JP5741279B2 - Magnetic flux density measuring device in continuous casting mold - Google Patents

Description

  The present invention is a measurement for measuring the magnetic flux density applied to the inner space of the mold by an AC moving magnetic field generator or a DC static magnetic field generator installed on the back of the mold copper plate to control the molten steel flow in the continuous casting mold. Relates to the device.

  In continuous casting of slab slabs, an AC moving magnetic field generator and a DC static magnetic field generator are placed on the back of the mold copper plate, and an AC moving magnetic field and a DC static magnetic field are applied from this magnetic field generator to move the molten steel in the mold horizontally. The flow of molten steel in the mold is controlled by swirling and stirring the molten steel discharged from the immersion nozzle, etc., to promote the floating and separation of non-metallic inclusions and gas bubbles in the molten steel from the molten steel. ing. However, since the magnetic field generator is disposed on the back surface of the mold copper plate, the magnetic flux density applied to the mold inner space is attenuated by the mold, and the magnetic flux density in the mold inner space cannot be obtained only from the specifications of the magnetic field generator.

  Therefore, it is measured how much the magnetic flux density applied to the mold inner space is. Accurate measurement of the magnetic flux density distribution in the mold inner space is an important point in producing a clean slab with few non-metallic inclusions and gas bubbles. In particular, in an AC moving magnetic field, the magnetic field moves in the width direction of the mold, and the magnetic flux density also changes with the movement of the magnetic field. Therefore, a magnetic flux density measuring device that can measure the maximum magnetic flux density accurately and quickly. Is desired.

  As an apparatus for measuring the magnetic flux density in the test object such as the internal space of the continuous casting mold, Patent Document 1 discloses the following magnetic flux density measuring apparatus. That is, in an apparatus for measuring a magnetic flux distribution in a body under test comprising a solenoid coil, the apparatus comprises at least two or more sets of rotating coils arranged at equal intervals in the circumferential direction with respect to the rotating shaft, A drive coil that is inserted into the drive coil, a magnetic flux measuring element that is connected to the drive coil and that measures the magnetic flux in the device under test, and an energization for energizing a control current to the drive coil When the power supply and the magnetic flux distribution measurement position are determined, control means for controlling energization of the control current from the power supply for energization to the drive coil so as to drive the magnetic flux measurement element to the determined measurement position; A magnetic flux density measuring device comprising: a computing means for obtaining a magnetic flux distribution in the device under test based on a signal relating to a measurement position from the control means and a magnetic flux measurement signal from the magnetic flux measuring element. There has been disclosed.

JP-A-62-239072

  However, when the magnetic flux density measuring device disclosed in Patent Document 1 is used for measuring the magnetic flux density of an AC moving magnetic field in a continuous casting mold, there are the following problems.

  Since the measuring device disclosed in Patent Document 1 is a device for obtaining a magnetic flux distribution in the device under test in which the solenoid has a uniform magnetic flux density, the moving speed of the measuring device can be adjusted by adjusting the control current. The maximum magnetic flux density at each magnetic flux distribution measurement position can be measured. However, with a magnetic flux density that changes with time, such as an alternating-current moving magnetic field in the mold, even if the control current is adjusted, the moving speed of the measuring device does not become constant due to the change in the magnetic flux density. Time is required and measurement time becomes long. Further, since the maximum value of the magnetic flux density varies depending on the magnetic flux measurement position, it is necessary to perform measurement at many measurement points in order to accurately grasp the position where the magnetic flux density is maximized and the position where the magnetic flux density is minimized.

  Separately from this method, the magnetic flux measuring element is fixed and measured at a certain measurement position without moving, and when the measurement is completed, the magnetic flux measuring element is moved to another measuring position and fixed there. There is also a method of measuring the magnetic flux density distribution by measuring and repeating this, but the measurement position is fixed, and the measurement position is not necessarily the maximum position or the minimum position of the magnetic flux density. Alternatively, the minimum value is not always accurately measured.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to be applied to the inner space of the mold from an AC moving magnetic field generator or a DC static magnetic field generator disposed on the back of the mold of a slab continuous casting machine. Provides a magnetic flux density measuring device in a continuous casting mold that can accurately measure the magnetic flux density of alternating-current moving magnetic fields and DC static magnetic fields that change over time in a short time and the maximum and minimum values of magnetic flux density. It is to be.

