JPH07108436B2 - Twin roll type continuous casting machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a twin roll continuous casting machine for manufacturing a thin plate material by rotating a pair of rolls arranged in parallel.

[Conventional technology]

The twin roll type continuous casting machine forms a solidified shell on the surface of both rolls while pouring molten metal between the rolls, and rotates the rolls in opposite directions so that the two solidified shells become the narrowest of the twin rolls. It is a thin plate continuous casting machine that manufactures thin plates by pressure bonding at the gap.

Here, a schematic diagram of a typical example of a twin roll type continuous casting machine is shown in FIG.
Shown in the figure. The ejection hole 4 of the nozzle 3 between the two rolls 1 and 2
More molten metal is supplied and the molten metal pool 5 is formed. This molten metal pool 5 has a long side weir 6 and a short side weir 7 as two rolls 1.
It will be pooled in the space formed by combining 2 without any gaps. The long side weir 6 and the short side weir 7 are made of heat-resistant refractory,
The temperature drop of the molten metal in the molten metal pool 5 is prevented. Roll 1,2
On the surface of, the molten metal is cooled with time, solidified shells 8 and 9 are formed, and by pressing the rolls in the direction of the arrow, the solidified shells 8 and 9 are pressure bonded at the twin roll narrowest gap portion C, and the thin plate 10 is manufactured.

By the way, Japanese Utility Model Laid-Open No. 58-157249 (hereinafter referred to as Document 1)
The method of continuously producing a thin plate using twin rolls, as disclosed in, is compared with a case where a slab is produced by a conventional slab continuous casting machine and rolled to obtain a thin sheet,
This is an extremely economical method because thin plates can be manufactured from molten metal at once.

In such a twin roll type continuous casting machine, a weir for pooling the molten metal between two rolls, that is, the sealing of the molten metal between the long side weir or the short side weir and the roll, which is described in the above-mentioned Document 1, is the present technology. This is the most important issue for achieving.

In the above-mentioned Document 1, a method of supplying a fluid such as an inert gas or oil between the roll and the weir in order to ensure this molten metal seal is adopted.

However, when the solidified shell cooled and shaped by the two rolls is pressure-bonded at the narrowest gap of the twin rolls, a separating force acts to separate the two rolls from each other.

Due to this separating force, the set gap between the two rolls changes in the example of the above-mentioned document 1. Therefore, a gap is formed between the roll surface and the weir, and sometimes at the seam between the short side weir and the roll. If this gap becomes large, the molten metal will penetrate into the seam,
As it solidifies and damages the short side weir, normal operation cannot be continued. This problem occurs not only in the case where the entire short-side weir is mounted inside both end faces of the roll as in the above example, but also in the case where a part of the short-side weir is mounted inside both ends of the roll. Also,
A continuous casting machine of the type in which the short side weir is pressed against the roll end surface has also been researched for practical use.However, in this type of continuous casting machine, the part of the short side weir that comes into contact with the roll end surface is a metal The part to be touched is made of refractory, so if the set gap between the two rolls increases, the molten metal will contact the metal part of the short side weir,
It solidifies, and when it is sent downward and crimped, a large resistance is generated. This force not only further increases the gap between the rolls but also spreads the short-side weir in the axial direction of the roll, creating a gap between the short-side weir and the roll end face. Increase must be avoided.

The method of supporting the separating force acting between the rolls described above is as follows.
The method disclosed in Japanese Patent Publication No. 147650 (hereinafter referred to as Document 2) is adopted.

That is, one roll is fixedly attached to a stand, and the other roll is brought close to or separated from this roll by a screw or the like, and a gap between the rolls is set.

In the twin roll type continuous casting machine of such a supporting method, when a separation force is generated between the rolls due to pressure bonding of the solidified shell, the clearance between the rolls changes by about 1 mm due to the bending of the screw and stand. As a result, a separation force of about 20 tons per 100 mm width of the manufactured plate acts, and a separation force of 200 tons is generated when trying to obtain a thin plate with a width of 1000 mm, and the rigidity of the screw and stand is also increased. Depending on the rigidity of the normal design, they are separated by about 1 mm.

If the twin rolls are separated from each other in this way, a gap is inevitably formed at the joint between the roll shown in Document 1 and the short side weir, and the molten metal leaks out, making it impossible to continue the casting operation. .

Therefore, in order to prevent the molten metal from leaking, it is desirable that the permissible gap of the joint be 0.2 mm or less. In order to do this, even if the rigidity is linear even in the low load range, it will be 1/5 of the current bending of 1 mm, so the cross-sectional area of the screw and stand will increase five times. It is an economy.

