JPS61179330A - Yarn unevenness analyzing apparatus of open end spinning machine - Google Patents

Abstract

PURPOSE:The titled apparatus, capable of digitizing yarn unevenness electric signals from a yarn unevenness detector, carrying out spectrum analysis in the real time system, and integrating and analyzing in the real time system at the same time, and analyzing the yarn uneveness signals with high accuracy. CONSTITUTION:Yarn unevenness electric signals (S) from a yarn unevenness detector 6 are passed through a low-pass filter 11, amplified with an amplifier 12, and digitized with an A/D converter 13. The digitized signals are then weighted in a window 15, passed through a Fourier converter 16 and subjected to vector synthesis to give a power spectrum, which is passed through an output processing circuit 18, analogized in a D/A converter 20, and indicated on a display 21 as a graph to read the periodic unevenness. Values analyzed in an integrator 23 are passed through an output processing circuit 24 and indicated on a display 26 as digital values to read the nonperiodic unevenness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a yarn unevenness information analysis device for a pneumatic spinning machine.

[Conventional technology]

When spinning yarn with a spinning machine, defects such as slabs attached to the yarn are detected during spinning operation by a slab catcher attached to the spinning machine itself, and are immediately cut and removed there. However, defects such as variations in yarn thickness were not detected during the spinning operation, and some of the wound bobbins were pulled out and the yarn wound on the bobbins was placed in a separate location in the last irregularity test. The unevenness of the yarn is evaluated using testing equipment such as a spectrograph and a spectrograph, and thereby the yarn is inspected and defects in the spinning machine that spun the yarn are estimated.

For ring spinning machines and pneumatic spinning machines, the fluctuations in yarn thickness mentioned above include periodic fluctuations in yarn thickness caused by eccentricity or deformation of the rollers, defects in the drive system, etc. and non-periodic unevenness caused by abrasion of the apron surface. Furthermore, in rotor-type oven-end spinning machines, regular fluctuations occur mainly due to fluctuations in resistance to twisting of loose fibers in the spinning rotor. Periodic fluctuations in thread thickness will appear as defects such as moiré patterns when fabric is woven using the thread, and will significantly reduce the commercial value of the fabric. Depending on the aspect, this can be a serious drawback.

However, in order to detect such yarn unevenness, using the above-mentioned inspection method requires time and labor for manual sampling and requires a long time for inspection using testing equipment such as a last unevenness tester or a spectrograph. Moreover, the accuracy is low, and the spinning machine is continuously operated before obtaining the final and reliable calyx analysis results, so the spinning machine with the above-mentioned defects will have defects and unevenness during that time. A large amount of yarn will be produced.

Furthermore, since the above-mentioned method is a labor-intensive work, not only is the work itself troublesome, but frequent inspection of each and every one of the many weights requires a large number of people and many inspection devices. In practice, however, it is almost impossible to do so, which makes it even more likely that the production of yarns with the above-mentioned drawbacks will be overlooked.

In other words, it is necessary to detect yarns with the above-mentioned defective unevenness as soon as possible, and to detect defective parts in spinning machines, etc. that are the cause of the defects as soon as possible and accurately, and to promptly correct the defects.

By the way, as mentioned above, the causes of yarn unevenness are different between ring spinning machines and oven-end spinning machines. In the case of a ring spinning machine, the draft ratio is 60 times the height, so even if yarn unevenness occurs, it is not a big problem.
In addition, since there is a limit to the amount of yarn that can be wound, sampling and evaluation of yarn unevenness is performed after spinning and winding to a large diameter using a winder.As a result, the types of yarn unevenness become miscellaneous and periodic unevenness becomes noticeable. There is no hail. Therefore, yarn unevenness does not pose much of a problem in ring spinning machines.

On the other hand, in the case of an open-end spinning frame, the defective location is limited to one location on the spin-jung rotor, so periodic unevenness becomes a major problem.

Therefore, in the past, the raw yarn signal was used as it was, as shown in Japanese Patent Application Laid-open No. 53-117461 and Japanese Patent Application Laid-Open No. 52-91936, mainly for open-end spinning machines. There is a method that detects periodic unevenness in yarn by performing approximate analysis.

[Problems to be Solved by the Invention] In the conventional method that performs the approximate analysis described above, when there is certainly one defective point that causes yarn unevenness, such as in open-end spinning machines, it is possible to simply solve the problem. It is suitable for efficiently detecting periodic yarn unevenness.