The gist of the present invention for solving the above problems is as follows.
(1) Measure the magnetic flux density of the AC moving magnetic field and / or DC static magnetic field applied to the inner space of the mold from the AC moving magnetic field generator and / or DC static magnetic field generator installed on the back of the mold of the slab continuous casting machine. A magnetic flux density measuring device, a magnetic flux measuring element for measuring magnetic flux density, a guide for holding the magnetic flux measuring element, a long side of a mold by manual operation while holding the guide and holding the guide A magnetic flux density measuring device in a continuous casting mold, comprising: a movable gantry capable of moving in a direction; and a fixed gantry for supporting the movable gantry.
(2) The continuous casting according to (1) above, wherein the guide can be arbitrarily set in the mold short side direction and the mold depth direction with respect to the movable frame. Magnetic flux density measuring device in the mold for use.

  According to the present invention, since the moving gantry holding the magnetic flux measuring element is moved manually, the influence of the driving current on the magnetic flux density when the moving gantry is driven using an electric motor or the like does not occur. The original strength can be measured, and the magnetic flux density can be measured by reciprocating the magnetic flux measuring element in the mold long side direction of the mold internal space by manual operation. Thus, even with an AC moving magnetic field that changes over time, the maximum value of the magnetic flux density and the position where the magnetic flux density reaches the maximum value are accurately measured by following the envelope of the maximum value of each measurement position. be able to. As a result, the measurement time of the magnetic flux density can be greatly shortened as compared with the conventional case.

It is the schematic which shows the structure of the magnetic flux density measuring apparatus which concerns on this invention. It is a figure which shows the condition which is measuring the magnetic flux density of the alternating current moving magnetic field applied to mold internal space using the magnetic flux density measuring apparatus which concerns on this invention. It is a figure which shows an example of the measurement result of the magnetic flux density in a mold width direction.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic view showing a configuration of a magnetic flux density measuring apparatus according to the present invention.

  In FIG. 1, a magnetic flux measuring element 2 for measuring the magnetic flux density of an AC moving magnetic field in a mold inner space is fixedly held at a lower end portion of a guide 3 facing in a substantially vertical direction. It is held by the movable gantry 4 facing the direction. A plurality of wheels 7 are respectively provided at both ends of the movable gantry 4, and these wheels 7 are on a fixed gantry 5 arranged in the horizontal direction. The fixed gantry 5 is a frame-shaped gantry having a rectangular space in the planar shape similar to the shape of the mold inner space of the slab continuous casting machine, and the wheels 7 are on the long side gantry of the fixed gantry 5. The long side of the rectangular fixed base 5 corresponds to the width direction of the mold internal space, and the short side of the fixed base 5 corresponds to the thickness direction of the mold internal space. A handle 6 is installed on the movable gantry 4, and by rotating the handle 6 by manual operation, the rotational movement of the handle 6 is transmitted to the wheel 7 by a transmission mechanism (not shown) such as a chain or a gear. The moving gantry 4 is configured to travel on the fixed gantry 5 as the wheels 7 rotate.

  The guide 3 can be arbitrarily set to the mounting position with respect to the movable frame 4. That is, by this, the installation position of the magnetic flux measuring element 2 can be set to an arbitrary position within the range surrounded by the frame of the fixed mount 5, in other words, in the mold inner space, the mold short side direction and the mold It can be set at an arbitrary position in the depth direction. For example, the holder 4a for holding the guide 3 via a bolt or the like is provided on the movable base 4, the guide 3 is attached to the holder 4a at an arbitrary height, and the slit 4b is provided in the longitudinal direction of the movable base 4. It can be realized by providing and moving the guide 3 inside the slit 4b.

  Further, a position detector 8 for measuring the position of the movable gantry 4 on the fixed gantry 5 is provided, and the measurement data of the position detector 8 is input to the position data processing device 10 and processed data ( Position data) is input to the storage device 11. On the other hand, measurement data of the magnetic flux measuring element 2 is input to the magnetic flux density calculator 9, and processing data (magnetic flux density value) by the magnetic flux density calculator 9 is input to the storage device 11. The storage device 11 uses the data input from the magnetic flux density calculator 9 and the position data processing device 10 to obtain a three-dimensional width direction, a thickness direction, and a depth direction within a range surrounded by a rectangular frame of the fixed base 5. The magnetic flux density for each position is stored and output. The magnetic flux density measuring apparatus 1 according to the present invention is configured in this way.

  FIG. 2 is a diagram showing a situation in which the magnetic flux density of the AC moving magnetic field applied from the AC moving magnetic field generator to the mold inner space is measured using the magnetic flux density measuring apparatus 1 according to the present invention. 1, the magnetic flux measuring element 2 is disposed in the mold inner space surrounded by the pair of opposed mold long sides 12, and the opposing AC moving magnetic field generator 13 is disposed on the back surface of the mold long side 12. In FIG. 2, the mold short side is not shown, but the mold short side is arranged in a state of being sandwiched between the opposed mold long sides 12.

