JPH05285607A - Device for controlling roll shape in twin roll type continuous caster - Google Patents

Abstract

PURPOSE:To correct thermal deformation of one pair of water cooling roll constituting a mold part caused by the sensible heat of molten metal in good responsiveness and to cast a cast strip having uniform thickness. CONSTITUTION:In a twin roll type continuous caster for casting the cast strip W by continuously supplying molten metal R into the mold part formed with one pair of the water cooling rolls 1, 1 rotated in mutually reverse direction, this device is composed of a mechanical volume expanding means (hydraulic chamber 53) arranged into both end parts in the shaft direction of the water cooling roll 1, a strip shape detecting means for measuring thickness distribution in the width direction of the cast strip W and an expanding quantity control means (control device 55) for adjusting expanding quantity in the mechanical volume expanding means by the detected value of the strip shape detecting means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a twin roll type continuous casting machine for mechanically correcting a change in shape due to a heat load of a water cooling roll.

[0002]

2. Description of the Related Art In a twin roll type continuous casting machine, the outer peripheral surface of a water-cooled roll expands due to the heat load caused by the sensible heat of the molten metal, and the axial expansion expands both ends of the outer peripheral surface in an arc shape in the roll axial direction. Since it is deformed to, the gap between both ends of the mold in the plate width direction expands, and the plate shape of the slab (plate thickness difference in the plate width direction)
Becomes worse. In order to solve this inconvenience, Japanese Unexamined Patent Publication No.
No. -104449 "Roll shape control device for twin roll type continuous casting machine" has been proposed.

In this device, as shown in FIGS.
Molten steel R is continuously supplied to a mold part formed by a pair of water-cooled rolls 1, 1 rotating in opposite directions shown by arrows and a pair of side dams 2 arranged so as to slide on both axial end surfaces thereof. Then, the slab W solidified into a plate shape is continuously cast. The outer peripheral surface shape of the water-cooling roll 1 whose both ends 1 are respectively deformed by δ ₀ by the heat load from the molten steel R is heated by the heater blocks 3 installed at both ends of the water-cooling roll 1 to expand in the circumferential direction. I am trying. The plate shape detector 4 detects the difference between the minimum plate thickness and the minimum plate thickness in the entire width L of the cast slab W coming out of the mold part, and sends the signal to the current controller 5, which in turn outputs this signal. The current value transmitted to the heater block 3 is controlled based on As a result, the heating amount of the heater block 3 is adjusted, both ends 1 of the water-cooling roll 1 are expanded in the circumferential direction and the surface shape is changed, and thermal deformation of both ends l of the water-cooling roll 1 is corrected. The shape of the mold W in the plate width direction can be maintained well.

[0004]

However, the above-mentioned conventional device has the following problems. (1) Water-cooled roll 1 due to thermal expansion of heater block 3
Since the outer peripheral surface of is deformed, it is necessary to bring the heater block 3 and the water cooling roll 1 into close contact with each other.

Therefore, the heater block 3 and the heater block fitting groove of the water-cooling roll 1 require a high degree of machining accuracy, and the machining thereof requires a long time. (2) Since the response of expansion and contraction of the heater block 3 due to temperature increase / decrease is slow, control of the plate shape of the slab is delayed. (3) Since the heater of the heater block 3 has a short life,
Frequent replacement will increase line downtime and reduce its productivity.

The present invention is intended to provide a roll shape control device for a twin roll type continuous casting machine which can solve the above problems.

[0007]

According to the present invention, a molten metal is continuously supplied to a casting mold formed by a pair of water-cooled rolls rotating in opposite directions to continuously cast a slab solidified into a plate shape. In the twin roll type continuous casting machine, mechanical volume expansion means respectively installed in both axial end portions of the water-cooled roll, plate shape detection means for measuring the plate width direction thickness distribution of the cast piece, And an expansion amount control unit for adjusting the expansion amount of the mechanical volume expansion unit according to the detection value of the plate shape detection unit.