However, there is a big problem when applying this approximate analysis to pneumatic spinning machines. That is, unlike ring spinning machines, pneumatic spinning machines have a particularly high draft ratio of 100 to 180 times. For this reason, periodic unevenness is likely to occur, and since the yarn speed is extremely high, periodic unevenness is particularly problematic. Furthermore, there is no limit to the amount of yarn that can be wound, and a large amount of yarn is directly wound without a winder step, so periodic unevenness remains and cannot be ignored. On the other hand, unlike open-end spinning machines, there is not just one defective location, but because the draft device of a ring spinning machine can be used as is, there are multiple defective locations such as the back roller, front roller, or drive system. Yaru. For this reason, it is not possible to effectively detect a wide variety of periodic unevenness by performing approximate analysis.

Furthermore, in approximate analysis using raw yarn signals as they are, small yarn unevenness signals tend to be ignored and only large yarn unevenness signals are emphasized, making it impossible to expect highly accurate detection.

[Objective of the Invention] The object of the present invention is to solve the above-mentioned conventional problems by applying spectral analysis using fast Fourier transform, which has already been developed, for periodic unevenness and integral analysis for non-periodic unevenness. To provide a yarn unevenness analysis device for a pneumatic spinning frame, which can solve the problems and realize a yarn unevenness monitoring system for multiple spindles that analyzes yarn unevenness signals with high precision and does not require any human intervention in the entire process. It is.

[Summary of the Invention] The present invention in accordance with the above objects includes a yarn unevenness detector attached to a pneumatic spinning machine, an A/D converter that digitizes the yarn unevenness electric signal from this yarn unevenness detector, and this A/D converter. It has a Fourier transformer that spectrally analyzes the signal digitized by the /D converter in real time, and an integrator that integrally analyzes the digitized signal in real time. The apparatus includes an alarm that is activated when each output of the Fourier transformer and the integrator exceeds a predetermined value, and a display that displays each output.

This makes it possible to perform a wide range of frequency analysis regardless of the size of the defect, and prevents a wide range of periodic unevenness from being effectively detected or from highlighting only some yarn unevenness signals. This is what I did.

[Example] Next, the present invention will be explained in detail based on examples.

In FIG. 1, 1 is a nozzle, back roller 2.
This method uses an air jet to twist the sliver drafted by the apron 3 and front roller 4.
The pneumatic spinning machine is configured such that the yarn Y produced by passing through the nozzle 1 passes through a delivery roller 5 and is wound onto a winding bobbin (not shown). is provided with a slab catcher 6 consisting of a light emitting diode 7 and a phototransistor 8 as shown in detail in FIG. This is used as a signal for yarn unevenness analysis.

That is, this slab catcher 6 is a highly sensitive and highly responsive detector 6 that uses a phototransistor 8 to detect the amount of light transmitted from the light emitting diode 7 and outputs the detected amount of light as an electrical displacement between terminals. When the slab passes through and an extremely large displacement of electricity is detected, the signal causes a cutting device (not shown) to operate and cut the thread Y at that point.This slab catcher 6, that is, the thread The electric signal S from the unevenness detector 6 is also digitized in the following manner and then input to a calculator 10, which will be described later, for analysis.

That is, as shown in FIG. 3, the yarn unevenness electric signal S first passes through a low-pass filter 11 to prevent aliasing, is amplified by an amplifier 12 to a voltage level most suitable for A/D conversion, and then The /D converter 13 converts the analog signal into a digital signal. This A/D converter 1
3 samples the input signal with an accurate oscillator (O20) 14 that creates a data sampling time determined according to the frequency bandwidth to be analyzed and converts it into a digital signal.

Then, the signal converted into a digital signal as described above is input to the following calculator 10, and in this example, spectrum analysis and integral analysis are performed.

First, to explain spectrum analysis, the A/D converter 13
The signals are first weighted in a window 15 and then sent to a Fourier transformer 16 for calculation, and the calculated results are vector-synthesized into a power spectrum by 17 and output as a power spectrum of each frequency component. Ru. The Fourier transformer 16 used here is not a time-consuming, complex, or expensive transformer, but one that was developed later and is capable of performing a relatively inexpensive and simplified high-speed Fourier transform.

The output processing circuit 18 converts the signal output as a power spectrum of each frequency component into a predetermined frequency,
For example, signals related to frequencies of 50 Hz or higher are processed to be suitable for analysis, such as cutting, etc., and the processed signals exit the calculator 1o, are input to the D/A converter 20, and are converted into analog values. It is displayed as a graph on the display 21 (FIG. 5). 22 is an alarm circuit which will be described later.

