Laser Head

Abstract

To provide a laser head that can replace an optical element readily more than before.SOLUTION: A laser head A1 with a lens 21 for refracting and emitting an incident laser beam includes: a plurality of optical elements 31, 32, 33, 34 for transmitting a laser beam therethrough; and a moving mechanism 6 for moving each of the plurality of optical elements 31, 32, 33, 34 to a function position intersecting with an optical path of the laser beam and a retreat position retreating from the optical path Op.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a laser head. [Background technology]

[0002] Laser processing using laser light is used as various processing means such as laser welding and laser cutting. Patent Documents 1 and 2 disclose examples of laser heads used in conventional laser processing. The laser heads disclosed in these documents include a collimator lens and a diffractive optical element. The collimator lens is an optical component that focuses the incident laser light to a desired spot diameter. The diffractive optical element transmits the light emitted from the collimator lens to arbitrarily set, for example, the irradiation shape of the laser light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 64-5790 [Patent Document 2] Japanese Utility Model Application Publication No. 63-101185 Summary of the Invention [Problem to be solved by the invention]

[0004] The laser head disclosed in the above-mentioned patent document is configured so that the diffractive optical element can be replaced. However, when replacing the diffractive optical element, the fixing mechanism such as a screw fastening mechanism must be manually released and the diffractive optical element in use must be removed. Then, a new diffractive optical element is attached to the laser head and fixed with a screw fastening or the like. For this reason, it is necessary to move the laser head away from the state where laser processing is being performed, and after the replacement work, set the laser head to a state where processing is possible again.

[0005] The present invention has been devised in light of the above circumstances, and an object of the present invention is to provide a laser head that allows for easier replacement of optical elements. [Means for solving the problem]

[0006] The laser head provided by the present invention is a laser head equipped with a lens that refracts and emits incident laser light, and is equipped with a plurality of optical elements that transmit the laser light, and a moving mechanism that moves each of the plurality of optical elements to a functional position that is a position where it intersects with the optical path of the laser light, and a retracted position where it is retracted from the optical path.

[0007] In a preferred embodiment of the present invention, the functional positions of the plurality of optical elements include two of the optical elements whose positions in a direction along the optical path are different from each other.

[0008] In a preferred embodiment of the present invention, the moving mechanism moves each of the plurality of optical elements along an arcuate trajectory.

[0009] In a preferred embodiment of the present invention, the plurality of optical elements include diffractive optical elements.

[0010] In a preferred embodiment of the present invention, the lens is a collimator lens, The functional positions of the optical elements are located on the output side of the lens in a direction along the optical path. Effect of the Invention

[0011] According to the laser head of the present invention, the optical elements can be replaced more easily.

[0012] Other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0013] According to the present invention, the optical element can be more easily replaced. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic perspective view showing a laser processing system in which a laser head according to a first embodiment of the present invention is used. [Diagram 2] 1 is a plan view showing a main part of a laser head according to a first embodiment of the present invention. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] 1A and 1B are diagrams showing an example of a state in which a laser head according to a first embodiment of the present invention is used, in which (a) is a plan view of a main portion, and (b) is a cross-sectional view of a main portion. [Diagram 5] 5A and 5B are views showing another example of a state in which the laser head according to the first embodiment of the present invention is used, in which (a) is a plan view of the essential parts, and (b) is a cross-sectional view of the essential parts. [Figure 6] FIG. 6 is a plan view of a main portion of a laser head according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a plan view of a main portion of a laser head according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0016] <First embodiment laser head A1> 1 to 5 show a laser processing system using a laser head according to a first embodiment of the present invention. The laser head A1 of this embodiment receives laser light transmitted from a laser source such as a laser oscillator Lo via an optical fiber or the like, and emits light suitable for processing an object Ob. The laser processing using the laser head A1 is not limited in any way, and examples thereof include laser welding, laser cutting, and laser surface treatment. In addition, the laser welding is not limited to welding using a laser light alone, and may be, for example, hybrid welding in which laser welding and arc welding are performed simultaneously.

