JP3644573B2 - Powder casting equipment for continuous casting - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a powder casting apparatus for continuous casting, and more particularly to a powder feeding apparatus that can uniformly spray powder on the surface of molten steel in a mold for continuous casting and can quickly and automatically throw it into a desired location as necessary. Is.
[0002]
[Prior art]
During continuous casting of steel, powder containing SiO ₂ , CaO, etc. as the main component is introduced into the molten steel surface (hereinafter referred to as the molten metal surface) injected into the mold to prevent the oxidation of the molten metal surface and inclusions in the steel of the mold. Absorption and lubrication between the mold wall and the molten steel. Recently, an automatic powder charging apparatus has been developed for this powder charging operation instead of a manual operation, and mechanical charging is generally performed.
[0003]
Various methods have been proposed as conventional powder charging devices, and some of the typical methods are briefly described as follows.
(1) A screw feeder is placed parallel to the mold long side direction and on the mold center, and the powder is extended from the slit at the bottom of the case of the feeder body corresponding to the mold long side length or a number of discharge holes to the mold surface. A method of feeding straightly in parallel with the side direction (Japanese Utility Model Publication No. 51-114413).
(2) Contrary to the above, the discharge end of the spring feeder, screw feeder, etc. faces the mold from the direction perpendicular to the long side of the mold, and the feeder is moved or swung in parallel, so that the powder charging position is set to the long side of the mold. A system that can move in the direction (Japanese Utility Model Publication No. 51-48581).
[0004]
(3) Powder is sent directly into the mold by air feeding, and the tip of the air feeding tube is moved in the same way as the method of (2), or the air feeding tube is configured in a loop, and this loop tube faces the mold. A method in which powder is introduced from a slit or a large number of holes at the bottom of the loop pipe (Japanese Patent Publication No. 53-25532, Japanese Utility Model Publication No. 51-14207).
(4) A charging device having a powder discharge hole substantially equal to the length in the long side direction of the mold, and using a belt feeder or powder fluidization by pneumatic feeding (Japanese Utility Model Publication No. 54-136317).
(5) A system having a plurality of powder feeding mechanisms, and putting it into a mold every proper amount unit (Japanese Patent Laid-Open No. 51-100903).
[0005]
However, with the recent high-speed casting and continuous casting of high-grade steel grades in the continuous casting method, the importance of powder has increased, and higher-quality powder is being used at the same time. There is a demand for a charging method that maximizes the effect.
In order to increase the effect of the powder, it is necessary to form an almost uniform molten powder layer over the entire surface of the hot water. It is difficult to expect to spread over the entire surface of the molten metal due to melting.
[0006]
Also, even if the powder is poured linearly along the mold center parallel to the mold long side direction, the effect is greater than that of the point casting, but it cannot be said that a sufficient charging effect is obtained. I have to shift to the introduction of. However, even when the powder is uniformly introduced into each part of the entire hot water surface, there are the following problems, and it cannot be said that the introduction is efficient.
[0007]
First, there is a flow of molten steel on the molten metal surface due to the influence of a jet submerged in the molten steel, and the required amount of powder is larger in the vicinity of the mold short side and in the vicinity of the nozzle than in other places. It has been confirmed that
Secondly, the required amount of powder is not the same even in places other than the above, and it is difficult to maintain the complete verticality of the nozzle due to physical errors when attaching the immersion nozzle to the tundish. There is still a slight inclination in the immersion nozzle, and this is one of the factors, and the position of the mold varies depending on the difference in the molten steel jet velocity flowing out from the nozzle tip and the variation in molten steel temperature. Strictly speaking, all of the required amount of powder in the plant is different.
[0008]
For example, in a normal symmetrical mold, it has been confirmed as a result of actual work that the required input amount of powder on the right and left sides of the nozzle differs by 20% or more. Furthermore, since the required amount at each position also changes as the casting time elapses, it is not always appropriate to take a fixed amount at each position. Therefore, in view of these points, the conventional charging method described above is an inappropriate linear charging method, or a fixed charging method that does not consider the difference in the required amount of powder at each position. Thus, the powder effect could not be fully achieved. In addition, some powders are not quick enough (it takes a long time to charge), and some have a structure that may interfere with other equipment around the mold or casting work. There is also a drawback that it is a malfunction.
[0009]
In contrast to the conventional example having such various drawbacks, the present applicants proposed a powder casting apparatus for continuous casting in which a defect is eliminated in Japanese Patent Publication No. 60-57937 and has been used for many years in actual work. . The apparatus is shown as a side view in FIG. 5A and as a plan view in FIG.
