JP3753103B2 - Sink roll for continuous molten metal plating equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a sink roll disposed in a plating bath filled with molten metal in a continuous molten metal plating apparatus.
[0002]
[Prior art]
In the continuous molten metal plating apparatus, a sink roll as a roll in the bath is disposed in the lower part of the plating bath filled with a high temperature molten metal. The sink roll is supported in a horizontal state on a roll support portion fixed to the plating bath, and is rotatably arranged through a bearing.
[0003]
And, the steel strip that has entered the plating bath at a predetermined plate speed changes its traveling direction by circling on the outer periphery of the sink roll at the bottom of the bath, and is continuously plated by being pulled out of the bath. Adhesion treatment is performed.
[0004]
[Problems to be solved by the invention]
There are various types of sink rolls, and a hollow cylindrical sink roll is known in which a pair of side plates are integrated at both ends of a cylindrical body. A sink roll of this shape is usually provided with an opening hole in the side plate so that the hollow part of the roll communicates with the outside, and the molten metal flows into the roll hollow part from the opening hole when placed in the plating bath. The generation of buoyancy is suppressed, and when pulling up from the plating bath, the molten metal in the roll hollow portion is discharged from the opening hole to the outside, thereby facilitating the pulling operation.
[0005]
By the way, the sink roll arranged in the plating bath increases the rotational resistance against the molten metal as the rotational speed increases, and the smooth rotational operation tends to be hindered. The speed of the steel strip that circulates on the outer periphery of the body section and the rotation speed of the sink roll are not the same, slip occurs between the body section and the steel strip, and the steel strip is scratched, resulting in poor product quality. There is a fear.
[0006]
In particular, the shape of the opening hole formed in the side plate tends to affect the rotational resistance when the sink roll rotates. That is, if there is an opening edge with a large area of the opening hole in the rotation direction of the sink roll (circumferential direction of the side plate), the molten metal that has collided with the opening edge becomes easy to peel off from the side plate, As a result, the pressure loss increases and the rotational resistance of the sink roll increases.
[0007]
For this reason, in order to improve the efficiency of the steel strip plating adhesion treatment and improve the product quality, it is necessary to form the opening hole formed in the side plate of the sink roll so as not to increase the rotational resistance.
Therefore, the present invention has been made in view of the above circumstances, and an object thereof is to provide a sink roll of a continuous molten metal plating apparatus in which an opening hole in which rotation resistance does not increase is provided in a side plate.
[0008]
[Means for Solving the Problems]
The sink roll of the continuous molten metal plating apparatus according to claim 1 comprises a cylindrical body portion and a pair of side plates integrated at both ends of the body portion to form a hollow cylindrical shape. The steel plate introduced into the plating bath is a roll for transferring the steel strip introduced into the plating bath along the outer periphery of the body portion, and an opening hole for communicating the inside and outside of the roll is formed on the outer peripheral side of the side plate. In the provided sink roll, when the opening hole is opened in a shape that is long in the circumferential direction, the length of the opening hole in the substantially radial direction is A, and the thickness of the side plate is C, A / C The relationship of ≦ 1 was satisfied.
[0009]
Further, the sink roll of the continuous molten metal plating apparatus according to claim 2 comprises a cylindrical body and a pair of side plates integrated at both ends of the body and has a hollow cylindrical shape, and is a continuous molten metal. It is a roll which is arranged in a plating bath of a plating apparatus and transports a steel strip introduced into the plating bath along the outer periphery of the trunk portion, and an opening hole which passes through the inside and outside of the roll on the outer peripheral side of the side plate In each of the sink rolls provided at a predetermined interval in the circumferential direction, each opening hole is opened in a shape that is long in the circumferential direction, and the length of the opening hole in the circumferential direction is B and adjacent to each other. An interval in the substantially circumferential direction between the opening holes was set to D, and an opening ratio R of the opening holes in the circumferential direction of the side plate defined by R = B / (B + D) was set to 50% or less.
[0010]
Furthermore, the sink roll of the continuous molten metal plating apparatus according to claim 3 comprises a cylindrical body portion and a pair of side plates integrated at both ends of the body portion to form a hollow cylindrical shape. It is a roll which is arranged in a plating bath of a plating apparatus and transports a steel strip introduced into the plating bath along the outer periphery of the trunk portion, and an opening hole which passes through the inside and outside of the roll on the outer peripheral side of the side plate In the sink roll provided with a plurality of gaps in the circumferential direction, each opening hole is opened in a long shape in the circumferential direction, the length of the opening hole in the substantially radial direction is A, and the side plate , Where A / C ≦ 1, the length in the substantially circumferential direction of the opening holes is B, the interval in the circumferential direction between adjacent opening holes is D, and R = In the circumferential direction of the side plate defined by B / (B + D) The aperture ratio R of the open hole was set to 50% or less.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a sink roll of a continuous molten metal plating apparatus according to the present invention will be described with reference to the drawings.
