JPS589753A - Horizontal type contiuous casting machine - Google Patents

Abstract

1. A method for the horizontal continuous casting of metals and their alloys wherein the elongate workpiece is drawn off continuously, intermittently or in the pilgrim step mode, characterised in that the continuous drawing stroke or the intermittent one or the one effected in the batchwise mode is or are carried out at a drawing off speed which always fluctuates above the zero value in an oscillating mode.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a horizontal continuous casting machine for metals and metal alloys, which performs continuous or intermittent strand drawing motion, which comprises a heat-retaining container having a horizontal ejection opening; It is of the type consisting of a cooled mold which is placed later and an electrically operated tensioning device.

In horizontal or vertical continuous casting of metals and metal alloys, varying relative movements between the mold and the strands are often employed in order to completely avoid destruction of the strands concerned and to provide qualitative advantages. It is known to give. This varying relative movement may, depending on what the particular working realities and mechanical means require or allow, reach a temporary stationary position or, in some cases, undergo a change in motion. I do things like that.

The above-mentioned movement course is usually obtained by means of a special movement device for the mold in the case of a continuous forward movement of the strand in a mold independent of the furnace, or by discontinuous ejection of the strand in a mold dependent on the furnace. It is carried out by

Such discontinuous dispensing by the Go-Stonozo method or the bank-step method has heretofore required very expensive drive equipment capable of maintaining a predetermined preselected withdrawal step with great precision. In the prior art, this high drive requirement was met by expensive electro-hydraulic devices. Many horizontal casting machines, in particular those which are advantageously equipped with a drive as described above, are operated in this way. In this case, it is easily possible to transport strands of circular, square or rectangular cross section or of hollow shape with the necessary movement sequence.

For example, Hae 5 Yami Kara 40011 II! A circular strand of diameter 1 is moved, the stroke speed being adapted to the solidification rate of the mold, for example at a value of 6 mm per second. With this type of device, it is possible to perform up to 1000 switchings per minute in order to achieve precise adjustment between the forward stroke/holding time I/reverse stroke/holding time ■. Recently, it has also become known to use step-operating DC motors, with appropriate electrical control, to draw out strands P from horizontal strand molds (see German Patent No. 2,340,636).

However, in particular those with a diameter of less than 15 mm, e.g.
In the case of expansion by continuous casting into thin B strands of O, it is necessary to significantly increase the drawing speed to, for example, 820 mm per second, and therefore the switching times in this case are short and, by extension, the number of switchings per minute is reduced. There will be more.

In order to maintain the conventional drawing speed, the uninventive problem is that the design requires a large increase in cost. In order to continuously cast rondos of 3 to 10 pieces, the drawing speed is preferably set to 10 per second.
00 tw+↑.

According to the invention, the above problem is solved by the fact that the tensioning device imparts to the strand a movement that oscillates between a predetermined maximum value and a predetermined minimum value within each stroke. -Yo? It was resolved. The driving device for this tensioning device is:
It is advantageous to use at least one alternating current operated steering motor which allows switching up to 5000 times per minute.

In the conventionally known go-stozzo method or the ζ-step method, the strand withdrawal speed within one stroke increases from zero degrees to the maximum value and then decreases to zero again, and there is a fixed stopping time between each stroke. In contrast, the strand drawing in the continuous casting machine of the present invention is carried out oscillatingly within the course of a continuous movement between the maximum value and the minimum value within each stroke. - In this case, the horizontal caster according to the invention can be operated with continuous strand withdrawal or with intermittent withdrawal, as in the go-stop or pack-step process. Good too.

In FIG. 1, the oscillatory movement profile within a stroke of approximately 40 mm is shown as a diagram 1b as an angle relative to the conveying distance. A duration of approximately 0.15 seconds follows the end of this 40III++ stroke whose motion is oscillated between approximately 2 seconds and 6 seconds-1.

When the horizontal continuous casting machine according to the present invention is used, fine markings can be seen on the surface of the cast strand (second
(see figure). Figure 2 shows that during strand unloading, which is carried out in each stroke with an oscillatory movement course of 1 degree in one stroke,
There is a mapping diagram ↑ for the case of the motion course shown in Figure 1.

