JPH0819454B2 - Tilt device with shock absorbing mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tilting device for a converter.

[0002]

2. Description of the Related Art A tilting device provided with a conventional cushioning mechanism is, for example, as disclosed in U.S. Pat. No. 3,400,603, a torsion bar is arranged below a converter tilting device and a lower part of the tilting device casing is cranked by a clevis. By fixing it to the arm and fixing both ends of the torsion bar to the ground with spherical bearings, load is not applied when torque does not act on the furnace body, and reaction force of tilting torque acts on the tilting device casing when the furnace body tilts, The casing was rotated and the torsion bar was twisted through the crank arm. The torsional rigidity of this torsion bar serves as a cushion to reduce the buffer torque acting on the tilting device.

In the conventional bottom-blowing converter operation, the bottom-blowing gas amount is not so large, and even if the regular repetitive force due to the rocking of the molten steel in the converter acts on the tilting device via the furnace body, its torque is generated. Since it is not so large, the influence on the tilting device was not a problem. However, when scrap melting or smelting reduction is performed in a converter, a large amount of gas or powder is blown into the molten steel, which causes large fluctuations in the molten steel, and a large regular repetitive force is applied to the tilting device via the furnace body. Act on. When this repetitive force reaches a certain magnitude, it strongly resonates with the tilting device, and an abnormally high torque acts on the tilting device, which may damage the tilting device.

In view of this, in Japanese Patent Application Laid-Open No. 222241/1990, the shock absorber is constrained during the blowing of the converter, and the natural frequency of the tilting device is changed without making it function to change a large regularity due to the rocking of the molten steel. It was proposed that the tilting device should be protected by avoiding resonance with repetitive force and releasing the restraint to act the original cushioning function at the time of charging / steeling under a large impact. And as a first example in FIGS. 9 to 11,
An example is shown in which a boss having a tapered hole is fixed to a crank arm which is a constituent part of a shock absorber, and a tapered rod is installed beside the boss so that the rod can be freely taken in and out. This prevents the resonance by inserting the tapered rod into the tapered hole and restraining the shock absorber during blowing of the converter, and removing the tapered rod from the tapered hole to release the restraint during charging and tapping. It is designed to act as a buffer function. Second
As an example of this, in FIG. 12, a tapered spacer is installed in the gap between the tilting device and the stopper so that the spacer can be freely taken in and out, and the rotation of the tilting device casing is locked during the blowing of the converter to restrain the buffer function. It shows an example of avoiding resonance and releasing the restraint at the time of start / stop that receives a large impact to activate the buffer function.

[0005]

In the prior art, the shock absorbing function is eliminated by restraining the shock absorbing device, the natural frequency of the tilting device is changed, and the rocking of the molten steel generated during the blowing causes regular fluctuation. Although it is an effective means for avoiding resonance with repetitive force, the regular repetitive force due to rocking of molten steel changes due to changes in the amount of molten steel and gas, and differences in the brick profile of the furnace body. When operating in a high region, the torque acting on the tilting device becomes large because the shock absorber is not operated.

Therefore, an object of the present invention is to change the natural frequency of the tilting device without impairing the shock absorbing function of the shock absorbing device even during the blowing so that the repetitive force between the tilting device and the periodical repetitive force due to the rocking of the molten steel is changed. It is intended to provide a tilting device provided with a cushioning mechanism for preventing the salvage tilting device from being broken.

[0007]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention provides a tilting device having a shock absorbing mechanism for mitigating an impact force during converter operation, in which a shock absorbing damper capable of being turned on and off is provided in the shock absorbing mechanism. The tilting device is provided with a cushioning mechanism.

[0008]

According to the present invention, the crank arm, which is integrated with the torsion bar that is the buffer spring of the buffer mechanism of the tilting device, is connected to the vibration damper that can be turned on and off, and the vibration damper is turned on during blowing to turn the molten steel into a molten steel. When the torsion bar is twisted by the swing of the crank arm and the crank arm moves up and down, a viscous resistance of oil is generated in the vibration damper, and the natural frequency of the tilting device is changed by transmitting this force to the torsion bar, Avoiding repetitive force due to rocking and resonance with the tilting device, the torque generated is reduced by the buffer spring function of the torsion bar in areas other than resonance, and the vibration damper is turned off during loading / unloading when a large shock is applied. Even if the displacement speed of the crank arm becomes faster, the buffer mechanism by the torsion bar is applied without applying an excessive force to the vibration damper. To function.

