SU526688A1 - Device for sorting knitted fabric by grade - Google Patents

Description

one

The invention relates to devices for monitoring web defects in a blend process, for example, for circular knitting machines and is intended for use in knitting production.

A device for detecting flaws on circular machines is known, which contains a photo-optical system for detecting flaws when a web is illuminated by a light flux and a device for recognizing the nature of defects by the change in intensity of the flux passing through the canvas.

However, this device is characterized by the presence of a mechanical beam scanning system and the use of an incandescent lamp as a light source. In addition, the device operates on visible radiation, which determines the effect of the chromaticity and composition of the yarn on the accuracy of defect detection; in fact, it is an indicator of web defects and does not allow for the classification of defects.

In order to recognize the size and classification of web defects by grade, as well as to improve the accuracy of defect control, the signal processing unit contains a number of selection channels for the duration of the signals whose inputs are electrically connected to the driver output and decoders connected to the corresponding outputs of each channel.

selection, and an infrared semiconductor emitter was used as a radiation source. The drawing shows a block diagram of the proposed device for sorting knitted fabrics by grade.

Optical modulator 1 contains a source of radiant flux and the modulator itself. The source of the radiant flux is an infrared LED, and the modulator is made on semiconductor elements.

The controlled knitted fabric 2 is located between the source of the radiant flux with the modulator 1 and the converter of the radiant flux 3 containing the radiation receiver with the preamplifier 4 and the amplifier 5 having a detector, the output of which is connected to the Schmitt trigger circuit.

Two analogous channels 7 and 8 of pulse duration selection are connected in parallel to the output of the imager b. The input, for example, of channel 7 is an inverter 9 (element NOT) connected to the single-oscillator 10. The output of the one-vibrator 10 is the input of the element H-HE 11, the other input of which is simultaneously the input of the inverter 9, and the output is the input of the single-oscillator 12. To the one-shot 12 is connected to the inverter 13. Output

the inverter 13 is the input element of the AND-

NOT 14, the other input of which is at the same time the output of the element AND-NOT 11. The output of the element AND-HE 14 will be the output of the entire channel 7 of the pulse selection for the duration.

The decoder signs 15 is connected to the outputs of two parallel channels 7 and 8 of the selection of pulses. The first output of the selection channel 7 is the input of the inverter 16, the output of the channel 8 is simultaneously the input of the NAND 17 element and the inverter 18, and the second output of the selection channel 7 is connected to the input of the NAND 19 element.

The output of the inverter 16 is the input of the element AND-NOT 17 and at the same time the input of the element AND-NOT 20. The output of the inverter 18 is the input of the element AND-NOT 19 and the input of the element AND-NOT 20. The output of the element 17 and the combined outputs of the elements 19 and 20 are connected respectively, to the devices registering a “small and” large level of defects.

The number of selection channels and decoders for the three levels of web sill thresholds is limited to two. With different technology requirements in the fabric range, their number varies and is determined by these requirements. Performing them is similar.

The device works as follows.

The radiant flux of infrared radiation modulated in the optical modulator 1 penetrates the web 2, is perceived by the photoreceiver with the preamplifier 4, is converted into electrical oscillations, amplified and detected by the amplifier 5.

When defects appear in polotne 2, impulses of defects appear in the photoelectric tract. Different in duration defects correspond in duration to the pulses appearing at the output of the amplifier 5 of the photo-path. From here, a pulse of a certain duration arrives at the input of the imager 6, which forms rectangular pulses of the corresponding duration.

The generated pulse is fed further to the selection channels 7 and 8 pulses for durability.

The selection channel 7 forms the output. Tulse them, when the duration T of the input pulse is equal to the specified one (the time diagram in the drawing explains the operation of the selection channel).

A defect pulse with a duration Tx from the output of the imaging unit 6 is fed to the inverter 9 (and simultaneously to the input of the element I-NE 11), and then to the one-oscillator 10. The single-oscillator 10, configured to form a pulse of a certain duration equal to the lower specified selection limit, starts and issues impulse duration TI to another input element AND-NOT 11.

If the pulse duration, then at the output of the element AND-HEN 11 a pulse of duration appears. This pulse simultaneously enters the one-shot 12 and the input element AND NOT 14.

The single-oscillator 12 is triggered, forms and delivers through the inverter 13 to the input of the AND-14 element a pulse with a duration of TgIpulse at the output of the AND-NE 14 element only when the condition is fulfilled:

(.Rt ,;

if Tz. (Tx-Ti), then AND-NO 14 will be closed.

The operation of the pulse-selection channel 8 is characterized in that if for channel 7 the selection level was set:

T, T, (T, + T,) +,

where t is the value of the possible mutual overlap of time intervals, then for channel 8 of the selection the condition should be fulfilled:

(7. + G,), G ,.

In order to isolate the signs of "large and" - small, respectively, II and I grades, the signals from the outputs of channel 7 and 8 of the selection go to the decoder circuit of signs 15. When the output of the channel of selection 7 appears

a pulse (Ti-JrTz) + -OH is fed through an inverter 16 to the input of the element AND-HE 17 (and at the same time to the input of the element AND-HE 19). At the input of the element, NAND 17 will maintain the state of the logical "I, and at the output of the element NAND 17 there will be a pulse determined only by the duration of its input pulse with a duration

(L + 7.) +

which will be fed through the inverter 18 to the input of the AND-NE element 19, which determines the state of the logical "1. At the output of the element NAND 19 there will be an impulse determined also by the duration of the input impulse.

If at the output of both channels of selection for Vtc, the defect pulses are of the duration

(T. + T,), + T,) + - the case of mutual overlap of the time intervals of the first and second channels (a sign of “large defect), - then the impulse indicating the presence of a defect is detected at the output of the element AND NOT 20 .

Thus, the proposed device makes it possible to assess the quality of the web, for example, on rounding machines from the point of view of the classification of web defects by grades directly on the machine.

Information output from the device is possible on any automatic recording and printing device in the process control system.

Form m u la II 3 about b e and e and

Claims (2)

I. A device for sorting knitted fabrics of a grade, for example, on circular filling machines, containing a radiation source and photo-detectors connected to the input of a radiant flux-to-electric conversion unit, the output of which through a shaper is electrically connected to a signal processing unit, characterized in that , in order to determine the size and classify the defects of the web by grade. The sig-1alis processing unit contains a series of selection channels for the duration of the signals whose inputs are electrically connected to the output of the driver, and decoders connected to the corresponding outputs of each of the selection channels. 2. The device according to claim 1, characterized in that, in order to increase the accuracy of defect control, an infrared semiconductor emitter is used as a source of radiation. / J, w