JPS628954Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a laser beam modulation device, and more specifically, it is equipped with a device that cuts a portion of a laser beam with a low energy density, and which pulses a continuous output laser beam. The present invention relates to a laser beam modulation device including a device.

2. Description of the Related Art A processing method in which a plate-shaped workpiece is cut using a laser processing device has been conventionally practiced. When cutting a workpiece with a laser processing device, it is known that the cutting accuracy of the cut surface is better when using a pulse output type laser oscillator than when using a continuous wave output type laser oscillator. There is. However,
A pulse output type laser oscillator having an output equivalent to a continuous wave output type laser oscillator is larger and more expensive than a continuous wave output type laser oscillator.

The present invention was devised in view of the above problems, and its first purpose is to achieve the same effect as using a pulsed output laser oscillator when cutting using a continuous output laser oscillator. The purpose is to provide a device that can obtain the desired results.

A second object of the present invention is to provide a device capable of cutting a portion of the laser beam from a laser oscillator with low energy density.

A third object of the invention is to provide an apparatus capable of pulsing a continuous beam from a laser oscillator.

A fourth object of the present invention is to provide an apparatus capable of modulating the power density distribution of a laser beam to a distribution suitable for laser processing.

A fifth object of the present invention is to provide an apparatus that allows the continuous beam to be selectively pulsed or non-pulsed.

In order to achieve each of the above-mentioned objects, the present invention is provided with a device capable of cutting off a portion of the laser beam from a laser oscillator with a low energy density and repeatedly narrowing down the laser beam.

Embodiments of the present invention will be described in detail below with reference to the drawings.

A laser modulation device 1 according to this embodiment is placed in the optical path of a laser beam LB from a laser oscillator in a laser processing device (not shown). A base plate 7 is integrally attached to a frame 3 of the laser processing device via a bracket 5, and a case 11 having an annular peripheral portion 9 is attached to the base plate 7.
Air cooling fins 15 are formed on the peripheral edge 9 of the case 11 to cool the inside of the space 13 of the case 11. Further, a cylindrical body 19 is fixed to the center of the side wall 17 of the case 11 with bolts or the like.
A first conduit 21 for guiding a laser beam LB from a laser oscillator is attached to this cylindrical body 19. Furthermore, an inner cylinder 23 that penetrates the side wall 17 of the case 11 is fitted into the cylinder body 19.
An annular cooling water chamber 25 is formed between the cylinder body 19 and the cylinder body 19 . The cooling water chamber 25 cools the cylinder 19 and the inner cylinder 23, and the cylinder 19 is provided with an inlet 27 and an outlet 29 for introducing cooling water into the cooling water chamber 25. . The inner cylinder 23 is formed to have a smaller diameter than the first conduit 21 . Therefore, the cylindrical body 19, etc.
This constitutes an aperture device A that cuts the peripheral portion where the energy density is low.

With the above configuration, from the laser oscillator to the first conduit 2
The peripheral portion of the laser beam LB that has traveled to the center 1 is cut off by the aperture device A where the energy density is low, and only the portion where the energy density is high travels inside the inner cylinder 23.

Further, the aperture device A is cooled by supplying cooling water into the cooling water chamber 25 from the inlet 27 of the cylindrical body 19 and discharging it from the outlet 29.

A second conduit 31 facing the inner tube 23 is fixed to the center of the base plate 7 with bolts or the like. Therefore, the laser beam LB from the laser oscillator passes through the first conduit 21, the inner cylinder 23, the space 13, and the second conduit 31, and proceeds to the condensing lens side of the laser processing device. .