[0010]
The powder in the powder storage tank 11 is supplied to the powder charging chute 4 whose tip is movable by the feeder 12 and extruded into the mold 1 by the pusher 3 so that it is uniformly sprayed on the surface of the molten steel, and if necessary, at the desired location. It is automatically entered.
The structure is such that a powder charging chute 4 is slidably held in the chute axis direction on a chute holding part 5 which is pivotably mounted on a traveling carriage 2, and the charging chute is located near the mold 1 in a position parallel to the long side of the mold. A flexible screw conveyor is disposed as a powder feeder 12 having a leading end connected to the charging chute 4 and a rear end connected to the powder storage tank 11. The pusher 3 for extruding an appropriate amount of powder supplied into the chute into the mold is installed.
[0011]
[Problems to be solved by the invention]
As described above, according to Japanese Examined Patent Publication No. 60-57937, the powder can be uniformly supplied to the inner surface of the casting mold for continuous casting. Although the device has an excellent effect that it can be performed, when the powder charging chute 4 (hereinafter referred to as a charging chute) is swung in the mold longitudinal direction, the tip of the charging chute 4 takes an arc-shaped locus as it is, A situation occurs in which the mold is separated (particularly when the width is long in a flat mold).
[0012]
Therefore, the rear end of the charging chute 4 is protruded from the chute holding part 5, and the rod of the pressing cylinder 7 installed on the charging chute holding part 5 is attached thereto to apply a pressing force in the mold direction, and at the front end side of the charging chute 4. Since the sliding roller 8 is provided in the lower part and is configured to abut on a guide 9 fixed on the mold cover in parallel with the long side of the mold 1, the charging chute 4 rotates and the angle of the charging chute 4 is set. Even when the pressure changes, due to the pressing force of the pressing cylinder 7 described above, the charging chute 4 is always pushed forward, and the tip of the charging chute 4 moves parallel to the long side of the mold 1, resulting in a distance from the mold 1. Is considered to be almost constant.
[0013]
In such an apparatus, the guide must be fixedly disposed on the mold cover. Therefore, the guide must be always attached to the mold cover.
Furthermore, in recent years, there has been an increasing need to install various measuring instruments in the vicinity of the mold in order to stabilize the cast state, so that it is required to have as much freedom as possible on the mold cover. Further, since the mold cover portion is heated by radiation and heat transfer from the molten steel, it is susceptible to deformation of the cover due to heat, and is not preferable as a guide disposition position.
[0014]
The present invention solves the drawbacks of these conventional powder charging equipment, and provides a powder casting apparatus for continuous casting that has excellent workability and has a large degree of freedom in the space around the mold and does not hinder the installation of other equipment. The purpose is to do.
[0015]
[Means for Solving the Problems]
In order to solve the above problems, the present invention takes the following means.
[0016]
A powder charging chute is slidably held in the chute axial direction on a chute holding part that is pivotably mounted on a traveling carriage, and the tip is connected to a hopper provided above the charging chute and the rear end is connected to a powder storage tank. In a powder casting apparatus for continuous casting in which a powder feeder that has been squeezed and a pusher that pushes an appropriate amount of powder supplied to the chute into the mold is installed in the casting chute, it has a rail shape with a convex shape in vertical section A guide provided in the vicinity of the tip on the traveling carriage and two vertical cylindrical rolling rollers that roll on both sides of the convex rail are fixed to the lower portion of the charging chute by a shaft support member. The guide has a circular arc shape that is opposite to the turning arc drawn by the tip of the charging chute, so that the powder is charged. Continuous casting powder dosing device, characterized in that the chute tip during turning of the chute is intended to face the mold above a side.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the powder injection device of the present invention will be described with reference to the drawings.
[0018]
FIG. 1 shows an example of a powder charging apparatus according to the present invention. In the figure, 1 is a continuous casting mold, 2 is a traveling carriage on the long side of the mold 1 and traveling on a rail, An input chute 4 having a pusher 3 is provided on the carriage so as to be slidable with respect to the input chute holding part 5, and the input chute holding part 5 is attached to the traveling carriage 2 via a turning shaft 6.
[0019]
The swivel drive unit is not particularly illustrated, but any system such as a system combining a screw jack and a crank, a worm gear system, or a gear system may be used. Here, 11 is a powder storage tank mounted on the rear part of the traveling carriage 2, and a powder supply machine 12 is connected between the powder storage tank 11 and the hopper 13 (located in front of the retracted pusher 3). For example, a flexible screw conveyor.
[0020]
Further, in the present invention, when the charging chute 4 is swung in the mold longitudinal direction as described in the problem section, the tip of the charging chute becomes an arc-shaped locus as it is, and the distance from the mold fluctuates, which is not preferable. Therefore, the optimum guide mounting position has been developed to compensate for the drawbacks.
