JPS6321556Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a continuous furnace for continuously post-annealing a strip-shaped steel plate that has been subjected to a hot-dip galvanizing process.

[Conventional technology]

In recent years, hot-dip galvanized steel plates, such as aluminum plated steel plates, have excellent corrosion resistance and heat resistance in the atmosphere.
The production of steel sheets for presses used in automobiles, heating appliances, etc. is increasing significantly.

Such hot-dip galvanized steel sheets are annealed after the hot-dip galvanizing process, so-called post treatment, in order to improve mechanical properties (particularly formability such as deep drawability and bendability) in consideration of workability during press forming. It is known to perform annealing.

[Problem that the invention attempts to solve]

Since this post-annealing is performed in a batch process (eg, in a bell-shaped annealing furnace), the process generally takes a very long time.Therefore, there is a method to improve this by using a continuous furnace. However, in a continuous furnace, the strip-shaped steel plate being processed is supported from below by hearth rolls, so the surface plating layer (especially the aluminum plating layer) of the steel plate is easily damaged by contact with the hearth rolls. There was a problem.

The present invention was developed in view of these circumstances, and its purpose is to develop a continuous furnace with a relatively short furnace length that can perform boss annealing without damaging the surface plating layer of the steel plate. is to provide.

[Means for solving problems]

In order to achieve this objective, the inventor of the present invention arranged turn rolls alternately at both ends of the furnace in order to avoid the furnace length from becoming extremely long, and the turn rolls were used to rotate the strips of material to be processed. Focusing on a continuous furnace in which the steel plate is transferred within the furnace, an overrunning clutch is installed at the connection between the turn roll and its drive system to support the strip-shaped steel plate in the furnace in a non-contact manner. We devised a continuous furnace equipped with a floater for this purpose.

[Effect]

When such a continuous furnace is used, the strip-shaped steel plate to be treated is supported by the floater in a non-contact manner except at both ends of the furnace, so that the surface plating layer of the steel plate is not damaged.

Furthermore, at both ends of the furnace where the strip-shaped steel plate to be processed comes into contact with the turn rolls provided to shorten the furnace length, overrunning clutches are installed at the connection between the turn rolls and their drive system. , The driving force of the drive system is transmitted to the turn roll only when the turn roll cannot follow the transfer speed of the strip-shaped steel plate to be processed, such as when starting processing or increasing the processing speed, and in other cases, the turn roll is idle. By doing so, the turn roll can be made to follow the movement of the strip-shaped steel plate to be processed. Therefore, slippage between the steel plate and the turn roll is reduced, and damage to the surface of the steel plate can be suppressed.

〔Example〕

FIG. 1 is a schematic vertical sectional view showing an example of a continuous furnace according to the present invention.

In the figure, 1 is a heating zone, 2 is a holding zone, and 3 is a cooling zone. After being heated to temperature, retention zone 2
After being fed into the cooling zone 3 and kept at constant temperature there for a predetermined period of time, it is fed into the cooling zone 3 where it is forcibly cooled.

In the holding zone 2, turn rolls 21, 21, 21 are arranged alternately on the left and right from above at both ends in the furnace, and the steel plate A is transferred in the furnace by the turn rolls 21, 21, 21. The direction is alternately changed between forward and reverse directions to be transferred and retained within the holding band 2 for a long period of time.

As shown in FIG. 2, an overrunning clutch 4 (strictly speaking, its inner ring) is attached to the shaft 21a of each turn roll 21. As shown in FIG. The chain (not shown) that is routed around the sprocket 5 attached to the overrunning clutch 4 (strictly speaking, its outer ring) is also routed to the sprocket (not shown) that is attached to the motor shaft. The rotation of the motor is controlled by the overrunning clutch 4.
(strictly speaking, the outer ring). That is, an overrunning clutch 4 is installed at the connection portion between each turn roll 21 and its drive system.

Further, below the position in the furnace where the steel plate A should pass, a large number of floaters 22, 22, . . . 22 are arranged at appropriate intervals in the direction of conveyance of the steel plate A.

As shown in FIG. 3, each floater 22 is arranged so as to close an opening formed on the upper surface of a box-shaped hollow body 22a extending in the width direction of the steel plate A to be fed, leaving a slight gap. A jamb board 22b is provided, and the hollow body 22a and the jamb board 2
The fluid is ejected toward the steel plate A from the gap between the steel plate A and the steel plate A.

