JP2575568B2 - Roll support device in hot-dip metal plating bath - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A roll supporting device in a hot-dip metal plating bath according to the present invention is incorporated in a plating device for continuously performing hot-dip metal coating such as hot-dip zinc on the surface of a long steel plate. Is used to rotatably support the roll that guides.

[0002]

2. Description of the Related Art When a plating layer of another metal is formed on a metal surface, in addition to plating by an electrochemical treatment, a metal serving as a core material is immersed in a plating bath in which the above-mentioned other metal is melted. Plating treatment using a hot-dip plating bath is widely performed. When galvanizing the surface of a long steel sheet by using such a hot-dip bath, for example,
As disclosed in Japanese Unexamined Patent Publication No. -90852, this is performed by an apparatus as shown in FIG.

[0003] The strip-shaped steel sheet 1 sent out from an uncoiler (not shown) is guided from a continuous furnace 3 through a snout 4 and guided into a plating tank 6 in which molten zinc 5 is stored, while being guided by an appropriate transport roll 2. The steel sheet 1 having the molten zinc 5 adhered to the surface by being turned upward by the sink roll 7 and being sent through the plating tank 6 is used by the support rolls 8, 8 to correct the warp and stabilize the passing plate. It is taken out of the plating tank 6 as a plated steel sheet 1a. Reference numerals 9 and 9 denote nozzles for controlling the amount of adhered molten metal such as molten zinc. The plated steel sheet 1a that has passed through the nozzles 9 and 9 is cooled and solidified from a metal such as zinc adhering to the surface, and then wound around a recoiler (not shown).

As described above, the sink roll 7 and the support rolls 8, 8 for guiding the steel sheet 1 or correcting the warpage of the steel sheet 1 while being immersed in the high-temperature molten zinc 5, For example, as shown in FIG. 4, the support arms 10 are rotatably supported at the distal ends thereof by rolling bearings 11. That is, the rolling bearings 11, 11 are provided between the inner peripheral surfaces of the circular holes 12, 12 formed at the distal end portions of the support arms 10, 10 and the outer peripheral surfaces of both ends of the shaft 13 supporting the support roll 8. Thus, the support roll 8 is rotated with a small force.

As the rolling bearings 11, 11 are required to have high heat resistance, for example, those made of ceramic are used. That is, each of the rolling bearings 11 includes an outer ring 14, an inner ring 15, and a plurality of rolling elements 16, 16 made of a ceramic such as silicon nitride.
Further, the plurality of rolling elements 16, 16 are held by a retainer 17 (see FIG. 2 showing an embodiment of the present invention).
The rollers 16 are held so as to be freely rollable with a predetermined space between them.

[0006]

However, in the case of the above-described conventional roll supporting apparatus in a hot-dip metal plating bath, the durability of each of the rolling bearings 11 is not necessarily improved due to the material of the retainer 17. Not enough.

That is, the ceramics such as silicon nitride forming the outer ring 14, the inner ring 15, and the plurality of rolling elements 16, 16 are so-called erosion that their surfaces are gradually scraped off even when immersed in a high-temperature molten metal such as molten zinc. (Or erosion) does not occur, but the metal cage 17 is easily eroded.
Since the strength of No. 7 decreased early, the rolling bearings 11 and 11 could not be used repeatedly.

[0008] Of course, if the cage 17 is made of ceramic, the durability of the cage 17 is improved similarly to the outer ring 14 and the like, but the cage is more complicated in shape than the outer ring 14, the inner ring 15 and the rolling elements 16. It is extremely difficult to make 17 from ceramic.

The apparatus for supporting a roll in a hot-dip metal plating bath of the present invention has been conceived in view of the above-mentioned circumstances.

[0010]

The roll supporting device in the hot-dip metal plating bath according to the present invention is similar to the roll supporting device in the conventional hot-dip metal plating bath described above. And a support arm for rotatably supporting the shaft via a rolling bearing.

In particular, in the roll supporting apparatus in a hot-dip metal plating bath of the present invention, the retainer of the rolling bearing is made of pure tantalum or a tantalum-tungsten alloy obtained by adding 10% by weight or less of tungsten to tantalum. And

[0012]

In the case of the roll supporting apparatus in the hot-dip metal plating bath of the present invention configured as described above, the cage made of pure tantalum or a tantalum-tungsten alloy is almost entirely made of molten metal such as molten zinc. Since the cage is not eroded, the durability of the cage is sufficient, and the rolling bearing including the cage can be used repeatedly.

For example, the inventor of the present invention described pure tantalum, a tantalum-tungsten alloy obtained by adding 10% by weight of tungsten to tantalum, and a metal conventionally used for forming a cage, When immersed in molten zinc and the degree of corrosion generated on each metal surface was measured, the results shown in the following table were obtained.

[0014]

[Table 1]

The experiment was conducted by immersing a test piece made of each metal material in molten zinc at 460 ° C. for 100 hours and then measuring the weight loss due to erosion. From the results of this experiment, pure tantalum and tantalum-tungsten alloy
It turns out that it has high durability in molten zinc.

The reason why the addition amount is set to 10% by weight or less even when tungsten is added is that if the addition amount of tungsten exceeds 10% by weight, the amount of corrosion in the molten zinc increases remarkably. It is. That is, the present inventor made a plurality of test pieces by varying the amount of tungsten added to tantalum, and placed each test piece in molten zinc at 460 ° C. for 10 times.
When the amount of erosion was measured after immersion for 0 hour, the result shown in FIG. 1 was obtained.

