The invention relates to the field of welding, cutting or the like with a laser beam and, more precisely, to laser machining equipment with a laser oscillator, optical path and laser head supplied from the same gas source, in particular a nitrogen source.
As illustrated in
The problem which arises on the industrial scale is that currently, when the gas used as process gas and lasing gas is of the same type, for example nitrogen, two separate supplies of the same gas are used, as schematized in
This, however, leads to greater complexity of the laser equipment and therefore a direct extra cost and a loss of operating time for the user. Furthermore, it also makes it necessary to provide dedicated gas cylinders which are immobilized on site and are used only for supplying the laser oscillator 1.
It is an object of the present invention to provide a solution to this problem.
More precisely, the invention relates to laser machining equipment comprising a laser oscillator for generating a laser beam, a laser head through which the laser beam passes, an optical path for transporting the laser beam between the laser oscillator and the laser head, and a gas source fluidically connected to the laser head by means of a main gas pipe, characterized in that it furthermore comprises a secondary pipe fluidically connecting said gas source to the laser oscillator.
In other words, according to the present invention, a common gas source of large capacity, such as a reservoir for storing gas in gaseous or liquid form, supplies both the laser head used for the machining and the laser oscillator used for generating the laser beam.
It should be emphasized that “laser machining” is intended to mean an operation of welding, cutting, marking or any other work using a laser beam.
Depending on the case, the equipment of the invention may have one or more of the following characteristics:
The invention also relates to a method for supplying laser machining equipment, comprising a laser oscillator, a laser head, and an optical path for transporting the laser beam between the laser oscillator and the laser head, with a gas coming from a gas source, in which:
characterized in that the oscillator is supplied with gas coming from said secondary pipe.
Depending on the case, the method of the invention may have one or more of the following characteristics:
The invention will now be understood more clearly from the following description of an embodiment provided with reference to the appended figures, in which:
As can be seen, a laser generator or oscillator 1 of the CO2 type makes it possible to generate a laser beam which is subsequently conveyed through an optical path or cavity 2 to a laser head 3, where it is focused by a focusing lens 4 or focusing mirror (in laser welding, a mirror has the purpose of directing and focusing the lens) or the like into the thickness or into the proximity of the surface of one or more parts 6 to be machined. For the sake of simplicity, it will be assumed below that the optical focusing device is a lens 4.
The lens 4 may have a single focus, i.e. a monofocal lens, or it may be multifocal, for example bifocal, that is to say focusing the beam onto two different focal points.
The lens 4 makes it possible to isolate the optical path 2 mechanically and fluidically from the laser head 3, because the pressures prevailing therein are not in general identical.
The laser oscillator 1 is supplied by 3 cylinders 11 of lasing gas, for example nitrogen of the LASAL™ brand 1, carbon dioxide (CO2) of the LASAL™ brand 2 and helium of the LASAL™ brand 4; the gases of the LASAL™ brand are marketed by L'Air Liquide. In some cases, the oscillator may also be supplied with a gaseous premix containing nitrogen (N2), helium and CO2, or other constituents such as CO.
Furthermore, a nitrogen storage reservoir 9 of the “bulk” type, the outlet of which is fluidically connected to a vaporizer or heat exchanger 10, makes it possible to supply the laser head 3 and the optical path 2 with gaseous nitrogen via one or more gas pipes 8 and dedicated inlets 13, 12, respectively. The inlets 13, 12 are generally located at a gas supply cabinet 5, as illustrated in
As can be seen in
This type of conventional equipment raises the problem of its complexity in the gas supplies.
The invention proposes to simplify the architecture of the equipment of
As illustrated in
Consequently, according to the invention, the liquid nitrogen storage reservoir 9 makes it possible to supply not only the laser head 3 but also the oscillator 1, and optionally the optical path 2, with “bulk” nitrogen coming from said storage reservoir 9, which is drawn therefrom in liquid form and vaporized in the vaporizer 10, before being transported on the one hand to the laser head 3 via the line 8 which branches, and on the other hand to the laser oscillator 1 via an additional line 18 which is connected to the line 8, that is to say a branch of the line 8.
Optionally, some of the nitrogen may also be transported in the optical path 2 which is used to recover the laser beam at the output of the laser generator 1, then transport it as far as the laser head 3 comprising a laser nozzle and a focusing device 4, such as a lens or a focusing mirror. The laser beam therefore passes through the laser head 3 while being focused therein, before striking the part or parts 6 to be welded or cut, for example, the head 3 furthermore being supplied with nitrogen coming from the reservoir 9.
The optical path 2 is typically formed by a passage provided with optical elements, such as mirrors and/or lenses.
The gas source or reservoir line is preferably a storage reservoir of large capacity, that is to say having a capacity of at least 900 liters, preferably at least 3000 liters of nitrogen.
Typically, this reservoir 1 is located outside the building in which the rest of the equipment is installed, i.e. principally the laser generator 1, the optical path 2 and the laser head 3, as well as the support table 7 on which the part or parts 6 to be machined rest, and the protective enclosure 15.
This is because it is then easier to fill the large-capacity reservoir 9 when it is empty or nearly empty, either by filling the reservoir 9 with nitrogen brought on site by a tanker, or by replacing the empty reservoir 1 with another full reservoir, in particular if the reservoir is a mobile reservoir of the “ranger” type.
Given that the working pressures of the gas inside the optical path 2, the laser head 3 and the laser oscillator 1 are generally different, it is preferable to provide one or more gas expansion devices 20, such as gas expanders, along the main pipe 8 and/or along the secondary pipe 18.
An expansion device 20 should be designed for and capable of reducing the pressure of the gas flowing in the main pipe 8 or secondary pipe 18, before it is introduced into the optical path 2, the head 3 or the oscillator 1.
Typically, the gas conveyed by the main pipe 8 is at a pressure of between 15 and 32 bar relative, for example of the order of 25 bar, while in the optical path, the gas is in overpressure in order to prevent the particles in the air from entering. The supply of the laser oscillator has a relative pressure of between 1 and 15 bar.
Furthermore,
Number | Date | Country | Kind |
---|---|---|---|
1051067 | Feb 2010 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/FR2011/050113 | 1/21/2011 | WO | 00 | 8/16/2012 |