JPS5979133A - Method and device for measuring tension - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and a device for contact-free measurement of tension JJ of fibrous products and moving surfaces.

"Fibrous products" are understood to mean textile yarns, plastic yarns, metallic or optical yarns, and textile yarns can be used or used in combination in China and Germany. It can be in the form of a continuous multifilament or multi-ply yarn, monofilament or spun yarn made from natural, recycled, synthetic or inorganic materials.

"Surface" is understood to mean the surface of a woven, knitted or non-woven textile, the surface of a plastic sheet, a sheet of yarn, a plastic, paper or metal tape or strip.

In the textile industry, the uniformity and consistency of the tension in the yarn being produced or converted is of particular importance; It is important in the irregularities in the degree of orientation that result in ply breakage, weak areas that cause ply breakage, and irregularities in the appearance of finished products using such yarns. In operation, for example, irregularities in tension can result in damage to the machine or defects in the finished woven or knitted material. The same is true for sheets of yarn in V-warp operation. Valid.

For metallic systems, irregularities in tension are associated with withdrawal and static t
This is especially important in The same applies, for example, to the production of plastic film when the plastic film is drawn off and rolled onto a reel. The same holds true for the regularity of the tension of the fibrous product in the budding or coaching.

In the following description, for the sake of brevity, "fibrous product" and "surface" will be referred to as "one product".

An object of the present invention is to provide a simple method and apparatus that allows continuous monitoring of the tension in various parts of the path followed by a moving product.

In accordance with the present invention, a method is provided for continuously measuring tension in an interlocking product, which method comprises measuring the tension in a lateral direction between two identified supports along a predetermined length path of a moving product. vibrations are applied to the product, this vibration is detected remotely by an optical device, and a signal representative of the detected vibration is transmitted to an electronic sensor device to apply a lateral force to the product. The vibration of ′j.

It consists of controlling a device that holds the tension and transmitting a signal to a device that reads the tension to determine the tension.

The method involves the use of optical detection devices, where the two fixed holding points of the path followed by the moving product are determined by the components of the equipment for the production or conversion of said product. Therefore, the method can be carried out without contact between the product and the detection device.

The term "without contact" is to be understood as meaning either no contact at all or very slight rubbing contact without compromising the quality of the product.

According to another aspect of the invention, there is provided an apparatus for continuously measuring the tension of a moving article, the apparatus comprising two spaced supports for a moving article; The supporting parts are spaced apart by a predetermined distance, and the products sent between the supporting parts are directed in the opposite direction.
a vibration excitation device for vibrating in a direction that crosses this;
and an electronic servo device for controlling the A vibration device in response to signals received from the optical device.

The aforementioned measuring principle is based on the law of vibrating threads, i.e. a part of the product with a thickness L (medium meter), for example between two guides or two rollers, or between a guide and a roller. The fundamental frequency of lateral vibration of the part sandwiched by f. (Hz funeral position) is 2[. =50/L-J-t
is related to the tension force t (force per unit surface area in g/lex) by . Optical observation of this frequency therefore makes it possible to determine -;reca in an intuitive manner.

It is also possible to provide harmonics of this fundamental frequency if this frequency is too low, in which case the fundamental frequency in item 1iiii is inappropriate for the measurement, in which case the relationship between frequency and tension is equal to the magnitude of the harmonic wave N, so that fN=N, so f0.

The above measurements can also be carried out in air or in an immersion medium.

The oscillating device used is a loudspeaker suitable for the frequency range to be transmitted and placed near the middle of the vibrating thread at a distance from the thread that can vary between 91 or l and 20 cm. Preferably a speaker. The acting energy can be concentrated by incorporating an acoustic cone, a nozzle, and an electrodynamic pipe whose vibrating part is placed in contact with the product and forms the force at the end of the vibrating thread. You can also use breaks.

Although the advantage of the loudspeaker mentioned above is that there is no contact with the product and the vibrations are transmitted by air, there are nevertheless some small drawbacks due to the phase shift between the vibration of the loudspeaker and the movement of the product. This may occur under high tensions. Electrodynamic vibrators have the advantage of never causing a phase shift, but...
On the other hand, this vibrator creates a slight contact with the product, often creating a triangular interlock that engages the normal vibration mode when the product vibrates at a frequency very far from its resonance. This triangular interlock is disadvantageous for electronic servo operation. Such unique phenomena can be suppressed by adjusting the electronic filter.

