JP6533883B2 - Cutting apparatus for continuous casting of steel - Google Patents

Description

  The present invention relates to an apparatus for cutting slabs in continuous casting of steel.

  In the case of billets with small cross sections in continuous steel casting, hydraulic shears are frequently used to cut slabs. Although the cut surface is generally flat, depending on the situation, inconveniences such as "striped unevenness", "muscle" and "bare" may occur. They inhibit biting during rolling and remain as flaws on the product near both ends. Since the end face of the billet is uniquely deformed when passing through the hole type, the above-mentioned defect is unexpectedly moved inward from the end. Therefore, the end of the rolled material is cut and removed appropriately during rolling. This is one cause of rolling yield loss. It is a long-felt desire of the person skilled in the art to cut the ends into shells to solve the above problems when cutting a continuous cast slab. In response to this request, it has been proposed from the old time to press the wedge-shaped teeth into a bowl-like shape similar to the cannonball type.

As the second problem regarding cutting, when speeding up continuous casting, the molten core is extended and the core is cut in the embrittled state or unsolidified state immediately after solidification, and in the case of shearing, the core is generated in addition to generation of jet The part is peeled off, moves to the edge of the slab and adheres, which hinders transportation. Alternatively, it can not be inserted between the blades and operation will stop.
This problem is also solved by the above-mentioned wedge-shaped press-in method, but a new problem arises. In shear, the widening ratio (= width after cutting / width before cutting) is about 1.2 or less, which is acceptable, but in the case of press-in, particularly in the case of press-in to a substantially hollow material, the ratio becomes considerably large Needed.

  Patent Document 1 (preceding example) discloses a concrete and economical solution to the above-mentioned problems (shortening of the rolling end defect portion, closing of the melting core, widening restraint) for billets. According to the method, wedge-shaped teeth are symmetrically press-fitted on both sides of a cast piece, and the cast piece lower surface is inclined and sinked smoothly, and melt core blockage is preceded and then cut. No cut surface occurs, and the defective portion of the terminal is shortened during rolling. The widening is solved by strengthening the restraint guard.

In the device aspect of the method, a press-fit frame incorporating a pair of wedge-shaped press-fit teeth and a two-step screw-in structure for symmetrically press-fitting the teeth, means (motor, reduction gear, pulley belt etc.) for driving the screw-in structure and the means It consists of a truck loaded.
Contrary to shearing, in the case of press-in, the load is maximized immediately before the parting and disappears instantaneously with the parting. Therefore, a large impact occurs and the durability of the device is a big problem. Furthermore, reliable cutting is required while avoiding collision of the tooth top. In the hydraulic mechanism, it is difficult to cope with control accuracy.
With regard to the above two problems, in the present invention, the motor is inverter-controlled to reduce the impact, and the belt pulley mechanism is interposed to elastically absorb the impact. A mechanism that facilitates end point control incorporating tip misplacement to avoid tip collision is appropriate.

Consider the problems of the method and equipment. First, the dimensions of the drive means become too large and interfere with adjacent strands when attached to a continuous caster. Measures such as unusual arrangement are indispensable. There are many work problems.
Second, the drive means is complicated and expensive. There is a problem, but there is a possibility of simple and inexpensive hydraulics.

Patent No. 5723051

  The present invention is an apparatus for cutting slabs of a continuous casting machine for billets of steel, 1) facilitating high-speed casting to improve the casting efficiency, 2) forming the billet on both end faces into a bowl shape to improve the rolling yield In order to cut continuous cast slabs, a known method is adopted in which a pair of opposing wedge-shaped cutting teeth sandwiching the slab is divided into a single side of the casting so as to be symmetrically press-fitted and cut off. Do. In this case, 1) to reduce the impact of impact which is an obstacle to press-in separation, 2) to provide a cutting device which is small in size and can be easily attached to an existing continuous casting line, and 3) has a simpler and cheaper facility. To be an issue to be solved.