[0017] The laser head A1 of this embodiment includes a case 1, a plurality of lenses 21, 22, a plurality of protective glasses 25, 26, a plurality of optical elements 31 to 34, and a moving mechanism 6. In Fig. 1, Fig. 2, Fig. 4(a), and Fig. 5(a), the optical elements 31 to 34 are hatched with discrete dots for ease of understanding. In Fig. 2, Fig. 4(a), and Fig. 5(a), the case 1 is omitted for ease of understanding. In addition, the optical path Op of the laser light that is incident on the laser head A1 and then emitted therefrom extends along the z direction, and the laser light travels from the top to the bottom in the z direction in Figs. 1 and 3.

[0018] [Case 1] The case 1 supports and houses the lenses 21, 22, the protective glasses 25, 26, the optical elements 31-34, and the moving mechanism 6. There are no limitations on the material of the case 1, and a material suitable for the environment, such as the temperature caused by the laser processing using the laser head A1, is appropriately selected, for example, metal. The case 1 may also be provided with a water-cooling mechanism or an air-cooling mechanism (both not shown) as appropriate. An inert gas or the like may also be blown into the case 1 as appropriate.

[0019] In this embodiment, the case 1 has a box-shaped portion 11, a cylindrical portion 12, and a cylindrical portion 13. The box-shaped portion 11 is a box-shaped portion as a whole. The box-shaped portion 11 has an opening 111 and an opening 112. The openings 111 and 112 are formed as through holes penetrating in the z direction, and are portions through which the optical path Op passes. The opening 111 is located on the incident side of the optical path Op, and the opening 112 is located on the exit side of the optical path Op.

[0020] The tubular portion 12 is provided on the incident side of the box-shaped portion 11, and in the illustrated example, is cylindrical. The tubular portion 12 has an opening 121 and an opening 122. The opening 121 is located on the incident side of the optical path Op, and the opening 122 is located on the exit side of the optical path Op. The tubular portion 13 is provided on the exit side of the box-shaped portion 11, and in the illustrated example, is cylindrical. The tubular portion 13 has an opening 131 and an opening 132. The opening 131 is located on the incident side of the optical path Op, and the opening 132 is located on the exit side of the optical path Op.

[0021] [Lens 21, 22] The lenses 21 and 22 are optical components for focusing the laser light from the laser oscillator Lo to a desired spot diameter, and intersect with the optical path Op. The specific configuration of the lenses 21 and 22 is not limited in any way, and in this embodiment, the lens 21 is a collimator lens. The lens 21 is disposed slightly on the entrance side with respect to the opening 122 of the cylindrical portion 12. The lens 22 is disposed slightly on the exit side with respect to the opening 131 of the cylindrical portion 13.

[0022] [Protective glass 25, 26] The multiple protective glasses 25, 26 are for protecting the lenses 21, 22 and the optical elements 31 to 34, and are made of transparent glass or the like that minimizes attenuation of the laser light from the laser oscillator Lo. The protective glass 25 is disposed in the opening 121 of the cylindrical portion 12. The protective glass 26 is disposed in the opening 132 of the cylindrical portion 13.

[0023] [Optical elements 31 to 34] The optical elements 31-34 are elements that change the laser light into a property suitable for the laser processing of the laser head A1 by transmitting the laser light. The number of optical elements included in the laser head of the present invention is not limited at all, and may be two or three, or may be five or more. Specific examples of the optical elements 31-34 are not limited at all, and may include, for example, a diffractive optical element (DOE), various optical filters, various lenses, etc., as appropriate. In this embodiment, a case where the optical elements 31-34 are diffractive optical elements will be described as an example. When the optical elements 31-34 are diffractive optical elements, each of them is a flat plate-like member, and in the illustrated example, it is circular. The diffractive optical element uses the diffraction of light to arbitrarily set the irradiation shape and irradiation pattern of the laser light.