[0009]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 shows a side view of a tilting device having a shock absorbing mechanism with a vibration damper according to the present invention. In the tilting device 2 mounted on the trunnion 1 of the converter, the cushioning mechanism rotatably supports both ends of the torsion bar 3 which is a cushioning spring on the bearing 4, and tilts the crank arm 5 which is an integral structure with the torsion bar. It is configured by connecting a pin to the bottom of the device with a clevis 6. The vibration damper 7 that can be turned on and off according to the present invention is connected to the tip of the crank arm by a pin, and the other end is connected to a converter bearing stand 8 that is a fixed side by a pin. FIG. 2 is a front view of a tilting device having a shock absorbing mechanism to which a vibration damper is attached. FIG. 3 is a side view of the tilting device having a shock absorbing mechanism to which the vibration damper is attached, as seen from AA, and shows a detailed view of a mounting portion of the vibration damper.

4 to 7 are circuit diagrams of the vibration damper of the present invention.

As the crank arm moves up and down, the cylinder 17 moves up and down with respect to the piston 16 to which the vibration damper is fixed.

4 and 5 show the flow of oil during blowing when the vibration damper 7 is turned on, and the solenoid valve 11 of the bypass line 12 is closed during blowing. During the blowing, the tilting device casing rotates due to the vibration of the converter, which causes the crank arm 5 to move up and down. When the crank arm moves upward, the oil in the chamber A on the piston head side is compressed and enters the chamber on the rod side B through the relief valve 14 provided in the piston 16 as shown in FIG. 9 and flows in the direction of the arrow to reach the oil sump C chamber. A damper effect is obtained by viscous resistance when the oil 10 passes through the orifice 9. Therefore, the viscous resistance is transmitted to the torsion bar that is integral with the crank arm fixed to the vibration damper, and as a result, the natural frequency of the tilting device changes. This viscous resistance is a small force and the buffer function of the torsion bar is not impaired. On the contrary, when the crank arm moves downward, the oil in the chamber B on the rod side is compressed in reverse, and the oil flows in the direction of the arrow through the orifice 9 shown in FIG. It goes through 15 to the head side room A. The viscous resistance of the oil 10 as it passes through the orifice 9 is transmitted to the torsion bar that is integral with the crank arm, and as a result, the natural frequency of the tilting device changes. This viscous resistance is also a small force and the buffer function of the torsion bar is not impaired.

FIG. 6 shows the flow of oil during charging and tapping when the vibration damper 7 is turned off. At this time, the solenoid valve 11
Open and the oil flows through the orifice 9 as well as through the bypass line 12 which has a very large cross section. Therefore, the resistance of the oil becomes so small that it can be ignored,
Even if a large impact torque acts to increase the displacement speed of the crank arm, the vibration damper does not substantially function and the oil resistance does not damage the vibration damper.

FIG. 7 shows the flow of oil when charging and tapping are performed when the solenoid valve 11 fails. At this time, if the oil pressure increases due to the resistance of the orifice 9, the emergency relief valve 13 opens and the oil flows, so that the oil pressure decreases and damage to the vibration damper is prevented.

In the tilting device having the cushioning mechanism constructed as described above, since the vibration damper is added so that it can be turned on and off, the rocking of the molten steel becomes large during blowing and a large regular repetitive force is generated. Even if it acts on the tilting device through the furnace body, the vibration damper is turned on, so the oil inside the vibration damper flows through the orifice due to the vertical movement of the crank arm, and its viscous resistance is transmitted to the torsion bar via the crank arm and tilts. At the time of loading / unloading, the device does not resonate with the tilting device by changing the natural frequency of the device, and reduces the generated torque by the buffer spring function of the torsion bar in the region other than the resonance, and a large impact torque acts. It is possible to turn off the vibration damper and activate the original cushioning mechanism.

