JP2001009557A - Metal strip continuous casting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately control thickness of a strip during casting. SOLUTION: A pair of parallel casting rolls 1 are mounted to stub shafts 21 and 22 which extend from the ends of the casting rolls 1 and are rotatably fixed to journal bearings 65 and 66, so as to constitute a metal strip continuous casting device. The casting rolls 1 are cooled with a water flow of an inside water flow passage, into which the water is supplied via a rotary water flow joint 40 mounted to the stub shaft 22 at one end of a roll assembly, and are rotated by an electric motor being a roll driving means 71 mounted to the opposite side end of the rotary water flow joint 40 of the roll assembly. The roll driving means 71 is supported on the stub shaft 21 and balanced with the supporting weight of the rotary water flow joint 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal strip continuous casting apparatus.

[0002]

2. Description of the Related Art In a twin-roll casting apparatus, molten metal is introduced between a pair of horizontal casting rolls that are cooled and rotate in mutually opposite directions, a metal shell is solidified on a moving roll surface, and the metal shells are formed in a roll gap. The metal shells are coalesced and fed downward from the nip between the rolls as a solidified strip. As used herein, the term "roll gap" is intended to refer to the entire area where the rolls are closest. The molten metal is poured from the ladle into one or a series of small containers, from which it flows to a metal feed nozzle located above the roll gap and into the roll gap, and consequently roll casting just above the roll gap A casting pool of molten metal supported on the surface can be formed. Usually, the casting pool is surrounded by side dams or side plates which are held in sliding engagement with the roll end faces to prevent overflow from both ends of the casting pool, but alternative means such as an electromagnetic barrier have also been proposed. Have been.

[0003]

In the twin-roll casting apparatus, the casting rolls must be set accurately, and the gap between the rolls must generally be correctly set to several mm or less. Some means must be provided to allow at least one of the casting rolls to move outward against the biasing force to absorb the pressure. Normally, one of the casting rolls is mounted on a fixed journal, and the other roll is rotatably mounted on a movable support against the action of the biasing means, so that it can be moved laterally to absorb variations in strip thickness. You can do it. The biasing means may be a coil spring or a pair of pressure fluid cylinder devices.

A strip casting apparatus that spring biases a laterally movable casting roll is disclosed in Australian Patent Application No. 85185/98. In this device, a bias spring acts between the roll support and a pair of thrust reaction structures, and the initial pressure of the spring is adjusted by setting the position of the thrust reaction structure by operating a pair of powered mechanical jacks. The initial pressure at both ends of the roll can be set equal. In order to produce a constant profile strip, the position of the roll support needs to be set and adjusted later so that the roll gap is uniform across the width of the roll.

When manufacturing a thin strip, particularly when manufacturing a strip having a thickness of 1 mm or less, the roll biasing force is very important, and these forces need to be as small as possible for accurate control. Thus, the dynamic biasing of the equilibrium forces of the rotating casting rolls can be very significant, which can prevent accurate control of the strip thickness during casting.

[0006] Australian Patent Application No. 85185/9
In the conventional casting apparatus disclosed in No. 8, each of the shafts to which the casting rolls are attached has a water flow joint, and the water flow joint has a longitudinal direction in which cooling water is spaced apart around the rolls via the shaft and a duct in the casting roll. Supply / discharge to the directional cooling passage. Each of the water flow joints is disposed at one end of a casting roll assembly, and the casting roll is driven by a common drive motor via a drive shaft connected to a stub shaft at the same end of the roll assembly. In this configuration, the rotating mass associated with the casting roll cannot be dynamically balanced, making it extremely difficult to provide adequate roll clearance for small strip thicknesses. The present invention provides an improved continuous metal strip casting apparatus that allows for a good dynamic balance of the rotating mass. The rolls can also be independently speed controlled, which can be beneficial for accurate strip thickness control as described later herein.