According to this mode of operation, the temperature of the hard casting shell at the point of contact between the hard casting shell and the liquid molten metal in the area of entry into the mold is lower than that of the go-stop or pack-step method. It falls more slowly than with step-by-step conveyance, and further ensures that the volumetric excursion during coagulation is evenly distributed over the entire length of the strand.

The advantage of the electric (alternating current) step motor of the present invention over conventional hydraulic pull-out devices is that it eliminates the need for all mechanical transmission lines such as transmissions, couplings, chains, etc. It is possible to operate. The drive roller is mounted directly on the shaft base of the slit Tanabata in a suitable manner. It must also be ensured that the diameter of the drive roller is optimally adapted to the diameter of the strand, with care being taken that, at a constant mounting force, the withdrawal speed increases as the rod diameter decreases.

A step motion is carried out by enlarging the diameter of the drive plate, but it is such that the rotational moment of inertia of the drive plate in question and the load moment of inertia of the strand to be delivered are still raised within an acceptable range. This is possible only insofar as possible.

If the fit is incorrect, the step motor will go out of cycle and stop. For the expert, the characteristic curve valid for a given stepper motor takes into account the rotational and translational moments of inertia of the various masses to be promoted for the respective withdrawal speed and rod diameter. Above, it is possible without difficulty to select the drive plate diameter accurately. For example, for a step motor of 26N7m (maximum rotational moment), a diameter of 200I is required for a rod with a diameter of 3mm.
A drive plate with a diameter of +1++1 has proven advantageous, and for rods with a diameter of 8 mm a drive plate with a diameter of 50+a.

In order to operate the continuous casting process without trouble and to obtain a qualitatively uniform product, it is important to maintain a constant strand exit temperature. To make this possible, according to the invention, an electronic control system is provided for adjusting the operating frequency of the stepper motor or stepper motors depending on the strand outlet temperature. Strand exit temperature is measured continuously. If it deviates from the target value, the operating frequency of the stepping motor or motors is changed to operate the strand outlet temperature from the actual value back to the target value.

The previously known adjustment method by varying the amount of cooling water is unsuitable at high strand penetration directions because of its low responsiveness.

, at least two separate stepping motors are arranged one after the other in the strand penetration direction in order to prevent the withdrawal movement of the transition point from the gummy par to the strand being disturbed when it passes through the tensioning device. Then, this step motor takes turns and captures the must strand while the grading point from the dummy par to the strand passes through the relevant tensioning device. The above transition point F1 1st
As soon as the stepper motor is reached, the pair of rolls driven by the motor is released, and the following stepper motor in the direction of strand running pulls the strand in question with the pair of rolls driven by the motor. As soon as the transition point from the dummy ζ to the strand passes the first stepper motor, the pull-off roller 2 of this motor is activated again and the roll pair driven by the second stepper motor is moved through the said transition. It is separated in order to penetrate the area. At high withdrawal speeds, the above-mentioned alternating operation also requires a suitable control, which according to the invention is carried out by an electronic control device, which synchronizes each stepper motor, i.e. The oscillatory movements of the motors are harmonized with each other, and each motor is assigned its own final output stage, thereby ensuring independent control of each motor. According to the above structure of the horizontal continuous casting machine of the present invention, it is possible to maintain a high drawing speed of 1% even at startup, and it is also possible to guide the strand in a straight line even better. is reduced.

By arranging the roller pairs of the tensioning device obliquely to the longitudinal axis of the strand, the drawing properties of the strand from the mold are positively influenced. Moreover, there is less friction due to the movement of the strand inside the mold.
Uneven wear within the mold is also avoided. This structure is particularly restricted to use with stranded strands of circular cross section.

The advantage of semi-continuous operation is that the deformation can be performed in isolation without the need for costly synchronization with stroke movements.

The advantage is that continuous processing steps such as heat treatment can be eliminated. In this case, it is also possible to adapt the strands to the same cross-sectional shape by means of the grooves a-ra or to change them to a different cross-sectional shape, for example from circular to oval f6.

