Patent Grant
8163229
The present invention relates to a support apparatus and method for supporting a long nozzle for discharging molten steel from a ladle to a tundish, an immersion nozzle for pouring molten nozzle from a tundish to a continuous casting mold or the like (hereinafter referred to collectively to “continuous casting nozzle”), while pressing the continuous casting nozzle against a sliding nozzle device (the “sliding nozzle” will hereinafter be abbreviated as SN) installed on a bottom of the ladle, the tundish or the like. The present invention also relates to a SN system comprising the support apparatus, and a continuous casting nozzle adapted to be suitably supported by the support apparatus.
In many cases, a continuous casting nozzle, such as a long nozzle or an immersion nozzle, is used with an SN device. For example, the long nozzle is often used under a condition that it is joined to a lower nozzle installed on a lower end of an SN device for use in discharge control of a ladle, or an intermediate nozzle joined to the lower nozzle. It is also joined to an SN plate installed to a lowermost metal frame, in some cases.
A joining section between the continuous casting nozzle and the SN device is structured such that they are joined together in close contact relation while being constantly pressed against each other in a nozzle axis direction (upward-downward direction). This is intended to shield a molten steel flow from ambient air to prevent oxidation, etc., of molten steel.
As a support apparatus for the continuous casting nozzle associated with the above pressing, the following Patent Document 1 disclosed one type adapted to press a continuous casting nozzle against a molten-steel discharge port by use of an arm as a “pry or lever” member.
Among continuous casting nozzles, a long nozzle to be attached on a lower side of a ladle is large in size and self-weight. Moreover, it is used in circumstances where an operator cannot directly perform an operation, for example, of attaching the long nozzle to a ladle at a position above a tundish. Therefore, the arm is used to support a self-weight of the long nozzle and allow an operator to remotely perform such an operation.
[Patent Document 1] JP 2008-6478A
The support apparatus using the above arm is designed such that a continuous casting nozzle is kept in close contact with and integrated with an SN device only by a surface pressure applied to joined surfaces thereof. Thus, when an SN plate in contact with the continuous casting nozzle is slidingly moved, the continuous casting nozzle is displaced while being dragged by the SN plate. Therefore, in order to prevent the occurrence of a gap in a joined section therebetween during the displacement, it is necessary to apply a surface pressure to the joined surfaces at a value far greater than a surface pressure required just for leakage, oxidation, etc., of molten steel. Specifically, a surface pressure is loaded with a strong force beyond a surface pressure required for maintaining sealing performance, for example, by increasing a length of the arm to obtain a larger lever ratio, or by lifting the arm itself with a larger force. This causes a problem that the support apparatus is increased in size.
Further, the sliding movement of the SN device is along a straight line, whereas a resulting displacement of the arm of the support apparatus is along a circular arc, which means that a direction of the sliding movement of the SN device and a direction of the displacement of the arm are not aligned with each other. Thus, along with the sliding movement of the SN device, a force causing shearing between the SN device and the continuous casting nozzle will act on the joined surface of the SN device with the continuous casting nozzle in a rotation direction. Consequently, a plate brick or the like of the SN device is liable to be damaged, which often leads to deterioration in the close contact in the joined section.
Moreover, after completion of pouring of molten steel, solidified substances, such as solidified steel, remain on respective inner bores of the continuous casting nozzle and the SN device. Thus, it is often the case that the continuous casting nozzle cannot be separated from the SN device simply by releasing the surface pressure and without relying on an additional manual operation.
Therefore, in a support technique for supporting a continuous casting nozzle using an arm, it is an object of the present invention to provide an improved support technique capable of enhancing sealing performance between a continuous casting nozzle and an SN device.
According to one aspect of the present invention, there is provided a continuous-casting-nozzle support apparatus for supporting a continuous casting nozzle while pressing the continuous casting nozzle against a sliding nozzle device. The continuous-casting-nozzle support apparatus comprises: a holding mechanism disposed to extend from a stationary column fixed onto a supporting surface, and adapted to be turnable in a horizontal direction and swingable or movable in an upward-downward direction; a lifting mechanism provided on the side of a distal end of the holding mechanism; a supporting mechanism provided on the side of a distal end of the lifting mechanism, and adapted to support the continuous casting nozzle; and a hooking device provided in the lifting mechanism, and adapted to allow the lifting mechanism to be hooked to a first engagement portion formed on a sliding metal frame of the sliding nozzle device, wherein the lifting mechanism is adapted to lift the continuous casting nozzle through the supporting mechanism.
In the continuous-casting-nozzle support apparatus of the present invention, based on the hooking device, the continuous casting nozzle can be integrated with the SN device with a surface pressure less than ever before to facilitate a reduction in size of the apparatus.