Around the second conduit 31, there are a plurality of (four in this embodiment) rotating shafts 33A, 33B, 33.
C and 33D are arranged at equal intervals. Each rotation axis 3
3A, 33B, 33C and 33D are bearings 35
It is rotatably supported on the base plate 7 via the respective rotating shafts 33A, 33.
B, 33C, and 33D have rotating wheels 37A and 37 of the same diameter, such as sprockets or pulleys, respectively.
B, 37C, and 37D are integrally attached with a key or the like. Each rotating wheel 37A, 37B, 37C, 3
An endless belt 39 such as a chain or a timing belt is wound around the belt 7D as shown in FIG. 2, and this endless belt 39 is stretched by a tension pulley 41 supported on the base plate 7. The rotating shafts 33A, 33B, 33C, 3
A rotating wheel 43 such as a sprocket or a pulley is integrally attached to one of the rotating shafts 33A by a key or the like. This rotating wheel 43
A rotary wheel 51 such as a sprocket or pulley is integrally attached to the output shaft 49 of a drive device 47 such as a motor with a key or the like via an endless belt 45 such as a chain or timing belt.
It is linked and linked. The drive device 47 is mounted on a motor base 53 that is fixed to the base plate 7 with bolts or the like.

Therefore, when the rotating shaft 33A is rotated via the rotating wheel 51, the endless band 45, and the rotating wheel 43 by driving the driving device 47, each rotating shaft 33A, 33
B, 33C, and 33D are rotated synchronously via the endless band 39.

Each of the rotating shafts 33A, 33B, 33C, 33D
One end protrudes into the space 13, and disk-shaped rotating bodies 55A, 55B, 55 are provided at each end.
C and 55D are installed respectively. Each rotating body 5
5A, 55B, 55C, 55D are laser beams
It constitutes a shutter device S that can freely aperture the laser beam LB, and can freely cross the optical path of the laser beam LB. Each rotating body 55A, 55B, 55C, 55D
As shown in FIGS. 1 and 3, they overlap each other in the optical path of the laser beam LB, and the rotating bodies 55A, 55B, 55C,
55D has appropriately shaped notches or transmission holes 57A, 57B, 5 through which the laser beam LB can freely pass through.
7C and 57D are formed at equal intervals.

As is clear from the above configuration, each rotating body 55
A, 55B, 55C, and 55D are constantly cooled by air cooling fins 15 in the space 13,
Each transmission hole 57A, 57B, 57C, 57D overlaps in the optical path of the laser beam LB, and each transmission hole 57A, 57B, 57C, 57D
When the two overlap, the laser beam LB is allowed to pass through. Therefore, each rotating body 55A, 55B, 55 is driven by the drive device 47.
When C and 55D are rotated synchronously, the laser beam
The optical path of LB is through each transmission hole 57A, 57B, 57
The aperture is periodically repeated and shut off by C and 57D. Therefore, the laser beam LB that has proceeded to the first conduit 21 is pulsed and proceeds to the second conduit 31 side.

An indexing plate 59 is integrally attached to one of the rotating shafts 33A, 33B, 33C, and 33D by a key or the like. This index plate 59 has cam grooves 61 formed at equal intervals corresponding to the transmission holes 57C. Base plate 7
The rotating bodies 55A, 55B, 55C, 55
A positioning device 63 for positioning D is attached. This positioning device 63 includes the index plate 5
A cam flow lower 65 that can be freely engaged with the cam groove 61 of 9
A dog 69 that operates a detection device 67, which will be described later, is provided so as to be movable forward and backward. The cam follower 65 and the dog 69 are integrally attached by bolts or the like to the tip of a sliding body 73 that is slidably supported by a bracket 71 fixed to the base plate 7. The base of the sliding body 73 is connected to a piston rod 77 of a reciprocating drive device 75 such as an air cylinder.
are linked together. The reciprocating drive device 75 is
It is attached to the bracket 71 and controlled by a control device (not shown). The detection device 67 is formed by a limit switch or the like, and is disposed at a position corresponding to the movement locus of the dog 69. This detection device 67 is attached to a bracket 79 fixed to the base plate 7. Therefore, by retracting the positioning device 63 downward in FIGS. 1 and 2 via the control device, the cam follower 65 is removed from the cam groove 61 of the indexing plate 59, and the dog 69 is moved to the detection device 67. The rotating bodies 55A, 55
B, 55C, and 55D are unlocked and become rotatable. Conversely, as shown in FIGS. 1 and 2, the positioning device 63 is advanced through the control device to engage the cam follower 65 with the cam groove 61 of the indexing plate 59, and the dog 69 engages with the detection device. By engaging with 67, the drive device 47 is stopped, and rotation of each rotating body 55A, 55B, 55C, 55D is prevented and fixed. As described above, each rotating body 55 is
When the rotation of each of the rotating bodies 55A, 55B, 55D is blocked,
Each transmission hole 57A, 57B, 57 of 55C, 55D
C and 57D are in an overlapping state in the optical path of the laser beam LB, allowing the laser beam LB to pass therethrough. Therefore, in this case, the laser beam LB is not pulsed and can maintain the output mode from the laser oscillator.

