JPH091367A - Cutting of metallic sheet - Google Patents

Abstract

PURPOSE: To prevent a bad copying of the height of a cutting nozzle due to a upward camber of a cut lug by cutting the lug a little longer in the longitudinal direction, cutting its short direction side at a reversely run and retreated position and successively cutting the longitudinal direction side again from the terminal position of the cutting path in the longitudinal direction. CONSTITUTION: In the case of cutting off lugs 2 consisting of 2a, 2b and 2c connecting with a steel sheet 1 in the longitudinal direction, cutting is performed in order of (1)-(7) along cutting paths (1), (2), (4), (5), (7) and a moving paths (3), (6) shown in a dot line (wherein cutting is not performed by the method such as a quick moving, etc., but a cutting torch only is moved.) In this case, the length up to each terminal position (qa) and (qb) of the cutting paths (1), (4) in the longitudinal direction are specified to be longer than a prescribed length (1a, 1b). By this method, since the height of the nozzle from the surface of the steel sheet is smoothly adjusted, a trouble such as the interruption during cutting is prevented and the cut surface of excellent quality is stably obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting method for separating selvedges from a metal plate.

[0002]

2. Description of the Related Art An as-rolled metal plate (a steel plate or the like, hereinafter referred to as a steel plate) is generally cut and removed, that is, selvage treatment, in order to adjust it to a predetermined product size. Most of the ear dust is a narrow strip-shaped metal piece, and a plurality of metal pieces are continuously arranged in the longitudinal direction. The reason why there are a plurality of selvages is that the length of each selvage is limited to about 1.6 to 2.0 m or less from the viewpoints of handling and size restrictions of the scrap storage container arranged downstream. Is. Then, as this cutting method, for example, fusing using various energy sources such as laser cutting and gas cutting is adopted.

By the way, the method of separating the ear scraps from the steel plate by fusing is conventionally performed by the process shown in FIG. 1, and the cut-out ear scraps are collected in a scrap container provided downstream and collected as scrap. To be done. Now,
In FIG. 1, when the selvage 2 consisting of selvage 2a, 2b, 2c which is continuous in the longitudinal direction is melt-cut from the steel plate 1, the conventional cutting process is as follows: a cutting path indicated by a solid line, and a dotted line. Along the following movement route (a route that does not perform cutting by a method such as fast-forwarding but only moves the cutting nozzle) and so on, the processes are performed in the order of to. Here, the end positions p _a and p _b of the cutting process of the ear scraps in the longitudinal direction were positions corresponding to the lengths of the ear scraps 2a and 2b, respectively.

[0004]

However, the above conventional method has the following disadvantages. That is, as shown in FIG. 2, after cutting along the cutting path, when the cutting along the cutting path is completed, the cut ear waste warps upward due to thermal deformation. The warped ear scraps are kept warped on the pedestal 4 supporting the steel plate. In this state, when the cutting of the selvedge is started after the following, the height of the cutting nozzle from the steel plate surface cannot be traced due to the warp, and the cutting surface becomes rough or the cutting is interrupted. Problems often occurred.

An object of the present invention is to propose a novel method by which a good quality cut surface can be stably obtained without causing the above problems when separating the ear waste by fusing. is there.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a method for separating ear debris by cutting a metal plate along the longitudinal direction of the ear debris and subsequently cutting it along the short side direction. The longer side of the cutting edge to a length longer than the planned ear waste length, the short side direction is cut at a position where a part of this cutting path is reversely retracted, and then again from the end position of the longitudinal cutting path. This is a method for cutting a metal plate, which is characterized in that the ear dust is cut off by repeatedly cutting in the longitudinal direction. here,
The cutting length in the longitudinal direction is 10 to 1 longer than the planned length of the ear waste.
It is preferable to increase the length in the range of 00 mm.

[0007]

The inventors investigated by a lab test and an actual machine test about a method in which the warpage due to thermal deformation is small and the effect on the subsequent cutting step is small even when the warpage occurs. As a result, it was concluded that the above problems can be solved all at once by adopting the cutting process as shown in FIG.