FIGS. 1A and 1B are views showing the sink roll 2 of the first embodiment.
The sink roll 2 of the present embodiment penetrates through a cylindrical body 4, a pair of circular side plates 6 that are integrated while closing both end openings of the body 4, and the center of the side plate 6. And a rotating shaft 8 extending in the longitudinal direction of the body portion 4, and a roll hollow portion 10 is provided therein.
[0012]
The side plate 6 of the sink roll 2 is formed with an opening hole 12 that communicates the roll hollow portion 10 with the outside. And if the said sink roll 2 is arrange | positioned in the plating bath of a continuous molten metal plating apparatus, molten metal will flow into the roll hollow part 10 from the opening hole 12, generation | occurrence | production of the buoyancy of the sink roll 2 will be suppressed, and from the plating bath When pulling up, since the molten metal in the roll hollow portion 10 is discharged to the outside from the opening hole 12, the pulling up operation of the sink roll 2 becomes easy.
[0013]
Here, the opening hole 12 is located on the outer peripheral side of the side plate 6 and is formed so as to extend substantially in the circumferential direction. That is, as shown in FIG. 1A, the opening hole 12 is opened in a rectangular shape, the opening edge 12a on the short side extends in the substantially radial direction, and the opening edge 12b on the long side. Is formed extending substantially in the circumferential direction.
Further, when the length of the opening edge portion 12a on the short side of the opening hole 12 is A and the thickness of the side plate 6 forming the opening hole 12 is C, the relationship between these A and C is expressed by the following (1 ).
[0014]
A / C ≦ 1 (1)
The inventors investigated the influence of the thickness C of the side plate 6 and the length A of the opening edge 12a on the rotational resistance of the sink roll 2 in the bath, and if the thickness C of the side plate is constant, In a region where the ratio A / C of the length A of the opening edge 12a to the length C exceeds 1, the rotational resistance of the sink roll 2 decreases as this ratio decreases. It turned out that even if it makes small, rotation resistance does not become small. Therefore, the thickness C of the side plate 6 and the length A of the opening edge portion 12a are set to satisfy the above formula (1).
[0015]
Thus, when the relationship between the length A of the opening edge 12a on the short side of the opening hole 12 and the thickness C of the side plate 6 is A / C ≦ 1, the rotation direction of the sink roll 2 (the side plate 6 The area of the opening edge 12a on the short side of the opening hole 12 facing in the circumferential direction is reduced, and the molten metal that collides with the opening edge 12a is less likely to peel from the side plate 6. Thereby, even when the sink roll 2 rotates at a high speed, almost no disturbance is generated in the molten metal, and the pressure loss is reduced, so that an increase in the rotational resistance of the sink roll 2 can be prevented.
[0016]
Therefore, when the sink roll 2 having the opening hole 12 having the above-described configuration is used in a continuous molten metal plating apparatus, the rotational resistance of the sink roll 2 can be reduced, and the sheet feeding speed of the steel strip and the rotation speed of the sink roll 2 are the same. The maximum plate passing speed is increased, and even if the plate is passed at a high speed, no slip occurs between the body 4 and the steel strip, so that the product quality of the steel strip can be improved and the steel strip The efficiency of the plating adhesion treatment can be achieved.
[0017]
Next, FIG. 2 is a diagram illustrating the sink roll 20 of the second embodiment. In addition, the same code | symbol is attached | subjected to the component same as the structure of the sink roll 20 shown in FIG. 1, and description is abbreviate | omitted.
In the side plate 6 of the sink roll 20 of the present embodiment, two opening holes 22 that communicate the roll hollow portion 10 and the outside are formed.
[0018]
The two opening holes 22 are located on the outer peripheral side of the side plate 6 and are formed to extend in the substantially circumferential direction. That is, these opening holes 22 are formed in a rectangular shape, with the opening edge 22a on the short side extending in the substantially radial direction and the opening edge 22b on the long side extending in the substantially circumferential direction. Has been.
The relationship between the length A of the opening edge 22a on the short side of each opening hole 22 and the plate thickness C of the side plate 6 forming the opening hole 22 is as follows, as in the first embodiment. (1).
[0019]
A / C ≦ 1 (1)
Further, the length of the opening edge 22b on the long side of the opening hole 22 is B, the distance between the two opening holes 22 in the substantially circumferential direction is D, and the opening of the opening hole 22 in the circumferential direction on the outer peripheral side of the side plate 6 is performed. The rate R is expressed by the following equation (2).
R = B / (B + D) (2)
And the opening ratio R of the opening hole 22 in the outer peripheral side circumferential direction of the side plate 6 is set to a range represented by the following expression (3).
