SU124145A2 - Device for automatic leveling terrain - Google Patents

Description

The known devices for controlling the quality of welded joints, based on the principle of magnetic scattering, occurring at the location of the defect during the magnetization of the contracted head, using a single inductive sensor with a magnetic system at two cores, do not eliminate the vibration of local deflections of the monitored steel stripes and therefore cannot be rationally used on mills of cold r | rokatka to detect a stitched (welded overlap) seam.

The described device, equipped with two sensors located on both sides of the monitored band, eliminates this drawback.

FIG. 1 shows a sensor circuit, FIG. 2 is a diagram of the first embodiment of the control of a welded overlap weld using two sensors; FIG. 3-scheme of the second option and fng. 4-scheme of the third option.

The main part of the described device is a magnetic sensor / consisting of a closed double-core core 2. On each core of core 2 there are coils of alternating current 3, the flow of which is closed along the core. On top of both AC coils is a DC coil 4, shorted through the air and creating a dissipation flow.

The principle of the sensor is based on the change in the flow jjaccented by the DC coil 4 depending on the thickness of the metal and the distance between the sensor and the steel strip. The cross section of the core 2 of the sensor / should be large enough to create such a scattering flow, which is under control No. 124144

The steel strip 5 would be close to saturation and its magnetic flux resistance would be commensurate with the air resistance, and 2 sensors / would be saturated.

With the passage of strip 5 twice the toli; iny (shchakh overlapped) in the zone of the sensor} the resistance to flow dissipation drops sharply. The core 2 of the sensor / is additionally magnetised by increasing the flux; the induction resistance of the coils 3 AC current drops, and the current in the sensor circuit / increases. The resulting pulse is applied to the stand roll control circuit and the rolls are diluted.

In order to avoid 1 vibration, or the vibration of the monitored band 5, on the sensor readings /, two sensors / are installed, one against the other (Fig. 2). One sensor J is installed above the strip 5, and the other under it. When sensors are located, the readings are summed. The total signal from the two sensors will be constant and independent from the vibrations of band 5 or its local deflections.

The control of the steel strip 5 can be carried out with the help of the described device and in accordance with another scheme (shown in Fig. 3). It is based on the shielding by the steel ferromagnetic strip 5 of a constant magnetic field created by the electromagnet 6 of a direct current. In this case, at the top and bottom of the strip 5 is installed one sensor 7 and one electromagnet 6 of direct current.

Sensors 7 and / consist of a closed double-core core 2. On each core core, the alternating-current coil of 3 alternating-current currents created by it is closed, which is closed along the core. Direct current coil 4 is missing.

When a steel ferromagnetic strip 5 of double thickness (pulley overlap) passes between the sensor 7 and the electromagnet 6. The field of the stationary electromagnet is shielded more, the note penetrating the sensor core decreases, the inductive resistance of the alternating current coils increases and the current in the sensor 7 circuit decreases. The resulting pulse is fed to the roll dilution control circuit and the rolls are diluted. And in this case, the total current from the two sensors 7 will be constant, regardless of the vibration of the band in the gap between the sensors 7 and electromagnets 6.

The control of steel hollow can also be carried out in the third scheme (shown in Fig. 4). It is based on a change in the magnetic state of the ferromagnetic core of the sensors 7, depending on the magnetic flux created by the steel strip 5 passing through the gap between the sensors 7, previously magnetized using an electromagnet 6.

This scheme is unsuitable for detecting the ditch of a steel strip, since its residual induction is very small or absent.

The described device eliminates the influence of vibration and local deflection of the controlled hollow on the total readings of the sensors.

Subject invention

Electromagnetic control device of steel sheet material on continuous cold rolling mills, made in the form of induction sensors, amplifiers and feeding devices, different in that, in order to avoid the influence of vibrations and local deflections of the controlled steel strip, two sensors are used that are installed on both sides of the edges strips one against the other.

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FIG. /