This method also allows for additional compression of the strands to remove residual porosity or simply change the cross-sectional area.
%be.

The parts of the tensioning device that are necessary only at the beginning of the strand casting process are the dummy parts as connecting members between the molten metal in the run-off passage of the heat-insulating container and the strand transport rollers.
There is t%. At the start of operation, the start command provides precise timing for the introduction of molten metal into the outlet passageway.
゛1 must be done. This problem has been solved by the use of a tubular diaphragm.
Adjustable to any length from O by two insulative trigger contacts mounted in the front opening of ζ- being conductively connected to each other by the molten metal and emitting a signal when the molten metal flows in. Depending on the delay time to be applied, a starting command for the tensioning device is issued via a preselectable time relay. Also, United States Patent No. 39
As described in the specification of No. 08747, the structure of the dummy gun as described above also works to capture the cast shell more reliably, and it is similar to the dummy gun as a conventional point member. 1, which is advantageous in its good welding bond compared to the structure of
In addition, a form-fitting connection of the dummy ζ and the casting strand is also effected by placing the bottle at right angles in the front part of the pin and allowing the molten metal to flow around the pin. . Furthermore, it is advantageous to insert the dummy 8 into the inlet opening of the mold at the beginning of the casting process and press it against the ceramic groove outlet by means of a seal made of insulating felt. As a result, the molten metal smoothly enters the inside of the tubular dummy ζ-, and is welded together with the dummy into a solid joint. On the other hand, due to this sealing member, molten metal may enter between the dummy d- and the mold, causing the dummy d- in the mold to get caught, preventing the dummy from being pulled out, or causing strong Scratches that caused mold wear are prevented.

In conventional pumping outlet structures, it is often difficult to obtain an accurate holding time of the start-up delay. If the time is too short, the dummy par will be removed before it is fully welded to the casting shell, creating the risk of the molten material breaking through.

If the time is too long, the solidified portion may advance into the exit passageway, making withdrawal difficult or even causing solidification of the molten metal within the exit passageway.

Furthermore, a tubular extension with a length of approximately 30 to 30 fins is provided at the ejection port, and this extension has an outer diameter of 10 to 25 m and is shaped like a snorkel and forms a nozzle portion fitted into the wall of the casting container. It is advantageous if it projects freely into the container in question through the opening. In this case, the outlet part is heated by the convection action of the molten metal surrounding the snorkel-shaped part, so that the formation of deposits in front of the opening can be reliably avoided. In this case, particularly high requirements are placed on the compatibility of the snorkel-shaped portion with the molten metal and the beak. In the case of casting hard alloys, this requirement can only be met insufficiently by the recently used boron nitride and not at all by the graphite used as an auxiliary. Furthermore, it has been found that when alundum masses are used, they form a strong melting bond with the strands on the rough surfaces of their run-off channels, so that no withdrawal movement can take place. Only by changing the material for this outlet to stabilized or semi-stabilized zirconium oxide can a reliable improvement be made for durability that is sufficient to withstand several hours of use even in hard alloy castings. is achieved.

The invention will now be explained with reference to the illustrated embodiment.

FIG. 3 shows a tension 9 device. Two step motors 20 are mounted within the torsionally strong molded frame structure 21. A wear-resistant drive roller 11 is mounted directly on the shaft end of each stepper motor.

This drive roller is provided with grooves in the form of a strip.
It is also possible to additionally form radially extending □ notches on the lateral side of the groove in order to ensure a good frictional connection between the rond and the drive roller. An additional radial bearing 15 is arranged on the side of the drive roller 11 facing away from the motor, which also receives the forces exerted by the suppression roller 10 . A cylindrical suppression roller 10, which is also wear-resistant and in each case arranged above the two drive rollers 11, is held in a vertical guide section by a piston of a pneumatic actuating cylinder 1.

By supplying compressed air to the actuating cylinder by controlling appropriate valves 1, each working thread can be made to act selectively or jointly on the respective strand to be discharged.