In the present invention, the holding mechanism is provided with the supporting mechanism on the side of the distal end thereof to serve as a means to hold a continuous casting nozzle attached to the supporting mechanism, by an arm extending from the stationary column and others. Specifically, the holding mechanism may comprise a joint 20, a rotary shaft 30, a support arm 40, an actuator 50, a horizontal-turn pivot shaft (pivot shaft for horizontal turn) 60, and a frame 74 (see
Preferably, in the continuous-casting-nozzle support apparatus of the present invention, the supporting mechanism includes a second engagement portion engageable with a protrusion provided on the continuous casting nozzle, wherein the lifting mechanism is adapted to be capable of lowering the continuous casting nozzle downwardly through the supporting mechanism. This makes it possible to easily separate the continuous casting nozzle from the SN device. More preferably, the second engagement portion is adapted to be engaged with a plurality of protrusions provided on the continuous casting nozzle from above the respective protrusions. In this case, during the operation of lowering the continuous casting nozzle downwardly by the lifting mechanism, a lowering force by the lifting mechanism can be efficiently applied to the continuous casting nozzle to more easily separate the continuous casting nozzle from the SN device.
Preferably, in the above continuous-casting-nozzle support apparatus, the lifting mechanism includes an arm adapted to be moved forwardly and backwardly by a driving device, and a bell crank having one end coupled to the arm and the other end coupled to the supporting mechanism, wherein the supporting mechanism is adapted, according to the forward and backward movements of the arm, to be moved upwardly and downwardly through the bell crank to lift and lower the continuous casting nozzle. More preferably, the lifting mechanism further includes a biasing device for constantly biasing the arm in a direction causing the supporting mechanism to be moved upwardly.
Alternatively, instead of the arm and the bell crank, the lifting mechanism may include a rack adapted to be moved forwardly and backwardly by a driving device, and a feed screw having one end with a pinion meshed with the rack and the other end screwed into the supporting mechanism. In this case, the supporting mechanism is adapted, according to the forward and backward movements of the rack, to be moved upwardly and downwardly through the feed screw to lift and lower the continuous casting nozzle.
Preferably, in the continuous-casting-nozzle support apparatus of the present invention, the holding mechanism includes: a rotary shaft coupled to the stationary column turnably about the stationary column; an extendable and retractable support arm coupled to the rotary shaft turnably in a horizontal direction and swingably in an upward-downward direction about the rotary shaft; and an actuator disposed between the rotary shaft and the support arm and adapted to swingingly move the support arm in the upward-downward direction, wherein the lifting mechanism is coupled to the support arm turnably in a horizontal direction, and the supporting mechanism is coupled to the lifting mechanism. In this case, based on a combination of horizontal turns about three axes of the stationary column, the rotary shaft and the horizontal-turn pivot shaft attached to the support arm, the lifting mechanism and the supporting mechanism can be displaced along a substantially straight line instead of a circular arc, so that a direction of a displacement of the continuous casting nozzle supported by the supporting mechanism can be substantially aligned with a direction of a sliding movement of the SN device.
According to another aspect of the present invention, there is provided a sliding nozzle system which comprises the above continuous-casting-nozzle support apparatus, and a sliding nozzle device having a sliding metal frame formed with the first engagement portion hookable by the hooking device of the continuous-casting-nozzle support apparatus.
According to yet another aspect of the present invention, there is provided a continuous casting nozzle which comprises a protrusion engageable with the second engagement portion of the above continuous-casting-nozzle support apparatus.
According to still another aspect of the present invention, there is provided a method for supporting a continuous casting nozzle while pressing the continuous casting nozzle against a sliding nozzle device. The method comprises the steps of: supporting the continuous casting nozzle by a supporting mechanism included in a lifting mechanism attached to a holding mechanism extending from a stationary column fixed onto a supporting surface; hooking the lifting mechanism to a first engagement portion formed on a sliding metal frame of the sliding nozzle device, through a hooking device; and lifting the continuous casting nozzle upwardly by the lifting mechanism through the supporting mechanism.
In an operation of separating the continuous casting nozzle from the sliding nozzle device, the above method may comprise the steps of: engaging a second engagement portion of the supporting mechanism with a protrusion provided on the continuous casting nozzle; and lowering the continuous casting nozzle downwardly by the lifting mechanism through the supporting mechanism.
The present invention makes it possible to integrate a continuous casting nozzle with an SN device with a surface pressure less than ever before.
a) is an explanatory diagram showing one example of a structure of an engagement portion to be hooked by the hooking device.
b) is an explanatory diagram showing one example of a structure of a hook portion of the hooking device adapted to be hooked with the engagement portion illustrated in
a) is a front view showing a lifting mechanism in a continuous-casting-nozzle support apparatus according to another embodiment of the present invention.
b) is a fragmentary sectional view of the lifting mechanism in
With reference to the accompanying drawings, a continuous-casting-nozzle support apparatus according to an embodiment of the present invention and a sliding nozzle system having the support apparatus will now be specifically described. The following description is of the best-contemplated mode of carrying out of the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense.
