えたコンピュータ端末からなるとともに、張力センサ２１用のインターフェース回路を有している。また、制御回路２２の内部メモリには、後述する判定処理プログラムが格納されており、制御回路２２は、この判定処理プログラムにより、張力の測定値が予め設定された基準値に対して所定の許容範囲内にあるか否かを判定する判定手段として機能するとともに、その判定結果に応じて前記基準値を更新する基準値更新手段としても機能する。
【００１５】
このように構成された本実施形態においては、次のような手順で基準値及び許容範囲の設定がされる。
予め所定の運転条件で正常な糸加工を試験的に行って、その糸加工中における張力センサ２１の張力測定データを制御回路２２の内部メモリに記憶させ、正常な運転条件における張力変動の範囲を調べる。そして、その正常な運転状態での張力変動の範囲に基づき、基準値とそれに対する±の許容変動幅とで糸Ｙの正常な張力変動範囲を設定する。
【００１６】
次いで、制御回路２２により、所定周期、例えば１０ｍｓ毎に、張力センサ２１の検出値をサンプリングして、図２に示すような異常判定の処理を繰り返し実行する。
まず、ステップＳ１でサンプリングされた張力値ｔを検出値として読み込み、ステップＳ２でこの検出値ｔが正常範囲内か否かを判別する。このとき、検出値ｔが正常範囲内であれば、次ステップＳ３において加工糸Ｙの張力は正常範囲内であると判断し、ステップＳ４にて、今回の測定値ｔを次回の異常判定の基準値ｔｐに設定する。
【００１７】
いま、通常の糸加工状態であれば、張力変動幅は、前回の測定値を基準値ｔｐとしてそれに対し予め設定した許容範囲内（図中に上方向矢印及び下方向矢印で示す範囲）に入るから、図２に示すように、基準値測定毎（サンプリング及び異常判定毎）に、前記基準値ｔｐが最後にサンプリングした最新の測定値ｔと等しい値に更新されることになる。
【００１８】
一方、何らかの理由によって今回の測定値ｔが前回の測定値を基準値ｔｐとする正常範囲から外れたとき、すなわち、基準値ｔｐが前回の測定値と等しい基準値ｔｐに更新された後に今回の測定値ｔがその基準値ｔｐ（前回の測定値）を中心とする許容範囲内から外れたときには、ステップＳ２において、検出値ｔが正常範囲内にない（図２中の「いいえ」）ことになる。この場合、次ステップＳ５において、測定値ｔが、正常範囲に対し同一方向（更新されていない基準値ｔｐに対して＋方向又は−方向のいずれか一方）に、ｎ回以上連続して外れたか否かを判別し、その判別結果が「いいえ」であれば、ステップＳ６にて、加工糸Ｙの張力は異常であると判断し、次ステップＳ７で異常判定の基準値ｔｐを更新することなく異常信号を発生する。この異常信号は、例えば警報を出すため、異常回数の管理（生産管理）とそれに応じた糸の切断のため、あるいは更にパッケージの払い出し等を行うための、トリガーとなる信号である。
【００１９】
ステップＳ５の判別の結果が、「はい」である場合、すなわち、測定値が2回続けて前記許容範囲内から同一方向に外れた場合、又は、測定値が２回以上の所定回数だけ前記許容範囲内から同一方向に外れた場合には、ステップＳ３に移って加工糸Ｙの張力は正常範囲内であるが原糸の切替えや運転条件の変化によって測定値がそれまでの基準値から外れたものと判断し、ステップＳ４にて、今回の測定値ｔを次回の異常判定の基準値ｔｐに設定する。すなわち、前記基準値ｔｐを最後にサンプリングした最新の測定値ｔと等しい値に更新した後、次回の処理に移る。
【００２０】
図３はこのような処理を行った場合の基準値の推移と、上述した異常信号の発生の仕方を説明する図であり、同図（ａ）は測定値ｔがｎ回未満、例えば3回だけ正常範囲から外れ、この間は基準値及び正常範囲が更新されない場合を示し、同図（ｂ）は、測定値ｔがｎ回以上、例えば５回だけ正常範囲から外れ、その５回目の異常判定処理においてｎ＋１回目に使用する基準値及び正常範囲が更新された場合を示している。なお、いずれの場合も、基準値を正常範囲の中心として表わしているが、基準値が正常範囲の中心値でなく、正常範囲内の任意の値でよいことはいうまでもない。
【００２１】
本実施形態においては、例えば原糸の切替えによって図４に示すようなステップ上の張力変動があっても、正常範囲が予め設定されたｎ回の値に対応する所定時間で迅速に追従し、正常範囲と判定すべき測定値を異常値と判定することがない。従って、図８に示した従来例のように、正常範囲の追従時間が不定なために、異常判定を迅速・正確に行うことができないという問題が解消されることになる。
【００２２】
また、起動後に機械温度が上昇して加工糸の張力が増加する場合、あるいは環境温度変化による緩やかな張力変化が生じる場合に、実際の加工状態に応じて、前記所定回数ｎを適宜変化させることで、正常範囲の追従性の度合いを加工条件に応じて適宜変更することができ、異常判定の誤判定を確実に防止することができる。