The control device has a centralized electronic control unit, which electronic control unit includes a preselection counter, a speed setting device, etc.
Combined with other components. The entire electronic control processor is called a high-speed control processor, as shown in the block diagram of Fig. The conversion takes place via both switchable final stages,
One of the two final stages is assigned to one of the step motors. The switching of the circuits is chosen in such a way that both stem motors can be operated independently of each other or together.

(For forward steps) ``In the preselection counter (1), the number of steps to be taken is determined by a digital Correspondingly, in the preselection counter (2) (for backward steps), the number of steps to be carried out by the stepper motor in the backward direction (i.e. in the opposite direction to the strand withdrawal direction) is digitally set. .

The digitally settable (preselected stop time) n't% allows the length of the stop interval between the forward (withdrawal) stroke and the backward stroke of the strand to be set. In the counter (for preselected stop time), which can also be set digitally, the length of the stop interval between the backward stroke of the strand and the next forward (withdrawal) stroke can be set to 1'4.

After receiving the start command, the step motor rotates in one rotational direction corresponding to the strand drawing direction (for example, clockwise) until the number of steps set in the forward step soil selection counter (1) is reached. This causes the strand to move forward by a corresponding stroke. Assuming that the number of steps is 51, the angle of one step is 1.8 degrees, and the diameter of the drive roller used is 5011 II+, this forward stroke is 40 degrees. If the sliding roller has a diameter twice as large as Φ, that is, 200 mm, in order to perform the same forward stroke, that is, a stroke of 40 m, the preselection for the forward step should be 1/4 of the number of steps, or 13 steps. All that is required is to set the counter (1).

When the step motor reaches the set number of steps, the forward step preselection counter (1) outputs the output signal C0INZ I
is sent to the control unit, whereby the control unit controls the preselected stop time counter (2) and stops the step motor for a time corresponding to the stop time set by the counter (2). , the counter for pre-selected stop time is
0 for a stop interval between 0 and 10 seconds;
It can be set digitally in 01 second increments.

When this set stop interval has elapsed, the preselected stop time counter gives an output signal INDEX to the control unit, based on which the control unit rotates the step motor in the opposite direction to the original rotational direction. direction (for example, counterclockwise). In this way, the step motor is set with the reverse step preselection counter (2).
Rotate in the backward direction by the number of steps. This corresponds to the so-called pilger (for example, 3 steps forward, 2 steps backward type) step method when drawing out the strand. When the step motor reaches the number of backward steps set in the backward step preselection counter (2), the backward step preselection counter (2) also sends an output signal, namely C0INZ It, to the control unit, which Based on this, the control unit activates the preselected stop time counter 2 to stop the stepper motor for a time corresponding to the set stop interval.

Preselected stop time function can also be set digitally for a stop interval between 0 and 10 seconds'1
%be. When this stop interval has elapsed, an output signal INDEX 1 is given from the preselection stop time counter I to the control unit, and on the basis of this, the control unit reacts to the forward step preselection counter I to start a new step. The cycle begins.

FIG. 5 shows the cooperation of the three system components, tensioning device, dummy and spout, at the beginning of the casting process. The tubular dummy pawl t-34 is captured by one or more driving rollers 11 and pressing rollers 10.

