JPS60118353A - Mold vibration device for continuous casting - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a mold vibration device for continuous casting.

Continuous casting involves continuously casting molten steel or other metal in a mold while cooling it and solidifying it into the desired shape. During this casting process, the mold and cast metal are prevented from seizing or sticking. Therefore, the mold is vibrated.

In order to vibrate the mold, a required number of actuators are placed around the mold, and these actuators are synchronously driven in the vertical direction at the required amplitude and frequency.

Conventional vibrating devices for vibrating such molds include:
There are mold vibrating devices using a circular eccentric cam using an electric motor and hydraulic servo type mold vibrating devices using a hydraulic cylinder, but these mold vibrating devices have the following drawbacks.

(i) Mold vibrating devices using circular eccentric cams and mold vibrating devices using hydraulic servo cylinders have a limited mechanical frequency response. synchronization is broken and cannot be put to practical use. For this reason, the maximum frequency of conventional mold vibration devices is 2~
The upper limit is 3Hz, and such a vibration frequency does not sufficiently prevent seizure and sticking, and at the same time leaves unevenness on the surface of the slab.
It was difficult to cast slabs with even surfaces.

(i+) In the above-mentioned two-vibration device, a large load is applied to the vibrating device because it suddenly enters a steady operating state and a stopped state when the vibrating operation starts and stops.

(g) In the above two vibration devices, the vibration frequency during vibration operation,
It is difficult to change the setting of the amplitude value midway, and it is especially impossible to change the setting in the circular eccentric cam system.

Since the Ovl hydraulic servo cylinder method uses analog amplifiers, etc., the amplitude center may shift due to drift.
Frequency disturbance occurs.

The present invention has been made to correct the above-mentioned drawbacks of the conventional @-mounting system, and uses a digital step cylinder as an actuator to enable digital control of vibration, thereby significantly increasing the vibration frequency and reducing vibration during vibration operation. This aims to improve the smoothness when changing conditions and when starting and stopping vibration operation.

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

FIG. 1 schematically shows a vibration device according to the present invention, in which a mold 1 is attached to a vibration table 2, and the vibration table 2 has left and right digital step cylinders (hereinafter abbreviated as digital cylinders).
3 and 4.

The oil flow necessary for the digital cylinders 3 and 4 is supplied from a hydraulic source 5, and the driving of the digital cylinders 3 and 4 is controlled by a control device 6. Further, the digital cylinders 3 and 4 are respectively provided with position detectors 7 and 8 for detecting the amount of protrusion of the cylinder rod, so as to detect the state of movement of the digital cylinders 3 and 4 and input the signal to the control device 9. It has become.

To briefly explain the digital cylinder here, it is a hydraulic cylinder that has a built-in control valve, and the amount of protrusion of the cylinder rod is determined by the position of the control valve.The control valve is moved and positioned by an electric pulse motor via a ball cicada. It was made in a similar manner. The amount of movement of the cylinder rod is determined by the number of pulses input to the pulse motor, the stopping accuracy is ±1 pulse, and the movement speed is determined by the frequency of the input pulses. Therefore, the mode of movement of the digital cylinder can be freely controlled by the way pulses are applied.

Furthermore, since the movement of the digital cylinders is guaranteed by input pulses, even when driving a plurality of digital cylinders, highly accurate synchronization can be achieved by applying the same pulse.

, FIG. 2 is a block diagram showing the configuration of the apparatus of the present invention, and in FIG. 2, the same components as in FIG. 1 are denoted by the same reference numerals.

The control device 6 mainly includes an input relay circuit 9 and an A/D converter 10.
, input buffer circuit 11, microcomputer 12,
It is composed of an output buffer circuit 13, a cylinder drive circuit 14, and an output relay circuit 15, and the input relay circuit 9 has a frequency setter 16, an amplitude value setter 17, a vibration frequency reading push button 18, an amplitude value reading push button 19, and a vibration start button. push button 2
0 and a vibration stop push button 21 are connected to each other, and left and right position detectors 7.8 are connected to the A/D converter 10.

In addition, the output relay circuit 15 has a vibration operation ready indicator lamp 22.
, a vibration operation indicator lamp 23, a digital cylinder synchronization status indicator lamp 24, etc. are connected to the output buffer circuit 13, a frequency value display 25, an amplitude value display 26, and the cylinder drive circuit 14 is connected to a frequency value display 25 and an amplitude value display 26. Step motor 27 for left and right digital cylinders 3 and 4 (see Figure 1)
are connected to constitute the mold vibrating device of the present invention.

As mentioned above, the digital cylinder 3.4, which is the actuator of this device, can be driven by digital control, and the vibration conditions, that is, the vibration waveform, can be set to any frequency and amplitude waveform by determining the pulse signal input state using software. can be obtained and easily changed.

