JPH07257512A - Binding method for hot coil - Google Patents

Abstract

PURPOSE:To provide a binding method boy which hot coils are rapidly and easily bound without cutting a strap and without loosening the coil afterward, by use of a binding machine. CONSTITUTION:A strap S is wound up at the part of a coil C to be bound and weakly fastened to closely contact the peripheral face of the coil C. The fastening force is retained for a while to raise the temperature of strap due to the heat of coil. And further, the strap S is fastened with an appropriate force corresponding to a low strength during a high temperature, on the way of rising temperature of the strap S with the heat of coil C. Thereafter, the strap is bound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot coil binding method (hereinafter simply referred to as a binding method). More specifically, for example, a high temperature metal coil such as a hot rolled strip coil is referred to as a metal strip (hereinafter referred to as a strap).
By means of a method for bundling without the risk of cutting the strap. The coil in this specification is not limited to a strip coil, and is used to include all metal materials wound in a coil shape, such as a wire rod coil.

[0002]

2. Description of the Related Art Conventionally, when a metal coil, which is in a high temperature state such as immediately after hot rolling or immediately after annealing, is bound with a metal strap, it is difficult to shrink due to high heat and subsequent cooling. Due to this, various problems have occurred. That is, (1) In the past, generally, a strap was wound around a hot coil and then immediately tightened to perform a seal cut (separate a subsequent strap at the same time as fastening the strap). In this case, the hot coil then cools and contracts, but when the strap is sealed, it is originally cool and remains at its length, so the vibration during transport loosens the coil, causing the strip ( Alternatively, there is a problem in that wire rods and rods) are rubbed against each other and scratched.

(2) As another method, in order to make the degree of shrinkage between the hot coil and the strap due to cooling as close as possible, the strap is tightened and brought into close contact with the hot coil, and then the tightened state is set before seal cutting. It was also carried out to heat the strap with the heat of the hot coil by maintaining it. However, since it takes a long time to heat the strap to a predetermined temperature, the binding cost increases, and as a result, the manufacturing cost of the steel plate, the steel rod, the steel wire and the like increases. Moreover, the tensile strength of the strap decreases as the temperature of the strap increases, so if you tighten the strap strongly, the strap itself will break.

The present invention has been made in order to solve the above problems, and a conventional binding machine can be used to quickly and easily cut the strap without causing the coil to loosen. Nonetheless, it aims to provide a method of bundling hot coils.

[0005]

According to the binding method of the present invention, when binding a metal coil heated to a high temperature with a metal strap, the strap is wound around the binding portion of the coil with a weak force. It is characterized in that it is tightened so as to be substantially brought into close contact with the circumferential surface of the coil, the temperature of the strap is increased by the heat of the coil, the strap is further tightened with an appropriate force, and then the strap is fastened.

In a binding method according to another aspect of the present invention, when binding a metal coil heated to a high temperature with a metal strap, the strap is wound around the binding portion of the coil and then the strap is permanently attached. It is characterized by tightening with a strong force that does not deform it and making it substantially adhere to the peripheral surface of the coil, waiting for the temperature of the strap to rise due to the heat of the coil, relaxing the tightening force to an appropriate force, and then tightening the strap. I am trying.

In a binding method according to still another aspect of the present invention, when binding a metal coil heated to a high temperature with a metal strap, the strap is wrapped around the binding portion of the coil, and then the strap is attached. Tighten with a strong force that does not permanently deform it and make it substantially adhere to the peripheral surface of the coil, wait for the temperature of the strap to rise due to the heat of the coil, then gradually increase the tightening force of the strap to an appropriate force with the passage of time The feature is that the strap is fastened after being lowered to.

The high temperature in the claims means a temperature of about 400 ° C. or higher.

[0009]

According to the binding method of the present invention, since the strap is first wound around the coil with a weak or strong force so as not to permanently deform the strap and the strap is brought into close contact with the coil, the temperature of the strap rises rapidly. I will do it. Therefore, instead of waiting for a long time until the temperature of the strap becomes close to the coil temperature, the tightening force of the strap is changed to a force corresponding to the strap strength at higher temperatures in a short time, so the binding time is shortened. Also, the strap does not break when the temperature is high.

When the coil is cooled, the strap is first cooled and contracts. However, since the strap is tightened with a force corresponding to the low strength at high temperature, the strap is excessively contracted due to the contraction difference between the strap and the coil. There is no risk of pulling force. Also, as the strength of the strap increases with cooling, and the repulsive force of the coil increases, there is no worry of the strap loosening.

