JP2001018087A - Laser beam machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of burring to an edge part, its vicinity or a piercing spot in cutting an object to be machined. SOLUTION: A throttling mechanism 8 capable of adjusting the size of an opening 8D is arranged to the lower position of a machining head 1. When the object to be machined is cut, the opening part 8D is reduced by the throttling mechanism 8 at the edge part of a cutting line, its or a piercing place. By this arrangement, the blowing area of the assist gas blown to these parts in cutting the edge part, its vicinity or a piercing place is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus,
More specifically, the present invention relates to a laser processing apparatus capable of adjusting a blowing area of an assist gas blown to a workpiece.

[0002]

2. Description of the Related Art Conventionally, a laser oscillator that oscillates a laser beam, a processing head that irradiates a laser beam oscillated from the laser oscillator onto a workpiece, and assists a processing location of the workpiece via the processing head. 2. Description of the Related Art There is known a laser processing apparatus that includes a supply unit that supplies gas, and performs a piercing process at a predetermined position on a workpiece before performing a cutting process. By the way, when cutting an object to be processed by the above-described laser processing apparatus, when an edge portion where a cutting line at the time of the cutting process is an acute angle is to be cut under the same processing conditions as other linear portions, When excessive assist gas (oxygen) is supplied around the edge portion, there is a disadvantage that burning (excessive melting) is likely to occur. Therefore, conventionally, when cutting the edge portion, the laser beam is switched from CW oscillation to pulse oscillation to reduce the output of the laser beam and reduce the machining speed (for example, Japanese Patent Publication No. Hei 8-29424).
Alternatively, a device that reduces the cutting speed together with the output of a laser beam (Japanese Patent Publication No. 2749382) has been proposed.

[0003]

However, in the above-mentioned conventional techniques, the cutting speed in cutting the edge portion becomes slower in any case, and the cutting time for the workpiece becomes longer. was there. In addition, when piercing is performed, particularly, the workpiece is 12 m
In the case of a thick plate having a thickness of not less than m, it takes a very long time to process the laser beam by pulse oscillation. Therefore, it is becoming common to process the laser beam in a short time by CW oscillation. However, if piercing is performed by CW oscillation with the nozzle diameter kept the same during piercing and cutting, the molten portion at the piercing position becomes larger than in the case of pulse oscillation, and the diameter of the piercing hole becomes larger. And the diameter of the small hole to be machined along the circumference after going outward from the piercing hole is limited. In addition, a laser processing apparatus in which the diameter of a nozzle is changed in accordance with the type of laser processing and the material of a workpiece has been proposed (for example, Japanese Patent Laid-Open No. 5-30).
No. 5475). However, Japanese Patent Application Laid-Open No.
In the apparatus of 5475, in order to prevent burning, the diameter of the nozzle is changed between the edge portion of the cutting line and the other portion, and the piercing and cutting are performed so that the piercing hole diameter does not become too large. No change in caliber was suggested. Therefore, an object of the present invention is to provide a laser processing apparatus suitable for piercing processing and processing of an edge portion or the like by adjusting the area where the assist gas is blown to a workpiece by a configuration as simple as possible. is there.

[0004]

That is, a laser oscillator that oscillates a laser beam, a processing head that irradiates a laser beam oscillated from the laser oscillator onto the workpiece, and a processing head that passes through the inside of the processing head. A laser processing apparatus that includes a supply unit that supplies an assist gas to a processing location and performs a piercing process at a predetermined position of the workpiece before performing the cutting process. Providing an adjusting means for adjusting a blowing area at which the assist gas is blown to a processing portion of the workpiece, an edge portion where a cutting line at an angle of not more than a right angle and a vicinity thereof or a small portion thereof when a cutting process is performed on the workpiece. The configuration is such that the blowing area of the assist gas to the hole drilling area is smaller than the blowing area of the assist gas to the other cutting processing areas. It is. According to a second aspect of the present invention, there is provided a laser oscillator that oscillates a laser beam, a processing head that irradiates a laser beam oscillated from the laser oscillator onto a workpiece, and a processing portion of the workpiece via a processing head. In a laser processing apparatus comprising a supply means for supplying an assist gas and performing a cutting process after performing a piercing process at a required position of the workpiece, a processing location when the piercing process is performed on the workpiece. Adjusting means for adjusting the blowing area where the assist gas is blown is provided, and the blowing area of the assist gas to the processing location when performing the above piercing processing, and the blowing of the assist gas to the processing location of the workpiece during the cutting processing are provided. It is configured to reduce the area.

