JP2010255043A - Roll for hot dip metal coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roll for hot dip metal coating, in particular, a large and long roll, having a shaft part which is hardly broken even when the load of the self weight of the roll itself is applied to the shaft part and the driving force when feeding a steel plate of a large area by rotating the roll is applied to the shaft part, and to provide a hot dip metal coating apparatus using the same. <P>SOLUTION: In the roll 10 for hot dip metal coating, ceramic-made shaft parts 12 each consisting of a supporting part 12b and a fitting part 12a to be respectively connected to a driven side and a driving side are provided on each end of a ceramic-made cylindrical barrel part 11. At least one shaft part 12 has either a plurality of through holes 13 passing through the supporting part 12b to the fitting part 12a or a plurality of through holes 13 passing through the fitting part 12a around the supporting part 12b. Since the roll 10 for hot dip metal coating has the shaft part 12 having excellent strength, the roll 10 can be used for a long time. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a ceramic hot metal plating roll called a sink roll or a support roll that is used in a hot metal plating apparatus for dipping in a hot metal such as aluminum or zinc to apply metal plating to a steel sheet.

  The body of an automobile is formed by processing a metal-plated steel sheet, and the molten metal plating is used to dip the surface-activated steel sheet into a molten metal such as aluminum or zinc. The device is used.

  FIG. 5 is a schematic configuration diagram showing an example of a molten metal plating apparatus.

  This molten metal plating apparatus 41 includes a molten metal tank 44 for containing a molten metal 45, a snout 43 for cleaning the surface of the steel plate 42, and a vertical direction by rotating the steel plate 42 along the outer periphery in the molten metal 45. The sink roll 46 that changes the orientation of the steel plate 42, the support roll 47 that feeds the steel plate 42 in the vertical direction while correcting the warpage in the width direction of the steel plate 42, and the steel plate 42 pulled up from the molten metal 45 The gas nozzle 48 adjusts the thickness of the metal plating on the surface of the steel plate 42 by blowing gas.

  Since the steel plate 42 sent out from the continuous annealing furnace in the reducing atmosphere is sent into the molten metal 45 through the snout 43, it is immersed in the molten metal 45 without being exposed to the air atmosphere. The steel plate 42 immersed in the molten metal 45 is moved along the outer periphery of the sink roll 46 provided in the vicinity of the bottom of the molten metal tank 44 so that the traveling direction is the bottom direction of the molten metal tank 44. To the liquid surface of the molten metal 45. Next, when the steel plate 42 passes between the two rotating support rolls 47, the warpage in the width direction of the steel plate 42 is corrected, and further, the steel plate 42 is sent in the vertical direction and pulled up from the molten metal 45. By blowing gas from the gas nozzle 48 to the steel plate 42, the steel plate 42 in which the thickness of the metal plating is uniformly adjusted can be obtained. An automobile body or the like can be formed by performing plastic working on the steel plate 42 to which metal plating has been applied.

  Here, as the material of the sink roll 46 and the support roll 47 constituting the molten metal plating apparatus 41, metal materials such as chrome steel and stainless steel have been conventionally used, but the material is immersed in the molten metal 45 for a long time. Therefore, the sink roll 46 and the support roll 47 made of these metal materials have a problem that their surfaces are easily eroded by the molten metal 45 and are easily worn.

  As described above, when the surface of the sink roll 46 and the support roll 47 is eroded by the molten metal 45 and is worn, the sink roll 46 and the support roll 47 are slightly vibrated during rotation. Therefore, it is difficult to obtain the steel plate 42 that has been subjected to heat treatment, so it is necessary to stop the molten metal plating apparatus 41 and replace the worn sink roll 46 and support roll 47, which increases maintenance costs and increases production efficiency. There was a problem that decreased.

  In response to this problem, various sink rolls 46 and support rolls 47 have been proposed in which a cemented carbide or ceramics having excellent corrosion resistance is thermally sprayed on the surface of a metal material to form a sprayed protective layer. The sink roll 46 and the support roll 47 formed with this thermal spray protective layer have better corrosion resistance than the sink roll 46 and the support roll 47 made of only a metal material, but the thermal spray protective layer has a lower density, and the thermal spray protective layer and the metal Since the thermal expansion coefficients of the sink roll 46 and the support roll 47 made of the material are different, the thermal spray protection layer is likely to crack, and the problem that the metal material is worn out by being eroded by the molten metal 45 entering the crack still remains. It was not solved.

