JPS6029204A - Cutting method of blooms - 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 method for cutting a steel billet, and more specifically, the present invention relates to a method for cutting a steel billet, and more specifically, in a continuous billet, the temperature is higher on the upper surface side than the lower surface side, or the temperature on the upper surface side and the lower surface side is equal. Although the position may vary, in general, the temperature of the steel piece is higher on the top side than on the side. This invention relates to a method for cutting a steel piece.

For example, continuously cast steel pieces such as slabs and blooms are continuously cast from a continuous casting machine. , transported horizontally. For this reason, in the continuous cast steel billet, in the curved conveyance section, the surface portion on the side toward the center of curvature has a radial diameter: 'i! Stress is generated, and tensile stress is generated on the surface portion in the direction of the center of recurvature. When the continuously cast steel slab reaches the horizontal conveyance section from this state, the surface portion on the side in the direction of the center of curvature, that is, the upper surface side, changes to tensile stress, and the surface portion on the side in the direction of IL1 in the curved base, that is, The stress on the lower surface changes to compressive stress. For this reason, the tensile stress generated on the upper surface side of the continuous cast steel piece J5 in the horizontal conveyance section causes cracks to occur on the soil surface of the continuous cast steel piece, causing internal cracks in the continuous cast steel piece.

As a method to prevent this, for example, when the continuously cast steel billet reaches the horizontal conveyance section, a cold 7
i11 Water is applied to reduce the elongation strain due to the tensile stress on the upper surface side. For this reason, the concentration on the upper surface side of the continuously cast steel slab is lower than that on the lower surface side.
As in the case of zero C, the difference in crystallinity between the negative side and the bottom side may be up to 200 b%.

As shown in Fig. 1, for example, V-shaped blades 1.1 of 1-j, which are vertically opposed to each other with a piece of steel 2 in between, are equally spaced. The horn bites into the steel piece 2 at a speed that moves the steel piece 2 to I, IJ [Ifi 17. Then, the temperature of the steel piece 2 is higher on the lower side 2b than on the upper side 2a, so the lower blade 1
Since the biting resistance against the steel piece 2 is small, the lower blade 1 bites into the steel slab 2 more than the lower blade 1, as shown in FIG. This biting difference C determines, for example, the temperature condition of an old piece of steel, and is about 25 mm for a steel plate with a thickness of 280 mm.

When such a phenomenon occurs, the steel billet 2 iJl is conveyed by the conveyance 1]-ra3 soil as shown in FIG. As the steel piece 2 is cut in the state shown in FIG. The conveyance rollers 3a and 3b located on the left and right sides of the lower blade 1 are used as fulcrums, and are bent downward and bite into the rollers 3a and 3b. The cutting force of the sword 1/)1+ acts directly on the rollers 3a, 31) via the steel piece 2. For this reason, the conveying roller 3 may be damaged or damaged, and it is necessary to make the conveying roller 3 itself sturdy. Furthermore, the JF marks of the rollers are also generated on the steel piece 2 itself, which reduces the value of the product.
There were drawbacks such as loss of IF. In addition, if excessive bending is applied to the steel slab 2 in this way, it may cause distortion in the steel slab 2 and defects in the internal weave in an unsolidified state, reducing the product value, or causing a pinch in the continuous casting machine. Is it too much for 1-le? It was stabilized due to the action of u4 and inhibited the extraction of 1ζ slab. In Fig. 3, the symbol (]l- represents the pass line of the steel billet 2, and the upper ends of all the conveyance rollers 3 are positioned above this pass line.In addition, each conveyance roller 3 is of a fixed type. be.

The present invention has been developed in view of these drawbacks, and therefore, when a steel piece is cut by a pair of V-shaped or approximately V-shaped blades that are placed vertically opposite each other with the steel piece in between, the lower In the vicinity of the blade, above the pass line of -1, while maintaining the desired gap between the bottom surface of the billet and the pass line of the billet,
Try to avoid turning off 147;.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

First, the first embodiment will be explained in detail.

