JPS6243793B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting method that uses charged particles, an energy beam such as a laser, and gas in combination, and particularly relates to a cutting method that prevents cutting slag called dross from adhering to one side of the cut surface. It is something.

Hereinafter, a conventional cutting method will be described with reference to FIGS. 1, 2a and 2b, and 3a and 3b, taking as an example a cutting method using an electron beam in the atmosphere. FIG. 1 shows a conventional cutting method, in which 1 is an electron beam, 2 is a processing head, 3 is an electromagnetic lens attached to the processing head 2, 4 is a gas inlet provided in the processing head 2, 5 is a cutting nozzle attached to the tip of the processing head 2, 6 is a nozzle opening at the tip of the cutting nozzle 5, 7 is an auxiliary gas ejected from the nozzle opening 6, and 8 is a material to be cut. Moreover, FIG. 2a is a bottom view of the cutting nozzle 5 of FIG. 1, and FIG. 2b is a longitudinal sectional view thereof. Figure 2a
In the figure, 9 indicates the center of the nozzle opening surface 6, and 10 indicates the cutting direction. FIG. 3a is a sectional view taken in a direction along a cutting line showing an outline of the cutting state, and FIG. 3b is a sectional view taken in a direction perpendicular to the cutting line. In Figure 3 a and b,
Reference numeral 11 indicates a cutting progress surface indicating a boundary between an uncut portion and a cut portion, 12 indicates a cut surface, and 13 indicates dross attached to both side edges of the back surface of the material 8 to be cut.

Generally, cutting with an electron beam in the atmosphere is
It is carried out in the following manner. That is, the processing head 2, electromagnetic lens 3, and cutting nozzle 5 are adjusted so that the electron beam 1 is concentrated on the surface of the material 8 to be cut, and the axis of the electron beam 1 and the center 9 of the nozzle opening surface 6 are aligned. do. Thereafter, at the same time as the material 8 to be cut is irradiated with the electron beam 1, an auxiliary gas 7 such as oxygen is introduced from the gas inlet 4 and ejected from the nozzle opening surface 6 to cut the material 8 or the processing head 2 in the cutting direction 10. electron beam cutting in the atmosphere is achieved by moving the Here, the auxiliary gas 7 plays the role of an oxidative exothermic reaction with the material to be cut 8 on the cutting surface 11 and the removal of dross 13 attached to both side edges of the lower part of the cutting surface 12.

In the conventional electron beam cutting method in the atmosphere as described above, the center 9 of the nozzle opening surface 6 was set to coincide with the axis of the electron beam 1.
As shown in FIGS. 3a and 3b, dross 13 tends to adhere to both side edges of the cut surface 12 on the back side of the material to be cut 8, and both sides of the cut surface 12 of the material to be cut 8 have approximately the same quality. Therefore, if one side of the material 8 to be cut becomes unnecessary scrap material, either the unnecessary side will be of excessive quality, or due to fluctuations in cutting conditions, both sides will be of poor quality. A drawback is that it is impossible to always maintain good quality only on the necessary material side even if the cutting conditions change.

This invention was made in order to eliminate the drawbacks of the conventional cutting method as described above, and uses a cutting nozzle whose nozzle opening surface has a line-symmetric shape, and uses a cutting nozzle whose nozzle opening surface has a line-symmetrical axis of symmetry with the cutting line. By aligning the axis of the electron beam with the perpendicular direction and offsetting the axis of the electron beam to one side from the center of the axis of symmetry of the nozzle opening surface on the axis of symmetry, only one side of the cut surface that is the side of the material to be used is cut. The purpose of this is to ensure that good cutting quality is obtained without the adhesion of dross.

An embodiment of the present invention will be described below with reference to the drawings. Figure 4 is a bottom view of the cutting nozzle, and Figure 5 is a bottom view of the cutting nozzle.
Figure a is a cross-sectional view in a direction perpendicular to the cutting line showing an outline of cutting by the method of the present invention using the cutting nozzle shown in Figure 4, and Figure 5 b is a cross-sectional view in a direction along the same cutting line. It is. In these figures,
14 is a cutting nozzle whose cross section at least at the lower part is oval; 15 is the nozzle opening surface of the elliptical cutting nozzle 14; 16 is the center of the axis of symmetry (centroid) of the nozzle opening surface 15; and 8a is the cutting nozzle. Materials used for material 8,
8b is a waste material of the material 8 to be cut.