According to a first aspect of the present invention, there is provided a press-fit frame through which a cast piece passes, a pair of wedge-shaped teeth disposed opposite to each other with the cast-piece in the press-fit frame, a hydraulic cylinder coupled to the press-fit frame and driving one of the wedge-shaped teeth A continuous cast slab cutting apparatus comprising: a main body comprising a pair of links for operating a pair of teeth symmetrically with respect to a slab pass core; and a transfer means for loading the main body and following the slab withdrawal. ,
1) Fix one wedge-shaped tooth in the press-fitting frame, and provide the other wedge-shaped tooth on the press-fitting toothed base fixed to the ram of the hydraulic cylinder so as to be elastically slidable in the slab withdrawal direction With both teeth in the direction of withdrawal,
2) The link is a three Z type having a hole at the center of the intermediate rod, and the pair of intermediate rods is fitted into a pair of horizontal suspension shafts provided in the moving means to make a fixed central fulcrum, press fit frame The body is connected to the transfer means by pinning a pair of horizontal press-fit frame trunnions provided at the top and a pair of horizontal press-fit bench trunnions provided at the press-fit side to each end of the link. Suspend,
3) Press the tooth tips of both teeth beyond the slab pass core according to the protrusion of the ram, and the side surfaces of the teeth approach, contact, and press each other, and slide the slidable wedge-shaped teeth back and forth It is a cutting device for a continuously cast slab characterized by dividing by a slab pass core while avoiding a collision.

According to a second aspect of the present invention, a press-fit frame through which a cast strip passes, a pair of wedge-shaped teeth arranged opposite to each other with the cast-strip within the press-fit frame, and a tooth base on which one of the wedge-shaped teeth is placed. Cutting a continuous cast slab consisting of a main body comprising a press-fit screw rod for moving the tooth base back and forth, a hydraulic motor for rotationally driving the press-fit screw rod, and a transfer means for loading the main body and following the cast strip withdrawal A device,
1) Fix one wedge-shaped tooth in the press-fit frame and place the other wedge-shaped tooth on the toothing plate so that it can elastically slide in the draw-out direction of the slab and stagger both teeth tips in the pull-out direction ,
2) The shape of the tooth base is formed into a cap nut shape and screwed to one end of the press-fit screw rod,
3) The shapes of the press-in frame and the screws formed on the tooth base are the same in the opposite direction and the same pitch,
4) The other end of the press-fit screw rod is rotated by the hydraulic motor to move the press-fit frame downward without rotation, and the tooth bed is moved upward without rotation so that the double-toothed teeth can be used as a pass core in the cast piece In contrast, the two teeth tips are advanced forward beyond the slab pass core, and the flanks of the teeth approach, contact, and press each other to slide back the slidable wedge teeth to avoid a collision. It is a cutting device of a continuous casting slab characterized by dividing with a slab pass core.

As a definition of the predicate, “slab pass core” is a drawing center line on design, and usually coincides with the center axis of the slab.
"Symmetric" means not exactly symmetrical due to the presence of a discrepancy.
The "transfer means" is any of a floor traveling carriage, a hanging traveling carriage, a pendulum for suspending the main body, a swing arm for suspending the main body, and a sliding stand for suspending the main body.

  When the speed of continuous casting drawing is increased, the unsolidified slab passes through the slab cutting device. In the present invention, since the molten core is sealed after being sealed by press-fitting wedge shaped teeth, there is no leakage from the molten core, and the improvement of the casting efficiency can be easily obtained.

  Since the surface is cut with a smooth wedge-shaped tooth by means of path-to-axis symmetrical pressing, no bending occurs in the steel piece and no end face is formed on both ends of the steel piece, and the surface is formed into a smooth axial wedge shape. The part is shortened to improve the rolling yield.