In the embodiment not shown in FIG. 4, while cutting a steel piece 2 whose temperature is higher on the lower side 2b than on the first side 2a, the lower surface of the steel piece 2 near the lower blade 1 is always cut. Set level 1-1 to lower blade 1 using the level detection device! The steel piece 2 in the vicinity of the lower blade 1 is detected by the two level detection rollers 4.4 placed on the right side, and the absolute speeds of the upper blade 1 and the lower blade 1 are controlled. The lower surface level I-L and the pass line P1- of the steel billet 2
The following describes a method for cutting a steel billet by keeping the gap A constant at f:L++1' to avoid applying cutting force to the conveying roller 3.

This method will be explained based on FIG. 5, which shows an example of a cutting device to which the present invention is applied.

First, to explain the structure of this cutting device 5, inside the main body frame 6, from top to bottom, an upper blade platen 7, a lower blade platen 8, and a bottom platen 9 are provided so as to be freely movable with respect to the main body frame 6. The two-blade platen 7 and the bottom platen 9 are integrally connected by a tie bar 10 slidably penetrating the lower blade platen 8. On the other hand, the lower blade platen 8 is integrally connected to a cutting ram 11 built in a ram chamber 11a which is provided in the bottom platen 9. A holding cylinder 14 is interposed, and its piston rod 14a is connected to the bottom platen 9. Also, a pullback cylinder 15 is provided between the lower blade platen 8 and the bottom platen 9. Further, V-shaped blades 1.1, which are an example of a cutter according to the present invention, are respectively attached to the upper blade platen 7 and the lower blade platen 8 so as to sandwich the steel J-'12 and face each other. . Level detection rollers 4.4 are provided on the left and right sides of the lower blade 1 below the steel piece 2, and this level detection roller 4.4 has one end attached to the main body frame 6 so as to be rotatable. The installed clevis-type cylinder/7'12 is rotatably attached to the tip of the piston rod from diagonally below (J is installed, -10,000,
It is supported diagonally from above by a connecting member 13, such as a turnbuckle, whose one end is rotatably supported on the main body frame 6. Therefore, each level detection roller of +5 4.4
By expanding and contracting the piston rod of the cylinder 12, the connecting member 13 can be attached to the main body frame 6 at the fulcrum 1.
It moves rotatably around 33a.

The level detector 1j-ra 4.4 that has been formed in this manner is then lifted upward by a desired distance near the blade 1 as shown in FIG. (:lJ) tl
During C1 cutting, contact with the lower surface 2b of the steel slab 2 to be cut, and the downward displacement of the lower surface 2+1 of the steel slab 2 is stopped.J'
Let's make tris come out. At this time, an earth force of 61 degrees is applied to the l\rad of the cylinder 12, which receives the own weight of the steel slab 2.Then, the T surface 21 of the steel slab 2
The speed of the piston rod 14a of the holding cylinder 14 is controlled according to the displacement at. In addition, level detection I]-ra 4.4 has such a configuration, so that during cutting, for example, due to a malfunction, the cutting force of the blade 1 acts and the steel piece 2 is pushed down. In such cases, it is pushed down one step downwards, so it can also function as a so-called depressing roller.
It's safe.

Note that if the piston rod of the cylinder 12 is extended, the blade 1
It is also possible to act in the vicinity to lift the steel piece 2 upward, for example. In addition, level detection [Cola 4.4
is the piston rod of the cylinder 12 and the connecting member 1.
3. When the steel piece 2 is not cut, the upper end of this level detection 1 cola 4.4 is aligned with the pass line P1-, so that the steel Let's take a look at the role of the 1112 feed roller for piece 2.

On the other hand, for level detection, on the left and right of 1-La 4.4, there are a plurality of steel plates I' with their ends aligned with one pass line L of steel slab 2
A fixed type 1 general feed roller 3 for d' 2 is provided.

Using the cutting scissors @5 configured in this way, the following 4
Cut using this method.

When the steel piece 2 being conveyed comes to the position where it is to be cut,
The conveying roller 3 is driven to the first position, and the steel piece 2 is stopped on the 1 m conveying roller.

In this state, first, hold the lower blade 1, synchronize the cylinder 12.12 for the right level detection roller 4.4, and lift both level detection rollers 4.4 upward by an equal amount. Raise #'l E' 2 near upper blade 1 to pass line l
p r et al. desired m△ () have'' - Ruru. This lifting amount A is, for example, 10 mm &! for steel j'12 with a plate thickness of 28 Q mm. It does not give any strain or internal defects to the steel (J) 12 due to bending, and the J:
It is desirable to make the pole diameter as small as possible to accurately control the speed of the holding cylinder 14.

