JPS6125751A - Cutting of side edge of steel plate - Google Patents

Abstract

PURPOSE:To improve the working efficiency when cutting the side edge of steel plate in steel plate regulation line, by constituting such that the rotary speed of pinch roll and roller table will increase when the load current flowing through the drive motor for cutting system is lower than predetermined level. CONSTITUTION:An ammeter 5 will measure the current flowing through the winding 9 of drive motor 9 to provide current level signal S to a comparator 6. The comparator 6 will compare said current level S with the upper limit level N provided from an upper limit setter 7 to regulate the rotary speed of drive motor M2 for the pinch rollers 3, 3' to be same with the rotary speed of the drive motor M2' for the roller table 4 if S is larger than N. If S will drop below N, the rotary speeds of said motors M2, M2' are increased. With such arrangement, useless operation of system is eliminated resulting in improvement of efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cutting the side edges of a steel plate, and more specifically, in a steel plate finishing line, the present invention uses a cutting device such as a milling cutter to cut irregular irregularities existing on both sides of a rolled steel plate. The present invention relates to a method for finishing the side edges by scraping them to form neat, linear side edges.

The steel plate as it comes out of the rolling mill has a slight margin at both longitudinal ends and the vertical edges on both sides, and the margin is trimmed using a shearing device on the steel plate finishing line to achieve the specified product dimensions. The conventional example is to finish it as follows. However, with recent advances in rolling technology, rolled steel plates having a planar shape close to a rectangle have been obtained, and dimensional accuracy has also improved. On the other hand, there are five conditions that require the presence of an allowance having a width of L to approximately equal to the thickness of the W4 root when shearing the side edge of a steel plate using a conventional shearing machine. If the margin is smaller than a predetermined value, there is a risk that the steel plate will get caught between the upper and lower blades of the shearing machine during shearing, thereby interfering with the operation of the shearing machine.

Therefore, if the steel plate taken out from the rolling machine is already a rectangular plate with highly accurate dimensions, the allowance for removal from both sides is small, making it unsuitable for being subjected to the conventional shearing machine. The side edges of the steel plate must be finished by cutting.

However, at present, cutting devices have the disadvantage of having a low throughput. In particular, since the steel plate to be cut only moves in a straight line and does not move in a rotational manner, the cutting margin that can be removed by one cutting cutter is only a few. Therefore, when installing the cutting devices, the required number of cutting devices is calculated from the capacity of the cutting device and the required amount of cutting, and this many devices are arranged in series. The ability of the cutting device is designed to be able to cut a predetermined depth of cut (for example, 1.5 #II++) from the uneven side edge of the steel plate. There are quite a few areas where 1.5M cutting is not required due to unevenness, resulting in wasteful operation of the cutting device. This waste is significant when using multiple cutting devices arranged in series on a roller I-table. The present invention is useful for easily solving the problem of copper plate finishing and lithography using a cutting device.

An object of the present invention is to reduce the amount of cutting of the side edges when using a cutting device to cut the side edge portions that protrude and recess irregularly in the width direction of the steel plate that exist on both sides of the steel plate taken out from the rolling mill. To provide a cutting method that eliminates waste in the operation of a cutting device and improves work efficiency by accelerating the running of a steel plate on a roller table when cutting a part.

The above object of the present invention is to cut the side edge of a steel plate on a roller table using a cutting device such as a milling cutter having a vertical axis of rotation installed adjacent to the side edge of the roller table. A cutting method in which a steel plate is pinched by upper and lower rollers of pinch rolls installed adjacent to the cutting device on the upstream or downstream side, and the normal cutting of the cutting device is performed from the outermost edge of the width of the steel plate. The cutting device is positioned so as to cut the side edge of the steel plate by the amount of the pinch roll, and after the start of the cutting operation, when the load current of the drive motor of the cutting device reaches a predetermined value, the roller rotation speed of the pinch roll is adjusted to A method for cutting side edges of a counterboard, characterized in that the speed of rotation of the rollers of the table is maintained at the same value, and when the load current decreases below a predetermined value, the rotation of the pinch rolls and roller table is accelerated. achieved.

An embodiment of the method of the present invention will now be described with reference to the accompanying drawings.

Figure 1 shows a steel plate 1 as rolled, and a steel plate 2 made into a product by removing the excess parts B from both side edges and ends.
This shows the relationship with 0.

Previously, the excess portion B was removed using a shearing device. When a shearing device is used, the width of the surplus portion B is required to be approximately the same as the thickness of the steel plate 1 even at its smallest portion.

Figures 3 and 2 show the operation of scraping the side edges from both sides of a relatively thick steel plate 10, using a shearing blade 21.

Figure 3 shows the side edges of both sides of the relatively thin steel plate 10.
A round blade called a rotary knife 22
use.