[0005]

According to this structure, the area of the assist gas blown to the edge portion, its vicinity, and the perforated portion of the small hole is smaller than that of the other portions. Is never sprayed. Therefore, it is possible to prevent burning from occurring at the edge portion and the like. In addition, since there is no need to reduce the processing speed when processing those processing portions, the processing time for the workpiece can be reduced as compared with the related art. Further, since the area of the assist gas sprayed in the piercing process can be reduced, the molten portion at the piercing position can be reduced, and the diameter of the piercing hole can be reduced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an illustrated embodiment. A processing head 1 of a laser processing apparatus is mounted on a movable frame (not shown), and a focusing lens for condensing a laser beam is provided inside the processing head 1. Built-in. The processing head 1 is supported vertically downward,
The nozzle 2 is integrally attached to the lower end of the processing head 1. A processing table (not shown) is provided below the processing head 1, and a plate-shaped workpiece 3 is horizontally placed on the processing table. The laser processing device includes a laser oscillator (not shown). A laser beam oscillated from the laser oscillator is guided into the processing head 1 by a plurality of reflecting mirrors (not shown), and then condensed by a condenser lens. The workpiece 3 is irradiated from the lower end opening of the nozzle 2. The laser processing apparatus includes a supply source of an assist gas (not shown), and this supply source is connected to the processing head 1 via a conduit 4. When cutting is performed by irradiating the workpiece 3 with the laser beam from the processing head 1, an assist gas (oxygen) is supplied into the processing head 1 from the supply source of the assist gas via the conduit 4. . Thereby, the assist gas is blown and supplied from the lower end opening of the nozzle 2 to the processing location of the workpiece 3. Next, a touch sensor 5 is provided adjacent to the processing head 1 on a movable frame (not shown) to which the processing head 1 is connected, and the tip of a bar 6 following the touch sensor 5 is positioned below the processing head 1. Is located. As shown in FIG. 2, a large-diameter through-hole 6a in the vertical direction is formed at the end of the profile bar 6, and the laser beam and the assist gas emitted from the nozzle 2 pass through the through-hole 6a. Then, the workpiece 3 is reached. Then, by supplying an assist gas to the workpiece 3 and irradiating a laser beam, the workpiece 3 and the processing head 1 are relatively moved on a horizontal plane by a drive mechanism (not shown), for example, as shown in FIG. Thus, the workpiece 3 can be cut into a required shape. The above configuration is no different from the conventionally known processing head and touch sensor.

In this embodiment, an adjusting means 7 for adjusting the blowing area of the assist gas blown from the nozzle 2 to the processing location of the workpiece 3 is provided on the above-mentioned profile bar 6. That is, in this embodiment, an annular aperture mechanism 8 is attached to the upper surface of the tip of the copying bar 6 so as to surround the through hole 6a. The aperture mechanism 8 is similar to an aperture mechanism used for a camera shutter, and includes an annular casing 8A fixed to the upper surface of the copying bar 6;
A number of blade members 8B housed in the casing 8A and provided to be able to advance and retreat from the slit provided in the inner peripheral portion of the casing 8A toward the axis of the casing 8A, and protrude outward from the slit of the casing 8A. And a sector gear 8C for synchronously moving the blade member 8B forward and backward. A circular opening 8D (hole) is formed by the inner edge of each of the blade members 8B, and the laser beam passes through the opening 8D and abuts on the processing position of the workpiece 3. As for the assist gas injected from the nozzle, only the gas that has passed through the opening 8D is blown to the workpiece. When the sector gear 8C as the operating member is moved forward and backward along the circumferential direction of the casing 8A, the respective blade members 8B are moved forward and backward toward the axis of the casing 8A in conjunction therewith. Thereby, the size of the circular opening 8D formed so as to surround the axis of the casing 8A can be adjusted. When the sector gear 8C is rotated to the movement end position in the counterclockwise direction with respect to the casing 8A, all the blade members 8B are housed in the casing 8A. Therefore, in that case, the through-hole 6a of the bar 6 substantially becomes an opening that allows the passage of the laser beam and the assist gas. On the other hand, when the sector gear 8C is rotated to the clockwise movement end position with respect to the casing 8A, the many blade members 8B are located at the forward end closest to the axis of the casing 8A, and The size of the circular opening 8D constituted by 8B is minimized. That is, the sector gear 8C
Is rotated, the size of the opening 8D formed by the large number of blade members 8B can be adjusted.

