JPS61193796A - Laser beam processing device - Google Patents

Abstract

PURPOSE:To make possible the stable holding of a mirror position even in long-period use by conducting the beam outputted from an oscillator to a moving mirror via a freely elongatable and contractable cylindrical body which connects a mirror holder for holding the moving mirror and a beam cover for protecting the beam route. CONSTITUTION:A screw cover holding base 13 is separated from the mirror holder 12 and the separated bases are respectively and the separated 7. A pipe 15 is provided between both in a freely supporting state by means of an O-ring 14. The pipe 15 has a function as a safety cover having a dust-proof effect to the beam 3 and has the function to prevent the axial force generated when a screw cover 9 freely elongatable and contractable in the optical axis direction elongates or contracts from being transmitted to the mirror holder 12. Not only the beam position is stabilized for a long period but also the reduction in the size and weight of the respective parts and the improvement in the degree of freedom of shape design are made possible by the above-mentioned constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a laser processing apparatus for performing processing such as cutting, drilling, welding, and scribing using focused beam energy.

2. Description of the Related Art Conventionally, as a device for accomplishing various types of processing by irradiating a workpiece with a beam output from a laser oscillator, a device mounted on a processing table main body 1 as shown in FIGS. A beam 3 output from a laser oscillator (not shown) is guided to a predetermined position with respect to the processed workpiece 2 using a reflecting mirror 4 fixed to the table body 1 and a moving reflecting mirror 6, It is common to use a condensing device such as a condensing lens 6 or a condensing mirror (not shown).

Therefore, as shown in FIG. 2, the movable mirror 5 is constructed to be installed on a moving body such as a gantry 7 and a processing head 8.

In addition, although FIGS. 2a and 2b show the beam 3 moving in both the X and Y directions, in some cases, the beam moves in only one direction and the other direction moves toward the workpiece, as shown in FIG. 2 C9a. 2 often moves.

When the size of the workpiece 2 is relatively large, this rera beam moving type processing table is used, for example, 1.2m x 2.4m.
It is often used to target all objects such as mild steel plates of so-called standard dimensions such as m.

In the beam movement type, from the viewpoint of safety for the beam 3 and dustproofing of the beam path, a screw cover 9 as shown in Fig. 3a or a bellows 11 supported by a guide rod 10 as shown in Fig. 3 is used. It has a structure in which it is combined with a holder 12 of a reflecting mirror 6. The guide plate 12 is for regulating the deflection of the bellows 11 due to its own weight.

Further, the mirror holder 12 is fixed to the gantry 7 in all examples of the folding mirror 5 shown in FIGS. 2a and 2b.

Problems to be Solved by the Invention However, in such a structure, in the case of FIG. 3a,
This includes factors that cause the mirror angle to change as the mirror 6 moves, and in Figs. There was a problem with this.

This is due to the following reasons.

In the structure shown in FIG. 3a, the entire screw cover 9 is composed of a spiral band plate having spring properties, and naturally,
As the table expands and contracts in response to its stroke, the generated force changes. It is necessary to keep the amount of deflection at the center of the screw cover 9 small so that the beam 3 is not blocked during the maximum stroke, so taking this into consideration,
A high initial setting pressure is applied to the screw cover 9.

In other words, when the screw cover 9 is contracted the most, the maximum reaction force will be applied to the mirror holder 12, but if the inner diameter is 60M11. Taking a screw cover with a stroke of about 1 m as an example, the maximum reaction force reaches about 2 kg, which is a value that cannot be ignored as an external force applied to the mirror holder 12.

As the stroke becomes longer, the amount of deflection at the center increases, so the reaction force becomes even larger.

The problem is that this reaction force fluctuates while the mirror 6 is moving, and installing a strong mirror holder 12 on the gantry 7 is an essential condition to suppress the angular fluctuation of the mirror 5. The actual situation is that the gantry 7 has a control structure and cannot have sufficient mechanical strength.

On the other hand, in the structure shown in FIG. 3, one end of the guide rod 10 is fixed to the entire mirror holder 12.