[0020]
R ≦ 50% (3)
With the relationship of the above expression (3), the ratio of the opening holes 22 in the circumferential region on the outer peripheral side of the side plate 6 is not too large, and the molten metal that collides with the opening edge 22a of each opening hole 22 is the side plate. It becomes difficult to peel from 6. Thereby, even when the sink roll 20 rotates at high speed, almost no disturbance is generated in the molten metal and the pressure loss is reduced, so that an increase in the rotational resistance of the sink roll 20 can be prevented.
[0021]
The relationship of the above formula (1) reduces the area of the opening edge 22a on the short side of each opening hole 22 facing the rotation direction of the sink roll 20, and further rotates the sink roll 20. Resistance decreases.
Therefore, when the sink roll 20 provided with a plurality of opening holes 22 according to the present embodiment is used in a continuous molten metal plating apparatus, the rotational resistance of the sink roll 2 can be reduced, and the sheet feeding speed of the steel strip and the rotational speed of the sink roll 2 can be reduced. The maximum sheeting speed that can be made the same is increased, and slipping does not occur between the body 4 and the steel strip even when it is passed at a high speed, so that the product quality of the steel strip can be improved, and the steel The efficiency of the strip plating treatment can be improved.
[0022]
In the second embodiment, the sink roll 20 having the relationship between the above-described formulas (1) and (3) has been described. However, even if the sync roll has only the relationship of the formula (3), the first The same effect as the embodiment can be obtained.
[0023]
【Example】
The slip evaluation of the sink roll 2 of the first embodiment and the slip evaluation of the sink roll 20 of the second embodiment were performed using an experimental apparatus using a water model of a continuous molten metal plating apparatus shown in FIG.
The experimental apparatus shown in FIG. 3 includes a water tank 32 filled with water W, a drive motor 34 disposed outside the water tank 32, a drive roll 36 that receives rotational force from the drive motor 34, and rotates in the atmosphere. A test sink roll TR that is disposed in the water tank 32 and rotates, a driven roll 40 that rotates in the atmosphere above the test sink roll TR, and a drive roll 36, a test sink roll TR, and a driven roll 40. An endless belt 42 is provided. The water in the water tank 32 is set to a temperature of approximately 20 ° C., and the water having a temperature of approximately 20 ° C. has a kinematic viscosity of 1.0038 mm ² / s, and is filled in, for example, a plating bath of a continuous hot dip galvanizing apparatus. The value is approximately twice the kinematic viscosity of molten zinc at about 450 ° C.
[0024]
Therefore, the size of the water model is set to ½ of the actual hot dip galvanizing apparatus, and the Reynolds number in the water model is set to the same level as that in the actual hot dip galvanizing apparatus, so that the actual machine can be simulated.
In this experimental apparatus, when the rotational resistance of the test sink roll TR is small enough not to cause a slip between the endless belt 42 and the test sink roll TR, the rotational speed of the drive roll 36 and the test sink roll TR When the rotational speed of the TR becomes the same and the rotational resistance of the test sink roll TR increases, slip occurs between the endless belt 42 and the test sink roll TR. The speed is reduced. When the rotational speed of the drive roll 36 is gradually increased from the low speed to the high speed side, the rotational resistance of the sink roll TR increases at a certain speed to cause a slip, and the test sink for the rotational speed of the drive roll 36 is increased. The ratio of the rotational speed of the roll TR becomes smaller than 1. Therefore, while measuring the rotational speed of the driving roll 36 and the test sink roll TR, the rotational speed of the driving roll 36 is increased, and the rotational speed when the ratio of the rotational speeds is smaller than 1 is obtained. The speed at which slip starts can be evaluated.
[0025]
Using the experimental apparatus configured as described above, when the sink roll 2 of the first embodiment is disposed as the test sink roll TR, and when the sink roll 20 of the second embodiment is disposed as the test sink roll TR The slip between the test sink roll and the endless belt 42 was evaluated.
FIG. 4 is a result of evaluating a slip between the sink roll 2 and the endless belt 42 in the case where the sink roll 2 of the first embodiment is disposed as the test sink roll TR using the experimental apparatus having the above configuration. . The vertical axis in this figure indicates the speed at which slip has started between the sink roll 2 and the endless belt 42 (slip speed), and the horizontal axis indicates the length A of the opening edge 12 a on the short side of the opening hole 12. And the ratio of the thickness C of the side plate 6 is shown. The solid line shows the sink roll 2 using the side plate 6 having a plate thickness C of 50 mm, and the broken line shows the sink roll 2 using the side plate 6 having a plate thickness C of 80 mm.