As a method for solving this drawback, Japanese Patent Application Laid-Open No. 61-212451 (hereinafter referred to as Document 3) is proposed. The technology disclosed in this is a skillful method of increasing the rigidity without increasing the cross-sectional area of the screw and stand, and interposing a rigid member that fixes the narrowest gap between the bearing boxes that support the roll. By providing an urging device for applying a tightening force larger than the maximum expected separating force to the rigid body member and keeping the tightening force constant, a member that is deformed by the separating force even if the separating force is generated becomes a rigid body member. It is limited.

As another method for solving the above-mentioned drawbacks, there is disclosed in JP-A-60-837471.
Japanese Patent Publication (hereinafter referred to as Document 4) is presented. The technique disclosed therein adopts a separation force support method similar to that of Document 2, but a load cell is installed between a bearing box and a cylinder supporting the same, and the separation force is detected to detect the separation force. The difference is that the narrowest roll gap is adjusted depending on the size.

[Problems to be Solved by the Invention]

In the prior art disclosed in the above-mentioned document 3, the twin rolls are heated during casting, and therefore the roll gaps must be expanded with time to compensate for the narrowest gap due to the radial thermal expansion of the twin rolls. Is not considered,
There has been a problem that the slab thickness gradually decreases, especially at the beginning of casting.

It should be noted that this Document 3 also shows an embodiment in which the lengths in the mutually opposing direction can be adjusted by using wedges, but this is for facilitating the change of the slab plate thickness during non-casting. During casting, it functions as a rigid body and does not solve the above problem.

Further, the conventional technique disclosed in the above-mentioned document 4 does not consider the reduction of the narrowest gap due to the thermal expansion of the twin rolls, and has the same problem as in the above-mentioned document 3. Even if this is taken into consideration when adjusting the roll gap, no consideration is given to the fact that the relationship between the load and the deformation becomes non-linear in the low load range, and the seal between the roll and the weir cannot be reliably performed. There was a problem.

It is an object of the present invention to minimize the change in the gap between the twin rolls caused by the separation force during pressure bonding of the solidified shell acting between the twin rolls to ensure the seal between the roll and the weir, and to make the roll gap necessary. According to the adjustment, the thickness of the product can be prevented from changing and stable casting operation can be performed.

[Means for Solving the Problems]

In order to achieve the above object, according to one aspect of the present invention,
A thin plate material is continuously manufactured by injecting a molten metal between a pair of rolls arranged in parallel and pressing the solidified shell generated on the roll surface at the narrowest gap between the pair of rotating rolls. In the twin roll type continuous casting machine, a rigid member that is provided between the bearing boxes that support the rolls and fixes the gap in the narrowest gap between the pair of rolls, and at least the bearing box. An urging device that is provided between one side and the housing and that applies a clamping force that acts on the rigid member side, a load meter that detects the force that acts on the urging device, and a signal from this load meter A twin roll type continuous casting machine including a calculation control device for calculating and controlling a stroke of an urging device is provided.

According to another aspect of the present invention, the molten metal is injected between a pair of rolls arranged in parallel, and the solidified shell formed on the roll surface is pressure-bonded at the narrowest gap between the pair of rotating rolls. A twin roll type continuous casting machine that continuously manufactures thin plate materials by being provided between the bearing boxes supporting the rolls to expand the gap of the narrowest gap between the pair of rolls. A pressure device, a biasing device that is provided between at least one of the bearing boxes and the housing, and applies a clamping force that acts on the pressure device side, and a load that detects the force that acts on the pressure device. There is provided a twin roll continuous casting machine including a meter, a device for detecting the amount of change in the bearing box spacing, and an arithmetic control device for arithmetically controlling the stroke of the biasing device based on a signal from the detection device.

According to still another aspect of the present invention, a molten metal is injected between a pair of rolls arranged in parallel, and a solidified shell formed on the roll surface is pressed at the narrowest gap between the pair of rolls. A twin roll type continuous casting machine that continuously manufactures thin plate materials by performing the above process, and presses the gap of the narrowest gap between the pair of rolls provided between the bearing boxes supporting the rolls. A pressure device that expands, a biasing device that applies a clamping force that acts on the pressure device side to at least one of the bearing boxes, a load meter that detects the force that acts on the pressure device, and the biasing device. There is provided a twin roll type continuous casting machine including a load meter that detects a force acting on the load meter, and a control device that changes the output of the pressurizing device to make the detection signal of the load meter constant.