The cutting method of the present invention uses a cutting nozzle 14 having a line-symmetrical elliptical nozzle opening surface 15,
The axis of symmetry of the nozzle opening surface 15 is set in a direction perpendicular to the cutting line 10, and the axis of the electron beam 1 is biased toward the work material 8a side with respect to the axis of symmetry center 16 of the nozzle opening surface 15, and the electron beam 1 is irradiated. At the same time, the auxiliary gas 7 is injected onto the material 8 to be cut. In this way, the maximum pressure point of the auxiliary gas 7 surrounding the electron beam 1 is shifted from the axis of the electron beam 1, and the auxiliary gas 7 is effectively distributed to the material 8 to be cut.
That is, the cutting width is formed symmetrically with respect to the axial center of the electron beam 1, which is the main heat source. The gas flowing into the cutting groove on the working material 8a side has a relatively smooth flow because it rarely hits the surface of the working material 8a.
On the other hand, the auxiliary gas 7 on the side of the waste material 8b hits the surface of the waste material 8b more than on the side of the used material 8a and disturbs the flow of the gas itself flowing into the cutting groove. Therefore, a strong gas flow occurs on the cut surface on the side of the used material 8a, while a weak gas flow occurs on the cut surface on the waste material 8b side. As a result of the above, on the back side of the material to be cut 8, a force is applied toward the waste material 8b near the cutting part, so the dross on the working material 8a side moves to the waste material 8b side, and the dross 13 is concentrated on the waste material 8b side. By adhering to the material 8a, there is almost no adhesion of dross on the material 8a side, and the material 8 has a good cut surface quality.
a can be obtained with good reproducibility.

In the above embodiment, the case where the nozzle opening surface of the cutting nozzle has an elliptical shape has been described, but this invention can also be applied to cases where the nozzle opening surface has other axisymmetric shapes such as a polygon, a droplet shape, a sector shape, etc. However, it has substantially the same effect. Moreover, the effect of the cutting method of the present invention is further improved when the long axis of the symmetry axis of the nozzle opening surface is made to coincide with the direction orthogonal to the cutting line. Further, although the above-mentioned embodiment has been explained using electron beam cutting in the atmosphere as an example, this invention
A similar effect can be achieved by cutting with another energy beam such as a laser.

As explained above, according to the present invention, the shape of the nozzle opening surface of the cutting nozzle is line-symmetrical, the axis of symmetry is made to coincide with the direction perpendicular to the cutting line, and the axis of the energy beam is aligned with the nozzle on the axis of symmetry. By using the cutting offset to one side from the center of the symmetry axis of the opening surface, good cutting quality can always be obtained without dross adhering to one side of the cutting surface, such as the working material side of the material to be cut. There is an effect.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an example of a cutting device that performs a conventional cutting method, FIGS. 2 a and b are a bottom view and a longitudinal sectional view of the cutting nozzle of the cutting device shown in FIG.
3A and 3B are a sectional view along the cutting line and a sectional view perpendicular to the cutting line showing the state of cutting by the conventional cutting method, and FIG. FIGS. 5A and 5B are a bottom view of the nozzle for cutting, and are a sectional view in a direction perpendicular to the cutting line and a sectional view in the direction along the cutting line, showing the cutting state by the cutting method of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Electron beam, 7... Auxiliary gas, 8... Material to be cut, 14... Cutting nozzle, 15... Nozzle opening surface, 16... Center of symmetry axis. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A cutting method in which a charged particle, an energy beam such as a laser, and a gas are simultaneously discharged from the same opening of a cutting nozzle to cut a material to be cut,
A cutting nozzle whose nozzle opening surface is line-symmetrical in shape is used, the axis of symmetry of the nozzle opening surface is aligned with a direction orthogonal to the cutting line, and the axis of the energy beam is aligned with the axis of symmetry of the nozzle opening surface on the axis of symmetry. A cutting method characterized in that the cutting is performed by making the cut off to one side from the center of the shaft. 2. The cutting method according to claim 1, wherein the long axis of the axis of symmetry of the nozzle opening surface is made to coincide with a direction perpendicular to the cutting line. 3. The cutting method according to claim 1 or 2, characterized in that a cutting nozzle having a line-symmetric nozzle opening surface shape that is polygonal, elliptical, droplet-shaped, or fan-shaped is used.