[0024] [Moving mechanism 6] The moving mechanism 6 is a mechanism for moving the optical elements 31 to 34. In this embodiment, the moving mechanism 6 moves the optical element 31 to the retracted position Pe1 and the functional position Pw, moves the optical element 32 to the retracted position Pe2 and the functional position Pw, moves the optical element 32 to the retracted position Pe3 and the functional position Pw, and moves the optical element 34 to the retracted position Pe4 and the functional position Pw. The functional position Pw is a position that intersects with the optical path Op of the laser light, and is a position where the optical elements 31 to 34 function as diffractive optical elements by being positioned respectively. The retracted positions Pe1 to Pe4 are retracted positions retracted from the optical path Op, and are positions where the optical elements 31 to 34 do not function as diffractive optical elements because they do not intersect with the optical path Op.

[0025] The specific configuration of the moving mechanism 6 is not limited in any way as long as it is configured to move the multiple optical elements 31-34 to the above-mentioned functional position Pw and the retracted positions Pe1-Pe4, respectively. The moving mechanism 6 of this embodiment has frames 71-74 and motors 81-84.

[0026] The frame 71 and the motor 81 move the optical element 31 along the orbit R1, which is a circular orbit. The frame 71 is made of, for example, metal and has a support portion 711 and a rod 712. The support portion 711 is a circular ring-shaped portion and supports the optical element 31. The rod 712 extends from the support portion 711 and is connected to the motor 81. The motor 81 is, for example, a servo motor, and is a drive source for rotating the frame 71. Note that in order to position the optical element 31 at the above-mentioned functional position Pw and the retracted position Pe1, a rotary encoder, a sensor such as a proximity switch, a stopper member, or the like may be appropriately used.

[0027] The frames 72 to 74 have a similar configuration to the frame 71, and the frame 72 has a support portion 721 and a rod 722, the frame 73 has a support portion 731 and a rod 732, and the frame 74 has a support portion 741 and a rod 742. The optical element 32 is supported by the support portion 721, the optical element 33 is supported by the support portion 731, and the optical element 34 is supported by the support portion 741. The rod 722 is connected to the motor 82, the rod 732 is connected to the motor 83, and the rod 742 is connected to the motor 84. As a result, like the optical element 31, the optical element 32 is moved along the orbit R2, the optical element 33 is moved along the orbit R3, and the optical element 34 is moved along the orbit R4. All of the orbits R2 to R4 are arc orbits.

[0028] As shown in Fig. 2 and Fig. 3, the optical elements 31 and 32 are provided on the right side of the functional position Pw in the x direction. The optical elements 33 and 34 are provided on the left side of the functional position Pw in the x direction. As can be seen from Fig. 1 and Fig. 3, the optical elements 31 and 32 are disposed at different positions in the z direction, which is the direction along the optical path Op. The optical elements 33 and 34 are disposed at different positions in the z direction. In the illustrated example, the optical elements 31 and 33 are disposed at the same position in the z direction, and the optical elements 32 and 34 are disposed at the same position in the z direction.

[0029] Moreover, the optical elements 31 to are located on the output side of the lens 21, which is a collimator lens, in the z direction. Moreover, the optical elements 31 to are located between the lens 21 and the lens 22 in the z direction.

[0030] 3, in this embodiment, motors 81 and 83 are attached to an entrance side portion in the z direction of box-shaped portion 11, and motors 82 and 84 are attached to an exit side portion in the z direction of box-shaped portion 11. Frames 71 and 72 are disposed between motors 81 and 82, and frames 73 and 74 are disposed between motors 83 and 84.

[0031] 4 shows an example of a usage state of the laser head A1. In the illustrated state, the frame 71 is rotated by the drive of the motor 81, and the optical element 31 is located from the retracted position Pe1 to the functional position Pw along the trajectory R1. Meanwhile, the motors 82-84 do not rotate the frames 72-74, and the optical elements 32-34 are located at the retracted positions Pe2-Pe4, respectively. In this case, the laser light emitted from the lens 21 passes through the optical element 31 and enters the lens 22. Therefore, the laser light emitted from the laser head A1 is set to a desired irradiation shape and irradiation pattern by the function of the optical element 31.

