SU1590153A1 - Apparatus for determining position of weld - Google Patents

Abstract

The invention relates to metallurgy and can be used in automated control systems for sheet rolling production. The purpose of the invention is to increase the reliability of determining the position of a weld by improving noise immunity. The device circuitry uses an armored-type sensor with a magnetizing coil and two measuring sensors placed at the ends of the outer magnetic circuit in diameter. The outputs of each coil through the amplifier and detector are connected respectively to the direct and inverting inputs of the adder. The output of the adder through the detector is connected to the input of the multiplying unit. The signal from the current sensor included in the magnetizing coil circuit is supplied to the other input of the latter. The device allows you to automatically change the setting mode of the mill when the weld passes through the cells 4 or more.

Description

The invention relates to metallurgy, namely, sheet-rolling production, and can be used in automated process control systems for monitoring strip and strip products.

The purpose of the invention is to increase the reliability of determining the position of the weld seam by improving the noise immunity.

Figure 1 shows the sensor of the proposed device, the cut; in figure 2 and. 3 - output signal diagrams; device at- (determining the overlap weld, respectively; FIG. 4 is a block diagram of the device.

The device contains an armored cylindrical magnetic circuit 1, per cent -. The magnetic rod of which is installed magnetizing coil 2. Under the external pole of the magnetic circuit are placed. two measuring coils 4 and 5, protected by a nonmagnetic krischka 3, mounted on the diametral axis and. included in the sequential, but counter. The internal cavity of the magnetic core 1 is filled with epoxy compound with quartz filler.

SL about:

The device works the next way. .

In a metal, a circular, radially directed magnet is excited, a flux F, according to the law of magnetostatics;

tcv F + V-i. (one)

where Zj, Zfif correspond to the com- petive magnetic resistances of the magnetic conductors, the air gap (P between the sensor and the countermeasure of the material;

I is magnetized. Force of coil 2. If the length of the magnetic force of the th line in sheet 1 and S is the cross section of the sheet through which the magnetic flux passes, then the magnetic resistance of the material being monitored depends on the thickness of the metal

l

| u

one

M SB

n

f / -h -b

(2)

h is the thickness of the metal;

b metal section width,

through which the stream passes.

As can be seen from formula (2), at constant values of 1, b, / and magnetic resistance Z depends on the thickness of the metal h.n Then the magnetic flux F penetrating the measuring coils, at constant Z and Z depends only on the thickness of the metal. The magnitude of the EMF induced by the magnetic flux in the measuring coils also depends only on the thickness of the metal, all other parameters being equal.

Fig. 2 shows a timing diagram of the output signal of the sensor as the welded weld passes under its poles.

Measuring coils 4 and 5 are conventionally labeled “and 5. In the absence of a weld, the thickness of the metal under coils a and S is the same, and it is obvious that the flows intersecting coils a and B are also the same due to the oncoming switching of the coils.

0 5

0 5

0

five

0 5

0

five

total signal j- in the absence of a seam is zero.

When the weld approaches the measuring coil, due to the increase in metal thickness, the resistance of the metal to the magnetic flux decreases, as a result of which the latter increases. Increasing the flow through the coil Of leads to a sharp increase in the signal taken from this coil. In this case, the signal removed from coil b remains the same, corresponding to the initial thickness of the sheet. The difference of the signals increases dramatically, which indicates the passage of the seam under the coils.

It can be seen from the diagram that after the passage of the seam, two opposite polarity signals Vj, -Vj- are formed at the output of the sensor. In order to obtain a single signal that fixes the passage of a seam, signals from coils o (and b are fed through two parallel channels / (Fig. 4) to amplifiers U1, U2, detectors D1, D2, after which the signals are subtracted on the adder. g is fed to a DZ detector, which passes a signal of only one polarity (Fig. 4). Thus, at the DZ output, a single signal is formed, the fixation of the weld (curve Ud

The sensitivity of the sensor to the change in the thickness of the metal is sufficiently high both at the overhead and at the butt joint (diagrams of the output signal for the butt weld are shown in FIG. 3).

A significant error in the sensor readings may introduce a change in the gap at the time of the seam passing under one of the measuring coils of the sensor. As can be seen from equation (1), all other things being equal, F depends on Z.

As the initial gap increases, the flow through coil 2 can be reduced to such a value that corresponds to the output signal of the sensor in the event that there is no seam. However, this error is eliminated by the fact that the device has a clearance node, which includes a current sensor that uses the current of the inductive sensor magnetizing coil. Since the magnetization reversal of the material is carried out by a radially directed circular magnetic field, the total magnetic permeability measured in different directions in the plane of the sheet remains unchanged for any quality of steel.

