JPH07276072A - Optical path protection device of laser working machine - Google Patents

Abstract

PURPOSE:To easily obtain clean air which protects the inside of the optical path of the laser working machine by a small-sized device. CONSTITUTION:The optical path protection device of the laser working machine which protects the inside of the optical path 9 by preventing dust, etc., from entering the optical path 9 by supplying the clean air into the optical path 9 guiding a laser beam to a machining head is provided with an exit-side solenoid valve 8, which is cut off while the laser working machine is at a stop and opened a specific time after operation is started, at the exit side of an air drying means 6. Then the clean air which is discharged when the exit-side solenoid 8 is opened is supplied into the optical path 9. Therefore, the clean air can easily be obtained by the small-sized air drying means 6 which is formed of a hollow thread film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical path protection device for a laser processing machine which prevents dust and the like from entering the optical path due to dry clean air.

[0002]

2. Description of the Related Art In a laser processing machine that heat-processes a work with a laser beam, a large amount of fumes are generated during the work, and the fumes adhere to an optical system such as a mirror or a lens forming an optical path. As a result, the output of the laser beam irradiated to the work from the processing head decreases,
The output distribution changes, which may cause cutting failure.
For this reason, conventionally, clean air is prevented from flowing into the optical path to prevent fume and the like from adhering to the optical system. Also, if water such as water vapor is contained in the clean air, it will adhere to the optical system and cause fog or cracks.Therefore, clean air that has been dried using a drying means has been allowed to flow into the optical path. Therefore, as a drying means, a refrigerating dryer using a refrigerating cycle, a heatless air dryer using a desiccant, etc. are generally adopted.

In the refrigerating air dryer, as shown in FIG. 1, the warm moist compressed air sucked from the air inlet a is pre-cooled by the aftercooler b, then cooled and dehumidified by the precooler c, and further the fluorocarbon gas is evaporated by the evaporator d. It is cooled to a preset temperature by the heat of vaporization, and the water vapor in the air becomes water droplets and is discharged from the drain e. The cooled and dehumidified air again flows into the precooler c, is warmed by exchanging heat with the warm moist air, and is discharged from the air outlet f.

On the other hand, the heatless air dryer is shown in FIG.
As shown in (1), it has a plurality of desiccant cylinders g containing desiccant, and by alternately flowing moist compressed air from the shuttle valve h to the desiccant cylinder g, while dehumidifying the water content in the air, Dry air is discharged from the outlet i.

[0005]

However, since the refrigerating air dryer uses Freon gas, the leaked Freon gas adversely affects the global environment such as destroying the ozone layer and requires electric power. There are problems such as high running costs. In addition, the heatless air dryer does not have the problem like the above-mentioned refrigeration type air dryer, but since fine powder of desiccant is mixed in the dry air,
When used as clean air, it is necessary to install a filter on the output side of the dryer to remove fine powder of desiccant, and if used for a long time, the capacity of the desiccant decreases, so multiple desiccant cylinders can be used. Since they must be provided and used alternately, the entire apparatus becomes large and requires a lot of space for installation, and the apparatus itself becomes expensive. The present invention has been made in order to improve the conventional problems, and a laser processing machine in which dry clean air obtained by a hollow fiber membrane is allowed to flow into the optical path to prevent dust and the like from entering the optical path. It is an object of the present invention to provide an optical path protection device.

[0006]

In order to achieve the above object, the present invention supplies clean air into an optical path for guiding a laser beam to a processing head to prevent dust and the like from entering the optical path 9. In the optical path protection device for a laser processing machine that protects the inside of the optical path by the above, it is shut off at the exit side of the air drying means made of a hollow fiber membrane when the laser processing machine is stopped, and is opened when a predetermined time has elapsed after the start of operation. An outlet side electromagnetic valve is provided and clean air discharged when the outlet side electromagnetic valve is opened is supplied into the optical path.

