JPH0242309B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a mixed gas supply device for laser processing that supplies a mixed gas to a processing portion of a workpiece together with laser light during processing such as laser welding and cutting.

[Technical background of the invention and its problems]

When welding or cutting workpieces made of steel or the like using laser light, this is usually done while supplying shield gas (welding) or assist gas (cutting) to the processing area. Conventionally, for laser welding of steel, He or Ar is used as the shielding gas.
For laser cutting, O ₂ gas was used solely as an assist gas. However, instead of this single gas, during laser welding,
It is known that using a gas mixture of He and Ar at 10% increases the penetration of the weld, and similarly, using a gas mixture of He and H ₂ increases the penetration of the weld. It is being Also, in laser cutting, if a gas mixture of O ₂ and a small amount of H ₂ is used,
It is known that cutting characteristics are improved.

However, when using such a mixed gas, it is effective to change the mixing ratio depending on the material, plate thickness, etc. of the workpiece in order to properly weld and cut the gas. Therefore, in laser processing using this mixed gas, as shown in FIG.
This cylinder 1 is connected to and supplied to a processing head 2.

However, if the cylinder 1 is filled with a gas mixture mixed at a predetermined ratio and supplied, many types of cylinders with different mixing ratios can be prepared in response to changes in the material, plate thickness, etc. of the workpiece W. This results in a lot of waste in terms of space and productivity.

[Purpose of the invention]

An object of the present invention is to enable a gas mixture in a required ratio to be easily supplied without preparing many types of cylinders in laser processing using a gas mixture as a shielding gas or an assist gas.

[Summary of the invention]

Two or more gases are introduced into a mixing chamber through a plurality of separate introduction nozzles and mixed uniformly,
The uniform gas mixture mixed in this mixing chamber is supplied from a supply nozzle attached to a cylindrical holder that supports the condenser lens to the processing section of the workpiece along with the laser light focused by the condenser lens. This makes it possible to easily supply the required mixed gas by simply preparing cylinders for several types of component gases required for mixing.

[Embodiments of the invention]

Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

FIG. 1 shows an example of a processing head for performing laser processing using a mixed gas as a shielding gas.
This processing head includes a holder part 10 that supports a condensing lens, a pair of introduction nozzles 11a and 11b attached to this holder part 10, a mixing chamber 12 provided in the holder part 10, and the holder 1.
0 and a supply nozzle 13 coaxially provided at one end of the supply nozzle 13.

The holder section 10 includes a cylindrical body 15 and a cylindrical body 1.
An annular lens support 1 attached to the inside of 5
6, and a condensing lens 17 for condensing laser light emitted from a laser oscillator is attached to this support body 16.

The pair of introduction nozzles 11a and 11b are arranged in parallel and spaced apart from each other in the cylinder 15. In particular, the introduction nozzle 11b arranged at one end of the cylinder 15 is spaced apart from the supply nozzle 13 and A mixing chamber 12 for mixing the gases introduced from each of the introduction nozzles 11a and 11b is formed between the two end surfaces of the two. Further, the introduction nozzle 11a on the condenser lens 17 side is preferably provided apart from the condenser lens 17 as shown in the drawing.

The pair of introduction nozzles 11a and 11b have the same structure, and each has an annular portion formed by combining a pair of annular bodies 20 and 21 to form an annular introduction hole 19. The inner diameter of this annular portion is the laser beam L focused by the condensing lens 17.
It is sized so that it can pass through without being blocked. The annular introduction hole 19 is connected to an introduction pipe 22 passing through the side wall of the cylinder 15, and the gas introduced from the cylinder through the introduction pipe 22 is formed in the pair of annular bodies 20 and 21, The liquid is discharged from annular discharge holes 23 that are inclined obliquely downward with respect to the axis of the cylindrical body 15 and open inside each annular body. Thus, the gas introduced from the introduction nozzle 11a flows into the mixing chamber 12 through the inside of the introduction nozzle 11b, and mixes in the mixing chamber 12 with the gas introduced from the introduction nozzle 11b.

Further, one end of the cylindrical body 15 is covered with an end plate 25 in which an opening having the same diameter as the base end of the supply nozzle 13 attached to this end is formed.
The mixed gas is supplied from the supply nozzle 13 to the processing portion of the workpiece W through the opening in the end plate 25.

The gas supplied to the processing head is supplied to a cylinder 27 filled with each component gas, as shown in FIG.
Pressure gauge 28 provided in the supply path from a, 27b
Then, the flow meter 29 adjusts the valve 30 to provide a predetermined pressure and flow rate, and the mixture is mixed in the mixing chamber 17 at a predetermined ratio.