When changing the tightening force to a force corresponding to the strap strength at a higher temperature, the initial tightening force (tightening force when the strap is brought into close contact with the coil peripheral surface)
Is set to be weaker than the final tightening force, the strap tightening force is increased, but when the initial tightening force is set to be stronger than the final tightening force, the strap tightening force is suddenly reduced, or gradually decreases over time. I will let you.

In short, the initial tightening force may be weak or strong as long as it does not permanently deform the strap and can bring the strap into close contact with the circumferential surface of the coil. Therefore, the final tightening force corresponding to the strength of the strap at a high temperature. In the process of changing the tightening force, there is a decrease or an increase in the tightening force.

[0013]

Next, the method of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a front view showing an example of a coil binding machine to which the method of the present invention is applied, and FIGS. 2 to 4 are graphs and diagrams schematically showing an example of changes in strap tightening force in the method of the present invention. 5 is a graph showing an example of changes in temperature and strength of the strap when wound around a coil.

In FIG. 1, as an example of a coil binding machine, the outer circumference of a strip coil is a steel strip (strap).
Device for staking with S (hereinafter simply referred to as binding machine) 1
It is shown. This binding machine 1 is a known one which has been conventionally used in a steelmaking factory or the like, and the strip coil C that has been conveyed stops in the frame 2 of the binding machine 1 for a short time, during which time the tightening device main body is reached. 3 wraps a strap around the outer circumference of the strip coil C, tightens it, and fastens it with a binding head (not shown), and then a strap feeder (not shown).
Disconnect the strap that is connected from.

The tightening of the strap is usually performed by using an air motor and an electropneumatic proportional valve (a control valve for sending air of a pressure proportional to the proportional change by changing the supply voltage), but it is not limited thereto. There is no. Further, by interposing a transmission in the output part of the air motor, the tightening force can be increased even though the rotational speed is reduced even when the air pressure is the same. For example, when the transmission is set to a reduced speed ratio, it is possible to change it in the range of 50 to 140 kg by changing the air pressure, but if switching to a high reduction ratio, the winding and tightening time will be relatively long, but the tightening force is strong. The same change in air pressure can be changed within the range of 500 to 1600 kg.

2 to 4 qualitatively and schematically show an example of the change over time of the strap tightening force. In each drawing, the symbol A indicates the time when the strap is wound around the outer circumference of the coil and brought into close contact therewith, and the symbol B indicates the time when the strap is cut off.

In FIG. 2, since the strap is pulled at high speed by reducing the transmission to a low speed ratio, the strap is instantly wound around the coil and tightened, but the tightening force is weak and the tightening device body (reference numeral 3 in FIG. 1). It is about 120 kg, for example, such that the strap is in close contact with the coil except for the portion of the binding head in FIG. Hold for about 4 seconds to heat the strap while tightened at 120 kg. Then, after about 7 seconds have passed since the strap was started to be pulled including this 4 seconds (during this period, for example, the transmission was switched to a high reduction ratio), the strap was tightened again (hereinafter referred to as final tightening). The tightening force of is about 100 kg, for example, about 600 kg, at which a tensile stress that does not exceed the tensile strength of the strap at a substantially maximum temperature that the strap can reach (a temperature close to the coil temperature) is generated.

Next, in FIG. 3, the strap is instantly wound around the coil at a reduced speed ratio, and then the transmission is switched to a high reduction ratio to tighten with a strong force. Naturally, the tightening force causes permanent deformation of the strap. Not enough strength, for example 180
It is about 0 kg. When tightening with such a strong force, the degree of adhesion of the strap to the coil becomes extremely high, so that the temperature rises instantly. Therefore, the holding time for heating is relatively short and is about 2 seconds. Then, after holding for 2 seconds, the tightening force is reduced. This final tightening force is also shown in Figure 2.
Similarly to the above, the weight is, for example, about 600 kg, but the action time is long and short, and various coil temperatures can be accommodated.

Next, in FIG. 4, as in FIG. 3, the strap is instantly wound around the coil at a reduced speed ratio, and then the transmission is switched to a high reduction ratio so that the strap is not permanently deformed. Tighten with force. Then, after holding for about 2 hours, the tightening force is reduced. This final tightening force is, for example, about 600 kg as in FIG.
Note that the tightening force in FIG. 4 is reduced stepwise by a variable timer after initial tightening according to a program that has been assembled in advance. In this case, since the tightening force gradually decreases in accordance with the decrease in the strength of the strap due to the temperature rise, the strap does not permanently deform and the degree of adhesion to the coil does not decrease. Becomes even shorter.

The value of the tightening force is not limited to the above value, but the supply air pressure and the deceleration of the transmission may be reduced according to the coil plate thickness, the cross-sectional area of the strap, the ambient temperature, the coil temperature, and the like. It may be appropriately selected by changing the ratio.