Depending on the spectrum graph displayed on the display 21, periodic unevenness in the yarn can be interpreted as described later.

Regarding the integral analysis, the yarn unevenness signal converted into a digital signal by the A/D converter 13 is input to the calculator 10 and sent to the integrator 23, and is sent to the integrator 23 at a constant value of 1! Regarding IJ (the yarn length to be measured) ρ, the absolute value of the displacement amount (shaded area) from the average value E of the amplitude is integrated (FIG. 6).

Then, the integrated value is sent to the output processing circuit 24, and if it is judged by the circuit that it is greater than a certain value, for example by rounding off the fraction to make the digits consistent, the alarm circuit 24 outputs the integrated value.
After processing such as issuing a signal to 5, the data is displayed as a digital value on the display 26 as it is.

Depending on the integral value displayed on this display 26,
Non-periodic unevenness in the thread is interpreted as described below.

Here, for example, a yarn Y having periodic unevenness as shown in an exaggerated manner in FIG. Suppose that an electric signal S is emitted at
(Fig. 5) are immediately displayed as integral values, so these displays can be interpreted as follows to inspect the yarn and estimate the defective location of the spinning machine.

That is, the spectrum graph shown in FIG. 5 has 28.
Since the peaks appear at frequencies of 6 Hz and 32.6 Hz, the yarn speed is 152+11/min, the diameter of the front top roller (Dt = 28 u), and the diameter of the front bottom roller (DB = 25nrn+). Period λt-(152x 100/60) ÷(
2,5xπ)-32,3r, p, s.

Front bottom roller period λ3- (152x 10
0/60)÷(2,8x yr) -28,8r,
Since p and s are calculated and known in advance, it can be seen that this thread unevenness is caused by the front top roller and front bottom roller.

If a peak appears in another fraction, it is due to another roller or a defect in the drive system, and this can also be estimated very accurately in the same manner as above.

From the integral value displayed on the display 26, a certain interval ρ
For example, if we measure for one minute in the above example, we can obtain the sum of the fluctuations for one length of 152 m, and if that value is, for example, 250, we can determine the desired fluctuation in advance. Since the amount range (for example, 50 to 200) is known, if 250 is beyond that, Apron 3
It is presumed that the surface of the blade is worn out, which is causing large unevenness in the draft.

The evaluation of yarn unevenness from the display shown on the displays 21 and 26 as described above may be performed by the operator, or, for example, at the output processing 18° 24, the amplitude of a certain component of the spectrum may be evaluated. If the integral value exceeds a certain value, the spinning machine can be configured to issue a stop signal and an alarm 22, which is displayed on the display 21, or if the integral value exceeds a certain value, the spinning machine can be stopped in the same way. Signals and alarms 25 may be configured and automated to issue and display on display 26.

Further, it is also possible to incorporate another analysis process into the above-mentioned calculator and perform it in addition to Fourier analysis and integral analysis.

Defects in the spinning machine discovered as described above will be immediately corrected by replacing the rollers, etc., and the spinning machine will be promptly restored to good condition.

As described above, the analyzer of the present invention digitizes the analog yarn unevenness electric signal sent from the yarn unevenness detector and processes the digitalized signal in real time using a calculator, so that the analog yarn unevenness The time required for analysis is extremely short compared to processing signals as they are in analog form, and the actual calculation time is on the order of milliseconds. The time required for the yarn to pass through the yarn unevenness detector, in other words, is approximately equal to the data collection time, and the analysis accuracy is also significantly higher than that of analog processing.For example, with analog processing, the top roller with a small difference in diameter This digitization process makes it possible to easily detect very close frequencies such as periodic irregularities caused by bottom rollers, etc., and to quickly detect yarns with defects, as well as to detect them with extremely high accuracy. It is possible to understand the nature of the defect, and therefore it is possible to accurately estimate the location of the defect in the spinning frame that causes the defect.

Further, the digitized yarn unevenness signal has the advantage that it is easy to process and has high accuracy when compared with a set level in output processing after being subjected to arithmetic processing.

In this invention, as mentioned above, the yarn unevenness per run can be analyzed in an extremely short time.
, 8 If you use the device shown in Figure 8, one calculator 10
As a result, even a large number of spindles can be monitored for yarn unevenness in sequence, and in this case, the time required for each analysis of yarn unevenness is extremely short. Since thread unevenness is frequently monitored at long time intervals, roller breakage, apron wear, etc. cannot occur within such a short period of time, so even if a large number of weights are used, only a small number of devices of the present invention can be used. This can be adequately monitored.