FIG. 8 shows the result of a numerical analysis of the relationship between the rocking force (horizontal force) of molten steel and the generated torque acting on the tilting device. Curve A shows the case of a conventional tilting device having a damping mechanism. At this time, horizontal force due to rocking of molten steel is 150 TON
Resonance occurs between 200 TON and 200 TON, and the generated torque acting on the tilting device is abnormally increased from 700 TON to 2000 TON.

Curve B represents the case where the cushioning mechanism is constrained and does not function in the above device. Since resonance does not occur in the entire range of horizontal force, the horizontal force due to rocking of molten steel is 150 TO
Between N and 200 TON, the torque is lower than the curve A, but in the other regions, the shock absorbing mechanism is restrained, so the generated torque acting on the tilting device is high. Curve C shows the case where the vibration damper according to the present invention is added to the cushioning mechanism and the vibration damper is turned on. At this time, since the natural frequency of the tilting device changes due to the damper effect, resonance with the rocking of the molten steel does not occur. Also, curve A and curve B in the entire range of horizontal force
It can be seen that the generated torque is lower than that, and the buffer function works without being impaired.

A circle mark indicates a measured value when the vibration damper is turned on in the tilting device having the buffer mechanism. It can be seen that it agrees well with the calculated value (curve C).

[0020]

As described above, according to the present invention, in the tilting device having the shock absorbing mechanism for alleviating the impact force during the operation, the shock absorbing damper is provided with the vibration absorbing damper which can be turned on and off. (ON state) Change the natural frequency of the tilting device without impairing the cushioning function to avoid resonance with the tilting device and regular repetitive force due to the rocking of molten steel, and reduce the generated torque in the areas other than resonance The shock absorber can be released (off state) during charging and tapping that is subjected to a large impact, and the original cushioning mechanism can be restored without applying excessive force to the shock absorber.

[Brief description of drawings]

FIG. 1 is a side view of a device according to an embodiment of the present invention in which a vibration absorbing damper that can be turned on and off is provided in a shock absorbing mechanism in a tilting device having a shock absorbing mechanism.

FIG. 2 is a front view thereof.

FIG. 3 is a detailed view of a portion where a vibration damper is attached to a cushioning mechanism of a tilting device.

FIG. 4 is a vibration damper circuit diagram showing the flow of oil during blowing according to the present invention.

FIG. 5 is a vibration damper circuit diagram showing the flow of oil during blowing.

FIG. 6 is a vibration damper circuit diagram showing the flow of oil during charging and tapping.

FIG. 7 is a vibration damper circuit diagram showing the flow of oil when the solenoid valve fails.

FIG. 8 is a diagram showing a result of a numerical analysis of a relationship between a rocking force (horizontal force) of molten steel and a generated torque acting on a tilting device.

FIG. 9 is a first example in which a boss having a tapered hole is fixed to a crank arm which is a constituent part of a shock absorber disclosed in Japanese Patent Laid-Open No. 2241/1990, and a tapered rod is installed beside the boss so that the rod can be freely inserted and removed. FIG. 6 is a front view of the tilting device.

FIG. 10 shows a detailed view of part a of FIG.

FIG. 11 is a diagram viewed from AA in FIG. 9.

FIG. 12 is a front view of a tilting device according to a second example of the prior art in which a tapered spacer is installed in a gap between a tilting device and a stopper, which is disclosed in JP-A-2-2241, so that the spacer can be freely inserted and removed.

[Explanation of symbols]

 1 ... Trunnion 2 ... Tilt device 3 ... Torsion bar 4 ... Bearing 5 ... Crank arm 6 ... Clevis 7 ... Vibration damper 8 ... Bearing stand 9 ... Orifice 10 ... Oil 11 ... Solenoid valve 12 ... Bypass line 13 ... Emergency relief valve 14 … Relief valve 15… Relief valve 16… Piston 17… Cylinder

Claims (1)

[Claims] 1. A tilting device provided with a shock absorbing mechanism for mitigating impact force during converter operation, wherein a shock absorbing damper capable of turning on and off is provided in the shock absorbing mechanism.