Next, as mentioned above, move the desired row 1△ near the lower blade 1. Symmetrical position I.

At this time, the holding cylinder 14d3 and the bullback cylinder 15 are used.

Cutting is started in this state. First, the cutting ram cylinder 11 is activated and the lower blade 1 is raised relative to the bottom platen 9 at a speed of V. At the same time, the holding cylinder 14 is activated and its piston l Kotto 14a V/2
Lower it at a speed of 1.

As a result, the upper blade 1 descends at a speed of V/2, and the lower blade 1 +
, tv - (v/2) = v/2. Therefore, the upper blade 1 and the lower blade 1 each rise at the same speed V/2 at time r.

In this way, the upper blade 1 and the lower blade 1 each start to bite into the steel slab 2, but for the steel slab 2 whose lower surface side 2b is higher in temperature than the upper surface side 2a, the upper surface side 2a and the lower surface side of the steel slab 2 211
The biting resistance of the cutter 1 differs between the two, and this resistance is smaller on the lower surface side 2b.

Therefore, as the cutter 1 bites, the lower blade 1 bites into the steel piece 2 more than the three sides 1, so the grip near the blade 1 -
■The bent steel piece 2 is pushed downward, and the initially set lifting amount △ decreases.

When this happens, the level detection roller 4.4, which is in contact with the lower surface 211 of the steel billet 2, descends together with the tip of the steel billet 2. Then, the Jz descending speed trace v/2 of the piston rod 14a of the holding cylinder 14 is reduced by a desired amount mα in accordance with this descending amount. That is, the absolute descending speed of the upper blade 1 is (
Move the holding cylinder 14 so that v/2>-α1w. At this time, the rising speed V of the cutting ram 11 relative to the bottom platen 9 is always kept constant. Therefore,
As mentioned above, the lower speed of the upper blade 1 is α t) Small and narrow TJ, the rising speed of the lower blade 1 is α and the absolute speed of the lower blade 1 is (v/2>10 α Therefore, the relative speed between the lower blade 1 and the first blade 1 is always a constant speed V. To adjust the blade speed of the upper and lower blades 1.1, set the cutting inner 1111 ram cylinder 11 to the speed control 911 SaU this year-(Saru,
Because this cutting ram cylinder 11t exerts a greater cutting force, the cylinder becomes larger (1).Actual speed control is difficult; It is easy to obtain reliable speed control.

In this way, the biting speed of the upper blade 1 is reduced, and the lower blade 1
By increasing the biting speed, the downward descent of the steel piece 1 is prevented. This J: control is always performed during cutting, and the steel piece 2 is cut while keeping the initially lifted ff1A substantially constant. Therefore, no cutting force is applied to the conveying roller 3 via the steel piece 2.

Then, the 1-blade 1 and the lower blade 1 bite into the steel piece 2 and the cutting is completed, but at the time the cutting is completed, the upper surface side 2a of 800
degree 01 lower side 2b is 900-1000 degrees C and upper side 2a
The temperature difference between and the bottom side 2b is 200 degrees G, and the thickness is 2F3Q
For a steel piece 2 of mm, the biting difference C between the upper and lower blades 1.1 is
will still be approximately 25 mm. Note that FIGS. 4 and 5 show the state immediately before the cutting is completed.

When the cutting is completed, the holding cylinder 14 and the pullback cylinder 15 are activated, the upper blade 1 and the lower blade 1 are moved from the steel piece 2 to the R1, and the two level detection rollers 4.4 are gradually lowered. In order to make the cut, the steel piece 2 held up near the sword 1 is lowered downward, the lower surface 21) of the steel piece 2 is returned to the pass line, and the conveyance roller 3 is driven to make the cut. ...Send the treated steel piece 2 to the next process. Then, the uncut piece of steel 2 is cut to the point where it should be cut.
'/, S, From here on, the same cutting operation is carried out, and the steel pieces 2 are successively cut.