[Action]

Generally, when several members are piled up and pressed, (1) unevenness of the seam (2) due to partial contact of the contacting member surfaces, the relationship between load and deflection is as shown in FIG. It is known that it exhibits large deformation and its characteristics are non-linear. Since the conventional technique of Document 4 considers this relationship to be linear, if the separation force is detected and an attempt is made to control the bearing box spacing so as to be constant, the following inconvenience occurs.

(1) When the separation force P is generated by using the spring constant K in the high load range, the bearing box space is narrowed by P / K.

This method causes insufficient correction of δ1.

(2) Let PA be the target crimping load and δA be the deflection at that time, and let K ′ be the gradient of the straight line passing through the origin and the point (δA, PA).
When the separation force P is generated, the bearing box space is narrowed by P / K '.

This method causes overcorrection or deficiency of δ2 or δ3 when P is different from PA.

According to the first aspect of the present invention, a rigid member for fixing the gap of the narrowest gap between the pair of rolls is interposed between the bearing boxes to reduce the tightening force of the biasing device to the low rigidity. Since the bearing box spacing is controlled to set the range above the range and the deflection due to the load is canceled in the range where the relationship between the load and the deflection is linear, the narrowest gap C between the rolls when the separating force acts.
It is possible to reduce the correction error of the gap.

According to the first aspect of the invention, the pressure of the pressurizing device is set to be in the low rigidity region or above, and the bearing box spacing is controlled to cancel the deflection due to the load within the range where the relationship between the load and the deflection is linear. It is possible to eliminate the correction error of the clearance of the narrowest clearance C between the rolls when the separating force is applied.

However, in the present invention, since the deformation amount of the screw and the stand also changes when the separating force changes, the second invention is
By increasing or decreasing the pressing force by the increase or decrease of the separating force and keeping the tightening force constant, it is intended to reduce the change of the bearing box interval and increase the rigidity itself. By doing so, the rigidity equal to or higher than that of the above-mentioned conventional example can be obtained, and further, the roll gap can be adjusted during casting as required for the thermal expansion compensation of the roll. According to the second aspect of the present invention, the thermal expansion amount of at least one of the rolls 1 and 2 during casting is detected in the first aspect, and (1) when the thermal expansion amount of one roll is detected: Part 2
(2) When the amount of thermal expansion of two rolls is detected, the urging device 15 is driven by the total amount to control the roll gap so that the roll gap is expanded. It is possible to prevent a reduction in plate thickness due to thermal expansion of the roll, which is a drawback of the apparatus.

Next, the relationship between the tightening force F, the separating force P, and the gap change δ of the bearing boxes 11 and 12 due to the separating force P in this device will be described with reference to the drawings.

First, set the distance between the bearing boxes 11 and 12 from the roll shafts 17 and 18 to the bearing boxes.
The force to push and spread 11, 12 acts, Fig. 1, 2
It is defined as the distance between points A and A'in the figure or in Figure 3.

The spring constant of the member from the point A to the bearing box 11, the rigid body 13, the bearing box 12, and the point A'is Kb (hereinafter referred to as the rigid body spring constant), and from the point A, the bearing box 11, the biasing device 15, the stand 14 or Cover member
19, load cell 16, bearing housing 12, spring constant up to A'point is Kh (hereinafter referred to as housing spring constant), initial tightening force Fo
Let us consider the separation force P and the change δ in the spacing between the bearing housings 11 and 12 when the bearings 11 and 12 are overwhelmed.

Repulsive force R is applied to the rigid member 13 by applying the initial tightening force Fo.
= Fo is applied and δ1 is compressed by Fo / Kb, the separation force P increases and a gap is created between the rigid body member 13 and the bearing housings 11 and 12, and no force is applied to the rigid body member 13. The separation force P1 is P1 = (Kb + Kh) ・ δ1 …… (1) Becomes When P <P1, F = P + R holds, and P = (Kb + Kh) · δ (3) When P = P1, R = 0 and F1 = P1. If the separation force P becomes larger than this value and the rigid member 13 is no longer exerted, (P-P1) = Kh ・ (δ-δ1) ∴P = Kb ・ δ1 + Kh ・ δ = Fo + Kh ・ δ (4) Become. This relationship is shown in Figure 3A.

Next, the relationship between the separation force P and the tightening force F is as follows: When P = 0, F = Fo (5) If F ≦ F1 from Eqs. (5) and (6) Therefore, when F ≧ F1, the rigid body member 13 is not overloaded, so naturally P = F. It is understood that if the tightening force F is detected from the above equations (7) and (8), the separating force P at that time can be obtained.

