JP3974881B2 - Metal strip continuous hot dipping equipment - Google Patents

Description

【００１４】
【発明の効果】
本発明により、金属溶融めっき浴中で金属製サポートロールを無駆動で安定して回転させることが可能となり、産業上有用な著しい効果を奏する。
【図面の簡単な説明】
【図１】 金属溶湯中の金属製サポートロールの直径Ｄｓ、軸部の直径Ｄａとの比Ｄｓ／Ｄａと金属製サポートロール無駆動回転の関係を示す図である。
【図２】 本発明を適用する金属帯の連続溶融めっき装置の一例を模式的に示す図である。
【図３】 従来のスリーブ形態と金属製サポートロール軸への取り付けを模式的に示す図である。
【図４】 本発明によるスリーブ形態と金属製サポートロール軸への取り付けを模式的に示す図である。
【図５】 本発明による押さえリングを介したスリーブ取り付け方法を模式的に示す図である。
【図６】 金属溶融めっき浴中のロール配置を模式的に示す図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a continuous hot dip plating apparatus for a metal strip, and more particularly to a roll and a bearing member used in a molten metal.
[0002]
[Prior art]
Metal strip continuous hot dip plating equipment for continuously plating metal strips by passing them through a zinc or other metal hot dip plating bath. Corrects the sink roll that guides the metal strip to the hot dip plating bath and the warpage in the width direction of the metal strip. Rotating parts such as support rolls, which are always immersed in the hot dipping bath during operation.
The support roll is forcibly rotated by an external drive. In general, the driving force transmission means for rotating the roll is one in which the driving force is transmitted from the electric motor installed outside the hot dipping bath to the support roll through the universal joint and the spindle. In this case, the connection between the spindle and the support roll in the hot dipping bath has a structure in which a cross pin integrated at the tip of the spindle is received by a cross pin receiving groove provided at the end of the roll shaft. For this reason, the rotation of the support roll is mechanically non-uniform, which causes vibrations in the metal band, and this vibration is the main cause of the adhesion of plating.
[0003]
As means for solving these problems, Patent Document 1 discloses that a spur gear is provided on an output shaft of an electric motor, a horizontal spindle is connected to a shaft end of a support roll, and a spur gear engaged with the spur gear is connected to the shaft end. An invention of a gear drive system that is provided and transmits power as rotational force by meshing a spur gear is disclosed.
Patent Document 2 discloses a method of eliminating the drive of the support roll itself. Further, Patent Literature 3, Patent Literature 4, Patent Literature 5, and the like disclose bearing structures for the purpose of rotating a support roll without driving.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 06-57389 [Patent Document 2]
Japanese Patent Laid-Open No. 06-128711 [Patent Document 3]
Japanese Patent Laid-Open No. 05-0400002 [Patent Document 4]
Japanese Patent Laid-Open No. 06-017212 [Patent Document 5]
Japanese Patent Laid-Open No. 2000-064008
[Problems to be solved by the invention]
However, the method as disclosed in Patent Document 1 has a problem that the equipment for driving the support roll becomes large and the equipment cost increases. In addition, since the driving force transmission mechanism is provided, maintenance and maintenance thereof are always required, which is not economical. Moreover, as shown in Patent Document 2, it is effective to eliminate the drive of the support roll, but Patent Document 2 does not show a specific measure for rotating the support roll without driving. On the other hand, Patent Document 3, Patent Document 4, and Patent Document 5 disclose specific improvements to the support roll bearing for rotating the support roll in a metal hot dipping bath without any drive. Even if applied, it does not actually lead to the non-drive of the support roll. This is because, especially in the upper support roll with a short winding length between the metal strip and the support roll, when the metal belt has a small cross-sectional area and the driving force applied to the support roll from the metal strip is small, the rotational resistance of the bearing portion is the roll drive. This is because the support roll cannot be stably rotated if the force is exceeded and, as a result, no drive is performed.
[0006]
Therefore, the present invention advantageously solves the above-described problems of the prior art and enables a metal support roll to be rotated stably in a metal hot dipping bath without being driven in a stable manner. It is an issue to provide.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention has the following structure as described in the claims.
(1) in a continuous hot dipping apparatus of a metal band and a sink roll and a metal support roll rotating is supported by a bearing in a molten metal, the diameter Ds of the support roll, the diameter of the shaft portion of the support roll Between Da,
Ds / Da > 4 . 2
A continuous hot dip plating apparatus for a metal band, wherein the support roll rotates without driving through a frictional force between the support roll and the metal band when the metal band is passed.
(2) The continuous hot dip plating apparatus for a metal strip according to (1), wherein the sleeve mounted on the shaft portion of the support roll has a flange portion on the support roll body portion side.
(3) The continuous hot dip plating apparatus for a metal strip as described in (2) above, wherein the means for fixing the sleeve to the support roll body side is welding at the flange edge.
(4) A means for fixing the sleeve to the support roll body side is provided by welding a pressing ring at a fixing position on the support roll body side, and fitting the flange edge to the pressing ring part. The continuous hot dip plating apparatus for a metal strip according to (2) above, wherein
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 2 is a diagram illustrating an example of a continuous hot dip plating apparatus for a metal strip targeted by the present invention, in which the metal strip to be plated is a steel plate. In the following description, the molten metal is zinc, and the metal band to be galvanized is mainly described as an example of a steel plate. However, the plating targeted by the present invention is galvanization, and the metal band. Needless to say, is not limited to steel plates.
[0009]
First, in the present invention as set forth in claim 1, between the diameter Da of the shank diameter Ds and a metal support rolls of metallic support rolls, Ds / Da> 4. The reason for limiting the relationship 2 will be described.
To undriven rotating the metallic support rolls in molten metal plating bath is with respect to the rotation resistance of the metal support roll axes may be the driving force that gives the steel a metallic support rolls is large enough. The driving force applied to the metal support roll from this steel plate is determined by the operating conditions of the plating section of the continuous hot dipping apparatus. However, unnecessarily changing the operating conditions only for the purpose of rotating the metal support roll without driving leads to unstable plating and is not allowed.
[0010]
Accordingly, the inventors pay attention to the relationship between the diameter of the metal support roll and the shaft diameter, and the ratio Ds / Da of the diameter Ds of the metal support roll in the molten metal and the diameter Da of the shaft portion and the metal support roll. We studied earnestly the situation of non-driven rotation. As a result, it has been found that by setting Ds / Da ≧ 3, a steel sheet that passes as a plated product can be obtained although fine slip occurs. However, since the condition of Ds / Da ≧ 3 is close to the limit of the condition for obtaining a steel sheet that passes as a plated product, in the present invention, Ds / Da > 4 . 2 . Furthermore, by setting Ds / Da ≧ 5, the non-driven rotation of the metal support roll is completely stable, and it is possible to produce the product without worrying about the quality of the plated steel sheet.
[0011]
Next, the sleeve to be mounted on the shaft portion of the metal support roll and the fixing means thereof in the present invention according to any one of claims 2 to 4 will be described.
The roll diameter Ds of the metal support roll cannot be easily changed due to the convenience of spare parts of the support roll. Therefore, Ds / Da > 4 . In order to obtain 2 , the shaft diameter Da of the metal support roll is reduced. However, if the shaft diameter Da is reduced, the strength of the shaft portion is weakened. Therefore, a shaft diameter Da larger than the minimum required strength can be ensured.
[0012]
Normally, the shaft portion of the metal support roll is used in a state in which a sleeve is welded and fixed to the shaft as shown in FIG. 3, but this welded portion is easily eroded by the molten metal, particularly in a metal hot dip plating bath. There was a problem that the shaft was easily broken starting from the eroded portion. When the shaft diameter Da is reduced, the possibility of shaft breakage due to erosion increases. Therefore, in the present invention, as a preventive measure, as shown in FIG. 4, the shape of the sleeve, a shape having a flange portion in the metal supporting roll barrel side, the fixed metal support roll barrel portion of the sleeve Is avoided by welding and fixing the flange edge to the metal support roll barrel or axle. Thereby, since there is no welded portion in the shaft portion itself, erosion with molten metal does not occur in the shaft portion, and shaft breakage can be avoided.
[0013]
The sleeve may be made of ceramics or the like for the purpose of improving wear resistance, but in this case, the sleeve cannot be welded. In that case, as shown in FIG. 5, the sleeve has a shape having a flange portion on the roll body side, and a weldable ring that is fixed so as to press the flange is installed. What is necessary is just to weld to an axle part.
In the continuous hot-dip plating apparatus for steel strips shown in FIG. 2, the rotation state of the metal support rolls without driving was confirmed under the conditions shown in Table 1. The result is shown in FIG. In addition, the roll arrangement | positioning in a metal hot dipping bath was performed by both the arrangement | positioning 1 and the arrangement | positioning 2 of FIG. In the Example of this invention, it turns out that a plated steel plate can be manufactured without a problem.
[Table 1]