In addition, in the IC product explained above, a steel piece 2 is cut which has higher wet marks on the lower surface side 2b than on the lower surface side 2a. ! However, in most cases, the temperature of the continuous piece of steel 2 is lower on the lower side 21) than on the negative side 2.
Is it higher than a, or is the position k in the length L 7j direction
In A3, there is a frequency (although it is less, on the contrary, the upper surface side 2a is higher than the lower surface side 2b, or the upper surface side 2a is higher than the lower surface side 2b).
The temperatures on the lower surface side 2 () may become equal or J. For example, when cutting at a position where the temperature of the upper side 2a is higher than that of the lower side 20, the upper blade 1 cuts the steel piece 2 more than the lower blade 1, contrary to the above. 7J, hold the steel piece 2 upwards and turn it so that it is -1tt. Therefore, in this case, lower blade 1 and upper blade 1
The speed is controlled as follows.

First, at the start of cutting, the two level detection rollers 4.4 are lifted upward and I5, as in the case of cutting the steel piece 2 whose lower surface side 2b has higher humidity than the upper surface side 2a. Then, move the steel M'2 upward in the vicinity of the lower blade 1 at a desired mA.
(For example, lift 10101R. In this state, use the holding cylinder 14 and pullback cylinder 15 to lift the upper blade 1.
and the lower blade 1 are placed in the lower position with the steel blade 2 in between. Then, in the same manner as described above, the ram 11 for one mole is raised upward at a speed of V, and the piston rod 1 of the holding cylinder 14 is moved upward.
4a is lowered at a speed of v/2. That is, the upper blade 1 and the F blade 1 are lowered at the same speed v/2,''4
? Then the cutting will begin. Then, as the double blade 1.1 bites into the steel piece 2, the initial position near the lower blade 1 (■Ata(
] The steel piece 2 that has been lifted up is further lifted upwards, and the level detection roller 4 follows.
4 and start moving upwards. After passing over the lifting stone A set in the first position, the cutting ram 11
Assuming that the rising speed ■ is constant, contrary to the above, the absolute descending speed of the piston rod 14a of the holding cylinder 14 is set to be faster than the initial setting value A by an amount commensurate with the lift R). do. That is, the holding cylinder 14 is controlled in speed so that the absolute descending speed of the lower blade 1 is (V/2>10β.As a result, the absolute ascending speed of the F sword 1 is (v/2>10β).
/2>-β. In this way, when cutting at a position where the temperature of the steel piece 2 is higher than the upper surface side 2a or the lower 1T11 side 21), the biting speed of the upper blade 1 is increased during cutting 1111i, and the upper blade 1 is By reducing the biting speed, the lifting phenomenon of the steel plate 2 is prevented,
Near the lower blade '116, the lower surface level 1-1- of the steel piece 2
and the pass line PL while keeping the gap almost constant.

On the other hand, even when cutting at a position where the temperature is different between the upper surface side 2a and the lower surface side 211, only the desired portion A of the steel piece 2 is cut at the initial stage of cutting.
Lift it up so that it will be cut.

d5, the puff of the steel piece 2 is on the top side 2a is 1τ side 2
When cutting a position higher than b, (61
, during cutting, the steel piece 2 is naturally lifted upwards, while,
When cutting at a position where the temperatures of the upper surface side 2a and the lower surface side 2b are equal, the steel j-12 does not move, so it can be completed without the need for such control.
If you always hold the cutting device upward in this way, you can control the operation of the cutting device more reliably without using compound interest, and even if the device malfunctions, Even if the steel piece is pushed downward and becomes free due to an abnormal load, it is possible to more reliably prevent cutting force from acting on the conveying roller 3.

In this way, while the relative speed of the upper blade 1 and the upper blade 1 is kept constant, the absolute speed of the upper blade 1 and the lower blade 1 is controlled. If J3 is placed in the vicinity of 1, the lower surface level L of steel slab 2 and the pass line 1] 1 is cut so as to maintain the gap approximately at -a, #I I"+'
Generally speaking, the lower side 21) is higher than the lower side 2a by 6, but even in this case, or when this is reversed, or between the lower side 2a and the lower side 21), 17
It is possible to correspond to any case, even if the positions where the angles are equal are facing each other.