In principle, the loudspeaker is a function of the nature of the product and its linear density (for fibrous products), as well as the constant tension of L, which is in the range of 10 g/tex in the case of spun yarns. It can be considered the most general excitation device for measurements. When using the device, the principles to be adapted concern the optical objectives and the adjustment of filters and gains, so that the one-dimensional servo technique can be established without problems for the resonance to be measured. When measuring tensions greater than the aforementioned limits, a phase shift occurs between the loudspeaker and the detector, which increases as the tension increases. If such a high tension causes a small fluctuation of about ±20% near 11, the phase shift iI will be approximately constant. Therefore, the normal operation of this device cannot be controlled. The phase shift in the opposite direction will be recovered.
: -1 is introduced into the servo loop.

High tension measurements thus require only one extra adjustment.
This can be implemented by the use of loudspeakers which do not require a wire, which is advantageous as the loudspeakers do not come into contact with the threads, as mentioned above. However, when dealing with high tensions, electrodynamic vibrators are preferred. In order to more easily understand the present invention, the following description will be made with reference to the drawings as examples.

Figure 1 shows two <H3,
4 shows a loudspeaker l placed near the middle of the vibrating thread forming the interlocking product between the two.

ft 52 shows an electrodynamic vibrator 5 in contact with the product 2, which vibrator is placed at one end 3 of the vibrating thread formed by the interlocking product 2 between the two points 3 and 4. .

Optical devices for remote detection of vibrations include, for example, helical cam/neon φ1.・
- An object that inverts a part of the light diffused, reflected or refracted by the product to a photodetector consisting of a phototransistor and its polarizer 'M, MA'. Preferably, the photodetector measures the intensity of the light reflected from the product. Lateral movements, the amplitude of which exceeds a few tens of degrees, modify the laser aiming of the product and thus the intensity of the light received by the photodetector, which is modulated at the frequency fo or fN. Identifies a signal that has a lot of strength. The lateral distribution of intensity in a cross section of a laser beam is crow-curve-like in character; as the product moves within a cross section, the irradiating liquid changes and the intensity received by the phototransistor changes. The size reflects the movement of the product. It must be emphasized that the frequency of the optical detector is the same as that of the exciter. The aiming of the laser should be adjusted so that the lateral movement of the thread scans one side of the crow characteristic distribution. This broadening of the distribution can be enhanced by incorporating a cylindrical lens between the radar products;
It may also be useful to hold the product in the beam when it floats laterally, for example during the manufacture of yarn, by a blower underneath the spindle, or because of poor winding stability on rollers or reels.Optics The distance between the target device and the product preferably varies within the range of 5 to 500 I11.The attached figure 3 shows the product 2, the laser 6, the movable lens 7 and the objective lens consisting entirely of a condenser lens. 8 and a phototransistor 9 are shown.

fir 4 Figure shows the transverse strength ■ force of the laser beam at a distance #H from the center point O.
It shows a curved distribution of fish.

In Figure 5, various laser irradiation conditions are shown, where O indicates the center point of the beam, P indicates the average position of the thread in this beam, and A is the amplitude of vibration of the product. ,
Therefore, FIG. 5a shows optimal irradiation conditions, FIG. 5b shows permissive conditions, and FIGS. 5c and 5d show non-permissive conditions.

The electronic search system which combines the two previously mentioned devices consists of a number of devices, and the principle of this 'electronic search' control of the device is illustrated in FIG.

An excitation device, such as a loud7 peaker l, has a gain stage i.

and 'LJj are supplied with energy by the low frequency generator 12 via the force amplification ill. The 11 o'clock signal generated by the detection device 13 is processed by a pair of adjustable high-pass and low-pass filters 14, whose function is as follows:
: The frequency range that includes the stationary wave number or its harmonics is selected. The signal SL sent to the excitation device l and the signal s2 are compared in a phase detector 15 which drives the generator 12 by means of a control voltage. The loop formed in this way automatically locks the phase match between the signal S1 and the signal S2 to the frequency that is desired. This frequency is the desired resonant frequency. This frequency? To avoid this, the blade 4 of the filter 14
h'+device f l 6 converted into pulse counter 1
σ for 7, this counter makes it possible to read the frequency measurement result by display and/or recording, and then the tension is determined by -',:t'!i or by a suitable calculator included in the circuit. For example, it is possible to use a frequency meter, a periodometer or a computer capable of performing such functions.In most cases, the gain control device 10 can be operated manually. It is sufficient to adjust the signal to a constant value that yields a signal of good quality.Then, when the amplitude of the signal of the detection device changes significantly, the gain stage lO is driven to maintain a signal of signal quality. To facilitate the adjustment of the optical aiming of the laser, the filter 14 and the gain device 10, the filter stage has two control outputs (before and after the fill operation) for display on the on-loss scope. signal).

