JPH03197658A - Roll drilling device for galvanizing equipment - Google Patents

Abstract

PURPOSE:To drive a roll without using driving force and to prevent the generation of surface flaws, etc., on a plated steel strip by disposing the magnet on the outer peripheral surface of the roll in contact with the steel strip and rotating the roll by the magnetic force between the roll with the magnet and the steel strip. CONSTITUTION:The permanent magnet 15 is disposed on the outer peripheral surface of the sink roll 13 in contact with the steel strip 2 in a galvanizing bath. The sink roll 13 is rotated by the magnetic force generated between the roll 13 with the magnet and the steel strip 2. The rotational driving of the roll is also possible by energizing a coil disposed in proximity to the roll with the magnet or conductor. The sink roll 13 is driven in this way without using an external motor and the wear, etc., of a joint are averted. The slipping of the roll 13 and the steel strip 2 and the generation of the surface flaws, roll marks, etc., of the steel strip 2 by the deposits on the surface of the roll 13 are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention provides a roll drive device for preventing surface flaws on a plated steel strip caused by slippage between the roll and the steel strip in a plating bath in continuous hot-dip galvanizing equipment. More specifically, the present invention relates to a device for driving a dipping roll using magnetic force without using power from a motor or the like.

Conventional technology Continuous hot-dip galvanized steel sheets are produced by immersing a steel strip whose surface has been cleaned and activated in a bath of molten zinc, changing the direction of travel with zinc rolls in the bath and pulling it upward, and removing the zinc adhesion by a gas wiping method, etc. Manufactured in controlled quantities.

As shown in Fig. 4, in the plating bath in this production facility for hot-dip galvanized steel sheets, there is a zinc roll (3) that changes the traveling direction of the steel strip (2) fed into the plating bath (1). A snap roll (4) is provided to guide the steel strip.

However, when a roll with a flat surface is used as a zinc roll or snap roll, molten zinc liquid enters the contact interface between the roll and the steel strip, causing a slip phenomenon between the roll and the steel strip, causing the plated steel to slip. Scratches occur on the surface of the band. When scratches occur, the appearance of the plated steel sheet is impaired and the quality is degraded, so it is necessary to prevent this.

As a countermeasure against this, conventionally, as shown in FIG. 5, a roll having fine grooves (5) cut in the roll surface is used to prevent slipping between the roll and the steel strip. This fine groove is provided so that the molten zinc liquid that has entered the contact interface between the roll and the steel strip can be discharged, and has an anti-slip effect. However, although the anti-slip effect can be achieved by the action of the grooves, surface flaws have not been completely prevented.

That is, dross (zinc-iron alloy particles) is attached to the roll surface. This dross is a high melting point granular material in which an alloy of iron and zinc is melted from a steel strip into a molten zinc bath and aggregated to a diameter of about 20 to 100 microns. The molten zinc liquid that has entered between the steel strip and the roll is discharged through the grooves formed on the roll surface as described above, but the high melting point particulates remain without being discharged from the grooves on the roll surface. Add scratches.

Furthermore, depending on the type of steel strip, the groove pattern of the rolls may be transferred to the surface of the steel strip, resulting in so-called roll marks, and therefore, grooved rolls cannot necessarily be said to be effective as a measure to prevent scratches. Ta.

Therefore, as another method, as shown in Fig. 6, for example, the snap roll (4) with a flat surface is
A method is known in which the rotary shaft (not shown) is driven via a rotating shaft (6) and a joint (7). However, this method is not preferable because it causes problems such as wear of the joint.

Problems to be Solved by the Invention As described above, the method of cutting grooves on the roll surface prevents the slip between the roll and the steel strip as a measure to prevent surface flaws caused by the slip phenomenon between the immersed roll and the steel strip in a hot-dip galvanizing bath. However, the dross that adheres to the roll surface (
Not only is it impossible to prevent scratches caused by high-melting-point particulates, but also roll marks may occur depending on the type of steel strip.

Further, a method in which the dipping roll is driven by an external motor is not preferable because it causes problems such as wear of the joints.