Next, a second example will be described.

This method uses the level detecting roller 4.4 as described above and a polishing detection device η for the steel piece 2 to detect the upper surface side 2a of the steel piece 2 in the vicinity of the lower blade 1. and bottom side 2b
Detects the actual temperature of the steel plate, predicts and calculates the amount of cutting into the steel piece 2 by the one-tooth blade 1 and the lower blade 1 according to this humidity, and similarly calculates the lower surface level L1- of the steel piece 2 and the pass line PL. Lower blades 1 and 1 should be cut so that the gap is uniformly cut
- 1-) to control the speed of the blade 1.

As an example of the cutting device in this case - (J, not shown in Fig. 5, in the cutting device 5, the level detection rollers 4.4 located on the left and right sides of the lower blade 1 are fixed-type general feeders). -", > binding, one end of this roller 4.4 may be aligned with the pass line 1). Then, the temperature of the 1st surface 2aJ5 and the lower surface 21 of the steel 12 can be detected. IJJ IIJi device 5 by installing the wrong humidity detection device respectively.
Provided on the 11 sides between the upper blade 1 and the upper blade 1 of the main body frame 6,
Steel piece 2 at the position to be cut + Ai 2 il i1j
A calculation device (not shown) that detects the actual surface temperature Iff of the upper and lower surfaces 21 and predicts and calculates the amount of penetration of the upper and lower blades 1 into the steel 112 corresponding to the surface temperature conditions of the upper and lower surfaces. I decided to input the surface temperature of the navel.
A speed control command is issued from the arithmetic unit to the holding cylinder 14 in response to the lower blade 1 and the biting of the lower blade 1, and during cutting, the lower surface level L L of the steel piece 2 and the pass line are set near the lower blade 1. For example, while keeping the relative speed of the upper blade 1 and the lower blade 1 constant so that the gap with the PL is almost constant, the absolute speed of the upper blade 1 and the lower blade 1 is adjusted to the surface temperature Iq of the steel piece 2. Control under appropriate conditions.

In addition, various biting skewers into the steel piece 2 by the upper blade 1 and the lower blade 1 are input in advance into the calculation device according to the temperature of the upper surface side 2a and lower surface side 21 of the steel piece 2. .

That is, for example, if the temperature of the steel slab 2 is higher on the lower surface side 21) than on the lower surface side 2a, the lower blade 1 will have more biting J, and as a result, 1!11"12 Clear skies below.

To avoid this, the absolute speed of the upper back of the lower blade 1 is controlled to be greater than the absolute downward speed of the upper blade 1, so that the lower surface level of the slab 2 and the pass line P1 are always controlled during cutting.
-The gap between the two ends should be kept almost constant. In this way, the phenomenon in which the cutting force acts on the conveyance roller 3 via the steel piece 2 during cutting can be prevented. I can do it.

In addition, in the above first and second embodiments, the case where the relative speed of the upper blade 1 and the lower blade 1 is kept constant and the absolute speed of the blade 1 and the lower blade 1 is avoided is explained. , of course, is not limited to this case. For example, while changing the phase difference 4j between the upper blade 1 and the lower blade 1, i.e., while changing the cutting speed, ]-blade '1 and lower blade Change the absolute velocity of 1 t
! You can also use the 911 system.

Next, the third embodiment will be explained with reference to FIGS.

This method is generally used for the -C bottom side 21] or the second side 2a.
When starting cutting...1 on a steel piece 2 whose temperature is higher than Blade due to difference 1.
The difference in the biting amount of 1 is C. [Holding piece 2 with lower blade 1]
Then, the upper blade 1 is brought into contact with the upper surface side 2a of the steel piece 2 in this state, that is, in the state shown in FIG. Y? This is to cut the steel piece 2.

As an example of a cutting device applied to this method,
As shown in the figure, in the cutting joint 5, both level detection rollers 4.4 are connected in the same manner as described in the second embodiment.
Fixed type conveyance with the pant aligned with the pass line P L []-
It is spelled La3.

This cutting method will be explained based on such a cutting device 5.