[0014]
【The invention's effect】
The present invention, in a metal hot dip plating bath becomes possible to rotate the metal support roll stably with no drive, exhibits the industrially useful remarkable effect.
[Brief description of the drawings]
FIG. 1 is a diagram showing a relationship between a ratio Ds / Da between a diameter Ds of a metal support roll in a molten metal and a diameter Da of a shaft portion and no rotation of the metal support roll.
FIG. 2 is a diagram schematically showing an example of a continuous hot dip plating apparatus for a metal strip to which the present invention is applied.
FIG. 3 is a diagram schematically showing a conventional sleeve configuration and attachment to a metal support roll shaft.
FIG. 4 is a diagram schematically showing a sleeve configuration and attachment to a metal support roll shaft according to the present invention.
FIG. 5 is a view schematically showing a sleeve attachment method via a pressing ring according to the present invention.
FIG. 6 is a diagram schematically showing a roll arrangement in a metal hot dipping plating bath.

Claims (4)

In a continuous hot dip plating apparatus for a metal strip comprising a sink roll and a metal support roll supported by a bearing in a molten metal, the diameter Ds of the support roll and the diameter Da of the shaft portion of the support roll Between,
Ds / Da > 4 . 2
A continuous hot dip plating apparatus for a metal band, wherein the support roll rotates without driving through a frictional force between the support roll and the metal band when the metal band is passed.   2. The continuous hot-dip plating apparatus for a metal strip according to claim 1, wherein the sleeve mounted on the shaft portion of the support roll has a flange portion on the support roll body portion side.   The continuous hot-dip plating apparatus for a metal strip according to claim 2, wherein the means for fixing the sleeve to the support roll body is welding at the flange edge.   The fixing means to the support roll body side of the sleeve is provided by welding a pressing ring at a fixing location on the support roll body side, and fitting the flange edge to the pressing ring part. The continuous hot dip plating apparatus for a metal strip according to claim 2, wherein the apparatus is a continuous hot dip plating apparatus.

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