JP4148106B2 - Laser oscillation device and laser processing machine - Google Patents

Description

  The present invention relates to a laser oscillation device using a centrifugal blower and a laser processing machine.

  In recent years, laser oscillators and laser processing machines have been put to practical use for cutting and welding of various materials and shapes because of the feature that workpieces can be processed in a non-contact manner and with little thermal influence. It is increasing.

  Conventionally, a gas laser blower as shown in FIG. 5 has been used.

  Hereinafter, description will be given with reference to the drawings.

  The gas laser blower 100 is installed vertically, and laser gas is sucked in from an upstream cooler (not shown) through a circulation path as indicated by an arrow 59, and divided into two directions as indicated by an arrow 80 and discharged in a centrifugal direction. The

  The shaft 52 supports the rotation of the impeller 51 of the housing (circulation path side casing) 58, and both are mechanically coupled to each other by nuts. A rotor 53 is fixed to the shaft 52 by shrink fitting along the outer periphery thereof. A stator 54 is provided outside the rotor 53.

  The bearing 55 is provided in a communication hole 121 a formed in the partition wall 121 between the housing 57 and the housing 58. Reference numeral 50 denotes an oil passage.

  This is shown in more detail in FIG. 6, which will be described.

In FIG. 6, an intermediate member 66 is inserted into the shaft 52, and two grooves 651 and 652 are formed as annular grooves in the intermediate member 66.
The partition wall 121 includes a bearing holder 60 to which the bearing 55 is attached and a ring holder 63 to which the ring 64 is attached. Two rings 641 and 642 are inserted as ring members 64 on the inner periphery of the ring holder 63.

  Reference numeral 55 denotes a bearing, 501 denotes an inner ring of the bearing 55, 60 denotes a bearing holder, 60a denotes a path formed in the bearing holder 60, 61 denotes a bearing cover, 62 denotes a discharge path, 63 denotes a ring holder, and 63a denotes a ring. A path 65 formed in the holder 63 is an annular groove (see, for example, Patent Document 1).

  The ring member 64 is made of a sintered stainless steel. This is for the purpose of ensuring corrosion resistance and wear resistance, like the intermediate member 66.

  FIG. 7 shows an example of a schematic configuration of another conventional laser oscillation apparatus.

  Hereinafter, a conventional laser oscillation apparatus will be described with reference to FIG.

In this figure, 1 is a discharge tube made of a dielectric material such as glass, and 2 and 3 are electrodes provided around the discharge tube 1. Reference numeral 4 denotes a power source connected to the electrodes 2 and 3. Reference numeral 5 denotes a discharge space in the discharge tube 1 sandwiched between the electrodes 2 and 3. 6 is a total reflection mirror, and 7 is a partial reflection mirror. Reference numeral 8 denotes a laser beam output from the partial reflection mirror 7.

  An arrow 9 indicates the direction in which the laser gas flows. Reference numeral 10 denotes a laser gas flow path, reference numerals 11 and 12 denote heat exchangers for lowering the temperature of the laser gas whose temperature has been raised by the discharge in the discharge space 5 and the operation of the centrifugal blower, and reference numeral 13 denotes a blowing means for circulating the laser gas. The laser gas flow path 10 and the discharge tube 1 are connected by a laser gas introduction part 14.

  FIG. 8 shows an example of a schematic configuration of a conventional laser processing machine. Hereinafter, a conventional laser beam machine will be described with reference to FIG.

  In this figure, 49 is a gas laser oscillation device, and the laser beam 8 outputted therefrom is reflected by the reflecting mirror 15 and guided to the vicinity of the workpiece 16. The laser beam 8 is condensed into a high-density energy beam by a condensing lens 18 provided inside the torch 17, irradiated onto the workpiece 16, and processed. The workpiece 16 is fixed on the machining table 19, and the torch 17 is moved relative to the workpiece 16 by the X-axis motor 20 or the Y-axis motor 21, whereby a predetermined shape is machined.