Further, a proximity switch 81 is attached to the base plate 7 at a position corresponding to the index plate 59. Therefore, the index position of the index plate 59 corresponding to this proximity switch 81 can be detected. Therefore, proximity switch 8
The positioning device 63 is actuated by the first detection signal via the control device.

As can be understood from the above description of the embodiments, the gist of the present invention is as stated in the claims for utility model registration. A plurality of rotating shafts are arranged at equal intervals around the optical path of the oscillated laser beam, and each rotating shaft is provided so that it can rotate synchronously and can be stopped and fixed. It is provided so that the vicinity of the outer circumference of the body crosses the optical path. A plurality of notches or transmission holes that allow the laser beam to pass through are provided at equal intervals in the portions where the rotating bodies overlap each other on the optical path.

Therefore, in the present invention, the laser beam is modulated outside the laser oscillator, and it can be applied very easily to conventional laser oscillators. Even in this case, the laser beam can be made into pulses by rotating each rotating shaft synchronously. In this case, laser beam transmission is allowed and pulsed only when the notches or transmission holes of each rotating body overlap each other. This is the period from the start of overlapping until the mutual overlapping is resolved. Therefore, the transmission time of the axial portion of the laser beam with high energy density is relatively long, and the transmission time of the peripheral portion of the laser beam with low energy density is short. Therefore, the periphery, which has a low energy density and does not contribute much to the cutting of the workpiece, is cut, and the workpiece is cut only at the axial center part, which has a high energy density, thereby reducing the thermal effect on the surrounding area. .

In addition, in the present invention, an aperture device that cuts the peripheral edge of the laser beam is placed on the optical path on the laser oscillator side from the position where each rotating body overlaps with the other, so the rotation of each of the rotating bodies is stopped. Therefore, even when using a continuous wave laser beam for laser processing without pulsing it, the peripheral edge of the laser beam is cut off, which can reduce the thermal effect on the surroundings of the laser processing equipment. be. Furthermore, since the peripheral edge of the laser beam is cut by the aperture device, the thermal influence on each of the rotating bodies is reduced by the cut amount, and the thermal distortion of each rotating body can be reduced accordingly. .

It should be noted that the present invention is not limited to the above-described embodiments, but can be implemented in other forms by making appropriate design changes. For example, various changes can be made, such as the arrangement and size of the rotating bodies in the shutter device, and the size and shape of the transmission holes.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a laser modulation device with an aperture device according to the present invention, and corresponds to a cross section taken along the line - in FIG. 2. FIG. 2 is a side view of FIG. 1 viewed from the left. FIG. 3 is an explanatory diagram showing the shutter device. Explanation of symbols representing the main parts of the drawing, LB...
...Laser beam, A...Apertia device, S...
Shutter device, 47... drive device.

Claims (1)

[Scope of utility model registration request] A plurality of rotation axes 33A arranged at equal intervals around the optical path of the laser beam LB from the laser oscillator.
- 33D are provided parallel to the optical path, and each rotating shaft 33A-33D is provided to be able to rotate synchronously and to be stopped and fixed, and each of the disc-shaped rotating bodies 55A-55D whose outer peripheral portion can freely cross the optical path is connected to each of the rotating shafts 33A-33D. Rotating axis 3
3A to 33D, each rotating body 55A to
55D overlap each other on the optical path, a plurality of notches or transmission holes are formed at equal intervals to allow transmission of the laser beam LB, and a laser oscillator is formed from the position where the rotating bodies 55A to 55D overlap each other. A laser beam modulation device characterized in that an aperture device A for cutting a peripheral portion of a laser beam LB is disposed on a side optical path, and the aperture device is cooled.