As apparent from FIG. 1, when the amount of tungsten added to tantalum is in the range of 0 to 10% by weight, the amount of erosion is extremely small, but the amount of tungsten added is 10% by weight. Above this, the amount of erosion increases significantly.
Therefore, as described above, the addition amount of tungsten is limited to 10% by weight or less.

[0018]

2A to 2C show three examples of a rolling bearing constituting a roll supporting apparatus in a hot-dip metal plating bath of the present invention. In any case, the outer ring 14, the inner ring 15, and the plurality of rolling elements 1 made of silicon nitride are used.
6 and 16. Also, the outer ring 14 is
3 is fitted and supported. Outer peripheral surface 14a of outer ring 14
Is a spherical convex surface, and the inner peripheral surface of the alignment ring 23 is a spherical concave surface so that the outer ring 14 can swing freely inside the alignment ring 23.

In the case of forming a roll support device, the centering ring 23 is connected to the support arms 10 and the circular holes 12 and
2 (FIG. 4), and the inner ring 15 is externally fitted and fixed to the end of the shaft 13 (FIG. 4). When the center axes of the circular holes 12 and 12 and the center axis of the shaft 13 are misaligned,
The misalignment is compensated for by the centering of the outer ring 14 inside 3. Therefore, no excessive force is applied to the plurality of rolling elements 16 provided between the outer ring 14 and the inner ring 15.

Further, the plurality of rolling elements 16, 16 are rotatably held by a retainer 17 with a predetermined interval between the adjacent rolling elements 16, 16.
2A of the retainer 17 is formed by connecting a pair of halves 18, 18 each formed in an annular shape with a bolt 19 and a nut 20. At the position where one side edge of each half 18, 18 is aligned with each other, semicircular notches 21, 21 are formed at equal intervals, and the notches 21, 21 of both halves 18, 18 are joined together. , A circular pocket 22. The rolling elements 16, 16 are rotatably held inside the respective pockets 22.

All the members constituting the retainer 17, that is, the pair of halves 18, 18 and the bolt 19 and the nut 20, are preferably made of pure tantalum or tantalum obtained by adding 10% by weight or less of tungsten to tantalum. -Made of tungsten alloy.

The cage 17 shown in FIG.
The pair of halves 18 are connected to each other by rivets 24. In this case, the rivets 24 as well as the halves 18, 18 are preferably made of pure tantalum or tantalum.
It is made of a tantalum-tungsten alloy to which 0% by weight or less of tungsten is added.

FIGS. 2A and 2B show a case where the retainer 17 is used.
An example in which a so-called squirrel cage is used is shown. As shown in FIG. 3C, a so-called waveform holder in which two holding plates 25, 25 each formed in a wave form are connected by a rivet 26. Can also be used. In this case, the rivets 26 as well as the two holding plates 25, 25 are preferably made of pure tantalum or a tantalum-tungsten alloy obtained by adding 10% by weight or less of tungsten to tantalum.

[0024]

As described above, the roll supporting apparatus in a hot-dip metal plating bath of the present invention is constructed and operated as described above. It can be used for a long time. Further, the rolling bearing can be used repeatedly. Therefore, the running cost of the hot-dip metal plating apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the amount of tungsten added to tantalum and the amount of corrosion.

FIG. 2 is a sectional view showing three examples of the structure of a rolling bearing.

FIG. 3 is a schematic vertical side view of a hot metal plating apparatus.

FIG. 4 is an enlarged sectional view taken along line XX of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel plate 1a Steel plate 2 Conveyance roll 3 Continuous furnace 4 Snout 5 Hot-dip zinc 6 Plating tank 7 Sink roll 8 Support roll 9 Nozzle 10 Support arm 11 Rolling bearing 12 Circular hole 13 Shaft 14 Outer ring 14a Outer peripheral surface 15 Inner ring 16 Rolling element 17 Cage 18 Half piece 19 Bolt 20 Nut 21 Notch 22 Pocket 23 Alignment ring 24 Rivets 25 Holding plate 26 Rivets

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display F16C 33/62 F16C 33/62 (72) Inventor Koji Ando 1-8 Fuso-cho, Amagasaki-shi, Hyogo Sumitomo Metal Industries Co., Ltd. (72) Inventor Toshihiro Mori 1-8 Fusocho, Amagasaki City, Hyogo Prefecture Sumitomo Metal Industries Co., Ltd. (72) Inventor Yukio Matsuda 1-8 Fusomachi, Amagasaki City, Hyogo Sumitomo Metal Industries Co., Ltd. In-house (56) References JP-A-60-82457 (JP, U) Japanese Patent Publication No. 1-28248 (JP, B2)

Claims (3)

(57) [Claims] An apparatus for supporting a roll in a hot-dip metal plating bath, comprising: a shaft at both ends of a roll provided in the hot-dip metal plating bath; and a support arm rotatably supporting the shaft via a rolling bearing. And a cage for the rolling bearing is made of pure tantalum or a tantalum-tungsten alloy obtained by adding 10% by weight or less of tungsten to tantalum. 2. The roll supporting apparatus in a hot-dip metal plating bath according to claim 1, wherein the outer ring, the inner ring, and the rolling elements constituting the rolling bearing are made of ceramic. 3. The hot-dip metal plating bath according to claim 1, wherein the hot-dip metal plating bath is a hot-dip galvanizing bath, and the outer ring, the inner ring, and the rolling elements constituting the rolling bearing are made of silicon nitride. Roll support device inside.