[0007]

According to the present invention, a pair of parallel casting rolls forming a roll gap therebetween, and a molten metal is supplied to the roll gap between the casting rolls to form a casting roll immediately above the roll gap. A metal supply means for forming a casting pool of molten metal supported on the surface, a storage enclosure means for enclosing the molten metal in the casting pool so as not to flow out from the end of the gap between the rolls, And a roll drive means for producing a solidified metal strip fed downward from the roll gap, wherein a stub shaft of each casting roll extends from both ends of the casting roll to rotate the casting roll about a central roll axis. The stub shaft at one end of the roll assembly was mounted on the stub shaft at the one end of the roll assembly, as mounted in journal bearings at both ends of the casting roll. In a metal strip continuous casting apparatus, which has an inner water flow duct connected to a water flow coupling and flowing water into and out of a water flow passage in a casting roll, a roll driving means is provided on each of the stub shafts at the end of the roll assembly on the side of the non-rotating water flow coupling. Provided is a metal strip continuous casting apparatus comprising a pair of roll drive motors mounted one by one, and supporting a roll drive means on a stub shaft to balance with a supporting weight of a rotary water flow joint at the other end of the stub shaft.

Preferably, a journal bearing attached to at least one of the casting rolls is supported on a pair of movable roll carriers that allow one casting roll as a whole to move toward and away from the other casting roll. A biasing means for biasing the casting roll to the other casting roll is provided.

[0009] Preferably, the roll drive motor as the roll drive means is an electric motor.

Preferably, the equilibrium relationship between the roll drive motor, which is the roll drive means, and the rotary water flow joint is such that the center of mass of each roll rotating structure is located substantially at the center between the journal bearings of each roll. is there. Further, the driving motor as the roll driving means can be constituted by a rotor fixed to each stub shaft and a stator supported on the stub shaft.

[0011] The stator can be supported on the stub shaft by rotational engagement with the rotor.

In order to provide an effective balance, the stators of the drive motor, which is the roll drive means, are supported on each stub shaft, and the stators are prevented from rotating in a less than completely supported manner. It's important to. For example,
The stator is a bearing support housing adjacent to the roll end, etc.
It can be engaged with a restraining pin driven to a predetermined position by a fluid cylinder device from a mounting portion at an appropriate position in the machine.

The drive motor can be operated to allow independent speed control so that the phase of the roll can be changed during casting. This can be very beneficial in resolving differences in solidification rates between the two casting rolls due to differences in surface properties.

In this way, since the weight of the rotary hydraulic joint and the total weight of the electric drive motor as the roll driving means are balanced, a dynamically balanced rotary assembly is achieved, and consequently the thickness of the strip being cast is reduced. Accurate control can be performed.

Further, since a small biasing force is applied to the casting roll by the biasing means, even with a small strip thickness, it is possible to operate with an appropriate roll gap and an effective dynamic balance of the rotating structure. .

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 to 4 show an embodiment of the present invention.
It is constituted by a casting roll 1 which is a pair of twin rolls forming a roll gap 2 therebetween. During the casting operation, the molten metal is supplied from the ladle 3 through the tundish 4 and the supply nozzle 5 to the roll gap 2 between the casting rolls 1 to create a casting pool 6 of the molten metal above the roll gap 2. Casting pool 6
Are engaged with the notched end of the casting roll 1 as shown below. Ladle 3
By moving the slide gate valve 8 provided in the tank, the molten metal can flow from the ladle 3 to the tundish 4 through the refractory shroud 9.

The casting roll 1 is provided with an inner water-cooling passage to which cooling water is supplied from the end of the casting roll 1 in a manner described in detail below. 11 is produced and fed downward from the roll gap 2 between the casting rolls 1.

To the extent described so far, the illustrated device is disclosed in US Pat. Nos. 5,184,668 and 5,2,698.
77,243 and Australian Patent 6331728.
In more detail. Reference may be made to these patents for details of the construction and operation of the device.

The two casting rolls 1 have the same configuration,
Each of the peripheral surfaces is provided with a longitudinal water flow passage 26, and a radial passage 3 is formed into the water flow passage 26 from one end of the casting roll 1.
Water is supplied / discharged via 5 and 36.

A solid tube or roll body 20 made of copper or copper alloy forming each casting roll 1 is placed between a pair of stub shafts 21 and 22 made of stainless steel.
2 and the roll body 20 are fixed coaxially and the casting roll 1
Mount to form A series of longitudinal water flow passages 26 are provided in the roll body 20 by drilling a long hole from one end to the other end, the end of which is closed by a plug 41 and a stub shaft fixing screw 70 in the manner described below.

An end notch 23 is provided in the tubular roll body 20 so that a pair of shoulders 2 can be engaged with the refractory side plate 10.
4 and a relatively thick walled main portion is formed between the pair of shoulders 24 to define the casting surface 25 of the roll.