Next, a bracket 11 is integrally attached to the copying bar 6, and the motor 1 is attached to the bracket 11.
2 is installed vertically downward. Bracket 11
A gear 13 is attached to the drive shaft of the motor 12 projecting downward.
The gear 13 is connected to the sector gear 8C.
Is engaged. The operation of the motor 12 is controlled by a control device (not shown). When the control device rotates the motor 12 in the normal and reverse directions by a required amount, the sector gear 8C is rotated in the normal and reverse directions along the circumferential direction of the casing 8A. The size can be adjusted. As can be understood from the above description, in this embodiment, the adjusting means 7 is constituted by the aperture mechanism 8, the motor 12, and the gear 13. In this embodiment, the laser beam is applied to the processing location of the workpiece 3 through the opening 8D and the through hole 6a of the profile bar 6, and is injected from the lower end opening of the nozzle 2. The assist gas also passes through the opening 8D and the through-hole 6a of the profile bar 6, and is blown to the processed portion of the workpiece. By changing the size of the opening 8D without changing the supply amount supplied from the supply source of the assist gas to the processing head 1, the assist gas actually blown to the processing location of the workpiece 3 is changed. Spray area can be changed. In the present embodiment, when the piercing process is performed on the workpiece 3, and when the cutting line when the cutting process is performed on the workpiece 3 is to form an acute portion and a right angle edge portion and the vicinity thereof and a small hole, Opening 8D
Is reduced to reduce the area of the assist gas to be blown to the processing location of the workpiece 3.

More specifically, as shown in FIG.
A case where the workpiece 3 is cut will be described. this
In this case, the workpiece 3 is shown in FIG.
For cutting and piercing to form
Required laser beam output, machining head 1 and workpiece 3
Relative moving speed, and processing from assist gas supply source
The amount of assist gas supplied into the head 1 and the material of the workpiece 3
Create a machining program based on the quality, plate thickness, etc.
In the control device. At the same time,
Of the contour (cut line) of the product when cutting the workpiece 3
Of these, the sharp and right-angled edge portions E1-E10 and
And places before and after it (the places shown by diagonal lines)
In the drawing machine,
The motor 12 is formed so that the opening 8D of the structure 8 becomes small.
The advance amount of the blade member 8B when moved is recorded in the control device in advance.
Remember. More specifically, for example,
The material of the object 3 is iron with a thickness of 6 mm and the lower end of the nozzle 2 is opened.
The inner diameter of the mouth is 2.6mm, and Assist to the processing head 1
Gas supply pressure is 0.6kg / cm^Two In the case of
Indicates that a straight line portion other than the edge portions E1-E10 is
Processing speed 2 with 1.5kW laser beam output
If cutting at 000 mm / min, the edge
The minute E1-E10 is a laser output of pulse oscillation 500W.
The cutting speed was 100mm / min.
It is. On the other hand, in this embodiment,
Similarly, the workpiece 3 is made of iron having a thickness of 6 mm,
The inner diameter of the lower end opening of the nozzle 2 is 2.6 mm,
Supply pressure is 0.6kg / cm^Two In the case of, the edge part
Output the minutes E1-E10 and other straight line parts.
Cutting a 5kW laser beam with CW (continuous oscillation)
In the edge portion E1-E10 and its vicinity,
The diameter of the opening 8D of the aperture mechanism 8 is set to 1 mm.
Is set to In other words, the edge portions E1-E10
Laser beam power and processing speed
Without further modification, these edge portions E1-E10 and their
Reduced area of assist gas blown to the vicinity
It is to reduce. Further, in this embodiment,
The material of the object 3 is 12 mm thick iron and the lower end of the nozzle 2
The inner diameter of the opening is 2.6 mm, and the supply pressure of the assist gas is 0.2 mm.
6Kg / cm ^Two When cutting in the case of
At the position E1-E10 and its vicinity, the aperture of the diaphragm mechanism 8 is set.
The diameter of the portion 8D is set to be 1.5 mm.
Thus, the edge portion E1-
The diameter of the opening 8D of the aperture mechanism 8 is changed at E10 and its vicinity.
I am trying to change it. Also apply piercing
At the positions P1 and P2, the opening 8D of the aperture mechanism 8 is
The motor 12 is operated so as to have a predetermined opening corresponding thereto.
The rotation amount at the time of the rotation is stored in the control device in advance. Also,
The laser beam is set to CW oscillation for high-speed processing.
In this embodiment, when the plate thickness is 12 mm,
Set to have a diameter of 1.0 mm at the opening of the retraction mechanism 8
In the case of a plate thickness of 18 mm, the aperture 1.
It is set to be 5 mm. In this embodiment,
Is a predetermined position of the workpiece 3 as a product as shown in FIG.
Since the small hole h1 is pierced, the small hole h1 is pierced.
At the point, the above squeezing
Motor 12 so that the opening 8D of the
The advance amount of the blade member 8B at the time of operating the
To be stored. In this embodiment, the small holes are
Means that the inner diameter is smaller than the plate thickness of the workpiece 3.
You. For example, when the thickness of the workpiece 3 is 6 mm,
The hole has an inner diameter of 6 mm or less. Furthermore, on
From the position P2 where the piercing process is performed to the contour of the product
The section of the cutting line that becomes a straight line
The motor 12 is formed so that the openings 8D have the same size.
The amount of rotation at the time of moving is stored in the control device in advance.

