JPS5842763A - Continuous hot dipping device for steel strip - Google Patents

Abstract

PURPOSE:To prevent the transverse oscillation of a steel strip in a titled device by installing an induction type linear motor on the upper stream side than a steering rolls in the cooling zone of a continuous heat treatment furnace and acting the thrust in the direction opposite from an advancing direction upon the steel strip. CONSTITUTION:A steel strip 1 passed through a continuous heat treatment furnace 2 is dipped in a plating bath 4, and is regulated of the coating weight of plating by gas wiping nozzles 6. The strip passes through a zero spangle device 7 and a galvanealing furnace 8 and is coiled. During this time, the strip is acted with tensile forces by bridle rolls 91, 92, but the tensile forces are weakened by the elongation generated in the steel strip by the effect of the heat of the furnace 2; therefore the strip is apt to oscillate transversely during the passage through the nozzles 6, the device 7 and the furnace 8. Therefore, electricity is conducted to a linear motor 10 to act the thrust in the direction opposite from the advancing direction of the strip 1 upon the strip 1 during operation. The tension on the strip 1 during the passage through the furnace 2 is weakened by said action and the tension on the strip 1 after the passage through the bath 4 is increased, whereby the transverse oscillation of the strip is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a continuous hot-dip plating apparatus for copper strips which is premised on in-line annealing.

In such a continuous plating apparatus, referring to FIG. 1, a copper strip (1) is first supplied from a payoff reel (not shown), passed through an inlet priddle roll (1), and then transferred to a continuous heat treatment furnace (2). ), where it undergoes recrystallization annealing at 700-900'C and the surface of the copper strip is cleaned, cooled to 450-500°C in the cooling zone (2a) of the furnace, and passed through the steering roll (3). Plating bath (4)
Head to. The steering roll (3) is capable of tilting left and right, and is used to correct the meandering of the copper strip (1). ◇It passes through the snout (moxibustion) that continues from the furnace (2) into the plating bath (4). The copper strip (1) introduced into the dipping roll (5)
is extracted from the plating bath by bypassing the During this time steel strip (1)
undergoes hot-dip plating from a plating solution. The plated steel sheet leaving the plating bath (4) is immediately passed through the gas wiping nozzle (6).
) The plated steel sheet obtained in this way is processed using a zero spangle device (7), which adjusts the surface ml pattern as necessary, or a Louvainir furnace (8), which further alloys the plated metal. It is wound up through the exit side priddle roll (9λ).

In such continuous plating equipment, the copper strip (1)
A tensile force (tension) is applied by the priddle roll ('i ('4) on the input side and the output side, so that the copper strip is loose in the middle of the line, but the above tension section is actually In addition, in the heat treatment furnace (2), the tension acting on the copper strip weakens due to the elongation of the steel strip due to heat, which causes the plating bath (2) to elongate.
The copper strip coming out from 4) is passed through a gas wiping nozzle (6) or further into a zero spangle device (7) or a galvanic furnace (8).
) It tends to sway sideways when passing. This lateral vibration phenomenon is
As a countermeasure against zero lateral runout, which makes the plating thickness adjustment by gas wiping and the effect of the alloying treatment in the galvanil furnace uneven, and ultimately leads to quality deterioration of the plated steel sheet, it is necessary to use bridle rolls ( It is conceivable to strengthen the tension between Φ('J), but strengthening the tension will increase the elongation of the copper strip in the heat treatment furnace (2) and cause a decrease in the length of the copper strip, so it is not a useful measure. It's hard to say.

The purpose of the present invention is to provide a continuous hot-dip plating apparatus that takes measures against this lateral runout.In order to achieve this, a so-called induction linear motor is provided upstream of the steering roll line in the cooling zone of a continuous heat treatment furnace, and this It is characterized by a structure in which the tension of the copper strip can be controlled to be small in the heat treatment furnace and to be greater in the downstream side of the plating bath where there is a risk of sideways vibration by applying a thrust force to the strip upstream of the line. do.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 shows the installation position of the induction linear motor of the device of the present invention. The induction linear motor 0I is a continuous heat treatment furnace (2
), more preferably near the latter half of the cooling zone (2a),
It is provided on the upstream side of the line from the steering roll (3). That is, first of all, it is necessary to provide the copper strip at a position beyond the point where there is a risk of large elongation of the copper strip due to tension.

The elongation of the copper strip in a continuous heat treatment furnace is remarkable until it reaches the cooling zone (2a), that is, where it receives the heating necessary for annealing. Since the temperature can be lowered to a temperature range of 450 to 500° C., that is, a temperature suitable for hot-dip plating, there is almost no concern about the elongation of the copper strip. In particular, the cooling zone (2a
), this concern disappears at all once you reach the latter half. As is well known, there are two methods for annealing in the metal line: the Sendzimir method and the non-oxidizing furnace method, and the configuration of the continuous heat treatment furnace (2) varies slightly between these two methods, but the linear motor Regarding the installation position of 01, the above explanation can be applied as is regardless of the difference in furnace configuration. Regarding the installation position of the linear motor α1, it is necessary to satisfy the condition that it is on the upstream side of the steering roll (3) line.In other words, the thickness of the copper strip generally varies slightly in the width direction and longitudinal direction. It must be said that when thrust is applied to the steel strip (1) by the linear motor OQ as described later, if there is a difference in the thickness of the copper strip as described above, the applied thrust will also vary, 6. Steering roll (3) This may cause the copper strip (1) to meander
As mentioned above, this is to correct the meandering of the copper strip, but if this steering roll is on the lower side of the line than the linear motor (10), the meandering of the steel strip due to variations in the thrust by the linear motor can be corrected. Also the steering roll (
This can be corrected by the correction function of 3), and the adverse effects of using the linear motor (1o) can be avoided.