At the beginning of the cutting process, first, as shown in FIG.
m11 +-, is the tip of the lower blade 1 and the lower surface 2 of the steel piece 2
At least a little more than the distance l1Ill L between the upper and lower blades 2a and 21) of the upper and lower blades 21) of the steel billet 2 due to the humidity difference. 2C () Set the amount of the upper blade 1 and lower blade 1 for the steel piece 2 so that it becomes larger.

In addition, according to the setting procedure I for the upper and lower blades 1.1 at this time, as shown in a3 in Fig. 5, for example, the piston rod 14a of the holding cylinder 1/1 is in the three-way stroke D-L or the upper stroke. The cutting ram 11 may be placed near the end of the stroke, and the cutting ram 11 may be placed near the end of the lower stroke or the end of the stroke.

Then, in the state shown in FIG. 7, the cutting ram 11 moves up the bottom platen 9 at a speed v? At the same time, lower the screw (-) of the holding cylinder 14 at a speed of v/2. In this way, the upper blade 1 and the lower blade 1 must be lowered and raised at the same speed, v7'2 and up, respectively. become.

Then, the upper blade 1 and the upper blade 1 each advance toward the steel piece 2, and the lower blade 1 moves a distance L2 (at the point when the upper blade 1 moves upward, the tip of the lower blade 1 moves toward the lower surface of the steel piece 2. 2b, and roughly hold the steel piece 2 near the lower blade 1 from the pass line l) l.
The distance is 1111 C while being ILJ, and it is 1 when it is on the upper back.
- abuts against the upper surface 2a of the blade 1 or the piece of steel 2; The state of 4 at this time is shown in Figure 3.

From this state, the upper blade 1 and the lower blade 1 begin to bite into the steel piece 2, and cutting is started. The lower blade 1 bites into the steel piece 2 whose temperature is higher on the lower side 2b than on the upper side 2a, and as the cutting progresses, the steel piece 2 The river C lifted by the lower blade 1 gradually decreases and is pushed downward. When the cutting is completed, the lower surface 2b of the steel piece 2 is aligned with the pass line P1-
Return above. Therefore, during cutting, the lower surface level L L of the steel piece 2 and the pass line p are always maintained in the vicinity of the lower blade 1.
Since the cutting can be performed while maintaining the gap between the steel M'2 and the conveying roller 3
can be prevented from acting on

d3, when the steel piece 2 is lifted near the lower blade 1 at the beginning of cutting, m is determined by the biting difference C between the upper and lower blades 1.1 (as mentioned above, for example, with a desired margin of 25 mm), For example, it is safer to do it as C+10-25+10=351111+1.In addition, this margin should be as small as possible to reduce the thermal effect of bending on the steel billet 2.
It is preferable to set it in a range where the influence of the impact load, etc. applied to the conveyance roller 3 when the steel piece 2 falls after cutting is completed is small.

In addition, even if the continuous steel slab 2 is cut at a position where the temperature of the upper surface side 2a is higher than that of the lower surface side 2b, or when the temperature of the upper surface side 2a and the lower surface side 21) are equal, Even if there is a case of cutting C, it may occur infrequently.C11) If the steel piece 2 is always lifted to one side with the lower blade 1 at the beginning of cutting as described in q, The method for making step 1 is easy.

In the embodiments described above, the V-shaped blade 1 was taken as an example of the blade L12, but the blade according to the present invention (not limited to this), for example, as shown in FIGS. As shown, single-stage blades 20 to 23 or multi-stage blades 24 to 27 having a ■ shape or a substantially ■ shape may be used.

Furthermore, the cutting part to which the present invention is applied; as an example of this, the steel piece 2 is stopped at a cutting part j~ as shown in FIG. 5, and the steel piece 2 is cut. Fixed j (glue [IJi
Although the device 5 has been described, the cutting device applied to the present invention is not limited to this, and for example,
While conveying the steel piece 2, the cutting blade 1.20 to 2
It may be a so-called running type cutting device that cuts the steel sheet 2 while moving the steel sheet 7.

As is clear from the above description, the present invention provides a method for cutting a piece of steel with a pair of ■-shaped or approximately V-shaped blades that are placed vertically opposite each other while holding a piece of rope between them. J5
Since the steel billet is cut while maintaining the desired gap between the bottom surface of the steel billet and the pass line of the billet above the pass line of the billet, the cutting force of the blade is not applied to the conveying roller during cutting. It is possible to prevent the effects of cavities.

