JPS60148645A - Oscillating device for continuous casting mold - Google Patents

Abstract

PURPOSE:To decrease oscillation marks by supporting elastically a casting mold with leaf springs having specific spring constants and providing revolution type exciters which apply very small rotational oscillations in two directions to the casting mold. CONSTITUTION:A casting mold 3 is supported by leaf springs having the spring constants at which the resonance points in the Z-axis direction, around the Z- axis, in the X-axis direction, around the X-axis and in the Y-axis direction with respect to the exciting oscillation W0 (the numger of revolutions of exciters 8a, 8b) of the mold 3 are substantially spaced from each other and the resonance points are approximate only around the Y-axis. The exciters 8a, 8b are then installed to the long side parts of the casting mold in such a way that the points of acting the respective exciting forces are shifted positionally with the center of the casting mold as a boundary. When the exciters 8a, 8b are rotated in the directions B, B' opposite from each other, the oscillation by the resonance around the Y-axis and the rotational oscillation around the X-axis are generated in the mold 3 so that the mold 3 and a billet 4 are finely oscillated relatively with each other. Oscillation marks are decreased by the above-mentioned method and the clean casting surface is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration device for a continuous casting mold, and more particularly, to a vibration device for a continuous casting mold that reduces oscillation marks and improves the casting surface in continuous casting equipment (1) that performs powder casting. Related to equipment.

Generally, in continuous casting equipment, oscillation marks that occur on the surface of the slab due to vibration of the mold are a problem, and if these marks become severe, they may cause surface defects on the slab.

That is, FIG. 1 is a layout diagram showing a part of a conventional continuous casting apparatus in cross section, in which molten metal 1a in a tundish 1 is poured into a mold 3 through a nozzle 2, and a slab 4 is poured into the mold 3 through a nozzle 2. is manufactured. At this time, the mold 3 is vertically vibrated as shown by the arrow A by the oscillation mechanism 5, and is constantly moving relative to the slab 4, thereby forming an oscillation mark. Further, the mold 3 is supported laterally by guide rollers 6 to prevent vibration in directions other than the vibration direction.

In order to prevent oscillation marks in this way,
It is known that increasing the vibration frequency and decreasing the vibration amplitude is effective, but the mechanical vibration method shown in Figure 1 has a limit of several hundred (2) cycles. Furthermore, in order to increase the vibration frequency, it is effective to elastically support the mold and then attach a halo vibrator directly to the mold.

Furthermore, with regard to the inflow of powder, it is effective to apply vertical and horizontal vibrations at the same time.

The present invention aims to solve the above-mentioned drawbacks, and specifically proposes a vibration device that properly elastically supports a mold and applies minute rotational vibrations in two directions to the mold.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Note that FIG. 2 is a layout diagram of continuous casting equipment equipped with a vibration device according to one embodiment of the present invention.

First, in FIG. 2, as in the continuous casting equipment shown in FIG. 1, numeral 1 indicates a tundish, 2 an immersion nozzle, 3 a mold, and 4 a slab. Molten metal is poured into a mold 3, and a slab 4 is cast.

Centrifugal type vibrators 8a with equal excitation force are provided on both sides of the mold 3,
8b is attached, and each vibrator 8a, 8b is
) is rotated in the opposite direction as shown by arrows B and B'. Also,
The mold 3 is elastically supported by a leaf spring 9, which is supported by a fixed frame 10.

As described above, a rotary vibrator is attached to each of the opposing outer wall surfaces of the elastically supported slab 3. At this time, the leaf spring 9 that supports the mold 3 has the following spring constant. Each of the vibrators 8a, 81) is configured to apply minute rotational vibrations to the mold 3 in two directions, for example around the X-axis and the Y-axis.

That is, when the mold 3 is supported by the leaf spring 9, the mold 3 has six degrees of freedom in total. To give rotational vibration in two directions among these degrees of freedom, for example, around the Y-axis and around the X-axis in FIG.
is supported by a plate spring 9 having an appropriate spring constant, and a pair of vibrators 8a, 81] are attached to the mold 3 as follows.

To explain in more detail, with respect to the excitation frequency Wo of the mold 3 (the rotational speed of the vibrators 8a, 81), there are 4) The resonance points of are sufficiently far apart, and the resonance points around the Y axis are W
A leaf spring is selected so that the vibration frequency is close to O, for example, 1.3 to 1.5 times WO, and J: supports the mold. In addition, in order to stably hold the mold 3,
In a static state, especially in the horizontal direction (X-axis direction)
is strengthened, and the leaf spring 9 is installed at a position that sandwich the center of gravity G of the mold 3 (see FIG. 2) and the vibrators 8a, 81) above and below.