Referring to FIG. 4, an as-rolled steel sheet 1 running on a roller table 4 and an apparatus 10 for use in the method of the invention are shown. The device 10 is a cutting device 2, 2' such as a milling cutter that scrapes the side edge portion of the steel plate 1.
and a pinch roller 3 installed adjacent to the cutting device. It is equipped with the following. In the illustrated example, a pair of cutting devices 2゜2' are arranged on both sides of the steel plate, but since the cutting devices / are arranged symmetrically to the cutting device 2 and have the same structure, the cutting devices will be described below. 2 will be explained. In addition, in the illustrated example, there are two pinch rolls 3 and 3'.
are shown on the upstream side and downstream side of the cutting device 2, respectively, and since both have the same structure, the pinch roll 3 will be explained below.

The drive motor MI of the cutting device 2 and its winding 9 are shown on the underside of the cutting device 2. An ammeter 5 is provided adjacent to the drive motor MI for measuring the current flowing through the winding 9 when the drive motor MI is in operation. The ammeter 5 is equipped with a current transformer that instructs the current flowing through the winding 9 of the drive motor MI by decreasing it at a predetermined rate. For 5W, the winding of the current transformer is small. The current sensor 5 is configured to output a signal S indicating the measured current value. Comparison device 6 on the right side of ammeter 5
has been installed. The comparator 6 receives the signal S output from the ammeter and the upper limit current setter 7 shown below the comparator.
It also accepts the signal I4 indicating the upper limit current value and compares both S and N. As a result of the comparison, if the signals S and N are equal, the comparator 6 does not issue a signal; however, if S is greater than N, or if the signal S is smaller than the signal N, the comparator 6 does not issue a signal. put out. A control mechanism 8 installed on the right side of the comparator 6 receives the signal output from the comparator 6 and decelerates or accelerates the rotation of the drive motors M2+M2' of the pinch roll 3 and the rotation of the drive motor of the table roller. .

As shown in Fig. 5, the load current T is approximately proportional to the actual cutting amount of the cutting device 2, and has a waveform that approximately matches the shape of the side edge of the steel plate 1. It is positioned so that a predetermined depth of cut is cut from the outer edge.The load current required to cut the side edge of the steel plate by the above depth of cut is set to lrn.
Then, since the cutting device 2 also cuts the side edge portion recessed in the board width direction from the outermost end, the upstream load current m becomes a so-called bald peak current, and at other than the outermost end, I
smaller than n, the cutting device is fully operational (・not).

A comparison device 6 momentarily compares the current of the motor Ml with the current value set by the setting device 7, and determines the load current I of the motor MI.
If is smaller than the set value, immediately pinch roll 3
Since it outputs a signal to accelerate the rotation of the electric motor M2 and the table roller drive motor, when the cutting amount of the cutting device 2 decreases below a predetermined value, the feeding of the steel plate 1 to the cutting device 2 is accelerated and the cutting device 2 ability can be utilized without waste.

In this way, as shown in FIG. 6, by constantly operating the load current of the cutting machine motor M1 near the upper limit set value of 7, the cutting machine's full ability is brought out and the most efficient cutting is performed. Therefore, the device of the present invention is effective in removing unevenness on the side edge of a steel plate at the initial stage of cutting work on the side edge of the steel plate.
It is possible to eliminate wasteful work and improve work efficiency.

1. Figure 1 is a plan view of a rolled steel plate processed by the method of the present invention, and Figure 2 is a perspective view of a conventional method for shearing the side edges of a rolled steel plate. , Figures 1 and 3 are perspective views showing another conventional method for shearing the side edges of rolled steel plates, Figures 1 and 1 are schematic diagrams showing the equipment used in the method of the present invention, Figures 1 and 5 are +4 (Member) Electric motor σ used for the main part of equipment j
) 1+: Current curve 'A', j' (Figure 'N shows the same current change as in Figure 15) J (-1 curved edge, (・,ru).

1 Steel plate as rolled 2
Cutting device 3.3' Pinch roll 4 Roller table 5
Ammeter 6 Comparison device 7 Upper limit current setting device 8 Control mechanism 9 Winding

Claims (1)

[Claims] A method for cutting the side edge of a steel plate on a roller table using a cutting device such as a milling cutter having a vertical rotation axis installed adjacent to the side edge of the roller table, the method comprising: cutting the side edge of a steel plate on a roller table; The steel plate is held between the upper and lower rollers of a pinch roll installed on the upstream or downstream side adjacent to the device, and the side edge of the steel plate is cut by the usual cutting depth of the cutting device from the outermost edge of the width of the steel plate. After starting the cutting operation, when the load current of the drive motor of the cutting device reaches a predetermined value, the rotation speed of the roller of the pinch roll is set to the same value as the rotation speed of the roller of the roller table. A method for cutting a side edge of a steel plate, the method comprising: maintaining the load current at a predetermined value, and accelerating the rotation of the pinch roll and the roller of the roller table when the load current decreases below a predetermined value.