JPH02212754A - Yarn spot measuring apparatus - Google Patents

Abstract

PURPOSE:To simplify a dye searching of a yarn by a method wherein yarn spot cycle signals with a cycle component preset are selected from among those from a detector and deviations of the cycle signals from a reference means are averaged to make a yarn deviation signal. CONSTITUTION:Yarn 1 is passed through a detector 2 and runs. A thicker spot, namely, a mass changing portion of the yarn 1 is introduced to a cycle selection means 3 with the detector 2 to extract signals with a specified yarn spot cycle. Yarn spot cycle signals with a specified band width extracted by the means 3 are introduced to a yarn spot computing means 6, which has a mean of signals within a fixed average period in an initial term of each computation cycle computed beforehand. The computing means computes deviations of the yarn spot cycle signals from the mean sequentially during a specified measuring period after the averaging period. A mean of the deviations is computed over the measuring period to be outputted as yarn spot deviation signal. The yarn spot deviation signal from the means 6 is compared with a yarn spot managing width preset by a comparison means 7, which outputs an abnormality signal when the yarn spot deviation signal is off the managing width.

Description

[Detailed Description of the Invention] [Field of Application] The present invention relates to a yarn unevenness measuring device for measuring yarn unevenness in running yarn, and particularly to a yarn unevenness measuring device suitable for yarn unevenness in running yarn with a long yarn unevenness cycle. .

[Prior art and problems] The most basic method for evaluating yarn quality is dyeing evaluation. It is well known that this difference in dyeing is caused by unevenness of the yarn, and is disclosed in Japanese Patent Application Laid-open No. 50-142058 and Japanese Patent Application Laid-Open No. 51-1989.
Japanese Patent No. 20343 discloses a capacitance type detector for measuring such thread unevenness. However, simply measuring the peak of the mass change of the yarn, as in this known prior art, can only detect signals such as breakage of a single yarn such as a multifilament or uneven thickness of the yarn that occurs instantaneously. There was a problem that it could not be applied to quality evaluation. In order to solve these problems, a method has been proposed in which the area average, peak value, or average peak value of the output electrical signal is compared with past data to obtain yarn quality information.

However, the output signal from the detector is based on oil and temperature.

It is a very complex combination of factors such as humidity, tension, and even viscosity changes in raw material polymers. Therefore, the staining spots that occur when dyeing the final product cannot be accurately correlated with mere information on the average value of the electrical signal from the detector, and the evaluation is based on staining tests on samples of a specified length. It is done in

By the way, in recent years, many brands of yarn have been manufactured (particularly in the melt spinning process of synthetic fibers), the viscosity of the raw R1 polymer has varied over a wide range from a few hundred voids to more than 5,000 voids, and the spinning nozzle has also been specially designed. As the number of shapes increases, yarn irregularities that occur randomly and have a period longer than the sample length have become a new problem in the dyeing process.

[Objective of the Invention 1 The present invention has been made with the above-mentioned circumstances in mind, and its purpose is to determine yarn irregularities in running yarn according to brands, from short to long yarn irregular cycles. The present invention provides a yarn unevenness measuring device that can perform the following steps.

1-Structure and operation of the invention] 1. The rope of the present invention converts yarn irregularities in running yarn by capacitance conversion 1.
The thread spot measuring device detects thread spots using three types of detectors.
a period selecting means for selecting a thread mottling periodic signal having a preset periodic component from among the thread mottling signals from the detector; Then, the standard average value is determined by averaging the deviations of the thread spot periodic signal "F" from the average value of the thread spot periodic signal "F" during a certain measurement time following the average time, and the thread spot deviation value is calculated as the "C thread spot deviation value". This is a thread unevenness measuring device characterized by being equipped with a thread unevenness calculating means.

Hereinafter, the present invention will be explained using the drawings.

FIG. 1 does not show the basic configuration of the present invention; it is a block diagram.

The thread 1 shown in Fig. 1 is passed through the detector 21 and the thread is fed. The detector 2 is of the capacitance conversion type that can measure the change in quality fNl of the yarn 1. The above-mentioned known device or a commercially available yarn unevenness measuring device can be used. .