The support arm 40 composed of an air cylinder is adapted to be extendable and retractable according to forward and backward movements of a cylinder rod 41 disposed on the side of a distal end thereof. The support arm 40 is not limited to the air cylinder but any other extendable/retractable mechanism, such as a hydraulic cylinder, may be used. The cylinder rod 41 is attached to a cylinder body 42 rotatably about a longitudinal axis thereof. For example, the cylinder rod 41 may be attached to the cylinder body 42 through a bearing device or the like to achieve the rotation about the longitudinal axis. A lifting mechanism 70 is coupled to a distal end of the cylinder rod 41 through a horizontal-turn pivot shaft (pivot shaft for horizontal turn) 60 composed of a spherical slide bearing. Thus, the lifting mechanism 70 can be moved about the horizontal-turn pivot shaft 60 in all directions to a certain extent. Alternatively, the lifting mechanism 70 may be designed such that the horizontal turn thereof is achieved by means of the horizontal-turn pivot shaft 60, and an upward-downward movement thereof is achieved by means of the actuator 50 of the support arm 40 or the like.
The lifting mechanism 70 includes an arm 72 adapted to be moved forwardly and backwardly by an air cylinder 71, and a pair of L-shaped bell cranks 73. Each of the bell cranks 73 has one end (first end) pivotally supported by a distal end of the arm 72 and the other end (second end) supporting a ring-shaped supporting mechanism 80 adapted to support a long nozzle 100 (continuous casting nozzle) from therebelow. The long nozzle 100 has two protrusions 101 symmetrically provided on a lateral surface of a metal casing covering an outer surface thereof, and the supporting mechanism 80 is provided with an engagement portion 81 adapted to be engaged with the protrusions 101 from thereabove.
The air cylinder 71 of the lifting mechanism 70 is supported by a frame 74 through an end of a cylinder rod 76 thereof. This frame 74 is attached to the distal end of the cylinder rod 41 through the horizontal-turn pivot shaft 60. The air cylinder 71 has a guide member 75 protruding upwardly. The guide member 75 has an engagement hole 75a engageable with an engagement pin 43 provided at the distal end of the cylinder rod 41 of the support arm 40. Each of the bell cranks 73 has an intermediate portion pivotally supported by a pivot shaft 73a fixed to the frame 74, so that the bell cranks 73 can be rotated about the pivot shafts 73a.
In addition to the above structure, the continuous-casting-nozzle support apparatus according to the first embodiment comprises a hooking device adapted to be hooked to an SN device 110. In the first embodiment illustrated in
With reference to
As shown in
In the positioned state, as shown in
Then, as shown in
Subsequently, as shown in
After applying a surface pressure, as shown in
When the continuous casting is terminated, the plate brick 113 is slidingly moved in a reverse direction to set the SN device 110 to a closed state.
Then, as shown in
After separating the long nozzle 100 from the lower nozzle 112, the support arm 40 is retracted, so that the hooking device 90 is moved backwardly, and the hook engagement between the hook portion 91 of the hooking device 90 and the engagement portion 111a of the lower nozzle sleeve 111 is released, as shown in
In the first embodiment, the arm 72 is moved forwardly by the cylinder 71 of the lifting mechanism 70 to press the long nozzle 100 against the lower nozzle 112 while applying a surface pressure thereto. In order to make it possible to apply a certain level of surface pressure even if the cylinder 71 breaks down, it is preferable to provide a biasing device for constantly biasing the arm 71 in a forward direction. For example, as shown in
In the first embodiment, in order to ensure the hook engagement between the hooking device 90 and the SN device, it is preferable that the hook portion 91 of the hooking device 90 is formed in a groove-like shape to provide a pair of hooking surfaces on upper and lower sides thereof, as shown in
In the first embodiment, the SN device may be designed to allow a position of the engagement portion 111a of the lower nozzle sleeve 111 to be adjusted depending on a positional relationship between the hooking device 90 and the engagement portion 111a. For this purpose, for example, as shown in
b) shows one example of a structure of the hook portion 91 of the hooking device 90 to be hooked to the engagement portion 111a illustrated in
In
a) is a front view showing a lifting mechanism in a continuous-casting-nozzle support apparatus according to a second embodiment of the present invention.
As shown in
The lifting mechanism 120 comprises a rack 122 adapted to be moved forwardly and backwardly by a hydraulic cylinder 121 serving as a driving device, and a feed screw 123 having one end with a pinion 123a meshed with the rack 122 and the other end screwed into a supporting mechanism 80.
