JPS6243792B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cutting method that uses a gas and an energy beam such as a charged particle or a laser, and in particular, cutting slag called dross adheres to the side edge of the cut surface on the back side of the material to be cut. This invention relates to a cutting method that reduces the amount of cutting.

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 device, 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 a cutting surface, and 13 indicating dross attached to 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, the electromagnetic lens 3, and the cutting nozzle 5 are arranged 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. adjust. Thereafter, at the same time as the material to be cut 8 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, thereby causing the material to be cut 8 or the processing head 2 to be irradiated with the electron beam 1.
By moving in the cutting progress direction 10, electron beam cutting in the atmosphere is achieved. 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 adhering to the lower side edge 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 the side edges of the cut surface 12 on the back side of the material to be cut 8,
Another disadvantage is that the quality of the cut surface is easily affected by the pressure of the auxiliary gas, especially when cutting at high speeds.
The aforementioned drawbacks were significant.

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 making the electron beams coincide with each other and shifting the axis of the electron beam forward in the cutting direction from the center of the symmetry axis of the nozzle opening surface, the auxiliary gas is efficiently injected onto the cutting surface, and dross is eliminated. The purpose of this is to make it possible to obtain good cut surface quality with less cutting surface.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a bottom view of the cutting nozzle, in which 14 is a cutting nozzle whose cross section at least at the lower part is oval, 15 is a nozzle opening surface of the elliptical cutting nozzle 14, and 16 is a nozzle opening. This is the center of the axis of symmetry (centroid) of the surface 15. FIG. 5a is a cross-sectional view taken in a direction perpendicular to the cutting line, illustrating the outline of cutting by the cutting method of the present invention using the cutting nozzle 14 shown in FIG. 4, and FIG. FIG.

In the cutting method of the present invention, the nozzle opening surface 15 of the cutting nozzle 14 is made into an elliptical shape with line symmetry that coincides with the cutting line, and the electron beam 1 is directed to the symmetry axis center 16 on this elliptical nozzle opening surface. The optical axis is shifted forward in the cutting direction on the cutting line, and the auxiliary gas 7 is injected from the nozzle opening onto the material 8 to be cut at the same time as the electron beam 1 is irradiated. In this way, the maximum pressure point of the auxiliary gas 7 surrounding the electron beam 1 is set behind the electron beam 1 in the cutting direction 10, so the auxiliary gas 7 is efficiently supplied to the cutting surface 11. Ru. Therefore, compared to conventional cutting methods, the amount of dross 13 attached to the back surface of the material to be cut 8 can be significantly reduced, and the quality of the cut surface can also be improved.

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. Further, in order to narrow the cutting width and effectively supply the auxiliary gas, the effect of the present invention is further improved by aligning the long axis of the symmetry axis of the nozzle opening surface with the cutting line. Furthermore, although the above-described embodiments have been described using electron beam cutting in the atmosphere as an example, the present invention can produce similar effects when cutting with other energy beams such as plasma or laser.

As explained above, according to the present invention, the shape of the nozzle opening surface of the cutting nozzle is line-symmetrical, and the optical axis of the energy beam is shifted forward in the cutting progress direction from the center of the symmetry axis on the same nozzle opening surface. , by making the cut in line with the cutting line,
The amount of dross attached can be significantly reduced,
The effect is that the quality of the cut surface can be improved.

[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,
Using a cutting nozzle whose nozzle opening surface is symmetrical in shape, the axis of symmetry of the nozzle opening surface is made to coincide with the cutting line, and the optical axis of the energy beam is set to advance cutting from the center of the axis of symmetry within the nozzle opening surface. A cutting method characterized in that the cutting is performed by biasing the cutting direction forward. 2. The cutting method according to claim 1, wherein the axis of symmetry of the long axis of the nozzle opening surface is made to coincide with 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.