[0021]
First, the guide 9 installed on the mold cover is stopped, and the guide 9 that guides the charging chute 4 in the vicinity of the front end of the traveling carriage 2 is turned. Provide to face The guide 9 is formed so as to draw an arc opposite to the trajectory of the turning arc drawn by the tip of the charging chute 4. This reverse arc shape is specified by the distance of the throw chute 4 from the turning axis. Further, the guide 9 may be a substantially circular arc, that is, an arc shape, and as shown in FIG. 3 , it may be a reverse polygonal shape approximating the turning arc drawn by the tip of the throwing chute 4. In this case, the guide 9 9 is more preferable if the length of one side of the polygon is formed so as to match the distance that the feeding chute 4 moves in the mold width direction.
[0022]
Since the sliding members 8 that contact these guides 9 are attached to the lower part of the charging chute, when the sliding member 8 moves along the guides 9, the charging chute 4 is correspondingly moved accordingly. Since the top moves, the tip position of the charging chute 4 always moves in parallel with the long side of the mold 1 even if the angle of the charging chute 4 changes. As a result, the distance between the tip of the charging chute 4 and the mold 1 is as follows. Can keep constant intervals constantly.
[0023]
FIG. 2 is a plan view of the powder charging device to which the charging chute 4 of FIG. 1 is attached. Even if the charging chute 4 is swung by the turning shaft 6, it is guided by the guide 9 and the leading end of the charging chute 4 is fixed distance from the mold 1. Shows that keep.
The charging chute 4 is formed in a bowl shape, and the material thereof is not particularly limited. However, since it is used in a high heat atmosphere, it has corrosion resistance and heat resistance, and it is slippery and difficult to adhere to powder. It is good to choose.
[0024]
Further, the width of the charging chute 4 is preferably a width size suitable for the division size so that when the entire surface of the mold is divided into an optimum number, the powder can be uniformly charged into the entire division. Furthermore, it is desirable that the pusher 3 is composed of, for example, a pneumatic or hydraulic cylinder, and the extrusion speed can be adjusted. A guide blade can be attached to the tip of the charging chute in order to uniformly charge the powder over one section.
As described above, the charging chute 4 and the pusher 3 enable the powder to be charged in a short time, and the chute width is uniform in the mold longitudinal direction and the pressing force of the pusher 3 is uniform in the short side direction for each section. Spraying becomes possible.
[0025]
It is desirable that the moving speed of the charging chute 4 in the mold longitudinal direction is as high as possible in order to be able to follow automatic control by a sensor, for example, and to quickly input the powder to the place where the powder is required. In this way, the number of powders can be increased. Further, in order to ensure that the closing chute 4 stops at a predetermined position, a necessary number of limit switches, cam switches, etc. may be provided in the traveling carriage 2 or a thing such as a pulse encoder may be used.
[0026]
Further, the powder supply will be described in detail. A hopper 13 is provided above the charging chute 4 at the tip of the powder supply machine (flexible screw conveyor) 12, and a slide gate (not shown) is provided below the hopper 13. Then, by opening the gate, one dose of powder to be charged into the mold is discharged onto the charging chute 4 and the gate is closed. After this, the powder feeder 12 continues to drive and the powder is supplied to the hopper 13 even when the pusher 3 pushes the powder into the mold, so that continuous operation is possible and cycle time is shortened. Can be achieved. If this powder supply machine 12 is used, it can be supplied with one screw, and the space can be reduced.
[0027]
Furthermore, if the traveling carriage 2 can be moved forward and backward with respect to the mold 1, it can be retracted when the tundish car travels during casting, so that it does not interfere with other operations and also interferes with other equipment. can avoid. In the case of the traveling method, since the stopping position accuracy of the cart at the time of powder injection is required to some extent, it is desirable to switch between two stages of high speed and low speed. It is preferable to attach a device.
[0028]
Next, the guide 9 and the abutting member 8 that abuts on the guide 9 will be described.
The guide 9 is provided at an appropriate position in the vicinity of the front end portion on the traveling carriage 2 such that the tip end portion of the input chute 4 faces the upper side of the mold with respect to the turning arc of the input chute 4, and the shape thereof is substantially the same as that of the input chute 4. An arc opposite to the turning arc is formed, and the arc degree is specified and designed according to the distance between the sliding member 8 attached to the lower portion of the making chute 4 and the turning axis of the making chute 4. Thus, the charging chute 4 can keep the distance from the mold constant over the entire length in the mold long side direction (width direction).