[0032] FIG. 5 shows another example of the usage state of the laser head A1. In the illustrated state, the frame 71 is rotated by driving the motor 81, and the optical element 31 is located from the retracted position Pe1 to the functional position Pw along the trajectory R1. Also, the frame 74 is rotated by driving the motor 84, and the optical element 34 is located from the retracted position Pe4 to the functional position Pw along the trajectory R4. In this case, as shown in FIG. 5(b), the optical element 31 and the optical element 34 are disposed at different positions in the z direction, and both intersect with the optical path Op. Then, the laser light emitted from the lens 21 passes through the optical element 31 and the optical element 34 and enters the lens 22. Therefore, the laser light emitted from the laser head A1 is set to a desired irradiation shape or irradiation pattern by the functions of the optical element 31 and the optical element 34.

[0033] Furthermore, according to the configuration of the laser head A1, it is possible to select a state in which only one of the optical elements 31 to 34 is positioned at the functional position Pw, a state in which the optical elements 31 and 34 are positioned, a state in which the optical elements 31 and 32 are positioned, a state in which the optical elements 33 and 34 are positioned, or a state in which the optical elements 32 and 33 are positioned.

[0034] Next, the operation of the laser head A1 will be described.

[0035] According to this embodiment, it is possible to use the moving mechanism 6 to retreat any one of the optical elements 31-34 from the functional position Pw and move the other optical elements 31-34 to the functional position Pw. Therefore, it is not necessary to retreat the laser head A1 from a state where laser processing is performed, perform the optical element replacement work, and then set the laser head A1 to a state where processing is possible again. Therefore, the laser head A1 makes it easier to replace the optical elements.

[0036] The optical elements 31 and 33, and the optical elements 32 and 34 are located at different positions in the z direction. This allows two of the optical elements 31 to 34 that are located at different positions in the z direction to be simultaneously arranged at the functional position Pw, as shown in Fig. 5. This allows for an increased variation in the arrangement of the optical elements 31 to 34 at the functional position Pw, and further diversifies the laser processing by the laser head A1.

[0037] The paths R1 to R4 along which the optical elements 31 to 34 are moved are circular paths, which reduces interference with the movements of the optical elements 31 to 34 and allows smoother movements to be achieved. This is also advantageous for making the moving mechanism 6 smaller.

[0038] Since the optical elements 31-34 are diffractive optical elements, even if there is a slight error in the position of the optical elements 31-34 relative to the optical path Op at the functional position Pw, the functions of the optical elements 31-34 are unlikely to be immediately disturbed. Therefore, there is no need to excessively increase the movement accuracy of the movement mechanism 6, which is advantageous for simplifying the mechanism and reducing costs.

[0039] The optical elements 31-34 are disposed on the exit side of the lens 21, which is a collimator lens, at the functional position Pw. This allows the optical elements 31-34 to appropriately set the irradiation shape and irradiation pattern without unduly interfering with the light collecting function of the lens 21.

[0040] 6 and 7 show another embodiment of the present invention. In these figures, elements that are the same as or similar to those in the above embodiment are given the same reference numerals as those in the above embodiment.

[0041] <Second embodiment laser head A2> 6 shows a laser head according to a second embodiment of the present invention. In the laser head A2 of this embodiment, the configuration of the moving mechanism 6 is different from that of the above-mentioned embodiment. In this embodiment, a plurality of optical elements 31-34 are moved along linear tracks R1-R4.

