JPH03198993A - Laser beam machining nozzle - Google Patents

Abstract

PURPOSE:To improve the durability of a nozzle by providing an insulating layer to insulate electrically a sensor from a nozzle main body on the tip of the nozzle main body of an electrically conductive member. CONSTITUTION:A nozzle hole 8 through which a laser beam L passes is formed on the nozzle main body 5. The electrostatic capacity type sensor 11 to detect under noncontact the distance (g) with a work 17 to be machined by the laser beam L is provided on the tip of the nozzle main body. The nozzle main body 5 is then formed of the electrically conductive member and the insulating layer 9 to insulate electrically the sensor 11 from the nozzle main body 5 is provided on the tip thereof. By this method, the nozzle main body can be miniaturized.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is directed to a laser processing device that is equipped with a capacitive sensor at its tip for non-contact measurement of the distance to a workpiece. Regarding nozzles.

(Prior Art) For example, when laser processing such as cutting is performed using a laser beam, a laser processing nozzle is provided at the tip of an arm of a two-dimensional laser processing machine or a three-dimensional laser processing machine. A nozzle hole is formed in this laser processing nozzle, and assist gas flows out toward the workpiece from this nozzle hole, and laser light passes through the nozzle hole. When using such a nozzle, it is important to maintain a constant distance between the workpiece and the nozzle tip in order to suppress variations in processing conditions.

In order to keep the distance between the workpiece and the nozzle tip constant, a capacitive sensor is installed at the tip of the nozzle, and this sensor measures the distance between the workpiece and the nozzle without contact. Based on this, these distances are maintained constant. In order to provide a capacitive sensor at the tip of the nozzle, this sensor must be provided electrically insulated from the nozzle.

Conventionally, in order to electrically insulate the sensor into the nozzle,
As shown in FIG. 4, an insulating member made of ceramic is provided at the tip of the nozzle body a, and the sensor C
I was trying to attach it.

However, if ceramics are used for the insulating material,
If an impact is applied directly to the insulating member or indirectly through the sensor C, the insulating member is likely to be damaged.

In order to make the insulating member less likely to be damaged by impact, it is necessary to increase the size of the insulating member to a certain extent to give it strength, but this would increase the size of the entire nozzle. In particular, in three-dimensional laser processing machines, the movement of the arm equipped with the nozzle becomes complicated.
Since there is a high probability that the nozzle will be damaged by colliding with a workpiece, it is desired to downsize the nozzle in order to reduce collisions with the workpiece and improve the durability of the nozzle.

(Problems to be Solved by the Invention) As described above, conventional laser processing nozzles have used ceramics to insulate the nozzle body and the sensor attached to the tip of the nozzle body. Therefore, if an impact is applied, the product may be damaged, and in order to provide strength against impact, the nozzle must be made larger.

This invention was made based on the above circumstances, and its purpose is to provide a nozzle for laser processing that can improve durability without increasing the size of the nozzle body. It's about doing.

[Structure of the Invention] (Means and Effects for Solving the Problems) In order to solve the above problems, the present invention provides processing using the laser beam at the tip of the nozzle body in which the nozzle hole through which the laser beam passes is formed. In a laser processing nozzle that is equipped with a capacitive sensor that detects the distance to the workpiece without contact, the nozzle body is made of a conductive member, and the tip of the nozzle body includes the sensor and the nozzle. An insulating layer is provided to electrically insulate the device from the main body.

According to such a configuration, the film-like insulating layer is not only less likely to be damaged by impact than an insulating member made of ceramics, but also can be made sufficiently thin, so that it is not necessary to increase the size of the nozzle body. Nor.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 3 shows a three-dimensional laser processing machine 1. As shown in FIG. This laser processing machine 1 has a holder 2, and this holder 2 is moved xly by a drive unit 3.

It is designed to be driven in the Z direction (three-dimensional direction).

A nozzle 4 is held in the holder 2.

This nozzle 4 consists of a nozzle body 5 made of a conductive member, for example a metal such as stainless steel or copper. As shown in FIG. 1, a lens 6 for focusing laser light is held inside the nozzle body 5, and an assist gas supply vibrator 7 is connected to the peripheral wall. Furthermore, a nozzle hole 8 is formed at the tip of the nozzle body 5, through which the laser beam focused by the lens 6 passes, and through which assist gas from the supply vibrator 7 flows out.