FIG. 3 shows that the steel plate 1 is continuous in the longitudinal direction.
Cut and cut the ear debris 2 consisting of the ear debris 2a, 2b, 2c
The cutting process according to the method of the present invention when detaching is shown.
Things. In FIG. 3, in the method of the present invention, it is shown by a solid line.
Cutting path ,,, and
Road (cutting torch without cutting by fast forward method etc.)
Only along the path) and along, of
This is done in order, and the major difference from the conventional method is that
Direction cutting path and each end position q of_aAnd q _b
Is the expected length of ear waste (l in Fig. 3)._a, L_b) Be longer
And

In this way, by lengthening the end position of the cutting path in the longitudinal direction, for example, when the ear debris 2a is separated, even if the ear debris warps after cutting along the path, the cutting nozzle will pass the path. Since it only has to move to q _a along the route without passing through, the profile of the height from the steel plate surface is not hindered by the warp and is performed without problems, and the cutting for the next selvage separation is started smoothly. , Can proceed. Here, the cutting length in the longitudinal direction in the present invention is
The length is sufficient to prevent interference between the cutting nozzle and the warp portion of the ear dust, and the length is preferably longer than the expected length of the ear dust, for example, in the range of 10 to 100 mm. . The moving path is shown by a straight line in FIG. 3, but the starting point q _{a of} the next longitudinal cutting of the ear dust,
Since it is sufficient to move to q _b , it is not always necessary to move linearly.

FIG. 4 shows another embodiment of the cutting process according to the present invention. In the case of FIG. 4, the process is performed in the order of to along the cutting route indicated by the solid line, and the moving route indicated by the dotted line. In this case, compared to the case of FIG. 3 described above,
It is the same in that the end positions q _a and q _b of the cutting path in the longitudinal direction are longer than the planned length of the ear waste, but they are different in that the order of the cutting path in the short side direction and the moving path is reversed. To do. The effect obtained in this case is almost the same as that obtained in FIG.

[0011]

[Example] 2500 mm x 6800 m with a plate thickness of 16 mm
From the width end of the steel plate of m (steel type: JIS SS400), width 2
A selvage cutting process was carried out in which four selvages of 00 mm and a length of 1700 mm were connected in series. Laser cutting method (output: 5
000 W) and the cutting speed was 1200 mm / min. In the method of the present invention (the method shown in FIG. 3 is adopted), the cutting length of the ear debris in the length direction was set to the planned ear debris length + 100 mm. For comparison, the cutting by the conventional method was also performed in the same manner.

As a result, according to the method of the present invention, no trouble was observed and a sound cut surface was obtained from the start of cutting to the end of all ear waste cutting processing. On the other hand, in the comparative example, the height of the cutting nozzle could not be traced, the cutting groove did not reach the back surface, and gouging and burning were generated, so that good cutting could not be performed.

[0013]

As described above, according to the present invention, the nozzle height from the steel plate surface can be adjusted smoothly,
Problems such as interruption of cutting work can be prevented, and a good quality cut surface can be stably obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional cutting path.

FIG. 2 is a diagram showing a state of warp of ear dust generated during cutting.

FIG. 3 is a diagram showing a cutting route according to the method of the present invention.

FIG. 4 is a diagram showing another embodiment of the cleavage path according to the method of the present invention.

[Description of sign]

 1 Steel plate 2 Ear waste 3 Cutting line 4 Stand

Claims (1)

[Claims] 1. A method for separating ear debris by cutting a metal plate along the longitudinal direction of the ear debris, followed by cutting along the short side direction, in which the longitudinal direction of the ear debris is planned. Cut longer than the length,
A part of this cutting path is cut backward in a backward direction, and the short side direction is cut, and then the longitudinal direction is cut again from the end position of the cutting path in the longitudinal direction. How to cut a metal plate.