[0008]

When the molten metal is continuously supplied to the casting mold and the strip-shaped slab is continuously cast, the outer peripheral surface of the water-cooled roll is subjected to a heat load due to the sensible heat of the molten metal, and the gap between both axial ends of both water-cooled rolls is increased. The space is enlarged, the plate width at both ends of the cast piece is increased, and the plate shape is deteriorated.

Therefore, in the present invention, the plate shape detecting means detects the difference between the central plate thickness and the both end plate thicknesses from the thickness distribution of the slab in the plate width direction, and controls the detected value for the expansion amount. Send to the means. The expansion amount control means expands the mechanical volume expansion means according to the detected value, and expands both axial ends of the water-cooling roll in the circumferential direction by this expansion to correct the deformation of the outer peripheral surface of the water-cooling roll.

Since the plate shape of the slab changes from moment to moment during casting, the plate shape detecting means always detects the plate shape and transmits the detected value to the expansion amount control means, which then expands. By adjusting the amount of expansion of the mechanical volume expansion means based on the detected value, the shapes of both ends of the water-cooled roll can be corrected quickly with good responsiveness, and the plate shape of the cast piece can be maintained well.

[0011]

1 is a plan view of the essential portions of a first embodiment of the present invention, and FIG. 2 is a side view of the same embodiment. In FIGS. 1 and 2, reference numeral 1 denotes a pair of water-cooled rolls that rotate in opposite directions as shown by arrows, and inside thereof, a water supply port 1a and a drainage port 1e provided near the axis and a water supply port 1a. A large number of water supply channels 1b connected to the water supply channel 1b, a plurality of water cooling paths 1c connected to the water supply channel 1b and extending near the outer peripheral surface of the roll 1, and a large number of drainage paths 1d connected to the water cooling path 1c and the drain port 1e.
Ring-shaped recesses are formed on the entire circumference of both end surfaces of the water-cooling roll 1 in the axial direction, and a hydraulic chamber 53 is formed by the expansion and contraction ring 52 that covers the recesses. Each hydraulic chamber 53 is connected to a hydraulic source (not shown) via a rotary joint 54 and a servo valve 56.

Reference numeral 2 denotes a pair of side dams, which are arranged so as to slide on both axial end surfaces of the rotating water-cooling roll 1, and are molded by the outer peripheral surfaces of both water-cooling rolls 1 and 1 and a pair of side dams 2 and 2. The part 6 is formed.

Numeral 4 is a plate thickness distribution of the entire width of the cast slab W (plate shape)
Is a plate shape detector for detecting the temperature of the water-cooled rolls 1, and is disposed at the slab outlets of both water-cooled rolls 1.

Reference numeral 55 is a control device, which is connected to the plate shape detector 4 and the servo valve 56. Then, as shown in FIG. 3, the control device 55 includes a plate shape allowable value comparison unit 61 to which the signal of the plate shape detector 4 is input, an expansion amount calculation unit 62,
The servo valve operation instructing unit 63 and the plate shape allowable value storage unit 64 that outputs the input plate shape defect value to the plate shape allowable value comparing unit 61 are configured.

In this embodiment, the molten steel R is continuously supplied to the mold part 6 while cooling and rotating both the water cooling rolls 1,
This is solidified to continuously cast a strip-shaped slab W. At this time, the outer peripheral surface of the water-cooled roll 1 is deformed by the heat load due to the sensible heat of the molten steel R in the same manner as in the conventional apparatus, and the plate thickness of the cast slab W becomes thicker at both ends, resulting in defective plate shape.