  FIG. 9 shows the structure around the centrifugal blower in the laser oscillation device.

  In the centrifugal fan, the motor stator 22b is disposed on the lower side of the centrifugal blower, and the motor rotor 22a is disposed in the vertical direction with respect to the gravity direction. An impeller 23 and a diffuser 24 are provided at the tip of a shaft 29 coupled to the motor rotor 22a.

  The laser gas is sucked from the suction port 25 from above in the direction of gravity, given kinetic energy by the centrifugal force generated by the rotation of the impeller 23, and then the kinetic energy is converted into pressure by the diffuser 24. Also, the gas having a pressure of about 1.5 times is discharged from the discharge port 26.

  Oil 27 is accommodated in the casing 31 portion in which the motor at the lower part of the blower is accommodated to lubricate the bearing 28 and cool the motor rotor 22a. When oil mist generated from this oil enters the laser gas circulated by the impeller, the purity of the laser gas is lowered, causing a major problem in laser oscillation.

  Therefore, in order to suppress the oil mist from entering the laser gas circulation portion, the partition wall portion 30 is provided to separate the motor chamber 34 and the gas circulation chamber 35 from each other. A gap of several tens to several hundreds of μm is provided between the partition wall and the shaft so that the rotation of the shaft is not hindered.

  As described above, since there is a gap of several tens to several hundreds of μm in the partition wall, oil mist enters the gas circulation chamber from the motor chamber through the gap due to vacuum diffusion. In order to prevent this, the vacuum pump 32 always exhausts a certain amount of gas from the motor chamber, and the motor chamber has a lower pressure than the gas circulation chamber. An electromagnetic valve 33 is provided between the motor chamber and the vacuum pump, and is opened and closed as necessary.

The detailed structure of the partition wall is shown in FIG. A gap of several tens to several hundreds of μm is provided between the shaft 29 and the metal seal 36, and a constant amount of laser gas always flows through the gap. This constantly flowing laser gas can prevent oil mist from entering the gas circulation chamber 35 from the motor chamber 34.
JP-A-8-335731 (pages 3-6, FIGS. 1 and 3)

  In the above-described conventional laser apparatus and laser processing machine, the laser gas flowing through the gap between the shaft 29 and the metal seal 36 is exhausted as it is from the vacuum pump, and the exhausted laser gas is separately provided in a separate system. Needs to be supplied to the gas circulation chamber. This is a consumption amount of laser gas per unit time in the laser oscillation device and the laser processing machine, and occupies a large weight of running cost.

  Therefore, how to reduce the amount of laser gas consumed per unit time has been a major issue in reducing running costs.

  An object of the present invention is to provide a laser oscillation apparatus and a laser processing machine apparatus that are particularly low in running cost by suppressing gas consumption and highly reliable.

In order to solve the above problems, a laser oscillation device of the present invention forms a discharge means for exciting a laser medium, a blower means for blowing laser gas, and a circulation path for laser gas between the discharge means and the blower means. A laser gas path, and the air blowing means includes a shaft portion provided with an impeller portion at a tip thereof, a driving portion that rotates the shaft portion, and a partition portion that separates the impeller portion and the driving portion, The shaft portion in the vicinity of the partition wall is provided with a groove, and the groove shape is formed by a spiral shape or an oblique groove , and the groove pitch of the shaft portion is rough, dense, rough from the impeller portion to the drive portion. changing, also, the groove pitch of the shaft portion is coarse toward the driver from the impeller part, dense, rough and Ru varied.

  The laser processing machine of the present invention includes a processing table on which a processing work is placed, a driving means for moving at least one of the movement of the processing table and the laser processing torch, a numerical control device for controlling the driving means, and a laser beam. And the above-mentioned laser oscillation device for generating the above.

  With the above configuration, the present invention can spontaneously produce the flow of the laser gas in the partition wall with a compressing action, and in particular, can reduce the running cost by suppressing the gas consumption and obtain a highly reliable apparatus.

