JP2897512B2 - Processing torch for laser processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus torch for improving the processing yield such as cutting and drilling of a workpiece and stabilizing the quality.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a laser processing apparatus to prevent the occurrence of processing directionality in cutting, thereby improving processing yield and stabilizing quality.

[0003] A conventional laser processing apparatus will be described below. FIG. 2 shows a configuration of a conventional laser processing apparatus. In FIG. 2, 1 is a numerical control device, 2 is a laser oscillator, 3 is a laser light guide, 4 is a bending mirror, 5 is a condenser lens, 6 is a processing torch, 6A is a condenser lens mount, 6A
B is an auxiliary gas inlet, 7 is an auxiliary gas cylinder, 7A is an auxiliary gas pipe, 8 is a workpiece, 9 is a processing table, and 9A is a sword mountain which supports the workpiece. Reference numeral 10 denotes a laser output command signal for determining the laser output, and reference numeral 11 denotes a processing table command signal for determining the movement of the processing table.

[0004] With respect to the laser processing apparatus constituted by the above components, the relationship and operation of the components will be described below. The laser light emitted from the laser oscillator 2 passes through the laser light guide 3, and the optical axis is turned to the direction of the condenser lens 5 by the bending mirror 4 provided on the way to be incident on the condenser lens 5 and condensed. Irradiate the workpiece 8 placed substantially near the focal point of the condenser lens 5. The workpiece 8 is placed on the workpiece supporting blade 9A on the processing table 9, and the workpiece 8 is moved by moving the processing table 9. The processing torch 6 narrows the inner diameter of the processing torch 6 as it approaches the workpiece 8 between the condenser lens 5 and the workpiece 8, and blows auxiliary gas onto the laser-irradiated portion of the workpiece 8 coaxially with the collected laser light. The processing torch 6 has a cylindrical shape larger than the outer diameter of the condensing lens 5, and has an auxiliary gas introduction section substantially perpendicular to the side surface. The numerical control device 1 which has input cutting conditions such as a processing shape and a laser output, a moving speed of the workpiece 8 and a height of the processing torch 6 with respect to the workpiece 8 outputs a laser output command signal 10 as a laser output, The servo command signal 11 is sent to the processing table 9 in accordance with the processing shape and the moving speed, and the workpiece 8 on the processing table 9 is moved to process into a required shape.

[0005]

However, in the above-mentioned conventional configuration, the purpose of the auxiliary gas in the laser processing apparatus generally used for cutting and drilling mild steel sheets is to process the workpiece melted by the heat of the laser beam. It may be blown off to the opposite side of the laser beam irradiation surface by the jet of the auxiliary gas. But,
As shown in FIG. 3, the flow of the auxiliary gas in the processing torch 6 is different from the opening diameter of the auxiliary gas introduction port 6B.
Since the inner diameter is sufficiently large, if the angle at which the auxiliary gas enters the processing torch 6 deviates from the center axis of the processing torch 6 by at least 90 degrees, a swirling flow occurs around the optical axis in the processing torch 6 and the processing torch 6 The swirling flow is maintained along the taper at the tip 6, and the jet of the auxiliary gas making a swirling motion hits the surface of the workpiece 8. At the time of cutting, the surface where the turning direction of the auxiliary gas jet and the cutting direction coincide with each other is strongly hit by the auxiliary gas, so that the cut surface is hollowed out. However, there is a problem that the quality of the cut surface becomes directional.

The present invention solves the above-mentioned conventional problems. An auxiliary gas blown to a workpiece flows in parallel to an optical axis without rotating, thereby preventing generation of a processing direction and improving a processing yield. It is an object of the present invention to provide a processing torch of a laser processing apparatus that stabilizes quality.

[0007]

In order to achieve this object, a processing torch of a laser processing apparatus according to the present invention has a diameter near the same height as an auxiliary gas inlet, which is intermediate between the inner diameter of the processing torch and the outer diameter of the laser beam. The working torch inner cylinder is provided concentrically with the working torch and the laser beam. A hole or a cutout gas vent is opened in the side of the converging lens mount and the joint end of the processing torch inner cylinder, a wire mesh is stretched, and a corrugated plate extending in a direction parallel to a laser optical axis is formed on the inner surface of the processing torch cylinder. It has a configuration in which a current plate is fitted.