In order to solve these problems, this invention can prevent the slip phenomenon between the steel strip and the roll by rotating the roll without creating grooves on the roll surface and without requiring power from a motor, etc. The present invention attempts to propose a driving device for a dipping roll that can completely prevent scratches and roll marks, and can also prevent scratches caused by high-melting point particles.

Means for Solving the Problem This invention uses magnets as a means to prevent slip reduction between the immersion roll and the steel strip, and improves the efficiency of transmitting driving force to the immersion roll by passing the steel strip and drives the immersion roll. This method employs a method in which the immersion roll is rotated in synchronization with the passing speed of the steel strip by applying an electromagnetic force.

That is, the present invention has a mechanism in which a magnet is arranged on the outer circumferential surface of the roll that contacts the steel strip, and the roll is rotated by the magnetic force generated between the roll with the magnet and the steel strip. It consists of a coil placed close to the roll, and when the coil is energized, the roll with a magnet rotates, and a good conductor is buried in the outer peripheral surface of the roll that comes into contact with the steel strip. The gist of the invention is that the roll includes a coil disposed close to the roll, and the roll with a good conductor rotates when the coil is energized.

Working When using a roll with a magnet (permanent magnet) attached to the surface that contacts the steel strip, if the steel strip is a magnetic material, a strong magnetic force acts between the steel strip and the roll with the magnet, The roll rotates as the band moves. Therefore, when a flat roll with a magnet without grooves is used, the molten zinc liquid in the contact interface between the roll and the steel strip is about 100μ thick, so the influence of the magnetic field is not sufficiently transmitted to the steel strip. , the roll rotates without slipping between the roll and the steel strip.

When the steel strip is a non-magnetic material, a current is generated in the steel strip when it crosses the magnetic field of the roll, and this current and the magnet interact to exert a rotational force on the roll. However, since the hot-dip galvanizing bath itself is a good conductor, the plating bath interferes with the rotation of the rolls, resulting in slow rotation of the rolls. In this case, the rotation of the roll can be assisted by energizing a coil arranged around the magnetized roll.

When a coil disposed close to a magnetized roll is energized in accordance with the passing speed of the steel strip, the coil is magnetized and rotational force is generated in the roll.

When a coil placed close to a roll with a good conductor is energized, current flows through the conductor in response to changes in the magnetic field generated by the coil, and a rotational force is generated between the current and the magnetic field, causing the roll to rotate. .

As described above, with the device of this invention, it is possible to secure the rotational driving force of the grooveless roll without roll marks, so that beautiful hot-dip galvanized steel sheets can be obtained, and
Since no power such as a motor is used to drive the rolls, there are no problems such as wear of joints.

Embodiment FIGS. 1 to 3 illustrate a roll drive device according to the present invention. FIG. 1 is a schematic diagram showing a zinc roll drive device in which permanent magnets are arranged on the roll surface, and FIG. A schematic diagram showing a roll drive device in which a coil is arranged close to each other around a zinc roll with a magnet, and Fig. 3 shows a roll drive device in which a coil is arranged close to each other around a zinc roll with a magnet, and a coil around a snap roll with a good conductor. FIG. 3 is a schematic diagram showing a roll drive device in which the rollers are arranged in close proximity to each other.

In Fig. 1, (13) is a zinc roll in which a plurality of permanent magnets (15) are arranged on the outer peripheral surface of the roll with a flat surface in contact with the steel strip (2), and the permanent magnets (15) are N pole and S pole, respectively. The poles are arranged alternately.

When the steel strip (2) is a magnetic material, a strong magnetic field acts between the steel strip (2) and the magnetized zinc roll (13), and the steel strip (2)
) The zinc roll (13) rotates in accordance with the movement of the zinc roll (13).

Note that even if the steel strip (2) is a non-magnetic material, rotational force is generated in the roll by the steel strip moving in the magnetic field around the roll, but as mentioned above, the action of the plating bath, which is a good conductor, is Therefore, in the case of a non-magnetic steel strip, a drive device in which a coil is placed close to a magnetized roll is used as shown in FIGS. 2 and 3.

