JP2676716B2 - Method of shearing running metal strips with a thickness of 0.3 mm or less by rotary shear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a running shearing method for shearing a metal strip such as a cold rolled steel strip, a plated steel strip, a stainless steel strip or an aluminum strip by a rotary shear during traveling.

[0002]

2. Description of the Related Art Generally, in a rotary shear for shearing a metal strip such as a cold rolled steel strip, a plated steel strip, a stainless steel strip, and an aluminum strip during movement, the peripheral speed of the knife portion is disclosed in JP-A-54-95089. As described in the official gazette, it is usual that the traveling speed of the metal plate to be sheared is completely synchronized to obtain an equal speed. Therefore, the rotary shear has a mechanical periodic non-uniform velocity motion. It is equipped with a generation mechanism and an electric synchronous circuit.

FIG. 1 shows an example of the structure of a rotary shear for shearing a steel strip such as a tinning sheet according to the present invention. 1 is a shear drum, 2 is a knife, 3 is a pinch roll, 4 is a measuring roll, and 5 is a shear drum 1. Drive motors, 6a and 6b are pulse generators, 7 is a controller, 8 is a support roll,
S is a steel strip, and S'is a steel strip (sheet) after shearing. A linear knife 2 is attached to a cylindrical surface of a shear drum 1 which is a roll-shaped rotating body, and a pair of upper and lower shear drums 1 is attached.
Rotates in conjunction with the steel strip S, and shearing is performed at a position where the upper and lower knives 2 mesh with each other.

Conventionally, as illustrated in the knife peripheral speed pattern of FIG. 4, the shear drum 1 is set so that the knife and the metal strip have completely equal speeds, in this example, 200 mpm from immediately before shearing to completion of shearing. Rotation control was performed. FIG.
In, P ₁ indicates the biting position of the knife, and P ₂ indicates the shearing position. When the knife position (phase) is 0 °, 360 ° ..., the upper and lower knives are engaged and shearing is performed.

Incidentally, in the middle between the shearing position and the shearing position,
The shear drum 1 idles, but the speed during that time is faster or slower than the steel strip speed depending on the shear length. These speed controls detect the steel strip feed length and the steel strip speed by the measuring roll 4 rotating in contact with the steel strip S,
In this example, the control device 7 such as an NC electrically controls the rotation of the drive motor 5 for the shear drum 1.

By the way, in such a conventional speed control method, there have been problems that the shearing surface of the metal strip does not become a right angle, and that the metal strip has scratches. This phenomenon is especially noticeable when the metal strip thickness is 0.3 mm or less.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve these problems and to realize a running shearing method for a metal strip by means of a rotary shear which has good shearing right angle accuracy and does not cause scratches. To do.

[0008]

Means for Solving the Problems As a result of pursuing causes such as poor shear right angle accuracy and generation of scratches, the present inventors found that the peripheral speed of the knife and the traveling speed of the metal strip are completely the same.
At the moment of shearing, it was found that the trailing metal plate had slack and flapping, which caused misalignment in the shearing direction and contact between the peripheral rolls and the metal strip to cause scratches. .

Therefore, at least immediately before the upper and lower knives are bitten into the metal strip to be sheared until the shearing is completed, the peripheral speed of the knife portion is kept slightly higher than the traveling speed of the metal strip, so that the material to be sheared is kept. The present invention has been completed by applying tension to the plate to eliminate slack and flapping. That is, the present invention, the roll-shaped rotating body provided with a linear knife on the cylindrical surface is arranged above and below the metal strip, and the roll-shaped rotating body is rotated in conjunction with the running of the metal strip to run the metal strip. However, in a rotary shear that shears in the lengthwise direction, the peripheral speed of the knife part should be 100.5% or more and less than 105.0% of the running speed of the metal strip from immediately before the upper and lower knives bite into the sheared metal strip to the end of shearing. It is a method of shearing during running of a metal band having a plate thickness of 0.3 mm or less by a rotary shear, which is characterized by holding.

[0010]

[Operation] According to the present invention, at least immediately before the upper and lower knives bite into the metal strip to be sheared to the completion of shearing, the peripheral speed of the knife portion is slightly higher than the traveling speed of the metal strip, that is, 100.5% or more of the running speed of the metal belt 10
By holding the material in the range of less than 5.0%, the material to be sheared was given tension so that slack and flapping were eliminated.

The peripheral speed of the knife portion is 1 of the running speed of the metal strip.
If it is less than 00.5%, the effect of the present invention does not appear because the action of the knife pulling the material to be sheared is insufficient. On the other hand, if it is 105.0% or more, a large force may be applied to the knife when the knife is bitten, which may cause a knife loss accident.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With respect to the rotary shear shown in FIG. 1 described above, a knife peripheral speed pattern in an example in which the present invention is implemented will be described with reference to FIG. The peripheral speed of the knife portion is 3% higher than the traveling speed of the metal strip of 200 mpm in the range including at least the knife biting position P ₁ to the shearing position P _2.
It is held at 6mpm. Fig. 3 shows the results obtained by shearing rectangular steel strips with temper DT4, plate thickness 0.20 mm and plate width 850 mm into a sheet with a length of 650 mm using this knife peripheral speed pattern, and tabulating the right angle accuracy values for 100 sheets. . On the other hand, the conventional method,
That is, FIG. 5 shows the right angle accuracy values obtained by shearing 100 sheets of the same material by the speed control shown in FIG. Even if you look at the average value,
It can be seen that this embodiment is greatly improved to 0.14 in comparison with the conventional method of 0.27. Scratches were found in 47 out of 100 sheets by the conventional method, but none could be found in this example.

[0013]

According to the present invention, there is an effect that the right angle accuracy of the sheared sheet is improved and the occurrence of scratches is almost eliminated, and the quality is greatly improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a rotary shear according to the present invention.

FIG. 2 is a graph showing a knife peripheral speed pattern in an example of the present invention.

FIG. 3 is a graph showing right angle accuracy values according to an embodiment of the present invention.

FIG. 4 is a graph showing a knife peripheral speed pattern according to a conventional technique.

FIG. 5 is a graph showing a quadrature accuracy value according to a conventional technique.

[Explanation of symbols]

 1 Shear drum 2 Knife 3 Pinch roll 4 Measuring roll 5 Drive motor 6a, 6b Pulse generator 7 Controller 8 Support roll S Steel strip

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 2-180519 (JP, A) JP-A 6-190405 (JP, A) JP-A 62-136308 (JP, A)

Claims (1)

(57) [Claims] 1. Roll-shaped rotary bodies provided with linear knives on a cylindrical surface are arranged above and below a metal strip, and the roll-shaped rotary body is rotated in association with the traveling of the metal strip to run the metal strip. However, in a rotary shear that shears in the lengthwise direction, the peripheral speed of the knife part is set to the running speed of the metal strip from immediately before the upper and lower knives bite into the sheared metal strip until the end of shearing.
A method of running shearing a metal strip having a plate thickness of 0.3 mm or less by a rotary shear, which is maintained at 100.5% or more and less than 105.0%.