JP2581895B2 - Hot coil binding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for binding a hot coil (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 connected to a metal strip (hereinafter, referred to as a strap).
And a method for tying the strap without risk of cutting the strap. In addition, the coil referred to 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 coil.

[0002]

2. Description of the Related Art Conventionally, when a metal coil in a high temperature state, such as immediately after hot rolling or immediately after annealing, is bound by a metal strap, shrinkage due to high heat or subsequent cooling is required. As a result, various problems have arisen. That is, (1) Conventionally, in general, the strap is wound around the hot coil and then immediately tightened to cut the seal (the subsequent strap is cut off simultaneously with the fastening of the strap). In this case, the hot coil then cools and contracts, but when the strap is sealed, it is naturally cool and remains at that length, so that the coil is loosened by the vibration during transport and the strip ( Alternatively, there is a problem that the wires and the rods are rubbed and damaged.

(2) As another method, in order to make the degree of contraction 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. Heating the strap with the heat of the hot coil by maintaining was also implemented. However, since it takes a long time to heat the strap to a predetermined temperature, the cost of bundling increases, and as a result, the manufacturing cost of steel plates, steel bars, steel wires, and the like increases. Moreover, since the tensile strength of the strap decreases when the temperature of the strap becomes high, if the strap is strongly tightened, the strap itself is cut.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and it is possible to quickly and easily use a conventional binding machine without cutting a strap and loosening a coil later. It is an object of the present invention to provide a method of bundling hot coils without any other means.

[0005]

According to the present invention, when a metal coil heated to a high temperature is bound by a metal strap, the strap is wrapped around a portion where the coil is bound and then the strap is made permanent. Tightened with a strong force that does not deform it, it was brought into close contact with the peripheral surface of the coil, and this initial tightening force was held for a short time
Then, the strap is fastened by loosening the tightening force to an appropriate force.

In such a binding method, the heat of the coil
Release the tightening force after the strap temperature rises.
The tightening force of the strap over time
To a suitable force and then the strap
Is preferably fastened.

[0007] The high temperature in the claims means a temperature of about 400 ° C or higher. Claims
The appropriate force is reduced by the temperature rise of the strap
Considering the strength of the coil and the repulsive force due to the temperature drop of the coil
The power to be determined.

[0008]

According to tying method of the present invention, to keep first strap wrapped around the coil is brought into close contact with the coil of strap strong force that is sufficiently weak to not permanently deform, the temperature of the strap is rapidly increased Go. Therefore, instead of waiting for a long time until the temperature of the strap becomes close to the coil temperature, the binding work time is shortened in order to reduce the tightening force of the strap to a force corresponding to the strap strength at a higher temperature in a short time. Also, the strap does not break at high temperatures.

When the coil is cooled, the strap is cooled first and contracts. However, since the strap is tightened with a force corresponding to a low strength at a high temperature, an excessively large difference is caused by the difference in contraction between the strap and the coil. There is no possibility that a tensile force will be applied. In addition, the strength of the strap increases with cooling, and the repulsive force of the coil increases, so that the strap does not have to be loosened.

[0010] If reduced to a force corresponding to the strap strength at higher temperature the tightening force, or at once to reduce the pull-out clamping force, or stepwise decrease with the passage of time.

[0011] In summary the initial tightening force is a force capable into close contact with strap and the coil periphery of the strap without permanent deformation, therefore, continuously process reduced to a force of the final tightening corresponding to strap strength at high temperatures
Some declines are intermittent, and others are intermittent .

[0012]

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 FIG. 2 is a strap tightening force.
3 and 4 are graphs each schematically showing an example of a change in strap tightening force in the method of the present invention, and FIG. 5 is a temperature change of the strap when wound around a coil. 6 is a graph showing an example of a change in intensity.

FIG. 1 shows an example of a coil binding machine in which the outer periphery of a strip coil is made of a steel band (strap).
Device for securing with S (hereinafter simply referred to as binding machine) 1
It is shown. The bundling machine 1 is a known one conventionally used in steel mills and the like, and the conveyed strip coil C stops in the frame 2 of the bundling machine 1 for a short time, during which the tightening device main body is used. 3, a strap is wound around the outer circumference of the strip coil C, tightened, fastened by a binding head (not shown), and then a strap feeder (not shown).
Cut off the strap connected from.

The tightening of the strap is usually performed using an air motor and an electro-pneumatic proportional valve (a control valve for sending air having a pressure proportional to the supply voltage by changing the supply voltage). There is no. Further, by interposing a transmission at the output portion of the air motor, the number of rotations can be reduced but the tightening force can be increased even at the same air pressure. For example, when the transmission is set at a reduced speed ratio, the speed can be changed in a range of 50 to 140 kg by a change in air pressure. However, when the transmission is switched to a high reduction ratio, the winding and tightening time is relatively long, but the tightening force is strong. Can be varied in the range of 500-1600 kg with the same change in air pressure.

FIGS. 2 to 4 qualitatively and schematically show an example of a temporal change of the strap tightening force. In each of the drawings, reference numeral A in the figure indicates a point in time when the strap is wound around and closely attached to the outer periphery of the coil, and reference numeral B indicates a point in time when the strap is seal-cut.