Cutting requires an inherently large load. In the case of cutting by press-in, contrary to shearing, the maximum load is obtained immediately before division, and at the same time a large impact acts on various places, which is not good for the durability of the mechanism.
In the prior art (cited reference 1), this problem is solved by interposing an inverter control of a motor and an elastic transmission mechanism, which is difficult to solve with oil pressure.
In the hydraulic system, there is a risk that both teeth may collide or leave a bit due to the lack of the end middle accuracy. In order to prevent this, according to the present invention, both teeth tips move beyond the middle point during press-fit, and when the tooth flanks come in contact, one tooth slides back in the pulling out direction, so no severe collisions occur and certainty Divided into

If the drive unit of the prior example is changed to a hydraulic motor as in the invention 2, the structure is simplified and miniaturized, and can be easily provided in the existing continuous casting line.
It will become simpler and less expensive if the rotational drive means and screwing structure of the prior example are changed to a single-push hydraulic cylinder as in the first invention. In this case, a mechanism for inserting both upper and lower teeth in a path-centered symmetric manner is newly required, but a simple Z-shaped link is interposed between the press-in frame and the press-in table to solve this problem.

It is a schematic longitudinal cross-sectional view explaining the slab cutting device of this invention in continuous casting. It is a front view which shows the method of suspending the cutting device main body of this invention to a trolley | bogie. It is a side view explaining symmetrical press-fit of both teeth in the cutting device body of the present invention. It is the side view and front view of the other example of the slab cutting device of this invention.

FIG. 1 is a schematic longitudinal sectional view of the main body of the cast slab cutting device of the present invention in continuous casting. FIG. 1A shows a state before cutting, and FIG. 1B shows a state immediately after cutting.
The slab cutting device according to the present invention penetrates the continuous casting slab and symmetrically press-fits and cuts a pair of wedge teeth sandwiching the slab, and the cutting device main body and the cutting device are loaded and the slab And a carriage which is a kind of transport means to follow the withdrawal of the
The cutting device main body is mainly composed of a hydraulic cylinder 1 and a press-fit frame 2 constituted by a bottomed cylindrical body covered with an outer periphery of the cylinder, a ram 3 of a cylinder core moving up and down inside the press-fit frame 2, and the ram A press-fit toothed table 4 placed on the upper surface 3; a slide wedge-shaped tooth 5 fitted on the press-fit tooth stand 4; a fixed wedge-shaped tooth 6 provided on the bottom of the cylinder and disposed symmetrically with the slide wedge-shaped tooth 5; It consists of The press-fit frame 2 is provided with a through hole 8 through which the cast slab 7 can pass.

The hydraulic pressure causes the ram 3 to protrude and the sliding wedge teeth 5 to advance toward the cast slab 7. At the same time, the press-fit frame 2 and the fixed wedge-shaped press-fit tooth 6 are lowered relative to the ground fixing point by the interposition of a Z-shaped link described later. As a result, the press-fit table 5 appropriately rises and falls, and both teeth are pressed in symmetrically with respect to the slab core axis (path core) 9, and the slab is cut so as to cut off at the path core.
At this time, the two tips are slightly deviated in the bill pull-out direction to prevent collision between the tips. The two tooth tips are advanced beyond the slab pass core 9 and the slab is divided at the stage where the tooth flanks are in contact with each other.

  A high power hydraulic cylinder has some impetus in operation, and it is difficult to stop at the same time the sides of both tips contact each other. A slight timing delay can cause collisions and shocks, causing damage to the device, and a slight advance will leave biting and cause an unreachable break. In order to solve the problem, the present invention takes the following measures.

The shape of the sliding wedge-shaped teeth 5 is obtained by turning a triangular prism over on a rectangular table. The press-in table 4 is formed with a rectangular recess along the pull-out direction into which the rectangular base is precisely fitted, and the dimension in the pull-out direction of the recess is larger than that of the rectangular base. The gap 11 is formed by pressing 11 to one side.
As shown in FIG. 1B, when the side surfaces of both the tips contact with each other, the sliding wedge-shaped teeth 5 slide back in the pulling direction due to the pressing force, thereby avoiding the collision and relieving the impact. The receding acts to tear off the slab just before the division, and the division is ensured.
Immediately after the division, reverse the hydraulic pressure and retract both teeth (away from the slab). The sliding wedge teeth 5 are returned to the standby position by the spring 11.