The final tightening force is selected in consideration of a decrease in strength due to temperature rise of the strap and an increase in repulsive force (force to open the coil) due to cooling of the coil. However, it is not preferable because it is difficult to measure the temperature of the strap and the coil during an actual work in a very short time, or the equipment cost is significantly increased. Therefore, data on the elapsed time such as the strength decrease due to the temperature rise of the strap due to the heat transfer from the high temperature coil and the increase in the elastic modulus due to the natural cooling of the coil was obtained in advance from test, analysis, and past measurement results. Then, this is corrected according to various conditions such as environmental temperature and strap size (in other words, the heat capacity of the strap). Based on the data so obtained, the final tightening force of the strap is determined.

For example, in the case of a steel strip coil immediately after hot rolling, its temperature is about 700 to 900 ° C., and therefore a steel strap having a thickness of 0.9 mm and a width of 32 mm is attached to the outer periphery of the strip coil at 800 ° C. in FIG. An example is the decrease in tensile strength due to the temperature rise when they are brought into close contact with each other. Since the strap is wound immediately after the hot rolling of the coil, at most 15
The temperature decrease due to the natural cooling of the coil during the period of about 2 seconds is not remarkable. Therefore, in the graph of FIG. 5, the temperature of the strip coil is kept constant at 800 ° C.

Both the temperature rise of the strap and the accompanying decrease in the tensile strength are rapid at the beginning when the strap is tightened and in close contact with the coil, and gradually become gentle. In the present invention, the initial tightening force is set to such an extent that the strap is not permanently deformed, and the problem of the prior art such as the disconnection of the strap which is likely to occur during this rapid change can be sufficiently prevented. Further, it is possible to effectively cope with the subsequent decrease in strength of the strap due to temperature rise and increase of repulsive force due to further cooling of the coil.

That is, since the final tightening force corresponds to the strength of the strap at a higher temperature, there is no risk of the strap being cut, and the repulsive force of the coil increases as it cools, but at the same time the strap pulls. Since the strength also increases (the coil's repulsive force and the strap's opposing force cool while balancing), good tension is generated in the strap by the coil's repulsive force, and the coil can be prevented from loosening. .

The method of the present invention is applied to a coil having a temperature of about 400 ° C. or higher, but a remarkable effect is seen in about 7.
This is a case where it is applied to a coil of 00 ° C. or higher.

[0027]

According to the present invention, since the strap is first wound around the coil with a force that does not cause its permanent deformation and is brought into close contact with the coil, the temperature of the strap is immediately raised, but there is no possibility of cutting. . And do not wait for a long time until the strap is heated to near the coil temperature,
Immediately after the initial tightening or after holding the initial tightening for a short period of time, the binding work time can be shortened because the tightening force is changed to an appropriate tightening force that can cope with the low strength at high temperature. There is no risk of excessive tension being applied to the strap due to the difference in contraction. As a result, there is no fear that the strap will fall off or the coils will be scratched during the conveyance of the coils.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a coil binding machine to which the method of the present invention is applied.

FIG. 2 is a graph schematically showing an example of changes in strap tightening force in the method of the present invention.

FIG. 3 is a graph schematically showing another example of changes in the strap tightening force in the method of the present invention.

FIG. 4 is a graph schematically showing still another example of changes in the strap tightening force in the method of the present invention.

FIG. 5 is a graph showing an example of temperature changes and strength changes of a strap when wound around a coil.

[Explanation of symbols]

 C: coil S: strap

Claims (3)

[Claims] 1. When binding a metal coil heated to a high temperature with a metal strap, the strap is wrapped around the binding portion of the coil and then tightened with a weak force to substantially adhere to the circumferential surface of the coil. A method for binding a hot coil, characterized by waiting for the temperature of the strap to rise due to the heat of the coil, further tightening the strap with an appropriate force, and then fastening the strap. 2. When binding a metal coil heated to a high temperature with a metal strap, the strap is wound around a portion where the coil is bound and is tightened with a strong force not to permanently deform the strap. A method for binding a hot coil, which is characterized in that the strap is fastened substantially to the peripheral surface, the temperature of the strap is increased by the heat of the coil, the tightening force is relaxed to an appropriate force, and then the strap is fastened. 3. When binding a metal coil heated to a high temperature with a metal strap, the strap is wound around a portion where the coil is bound and the strap is tightened with a strong force not to permanently deform the coil. When the strap is tightened, the strap tightening force is gradually reduced to an appropriate force over time, waiting for the temperature of the strap to rise due to the heat of the coil. Characteristic hot coil binding method.