On the other hand, the relationship between the tightening force F and the change δ in the spacing between the bearing housings 11 and 12 is F ≦ F1 When F ≧ F1 Therefore, there is a state in which the force is not applied to the rigid body member 13 depending on the magnitude of the separation force P, and there is a state in which the force is not applied, but the relationship between F and δ is expressed by the same formula in both states. This relationship is shown in Figure 3B. Therefore, the amount of increase in the tightening force during casting Fc
If −Fo is known, δc at that time can be calculated by the above formula. Therefore, if the stroke of the urging device 15 is controlled so as to cancel it, the spacing between the bearing boxes 11 and 12 changes even if the spacing force P fluctuates. Can be reduced.

Further, when the roll gap is reduced by ΔD due to the thermal expansion of the rolls 1 and 2, in order to widen the roll gap, the separating force in the state in which the stroke of the biasing device 15 is changed by S in the direction of expanding the roll gap from the above state. The relationship between P and the change δ in the spacing between the bearing housings 11 and 12 is expressed as follows using the symbols shown in FIG. 2A. In the figure, the state when S = 0 is broken line 10,
The states where the sizes of S are different are shown by broken lines 11 and 12.

When the stroke of the biasing device 15 is increased, the rigid member 13
Loses power. The value of S at this time is So = (Kh + K
b) ・ Since it is δ1 / Kh, the calculation formula differs depending on whether S is smaller or larger than So.

(1) When S ≦ So (broken line 11) When δ <δ1 R = Kb · (δ1-δ) …… (11) F = F−Kh · (S−δ) …… (12) P = F −R = (Kh + Kb) · δ−Kh · S (13) When δ = δ1, substitutes this into equation (13) and P1 ′ = Kh · δ1 + Fo−Kh · S …… (14) δ> When δ1 P = Fo−Kh · (S−δ) …… (15) (2) S> So (straight line 12) P = Fo−Kh · (S−δ) …… (16) Next, the separation force Stroke S of the biasing device 15 with P = Pc
The relationship between the change Δδ in the spacing between the bearing housings 11 and 12 and S when the value is changed will be described.

Here, Δδ is the difference between the spread amount δc of the spacing between the bearing housings 11 and 12 when P = Pc and the spread amount δc ′ when the stroke of the biasing device 15 is S Δδ = Δδc′−δc. (17)

(1) When Pc ≧ P1 At this time, as shown in FIG. 2A, S increases and P = Pc
Even if δ = δc is larger than δc ′, the relation between P and δ is expressed by the same equations (15) and (16), so Δδ = S (18).

(2) When Pc <P1 When P1 ′> Pc The following relationships are established using equations (3) and (13).

Pc = (Kh + Kb) · δc = (Kh + Kb) · δc'-Kh · S From both equations When P1 '= Pc, use equation (14) From equation (19) When P1 ′ <Pc The following relationships are established using equations (3), (15) and (16).

Pc = (Kh + Kb) .delta.c = Fo-Kh. (S-deltac ') The above relationship is shown in FIG. 2B. If the decrease amount ΔD of the roll gap due to thermal expansion of rolls 1 and 2 is known,
By calculating S for δ = ΔD and controlling the stroke of the urging device 15 to obtain this value, the reduction of the roll gap due to the thermal expansion of the rolls 1 and 2 can be corrected.

At this time, if the stroke S of the biasing device 15 is changed, Pc> P1
If so, the tightening force F does not change, so the roll gap control by F is performed correctly. Conversely, if Pc <P1, the tightening force F
Changes, so we need to consider this effect.

The relationship between F and S is as follows, if only the conclusion is stated.

When P = Pc and stroke S = 0, tightening force is Fc, P = Pc
When the tightening force when the stroke is S is Fc ', when Pc <P1' When Pc> P1 ′ In the fourth embodiment of the present invention, the pressing force of the pressurizing device is set above this low rigidity region, and the bearing box spacing is controlled so as to cancel the deflection due to the load within the range where the relationship between the load and the deflection is linear. Therefore, it is possible to reduce the correction error of the gap of the narrowest gap portion C between the rolls when the separating force acts.

However, in the present invention, since the deformation amount of the stand and the screw also changes when the separation force changes, in the fifth embodiment, the pressing force is increased and decreased by the increase and decrease of the separation force to keep the tightening force constant. It aims to increase the rigidity itself by reducing the change in the bearing box spacing. By doing so, the rigidity equal to or higher than that of the conventional example can be obtained, and the roll gap can be adjusted during the casting as required for the thermal expansion compensation of the roll.

〔Example〕

FIG. 1 shows the basic configuration according to the first embodiment of the present invention.
As shown in the figure, the two rolls 1 and 2 are supported by bearing boxes 11 and 12 that support roll shafts 17 and 18, respectively, and are housed in a stand 14.

