JPS6321560Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a conveying roll (for example, a hearth roll) disposed in a furnace for performing heat treatment after melt plating treatment.

[Conventional technology]

A continuous heat treatment furnace such as a post-annealing furnace is used to continuously perform heat treatment such as annealing on a long steel strip after hot-dip galvanizing.

The continuous heat treatment furnace is generally equipped with a number of hearth rolls that support the continuously fed steel strip from below and allow it to pass through a predetermined position inside the furnace. It is passed through a furnace set at a predetermined temperature at a predetermined moving speed while being supported in contact with the substrate, and is subjected to a predetermined heat treatment.

[Problem that the invention attempts to solve]

However, when the moving speed of the steel strip and the circumferential speed of the hearth roll completely match (in other words, when the hearth roll completely follows the movement of the steel strip), the distance between the steel strip and the hearth roll is There is no slippage and no damage to the steel strip surface.
If the two speeds do not match, a problem arises in that slips occur between the steel strip and the hearth roll, and the surface of the steel strip is damaged.

Since a plating metal layer (for example, a molten aluminum plating layer) is formed on the surface of the steel strip after the hot-dip galvanizing process, the above-mentioned damage to the surface of the steel strip is particularly likely to occur. This is because the melt-plated layer is originally soft, and becomes even softer when heated (depending on the heat treatment conditions, it becomes the most easily damaged state).On the other hand, when looking at hearth rolls, , when a slip occurs between the steel strip and the hearth roll,
A problem arises in that the surface of the hearth roll (which surface is made as soft as possible to prevent damage to the surface of the steel strip) is worn out.

Therefore, if each hearth roll is connected to a drive system and the rotation of each hearth roll is controlled by the drive system so that its circumferential speed matches the moving speed of the steel strip, the steel strip and hearth roll No slip occurs between the two, and the above-mentioned problem does not occur.

However, it is unrealistic from the point of view of the equipment to connect each hearth roll to a drive system (it is more practical to drive a plurality of hearth rolls in groups by a common drive source), and the above-mentioned Performing such rotation control for each hearth roll is difficult because the outer diameter of each hearth roll is different (all diameters can be the same when new, but due to differences in the amount of wear afterwards, etc.) (depending on the situation), it is difficult.

Furthermore, when a plurality of hearth rolls are group-driven by a common drive source, the rotation control as described above is virtually impossible unless all the hearth rolls have the same outer diameter.

The present invention was developed in view of the above circumstances, and is designed to prevent the steel strip surface from being damaged when the steel strip with a soft plated metal layer formed on the surface is transported through the furnace, and to prevent the roll surface from being abraded. It is an object of the present invention to provide a conveying roll that can prevent slips from occurring between a steel strip and the conveying roll.

In particular, even when multiple transport rolls with slightly different outer diameters are driven in groups by a common drive source, the above-mentioned slips can be suppressed to prevent damage to the steel strip surface and wear on the roll surface. It is an object of the present invention to provide a conveyance roll that can prevent the above-mentioned problems.

[Means for solving problems]

The conveyance roll according to the present invention, that is, the conveyance roll disposed in a furnace for heat-treating the steel strip after hot-dip galvanizing, has an overrunning clutch at the connection part between the roll and the drive system that drives it. It is characterized in that a coating layer that is softer than the plated metal layer is formed on the surface.

For example, such a conveyance roll can be connected to a roll and its drive system by a chain that is attached to both the sprocket attached to the roll shaft and the sprocket attached to the drive shaft of the drive system. It is conceivable that an overrunning clutch is interposed between the roll shaft and the sprocket to be attached to the roll shaft.

In addition, it is also possible to drive a plurality of conveyance rolls by a common drive source by attaching the chain so as to span all of the sprockets attached to each of the plurality of conveyance rolls. Ideas can be applied.

The drive condition of the drive system of the conveyance roll is such that when the overrunning clutch is engaged and the conveyance roll is rotationally driven by the drive system, the circumferential speed of the conveyance roll is Set it so that it is slightly slower than the movement speed.

The overrunning clutch is configured such that when the rotational speed of the transporting roll is smaller than the rotational speed of the drive system, the clutch becomes stiff and causes the transporting roll to be rotationally driven by the drive system. When the rotational speed of the conveying roll increases to exceed the rotational speed of the drive system, the clutch is disengaged and the conveying roll is allowed to idle.

Note that the conveying roll of the present invention has a coating layer softer than the plated metal layer formed on its surface, but specifically, it is possible to wrap an asbestos sheet around the roll body, or to A soft covering layer is formed by arranging asbestos rings in the axial direction, fitting and fixing them around the outer periphery of the main body, and then wrapping an asbestos sheet over the asbestos rings.