[0007]

[Operation] With the above configuration, dry clean air can be supplied into the optical path within the operation preparation time of the laser processing machine to prevent dust such as fumes from entering the optical path. Also, by providing an inlet side solenoid valve on the inlet side of the air drying means and opening it only when the laser processing machine is operating,
Since the compressed air does not flow to the air drying means while the laser processing machine is at rest, wasteful consumption of the compressed air can be prevented.

[0008]

Embodiment An embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. Figure 3 shows the circuit diagram of this device.
4 shows the same configuration diagram, and FIG. 5 shows the principle of dehumidification of the hollow fiber membrane. Compressed air sent under pressure from an air source (not shown) is supplied from the inlet 1 of the circuit to the air filter 3 via the inlet side solenoid valve 2. It has become so. The compressed air from which dust and the like in the air has been removed by the air filter 3 has oil mist mixed in the air removed by an oil mist filter 4, and a part of the compressed air is used as drive air from a drive air outlet 5 (not shown). It is sent to the chainer, and the rest is the hollow fiber membrane 6
It is sent to the air drying means 6 made of a, and the moisture in the air is dehumidified by the air drying means 6. Hollow fiber membrane 6a used in the air drying means 6
5 has a hollow fiber shape as shown in FIG. 5, and when compressed air containing water is supplied and a part of dry air is supplied to the outer peripheral portion as purge air, the partial pressure difference of water vapor between the inside and outside of the membrane 6a is increased. Thus, the water vapor in the compressed air permeates the membrane 6b to dehumidify the compressed air.
The steam that has permeated through is discharged by the purge air, so that the compressed air can be continuously dehumidified.

A large number of the hollow fiber membranes 6a are accommodated in a case 6c of the air drying means 6 shown in FIG. 4 in a bundled state, and the compressed air supplied from the air inlet 6d is a hollow fiber in the case 6c. Water in the air is removed when passing through the membrane 6a, and at the same time, minute dust and the like that cannot be removed by the air filter 3 are also removed. Then, the dry clean air is sent from the air outlet 6e to the regulator 7 and adjusted to a constant pressure, and then sent into the optical path 9 of the laser processing machine through the outlet side electromagnetic valve 8.

On the other hand, each component forming the circuit shown in FIG. 3 is unitized as shown in FIG. That is, the air filter 3 is connected to the inlet side solenoid valve 2, and the air filter 3
An oil mist filter 4 is connected to. At the bottom of the air filter 3 and the oil mist filter 4, a drain discharge port 3a for discharging the removed dust and oil mist,
4a is provided and the oil mist filter 4 is provided.
At the top of the, the differential pressure gauge 1 that displays the differential pressure between the inlet side and the outlet side
0 is attached.

Further, the oil mist filter 4 and the air drying means 6 are connected to each other, a drive air outlet 5 is provided between them, and the air drying means 6 is provided with a regulator 7 and the regulator 7 is provided with an outlet side electromagnetic wave. The valve 8 is connected to form an integrated unit structure,
The inlet side solenoid valve 2 and the outlet side solenoid valve 8 can be used by connecting them to the pipes.

The operation will be described next. In a general laser processing machine, when the operation switch is turned on, the vacuum pump is first activated, and when the gas pressure becomes 4.5 Torr, the laser gas charge circulation pump is activated. Gas pressure is 50To
When rr is reached, preparation is completed, and this operation requires about 3 to 5 minutes, during which time machining cannot be started.

On the other hand, the air drying means 6 using the hollow fiber membrane 6a uses the time until the laser processing machine can start processing because the dehumidifying function does not work sufficiently until the internal pressure reaches a predetermined pressure. That is, the inlet side solenoid valve 2 and the outlet side solenoid valve 8 are shut off while the laser processing machine is at rest, and when the operation switch of the laser processing machine is turned on in this state,
The inlet side solenoid valve 2 is opened, and the outlet side solenoid valve 8 remains blocked. As a result, the compressed air supplied to the inlet 1 has its dust removed by the air filter 3 and then has its oil mist removed by the oil mist filter 4. Then, a part of the compressed air is discharged as driving air from the driving air outlet 5, and the rest is supplied to the air drying means 6 to dehumidify the water content in the air by the hollow fiber membrane 6a.