The method and structure for suspending the cutting device body from the carriage will be described according to FIGS. The dolly and the suspension structure are symmetrical in the drawing, and only one of the parts is picked up.
The carriage 21 is moved in the pulling direction following the cast slab simultaneously with the press-fitting of the teeth via the wheel 22 and the track 23. The carriage 21 is provided with a pair of suspension shafts 25 for supporting the main body and a pair of columns 24 for supporting the suspension shafts. The suspension shaft 25 is disposed orthogonal to and horizontally to the cast slab and is connected to both sides of the main body through the Z-shaped link 30.
The Z-shaped link 30 is composed of upper, middle, lower, and three connecting rods (including pins) b1, b2 and b3. A central hole of the intermediate rod b2 is fitted into the suspension shaft 25 to serve as a fixed fulcrum. The end hole of the upper connecting rod b1 is fitted in the press-fit frame trunnion 27 (parallel to the suspension shaft 25) provided in the press-fit frame 26, and the end hole of the lower connecting rod b3 is provided in the tooth base 28. Fit parallel to the suspension axis).

As in FIG. 3A, the links form a Z-shape which extends for an equal distance between the five centers of rotation. The height of the suspension shaft 25 is an intermediate point between the height of the press-fit frame trunnion 27 and the height of the tooth base trunnion 28 and is a fixed point.
When the ram 31 protrudes by a distance L, the press-fit frame 26 fixed to the cylinder 32 is lowered by 1/2 × L, and the ram 31 is raised by 1/2 × L. Therefore, both wedge teeth approach symmetrically towards the slab pass core, and at the time of cutting, the links become Z-shaped as shown in FIG. 3B. The reason for pressing from both sides and cutting with the pass core is that the slab can be bent by one-sided pressing.
The above-mentioned cutting device is extremely compact and can be easily arranged in the existing continuous casting line.

FIG. 4 shows another example of the cutting device of the present invention, and FIG. 4A shows a side view and FIG. 4B shows a front view (viewed in the pulling direction).
The present invention is simplified by replacing the complicated rotary drive means with only a hydraulic cylinder in the prior art (FIG. 7 in the cited reference), and improved by adding the sliding retraction mechanism of the wedge-shaped teeth of the present invention. is there.
The cutting device according to the present invention mainly comprises an O-shaped press-fit frame 42 for penetrating the cast piece 41, a sliding wedge-shaped tooth 43 fitted into the upper inner side surface of the O-shaped press-fit frame 42 and the O-shaped press-fit frame 42. A screw hole 44 screwed to the lower side, a press-fit screw rod 45 screwed into the screw hole 44, and a nut-like tooth base 47 in which a lower nut 46 is placed on the press-fit screw rod 45 by reverse screw fitting. And a carriage 49 for fixedly loading the hydraulic motor 48 and a widening restraint guard 50.

Due to the rotation of the hydraulic motor 48, the press-fit screw rod 45 is rotated to cause the press-fit frame 42 to be non-rotationally lowered by screw action. As the frame descends, the sliding wedge teeth 43 descend and move toward pressing. The sliding wedge teeth have the same structure as the wedge teeth in FIG. On the other hand, since the toothed table 47 fitted to the other end of the press-fit screw rod 45 has the opposite screw direction, it is raised without rotation, and the lower wedge-shaped teeth 46 move toward the press-fit. Since the thread pitches are the same, both wedge teeth act symmetrically with respect to the slab pass core.
When both tooth tips pass through the slab pass core and the tooth flanks come in contact with each other, the sliding wedge teeth 43 recede along the pulling direction along with the billet division, and the collision and the impact are alleviated.
Although it is difficult to stop the large output hydraulic motor instantaneously, this method solves the problem. Furthermore, the entire apparatus is simplified and miniaturized, and can be inexpensive and easily placed on an existing continuous casting line.