【００２３】
勿論、図５（ａ）に示すような張力の急変動や、図５（ｂ）に示すようなステップ状の張力変動に対して、基準値及び正常範囲の設定のために余計な処理をしなくて済むとともに、迅速・確実な糸条の張力異常判定を行うことができる。
これに対し、平均値を基準値とする従来方法では、図７（ａ）及び図７（ｂ）に示すように、正常範囲の追従性が悪いか、あるいは、追従性を高めるべく平均回数を少なくすると、余計な計算処理を行うことになり、しかも、基準値を大きく変動させることになるから、いずれも誤判定を生じ易い。
【００２４】
【発明の効果】
本発明に係る糸条の張力測定方法によれば、実質的に大きな張力変動がない場合には正常と判定された測定値を次回の異常判定の基準値とし、張力の急変動や原糸切替え等によるステップ状の張力変動等が生じた場合には、所定の測定回数までに正確に異常判定を行うことができる。すなわち、異常判定を所定の測定回数内で確実に行うことができ、急な張力変動に対しても、正常範囲を迅速に追従させて、張力の異常判定を迅速、正確に行うことができる。
【００２５】
また、原糸切り替え時等のようにステップ状の張力変動が生じ易い場合、起動後に機械温度が上昇して加工糸の張力が増加する場合、あるいは環境温度変化による緩やかな張力変化が生じる場合といったように、実際の加工状態に応じて、前記所定回数を変化させることで、正常範囲の追従性の度合いを加工条件に応じて適宜変更することができ、異常判定の誤判定を確実に防止することができる。
【００２６】
さらに、本発明に係る糸条の張力測定装置によれば、上記の方法と同様に、急な張力変動に対しても、正常範囲を迅速に追従させ、正常範囲と判定すべき測定値を異常値と判定することがないようにし、前記所定回数を変化させることで、正常範囲の追従性の度合いを加工条件に応じて適宜変更することができ、異常判定の誤判定を確実に防止することのできる糸条の張力測定装置を提供することができる。
【図面の簡単な説明】
【図１】本発明に係る糸条の張力検出装置の一実施形態を示す同装置を装備した仮撚機の全体概略構成図である。
【図２】本発明に係る糸条の張力検出方法の一実施形態を説明するフローチャートである。
【図３】図２に示す処理による張力の基準値及び正常範囲の推移を説明する図で、（ａ）は測定値ｔがｎ回未満だけ正常範囲から外れたが基準値及び正常範囲が更新されない場合を示し、（ｂ）は測定値ｔがｎ回以上正常範囲から外れてｎ＋１回目に使用する基準値及び正常範囲が更新された場合を示している。
【図４】ステップ状の張力変動に対する、一実施形態の張力検出方法での基準値の推移を示す図である。
【図５】張力の瞬間的な変動及び復帰に対する、一実施形態の張力検出方法での基準値の推移を示す図である。
【図６】従来例の糸条の張力検出及び異常判定法を説明する図である。
【図７】従来の張力変動時の問題を説明する図である。
【図８】従来の原糸切替え時の問題を説明する図である。
【符号の説明】
１０ 延伸仮撚機（糸加工装置）
１１ 供給部
１２ 第１フィードローラ
１３ 第２フィードローラ
１４ 仮撚ユニット
１５ 糸条加熱用のヒータ
１６ 巻取りローラ
２１ 張力センサ（測定手段）
２２ 制御回路（測定手段、判定手段、基準値更新手段）
Ｙ 加工糸（走行糸条）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a yarn tension detecting method and apparatus for continuously detecting the tension of a processed yarn in a drawing false twister and detecting an abnormality in the tension.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a yarn processing apparatus such as a false twister, a tension sensor that continuously measures the tension of a processed yarn (hereinafter also referred to as a processed yarn) is provided, and the tension of the processed yarn is measured online. Therefore, the occurrence of abnormality in the machining state is monitored.