The stand 14 has an upper cover member 19, and the rolls 1 and 2 can be recombined by removing this member. A member 13 made of a rigid body is inserted between the two bearing boxes 11 and 12, these are incorporated in a stand 14, and an urging device composed of a worm jack driven by an electric motor 26 between the stand 14 and the bearing box 11. Provide 15 and stand 14
A load detector 16 is provided between the bearing box 12 and the bearing box 12.

The molten metal 5 is made into two rolls 1 and 2 by the ejection hole 4 of the nozzle 3.
It is injected and pooled between the short side weirs 7.

The molten metal 5 is cooled by the rolls 1 and 2 to form solidified shells 8 and 9 (see FIG. 9), but the thin plate 10 is manufactured by rotating the rolls 1 and 2 in the directions opposite to each other in the direction of the arrow.

Prior to the start of casting, the urging device 15 is activated to set the initial setting force Fo.
To act. The roll gap is set to a desired value by changing the length of the rigid member 13. Energizing device at this time
The tightening force Fo of 15 is set to an appropriate value such that the relationship between the tightening force and the bending is in the linear range.

The relationship between the separation force P in this state and the amount of change δ in the bearing box space is shown in FIG. 3A together with the case of the conventional device. As shown in the figure, the rigidity of the rigid body portion contributes in the range of P ≦ P1, and since there is no low rigidity in the low load range as seen in the conventional device, the rigidity can be increased.

In this state, when the separating force P for pressing the solidified shell in the narrowest gap C between the twin rolls 1 and 2 is generated and the tightening force becomes F, the electric motor 26 is driven as follows. By controlling the roll gap by means of a roll, changes in the gap between the twin rolls 1 and 2 are reduced.

The arithmetic unit 22 calculates the amount of change δ of the distance between the bearing housings 11 and 12 corresponding to the separation force P using the signal F from the load detector 16 by the formula δ = (F−Fo) / Kh Energizing device by multiplying control gain α
Make 15 required strokes. The magnitude of the control gain α is selected in the range of 0 to 1 so that the control characteristic does not become unstable. The controller 25 compares the signals α and δ from the arithmetic unit 22 with the current stroke, and if there is a difference, outputs the rotation speed N of the electric motor 26 to the electric motor 26 so as to eliminate the difference. That is, if the spacing force P increases, the spacing between the bearing housings 11 and 12 will be α
-(F-Fo) / Kh is controlled so as to decrease with respect to the spacing between the bearing housings before the separation force P is generated.

By controlling in this way, the apparent spring constant Kc in the housing portion becomes large as Kc = Kh / (1-α).

Next, a second embodiment of the present invention will be described with reference to FIG. Here, the description of the same parts as those in the first embodiment will be omitted. As shown in FIG. 2, gear sensors 20, 21 are provided so as to face the lower ends of the rolls 1, 2. The detection values of the gear sensor 20, 21 are sent to the arithmetic unit 23. In this embodiment, the initial tightening force Fo is selected so that Pc> P1, and the signal S calculated by the arithmetic unit 23 using the above equation (18) is added by the adder.
Sent to 24. Here, the signal S and the signal −α · (F−Fo) / Kh from the arithmetic unit 22 are added. The controller 25 compares the signal from the adder 24 with the current stroke, and if there is a difference, outputs the rotation speed N of the electric motor 26 to the electric motor 26 so as to eliminate it.

When Pc <P1, the arithmetic unit 22 uses the equation (7),
(8) is used to calculate P from F, and this is calculated by the calculation device
23, and in the arithmetic unit 23, equations (18), (19), (2
The stroke S of the biasing device 15 may be calculated by using 1) and (22), and at the same time, the stroke S may be output to the calculation device 22 to correct the change in F due to the stroke S.

Next, a third embodiment of the present invention will be described with reference to FIG. Here, the description of the same parts as those of the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 2 will be omitted. As shown in FIG. 3, the computing unit 27 calculates the separation force P from the signal F from the load detector 16 by the equations (7) and (8), and the separation force P is calculated according to the change of the separation force P. The rotation speed of the rolls 1 and 2 is controlled so that the force P becomes constant.

That is, since the rolls 1 and 2 are driven by the motor 36 via the pinion stands 32 and 33 and the shafts 34 and 35, the rolls 1 and 2 are compared with the set value Po of the setter 37 so that the separating force P becomes constant. By doing so, the arithmetic and control unit 38 can adjust and control the speed of the motor 36. As a result, the separation force P related to defects such as slab cracking and porosity can be maintained at an optimum value.