Then, the processing head 1 is positioned above a position P2 on the workpiece 3 where piercing is to be performed. The processing head 1 is irradiated with a laser beam and an assist gas is supplied into the processing head 1. Then, the laser beam is applied to the position P2, and only the assist gas that has passed through the opening 8D is blown to the position P2. In other words, of the assist gas ejected from the nozzle 2 of the processing head 1, only the assist gas that has passed through the opening 8D is blown to the processing position P2 of the workpiece 3, and the other assist gas surrounds the opening 8D. The supply to the position P2 is prevented by the blade member 8B. Thus, since the area of the assist gas blown to the position P2 where the piercing is performed is small, the hole diameter of the piercing can be minimized, and the hole surrounding the piercing position can have a smaller area. Further, since the assist gas is prevented from being excessively supplied to the position P where the piercing process is performed, a large amount of spatter or blow-up does not occur at the position P. Next, in a state where the supply of the laser beam and the assist gas to the processing head 1 is continuously performed, the processing head 1 is continuously moved from the position P toward the edge portion E1 that comes into contact with the contour of the product. At this time, the control device controls the operation of the motor 12 to enlarge the opening 8D by a predetermined amount to a predetermined degree of opening, and the cutting process is started in that state. And
Further, when the processing head 1 moves to a position indicated by oblique lines near the first edge portion E1, the control device controls the operation of the motor 12 to reduce the opening 8D by a predetermined amount, and changes the state to the edge. It is maintained until the portion E1 and the portion indicated by oblique lines adjacent thereto are passed. Then, at a position where the cutting line thereafter becomes a straight line portion, the control device
2 is controlled to enlarge the opening 8D by a predetermined amount. Further, at the second edge portion E2 and the position indicated by oblique lines near the second edge portion E2, the control device controls the operation of the motor 12 to reduce the opening 8D by a predetermined amount. Hereinafter, when cutting each of the edge portions E3-E10 and a portion near the edge portion (a portion indicated by oblique lines), compared with a case where other portions on the cutting line without diagonal lines are cut and processed, The opening 8D is reduced by the control device.
In this way, the product having the shape including the edge portions E1-E10 is continuously cut. Note that the small hole h1 shown in FIG. 3 is drilled prior to cutting the contour of the product. In drilling the small hole h1, first, the center P1 is pierced, then the cutting process is continued toward the outer side, and then the cutting process is performed along the circumference of the small hole h1. . At this time, the opening degree of the opening 8D of the aperture mechanism 8 is made smaller than that of the cut portion of the straight line portion which is the contour of the product. Thereby, it is possible to prevent the occurrence of burning even at the perforated portion of the small hole h1.

As described above, in the present embodiment, the supply amount (supply pressure) of the assist gas supplied from the supply source of the assist gas to the processing head 1 is kept constant, and the edge of the workpiece 3 is adjusted by the adjusting means 7. Cutting is performed by reducing the spray area of the assist gas actually supplied to the portion E1-E10, its vicinity, and the perforated portion of the small hole h1. Therefore, the edge portions E1-E10 of the workpiece 3
When the cutting process is performed, the assist gas is not excessively supplied, so that it is possible to prevent the occurrence of burning at those portions. Further, in this embodiment, when cutting the edge portions E1-E10, a laser beam is irradiated to the workpiece 3 by CW oscillation, and the pulsed laser beam is applied to the edge portions E1-E10.
Since the laser beam is not applied to the laser beam 10, the processing speed does not need to be reduced, and the time required for the cutting process can be shortened as compared with the conventional case.

