SU1471093A1 - Apparatus for measuring strain in web material - Google Patents

Abstract

The invention relates to instruments for monitoring the technological parameters of production processes in the light and textile industries, namely for controlling the tension of the roll materials. The purpose of the invention is to reduce the measurement error. The converter is equipped with a screen-magnetic core, the base element is made elastic, the elastic and base elements have a U-shaped cross section, the two-section differential inductance coil is located in the space formed by the elastic and base elements and is placed in the screen magnetic core mounted on the elastic element, and the core is mounted on the base element, the elastic and base elements being made of a soft magnetic material, and the scaling converter is equipped with an integrating PC-chain. The screen-magnetic core has a cup-like shape with two flat cuts made symmetrically about the axis, the height of which is equal to the internal height of the face of the elastic element, and the distance between the planes of the cut-outs is equal to the internal width of the elastic element. 1 hp ff, 5 ill.

Description

CD OE

The invention relates to instruments for monitoring technological parameters of industrial processes in light and textile industry, namely for controlling the tension of coiled materials.

The aim of the invention is to reduce the measurement error.

FIG. 1 shows the proposed device, side view; in fig. 2 the same, front view; in fig. 3 - section A-A in FIG. 1 (means for indicating reciprocal movement); in fig. 4 - inductance coil placed in a shield-magnetic circuit; in fig. 5 t converter circuit.

A device for measuring the tension of a web material contains a base element 1, on which, by means of a fastening element 2, a console

but an elastic element 3 is fixed. A support bracket 4 is fixed on the base element 1, at the ends of which are on different sides. Rotating support rollers 5 are mounted from the base element 1. On the elastic element 3 there is also a rotating support roller 6. The basic 1 and elastic 3 elements are made made of a magnet of a soft material, have a U-shaped cross section and are installed in such a way that in the space between them there is a two-section differential inductance coil 7 placed in a shield-magnetic conductor 8. The magnetically conductive shield 8 has a bowl znuyu shape (FIG. 4) Two cutout formed symmetrically about the axis, have dimensions due sectional dimensions of the elastic member 3; the height h of the tips is equal to the internal height of the face of the elastic element 3, and the distance between them S is equal to the internal width of the elastic epemet,

Compliance with these relations allows an increase in the diameter of the inductor 7 and, consequently, the number of turns on it, which leads to a higher sensitivity of the device.

The core 9 of the inductor 7 is mounted on the base element and mounted on an adjusting screw 10 mounted in a threaded bushing of the adjusting screw 11 mounted on the base element 1. A compression spring 12 is placed between the core 9 and the sleeve 11, which eliminates backlash. the core 9, the tool for kabravki contains a micrometer screw 13 having a handle 14 and a nonius 15. The micrometer screw 13 is installed in a threaded sleeve 16 attached to the elastic element 3 coaxially with the core 9. For convenience, the device is equipped with a handle 17 fixed in place of the console the connection of the elastic 3 and the base 1 elements of the two-section differential inductor 7 is connected to the converter via a cable 18 and a connector -19,

The converter (Fig. 5) contains a phase-sensitive detector (PD) made in an annular circuit on semiconductor diodes D, a dial gauge

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(i) of a magnetoelectric system, connected to a phase-sensitive detector, a sinusoidal voltage generator (g), loaded onto a separation transformer (Tr), as well as a set of capacitors C - C „and a constant time switch connected in parallel to the measuring device AND.

The device works as follows.

Holding the device by the handle 17, it is positioned with respect to the tensioned material 20, as shown in FIG. 2

The tension of the material 20 tends to push the support rollers 5 and 6, causing the base 1 and the elastic 3 elements to move each other, and this also causes the core 9 to move relative to the differential inductance coil 7, resulting in a change in the inductance of the coil 7 windings, which is recorded Converter, which works as follows.

The alternating voltage of the audio frequency from the generator G through the separation transformer Tp is supplied to the primary winding of the differential-transformer displacement transducer DT. DT secondary winding is made of two identical sections included in opposite. When the core 9 is displaced relative to the two-section differential inductance coil 7, the voltage in one winding section increases and decreases in the other, so that the amplitude of the resulting voltage at the DT output is a linear function of the core 9 moving, and when the latter passes through the middle position, the amplitude of the fundamental harmonic decreases to zero, and the phase changes to 180. The output signal of the DT is applied to the signal input of the phase-sensitive PD detector, in which diodes DJ | - D operate in the mode of controlled keys whose. The control voltage is supplied to the circuit from the third winding of the isolation transformer Tr. As a load, an analog measuring instrument AND a magnetoelectric system, recording the average value of the current complex, is used; forms. Averaging readings is performed.

bones C, connecting C ..

The resistance of the measuring device and capacitance C, - C form an integrating RC circuit. In order to effectively suppress the effect of pulsation of the web tension, the time constant of this chain exceeds the period of the main harmonic of the tension variation.

The adjustment of the device is made by rotating the adjusting screw 10. In this case, the core 9 is moved inside the coil 7 of the inductance.

To calibrate the device, the micrometer screw 13 is brought into contact with the end surface of the core 9 and, on the vernier scale, determines the position of the core, which is unambiguously related to the tension of the roll-on material 20.

The elastic 3 and the base 1 elements are made of a magnet of a soft material, thus being an additional magnetic core for the coil

inductance. The elastic element 3, in addition, is directly an element of the screen-magnetic conductor 8. The implementation of these elements having a U-shaped cross section in combination with the use of a magnetically soft material makes it possible to shield the inductance coil 7, which protects it from external influences and allows to reduce the measurement error.

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Claims (2)

1. DEVICE FOR MEASURING TENSION OF ROLL MATERIAL, comprising a base element with two support rollers mounted on it, mounted for rotation, an elastic element cantileverly mounted on the base element, with a support roller mounted on it and a sensor for mutual movement of the base and elastic elements, comprising a two-section differential inductor, a core and a scaling converter, characterized in that, in order to reduce the error, it is equipped with a screen m, and the basic element is made elastic, the elastic and basic elements have a Π-shaped cross section, the two-section differential inductor is located in the space formed by the elastic and basic elements, and is placed in the magnetic shield screen mounted on the elastic element, and the core is mounted on the basic element moreover, the elastic and basic elements are made of soft magnetic material, and the scaling transducer is equipped with an integrating RC-chain. ® 2. The device pop. 1, characterized in that the magnetic conductor has a cup-shaped shape with two flat cutouts ’made symmetrically about an axis, the height of which is equal to the internal height of the face of the elastic element, and the distance between the planes of the cuts is equal to the internal width of the elastic element. SU „„ 1471093