In the above embodiment, the explanation has been made by focusing on the change in the spacing between the bearing boxes 11 and 12, but the computing device 22 computes the spacing force P, and from this the flatness of the roll surface and the bending of the roll shafts 17 and 18 are calculated. If the roll opening amount is calculated and added to the amount of change in the gap between the bearing boxes 11 and 12 to control the roll gap, more accurate constant roll gap control can be performed.

Further, in the above-described embodiment, the gearup sensors 20 and 21 are used to detect the thermal expansion amount of the rolls 1 and 2, but this is (1) The relationship between the casting time and the thermal expansion amount is obtained in advance, and Inferred indirectly from the relationship.

(2) The roll temperature is measured instead of the thermal expansion amount, and the thermal expansion amount of the roll is indirectly estimated from this.

Of course, the same effect can be obtained by adopting the above method.

Next, a fourth embodiment of the present invention will be described with reference to FIG. Here, the description of the same parts as those in the first embodiment shown in FIG. 1 will be omitted. As shown in Fig. 4, two bearing housings 11, 12
A pressure device 13 'is inserted between them. These two bearing boxes 11 and 12 are pressurized by supplying hydraulic pressure from the pump 44 to the pressurizing device 13 'via the hydraulic pressure switching valve 46.
The pressing force is adjusted by adjusting the hydraulic pressure with the hydraulic pressure adjusting valve 45 so that the pressing force is equal to or higher than the low rigidity region. This hydraulic pressure is detected by the compression cell 40.

Prior to the start of casting, the pressurizing device 13 'was activated to set the initial setting force.
While applying Ro, the biasing device 15 sets the roll interval to a desired value. The tightening force Fo of the urging device 15 at this time is Fo =
Ro is set to an appropriate value such that the relationship between the separation force and the deflection is in the linear range by adjusting the pressure adjusting valve 45.

The change amount detecting device of the gap between the bearing housings 11 and 12 in the fourth embodiment is composed of a load detector 16, a pressure cell 40, an arithmetic and control unit.
43, and detects the change amount δ as follows.

That is, the arithmetic unit 42 compares the signal F from the load detector 16 with the value R obtained by converting the measured value pM of the hydraulic pressure on the pressurizing device 13 'into a load, and the difference signal P = F- The R is output to the arithmetic and control unit 43. In the fourth embodiment, the pM during casting is measured to correct the transient fluctuation of the hydraulic pressure supplied to the pressurizing device 13 'when the stroke of the biasing device 15 is changed. It is not always necessary, and P = F-Ro may be set.

In the arithmetic and control unit 43, the amount of change δ in the distance between the bearing boxes 11 and 12 corresponding to the separating force P is calculated by δ = P / K, where K is the spring constant in the bearing box, and the control gain α To obtain the required stroke of the biasing device 15. The magnitude of the control gain α is selected in the range of 0 to 1 so that the control characteristic does not become unstable. This is compared with the current stroke, and if there is a difference, the rotation speed N of the electric motor 26 is output to the electric motor 26 so as to eliminate it.
That is, if the spacing force P increases, the spacing between the bearing boxes 11 and 12 is controlled to decrease by .alpha..multidot. (P / K) with respect to the spacing between the bearing boxes before the spacing force P is generated. By controlling in this way, the apparent spring constant Kc in the bearing housing is Kc = K /
It becomes as large as (1-α), and by superimposing the roll thermal expansion compensation signal on the roll gap control signal, not only the load variation during casting but also the roll gap variation due to the roll thermal expansion can be reduced.

Next, a fifth embodiment of the present invention will be described with reference to FIG. Here, the description of the same parts as those of the first embodiment shown in FIG. 1 and the fourth embodiment shown in FIG. 4 will be omitted. As shown in FIG. 5, the two bearing boxes 11 and 12 are pressurized by the pressure device 13 '. This pressure is used to adjust the hydraulic pressure
Adjusted by adjusting by 58, the hydraulic pressure is detected by the press cell 40. The secondary pressure of the hydraulic pressure adjustment valve 58 is
The characteristic is that the higher the value of the current supplied to this, the higher the voltage.

Prior to the start of casting, the pressurizing device 13 'was activated to set the initial setting force.
The roll gap is set to a desired value by the biasing device 15 while operating Ro. The tightening force Fo of the urging device 15 at this time is Fo = Ro
And is set to be larger than the expected maximum value of the separation force P.

In this state, when the separation force P for pressing the solidified shell in the narrowest gap C between the twin rolls 1 and 2 is generated and the tightening force becomes F, the pressing force R is controlled as follows. By doing so, the change in the gap between the twin rolls 1 and 2 is reduced.