  Therefore, as the sink roll 46 and the support roll 47 which are further excellent in corrosion resistance and wear resistance, for example, in Patent Document 1, the roll body portion and the shaft portion are formed in a hollow shape by ceramics, and the inner surface of the roll body portion A continuous molten metal plating roll has been proposed in which a shaft portion is fitted and assembled to both ends of a roll body portion so as to have a gap between the outer surface of the shaft portion.

  In Patent Document 2, the roll body part and the shaft part are respectively formed hollow by ceramics, and the shaft part is joined to both ends of the roll body part, and the molten metal is discharged to the outer periphery of the shaft part. There has been proposed a roll for continuous molten metal plating in which a hole is formed.

  Further, Patent Document 3 discloses a continuous molten metal that is used by being immersed in a molten metal bath in which a roll body portion and a shaft portion are formed hollow with ceramics and the shaft portions are joined to both ends of the roll body portion. Plating rolls have been proposed.

  If these rolls for continuous molten metal plating of Patent Documents 1 to 3 are excellent in corrosion resistance, heat resistance, wear resistance, etc., the service life is long, and the roll is lightweight because it is formed in a hollow shape. Therefore, it can be rotated following the change in the traveling speed of the steel sheet.

Japanese Patent No. 3765485 Japanese Patent No. 4123457 Japanese Patent No. 4147509

  However, the rolls for continuous molten metal plating described in Patent Documents 1 to 3 are all formed in a hollow shape in the shaft portion and have been reduced in weight. In order to perform metal plating, a large and long sink roll 46 and a support roll 47 having an outer diameter exceeding 150 mm and a length of 1500 to 3000 mm are required, and continuous melting described in Patent Documents 1 to 3 is required. When a large-diameter hole centered on the shaft diameter is opened like a metal plating roll, the load due to the weight of the roll itself and the driving force when rotating the roll to feed a large-area steel plate 42 are generated. Since it is applied to the shaft portion, the shaft portion may not be sufficiently strong and may be damaged.

  The present invention has been devised to solve the above problems, and particularly in a large and long roll, the load due to the weight of the roll itself and the driving force when rotating the roll to feed a large area steel sheet are present. An object of the present invention is to provide a molten metal plating roll having a shaft portion that is less likely to be damaged even if it is applied to the shaft portion, and a molten metal plating apparatus using the roll.

  The roll for hot metal plating of the present invention has a ceramic shaft portion including a fitting portion and a support portion connected to the driven side and the driving side, respectively, at the end of the cylindrical barrel portion made of ceramic. In the molten metal plating roll, at least one of the shaft portions includes at least one of a plurality of through holes that penetrate from the support portion to the fitting portion and a plurality of through holes that penetrate the fitting portion around the support portion. It is characterized by having one side.

  Moreover, the roll for molten metal plating of this invention WHEREIN: The said structure WHEREIN: The through-hole which penetrates the said fitting part around the said support part is larger than the through-hole which penetrates from the said support part to the said fitting part. It is a feature.

  Moreover, the roll for hot metal plating of the present invention is characterized in that, in any one of the above-described configurations, the fitting portion is provided with holes connected to the plurality of through holes penetrating from the support portion to the fitting portion. It is what.

  Moreover, the roll for hot metal plating of the present invention is characterized in that, in any of the above-described configurations, the body portion and the shaft portion are made of a silicon nitride sintered body.

  Moreover, the molten metal plating apparatus of the present invention is characterized in that the molten metal plating roll having any one of the above configurations is used as a roll for handling the object to be plated in the molten metal.