[0026]
From the results of FIG. 4, it can be seen that the slip speed increases when A / C ≦ 1. That is, when A / C ≦ 1, slip does not easily occur between the sink roll 2 and the endless belt 42, and an increase in rotational resistance can be prevented even if the sink roll 2 rotates at a high speed.
FIG. 5 is a result of evaluating the slip between the sink roll 20 and the endless belt 42 when the experimental roll having the above-described configuration is used and the sink roll 20 of the second embodiment is disposed as the test sink roll TR. It is. The vertical axis in this figure indicates the speed at which slip has started between the sink roll 20 and the endless belt 42 (slip speed), and the horizontal axis indicates the opening ratio R of the opening hole 22 in the outer peripheral side circumferential direction of the side plate 6. Show.
[0027]
From the results of FIG. 5, it can be seen that the slip speed increases when R ≦ 50%. That is, when R ≦ 50%, slip does not easily occur between the sink roll 20 and the endless belt 42, and an increase in rotational resistance can be prevented even if the sink roll 20 rotates at a high speed.
[0028]
【The invention's effect】
As described above, according to the sink roll of the continuous molten metal plating apparatus of the present invention, even when the sink roll rotates at a high speed, there is almost no disturbance in the molten metal around the opening hole provided in the side plate, and the pressure Since the loss is reduced, an increase in rotational resistance can be prevented.
[Brief description of the drawings]
FIG. 1 is a view showing a sink roll according to a first embodiment of the present invention, (a) is a view showing the sink roll from the side plate side, and (b) is an axial cross section of the sink roll. FIG.
FIG. 2 is a view showing a sink roll of a second embodiment according to the present invention from the side plate side.
FIG. 3 is a view showing an experimental apparatus used for evaluating the slip of the sink roll according to the present invention.
FIG. 4 is a graph showing the results of slip evaluation of the sink roll according to the first embodiment of the present invention.
FIG. 5 is a graph showing the result of slip evaluation of the sink roll of the second embodiment according to the present invention.
[Explanation of symbols]
2,20 sink roll 4 trunk 6 side plate 10 roll hollow part (inside roll)
12, 22 Opening hole 12a Opening edge (edge extending in the substantially radial direction of the opening hole)
12b Opening edge (edge extending substantially in the circumferential direction of the opening hole)
22a Opening edge (edge extending substantially in the radial direction of the opening hole)
22b Opening edge (edge extending in the substantially circumferential direction of the opening hole)
C Thickness of the side plate R Opening ratio of the opening hole in the outer peripheral side circumferential direction of the side plate

Claims (3)

Steel provided with a cylindrical body and a pair of side plates integrated at both ends of the body to form a hollow cylindrical shape, disposed in a plating bath of a continuous molten metal plating apparatus, and introduced into the plating bath A roll that transports a belt along the outer periphery of the body part, and a sink roll provided with an opening hole that communicates the inside and outside of the roll on the outer peripheral side of the side plate,
The opening hole opens in a shape that is long in the circumferential direction, and if the length of the opening hole in the substantially radial direction is A and the plate thickness of the side plate is C, the relationship of A / C ≦ 1 is satisfied. A sink roll for a continuous molten metal plating apparatus. Steel provided with a cylindrical body and a pair of side plates integrated at both ends of the body to form a hollow cylindrical shape, disposed in a plating bath of a continuous molten metal plating apparatus, and introduced into the plating bath In the roll that transports the belt along the outer periphery of the body part, and on the outer peripheral side of the side plate, in the sink roll provided with a plurality of opening holes through the roll inside and outside with a predetermined interval in the circumferential direction,
Each opening hole is opened in a shape that is long in the circumferential direction, the length in the substantially circumferential direction of the opening hole is B, the interval in the circumferential direction between adjacent opening holes is D, and R = B A sink roll of a continuous molten metal plating apparatus, wherein an opening ratio R of the opening holes in the circumferential direction of the side plate defined by / (B + D) is set to 50% or less. Steel provided with a cylindrical body and a pair of side plates integrated at both ends of the body to form a hollow cylindrical shape, disposed in a plating bath of a continuous molten metal plating apparatus, and introduced into the plating bath In the roll that transports the belt along the outer periphery of the body part, and on the outer peripheral side of the side plate, in the sink roll provided with a plurality of opening holes through the roll inside and outside with a predetermined interval in the circumferential direction,
Each opening hole is opened in a shape that is long in the circumferential direction, and when the length of the opening hole in the substantially radial direction is A and the plate thickness of the side plate is C, the relationship of A / C ≦ 1 is established. Meet and
The length of the opening hole in the circumferential direction is B, the distance between adjacent opening holes in the circumferential direction is D, and the opening hole in the circumferential direction of the side plate defined by R = B / (B + D) A sink roll of a continuous molten metal plating apparatus, wherein the opening ratio R is set to 50% or less.

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