Further, the stub shafts 21 and 22 are
End forming portions 27, 28 fitted inside the respective ends of the rolls, and circumferential flanges 29, 3 abutting against the respective wall end surfaces of the roll body 20.
0. The stub shafts 21 and 22 are fixed to the ends of the roll body 20. The stub shafts 21 and 22 pass through holes formed in the circumferential flanges 29 and 30 through stub shaft fixing screws 70, which are fasteners, to form the longitudinal water flow passage 26. This is done by screwing into the thread tapped end of part of the hole. The ends of the remaining holes are closed by stoppers 41 as described below.

A rotary water flow joint 40 that supplies and discharges water through a supply line 31 and a discharge line 32 is fitted to the stub shaft 22. The cooling water extends through the circumferential flanges 29, 30 of the stub shafts 21, 22 and the end of the roll body 20,
Radial passages 35, 36 connected to annular gallery 50
Is supplied to and discharged from the water flow passage 26 in the longitudinal direction. The annular gallery 50 is formed on the outer periphery of the roll body 20 and communicates with the water flow passage 26 in the longitudinal direction of the roll circumference. Stub shaft 2
Central spacer tubes 37 and 38 are fitted into the first and second 22 and form separate inner water flow ducts for water inflow and outflow in the casting roll 1. That is, the radial passage 36 serving as the inner water duct communicates with the supply line 31 through the annular duct 39 and the radial water outlet 33 of the inner water duct arranged outside the central spacer tube 38, while the casting roll 1 The radial passage 35 at the end communicates with the rotary connection at the end of the rotary hydraulic joint 40 via a duct formed by the hollow interior of the casting roll 1 and the interior of the central spacer tubes 37,38.

A rotary water flow joint 40 is connected to a supply line 31 and a discharge line 32 so that water can be supplied and discharged in either direction of the roll.
No. 5,36 can be provided to provide multiple passes of cooling water across the rolls in a manner further detailed in Applicant's Australian Patent Application No. 23779/99.

According to the present invention, the casting roll 1 is driven by an electric drive motor which is a pair of roll driving means 71 directly attached to the shaft at one end of the roll assembly. The roll assembly is supported at the other end of the shaft at the other end in a simplified manner. The stub shafts 21, 22 of the casting roll 1 are mounted on the movable roll carriers 67, 69 via journal bearings 65, 66. The movable roll carriers 67 and 69 can change the roll gap 2 between them by moving the entire casting roll 1 toward and away from each other. The movable roll carrier 69 is movable by a pair of fluid cylinder devices 72 that can lock and hold one of the casting rolls 1 at a fixed position. A spring 68 acts on the movable roll carrier 67, and biases the casting roll 1 supported by the spring 68 toward the other casting roll 1 with an essentially constant biasing force.

The rotor of the electric drive motor serving as the roll drive means 71 is directly connected to the end of the stub shaft 21. The stator of the electric drive motor is supported by the stub shaft 21 via the rotor, and is prevented from rotating by appropriate means. The appropriate means does not support the weight of the electric drive motor, but ensures that the electric drive motor is sufficiently supported at the end of the stub shaft 21. For example, the stator can be restrained by pneumatically or hydraulically driven pins mounted on adjacent roll bearing housings. Thus, by balancing the weight of the rotary water flow joint 40 and the total weight of the electric drive motor serving as the roll drive means 71, a dynamically balanced rotary assembly can be achieved.

The rotary water flow joint 40 is sufficiently supported by the stub shaft 22 close to the journal bearing 65 at the end of the roll assembly on the side opposite to the roll driving means 71. Roll driving means 7
The weight of the electric drive motor, which is 1, is exactly balanced with the weight of the rotary water flow joint 40 of each roll rotary structure, and the center of mass of each roll rotary structure is between the journal bearings 65 and 66 which are roll support bearings. Can be located just in the middle of This greatly reduces vibration and eccentricity control problems. This makes it possible to apply a relatively small biasing force to the moving casting roll 1 with the spring 68 and to operate with a relatively effective clearance control system. The electric drive motor as the roll drive means 71 can be driven independently,
Rotary encoders not only address those speeds due to instantaneous thickness variations due to roll eccentricity, but also allow for phase variations between the two casting rolls and allow for solidification speed differences on the rolls due to other factors. Can be controlled by For example, the casting roll 1 can produce different heat flux values due to differences in the texture of the roll surface.