[0003]
The abnormality detection method is as follows: normal yarn processing is experimentally performed under predetermined operating conditions in advance, and the normal tension range under the operating conditions is determined from the tension measurement data during the yarn processing, and the subsequent operation is performed. Sometimes, if the measured tension value deviates from this normal range, it is determined as abnormal.
By the way, when the tension of the work yarn changes gradually with the temperature change of the false twisting machine, for example, the temperature change of the false twisting unit (a plurality of friction disks), the normal range is set so as not to determine that this is abnormal. It is necessary to decide.
[0004]
Therefore, conventionally, as shown in FIG. 6, for example, an average of sampling values every 10 ms (average of 50 to 200) is taken and used as a reference.

The normal range (average value X ± allowable value) is set by the average value X calculated here and the preset allowable value.
[0005]
[Problems to be solved by the invention]
However, in the conventional method for detecting the tension of the yarn, since the normal range is set using the average value, there is a problem in responsiveness to a sudden change in tension.
Specifically, as shown in FIG. 7, in order to obtain an average value, it takes time to follow the normal range with respect to the actual tension fluctuation. In some cases, the measured value (d1 in FIG. 7) that should normally be determined as the normal range is determined as an abnormal value.
[0006]
In addition, the required degree of follow-up varies depending on the machining conditions, but the follow-up responsiveness for the normal range is set uniformly. It was easy to occur. For example, when a step-like tension fluctuation as shown in FIG. 8 occurs due to the switching of the yarn, the follow-up time in the normal range varies depending on the fluctuation range. Could not be done accurately.
[0007]
Therefore, the present invention realizes a thread-like tension detection method and apparatus capable of quickly and accurately performing tension abnormality determination even for sudden fluctuations in tension, etc., without being affected by changes in the state of yarn processing. To do.
[0008]
[Means for Solving the Problems]
As a means for solving the above problems, a yarn tension measuring method according to the present invention is a yarn tension detecting method for measuring the tension of a traveling yarn at a predetermined measurement cycle and detecting an abnormality in the tension. Determining whether or not the measured value of the tension is within a predetermined allowable range with respect to a reference value, and updating the reference value to a value equal to the measured value when the measured value is within the allowable range. When the measured value deviates from the allowable range for the first time after the update, the next measurement is performed without updating the reference value, and the measured value deviates from the allowable range in the same direction by a predetermined number of times. The reference value may be updated, and the predetermined number of times may be set to any two or more times and the predetermined allowable range may be variably set. Good.
[0009]
In the present invention, since the measurement value determined to be normal is used as a reference value for the next abnormality determination, the normal range quickly follows even a sudden change in tension, and should be determined as the normal range. The value is not determined to be an abnormal value.