In FIG. 2, the strap is instantly wound around the coil and tightened to pull the strap at high speed with the transmission reduced in speed ratio. However, the tightening force is weak, and the tightening device main body (reference numeral 3 in FIG. 1) is used. Except for the binding head portion in the parentheses, the strap is in close contact with the coil, for example, about 120 kg. Hold for about 4 seconds to heat the strap while tightening at 120 kg. Then, after about seven seconds (for example, switching the transmission to a high reduction ratio) during the time that the strap is started to be pulled including the four seconds, the strap is tightened again (hereinafter, referred to as final tightening). Has a tensile strength that does not exceed the tensile strength of the strap at substantially the maximum temperature that the strap can reach (a temperature close to the coil temperature), for example, about 600 kg.

Next, in FIG. 3, the transmission is reduced to a reduced speed ratio, and the strap is instantly wound around the coil. Then, the transmission is switched to a high reduction ratio and tightened with a strong force. Strong enough not to cause
It is about 0kg. When the strap is tightened with such a strong force, the degree of adhesion of the strap to the coil becomes extremely high, so that the temperature rises instantaneously. Therefore, the holding time for heating is relatively short, about 2 seconds. After the holding for 2 seconds, the tightening force is reduced. This final tightening force is also
As in the case of (1), for example, it is about 600 kg, but it is possible to cope with various coil temperatures depending on the length of operation time.

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

It should be noted that the value of the tightening force is not limited to the above, and the supply air pressure and the speed reduction of the transmission are determined according to the coil thickness, the cross-sectional area of the strap, the environmental temperature, the coil temperature, and the like. What is necessary is just to select suitably by changing a ratio.

The final tightening force is selected in consideration of a decrease in strength due to a rise in temperature of the strap and an increase in a repulsive force (force for opening the coil) due to cooling of the coil. However, it is difficult to measure the temperatures of the strap and the coil in a very short time during actual work, or this is not preferable because the cost of equipment is significantly increased. Therefore, in advance, data on the elapsed time, such as the decrease in strength 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 from tests, analysis, past actual measurement results, etc. This is corrected by various conditions such as environmental temperature and strap dimensions (in other words, heat capacity of the strap). Based on the data thus obtained, a final tightening force of the strap is determined.

For example, in the case of a steel strip coil immediately after hot rolling, the temperature is about 700 to 900 ° C. Therefore, FIG. 5 shows that a steel strap having a thickness of 0.9 mm and a width of 32 mm is provided on the outer periphery of the 800 ° C. strip coil. As an example, a decrease in tensile strength due to an increase in temperature when brought into close contact is described. The strap is wound immediately after the hot rolling of the coil, so that the
The temperature drop due to spontaneous cooling of the coil in about a second is not significant. Accordingly, the graph of FIG. 5 is obtained by keeping the temperature of the strip coil constant at 800 ° C.

Both the temperature rise of the strap and the accompanying decrease in 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 problems of the prior art, such as the cutting of the strap, which is likely to occur during the sudden change, can be sufficiently prevented. Further, it is possible to effectively cope with a decrease in strength due to a subsequent rise in the temperature of the strap and an increase in repulsion 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 danger of the strap being cut off, and the repulsive force of the coil increases as it cools, but at the same time, the tension of the strap is increased. The strength also increases (cooling while balancing the repulsive force of the coil and the opposing force of the strap), so that a good tension is generated in the strap by the repulsive force of the coil, which can prevent the coil from loosening. .

Although the method of the present invention is applied to a coil having a temperature of about 400 ° C. or more, a remarkable effect is obtained only for about 7 ° C.
This is a case where the measurement is performed on a coil of 00 ° C. or more.

[0026]

According to the present invention, the strap is first wound around the coil with a force that does not cause permanent deformation of the strap so that the strap is brought into close contact with the coil. . And do not wait for a long time for the strap to heat up near the coil temperature,
Immediately after the initial tightening or after maintaining the initial tightening for a short period of time, the binding work time is short to change to an appropriate tightening force that can cope with low strength at high temperatures, and the strap and coil There is no possibility that excessive tension is applied to the strap due to the difference in contraction. As a result, there is no danger that the strap will fall off or the coils will be scratched during transportation of the coils.

[Brief description of 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.

2 is a graph schematically showing a reference example of a change in the strap tightening force.

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

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

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

[Explanation of symbols]

 C: coil S: strap

Claims (2)

(57) [Claims] In the method according to claim 1 the metal coil is heated to a high temperature for binding by a metallic strap, tightening with strong force that is sufficiently weak to not permanently deform the strap in terms of the strap was circulating at the site of binding of the coil coil Substantially in contact with the peripheral surface of this initial
Before the tightening force until the appropriate force after holding a short time
A method for binding a hot coil, wherein a strap is fastened by loosening a tightening force . 2. The temperature of the strap due to heat of the coil.
After ascending, the tightening force of the strap over time
After gradually lowering the
The method for binding a hot coil according to claim 1, wherein the fastening is performed.