[0029]

According to the metal strip continuous casting apparatus of the present invention, the following various excellent effects can be obtained.

(I) The balance of the weight of the rotating water flow joint and the total weight of the electric drive motor as the roll driving means is achieved, so that a dynamically balanced rotating assembly is achieved, and consequently the strip thickness during casting is accurately determined. Control can be performed.

(II) Since a small biasing force is applied to the casting roll by the biasing means, even with a small strip thickness, it is possible to operate with an appropriate roll gap and an effective dynamic balance of the rotating structure. it can.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a continuous metal strip casting apparatus constructed according to the present invention.

FIG. 2 is a view showing one section of a casting roll of the casting apparatus shown in FIG. 1;

FIG. 3 is a schematic elevation view of a main part of the casting apparatus.

FIG. 4 is a schematic plan view of components of the casting apparatus shown in FIG. 3;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 casting roll 2 roll gap 3 ladle (metal supply means) 4 tundish (metal supply means) 5 supply nozzle (metal supply means) 6 casting reservoir 10 refractory side plate (reservoir surrounding means) 11 solidified metal strip 21 stub Shaft 22 Stub shaft 26 Water flow passage 36 Radial passage (inner water flow duct) 39 Annular duct (inner water flow duct) 40 Rotary water flow joint 65 Journal bearing 66 Journal bearing 67 Movable roll carrier 68 Spring (deviation means) 71 Roll driving means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Heiji Kato 2-36-2 Nobi, Yokosuka City, Kanagawa Prefecture (72) Inventor John Andrew Fish Australia 2517 New South Wales Unona Charlotte Harrison Drive 6

Claims (7)

[Claims] A pair of parallel casting rolls (1) forming a roll gap (2) between them, and a molten metal is supplied to a roll gap (2) between the casting rolls (1) to form a roll gap (2). Metal supply means (3) (4) for forming a casting pool (6) of molten metal supported on the casting roll surface immediately above
(5) and a storage enclosing means (1) for enclosing the molten metal in the casting pool (6) so as not to flow out from the end of the roll gap (2).
0) and a roll driving means (71) for rotating the casting roll (1) in the mutual direction to produce a solidified metal strip (11) fed downward from the roll gap (2). Journal bearings (65) (66) at both ends of the casting roll (1) such that the stub shafts (21) (22) of each casting roll (1) extend from both ends of the casting roll and rotate the casting roll (1) about the center roll axis. ), Mounted inside the stub shaft (22) at one end of the roll assembly
An inner water flow duct (36) connected at one end of the roll assembly to a rotary water flow fitting (40) mounted on a stub shaft (22) to allow water to flow into and out of a water flow passage (26) in the casting roll (1). (39) In the continuous metal strip casting apparatus having a roll drive means (71), a pair of roll drives each having one roll drive means (71) attached to each of the stub shafts (21) at the end of the roll assembly on the side of the non-rotating water flow joint (40). A motor is provided, and the roll driving means (71) is driven by a stub shaft (2).
1) A continuous metal strip casting apparatus characterized in that the metal strip is supported on the stub shaft (22) and balances with the supporting weight of the rotary water flow joint (40) at the other end. 2. The journal bearings (65) and (66) attached to at least one of the casting rolls (1) are provided so that one casting roll (1) as a whole can move toward and away from the other casting roll (1). Pair of movable roll carriers (67)
2. The continuous metal strip casting apparatus according to claim 1, further comprising a biasing means (68) supported thereon for biasing one casting roll (1) with respect to the other casting roll (1). 3. 3. The metal strip continuous casting apparatus according to claim 1, wherein the roll drive motor serving as the roll drive means (71) is an electric motor. 4. A rotator having a roll driving motor (71) fixed to each stub shaft (21);
3. The continuous metal strip casting apparatus according to claim 2, comprising a stator supported on a stub shaft (21). 5. The continuous metal strip casting apparatus according to claim 4, wherein the stator is supported on the stub shaft (21) by rotational engagement with the rotor. 6. The continuous metal strip casting apparatus according to claim 5, wherein the stator is prevented from rotating in a manner that does not support the weight. 7. An equilibrium relationship between a roll drive motor as a roll drive means (71) and a rotary water flow joint (40) is as follows.
7. A continuous metal strip according to any one of the preceding claims, wherein the center of mass of each roll rotating structure is arranged approximately at the center between the journal bearings (65), (66) of each casting roll (1). Casting equipment.