In the detector 2, changes in the thickness and mass of the yarn 1 are converted into electrical signals, which are introduced into the period I'l1 selection means 33 and passed through a high-pass filter with a predetermined low cutoff frequency of the period selection means 3. 4) At the low cut-off frequency J, a signal having a predetermined thread mottling period set by the low-pass noilter 5 having a predetermined high cut-off frequency of 1115 is extracted.

The thread unevenness periodic signal in the predetermined band extracted by the cycle selection means 3 is a signal that is a combination of factors such as oil, temperature, humidity, thread tension, etc., and is therefore guided to the thread unevenness calculation means 6 for the purpose of removing these factors. It will be destroyed. The yarn irregularity calculation means 6 is composed of one viewer, and processes the signal manually inputted from the period selection means 3 at a constant calculation period as follows. That is, the average value of the signal within a certain average period at the beginning of each calculation period is calculated, and the deviation of the average value of the thread mottling periodic signal is calculated sequentially during a predetermined measurement period after the average period. Measurement period 1:
The average value of the deviations is calculated and outputted as a yarn unevenness deviation signal. In this way, the computed thread unevenness deviation signal effectively captures only the change in the mass of the yarn within a certain period of time in which factors other than thread unevenness have been removed, that is, the true thread unevenness. The thread spot deviation signal from the thread spot calculating means 6 is compared with the value in the judgment management width storage section 8 which is set in advance by the comparison and judgment means 7 and stores the thread spot management width, and the thread spot is determined to be within the quality control width. It is determined whether or not it is out of the range.

The comparison/judgment means 7 outputs an abnormality signal when the yarn unevenness deviation signal is outside the control range. Then, necessary measures such as stopping the corresponding weight and generating an alarm are performed based on this stomach trust ÷ J. Note that the comparison and determination means 7 is configured in the same computer as the thread spotting performance means 6.

The yarn unevenness of four types of threads was measured using the above yarn unevenness measuring device. All of these samples require long-period thread spotting determination over several hundred meters.

For measurement, the low cutoff frequency of high-pass filter 4 was set to 0.08.
11 z , the high cutoff frequency of the low pass filter 5 is set to 1
．． The calculation was conducted at a frequency of 58 Hz and a calculation cycle of 21 seconds.

Figure 2 shows the relationship between the results of offline measurement of yarn unevenness on these samples using a 1% meter (manufactured by Tsebeger Kusta) and the one-line measurement using the yarn unevenness measuring device of this embodiment. It shows. Note that the measurement results of this example are the values of the yarn unevenness deviation signal, and the numerical values are the output values themselves without calibration. From this result, it can be seen that the present invention has a (1% measuring instrument) and good linear characteristics, and that it is possible to measure with sufficient accuracy for practical use if calibrated. This made it possible to evaluate the quality of long-period yarn irregularities that were difficult to detect through manual sensory testing, which used to evaluate dyeing by knitting approximately 70 m long samples.

As is clear from the above examples, in the present invention, quality can be evaluated without dyeing the yarn regardless of the cycle of yarn unevenness, and a significant improvement in quality and a reduction in the number of saws can be achieved.

A3. It goes without saying that it is also possible to provide a plurality of period selection means in the upper peeling process so that many types of thread irregularities can be determined at the same time.

[Effects of the Invention] As described above, the thread spot measuring device of the present invention is a device that can be used as an online quality evaluation method for thread spots of any period, and is a device that can be sufficiently distinguished, and the dyeing inspection of threads is simplified and labor-saving. In addition, it has the effect of greatly improving the quality of the yarn product.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a graph of the relationship between measurement results and U% in this embodiment. 1: Thread 2: Detector 3: Cycle selection means 6: Thread spot calculation means 7: Comparison and determination means Patent applicant Teijin Co., Ltd.
Ceremony Ceremony Attorney Patent Attorney 1) Jun Hiroshi 1
)Iris/Rotate

Claims (1)

[Claims] A thread spot measuring device for detecting thread spots on a running yarn using a capacitance conversion type detector, comprising: a cycle selection means for selecting a thread spot periodic signal having a preset periodic component from among thread spot signals from the detector; A reference average value is obtained by averaging the thread mottling periodic signals during a certain average time at the beginning of the sampling period, and from the reference average value of the thread mottling periodic signals during a certain measurement time following the averaging time. What is claimed is: 1. A thread unevenness measuring device comprising: a thread unevenness calculation means for averaging the deviations of the above and outputting the average deviation as a thread unevenness deviation signal.