Also, when stepwise tension fluctuations are likely to occur, such as when changing the raw yarn, when the machine temperature rises after startup and the tension of the work yarn increases, or when moderate tension changes due to environmental temperature changes As described above, by changing the predetermined number of times according to the actual machining state, the degree of followability of the normal range can be changed as appropriate according to the machining conditions, and erroneous determination of abnormality determination is reliably prevented. be able to.
[0010]
The yarn tension measuring device according to the present invention includes a measuring means for measuring the tension of the traveling yarn at a predetermined measurement cycle, and whether or not the measured value of the tension is within a predetermined allowable range with respect to the reference value. When the measured value is within the allowable range, the reference value is updated to a value equal to the measured value, and when the measured value is first out of the allowable range after the update The reference value reference value updating means for performing the next measurement without updating the reference value and updating the reference value when the measured value deviates from the allowable range in the same direction by a predetermined number of times of two or more times. It is characterized by comprising.
[0011]
Therefore, as in the above method, the normal range quickly follows even a sudden change in tension, the measured value to be determined as the normal range is not determined as an abnormal value, and the predetermined number of times is changed. By doing so, it is possible to provide a yarn tension measuring device that can appropriately change the degree of followability in the normal range according to the machining conditions and can reliably prevent erroneous determination of abnormality.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a view showing an embodiment of a yarn tension measuring device according to the present invention.
As shown in FIG. 1, the yarn tension measuring device of this embodiment is equipped with a drawing false twisting machine (yarn processing device) 10 for processing a predetermined yarn in a running state.
[0013]
The drawing false twisting machine 10 includes a supply unit 11 that supplies a preoriented yarn Y, and a first feed roller 12 and a second feed roller 13 that cause the yarn Y from the supply unit 11 to travel along a predetermined traveling path. A false twisting unit 14 for twisting the traveling yarn Y by a plurality of (for example, three or more) friction disks that are close to each other at a predetermined passing position between the two feed rollers 12 and 13, and a first feed roller 12; A yarn heating heater 15 that heats the yarn Y in the twisting section between the false twisting units 14, and a winding roller that winds the yarn Y that has passed through the second feed roller 13 around a predetermined bobbin (for example, a paper tube). 16.
[0014]
In addition, the yarn tension measuring device of the present embodiment includes a tension sensor 21 that detects the tension of the processed yarn Y (running yarn) that has passed through the false twisting unit 14 and entered the untwisting section, and the tension sensor 21. A control circuit 22 that samples the tension detection information at a predetermined period and stores the measured value in an internal memory (not shown).
The tension sensor 21 and the control circuit 22 constitute measurement means for measuring the tension of the traveling yarn Y at a predetermined measurement cycle. The control circuit 22 is an auxiliary memory such as an internal memory such as ROM and RAM and a hard disk. The computer terminal includes a storage device, and has an interface circuit for the tension sensor 21. Further, a determination processing program to be described later is stored in the internal memory of the control circuit 22, and the control circuit 22 uses the determination processing program to allow the measured value of the tension to have a predetermined tolerance with respect to a preset reference value. In addition to functioning as a determination unit that determines whether or not it is within the range, it also functions as a reference value update unit that updates the reference value according to the determination result.
[0015]
In the present embodiment configured as described above, the reference value and the allowable range are set in the following procedure.
The normal yarn processing is performed experimentally under predetermined operating conditions in advance, and the tension measurement data of the tension sensor 21 during the yarn processing is stored in the internal memory of the control circuit 22, and the tension fluctuation range under the normal operating conditions is determined. Investigate. Then, based on the tension fluctuation range in the normal operation state, the normal tension fluctuation range of the yarn Y is set with the reference value and the ± allowable fluctuation range.
[0016]
Next, the control circuit 22 samples the detection value of the tension sensor 21 at a predetermined period, for example, every 10 ms, and repeatedly executes the abnormality determination process as shown in FIG.
First, the tension value t sampled in step S1 is read as a detected value, and in step S2, it is determined whether or not the detected value t is within the normal range. At this time, if the detected value t is within the normal range, it is determined in the next step S3 that the tension of the processed yarn Y is within the normal range, and in step S4, the current measured value t is used as a reference for the next abnormality determination. Set to the value tp.