  According to the molten metal plating roll of the present invention, a ceramic shaft portion comprising a fitting portion and a support portion respectively connected to the driven side and the driving side at the end portion of the ceramic cylindrical body portion. In at least one of the shafts for molten metal plating, at least one of the shaft portions penetrates from the support portion to the fitting portion, and a plurality of through holes penetrates the fitting portion around the support portion. By having at least one of the above, the load due to the weight of the molten metal plating roll itself or the driving force when rotating the molten metal plating roll to feed the steel plate is easily damaged. There is little, and durability can be improved more.

  Moreover, according to the roll for hot metal plating of the present invention, the through-hole penetrating the fitting portion around the support portion is larger than the through-hole penetrating from the support portion to the fitting portion. In addition to having a strength that can withstand the operation of a molten metal plating apparatus that performs metal plating on the metal, it is possible to reduce the weight, so that the load applied to the shaft portion can be reduced.

  Moreover, according to the roll for hot metal plating of the present invention, the fitting portion is provided with holes connected to the plurality of through holes penetrating from the support portion to the fitting portion, whereby the steel plate is subjected to metal plating. While having the strength that can withstand the operation of the applied molten metal plating apparatus, it is possible to reduce the weight, so that the load applied to the shaft portion can be reduced.

  According to the molten metal plating roll of the present invention, the body portion and the shaft portion are made of a silicon nitride-based sintered body, so that the load due to the weight of the molten metal plating roll itself or the molten metal plating roll can be reduced. Since it has mechanical strength that can withstand the driving force when rotating and feeding the steel sheet, and its wettability with molten metal is low, when the roll for molten metal plating of the present invention is taken out from the molten metal, Maintenance can be easily performed with very little adhesion of molten metal to the part and the shaft part.

  Further, according to the molten metal plating apparatus of the present invention, by using the roll for molten metal plating of the present invention as a roll for handling the object to be plated in the molten metal, the metal to the steel plate can be stably obtained over a long period of time. Since plating can be performed, the maintenance cost can be reduced and the replacement frequency is reduced, so that the production efficiency can be improved.

It is a schematic block diagram which shows an example of embodiment of the molten metal plating apparatus using the roll for molten metal plating of this invention. An example of embodiment of the roll for molten metal plating of this invention is shown, (a) is sectional drawing of the axial direction of the roll for molten metal plating, (b) is the AA 'line of (a). It is an enlarged view of a cross section. The other example of embodiment of the roll for hot metal plating of this invention is shown, (a) is sectional drawing of the axial direction of the roll for hot metal plating, (b) is the BB 'line | wire of (a). FIG. (A), (b), (c) which shows the further another example of embodiment of the roll for molten metal plating of this invention is all sectional drawing of the axial direction of the roll for molten metal plating. It is a schematic block diagram which shows a molten metal plating apparatus.

  Hereinafter, examples of embodiments of a molten metal plating roll and a molten metal plating apparatus using the same according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an example of an embodiment of a molten metal plating apparatus using the roll for molten metal plating of the present invention.

  The molten metal plating apparatus 1 includes a molten metal tank 4 for containing a molten metal 5, a snout 3 for cleaning the surface of the steel plate 2, and the steel plate 2 rotating in the molten metal 5 along the outer periphery in the vertical direction. Gas is applied to the sink roll 6 that changes the direction of the steel plate 2, the support roll 7 that sends the steel plate 2 in the vertical direction while correcting the warpage in the width direction of the steel plate 2, and the steel plate 2 pulled up from the molten metal 5. The gas nozzle 8 adjusts the thickness of the metal plating on the surface of the steel plate 2 by spraying.

  And since the steel plate 2 sent out from the continuous annealing furnace of a reducing atmosphere is sent out into the molten metal 5 through the snout 3, it is immersed in the molten metal 5 without being exposed to an air atmosphere. The steel plate 2 immersed in the molten metal 5 is moved along the outer periphery of the sink roll 6 provided near the bottom of the molten metal tank 4 and the sink roll 6 rotates, so that the traveling direction is the bottom direction of the molten metal tank 4. To the liquid surface direction of the molten metal 5. Next, when the steel plate 2 passes between the two rotating support rolls 7, the warp in the width direction of the steel plate 2 is corrected, and further, the steel plate 2 is sent in the vertical direction and pulled up from the molten metal 5. By blowing gas from the gas nozzle 8 to the steel plate 2 obtained, the steel plate 2 in which the thickness of the metal plating is uniformly adjusted can be obtained. The molten metal plating roll 10 of the present invention is applied to the sink roll 6 and the support roll 7 constituting the molten metal plating apparatus 1.