FIG. 2 shows a roll driving device in which a plurality of coils (16) are arranged close to each other around the magnetized zinc roll (13), and the zinc roll ( 13) rotates in synchronization with the steel strip (2).

Note that the coil (16) can be controlled by, for example, a sequencer for controlling a synchronous rotating motor.

That is, the coils are controlled to be sequentially energized so that the rolls are driven to rotate in accordance with the passing speed of the steel strip that is measured before entering the hot-dip galvanizing apparatus.

In Fig. 3, (14) is a snap roll in which a plurality of good conductors (18) are embedded in the outer peripheral surface of the roll with a flat surface that contacts the steel strip (2), and a plurality of coils (18) are embedded around this snap roll. 16) are arranged in close proximity to each other.

In the case of this drive device, the good conductor (18) responds to changes in the magnetic field generated by energizing the coil (16).
A current flows through the snap roll (14), and a rotational force is generated in the snap roll (14) between this current and the magnetic field.

In addition, malrotation of a roll in a drive device consisting of a roll with a magnet and a coil can be detected by an increase in the back electromotive force applied to the coil.

As described in detail, the device of this invention provides a permanent magnet or a good conductor on the outer circumferential surface of the roll that comes into contact with the steel strip, and further arranges a coil close to the roll with the magnet or the roll with the good conductor. Since the rolls are rotationally driven by force, it is possible to use flat surface rolls without grooves for the zinc rolls and snap rolls in hot-dip galvanized bathtubs, which greatly reduces slip defects and eliminates roll marks. It becomes possible to manufacture hot-dip galvanized steel sheets with beautiful surfaces.

In addition, since no power such as a motor is used as the drive source, there are no problems such as joint wear, and since no special equipment or technology is required, it can be easily applied to existing equipment. It has a great effect on

[Brief explanation of drawings]

Figures 1 to 3 illustrate a roll drive device according to the present invention, and Figure 1 is a schematic diagram showing a zinc roll drive device with permanent magnets arranged on the roll surface, and Figure 2 is a schematic diagram showing a zinc roll drive device with permanent magnets arranged on the roll surface. A schematic diagram showing a roll drive device in which all coils are arranged close to each other around a zinc roll, and FIG. 3 shows a roll drive device in which coils are arranged close to each other around a zinc roll equipped with a magnet,
FIG. 4 is a schematic diagram showing a roll drive device in which a coil is arranged closely around a snap roll with a good conductor; FIG. 4 is a schematic diagram showing a dipped roll and a steel strip in a hot dip galvanizing bath; 5 is a side view showing an example of a zinc roll with grooves cut on the roll surface, and FIG. 6 is a schematic diagram showing an example of driving a snap roll in a hot-dip galvanizing bath with a motor. 2... Steel strip 13... Zinc roll with magnet 14... Snap roll with good conductor 15... Permanent magnet 16... Coil 18... Good conductor

Claims (1)

[Claims] 1. A roll drive device in a hot-dip galvanizing bath, in which a magnet is arranged on the outer peripheral surface of the roll in contact with a steel strip, and the magnetic force generated between the roll with the magnet and the steel strip is used to drive the roll in a hot-dip galvanizing bath. A roll drive in hot-dip galvanizing equipment characterized by a mechanism in which the rolls rotate. Device. 2. A roll drive device in a hot-dip galvanizing bath, consisting of a roll with a magnet arranged on the outer peripheral surface of the roll in contact with the steel strip, and a coil arranged close to the roll with the magnet, and by energizing the coil. A roll drive device for hot-dip galvanizing equipment, characterized by a mechanism in which a roll with a magnet rotates. 3. A roll drive device in a hot-dip galvanizing bath, comprising a roll with a good conductor embedded in the outer peripheral surface of the roll that contacts the steel strip;
1. A roll drive device for hot-dip galvanizing equipment, comprising a coil disposed close to the roll with a good conductor, and the roll with a good conductor rotates when the coil is energized.