In order to prevent this defective plate shape, the plate shape detector 4 constantly detects the plate shape of the cast slab W to detect the cast slab W.
Always detect the difference in plate thickness between the center and both ends in the plate width direction of
This signal is transmitted to the control device 55. The plate shape allowable value storage unit 64 of the control device 55 is preliminarily input with the allowable value of the plate shape defect, and the plate shape allowable value comparison unit 61 calculates the plate shape detected value as the plate shape detected value as shown in FIGS. 3 and 4. If the detected value exceeds the allowable value, the expansion amount calculating unit 62 calculates the required expansion amount of the hydraulic chamber 53, and the servo valve operation instructing unit 63 operates the servo valve 56. Pressure oil is supplied to the hydraulic chamber 53 to expand the hydraulic chamber 53. Thereby, the deformation of the outer peripheral surface of the water-cooled roll 1 is corrected, and the plate thickness difference of the slab W in the plate width direction is kept within the allowable value. When the plate thickness at both ends of the cast slab W becomes smaller than the plate thickness at the central part, the expansion amount of the hydraulic chamber 53 is reduced by the same method as described above.

A second embodiment of the present invention will be described with reference to FIGS. In this embodiment, a rubber bag or a steel bellows 73 connected to a rotary joint 54 is used as a mechanical volume expanding means instead of the expansion ring 52 of the first embodiment, and all the end faces of the water-cooling roll 1 are covered. A ring-shaped stopper 72 is mounted inside a ring-shaped recess formed around the circumference, covers a rubber bag or a steel bellows 73, and is mounted such that the outer peripheral side end also slides on the end face of the water-cooling roll 1. The other configurations are similar to those of the first embodiment.

In this embodiment, instead of the hydraulic chamber 53 of the first embodiment, pressure oil is supplied to a rubber bag or a steel bellows 73 via a servo valve 56 to expand its volume, thereby water cooling. Correct the deformation of the outer peripheral surface of roll 1,
This is to improve the plate shape of the cast slab W.

[0019]

According to the present invention, the thickness distribution of the slab in the plate width direction is detected, and the volume of the mechanical volume expansion means installed at both axial ends of the water-cooling roll is adjusted by the detected value to obtain the molten metal. By correcting the axial shape of the outer peripheral surface of the water-cooled roll which is deformed by the heat load due to the sensible heat, the following effects can be obtained. (1) Since the processing for mounting the mechanical volume expansion means does not require high accuracy, the processing time can be shortened. (2) Since the responsiveness when adjusting the expansion amount, that is, when correcting the axial shape of the water-cooled roll is improved, it is possible to perform timely plate shape control of the slab. (3) Since the mechanical volume expansion means has a long life, the frequency of replacement is reduced and the downtime of the line is reduced, so that the productivity is improved.

[Brief description of drawings]

FIG. 1 is a plan view showing a main part of a twin roll type continuous casting machine according to a first embodiment of the present invention.

FIG. 2 is a side view of the embodiment.

FIG. 3 is a block diagram of a control system of the same embodiment.

FIG. 4 is a flowchart of a control procedure of the embodiment.

FIG. 5 is a plan view showing a main part of a twin roll type continuous casting machine according to a second embodiment of the present invention.

FIG. 6 is a side view of the embodiment.

FIG. 7 is a plan view showing a main part of an example of a conventional twin roll type continuous casting machine.

FIG. 8 is a side view of the conventional twin roll type continuous casting machine.

FIG. 9 is an explanatory view showing thermal deformation of a water-cooled roll of a conventional twin roll type continuous casting machine.

[Explanation of symbols]

 1 Water-cooled roll 2 Side dam 4 Plate shape detector 6 Mold part 52 Expansion ring 53 Hydraulic chamber 55 Control device 56 Servo valve 72 Stopper 73 Rubber bag or steel bellows R Molten steel W Slab

Claims (1)

[Claims] 1. A twin roll type continuous casting machine for continuously casting a slab solidified in a plate form by continuously supplying a molten metal to a mold portion formed by a pair of water-cooled rolls rotating in opposite directions, Mechanical volume expansion means respectively installed at both ends in the axial direction of the water-cooled roll, plate shape detection means for measuring the plate width direction thickness distribution of the cast piece, by the detection value of this plate shape detection means A roll shape control device for a twin roll type continuous casting machine, comprising: an expansion amount control means for adjusting an expansion amount of the mechanical volume expansion means.