  When measuring the magnetic flux density of the AC moving magnetic field applied from the AC moving magnetic field generator 13 to the inner space of the mold, the position of the magnetic flux measuring element 2 in the mold short side direction and the position in the mold depth direction are adjusted to predetermined positions, In this state, the handle 6 is manually rotated, and the magnetic flux density is continuously measured by the magnetic flux measuring element 2 while the movable frame 4 is repeatedly reciprocated in the length direction of the mold long side 12. Since the flow of molten steel in the mold is affected by the maximum value of the magnetic flux density, measure the maximum value of the magnetic flux density at each position in the width direction, thickness direction, and depth direction of the mold internal space. To do.

  FIG. 3 shows an example of the measurement result of the magnetic flux density in the mold width direction. This measured value is obtained from the AC moving magnetic field generator composed of a total of four magnetic field generators separated into two in the mold width direction with the central portion of the mold long side 12 (position of the immersion nozzle) as a boundary. This is a result of measuring the magnetic flux density of the alternating-current moving magnetic field applied to, while repeatedly moving the moving gantry 4, that is, the magnetic flux measuring element 2, in the length direction of the mold long side 12.

  As shown in FIG. 3, in the present invention, instead of measuring the maximum value of the magnetic flux density at each measurement position, the instantaneous value of the magnetic flux density is obtained by continuously measuring while moving, and the length of the mold long side 12 is By measuring the number of reciprocations in the direction, that is, the mold width direction, the distribution and the maximum value of the magnetic flux density in the mold width direction are obtained. That is, as shown in FIG. 3, it is possible to obtain the distribution and maximum value of the magnetic flux density in the mold width direction by following the envelope of the maximum value.

  By the way, by measuring the magnetic flux density of the AC moving magnetic field using the magnetic flux density measuring apparatus 1 of the present invention, it has been spent about 2 hours for measuring 100 points in the past, but it can be completed in about 5 minutes. It has become. Moreover, the magnetic flux density measuring apparatus 1 of the present invention is not limited to the apparatus that measures the magnetic flux density of the AC moving magnetic field, and can also measure a DC static magnetic field or a magnetic flux density in which the AC moving magnetic field and the DC static magnetic field are superimposed.

  As described above, according to the present invention, the moving gantry 4 holding the magnetic flux measuring element 2 is moved manually, so that the magnetic flux density due to the drive current when the moving gantry 4 is driven using an electric motor or the like. The magnetic flux density can be measured with no influence, and the magnetic flux density can be measured while moving the magnetic flux measuring element 2 repeatedly in the mold long side direction of the mold internal space by manual operation. By measuring in this way, the maximum value of the magnetic flux density and the magnetic flux density can be obtained by following the envelope of the maximum value at each measurement position, even with an alternating-current moving magnetic field that varies with time. The position where the maximum value can be measured accurately.

DESCRIPTION OF SYMBOLS 1 Magnetic flux density measuring apparatus 2 Magnetic flux measuring element 3 Guide 4 Moving mount 4a Holder 4b Slit 5 Fixed mount 6 Handle 7 Wheel 8 Position detector 9 Magnetic flux density calculator 10 Position data processing apparatus 11 Storage apparatus 12 Mold long side 13 AC moving magnetic field Generator

Claims (2)

Magnetic flux density measurement to measure the magnetic flux density of the AC moving magnetic field and / or DC static magnetic field applied to the mold internal space from the AC moving magnetic field generator and / or DC static magnetic field generator installed on the back of the mold of the slab continuous casting machine A device,
A magnetic flux measuring element for measuring the magnetic flux density, a guide for holding the magnetic flux measuring element, and a movement capable of moving in the mold long side direction by manual operation while holding the guide and holding the guide a frame, a fixed frame for supporting the moving platform, was closed,
The magnetic flux density is continuously measured while the magnetic flux measuring element moves in the mold long side direction, and the instantaneous value of the magnetic flux density continuously measured by a plurality of reciprocations of the magnetic flux measuring element in the mold long side direction. A magnetic flux density measuring device in a continuous casting mold, characterized in that the distribution and the maximum value of the magnetic flux density in the mold width direction are obtained based on the maximum value envelope in FIG .   2. The continuous casting mold according to claim 1, wherein the guide can be arbitrarily set to a mounting position in a mold short side direction and a mold depth direction with respect to the movable frame. Magnetic flux density measuring device.

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