(Second Embodiment) FIG. 4 shows a second embodiment of the present invention.
It shows an example. In the second embodiment, a disk 108 is used as the diaphragm mechanism 8. That is,
1, a motor 12 is provided on the bracket 11 of the touch sensor 5, and the center of the disk 108 is connected to the drive shaft of the motor 12. Thereby, the disk 1
08 is supported horizontally and is rotatable, and the disk 1
08 is located on the lower side of the processing head 1 and closes the through hole 6a of the tracing bar 6 from above. A plurality of through-holes 108A having different diameters are formed in the circular plate 108 at equal circumferential positions. In the second embodiment, an opening through which the assist gas passes is formed by each through hole 108A by rotating the motor 12, and each through hole 108A is located at a position immediately below the nozzle 2. . As a result, the area of the assist gas to be blown through the through-hole 108A to the processing location of the workpiece 3 is reduced. Other configurations are the same as those of the first embodiment shown in FIG. In the second embodiment having such a configuration, the same operation and effect as those of the first embodiment can be obtained. In each of the above embodiments, the adjusting means 7 is provided on the copy bar 6 of the touch sensor 5.
For example, an L-shaped bracket may be integrally connected to the processing head 1, and the adjusting means 7 may be provided on the bracket.

[0013]

As described above, according to the present invention, the occurrence of burning at the edge portion of the cutting line and its vicinity or at the perforated portion of the small hole when cutting the workpiece is favorably prevented. The effect that it can be obtained is obtained.
In addition, an effect is obtained that the processing time for the workpiece can be reduced as compared with the related art. Further, at the time of piercing, it is possible to minimize the diameter of the piercing hole, to minimize the occurrence of spatter, and to prevent the occurrence of blow-up. .

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing one embodiment of the present invention.

FIG. 2 is a bottom view of a main part shown in FIG. 1;

FIG. 3 is a plan view showing a cutting line when cutting a workpiece.

FIG. 4 is a schematic perspective view showing a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Processing head 2 Nozzle 3 Workpiece 7 Adjusting means 8 Throttle mechanism 12 Motor E1-E10 Edge part P Piercing position

Claims (7)

[Claims] A laser oscillator for oscillating a laser beam;
A processing head for irradiating the workpiece with a laser beam oscillated from a laser oscillator, and supply means for supplying an assist gas to a processing location of the workpiece via the inside of the processing head; Adjusting means for adjusting a blowing area in which an assist gas is blown to a processing portion of a workpiece when performing a cutting process on the workpiece in a laser processing apparatus which performs a cutting process after performing a piercing process on the workpiece. The cutting area when the cutting process is performed on the workpiece is at an angle equal to or less than a right angle, and the area of the assist gas sprayed to the vicinity of the edge portion or the perforated portion of the small hole is changed to the assist gas for the other cutting portion. A laser processing apparatus characterized in that the laser processing apparatus is configured to reduce the sprayed area of the laser beam. 2. A laser oscillator for oscillating a laser beam,
A processing head for irradiating the workpiece with a laser beam oscillated from a laser oscillator, and supply means for supplying an assist gas to a processing location of the workpiece via the inside of the processing head; In a laser processing apparatus that performs a cutting process after performing a piercing process, an adjusting device that adjusts a blowing area where an assist gas is blown to a processing location when performing a piercing process on a workpiece is provided, A laser processing apparatus characterized in that the area of spraying the assist gas to the processing location when performing the piercing process is made smaller than the blowing area of the assist gas to the processing location of the workpiece during the cutting process. . 3. The laser processing apparatus according to claim 1, wherein said adjusting means adjusts a blowing area of the assist gas according to a thickness of the workpiece. 4. An aperture mechanism disposed below the processing head and capable of expanding and contracting the size of an opening through which an assist gas passes, and a drive mechanism for expanding and contracting the aperture of the aperture mechanism. 2. The method according to claim 1, further comprising:
The laser processing device according to any one of claims 1 to 3. 5. The throttle mechanism includes an annular casing,
A plurality of blade members housed in the casing and constituting the opening, and capable of moving forward and backward in synchronization with the axis of the casing, are provided rotatably along the circumferential direction of the casing. An actuating member that moves the blade member forward and backward in synchronization with each other, wherein the drive mechanism includes a gear that engages with an actuating member of the aperture mechanism, and a motor that rotates the gear. 5. The laser processing apparatus according to 4. 6. The diaphragm mechanism comprises a disc provided with a plurality of through holes having different diameters along a circumferential direction and provided rotatably, and the opening is provided in each of the discs. 5. The laser processing apparatus according to claim 4, wherein the laser processing apparatus includes a through hole, and the driving mechanism includes a motor that rotates the disk. 7. A touch sensor having a profile bar at a position adjacent to and below the processing head, wherein the adjusting means is provided on the profile bar of the touch sensor. The laser processing device according to any one of the above.