Therefore, breakage and damage to the conveyor roller can be eliminated.
Not only can smooth operation be performed, but also operational efficiency can be improved. Then, there is no need to make the conveyance rollers more sturdy than necessary.

Since the latch does not apply excessive bending to the steel billet, there will be no damage to the internal structure of the steel billet, which is not yet solidified due to high humidity. Since there are no impressions or the like on the conveying rollers, the value of the product is not lost and products of stable quality can be obtained.

When the present invention is applied to, for example, a running-type cutting device installed at the rear of the continuous casting H rig, an excessive load may not be applied to the pinch rolls, etc. at the end of the continuous casting device. Since there is no mold, stable continuous casting is possible.

From the above, when cutting a piece of steel with a pair of V-shaped or approximately V-shaped blades, it is possible to sufficiently pull out the cut pieces. In other words, the cut section is preformed into a tapered shape at the same time as it is cut, and the cut burr is generated near the center in the thickness direction, so the cut steel piece is passed through a rolling roll. The extended opening (), the reduction of the so-called cropping amount of the irregularly shaped portions that occur at the front and rear ends of the product, and the reduction of the amount of bald spots (1) can be made, contributing to an improvement in product yield.

In addition, since the cutting part is tapered, there is no chance of the cut steel piece being poked by the conveyance roller when it is conveyed by the conveyance roller, and the resistance to biting into the rolling roll is also very good. Operation efficiency can be improved.

[Brief explanation of the drawing]

Figure 1 is a diagram explaining the conventional cutting method, and Figure 2 is a diagram explaining the difference in biting between the upper and lower blades when cutting by the conventional method.
FIG. 3 is a diagram explaining the state of a steel billet when it is cut by a conventional cutting method, FIG. 4 is a diagram explaining one embodiment of the present invention, and FIG. FIG. 6 is a front view (partial view) showing one example of the cutting device applied to the present invention, FIG. 6 is a diagram illustrating another embodiment of the present invention, and FIG. FIG. 8, which is a supplementary explanation of the embodiment shown in the figure, shows another embodiment of the blade according to the present invention. 1.20-27...V-shaped or approximately V-shaped blade, 2.
... Steel piece, 3 ... Conveyance roller, 4 ... Level detection roller, 5 ... Cutting device, 7 ... Upper blade platen, 8 ...
...Lower blade platen, 9...Bottom platen, 11...
・For cutting 1~. 14...Holding cylinder, PL...
Pass line, LL...lower surface level of steel billet. Figure 1 Figure 3 Figure 6 Figure 8 (A) (B) (C) (D) (E) (F) (G) (H)

Claims (4)

[Claims] (1) Steel pieces are arranged vertically facing each other with the steel pieces sandwiched in between.
When cutting with a pair of V-shaped or approximately V-shaped blades,
A method of cutting a steel billet in the vicinity of the lower blade, above the pass line of the steel billet, while maintaining a desired gap between the lower surface of the steel billet and the pass line of the billet. Cut IIi method. (2) While cutting a 1M piece, the level detection device always detects the lower surface level of the steel piece near the lower blade, and by controlling the absolute speed between the upper blade and the lower blade, 2. The method for cutting a steel billet according to claim 1, wherein the steel billet is cut while keeping a substantially constant gap between the lower surface of the steel billet and a pass line of the steel billet. (3) While cutting a steel piece, by detecting the temperature on the upper and lower sides of the steel piece with a temperature detection device, the calculation device predicts and calculates the amount of penetration of the lower blade into the steel piece. , a patent characterized in that by controlling the absolute speeds of the upper and lower blades, the steel billet is cut while keeping the gap between the lower surface of the steel billet and the pass line of the steel bill substantially constant in the vicinity of the lower blade. A method for cutting a steel piece according to claim 1. (4) When starting cutting, place J5 near the lower blade, and at least check the difference in the biting depth m between the upper and lower blades. The method for cutting a steel billet according to claim 1, characterized in that the steel billet is cut by bringing the upper blade and the lower blade into contact with each other and biting into the steel billet at the same speed.