BEAM BENDER FOR LASER BEAM MACHINING

Abstract: A beam bender for laser beam machining, which is adapted to change the direction of a laser beam. The beam ben­ der consists of a base (1), a flange (2), a beam guide passage (3) and a mirror holder (6). In accordance with the direction of incidence of a laser beam, the flange (2) on the base (1) is moved to the opposite side, and the beam guide passage (5) is turned, whereby a bender mirror can be set so as to face the direction of incidence of the laser beam. This enables a beam bender capable of readily adapting itself to a change of the direction of incidence of a laser beam to be obtained. ABSTRACT A beam bender changes the direction of a laser beam in laser-beam machining. The beam bender comprises a base (1), a flange (2), a member (3), and a mirror holder (6) housing a bender mirror (7). Dependent on the direction in which the laser beam is applied to the beam bender, the flange (2) on the base (1) is displaced toward an opposite side and the light-guide member (5) is rotated to orient the bender mirror (7) in the direction in which the laser beam is applied. Therefore, the beam bender can bend a laser beam even when it is applied to the beam bender in different directions.

Description: The present invention relates to a beam bender for changing the direction of a laser beam in laser-beam machining, and more particularly to a beam bender which can bend a laser beam even if the direction in which the laser beam is applied to the beam bender is varied. In laser-beam machining, a laser beam produced by a laser oscillator is deflected by a beam bender and then focused onto a workpiece by a lens. FIG. 6 of the accompanying drawings schematically shows the relationship between the laser oscillator and the beam bender. The laser oscillator, denoted at 20, is supplied with a laser gas through a gas pipe 21 and also with cooling water through a cooling water pipe 22 for cooling the laser oscillator 20 itself and a bender mirror. A laser-beam machining table 23 places a workpiece 27 thereon. A beam bender 24 serves to deflect a laser beam generated by the laser oscillator, in a direction from the viewer of FIG. 6 toward the sheet of FIG. 6 so as to apply the deflected laser beam to the workpiece 27 on the table 23. In some applications, the laser oscillator should be placed on the righthand side of the beam bender as indicated by the two-dot-and-dash lines in FIG. 6, owing to limitations imposed by the space where the laser-beam machining apparatus is installed and positional limitations of the gas pipe 21 and the cooling water pipe 22. The beam bender 24 is arranged to bend the laser beam which is applied to the beam bender 24 only in one direction, i.e., a direction from the left. Therefore, if the laser oscillator is to be positioned on the righthand side of the beam bender 24, the beam bender 24 has to be designed again to meet the positional requirement. However, it is tedious and time-consuming to design and manufacture a beam bender all over again to meet a specific location where the laser-beam machining apparatus is placed, and a period of time required to customize the beam bender is long. GB-A-2134071 discloses a laser system for machining in which light-guides are provided on articulated arms, bender mirrors being positioned at the joints of the arms. It is an object of the present invention to provide a beam bender which can bend a laser beam in laser-beam machining even when the direction in which the laser beam is applied is varied. In accordance with the a first aspect of the present invention, there is provided a beam bender for changing the direction of a laser beam in laser-beam machining, comprising: a base having a circular hole; a hollow light-guide member of an inverted L shape having one end rotatably mounted on the base; a mirror holder fixed to the light-guide member; and, a bender mirror mounted on the mirror holder, the mirror holder having a first fine adjustement mechanism for adjusting the direction of the bender mirror; characterised by: a flange screwed to the base, the other end of the light-guide member being held movably against the flange, the first end being inserted in said hole in said base; and, a second fine adjustment mechanism for adjusting the position of the hollow light-guide member in the direction of the axis of said hole. In accordance with a second aspect of the present invention, there is provided a beam bender for changing the direction of a laser beam in laser-beam machining, comprising: a base having a rectangular hole; a hollow light-guide member of an inverted L shape; a mirror holder fixed to the light-guide member; and, a bender mirror mounted on the mirror holder, the mirror holder having a first fine adjustment mechanism for adjusting the direction of the bender mirror; characterised by: a flange screwed to the base, the light guide member having one end inserted in the hole and removable therefrom dependent on the direction in which the laser beam is applied, the opposite end of the light guide member being held movably against the flange; and, a second fine adjustment mechanism for adjusting the position of the hollow light guide member in the direction of the axis of said hole. Dependent on the direction in which the laser beam is applied to the beam bender, the flange on the base is displaced toward an opposite side and the light-guide member is rotated to orient the bender mirror in the direction in which the laser beam is applied. Alternatively, the flange on the base is displaced toward an opposite side, and the light-guide member is removed from the hole, rotated into the opposite direction, and inserted again into the hole to orient the bender mirror in the direction in which the laser beam is applied. In the drawings:- FIG. 1 is an elevational view, partly in crosssection, of a beam bender according to a first embodiment of the present invention; FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1; FIG. 3 is an elevational view of the beam bender with a mirror holder and a flange displaced to a righthand side; FIG. 4 is a cross-sectional view of a light-guide member and a base according to a second embodiment of the present invention; FIG. 5 is a cross-sectional view of a light-guide member and a base according to a third embodiment of the present invention; and, FIG. 6 is a schematic view showing the relationship between a laser oscillator and a beam bender. Embodiments of the present invention will hereinafter be described with reference to the drawings. FIG. 1 shows a beam bender according to a first embodiment of the present invention. The beam bender includes a base 1 having a central hole defined therein. A flange 2 is fastened to the base 1 by a screw 11 and has a side 2a against which a light-guide member (described below) is slidably held. A micrometer 4 is fixed to a member 3 mounted on an upper surface of the flange 2. A light-guide member 5 is of an inverted L shape and has a hollow structure for allowing a laser beam 12 to pass therethrough. The light-guide member 5 has a surface held vertically slidably against the side 2a of the flange 2, and can be slid vertically by the micrometer 4. A mirror holder 6 is fixed to the light-guide member 5 and houses a bender mirror 7 therein. The mirror holder 6 is adjustable in small angular increments with respect to the light-guide member 5 by means of micrometers 8, 9 to adjust the angle of the bender mirror 7 for adjusting the guide passage for the laser beam 12 in the light-guide member 5. A flange 10 is fastened to the lower surface of the base 1 by means of a screw 13. A cooling structure for the bender mirror 7 is omitted from illustration. FIG. 2 shows the cross section of the beam bender taken along line A - A of FIG. 1. While the base 1 and the light-guide member 5 are shown as being spaced from each other, they are actually held in intimate contact with each other but rotatable relatively to each other. When the direction in which the laser beam is applied is changed from left to right because of requirements of the laser-beam machining apparatus, the screw 11 is removed to release the flange 2, the light-guide member 5 is rotated in the direction indicated by the arrow B, and the flange 2 is fixed to the base 1 by the screw 11 as shown by the two-dot-and-dash lines in FIG. 1. Now the bender mirror 7 is directed to the right, as shown in FIG. 3. The laser beam 12 is applied from the right and deflected by the bender mirror 7. Therefore, requirements of the laser-beam machining apparatus for placing the laser oscillator on the righthand side of the beam bender can easily be met. A second embodiment of the present invention will be described below. According to the second embodiment, a light-guide member 5 and a base 1 are coupled to each other through a square hole defined in the base 1, as shown in FIG. 4 which corresponds to the cross section of the beam bender taken along line A - A of FIG. 1. The base 1 and the light-guide member 5 are shown as being spaced from each other by a gap which is shown as being larger than actual. When the direction in which the laser beam is applied is changed, the screw 11 is removed, the flange 2, the light-guide member 5, and the mirror holder 6 are pulled upwards, oriented to the right, and inserted again, and the flange 2 is fastened to the base 1 on an opposite side. A third embodiment of the present invention will be described below. The third embodiment is shown in FIG. 5 which corresponds to the cross section of the beam bender taken along line A - A of FIG. 1. The third embodiment differs from the second embodiment in that the hole in the base and the light-guide member 5 are angularly displaced 45° though they are the same configuration as with the second embodiment. With this arrangement, wobbling movement of the light-guide member 5 in the vertical and horizontal directions in FIG. 5 can be reduced. In the above embodiments, the beam bender can bend a laser beam even when it is applied in a leftward or rightward direction. However, the beam bender can also be adjusted to bend a laser beam which may be applied in one of four directions, i.e., forward, rearward, leftward, and rightward directions. With the present invention, as described above, dependent on the direction in which the laser beam is applied to the beam bender, the flange on the base is displaced toward an opposite side and the light-guide member is rotated to orient the bender mirror in the direction in which the laser beam is applied. Therefore, the same beam bender can be used in laser-beam machining apparatus in which laser beams are applied in different directions. Alternatively, the flange on the base is displaced toward an opposite side, and the light-guide member is removed from the hole, rotated into the opposite direction, and inserted again into the hole to orient the bender mirror in the direction in which the laser beam is applied. Accordingly, the beam bender can easily meet different directions in which the laser beam is applied.