(Embodiment)
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing an embodiment of the present invention.

  In this figure, 1 is a discharge tube made of a dielectric material such as glass, and 2 and 3 are electrodes provided around the discharge tube 1. Reference numeral 4 denotes a power source connected to the electrodes 2 and 3. Reference numeral 5 denotes a discharge space in the discharge tube 1 sandwiched between the electrodes 2 and 3. 6 is a total reflection mirror, and 7 is a partial reflection mirror. Reference numeral 8 denotes a laser beam output from the partial reflection mirror 7.

  An arrow 9 indicates the direction in which the laser gas flows. Reference numeral 10 denotes a laser gas flow path, reference numerals 11 and 12 denote a heat exchanger for lowering the temperature of the laser gas whose temperature has risen due to discharge in the discharge space 5 and the operation of the centrifugal fan, and reference numeral 43 denotes a centrifugal fan for circulating the laser gas. The laser gas flow path 10 and the discharge tube 1 are connected by a laser gas introduction part 14.

  Here, since it is the same as that of what was demonstrated by background art except the centrifugal blower 43, it demonstrates with reference to FIG. 2 centering on this centrifugal blower 43 here.

  FIG. 2 shows a detailed drawing of the metal seal 36 and the shaft portion 29 of the partition wall in the centrifugal blower 43.

  The shaft portion 29 is provided with a spiral groove 37a in the vicinity of the partition wall portion, and at least one of the metal seal 36 in the partition wall portion in the vicinity of the shaft portion 29 and the shaft portion 29 in the vicinity of the metal seal 36 in the partition wall portion has a tapered shape. In addition, an auxiliary impeller 38 is provided in the vicinity of the partition on the drive unit side.

  The width of the spiral groove 37a provided in the shaft portion 29 is changed from wide to narrow and wide from the impeller portion to the driving portion. Further, this width may be narrowed from the impeller portion toward the drive portion.

  The taper shape provided in the metal seal 36 and the shaft portion 29 is configured such that the taper angle widens from the impeller portion toward the drive portion.

  Further, the groove pitch of the shaft portion 29 is changed from rough, dense, and rough toward the drive portion from the impeller portion.

  The operation of the partition wall configured as described above will be described.

  When the shaft 29 rotates, the laser gas flows along the spiral groove 37a. In this embodiment, since the width of the groove 37 is wide on the impeller portion side, the surrounding laser gas can be easily caught by the groove, and the width of the groove 37a is made narrow near the center of the partition wall portion, so that the captured laser gas can be reduced. Once compressed, the width of the groove 37a on the drive unit side is widened again to expand the compressed laser gas. As a result, a smooth laser gas flow from the impeller unit to the drive unit is obtained. .

  Further, the centrifugal force generated by the rotation of the shaft 29 due to the taper shape provided on the metal seal 36 and the shaft portion 29 is applied to the centrifugal force generated by the rotation of the shaft 29 due to the viscosity of the laser gas. Since it becomes larger as it goes from the impeller portion to the drive portion, it has an effect of generating and increasing the flow of the laser gas.

  The auxiliary impeller 38 provided in the vicinity of the drive unit side partition is disposed so as to generate a flow of laser gas in the direction from the impeller to the drive unit with respect to the rotation direction of the shaft 29. The pressure becomes lower than the surroundings due to the flow of the laser gas. The local low pressure in the vicinity of the auxiliary impeller 38 generates and increases the flow of the laser gas that passes through the partition wall.

  The shape of the groove 37a of the shaft portion 29 may be a groove 37b formed obliquely as shown in FIG.

  The flow rate of the laser gas passing through the partition wall can be set to a desired laser gas amount by setting the groove shape, taper shape, and auxiliary impeller performance.

  By the above operation, it becomes possible to spontaneously generate a flow of laser gas passing through the partition wall. In order to prevent the oil mist from entering the gas circulation chamber from the motor chamber because the laser gas compression and the generation of local low pressure near the auxiliary impeller are used in the process of generating the laser gas flow. The required flow rate of the laser gas can be reduced as compared with the conventional technique.