[0017]
Now, in the normal yarn processing state, the tension fluctuation range falls within an allowable range set in advance with respect to the previous measurement value as a reference value tp (a range indicated by an upward arrow and a downward arrow in the figure). Therefore, as shown in FIG. 2, the reference value tp is updated to a value equal to the latest measured value t sampled last time for every reference value measurement (sampling and abnormality determination).
[0018]
On the other hand, when the current measurement value t deviates from the normal range where the previous measurement value is the reference value tp for some reason, that is, after the reference value tp is updated to the reference value tp equal to the previous measurement value, When the measured value t deviates from the allowable range centered on the reference value tp (previous measured value), the detected value t is not within the normal range (“No” in FIG. 2) in step S2. Become. In this case, in the next step S5, has the measured value t continuously deviated n times or more in the same direction with respect to the normal range (either in the + direction or the − direction with respect to the reference value tp that has not been updated)? If the determination result is “NO”, it is determined in step S6 that the tension of the processed yarn Y is abnormal, and in the next step S7, the abnormality determination reference value tp is not updated. An abnormal signal is generated. This abnormality signal is a trigger signal for, for example, issuing an alarm, managing the number of times of abnormality (production management) and cutting the yarn in accordance therewith, or further delivering the package.
[0019]
If the result of determination in step S5 is “Yes”, that is, if the measured value deviates from the allowable range in the same direction twice, or if the measured value is two or more times, the allowable value If it is out of the same direction from the range, the process proceeds to step S3, and the tension of the processed yarn Y is within the normal range, but the measured value deviates from the reference value so far due to the change of the raw yarn or the change of the operating condition. In step S4, the current measurement value t is set as the reference value tp for the next abnormality determination. That is, the reference value tp is updated to a value equal to the latest measured value t sampled last, and then the next process is performed.
[0020]
FIG. 3 is a diagram for explaining the transition of the reference value when such processing is performed and the manner of generation of the abnormal signal described above. FIG. 3A shows the measured value t less than n times, for example, 3 times. In this period, the reference value and the normal range are not updated. FIG. 5B shows that the measured value t is not less than n times, for example, 5 times, and the abnormality is determined for the fifth time. This shows a case where the reference value and the normal range used at the (n + 1) th time in the process are updated. In any case, the reference value is represented as the center of the normal range, but it goes without saying that the reference value is not the center value of the normal range but may be any value within the normal range.
[0021]
In the present embodiment, for example, even when there is a tension fluctuation on the step as shown in FIG. 4 due to the switching of the raw yarn, the normal range quickly follows in a predetermined time corresponding to n preset values, A measured value that should be determined as the normal range is not determined as an abnormal value. Therefore, as in the conventional example shown in FIG. 8, since the follow-up time in the normal range is indefinite, the problem that the abnormality determination cannot be performed quickly and accurately is solved.
[0022]
In addition, when the machine temperature rises after startup and the tension of the work yarn increases, or when a gradual change in tension occurs due to a change in the environmental temperature, the predetermined number n is appropriately changed according to the actual processing state. Thus, the degree of followability in the normal range can be changed as appropriate according to the machining conditions, and erroneous determination of abnormality determination can be reliably prevented.
[0023]
Of course, for the sudden fluctuation of tension as shown in FIG. 5A and the stepwise tension fluctuation as shown in FIG. 5B, extra processing is performed for setting the reference value and the normal range. This eliminates the need for the yarn tension abnormality determination.
On the other hand, in the conventional method using the average value as the reference value, as shown in FIGS. 7A and 7B, the follow-up performance in the normal range is poor, or the average number of times is set to improve the follow-up performance. If the number is reduced, extra calculation processing is performed, and the reference value is greatly changed.