Consequently, the change in current in the magnetizing coil 2 is only a measure of the air gap a. As jo increases, the inductive resistance of the magnetizing coil decreases, which leads to an increase in current, and vice versa. In U-shaped inductive converters js zones of the heating chamber

channel current sensor and meter coils.

The signal from the device arrives at the rolling mill mill, which allows automatic change of the mode to the mill when the weld passes through the cages. In addition, the device can be used in the automated control system - the logical process of the decarburized oTKiira, which provides for changing pairs (strip transport speeds

An inductive gap meter (the same magnetizing coil) carries information not only about the size of the gap, but also about the magnetic properties of the metal, since the magnetic circuit of the inductive converter includes a section of the metal being monitored. Therefore, when monitoring electrical steels, the signal of U-shaped inductive gap meters with an unchanged air gap differs significantly depending on the property of the metal. The latter leads to false readings of the sensor. Therefore, the proposed form of the sensor's magnetic circuit makes it possible to solve the problem of detuning from the gap without using special gap meters.

The node of the detuning from the gap (figure 4) includes a DT current sensor and a multiplying device, one input of which receives a signal from the measuring coils 4 and 5 of the sensor, the other - a signal from the current sensor dependent on the gap between the sensor poles and stripe.

The node works as follows.

If the gap changes at those times when the seam under the sensor poles is missing, then the sensor signal V j Vg-V5 0, while the signal from the output of the multiplier ((() is also zero).

If the gap increased at the time of the seam passage, then the signal is significantly reduced (to the level of interference), however, the signal of the current sensor increases significantly. In this case, the product of the signals V (Vj, -V 5) also increases to the level of the signal corresponding to the presence of a seam at a correctly chosen current transfer coefficient for

etc.) upon receipt of a new smelting process with other passport data. At the same time, the signal coming from the device to the UVN at the time of the 20th passage of the inter alloy line 1 determines the change in the mode of metal processing.

Claims (1)

Formula invented 25 A device for determining the welding of the weld, containing a contactless inductive sensor in a magnetic circuit with a magnetizing 30 measuring coils, differing by the fact that, with the aim of increasing the reliability of determining the position of the seam at the research institute due to improved noise immunity, introducing two amplifiers, three detectors, a sump, a multiplier unit and a current coil current sensor, the proximity sensor of the inductive sensor is made in the form of an armored magnet, open-type wires, on the inner rod of which there is a magnetisation coil, and the measuring coils are dimensioned on the diameter but opposite sides of the end of the outer part of the magnetic circuit, and the output of the Toka sensor is to us Agnich coil circuit is connected to the first duplicating unit, the second in which through the first detector is connected to the accumulator output, to the non-rotating input of which the first amplifier and second detector are connected to the output of the first meter of the coil, and the third detector is connected to the inverter input of the adder through the second amplifier Leaving the measuring coil swarm. 35 40 45 50 55,   zones of the heating chamber channel current sensor and measuring coils. The signal from the device enters the ULVM of the rolling mill, which allows automatically changing the mill setting mode when the weld passes through the cages. In addition, the device can be used in the automated control system of the decarburization process of the oTKiira, which provides for changing parameters (strip transportation speeds, jo js heating chamber zones etc.) when a new heat is received for processing with other reference data. At the same time, the signal from the device to the UVN at the time of the 20th passage of the interflatting tunnel determines the change in the mode of metal processing. Invention Formula 25 A device for determining the position of the weld, containing a contactless inductive sensor in the form of a magnetic circuit with a magnetizing and 30 measuring coils, characterized in that, in order to increase the reliability, the research institute determines the weld position by improving noise immunity, two amplifiers, three detectors, an adder, a multiplier unit and a pre-coil current sensor are introduced in it, the proximity sensor is designed as an open-type armored magnetic core, on the inner core of which there is a magnetizing coil, and the measuring coils are dimensioned on diametrically opposite sides of the end of the outer part of the magnetic circuit, In this way, the output of the Toka sensor magnetizes the coil circuit to the first input of the multiplication unit, the second input of which is connected through the first detector to the output of the adder, to the non-inverting input of which through the first amplifier and the second detector the output of the first measuring coil is connected, and to the inverting input of the adder through the second amplifier and The third detector is connected. The output of the second measuring coil. 35 40 45 50 55, ut. i Weld seam 777/777 {approx ( l  & V rolling //// l: sh1sh. u VvyMvy..v / d / h 1 / UUL .. Iw2 (  & / Butt tuoS Rolling handling 14-v. , / / V / LA / Amplifiers & Integrators Editor I.Shmakova FIG. Compiled by V.Tkachenko Tehred L. Serdyukova Proofreader L. Patay Multiplier  -.