Claims: 1. A beam bender for changing the direction of a laser beam in laser-beam machining, comprising: a base (1) having a circular hole; a hollow light-guide member (5) of an inverted L shape having one end rotatably mounted on the base (1); a mirror holder (6) fixed to the light-guide member (5); and, a bender mirror (7) mounted on the mirror holder (6), the mirror holder (6) having a first fine adjustment mechanism (8,9) for adjusting the direction of the bender mirror (7); characterised by: a flange (2) screwed to the base (1), the other end of the light-guide member (5) being held movably against the flange (2), the first end being inserted in said hole in said base (1); and, a second fine adjustment mechanism (4) for adjusting the position of the hollow light-guide member (5) in the direction of the axis of said hole. 2. A beam bender for changing the direction of a laser beam in laser-beam machining, comprising: a base (1) having a rectangular hole; a hollow light-guide member (5) of an inverted L shape; a mirror holder (6) fixed to the light-guide member (5); and, a bender mirror (7) mounted on the mirror holder (6), the mirror holder (6) having a first fine adjustment mechanism (8,9) for adjusting the direction of the bender mirror (7); characterised by: a flange (2) screwed to the base (1), the light guide member (5) having one end inserted in the hole and removable therefrom dependent on the direction in which the laser beam is applied, the opposite end of the light guide member (5) being held movably against the flange (2); and, a second fine adjustment mechanism (4) for adjusting the position of the hollow light guide member (5) in the direction of the axis of said hole.

Inventors: ARAI, TAKEJI FANUC MANSION HARIMOMI 3-309
Applicants: FANUC LTD.
Application year: 1988
Main classification: B23K26
IPC codes: G02B7, H01S3, B23K26