Furthermore, the excitation force of the left and right vibrators 8a and 8b is adjusted so that the amplitude of rotational vibration around the X-axis becomes a predetermined value.

In this case, adjustment can be made in any manner, but it can also be achieved by shifting the phase of the unbalanced masses on both sides of the vibrator and shifting the point of application of the excitation force from the center of gravity G of the mold 3. Alternatively, this can also be achieved by appropriately shifting the mounting position of the vibrator.

For example, FIG. 4 shows the long sides of the mold, and if the vibrators 8a and 8b are attached to the long sides on both sides of the mold, one of the vibrators 8a is attached to one of the long sides. When the center of the surface is shifted by a distance of 5 (5), an excitation force is applied to 10a, and on the other long side, the distance is S.
The excitation force of the other vibrator 81) is applied to. When installed (pull) in this way, rotational force is generated around the X axis.

Next, when actually configuring the vibration device according to the present invention as shown in FIG. 2, when the vibration frequency Wo of the vibrator is 60)1z, using a leaf spring with an appropriate spring constant, Vibrator 8a
, 8b are adjusted and installed.This example will be explained as follows.

A total of eight plate springs 9 are attached to the side surface of the mold 3 as shown in FIG. The set positions of the left and right sides were shifted in opposite directions by 30 mm from the center of the mold in a direction perpendicular to the plane of the paper.

In this state, when an excitation force is applied by the centrifugal vibrators 8a, 81], the motion of the mold 3 is caused by the vibrations around the Y-axis dominated by the resonance point around the Y-axis and the rotational moment around the X-axis. Rotational vibration around the axis was generated, and a horizontal amplitude of ±0.1 mm was obtained at the upper end of the mold in both the X and Y directions.

The vibration amplitude can be easily adjusted by (7) adjustment of the unbalanced mass of the vibrator, the vibration exciter mounting position (or the unbalanced mass phase on both sides of the vibrator), and the casting speed and steel type. etc., can be selected arbitrarily.

As described above, by supporting the mold with a leaf spring and appropriately selecting the mounting position and shape of this leaf spring, the mold 3 can be
It is possible to have a mouth that gives a slight rotational vibration in the direction, and
There is no need to add electrical or mechanical tuning mechanisms to the exciter.

When such a mechanism is used to apply slight rotational vibrations to the mold in two directions, the mold and slab are always aligned vertically and horizontally over the entire surface.
This causes relative slight vibration in the direction, which is extremely effective in preventing seizure between the mold and the slab, and the oscillation marks are smaller than normal oscillation, resulting in an extremely clean casting surface. .

The vibration conditions can be easily changed by adjusting the excitation force of the vibrator, adjusting the set position, changing the frequency, and installing a leaf spring that matches the vibration conditions.

(8) Furthermore, in the above example, the resonance points in four directions are passed by the predetermined number of rotations, but the effect on the vibration system is slight because the excitation force at the time of passing is small and the passage is instantaneous.

[Brief explanation of the drawing]

Fig. 1 is a layout diagram of a conventional continuous casting equipment, Fig. 2 is a layout diagram of a continuous casting equipment having a vibration device according to an embodiment of the present invention, and Fig. 3 is a perspective view of the mold part of Fig. 2. 4 are explanatory diagrams showing the mounting position of the vibrator. Code 1... Tandish 2... Nozzle 3... Mold 4... Slab 5...
... Oscillation device 6 ... Guide roller 7 ... Molten metal 8a, 8b ... Vibrator 9 ... Leaf spring 10 ...・Fixed frame patent applicant Kawasaki Steel Corporation Agent Patent attorney Yoshikatsu Matsushita Attorney Fumi Soejima (9) Figure 1 @ Figure 2 Figure 13

Claims (1)

[Claims] A rotary vibrator that vibrates the mold by rotation is installed on each opposing outer wall surface of the mold into which molten metal is continuously poured, and the point of application of the excitation force of each vibrator is the center of the mold. At the same time, the exciters are placed on each opposing outer wall of the mold, and horizontally two
The natural frequencies in the directions (X-axis direction, Y-axis direction) and the vertical direction (l-axis direction) and the resonance points around the A vibration device for a continuous casting mold, characterized in that a plate spring having a spring constant such that the resonance point of the vibration source is close to the vibration frequency of the vibrator is attached, and the mold is supported by these plate springs.