[0008]

In this configuration, the auxiliary gas entering from the introduction portion flows along the outer wall of the inner cylinder of the torch in the processing torch, and enters a place through which a laser beam passes through the inner cylinder of the torch through a gas vent. At this time, the gas stream passing through the wire mesh is finely stirred and becomes turbulent. In the processing torch inner cylinder, the auxiliary gas is swept away by the pressure difference between the opening at the tip of the processing torch and the auxiliary gas source pressure, but is again streamlined by a straightening plate provided in parallel along the optical axis of the processing torch inner cylinder inner surface. Is machined in parallel with the optical axis to spray on the workpiece.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. The same components as those in the conventional example are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG.
Is a processing torch inner cylinder, 12a is a gas vent, 13 is a wire mesh, and 14 is a current plate. The processing torch 6 has a condensing lens mount 6A having a built-in condensing lens 5 at the upper end, and has a tapered shape at the lower end, and an opening at the tip is a hole having a diameter several times the diameter of the condensed beam. A processing torch inner cylinder 12 is attached to the lower side of the condenser lens mount 6A, and the lower end thereof reaches a tapered portion at the tip of the processing torch 6, and the upper and lower condenser lens mounts 6A and the processing torch inner cylinder 12 are processed. The space between the torch 6 and the tapered portion is tightly closed and airtight. The joint between the inner cylinder of the processing torch 12 and the lens mount 6A has a gas vent port 12A for degassing, which is divided into four equal to about 1/4 of the outer peripheral surface of the inner cylinder of the processing torch 12, and a wire mesh 13 is attached. You. The rectifying plate 14 is a corrugated plate having an uneven step substantially equal to the difference between the inner diameter of the processing torch inner cylinder 12 and the opening diameter of the condenser lens mount 6A. Over the length up to the joint, the concave and convex grooves are rounded so as to be parallel to the optical axis and fitted into the inner surface of the processing torch inner cylinder 12. Although not shown in the figure, other components are the same as the conventional example.

The operation of the laser torch configured as described above will be described with reference to FIG. The laser light emitted from the laser oscillator is incident on the condenser lens 5 and is condensed. The laser light is irradiated on a workpiece placed near the focal point of the condenser lens 5 for processing. The auxiliary gas entered from the auxiliary gas inlet 6B flows along the outer wall of the inner cylinder 12 of the processing torch,
The laser beam enters the processing torch inner cylinder 12 through the gas vent port 12A at the upper end. At this time, the gas stream lines passing through the wire mesh 13 are finely stirred and become turbulent. The auxiliary gas is swept away inside the processing torch inner cylinder 12 by the pressure difference between the opening at the tip of the processing torch 6 and the auxiliary gas source pressure.
Since the flow is made to flow along the irregularities of the current plate 14 on the inner surface of the inner cylinder 12 of the processing torch, the stream lines can be arranged parallel to the optical axis.

As described above, according to the present embodiment, since the auxiliary gas can be blown onto the workpiece while being formed into a jet flow parallel to the optical axis, the processing can be performed. In addition, the processing yield can be improved and the quality can be stabilized.

[0012]

As is clear from the above description of the embodiment, the present invention can always blow an auxiliary gas jet parallel to the optical axis from a processing torch to a workpiece, thereby preventing generation of directionality at the time of cutting. As a result, an excellent processing torch of a laser processing apparatus capable of improving the processing yield and stabilizing the quality can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view of a processing torch of a laser processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing the concept of a conventional laser processing apparatus.

FIG. 3 is a sectional view of the processing torch.

[Explanation of symbols]

 Reference Signs List 6 Processing torch 6A Condenser lens mount 6B Auxiliary gas inlet 12 Processing torch inner cylinder 12a Gas vent 13 Wire mesh 14 Rectifier plate

Claims (1)

(57) [Claims] 1. A processing torch inner cylinder having a diameter larger than a laser beam outer diameter is provided on a concentric circle with the outer wall of the processing torch and a laser optical axis near the same height as an auxiliary gas inlet in the processing torch;
A gas flow opening is formed at the joint of the processing torch inner cylinder with the condenser lens mount, a wire mesh is stretched, and a rectifying plate in which irregularities extending in a direction parallel to the laser optical axis are uniformly arranged on the inner surface of the processing torch inner cylinder. A processing torch of a laser processing device provided.