  Next, the laser processing machine will be described with reference to FIG.

In this figure, reference numeral 45 denotes a gas laser oscillator, which is the laser oscillator described above, and the laser beam 8 outputted therefrom is reflected by the reflecting mirror 15 and guided to the vicinity of the workpiece 16. The laser beam 8 is condensed into a high-density energy beam by a condensing lens 18 provided inside the torch 17, irradiated onto the workpiece 16, and processed. The workpiece 16 is fixed on the machining table 19, and the torch 17 is moved relative to the workpiece 16 by the X-axis motor 20 or the Y-axis motor 21, whereby a predetermined shape is machined.

  As described above, the machining table 19 on which the machining workpiece 16 is placed, the drive means such as the X-axis motor 20 and the Y-axis motor 21 that move at least one of the movement of the machining table 19 and the laser machining torch 17, and the drive means are controlled. By configuring each laser oscillation device in the above-described embodiment in a numerical control device (not shown) that performs the laser beam 8 passing through the condenser lens 18 and a laser processing machine that generates a laser, A reliable laser processing machine that can reduce running costs by suppressing consumption and can be used stably over a long period of time can be obtained.

  The laser oscillation device and laser processing machine according to the present invention can provide a highly reliable device that can be used stably over a long period of time, especially by reducing running costs by suppressing gas consumption.

Explanatory drawing of the laser oscillation apparatus in embodiment of this invention Explanatory drawing of the partition part of the laser oscillation apparatus in the same embodiment Explanatory drawing when the shaft groove shape in the embodiment is an oblique groove Explanatory drawing of the laser beam machine in the same embodiment Illustration of a conventional laser oscillation device Detailed explanatory diagram of a conventional laser oscillation device Explanatory drawing of other conventional laser oscillation devices Illustration of a conventional laser processing machine Structural diagram of centrifugal blower unit in general laser oscillator Explanatory drawing of the partition part in the conventional laser oscillation apparatus

Explanation of symbols

9 Laser gas flow direction 10 Laser gas flow path 15 Reflector 16 Work 17 Torch 18 Condensing lens 19 Processing table 20 X-axis motor 21 Y-axis motor 29 Shaft part 30, 30a, 30b Partition part 36 Metal seal 37a, 37b Groove 38 Auxiliary Impeller 43 Centrifugal blower 45 Gas laser oscillator

Claims (5)

Discharge means for exciting a laser medium, blower means for blowing laser gas, and a laser gas path forming a laser gas circulation path between the discharge means and the blower means, wherein the blower means has an impeller portion at the tip. A shaft portion provided, a driving portion for rotating the shaft portion, a partition portion for separating the impeller portion and the driving portion, and a spiral groove or an obliquely formed shape in the shaft portion near the partition portion And the width of the groove shape of the shaft portion is changed from wide to narrow to wide from the impeller portion to the drive portion . Discharge means for exciting a laser medium, blower means for blowing laser gas, and a laser gas path that forms a circulation path of laser gas between the discharge means and the blower means, and the blower means has an impeller portion at the tip. A shaft portion provided, a driving portion for rotating the shaft portion, a partition portion for separating the impeller portion and the driving portion, and a spiral groove or an obliquely formed shape in the shaft portion near the partition portion A laser oscillation device in which the groove pitch of the shaft portion is changed from coarse to dense to coarse from the impeller portion to the drive portion . 3. The laser oscillation device according to claim 1 , wherein at least one of the partition wall near the shaft and the shaft near the partition is tapered . 4. The laser oscillation apparatus according to claim 1, further comprising an auxiliary impeller near the partition wall . 5. A machining table on which a workpiece is placed, drive means for moving at least one of the movement of the machining table and a laser machining torch, a numerical controller for controlling the drive means, and laser light generation. A laser processing machine comprising the laser oscillation device according to claim 1 .

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