The signal F from the load detector 16 and the signal Fo from the target load setting device 59 are compared by the arithmetic unit 50, and the difference signal ΔF = F between them.
-Fo is output to the arithmetic and control unit 51.

The arithmetic and control unit 51 calculates the hydraulic pressure pA corresponding to Ro-ΔF, and the actual measured value p of the hydraulic pressure applied to this and the pressurizing device 13 '.
When pM> pA, the current signal to the hydraulic pressure adjusting valve 58 is reduced to lower the hydraulic pressure. If pM <pA, control is reversed. By controlling in this way, F is always kept at a constant value Fo, so that when the separation force P is generated,
Two bearing boxes 11 and 12, which were inevitable in the case of Reference 3,
The change of the member inserted between the bearing boxes 11 and 12 is eliminated, and the rigidity can be increased correspondingly, and it is also possible to compensate for the change of the roll gap due to the thermal expansion of the roll as in the fourth embodiment.

Next, a sixth embodiment of the present invention will be described with reference to FIG. Here, the description of the same parts as those of the first embodiment shown in FIG. 1 and the fifth embodiment shown in FIG. 5 will be omitted. As shown in FIG. 6, the separation force is calculated from the signal F from the load detector 16 and the value R obtained by converting the measured value pM of the hydraulic pressure on the pressurizing device 13 'into a load by the equation P = F-R. P is calculated, and the rotational speeds of the rolls 1 and 2 are controlled so that the separating force P becomes constant according to the change in the separating force P.

That is, since the rolls 1 and 2 are driven by the motor 66 via the pinion stands 62 and 63 and the shafts 64 and 65, the rolls 1 and 2 are compared with the set value Po of the setter 67 so that the separating force P becomes constant. The operation control device 68 can adjust and control the speed of the motor 66. As a result, it is possible to maintain the separation force P related to defects such as slab cracking and defects such as porosity at an optimum value.

In the above embodiment, the rolls 1 and 2 are used to keep the separation force P constant.
The rotation speed of the rolls was controlled, but it is not limited to this. (1) Control the height of the pool surface pooled between the rolls 1 and 2 (2) The part of the rolls 1 and 2 that contacts the pool surface It is also possible to adopt an appropriate means such as providing an arc-shaped plate for suppressing the start of solidification on the surface including the above and controlling it at this position, or controlling the clearance between the bearing boxes 11 and 12 by the separating force P in the fourth embodiment. Needless to say, may be used together.

FIG. 7 shows another embodiment of the variation detecting device for the spacing between the bearing housings according to the fourth embodiment. In the fourth embodiment shown in FIG. 4, the amount of change in the spacing of the bearing housings was detected as P / K from the separation force P, but this embodiment directly detects this.

That is, a non-contact displacement gauge 73 is attached to a portion of the casing 70 constituting the pressurizing device 13 ″ facing the shaft center of the anti-rod 71, and the displacement gauge 73 measures the change in the central portion A of the piston 72. The stroke of the biasing device 15 is controlled so that this displacement matches the displacement at the start of casting.

In general, bearing housings 11 and 12 rotate around shafts 17 and 18, and shafts 17 and 1
Since it tilts following the bend of 8, the measurement accuracy can be improved by measuring the axial displacement of the rod 71 as in the present embodiment, as compared with mounting the displacement gauge 73 outside the pressure device 13 ″. Can be made.

In the above embodiment, the explanation has been given with an emphasis on the change in the gap between the bearing boxes 11 and 12, but the arithmetic control unit 43 causes the separation force P to flatten the roll surface and the roll shafts 17 and 18 to open the roll. A more accurate constant control of the roll interval can be performed by calculating the amount and adding it to the amount of change in the interval between the bearing housings 11 and 12 to control the roll interval.

Further, in the above description, the pressure cell 13 is used as the load cell for detecting the force acting on the pressure devices 13 ′, 13 ″,
Pressurizing device 13 ', 13 "when the spacing between bearing housings 11, 12 is large
It goes without saying that appropriate changes can be made without departing from the spirit of the present invention, such as installing a load cell between the bearing housings 11 and 12.

In the twin roll type continuous casting machine of the present invention, the roll diameter is 800 mm.
A twin roll with φ and face length of 1200 mm is used, and S with a plate thickness of 2 to 4 mm
US thin plates could be stably manufactured at a speed of 20-40 m / min.

〔The invention's effect〕

According to the present invention, the change in the gap between the twin rolls caused by the separation force acting between the twin rolls during the pressure bonding of the solidified shell is minimized to ensure the seal between the roll and the weir, and the roll gap is required. In order to perform stable casting work, it is possible to prevent changes in the product plate thickness.