  FIG. 2 shows an example of an embodiment of a roll for hot metal plating according to the present invention, (a) is an axial sectional view of the hot metal plating roll, and (b) is an AA view of (a). It is an enlarged view of the cross section by a line.

  The molten metal plating roll 10 of the present invention shown in FIG. 2 includes a ceramic cylindrical body 11, and fitting parts 12 a and support parts 12 b connected to both ends of the cylindrical body 11. The shaft portion 12 is made of ceramic, and one end of the shaft portion 12 is connected to a rotation shaft on the driving side that is a driving source for the rotation of the roll, and the other is rotated according to the driving force applied from the driving source. Connected to the driven bearing. In addition, at least one of the shaft portions 12 connected to the driven side and the driving side respectively has a plurality of through holes 13a penetrating from the support portion 12b to the fitting portion 12a and the fitting portions 12a around the support portion 12b. It is important to have at least one of the through holes 13b. In FIG. 2 (a), reference numerals for the same parts as in the right part are omitted in the left part of the figure.

  Thus, the roll 10 for molten metal plating has at least one of the through-hole 13a and the through-hole 13b in the axial part 12, By this, it is a large sized used especially for metal-plating to the steel plate 2 of a large area. Even in the case of a long roll, the load caused by the weight of the molten metal plating roll 10 itself or the driving force when the large metal plate 2 is fed by rotating the molten metal plating roll 10 is applied to the shaft portion 12. It is possible to obtain a roll 10 for molten metal plating that is less easily broken and has improved durability. Further, when the shaft portion 12 has at least one of the through hole 13a and the through hole 13b, the sink roll 6 and the support roll 7 made of the molten metal plating roll 10 are taken out from the molten metal 5. The molten metal 5 accumulated in the cylindrical body portion 11 can be discharged from the through hole 13a and the through hole 13b in the same manner as a conventional roll formed in a hollow shape.

  In addition, when a shaft portion formed in a hollow shape as in the past is cracked even in a part of the shaft portion, the crack may propagate to the whole due to a load due to its own weight or a continuous driving force, and may be damaged. However, if the shaft portion 12 has a plurality of through holes 13a and through holes 13b as in the present invention, even if a crack occurs in a part of the shaft portion 12, the vicinity of the generated crack Propagation of cracks can be prevented by the through holes 13a and the through holes 13b.

  Further, as in the example shown in FIG. 2, it is preferable that the through holes 13a, the through holes 13b, and the distances between the through holes 13a and the through holes 13b are equal. If these intervals are provided equally, the strength of the fitting portion 12a and the support portion 12b is less likely to vary, and the molded body to be the shaft portion 12 is cut to form the through holes 13a and 13b. There are few defects such as cracks when they are formed or fired.

  Further, in the molten metal plating roll 10 of the example shown in FIG. 2, a plurality of through holes 13a penetrating from the support portion 12b to the fitting portion 12a and fitting around the support portion 12b are provided on both the driven side and the driving side. Although the shaft portion 12 having a plurality of through holes 13b penetrating the portion 12a is shown, since the strength is required for the driving-side shaft portion 12 to which the driving force of the driving source is directly applied rather than the driven side, the driven side is hollow. As a combination having at least one of a plurality of through-holes 13a and 13b in the driving-side shaft portion 12, or by changing the diameter of the through-hole 13a and the through-hole 13b formed in the driving-side shaft portion 12 to the driven-side shaft portion The through-hole 13a and the through-hole 13b are formed smaller than the through-hole 13a or the through-hole 13b, or the driven-side shaft portion 12 is formed with the through-hole 13a and the through-hole 13b. The shaft 12 on the driving side is stronger than the driven side, such as by forming one of the holes 13b. It may have a.