Therefore, when the machining head is configured as described above, depending on the type of machining, the material and thickness of the workpiece W, the cylinder can be switched and the supplied gas pressure and flow rate can be adjusted for each introduction. Nozzle 11a,
11b, the mixed gas mixed at a predetermined ratio from the supply nozzle 13 is supplied to the workpiece W.
The required gas mixture can be made by simply preparing several types of cylinders filled with the component gases necessary for producing the gas mixture. There is no need to prepare multiple types of cylinders with different mixing ratios. Furthermore, the gases can be sufficiently mixed in the mixing chamber and a uniform gas mixture can be supplied to the processing section of the workpiece W.
In addition, since the annular portions of the introduction nozzles 11a and 11b are provided in the holder portion 10 that supports the condenser lens 17, the condenser lens 17 is prevented from being damaged by flying debris generated during processing.
damage can be reduced.

Next, other embodiments will be described.

In the above embodiment, two types of gas are introduced through a pair of introduction nozzles and mixed in one mixing chamber, but as shown in FIG.
The inside of the chamber is divided by a partition wall 32 having an opening through which the laser beam L focused by the condensing lens 17 passes without being blocked, and the chamber adjacent to the condensing lens 17 is divided by a pair of introduction nozzles 11a, A first mixing chamber 12 into which component gases are introduced from 11b and mixed.
a, the chamber on the nozzle 13 side separated by the partition wall 32 is the second mixing chamber 12b, and the first mixing chamber 1
The gases mixed in step 2a may be further uniformly mixed in second mixing chamber 12b and then supplied to the processing portion of workpiece W from supply nozzle 13.

Further, in the above embodiment, the discharge holes of the pair of introduction nozzles were provided so as to be inclined obliquely downward from the introduction hole, and opened inside each introduction nozzle. However, as shown in FIG. The discharge hole 23 of the introduction nozzle 11a provided on the side is oriented in the same direction as in the first illustrated embodiment, and the discharge hole 23 of the introduction nozzle 11b provided on the emission nozzle 13 side is oriented in the opposite direction to the direction of the converging lens. The first mixing chamber 12 is inserted between the pair of introduction nozzles 11a and 11b so that the
a, the space between the introduction nozzle 11b and the supply nozzle 13 is defined as the second mixing chamber 12b, and each introduction nozzle 11a,
The gas introduced from 11b may be mixed and supplied from the supply nozzle 13 to the processing section of the workpiece.

In addition, in the above embodiment, a method of mixing and supplying two types of gas was described, but this invention
Even when supplying a mixture of two or more types of gas,
It goes without saying that its gist can be easily applied without modification.

〔Effect of the invention〕

Two or more types of gases are introduced into a mixing chamber through a plurality of separate introduction nozzles and mixed uniformly, and the homogeneous gas mixture mixed in the mixing chamber is transferred to a cylindrical holder that supports a condenser lens. Since the supply nozzle attached to the part is supplied to the processing part of the workpiece together with the laser light focused by the condensing lens, all you need to do is prepare the cylinders of the several types of component gases necessary for mixing. The required gas mixture can be easily supplied. Moreover, by providing a mixing chamber and introducing a specially constructed introduction nozzle for introducing gas into the mixing chamber, the gas can be uniformly mixed and supplied to the processing section of the workpiece.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a processing head equipped with a mixed gas supply device for laser processing according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a mixed gas production method, and FIG.
4 and 4 are sectional views of processing heads showing other different embodiments, respectively, and FIG. 5 is an explanatory diagram of a conventional method of supplying a mixed gas for laser processing. 10...Holder part, 11a, 11b...Introduction nozzle, 12...Mixing chamber, 12a...First mixing chamber,
12b...Second mixing chamber, 13...Discharge nozzle, 1
7...Condenser lens, 19...Introduction hole, 22...Introduction tube, 23...Emission hole, 37...Partition wall, L...Laser light, W...Workpiece.

Claims (1)

[Claims] 1. A mixing chamber for mixing two or more gases provided in a cylindrical holder portion that supports a condensing lens that condenses laser light emitted from a laser oscillator, and the condensing lens. and the mixing chamber are arranged in parallel in the holder part, and constitute an annular introduction hole that guides the gas introduced into the mixing chamber, and do not block the laser beam focused by the condenser lens. a plurality of introduction nozzles having an annular portion having an inner diameter to allow the gas to pass through, and a discharge hole for discharging the gas guided into the introduction hole into the mixing chamber; 1. A mixed gas supply device for laser processing, comprising a supply nozzle that supplies a laser beam condensed by a laser beam to a processing section of a workpiece. 2. Claim 1, wherein each discharge hole of the plurality of introduction nozzles is inclined with respect to the axis of the holder part so as to discharge the gas introduced into the annular introduction hole toward the mixing chamber. A mixed gas supply device for laser processing as described in . 3 Among the plurality of introduction nozzles, the discharge hole of the introduction nozzle closest to the mixing chamber is inclined with respect to the axis of the holder part so as to discharge the gas introduced into the annular introduction hole toward the condenser lens, and Claim 1, wherein the discharge hole of the adjacent introduction nozzle is inclined with respect to the axis of the holder part so as to discharge the gas introduced into the annular introduction hole toward the mixing chamber. Mixed gas supply device for laser processing.