The device can also be used to perform linear tolerance measurements on fibrous products such as spun yarns, in which a length of yarn is pulled by an applied force F (medium g). When the tension t (medium g/lex), Mll:po makes it possible to obtain its straight density from the relational expression t. That is, T (tex) = F (g) / t (
g/lex) Thus, two advantages are achieved, namely optical remote sensing using a laser which avoids obstruction of the air flow around e.g. It has been found that it is possible to measure the linear tension in such products thanks to a phase sensitive servo control (phase detection device) which makes it possible to obtain precision.

1) As mentioned in 1j, water devices can be used to measure tension during product manufacturing or conversion operations at any product speed.

[:), the following examples are illustrative of the present application, but are not intended to limit it.

It is necessary to measure the tension of the monofilament I yarn during production between the spinning 11-karat gold and the take-out roller.

Yarn under spinning conditions (hexamethylene adipamide) - straight ply at take-out roller! M￥F degrees = 1tex (product yarn 44/13) 1 roller speed 1,030 m/'min - spinning 1'' Distance between gold and roller 2.00 mA, 111
Foot condition one focus ll11! 211 with #80 open cylindrical lens
Ill helium/neon laser (distance between optics and thread: 30 cm) Loudspeaker with a diaphragm of diameter 20CI11 mounted on a protective panel without one cone nozzle Thread distance: 2 to 10
CDI) 41 The tension was set at 2.4±O, Ig/le. All under severe conditions that create turbulence in the F direction of the spinneret.
! However, this tension measurement method is nevertheless
I, in view of the consistency of its values, makes it possible to determine possible changes in the temperature or rheological behavior of the polymer.

This example concerns the measurement of the tension between the aforementioned take-off roller and oiling roller.

Spinning conditions - Polyethylene terephthalate yarn with a ply linear density of 4 dtex/ply - Distance between the take-out roller and the oiling roller 1 - 0.50 m, the oiling roller is placed between the take-out roller and the pull-out roller, Add 1 piece of oil to thread-1 and 7
Make it 1.

-IB! IHL roller speed: Et00 m/min - withdrawal roller speed: 2,500 m/min A+1 constant conditions 2 mW helium/neon φ laser A11 without cylindrical lens placed at a distance of 30 cm from the wire
A loudspeaker with a diameter of 20 cm without a cone nozzle placed at a distance of 1 to 5 cm from the thread to be manufactured has a value of 140 dtex/30 ply.

The measured tension up to ±2% is 4.6 g/tex at a withdrawal speed of 6.25 g/tex
6.75 g/tex at a withdrawal speed of 4.8
This example uses 280 dLex / 60 of polyethylene terephthalate between the supply roller and the interwoven jet I.
Concerning the measurement of ply yarns.

Speed of Ippu candy roller: 3,000 m/'min All
2 mW helium/neon laser without cylindrical lens placed at a distance of 30 cm from the constant system - 20 cm diameter loudspeaker without cone nozzle placed at a distance of 1 to 5 cm from the thread being measured. Al11 constant tension is 0.80 g/te++±2 at winding speed of interwoven yarn of 2,900 m7min
%Met.

Actual Difference A In order to be able to characterize the behavior of polyethylene terephthalate yarns in dynamometric measurements, a pair of rollers, an overdrawing pair, is inserted into the raw Jr line after the drawing rollers. The speed of this pair is IT! It can be varied linearly with respect to r, thus giving a progressive additional elongation to the yarn. A linear dynamometric curve is obtained by recording the change in tension while the rollers of the over IS rowing pair are accelerated. This curve, shown in FIG.
The ceramic fin force is pulled out to precisely locate the node of one part of the vibrating thread and placed on the feed side of the 0-ra.

"lJa conditions are as shown in F. That is, the threading rate of the spun LI gold, % amount: 140 dtex / 40 g/min for 30 ply yarn, the speed of the drawing roller: 3.000
m 7 minutes.