[0042] The specific configuration of the moving mechanism 6 for moving along the tracks R1 to R4 is not limited at all. In this embodiment, the moving mechanism 6 has linear actuators 85 to 88. The linear actuators 85 to 88 are drive sources for reciprocating the frames 71 to 74 between the functional position Pw and the retracted positions Pe1 to Pe4 along the tracks R1 to R4, respectively. The linear actuators 85 to 88 may be, for example, electric cylinders or air cylinders as appropriate. In addition, the positions of the optical elements 31 to 34 in the z direction may be the same as or different from that of the laser head A1.

[0043] This embodiment also makes it easier to replace the multiple optical elements 31 to 34. As can be understood from this embodiment, the shapes of the tracks R1 to R4 along which the multiple optical elements 31 to 34 move are not limited in any way, and various shapes such as an arc shape, a straight line shape, a curved shape, etc. may be appropriately adopted. Furthermore, the multiple tracks R1 to R4 may have different shapes from each other.

[0044] <Third embodiment laser head A3> 7 shows a laser head according to a third embodiment of the present invention. The laser head A3 of this embodiment differs from the above-mentioned embodiments in the configuration of the moving mechanism 6. In this embodiment, a plurality of optical elements 31 to 34 are moved collectively along a single circular track R.

[0045] The movement mechanism 6 of the present embodiment has a frame 75. The frame 75 is generally circular, and has a plurality of openings 750-754 and a rotation shaft 759. The rotation shaft 759 is connected to a driving source such as a motor (not shown), and is the center of rotation of the frame 75. The plurality of openings 750-754 are each through holes that penetrate the frame 75 in the z direction, and are arranged at equal pitches on the same circle centered on the rotation shaft 759.

[0046] The optical element 31 is disposed in the opening 751, the optical element 32 is disposed in the opening 752, the optical element 33 is disposed in the opening 753, and the optical element 34 is disposed in the opening 754. No optical element is disposed in the opening 750. In this embodiment, the optical elements 31 to 34 are disposed at the same positions as each other in the z direction. When the laser head A3 is used, the frame 75 is rotated to selectively position either the opening 750 or the optical elements 31 to 34 at the functional position Pw.

[0047] This embodiment also makes it easier to replace the multiple optical elements 31-34. Moreover, in this embodiment, the movement mechanism 6 needs to include only one drive source such as a motor that rotates the frame 75. Furthermore, since the multiple optical elements 31-34 are positioned at the same position in the z direction, the dimension of the laser head A3 in the z direction can be reduced.

[0048] The laser head according to the present invention is not limited to the above-described embodiment, and the specific configuration of each part of the laser head according to the present invention can be freely designed in various ways. [Explanation of symbols]

[0049] A1, A2, A3: Laser head 1: Case 11: Box-shaped part 12, 13: Cylindrical section 111,112,121,122,131,132: Opening 21, 22: Lens 25, 26: Protective glass 31, 32, 33, 34: Optical elements 6: Movement mechanism 71, 72, 73, 74, 75: Frame 81, 82, 83, 84: Motor 85, 86, 87, 88: Linear actuator 711,721,731,741: Support part 712,722,732,742: Rod 750,751,752,753,754:Aperture 759: Rotating shaft Lo: Laser oscillator Ob: Object to be processed Op: Optical path Pe1, Pe2, Pe3, Pe4, Pw: functional position R ,R1,R2,R3,R4: Orbit

Claims

1. A laser head including a lens that refracts and emits an incident laser beam, A plurality of optical elements that transmit the laser light; a moving mechanism that moves each of the plurality of optical elements to a functional position at which the optical element intersects with the optical path of the laser light and to a retracted position at which the optical element is retracted from the optical path, the functional positions of the plurality of optical elements include two of the optical elements whose positions in a direction along the optical path are different from each other, The moving mechanism simultaneously positions the two optical elements at the functional position, the lens is a collimator lens, A laser head, wherein the functional positions of the plurality of optical elements are located on the output side of the lens in a direction along the optical path.

2. The laser head according to claim 1 , wherein the moving mechanism moves each of the plurality of optical elements along an arcuate trajectory.

3. The laser head according to claim 1 , wherein the plurality of optical elements include a diffractive optical element.

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