According to the forward and backward movements of the rack 122, the feed screw 123 is rotated, so that the supporting mechanism 80 is moved upwardly and downwardly to lift and lower a continuous casting nozzle 100.
In the lifting mechanism 120 based on the above rack and pinion mechanism, even if the hydraulic cylinder 121 serving as the driving device breaks down, the rack 122 and the pinion 123a are kept still at their positions to maintain a surface pressure. Thus, there is no need to provide a biasing device (spring 76) as in the lifting mechanism 70 based on the bell crank mechanism. In addition, the supporting mechanism 80 can be moved accurately vertically by the rack and pinion mechanism and the feed screw 123, which makes it possible to more uniformly apply a surface pressure, as compared with the afore-mentioned lifting mechanism 70 based on the bell crank mechanism.
In the above continuous-casting-nozzle support apparatus according to the second embodiment, after supporting the long nozzle 100 by the supporting mechanism 80, the supporting mechanism 80 is positioned such that a position of a hook portion 91 of a hooking device 90 is aligned with a position of an engagement portion 111a. This positioning is performed based on a combination of a horizontal turning movement of the support arm 40 about the stationary column 10, an upward-downward movement of the support arm 40 along the stationary column 10, and a forward-backward movement of the hooking device 90 according to the extension and retraction of the support arm 40. After the positioning, the hook portion of the hooking device 90 is hooked to the engagement portion 111a.
Then, the rack 122 is moved forwardly to rotate the feed screw 123, so that the supporting mechanism 80 is moved upwardly to lift the continuous casting nozzle 100. Thus, according to the upward movement of the supporting mechanism 80 supporting the long nozzle 100, the long nozzle 100 is pressed against a lower nozzle 112 while applying a surface pressure thereto.
After applying a surface pressure, a plate brick of an SN device 110 is slidingly moved to set the SN device 110 to an open state so as to start continuous casting. During the operation of slidingly moving the SN device, the lifting mechanism 120 and the supporting mechanism 80 can be displaced along a substantially straight line, based on a combination of horizontal turns about two axes of the stationary column 10 and a horizontal-turn pivot shaft 60, and the extension/retraction of the arm 41.
In an operation of detaching the long nozzle 100, the rack 122 is moved backwardly to rotate the feed screw 123, so that the supporting mechanism 80 is moved downwardly.
In
The support arm 40 may have any structure where a forward end thereof is extendable and retractable with respect to the stationary column 10. For example, the support arm 40 may be designed such that the entire arm is moved forwardly and rearwardly with respect to the stationary column 10 so as to adjust a length of the forward end.
Although the first and second embodiments have been described based on a long nozzle to be installed on a bottom side of a ladle, the present invention is usable in any other suitable type of continuous-casting-nozzle support apparatus having a mechanism for pressing a continuous casting nozzle, such as an immersion nozzle to be installed on a bottom side of a tundish, against an SN device while holding the nozzle by an arm.
As above, in the continuous-casting-nozzle support apparatuses according to the above embodiments, sealing performance can be ensured with a surface pressure less than ever before to facilitate a reduction in size of the apparatus. In addition, the reduction in surface pressure makes it possible to reduce damage of a brick constituting a continuous casting nozzle and an SN device.
Further, the lifting mechanism and supporting mechanism are supported through two or three horizontal-turn pivot shafts. Thus, it becomes possible to substantially align a direction of a displacement of the continuous casting nozzle with a direction of a sliding movement of the SN device to prevent damage of the brick and deterioration in close contact in a joined section, which would otherwise be caused by the sliding movement of the SN device.
Further, a second engagement portion is provided on the supporting mechanism. Thus, under a condition that an engagement portion provided on the continuous casting nozzle is engaged with the second engagement portion, the supporting mechanism can be moved downwardly by the lifting mechanism to lower the continuous casting nozzle downwardly, so that the continuous casting nozzle can be easily separated from the SN device.
Further, the hooking device can be selectively hooked to and unhooked from a first engagement portion of the SN device according to a movement of the support arm, and the continuous casting nozzle can be selectively lifted and lowered by the lifting mechanism. Thus, even under a condition that the continuous-casting-nozzle support apparatus is coupled to and integrated with the SN device, the above operations can be controlled at a position distant from a molten metal vessel.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2009-72503 | Mar 2009 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4131220 | Bode et al. | Dec 1978 | A |
| 4313596 | King | Feb 1982 | A |
| 4316561 | Grosko | Feb 1982 | A |
| 4550867 | Bell et al. | Nov 1985 | A |
| 5665264 | Sato et al. | Sep 1997 | A |
| Number | Date | Country |
|---|---|---|
| 2008-006478 | Jun 2006 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20100244335 A1 | Sep 2010 | US |