The dummy pawl ζ-34 is inserted into the mold 33 toward the short and large opening until the dummy pawl ζ-34 abuts the ejection port 31 with the ring-shaped seal member 37,
This prevents molten metal from flowing into the narrow annular gap between the mold 33 and the dummy pawl ζ-34. In the front opening of the tubular dummy 34 there is provided a perpendicularly disposed bin 36, which serves to form a weld as well as a shape between the cast strand 38 and the dummy 34. Connective coupling is taking place. Furthermore, two trigger contacts 35 are disposed within the front opening of this dummy par 34, and when these trigger contacts 35 come into contact with intruding molten metal, they issue a signal to a time relay for delaying the start. ing. Solidified cast strand 3 provided by the conical shape of the inner bore of the outlet 31
The shape of the solidification front 40 between 8 and the molten metal 39 prevents solidification of the strands in the run-off channel 1 and allows easy withdrawal of the solidified strands.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a diagram showing the course of the angular velocity of the drive roller within one stroke during the casting process, and FIG. 2 is a diagram showing the strand conveyance according to FIG. 1. Fig. 3 is a diagram showing the markings formed on the surface of the cast strand by the course of the movement; Fig. 3 is a view of the tensioning device seen from three directions a), b), and c); Fig. 4 is a diagram showing the step motor of the tensioning device. FIG. 5 is a circuit block diagram of an electrically or electronically controlled reservoir, showing a dummy ζ-device consisting of a tensioning device, a dummy par and an ejection opening. 1...Operation cylinder, 10...Press roller, 11...
Drive roller, 15... Radial bearing, 20... Step motor, 21... Molded frame structure, ■...
Lifting port, 33... Mold, 34... Dummy par, 35
... Trigger contact, 36 ... Pin, 37 ... Seal member, 38 ... Casting strand, 39 ... Molten metal, 40 ... Printing of solidification float 7 drawing (Contents: No changes) 1'II [ICFig, 3a Continued from page 1 0 Inventor Beter, Sch - Frefeld-Vorst Waldstrasse, Federal Republic of Germany 707 0 Inventor Wolfgang Spiller, Frefeld-Bremersheimstrasse, Federal Republic of Germany 12 0 Inventor Rainer Thielmann Frefeld Wilhelmspofale, Federal Republic of Germany 57 Procedural Amendment (Method) August 2, 1980 Director-General of the Patent Office / Indication of Case Patent Application No. 73498, 1988 No. λ
Name of the invention: Horizontal continuous casting machine 3; Name of the person making the amendment: Technicagus Gesellschaft Mitsut Beschrenchtel Hufsung 4; Name of the sub-agent (6181); Patent attorney Toshio Yano 5;
Date of amendment order: July 27, v1157 EI CR sent EI
) Subject of the amendment (1) Kusunoki, the inventor of Application 1 (2) Drawings (3) Assignment document 7, contents of the amendment (1) (2) (2) (9) are both attached

Claims (1)

[Claims] 1. Horizontal continuous casting machine with continuous or intermittent strand drawing motion for gold sails and metal alloys
Therefore, in a type consisting of a heat-retaining container with a horizontal ejection opening, a cooled mold placed behind it, and an electric tensioning device, the tensioning device is used to tighten the strands at each stroke. (1) A horizontal continuous casting machine, characterized in that it is provided with a motion that oscillates between a predetermined maximum value and a predetermined minimum value. 2. Continuous casting machine according to claim 1, wherein the drive device for the tensioning device comprises at least one AC-operated stepping motor 1'4. 3. The continuous casting machine according to claim 2, further comprising an electronic control device for adjusting the operating frequency of one or more step motors in accordance with the strand outlet temperature. At least two stepper motors are arranged one after the other in the direction of strand passage, and an electronic control device is configured for synchronizing the stepper motors and each motor has a unique A continuous casting machine according to claim 3, to which a final output stage is assigned;
J5. Continuous casting machine according to claim 1, wherein each pair of rollers of the tensioning device is positioned obliquely to the longitudinal axis of the strand. 6. The continuous casting machine according to claim 1, wherein means for applying pressure to plastically deform the strands is disposed on the pair of rollers. 7. Within the mold ↑ dummy ζ- is provided with a tubular section sealed and attached to the sprue,
Continuous casting machine according to claim 1, characterized in that a trigger contact is arranged in this section. 8. Continuous casting according to claim 7, wherein in said tubular section of the dummy ζ- there is arranged a fastening member, such as a pin or joint inserted at right angles or the like. Machine. 9. The continuous casting machine according to claim 1, wherein the ejection port has a tubular section that has an inner hole that expands outward in a conical shape and reaches the inside of the heat-retaining container. . 10. Claim 9, wherein said tubular section is characterized in that the stabilizing element consists of semi-stabilized zirconium oxide.
Continuous casting machine as described in section.