  FIG. 3 shows another example of the embodiment of the roll for hot metal plating of the present invention, (a) is a sectional view in the axial direction of the hot metal plating roll, and (b) is B of (a). It is an enlarged view of the section in a -B 'line. In FIG. 3A as well, in the left part of the figure, reference numerals for the same parts as in the right part are omitted.

  In the example of the molten metal plating roll 10 of the present invention shown in FIG. 3, the through hole 13b penetrating the fitting portion 12a around the support portion 12b is more than the through hole 13a penetrating from the support portion 12b to the fitting portion 12a. By being large, since it has the intensity | strength which can endure the driving | operation of the molten metal plating apparatus 1 which metal-plates on the steel plate 2, weight reduction can be achieved, Therefore The load concerning the axial part 12 can be reduced.

  Moreover, in FIG.3 (b), although the cross-sectional shape of the through-hole 13a was circular, and the cross-sectional shape of the through-hole 13b showed the fan shape, it can be set not only to this but various shapes, And it can be set as the combination of various shapes. Further, in order not to vary the strength of the shaft portion 12, the through holes 13a and the through holes 13b are provided symmetrically with respect to the axis C, and the distance between the through holes 13a and the distance between the through holes 13a and the through holes 13b. The intervals are preferably equal.

  Further, since the load applied to the shaft portion 12 is dispersed and applied as stress to the outer peripheral portion of the through-hole 13a and the through-hole 13b, the through-hole 13a and the through-hole when viewed in cross section as in the example shown in FIG. In the shape of the hole 13b, it is preferable that there is no sharp portion that causes stress concentration. Therefore, when the shape of the through hole 13a or the through hole 13b is a fan shape or a polygonal shape, it is preferable to disperse stress by processing the portion that becomes the apex of the hole into an R shape.

  Further, the boundary portion between the fitting portion 12a and the support portion 12b of the shaft portion 12 is preferably formed into a tapered shape, and more preferably, because the weight of the molten metal plating roll 10 is likely to be concentrated as a load. Is preferably R-shaped as in the example shown in FIG.

  FIG. 4 shows still another example of the embodiment of the molten metal plating roll of the present invention. (A), (b), and (c) are all sectional views in the axial direction of the molten metal plating roll. is there. Also in these drawings, the reference numerals for the same parts as those in the right part are omitted in the left part of the figure.

  In the example of the molten metal plating roll 10 of the present invention shown in FIG. 4, a large-diameter hole 14 connected to a plurality of through holes 13a penetrating from the support portion 12b to the fitting portion 12a is provided in the fitting portion 12a. Therefore, it has strength that can withstand the operation of the molten metal plating apparatus 1 that performs metal plating on the steel plate 2 and can reduce the weight, so that the load applied to the shaft portion 12 can be reduced. In order to maintain the strength of the fitting part 12a when the volume occupied by the fitting part 12a is 100% when the hole 14 does not exist in the shaft part 12, the ratio of the volume of the hole 14 is Is preferably 50% or less.

  In addition, various ceramics such as alumina, zirconia, silicon nitride, silicon carbide, cordierite can be used as the material of the body 11 and the shaft 12 constituting the roll 10 for molten metal plating of the present invention. It is preferable that the shaft portion 12 is made of a silicon nitride-based sintered body in that it has excellent mechanical strength and low wettability with the molten metal 5. By forming the body 11 and the shaft 12 constituting the molten metal plating roll 10 of the present invention from a silicon nitride sintered body, the load due to the weight of the molten metal plating roll 10 itself and the molten metal plating roll 10 can be reduced. The sink roll 6 and the support roll made of the molten metal plating roll 10 of the present invention have mechanical strength that can withstand the driving force when the steel sheet 2 is rotated and are low in wettability with the molten metal 5. When 7 is taken out from the molten metal 5, the adhesion of the molten metal 5 to the body portion 11 and the shaft portion 12 is extremely small, and maintenance can be easily performed. In addition, because the body 11 and the shaft 12 are made of the same silicon nitride sintered body, the fit may be loosened or cracks or breakage may occur due to the difference in thermal expansion between the body 11 and the shaft 12. Is preferable.