[Effect]

When a steel strip is transported using such a transport roll and a predetermined heat treatment is applied to the steel strip, the transport roll follows the movement of the steel strip, for example, at the start of treatment, when increasing the processing speed, etc. Only when this is not possible, the overrunning clutch is engaged and the conveying roll is rotated by the drive system, increasing the number of rotations of the conveying roll to increase the speed of the conveying roll to move the steel strip. When the rolls are able to follow the flow, the overrunning clutch is disengaged and the transport rolls spin idly.
The conveying rolls follow the movement of the steel strip. Therefore, even at the start of processing or when the processing speed is increased, the conveying rolls rotate sufficiently, and the occurrence of slips between the steel strip and the conveying rolls is suppressed, which prevents damage to the steel strip surface. In addition to preventing this, abrasion of the soft roll surface can also be suppressed.

Furthermore, even when multiple transport rolls with slightly different outer diameters are driven by a common drive source, the rotation of the transport rolls is controlled as described above at the start of processing or when increasing the processing speed. In addition to suppressing the occurrence of slips between the steel strip and the conveying roll and preventing damage (wear) to the surface of the steel strip and the roll, the rotation speed of the conveying roll increases to maintain a steady state. If this occurs, the conveying rolls will idle and follow the movement of the steel strip, so if the outer diameters of the conveying rolls that are driven by a common drive source are slightly different, The occurrence of slips between the steel strip and the conveying roll is suppressed, and the steel strip surface and roll surface are not damaged (worn).

〔Example〕

The conveyance roll of the present invention will be explained based on drawings showing specific examples thereof.

FIG. 1 is a longitudinal cross-sectional view showing the main parts of a conveying roll according to the present invention. In addition, the cross section of the conveyance roll is not shown in the figure.

In the figure, reference numeral 1 denotes a transport roll having a coating layer softer than the plated metal layer formed on its surface, and its roll shaft 1a is press-fitted into an inner ring 2a of an overrunning clutch 2. Note that a key (not shown) is interposed between the roll shaft 1a and the inner ring 2a to prevent them from shifting from each other in the circumferential direction.

On the other hand, the outer ring 2 of the overrunning clutch 2
A sprocket 3 is attached to b using bolts 4...4.

A chain (not shown) is connected to the sprocket 3 and is connected to a sprocket attached to a drive shaft of a drive system.

The driving condition of the drive system is such that when the overrunning clutch 2 is engaged and the transport roll 1 is rotationally driven by the drive system, the circumferential speed of the transport roll 1 is such that the movement of the steel strip is It is set to be slightly slower than the speed.

As described above, since the overrunning clutch 2 is interposed between the roll shaft 1a and the sprocket 3, the rotational speed of the conveying roll 1 ((i.e., the inner ring 2 of the overrunning clutch 2
a) is the rotational speed of the drive system (i.e., the rotational speed of the outer ring 2b of the overrunning clutch)
If it is smaller than , the conveyor roll 1 will be rotationally driven by the drive system when the clutch is hardened, and the rotational speed of the conveyor roll 1 (i.e.,
When the rotational speed of the inner ring 2a increases to exceed the rotational speed of the drive system (i.e., the rotational speed of the outer ring 2b), the clutch is disengaged and the conveying roll 1 becomes idling, causing the steel strip to be conveyed to move. It will rotate accordingly.

Note that the overrunning clutch 2 is brought into the engaged state and disengaged by a large number of cams (Fig. (not shown).

As mentioned above, the presence of the overrunning clutch 2 suppresses the occurrence of slips between the steel strip and the conveying rolls even at the start of processing or when increasing the processing speed, thereby preventing the occurrence of slips between the steel strip surface and the roll surface. This can prevent damage (wear) from occurring. Additionally, when multiple conveyance rolls are driven in groups by a common drive source, the occurrence of slips between the steel strip and the conveyance rolls, which is caused by slight differences in the outer diameter of the rolls, can be suppressed. There is no damage (wear) to the steel strip surface or roll surface.

[Effect of idea]

As detailed above, when using the conveying roll according to the present invention, sufficient care must be taken not to damage the plated metal layer formed on the surface of the steel strip being conveyed in the furnace by the conveying roll. In addition, it is possible to suppress wear on the roll surface.
Therefore, when a steel strip that has been subjected to hot-dip galvanizing treatment whose surface is easily damaged is sent into a continuous heat treatment furnace for heat treatment (for example, post-annealing), the steel strip passing through the heat treatment furnace is The conveyor roll of the present invention is most suitable as a hearth roll that is supported from the ground. It goes without saying that the conveyance roll of the present invention can be applied not only to hearth rolls but also to conveyance rolls such as turn rolls and deflection rolls that change the direction of conveyance of the steel strip in a furnace.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing the main parts of the conveying roll according to the present invention. DESCRIPTION OF SYMBOLS 1... Conveyance roll, 2... Overrunning clutch, 2a... Inner ring, 2b... Outer ring.

Claims (1)

[Scope of utility model registration request] An overrunning clutch is attached to the connection between the roll and the drive system that drives the roll in a conveyor roll placed in a furnace for heat-treating the steel strip after hot-dip galvanizing. A conveyance roll characterized by having a coating layer formed thereon that is softer than the metal layer.