At this time, since the outlet-side electromagnetic valve 8 is shut off, the compressed air that has not been sufficiently dried is discharged as purge air and is not supplied to the optical path 9 of the laser processing machine. Then, after the inside of the air drying means 6 reaches a predetermined pressure and the moisture in the compressed air is sufficiently dehumidified, for example, after 3 minutes, the outlet side electromagnetic valve 8 is opened and the dry clean air is sent to the optical path 9 of the laser processing machine. Like After that, the preparation of the laser processing machine is completed and the processing of the work is started, but during the operation of the laser processing machine, dry air is always fed into the optical path 9 even when the work is not cut,
The fumes generated during cutting and the fumes and dust floating in the air after cutting are prevented from entering the optical path 9 and protect the inside of the optical path 9.
It is possible to prevent the output from being reduced by being attached to the upper optical system.

In the above embodiment, since the factory air is used as the air source, the air filter 3 and the oil mist filter 4 are connected to the inlet side of the drying means 6, but when using clean air without dust or oil, The inlet side solenoid valve 2 may be directly connected to the inlet of the air drying means 6 to form a unit, and the air filter 3 and the air mist filter 4 may be omitted.

[0016]

As described in detail above, the present invention supplies clean air dehumidified by the air drying means using a hollow fiber membrane into the optical path of a laser beam machine to prevent fumes from entering the optical path. Since CFCs are prevented, CFCs are not used unlike conventional refrigeration air dryers, which does not adversely affect the global environment, and the installation space can be reduced because the device can be downsized. Moreover, unlike the heatless air dryer, fine powder of the desiccant is not mixed in the dry air, so clean dry air can be easily obtained, and multiple desiccant cylinders are provided alternately like the heatless air dryer. Since there is no need to use it, the overall size of the device can be reduced and the cost can be reduced.

Further, since the air drying means is started by using the preparation time of the laser processing machine, there is no time loss,
In addition, the outlet side solenoid valve was shut off during this time to prevent air from being supplied into the optical path, so wasteful consumption of compressed air can be reduced and clean air that is not sufficiently dried can be supplied into the optical path. Since there is no such problem, it is possible to solve problems such as clouding or cracking of the optical system. Moreover, a solenoid valve was installed on the inlet side of the air drying means, and this solenoid valve was shut off during the rest of the laser processing machine so that air was not supplied to the air drying means. Therefore, wasteful consumption of compressed air can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a conventional refrigeration type air dryer.

FIG. 2 is an explanatory view showing a conventional heatless air dryer.

FIG. 3 is a circuit diagram showing an optical path protection device of a laser processing machine according to an embodiment.

FIG. 4 is a configuration diagram showing an optical path protection device of a laser processing machine according to an embodiment of the present invention.

FIG. 5 is a configuration diagram showing a principle of dehumidifying a hollow fiber membrane used in an optical path protection device of a laser beam machine according to an embodiment of the present invention.

[Explanation of symbols]

2 ... inlet side solenoid valve, 6 ... air drying means, 6a ... hollow fiber membrane, 8 ... outlet side solenoid valve, 9 ... optical path.

Claims (2)

[Claims] 1. An optical path of a laser processing machine that protects the inside of the optical path 9 by supplying clean air into the optical path 9 that guides a laser beam to the processing head to prevent dust and the like from entering the optical path 9. In the protective device, an outlet side electromagnetic valve 8 is provided on the outlet side of the air drying means 6 made of the hollow fiber membrane 6a, which is shut off when the laser beam machine is stopped and is opened when a predetermined time has passed after the start of operation. An optical path protection device for a laser processing machine, characterized in that clean air discharged when the outlet-side electromagnetic valve 8 is opened is supplied into the optical path 9. 2. The optical path protection device for a laser processing machine according to claim 1, wherein an inlet side electromagnetic valve 2 which is opened when the operation of the laser processing machine is started is provided on the inlet side of the air drying means 6.