  Next, as an example of the manufacturing method of the molten metal plating roll 10 of the present invention, details of an example using a silicon nitride sintered body for the cylindrical body portion 11 and the shaft portion 12 having the shape shown in FIG. 2 will be described. To do.

  First, silicon nitride powder having an average particle diameter of 1 μm is prepared as a primary material, and a predetermined amount is weighed, and a binder and a solvent are added to form a slurry. Next, this slurry is sprayed and granulated with a spray dryer to obtain a secondary raw material. Then, the secondary raw material is put into a predetermined mold, and using a hydrostatic press molding apparatus (rubber press apparatus), a cylindrical molded body that becomes the cylindrical body portion 11 and a cylindrical shape that becomes the shaft portion 12. Each molded body is molded. Thereafter, these molded bodies are cut into a predetermined shape to form a cylindrical molded body that becomes the cylindrical body 11 and a convex shape when viewed in cross-section in the axial direction that becomes the shaft portion 12. The body is placed in a reducing atmosphere furnace and fired at a maximum temperature of 1950 ° C. to obtain a sintered body. After firing, the cylindrical body portion 11 and the shaft portion 12 made of a silicon nitride sintered body are obtained by grinding the surface of the sintered body.

  Next, the obtained cylindrical body portion 11 and the fitting portion 12a of the shaft portion 12 are fitted and joined. As a method for joining the cylindrical body portion 11 and the shaft portion 12, any method can be applied as long as it is a method for joining members generally, such as shrink fitting or screw fastening. When shrink fitting is used, the cylindrical body 11 is precisely ground to the size that allows the inner circumference of the cylindrical body 11 and the outer periphery of the fitting portion 12a of the shaft 12 to be shrink-fitted, and then the cylindrical body. The part 11 is heated and expanded by a gas burner, and the fitting part 12a of the shaft part 12 is fitted along the inner periphery of the cylindrical body part 11, and is slowly cooled and shrink-fitted. When using screw fastening, screw processing is performed so that the inner peripheral portion near the end surface of the cylindrical body 11 and the outer peripheral portion of the fitting portion 12a of the shaft portion 12 can be fastened, and screw fastening is performed. When screw fastening is performed at this time, it is preferable to perform screw processing in the direction opposite to the rotation direction of the molten metal plating roll 1 so that the screw does not loosen when rotated.

  It should be noted that the shaft portion 12 constituting the molten metal plating roll 10 of the present invention shown in FIGS. 3 (a) and 3 (b) and FIGS. Needless to say, can be formed.

  The roll 10 for molten metal plating of the present invention thus obtained is particularly large and long, and the load due to the weight of the roll itself is applied to the shaft, and the roll is rotated to feed a large-area steel plate. Even if the driving force is applied to the shaft portion, the molten metal plating roll 10 has a shaft portion that is not easily damaged and can be used for a long time. Further, if the roll 10 for molten metal plating of the present invention is used as a roll for handling the steel plate 2 which is the object to be plated in the molten metal 5, the steel plate 2 can be subjected to metal plating for a long time. The cost can be reduced and the replacement frequency is reduced, so that the production efficiency can be improved.

  Examples of the roll for hot metal plating of the present invention are shown below.

  2 is manufactured as an example of an embodiment of the present invention, and is installed as a support roll 7 of a molten metal plating apparatus 1 schematically shown in FIG. A test for metal plating was performed. Details are shown below.

<Manufacture of cylindrical body 11>
Production of a cylindrical body 11 made of ceramics as shown in FIGS. 2 (a) and 2 (b) was carried out. First, silicon nitride powder having an average particle diameter of 1 μm was prepared as a primary material, and a predetermined amount was weighed, and a binder and a solvent were added to form a slurry. Next, this slurry was sprayed and granulated with a spray dryer to obtain a secondary raw material. Then, this secondary raw material is put into a rubber mold capable of obtaining a cylindrical molded product, and a cylindrical molded body that becomes the cylindrical body portion 11 using an isostatic press molding apparatus (rubber press apparatus). Got. And the cutting required for the inner periphery, outer periphery, etc. of this cylindrical molded object was given. Then, it put into the reducing atmosphere furnace and baked at the highest temperature of 1950 degreeC, and obtained the sintered compact. After firing, the surface of the sintered body was ground to obtain a cylindrical body 11 made of a silicon nitride sintered body having an outer diameter of 300 mm, an inner diameter of 220 mm, and a length of 2000 mm.