Oats' - drawing phantom speed: 3,000 to 3,150 m/min, length of vibrating thread between ceramic fin force and electric pipe rake: 0.34 m, computer result: One point in Figure 7 is Speed: 1 point/corresponding to 1 count in 10 cycles
′ seconds.

L construction J.

The tension in a steel wire energized by brass of 0.385 g/m is 7 J in a winder winding the wire at a speed of 90 m/min.
IF, measured on the side.

A111 was determined using the device of the present invention, and its value was 1,8
Kg. 1 controlled by Rothschild tension 51
1", r, 1l11 The determined tension is 1.9 Kg, which is a comparable measurement result. However, in the case of contact type tension scrap 1, this value is J? rub against the measuring stage, and variations in the diameter of the brass-coated steel wire, whether large or small.

U-Example J The tension of four strands of brass-coated steel wire is 90n.
o, Measured on the 1-stream side of the winder winding the strands at a speed of 7 minutes. The measured tension was measured using the device of the invention at 7
Kg and Rothschild contacts! ! ! It was 8 kg using a mold tensiometer.

At a winding speed of 320 m/min, the instantaneous tension determined by the device according to the invention was 12.5 kg, compared to 12 kg for other contact-type devices, which have the drawbacks already mentioned regarding contact.

Sake 1 Tension is 17g/m at a winding speed of 90m/min
measured on a twisted cable. In the case of 1llll constant using the device of the present invention, the value is ]OXg and the stable state 7
ij'', but in the case of the contact type Harikaru 11 Koyoru Oki 1st, the value is unreliable due to twist, and 9 no Ji511
Kg (r), which shows the advantages of using the non-contact tensiometer of the present invention.

[Brief explanation of drawings]

1 is a schematic diagram showing a moving thread with its tension measured by an example of the method according to the invention; FIG. 2 is a similar diagram showing a modified method; and FIG. A schematic diagram showing a laser vibration detection device forming part of an embodiment, Figure 4 shows the distance from the center of vibration.
Figures 5a to 5d are graphs showing conditions for different types of laser irradiation; Figure 6 is an implementation of the device according to the invention; FIG. 7 is a block diagram illustrating an example, and a curve illustrating the relationship between a constant tension in the yarn and the circumferential speed of a pair of overdraw rollers according to Example 4. J... Loudspeaker, 2... Product, 3.4...
point. 5...Electric pie break, 6...Laser, 7...
- Movable lens, 8...Objective lens j, 9...Phototensistor, 10...Gain control l+ device, 11...
- Power amplifier, 12...Low frequency generator, 13...Detection device, 14...High pass filter and low pass filter,
15... Phase detector, 1B... Rectangular wave shaping device, 1
7...Pulse φ counter. Patent Applicant: Lawn-Bouland-Feubre Agent: Patent Attorney: Odajima

Claims (1)

[Claims] 1, i+1i41. A method for continuously measuring the tension in a product to be moved includes subjecting said moving product to transverse vibration between two fixed supports over a path of three predetermined lengths at t″+. , remotely detecting said vibrations by means of an optical system, and generating a signal 4 representing the detected vibrations.
It consists of a small servo sensor, which controls the device which exposes the product to transverse vibrations, and which sends the signal to a device which reads the signal and gives the tension value. A method characterized by: 2. The method according to claim 1, wherein the product iii is an Hk#-shaped product. 3. Claim 1 or f, characterized in that the optical system for detecting vibrations includes a laser. J
2. The method described in RL. 4. The optical detection device exposes the product to lateral vibration τ11
Claim 1J, characterized in that it provides an oscillation signal at the same frequency as the listening signal for driving the device described in claim 1.
j4. The method according to any one of paragraphs 2 and 3. 5. A device for continuously measuring the tension of a moving product, comprising two spaced apart supports for the moving product, the supports being separated by a predetermined distance;
an oscillating device for vibrating the product fed between the supports in a direction transverse to the direction of feeding; an optical system for remote detection of vibrations received from the optical system; and an electronic surfing device for controlling the oscillation device in response to a signal. 6. The device according to claim 5srt, wherein the optical system for detecting the vibration includes a laser. 7. The optical system provides an oscillation value at the same frequency as a signal for driving the device for exposing the product to transverse vibrations.
15. The device according to 14.