[0029]
Various forms of the contact state between the guide 9 and the sliding member 8 are conceivable. For example, as shown in FIG. 1, the rear end of the charging chute 4 protrudes from the charging chute holding portion 5 and holds the charging chute. A rod of the pressing cylinder 7 installed on the portion 5 is attached to apply a pressing force in the molding direction, and a support member 10 for holding a vertical cylindrical sliding roller shaft is provided at the lower portion of the charging chute 4. If it is brought into contact with the rail guide 9a having a vertical sliding surface vertically, the charging chute 4 turns, and even if the angle of the charging chute 4 changes, the charging chute 4 always pushes the charging chute 4 forward. The tip of the charging chute 4 moves parallel to the long side of the mold 1.
[0030]
Further, as shown in FIG. 4A, the guide 9 is a groove rail 9b having a concave cross section, the sliding member 8 is a rolling roller that can be inserted into the rail groove, and a bearing member that holds the shaft of the rolling roller. 10 is fixed to the lower portion of the charging chute 4. The diameter of the rolling roller inserted in the concave rail groove is slightly smaller than the width of the concave inner surface, and the guide of the charging chute 4 can be accurately guided by contacting any one of the concave inner surfaces. Can be done. In this case, the pressing cylinder 7 as described above is not necessary, and there is an effect that the equipment cost can be reduced.
[0031]
Further, as shown in FIG. 4 (b), the guide 9 is a rail 9c having a convex cross section, and the sliding member 8 has two rolling rollers that roll while holding both sides of the convex rail 9 and its rolling. By configuring the bearing member 10 to hold the shaft of the moving roller and fixing the bearing member 10 to the lower portion of the charging chute 4, the same effect as in FIG. 4A can be obtained.
[0032]
Next, an example of powder supply work using the apparatus of the present invention will be described.
When the powder is charged, the traveling carriage 2 is driven to stop when it reaches a predetermined position, and the carriage 2 is fixed at that position. At this time, if the powder feeder 12 is already driven from the storage tank 11 to transfer the powder into the hopper 13 and the charging chute 4 is set to move toward the desired charging location on the hot water surface in the mold 1, The slide gate is opened and powder is supplied onto the charging chute 4. Next, the pusher 3 is operated and the powder is charged and sprayed on the hot water surface. Since the powder spraying is not a dot or linear charging, but a surface charging, it is uniformly sprayed over the entire section.
[0033]
As mentioned above, the amount of powder consumed on the hot water surface varies depending on the position of the mold and changes over time. The apparatus of the present invention can be operated and powder can be charged automatically. Furthermore, it is also possible to always grasp the state of the hot water using a separately installed hot water level detecting device, interlock it with the powder charging device, and supply powder to the required place each time the hot water level changes.
[0034]
【The invention's effect】
According to the powder charging device of the present invention, the powder charging effect can be maximized, and the guide for powder charging equipment is not provided on the mold cover. Further, since the guide itself is installed on the traveling carriage, the shape of the guide can be freely adopted when contacting the sliding member, and the sliding displacement at the time of contact between the guide and the sliding member can be freely achieved. In addition, there is no occurrence of unevenness, and countermeasures against powder charging can be made on the charging device main body side, so that the device becomes independent and has a great effect of contributing to continuous casting work.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of the powder charging device of the present invention. FIG. 2 is a plan view showing a part of FIG. 1. FIG. 3 is a view showing an example of a guide having a polygonal shape. The figure which shows the example of the contact | abutting state of a chute | shoot and a sliding member. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mold 2 Traveling trolley 3 Pusher 4 Powder injection chute 5 Chute holding part 6 Rotating shaft 7 Pushing cylinder 8 Sliding member (rolling roller)
9 Guide 10 Bearing member 11 Powder storage tank 12 Powder feeder 13 Hopper

Claims (1)

A powder charging chute is slidably held in the chute axial direction on a chute holding part that is pivotably mounted on a traveling carriage, and the tip is connected to a hopper provided above the charging chute and the rear end is connected to a powder storage tank. In a powder casting apparatus for continuous casting in which a powder feeder that has been squeezed and a pusher that pushes an appropriate amount of powder supplied to the chute into the mold is installed in the casting chute, it has a rail shape with a convex shape in vertical section A guide provided in the vicinity of the tip on the traveling carriage and two vertical cylindrical rolling rollers that roll on both sides of the convex rail are fixed to the lower portion of the charging chute by a shaft support member. The guide has a circular arc shape that is opposite to the turning arc drawn by the tip of the charging chute, so that the powder is charged. Continuous casting powder dosing device, characterized in that the chute tip during turning of the chute is intended to face the mold above a side.

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