<Manufacture of shaft 12>
The ceramic shaft 12 shown in FIGS. 2A and 2B was manufactured. The same silicon nitride secondary material used for the production of the cylindrical body 11 is placed in a rubber mold capable of obtaining a cylindrical molded product, and using a hydrostatic press molding apparatus (rubber press apparatus), A cylindrical shaped body was obtained. And the part which becomes the support part 12b of a column-shaped molded object was cut, and the molded object whose shape when it sees a cross section in an axial direction was convex was obtained. Further, the through hole 13a, 13b was formed by cutting, and a molded body to be the shaft portion 12 was obtained. Then, it put into the reducing atmosphere furnace and baked at the highest temperature of 1950 degreeC, and obtained the sintered compact. After firing, the surface of the sintered body is ground, the fitting portion 12a has an outer diameter of 220 mm and a length of 100 mm, and the support portion 12b has an outer diameter of 150 mm and a length of 250 mm. A shaft portion 12 made of a silicon nitride sintered body having inner diameters of 13a and 13b of 16 mm was obtained.

<Bonding of cylindrical body 11 and shaft 12>
The cylindrical body 11 made of a silicon nitride sintered body and the shaft 12 were joined by shrink fitting. First, the cylindrical body part 11 was heated with a gas burner, and expanded until the fitting part 12a of the shaft part 12 had an inner diameter that could be fitted. Thereafter, the fitting portion 12a of the shaft portion 12 is fitted into the cylindrical body portion 11 and slowly cooled to join the tubular body portion 11 and the shaft portion 12, and the molten metal plating roll 10 of the present invention is bonded. Obtained.

<Metal plating test on steel plate 2>
As the support roll 7 of the molten metal plating apparatus 1 shown in FIG. 1, a test for performing metal plating on the steel sheet 2 by actually operating the molten metal plating apparatus 1 continuously was performed using the roll 10 for molten metal plating of the present invention. . In the test, three types of stainless steel plates 2 having a thickness of 2 mm and widths of 1300 mm, 1500 mm, and 1800 mm were used, and zinc was used as the molten metal 5.

  Moreover, the roll of the comparative example which formed the trunk | drum and the axial part in the hollow shape was also prepared for the test. In addition, the roll of the comparative example is the same using the same raw material as the roll 10 for molten metal plating of the present invention except that the shaft part is hollow and the thickness of the fitting part and the support part is 30 mm. What was manufactured so that it might become a size was used.

<Test results>
Regarding the roll of the comparative example in which the body part and the shaft part were formed in a hollow shape, the steel plate 2 having a width of 1300 mm was galvanized, and the shaft part on the drive side was damaged after two weeks of continuous operation. Further, when the steel plate 2 having a width of 1500 mm and 1800 mm was galvanized, the shaft portion on the drive side was damaged within one week.

  On the other hand, in the roll 10 for molten metal plating of the present invention, when zinc plating was performed on three types of stainless steel plates 2 having a plate thickness of 2 mm and widths of 1300 mm, 1500 mm, and 1800 mm, the shaft portion 12 was cracked. In either case, the molten metal plating apparatus 1 could be continuously operated for more than 2 weeks. Thereby, in a large and long roll, even if the load due to the weight of the roll itself is applied to the shaft portion 12 and the driving force when the roll is rotated to feed the large-area steel plate 2 is applied to the shaft portion 12, It was confirmed that the roll 10 was a molten metal plating roll 10 having a shaft portion 12 that was not easily damaged.

  Further, in the comparative example, since it was the shaft portion on the drive side that was damaged, the shaft portion on the drive side to which the drive force of the drive source directly applied constitutes the molten metal plating roll 10 of the present invention. It is preferable that the shaft portion 12 has at least one of a plurality of through holes 13a penetrating from the support portion 12b to the fitting portion 12a and a plurality of through holes 13b penetrating the fitting portion 12a around the support portion 12b. Was confirmed.