FIG. 2 is a longitudinal sectional side view showing details of the linear motor 00. αυ and α force are a pair of moving magnetic field generators installed vertically symmetrically with the copper strip (1) in between.

Although not shown, a three-phase coil wound around a fixed iron core is used. This pair of devices generates a magnetic field that moves along a direction (2) opposite to the traveling direction of the copper strip (1) by energizing the coil, and at the same time, this moving magnetic field creates an eddy current in the copper strip (1). The eddy current and the moving magnetic field generate a thrust force in the inward direction of the copper strip (1). When a thrust force is applied to the copper strip by this device, an upward or downward suction force is simultaneously applied to the copper strip, but in order to prevent this from destabilizing the transport of the copper strip, in the illustrated example, a suction force is applied in advance to the copper strip. Touch roll Q is placed on the top side of the copper strip corresponding to the hearth roll (A) (6) of the furnace.
A force of 3α is provided to stabilize the copper strip between the hearth roll and the α-force. Moving magnetic field generator αυ (1
It is also preferable that the distance between υ and the steel strip (1) is adjustable (the peaks are provided so that the strength of the generated magnetic field can be controlled depending on the operating conditions, etc.).The above-mentioned distance (d) adjustment mechanism as,
As shown in the illustrated example, a structure can be adopted in which a drive source α, such as a hydraulic motor, is provided on the outer wall Q4 of the heat treatment furnace, and this is used to raise the magnetic field generator Q1 via the jack mechanism α. Although not shown, the magnetic field generator 01
) to protect it from the heat inside the furnace, it is recommended to install a cooling jacket around it and provide water through it. Needless to say, when installing a device that spans the inside and outside of the furnace, it is necessary to consider the sealing performance of the furnace.

In the device of the present invention having the above configuration, the linear motor α during operation is
By energizing the copper strip and applying a thrust in the direction A in the figure, the tension of the copper strip, which is likely to stretch due to tension while passing through the heat treatment furnace, is weakened, while the tension of the copper strip, which is likely to stretch due to tension, is weakened. Tension control can be achieved by applying strong tension to the copper strip after it has passed through the bath. That is, to explain using the schematic diagram in Fig. 3, in a general structure, the copper strip (1) passing through the line has a tension Fl at the entry side priddle roll (curvature) as shown in Fig. 3 (a). The tension F2 at the output side priddle roll (Q) must maintain a balance of %F2≧F1.On the other hand, in the case of the device of the present invention, the tension f by the linear motor α1 is added to the above tension balance, so that F2≧ F++f.In other words, the tension F2 at the exit side priddle roll is the above (
If the case is the same as in case (a), the tension Fl at the entrance priddle roll will be smaller than in case (a) by the tension due to linear motor 00, nf, and this means that there is no need to modify the process and heat treatment is required. This means that the tension in the furnace (2) can be freely adjusted to be lower than the tension after passing through the plating bath (4).

Needless to say, the tension f can be adjusted by controlling the amount of electricity supplied to the linear motor θO.

Therefore, if the tension of the copper strip is controlled using three parts, the priddle roll (ζ) (shelling near motor 00) on the inlet side and the outlet side, the steel strip can be prevented from elongating due to the tension in the heat treatment furnace (2). At the same time, it is possible to avoid the shrinkage of the inside, suppress the lateral vibration after passing through the plating bath, and stabilize the effect of plating thickness adjustment by gas wiping (6) and alloying treatment of the plating layer in the galvanil furnace (8). It also becomes possible.

According to the results of the present inventors, with the structure described above (equipped with a galvanyl furnace), the linear motor 00 has a 25
With the plating apparatus of the present invention using 0 KVA,
A current of 35 OA was applied to the linear motor, and the tension of the copper strip after passing through the plating was adjusted to 1,400 kg, and the tension in the heat treatment furnace was adjusted to 500 mm, and the cold rolled steel strip (thickness: 1 cm x width: 918 days) was galvanized. When we tried this, we were able to reliably prevent the width of the copper strip from shrinking, and furthermore, the lateral vibration of the copper strip in the gas wiping nozzle (6) and the galvanic furnace (8) was kept to a minimum, and the copper strip was uniformly 10 μ thick and sufficiently alloyed. An alloyed hot-dip lead-plated steel sheet having a hard-coated plating layer was obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic line diagram showing the arrangement position of the linear motor in the continuous plating apparatus of the present invention, Fig. 2 is an enlarged longitudinal cross-sectional side view of the main parts of the same apparatus, and Fig. 3 is a diagram illustrating the tension balance of the copper strip in the continuous plating line. (a) shows the conventional case, and (b) shows the case of implementing the present invention. In the figure 1: Copper strip, 2: Continuous heat treatment furnace, 2a: Cooling L
3 Ni steering roll, 4: Plating bath, 5: Dipping roll, 6: Gas wiping nozzle, 7: Zero spangle device, 8: Galvanic furnace, 9 Nibridle roll, 1
0: Linear motor, 11: Moving magnetic field generator, 12: Hearth roll, 13: Touch roll, 14: Furnace outer wall, 15
: Drive source, 16: Jacking mechanism

Claims (1)

[Claims] (1) In a continuous hot-dip plating apparatus for a copper strip in which the copper strip passes through at least a gas wiping nozzle device after being immersed in a plating bath through a continuous heat treatment furnace, in the cooling zone of the continuous heat treatment furnace, on the upstream side of the line from the steering roll, A continuous hot-dip plating apparatus for copper strips, characterized in that an induction linear motor is installed to exert a thrust force on the copper strip in the direction opposite to the direction in which the copper strip moves.