As an effect of the present invention, in high speed casting, the melting core 12 may be extended and may remain at a normal cutting site. In the cutting of this method, the press-fit of the wedge-shaped teeth causes the portion to sink in an inclined manner, and the molten core is closed prior to the cutting, and no problem occurs. Facilitates high speed casting.
The surface texture of the press-in portion is as smooth as rolling because it is a flat mold pressure. Since the shape is wedge-shaped, plastic flow is not disturbed largely at the time of biting into the roll as in a normal vertical surface. For these two reasons, the length of the end defect in rolling can be shortened. In addition, the trapezoid is free from catching at the time of conveyance, and biting on the roll is also ensured.

The sliding wedge teeth and the fixed wedge teeth may be reversed. Although in FIG. 4 the sliding wedge teeth are arranged on the side of the press-fit frame, the reverse is usually easier to do maintenance work.
The restraint guard may be similar to known methods and structures.
Since the hydraulic motor shaft and the screw bar are directly connected, the screw bar is upright. On the other hand, since the press-fit frame moves up and down without rotation, it is supported by a restraint frame (not shown) provided on the carriage.
There are various possible transportation means. In addition to the floor traveling carriage as illustrated, any of a suspension traveling carriage, a pendulum for suspending the main body, a swing arm for suspending the main body, and a sliding stand for suspending the main body may be used. Adapt to the existing equipment situation.

  In producing common carbon steel billets, the appropriate conditions for applying the cutting device of the present invention are summarized in Table 1. There are no particular difficulties in implementation.

DESCRIPTION OF SYMBOLS 1; Hydraulic cylinder 2; Press-fit frame 3; Ram 4; Press-fit tooth stand 5; Sliding wedge-shaped tooth 6; Fixed wedge-shaped tooth 7; Cast piece 8; Through hole 9; Cast piece path core 10; Sliding gap 11; Bogie 22; wheel 23; track 24; suspension post 25; suspension shaft 26; press-fit frame 27; press-fit frame trunnion 28; tooth base 29; tooth-bed trunnion 30; Z-link 31; ram 32; O-shaped press-fitting frame 43; sliding wedge teeth 44; screw holes 45; press-fitting threaded rods 46; lower wedge teeth 47;

Claims (1)

A press-fit frame through which the slab passes, a pair of wedge teeth arranged opposite to each other with the slab in the press-fit frame, a hydraulic cylinder coupled to the press-fit frame and driving one of the wedge teeth, and the wedge tooth pair A continuous cast slab cutting apparatus comprising: a main body comprising a pair of links operated symmetrically with respect to a pass core; and a transfer means for loading the main body and following the strip withdrawal;
1) Fix one wedge-shaped tooth in the press-fitting frame, and provide the other wedge-shaped tooth on the press-fitting toothed base fixed to the ram of the hydraulic cylinder so as to be elastically slidable in the slab withdrawal direction With both teeth in the direction of withdrawal,
2) The link is a three Z type having a hole at the center of the intermediate rod, and the pair of intermediate rods is fitted into a pair of horizontal suspension shafts provided in the moving means to make a fixed central fulcrum, press fit frame The body is connected to the transfer means by pinning a pair of horizontal press-fit frame trunnions provided at the top and a pair of horizontal press-fit bench trunnions provided at the press-fit side to each end of the link. Suspend,
3) Press the tooth tips of both teeth beyond the slab pass core according to the protrusion of the ram, and the side surfaces of the teeth approach, contact, and press each other, and slide the slidable wedge-shaped teeth back and forth A cutting device for a continuously cast slab characterized by dividing by a slab pass core while avoiding a collision.

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