  In addition, when higher strength is required for the driving-side shaft portion 12 with respect to the molten metal plating roll 10 of the present invention, the driven-side shaft portion 12 has a plurality of through-holes 13a and 13b. The drive-side shaft portion 12 may be a combination having at least one of the through-hole 13a and the through-hole 13b having a smaller diameter than the driven-side shaft portion 12 or the through-hole 13a and the through-hole 13b.

  Next, in the same manufacturing method as that of Example 1, it is larger than the through-hole 13a penetrating from the support portion 12b to the fitting portion 12a as shown in FIGS. 3 (a) and 3 (b) and around the support portion 12b. A roll 10 for molten metal plating according to the present invention in which a plurality of fan-shaped through holes 13b penetrating the fitting portion 12a was formed.

  And the roll 10 for molten metal plating of this invention which formed the fan-shaped through-hole 13b was used as the support roll 7 of the molten metal plating apparatus 1 shown in FIG. When galvanizing was applied to a 1800 mm stainless steel plate 2, the shaft 12 was not cracked or damaged, and the steel plate 2 could be galvanized without problems even during continuous operation over 2 weeks. .

  Moreover, it has the intensity | strength which can endure the driving | operation of the molten metal plating apparatus 1 which galvanizes the steel plate 2 while aiming at weight reduction from the roll for molten metal plating of this invention manufactured in Example 1, and is excellent. It was found that this was a roll 10 for molten metal plating.

  Next, a large-diameter hole connected to a plurality of through-holes 13a penetrating from the support portion 12b to the fitting portion 12a in the fitting portion 12a as shown in FIG. A roll for hot metal plating 10 of the present invention provided with 14 was produced. The length, outer diameter, etc. of the shaft portion 12 were the same as in Example 1, and a hole 14 having an outer diameter of 150 mm and a depth of 40 mm was formed on the cylindrical body portion 11 side of the fitting portion 12a.

  And the roll 10 for molten metal plating of this invention which formed the hole 14 in the axial part 12 is used as the support roll 7 of the molten metal plating apparatus 1 shown in FIG. When galvanizing was performed on a stainless steel plate 2 having a width of 1800 mm, the shaft portion 12 was not cracked or damaged, and the steel plate 2 could be galvanized without problems even in continuous operation over 2 weeks. It was.

  Further, in the same manner as the molten metal plating roll 10 of the present invention manufactured in Example 2, the steel plate 2 is galvanized while reducing the weight as compared with the molten metal plating roll 10 of the present invention manufactured in Example 1. It has been found that the molten metal plating roll 1 has a strength that can withstand the operation of the molten metal plating apparatus 1 and provides an excellent molten metal plating roll 10.

1: Molten metal plating apparatus 2: Steel plate 3: Snout 4: Molten metal tank 5: Molten metal 6: Sink roll 7: Support roll 8: Gas nozzle
10: Roll for molten metal plating
11: Torso
12: Shaft
12a: Fitting part
12b: Support part
13a, 13b: Through hole
14: Hole

Claims (5)

In a molten metal plating roll having a ceramic shaft portion comprising a fitting portion and a support portion connected to a driven side and a driving side, respectively, at an end of a ceramic cylindrical body portion, at least one of them The shaft portion has at least one of a plurality of through holes penetrating from the support portion to the fitting portion and a plurality of through holes penetrating the fitting portion around the support portion. Plating roll. 2. The roll for hot metal plating according to claim 1, wherein a through-hole penetrating the fitting portion around the support portion is larger than a through-hole penetrating from the support portion to the fitting portion. 3. The molten metal plating roll according to claim 1, wherein a hole connected to the plurality of through holes penetrating from the support portion to the fitting portion is provided in the fitting portion. The hot metal plating roll according to any one of claims 1 to 3, wherein the body portion and the shaft portion are made of a silicon nitride sintered body. A molten metal plating apparatus using the roll for molten metal plating according to any one of claims 1 to 4 as a roll for handling an object to be plated in the molten metal.

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