[Brief description of drawings]

FIG. 1 is a structural view showing a first embodiment of the present invention, FIG. 2 is a structural view showing a second embodiment of the present invention, and FIG. 2A is a case where the stroke of the biasing device in the second embodiment is changed. Separation force-deflection diagram, FIG. 2B is a bearing box spacing change-stroke diagram when the stroke of the biasing device in the second embodiment is changed,
FIG. 3 is a structural view showing a third embodiment of the present invention, FIG. 3A is a separation force-deflection diagram of the conventional device and the first, second and third embodiments, and FIG. 3B is a first and second embodiment. And a tightening force-deflection diagram of the third embodiment, FIG. 4 is a structural view showing the fourth embodiment of the present invention, and FIG.
FIG. 7 is a structural diagram showing a fifth embodiment of the present invention, FIG. 6 is a structural diagram showing a sixth embodiment of the present invention, and FIG. FIG. 8 is a structural diagram showing an embodiment, FIG. 8 is a load-deflection diagram for explaining the problems of the conventional apparatus, and FIG. 9 is an explanatory diagram showing the manufacturing principle of a thin plate material by a twin roll type continuous casting machine. 1,2 …… Roll, 11,12 …… Bearing box, 13 …… Rigid member, 1
3 '... pressurizing device, 15 ... biasing device, 16 ... load detector, 22, 27 ... arithmetic unit, 25 ... control unit, 38, 43 ... arithmetic control unit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsugeo Chika 4976 Tomita, Shinnanyo, Yamaguchi Prefecture Shunan Steel Works, Nisshin Steel Co., Ltd. (72) Inventor Shigeru Matsunaga 4976 Tomita, Shinnanyo, Yamaguchi Prefecture Nisshin Steel Co., Ltd. Shunan Steel Works (56) References Japanese Patent Publication No. 5-49383 (JP, B2)

Claims (6)

[Claims] 1. A thin plate material by pouring a molten metal between a pair of rolls arranged in parallel and pressing the solidified shell formed on the roll surface at the narrowest gap between the pair of rotating rolls. In a twin roll type continuous casting machine for continuously manufacturing the above, a rigid member that is provided between each bearing box that supports the rolls and fixes a gap in the narrowest gap between the pair of rolls, and the bearings. A biasing device that is provided between at least one of the box and the housing to apply a clamping force that acts on the rigid member side, a load meter that detects the force that acts on the biasing device, and a load meter from this load meter. A twin roll type continuous casting machine including a calculation control device for calculating and controlling the stroke of the urging device by a signal. 2. The twin roll type according to claim 1, further comprising a device for detecting a thermal expansion amount of at least one of the pair of rolls, and a control device for controlling an interval between the pair of rolls based on the detected value. Continuous casting machine. 3. Clamping force at the start of casting and during casting,
3. A calculation device for calculating a force for separating the pair of rolls during casting from the rigid member and the spring constant of the housing portion, and a control device for controlling the calculated separation force to be constant. Twin roll type continuous casting machine. 4. A thin plate material by injecting a molten metal between a pair of rolls arranged in parallel and pressing the solidified shell formed on the roll surface at the narrowest gap between the pair of rotating rolls. In a twin roll type continuous casting machine for continuously producing, a pressurizing device that is provided between the bearing boxes that support the rolls and that expands the gap of the narrowest gap between the pair of rolls, A biasing device that is provided between at least one of the bearing boxes and the housing and applies a tightening force that acts on the pressure device side, a load meter that detects the force that acts on the pressure device, and the bearing box. A twin roll type continuous casting machine including a device for detecting the amount of change in the interval, and an arithmetic and control unit for arithmetically controlling the stroke of the urging device based on a signal from the detector. 5. A thin plate material by injecting a molten metal between a pair of rolls arranged in parallel and pressing the solidified shell generated on the surface of the roll at the narrowest gap between the pair of rotating rolls. In a twin roll type continuous casting machine for continuously producing, a pressurizing device that is provided between each bearing box that supports the rolls and that expands the gap of the narrowest gap between the pair of rolls, A biasing device that applies a clamping force that acts on the pressure device side to at least one of the bearing boxes, a load meter that detects the force that acts on the pressure device, and a force that acts on the bias device. A twin roll type continuous casting machine including a load meter and a control device that varies the output of the pressurizing device to keep the detection signal of the load meter constant. 6. The twin roll type continuous casting machine according to claim 4 or 5, further comprising detection means for detecting a force for separating the rolls during casting, and a control device for controlling the separation force to be constant.