A slit 22b' is formed on the upper surface of the heater 22' as shown in FIG. 4, that is, a cylindrical hollow body 22a' extending in the width direction of the steel plate A to be fed. Each heater 22', which blows out hot air heated to a predetermined temperature toward the steel plate A, is also arranged at appropriate intervals in the direction in which the steel plate A is transported.

Additionally, auxiliary rolls 23 are provided between the adjacent floaters 22, 22, but these are used to support the steel plate A from below, which tends to sag when the line operation is stopped. The auxiliary roll 23 does not make any contact with the steel plate A while the steel plate A is being transferred.

When post-annealing steel plate A using the continuous furnace configured as described above, each turn roll 21
The rotation speed of the drive system is set so that the circumferential speed of the turn roll 21 is slightly slower than the transport speed of the steel plate A when the turn roll 21 is driven thereby.

However, when the circumferential speed obtained by the rotational force of the turn roll 21 cannot follow the transfer speed of the steel plate A, such as when starting processing or increasing the processing speed, the overrunning clutch 4 engages. In particular, the driving force from the drive system is applied to the turn roll 21, but it is necessary to make sure that the turn roll 21 rotates sufficiently so that it can sufficiently follow the movement of the steel plate A being fed. When this happens, the clutch 4 is disengaged and the turn roll 21 rotates idly, and the turn roll 21 rotates following the movement of the steel plate A being fed. When each turn roll 21 operates in this manner, slippage between the fed steel plate A and each turn roll 21 is reduced, and damage to the surface of the steel plate A is suppressed.

Note that when the drive systems of each turn roll 21 are the same, in other words, when the rotation speed of the drive shaft of each turn roll 21 is the same, the overrunning clutch 4 is not installed as in the present invention. Sometimes, if the outer diameters of the respective turn rolls 21 are not the same, slips may occur between at least one of the turn rolls 21 and the steel plate A to be fed, since the transfer speed of the fed steel plate A is constant. However, if the overrunning clutch 4 is attached to the connection between each turn roll 21 and its drive system as in the present invention, each turn roll 21 will be fed when the rotation speed exceeds a predetermined number. Since the turning rolls 21 follow the movement of the steel plate A, the above-mentioned problem due to non-uniformity of the outer diameter of each turn roll 21 does not occur.

Further, between the respective turn rolls 21, the steel plate A is supported by each floater 22 in a non-contact state, so that the surface of the steel plate A is not damaged between the respective turn rolls 21. do not have.

[Effect of idea]

As described above, in the continuous furnace of the present invention, although turn rolls are used to shorten the length of the continuous furnace for performing post-annealing, which is a long process, Damage to the surface plating layer of the steel plate to be treated can be suppressed. Moreover, since the steel plate is supported by the floater in a non-contact manner in the parts other than both ends of the furnace, no damage occurs to the surface plating layer of the steel plate. Therefore, it can be said that the present invention provides an extremely effective means for manufacturing aluminum-plated steel sheets and the like.

Although FIG. 1 shows a continuous furnace in which three turn rolls are arranged, it goes without saying that the present invention can be applied regardless of the number of turn rolls.

Furthermore, although Fig. 1 shows a continuous furnace in which floaters are provided only in the holding zone, it is also possible to use a continuous furnace in which floaters are also provided in the heating zone and/or cooling zone. Not even.

[Brief explanation of the drawing]

Fig. 1 is a schematic longitudinal sectional view showing a continuous furnace according to the present invention, Fig. 2 is a front view showing details of the shaft of the turn roll, and Fig. 3 is a diagram of a floater disposed in the continuous furnace. FIG. 4 is a perspective view showing an example of a heater disposed in the continuous furnace. 1... Heating zone, 2... Holding zone, 3... Cooling zone,
4... Overrunning clutch, 5... Sprocket, 21... Turn roll, 22... Floater, A... Steel plate to be treated.

Claims (1)

[Scope of utility model claims] This is a continuous post-annealing furnace that follows hot-dip galvanizing equipment, and includes turn rolls and their drive systems that are arranged alternately at both ends of the furnace to transport a strip-shaped steel plate to be treated within the furnace. At the connection part of
An overrunning clutch is installed,
This is a continuous furnace in which floaters are arranged at appropriate intervals to support the strip-shaped steel plate to be treated in a non-contact manner.