The microcomputer 12 calculates a vibration waveform based on the frequency and amplitude values set and inputted from the frequency setter 16 and the amplitude value setter 17 according to a manually programmed program, and the digital cylinder 3.4 calculates the set vibration. A pulse signal that operates to satisfy the conditions of number and amplitude value is input to the cylinder drive circuit 14, and the drive circuit 14 converts this pulse signal into a pulse signal for driving the digital cylinders 3 and 4. Enter in 3 and 4.

Here, the relationship between the vibration waveform and the pulse signal Pn output from the microcomputer 12 will be explained with reference to FIG.

Here, the type of vibration waveform is a sine wave.

If the vibration waveform a is made up of a predetermined number of pulses,
By setting the frequency and amplitude value, a sinusoidal vibration waveform a is calculated as shown in FIG. 3, and the pulse interval tn (time) and the number of pulses zn are calculated. Therefore,
The cylinder drive circuit 14 outputs a drive signal with a number of pulses suitable for forming the vibration waveform 28 at predetermined time intervals to the left and right digital cylinders 3 and 4.

Furthermore, this can be easily achieved by changing the frequency, the pulse interval, and the number of pulses that change the amplitude value.

Furthermore, when starting, stopping, changing the frequency, or changing the vibration value, it is possible to create a transient state using software so that these changes are performed smoothly.

For example, at startup, as shown in Figure 4 (a), a transient state is set in which the frequency and amplitude values gradually increase from the startup time toward a steady state, and the frequency is changed as shown in Figure 4 (a). In the case of changing the amplitude value, a transient state C1 in which the amplitude value gradually changes is set.

These transient states also follow pre-programmed conditions.
It can be easily created by determining the pulse interval and number of pulses.

Note that the above-mentioned case applies to intentionally changing the vibration waveform, but there is a dynamic characteristic that generally when the frequency is increased, the gain of the output of the drive circuit 14 decreases and the amplitude becomes smaller than the set value. If the computer 12 includes a dynamic characteristic correction circuit that compensates for a decrease in gain due to a decrease in frequency, it is possible to maintain the amplitude value at a set value regardless of an increase in frequency.

Next, the flow of operation will be explained based on FIG.

First, set a predetermined frequency and amplitude value using the frequency setter 16 and the amplitude (fi setter 17), and press the vibration frequency reading push button 1.
8. By operating the amplitude value reading push button 19, the set value is input to the microcomputer 12 via the input relay circuit 9 and the input buffer circuit 11. The microcomputer 12 calculates the vibration waveform as described above based on the input setting values, determines the time interval of pulses and the number of pulses so that the vibration waveform is formed, enables output, and sets the transient state. .

Vibration is started by operating the vibration start push button 20.

By operating the vibration activation push button 20, a signal output from the microcomputer 12 is converted into a driving pulse signal by the cylinder drive circuit 14 and input to the left and right digital cylinders 3.4. Then the left and right digital cylinders 3
, 4 moves in response to the input pulses and shakes the vibration table 2.
vibrate.

Since the digital cylinders 3 and 4 move in accordance with the pulses as described above, they can be driven with extremely high synchronization accuracy as long as pulses are input to both digital cylinders 3 and 4 under the same conditions.

The movements of the left and right digital cylinders 3 and 4 are detected by the left and right position detectors 7 and 8, which are controlled by the A/D converter 1o and the input buffer circuit 1.
1 to the microcomputer 12, the microcomputer 12 calculates the synchronization state, and the calculation result is displayed on the cylinder synchronization state display lamp 24 via the output buffer circuit 13 and the output relay circuit 15.

The vibration operation ready indicator lamp 22 indicates that the device is ready for operation, the vibration operation indicator lamp 23 indicates that the device is in operation, and the frequency value display 25 and amplitude value display 26 indicate that the device is in operation. This is provided to inform the operator whether the set value is accurate or not.

If it is desired to stop the device after casting is complete or for other reasons, the vibration stop push button 21 is operated.

Even when it stops, it gradually stops after going through a transient state according to instructions from the microcomputer 12.

As described above, according to the present invention, (i) the synchronization for high response is good, so the vibration frequency can be significantly increased compared to the conventional one, and (G) the vibration frequency and amplitude can be changed at any time and at any time. (b) Since it is a digital control system, the circuit can be simplified. When vibration conditions change, such as when starting or stopping, a transient state can be created, so It exhibits excellent effects such as reducing the load at times and making it possible to smoothly shift to steady operation and stop conditions.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a vibration device according to the present invention, Fig. 2 is a block diagram showing the configuration of the device, Fig. 3 is a pictorial diagram showing the relationship between vibration waveforms and pulse signals, and Fig. 4 [A] ( B) I/~ is an explanatory diagram showing the process of changing the vibration waveform. 1 is a mold, 2 is a vibration table, 3 and 4 are digital step cylinders, and 6 is a control device.

Claims (1)

[Claims] 1) For continuous casting, characterized in that the vibration table on which the mold is installed is not supported by a digital step cylinder, and is configured so that a pulse drive signal corresponding to a desired vibration waveform is manually applied to the digital step cylinder from a control device. Mold vibration device.