[0024]
【The invention's effect】
According to the yarn tension measuring method according to the present invention, when there is substantially no fluctuation in tension, the measurement value determined to be normal is used as a reference value for the next abnormality determination, and a rapid change in tension or switching of the yarn is performed. When a step-like tension fluctuation or the like occurs due to, for example, abnormality determination can be accurately performed by a predetermined number of times of measurement. That is, the abnormality determination can be reliably performed within a predetermined number of measurements, and the abnormality determination of the tension can be quickly and accurately performed by quickly following the normal range even with a sudden change in tension.
[0025]
Also, when stepwise tension fluctuations are likely to occur, such as when changing the raw yarn, when the machine temperature rises after startup and the tension of the work yarn increases, or when moderate tension changes due to environmental temperature changes As described above, by changing the predetermined number of times according to the actual machining state, the degree of followability of the normal range can be changed as appropriate according to the machining conditions, and erroneous determination of abnormality determination is reliably prevented. be able to.
[0026]
Furthermore, according to the yarn tension measuring apparatus according to the present invention, as in the above-described method, the normal range can be quickly followed even with a sudden change in tension, and the measured value to be determined as the normal range is abnormal. By changing the predetermined number of times so that it is not determined as a value, the degree of followability of the normal range can be changed as appropriate according to the processing conditions, and erroneous determination of abnormality determination can be reliably prevented It is possible to provide a yarn tension measuring device capable of performing the above.
[Brief description of the drawings]
FIG. 1 is an overall schematic configuration diagram of a false twisting machine equipped with the yarn tension detecting device according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating an embodiment of a yarn tension detection method according to the present invention.
FIG. 3 is a diagram for explaining the transition of the reference value of tension and the normal range by the process shown in FIG. (B) shows a case where the reference value and the normal range used at the (n + 1) th time are updated after the measurement value t has deviated from the normal range n times or more.
FIG. 4 is a diagram showing a transition of a reference value in a tension detection method according to an embodiment with respect to a step-like tension fluctuation.
FIG. 5 is a diagram illustrating a transition of a reference value in a tension detection method according to an embodiment with respect to instantaneous fluctuation and return of tension.
FIG. 6 is a diagram for explaining a yarn tension detection and abnormality determination method of a conventional example.
FIG. 7 is a diagram for explaining a problem at the time of conventional tension fluctuation.
FIG. 8 is a diagram for explaining a problem at the time of conventional yarn switching.
[Explanation of symbols]
10 Drawing false twisting machine (yarn processing equipment)
DESCRIPTION OF SYMBOLS 11 Supply part 12 1st feed roller 13 2nd feed roller 14 False twisting unit 15 Heater 16 for yarn heating Winding roller 21 Tension sensor (measuring means)
22 Control circuit (measuring means, judging means, reference value updating means)
Y processed yarn (running yarn)

Claims (3)

A yarn tension detection method for measuring the tension of a traveling yarn at a predetermined measurement cycle and detecting an abnormality in the tension,
Determining whether the measured value of the tension is within a predetermined tolerance with respect to a reference value;
When the measured value is within the tolerance, the reference value is updated to a value equal to the measured value;
When the measurement value is out of the first allowable range after the update, the next measurement is performed without updating the reference value,
The yarn tension detection method according to claim 1, wherein the reference value is updated when the measured value deviates from the permissible range in the same direction a predetermined number of times. The yarn tension detection method according to claim 1,
The predetermined number of times is set to an arbitrary plural number of two times or more,
The yarn tension detecting method according to claim 1, wherein the predetermined allowable range is variably set. A measuring means for measuring the tension of the running yarn at a predetermined measuring cycle;
Determination means for determining whether the measured value of the tension is within a predetermined allowable range with respect to the reference value;
When the measured value is within the allowable range, the reference value is updated to a value equal to the measured value, and when the measured value is out of the allowable range for the first time after the update, the reference value is updated. And a reference value update means for updating the reference value when the measured value deviates in the same direction from the allowable range by a predetermined number of times equal to or more than twice. A yarn tension detecting device characterized by:

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