The tip of the nozzle body 5 is formed into a tapered portion 5a whose diameter becomes smaller toward the tip, and an insulating layer 9 is coated in the form of a film on the inner surface and surface of the tip. This insulating layer 9 is made of, for example, polyimide resin, which is an electrically insulating material with excellent heat resistance, and is applied to the tip of the nozzle body 5 by dip treatment or the like.
It is prepared by heat treatment at around 0°C for about 1 hour.

A capacitive sensor 11 is provided at the tip of the nozzle body 5.
is provided. This sensor 11 includes a funnel part 12 having a shape corresponding to the inner peripheral surface of the tapered part 5a of the nozzle body 5, and a ring part 13 fitted into a cylindrical part 12a formed at the tip of the funnel part 12. Become. And sensor 11
In this case, the funnel portion 12 is inserted into the tapered portion a of the nozzle body 5, and the cylindrical portion 12a formed at the tip thereof is made to protrude from the nozzle hole 8. The ring portion 1 is connected to the portion of the cylindrical portion 12a that protrudes from the nozzle hole 8 through a buffer member 14 made of a material such as Teflon and having heat resistance and elasticity.
3 are fitted together, and the ring portion 13 and the cylindrical portion 12a are laser welded to be integrated and attached to the nozzle body 5. As a result, although the insulating layer 9 is interposed between the sensor 11 and the nozzle body 5,
The sensor 11 is electrically insulated from the nozzle body 5.

A sensor amplifier 16 is connected to the sensor 11 through a first lead wire 15 . A measurement signal corresponding to the distance g from the workpiece 17 detected by the sensor 11 is input to the sensor amplifier 16.

A control section 19 is connected to this sensor amplifier 16 via a second lead wire 18 . This control section 19 is configured to drive and control the drive section 3 in the vertical direction according to the measurement signal from the sensor 11.

In this way, the film-like insulating layer 9 is used to electrically insulate the nozzle body 5 of the nozzle 4 from the sensor 11 attached to the tip of the nozzle body 5.

This insulating layer 9 can be made very thin, so that ceramics can be used to connect the nozzle body 5 and the sensor 1.
1, the nozzle body 5 can be made smaller in size. If the nozzle body 5 is made smaller, the probability of collision with the workpiece 17 can be reduced when three-dimensional movement is required, thereby improving the durability of the nozzle body 50. Not only can it be measured, but it can also be handled as a product.

Furthermore, the insulating layer 9 does not reduce the durability of the nozzle body 5 unlike when ceramics are used.

Note that the present invention is not limited to the above-mentioned embodiment, and can be modified without departing from the spirit thereof. For example, in the above embodiment, a polyimide film was used as the insulating film, but the nozzle body is formed of aluminum, and at least the part at the tip where the sensor is attached is provided with a hard anodic oxide film, which is an insulating film, by alumite treatment. You can do it like this.

Further, in the above embodiment, a buffer member is interposed between the tip end surface of the nozzle body and the sensor to absorb the shock applied to the sensor, but this buffer member may not be used.

[Effects of the Invention] As described above, in the present invention, an insulating layer for electrically insulating the sensor and the nozzle body is provided at the tip of the nozzle body made of a conductive member. Since the insulating layer can be made sufficiently thin, the nozzle body can not only be made smaller compared to the conventional nozzle body using ceramics, but also its durability can be improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a nozzle showing an embodiment of the present invention;
FIG. 2 is an exploded sectional view of the sensor, FIG. 3 is a schematic configuration diagram of a three-dimensional laser processing machine, and FIG. 4 is a sectional view of the tip of a conventional nozzle. 5... Nozzle body, 8... Nozzle hole, 9... Insulating layer, 11... Sensor, 17... Work.

Claims (1)

[Claims] In a laser processing nozzle, a capacitive sensor is provided at the tip of a nozzle body in which a nozzle hole through which a laser beam passes is formed, and a capacitance sensor that non-contact detects the distance to a workpiece to be processed by the laser beam. . A nozzle for laser processing, characterized in that the nozzle body is made of a conductive member, and an insulating layer is provided at the tip of the nozzle body to electrically insulate the sensor and the nozzle body.