In this case, the bellows 11 as a beam cover is made of non-combustible cloth, so the force generated as it expands and contracts is very small and does not pose a problem as in the case of the screw cover 9, but the bellows 11 A guide rod 10 and a guide plate 12 are required to ensure straightness.

In this structure, there is no problem in normal use, but when the position of the beam 3 is readjusted or the mounting position of the mirror 5 is shifted, it becomes necessary to shift the entire mirror holder 12.

However, since one end of the guide rod 1o is fixed to the mirror holder 12, it is necessary to adjust the other end of the guide rod 1o to readjust the length.

This means that the tensile force F applied to the mirror holder 12 by the guide rod 10 changes before and after adjustment, and it becomes necessary to readjust the entire angle of the mirror 5. If the position shifts during use, the time and effort required for readjustment will be significantly greater than in the case shown in FIG. 3a.

Therefore, the present invention seeks to improve long-term reliability by eliminating the external force applied to the mirror holder during beam movement, and also to improve work efficiency during beam position adjustment.

Means for solving the problems and technical means of the present invention for solving all the above problems are:
In particular, the mirror holder and a portion of the beam cover are connected by a cylindrical body that is expandable and retractable in the optical axis direction.

action The effect of this technical means is as follows.

With the above configuration, the fluctuating load on the part of the beam cover is not directly transmitted to the mirror holder, and even when adjusting the beam position, the part of the beam cover and the mirror holder can each be adjusted independently. Work efficiency will be greatly improved.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. Although FIG. 1 shows the case where a screw cover 9 is used, it is of course possible to replace it with a bellows body.

The screw cover holding base 13 is separated from the mirror holder 12, and each is directly fixed to the gantry. Between the two is a pipe 16 freely supported by an O-ring 14.
is provided to function as a safety cover with a dustproof effect for the beam 3, and also to mirror the axial force generated when the screw cover (cylindrical body) 9, which can be expanded and contracted in the optical axis direction, expands and contracts. It is arranged so that it is not transmitted to the holder 12.

The pipe portion of this free support structure can also be replaced with a bellows structure to provide the same function.

Furthermore, when adjusting the position of the beam 3, it is sufficient to readjust the mirror holder 12 alone in response to a positional shift of the mirror 6. This is because the screw cover 9 or bellows of the beam cover has a large internal dimension with respect to the diameter of the beam 3, and the displacement caused by adjusting the mirror holder 12 is absorbed by the intermediate pipe 16. .

Therefore, the working time required to readjust the position of the beam 3 can be significantly shortened compared to the conventional structure.

Effects of the Invention As mentioned above, the present invention is effective in stabilizing the mirror holding during long-term use, that is, in preventing beam position fluctuations, and has the advantage that only a portion of the mirror needs to be adjusted when making adjustments. . In addition, the following effects are also achieved.

(1) It becomes possible to design a beam cover that is not restricted by the dimensions of the mirror holder, increasing the degree of freedom.

(2) Since the external force caused by expansion and contraction of the beam cover can be ignored, the mirror holder can be made smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view of a folding mirror of a laser processing device showing an embodiment of the present invention; FIG. 1 is a side view of the same;
Figures 2a and 2b are a plan view and a front view of a double-axis beam moving type laser processing device, Figures 2c and d are a plan view and a front view of a single-axis beam moving type laser processing unit, and Figure 3a is a conventional FIG. 3 is a partially cutaway front view of a part of the folding mirror in the laser processing apparatus, and FIG. 3 is a side view of the same. 3...Beam, 6...Reflection mirror, 7
... Gantry, 9 ... Screw cover, 11 ... Bellows, 12 ... Mirror holder, 13 ... Screw cover holding base, 16 ······pipe. Name of agent: Patent attorney Toshio Nakao (1st person)
figure

Claims (1)

[Claims] A mirror holder for holding the movable mirror in a beam movable laser processing device that guides a beam output from an oscillator to a predetermined position using a movable mirror and irradiates a workpiece with the beam focused by a condensing device. and a beam cover that protects the beam path are connected by a cylindrical body that is expandable and retractable in the optical axis direction.