SU1760402A1 - Device for determining tension strength of moving thread - Google Patents

Abstract

Use: to determine the strength characteristics of moving textile yarns. SUMMARY OF THE INVENTION: In a device comprising a supply and output drive pairs of rollers, the drive roller is mounted freely on the drive shaft and is kinematically connected with it by means of a flat spring fixed at one end to the shaft. The forces arising in the filament are recorded using strain gauges mounted on a flat spring. The device makes it possible to reveal the weak parts of the thread, which is cut off by the action of tension, if the strain is greater than the specified deformation or if the tensile force exceeds the breaking load of the thread between two pairs of rollers, 1 sludge.

Description

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The invention relates to the textile industry, in particular to devices for testing moving long textile material: yarns, yarn and their semi-finished products.

A device for measuring the breaking force of a continuously moving long-length textile material is known, comprising a feed roller pair, an outlet roller pair and a tensile force sensor mounted on one of the elements of the feed roller pair or by means of a hoop roller with measurement elements located between the roller pairs (patent West Germany 857696, class 42 K 50, 1959).

A disadvantage of the known implementation lies in the insufficient accuracy of measuring the force of rupture of a moving long textile material due to measurement errors related to

both with the use of sensors that are in direct contact with a textile material (one of the rollers, a feed pair or a contact roller), and with the area itself recording the breaking forces when pulling a textile material located in the feed pair of rollers or between roller pairs. In this measurement, no recordings are made of the forces associated with the distribution of elastic elastic deformation of the fibrous material for the following reasons:

the redistribution of the elastic-elastic characteristics of the moving yarn in the working area between the roller clamps,

due to the considerable mass and inertia of the pressure and recording parts of the device, the air gap and the moving thread in the feed roller pair are deformed,

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during the force measurement process, the working length of the yarn in the stretching zone changes.

The purpose of the invention is to improve the measurement accuracy.

To do this, in a device for determining the resistance of moving yarns to stretching containing one pair of feed rollers mounted one above the other, a pair of output rollers, one of which is mounted on the drive shaft, and a force sensor according to the invention, the drive roller is mounted on the drive shaft freely and kinematically connected with it, while the kinematic connection is made in the form of a flat spring fixed to the drive shaft with one end, and the sensitive element of the force sensor is made in the form of resistance strain gages fixed ennyh flat spring.

The drawing shows the proposed device.

The device contains a roller feed pair 1, an output roller pair 2, the drive roller 3 of which is mounted on the drive shaft 4 freely by means of a bearing 5 and kinematically connected with it by a flat spring 6, the height meter is made in the form of strain gages 7 fixed on the spring 6.

The device works as follows.

Moving between the feed and input pair of rollers, the speed difference of which is smoothly controlled by the drive speed control unit, the thread in the zone between the roller pairs is subjected to elongation. The replaceable driving drive roller 3 is driven by the interaction of a spring rigidly connected to the drive shaft with a triangular prism 8 located at the end of the roller 3. The tensile force acting in the area between the clamps of two roller pairs 1 and 2 on the moving thread causes the corresponding deformation of the thread. The deformation arising in the thread causes a force to resist stretching. During operation of the device, the flat spring 6, which transmits motion through the triangular prism 8 to the drive roller 3, overcomes the bending moment from the action of the tensile strength of the thread. This moment with the help of a triangular prism 8, rigidly fixed on the side surface of the roller, causes the spring 6 to bend. At the moment when the accumulated deformation of the thread exceeds the breaking, the thread breaks. The deformation of the beam causes a change in the electrical signal from the strain gages 7, which allows the forces arising to be converted into an electrical signal. Then, the signal, proportional to the force acting on it, enters the amplification and scaling unit 9, where the signal is applied to a standard value at maximum load and the gain is scaled. Next, the signal enters the block 10 analog-to-digital Converter, where

converted to digital form and fed to computer processing. From the ADC block, the signal enters the current and maximum value indication blocks 11.

The proposed device makes it possible to determine in the same yarn weak points that are associated not only with the breaking load, but also with the elongation. The process of deformation of a moving thread is characterized by a constant redistribution of deformation on

incoming sections of thread.

The thread breakage in the proposed device occurs when a weak spot is detected by at least one of the two factors that weaken the thread:

the incoming element of the thread is not able to withstand the strain accumulated in the loading zone,

breaking load less tensile force.

Since the tensile force sensor is mounted on the outlet roller pair, it is connected with the kinematic coupling of the roller with the drive shaft, this device used to determine the discontinuous

characteristics of a textile material according to the moving thread method, makes it possible to impart to a large sample size a more random character of weakness, at least by one factor, the magnitude of the measurement

can vary in any range (so the sensor deviation is from 0 to 360 ° C). All this affects the reduction of the significance of correlation and its effect on the indicators of discontinuous characteristics and increases the reliability of the obtained characteristics of the physicomechanical properties.

When testing a moving fabric, thread or their semi-finished products with the proposed device, the combination of stronger and less durable places constantly varies and is random, therefore between the correlation coefficients h (r. Ep,), H (P, g) there is a direct algebraic connection and

5 correlation values are lower. Thus, the proposed device allows the selection of weak points by one of their characteristics, weakened by the indicator of breaking load or by elongation.

Claims (1)

Invention Formula A device for determining the resistance of the moving yarns to stretching, comprising a pair of feed rollers mounted one above the other, a pair of output rollers, one of which is mounted on the drive shaft, and a force sensor, characterized in that Test results table 2 @ h 0 increase the accuracy of measurement results, the drive roller is mounted on the drive shaft freely and kinematically connected with it, while the kinematic connection is made in the form of a flat spring fixed to the drive shaft with one end, and the sensing element of the force sensor is made in the form of strain gages mounted on a flat spring. hmm