That is, what is shown in FIG. 7.8 is a system in which a yarn unevenness detector 6 attached to each spindle of a 60-spindle pneumatic spinning frame 30 and one calculator 10 are connected by a known multiplexer 31. The multiplexer 31 is configured to electrically connect the pneumatic spinning frame 30 and the calculator 10 at set time intervals in order of -10, and for example, one measurement time for one spindle is 60 minutes. If the time is seconds, then thread unevenness analysis will be performed once every hour for a given spindle.

32 is a yarn unevenness signal line, and 33 is a control signal line.

The above measurement time per measurement can be further shortened depending on the yarn speed and yarn length to be measured, and if the number of weights to be handled is small, the interval for the yarn unevenness analysis described above can be further shortened. is possible.

[Effects of the Invention] In summary, the present invention exhibits the following excellent effects.

(1) By configuring one device to include a Fourier transformer and an integrator, the structure can be simplified. Also,
Periodic yarn unevenness can be detected by spectrum analysis of the yarn unevenness signal, and non-periodic unevenness can be detected by integral analysis, making it extremely easy to analyze yarn unevenness information.

(2) Unlike conventional approximation analysis, which ends up emphasizing only some frequencies, spectrum analysis over a wide range of frequencies is performed, making it possible to distinguish extremely close frequencies and to detect a wide range of frequencies. Because it is possible to determine the
Periodic irregularities inherent in pneumatic spinning machines caused by defects in multiple areas such as backrows, front rollers, or drive systems can be analyzed with high precision. Furthermore, since the analysis results are output to the alarm and the display, it is possible to easily confirm the peak of the spectrum analysis results that appears at a frequency specific to the defective location.

(3) If a peak appears at a frequency other than the frequency specific to the defective location, the frequency and shape of the peak can be compared and verified at the same time as the results of integral analysis to estimate the defective location.

(The raw yarn unevenness electrical signal sent to the 4-Fourier transformer is weighted in advance, so unlike the conventional method, which processes the raw yarn unevenness signal as it is, even small-value electrical signals are ignored. This makes it possible to detect peaks over a wide range of frequencies, making it possible to analyze yarn unevenness information with extremely high accuracy.

(5) In particular, by connecting the yarn unevenness detector attached to each spindle of a multi-spindle pneumatic spinning frame and this analyzer using a known multiplexer, no human intervention is required in the entire process. It is possible to realize a thread unevenness monitoring system for multiple spindles.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the draft and nozzle device of a pneumatic spinning machine equipped with the analysis device of this invention, Fig. 2 is a schematic circuit diagram showing the structure of a yarn unevenness detector, and Fig. 3 is an analysis of the invention. A block diagram showing the device, Fig. 4 shows an example of the electric signal from the yarn unevenness detector, Fig. 5 shows an example of the spectrum after analysis, and Fig. 6 shows the principle of integral analysis. 7 is a schematic diagram showing an embodiment in which the analysis device of the present invention is applied to a multi-spindle pneumatic spinning machine, and FIG. 8 is a schematic circuit diagram showing details of a part thereof. It is. 2 is a back roller, 3 is an apron, 4 is a front roller, 5 is a delivery roller, 6 is a thread unevenness detector, 13
is an A/D converter, 16 is a Fourier transformer, 21.26 is a display, 22.25 is an alarm circuit, 23 is an integrator,
30 is a pneumatic spinning machine. Patent Applicant Murata Machinery Co., Ltd. Representative Patent Attorney Nobuo Kinutani Figure 1 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] In an analysis device for yarn unevenness information of a pneumatic spinning machine, which generates yarn by twisting the sliver drafted by the back roller, apron, and front roller using an air jet, and then winding the yarn onto the take-up bobbin via the delivery roller.
A yarn unevenness detector attached to the above pneumatic spinning machine and an A/D that digitizes the yarn unevenness electric signal from the yarn unevenness detector.
a converter, a Fourier transformer that spectrally analyzes a signal digitized by the A/D converter in real time, an integrator that integrally analyzes the digitized signal in real time, and the Fourier transformer and integrator. 1. A yarn unevenness information analysis device for a pneumatic spinning machine, comprising: an alarm that operates when each of the outputs exceeds a predetermined value; and a display that displays each of the outputs.